tcp_lro.c

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    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 2007, Myricom Inc.
    5  * Copyright (c) 2008, Intel Corporation.
    6  * Copyright (c) 2012 The FreeBSD Foundation
    7  * Copyright (c) 2016-2021 Mellanox Technologies.
    8  * All rights reserved.
    9  *
   10  * Portions of this software were developed by Bjoern Zeeb
   11  * under sponsorship from the FreeBSD Foundation.
   12  *
   13  * Redistribution and use in source and binary forms, with or without
   14  * modification, are permitted provided that the following conditions
   15  * are met:
   16  * 1. Redistributions of source code must retain the above copyright
   17  *    notice, this list of conditions and the following disclaimer.
   18  * 2. Redistributions in binary form must reproduce the above copyright
   19  *    notice, this list of conditions and the following disclaimer in the
   20  *    documentation and/or other materials provided with the distribution.
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   32  * SUCH DAMAGE.
   33  */
   34 
   35 #include <sys/cdefs.h>
   36 __FBSDID("$FreeBSD$");
   37 
   38 #include "opt_inet.h"
   39 #include "opt_inet6.h"
   40 
   41 #include <sys/param.h>
   42 #include <sys/systm.h>
   43 #include <sys/kernel.h>
   44 #include <sys/malloc.h>
   45 #include <sys/mbuf.h>
   46 #include <sys/socket.h>
   47 #include <sys/socketvar.h>
   48 #include <sys/sockbuf.h>
   49 #include <sys/sysctl.h>
   50 
   51 #include <net/if.h>
   52 #include <net/if_var.h>
   53 #include <net/ethernet.h>
   54 #include <net/bpf.h>
   55 #include <net/vnet.h>
   56 #include <net/if_dl.h>
   57 #include <net/if_media.h>
   58 #include <net/if_types.h>
   59 #include <net/infiniband.h>
   60 #include <net/if_lagg.h>
   61 
   62 #include <netinet/in_systm.h>
   63 #include <netinet/in.h>
   64 #include <netinet/ip6.h>
   65 #include <netinet/ip.h>
   66 #include <netinet/ip_var.h>
   67 #include <netinet/in_pcb.h>
   68 #include <netinet6/in6_pcb.h>
   69 #include <netinet/tcp.h>
   70 #include <netinet/tcp_seq.h>
   71 #include <netinet/tcp_lro.h>
   72 #include <netinet/tcp_var.h>
   73 #include <netinet/tcpip.h>
   74 #include <netinet/tcp_hpts.h>
   75 #include <netinet/tcp_log_buf.h>
   76 #include <netinet/tcp_fsm.h>
   77 #include <netinet/udp.h>
   78 #include <netinet6/ip6_var.h>
   79 
   80 #include <machine/in_cksum.h>
   81 
   82 static MALLOC_DEFINE(M_LRO, "LRO", "LRO control structures");
   83 
   84 #define TCP_LRO_TS_OPTION \
   85     ntohl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | \
   86           (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)
   87 
   88 static void     tcp_lro_rx_done(struct lro_ctrl *lc);
   89 static int      tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m,
   90                     uint32_t csum, bool use_hash);
   91 
   92 #ifdef TCPHPTS
   93 static bool     do_bpf_strip_and_compress(struct inpcb *, struct lro_ctrl *,
   94                 struct lro_entry *, struct mbuf **, struct mbuf **, struct mbuf **,
   95                 bool *, bool, bool, struct ifnet *, bool);
   96 
   97 #endif
   98 
   99 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, lro,  CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
  100     "TCP LRO");
  101 
  102 static long tcplro_stacks_wanting_mbufq;
  103 counter_u64_t tcp_inp_lro_direct_queue;
  104 counter_u64_t tcp_inp_lro_wokeup_queue;
  105 counter_u64_t tcp_inp_lro_compressed;
  106 counter_u64_t tcp_inp_lro_locks_taken;
  107 counter_u64_t tcp_extra_mbuf;
  108 counter_u64_t tcp_would_have_but;
  109 counter_u64_t tcp_comp_total;
  110 counter_u64_t tcp_uncomp_total;
  111 counter_u64_t tcp_bad_csums;
  112 
  113 static unsigned tcp_lro_entries = TCP_LRO_ENTRIES;
  114 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, entries,
  115     CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_entries, 0,
  116     "default number of LRO entries");
  117 
  118 static uint32_t tcp_lro_cpu_set_thresh = TCP_LRO_CPU_DECLARATION_THRESH;
  119 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, lro_cpu_threshold,
  120     CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_cpu_set_thresh, 0,
  121     "Number of interrupts in a row on the same CPU that will make us declare an 'affinity' cpu?");
  122 
  123 static uint32_t tcp_less_accurate_lro_ts = 0;
  124 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, lro_less_accurate,
  125     CTLFLAG_MPSAFE, &tcp_less_accurate_lro_ts, 0,
  126     "Do we trade off efficency by doing less timestamp operations for time accuracy?");
  127 
  128 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, fullqueue, CTLFLAG_RD,
  129     &tcp_inp_lro_direct_queue, "Number of lro's fully queued to transport");
  130 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, wokeup, CTLFLAG_RD,
  131     &tcp_inp_lro_wokeup_queue, "Number of lro's where we woke up transport via hpts");
  132 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, compressed, CTLFLAG_RD,
  133     &tcp_inp_lro_compressed, "Number of lro's compressed and sent to transport");
  134 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lockcnt, CTLFLAG_RD,
  135     &tcp_inp_lro_locks_taken, "Number of lro's inp_wlocks taken");
  136 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, extra_mbuf, CTLFLAG_RD,
  137     &tcp_extra_mbuf, "Number of times we had an extra compressed ack dropped into the tp");
  138 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, would_have_but, CTLFLAG_RD,
  139     &tcp_would_have_but, "Number of times we would have had an extra compressed, but mget failed");
  140 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, with_m_ackcmp, CTLFLAG_RD,
  141     &tcp_comp_total, "Number of mbufs queued with M_ACKCMP flags set");
  142 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, without_m_ackcmp, CTLFLAG_RD,
  143     &tcp_uncomp_total, "Number of mbufs queued without M_ACKCMP");
  144 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lro_badcsum, CTLFLAG_RD,
  145     &tcp_bad_csums, "Number of packets that the common code saw with bad csums");
  146 
  147 void
  148 tcp_lro_reg_mbufq(void)
  149 {
  150         atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, 1);
  151 }
  152 
  153 void
  154 tcp_lro_dereg_mbufq(void)
  155 {
  156         atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, -1);
  157 }
  158 
  159 static __inline void
  160 tcp_lro_active_insert(struct lro_ctrl *lc, struct lro_head *bucket,
  161     struct lro_entry *le)
  162 {
  163 
  164         LIST_INSERT_HEAD(&lc->lro_active, le, next);
  165         LIST_INSERT_HEAD(bucket, le, hash_next);
  166 }
  167 
  168 static __inline void
  169 tcp_lro_active_remove(struct lro_entry *le)
  170 {
  171 
  172         LIST_REMOVE(le, next);          /* active list */
  173         LIST_REMOVE(le, hash_next);     /* hash bucket */
  174 }
  175 
  176 int
  177 tcp_lro_init(struct lro_ctrl *lc)
  178 {
  179         return (tcp_lro_init_args(lc, NULL, tcp_lro_entries, 0));
  180 }
  181 
  182 int
  183 tcp_lro_init_args(struct lro_ctrl *lc, struct ifnet *ifp,
  184     unsigned lro_entries, unsigned lro_mbufs)
  185 {
  186         struct lro_entry *le;
  187         size_t size;
  188         unsigned i, elements;
  189 
  190         lc->lro_bad_csum = 0;
  191         lc->lro_queued = 0;
  192         lc->lro_flushed = 0;
  193         lc->lro_mbuf_count = 0;
  194         lc->lro_mbuf_max = lro_mbufs;
  195         lc->lro_cnt = lro_entries;
  196         lc->lro_ackcnt_lim = TCP_LRO_ACKCNT_MAX;
  197         lc->lro_length_lim = TCP_LRO_LENGTH_MAX;
  198         lc->ifp = ifp;
  199         LIST_INIT(&lc->lro_free);
  200         LIST_INIT(&lc->lro_active);
  201 
  202         /* create hash table to accelerate entry lookup */
  203         if (lro_entries > lro_mbufs)
  204                 elements = lro_entries;
  205         else
  206                 elements = lro_mbufs;
  207         lc->lro_hash = phashinit_flags(elements, M_LRO, &lc->lro_hashsz,
  208             HASH_NOWAIT);
  209         if (lc->lro_hash == NULL) {
  210                 memset(lc, 0, sizeof(*lc));
  211                 return (ENOMEM);
  212         }
  213 
  214         /* compute size to allocate */
  215         size = (lro_mbufs * sizeof(struct lro_mbuf_sort)) +
  216             (lro_entries * sizeof(*le));
  217         lc->lro_mbuf_data = (struct lro_mbuf_sort *)
  218             malloc(size, M_LRO, M_NOWAIT | M_ZERO);
  219 
  220         /* check for out of memory */
  221         if (lc->lro_mbuf_data == NULL) {
  222                 free(lc->lro_hash, M_LRO);
  223                 memset(lc, 0, sizeof(*lc));
  224                 return (ENOMEM);
  225         }
  226         /* compute offset for LRO entries */
  227         le = (struct lro_entry *)
  228             (lc->lro_mbuf_data + lro_mbufs);
  229 
  230         /* setup linked list */
  231         for (i = 0; i != lro_entries; i++)
  232                 LIST_INSERT_HEAD(&lc->lro_free, le + i, next);
  233 
  234         return (0);
  235 }
  236 
  237 struct vxlan_header {
  238         uint32_t        vxlh_flags;
  239         uint32_t        vxlh_vni;
  240 };
  241 
  242 static inline void *
  243 tcp_lro_low_level_parser(void *ptr, struct lro_parser *parser, bool update_data, bool is_vxlan, int mlen)
  244 {
  245         const struct ether_vlan_header *eh;
  246         void *old;
  247         uint16_t eth_type;
  248 
  249         if (update_data)
  250                 memset(parser, 0, sizeof(*parser));
  251 
  252         old = ptr;
  253 
  254         if (is_vxlan) {
  255                 const struct vxlan_header *vxh;
  256                 vxh = ptr;
  257                 ptr = (uint8_t *)ptr + sizeof(*vxh);
  258                 if (update_data) {
  259                         parser->data.vxlan_vni =
  260                             vxh->vxlh_vni & htonl(0xffffff00);
  261                 }
  262         }
  263 
  264         eh = ptr;
  265         if (__predict_false(eh->evl_encap_proto == htons(ETHERTYPE_VLAN))) {
  266                 eth_type = eh->evl_proto;
  267                 if (update_data) {
  268                         /* strip priority and keep VLAN ID only */
  269                         parser->data.vlan_id = eh->evl_tag & htons(EVL_VLID_MASK);
  270                 }
  271                 /* advance to next header */
  272                 ptr = (uint8_t *)ptr + ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
  273                 mlen -= (ETHER_HDR_LEN  + ETHER_VLAN_ENCAP_LEN);
  274         } else {
  275                 eth_type = eh->evl_encap_proto;
  276                 /* advance to next header */
  277                 mlen -= ETHER_HDR_LEN;
  278                 ptr = (uint8_t *)ptr + ETHER_HDR_LEN;
  279         }
  280         if (__predict_false(mlen <= 0))
  281                 return (NULL);
  282         switch (eth_type) {
  283 #ifdef INET
  284         case htons(ETHERTYPE_IP):
  285                 parser->ip4 = ptr;
  286                 if (__predict_false(mlen < sizeof(struct ip)))
  287                         return (NULL);
  288                 /* Ensure there are no IPv4 options. */
  289                 if ((parser->ip4->ip_hl << 2) != sizeof (*parser->ip4))
  290                         break;
  291                 /* .. and the packet is not fragmented. */
  292                 if (parser->ip4->ip_off & htons(IP_MF|IP_OFFMASK))
  293                         break;
  294                 ptr = (uint8_t *)ptr + (parser->ip4->ip_hl << 2);
  295                 mlen -= sizeof(struct ip);
  296                 if (update_data) {
  297                         parser->data.s_addr.v4 = parser->ip4->ip_src;
  298                         parser->data.d_addr.v4 = parser->ip4->ip_dst;
  299                 }
  300                 switch (parser->ip4->ip_p) {
  301                 case IPPROTO_UDP:
  302                         if (__predict_false(mlen < sizeof(struct udphdr)))
  303                                 return (NULL);
  304                         parser->udp = ptr;
  305                         if (update_data) {
  306                                 parser->data.lro_type = LRO_TYPE_IPV4_UDP;
  307                                 parser->data.s_port = parser->udp->uh_sport;
  308                                 parser->data.d_port = parser->udp->uh_dport;
