FreeBSD/Linux Kernel Cross Reference
sys/netinet/sctp_indata.c

     /*-
      * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
      * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
      * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions are met:
      *
      * a) Redistributions of source code must retain the above copyright notice,
     *    this list of conditions and the following disclaimer.
     *
     * b) Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in
     *    the documentation and/or other materials provided with the distribution.
     *
     * c) Neither the name of Cisco Systems, Inc. nor the names of its
     *    contributors may be used to endorse or promote products derived
     *    from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
     * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
     * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
     * THE POSSIBILITY OF SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <netinet/sctp_os.h>
    #include <netinet/sctp_var.h>
    #include <netinet/sctp_sysctl.h>
    #include <netinet/sctp_pcb.h>
    #include <netinet/sctp_header.h>
    #include <netinet/sctputil.h>
    #include <netinet/sctp_output.h>
    #include <netinet/sctp_input.h>
    #include <netinet/sctp_indata.h>
    #include <netinet/sctp_uio.h>
    #include <netinet/sctp_timer.h>
    
    
    /*
     * NOTES: On the outbound side of things I need to check the sack timer to
     * see if I should generate a sack into the chunk queue (if I have data to
     * send that is and will be sending it .. for bundling.
     *
     * The callback in sctp_usrreq.c will get called when the socket is read from.
     * This will cause sctp_service_queues() to get called on the top entry in
     * the list.
     */
    
    void
    sctp_set_rwnd(struct sctp_tcb *stcb, struct sctp_association *asoc)
    {
            asoc->my_rwnd = sctp_calc_rwnd(stcb, asoc);
    }
    
    /* Calculate what the rwnd would be */
    uint32_t
    sctp_calc_rwnd(struct sctp_tcb *stcb, struct sctp_association *asoc)
    {
            uint32_t calc = 0;
    
            /*
             * This is really set wrong with respect to a 1-2-m socket. Since
             * the sb_cc is the count that everyone as put up. When we re-write
             * sctp_soreceive then we will fix this so that ONLY this
             * associations data is taken into account.
             */
            if (stcb->sctp_socket == NULL)
                    return (calc);
    
            if (stcb->asoc.sb_cc == 0 &&
                asoc->size_on_reasm_queue == 0 &&
                asoc->size_on_all_streams == 0) {
                    /* Full rwnd granted */
                    calc = max(SCTP_SB_LIMIT_RCV(stcb->sctp_socket), SCTP_MINIMAL_RWND);
                    return (calc);
            }
            /* get actual space */
            calc = (uint32_t) sctp_sbspace(&stcb->asoc, &stcb->sctp_socket->so_rcv);
    
            /*
             * take out what has NOT been put on socket queue and we yet hold
             * for putting up.
             */
            calc = sctp_sbspace_sub(calc, (uint32_t) (asoc->size_on_reasm_queue +
                asoc->cnt_on_reasm_queue * MSIZE));
            calc = sctp_sbspace_sub(calc, (uint32_t) (asoc->size_on_all_streams +
                asoc->cnt_on_all_streams * MSIZE));
    
            if (calc == 0) {
                   /* out of space */
                   return (calc);
           }
           /* what is the overhead of all these rwnd's */
           calc = sctp_sbspace_sub(calc, stcb->asoc.my_rwnd_control_len);
           /*
            * If the window gets too small due to ctrl-stuff, reduce it to 1,
            * even it is 0. SWS engaged
            */
           if (calc < stcb->asoc.my_rwnd_control_len) {
                   calc = 1;
           }
           return (calc);
   }
   
   
   
   /*
    * Build out our readq entry based on the incoming packet.
    */
   struct sctp_queued_to_read *
   sctp_build_readq_entry(struct sctp_tcb *stcb,
       struct sctp_nets *net,
       uint32_t tsn, uint32_t ppid,
       uint32_t context, uint16_t stream_no,
       uint16_t stream_seq, uint8_t flags,
       struct mbuf *dm)
   {
           struct sctp_queued_to_read *read_queue_e = NULL;
   
           sctp_alloc_a_readq(stcb, read_queue_e);
           if (read_queue_e == NULL) {
                   goto failed_build;
           }
           read_queue_e->sinfo_stream = stream_no;
           read_queue_e->sinfo_ssn = stream_seq;
           read_queue_e->sinfo_flags = (flags << 8);
           read_queue_e->sinfo_ppid = ppid;
           read_queue_e->sinfo_context = context;
           read_queue_e->sinfo_timetolive = 0;
           read_queue_e->sinfo_tsn = tsn;
           read_queue_e->sinfo_cumtsn = tsn;
           read_queue_e->sinfo_assoc_id = sctp_get_associd(stcb);
           read_queue_e->whoFrom = net;
           read_queue_e->length = 0;
           atomic_add_int(&net->ref_count, 1);
           read_queue_e->data = dm;
           read_queue_e->spec_flags = 0;
           read_queue_e->tail_mbuf = NULL;
           read_queue_e->aux_data = NULL;
           read_queue_e->stcb = stcb;
           read_queue_e->port_from = stcb->rport;
           read_queue_e->do_not_ref_stcb = 0;
           read_queue_e->end_added = 0;
           read_queue_e->some_taken = 0;
           read_queue_e->pdapi_aborted = 0;
   failed_build:
           return (read_queue_e);
   }
   
   
   /*
    * Build out our readq entry based on the incoming packet.
    */
   static struct sctp_queued_to_read *
   sctp_build_readq_entry_chk(struct sctp_tcb *stcb,
       struct sctp_tmit_chunk *chk)
   {
           struct sctp_queued_to_read *read_queue_e = NULL;
   
           sctp_alloc_a_readq(stcb, read_queue_e);
           if (read_queue_e == NULL) {
                   goto failed_build;
           }
           read_queue_e->sinfo_stream = chk->rec.data.stream_number;
           read_queue_e->sinfo_ssn = chk->rec.data.stream_seq;
           read_queue_e->sinfo_flags = (chk->rec.data.rcv_flags << 8);
           read_queue_e->sinfo_ppid = chk->rec.data.payloadtype;
           read_queue_e->sinfo_context = stcb->asoc.context;
           read_queue_e->sinfo_timetolive = 0;
           read_queue_e->sinfo_tsn = chk->rec.data.TSN_seq;
           read_queue_e->sinfo_cumtsn = chk->rec.data.TSN_seq;
           read_queue_e->sinfo_assoc_id = sctp_get_associd(stcb);
           read_queue_e->whoFrom = chk->whoTo;
           read_queue_e->aux_data = NULL;
           read_queue_e->length = 0;
           atomic_add_int(&chk->whoTo->ref_count, 1);
           read_queue_e->data = chk->data;
           read_queue_e->tail_mbuf = NULL;
           read_queue_e->stcb = stcb;
           read_queue_e->port_from = stcb->rport;
           read_queue_e->spec_flags = 0;
           read_queue_e->do_not_ref_stcb = 0;
           read_queue_e->end_added = 0;
           read_queue_e->some_taken = 0;
           read_queue_e->pdapi_aborted = 0;
   failed_build:
           return (read_queue_e);
   }
   
   
   struct mbuf *
   sctp_build_ctl_nchunk(struct sctp_inpcb *inp, struct sctp_sndrcvinfo *sinfo)
   {
           struct sctp_extrcvinfo *seinfo;
           struct sctp_sndrcvinfo *outinfo;
           struct sctp_rcvinfo *rcvinfo;
           struct sctp_nxtinfo *nxtinfo;
           struct cmsghdr *cmh;
           struct mbuf *ret;
           int len;
           int use_extended;
           int provide_nxt;
   
           if (sctp_is_feature_off(inp, SCTP_PCB_FLAGS_RECVDATAIOEVNT) &&
               sctp_is_feature_off(inp, SCTP_PCB_FLAGS_RECVRCVINFO) &&
               sctp_is_feature_off(inp, SCTP_PCB_FLAGS_RECVNXTINFO)) {
                   /* user does not want any ancillary data */
                   return (NULL);
           }
           len = 0;
           if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_RECVRCVINFO)) {
                   len += CMSG_SPACE(sizeof(struct sctp_rcvinfo));
           }
           seinfo = (struct sctp_extrcvinfo *)sinfo;
           if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_RECVNXTINFO) &&
               (seinfo->serinfo_next_flags & SCTP_NEXT_MSG_AVAIL)) {
                   provide_nxt = 1;
                   len += CMSG_SPACE(sizeof(struct sctp_nxtinfo));
           } else {
                   provide_nxt = 0;
           }
           if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_RECVDATAIOEVNT)) {
                   if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_EXT_RCVINFO)) {
                           use_extended = 1;
                           len += CMSG_SPACE(sizeof(struct sctp_extrcvinfo));
                   } else {
                           use_extended = 0;
                           len += CMSG_SPACE(sizeof(struct sctp_sndrcvinfo));
                   }
           } else {
                   use_extended = 0;
           }
   
           ret = sctp_get_mbuf_for_msg(len, 0, M_NOWAIT, 1, MT_DATA);
           if (ret == NULL) {
                   /* No space */
                   return (ret);
           }
           SCTP_BUF_LEN(ret) = 0;
   
           /* We need a CMSG header followed by the struct */
           cmh = mtod(ret, struct cmsghdr *);
           /*
            * Make sure that there is no un-initialized padding between the
            * cmsg header and cmsg data and after the cmsg data.
            */
           memset(cmh, 0, len);
           if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_RECVRCVINFO)) {
                   cmh->cmsg_level = IPPROTO_SCTP;
                   cmh->cmsg_len = CMSG_LEN(sizeof(struct sctp_rcvinfo));
                   cmh->cmsg_type = SCTP_RCVINFO;
                   rcvinfo = (struct sctp_rcvinfo *)CMSG_DATA(cmh);
                   rcvinfo->rcv_sid = sinfo->sinfo_stream;
                   rcvinfo->rcv_ssn = sinfo->sinfo_ssn;
                   rcvinfo->rcv_flags = sinfo->sinfo_flags;
                   rcvinfo->rcv_ppid = sinfo->sinfo_ppid;
                   rcvinfo->rcv_tsn = sinfo->sinfo_tsn;
                   rcvinfo->rcv_cumtsn = sinfo->sinfo_cumtsn;
                   rcvinfo->rcv_context = sinfo->sinfo_context;
                   rcvinfo->rcv_assoc_id = sinfo->sinfo_assoc_id;
                   cmh = (struct cmsghdr *)((caddr_t)cmh + CMSG_SPACE(sizeof(struct sctp_rcvinfo)));
                   SCTP_BUF_LEN(ret) += CMSG_SPACE(sizeof(struct sctp_rcvinfo));
           }
           if (provide_nxt) {
                   cmh->cmsg_level = IPPROTO_SCTP;
                   cmh->cmsg_len = CMSG_LEN(sizeof(struct sctp_nxtinfo));
                   cmh->cmsg_type = SCTP_NXTINFO;
                   nxtinfo = (struct sctp_nxtinfo *)CMSG_DATA(cmh);
                   nxtinfo->nxt_sid = seinfo->serinfo_next_stream;
                   nxtinfo->nxt_flags = 0;
                   if (seinfo->serinfo_next_flags & SCTP_NEXT_MSG_IS_UNORDERED) {
                           nxtinfo->nxt_flags |= SCTP_UNORDERED;
                   }
                   if (seinfo->serinfo_next_flags & SCTP_NEXT_MSG_IS_NOTIFICATION) {
                           nxtinfo->nxt_flags |= SCTP_NOTIFICATION;
                   }
                   if (seinfo->serinfo_next_flags & SCTP_NEXT_MSG_ISCOMPLETE) {
                           nxtinfo->nxt_flags |= SCTP_COMPLETE;
                   }
                   nxtinfo->nxt_ppid = seinfo->serinfo_next_ppid;
                   nxtinfo->nxt_length = seinfo->serinfo_next_length;
                   nxtinfo->nxt_assoc_id = seinfo->serinfo_next_aid;
                   cmh = (struct cmsghdr *)((caddr_t)cmh + CMSG_SPACE(sizeof(struct sctp_nxtinfo)));
                   SCTP_BUF_LEN(ret) += CMSG_SPACE(sizeof(struct sctp_nxtinfo));
           }
           if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_RECVDATAIOEVNT)) {
                   cmh->cmsg_level = IPPROTO_SCTP;
                   outinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmh);
                   if (use_extended) {
                           cmh->cmsg_len = CMSG_LEN(sizeof(struct sctp_extrcvinfo));
                           cmh->cmsg_type = SCTP_EXTRCV;
                           memcpy(outinfo, sinfo, sizeof(struct sctp_extrcvinfo));
                           SCTP_BUF_LEN(ret) += CMSG_SPACE(sizeof(struct sctp_extrcvinfo));
                   } else {
                           cmh->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
                           cmh->cmsg_type = SCTP_SNDRCV;
                           *outinfo = *sinfo;
                           SCTP_BUF_LEN(ret) += CMSG_SPACE(sizeof(struct sctp_sndrcvinfo));
                   }
           }
           return (ret);
   }
   
   
   static void
   sctp_mark_non_revokable(struct sctp_association *asoc, uint32_t tsn)
   {
           uint32_t gap, i, cumackp1;
           int fnd = 0;
   
           if (SCTP_BASE_SYSCTL(sctp_do_drain) == 0) {
                   return;
           }
           cumackp1 = asoc->cumulative_tsn + 1;
           if (SCTP_TSN_GT(cumackp1, tsn)) {
                   /*
                    * this tsn is behind the cum ack and thus we don't need to
                    * worry about it being moved from one to the other.
                    */
                   return;
           }
           SCTP_CALC_TSN_TO_GAP(gap, tsn, asoc->mapping_array_base_tsn);
           if (!SCTP_IS_TSN_PRESENT(asoc->mapping_array, gap)) {
                   SCTP_PRINTF("gap:%x tsn:%x\n", gap, tsn);
                   sctp_print_mapping_array(asoc);
   #ifdef INVARIANTS
                   panic("Things are really messed up now!!");
   #endif
           }
           SCTP_SET_TSN_PRESENT(asoc->nr_mapping_array, gap);
           SCTP_UNSET_TSN_PRESENT(asoc->mapping_array, gap);
           if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_nr_map)) {
                   asoc->highest_tsn_inside_nr_map = tsn;
           }
           if (tsn == asoc->highest_tsn_inside_map) {
                   /* We must back down to see what the new highest is */
                   for (i = tsn - 1; SCTP_TSN_GE(i, asoc->mapping_array_base_tsn); i--) {
                           SCTP_CALC_TSN_TO_GAP(gap, i, asoc->mapping_array_base_tsn);
                           if (SCTP_IS_TSN_PRESENT(asoc->mapping_array, gap)) {
                                   asoc->highest_tsn_inside_map = i;
                                   fnd = 1;
                                   break;
                           }
                   }
                   if (!fnd) {
                           asoc->highest_tsn_inside_map = asoc->mapping_array_base_tsn - 1;
                   }
           }
   }
   
   
   /*
    * We are delivering currently from the reassembly queue. We must continue to
    * deliver until we either: 1) run out of space. 2) run out of sequential
    * TSN's 3) hit the SCTP_DATA_LAST_FRAG flag.
    */
   static void
   sctp_service_reassembly(struct sctp_tcb *stcb, struct sctp_association *asoc)
   {
           struct sctp_tmit_chunk *chk, *nchk;
           uint16_t nxt_todel;
           uint16_t stream_no;
           int end = 0;
           int cntDel;
           struct sctp_queued_to_read *control, *ctl, *nctl;
   
           if (stcb == NULL)
                   return;
   
           cntDel = stream_no = 0;
           if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) ||
               (stcb->asoc.state & SCTP_STATE_ABOUT_TO_BE_FREED) ||
               (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET)) {
                   /* socket above is long gone or going.. */
   abandon:
                   asoc->fragmented_delivery_inprogress = 0;
                   TAILQ_FOREACH_SAFE(chk, &asoc->reasmqueue, sctp_next, nchk) {
                           TAILQ_REMOVE(&asoc->reasmqueue, chk, sctp_next);
                           asoc->size_on_reasm_queue -= chk->send_size;
                           sctp_ucount_decr(asoc->cnt_on_reasm_queue);
                           /*
                            * Lose the data pointer, since its in the socket
                            * buffer
                            */
                           if (chk->data) {
                                   sctp_m_freem(chk->data);
                                   chk->data = NULL;
                           }
                           /* Now free the address and data */
                           sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
                           /* sa_ignore FREED_MEMORY */
                   }
                   return;
           }
           SCTP_TCB_LOCK_ASSERT(stcb);
           TAILQ_FOREACH_SAFE(chk, &asoc->reasmqueue, sctp_next, nchk) {
                   if (chk->rec.data.TSN_seq != (asoc->tsn_last_delivered + 1)) {
                           /* Can't deliver more :< */
                           return;
                   }
                   stream_no = chk->rec.data.stream_number;
                   nxt_todel = asoc->strmin[stream_no].last_sequence_delivered + 1;
                   if (nxt_todel != chk->rec.data.stream_seq &&
                       (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0) {
                           /*
                            * Not the next sequence to deliver in its stream OR
                            * unordered
                            */
                           return;
                   }
                   if (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
   
                           control = sctp_build_readq_entry_chk(stcb, chk);
                           if (control == NULL) {
                                   /* out of memory? */
                                   return;
                           }
                           /* save it off for our future deliveries */
                           stcb->asoc.control_pdapi = control;
                           if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG)
                                   end = 1;
                           else
                                   end = 0;
                           sctp_mark_non_revokable(asoc, chk->rec.data.TSN_seq);
                           sctp_add_to_readq(stcb->sctp_ep,
                               stcb, control, &stcb->sctp_socket->so_rcv, end,
                               SCTP_READ_LOCK_NOT_HELD, SCTP_SO_NOT_LOCKED);
                           cntDel++;
                   } else {
                           if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG)
                                   end = 1;
                           else
                                   end = 0;
                           sctp_mark_non_revokable(asoc, chk->rec.data.TSN_seq);
                           if (sctp_append_to_readq(stcb->sctp_ep, stcb,
                               stcb->asoc.control_pdapi,
                               chk->data, end, chk->rec.data.TSN_seq,
                               &stcb->sctp_socket->so_rcv)) {
                                   /*
                                    * something is very wrong, either
                                    * control_pdapi is NULL, or the tail_mbuf
                                    * is corrupt, or there is a EOM already on
                                    * the mbuf chain.
                                    */
                                   if (stcb->asoc.state & SCTP_STATE_ABOUT_TO_BE_FREED) {
                                           goto abandon;
                                   } else {
   #ifdef INVARIANTS
                                           if ((stcb->asoc.control_pdapi == NULL) || (stcb->asoc.control_pdapi->tail_mbuf == NULL)) {
                                                   panic("This should not happen control_pdapi NULL?");
                                           }
                                           /* if we did not panic, it was a EOM */
                                           panic("Bad chunking ??");
   #else
                                           if ((stcb->asoc.control_pdapi == NULL) || (stcb->asoc.control_pdapi->tail_mbuf == NULL)) {
                                                   SCTP_PRINTF("This should not happen control_pdapi NULL?\n");
                                           }
                                           SCTP_PRINTF("Bad chunking ??\n");
                                           SCTP_PRINTF("Dumping re-assembly queue this will probably hose the association\n");
   
   #endif
                                           goto abandon;
                                   }
                           }
                           cntDel++;
                   }
                   /* pull it we did it */
                   TAILQ_REMOVE(&asoc->reasmqueue, chk, sctp_next);
                   if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                           asoc->fragmented_delivery_inprogress = 0;
                           if ((chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0) {
                                   asoc->strmin[stream_no].last_sequence_delivered++;
                           }
                           if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) == 0) {
                                   SCTP_STAT_INCR_COUNTER64(sctps_reasmusrmsgs);
                           }
                   } else if (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                           /*
                            * turn the flag back on since we just  delivered
                            * yet another one.
                            */
                           asoc->fragmented_delivery_inprogress = 1;
                   }
                   asoc->tsn_of_pdapi_last_delivered = chk->rec.data.TSN_seq;
                   asoc->last_flags_delivered = chk->rec.data.rcv_flags;
                   asoc->last_strm_seq_delivered = chk->rec.data.stream_seq;
                   asoc->last_strm_no_delivered = chk->rec.data.stream_number;
   
                   asoc->tsn_last_delivered = chk->rec.data.TSN_seq;
                   asoc->size_on_reasm_queue -= chk->send_size;
                   sctp_ucount_decr(asoc->cnt_on_reasm_queue);
                   /* free up the chk */
                   chk->data = NULL;
                   sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
   
                   if (asoc->fragmented_delivery_inprogress == 0) {
                           /*
                            * Now lets see if we can deliver the next one on
                            * the stream
                            */
                           struct sctp_stream_in *strm;
   
                           strm = &asoc->strmin[stream_no];
                           nxt_todel = strm->last_sequence_delivered + 1;
                           TAILQ_FOREACH_SAFE(ctl, &strm->inqueue, next, nctl) {
                                   /* Deliver more if we can. */
                                   if (nxt_todel == ctl->sinfo_ssn) {
                                           TAILQ_REMOVE(&strm->inqueue, ctl, next);
                                           asoc->size_on_all_streams -= ctl->length;
                                           sctp_ucount_decr(asoc->cnt_on_all_streams);
                                           strm->last_sequence_delivered++;
                                           sctp_mark_non_revokable(asoc, ctl->sinfo_tsn);
                                           sctp_add_to_readq(stcb->sctp_ep, stcb,
                                               ctl,
                                               &stcb->sctp_socket->so_rcv, 1,
                                               SCTP_READ_LOCK_NOT_HELD, SCTP_SO_NOT_LOCKED);
                                   } else {
                                           break;
                                   }
                                   nxt_todel = strm->last_sequence_delivered + 1;
                           }
                           break;
                   }
           }
   }
   
   /*
    * Queue the chunk either right into the socket buffer if it is the next one
    * to go OR put it in the correct place in the delivery queue.  If we do
    * append to the so_buf, keep doing so until we are out of order. One big
    * question still remains, what to do when the socket buffer is FULL??
    */
   static void
   sctp_queue_data_to_stream(struct sctp_tcb *stcb, struct sctp_association *asoc,
       struct sctp_queued_to_read *control, int *abort_flag)
   {
           /*
            * FIX-ME maybe? What happens when the ssn wraps? If we are getting
            * all the data in one stream this could happen quite rapidly. One
            * could use the TSN to keep track of things, but this scheme breaks
            * down in the other type of stream useage that could occur. Send a
            * single msg to stream 0, send 4Billion messages to stream 1, now
            * send a message to stream 0. You have a situation where the TSN
            * has wrapped but not in the stream. Is this worth worrying about
            * or should we just change our queue sort at the bottom to be by
            * TSN.
            * 
            * Could it also be legal for a peer to send ssn 1 with TSN 2 and ssn 2
            * with TSN 1? If the peer is doing some sort of funky TSN/SSN
            * assignment this could happen... and I don't see how this would be
            * a violation. So for now I am undecided an will leave the sort by
            * SSN alone. Maybe a hybred approach is the answer
            * 
            */
           struct sctp_stream_in *strm;
           struct sctp_queued_to_read *at;
           int queue_needed;
           uint16_t nxt_todel;
           struct mbuf *op_err;
           char msg[SCTP_DIAG_INFO_LEN];
   
           queue_needed = 1;
           asoc->size_on_all_streams += control->length;
           sctp_ucount_incr(asoc->cnt_on_all_streams);
           strm = &asoc->strmin[control->sinfo_stream];
           nxt_todel = strm->last_sequence_delivered + 1;
           if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                   sctp_log_strm_del(control, NULL, SCTP_STR_LOG_FROM_INTO_STRD);
           }
           SCTPDBG(SCTP_DEBUG_INDATA1,
               "queue to stream called for sid:%u ssn:%u tsn:%u lastdel:%u nxt:%u\n",
               (uint32_t) control->sinfo_stream, (uint32_t) control->sinfo_ssn,
               (uint32_t) control->sinfo_tsn,
               (uint32_t) strm->last_sequence_delivered, (uint32_t) nxt_todel);
           if (SCTP_SSN_GE(strm->last_sequence_delivered, control->sinfo_ssn)) {
                   /* The incoming sseq is behind where we last delivered? */
                   SCTPDBG(SCTP_DEBUG_INDATA1, "Duplicate S-SEQ:%d delivered:%d from peer, Abort association\n",
                       control->sinfo_ssn, strm->last_sequence_delivered);
   protocol_error:
                   /*
                    * throw it in the stream so it gets cleaned up in
                    * association destruction
                    */
                   TAILQ_INSERT_HEAD(&strm->inqueue, control, next);
                   snprintf(msg, sizeof(msg), "Delivered SSN=%4.4x, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                       strm->last_sequence_delivered, control->sinfo_tsn,
                       control->sinfo_stream, control->sinfo_ssn);
                   op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                   stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_1;
                   sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                   *abort_flag = 1;
                   return;
   
