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

     /*-
      * SPDX-License-Identifier: BSD-3-Clause
      *
      * Copyright (c) 1982, 1986, 1991, 1993, 1995
      *      The Regents of the University of California.
      * Copyright (c) 2007-2009 Robert N. M. Watson
      * Copyright (c) 2010-2011 Juniper Networks, Inc.
      * All rights reserved.
      *
     * Portions of this software were developed by Robert N. M. Watson under
     * contract to Juniper Networks, Inc.
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. 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.
     * 3. Neither the name of the University 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 REGENTS 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 REGENTS 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.
     *
     *      @(#)in_pcb.c    8.4 (Berkeley) 5/24/95
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include "opt_ddb.h"
    #include "opt_ipsec.h"
    #include "opt_inet.h"
    #include "opt_inet6.h"
    #include "opt_ratelimit.h"
    #include "opt_pcbgroup.h"
    #include "opt_rss.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/lock.h>
    #include <sys/malloc.h>
    #include <sys/mbuf.h>
    #include <sys/callout.h>
    #include <sys/eventhandler.h>
    #include <sys/domain.h>
    #include <sys/protosw.h>
    #include <sys/rmlock.h>
    #include <sys/smp.h>
    #include <sys/socket.h>
    #include <sys/socketvar.h>
    #include <sys/sockio.h>
    #include <sys/priv.h>
    #include <sys/proc.h>
    #include <sys/refcount.h>
    #include <sys/jail.h>
    #include <sys/kernel.h>
    #include <sys/sysctl.h>
    
    #ifdef DDB
    #include <ddb/ddb.h>
    #endif
    
    #include <vm/uma.h>
    
    #include <net/if.h>
    #include <net/if_var.h>
    #include <net/if_types.h>
    #include <net/if_llatbl.h>
    #include <net/route.h>
    #include <net/rss_config.h>
    #include <net/vnet.h>
    
    #if defined(INET) || defined(INET6)
    #include <netinet/in.h>
    #include <netinet/in_pcb.h>
    #ifdef INET
    #include <netinet/in_var.h>
    #endif
    #include <netinet/ip_var.h>
    #include <netinet/tcp_var.h>
    #ifdef TCPHPTS
    #include <netinet/tcp_hpts.h>
    #endif
    #include <netinet/udp.h>
    #include <netinet/udp_var.h>
    #ifdef INET6
   #include <netinet/ip6.h>
   #include <netinet6/in6_pcb.h>
   #include <netinet6/in6_var.h>
   #include <netinet6/ip6_var.h>
   #endif /* INET6 */
   #endif
   
   #include <netipsec/ipsec_support.h>
   
   #include <security/mac/mac_framework.h>
   
   #define INPCBLBGROUP_SIZMIN     8
   #define INPCBLBGROUP_SIZMAX     256
   
   static struct callout   ipport_tick_callout;
   
   /*
    * These configure the range of local port addresses assigned to
    * "unspecified" outgoing connections/packets/whatever.
    */
   VNET_DEFINE(int, ipport_lowfirstauto) = IPPORT_RESERVED - 1;    /* 1023 */
   VNET_DEFINE(int, ipport_lowlastauto) = IPPORT_RESERVEDSTART;    /* 600 */
   VNET_DEFINE(int, ipport_firstauto) = IPPORT_EPHEMERALFIRST;     /* 10000 */
   VNET_DEFINE(int, ipport_lastauto) = IPPORT_EPHEMERALLAST;       /* 65535 */
   VNET_DEFINE(int, ipport_hifirstauto) = IPPORT_HIFIRSTAUTO;      /* 49152 */
   VNET_DEFINE(int, ipport_hilastauto) = IPPORT_HILASTAUTO;        /* 65535 */
   
   /*
    * Reserved ports accessible only to root. There are significant
    * security considerations that must be accounted for when changing these,
    * but the security benefits can be great. Please be careful.
    */
   VNET_DEFINE(int, ipport_reservedhigh) = IPPORT_RESERVED - 1;    /* 1023 */
   VNET_DEFINE(int, ipport_reservedlow);
   