  309                         } else {
  310                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_UDP);
  311                         }
  312                         ptr = ((uint8_t *)ptr + sizeof(*parser->udp));
  313                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
  314                         return (ptr);
  315                 case IPPROTO_TCP:
  316                         parser->tcp = ptr;
  317                         if (__predict_false(mlen < sizeof(struct tcphdr)))
  318                                 return (NULL);
  319                         if (update_data) {
  320                                 parser->data.lro_type = LRO_TYPE_IPV4_TCP;
  321                                 parser->data.s_port = parser->tcp->th_sport;
  322                                 parser->data.d_port = parser->tcp->th_dport;
  323                         } else {
  324                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_TCP);
  325                         }
  326                         if (__predict_false(mlen < (parser->tcp->th_off << 2)))
  327                                 return (NULL);
  328                         ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
  329                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
  330                         return (ptr);
  331                 default:
  332                         break;
  333                 }
  334                 break;
  335 #endif
  336 #ifdef INET6
  337         case htons(ETHERTYPE_IPV6):
  338                 parser->ip6 = ptr;
  339                 if (__predict_false(mlen < sizeof(struct ip6_hdr)))
  340                         return (NULL);
  341                 ptr = (uint8_t *)ptr + sizeof(*parser->ip6);
  342                 if (update_data) {
  343                         parser->data.s_addr.v6 = parser->ip6->ip6_src;
  344                         parser->data.d_addr.v6 = parser->ip6->ip6_dst;
  345                 }
  346                 mlen -= sizeof(struct ip6_hdr);
  347                 switch (parser->ip6->ip6_nxt) {
  348                 case IPPROTO_UDP:
  349                         if (__predict_false(mlen < sizeof(struct udphdr)))
  350                                 return (NULL);
  351                         parser->udp = ptr;
  352                         if (update_data) {
  353                                 parser->data.lro_type = LRO_TYPE_IPV6_UDP;
  354                                 parser->data.s_port = parser->udp->uh_sport;
  355                                 parser->data.d_port = parser->udp->uh_dport;
  356                         } else {
  357                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_UDP);
  358                         }
  359                         ptr = (uint8_t *)ptr + sizeof(*parser->udp);
  360                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
  361                         return (ptr);
  362                 case IPPROTO_TCP:
  363                         if (__predict_false(mlen < sizeof(struct tcphdr)))
  364                                 return (NULL);
  365                         parser->tcp = ptr;
  366                         if (update_data) {
  367                                 parser->data.lro_type = LRO_TYPE_IPV6_TCP;
  368                                 parser->data.s_port = parser->tcp->th_sport;
  369                                 parser->data.d_port = parser->tcp->th_dport;
  370                         } else {
  371                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_TCP);
  372                         }
  373                         if (__predict_false(mlen < (parser->tcp->th_off << 2)))
  374                                 return (NULL);
  375                         ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
  376                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
  377                         return (ptr);
  378                 default:
  379                         break;
  380                 }
  381                 break;
  382 #endif
  383         default:
  384                 break;
  385         }
  386         /* Invalid packet - cannot parse */
  387         return (NULL);
  388 }
  389 
  390 static const int vxlan_csum = CSUM_INNER_L3_CALC | CSUM_INNER_L3_VALID |
  391     CSUM_INNER_L4_CALC | CSUM_INNER_L4_VALID;
  392 
  393 static inline struct lro_parser *
  394 tcp_lro_parser(struct mbuf *m, struct lro_parser *po, struct lro_parser *pi, bool update_data)
  395 {
  396         void *data_ptr;
  397 
  398         /* Try to parse outer headers first. */
  399         data_ptr = tcp_lro_low_level_parser(m->m_data, po, update_data, false, m->m_len);
  400         if (data_ptr == NULL || po->total_hdr_len > m->m_len)
  401                 return (NULL);
  402 
  403         if (update_data) {
  404                 /* Store VLAN ID, if any. */
  405                 if (__predict_false(m->m_flags & M_VLANTAG)) {
  406                         po->data.vlan_id =
  407                             htons(m->m_pkthdr.ether_vtag) & htons(EVL_VLID_MASK);
  408                 }
  409                 /* Store decrypted flag, if any. */
  410                 if (__predict_false((m->m_pkthdr.csum_flags &
  411                     CSUM_TLS_MASK) == CSUM_TLS_DECRYPTED))
  412                         po->data.lro_flags |= LRO_FLAG_DECRYPTED;
  413         }
  414 
  415         switch (po->data.lro_type) {
  416         case LRO_TYPE_IPV4_UDP:
  417         case LRO_TYPE_IPV6_UDP:
  418                 /* Check for VXLAN headers. */
  419                 if ((m->m_pkthdr.csum_flags & vxlan_csum) != vxlan_csum)
  420                         break;
  421 
  422                 /* Try to parse inner headers. */
  423                 data_ptr = tcp_lro_low_level_parser(data_ptr, pi, update_data, true,
  424                                                     (m->m_len - ((caddr_t)data_ptr - m->m_data)));
  425                 if (data_ptr == NULL || (pi->total_hdr_len + po->total_hdr_len) > m->m_len)
  426                         break;
  427 
  428                 /* Verify supported header types. */
  429                 switch (pi->data.lro_type) {
  430                 case LRO_TYPE_IPV4_TCP:
  431                 case LRO_TYPE_IPV6_TCP:
  432                         return (pi);
  433                 default:
  434                         break;
  435                 }
  436                 break;
  437         case LRO_TYPE_IPV4_TCP:
  438         case LRO_TYPE_IPV6_TCP:
  439                 if (update_data)
  440                         memset(pi, 0, sizeof(*pi));
  441                 return (po);
  442         default:
  443                 break;
  444         }
  445         return (NULL);
  446 }
  447 
  448 static inline int
  449 tcp_lro_trim_mbuf_chain(struct mbuf *m, const struct lro_parser *po)
  450 {
  451         int len;
  452 
  453         switch (po->data.lro_type) {
  454 #ifdef INET
  455         case LRO_TYPE_IPV4_TCP:
  456                 len = ((uint8_t *)po->ip4 - (uint8_t *)m->m_data) +
  457                     ntohs(po->ip4->ip_len);
  458                 break;
  459 #endif
  460 #ifdef INET6
  461         case LRO_TYPE_IPV6_TCP:
  462                 len = ((uint8_t *)po->ip6 - (uint8_t *)m->m_data) +
  463                     ntohs(po->ip6->ip6_plen) + sizeof(*po->ip6);
  464                 break;
  465 #endif
  466         default:
  467                 return (TCP_LRO_CANNOT);
  468         }
  469 
  470         /*
  471          * If the frame is padded beyond the end of the IP packet,
  472          * then trim the extra bytes off:
  473          */
  474         if (__predict_true(m->m_pkthdr.len == len)) {
  475                 return (0);
  476         } else if (m->m_pkthdr.len > len) {
  477                 m_adj(m, len - m->m_pkthdr.len);
  478                 return (0);
  479         }
  480         return (TCP_LRO_CANNOT);
  481 }
  482 
  483 static struct tcphdr *
  484 tcp_lro_get_th(struct mbuf *m)
  485 {
  486         return ((struct tcphdr *)((uint8_t *)m->m_data + m->m_pkthdr.lro_tcp_h_off));
  487 }
  488 
  489 static void
  490 lro_free_mbuf_chain(struct mbuf *m)
  491 {
  492         struct mbuf *save;
  493 
  494         while (m) {
  495                 save = m->m_nextpkt;
  496                 m->m_nextpkt = NULL;
  497                 m_freem(m);
  498                 m = save;
  499         }
  500 }
  501 
  502 void
  503 tcp_lro_free(struct lro_ctrl *lc)
  504 {
  505         struct lro_entry *le;
  506         unsigned x;
  507 
  508         /* reset LRO free list */
  509         LIST_INIT(&lc->lro_free);
  510 
  511         /* free active mbufs, if any */
  512         while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
  513                 tcp_lro_active_remove(le);
  514                 lro_free_mbuf_chain(le->m_head);
  515         }
  516 
  517         /* free hash table */
  518         free(lc->lro_hash, M_LRO);
  519         lc->lro_hash = NULL;
  520         lc->lro_hashsz = 0;
  521 
  522         /* free mbuf array, if any */
  523         for (x = 0; x != lc->lro_mbuf_count; x++)
  524                 m_freem(lc->lro_mbuf_data[x].mb);
  525         lc->lro_mbuf_count = 0;
  526 
  527         /* free allocated memory, if any */
  528         free(lc->lro_mbuf_data, M_LRO);
  529         lc->lro_mbuf_data = NULL;
  530 }
  531 
  532 static uint16_t
  533 tcp_lro_rx_csum_tcphdr(const struct tcphdr *th)
  534 {
  535         const uint16_t *ptr;
  536         uint32_t csum;
  537         uint16_t len;
  538 
  539         csum = -th->th_sum;     /* exclude checksum field */
  540         len = th->th_off;
  541         ptr = (const uint16_t *)th;
  542         while (len--) {
  543                 csum += *ptr;
  544                 ptr++;
  545                 csum += *ptr;
  546                 ptr++;
  547         }
  548         while (csum > 0xffff)
  549                 csum = (csum >> 16) + (csum & 0xffff);
  550 
  551         return (csum);
  552 }
  553 
  554 static uint16_t
  555 tcp_lro_rx_csum_data(const struct lro_parser *pa, uint16_t tcp_csum)
  556 {
  557         uint32_t c;
  558         uint16_t cs;
  559 
  560         c = tcp_csum;
  561 
  562         switch (pa->data.lro_type) {
  563 #ifdef INET6
  564         case LRO_TYPE_IPV6_TCP:
  565                 /* Compute full pseudo IPv6 header checksum. */
  566                 cs = in6_cksum_pseudo(pa->ip6, ntohs(pa->ip6->ip6_plen), pa->ip6->ip6_nxt, 0);
  567                 break;
  568 #endif
  569 #ifdef INET
  570         case LRO_TYPE_IPV4_TCP:
  571                 /* Compute full pseudo IPv4 header checsum. */
  572                 cs = in_addword(ntohs(pa->ip4->ip_len) - sizeof(*pa->ip4), IPPROTO_TCP);
  573                 cs = in_pseudo(pa->ip4->ip_src.s_addr, pa->ip4->ip_dst.s_addr, htons(cs));
  574                 break;
  575 #endif
  576         default:
  577                 cs = 0;         /* Keep compiler happy. */
  578                 break;
  579         }
  580 
  581         /* Complement checksum. */
  582         cs = ~cs;
  583         c += cs;
  584 
  585         /* Remove TCP header checksum. */
  586         cs = ~tcp_lro_rx_csum_tcphdr(pa->tcp);
  587         c += cs;
  588 
  589         /* Compute checksum remainder. */
  590         while (c > 0xffff)
  591                 c = (c >> 16) + (c & 0xffff);
  592 
  593         return (c);
  594 }
  595 
  596 static void
  597 tcp_lro_rx_done(struct lro_ctrl *lc)
  598 {
  599         struct lro_entry *le;
  600 
  601         while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
  602                 tcp_lro_active_remove(le);
  603                 tcp_lro_flush(lc, le);
  604         }
  605 }
  606 
  607 static void
  608 tcp_lro_flush_active(struct lro_ctrl *lc)
  609 {
  610         struct lro_entry *le;
  611 
  612         /*
  613          * Walk through the list of le entries, and
  614          * any one that does have packets flush. This
  615          * is called because we have an inbound packet
  616          * (e.g. SYN) that has to have all others flushed
  617          * in front of it. Note we have to do the remove
  618          * because tcp_lro_flush() assumes that the entry
  619          * is being freed. This is ok it will just get
  620          * reallocated again like it was new.