           }
   #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
           struct socket *so;
   
           so = SCTP_INP_SO(stcb->sctp_ep);
           atomic_add_int(&stcb->asoc.refcnt, 1);
           SCTP_TCB_UNLOCK(stcb);
           SCTP_SOCKET_LOCK(so, 1);
           SCTP_TCB_LOCK(stcb);
           atomic_subtract_int(&stcb->asoc.refcnt, 1);
           if (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) {
                   SCTP_SOCKET_UNLOCK(so, 1);
                   return;
           }
   #endif
           if (nxt_todel == control->sinfo_ssn) {
                   /* can be delivered right away? */
                   if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                           sctp_log_strm_del(control, NULL, SCTP_STR_LOG_FROM_IMMED_DEL);
                   }
                   /* EY it wont be queued if it could be delivered directly */
                   queue_needed = 0;
                   asoc->size_on_all_streams -= control->length;
                   sctp_ucount_decr(asoc->cnt_on_all_streams);
                   strm->last_sequence_delivered++;
   
                   sctp_mark_non_revokable(asoc, control->sinfo_tsn);
                   sctp_add_to_readq(stcb->sctp_ep, stcb,
                       control,
                       &stcb->sctp_socket->so_rcv, 1,
                       SCTP_READ_LOCK_NOT_HELD, SCTP_SO_LOCKED);
                   TAILQ_FOREACH_SAFE(control, &strm->inqueue, next, at) {
                           /* all delivered */
                           nxt_todel = strm->last_sequence_delivered + 1;
                           if (nxt_todel == control->sinfo_ssn) {
                                   TAILQ_REMOVE(&strm->inqueue, control, next);
                                   asoc->size_on_all_streams -= control->length;
                                   sctp_ucount_decr(asoc->cnt_on_all_streams);
                                   strm->last_sequence_delivered++;
                                   /*
                                    * We ignore the return of deliver_data here
                                    * since we always can hold the chunk on the
                                    * d-queue. And we have a finite number that
                                    * can be delivered from the strq.
                                    */
                                   if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                                           sctp_log_strm_del(control, NULL,
                                               SCTP_STR_LOG_FROM_IMMED_DEL);
                                   }
                                   sctp_mark_non_revokable(asoc, control->sinfo_tsn);
                                   sctp_add_to_readq(stcb->sctp_ep, stcb,
                                       control,
                                       &stcb->sctp_socket->so_rcv, 1,
                                       SCTP_READ_LOCK_NOT_HELD,
                                       SCTP_SO_LOCKED);
                                   continue;
                           }
                           break;
                   }
           }
           if (queue_needed) {
                   /*
                    * Ok, we did not deliver this guy, find the correct place
                    * to put it on the queue.
                    */
                   if (SCTP_TSN_GE(asoc->cumulative_tsn, control->sinfo_tsn)) {
   #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                           SCTP_SOCKET_UNLOCK(so, 1);
   #endif
                           goto protocol_error;
                   }
                   if (TAILQ_EMPTY(&strm->inqueue)) {
                           /* Empty queue */
                           if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                                   sctp_log_strm_del(control, NULL, SCTP_STR_LOG_FROM_INSERT_HD);
                           }
                           TAILQ_INSERT_HEAD(&strm->inqueue, control, next);
                   } else {
                           TAILQ_FOREACH(at, &strm->inqueue, next) {
                                   if (SCTP_SSN_GT(at->sinfo_ssn, control->sinfo_ssn)) {
                                           /*
                                            * one in queue is bigger than the
                                            * new one, insert before this one
                                            */
                                           if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                                                   sctp_log_strm_del(control, at,
                                                       SCTP_STR_LOG_FROM_INSERT_MD);
                                           }
                                           TAILQ_INSERT_BEFORE(at, control, next);
                                           break;
                                   } else if (at->sinfo_ssn == control->sinfo_ssn) {
                                           /*
                                            * Gak, He sent me a duplicate str
                                            * seq number
                                            */
                                           /*
                                            * foo bar, I guess I will just free
                                            * this new guy, should we abort
                                            * too? FIX ME MAYBE? Or it COULD be
                                            * that the SSN's have wrapped.
                                            * Maybe I should compare to TSN
                                            * somehow... sigh for now just blow
                                            * away the chunk!
                                            */
   
                                           if (control->data)
                                                   sctp_m_freem(control->data);
                                           control->data = NULL;
                                           asoc->size_on_all_streams -= control->length;
                                           sctp_ucount_decr(asoc->cnt_on_all_streams);
                                           if (control->whoFrom) {
                                                   sctp_free_remote_addr(control->whoFrom);
                                                   control->whoFrom = NULL;
                                           }
                                           sctp_free_a_readq(stcb, control);
   #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                                           SCTP_SOCKET_UNLOCK(so, 1);
   #endif
                                           return;
                                   } else {
                                           if (TAILQ_NEXT(at, next) == NULL) {
                                                   /*
                                                    * We are at the end, insert
                                                    * it after this one
                                                    */
                                                   if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                                                           sctp_log_strm_del(control, at,
                                                               SCTP_STR_LOG_FROM_INSERT_TL);
                                                   }
                                                   TAILQ_INSERT_AFTER(&strm->inqueue,
                                                       at, control, next);
                                                   break;
                                           }
                                   }
                           }
                   }
           }
   #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
           SCTP_SOCKET_UNLOCK(so, 1);
   #endif
   }
   
   /*
    * Returns two things: You get the total size of the deliverable parts of the
    * first fragmented message on the reassembly queue. And you get a 1 back if
    * all of the message is ready or a 0 back if the message is still incomplete
    */
   static int
   sctp_is_all_msg_on_reasm(struct sctp_association *asoc, uint32_t * t_size)
   {
           struct sctp_tmit_chunk *chk;
           uint32_t tsn;
   
           *t_size = 0;
           chk = TAILQ_FIRST(&asoc->reasmqueue);
           if (chk == NULL) {
                   /* nothing on the queue */
                   return (0);
           }
           if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) == 0) {
                   /* Not a first on the queue */
                   return (0);
           }
           tsn = chk->rec.data.TSN_seq;
           TAILQ_FOREACH(chk, &asoc->reasmqueue, sctp_next) {
                   if (tsn != chk->rec.data.TSN_seq) {
                           return (0);
                   }
                   *t_size += chk->send_size;
                   if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                           return (1);
                   }
                   tsn++;
           }
           return (0);
   }
   
   static void
   sctp_deliver_reasm_check(struct sctp_tcb *stcb, struct sctp_association *asoc)
   {
           struct sctp_tmit_chunk *chk;
           uint16_t nxt_todel;
           uint32_t tsize, pd_point;
   
   doit_again:
           chk = TAILQ_FIRST(&asoc->reasmqueue);
           if (chk == NULL) {
                   /* Huh? */
                   asoc->size_on_reasm_queue = 0;
                   asoc->cnt_on_reasm_queue = 0;
                   return;
           }
           if (asoc->fragmented_delivery_inprogress == 0) {
                   nxt_todel =
                       asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered + 1;
                   if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) &&
                       (nxt_todel == chk->rec.data.stream_seq ||
                       (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED))) {
                           /*
                            * Yep the first one is here and its ok to deliver
                            * but should we?
                            */
                           if (stcb->sctp_socket) {
                                   pd_point = min(SCTP_SB_LIMIT_RCV(stcb->sctp_socket) >> SCTP_PARTIAL_DELIVERY_SHIFT,
                                       stcb->sctp_ep->partial_delivery_point);
                           } else {
                                   pd_point = stcb->sctp_ep->partial_delivery_point;
                           }
                           if (sctp_is_all_msg_on_reasm(asoc, &tsize) || (tsize >= pd_point)) {
                                   /*
                                    * Yes, we setup to start reception, by
                                    * backing down the TSN just in case we
                                    * can't deliver. If we
                                    */
                                   asoc->fragmented_delivery_inprogress = 1;
                                   asoc->tsn_last_delivered =
                                       chk->rec.data.TSN_seq - 1;
                                   asoc->str_of_pdapi =
                                       chk->rec.data.stream_number;
                                   asoc->ssn_of_pdapi = chk->rec.data.stream_seq;
                                   asoc->pdapi_ppid = chk->rec.data.payloadtype;
                                   asoc->fragment_flags = chk->rec.data.rcv_flags;
                                   sctp_service_reassembly(stcb, asoc);
                           }
                   }
           } else {
                   /*
                    * Service re-assembly will deliver stream data queued at
                    * the end of fragmented delivery.. but it wont know to go
                    * back and call itself again... we do that here with the
                    * got doit_again
                    */
                   sctp_service_reassembly(stcb, asoc);
                   if (asoc->fragmented_delivery_inprogress == 0) {
                           /*
                            * finished our Fragmented delivery, could be more
                            * waiting?
                            */
                           goto doit_again;
                   }
           }
   }
   
   /*
    * Dump onto the re-assembly queue, in its proper place. After dumping on the
    * queue, see if anthing can be delivered. If so pull it off (or as much as
    * we can. If we run out of space then we must dump what we can and set the
    * appropriate flag to say we queued what we could.
    */
   static void
   sctp_queue_data_for_reasm(struct sctp_tcb *stcb, struct sctp_association *asoc,
       struct sctp_tmit_chunk *chk, int *abort_flag)
   {
           struct mbuf *op_err;
           char msg[SCTP_DIAG_INFO_LEN];
           uint32_t cum_ackp1, prev_tsn, post_tsn;
           struct sctp_tmit_chunk *at, *prev, *next;
   
           prev = next = NULL;
           cum_ackp1 = asoc->tsn_last_delivered + 1;
           if (TAILQ_EMPTY(&asoc->reasmqueue)) {
                   /* This is the first one on the queue */
                   TAILQ_INSERT_HEAD(&asoc->reasmqueue, chk, sctp_next);
                   /*
                    * we do not check for delivery of anything when only one
                    * fragment is here
                    */
                   asoc->size_on_reasm_queue = chk->send_size;
                   sctp_ucount_incr(asoc->cnt_on_reasm_queue);
                   if (chk->rec.data.TSN_seq == cum_ackp1) {
                           if (asoc->fragmented_delivery_inprogress == 0 &&
                               (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) !=
                               SCTP_DATA_FIRST_FRAG) {
                                   /*
                                    * An empty queue, no delivery inprogress,
                                    * we hit the next one and it does NOT have
                                    * a FIRST fragment mark.
                                    */
                                   SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, its not first, no fragmented delivery in progress\n");
                                   snprintf(msg, sizeof(msg),
                                       "Expected B-bit for TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                       chk->rec.data.TSN_seq,
                                       chk->rec.data.stream_number,
                                       chk->rec.data.stream_seq);
                                   op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                   stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_2;
                                   sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                   *abort_flag = 1;
                           } else if (asoc->fragmented_delivery_inprogress &&
                               (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) == SCTP_DATA_FIRST_FRAG) {
                                   /*
                                    * We are doing a partial delivery and the
                                    * NEXT chunk MUST be either the LAST or
                                    * MIDDLE fragment NOT a FIRST
                                    */
                                   SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, it IS a first and fragmented delivery in progress\n");
                                   snprintf(msg, sizeof(msg),
                                       "Didn't expect B-bit for TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                       chk->rec.data.TSN_seq,
                                       chk->rec.data.stream_number,
                                       chk->rec.data.stream_seq);
                                   op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                   stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_3;
                                   sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                   *abort_flag = 1;
                           } else if (asoc->fragmented_delivery_inprogress) {
                                   /*
                                    * Here we are ok with a MIDDLE or LAST
                                    * piece
                                    */
                                   if (chk->rec.data.stream_number !=
                                       asoc->str_of_pdapi) {
                                           /* Got to be the right STR No */
                                           SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, it IS not same stream number %d vs %d\n",
                                               chk->rec.data.stream_number,
                                               asoc->str_of_pdapi);
                                           snprintf(msg, sizeof(msg),
                                               "Expected SID=%4.4x, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                               asoc->str_of_pdapi,
                                               chk->rec.data.TSN_seq,
                                               chk->rec.data.stream_number,
                                               chk->rec.data.stream_seq);
                                           op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                           stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_4;
                                           sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                           *abort_flag = 1;
                                   } else if ((asoc->fragment_flags & SCTP_DATA_UNORDERED) !=
                                               SCTP_DATA_UNORDERED &&
                                       chk->rec.data.stream_seq != asoc->ssn_of_pdapi) {
                                           /* Got to be the right STR Seq */
                                           SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, it IS not same stream seq %d vs %d\n",
                                               chk->rec.data.stream_seq,
                                               asoc->ssn_of_pdapi);
                                           snprintf(msg, sizeof(msg),
                                               "Expected SSN=%4.4x, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                               asoc->ssn_of_pdapi,
                                               chk->rec.data.TSN_seq,
                                               chk->rec.data.stream_number,
                                               chk->rec.data.stream_seq);
                                           op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                           stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_5;
                                           sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                           *abort_flag = 1;
                                   }
                           }
                   }
                   return;
           }
           /* Find its place */
           TAILQ_FOREACH(at, &asoc->reasmqueue, sctp_next) {
                   if (SCTP_TSN_GT(at->rec.data.TSN_seq, chk->rec.data.TSN_seq)) {
                           /*
                            * one in queue is bigger than the new one, insert
                            * before this one
                            */
                           /* A check */
                           asoc->size_on_reasm_queue += chk->send_size;
                           sctp_ucount_incr(asoc->cnt_on_reasm_queue);
                           next = at;
                           TAILQ_INSERT_BEFORE(at, chk, sctp_next);
                           break;
                   } else if (at->rec.data.TSN_seq == chk->rec.data.TSN_seq) {
                           /* Gak, He sent me a duplicate str seq number */
                           /*
                            * foo bar, I guess I will just free this new guy,
                            * should we abort too? FIX ME MAYBE? Or it COULD be
                            * that the SSN's have wrapped. Maybe I should
                            * compare to TSN somehow... sigh for now just blow
                            * away the chunk!
                            */
                           if (chk->data) {
                                   sctp_m_freem(chk->data);
                                   chk->data = NULL;
                           }
                           sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
                           return;
                   } else {
                           prev = at;
                           if (TAILQ_NEXT(at, sctp_next) == NULL) {
                                   /*
                                    * We are at the end, insert it after this
                                    * one
                                    */
                                   /* check it first */
                                   asoc->size_on_reasm_queue += chk->send_size;
                                   sctp_ucount_incr(asoc->cnt_on_reasm_queue);
                                   TAILQ_INSERT_AFTER(&asoc->reasmqueue, at, chk, sctp_next);
                                   break;
                           }
                   }
           }
           /* Now the audits */
           if (prev) {
                   prev_tsn = chk->rec.data.TSN_seq - 1;
                   if (prev_tsn == prev->rec.data.TSN_seq) {
                           /*
                           * Ok the one I am dropping onto the end is the
                           * NEXT. A bit of valdiation here.
                           */
                          if ((prev->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                              SCTP_DATA_FIRST_FRAG ||
                              (prev->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                              SCTP_DATA_MIDDLE_FRAG) {
                                  /*
                                   * Insert chk MUST be a MIDDLE or LAST
                                   * fragment
                                   */
                                  if ((chk->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                                      SCTP_DATA_FIRST_FRAG) {
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Prev check - It can be a midlle or last but not a first\n");
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, it's a FIRST!\n");
                                          snprintf(msg, sizeof(msg),
                                              "Can't handle B-bit, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                              chk->rec.data.TSN_seq,
                                              chk->rec.data.stream_number,
                                              chk->rec.data.stream_seq);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_6;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          return;
                                  }
                                  if (chk->rec.data.stream_number !=
                                      prev->rec.data.stream_number) {
                                          /*
                                           * Huh, need the correct STR here,
                                           * they must be the same.
                                           */
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Prev check - Gak, Evil plot, sid:%d not the same as at:%d\n",
                                              chk->rec.data.stream_number,
                                              prev->rec.data.stream_number);
                                          snprintf(msg, sizeof(msg),
                                              "Expect SID=%4.4x, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                              prev->rec.data.stream_number,
                                              chk->rec.data.TSN_seq,
                                              chk->rec.data.stream_number,
                                              chk->rec.data.stream_seq);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_7;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          return;
                                  }
                                  if ((chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) !=
                                      (prev->rec.data.rcv_flags & SCTP_DATA_UNORDERED)) {
                                          /*
                                           * Huh, need the same ordering here,
                                           * they must be the same.
                                           */
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Prev check - Gak, Evil plot, U-bit not constant\n");
                                          snprintf(msg, sizeof(msg),
                                              "Expect U-bit=%d for TSN=%8.8x, got U-bit=%d",
                                              (prev->rec.data.rcv_flags & SCTP_DATA_UNORDERED) ? 1 : 0,
                                              chk->rec.data.TSN_seq,
                                              (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) ? 1 : 0);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_8;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          return;
                                  }
                                  if ((prev->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0 &&
                                      chk->rec.data.stream_seq !=
                                      prev->rec.data.stream_seq) {
                                          /*
                                           * Huh, need the correct STR here,
                                           * they must be the same.
                                           */
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Prev check - Gak, Evil plot, sseq:%d not the same as at:%d\n",
                                              chk->rec.data.stream_seq,
                                              prev->rec.data.stream_seq);
                                          snprintf(msg, sizeof(msg),
                                              "Expect SSN=%4.4x, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                              prev->rec.data.stream_seq,
                                              chk->rec.data.TSN_seq,
                                              chk->rec.data.stream_number,
                                              chk->rec.data.stream_seq);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_9;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          return;
                                  }
                          } else if ((prev->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                              SCTP_DATA_LAST_FRAG) {
                                  /* Insert chk MUST be a FIRST */
                                  if ((chk->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) !=
                                      SCTP_DATA_FIRST_FRAG) {
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Prev check - Gak, evil plot, its not FIRST and it must be!\n");
                                          snprintf(msg, sizeof(msg),
                                              "Expect B-bit, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                              chk->rec.data.TSN_seq,
                                              chk->rec.data.stream_number,
                                              chk->rec.data.stream_seq);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_10;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          return;
                                  }
                          }
                  }
          }
          if (next) {
                  post_tsn = chk->rec.data.TSN_seq + 1;
                  if (post_tsn == next->rec.data.TSN_seq) {
                          /*
                           * Ok the one I am inserting ahead of is my NEXT
                           * one. A bit of valdiation here.
                           */
                          if (next->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                                  /* Insert chk MUST be a last fragment */
                                  if ((chk->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK)
                                      != SCTP_DATA_LAST_FRAG) {
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Next chk - Next is FIRST, we must be LAST\n");
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, its not a last!\n");
                                          snprintf(msg, sizeof(msg),
                                              "Expect only E-bit, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                              chk->rec.data.TSN_seq,
                                              chk->rec.data.stream_number,
                                              chk->rec.data.stream_seq);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_11;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          return;
                                  }
                          } else if ((next->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                                      SCTP_DATA_MIDDLE_FRAG ||
                                      (next->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                              SCTP_DATA_LAST_FRAG) {
                                  /*
                                   * Insert chk CAN be MIDDLE or FIRST NOT
                                   * LAST
                                   */
                                  if ((chk->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                                      SCTP_DATA_LAST_FRAG) {
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Next chk - Next is a MIDDLE/LAST\n");
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, new prev chunk is a LAST\n");
                                          snprintf(msg, sizeof(msg),
                                              "Didn't expect E-bit, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                              chk->rec.data.TSN_seq,
                                              chk->rec.data.stream_number,
                                              chk->rec.data.stream_seq);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_12;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          return;
                                  }
                                  if (chk->rec.data.stream_number !=
                                      next->rec.data.stream_number) {
                                          /*
                                           * Huh, need the correct STR here,
                                           * they must be the same.
                                           */
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Next chk - Gak, Evil plot, ssn:%d not the same as at:%d\n",
                                              chk->rec.data.stream_number,
                                              next->rec.data.stream_number);
                                          snprintf(msg, sizeof(msg),
                                              "Required SID %4.4x, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                              next->rec.data.stream_number,
                                              chk->rec.data.TSN_seq,
                                              chk->rec.data.stream_number,
                                              chk->rec.data.stream_seq);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_13;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          return;
                                  }
                                  if ((chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) !=
                                      (next->rec.data.rcv_flags & SCTP_DATA_UNORDERED)) {
                                          /*
                                           * Huh, need the same ordering here,
                                           * they must be the same.
                                           */
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Next check - Gak, Evil plot, U-bit not constant\n");
                                          snprintf(msg, sizeof(msg),
                                              "Expect U-bit=%d for TSN=%8.8x, got U-bit=%d",
                                              (next->rec.data.rcv_flags & SCTP_DATA_UNORDERED) ? 1 : 0,
                                              chk->rec.data.TSN_seq,
                                              (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) ? 1 : 0);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_14;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          return;
                                  }
                                  if ((next->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0 &&
                                      chk->rec.data.stream_seq !=
                                      next->rec.data.stream_seq) {
                                          /*
                                           * Huh, need the correct STR here,
                                           * they must be the same.
                                           */
                                          SCTPDBG(SCTP_DEBUG_INDATA1, "Next chk - Gak, Evil plot, sseq:%d not the same as at:%d\n",
                                              chk->rec.data.stream_seq,
                                              next->rec.data.stream_seq);
                                          snprintf(msg, sizeof(msg),
                                              "Required SSN %4.4x, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                              next->rec.data.stream_seq,
                                              chk->rec.data.TSN_seq,
                                              chk->rec.data.stream_number,
                                              chk->rec.data.stream_seq);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_15;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          return;
                                  }
                          }
                  }
          }
          /* Do we need to do some delivery? check */
          sctp_deliver_reasm_check(stcb, asoc);
  }
  
  /*
   * This is an unfortunate routine. It checks to make sure a evil guy is not
   * stuffing us full of bad packet fragments. A broken peer could also do this
   * but this is doubtful. It is to bad I must worry about evil crackers sigh
   * :< more cycles.
   */
  static int
  sctp_does_tsn_belong_to_reasm(struct sctp_association *asoc,
      uint32_t TSN_seq)
  {
          struct sctp_tmit_chunk *at;
          uint32_t tsn_est;
  
          TAILQ_FOREACH(at, &asoc->reasmqueue, sctp_next) {
                  if (SCTP_TSN_GT(TSN_seq, at->rec.data.TSN_seq)) {
                          /* is it one bigger? */
                          tsn_est = at->rec.data.TSN_seq + 1;
                          if (tsn_est == TSN_seq) {
                                  /* yep. It better be a last then */
                                  if ((at->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) !=
                                      SCTP_DATA_LAST_FRAG) {
                                          /*
                                           * Ok this guy belongs next to a guy
                                           * that is NOT last, it should be a
                                           * middle/last, not a complete
                                           * chunk.
                                           */
                                          return (1);
                                  } else {
                                          /*
                                           * This guy is ok since its a LAST
                                           * and the new chunk is a fully
                                           * self- contained one.
                                           */
                                          return (0);
                                  }
                          }
                  } else if (TSN_seq == at->rec.data.TSN_seq) {
                          /* Software error since I have a dup? */
                          return (1);
                  } else {
                          /*
                           * Ok, 'at' is larger than new chunk but does it
                           * need to be right before it.
                           */
                          tsn_est = TSN_seq + 1;
                          if (tsn_est == at->rec.data.TSN_seq) {
                                  /* Yep, It better be a first */
                                  if ((at->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) !=
                                      SCTP_DATA_FIRST_FRAG) {
                                          return (1);
                                  } else {
                                          return (0);
                                  }
                          }
                  }
          }
          return (0);
  }
  
  static int
  sctp_process_a_data_chunk(struct sctp_tcb *stcb, struct sctp_association *asoc,
      struct mbuf **m, int offset, struct sctp_data_chunk *ch, int chk_length,
      struct sctp_nets *net, uint32_t * high_tsn, int *abort_flag,
      int *break_flag, int last_chunk)
  {
          /* Process a data chunk */
          /* struct sctp_tmit_chunk *chk; */
          struct sctp_tmit_chunk *chk;
          uint32_t tsn, gap;
          struct mbuf *dmbuf;
          int the_len;
          int need_reasm_check = 0;
          uint16_t strmno, strmseq;
          struct mbuf *op_err;
          char msg[SCTP_DIAG_INFO_LEN];
          struct sctp_queued_to_read *control;
          int ordered;
          uint32_t protocol_id;
          uint8_t chunk_flags;
          struct sctp_stream_reset_list *liste;
  
          chk = NULL;
          tsn = ntohl(ch->dp.tsn);
          chunk_flags = ch->ch.chunk_flags;
          if ((chunk_flags & SCTP_DATA_SACK_IMMEDIATELY) == SCTP_DATA_SACK_IMMEDIATELY) {
                  asoc->send_sack = 1;
          }
          protocol_id = ch->dp.protocol_id;
          ordered = ((chunk_flags & SCTP_DATA_UNORDERED) == 0);
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                  sctp_log_map(tsn, asoc->cumulative_tsn, asoc->highest_tsn_inside_map, SCTP_MAP_TSN_ENTERS);
          }
          if (stcb == NULL) {
                  return (0);
          }
          SCTP_LTRACE_CHK(stcb->sctp_ep, stcb, ch->ch.chunk_type, tsn);
          if (SCTP_TSN_GE(asoc->cumulative_tsn, tsn)) {
                  /* It is a duplicate */
                  SCTP_STAT_INCR(sctps_recvdupdata);
                  if (asoc->numduptsns < SCTP_MAX_DUP_TSNS) {
                          /* Record a dup for the next outbound sack */
                          asoc->dup_tsns[asoc->numduptsns] = tsn;
                          asoc->numduptsns++;
                  }
                  asoc->send_sack = 1;
                  return (0);
          }
          /* Calculate the number of TSN's between the base and this TSN */
          SCTP_CALC_TSN_TO_GAP(gap, tsn, asoc->mapping_array_base_tsn);
          if (gap >= (SCTP_MAPPING_ARRAY << 3)) {
                  /* Can't hold the bit in the mapping at max array, toss it */
                  return (0);
          }
          if (gap >= (uint32_t) (asoc->mapping_array_size << 3)) {
                  SCTP_TCB_LOCK_ASSERT(stcb);
                  if (sctp_expand_mapping_array(asoc, gap)) {
                          /* Can't expand, drop it */
                          return (0);
                  }
          }
          if (SCTP_TSN_GT(tsn, *high_tsn)) {
                  *high_tsn = tsn;
          }
          /* See if we have received this one already */
          if (SCTP_IS_TSN_PRESENT(asoc->mapping_array, gap) ||
              SCTP_IS_TSN_PRESENT(asoc->nr_mapping_array, gap)) {
                  SCTP_STAT_INCR(sctps_recvdupdata);
                  if (asoc->numduptsns < SCTP_MAX_DUP_TSNS) {
                          /* Record a dup for the next outbound sack */
                          asoc->dup_tsns[asoc->numduptsns] = tsn;
                          asoc->numduptsns++;
                  }
                  asoc->send_sack = 1;
                  return (0);
          }
          /*
           * Check to see about the GONE flag, duplicates would cause a sack
           * to be sent up above
           */
          if (((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) ||
              (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_ALLGONE) ||
              (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET))) {
                  /*
                   * wait a minute, this guy is gone, there is no longer a
                   * receiver. Send peer an ABORT!
                   */
                  op_err = sctp_generate_cause(SCTP_CAUSE_OUT_OF_RESC, "");
                  sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                  *abort_flag = 1;
                  return (0);
          }
          /*
           * Now before going further we see if there is room. If NOT then we
           * MAY let one through only IF this TSN is the one we are waiting
           * for on a partial delivery API.
           */
  