   /* Variables dealing with random ephemeral port allocation. */
   VNET_DEFINE(int, ipport_randomized) = 1;        /* user controlled via sysctl */
   VNET_DEFINE(int, ipport_randomcps) = 10;        /* user controlled via sysctl */
   VNET_DEFINE(int, ipport_randomtime) = 45;       /* user controlled via sysctl */
   VNET_DEFINE(int, ipport_stoprandom);            /* toggled by ipport_tick */
   VNET_DEFINE(int, ipport_tcpallocs);
   VNET_DEFINE_STATIC(int, ipport_tcplastcount);
   
   #define V_ipport_tcplastcount           VNET(ipport_tcplastcount)
   
   static void     in_pcbremlists(struct inpcb *inp);
   #ifdef INET
   static struct inpcb     *in_pcblookup_hash_locked(struct inpcbinfo *pcbinfo,
                               struct in_addr faddr, u_int fport_arg,
                               struct in_addr laddr, u_int lport_arg,
                               int lookupflags, struct ifnet *ifp);
   
   #define RANGECHK(var, min, max) \
           if ((var) < (min)) { (var) = (min); } \
           else if ((var) > (max)) { (var) = (max); }
   
   static int
   sysctl_net_ipport_check(SYSCTL_HANDLER_ARGS)
   {
           int error;
   
           error = sysctl_handle_int(oidp, arg1, arg2, req);
           if (error == 0) {
                   RANGECHK(V_ipport_lowfirstauto, 1, IPPORT_RESERVED - 1);
                   RANGECHK(V_ipport_lowlastauto, 1, IPPORT_RESERVED - 1);
                   RANGECHK(V_ipport_firstauto, IPPORT_RESERVED, IPPORT_MAX);
                   RANGECHK(V_ipport_lastauto, IPPORT_RESERVED, IPPORT_MAX);
                   RANGECHK(V_ipport_hifirstauto, IPPORT_RESERVED, IPPORT_MAX);
                   RANGECHK(V_ipport_hilastauto, IPPORT_RESERVED, IPPORT_MAX);
           }
           return (error);
   }
   
   #undef RANGECHK
   
   static SYSCTL_NODE(_net_inet_ip, IPPROTO_IP, portrange, CTLFLAG_RW, 0,
       "IP Ports");
   
   SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowfirst,
           CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW,
           &VNET_NAME(ipport_lowfirstauto), 0, &sysctl_net_ipport_check, "I", "");
   SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowlast,
           CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW,
           &VNET_NAME(ipport_lowlastauto), 0, &sysctl_net_ipport_check, "I", "");
   SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, first,
           CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW,
           &VNET_NAME(ipport_firstauto), 0, &sysctl_net_ipport_check, "I", "");
   SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, last,
           CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW,
           &VNET_NAME(ipport_lastauto), 0, &sysctl_net_ipport_check, "I", "");
   SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hifirst,
           CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW,
           &VNET_NAME(ipport_hifirstauto), 0, &sysctl_net_ipport_check, "I", "");
   SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hilast,
           CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW,
           &VNET_NAME(ipport_hilastauto), 0, &sysctl_net_ipport_check, "I", "");
   SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, reservedhigh,
           CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE,
           &VNET_NAME(ipport_reservedhigh), 0, "");
   SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, reservedlow,
           CTLFLAG_RW|CTLFLAG_SECURE, &VNET_NAME(ipport_reservedlow), 0, "");
   SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, randomized,
           CTLFLAG_VNET | CTLFLAG_RW,
           &VNET_NAME(ipport_randomized), 0, "Enable random port allocation");
   SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, randomcps,
           CTLFLAG_VNET | CTLFLAG_RW,
           &VNET_NAME(ipport_randomcps), 0, "Maximum number of random port "
           "allocations before switching to a sequential one");
   SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, randomtime,
           CTLFLAG_VNET | CTLFLAG_RW,
           &VNET_NAME(ipport_randomtime), 0,
           "Minimum time to keep sequential port "
           "allocation before switching to a random one");
   #endif /* INET */
   