  621          */
  622         LIST_FOREACH(le, &lc->lro_active, next) {
  623                 if (le->m_head != NULL) {
  624                         tcp_lro_active_remove(le);
  625                         tcp_lro_flush(lc, le);
  626                 }
  627         }
  628 }
  629 
  630 void
  631 tcp_lro_flush_inactive(struct lro_ctrl *lc, const struct timeval *timeout)
  632 {
  633         struct lro_entry *le, *le_tmp;
  634         uint64_t now, tov;
  635         struct bintime bt;
  636 
  637         NET_EPOCH_ASSERT();
  638         if (LIST_EMPTY(&lc->lro_active))
  639                 return;
  640 
  641         /* get timeout time and current time in ns */
  642         binuptime(&bt);
  643         now = bintime2ns(&bt);
  644         tov = ((timeout->tv_sec * 1000000000) + (timeout->tv_usec * 1000));
  645         LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) {
  646                 if (now >= (bintime2ns(&le->alloc_time) + tov)) {
  647                         tcp_lro_active_remove(le);
  648                         tcp_lro_flush(lc, le);
  649                 }
  650         }
  651 }
  652 
  653 #ifdef INET
  654 static int
  655 tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4)
  656 {
  657         uint16_t csum;
  658 
  659         /* Legacy IP has a header checksum that needs to be correct. */
  660         if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
  661                 if (__predict_false((m->m_pkthdr.csum_flags & CSUM_IP_VALID) == 0)) {
  662                         lc->lro_bad_csum++;
  663                         return (TCP_LRO_CANNOT);
  664                 }
  665         } else {
  666                 csum = in_cksum_hdr(ip4);
  667                 if (__predict_false(csum != 0)) {
  668                         lc->lro_bad_csum++;
  669                         return (TCP_LRO_CANNOT);
  670                 }
  671         }
  672         return (0);
  673 }
  674 #endif
  675 
  676 #ifdef TCPHPTS
  677 static void
  678 tcp_lro_log(struct tcpcb *tp, const struct lro_ctrl *lc,
  679     const struct lro_entry *le, const struct mbuf *m,
  680     int frm, int32_t tcp_data_len, uint32_t th_seq,
  681     uint32_t th_ack, uint16_t th_win)
  682 {
  683         if (tp->t_logstate != TCP_LOG_STATE_OFF) {
  684                 union tcp_log_stackspecific log;
  685                 struct timeval tv, btv;
  686                 uint32_t cts;
  687 
  688                 cts = tcp_get_usecs(&tv);
  689                 memset(&log, 0, sizeof(union tcp_log_stackspecific));
  690                 log.u_bbr.flex8 = frm;
  691                 log.u_bbr.flex1 = tcp_data_len;
  692                 if (m)
  693                         log.u_bbr.flex2 = m->m_pkthdr.len;
  694                 else
  695                         log.u_bbr.flex2 = 0;
  696                 if (le->m_head) {
  697                         log.u_bbr.flex3 = le->m_head->m_pkthdr.lro_nsegs;
  698                         log.u_bbr.flex4 = le->m_head->m_pkthdr.lro_tcp_d_len;
  699                         log.u_bbr.flex5 = le->m_head->m_pkthdr.len;
  700                         log.u_bbr.delRate = le->m_head->m_flags;
  701                         log.u_bbr.rttProp = le->m_head->m_pkthdr.rcv_tstmp;
  702                 }
  703                 log.u_bbr.inflight = th_seq;
  704                 log.u_bbr.delivered = th_ack;
  705                 log.u_bbr.timeStamp = cts;
  706                 log.u_bbr.epoch = le->next_seq;
  707                 log.u_bbr.lt_epoch = le->ack_seq;
  708                 log.u_bbr.pacing_gain = th_win;
  709                 log.u_bbr.cwnd_gain = le->window;
  710                 log.u_bbr.lost = curcpu;
  711                 log.u_bbr.cur_del_rate = (uintptr_t)m;
  712                 log.u_bbr.bw_inuse = (uintptr_t)le->m_head;
  713                 bintime2timeval(&lc->lro_last_queue_time, &btv);
  714                 log.u_bbr.flex6 = tcp_tv_to_usectick(&btv);
  715                 log.u_bbr.flex7 = le->compressed;
  716                 log.u_bbr.pacing_gain = le->uncompressed;
  717                 if (in_epoch(net_epoch_preempt))
  718                         log.u_bbr.inhpts = 1;
  719                 else
  720                         log.u_bbr.inhpts = 0;
  721                 TCP_LOG_EVENTP(tp, NULL, &tptosocket(tp)->so_rcv,
  722                     &tptosocket(tp)->so_snd,
  723                     TCP_LOG_LRO, 0, 0, &log, false, &tv);
  724         }
  725 }
  726 #endif
  727 
  728 static inline void
  729 tcp_lro_assign_and_checksum_16(uint16_t *ptr, uint16_t value, uint16_t *psum)
  730 {
  731         uint32_t csum;
  732 
  733         csum = 0xffff - *ptr + value;
  734         while (csum > 0xffff)
  735                 csum = (csum >> 16) + (csum & 0xffff);
  736         *ptr = value;
  737         *psum = csum;
  738 }
  739 
  740 static uint16_t
  741 tcp_lro_update_checksum(const struct lro_parser *pa, const struct lro_entry *le,
  742     uint16_t payload_len, uint16_t delta_sum)
  743 {
  744         uint32_t csum;
  745         uint16_t tlen;
  746         uint16_t temp[5] = {};
  747 
  748         switch (pa->data.lro_type) {
  749         case LRO_TYPE_IPV4_TCP:
  750                 /* Compute new IPv4 length. */
  751                 tlen = (pa->ip4->ip_hl << 2) + (pa->tcp->th_off << 2) + payload_len;
  752                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
  753 
  754                 /* Subtract delta from current IPv4 checksum. */
  755                 csum = pa->ip4->ip_sum + 0xffff - temp[0];
  756                 while (csum > 0xffff)
  757                         csum = (csum >> 16) + (csum & 0xffff);
  758                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
  759                 goto update_tcp_header;
  760 
  761         case LRO_TYPE_IPV6_TCP:
  762                 /* Compute new IPv6 length. */
  763                 tlen = (pa->tcp->th_off << 2) + payload_len;
  764                 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
  765                 goto update_tcp_header;
  766 
  767         case LRO_TYPE_IPV4_UDP:
  768                 /* Compute new IPv4 length. */
  769                 tlen = (pa->ip4->ip_hl << 2) + sizeof(*pa->udp) + payload_len;
  770                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
  771 
  772                 /* Subtract delta from current IPv4 checksum. */
  773                 csum = pa->ip4->ip_sum + 0xffff - temp[0];
  774                 while (csum > 0xffff)
  775                         csum = (csum >> 16) + (csum & 0xffff);
  776                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
  777                 goto update_udp_header;
  778 
  779         case LRO_TYPE_IPV6_UDP:
  780                 /* Compute new IPv6 length. */
  781                 tlen = sizeof(*pa->udp) + payload_len;
  782                 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
  783                 goto update_udp_header;
  784 
  785         default:
  786                 return (0);
  787         }
  788 
  789 update_tcp_header:
  790         /* Compute current TCP header checksum. */
  791         temp[2] = tcp_lro_rx_csum_tcphdr(pa->tcp);
  792 
  793         /* Incorporate the latest ACK into the TCP header. */
  794         pa->tcp->th_ack = le->ack_seq;
  795         pa->tcp->th_win = le->window;
  796 
  797         /* Incorporate latest timestamp into the TCP header. */
  798         if (le->timestamp != 0) {
  799                 uint32_t *ts_ptr;
  800 
  801                 ts_ptr = (uint32_t *)(pa->tcp + 1);
  802                 ts_ptr[1] = htonl(le->tsval);
  803                 ts_ptr[2] = le->tsecr;
  804         }
  805 
  806         /* Compute new TCP header checksum. */
  807         temp[3] = tcp_lro_rx_csum_tcphdr(pa->tcp);
  808 
  809         /* Compute new TCP checksum. */
  810         csum = pa->tcp->th_sum + 0xffff - delta_sum +
  811             0xffff - temp[0] + 0xffff - temp[3] + temp[2];
  812         while (csum > 0xffff)
  813                 csum = (csum >> 16) + (csum & 0xffff);
  814 
  815         /* Assign new TCP checksum. */
  816         tcp_lro_assign_and_checksum_16(&pa->tcp->th_sum, csum, &temp[4]);
  817 
  818         /* Compute all modififications affecting next checksum. */
  819         csum = temp[0] + temp[1] + 0xffff - temp[2] +
  820             temp[3] + temp[4] + delta_sum;
  821         while (csum > 0xffff)
  822                 csum = (csum >> 16) + (csum & 0xffff);
  823 
  824         /* Return delta checksum to next stage, if any. */
  825         return (csum);
  826 
  827 update_udp_header:
  828         tlen = sizeof(*pa->udp) + payload_len;
  829         /* Assign new UDP length and compute checksum delta. */
  830         tcp_lro_assign_and_checksum_16(&pa->udp->uh_ulen, htons(tlen), &temp[2]);
  831 
  832         /* Check if there is a UDP checksum. */
  833         if (__predict_false(pa->udp->uh_sum != 0)) {
  834                 /* Compute new UDP checksum. */
  835                 csum = pa->udp->uh_sum + 0xffff - delta_sum +
  836                     0xffff - temp[0] + 0xffff - temp[2];
  837                 while (csum > 0xffff)
  838                         csum = (csum >> 16) + (csum & 0xffff);
  839                 /* Assign new UDP checksum. */
  840                 tcp_lro_assign_and_checksum_16(&pa->udp->uh_sum, csum, &temp[3]);
  841         }
  842 
  843         /* Compute all modififications affecting next checksum. */
  844         csum = temp[0] + temp[1] + temp[2] + temp[3] + delta_sum;
  845         while (csum > 0xffff)
  846                 csum = (csum >> 16) + (csum & 0xffff);
  847 
  848         /* Return delta checksum to next stage, if any. */
  849         return (csum);
  850 }
  851 
  852 static void