          /* now do the tests */
          if (((asoc->cnt_on_all_streams +
              asoc->cnt_on_reasm_queue +
              asoc->cnt_msg_on_sb) >= SCTP_BASE_SYSCTL(sctp_max_chunks_on_queue)) ||
              (((int)asoc->my_rwnd) <= 0)) {
                  /*
                   * When we have NO room in the rwnd we check to make sure
                   * the reader is doing its job...
                   */
                  if (stcb->sctp_socket->so_rcv.sb_cc) {
                          /* some to read, wake-up */
  #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                          struct socket *so;
  
                          so = SCTP_INP_SO(stcb->sctp_ep);
                          atomic_add_int(&stcb->asoc.refcnt, 1);
                          SCTP_TCB_UNLOCK(stcb);
                          SCTP_SOCKET_LOCK(so, 1);
                          SCTP_TCB_LOCK(stcb);
                          atomic_subtract_int(&stcb->asoc.refcnt, 1);
                          if (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET) {
                                  /* assoc was freed while we were unlocked */
                                  SCTP_SOCKET_UNLOCK(so, 1);
                                  return (0);
                          }
  #endif
                          sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
  #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                          SCTP_SOCKET_UNLOCK(so, 1);
  #endif
                  }
                  /* now is it in the mapping array of what we have accepted? */
                  if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_map) &&
                      SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_nr_map)) {
                          /* Nope not in the valid range dump it */
                          sctp_set_rwnd(stcb, asoc);
                          if ((asoc->cnt_on_all_streams +
                              asoc->cnt_on_reasm_queue +
                              asoc->cnt_msg_on_sb) >= SCTP_BASE_SYSCTL(sctp_max_chunks_on_queue)) {
                                  SCTP_STAT_INCR(sctps_datadropchklmt);
                          } else {
                                  SCTP_STAT_INCR(sctps_datadroprwnd);
                          }
                          *break_flag = 1;
                          return (0);
                  }
          }
          strmno = ntohs(ch->dp.stream_id);
          if (strmno >= asoc->streamincnt) {
                  struct sctp_error_invalid_stream *cause;
  
                  op_err = sctp_get_mbuf_for_msg(sizeof(struct sctp_error_invalid_stream),
                      0, M_NOWAIT, 1, MT_DATA);
                  if (op_err != NULL) {
                          /* add some space up front so prepend will work well */
                          SCTP_BUF_RESV_UF(op_err, sizeof(struct sctp_chunkhdr));
                          cause = mtod(op_err, struct sctp_error_invalid_stream *);
                          /*
                           * Error causes are just param's and this one has
                           * two back to back phdr, one with the error type
                           * and size, the other with the streamid and a rsvd
                           */
                          SCTP_BUF_LEN(op_err) = sizeof(struct sctp_error_invalid_stream);
                          cause->cause.code = htons(SCTP_CAUSE_INVALID_STREAM);
                          cause->cause.length = htons(sizeof(struct sctp_error_invalid_stream));
                          cause->stream_id = ch->dp.stream_id;
                          cause->reserved = htons(0);
                          sctp_queue_op_err(stcb, op_err);
                  }
                  SCTP_STAT_INCR(sctps_badsid);
                  SCTP_TCB_LOCK_ASSERT(stcb);
                  SCTP_SET_TSN_PRESENT(asoc->nr_mapping_array, gap);
                  if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_nr_map)) {
                          asoc->highest_tsn_inside_nr_map = tsn;
                  }
                  if (tsn == (asoc->cumulative_tsn + 1)) {
                          /* Update cum-ack */
                          asoc->cumulative_tsn = tsn;
                  }
                  return (0);
          }
          /*
           * Before we continue lets validate that we are not being fooled by
           * an evil attacker. We can only have 4k chunks based on our TSN
           * spread allowed by the mapping array 512 * 8 bits, so there is no
           * way our stream sequence numbers could have wrapped. We of course
           * only validate the FIRST fragment so the bit must be set.
           */
          strmseq = ntohs(ch->dp.stream_sequence);
  #ifdef SCTP_ASOCLOG_OF_TSNS
          SCTP_TCB_LOCK_ASSERT(stcb);
          if (asoc->tsn_in_at >= SCTP_TSN_LOG_SIZE) {
                  asoc->tsn_in_at = 0;
                  asoc->tsn_in_wrapped = 1;
          }
          asoc->in_tsnlog[asoc->tsn_in_at].tsn = tsn;
          asoc->in_tsnlog[asoc->tsn_in_at].strm = strmno;
          asoc->in_tsnlog[asoc->tsn_in_at].seq = strmseq;
          asoc->in_tsnlog[asoc->tsn_in_at].sz = chk_length;
          asoc->in_tsnlog[asoc->tsn_in_at].flgs = chunk_flags;
          asoc->in_tsnlog[asoc->tsn_in_at].stcb = (void *)stcb;
          asoc->in_tsnlog[asoc->tsn_in_at].in_pos = asoc->tsn_in_at;
          asoc->in_tsnlog[asoc->tsn_in_at].in_out = 1;
          asoc->tsn_in_at++;
  #endif
          if ((chunk_flags & SCTP_DATA_FIRST_FRAG) &&
              (TAILQ_EMPTY(&asoc->resetHead)) &&
              (chunk_flags & SCTP_DATA_UNORDERED) == 0 &&
              SCTP_SSN_GE(asoc->strmin[strmno].last_sequence_delivered, strmseq)) {
                  /* The incoming sseq is behind where we last delivered? */
                  SCTPDBG(SCTP_DEBUG_INDATA1, "EVIL/Broken-Dup S-SEQ:%d delivered:%d from peer, Abort!\n",
                      strmseq, asoc->strmin[strmno].last_sequence_delivered);
  
                  snprintf(msg, sizeof(msg), "Delivered SSN=%4.4x, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                      asoc->strmin[strmno].last_sequence_delivered,
                      tsn, strmno, strmseq);
                  op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                  stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_16;
                  sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                  *abort_flag = 1;
                  return (0);
          }
          /************************************
           * From here down we may find ch-> invalid
           * so its a good idea NOT to use it.
           *************************************/
  
          the_len = (chk_length - sizeof(struct sctp_data_chunk));
          if (last_chunk == 0) {
                  dmbuf = SCTP_M_COPYM(*m,
                      (offset + sizeof(struct sctp_data_chunk)),
                      the_len, M_NOWAIT);
  #ifdef SCTP_MBUF_LOGGING
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MBUF_LOGGING_ENABLE) {
                          sctp_log_mbc(dmbuf, SCTP_MBUF_ICOPY);
                  }
  #endif
          } else {
                  /* We can steal the last chunk */
                  int l_len;
  
                  dmbuf = *m;
                  /* lop off the top part */
                  m_adj(dmbuf, (offset + sizeof(struct sctp_data_chunk)));
                  if (SCTP_BUF_NEXT(dmbuf) == NULL) {
                          l_len = SCTP_BUF_LEN(dmbuf);
                  } else {
                          /*
                           * need to count up the size hopefully does not hit
                           * this to often :-0
                           */
                          struct mbuf *lat;
  
                          l_len = 0;
                          for (lat = dmbuf; lat; lat = SCTP_BUF_NEXT(lat)) {
                                  l_len += SCTP_BUF_LEN(lat);
                          }
                  }
                  if (l_len > the_len) {
                          /* Trim the end round bytes off  too */
                          m_adj(dmbuf, -(l_len - the_len));
                  }
          }
          if (dmbuf == NULL) {
                  SCTP_STAT_INCR(sctps_nomem);
                  return (0);
          }
          if ((chunk_flags & SCTP_DATA_NOT_FRAG) == SCTP_DATA_NOT_FRAG &&
              asoc->fragmented_delivery_inprogress == 0 &&
              TAILQ_EMPTY(&asoc->resetHead) &&
              ((ordered == 0) ||
              ((uint16_t) (asoc->strmin[strmno].last_sequence_delivered + 1) == strmseq &&
              TAILQ_EMPTY(&asoc->strmin[strmno].inqueue)))) {
                  /* Candidate for express delivery */
                  /*
                   * Its not fragmented, No PD-API is up, Nothing in the
                   * delivery queue, Its un-ordered OR ordered and the next to
                   * deliver AND nothing else is stuck on the stream queue,
                   * And there is room for it in the socket buffer. Lets just
                   * stuff it up the buffer....
                   */
  
                  /* It would be nice to avoid this copy if we could :< */
                  sctp_alloc_a_readq(stcb, control);
                  sctp_build_readq_entry_mac(control, stcb, asoc->context, net, tsn,
                      protocol_id,
                      strmno, strmseq,
                      chunk_flags,
                      dmbuf);
                  if (control == NULL) {
                          goto failed_express_del;
                  }
                  SCTP_SET_TSN_PRESENT(asoc->nr_mapping_array, gap);
                  if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_nr_map)) {
                          asoc->highest_tsn_inside_nr_map = tsn;
                  }
                  sctp_add_to_readq(stcb->sctp_ep, stcb,
                      control, &stcb->sctp_socket->so_rcv,
                      1, SCTP_READ_LOCK_NOT_HELD, SCTP_SO_NOT_LOCKED);
  
                  if ((chunk_flags & SCTP_DATA_UNORDERED) == 0) {
                          /* for ordered, bump what we delivered */
                          asoc->strmin[strmno].last_sequence_delivered++;
                  }
                  SCTP_STAT_INCR(sctps_recvexpress);
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                          sctp_log_strm_del_alt(stcb, tsn, strmseq, strmno,
                              SCTP_STR_LOG_FROM_EXPRS_DEL);
                  }
                  control = NULL;
  
                  goto finish_express_del;
          }
  failed_express_del:
          /* If we reach here this is a new chunk */
          chk = NULL;
          control = NULL;
          /* Express for fragmented delivery? */
          if ((asoc->fragmented_delivery_inprogress) &&
              (stcb->asoc.control_pdapi) &&
              (asoc->str_of_pdapi == strmno) &&
              (asoc->ssn_of_pdapi == strmseq)
              ) {
                  control = stcb->asoc.control_pdapi;
                  if ((chunk_flags & SCTP_DATA_FIRST_FRAG) == SCTP_DATA_FIRST_FRAG) {
                          /* Can't be another first? */
                          goto failed_pdapi_express_del;
                  }
                  if (tsn == (control->sinfo_tsn + 1)) {
                          /* Yep, we can add it on */
                          int end = 0;
  
                          if (chunk_flags & SCTP_DATA_LAST_FRAG) {
                                  end = 1;
                          }
                          if (sctp_append_to_readq(stcb->sctp_ep, stcb, control, dmbuf, end,
                              tsn,
                              &stcb->sctp_socket->so_rcv)) {
                                  SCTP_PRINTF("Append fails end:%d\n", end);
                                  goto failed_pdapi_express_del;
                          }
                          SCTP_SET_TSN_PRESENT(asoc->nr_mapping_array, gap);
                          if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_nr_map)) {
                                  asoc->highest_tsn_inside_nr_map = tsn;
                          }
                          SCTP_STAT_INCR(sctps_recvexpressm);
                          asoc->tsn_last_delivered = tsn;
                          asoc->fragment_flags = chunk_flags;
                          asoc->tsn_of_pdapi_last_delivered = tsn;
                          asoc->last_flags_delivered = chunk_flags;
                          asoc->last_strm_seq_delivered = strmseq;
                          asoc->last_strm_no_delivered = strmno;
                          if (end) {
                                  /* clean up the flags and such */
                                  asoc->fragmented_delivery_inprogress = 0;
                                  if ((chunk_flags & SCTP_DATA_UNORDERED) == 0) {
                                          asoc->strmin[strmno].last_sequence_delivered++;
                                  }
                                  stcb->asoc.control_pdapi = NULL;
                                  if (TAILQ_EMPTY(&asoc->reasmqueue) == 0) {
                                          /*
                                           * There could be another message
                                           * ready
                                           */
                                          need_reasm_check = 1;
                                  }
                          }
                          control = NULL;
                          goto finish_express_del;
                  }
          }
  failed_pdapi_express_del:
          control = NULL;
          if (SCTP_BASE_SYSCTL(sctp_do_drain) == 0) {
                  SCTP_SET_TSN_PRESENT(asoc->nr_mapping_array, gap);
                  if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_nr_map)) {
                          asoc->highest_tsn_inside_nr_map = tsn;
                  }
          } else {
                  SCTP_SET_TSN_PRESENT(asoc->mapping_array, gap);
                  if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_map)) {
                          asoc->highest_tsn_inside_map = tsn;
                  }
          }
          if ((chunk_flags & SCTP_DATA_NOT_FRAG) != SCTP_DATA_NOT_FRAG) {
                  sctp_alloc_a_chunk(stcb, chk);
                  if (chk == NULL) {
                          /* No memory so we drop the chunk */
                          SCTP_STAT_INCR(sctps_nomem);
                          if (last_chunk == 0) {
                                  /* we copied it, free the copy */
                                  sctp_m_freem(dmbuf);
                          }
                          return (0);
                  }
                  chk->rec.data.TSN_seq = tsn;
                  chk->no_fr_allowed = 0;
                  chk->rec.data.stream_seq = strmseq;
                  chk->rec.data.stream_number = strmno;
                  chk->rec.data.payloadtype = protocol_id;
                  chk->rec.data.context = stcb->asoc.context;
                  chk->rec.data.doing_fast_retransmit = 0;
                  chk->rec.data.rcv_flags = chunk_flags;
                  chk->asoc = asoc;
                  chk->send_size = the_len;
                  chk->whoTo = net;
                  atomic_add_int(&net->ref_count, 1);
                  chk->data = dmbuf;
          } else {
                  sctp_alloc_a_readq(stcb, control);
                  sctp_build_readq_entry_mac(control, stcb, asoc->context, net, tsn,
                      protocol_id,
                      strmno, strmseq,
                      chunk_flags,
                      dmbuf);
                  if (control == NULL) {
                          /* No memory so we drop the chunk */
                          SCTP_STAT_INCR(sctps_nomem);
                          if (last_chunk == 0) {
                                  /* we copied it, free the copy */
                                  sctp_m_freem(dmbuf);
                          }
                          return (0);
                  }
                  control->length = the_len;
          }
  
          /* Mark it as received */
          /* Now queue it where it belongs */
          if (control != NULL) {
                  /* First a sanity check */
                  if (asoc->fragmented_delivery_inprogress) {
                          /*
                           * Ok, we have a fragmented delivery in progress if
                           * this chunk is next to deliver OR belongs in our
                           * view to the reassembly, the peer is evil or
                           * broken.
                           */
                          uint32_t estimate_tsn;
  
                          estimate_tsn = asoc->tsn_last_delivered + 1;
                          if (TAILQ_EMPTY(&asoc->reasmqueue) &&
                              (estimate_tsn == control->sinfo_tsn)) {
                                  /* Evil/Broke peer */
                                  sctp_m_freem(control->data);
                                  control->data = NULL;
                                  if (control->whoFrom) {
                                          sctp_free_remote_addr(control->whoFrom);
                                          control->whoFrom = NULL;
                                  }
                                  sctp_free_a_readq(stcb, control);
                                  snprintf(msg, sizeof(msg), "Reas. queue emtpy, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                      tsn, strmno, strmseq);
                                  op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                  stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_17;
                                  sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                  *abort_flag = 1;
                                  if (last_chunk) {
                                          *m = NULL;
                                  }
                                  return (0);
                          } else {
                                  if (sctp_does_tsn_belong_to_reasm(asoc, control->sinfo_tsn)) {
                                          sctp_m_freem(control->data);
                                          control->data = NULL;
                                          if (control->whoFrom) {
                                                  sctp_free_remote_addr(control->whoFrom);
                                                  control->whoFrom = NULL;
                                          }
                                          sctp_free_a_readq(stcb, control);
                                          snprintf(msg, sizeof(msg), "PD ongoing, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                              tsn, strmno, strmseq);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_18;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          if (last_chunk) {
                                                  *m = NULL;
                                          }
                                          return (0);
                                  }
                          }
                  } else {
                          /* No PDAPI running */
                          if (!TAILQ_EMPTY(&asoc->reasmqueue)) {
                                  /*
                                   * Reassembly queue is NOT empty validate
                                   * that this tsn does not need to be in
                                   * reasembly queue. If it does then our peer
                                   * is broken or evil.
                                   */
                                  if (sctp_does_tsn_belong_to_reasm(asoc, control->sinfo_tsn)) {
                                          sctp_m_freem(control->data);
                                          control->data = NULL;
                                          if (control->whoFrom) {
                                                  sctp_free_remote_addr(control->whoFrom);
                                                  control->whoFrom = NULL;
                                          }
                                          sctp_free_a_readq(stcb, control);
                                          snprintf(msg, sizeof(msg), "No PD ongoing, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                                              tsn, strmno, strmseq);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_19;
                                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          *abort_flag = 1;
                                          if (last_chunk) {
                                                  *m = NULL;
                                          }
                                          return (0);
                                  }
                          }
                  }
                  /* ok, if we reach here we have passed the sanity checks */
                  if (chunk_flags & SCTP_DATA_UNORDERED) {
                          /* queue directly into socket buffer */
                          sctp_mark_non_revokable(asoc, control->sinfo_tsn);
                          sctp_add_to_readq(stcb->sctp_ep, stcb,
                              control,
                              &stcb->sctp_socket->so_rcv, 1, SCTP_READ_LOCK_NOT_HELD, SCTP_SO_NOT_LOCKED);
                  } else {
                          /*
                           * Special check for when streams are resetting. We
                           * could be more smart about this and check the
                           * actual stream to see if it is not being reset..
                           * that way we would not create a HOLB when amongst
                           * streams being reset and those not being reset.
                           * 
                           * We take complete messages that have a stream reset
                           * intervening (aka the TSN is after where our
                           * cum-ack needs to be) off and put them on a
                           * pending_reply_queue. The reassembly ones we do
                           * not have to worry about since they are all sorted
                           * and proceessed by TSN order. It is only the
                           * singletons I must worry about.
                           */
                          if (((liste = TAILQ_FIRST(&asoc->resetHead)) != NULL) &&
                              SCTP_TSN_GT(tsn, liste->tsn)) {
                                  /*
                                   * yep its past where we need to reset... go
                                   * ahead and queue it.
                                   */
                                  if (TAILQ_EMPTY(&asoc->pending_reply_queue)) {
                                          /* first one on */
                                          TAILQ_INSERT_TAIL(&asoc->pending_reply_queue, control, next);
                                  } else {
                                          struct sctp_queued_to_read *ctlOn,
                                                             *nctlOn;
                                          unsigned char inserted = 0;
  
                                          TAILQ_FOREACH_SAFE(ctlOn, &asoc->pending_reply_queue, next, nctlOn) {
                                                  if (SCTP_TSN_GT(control->sinfo_tsn, ctlOn->sinfo_tsn)) {
                                                          continue;
                                                  } else {
                                                          /* found it */
                                                          TAILQ_INSERT_BEFORE(ctlOn, control, next);
                                                          inserted = 1;
                                                          break;
                                                  }
                                          }
                                          if (inserted == 0) {
                                                  /*
                                                   * must be put at end, use
                                                   * prevP (all setup from
                                                   * loop) to setup nextP.
                                                   */
                                                  TAILQ_INSERT_TAIL(&asoc->pending_reply_queue, control, next);
                                          }
                                  }
                          } else {
                                  sctp_queue_data_to_stream(stcb, asoc, control, abort_flag);
                                  if (*abort_flag) {
                                          if (last_chunk) {
                                                  *m = NULL;
                                          }
                                          return (0);
                                  }
                          }
                  }
          } else {
                  /* Into the re-assembly queue */
                  sctp_queue_data_for_reasm(stcb, asoc, chk, abort_flag);
                  if (*abort_flag) {
                          /*
                           * the assoc is now gone and chk was put onto the
                           * reasm queue, which has all been freed.
                           */
                          if (last_chunk) {
                                  *m = NULL;
                          }
                          return (0);
                  }
          }
  finish_express_del:
          if (tsn == (asoc->cumulative_tsn + 1)) {
                  /* Update cum-ack */
                  asoc->cumulative_tsn = tsn;
          }
          if (last_chunk) {
                  *m = NULL;
          }
          if (ordered) {
                  SCTP_STAT_INCR_COUNTER64(sctps_inorderchunks);
          } else {
                  SCTP_STAT_INCR_COUNTER64(sctps_inunorderchunks);
          }
          SCTP_STAT_INCR(sctps_recvdata);
          /* Set it present please */
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                  sctp_log_strm_del_alt(stcb, tsn, strmseq, strmno, SCTP_STR_LOG_FROM_MARK_TSN);
          }
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                  sctp_log_map(asoc->mapping_array_base_tsn, asoc->cumulative_tsn,
                      asoc->highest_tsn_inside_map, SCTP_MAP_PREPARE_SLIDE);
          }
          /* check the special flag for stream resets */
          if (((liste = TAILQ_FIRST(&asoc->resetHead)) != NULL) &&
              SCTP_TSN_GE(asoc->cumulative_tsn, liste->tsn)) {
                  /*
                   * we have finished working through the backlogged TSN's now
                   * time to reset streams. 1: call reset function. 2: free
                   * pending_reply space 3: distribute any chunks in
                   * pending_reply_queue.
                   */
                  struct sctp_queued_to_read *ctl, *nctl;
  
                  sctp_reset_in_stream(stcb, liste->number_entries, liste->list_of_streams);
                  TAILQ_REMOVE(&asoc->resetHead, liste, next_resp);
                  sctp_send_deferred_reset_response(stcb, liste, SCTP_STREAM_RESET_RESULT_PERFORMED);
                  SCTP_FREE(liste, SCTP_M_STRESET);
                  /* sa_ignore FREED_MEMORY */
                  liste = TAILQ_FIRST(&asoc->resetHead);
                  if (TAILQ_EMPTY(&asoc->resetHead)) {
                          /* All can be removed */
                          TAILQ_FOREACH_SAFE(ctl, &asoc->pending_reply_queue, next, nctl) {
                                  TAILQ_REMOVE(&asoc->pending_reply_queue, ctl, next);
                                  sctp_queue_data_to_stream(stcb, asoc, ctl, abort_flag);
                                  if (*abort_flag) {
                                          return (0);
                                  }
                          }
                  } else {
                          TAILQ_FOREACH_SAFE(ctl, &asoc->pending_reply_queue, next, nctl) {
                                  if (SCTP_TSN_GT(ctl->sinfo_tsn, liste->tsn)) {
                                          break;
                                  }
                                  /*
                                   * if ctl->sinfo_tsn is <= liste->tsn we can
                                   * process it which is the NOT of
                                   * ctl->sinfo_tsn > liste->tsn
                                   */
                                  TAILQ_REMOVE(&asoc->pending_reply_queue, ctl, next);
                                  sctp_queue_data_to_stream(stcb, asoc, ctl, abort_flag);
                                  if (*abort_flag) {
                                          return (0);
                                  }
                          }
                  }
                  /*
                   * Now service re-assembly to pick up anything that has been
                   * held on reassembly queue?
                   */
                  sctp_deliver_reasm_check(stcb, asoc);
                  need_reasm_check = 0;
          }
          if (need_reasm_check) {
                  /* Another one waits ? */
                  sctp_deliver_reasm_check(stcb, asoc);
          }
          return (1);
  }
  
  int8_t sctp_map_lookup_tab[256] = {
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 4,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 5,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 4,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 6,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 4,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 5,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 4,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 7,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 4,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 5,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 4,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 6,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 4,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 5,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 4,
          0, 1, 0, 2, 0, 1, 0, 3,
          0, 1, 0, 2, 0, 1, 0, 8
  };
  
  
  void
  sctp_slide_mapping_arrays(struct sctp_tcb *stcb)
  {
          /*
           * Now we also need to check the mapping array in a couple of ways.
           * 1) Did we move the cum-ack point?
           * 
           * When you first glance at this you might think that all entries that
           * make up the postion of the cum-ack would be in the nr-mapping
           * array only.. i.e. things up to the cum-ack are always
           * deliverable. Thats true with one exception, when its a fragmented
           * message we may not deliver the data until some threshold (or all
           * of it) is in place. So we must OR the nr_mapping_array and
           * mapping_array to get a true picture of the cum-ack.
           */
          struct sctp_association *asoc;
          int at;
          uint8_t val;
          int slide_from, slide_end, lgap, distance;
          uint32_t old_cumack, old_base, old_highest, highest_tsn;
  
          asoc = &stcb->asoc;
  
          old_cumack = asoc->cumulative_tsn;
          old_base = asoc->mapping_array_base_tsn;
          old_highest = asoc->highest_tsn_inside_map;
          /*
           * We could probably improve this a small bit by calculating the
           * offset of the current cum-ack as the starting point.
           */
          at = 0;
          for (slide_from = 0; slide_from < stcb->asoc.mapping_array_size; slide_from++) {
                  val = asoc->nr_mapping_array[slide_from] | asoc->mapping_array[slide_from];
                  if (val == 0xff) {
                          at += 8;
                  } else {
                          /* there is a 0 bit */
                          at += sctp_map_lookup_tab[val];
                          break;
                  }
          }
          asoc->cumulative_tsn = asoc->mapping_array_base_tsn + (at - 1);
  
          if (SCTP_TSN_GT(asoc->cumulative_tsn, asoc->highest_tsn_inside_map) &&
              SCTP_TSN_GT(asoc->cumulative_tsn, asoc->highest_tsn_inside_nr_map)) {
  #ifdef INVARIANTS
                  panic("huh, cumack 0x%x greater than high-tsn 0x%x in map",
                      asoc->cumulative_tsn, asoc->highest_tsn_inside_map);
  #else
                  SCTP_PRINTF("huh, cumack 0x%x greater than high-tsn 0x%x in map - should panic?\n",
                      asoc->cumulative_tsn, asoc->highest_tsn_inside_map);
                  sctp_print_mapping_array(asoc);
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                          sctp_log_map(0, 6, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
                  }
                  asoc->highest_tsn_inside_map = asoc->cumulative_tsn;
                  asoc->highest_tsn_inside_nr_map = asoc->cumulative_tsn;
  #endif
          }
          if (SCTP_TSN_GT(asoc->highest_tsn_inside_nr_map, asoc->highest_tsn_inside_map)) {
                  highest_tsn = asoc->highest_tsn_inside_nr_map;
          } else {
                  highest_tsn = asoc->highest_tsn_inside_map;
          }
          if ((asoc->cumulative_tsn == highest_tsn) && (at >= 8)) {
                  /* The complete array was completed by a single FR */
                  /* highest becomes the cum-ack */
                  int clr;
  