  853 tcp_flush_out_entry(struct lro_ctrl *lc, struct lro_entry *le)
  854 {
  855         /* Check if we need to recompute any checksums. */
  856         if (le->needs_merge) {
  857                 uint16_t csum;
  858 
  859                 switch (le->inner.data.lro_type) {
  860                 case LRO_TYPE_IPV4_TCP:
  861                         csum = tcp_lro_update_checksum(&le->inner, le,
  862                             le->m_head->m_pkthdr.lro_tcp_d_len,
  863                             le->m_head->m_pkthdr.lro_tcp_d_csum);
  864                         csum = tcp_lro_update_checksum(&le->outer, NULL,
  865                             le->m_head->m_pkthdr.lro_tcp_d_len +
  866                             le->inner.total_hdr_len, csum);
  867                         le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
  868                             CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
  869                         le->m_head->m_pkthdr.csum_data = 0xffff;
  870                         if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
  871                                 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
  872                         break;
  873                 case LRO_TYPE_IPV6_TCP:
  874                         csum = tcp_lro_update_checksum(&le->inner, le,
  875                             le->m_head->m_pkthdr.lro_tcp_d_len,
  876                             le->m_head->m_pkthdr.lro_tcp_d_csum);
  877                         csum = tcp_lro_update_checksum(&le->outer, NULL,
  878                             le->m_head->m_pkthdr.lro_tcp_d_len +
  879                             le->inner.total_hdr_len, csum);
  880                         le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
  881                             CSUM_PSEUDO_HDR;
  882                         le->m_head->m_pkthdr.csum_data = 0xffff;
  883                         if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
  884                                 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
  885                         break;
  886                 case LRO_TYPE_NONE:
  887                         switch (le->outer.data.lro_type) {
  888                         case LRO_TYPE_IPV4_TCP:
  889                                 csum = tcp_lro_update_checksum(&le->outer, le,
  890                                     le->m_head->m_pkthdr.lro_tcp_d_len,
  891                                     le->m_head->m_pkthdr.lro_tcp_d_csum);
  892                                 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
  893                                     CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
  894                                 le->m_head->m_pkthdr.csum_data = 0xffff;
  895                                 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
  896                                         le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
  897                                 break;
  898                         case LRO_TYPE_IPV6_TCP:
  899                                 csum = tcp_lro_update_checksum(&le->outer, le,
  900                                     le->m_head->m_pkthdr.lro_tcp_d_len,
  901                                     le->m_head->m_pkthdr.lro_tcp_d_csum);
  902                                 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
  903                                     CSUM_PSEUDO_HDR;
  904                                 le->m_head->m_pkthdr.csum_data = 0xffff;
  905                                 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
  906                                         le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
  907                                 break;
  908                         default:
  909                                 break;
  910                         }
  911                         break;
  912                 default:
  913                         break;
  914                 }
  915         }
  916 
  917         /*
  918          * Break any chain, this is not set to NULL on the singleton
  919          * case m_nextpkt points to m_head. Other case set them
  920          * m_nextpkt to NULL in push_and_replace.
  921          */
  922         le->m_head->m_nextpkt = NULL;
  923         lc->lro_queued += le->m_head->m_pkthdr.lro_nsegs;
  924         (*lc->ifp->if_input)(lc->ifp, le->m_head);
  925 }
  926 
  927 static void
  928 tcp_set_entry_to_mbuf(struct lro_ctrl *lc, struct lro_entry *le,
  929     struct mbuf *m, struct tcphdr *th)
  930 {
  931         uint32_t *ts_ptr;
  932         uint16_t tcp_data_len;
  933         uint16_t tcp_opt_len;
  934 
  935         ts_ptr = (uint32_t *)(th + 1);
  936         tcp_opt_len = (th->th_off << 2);
  937         tcp_opt_len -= sizeof(*th);
  938 
  939         /* Check if there is a timestamp option. */
  940         if (tcp_opt_len == 0 ||
  941             __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
  942             *ts_ptr != TCP_LRO_TS_OPTION)) {
  943                 /* We failed to find the timestamp option. */
  944                 le->timestamp = 0;
  945         } else {
  946                 le->timestamp = 1;
  947                 le->tsval = ntohl(*(ts_ptr + 1));
  948                 le->tsecr = *(ts_ptr + 2);
  949         }
  950 
  951         tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
  952 
  953         /* Pull out TCP sequence numbers and window size. */
  954         le->next_seq = ntohl(th->th_seq) + tcp_data_len;
  955         le->ack_seq = th->th_ack;
  956         le->window = th->th_win;
  957         le->flags = tcp_get_flags(th);
  958         le->needs_merge = 0;
  959 
  960         /* Setup new data pointers. */
  961         le->m_head = m;
  962         le->m_tail = m_last(m);
  963 }
  964 
  965 static void
  966 tcp_push_and_replace(struct lro_ctrl *lc, struct lro_entry *le, struct mbuf *m)
  967 {
  968         struct lro_parser *pa;
  969 
  970         /*
  971          * Push up the stack of the current entry
  972          * and replace it with "m".
  973          */
  974         struct mbuf *msave;
  975 
  976         /* Grab off the next and save it */
  977         msave = le->m_head->m_nextpkt;
  978         le->m_head->m_nextpkt = NULL;
  979 
  980         /* Now push out the old entry */
  981         tcp_flush_out_entry(lc, le);
  982 
  983         /* Re-parse new header, should not fail. */
  984         pa = tcp_lro_parser(m, &le->outer, &le->inner, false);
  985         KASSERT(pa != NULL,
  986             ("tcp_push_and_replace: LRO parser failed on m=%p\n", m));
  987 
  988         /*
  989          * Now to replace the data properly in the entry
  990          * we have to reset the TCP header and
  991          * other fields.
  992          */
  993         tcp_set_entry_to_mbuf(lc, le, m, pa->tcp);
  994 
  995         /* Restore the next list */
  996         m->m_nextpkt = msave;
  997 }
  998 
  999 static void
 1000 tcp_lro_mbuf_append_pkthdr(struct lro_entry *le, const struct mbuf *p)
 1001 {
 1002         struct mbuf *m;
 1003         uint32_t csum;
 1004 
 1005         m = le->m_head;
 1006         if (m->m_pkthdr.lro_nsegs == 1) {
 1007                 /* Compute relative checksum. */
 1008                 csum = p->m_pkthdr.lro_tcp_d_csum;
 1009         } else {
 1010                 /* Merge TCP data checksums. */
 1011                 csum = (uint32_t)m->m_pkthdr.lro_tcp_d_csum +
 1012                     (uint32_t)p->m_pkthdr.lro_tcp_d_csum;
 1013                 while (csum > 0xffff)
 1014                         csum = (csum >> 16) + (csum & 0xffff);
 1015         }
 1016 
 1017         /* Update various counters. */
 1018         m->m_pkthdr.len += p->m_pkthdr.lro_tcp_d_len;
 1019         m->m_pkthdr.lro_tcp_d_csum = csum;
 1020         m->m_pkthdr.lro_tcp_d_len += p->m_pkthdr.lro_tcp_d_len;
 1021         m->m_pkthdr.lro_nsegs += p->m_pkthdr.lro_nsegs;
 1022         le->needs_merge = 1;
 1023 }
 1024 
 1025 static void
 1026 tcp_lro_condense(struct lro_ctrl *lc, struct lro_entry *le)
 1027 {
 1028         /*
 1029          * Walk through the mbuf chain we
 1030          * have on tap and compress/condense
 1031          * as required.
 1032          */
 1033         uint32_t *ts_ptr;
 1034         struct mbuf *m;
 1035         struct tcphdr *th;
 1036         uint32_t tcp_data_len_total;
 1037         uint32_t tcp_data_seg_total;
 1038         uint16_t tcp_data_len;
 1039         uint16_t tcp_opt_len;
 1040 
 1041         /*
 1042          * First we must check the lead (m_head)
 1043          * we must make sure that it is *not*
 1044          * something that should be sent up
 1045          * right away (sack etc).
 1046          */
 1047 again:
 1048         m = le->m_head->m_nextpkt;
 1049         if (m == NULL) {
 1050                 /* Just one left. */
 1051                 return;
 1052         }
 1053 
 1054         th = tcp_lro_get_th(m);
 1055         tcp_opt_len = (th->th_off << 2);
 1056         tcp_opt_len -= sizeof(*th);
 1057         ts_ptr = (uint32_t *)(th + 1);
 1058 
 1059         if (tcp_opt_len != 0 && __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
 1060             *ts_ptr != TCP_LRO_TS_OPTION)) {
 1061                 /*
 1062                  * Its not the timestamp. We can't
 1063                  * use this guy as the head.
 1064                  */
 1065                 le->m_head->m_nextpkt = m->m_nextpkt;
 1066                 tcp_push_and_replace(lc, le, m);
 1067                 goto again;
 1068         }
 1069         if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH)) != 0) {
 1070                 /*
 1071                  * Make sure that previously seen segments/ACKs are delivered
 1072                  * before this segment, e.g. FIN.
 1073                  */
 1074                 le->m_head->m_nextpkt = m->m_nextpkt;
 1075                 tcp_push_and_replace(lc, le, m);
 1076                 goto again;
 1077         }
 1078         while((m = le->m_head->m_nextpkt) != NULL) {
 1079                 /*
 1080                  * condense m into le, first
 1081                  * pull m out of the list.
 1082                  */
 1083                 le->m_head->m_nextpkt = m->m_nextpkt;
 1084                 m->m_nextpkt = NULL;
 1085                 /* Setup my data */
 1086                 tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
 1087                 th = tcp_lro_get_th(m);
 1088                 ts_ptr = (uint32_t *)(th + 1);
 1089                 tcp_opt_len = (th->th_off << 2);
 1090                 tcp_opt_len -= sizeof(*th);
 1091                 tcp_data_len_total = le->m_head->m_pkthdr.lro_tcp_d_len + tcp_data_len;
 1092                 tcp_data_seg_total = le->m_head->m_pkthdr.lro_nsegs + m->m_pkthdr.lro_nsegs;
 1093 
 1094                 if (tcp_data_seg_total >= lc->lro_ackcnt_lim ||
 1095                     tcp_data_len_total >= lc->lro_length_lim) {
 1096                         /* Flush now if appending will result in overflow. */
 1097                         tcp_push_and_replace(lc, le, m);
 1098                         goto again;
 1099                 }
 1100                 if (tcp_opt_len != 0 &&
 1101                     __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
 1102                     *ts_ptr != TCP_LRO_TS_OPTION)) {
 1103                         /*
 1104                          * Maybe a sack in the new one? We need to
 1105                          * start all over after flushing the
 1106                          * current le. We will go up to the beginning
 1107                          * and flush it (calling the replace again possibly
 1108                          * or just returning).
 1109                          */
 1110                         tcp_push_and_replace(lc, le, m);
 1111                         goto again;
 1112                 }
 1113                 if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH)) != 0) {
 1114                         tcp_push_and_replace(lc, le, m);
 1115                         goto again;
 1116                 }
 1117                 if (tcp_opt_len != 0) {
 1118                         uint32_t tsval = ntohl(*(ts_ptr + 1));
 1119                         /* Make sure timestamp values are increasing. */
 1120                         if (TSTMP_GT(le->tsval, tsval))  {
 1121                                 tcp_push_and_replace(lc, le, m);
 1122                                 goto again;
 1123                         }
 1124                         le->tsval = tsval;
 1125                         le->tsecr = *(ts_ptr + 2);
 1126                 }
 1127                 /* Try to append the new segment. */
 1128                 if (__predict_false(ntohl(th->th_seq) != le->next_seq ||
 1129                                     ((tcp_get_flags(th) & TH_ACK) !=
 1130                                       (le->flags & TH_ACK)) ||
 1131                                     (tcp_data_len == 0 &&
 1132                                      le->ack_seq == th->th_ack &&
 1133                                      le->window == th->th_win))) {
 1134                         /* Out of order packet, non-ACK + ACK or dup ACK. */
 1135                         tcp_push_and_replace(lc, le, m);
 1136                         goto again;
 1137                 }
 1138                 if (tcp_data_len != 0 ||
 1139                     SEQ_GT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
 1140                         le->next_seq += tcp_data_len;
 1141                         le->ack_seq = th->th_ack;
 1142                         le->window = th->th_win;
 1143                         le->needs_merge = 1;
 1144                 } else if (th->th_ack == le->ack_seq) {
 1145                         if (WIN_GT(th->th_win, le->window)) {
 1146                                 le->window = th->th_win;
 1147                                 le->needs_merge = 1;
 1148                         }
 1149                 }
 1150 
 1151                 if (tcp_data_len == 0) {
 1152                         m_freem(m);
 1153                         continue;
 1154                 }
 1155 
 1156                 /* Merge TCP data checksum and length to head mbuf. */
 1157                 tcp_lro_mbuf_append_pkthdr(le, m);
 1158 
 1159                 /*
 1160                  * Adjust the mbuf so that m_data points to the first byte of
 1161                  * the ULP payload.  Adjust the mbuf to avoid complications and
 1162                  * append new segment to existing mbuf chain.
 1163                  */
 1164                 m_adj(m, m->m_pkthdr.len - tcp_data_len);
 1165                 m_demote_pkthdr(m);
 1166                 le->m_tail->m_next = m;
 1167                 le->m_tail = m_last(m);
 1168         }
 1169 }
 1170 
 1171 #ifdef TCPHPTS
 1172 static void
 1173 tcp_queue_pkts(struct inpcb *inp, struct tcpcb *tp, struct lro_entry *le)
 1174 {
 1175         INP_WLOCK_ASSERT(inp);
 1176         if (tp->t_in_pkt == NULL) {
 1177                 /* Nothing yet there */
 1178                 tp->t_in_pkt = le->m_head;
 1179                 tp->t_tail_pkt = le->m_last_mbuf;
 1180         } else {
 1181                 /* Already some there */
 1182                 tp->t_tail_pkt->m_nextpkt = le->m_head;
 1183                 tp->t_tail_pkt = le->m_last_mbuf;
 1184         }
 1185         le->m_head = NULL;
 1186         le->m_last_mbuf = NULL;
 1187 }
 1188 
 1189 static struct mbuf *
 1190 tcp_lro_get_last_if_ackcmp(struct lro_ctrl *lc, struct lro_entry *le,
 1191     struct inpcb *inp, int32_t *new_m, bool can_append_old_cmp)
 1192 {
 1193         struct tcpcb *tp;
 1194         struct mbuf *m;
 1195 
 1196         tp = intotcpcb(inp);
 1197         if (__predict_false(tp == NULL))
 1198                 return (NULL);
 1199 
 1200         /* Look at the last mbuf if any in queue */
 1201         if (can_append_old_cmp) {
 1202                 m = tp->t_tail_pkt;
 1203                 if (m != NULL && (m->m_flags & M_ACKCMP) != 0) {
 1204                         if (M_TRAILINGSPACE(m) >= sizeof(struct tcp_ackent)) {
 1205                                 tcp_lro_log(tp, lc, le, NULL, 23, 0, 0, 0, 0);
 1206                                 *new_m = 0;
 1207                                 counter_u64_add(tcp_extra_mbuf, 1);
 1208                                 return (m);
 1209                         } else {
 1210                                 /* Mark we ran out of space */
 1211                                 inp->inp_flags2 |= INP_MBUF_L_ACKS;
 1212                         }
 1213                 }
 1214         }
 1215         /* Decide mbuf size. */
 1216         tcp_lro_log(tp, lc, le, NULL, 21, 0, 0, 0, 0);
 1217         if (inp->inp_flags2 & INP_MBUF_L_ACKS)
 1218                 m = m_getcl(M_NOWAIT, MT_DATA, M_ACKCMP | M_PKTHDR);
 1219         else
 1220                 m = m_gethdr(M_NOWAIT, MT_DATA);
 1221 
 1222         if (__predict_false(m == NULL)) {
 1223                 counter_u64_add(tcp_would_have_but, 1);
 1224                 return (NULL);
 1225         }
 1226         counter_u64_add(tcp_comp_total, 1);
 1227         m->m_pkthdr.rcvif = lc->ifp;
 1228         m->m_flags |= M_ACKCMP;
 1229         *new_m = 1;
 1230         return (m);
 1231 }
 1232 
 1233 static struct inpcb *
 1234 tcp_lro_lookup(struct ifnet *ifp, struct lro_parser *pa)
 1235 {
 1236         struct inpcb *inp;
 1237 
 1238         switch (pa->data.lro_type) {
 1239 #ifdef INET6
 1240         case LRO_TYPE_IPV6_TCP:
 1241                 inp = in6_pcblookup(&V_tcbinfo,
 1242                     &pa->data.s_addr.v6,
 1243                     pa->data.s_port,
 1244                     &pa->data.d_addr.v6,
 1245                     pa->data.d_port,
 1246                     INPLOOKUP_WLOCKPCB,
 1247                     ifp);
 1248                 break;
 1249 #endif
 1250 #ifdef INET
 1251         case LRO_TYPE_IPV4_TCP:
 1252                 inp = in_pcblookup(&V_tcbinfo,
 1253                     pa->data.s_addr.v4,
 1254                     pa->data.s_port,
 1255                     pa->data.d_addr.v4,
 1256                     pa->data.d_port,
 1257                     INPLOOKUP_WLOCKPCB,
 1258                     ifp);
 1259                 break;
 1260 #endif
 1261         default:
 1262                 inp = NULL;
 1263                 break;
 1264         }
 1265         return (inp);
 1266 }
 1267 
 1268 static inline bool
 1269 tcp_lro_ack_valid(struct mbuf *m, struct tcphdr *th, uint32_t **ppts, bool *other_opts)
 1270 {
 1271         /*
 1272          * This function returns two bits of valuable information.
 1273          * a) Is what is present capable of being ack-compressed,
 1274          *    we can ack-compress if there is no options or just
 1275          *    a timestamp option, and of course the th_flags must
 1276          *    be correct as well.
 1277          * b) Our other options present such as SACK. This is
 1278          *    used to determine if we want to wakeup or not.
 1279          */
 1280         bool ret = true;
 1281 
 1282         switch (th->th_off << 2) {
 1283         case (sizeof(*th) + TCPOLEN_TSTAMP_APPA):
 1284                 *ppts = (uint32_t *)(th + 1);
 1285                 /* Check if we have only one timestamp option. */
 1286                 if (**ppts == TCP_LRO_TS_OPTION)
 1287                         *other_opts = false;
 1288                 else {
 1289                         *other_opts = true;
 1290                         ret = false;
 1291                 }
 1292                 break;
 1293         case (sizeof(*th)):
 1294                 /* No options. */
 1295                 *ppts = NULL;
 1296                 *other_opts = false;
 1297                 break;
 1298         default:
 1299                 *ppts = NULL;
 1300                 *other_opts = true;
 1301                 ret = false;
 1302                 break;
 1303         }
 1304         /* For ACKCMP we only accept ACK, PUSH, ECE and CWR. */
 1305         if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH | TH_ECE | TH_CWR)) != 0)
 1306                 ret = false;
 1307         /* If it has data on it we cannot compress it */
 1308         if (m->m_pkthdr.lro_tcp_d_len)
 1309                 ret = false;
 1310 
 1311         /* ACK flag must be set. */
 1312         if (!(tcp_get_flags(th) & TH_ACK))
 1313                 ret = false;
 1314         return (ret);
 1315 }
 1316 
 1317 static int
 1318 tcp_lro_flush_tcphpts(struct lro_ctrl *lc, struct lro_entry *le)
 1319 {
 1320         struct inpcb *inp;
 1321         struct tcpcb *tp;
 1322         struct mbuf **pp, *cmp, *mv_to;
 1323         struct ifnet *lagg_ifp;
 1324         bool bpf_req, lagg_bpf_req, should_wake, can_append_old_cmp;
 1325 
 1326         /* Check if packet doesn't belongs to our network interface. */
 1327         if ((tcplro_stacks_wanting_mbufq == 0) ||
 1328             (le->outer.data.vlan_id != 0) ||
 1329             (le->inner.data.lro_type != LRO_TYPE_NONE))
 1330                 return (TCP_LRO_CANNOT);
 1331 
 1332 #ifdef INET6
 1333         /*
 1334          * Be proactive about unspecified IPv6 address in source. As
 1335          * we use all-zero to indicate unbounded/unconnected pcb,
 1336          * unspecified IPv6 address can be used to confuse us.