  #ifdef INVARIANTS
                  unsigned int i;
  
  #endif
  
                  /* clear the array */
                  clr = ((at + 7) >> 3);
                  if (clr > asoc->mapping_array_size) {
                          clr = asoc->mapping_array_size;
                  }
                  memset(asoc->mapping_array, 0, clr);
                  memset(asoc->nr_mapping_array, 0, clr);
  #ifdef INVARIANTS
                  for (i = 0; i < asoc->mapping_array_size; i++) {
                          if ((asoc->mapping_array[i]) || (asoc->nr_mapping_array[i])) {
                                  SCTP_PRINTF("Error Mapping array's not clean at clear\n");
                                  sctp_print_mapping_array(asoc);
                          }
                  }
  #endif
                  asoc->mapping_array_base_tsn = asoc->cumulative_tsn + 1;
                  asoc->highest_tsn_inside_nr_map = asoc->highest_tsn_inside_map = asoc->cumulative_tsn;
          } else if (at >= 8) {
                  /* we can slide the mapping array down */
                  /* slide_from holds where we hit the first NON 0xff byte */
  
                  /*
                   * now calculate the ceiling of the move using our highest
                   * TSN value
                   */
                  SCTP_CALC_TSN_TO_GAP(lgap, highest_tsn, asoc->mapping_array_base_tsn);
                  slide_end = (lgap >> 3);
                  if (slide_end < slide_from) {
                          sctp_print_mapping_array(asoc);
  #ifdef INVARIANTS
                          panic("impossible slide");
  #else
                          SCTP_PRINTF("impossible slide lgap:%x slide_end:%x slide_from:%x? at:%d\n",
                              lgap, slide_end, slide_from, at);
                          return;
  #endif
                  }
                  if (slide_end > asoc->mapping_array_size) {
  #ifdef INVARIANTS
                          panic("would overrun buffer");
  #else
                          SCTP_PRINTF("Gak, would have overrun map end:%d slide_end:%d\n",
                              asoc->mapping_array_size, slide_end);
                          slide_end = asoc->mapping_array_size;
  #endif
                  }
                  distance = (slide_end - slide_from) + 1;
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                          sctp_log_map(old_base, old_cumack, old_highest,
                              SCTP_MAP_PREPARE_SLIDE);
                          sctp_log_map((uint32_t) slide_from, (uint32_t) slide_end,
                              (uint32_t) lgap, SCTP_MAP_SLIDE_FROM);
                  }
                  if (distance + slide_from > asoc->mapping_array_size ||
                      distance < 0) {
                          /*
                           * Here we do NOT slide forward the array so that
                           * hopefully when more data comes in to fill it up
                           * we will be able to slide it forward. Really I
                           * don't think this should happen :-0
                           */
  
                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                                  sctp_log_map((uint32_t) distance, (uint32_t) slide_from,
                                      (uint32_t) asoc->mapping_array_size,
                                      SCTP_MAP_SLIDE_NONE);
                          }
                  } else {
                          int ii;
  
                          for (ii = 0; ii < distance; ii++) {
                                  asoc->mapping_array[ii] = asoc->mapping_array[slide_from + ii];
                                  asoc->nr_mapping_array[ii] = asoc->nr_mapping_array[slide_from + ii];
  
                          }
                          for (ii = distance; ii < asoc->mapping_array_size; ii++) {
                                  asoc->mapping_array[ii] = 0;
                                  asoc->nr_mapping_array[ii] = 0;
                          }
                          if (asoc->highest_tsn_inside_map + 1 == asoc->mapping_array_base_tsn) {
                                  asoc->highest_tsn_inside_map += (slide_from << 3);
                          }
                          if (asoc->highest_tsn_inside_nr_map + 1 == asoc->mapping_array_base_tsn) {
                                  asoc->highest_tsn_inside_nr_map += (slide_from << 3);
                          }
                          asoc->mapping_array_base_tsn += (slide_from << 3);
                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                                  sctp_log_map(asoc->mapping_array_base_tsn,
                                      asoc->cumulative_tsn, asoc->highest_tsn_inside_map,
                                      SCTP_MAP_SLIDE_RESULT);
                          }
                  }
          }
  }
  
  void
  sctp_sack_check(struct sctp_tcb *stcb, int was_a_gap)
  {
          struct sctp_association *asoc;
          uint32_t highest_tsn;
  
          asoc = &stcb->asoc;
          if (SCTP_TSN_GT(asoc->highest_tsn_inside_nr_map, asoc->highest_tsn_inside_map)) {
                  highest_tsn = asoc->highest_tsn_inside_nr_map;
          } else {
                  highest_tsn = asoc->highest_tsn_inside_map;
          }
  
          /*
           * Now we need to see if we need to queue a sack or just start the
           * timer (if allowed).
           */
          if (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_SENT) {
                  /*
                   * Ok special case, in SHUTDOWN-SENT case. here we maker
                   * sure SACK timer is off and instead send a SHUTDOWN and a
                   * SACK
                   */
                  if (SCTP_OS_TIMER_PENDING(&stcb->asoc.dack_timer.timer)) {
                          sctp_timer_stop(SCTP_TIMER_TYPE_RECV,
                              stcb->sctp_ep, stcb, NULL,
                              SCTP_FROM_SCTP_INDATA + SCTP_LOC_20);
                  }
                  sctp_send_shutdown(stcb,
                      ((stcb->asoc.alternate) ? stcb->asoc.alternate : stcb->asoc.primary_destination));
                  sctp_send_sack(stcb, SCTP_SO_NOT_LOCKED);
          } else {
                  int is_a_gap;
  
                  /* is there a gap now ? */
                  is_a_gap = SCTP_TSN_GT(highest_tsn, stcb->asoc.cumulative_tsn);
  
                  /*
                   * CMT DAC algorithm: increase number of packets received
                   * since last ack
                   */
                  stcb->asoc.cmt_dac_pkts_rcvd++;
  
                  if ((stcb->asoc.send_sack == 1) ||      /* We need to send a
                                                           * SACK */
                      ((was_a_gap) && (is_a_gap == 0)) || /* was a gap, but no
                                                           * longer is one */
                      (stcb->asoc.numduptsns) ||  /* we have dup's */
                      (is_a_gap) ||       /* is still a gap */
                      (stcb->asoc.delayed_ack == 0) ||    /* Delayed sack disabled */
                      (stcb->asoc.data_pkts_seen >= stcb->asoc.sack_freq) /* hit limit of pkts */
                      ) {
  
                          if ((stcb->asoc.sctp_cmt_on_off > 0) &&
                              (SCTP_BASE_SYSCTL(sctp_cmt_use_dac)) &&
                              (stcb->asoc.send_sack == 0) &&
                              (stcb->asoc.numduptsns == 0) &&
                              (stcb->asoc.delayed_ack) &&
                              (!SCTP_OS_TIMER_PENDING(&stcb->asoc.dack_timer.timer))) {
  
                                  /*
                                   * CMT DAC algorithm: With CMT, delay acks
                                   * even in the face of
                                   * 
                                   * reordering. Therefore, if acks that do not
                                   * have to be sent because of the above
                                   * reasons, will be delayed. That is, acks
                                   * that would have been sent due to gap
                                   * reports will be delayed with DAC. Start
                                   * the delayed ack timer.
                                   */
                                  sctp_timer_start(SCTP_TIMER_TYPE_RECV,
                                      stcb->sctp_ep, stcb, NULL);
                          } else {
                                  /*
                                   * Ok we must build a SACK since the timer
                                   * is pending, we got our first packet OR
                                   * there are gaps or duplicates.
                                   */
                                  (void)SCTP_OS_TIMER_STOP(&stcb->asoc.dack_timer.timer);
                                  sctp_send_sack(stcb, SCTP_SO_NOT_LOCKED);
                          }
                  } else {
                          if (!SCTP_OS_TIMER_PENDING(&stcb->asoc.dack_timer.timer)) {
                                  sctp_timer_start(SCTP_TIMER_TYPE_RECV,
                                      stcb->sctp_ep, stcb, NULL);
                          }
                  }
          }
  }
  
  void
  sctp_service_queues(struct sctp_tcb *stcb, struct sctp_association *asoc)
  {
          struct sctp_tmit_chunk *chk;
          uint32_t tsize, pd_point;
          uint16_t nxt_todel;
  
          if (asoc->fragmented_delivery_inprogress) {
                  sctp_service_reassembly(stcb, asoc);
          }
          /* Can we proceed further, i.e. the PD-API is complete */
          if (asoc->fragmented_delivery_inprogress) {
                  /* no */
                  return;
          }
          /*
           * Now is there some other chunk I can deliver from the reassembly
           * queue.
           */
  doit_again:
          chk = TAILQ_FIRST(&asoc->reasmqueue);
          if (chk == NULL) {
                  asoc->size_on_reasm_queue = 0;
                  asoc->cnt_on_reasm_queue = 0;
                  return;
          }
          nxt_todel = asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered + 1;
          if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) &&
              ((nxt_todel == chk->rec.data.stream_seq) ||
              (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED))) {
                  /*
                   * Yep the first one is here. We setup to start reception,
                   * by backing down the TSN just in case we can't deliver.
                   */
  
                  /*
                   * Before we start though either all of the message should
                   * be here or the socket buffer max or nothing on the
                   * delivery queue and something can be delivered.
                   */
                  if (stcb->sctp_socket) {
                          pd_point = min(SCTP_SB_LIMIT_RCV(stcb->sctp_socket) >> SCTP_PARTIAL_DELIVERY_SHIFT,
                              stcb->sctp_ep->partial_delivery_point);
                  } else {
                          pd_point = stcb->sctp_ep->partial_delivery_point;
                  }
                  if (sctp_is_all_msg_on_reasm(asoc, &tsize) || (tsize >= pd_point)) {
                          asoc->fragmented_delivery_inprogress = 1;
                          asoc->tsn_last_delivered = chk->rec.data.TSN_seq - 1;
                          asoc->str_of_pdapi = chk->rec.data.stream_number;
                          asoc->ssn_of_pdapi = chk->rec.data.stream_seq;
                          asoc->pdapi_ppid = chk->rec.data.payloadtype;
                          asoc->fragment_flags = chk->rec.data.rcv_flags;
                          sctp_service_reassembly(stcb, asoc);
                          if (asoc->fragmented_delivery_inprogress == 0) {
                                  goto doit_again;
                          }
                  }
          }
  }
  
  int
  sctp_process_data(struct mbuf **mm, int iphlen, int *offset, int length,
      struct sctp_inpcb *inp, struct sctp_tcb *stcb,
      struct sctp_nets *net, uint32_t * high_tsn)
  {
          struct sctp_data_chunk *ch, chunk_buf;
          struct sctp_association *asoc;
          int num_chunks = 0;     /* number of control chunks processed */
          int stop_proc = 0;
          int chk_length, break_flag, last_chunk;
          int abort_flag = 0, was_a_gap;
          struct mbuf *m;
          uint32_t highest_tsn;
  
          /* set the rwnd */
          sctp_set_rwnd(stcb, &stcb->asoc);
  
          m = *mm;
          SCTP_TCB_LOCK_ASSERT(stcb);
          asoc = &stcb->asoc;
          if (SCTP_TSN_GT(asoc->highest_tsn_inside_nr_map, asoc->highest_tsn_inside_map)) {
                  highest_tsn = asoc->highest_tsn_inside_nr_map;
          } else {
                  highest_tsn = asoc->highest_tsn_inside_map;
          }
          was_a_gap = SCTP_TSN_GT(highest_tsn, stcb->asoc.cumulative_tsn);
          /*
           * setup where we got the last DATA packet from for any SACK that
           * may need to go out. Don't bump the net. This is done ONLY when a
           * chunk is assigned.
           */
          asoc->last_data_chunk_from = net;
  
          /*-
           * Now before we proceed we must figure out if this is a wasted
           * cluster... i.e. it is a small packet sent in and yet the driver
           * underneath allocated a full cluster for it. If so we must copy it
           * to a smaller mbuf and free up the cluster mbuf. This will help
           * with cluster starvation. Note for __Panda__ we don't do this
           * since it has clusters all the way down to 64 bytes.
           */
          if (SCTP_BUF_LEN(m) < (long)MLEN && SCTP_BUF_NEXT(m) == NULL) {
                  /* we only handle mbufs that are singletons.. not chains */
                  m = sctp_get_mbuf_for_msg(SCTP_BUF_LEN(m), 0, M_NOWAIT, 1, MT_DATA);
                  if (m) {
                          /* ok lets see if we can copy the data up */
                          caddr_t *from, *to;
  
                          /* get the pointers and copy */
                          to = mtod(m, caddr_t *);
                          from = mtod((*mm), caddr_t *);
                          memcpy(to, from, SCTP_BUF_LEN((*mm)));
                          /* copy the length and free up the old */
                          SCTP_BUF_LEN(m) = SCTP_BUF_LEN((*mm));
                          sctp_m_freem(*mm);
                          /* sucess, back copy */
                          *mm = m;
                  } else {
                          /* We are in trouble in the mbuf world .. yikes */
                          m = *mm;
                  }
          }
          /* get pointer to the first chunk header */
          ch = (struct sctp_data_chunk *)sctp_m_getptr(m, *offset,
              sizeof(struct sctp_data_chunk), (uint8_t *) & chunk_buf);
          if (ch == NULL) {
                  return (1);
          }
          /*
           * process all DATA chunks...
           */
          *high_tsn = asoc->cumulative_tsn;
          break_flag = 0;
          asoc->data_pkts_seen++;
          while (stop_proc == 0) {
                  /* validate chunk length */
                  chk_length = ntohs(ch->ch.chunk_length);
                  if (length - *offset < chk_length) {
                          /* all done, mutulated chunk */
                          stop_proc = 1;
                          continue;
                  }
                  if (ch->ch.chunk_type == SCTP_DATA) {
                          if ((size_t)chk_length < sizeof(struct sctp_data_chunk)) {
                                  /*
                                   * Need to send an abort since we had a
                                   * invalid data chunk.
                                   */
                                  struct mbuf *op_err;
                                  char msg[SCTP_DIAG_INFO_LEN];
  
                                  snprintf(msg, sizeof(msg), "DATA chunk of length %d",
                                      chk_length);
                                  op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                  stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_21;
                                  sctp_abort_an_association(inp, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                  return (2);
                          }
                          if ((size_t)chk_length == sizeof(struct sctp_data_chunk)) {
                                  /*
                                   * Need to send an abort since we had an
                                   * empty data chunk.
                                   */
                                  struct mbuf *op_err;
  
                                  op_err = sctp_generate_no_user_data_cause(ch->dp.tsn);
                                  stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_22;
                                  sctp_abort_an_association(inp, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                  return (2);
                          }
  #ifdef SCTP_AUDITING_ENABLED
                          sctp_audit_log(0xB1, 0);
  #endif
                          if (SCTP_SIZE32(chk_length) == (length - *offset)) {
                                  last_chunk = 1;
                          } else {
                                  last_chunk = 0;
                          }
                          if (sctp_process_a_data_chunk(stcb, asoc, mm, *offset, ch,
                              chk_length, net, high_tsn, &abort_flag, &break_flag,
                              last_chunk)) {
                                  num_chunks++;
                          }
                          if (abort_flag)
                                  return (2);
  
                          if (break_flag) {
                                  /*
                                   * Set because of out of rwnd space and no
                                   * drop rep space left.
                                   */
                                  stop_proc = 1;
                                  continue;
                          }
                  } else {
                          /* not a data chunk in the data region */
                          switch (ch->ch.chunk_type) {
                          case SCTP_INITIATION:
                          case SCTP_INITIATION_ACK:
                          case SCTP_SELECTIVE_ACK:
                          case SCTP_NR_SELECTIVE_ACK:
                          case SCTP_HEARTBEAT_REQUEST:
                          case SCTP_HEARTBEAT_ACK:
                          case SCTP_ABORT_ASSOCIATION:
                          case SCTP_SHUTDOWN:
                          case SCTP_SHUTDOWN_ACK:
                          case SCTP_OPERATION_ERROR:
                          case SCTP_COOKIE_ECHO:
                          case SCTP_COOKIE_ACK:
                          case SCTP_ECN_ECHO:
                          case SCTP_ECN_CWR:
                          case SCTP_SHUTDOWN_COMPLETE:
                          case SCTP_AUTHENTICATION:
                          case SCTP_ASCONF_ACK:
                          case SCTP_PACKET_DROPPED:
                          case SCTP_STREAM_RESET:
                          case SCTP_FORWARD_CUM_TSN:
                          case SCTP_ASCONF:
                                  /*
                                   * Now, what do we do with KNOWN chunks that
                                   * are NOT in the right place?
                                   * 
                                   * For now, I do nothing but ignore them. We
                                   * may later want to add sysctl stuff to
                                   * switch out and do either an ABORT() or
                                   * possibly process them.
                                   */
                                  if (SCTP_BASE_SYSCTL(sctp_strict_data_order)) {
                                          struct mbuf *op_err;
                                          char msg[SCTP_DIAG_INFO_LEN];
  
                                          snprintf(msg, sizeof(msg), "DATA chunk followed by chunk of type %2.2x",
                                              ch->ch.chunk_type);
                                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                          sctp_abort_an_association(inp, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                          return (2);
                                  }
                                  break;
                          default:
                                  /* unknown chunk type, use bit rules */
                                  if (ch->ch.chunk_type & 0x40) {
                                          /* Add a error report to the queue */
                                          struct mbuf *op_err;
                                          struct sctp_gen_error_cause *cause;
  
                                          op_err = sctp_get_mbuf_for_msg(sizeof(struct sctp_gen_error_cause),
                                              0, M_NOWAIT, 1, MT_DATA);
                                          if (op_err != NULL) {
                                                  cause = mtod(op_err, struct sctp_gen_error_cause *);
                                                  cause->code = htons(SCTP_CAUSE_UNRECOG_CHUNK);
                                                  cause->length = htons(chk_length + sizeof(struct sctp_gen_error_cause));
                                                  SCTP_BUF_LEN(op_err) = sizeof(struct sctp_gen_error_cause);
                                                  SCTP_BUF_NEXT(op_err) = SCTP_M_COPYM(m, *offset, chk_length, M_NOWAIT);
                                                  if (SCTP_BUF_NEXT(op_err) != NULL) {
                                                          sctp_queue_op_err(stcb, op_err);
                                                  } else {
                                                          sctp_m_freem(op_err);
                                                  }
                                          }
                                  }
                                  if ((ch->ch.chunk_type & 0x80) == 0) {
                                          /* discard the rest of this packet */
                                          stop_proc = 1;
                                  }       /* else skip this bad chunk and
                                           * continue... */
                                  break;
                          }       /* switch of chunk type */
                  }
                  *offset += SCTP_SIZE32(chk_length);
                  if ((*offset >= length) || stop_proc) {
                          /* no more data left in the mbuf chain */
                          stop_proc = 1;
                          continue;
                  }
                  ch = (struct sctp_data_chunk *)sctp_m_getptr(m, *offset,
                      sizeof(struct sctp_data_chunk), (uint8_t *) & chunk_buf);
                  if (ch == NULL) {
                          *offset = length;
                          stop_proc = 1;
                          continue;
                  }
          }
          if (break_flag) {
                  /*
                   * we need to report rwnd overrun drops.
                   */
                  sctp_send_packet_dropped(stcb, net, *mm, length, iphlen, 0);
          }
          if (num_chunks) {
                  /*
                   * Did we get data, if so update the time for auto-close and
                   * give peer credit for being alive.
                   */
                  SCTP_STAT_INCR(sctps_recvpktwithdata);
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
                          sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
                              stcb->asoc.overall_error_count,
                              0,
                              SCTP_FROM_SCTP_INDATA,
                              __LINE__);
                  }
                  stcb->asoc.overall_error_count = 0;
                  (void)SCTP_GETTIME_TIMEVAL(&stcb->asoc.time_last_rcvd);
          }
          /* now service all of the reassm queue if needed */
          if (!(TAILQ_EMPTY(&asoc->reasmqueue)))
                  sctp_service_queues(stcb, asoc);
  
          if (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_SENT) {
                  /* Assure that we ack right away */
                  stcb->asoc.send_sack = 1;
          }
          /* Start a sack timer or QUEUE a SACK for sending */
          sctp_sack_check(stcb, was_a_gap);
          return (0);
  }
  
  static int
  sctp_process_segment_range(struct sctp_tcb *stcb, struct sctp_tmit_chunk **p_tp1, uint32_t last_tsn,
      uint16_t frag_strt, uint16_t frag_end, int nr_sacking,
      int *num_frs,
      uint32_t * biggest_newly_acked_tsn,
      uint32_t * this_sack_lowest_newack,
      int *rto_ok)
  {
          struct sctp_tmit_chunk *tp1;
          unsigned int theTSN;
          int j, wake_him = 0, circled = 0;
  
          /* Recover the tp1 we last saw */
          tp1 = *p_tp1;
          if (tp1 == NULL) {
                  tp1 = TAILQ_FIRST(&stcb->asoc.sent_queue);
          }
          for (j = frag_strt; j <= frag_end; j++) {
                  theTSN = j + last_tsn;
                  while (tp1) {
                          if (tp1->rec.data.doing_fast_retransmit)
                                  (*num_frs) += 1;
  
                          /*-
                           * CMT: CUCv2 algorithm. For each TSN being
                           * processed from the sent queue, track the
                           * next expected pseudo-cumack, or
                           * rtx_pseudo_cumack, if required. Separate
                           * cumack trackers for first transmissions,
                           * and retransmissions.
                           */
                          if ((tp1->sent < SCTP_DATAGRAM_RESEND) &&
                              (tp1->whoTo->find_pseudo_cumack == 1) &&
                              (tp1->snd_count == 1)) {
                                  tp1->whoTo->pseudo_cumack = tp1->rec.data.TSN_seq;
                                  tp1->whoTo->find_pseudo_cumack = 0;
                          }
                          if ((tp1->sent < SCTP_DATAGRAM_RESEND) &&
                              (tp1->whoTo->find_rtx_pseudo_cumack == 1) &&
                              (tp1->snd_count > 1)) {
                                  tp1->whoTo->rtx_pseudo_cumack = tp1->rec.data.TSN_seq;
                                  tp1->whoTo->find_rtx_pseudo_cumack = 0;
                          }
                          if (tp1->rec.data.TSN_seq == theTSN) {
                                  if (tp1->sent != SCTP_DATAGRAM_UNSENT) {
                                          /*-
                                           * must be held until
                                           * cum-ack passes
                                           */
                                          if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                                  /*-
                                                   * If it is less than RESEND, it is
                                                   * now no-longer in flight.
                                                   * Higher values may already be set
                                                   * via previous Gap Ack Blocks...
                                                   * i.e. ACKED or RESEND.
                                                   */
                                                  if (SCTP_TSN_GT(tp1->rec.data.TSN_seq,
                                                      *biggest_newly_acked_tsn)) {
                                                          *biggest_newly_acked_tsn = tp1->rec.data.TSN_seq;
                                                  }
                                                  /*-
                                                   * CMT: SFR algo (and HTNA) - set
                                                   * saw_newack to 1 for dest being
                                                   * newly acked. update
                                                   * this_sack_highest_newack if
                                                   * appropriate.
                                                   */
                                                  if (tp1->rec.data.chunk_was_revoked == 0)
                                                          tp1->whoTo->saw_newack = 1;
  