 1337          *
 1338          * Note that packets with unspecified IPv6 destination is
 1339          * already dropped in ip6_input.
 1340          */
 1341         if (__predict_false(le->outer.data.lro_type == LRO_TYPE_IPV6_TCP &&
 1342             IN6_IS_ADDR_UNSPECIFIED(&le->outer.data.s_addr.v6)))
 1343                 return (TCP_LRO_CANNOT);
 1344 
 1345         if (__predict_false(le->inner.data.lro_type == LRO_TYPE_IPV6_TCP &&
 1346             IN6_IS_ADDR_UNSPECIFIED(&le->inner.data.s_addr.v6)))
 1347                 return (TCP_LRO_CANNOT);
 1348 #endif
 1349         /* Lookup inp, if any. */
 1350         inp = tcp_lro_lookup(lc->ifp,
 1351             (le->inner.data.lro_type == LRO_TYPE_NONE) ? &le->outer : &le->inner);
 1352         if (inp == NULL)
 1353                 return (TCP_LRO_CANNOT);
 1354 
 1355         counter_u64_add(tcp_inp_lro_locks_taken, 1);
 1356 
 1357         /* Get TCP control structure. */
 1358         tp = intotcpcb(inp);
 1359 
 1360         /* Check if the inp is dead, Jim. */
 1361         if (tp->t_state == TCPS_TIME_WAIT) {
 1362                 INP_WUNLOCK(inp);
 1363                 return (TCP_LRO_CANNOT);
 1364         }
 1365         if ((inp->inp_irq_cpu_set == 0)  && (lc->lro_cpu_is_set == 1)) {
 1366                 inp->inp_irq_cpu = lc->lro_last_cpu;
 1367                 inp->inp_irq_cpu_set = 1;
 1368         }
 1369         /* Check if the transport doesn't support the needed optimizations. */
 1370         if ((inp->inp_flags2 & (INP_SUPPORTS_MBUFQ | INP_MBUF_ACKCMP)) == 0) {
 1371                 INP_WUNLOCK(inp);
 1372                 return (TCP_LRO_CANNOT);
 1373         }
 1374 
 1375         if (inp->inp_flags2 & INP_MBUF_QUEUE_READY)
 1376                 should_wake = false;
 1377         else
 1378                 should_wake = true;
 1379         /* Check if packets should be tapped to BPF. */
 1380         bpf_req = bpf_peers_present(lc->ifp->if_bpf);
 1381         lagg_bpf_req = false;
 1382         lagg_ifp = NULL;
 1383         if (lc->ifp->if_type == IFT_IEEE8023ADLAG ||
 1384             lc->ifp->if_type == IFT_INFINIBANDLAG) {
 1385                 struct lagg_port *lp = lc->ifp->if_lagg;
 1386                 struct lagg_softc *sc = lp->lp_softc;
 1387 
 1388                 lagg_ifp = sc->sc_ifp;
 1389                 if (lagg_ifp != NULL)
 1390                         lagg_bpf_req = bpf_peers_present(lagg_ifp->if_bpf);
 1391         }
 1392 
 1393         /* Strip and compress all the incoming packets. */
 1394         can_append_old_cmp = true;
 1395         cmp = NULL;
 1396         for (pp = &le->m_head; *pp != NULL; ) {
 1397                 mv_to = NULL;
 1398                 if (do_bpf_strip_and_compress(inp, lc, le, pp,
 1399                         &cmp, &mv_to, &should_wake, bpf_req,
 1400                         lagg_bpf_req, lagg_ifp, can_append_old_cmp) == false) {
 1401                         /* Advance to next mbuf. */
 1402                         pp = &(*pp)->m_nextpkt;
 1403                         /*
 1404                          * Once we have appended we can't look in the pending
 1405                          * inbound packets for a compressed ack to append to.
 1406                          */
 1407                         can_append_old_cmp = false;
 1408                         /*
 1409                          * Once we append we also need to stop adding to any
 1410                          * compressed ack we were remembering. A new cmp
 1411                          * ack will be required.
 1412                          */
 1413                         cmp = NULL;
 1414                         tcp_lro_log(tp, lc, le, NULL, 25, 0, 0, 0, 0);
 1415                 } else if (mv_to != NULL) {
 1416                         /* We are asked to move pp up */
 1417                         pp = &mv_to->m_nextpkt;
 1418                         tcp_lro_log(tp, lc, le, NULL, 24, 0, 0, 0, 0);
 1419                 } else
 1420                         tcp_lro_log(tp, lc, le, NULL, 26, 0, 0, 0, 0);
 1421         }
 1422         /* Update "m_last_mbuf", if any. */
 1423         if (pp == &le->m_head)
 1424                 le->m_last_mbuf = *pp;
 1425         else
 1426                 le->m_last_mbuf = __containerof(pp, struct mbuf, m_nextpkt);
 1427 
 1428         /* Check if any data mbufs left. */
 1429         if (le->m_head != NULL) {
 1430                 counter_u64_add(tcp_inp_lro_direct_queue, 1);
 1431                 tcp_lro_log(tp, lc, le, NULL, 22, 1, inp->inp_flags2, 0, 1);
 1432                 tcp_queue_pkts(inp, tp, le);
 1433         }
 1434         if (should_wake) {
 1435                 /* Wakeup */
 1436                 counter_u64_add(tcp_inp_lro_wokeup_queue, 1);
 1437                 if ((*tp->t_fb->tfb_do_queued_segments)(inp->inp_socket, tp, 0))
 1438                         inp = NULL;
 1439         }
 1440         if (inp != NULL)
 1441                 INP_WUNLOCK(inp);
 1442         return (0);     /* Success. */
 1443 }
 1444 #endif
 1445 
 1446 void
 1447 tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le)
 1448 {
 1449         /* Only optimise if there are multiple packets waiting. */
 1450 #ifdef TCPHPTS
 1451         int error;
 1452 #endif
 1453 
 1454         NET_EPOCH_ASSERT();
 1455 #ifdef TCPHPTS
 1456         CURVNET_SET(lc->ifp->if_vnet);
 1457         error = tcp_lro_flush_tcphpts(lc, le);
 1458         CURVNET_RESTORE();
 1459         if (error != 0) {
 1460 #endif
 1461                 tcp_lro_condense(lc, le);
 1462                 tcp_flush_out_entry(lc, le);
 1463 #ifdef TCPHPTS
 1464         }
 1465 #endif
 1466         lc->lro_flushed++;
 1467         bzero(le, sizeof(*le));
 1468         LIST_INSERT_HEAD(&lc->lro_free, le, next);
 1469 }
 1470 
 1471 #ifdef HAVE_INLINE_FLSLL
 1472 #define tcp_lro_msb_64(x) (1ULL << (flsll(x) - 1))
 1473 #else
 1474 static inline uint64_t
 1475 tcp_lro_msb_64(uint64_t x)
 1476 {
 1477         x |= (x >> 1);
 1478         x |= (x >> 2);
 1479         x |= (x >> 4);
 1480         x |= (x >> 8);
 1481         x |= (x >> 16);
 1482         x |= (x >> 32);
 1483         return (x & ~(x >> 1));
 1484 }
 1485 #endif
 1486 
 1487 /*
 1488  * The tcp_lro_sort() routine is comparable to qsort(), except it has
 1489  * a worst case complexity limit of O(MIN(N,64)*N), where N is the
 1490  * number of elements to sort and 64 is the number of sequence bits
 1491  * available. The algorithm is bit-slicing the 64-bit sequence number,
 1492  * sorting one bit at a time from the most significant bit until the
 1493  * least significant one, skipping the constant bits. This is
 1494  * typically called a radix sort.
 1495  */
 1496 static void
 1497 tcp_lro_sort(struct lro_mbuf_sort *parray, uint32_t size)
 1498 {
 1499         struct lro_mbuf_sort temp;
 1500         uint64_t ones;
 1501         uint64_t zeros;
 1502         uint32_t x;
 1503         uint32_t y;
 1504 
 1505 repeat:
 1506         /* for small arrays insertion sort is faster */
 1507         if (size <= 12) {
 1508                 for (x = 1; x < size; x++) {
 1509                         temp = parray[x];
 1510                         for (y = x; y > 0 && temp.seq < parray[y - 1].seq; y--)
 1511                                 parray[y] = parray[y - 1];
 1512                         parray[y] = temp;
 1513                 }
 1514                 return;
 1515         }
 1516 
 1517         /* compute sequence bits which are constant */
 1518         ones = 0;
 1519         zeros = 0;
 1520         for (x = 0; x != size; x++) {
 1521                 ones |= parray[x].seq;
 1522                 zeros |= ~parray[x].seq;
 1523         }
 1524 
 1525         /* compute bits which are not constant into "ones" */
 1526         ones &= zeros;
 1527         if (ones == 0)
 1528                 return;
 1529 
 1530         /* pick the most significant bit which is not constant */
 1531         ones = tcp_lro_msb_64(ones);
 1532 
 1533         /*
 1534          * Move entries having cleared sequence bits to the beginning
 1535          * of the array:
 1536          */
 1537         for (x = y = 0; y != size; y++) {
 1538                 /* skip set bits */
 1539                 if (parray[y].seq & ones)
 1540                         continue;
 1541                 /* swap entries */
 1542                 temp = parray[x];
 1543                 parray[x] = parray[y];
 1544                 parray[y] = temp;
 1545                 x++;
 1546         }
 1547 
 1548         KASSERT(x != 0 && x != size, ("Memory is corrupted\n"));
 1549 
 1550         /* sort zeros */
 1551         tcp_lro_sort(parray, x);
 1552 
 1553         /* sort ones */
 1554         parray += x;
 1555         size -= x;
 1556         goto repeat;
 1557 }
 1558 
 1559 void
 1560 tcp_lro_flush_all(struct lro_ctrl *lc)
 1561 {
 1562         uint64_t seq;
 1563         uint64_t nseq;
 1564         unsigned x;
 1565 
 1566         NET_EPOCH_ASSERT();
 1567         /* check if no mbufs to flush */
 1568         if (lc->lro_mbuf_count == 0)
 1569                 goto done;
 1570         if (lc->lro_cpu_is_set == 0) {
 1571                 if (lc->lro_last_cpu == curcpu) {
 1572                         lc->lro_cnt_of_same_cpu++;
 1573                         /* Have we reached the threshold to declare a cpu? */
 1574                         if (lc->lro_cnt_of_same_cpu > tcp_lro_cpu_set_thresh)
 1575                                 lc->lro_cpu_is_set = 1;
 1576                 } else {
 1577                         lc->lro_last_cpu = curcpu;
 1578                         lc->lro_cnt_of_same_cpu = 0;
 1579                 }
 1580         }
 1581         CURVNET_SET(lc->ifp->if_vnet);
 1582 
 1583         /* get current time */
 1584         binuptime(&lc->lro_last_queue_time);
 1585 
 1586         /* sort all mbufs according to stream */
 1587         tcp_lro_sort(lc->lro_mbuf_data, lc->lro_mbuf_count);
 1588 
 1589         /* input data into LRO engine, stream by stream */
 1590         seq = 0;
 1591         for (x = 0; x != lc->lro_mbuf_count; x++) {
 1592                 struct mbuf *mb;
 1593 
 1594                 /* get mbuf */
 1595                 mb = lc->lro_mbuf_data[x].mb;
 1596 
 1597                 /* get sequence number, masking away the packet index */
 1598                 nseq = lc->lro_mbuf_data[x].seq & (-1ULL << 24);
 1599 
 1600                 /* check for new stream */
 1601                 if (seq != nseq) {
 1602                         seq = nseq;
 1603 
 1604                         /* flush active streams */
 1605                         tcp_lro_rx_done(lc);
 1606                 }
 1607 
 1608                 /* add packet to LRO engine */
 1609                 if (tcp_lro_rx_common(lc, mb, 0, false) != 0) {
 1610                         /* Flush anything we have acummulated */
 1611                         tcp_lro_flush_active(lc);
 1612                         /* input packet to network layer */
 1613                         (*lc->ifp->if_input)(lc->ifp, mb);
 1614                         lc->lro_queued++;
 1615                         lc->lro_flushed++;
 1616                 }
 1617         }
 1618         CURVNET_RESTORE();
 1619 done:
 1620         /* flush active streams */
 1621         tcp_lro_rx_done(lc);
 1622 
 1623 #ifdef TCPHPTS
 1624         tcp_run_hpts();
 1625 #endif
 1626         lc->lro_mbuf_count = 0;
 1627 }
 1628 
 1629 #ifdef TCPHPTS
 1630 static void
 1631 build_ack_entry(struct tcp_ackent *ae, struct tcphdr *th, struct mbuf *m,
 1632     uint32_t *ts_ptr, uint16_t iptos)
 1633 {
 1634         /*
 1635          * Given a TCP ACK, summarize it down into the small TCP ACK
 1636          * entry.
 1637          */
 1638         ae->timestamp = m->m_pkthdr.rcv_tstmp;
 1639         ae->flags = 0;
 1640         if (m->m_flags & M_TSTMP_LRO)
 1641                 ae->flags |= TSTMP_LRO;
 1642         else if (m->m_flags & M_TSTMP)
 1643                 ae->flags |= TSTMP_HDWR;
 1644         ae->seq = ntohl(th->th_seq);
 1645         ae->ack = ntohl(th->th_ack);
 1646         ae->flags |= tcp_get_flags(th);
 1647         if (ts_ptr != NULL) {
 1648                 ae->ts_value = ntohl(ts_ptr[1]);
 1649                 ae->ts_echo = ntohl(ts_ptr[2]);
 1650                 ae->flags |= HAS_TSTMP;
 1651         }
 1652         ae->win = ntohs(th->th_win);
 1653         ae->codepoint = iptos;
 1654 }
 1655 
 1656 /*
 1657  * Do BPF tap for either ACK_CMP packets or MBUF QUEUE type packets
 1658  * and strip all, but the IPv4/IPv6 header.
 1659  */
 1660 static bool
 1661 do_bpf_strip_and_compress(struct inpcb *inp, struct lro_ctrl *lc,
 1662     struct lro_entry *le, struct mbuf **pp, struct mbuf **cmp, struct mbuf **mv_to,
 1663     bool *should_wake, bool bpf_req, bool lagg_bpf_req, struct ifnet *lagg_ifp, bool can_append_old_cmp)
 1664 {
 1665         union {
 1666                 void *ptr;
 1667                 struct ip *ip4;
 1668                 struct ip6_hdr *ip6;
 1669         } l3;
 1670         struct mbuf *m;
 1671         struct mbuf *nm;
 1672         struct tcphdr *th;
 1673         struct tcp_ackent *ack_ent;
 1674         uint32_t *ts_ptr;
 1675         int32_t n_mbuf;
 1676         bool other_opts, can_compress;
 1677         uint8_t lro_type;
 1678         uint16_t iptos;
 1679         int tcp_hdr_offset;
 1680         int idx;
 1681 
 1682         /* Get current mbuf. */
 1683         m = *pp;
 1684 
 1685         /* Let the BPF see the packet */
 1686         if (__predict_false(bpf_req))
 1687                 ETHER_BPF_MTAP(lc->ifp, m);
 1688 
 1689         if (__predict_false(lagg_bpf_req))
 1690                 ETHER_BPF_MTAP(lagg_ifp, m);
 1691 
 1692         tcp_hdr_offset = m->m_pkthdr.lro_tcp_h_off;
 1693         lro_type = le->inner.data.lro_type;
 1694         switch (lro_type) {
 1695         case LRO_TYPE_NONE:
 1696                 lro_type = le->outer.data.lro_type;
 1697                 switch (lro_type) {
 1698                 case LRO_TYPE_IPV4_TCP:
 1699                         tcp_hdr_offset -= sizeof(*le->outer.ip4);
 1700                         m->m_pkthdr.lro_etype = ETHERTYPE_IP;
 1701                         break;
 1702                 case LRO_TYPE_IPV6_TCP:
 1703                         tcp_hdr_offset -= sizeof(*le->outer.ip6);
 1704                         m->m_pkthdr.lro_etype = ETHERTYPE_IPV6;
 1705                         break;
 1706                 default:
 1707                         goto compressed;
 1708                 }
 1709                 break;
 1710         case LRO_TYPE_IPV4_TCP:
 1711                 tcp_hdr_offset -= sizeof(*le->outer.ip4);
 1712                 m->m_pkthdr.lro_etype = ETHERTYPE_IP;
 1713                 break;
 1714         case LRO_TYPE_IPV6_TCP:
 1715                 tcp_hdr_offset -= sizeof(*le->outer.ip6);
 1716                 m->m_pkthdr.lro_etype = ETHERTYPE_IPV6;
 1717                 break;
 1718         default:
 1719                 goto compressed;
 1720         }
 1721 
 1722         MPASS(tcp_hdr_offset >= 0);
 1723 
 1724         m_adj(m, tcp_hdr_offset);
 1725         m->m_flags |= M_LRO_EHDRSTRP;
 1726         m->m_flags &= ~M_ACKCMP;
 1727         m->m_pkthdr.lro_tcp_h_off -= tcp_hdr_offset;
 1728 
 1729         th = tcp_lro_get_th(m);
 1730 
 1731         th->th_sum = 0;         /* TCP checksum is valid. */
 1732 
 1733         /* Check if ACK can be compressed */
 1734         can_compress = tcp_lro_ack_valid(m, th, &ts_ptr, &other_opts);
 1735 
 1736         /* Now lets look at the should wake states */
 1737         if ((other_opts == true) &&
 1738             ((inp->inp_flags2 & INP_DONT_SACK_QUEUE) == 0)) {
 1739                 /*
 1740                  * If there are other options (SACK?) and the
 1741                  * tcp endpoint has not expressly told us it does
 1742                  * not care about SACKS, then we should wake up.
 1743                  */
 1744                 *should_wake = true;
 1745         }
 1746         /* Is the ack compressable? */
 1747         if (can_compress == false)
 1748                 goto done;
 1749         /* Does the TCP endpoint support ACK compression? */
 1750         if ((inp->inp_flags2 & INP_MBUF_ACKCMP) == 0)
 1751                 goto done;
 1752 
 1753         /* Lets get the TOS/traffic class field */
 1754         l3.ptr = mtod(m, void *);
 1755         switch (lro_type) {
 1756         case LRO_TYPE_IPV4_TCP:
 1757                 iptos = l3.ip4->ip_tos;
 1758                 break;
 1759         case LRO_TYPE_IPV6_TCP:
 1760                 iptos = IPV6_TRAFFIC_CLASS(l3.ip6);
 1761                 break;
 1762         default:
 1763                 iptos = 0;      /* Keep compiler happy. */
 1764                 break;
 1765         }
 1766         /* Now lets get space if we don't have some already */
 1767         if (*cmp == NULL) {
 1768 new_one:
 1769                 nm = tcp_lro_get_last_if_ackcmp(lc, le, inp, &n_mbuf, can_append_old_cmp);
 1770                 if (__predict_false(nm == NULL))
 1771                         goto done;
 1772                 *cmp = nm;
 1773                 if (n_mbuf) {
 1774                         /*
 1775                          *  Link in the new cmp ack to our in-order place,
 1776                          * first set our cmp ack's next to where we are.
 1777                          */
 1778                         nm->m_nextpkt = m;
 1779                         (*pp) = nm;
 1780                         /*
 1781                          * Set it up so mv_to is advanced to our
 1782                          * compressed ack. This way the caller can
 1783                          * advance pp to the right place.
 1784                          */
 1785                         *mv_to = nm;
 1786                         /*
 1787                          * Advance it here locally as well.