                                                  if (SCTP_TSN_GT(tp1->rec.data.TSN_seq,
                                                      tp1->whoTo->this_sack_highest_newack)) {
                                                          tp1->whoTo->this_sack_highest_newack =
                                                              tp1->rec.data.TSN_seq;
                                                  }
                                                  /*-
                                                   * CMT DAC algo: also update
                                                   * this_sack_lowest_newack
                                                   */
                                                  if (*this_sack_lowest_newack == 0) {
                                                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                                                                  sctp_log_sack(*this_sack_lowest_newack,
                                                                      last_tsn,
                                                                      tp1->rec.data.TSN_seq,
                                                                      0,
                                                                      0,
                                                                      SCTP_LOG_TSN_ACKED);
                                                          }
                                                          *this_sack_lowest_newack = tp1->rec.data.TSN_seq;
                                                  }
                                                  /*-
                                                   * CMT: CUCv2 algorithm. If (rtx-)pseudo-cumack for corresp
                                                   * dest is being acked, then we have a new (rtx-)pseudo-cumack. Set
                                                   * new_(rtx_)pseudo_cumack to TRUE so that the cwnd for this dest can be
                                                   * updated. Also trigger search for the next expected (rtx-)pseudo-cumack.
                                                   * Separate pseudo_cumack trackers for first transmissions and
                                                   * retransmissions.
                                                   */
                                                  if (tp1->rec.data.TSN_seq == tp1->whoTo->pseudo_cumack) {
                                                          if (tp1->rec.data.chunk_was_revoked == 0) {
                                                                  tp1->whoTo->new_pseudo_cumack = 1;
                                                          }
                                                          tp1->whoTo->find_pseudo_cumack = 1;
                                                  }
                                                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
                                                          sctp_log_cwnd(stcb, tp1->whoTo, tp1->rec.data.TSN_seq, SCTP_CWND_LOG_FROM_SACK);
                                                  }
                                                  if (tp1->rec.data.TSN_seq == tp1->whoTo->rtx_pseudo_cumack) {
                                                          if (tp1->rec.data.chunk_was_revoked == 0) {
                                                                  tp1->whoTo->new_pseudo_cumack = 1;
                                                          }
                                                          tp1->whoTo->find_rtx_pseudo_cumack = 1;
                                                  }
                                                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                                                          sctp_log_sack(*biggest_newly_acked_tsn,
                                                              last_tsn,
                                                              tp1->rec.data.TSN_seq,
                                                              frag_strt,
                                                              frag_end,
                                                              SCTP_LOG_TSN_ACKED);
                                                  }
                                                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                                          sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_GAP,
                                                              tp1->whoTo->flight_size,
                                                              tp1->book_size,
                                                              (uintptr_t) tp1->whoTo,
                                                              tp1->rec.data.TSN_seq);
                                                  }
                                                  sctp_flight_size_decrease(tp1);
                                                  if (stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) {
                                                          (*stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) (tp1->whoTo,
                                                              tp1);
                                                  }
                                                  sctp_total_flight_decrease(stcb, tp1);
  
                                                  tp1->whoTo->net_ack += tp1->send_size;
                                                  if (tp1->snd_count < 2) {
                                                          /*-
                                                           * True non-retransmited chunk
                                                           */
                                                          tp1->whoTo->net_ack2 += tp1->send_size;
  
                                                          /*-
                                                           * update RTO too ?
                                                           */
                                                          if (tp1->do_rtt) {
                                                                  if (*rto_ok) {
                                                                          tp1->whoTo->RTO =
                                                                              sctp_calculate_rto(stcb,
                                                                              &stcb->asoc,
                                                                              tp1->whoTo,
                                                                              &tp1->sent_rcv_time,
                                                                              sctp_align_safe_nocopy,
                                                                              SCTP_RTT_FROM_DATA);
                                                                          *rto_ok = 0;
                                                                  }
                                                                  if (tp1->whoTo->rto_needed == 0) {
                                                                          tp1->whoTo->rto_needed = 1;
                                                                  }
                                                                  tp1->do_rtt = 0;
                                                          }
                                                  }
                                          }
                                          if (tp1->sent <= SCTP_DATAGRAM_RESEND) {
                                                  if (SCTP_TSN_GT(tp1->rec.data.TSN_seq,
                                                      stcb->asoc.this_sack_highest_gap)) {
                                                          stcb->asoc.this_sack_highest_gap =
                                                              tp1->rec.data.TSN_seq;
                                                  }
                                                  if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                                                          sctp_ucount_decr(stcb->asoc.sent_queue_retran_cnt);
  #ifdef SCTP_AUDITING_ENABLED
                                                          sctp_audit_log(0xB2,
                                                              (stcb->asoc.sent_queue_retran_cnt & 0x000000ff));
  #endif
                                                  }
                                          }
                                          /*-
                                           * All chunks NOT UNSENT fall through here and are marked
                                           * (leave PR-SCTP ones that are to skip alone though)
                                           */
                                          if ((tp1->sent != SCTP_FORWARD_TSN_SKIP) &&
                                              (tp1->sent != SCTP_DATAGRAM_NR_ACKED)) {
                                                  tp1->sent = SCTP_DATAGRAM_MARKED;
                                          }
                                          if (tp1->rec.data.chunk_was_revoked) {
                                                  /* deflate the cwnd */
                                                  tp1->whoTo->cwnd -= tp1->book_size;
                                                  tp1->rec.data.chunk_was_revoked = 0;
                                          }
                                          /* NR Sack code here */
                                          if (nr_sacking &&
                                              (tp1->sent != SCTP_DATAGRAM_NR_ACKED)) {
                                                  if (stcb->asoc.strmout[tp1->rec.data.stream_number].chunks_on_queues > 0) {
                                                          stcb->asoc.strmout[tp1->rec.data.stream_number].chunks_on_queues--;
  #ifdef INVARIANTS
                                                  } else {
                                                          panic("No chunks on the queues for sid %u.", tp1->rec.data.stream_number);
  #endif
                                                  }
                                                  if ((stcb->asoc.strmout[tp1->rec.data.stream_number].chunks_on_queues == 0) &&
                                                      (stcb->asoc.strmout[tp1->rec.data.stream_number].state == SCTP_STREAM_RESET_PENDING) &&
                                                      TAILQ_EMPTY(&stcb->asoc.strmout[tp1->rec.data.stream_number].outqueue)) {
                                                          stcb->asoc.trigger_reset = 1;
                                                  }
                                                  tp1->sent = SCTP_DATAGRAM_NR_ACKED;
                                                  if (tp1->data) {
                                                          /*
                                                           * sa_ignore
                                                           * NO_NULL_CHK
                                                           */
                                                          sctp_free_bufspace(stcb, &stcb->asoc, tp1, 1);
                                                          sctp_m_freem(tp1->data);
                                                          tp1->data = NULL;
                                                  }
                                                  wake_him++;
                                          }
                                  }
                                  break;
                          }       /* if (tp1->TSN_seq == theTSN) */
                          if (SCTP_TSN_GT(tp1->rec.data.TSN_seq, theTSN)) {
                                  break;
                          }
                          tp1 = TAILQ_NEXT(tp1, sctp_next);
                          if ((tp1 == NULL) && (circled == 0)) {
                                  circled++;
                                  tp1 = TAILQ_FIRST(&stcb->asoc.sent_queue);
                          }
                  }               /* end while (tp1) */
                  if (tp1 == NULL) {
                          circled = 0;
                          tp1 = TAILQ_FIRST(&stcb->asoc.sent_queue);
                  }
                  /* In case the fragments were not in order we must reset */
          }                       /* end for (j = fragStart */
          *p_tp1 = tp1;
          return (wake_him);      /* Return value only used for nr-sack */
  }
  
  
  static int
  sctp_handle_segments(struct mbuf *m, int *offset, struct sctp_tcb *stcb, struct sctp_association *asoc,
      uint32_t last_tsn, uint32_t * biggest_tsn_acked,
      uint32_t * biggest_newly_acked_tsn, uint32_t * this_sack_lowest_newack,
      int num_seg, int num_nr_seg, int *rto_ok)
  {
          struct sctp_gap_ack_block *frag, block;
          struct sctp_tmit_chunk *tp1;
          int i;
          int num_frs = 0;
          int chunk_freed;
          int non_revocable;
          uint16_t frag_strt, frag_end, prev_frag_end;
  
          tp1 = TAILQ_FIRST(&asoc->sent_queue);
          prev_frag_end = 0;
          chunk_freed = 0;
  
          for (i = 0; i < (num_seg + num_nr_seg); i++) {
                  if (i == num_seg) {
                          prev_frag_end = 0;
                          tp1 = TAILQ_FIRST(&asoc->sent_queue);
                  }
                  frag = (struct sctp_gap_ack_block *)sctp_m_getptr(m, *offset,
                      sizeof(struct sctp_gap_ack_block), (uint8_t *) & block);
                  *offset += sizeof(block);
                  if (frag == NULL) {
                          return (chunk_freed);
                  }
                  frag_strt = ntohs(frag->start);
                  frag_end = ntohs(frag->end);
  
                  if (frag_strt > frag_end) {
                          /* This gap report is malformed, skip it. */
                          continue;
                  }
                  if (frag_strt <= prev_frag_end) {
                          /* This gap report is not in order, so restart. */
                          tp1 = TAILQ_FIRST(&asoc->sent_queue);
                  }
                  if (SCTP_TSN_GT((last_tsn + frag_end), *biggest_tsn_acked)) {
                          *biggest_tsn_acked = last_tsn + frag_end;
                  }
                  if (i < num_seg) {
                          non_revocable = 0;
                  } else {
                          non_revocable = 1;
                  }
                  if (sctp_process_segment_range(stcb, &tp1, last_tsn, frag_strt, frag_end,
                      non_revocable, &num_frs, biggest_newly_acked_tsn,
                      this_sack_lowest_newack, rto_ok)) {
                          chunk_freed = 1;
                  }
                  prev_frag_end = frag_end;
          }
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                  if (num_frs)
                          sctp_log_fr(*biggest_tsn_acked,
                              *biggest_newly_acked_tsn,
                              last_tsn, SCTP_FR_LOG_BIGGEST_TSNS);
          }
          return (chunk_freed);
  }
  
  static void
  sctp_check_for_revoked(struct sctp_tcb *stcb,
      struct sctp_association *asoc, uint32_t cumack,
      uint32_t biggest_tsn_acked)
  {
          struct sctp_tmit_chunk *tp1;
  
          TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                  if (SCTP_TSN_GT(tp1->rec.data.TSN_seq, cumack)) {
                          /*
                           * ok this guy is either ACK or MARKED. If it is
                           * ACKED it has been previously acked but not this
                           * time i.e. revoked.  If it is MARKED it was ACK'ed
                           * again.
                           */
                          if (SCTP_TSN_GT(tp1->rec.data.TSN_seq, biggest_tsn_acked)) {
                                  break;
                          }
                          if (tp1->sent == SCTP_DATAGRAM_ACKED) {
                                  /* it has been revoked */
                                  tp1->sent = SCTP_DATAGRAM_SENT;
                                  tp1->rec.data.chunk_was_revoked = 1;
                                  /*
                                   * We must add this stuff back in to assure
                                   * timers and such get started.
                                   */
                                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                          sctp_misc_ints(SCTP_FLIGHT_LOG_UP_REVOKE,
                                              tp1->whoTo->flight_size,
                                              tp1->book_size,
                                              (uintptr_t) tp1->whoTo,
                                              tp1->rec.data.TSN_seq);
                                  }
                                  sctp_flight_size_increase(tp1);
                                  sctp_total_flight_increase(stcb, tp1);
                                  /*
                                   * We inflate the cwnd to compensate for our
                                   * artificial inflation of the flight_size.
                                   */
                                  tp1->whoTo->cwnd += tp1->book_size;
                                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                                          sctp_log_sack(asoc->last_acked_seq,
                                              cumack,
                                              tp1->rec.data.TSN_seq,
                                              0,
                                              0,
                                              SCTP_LOG_TSN_REVOKED);
                                  }
                          } else if (tp1->sent == SCTP_DATAGRAM_MARKED) {
                                  /* it has been re-acked in this SACK */
                                  tp1->sent = SCTP_DATAGRAM_ACKED;
                          }
                  }
                  if (tp1->sent == SCTP_DATAGRAM_UNSENT)
                          break;
          }
  }
  
  
  static void
  sctp_strike_gap_ack_chunks(struct sctp_tcb *stcb, struct sctp_association *asoc,
      uint32_t biggest_tsn_acked, uint32_t biggest_tsn_newly_acked, uint32_t this_sack_lowest_newack, int accum_moved)
  {
          struct sctp_tmit_chunk *tp1;
          int strike_flag = 0;
          struct timeval now;
          int tot_retrans = 0;
          uint32_t sending_seq;
          struct sctp_nets *net;
          int num_dests_sacked = 0;
  
          /*
           * select the sending_seq, this is either the next thing ready to be
           * sent but not transmitted, OR, the next seq we assign.
           */
          tp1 = TAILQ_FIRST(&stcb->asoc.send_queue);
          if (tp1 == NULL) {
                  sending_seq = asoc->sending_seq;
          } else {
                  sending_seq = tp1->rec.data.TSN_seq;
          }
  
          /* CMT DAC algo: finding out if SACK is a mixed SACK */
          if ((asoc->sctp_cmt_on_off > 0) &&
              SCTP_BASE_SYSCTL(sctp_cmt_use_dac)) {
                  TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                          if (net->saw_newack)
                                  num_dests_sacked++;
                  }
          }
          if (stcb->asoc.prsctp_supported) {
                  (void)SCTP_GETTIME_TIMEVAL(&now);
          }
          TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                  strike_flag = 0;
                  if (tp1->no_fr_allowed) {
                          /* this one had a timeout or something */
                          continue;
                  }
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                          if (tp1->sent < SCTP_DATAGRAM_RESEND)
                                  sctp_log_fr(biggest_tsn_newly_acked,
                                      tp1->rec.data.TSN_seq,
                                      tp1->sent,
                                      SCTP_FR_LOG_CHECK_STRIKE);
                  }
                  if (SCTP_TSN_GT(tp1->rec.data.TSN_seq, biggest_tsn_acked) ||
                      tp1->sent == SCTP_DATAGRAM_UNSENT) {
                          /* done */
                          break;
                  }
                  if (stcb->asoc.prsctp_supported) {
                          if ((PR_SCTP_TTL_ENABLED(tp1->flags)) && tp1->sent < SCTP_DATAGRAM_ACKED) {
                                  /* Is it expired? */
                                  if (timevalcmp(&now, &tp1->rec.data.timetodrop, >)) {
                                          /* Yes so drop it */
                                          if (tp1->data != NULL) {
                                                  (void)sctp_release_pr_sctp_chunk(stcb, tp1, 1,
                                                      SCTP_SO_NOT_LOCKED);
                                          }
                                          continue;
                                  }
                          }
                  }
                  if (SCTP_TSN_GT(tp1->rec.data.TSN_seq, asoc->this_sack_highest_gap)) {
                          /* we are beyond the tsn in the sack  */
                          break;
                  }
                  if (tp1->sent >= SCTP_DATAGRAM_RESEND) {
                          /* either a RESEND, ACKED, or MARKED */
                          /* skip */
                          if (tp1->sent == SCTP_FORWARD_TSN_SKIP) {
                                  /* Continue strikin FWD-TSN chunks */
                                  tp1->rec.data.fwd_tsn_cnt++;
                          }
                          continue;
                  }
                  /*
                   * CMT : SFR algo (covers part of DAC and HTNA as well)
                   */
                  if (tp1->whoTo && tp1->whoTo->saw_newack == 0) {
                          /*
                           * No new acks were receieved for data sent to this
                           * dest. Therefore, according to the SFR algo for
                           * CMT, no data sent to this dest can be marked for
                           * FR using this SACK.
                           */
                          continue;
                  } else if (tp1->whoTo && SCTP_TSN_GT(tp1->rec.data.TSN_seq,
                      tp1->whoTo->this_sack_highest_newack)) {
                          /*
                           * CMT: New acks were receieved for data sent to
                           * this dest. But no new acks were seen for data
                           * sent after tp1. Therefore, according to the SFR
                           * algo for CMT, tp1 cannot be marked for FR using
                           * this SACK. This step covers part of the DAC algo
                           * and the HTNA algo as well.
                           */
                          continue;
                  }
                  /*
                   * Here we check to see if we were have already done a FR
                   * and if so we see if the biggest TSN we saw in the sack is
                   * smaller than the recovery point. If so we don't strike
                   * the tsn... otherwise we CAN strike the TSN.
                   */
                  /*
                   * @@@ JRI: Check for CMT if (accum_moved &&
                   * asoc->fast_retran_loss_recovery && (sctp_cmt_on_off ==
                   * 0)) {
                   */
                  if (accum_moved && asoc->fast_retran_loss_recovery) {
                          /*
                           * Strike the TSN if in fast-recovery and cum-ack
                           * moved.
                           */
                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                  sctp_log_fr(biggest_tsn_newly_acked,
                                      tp1->rec.data.TSN_seq,
                                      tp1->sent,
                                      SCTP_FR_LOG_STRIKE_CHUNK);
                          }
                          if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                  tp1->sent++;
                          }
                          if ((asoc->sctp_cmt_on_off > 0) &&
                              SCTP_BASE_SYSCTL(sctp_cmt_use_dac)) {
                                  /*
                                   * CMT DAC algorithm: If SACK flag is set to
                                   * 0, then lowest_newack test will not pass
                                   * because it would have been set to the
                                   * cumack earlier. If not already to be
                                   * rtx'd, If not a mixed sack and if tp1 is
                                   * not between two sacked TSNs, then mark by
                                   * one more. NOTE that we are marking by one
                                   * additional time since the SACK DAC flag
                                   * indicates that two packets have been
                                   * received after this missing TSN.
                                   */
                                  if ((tp1->sent < SCTP_DATAGRAM_RESEND) && (num_dests_sacked == 1) &&
                                      SCTP_TSN_GT(this_sack_lowest_newack, tp1->rec.data.TSN_seq)) {
                                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                                  sctp_log_fr(16 + num_dests_sacked,
                                                      tp1->rec.data.TSN_seq,
                                                      tp1->sent,
                                                      SCTP_FR_LOG_STRIKE_CHUNK);
                                          }
                                          tp1->sent++;
                                  }
                          }
                  } else if ((tp1->rec.data.doing_fast_retransmit) &&
                      (asoc->sctp_cmt_on_off == 0)) {
                          /*
                           * For those that have done a FR we must take
                           * special consideration if we strike. I.e the
                           * biggest_newly_acked must be higher than the
                           * sending_seq at the time we did the FR.
                           */
                          if (
  #ifdef SCTP_FR_TO_ALTERNATE
                          /*
                           * If FR's go to new networks, then we must only do
                           * this for singly homed asoc's. However if the FR's
                           * go to the same network (Armando's work) then its
                           * ok to FR multiple times.
                           */
                              (asoc->numnets < 2)
  #else
                              (1)
  #endif
                              ) {
  
                                  if (SCTP_TSN_GE(biggest_tsn_newly_acked,
                                      tp1->rec.data.fast_retran_tsn)) {
                                          /*
                                           * Strike the TSN, since this ack is
                                           * beyond where things were when we
                                           * did a FR.
                                           */
                                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                                  sctp_log_fr(biggest_tsn_newly_acked,
                                                      tp1->rec.data.TSN_seq,
                                                      tp1->sent,
                                                      SCTP_FR_LOG_STRIKE_CHUNK);
                                          }
                                          if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                                  tp1->sent++;
                                          }
                                          strike_flag = 1;
                                          if ((asoc->sctp_cmt_on_off > 0) &&
                                              SCTP_BASE_SYSCTL(sctp_cmt_use_dac)) {
                                                  /*
                                                   * CMT DAC algorithm: If
                                                   * SACK flag is set to 0,
                                                   * then lowest_newack test
                                                   * will not pass because it
                                                   * would have been set to
                                                   * the cumack earlier. If
                                                   * not already to be rtx'd,
                                                   * If not a mixed sack and
                                                   * if tp1 is not between two
                                                   * sacked TSNs, then mark by
                                                   * one more. NOTE that we
                                                   * are marking by one
                                                   * additional time since the
                                                   * SACK DAC flag indicates
                                                   * that two packets have
                                                   * been received after this
                                                   * missing TSN.
                                                   */
                                                  if ((tp1->sent < SCTP_DATAGRAM_RESEND) &&
                                                      (num_dests_sacked == 1) &&
                                                      SCTP_TSN_GT(this_sack_lowest_newack,
                                                      tp1->rec.data.TSN_seq)) {
                                                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                                                  sctp_log_fr(32 + num_dests_sacked,
                                                                      tp1->rec.data.TSN_seq,
                                                                      tp1->sent,
                                                                      SCTP_FR_LOG_STRIKE_CHUNK);
                                                          }
                                                          if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                                                  tp1->sent++;
                                                          }
                                                  }
                                          }
                                  }
                          }
                          /*
                           * JRI: TODO: remove code for HTNA algo. CMT's SFR
                           * algo covers HTNA.
                           */
                  } else if (SCTP_TSN_GT(tp1->rec.data.TSN_seq,
                      biggest_tsn_newly_acked)) {
                          /*
                           * We don't strike these: This is the  HTNA
                           * algorithm i.e. we don't strike If our TSN is
                           * larger than the Highest TSN Newly Acked.
                           */
                          ;
                  } else {
                          /* Strike the TSN */
                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                  sctp_log_fr(biggest_tsn_newly_acked,
                                      tp1->rec.data.TSN_seq,
                                      tp1->sent,
                                      SCTP_FR_LOG_STRIKE_CHUNK);
                          }
                          if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                  tp1->sent++;
                          }
                          if ((asoc->sctp_cmt_on_off > 0) &&
                              SCTP_BASE_SYSCTL(sctp_cmt_use_dac)) {
                                  /*
                                   * CMT DAC algorithm: If SACK flag is set to
                                   * 0, then lowest_newack test will not pass
                                   * because it would have been set to the
                                   * cumack earlier. If not already to be
                                   * rtx'd, If not a mixed sack and if tp1 is
                                   * not between two sacked TSNs, then mark by
                                   * one more. NOTE that we are marking by one
                                   * additional time since the SACK DAC flag
                                   * indicates that two packets have been
                                   * received after this missing TSN.
                                   */
                                  if ((tp1->sent < SCTP_DATAGRAM_RESEND) && (num_dests_sacked == 1) &&
                                      SCTP_TSN_GT(this_sack_lowest_newack, tp1->rec.data.TSN_seq)) {
                                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                                  sctp_log_fr(48 + num_dests_sacked,
                                                      tp1->rec.data.TSN_seq,
                                                      tp1->sent,
                                                      SCTP_FR_LOG_STRIKE_CHUNK);
                                          }
                                          tp1->sent++;
                                  }
                          }
                  }
                  if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                          struct sctp_nets *alt;
  
                          /* fix counts and things */
                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                  sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_RSND,
                                      (tp1->whoTo ? (tp1->whoTo->flight_size) : 0),
                                      tp1->book_size,
                                      (uintptr_t) tp1->whoTo,
                                      tp1->rec.data.TSN_seq);
                          }
                          if (tp1->whoTo) {
                                  tp1->whoTo->net_ack++;
                                  sctp_flight_size_decrease(tp1);
                                  if (stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) {
                                          (*stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) (tp1->whoTo,
                                              tp1);
                                  }
                          }
                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_RWND_ENABLE) {
                                  sctp_log_rwnd(SCTP_INCREASE_PEER_RWND,
                                      asoc->peers_rwnd, tp1->send_size, SCTP_BASE_SYSCTL(sctp_peer_chunk_oh));
                          }
                          /* add back to the rwnd */
                          asoc->peers_rwnd += (tp1->send_size + SCTP_BASE_SYSCTL(sctp_peer_chunk_oh));
  
                          /* remove from the total flight */
                          sctp_total_flight_decrease(stcb, tp1);
  
                          if ((stcb->asoc.prsctp_supported) &&
                              (PR_SCTP_RTX_ENABLED(tp1->flags))) {
                                  /*
                                   * Has it been retransmitted tv_sec times? -
                                   * we store the retran count there.
                                   */
                                  if (tp1->snd_count > tp1->rec.data.timetodrop.tv_sec) {
                                          /* Yes, so drop it */
                                          if (tp1->data != NULL) {
                                                  (void)sctp_release_pr_sctp_chunk(stcb, tp1, 1,
                                                      SCTP_SO_NOT_LOCKED);
                                          }
                                          /* Make sure to flag we had a FR */
                                          tp1->whoTo->net_ack++;
                                          continue;
                                  }
                          }
                          /*
                           * SCTP_PRINTF("OK, we are now ready to FR this
                           * guy\n");
                           */
                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                  sctp_log_fr(tp1->rec.data.TSN_seq, tp1->snd_count,
                                      0, SCTP_FR_MARKED);
                          }
                          if (strike_flag) {
                                  /* This is a subsequent FR */
                                  SCTP_STAT_INCR(sctps_sendmultfastretrans);
                          }
                          sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
                          if (asoc->sctp_cmt_on_off > 0) {
                                  /*
                                   * CMT: Using RTX_SSTHRESH policy for CMT.
                                   * If CMT is being used, then pick dest with
                                   * largest ssthresh for any retransmission.
                                   */
                                  tp1->no_fr_allowed = 1;
                                  alt = tp1->whoTo;
                                  /* sa_ignore NO_NULL_CHK */
                                  if (asoc->sctp_cmt_pf > 0) {
                                          /*
                                           * JRS 5/18/07 - If CMT PF is on,
                                           * use the PF version of
                                           * find_alt_net()
                                           */
                                          alt = sctp_find_alternate_net(stcb, alt, 2);
                                  } else {
                                          /*
                                           * JRS 5/18/07 - If only CMT is on,
                                           * use the CMT version of
                                           * find_alt_net()
                                           */
                                          /* sa_ignore NO_NULL_CHK */
                                          alt = sctp_find_alternate_net(stcb, alt, 1);
                                  }
                                  if (alt == NULL) {
                                          alt = tp1->whoTo;
                                  }
                                  /*
                                   * CUCv2: If a different dest is picked for
                                   * the retransmission, then new
                                   * (rtx-)pseudo_cumack needs to be tracked
                                   * for orig dest. Let CUCv2 track new (rtx-)
                                   * pseudo-cumack always.
                                   */
                                  if (tp1->whoTo) {
                                          tp1->whoTo->find_pseudo_cumack = 1;
                                          tp1->whoTo->find_rtx_pseudo_cumack = 1;
                                  }
                          } else {/* CMT is OFF */
  