 1788                          */
 1789                         pp = &nm->m_nextpkt;
 1790                 }
 1791         } else {
 1792                 /* We have one already we are working on */
 1793                 nm = *cmp;
 1794                 if (M_TRAILINGSPACE(nm) < sizeof(struct tcp_ackent)) {
 1795                         /* We ran out of space */
 1796                         inp->inp_flags2 |= INP_MBUF_L_ACKS;
 1797                         goto new_one;
 1798                 }
 1799         }
 1800         MPASS(M_TRAILINGSPACE(nm) >= sizeof(struct tcp_ackent));
 1801         counter_u64_add(tcp_inp_lro_compressed, 1);
 1802         le->compressed++;
 1803         /* We can add in to the one on the tail */
 1804         ack_ent = mtod(nm, struct tcp_ackent *);
 1805         idx = (nm->m_len / sizeof(struct tcp_ackent));
 1806         build_ack_entry(&ack_ent[idx], th, m, ts_ptr, iptos);
 1807 
 1808         /* Bump the size of both pkt-hdr and len */
 1809         nm->m_len += sizeof(struct tcp_ackent);
 1810         nm->m_pkthdr.len += sizeof(struct tcp_ackent);
 1811 compressed:
 1812         /* Advance to next mbuf before freeing. */
 1813         *pp = m->m_nextpkt;
 1814         m->m_nextpkt = NULL;
 1815         m_freem(m);
 1816         return (true);
 1817 done:
 1818         counter_u64_add(tcp_uncomp_total, 1);
 1819         le->uncompressed++;
 1820         return (false);
 1821 }
 1822 #endif
 1823 
 1824 static struct lro_head *
 1825 tcp_lro_rx_get_bucket(struct lro_ctrl *lc, struct mbuf *m, struct lro_parser *parser)
 1826 {
 1827         u_long hash;
 1828 
 1829         if (M_HASHTYPE_ISHASH(m)) {
 1830                 hash = m->m_pkthdr.flowid;
 1831         } else {
 1832                 for (unsigned i = hash = 0; i != LRO_RAW_ADDRESS_MAX; i++)
 1833                         hash += parser->data.raw[i];
 1834         }
 1835         return (&lc->lro_hash[hash % lc->lro_hashsz]);
 1836 }
 1837 
 1838 static int
 1839 tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum, bool use_hash)
 1840 {
 1841         struct lro_parser pi;   /* inner address data */
 1842         struct lro_parser po;   /* outer address data */
 1843         struct lro_parser *pa;  /* current parser for TCP stream */
 1844         struct lro_entry *le;
 1845         struct lro_head *bucket;
 1846         struct tcphdr *th;
 1847         int tcp_data_len;
 1848         int tcp_opt_len;
 1849         int error;
 1850         uint16_t tcp_data_sum;
 1851 
 1852 #ifdef INET
 1853         /* Quickly decide if packet cannot be LRO'ed */
 1854         if (__predict_false(V_ipforwarding != 0))
 1855                 return (TCP_LRO_CANNOT);
 1856 #endif
 1857 #ifdef INET6
 1858         /* Quickly decide if packet cannot be LRO'ed */
 1859         if (__predict_false(V_ip6_forwarding != 0))
 1860                 return (TCP_LRO_CANNOT);
 1861 #endif
 1862         if (((m->m_pkthdr.csum_flags & (CSUM_DATA_VALID | CSUM_PSEUDO_HDR)) !=
 1863              ((CSUM_DATA_VALID | CSUM_PSEUDO_HDR))) || 
 1864             (m->m_pkthdr.csum_data != 0xffff)) {
 1865                 /* 
 1866                  * The checksum either did not have hardware offload
 1867                  * or it was a bad checksum. We can't LRO such
 1868                  * a packet.
 1869                  */
 1870                 counter_u64_add(tcp_bad_csums, 1);
 1871                 return (TCP_LRO_CANNOT);
 1872         }
 1873         /* We expect a contiguous header [eh, ip, tcp]. */
 1874         pa = tcp_lro_parser(m, &po, &pi, true);
 1875         if (__predict_false(pa == NULL))
 1876                 return (TCP_LRO_NOT_SUPPORTED);
 1877 
 1878         /* We don't expect any padding. */
 1879         error = tcp_lro_trim_mbuf_chain(m, pa);
 1880         if (__predict_false(error != 0))
 1881                 return (error);
 1882 
 1883 #ifdef INET
 1884         switch (pa->data.lro_type) {
 1885         case LRO_TYPE_IPV4_TCP:
 1886                 error = tcp_lro_rx_ipv4(lc, m, pa->ip4);
 1887                 if (__predict_false(error != 0))
 1888                         return (error);
 1889                 break;
 1890         default:
 1891                 break;
 1892         }
 1893 #endif
 1894         /* If no hardware or arrival stamp on the packet add timestamp */
 1895         if ((m->m_flags & (M_TSTMP_LRO | M_TSTMP)) == 0) {
 1896                 m->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time); 
 1897                 m->m_flags |= M_TSTMP_LRO;
 1898         }
 1899 
 1900         /* Get pointer to TCP header. */
 1901         th = pa->tcp;
 1902 
 1903         /* Don't process SYN packets. */
 1904         if (__predict_false(tcp_get_flags(th) & TH_SYN))
 1905                 return (TCP_LRO_CANNOT);
 1906 
 1907         /* Get total TCP header length and compute payload length. */
 1908         tcp_opt_len = (th->th_off << 2);
 1909         tcp_data_len = m->m_pkthdr.len - ((uint8_t *)th -
 1910             (uint8_t *)m->m_data) - tcp_opt_len;
 1911         tcp_opt_len -= sizeof(*th);
 1912 
 1913         /* Don't process invalid TCP headers. */
 1914         if (__predict_false(tcp_opt_len < 0 || tcp_data_len < 0))
 1915                 return (TCP_LRO_CANNOT);
 1916 
 1917         /* Compute TCP data only checksum. */
 1918         if (tcp_data_len == 0)
 1919                 tcp_data_sum = 0;       /* no data, no checksum */
 1920         else if (__predict_false(csum != 0))
 1921                 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~csum);
 1922         else
 1923                 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~th->th_sum);
 1924 
 1925         /* Save TCP info in mbuf. */
 1926         m->m_nextpkt = NULL;
 1927         m->m_pkthdr.rcvif = lc->ifp;
 1928         m->m_pkthdr.lro_tcp_d_csum = tcp_data_sum;
 1929         m->m_pkthdr.lro_tcp_d_len = tcp_data_len;
 1930         m->m_pkthdr.lro_tcp_h_off = ((uint8_t *)th - (uint8_t *)m->m_data);
 1931         m->m_pkthdr.lro_nsegs = 1;
 1932 
 1933         /* Get hash bucket. */
 1934         if (!use_hash) {
 1935                 bucket = &lc->lro_hash[0];
 1936         } else {
 1937                 bucket = tcp_lro_rx_get_bucket(lc, m, pa);
 1938         }
 1939 
 1940         /* Try to find a matching previous segment. */
 1941         LIST_FOREACH(le, bucket, hash_next) {
 1942                 /* Compare addresses and ports. */
 1943                 if (lro_address_compare(&po.data, &le->outer.data) == false ||
 1944                     lro_address_compare(&pi.data, &le->inner.data) == false)
 1945                         continue;
 1946 
 1947                 /* Check if no data and old ACK. */
 1948                 if (tcp_data_len == 0 &&
 1949                     SEQ_LT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
 1950                         m_freem(m);
 1951                         return (0);
 1952                 }
 1953 
 1954                 /* Mark "m" in the last spot. */
 1955                 le->m_last_mbuf->m_nextpkt = m;
 1956                 /* Now set the tail to "m". */
 1957                 le->m_last_mbuf = m;
 1958                 return (0);
 1959         }
 1960 
 1961         /* Try to find an empty slot. */
 1962         if (LIST_EMPTY(&lc->lro_free))
 1963                 return (TCP_LRO_NO_ENTRIES);
 1964 
 1965         /* Start a new segment chain. */
 1966         le = LIST_FIRST(&lc->lro_free);
 1967         LIST_REMOVE(le, next);
 1968         tcp_lro_active_insert(lc, bucket, le);
 1969 
 1970         /* Make sure the headers are set. */
 1971         le->inner = pi;
 1972         le->outer = po;
 1973 
 1974         /* Store time this entry was allocated. */
 1975         le->alloc_time = lc->lro_last_queue_time;
 1976 
 1977         tcp_set_entry_to_mbuf(lc, le, m, th);
 1978 
 1979         /* Now set the tail to "m". */
 1980         le->m_last_mbuf = m;
 1981 
 1982         return (0);
 1983 }
 1984 
 1985 int
 1986 tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
 1987 {
 1988         int error;
 1989 
 1990         if (((m->m_pkthdr.csum_flags & (CSUM_DATA_VALID | CSUM_PSEUDO_HDR)) !=
 1991              ((CSUM_DATA_VALID | CSUM_PSEUDO_HDR))) || 
 1992             (m->m_pkthdr.csum_data != 0xffff)) {
 1993                 /* 
 1994                  * The checksum either did not have hardware offload
 1995                  * or it was a bad checksum. We can't LRO such
 1996                  * a packet.
 1997                  */
 1998                 counter_u64_add(tcp_bad_csums, 1);
 1999                 return (TCP_LRO_CANNOT);
 2000         }
 2001         /* get current time */
 2002         binuptime(&lc->lro_last_queue_time);
 2003         CURVNET_SET(lc->ifp->if_vnet);
 2004         error = tcp_lro_rx_common(lc, m, csum, true);
 2005         if (__predict_false(error != 0)) {
 2006                 /*
 2007                  * Flush anything we have acummulated
 2008                  * ahead of this packet that can't
 2009                  * be LRO'd. This preserves order.
 2010                  */
 2011                 tcp_lro_flush_active(lc);
 2012         }
 2013         CURVNET_RESTORE();
 2014 
 2015         return (error);
 2016 }
 2017 
 2018 void
 2019 tcp_lro_queue_mbuf(struct lro_ctrl *lc, struct mbuf *mb)
 2020 {
 2021         NET_EPOCH_ASSERT();
 2022         /* sanity checks */
 2023         if (__predict_false(lc->ifp == NULL || lc->lro_mbuf_data == NULL ||
 2024             lc->lro_mbuf_max == 0)) {
 2025                 /* packet drop */
 2026                 m_freem(mb);
 2027                 return;
 2028         }
 2029 
 2030         /* check if packet is not LRO capable */
 2031         if (__predict_false((lc->ifp->if_capenable & IFCAP_LRO) == 0)) {
 2032                 /* input packet to network layer */
 2033                 (*lc->ifp->if_input) (lc->ifp, mb);
 2034                 return;
 2035         }
 2036 
 2037         /* If no hardware or arrival stamp on the packet add timestamp */
 2038         if ((tcplro_stacks_wanting_mbufq > 0) &&
 2039             (tcp_less_accurate_lro_ts == 0) &&
 2040             ((mb->m_flags & M_TSTMP) == 0)) {
 2041                 /* Add in an LRO time since no hardware */
 2042                 binuptime(&lc->lro_last_queue_time);
 2043                 mb->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time); 
 2044                 mb->m_flags |= M_TSTMP_LRO;
 2045         }
 2046 
 2047         /* create sequence number */
 2048         lc->lro_mbuf_data[lc->lro_mbuf_count].seq =
 2049             (((uint64_t)M_HASHTYPE_GET(mb)) << 56) |
 2050             (((uint64_t)mb->m_pkthdr.flowid) << 24) |
 2051             ((uint64_t)lc->lro_mbuf_count);
 2052 
 2053         /* enter mbuf */
 2054         lc->lro_mbuf_data[lc->lro_mbuf_count].mb = mb;
 2055 
 2056         /* flush if array is full */
 2057         if (__predict_false(++lc->lro_mbuf_count == lc->lro_mbuf_max))
 2058                 tcp_lro_flush_all(lc);
 2059 }
 2060 
 2061 /* end */
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FreeBSD/Linux Kernel Cross Reference sys/netinet/tcp_lro.c

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