  #ifdef SCTP_FR_TO_ALTERNATE
                                  /* Can we find an alternate? */
                                  alt = sctp_find_alternate_net(stcb, tp1->whoTo, 0);
  #else
                                  /*
                                   * default behavior is to NOT retransmit
                                   * FR's to an alternate. Armando Caro's
                                   * paper details why.
                                   */
                                  alt = tp1->whoTo;
  #endif
                          }
  
                          tp1->rec.data.doing_fast_retransmit = 1;
                          tot_retrans++;
                          /* mark the sending seq for possible subsequent FR's */
                          /*
                           * SCTP_PRINTF("Marking TSN for FR new value %x\n",
                           * (uint32_t)tpi->rec.data.TSN_seq);
                           */
                          if (TAILQ_EMPTY(&asoc->send_queue)) {
                                  /*
                                   * If the queue of send is empty then its
                                   * the next sequence number that will be
                                   * assigned so we subtract one from this to
                                   * get the one we last sent.
                                   */
                                  tp1->rec.data.fast_retran_tsn = sending_seq;
                          } else {
                                  /*
                                   * If there are chunks on the send queue
                                   * (unsent data that has made it from the
                                   * stream queues but not out the door, we
                                   * take the first one (which will have the
                                   * lowest TSN) and subtract one to get the
                                   * one we last sent.
                                   */
                                  struct sctp_tmit_chunk *ttt;
  
                                  ttt = TAILQ_FIRST(&asoc->send_queue);
                                  tp1->rec.data.fast_retran_tsn =
                                      ttt->rec.data.TSN_seq;
                          }
  
                          if (tp1->do_rtt) {
                                  /*
                                   * this guy had a RTO calculation pending on
                                   * it, cancel it
                                   */
                                  if ((tp1->whoTo != NULL) &&
                                      (tp1->whoTo->rto_needed == 0)) {
                                          tp1->whoTo->rto_needed = 1;
                                  }
                                  tp1->do_rtt = 0;
                          }
                          if (alt != tp1->whoTo) {
                                  /* yes, there is an alternate. */
                                  sctp_free_remote_addr(tp1->whoTo);
                                  /* sa_ignore FREED_MEMORY */
                                  tp1->whoTo = alt;
                                  atomic_add_int(&alt->ref_count, 1);
                          }
                  }
          }
  }
  
  struct sctp_tmit_chunk *
  sctp_try_advance_peer_ack_point(struct sctp_tcb *stcb,
      struct sctp_association *asoc)
  {
          struct sctp_tmit_chunk *tp1, *tp2, *a_adv = NULL;
          struct timeval now;
          int now_filled = 0;
  
          if (asoc->prsctp_supported == 0) {
                  return (NULL);
          }
          TAILQ_FOREACH_SAFE(tp1, &asoc->sent_queue, sctp_next, tp2) {
                  if (tp1->sent != SCTP_FORWARD_TSN_SKIP &&
                      tp1->sent != SCTP_DATAGRAM_RESEND &&
                      tp1->sent != SCTP_DATAGRAM_NR_ACKED) {
                          /* no chance to advance, out of here */
                          break;
                  }
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_TRY_ADVANCE) {
                          if ((tp1->sent == SCTP_FORWARD_TSN_SKIP) ||
                              (tp1->sent == SCTP_DATAGRAM_NR_ACKED)) {
                                  sctp_misc_ints(SCTP_FWD_TSN_CHECK,
                                      asoc->advanced_peer_ack_point,
                                      tp1->rec.data.TSN_seq, 0, 0);
                          }
                  }
                  if (!PR_SCTP_ENABLED(tp1->flags)) {
                          /*
                           * We can't fwd-tsn past any that are reliable aka
                           * retransmitted until the asoc fails.
                           */
                          break;
                  }
                  if (!now_filled) {
                          (void)SCTP_GETTIME_TIMEVAL(&now);
                          now_filled = 1;
                  }
                  /*
                   * now we got a chunk which is marked for another
                   * retransmission to a PR-stream but has run out its chances
                   * already maybe OR has been marked to skip now. Can we skip
                   * it if its a resend?
                   */
                  if (tp1->sent == SCTP_DATAGRAM_RESEND &&
                      (PR_SCTP_TTL_ENABLED(tp1->flags))) {
                          /*
                           * Now is this one marked for resend and its time is
                           * now up?
                           */
                          if (timevalcmp(&now, &tp1->rec.data.timetodrop, >)) {
                                  /* Yes so drop it */
                                  if (tp1->data) {
                                          (void)sctp_release_pr_sctp_chunk(stcb, tp1,
                                              1, SCTP_SO_NOT_LOCKED);
                                  }
                          } else {
                                  /*
                                   * No, we are done when hit one for resend
                                   * whos time as not expired.
                                   */
                                  break;
                          }
                  }
                  /*
                   * Ok now if this chunk is marked to drop it we can clean up
                   * the chunk, advance our peer ack point and we can check
                   * the next chunk.
                   */
                  if ((tp1->sent == SCTP_FORWARD_TSN_SKIP) ||
                      (tp1->sent == SCTP_DATAGRAM_NR_ACKED)) {
                          /* advance PeerAckPoint goes forward */
                          if (SCTP_TSN_GT(tp1->rec.data.TSN_seq, asoc->advanced_peer_ack_point)) {
                                  asoc->advanced_peer_ack_point = tp1->rec.data.TSN_seq;
                                  a_adv = tp1;
                          } else if (tp1->rec.data.TSN_seq == asoc->advanced_peer_ack_point) {
                                  /* No update but we do save the chk */
                                  a_adv = tp1;
                          }
                  } else {
                          /*
                           * If it is still in RESEND we can advance no
                           * further
                           */
                          break;
                  }
          }
          return (a_adv);
  }
  
  static int
  sctp_fs_audit(struct sctp_association *asoc)
  {
          struct sctp_tmit_chunk *chk;
          int inflight = 0, resend = 0, inbetween = 0, acked = 0, above = 0;
          int ret;
  
  #ifndef INVARIANTS
          int entry_flight, entry_cnt;
  
  #endif
  
          ret = 0;
  #ifndef INVARIANTS
          entry_flight = asoc->total_flight;
          entry_cnt = asoc->total_flight_count;
  #endif
          if (asoc->pr_sctp_cnt >= asoc->sent_queue_cnt)
                  return (0);
  
          TAILQ_FOREACH(chk, &asoc->sent_queue, sctp_next) {
                  if (chk->sent < SCTP_DATAGRAM_RESEND) {
                          SCTP_PRINTF("Chk TSN:%u size:%d inflight cnt:%d\n",
                              chk->rec.data.TSN_seq,
                              chk->send_size,
                              chk->snd_count);
                          inflight++;
                  } else if (chk->sent == SCTP_DATAGRAM_RESEND) {
                          resend++;
                  } else if (chk->sent < SCTP_DATAGRAM_ACKED) {
                          inbetween++;
                  } else if (chk->sent > SCTP_DATAGRAM_ACKED) {
                          above++;
                  } else {
                          acked++;
                  }
          }
  
          if ((inflight > 0) || (inbetween > 0)) {
  #ifdef INVARIANTS
                  panic("Flight size-express incorrect? \n");
  #else
                  SCTP_PRINTF("asoc->total_flight:%d cnt:%d\n",
                      entry_flight, entry_cnt);
  
                  SCTP_PRINTF("Flight size-express incorrect F:%d I:%d R:%d Ab:%d ACK:%d\n",
                      inflight, inbetween, resend, above, acked);
                  ret = 1;
  #endif
          }
          return (ret);
  }
  
  
  static void
  sctp_window_probe_recovery(struct sctp_tcb *stcb,
      struct sctp_association *asoc,
      struct sctp_tmit_chunk *tp1)
  {
          tp1->window_probe = 0;
          if ((tp1->sent >= SCTP_DATAGRAM_ACKED) || (tp1->data == NULL)) {
                  /* TSN's skipped we do NOT move back. */
                  sctp_misc_ints(SCTP_FLIGHT_LOG_DWN_WP_FWD,
                      tp1->whoTo ? tp1->whoTo->flight_size : 0,
                      tp1->book_size,
                      (uintptr_t) tp1->whoTo,
                      tp1->rec.data.TSN_seq);
                  return;
          }
          /* First setup this by shrinking flight */
          if (stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) {
                  (*stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) (tp1->whoTo,
                      tp1);
          }
          sctp_flight_size_decrease(tp1);
          sctp_total_flight_decrease(stcb, tp1);
          /* Now mark for resend */
          tp1->sent = SCTP_DATAGRAM_RESEND;
          sctp_ucount_incr(asoc->sent_queue_retran_cnt);
  
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                  sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_WP,
                      tp1->whoTo->flight_size,
                      tp1->book_size,
                      (uintptr_t) tp1->whoTo,
                      tp1->rec.data.TSN_seq);
          }
  }
  
  void
  sctp_express_handle_sack(struct sctp_tcb *stcb, uint32_t cumack,
      uint32_t rwnd, int *abort_now, int ecne_seen)
  {
          struct sctp_nets *net;
          struct sctp_association *asoc;
          struct sctp_tmit_chunk *tp1, *tp2;
          uint32_t old_rwnd;
          int win_probe_recovery = 0;
          int win_probe_recovered = 0;
          int j, done_once = 0;
          int rto_ok = 1;
  
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_SACK_ARRIVALS_ENABLE) {
                  sctp_misc_ints(SCTP_SACK_LOG_EXPRESS, cumack,
                      rwnd, stcb->asoc.last_acked_seq, stcb->asoc.peers_rwnd);
          }
          SCTP_TCB_LOCK_ASSERT(stcb);
  #ifdef SCTP_ASOCLOG_OF_TSNS
          stcb->asoc.cumack_log[stcb->asoc.cumack_log_at] = cumack;
          stcb->asoc.cumack_log_at++;
          if (stcb->asoc.cumack_log_at > SCTP_TSN_LOG_SIZE) {
                  stcb->asoc.cumack_log_at = 0;
          }
  #endif
          asoc = &stcb->asoc;
          old_rwnd = asoc->peers_rwnd;
          if (SCTP_TSN_GT(asoc->last_acked_seq, cumack)) {
                  /* old ack */
                  return;
          } else if (asoc->last_acked_seq == cumack) {
                  /* Window update sack */
                  asoc->peers_rwnd = sctp_sbspace_sub(rwnd,
                      (uint32_t) (asoc->total_flight + (asoc->total_flight_count * SCTP_BASE_SYSCTL(sctp_peer_chunk_oh))));
                  if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                          /* SWS sender side engages */
                          asoc->peers_rwnd = 0;
                  }
                  if (asoc->peers_rwnd > old_rwnd) {
                          goto again;
                  }
                  return;
          }
          /* First setup for CC stuff */
          TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  if (SCTP_TSN_GT(cumack, net->cwr_window_tsn)) {
                          /* Drag along the window_tsn for cwr's */
                          net->cwr_window_tsn = cumack;
                  }
                  net->prev_cwnd = net->cwnd;
                  net->net_ack = 0;
                  net->net_ack2 = 0;
  
                  /*
                   * CMT: Reset CUC and Fast recovery algo variables before
                   * SACK processing
                   */
                  net->new_pseudo_cumack = 0;
                  net->will_exit_fast_recovery = 0;
                  if (stcb->asoc.cc_functions.sctp_cwnd_prepare_net_for_sack) {
                          (*stcb->asoc.cc_functions.sctp_cwnd_prepare_net_for_sack) (stcb, net);
                  }
          }
          if (SCTP_BASE_SYSCTL(sctp_strict_sacks)) {
                  uint32_t send_s;
  
                  if (!TAILQ_EMPTY(&asoc->sent_queue)) {
                          tp1 = TAILQ_LAST(&asoc->sent_queue,
                              sctpchunk_listhead);
                          send_s = tp1->rec.data.TSN_seq + 1;
                  } else {
                          send_s = asoc->sending_seq;
                  }
                  if (SCTP_TSN_GE(cumack, send_s)) {
                          struct mbuf *op_err;
                          char msg[SCTP_DIAG_INFO_LEN];
  
                          *abort_now = 1;
                          /* XXX */
                          snprintf(msg, sizeof(msg), "Cum ack %8.8x greater or equal than TSN %8.8x",
                              cumack, send_s);
                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_23;
                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                          return;
                  }
          }
          asoc->this_sack_highest_gap = cumack;
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
                  sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
                      stcb->asoc.overall_error_count,
                      0,
                      SCTP_FROM_SCTP_INDATA,
                      __LINE__);
          }
          stcb->asoc.overall_error_count = 0;
          if (SCTP_TSN_GT(cumack, asoc->last_acked_seq)) {
                  /* process the new consecutive TSN first */
                  TAILQ_FOREACH_SAFE(tp1, &asoc->sent_queue, sctp_next, tp2) {
                          if (SCTP_TSN_GE(cumack, tp1->rec.data.TSN_seq)) {
                                  if (tp1->sent == SCTP_DATAGRAM_UNSENT) {
                                          SCTP_PRINTF("Warning, an unsent is now acked?\n");
                                  }
                                  if (tp1->sent < SCTP_DATAGRAM_ACKED) {
                                          /*
                                           * If it is less than ACKED, it is
                                           * now no-longer in flight. Higher
                                           * values may occur during marking
                                           */
                                          if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                                          sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_CA,
                                                              tp1->whoTo->flight_size,
                                                              tp1->book_size,
                                                              (uintptr_t) tp1->whoTo,
                                                              tp1->rec.data.TSN_seq);
                                                  }
                                                  sctp_flight_size_decrease(tp1);
                                                  if (stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) {
                                                          (*stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) (tp1->whoTo,
                                                              tp1);
                                                  }
                                                  /* sa_ignore NO_NULL_CHK */
                                                  sctp_total_flight_decrease(stcb, tp1);
                                          }
                                          tp1->whoTo->net_ack += tp1->send_size;
                                          if (tp1->snd_count < 2) {
                                                  /*
                                                   * True non-retransmited
                                                   * chunk
                                                   */
                                                  tp1->whoTo->net_ack2 +=
                                                      tp1->send_size;
  
                                                  /* update RTO too? */
                                                  if (tp1->do_rtt) {
                                                          if (rto_ok) {
                                                                  tp1->whoTo->RTO =
                                                                  /*
                                                                   * sa_ignore
                                                                   * NO_NULL_CH
                                                                   * K
                                                                   */
                                                                      sctp_calculate_rto(stcb,
                                                                      asoc, tp1->whoTo,
                                                                      &tp1->sent_rcv_time,
                                                                      sctp_align_safe_nocopy,
                                                                      SCTP_RTT_FROM_DATA);
                                                                  rto_ok = 0;
                                                          }
                                                          if (tp1->whoTo->rto_needed == 0) {
                                                                  tp1->whoTo->rto_needed = 1;
                                                          }
                                                          tp1->do_rtt = 0;
                                                  }
                                          }
                                          /*
                                           * CMT: CUCv2 algorithm. From the
                                           * cumack'd TSNs, for each TSN being
                                           * acked for the first time, set the
                                           * following variables for the
                                           * corresp destination.
                                           * new_pseudo_cumack will trigger a
                                           * cwnd update.
                                           * find_(rtx_)pseudo_cumack will
                                           * trigger search for the next
                                           * expected (rtx-)pseudo-cumack.
                                           */
                                          tp1->whoTo->new_pseudo_cumack = 1;
                                          tp1->whoTo->find_pseudo_cumack = 1;
                                          tp1->whoTo->find_rtx_pseudo_cumack = 1;
  
                                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
                                                  /* sa_ignore NO_NULL_CHK */
                                                  sctp_log_cwnd(stcb, tp1->whoTo, tp1->rec.data.TSN_seq, SCTP_CWND_LOG_FROM_SACK);
                                          }
                                  }
                                  if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                                          sctp_ucount_decr(asoc->sent_queue_retran_cnt);
                                  }
                                  if (tp1->rec.data.chunk_was_revoked) {
                                          /* deflate the cwnd */
                                          tp1->whoTo->cwnd -= tp1->book_size;
                                          tp1->rec.data.chunk_was_revoked = 0;
                                  }
                                  if (tp1->sent != SCTP_DATAGRAM_NR_ACKED) {
                                          if (asoc->strmout[tp1->rec.data.stream_number].chunks_on_queues > 0) {
                                                  asoc->strmout[tp1->rec.data.stream_number].chunks_on_queues--;
  #ifdef INVARIANTS
                                          } else {
                                                  panic("No chunks on the queues for sid %u.", tp1->rec.data.stream_number);
  #endif
                                          }
                                  }
                                  if ((asoc->strmout[tp1->rec.data.stream_number].chunks_on_queues == 0) &&
                                      (asoc->strmout[tp1->rec.data.stream_number].state == SCTP_STREAM_RESET_PENDING) &&
                                      TAILQ_EMPTY(&asoc->strmout[tp1->rec.data.stream_number].outqueue)) {
                                          asoc->trigger_reset = 1;
                                  }
                                  TAILQ_REMOVE(&asoc->sent_queue, tp1, sctp_next);
                                  if (tp1->data) {
                                          /* sa_ignore NO_NULL_CHK */
                                          sctp_free_bufspace(stcb, asoc, tp1, 1);
                                          sctp_m_freem(tp1->data);
                                          tp1->data = NULL;
                                  }
                                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                                          sctp_log_sack(asoc->last_acked_seq,
                                              cumack,
                                              tp1->rec.data.TSN_seq,
                                              0,
                                              0,
                                              SCTP_LOG_FREE_SENT);
                                  }
                                  asoc->sent_queue_cnt--;
                                  sctp_free_a_chunk(stcb, tp1, SCTP_SO_NOT_LOCKED);
                          } else {
                                  break;
                          }
                  }
  
          }
          /* sa_ignore NO_NULL_CHK */
          if (stcb->sctp_socket) {
  #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                  struct socket *so;
  
  #endif
                  SOCKBUF_LOCK(&stcb->sctp_socket->so_snd);
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_WAKE_LOGGING_ENABLE) {
                          /* sa_ignore NO_NULL_CHK */
                          sctp_wakeup_log(stcb, 1, SCTP_WAKESND_FROM_SACK);
                  }
  #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                  so = SCTP_INP_SO(stcb->sctp_ep);
                  atomic_add_int(&stcb->asoc.refcnt, 1);
                  SCTP_TCB_UNLOCK(stcb);
                  SCTP_SOCKET_LOCK(so, 1);
                  SCTP_TCB_LOCK(stcb);
                  atomic_subtract_int(&stcb->asoc.refcnt, 1);
                  if (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET) {
                          /* assoc was freed while we were unlocked */
                          SCTP_SOCKET_UNLOCK(so, 1);
                          return;
                  }
  #endif
                  sctp_sowwakeup_locked(stcb->sctp_ep, stcb->sctp_socket);
  #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                  SCTP_SOCKET_UNLOCK(so, 1);
  #endif
          } else {
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_WAKE_LOGGING_ENABLE) {
                          sctp_wakeup_log(stcb, 1, SCTP_NOWAKE_FROM_SACK);
                  }
          }
  
          /* JRS - Use the congestion control given in the CC module */
          if ((asoc->last_acked_seq != cumack) && (ecne_seen == 0)) {
                  TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                          if (net->net_ack2 > 0) {
                                  /*
                                   * Karn's rule applies to clearing error
                                   * count, this is optional.
                                   */
                                  net->error_count = 0;
                                  if (!(net->dest_state & SCTP_ADDR_REACHABLE)) {
                                          /* addr came good */
                                          net->dest_state |= SCTP_ADDR_REACHABLE;
                                          sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_UP, stcb,
                                              0, (void *)net, SCTP_SO_NOT_LOCKED);
                                  }
                                  if (net == stcb->asoc.primary_destination) {
                                          if (stcb->asoc.alternate) {
                                                  /*
                                                   * release the alternate,
                                                   * primary is good
                                                   */
                                                  sctp_free_remote_addr(stcb->asoc.alternate);
                                                  stcb->asoc.alternate = NULL;
                                          }
                                  }
                                  if (net->dest_state & SCTP_ADDR_PF) {
                                          net->dest_state &= ~SCTP_ADDR_PF;
                                          sctp_timer_stop(SCTP_TIMER_TYPE_HEARTBEAT,
                                              stcb->sctp_ep, stcb, net,
                                              SCTP_FROM_SCTP_INDATA + SCTP_LOC_24);
                                          sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb, net);
                                          asoc->cc_functions.sctp_cwnd_update_exit_pf(stcb, net);
                                          /* Done with this net */
                                          net->net_ack = 0;
                                  }
                                  /* restore any doubled timers */
                                  net->RTO = (net->lastsa >> SCTP_RTT_SHIFT) + net->lastsv;
                                  if (net->RTO < stcb->asoc.minrto) {
                                          net->RTO = stcb->asoc.minrto;
                                  }
                                  if (net->RTO > stcb->asoc.maxrto) {
                                          net->RTO = stcb->asoc.maxrto;
                                  }
                          }
                  }
                  asoc->cc_functions.sctp_cwnd_update_after_sack(stcb, asoc, 1, 0, 0);
          }
          asoc->last_acked_seq = cumack;
  
          if (TAILQ_EMPTY(&asoc->sent_queue)) {
                  /* nothing left in-flight */
                  TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                          net->flight_size = 0;
                          net->partial_bytes_acked = 0;
                  }
                  asoc->total_flight = 0;
                  asoc->total_flight_count = 0;
          }
          /* RWND update */
          asoc->peers_rwnd = sctp_sbspace_sub(rwnd,
              (uint32_t) (asoc->total_flight + (asoc->total_flight_count * SCTP_BASE_SYSCTL(sctp_peer_chunk_oh))));
          if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                  /* SWS sender side engages */
                  asoc->peers_rwnd = 0;
          }
          if (asoc->peers_rwnd > old_rwnd) {
                  win_probe_recovery = 1;
          }
          /* Now assure a timer where data is queued at */
  again:
          j = 0;
          TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  int to_ticks;
  
                  if (win_probe_recovery && (net->window_probe)) {
                          win_probe_recovered = 1;
                          /*
                           * Find first chunk that was used with window probe
                           * and clear the sent
                           */
                          /* sa_ignore FREED_MEMORY */
                          TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                                  if (tp1->window_probe) {
                                          /* move back to data send queue */
                                          sctp_window_probe_recovery(stcb, asoc, tp1);
                                          break;
                                  }
                          }
                  }
                  if (net->RTO == 0) {
                          to_ticks = MSEC_TO_TICKS(stcb->asoc.initial_rto);
                  } else {
                          to_ticks = MSEC_TO_TICKS(net->RTO);
                  }
                  if (net->flight_size) {
                          j++;
                          (void)SCTP_OS_TIMER_START(&net->rxt_timer.timer, to_ticks,
                              sctp_timeout_handler, &net->rxt_timer);
                          if (net->window_probe) {
                                  net->window_probe = 0;
                          }
                  } else {
                          if (net->window_probe) {
                                  /*
                                   * In window probes we must assure a timer
                                   * is still running there
                                   */
                                  net->window_probe = 0;
                                  if (!SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                                          SCTP_OS_TIMER_START(&net->rxt_timer.timer, to_ticks,
                                              sctp_timeout_handler, &net->rxt_timer);
                                  }
                          } else if (SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                                  sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                                      stcb, net,
                                      SCTP_FROM_SCTP_INDATA + SCTP_LOC_25);
                          }
                  }
          }
          if ((j == 0) &&
              (!TAILQ_EMPTY(&asoc->sent_queue)) &&
              (asoc->sent_queue_retran_cnt == 0) &&
              (win_probe_recovered == 0) &&
              (done_once == 0)) {
                  /*
                   * huh, this should not happen unless all packets are
                   * PR-SCTP and marked to skip of course.
                   */
                  if (sctp_fs_audit(asoc)) {
                          TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                                  net->flight_size = 0;
                          }
                          asoc->total_flight = 0;
                          asoc->total_flight_count = 0;
                          asoc->sent_queue_retran_cnt = 0;
                          TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                                  if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                          sctp_flight_size_increase(tp1);
                                          sctp_total_flight_increase(stcb, tp1);
                                  } else if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                                          sctp_ucount_incr(asoc->sent_queue_retran_cnt);
                                  }
                          }
                  }
                  done_once = 1;
                  goto again;
          }
          /**********************************/
          /* Now what about shutdown issues */
          /**********************************/
          if (TAILQ_EMPTY(&asoc->send_queue) && TAILQ_EMPTY(&asoc->sent_queue)) {
                  /* nothing left on sendqueue.. consider done */
                  /* clean up */
                  if ((asoc->stream_queue_cnt == 1) &&
                      ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) ||
                      (asoc->state & SCTP_STATE_SHUTDOWN_RECEIVED)) &&
                      (asoc->locked_on_sending)
                      ) {
                          struct sctp_stream_queue_pending *sp;
  
                          /*
                           * I may be in a state where we got all across.. but
                           * cannot write more due to a shutdown... we abort
                           * since the user did not indicate EOR in this case.
                           * The sp will be cleaned during free of the asoc.
                           */
                          sp = TAILQ_LAST(&((asoc->locked_on_sending)->outqueue),
                              sctp_streamhead);
                          if ((sp) && (sp->length == 0)) {
                                  /* Let cleanup code purge it */
                                  if (sp->msg_is_complete) {
                                          asoc->stream_queue_cnt--;
                                  } else {
                                          asoc->state |= SCTP_STATE_PARTIAL_MSG_LEFT;
                                          asoc->locked_on_sending = NULL;
                                          asoc->stream_queue_cnt--;
                                  }
                          }
                  }
                  if ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) &&
                      (asoc->stream_queue_cnt == 0)) {
                          if (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT) {
                                  /* Need to abort here */
                                  struct mbuf *op_err;
  
                  abort_out_now:
                                  *abort_now = 1;
                                  /* XXX */
                                  op_err = sctp_generate_cause(SCTP_CAUSE_USER_INITIATED_ABT, "");
                                  stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_26;
                                  sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                  return;
                          } else {
                                  struct sctp_nets *netp;
  
                                  if ((SCTP_GET_STATE(asoc) == SCTP_STATE_OPEN) ||
                                      (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED)) {
                                          SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                                  }
                                  SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_SENT);
                                  SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
                                  sctp_stop_timers_for_shutdown(stcb);
                                  if (asoc->alternate) {
                                          netp = asoc->alternate;
                                  } else {
                                          netp = asoc->primary_destination;
                                  }
                                  sctp_send_shutdown(stcb, netp);
                                  sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWN,
                                      stcb->sctp_ep, stcb, netp);
                                  sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNGUARD,
                                      stcb->sctp_ep, stcb, netp);
                          }
                  } else if ((SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED) &&
                      (asoc->stream_queue_cnt == 0)) {
                          struct sctp_nets *netp;
  
                          if (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT) {
                                  goto abort_out_now;
                          }
                          SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                          SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_ACK_SENT);
                          SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
                          sctp_stop_timers_for_shutdown(stcb);
                          if (asoc->alternate) {
                                  netp = asoc->alternate;
                          } else {
                                  netp = asoc->primary_destination;
                          }
                          sctp_send_shutdown_ack(stcb, netp);
                          sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNACK,
                              stcb->sctp_ep, stcb, netp);
                  }
          }
          /*********************************************/
          /* Here we perform PR-SCTP procedures        */
          /* (section 4.2)                             */
          /*********************************************/
          /* C1. update advancedPeerAckPoint */
          if (SCTP_TSN_GT(cumack, asoc->advanced_peer_ack_point)) {
                  asoc->advanced_peer_ack_point = cumack;
          }
          /* PR-Sctp issues need to be addressed too */
          if ((asoc->prsctp_supported) && (asoc->pr_sctp_cnt > 0)) {
                  struct sctp_tmit_chunk *lchk;
                  uint32_t old_adv_peer_ack_point;
  
                  old_adv_peer_ack_point = asoc->advanced_peer_ack_point;
                  lchk = sctp_try_advance_peer_ack_point(stcb, asoc);
                  /* C3. See if we need to send a Fwd-TSN */
                  if (SCTP_TSN_GT(asoc->advanced_peer_ack_point, cumack)) {
                          /*
                           * ISSUE with ECN, see FWD-TSN processing.
                           */
                          if (SCTP_TSN_GT(asoc->advanced_peer_ack_point, old_adv_peer_ack_point)) {
                                  send_forward_tsn(stcb, asoc);
                          } else if (lchk) {
                                  /* try to FR fwd-tsn's that get lost too */
                                  if (lchk->rec.data.fwd_tsn_cnt >= 3) {
                                          send_forward_tsn(stcb, asoc);
                                  }
                          }
                  }
                  if (lchk) {
                          /* Assure a timer is up */
                          sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                              stcb->sctp_ep, stcb, lchk->whoTo);
                  }
          }
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_RWND_LOGGING_ENABLE) {
                  sctp_misc_ints(SCTP_SACK_RWND_UPDATE,
                      rwnd,
                      stcb->asoc.peers_rwnd,
                      stcb->asoc.total_flight,
                      stcb->asoc.total_output_queue_size);
          }
  }
  
  void
  sctp_handle_sack(struct mbuf *m, int offset_seg, int offset_dup,
      struct sctp_tcb *stcb,
      uint16_t num_seg, uint16_t num_nr_seg, uint16_t num_dup,
      int *abort_now, uint8_t flags,
      uint32_t cum_ack, uint32_t rwnd, int ecne_seen)
  {
          struct sctp_association *asoc;
          struct sctp_tmit_chunk *tp1, *tp2;
          uint32_t last_tsn, biggest_tsn_acked, biggest_tsn_newly_acked, this_sack_lowest_newack;
          uint16_t wake_him = 0;
          uint32_t send_s = 0;
          long j;
          int accum_moved = 0;
          int will_exit_fast_recovery = 0;
          uint32_t a_rwnd, old_rwnd;
          int win_probe_recovery = 0;
          int win_probe_recovered = 0;
          struct sctp_nets *net = NULL;
          int done_once;
          int rto_ok = 1;
          uint8_t reneged_all = 0;
          uint8_t cmt_dac_flag;
  
          /*
           * we take any chance we can to service our queues since we cannot
           * get awoken when the socket is read from :<
           */
          /*
           * Now perform the actual SACK handling: 1) Verify that it is not an
           * old sack, if so discard. 2) If there is nothing left in the send
           * queue (cum-ack is equal to last acked) then you have a duplicate
           * too, update any rwnd change and verify no timers are running.
           * then return. 3) Process any new consequtive data i.e. cum-ack
           * moved process these first and note that it moved. 4) Process any
           * sack blocks. 5) Drop any acked from the queue. 6) Check for any
           * revoked blocks and mark. 7) Update the cwnd. 8) Nothing left,
           * sync up flightsizes and things, stop all timers and also check
           * for shutdown_pending state. If so then go ahead and send off the
           * shutdown. If in shutdown recv, send off the shutdown-ack and
           * start that timer, Ret. 9) Strike any non-acked things and do FR
           * procedure if needed being sure to set the FR flag. 10) Do pr-sctp
           * procedures. 11) Apply any FR penalties. 12) Assure we will SACK
           * if in shutdown_recv state.
           */
          SCTP_TCB_LOCK_ASSERT(stcb);
          /* CMT DAC algo */
          this_sack_lowest_newack = 0;
          SCTP_STAT_INCR(sctps_slowpath_sack);
          last_tsn = cum_ack;
          cmt_dac_flag = flags & SCTP_SACK_CMT_DAC;
  #ifdef SCTP_ASOCLOG_OF_TSNS
          stcb->asoc.cumack_log[stcb->asoc.cumack_log_at] = cum_ack;
          stcb->asoc.cumack_log_at++;
          if (stcb->asoc.cumack_log_at > SCTP_TSN_LOG_SIZE) {
                  stcb->asoc.cumack_log_at = 0;
          }
  #endif
          a_rwnd = rwnd;
  
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_SACK_ARRIVALS_ENABLE) {
                  sctp_misc_ints(SCTP_SACK_LOG_NORMAL, cum_ack,
                      rwnd, stcb->asoc.last_acked_seq, stcb->asoc.peers_rwnd);
          }
          old_rwnd = stcb->asoc.peers_rwnd;
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
                  sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
                      stcb->asoc.overall_error_count,
                      0,
                      SCTP_FROM_SCTP_INDATA,
                      __LINE__);
          }
          stcb->asoc.overall_error_count = 0;
          asoc = &stcb->asoc;
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                  sctp_log_sack(asoc->last_acked_seq,
                      cum_ack,
                      0,
                      num_seg,
                      num_dup,
                      SCTP_LOG_NEW_SACK);
          }
          if ((num_dup) && (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE)) {
                  uint16_t i;
                  uint32_t *dupdata, dblock;
  
                  for (i = 0; i < num_dup; i++) {
                          dupdata = (uint32_t *) sctp_m_getptr(m, offset_dup + i * sizeof(uint32_t),
                              sizeof(uint32_t), (uint8_t *) & dblock);
                          if (dupdata == NULL) {
                                  break;
                          }
                          sctp_log_fr(*dupdata, 0, 0, SCTP_FR_DUPED);
                  }
          }
          if (SCTP_BASE_SYSCTL(sctp_strict_sacks)) {
                  /* reality check */
                  if (!TAILQ_EMPTY(&asoc->sent_queue)) {
                          tp1 = TAILQ_LAST(&asoc->sent_queue,
                              sctpchunk_listhead);
                          send_s = tp1->rec.data.TSN_seq + 1;
                  } else {
                          tp1 = NULL;
                          send_s = asoc->sending_seq;
                  }
                  if (SCTP_TSN_GE(cum_ack, send_s)) {
                          struct mbuf *op_err;
                          char msg[SCTP_DIAG_INFO_LEN];
  
                          /*
                           * no way, we have not even sent this TSN out yet.
                           * Peer is hopelessly messed up with us.
                           */
                          SCTP_PRINTF("NEW cum_ack:%x send_s:%x is smaller or equal\n",
                              cum_ack, send_s);
                          if (tp1) {
                                  SCTP_PRINTF("Got send_s from tsn:%x + 1 of tp1:%p\n",
                                      tp1->rec.data.TSN_seq, (void *)tp1);
                          }
          hopeless_peer:
                          *abort_now = 1;
                          /* XXX */
                          snprintf(msg, sizeof(msg), "Cum ack %8.8x greater or equal than TSN %8.8x",
                              cum_ack, send_s);
                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_27;
                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                          return;
                  }
          }
          /**********************/
          /* 1) check the range */
          /**********************/
          if (SCTP_TSN_GT(asoc->last_acked_seq, last_tsn)) {
                  /* acking something behind */
                  return;
          }
          /* update the Rwnd of the peer */
          if (TAILQ_EMPTY(&asoc->sent_queue) &&
              TAILQ_EMPTY(&asoc->send_queue) &&
              (asoc->stream_queue_cnt == 0)) {
                  /* nothing left on send/sent and strmq */
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_RWND_ENABLE) {
                          sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                              asoc->peers_rwnd, 0, 0, a_rwnd);
                  }
                  asoc->peers_rwnd = a_rwnd;
                  if (asoc->sent_queue_retran_cnt) {
                          asoc->sent_queue_retran_cnt = 0;
                  }
                  if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                          /* SWS sender side engages */
                          asoc->peers_rwnd = 0;
                  }
                  /* stop any timers */
                  TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                          sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                              stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_28);
                          net->partial_bytes_acked = 0;
                          net->flight_size = 0;
                  }
                  asoc->total_flight = 0;
                  asoc->total_flight_count = 0;
                  return;
          }
          /*
           * We init netAckSz and netAckSz2 to 0. These are used to track 2
           * things. The total byte count acked is tracked in netAckSz AND
           * netAck2 is used to track the total bytes acked that are un-
           * amibguious and were never retransmitted. We track these on a per
           * destination address basis.
           */
          TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  if (SCTP_TSN_GT(cum_ack, net->cwr_window_tsn)) {
                          /* Drag along the window_tsn for cwr's */
                          net->cwr_window_tsn = cum_ack;
                  }
                  net->prev_cwnd = net->cwnd;
                  net->net_ack = 0;
                  net->net_ack2 = 0;
  
                  /*
                   * CMT: Reset CUC and Fast recovery algo variables before
                   * SACK processing
                   */
                  net->new_pseudo_cumack = 0;
                  net->will_exit_fast_recovery = 0;
                  if (stcb->asoc.cc_functions.sctp_cwnd_prepare_net_for_sack) {
                          (*stcb->asoc.cc_functions.sctp_cwnd_prepare_net_for_sack) (stcb, net);
                  }
          }
          /* process the new consecutive TSN first */
          TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                  if (SCTP_TSN_GE(last_tsn, tp1->rec.data.TSN_seq)) {
                          if (tp1->sent != SCTP_DATAGRAM_UNSENT) {
                                  accum_moved = 1;
                                  if (tp1->sent < SCTP_DATAGRAM_ACKED) {
                                          /*
                                           * If it is less than ACKED, it is
                                           * now no-longer in flight. Higher
                                           * values may occur during marking
                                           */
                                          if ((tp1->whoTo->dest_state &
                                              SCTP_ADDR_UNCONFIRMED) &&
                                              (tp1->snd_count < 2)) {
                                                  /*
                                                   * If there was no retran
                                                   * and the address is
                                                   * un-confirmed and we sent
                                                   * there and are now
                                                   * sacked.. its confirmed,
                                                   * mark it so.
                                                   */
                                                  tp1->whoTo->dest_state &=
                                                      ~SCTP_ADDR_UNCONFIRMED;
                                          }
                                          if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                                          sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_CA,
                                                              tp1->whoTo->flight_size,
                                                              tp1->book_size,
                                                              (uintptr_t) tp1->whoTo,
                                                              tp1->rec.data.TSN_seq);
                                                  }
                                                  sctp_flight_size_decrease(tp1);
                                                  sctp_total_flight_decrease(stcb, tp1);
                                                  if (stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) {
                                                          (*stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) (tp1->whoTo,
                                                              tp1);
                                                  }
                                          }
                                          tp1->whoTo->net_ack += tp1->send_size;
  
                                          /* CMT SFR and DAC algos */
                                          this_sack_lowest_newack = tp1->rec.data.TSN_seq;
                                          tp1->whoTo->saw_newack = 1;
  
                                          if (tp1->snd_count < 2) {
                                                  /*
                                                   * True non-retransmited
                                                   * chunk
                                                   */
                                                  tp1->whoTo->net_ack2 +=
                                                      tp1->send_size;
  
                                                  /* update RTO too? */
                                                  if (tp1->do_rtt) {
                                                          if (rto_ok) {
                                                                  tp1->whoTo->RTO =
                                                                      sctp_calculate_rto(stcb,
                                                                      asoc, tp1->whoTo,
                                                                      &tp1->sent_rcv_time,
                                                                      sctp_align_safe_nocopy,
                                                                      SCTP_RTT_FROM_DATA);
                                                                  rto_ok = 0;
                                                          }
                                                          if (tp1->whoTo->rto_needed == 0) {
                                                                  tp1->whoTo->rto_needed = 1;
                                                          }
                                                          tp1->do_rtt = 0;
                                                  }
                                          }
                                          /*
                                           * CMT: CUCv2 algorithm. From the
                                           * cumack'd TSNs, for each TSN being
                                           * acked for the first time, set the
                                           * following variables for the
                                           * corresp destination.
                                           * new_pseudo_cumack will trigger a
                                           * cwnd update.
                                           * find_(rtx_)pseudo_cumack will
                                           * trigger search for the next
                                           * expected (rtx-)pseudo-cumack.
                                           */
                                          tp1->whoTo->new_pseudo_cumack = 1;
                                          tp1->whoTo->find_pseudo_cumack = 1;
                                          tp1->whoTo->find_rtx_pseudo_cumack = 1;
  
  
                                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                                                  sctp_log_sack(asoc->last_acked_seq,
                                                      cum_ack,
                                                      tp1->rec.data.TSN_seq,
                                                      0,
                                                      0,
                                                      SCTP_LOG_TSN_ACKED);
                                          }
                                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
                                                  sctp_log_cwnd(stcb, tp1->whoTo, tp1->rec.data.TSN_seq, SCTP_CWND_LOG_FROM_SACK);
                                          }
                                  }
                                  if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                                          sctp_ucount_decr(asoc->sent_queue_retran_cnt);
  #ifdef SCTP_AUDITING_ENABLED
                                          sctp_audit_log(0xB3,
                                              (asoc->sent_queue_retran_cnt & 0x000000ff));
  #endif
                                  }
                                  if (tp1->rec.data.chunk_was_revoked) {
                                          /* deflate the cwnd */
                                          tp1->whoTo->cwnd -= tp1->book_size;
                                          tp1->rec.data.chunk_was_revoked = 0;
                                  }
                                  if (tp1->sent != SCTP_DATAGRAM_NR_ACKED) {
                                          tp1->sent = SCTP_DATAGRAM_ACKED;
                                  }
                          }
                  } else {
                          break;
                  }
          }
          biggest_tsn_newly_acked = biggest_tsn_acked = last_tsn;
          /* always set this up to cum-ack */
          asoc->this_sack_highest_gap = last_tsn;
  
          if ((num_seg > 0) || (num_nr_seg > 0)) {
  
                  /*
                   * CMT: SFR algo (and HTNA) - this_sack_highest_newack has
                   * to be greater than the cumack. Also reset saw_newack to 0
                   * for all dests.
                   */
                  TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                          net->saw_newack = 0;
                          net->this_sack_highest_newack = last_tsn;
                  }
  
                  /*
                   * thisSackHighestGap will increase while handling NEW
                   * segments this_sack_highest_newack will increase while
                   * handling NEWLY ACKED chunks. this_sack_lowest_newack is
                   * used for CMT DAC algo. saw_newack will also change.
                   */
                  if (sctp_handle_segments(m, &offset_seg, stcb, asoc, last_tsn, &biggest_tsn_acked,
                      &biggest_tsn_newly_acked, &this_sack_lowest_newack,
                      num_seg, num_nr_seg, &rto_ok)) {
                          wake_him++;
                  }
                  if (SCTP_BASE_SYSCTL(sctp_strict_sacks)) {
                          /*
                           * validate the biggest_tsn_acked in the gap acks if
                           * strict adherence is wanted.
                           */
                          if (SCTP_TSN_GE(biggest_tsn_acked, send_s)) {
                                  /*
                                   * peer is either confused or we are under
                                   * attack. We must abort.
                                   */
                                  SCTP_PRINTF("Hopeless peer! biggest_tsn_acked:%x largest seq:%x\n",
                                      biggest_tsn_acked, send_s);
                                  goto hopeless_peer;
                          }
                  }
          }
          /*******************************************/
          /* cancel ALL T3-send timer if accum moved */
          /*******************************************/
          if (asoc->sctp_cmt_on_off > 0) {
                  TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                          if (net->new_pseudo_cumack)
                                  sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                                      stcb, net,
                                      SCTP_FROM_SCTP_INDATA + SCTP_LOC_29);
  
                  }
          } else {
                  if (accum_moved) {
                          TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                                  sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                                      stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_30);
                          }
                  }
          }
          /********************************************/
          /* drop the acked chunks from the sentqueue */
          /********************************************/
          asoc->last_acked_seq = cum_ack;
  
          TAILQ_FOREACH_SAFE(tp1, &asoc->sent_queue, sctp_next, tp2) {
                  if (SCTP_TSN_GT(tp1->rec.data.TSN_seq, cum_ack)) {
                          break;
                  }
                  if (tp1->sent != SCTP_DATAGRAM_NR_ACKED) {
                          if (asoc->strmout[tp1->rec.data.stream_number].chunks_on_queues > 0) {
                                  asoc->strmout[tp1->rec.data.stream_number].chunks_on_queues--;
  #ifdef INVARIANTS
                          } else {
                                  panic("No chunks on the queues for sid %u.", tp1->rec.data.stream_number);
  #endif
                          }
                  }
                  if ((asoc->strmout[tp1->rec.data.stream_number].chunks_on_queues == 0) &&
                      (asoc->strmout[tp1->rec.data.stream_number].state == SCTP_STREAM_RESET_PENDING) &&
                      TAILQ_EMPTY(&asoc->strmout[tp1->rec.data.stream_number].outqueue)) {
                          asoc->trigger_reset = 1;
                  }
                  TAILQ_REMOVE(&asoc->sent_queue, tp1, sctp_next);
                  if (PR_SCTP_ENABLED(tp1->flags)) {
                          if (asoc->pr_sctp_cnt != 0)
                                  asoc->pr_sctp_cnt--;
                  }
                  asoc->sent_queue_cnt--;
                  if (tp1->data) {
                          /* sa_ignore NO_NULL_CHK */
                          sctp_free_bufspace(stcb, asoc, tp1, 1);
                          sctp_m_freem(tp1->data);
                          tp1->data = NULL;
                          if (asoc->prsctp_supported && PR_SCTP_BUF_ENABLED(tp1->flags)) {
                                  asoc->sent_queue_cnt_removeable--;
                          }
                  }
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                          sctp_log_sack(asoc->last_acked_seq,
                              cum_ack,
                              tp1->rec.data.TSN_seq,
                              0,
                              0,
                              SCTP_LOG_FREE_SENT);
                  }
                  sctp_free_a_chunk(stcb, tp1, SCTP_SO_NOT_LOCKED);
                  wake_him++;
          }
          if (TAILQ_EMPTY(&asoc->sent_queue) && (asoc->total_flight > 0)) {
  #ifdef INVARIANTS
                  panic("Warning flight size is postive and should be 0");
  #else
                  SCTP_PRINTF("Warning flight size incorrect should be 0 is %d\n",
                      asoc->total_flight);
  #endif
                  asoc->total_flight = 0;
          }
          /* sa_ignore NO_NULL_CHK */
          if ((wake_him) && (stcb->sctp_socket)) {
  #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                  struct socket *so;
  
  #endif
                  SOCKBUF_LOCK(&stcb->sctp_socket->so_snd);
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_WAKE_LOGGING_ENABLE) {
                          sctp_wakeup_log(stcb, wake_him, SCTP_WAKESND_FROM_SACK);
                  }
  #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                  so = SCTP_INP_SO(stcb->sctp_ep);
                  atomic_add_int(&stcb->asoc.refcnt, 1);
                  SCTP_TCB_UNLOCK(stcb);
                  SCTP_SOCKET_LOCK(so, 1);
                  SCTP_TCB_LOCK(stcb);
                  atomic_subtract_int(&stcb->asoc.refcnt, 1);
                  if (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET) {
                          /* assoc was freed while we were unlocked */
                          SCTP_SOCKET_UNLOCK(so, 1);
                          return;
                  }
  #endif
                  sctp_sowwakeup_locked(stcb->sctp_ep, stcb->sctp_socket);
  #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                  SCTP_SOCKET_UNLOCK(so, 1);
  #endif
          } else {
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_WAKE_LOGGING_ENABLE) {
                          sctp_wakeup_log(stcb, wake_him, SCTP_NOWAKE_FROM_SACK);
                  }
          }
  
          if (asoc->fast_retran_loss_recovery && accum_moved) {
                  if (SCTP_TSN_GE(asoc->last_acked_seq, asoc->fast_recovery_tsn)) {
                          /* Setup so we will exit RFC2582 fast recovery */
                          will_exit_fast_recovery = 1;
                  }
          }
          /*
           * Check for revoked fragments:
           * 
           * if Previous sack - Had no frags then we can't have any revoked if
           * Previous sack - Had frag's then - If we now have frags aka
           * num_seg > 0 call sctp_check_for_revoked() to tell if peer revoked
           * some of them. else - The peer revoked all ACKED fragments, since
           * we had some before and now we have NONE.
           */
  
          if (num_seg) {
                  sctp_check_for_revoked(stcb, asoc, cum_ack, biggest_tsn_acked);
                  asoc->saw_sack_with_frags = 1;
          } else if (asoc->saw_sack_with_frags) {
                  int cnt_revoked = 0;
  
                  /* Peer revoked all dg's marked or acked */
                  TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                          if (tp1->sent == SCTP_DATAGRAM_ACKED) {
                                  tp1->sent = SCTP_DATAGRAM_SENT;
                                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                          sctp_misc_ints(SCTP_FLIGHT_LOG_UP_REVOKE,
                                              tp1->whoTo->flight_size,
                                              tp1->book_size,
                                              (uintptr_t) tp1->whoTo,
                                              tp1->rec.data.TSN_seq);
                                  }
                                  sctp_flight_size_increase(tp1);
                                  sctp_total_flight_increase(stcb, tp1);
                                  tp1->rec.data.chunk_was_revoked = 1;
                                  /*
                                   * To ensure that this increase in
                                   * flightsize, which is artificial, does not
                                   * throttle the sender, we also increase the
                                   * cwnd artificially.
                                   */
                                  tp1->whoTo->cwnd += tp1->book_size;
                                  cnt_revoked++;
                          }
                  }
                  if (cnt_revoked) {
                          reneged_all = 1;
                  }
                  asoc->saw_sack_with_frags = 0;
          }
          if (num_nr_seg > 0)
                  asoc->saw_sack_with_nr_frags = 1;
          else
                  asoc->saw_sack_with_nr_frags = 0;
  
          /* JRS - Use the congestion control given in the CC module */
          if (ecne_seen == 0) {
                  TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                          if (net->net_ack2 > 0) {
                                  /*
                                   * Karn's rule applies to clearing error
                                   * count, this is optional.
                                   */
                                  net->error_count = 0;
                                  if (!(net->dest_state & SCTP_ADDR_REACHABLE)) {
                                          /* addr came good */
                                          net->dest_state |= SCTP_ADDR_REACHABLE;
                                          sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_UP, stcb,
                                              0, (void *)net, SCTP_SO_NOT_LOCKED);
                                  }
                                  if (net == stcb->asoc.primary_destination) {
                                          if (stcb->asoc.alternate) {
                                                  /*
                                                   * release the alternate,
                                                   * primary is good
                                                   */
                                                  sctp_free_remote_addr(stcb->asoc.alternate);
                                                  stcb->asoc.alternate = NULL;
                                          }
                                  }
                                  if (net->dest_state & SCTP_ADDR_PF) {
                                          net->dest_state &= ~SCTP_ADDR_PF;
                                          sctp_timer_stop(SCTP_TIMER_TYPE_HEARTBEAT,
                                              stcb->sctp_ep, stcb, net,
                                              SCTP_FROM_SCTP_INDATA + SCTP_LOC_31);
                                          sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb, net);
                                          asoc->cc_functions.sctp_cwnd_update_exit_pf(stcb, net);
                                          /* Done with this net */
                                          net->net_ack = 0;
                                  }
                                  /* restore any doubled timers */
                                  net->RTO = (net->lastsa >> SCTP_RTT_SHIFT) + net->lastsv;
                                  if (net->RTO < stcb->asoc.minrto) {
                                          net->RTO = stcb->asoc.minrto;
                                  }
                                  if (net->RTO > stcb->asoc.maxrto) {
                                          net->RTO = stcb->asoc.maxrto;
                                  }
                          }
                  }
                  asoc->cc_functions.sctp_cwnd_update_after_sack(stcb, asoc, accum_moved, reneged_all, will_exit_fast_recovery);
          }
          if (TAILQ_EMPTY(&asoc->sent_queue)) {
                  /* nothing left in-flight */
                  TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                          /* stop all timers */
                          sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                              stcb, net,
                              SCTP_FROM_SCTP_INDATA + SCTP_LOC_32);
                          net->flight_size = 0;
                          net->partial_bytes_acked = 0;
                  }
                  asoc->total_flight = 0;
                  asoc->total_flight_count = 0;
          }
          /**********************************/
          /* Now what about shutdown issues */
          /**********************************/
          if (TAILQ_EMPTY(&asoc->send_queue) && TAILQ_EMPTY(&asoc->sent_queue)) {
                  /* nothing left on sendqueue.. consider done */
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_RWND_ENABLE) {
                          sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                              asoc->peers_rwnd, 0, 0, a_rwnd);
                  }
                  asoc->peers_rwnd = a_rwnd;
                  if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                          /* SWS sender side engages */
                          asoc->peers_rwnd = 0;
                  }
                  /* clean up */
                  if ((asoc->stream_queue_cnt == 1) &&
                      ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) ||
                      (asoc->state & SCTP_STATE_SHUTDOWN_RECEIVED)) &&
                      (asoc->locked_on_sending)
                      ) {
                          struct sctp_stream_queue_pending *sp;
  
                          /*
                           * I may be in a state where we got all across.. but
                           * cannot write more due to a shutdown... we abort
                           * since the user did not indicate EOR in this case.
                           */
                          sp = TAILQ_LAST(&((asoc->locked_on_sending)->outqueue),
                              sctp_streamhead);
                          if ((sp) && (sp->length == 0)) {
                                  asoc->locked_on_sending = NULL;
                                  if (sp->msg_is_complete) {
                                          asoc->stream_queue_cnt--;
                                  } else {
                                          asoc->state |= SCTP_STATE_PARTIAL_MSG_LEFT;
                                          asoc->stream_queue_cnt--;
                                  }
                          }
                  }
                  if ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) &&
                      (asoc->stream_queue_cnt == 0)) {
                          if (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT) {
                                  /* Need to abort here */
                                  struct mbuf *op_err;
  
                  abort_out_now:
                                  *abort_now = 1;
                                  /* XXX */
                                  op_err = sctp_generate_cause(SCTP_CAUSE_USER_INITIATED_ABT, "");
                                  stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_33;
                                  sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                                  return;
                          } else {
                                  struct sctp_nets *netp;
  
                                  if ((SCTP_GET_STATE(asoc) == SCTP_STATE_OPEN) ||
                                      (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED)) {
                                          SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                                  }
                                  SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_SENT);
                                  SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
                                  sctp_stop_timers_for_shutdown(stcb);
                                  if (asoc->alternate) {
                                          netp = asoc->alternate;
                                  } else {
                                          netp = asoc->primary_destination;
                                  }
                                  sctp_send_shutdown(stcb, netp);
                                  sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWN,
                                      stcb->sctp_ep, stcb, netp);
                                  sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNGUARD,
                                      stcb->sctp_ep, stcb, netp);
                          }
                          return;
                  } else if ((SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED) &&
                      (asoc->stream_queue_cnt == 0)) {
                          struct sctp_nets *netp;
  
                          if (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT) {
                                  goto abort_out_now;
                          }
                          SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                          SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_ACK_SENT);
                          SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
                          sctp_stop_timers_for_shutdown(stcb);
                          if (asoc->alternate) {
                                  netp = asoc->alternate;
                          } else {
                                  netp = asoc->primary_destination;
                          }
                          sctp_send_shutdown_ack(stcb, netp);
                          sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNACK,
                              stcb->sctp_ep, stcb, netp);
                          return;
                  }
          }
          /*
           * Now here we are going to recycle net_ack for a different use...
           * HEADS UP.
           */
          TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  net->net_ack = 0;
          }
  
          /*
           * CMT DAC algorithm: If SACK DAC flag was 0, then no extra marking
           * to be done. Setting this_sack_lowest_newack to the cum_ack will
           * automatically ensure that.
           */
          if ((asoc->sctp_cmt_on_off > 0) &&
              SCTP_BASE_SYSCTL(sctp_cmt_use_dac) &&
              (cmt_dac_flag == 0)) {
                  this_sack_lowest_newack = cum_ack;
          }
          if ((num_seg > 0) || (num_nr_seg > 0)) {
                  sctp_strike_gap_ack_chunks(stcb, asoc, biggest_tsn_acked,
                      biggest_tsn_newly_acked, this_sack_lowest_newack, accum_moved);
          }
          /* JRS - Use the congestion control given in the CC module */
          asoc->cc_functions.sctp_cwnd_update_after_fr(stcb, asoc);
  
          /* Now are we exiting loss recovery ? */
          if (will_exit_fast_recovery) {
                  /* Ok, we must exit fast recovery */
                  asoc->fast_retran_loss_recovery = 0;
          }
          if ((asoc->sat_t3_loss_recovery) &&
              SCTP_TSN_GE(asoc->last_acked_seq, asoc->sat_t3_recovery_tsn)) {
                  /* end satellite t3 loss recovery */
                  asoc->sat_t3_loss_recovery = 0;
          }
          /*
           * CMT Fast recovery
           */
          TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  if (net->will_exit_fast_recovery) {
                          /* Ok, we must exit fast recovery */
                          net->fast_retran_loss_recovery = 0;
                  }
          }
  
          /* Adjust and set the new rwnd value */
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_RWND_ENABLE) {
                  sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                      asoc->peers_rwnd, asoc->total_flight, (asoc->total_flight_count * SCTP_BASE_SYSCTL(sctp_peer_chunk_oh)), a_rwnd);
          }
          asoc->peers_rwnd = sctp_sbspace_sub(a_rwnd,
              (uint32_t) (asoc->total_flight + (asoc->total_flight_count * SCTP_BASE_SYSCTL(sctp_peer_chunk_oh))));
          if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                  /* SWS sender side engages */
                  asoc->peers_rwnd = 0;
          }
          if (asoc->peers_rwnd > old_rwnd) {
                  win_probe_recovery = 1;
          }
          /*
           * Now we must setup so we have a timer up for anyone with
           * outstanding data.
           */
          done_once = 0;
  again:
          j = 0;
          TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  if (win_probe_recovery && (net->window_probe)) {
                          win_probe_recovered = 1;
                          /*-
                           * Find first chunk that was used with
                           * window probe and clear the event. Put
                           * it back into the send queue as if has
                           * not been sent.
                           */
                          TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                                  if (tp1->window_probe) {
                                          sctp_window_probe_recovery(stcb, asoc, tp1);
                                          break;
                                  }
                          }
                  }
                  if (net->flight_size) {
                          j++;
                          if (!SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                                  sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                                      stcb->sctp_ep, stcb, net);
                          }
                          if (net->window_probe) {
                                  net->window_probe = 0;
                          }
                  } else {
                          if (net->window_probe) {
                                  /*
                                   * In window probes we must assure a timer
                                   * is still running there
                                   */
                                  if (!SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                                          sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                                              stcb->sctp_ep, stcb, net);
  
                                  }
                          } else if (SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                                  sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                                      stcb, net,
                                      SCTP_FROM_SCTP_INDATA + SCTP_LOC_34);
                          }
                  }
          }
          if ((j == 0) &&
              (!TAILQ_EMPTY(&asoc->sent_queue)) &&
              (asoc->sent_queue_retran_cnt == 0) &&
              (win_probe_recovered == 0) &&
              (done_once == 0)) {
                  /*
                   * huh, this should not happen unless all packets are
                   * PR-SCTP and marked to skip of course.
                   */
                  if (sctp_fs_audit(asoc)) {
                          TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                                  net->flight_size = 0;
                          }
                          asoc->total_flight = 0;
                          asoc->total_flight_count = 0;
                          asoc->sent_queue_retran_cnt = 0;
                          TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                                  if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                          sctp_flight_size_increase(tp1);
                                          sctp_total_flight_increase(stcb, tp1);
                                  } else if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                                          sctp_ucount_incr(asoc->sent_queue_retran_cnt);
                                  }
                          }
                  }
                  done_once = 1;
                  goto again;
          }
          /*********************************************/
          /* Here we perform PR-SCTP procedures        */
          /* (section 4.2)                             */
          /*********************************************/
          /* C1. update advancedPeerAckPoint */
          if (SCTP_TSN_GT(cum_ack, asoc->advanced_peer_ack_point)) {
                  asoc->advanced_peer_ack_point = cum_ack;
          }
          /* C2. try to further move advancedPeerAckPoint ahead */
          if ((asoc->prsctp_supported) && (asoc->pr_sctp_cnt > 0)) {
                  struct sctp_tmit_chunk *lchk;
                  uint32_t old_adv_peer_ack_point;
  
                  old_adv_peer_ack_point = asoc->advanced_peer_ack_point;
                  lchk = sctp_try_advance_peer_ack_point(stcb, asoc);
                  /* C3. See if we need to send a Fwd-TSN */
                  if (SCTP_TSN_GT(asoc->advanced_peer_ack_point, cum_ack)) {
                          /*
                           * ISSUE with ECN, see FWD-TSN processing.
                           */
                          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_TRY_ADVANCE) {
                                  sctp_misc_ints(SCTP_FWD_TSN_CHECK,
                                      0xee, cum_ack, asoc->advanced_peer_ack_point,
                                      old_adv_peer_ack_point);
                          }
                          if (SCTP_TSN_GT(asoc->advanced_peer_ack_point, old_adv_peer_ack_point)) {
                                  send_forward_tsn(stcb, asoc);
                          } else if (lchk) {
                                  /* try to FR fwd-tsn's that get lost too */
                                  if (lchk->rec.data.fwd_tsn_cnt >= 3) {
                                          send_forward_tsn(stcb, asoc);
                                  }
                          }
                  }
                  if (lchk) {
                          /* Assure a timer is up */
                          sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                              stcb->sctp_ep, stcb, lchk->whoTo);
                  }
          }
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_RWND_LOGGING_ENABLE) {
                  sctp_misc_ints(SCTP_SACK_RWND_UPDATE,
                      a_rwnd,
                      stcb->asoc.peers_rwnd,
                      stcb->asoc.total_flight,
                      stcb->asoc.total_output_queue_size);
          }
  }
  
  void
  sctp_update_acked(struct sctp_tcb *stcb, struct sctp_shutdown_chunk *cp, int *abort_flag)
  {
          /* Copy cum-ack */
          uint32_t cum_ack, a_rwnd;
  
          cum_ack = ntohl(cp->cumulative_tsn_ack);
          /* Arrange so a_rwnd does NOT change */
          a_rwnd = stcb->asoc.peers_rwnd + stcb->asoc.total_flight;
  
          /* Now call the express sack handling */
          sctp_express_handle_sack(stcb, cum_ack, a_rwnd, abort_flag, 0);
  }
  
  static void
  sctp_kick_prsctp_reorder_queue(struct sctp_tcb *stcb,
      struct sctp_stream_in *strmin)
  {
          struct sctp_queued_to_read *ctl, *nctl;
          struct sctp_association *asoc;
          uint16_t tt;
  
          asoc = &stcb->asoc;
          tt = strmin->last_sequence_delivered;
          /*
           * First deliver anything prior to and including the stream no that
           * came in
           */
          TAILQ_FOREACH_SAFE(ctl, &strmin->inqueue, next, nctl) {
                  if (SCTP_SSN_GE(tt, ctl->sinfo_ssn)) {
                          /* this is deliverable now */
                          TAILQ_REMOVE(&strmin->inqueue, ctl, next);
                          /* subtract pending on streams */
                          asoc->size_on_all_streams -= ctl->length;
                          sctp_ucount_decr(asoc->cnt_on_all_streams);
                          /* deliver it to at least the delivery-q */
                          if (stcb->sctp_socket) {
                                  sctp_mark_non_revokable(asoc, ctl->sinfo_tsn);
                                  sctp_add_to_readq(stcb->sctp_ep, stcb,
                                      ctl,
                                      &stcb->sctp_socket->so_rcv, 1, SCTP_READ_LOCK_HELD, SCTP_SO_NOT_LOCKED);
                          }
                  } else {
                          /* no more delivery now. */
                          break;
                  }
          }
          /*
           * now we must deliver things in queue the normal way  if any are
           * now ready.
           */
          tt = strmin->last_sequence_delivered + 1;
          TAILQ_FOREACH_SAFE(ctl, &strmin->inqueue, next, nctl) {
                  if (tt == ctl->sinfo_ssn) {
                          /* this is deliverable now */
                          TAILQ_REMOVE(&strmin->inqueue, ctl, next);
                          /* subtract pending on streams */
                          asoc->size_on_all_streams -= ctl->length;
                          sctp_ucount_decr(asoc->cnt_on_all_streams);
                          /* deliver it to at least the delivery-q */
                          strmin->last_sequence_delivered = ctl->sinfo_ssn;
                          if (stcb->sctp_socket) {
                                  sctp_mark_non_revokable(asoc, ctl->sinfo_tsn);
                                  sctp_add_to_readq(stcb->sctp_ep, stcb,
                                      ctl,
                                      &stcb->sctp_socket->so_rcv, 1, SCTP_READ_LOCK_HELD, SCTP_SO_NOT_LOCKED);
  
                          }
                          tt = strmin->last_sequence_delivered + 1;
                  } else {
                          break;
                  }
          }
  }
  
  static void
  sctp_flush_reassm_for_str_seq(struct sctp_tcb *stcb,
      struct sctp_association *asoc,
      uint16_t stream, uint16_t seq)
  {
          struct sctp_tmit_chunk *chk, *nchk;
  
          /* For each one on here see if we need to toss it */
          /*
           * For now large messages held on the reasmqueue that are complete
           * will be tossed too. We could in theory do more work to spin
           * through and stop after dumping one msg aka seeing the start of a
           * new msg at the head, and call the delivery function... to see if
           * it can be delivered... But for now we just dump everything on the
           * queue.
           */
          TAILQ_FOREACH_SAFE(chk, &asoc->reasmqueue, sctp_next, nchk) {
                  /*
                   * Do not toss it if on a different stream or marked for
                   * unordered delivery in which case the stream sequence
                   * number has no meaning.
                   */
                  if ((chk->rec.data.stream_number != stream) ||
                      ((chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == SCTP_DATA_UNORDERED)) {
                          continue;
                  }
                  if (chk->rec.data.stream_seq == seq) {
                          /* It needs to be tossed */
                          TAILQ_REMOVE(&asoc->reasmqueue, chk, sctp_next);
                          if (SCTP_TSN_GT(chk->rec.data.TSN_seq, asoc->tsn_last_delivered)) {
                                  asoc->tsn_last_delivered = chk->rec.data.TSN_seq;
                                  asoc->str_of_pdapi = chk->rec.data.stream_number;
                                  asoc->ssn_of_pdapi = chk->rec.data.stream_seq;
                                  asoc->fragment_flags = chk->rec.data.rcv_flags;
                          }
                          asoc->size_on_reasm_queue -= chk->send_size;
                          sctp_ucount_decr(asoc->cnt_on_reasm_queue);
  
                          /* Clear up any stream problem */
                          if ((chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) != SCTP_DATA_UNORDERED &&
                              SCTP_SSN_GT(chk->rec.data.stream_seq, asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered)) {
                                  /*
                                   * We must dump forward this streams
                                   * sequence number if the chunk is not
                                   * unordered that is being skipped. There is
                                   * a chance that if the peer does not
                                   * include the last fragment in its FWD-TSN
                                   * we WILL have a problem here since you
                                   * would have a partial chunk in queue that
                                   * may not be deliverable. Also if a Partial
                                   * delivery API as started the user may get
                                   * a partial chunk. The next read returning
                                   * a new chunk... really ugly but I see no
                                   * way around it! Maybe a notify??
                                   */
                                  asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered = chk->rec.data.stream_seq;
                          }
                          if (chk->data) {
                                  sctp_m_freem(chk->data);
                                  chk->data = NULL;
                          }
                          sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
                  } else if (SCTP_SSN_GT(chk->rec.data.stream_seq, seq)) {
                          /*
                           * If the stream_seq is > than the purging one, we
                           * are done
                           */
                          break;
                  }
          }
  }
  
  
  void
  sctp_handle_forward_tsn(struct sctp_tcb *stcb,
      struct sctp_forward_tsn_chunk *fwd,
      int *abort_flag, struct mbuf *m, int offset)
  {
          /* The pr-sctp fwd tsn */
          /*
           * here we will perform all the data receiver side steps for
           * processing FwdTSN, as required in by pr-sctp draft:
           * 
           * Assume we get FwdTSN(x):
           * 
           * 1) update local cumTSN to x 2) try to further advance cumTSN to x +
           * others we have 3) examine and update re-ordering queue on
           * pr-in-streams 4) clean up re-assembly queue 5) Send a sack to
           * report where we are.
           */
          struct sctp_association *asoc;
          uint32_t new_cum_tsn, gap;
          unsigned int i, fwd_sz, m_size;
          uint32_t str_seq;
          struct sctp_stream_in *strm;
          struct sctp_tmit_chunk *chk, *nchk;
          struct sctp_queued_to_read *ctl, *sv;
  
          asoc = &stcb->asoc;
          if ((fwd_sz = ntohs(fwd->ch.chunk_length)) < sizeof(struct sctp_forward_tsn_chunk)) {
                  SCTPDBG(SCTP_DEBUG_INDATA1,
                      "Bad size too small/big fwd-tsn\n");
                  return;
          }
          m_size = (stcb->asoc.mapping_array_size << 3);
          /*************************************************************/
          /* 1. Here we update local cumTSN and shift the bitmap array */
          /*************************************************************/
          new_cum_tsn = ntohl(fwd->new_cumulative_tsn);
  
          if (SCTP_TSN_GE(asoc->cumulative_tsn, new_cum_tsn)) {
                  /* Already got there ... */
                  return;
          }
          /*
           * now we know the new TSN is more advanced, let's find the actual
           * gap
           */
          SCTP_CALC_TSN_TO_GAP(gap, new_cum_tsn, asoc->mapping_array_base_tsn);
          asoc->cumulative_tsn = new_cum_tsn;
          if (gap >= m_size) {
                  if ((long)gap > sctp_sbspace(&stcb->asoc, &stcb->sctp_socket->so_rcv)) {
                          struct mbuf *op_err;
                          char msg[SCTP_DIAG_INFO_LEN];
  
                          /*
                           * out of range (of single byte chunks in the rwnd I
                           * give out). This must be an attacker.
                           */
                          *abort_flag = 1;
                          snprintf(msg, sizeof(msg),
                              "New cum ack %8.8x too high, highest TSN %8.8x",
                              new_cum_tsn, asoc->highest_tsn_inside_map);
                          op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                          stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_35;
                          sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
                          return;
                  }
                  SCTP_STAT_INCR(sctps_fwdtsn_map_over);
  
                  memset(stcb->asoc.mapping_array, 0, stcb->asoc.mapping_array_size);
                  asoc->mapping_array_base_tsn = new_cum_tsn + 1;
                  asoc->highest_tsn_inside_map = new_cum_tsn;
  
                  memset(stcb->asoc.nr_mapping_array, 0, stcb->asoc.mapping_array_size);
                  asoc->highest_tsn_inside_nr_map = new_cum_tsn;
  
                  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                          sctp_log_map(0, 3, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
                  }
          } else {
                  SCTP_TCB_LOCK_ASSERT(stcb);
                  for (i = 0; i <= gap; i++) {
                          if (!SCTP_IS_TSN_PRESENT(asoc->mapping_array, i) &&
                              !SCTP_IS_TSN_PRESENT(asoc->nr_mapping_array, i)) {
                                  SCTP_SET_TSN_PRESENT(asoc->nr_mapping_array, i);
                                  if (SCTP_TSN_GT(asoc->mapping_array_base_tsn + i, asoc->highest_tsn_inside_nr_map)) {
                                          asoc->highest_tsn_inside_nr_map = asoc->mapping_array_base_tsn + i;
                                  }
                          }
                  }
          }
          /*************************************************************/
          /* 2. Clear up re-assembly queue                             */
          /*************************************************************/
          /*
           * First service it if pd-api is up, just in case we can progress it
           * forward
           */
          if (asoc->fragmented_delivery_inprogress) {
                  sctp_service_reassembly(stcb, asoc);
          }
          /* For each one on here see if we need to toss it */
          /*
           * For now large messages held on the reasmqueue that are complete
           * will be tossed too. We could in theory do more work to spin
           * through and stop after dumping one msg aka seeing the start of a
           * new msg at the head, and call the delivery function... to see if
           * it can be delivered... But for now we just dump everything on the
           * queue.
           */
          TAILQ_FOREACH_SAFE(chk, &asoc->reasmqueue, sctp_next, nchk) {
                  if (SCTP_TSN_GE(new_cum_tsn, chk->rec.data.TSN_seq)) {
                          /* It needs to be tossed */
                          TAILQ_REMOVE(&asoc->reasmqueue, chk, sctp_next);
                          if (SCTP_TSN_GT(chk->rec.data.TSN_seq, asoc->tsn_last_delivered)) {
                                  asoc->tsn_last_delivered = chk->rec.data.TSN_seq;
                                  asoc->str_of_pdapi = chk->rec.data.stream_number;
                                  asoc->ssn_of_pdapi = chk->rec.data.stream_seq;
                                  asoc->fragment_flags = chk->rec.data.rcv_flags;
                          }
                          asoc->size_on_reasm_queue -= chk->send_size;
                          sctp_ucount_decr(asoc->cnt_on_reasm_queue);
  
                          /* Clear up any stream problem */
                          if ((chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) != SCTP_DATA_UNORDERED &&
                              SCTP_SSN_GT(chk->rec.data.stream_seq, asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered)) {
                                  /*
                                   * We must dump forward this streams
                                   * sequence number if the chunk is not
                                   * unordered that is being skipped. There is
                                   * a chance that if the peer does not
                                   * include the last fragment in its FWD-TSN
                                   * we WILL have a problem here since you
                                   * would have a partial chunk in queue that
                                   * may not be deliverable. Also if a Partial
                                   * delivery API as started the user may get
                                   * a partial chunk. The next read returning
                                   * a new chunk... really ugly but I see no
                                   * way around it! Maybe a notify??
                                   */
                                  asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered = chk->rec.data.stream_seq;
                          }
                          if (chk->data) {
                                  sctp_m_freem(chk->data);
                                  chk->data = NULL;
                          }
                          sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
                  } else {
                          /*
                           * Ok we have gone beyond the end of the fwd-tsn's
                           * mark.
                           */
                          break;
                  }
          }
          /*******************************************************/
          /* 3. Update the PR-stream re-ordering queues and fix  */
          /* delivery issues as needed.                       */
          /*******************************************************/
          fwd_sz -= sizeof(*fwd);
          if (m && fwd_sz) {
                  /* New method. */
                  unsigned int num_str;
                  struct sctp_strseq *stseq, strseqbuf;
  
                  offset += sizeof(*fwd);
  
                  SCTP_INP_READ_LOCK(stcb->sctp_ep);
                  num_str = fwd_sz / sizeof(struct sctp_strseq);
                  for (i = 0; i < num_str; i++) {
                          uint16_t st;
  
                          stseq = (struct sctp_strseq *)sctp_m_getptr(m, offset,
                              sizeof(struct sctp_strseq),
                              (uint8_t *) & strseqbuf);
                          offset += sizeof(struct sctp_strseq);
                          if (stseq == NULL) {
                                  break;
                          }
                          /* Convert */
                          st = ntohs(stseq->stream);
                          stseq->stream = st;
                          st = ntohs(stseq->sequence);
                          stseq->sequence = st;
  
                          /* now process */
  
                          /*
                           * Ok we now look for the stream/seq on the read
                           * queue where its not all delivered. If we find it
                           * we transmute the read entry into a PDI_ABORTED.
                           */
                          if (stseq->stream >= asoc->streamincnt) {
                                  /* screwed up streams, stop!  */
                                  break;
                          }
                          if ((asoc->str_of_pdapi == stseq->stream) &&
                              (asoc->ssn_of_pdapi == stseq->sequence)) {
                                  /*
                                   * If this is the one we were partially
                                   * delivering now then we no longer are.
                                   * Note this will change with the reassembly
                                   * re-write.
                                   */
                                  asoc->fragmented_delivery_inprogress = 0;
                          }
                          sctp_flush_reassm_for_str_seq(stcb, asoc, stseq->stream, stseq->sequence);
                          TAILQ_FOREACH(ctl, &stcb->sctp_ep->read_queue, next) {
                                  if ((ctl->sinfo_stream == stseq->stream) &&
                                      (ctl->sinfo_ssn == stseq->sequence)) {
                                          str_seq = (stseq->stream << 16) | stseq->sequence;
                                          ctl->end_added = 1;
                                          ctl->pdapi_aborted = 1;
                                          sv = stcb->asoc.control_pdapi;
                                          stcb->asoc.control_pdapi = ctl;
                                          sctp_ulp_notify(SCTP_NOTIFY_PARTIAL_DELVIERY_INDICATION,
                                              stcb,
                                              SCTP_PARTIAL_DELIVERY_ABORTED,
                                              (void *)&str_seq,
                                              SCTP_SO_NOT_LOCKED);
                                          stcb->asoc.control_pdapi = sv;
                                          break;
                                  } else if ((ctl->sinfo_stream == stseq->stream) &&
                                      SCTP_SSN_GT(ctl->sinfo_ssn, stseq->sequence)) {
                                          /* We are past our victim SSN */
                                          break;
                                  }
                          }
                          strm = &asoc->strmin[stseq->stream];
                          if (SCTP_SSN_GT(stseq->sequence, strm->last_sequence_delivered)) {
                                  /* Update the sequence number */
                                  strm->last_sequence_delivered = stseq->sequence;
                          }
                          /* now kick the stream the new way */
                          /* sa_ignore NO_NULL_CHK */
                          sctp_kick_prsctp_reorder_queue(stcb, strm);
                  }
                  SCTP_INP_READ_UNLOCK(stcb->sctp_ep);
          }
          /*
           * Now slide thing forward.
           */
          sctp_slide_mapping_arrays(stcb);
  
          if (!TAILQ_EMPTY(&asoc->reasmqueue)) {
                  /* now lets kick out and check for more fragmented delivery */
                  /* sa_ignore NO_NULL_CHK */
                  sctp_deliver_reasm_check(stcb, &stcb->asoc);
          }
  }