   /*
    * in_pcb.c: manage the Protocol Control Blocks.
    *
    * NOTE: It is assumed that most of these functions will be called with
    * the pcbinfo lock held, and often, the inpcb lock held, as these utility
    * functions often modify hash chains or addresses in pcbs.
    */
   
   static struct inpcblbgroup *
   in_pcblbgroup_alloc(struct inpcblbgrouphead *hdr, u_char vflag,
       uint16_t port, const union in_dependaddr *addr, int size)
   {
           struct inpcblbgroup *grp;
           size_t bytes;
   
           bytes = __offsetof(struct inpcblbgroup, il_inp[size]);
           grp = malloc(bytes, M_PCB, M_ZERO | M_NOWAIT);
           if (!grp)
                   return (NULL);
           grp->il_vflag = vflag;
           grp->il_lport = port;
           grp->il_dependladdr = *addr;
           grp->il_inpsiz = size;
           CK_LIST_INSERT_HEAD(hdr, grp, il_list);
           return (grp);
   }
   
   static void
   in_pcblbgroup_free_deferred(epoch_context_t ctx)
   {
           struct inpcblbgroup *grp;
   
           grp = __containerof(ctx, struct inpcblbgroup, il_epoch_ctx);
           free(grp, M_PCB);
   }
   
   static void
   in_pcblbgroup_free(struct inpcblbgroup *grp)
   {
   
           CK_LIST_REMOVE(grp, il_list);
           epoch_call(net_epoch_preempt, &grp->il_epoch_ctx,
               in_pcblbgroup_free_deferred);
   }
   
   static struct inpcblbgroup *
   in_pcblbgroup_resize(struct inpcblbgrouphead *hdr,
       struct inpcblbgroup *old_grp, int size)
   {
           struct inpcblbgroup *grp;
           int i;
   
           grp = in_pcblbgroup_alloc(hdr, old_grp->il_vflag,
               old_grp->il_lport, &old_grp->il_dependladdr, size);
           if (grp == NULL)
                   return (NULL);
   
           KASSERT(old_grp->il_inpcnt < grp->il_inpsiz,
               ("invalid new local group size %d and old local group count %d",
                grp->il_inpsiz, old_grp->il_inpcnt));
   
           for (i = 0; i < old_grp->il_inpcnt; ++i)
                   grp->il_inp[i] = old_grp->il_inp[i];
           grp->il_inpcnt = old_grp->il_inpcnt;
           in_pcblbgroup_free(old_grp);
           return (grp);
   }
   
   /*
    * PCB at index 'i' is removed from the group. Pull up the ones below il_inp[i]
    * and shrink group if possible.
    */
   static void
   in_pcblbgroup_reorder(struct inpcblbgrouphead *hdr, struct inpcblbgroup **grpp,
       int i)
   {
           struct inpcblbgroup *grp, *new_grp;
   
           grp = *grpp;
           for (; i + 1 < grp->il_inpcnt; ++i)
                   grp->il_inp[i] = grp->il_inp[i + 1];
           grp->il_inpcnt--;
   
           if (grp->il_inpsiz > INPCBLBGROUP_SIZMIN &&
               grp->il_inpcnt <= grp->il_inpsiz / 4) {
                   /* Shrink this group. */
                   new_grp = in_pcblbgroup_resize(hdr, grp, grp->il_inpsiz / 2);
                   if (new_grp != NULL)
                           *grpp = new_grp;
           }
   }
   
   /*
    * Add PCB to load balance group for SO_REUSEPORT_LB option.
    */
   static int
   in_pcbinslbgrouphash(struct inpcb *inp)
   {
           const static struct timeval interval = { 60, 0 };
           static struct timeval lastprint;
           struct inpcbinfo *pcbinfo;
           struct inpcblbgrouphead *hdr;
           struct inpcblbgroup *grp;
           uint32_t idx;
   
           pcbinfo = inp->inp_pcbinfo;
   
           INP_WLOCK_ASSERT(inp);
           INP_HASH_WLOCK_ASSERT(pcbinfo);
   
           /*
            * Don't allow jailed socket to join local group.
            */
           if (inp->inp_socket != NULL && jailed(inp->inp_socket->so_cred))
                   return (0);
   
   #ifdef INET6
           /*
            * Don't allow IPv4 mapped INET6 wild socket.
            */
           if ((inp->inp_vflag & INP_IPV4) &&
               inp->inp_laddr.s_addr == INADDR_ANY &&
               INP_CHECK_SOCKAF(inp->inp_socket, AF_INET6)) {
                   return (0);
           }
   #endif
   
           idx = INP_PCBPORTHASH(inp->inp_lport, pcbinfo->ipi_lbgrouphashmask);
           hdr = &pcbinfo->ipi_lbgrouphashbase[idx];
           CK_LIST_FOREACH(grp, hdr, il_list) {
                   if (grp->il_vflag == inp->inp_vflag &&
                       grp->il_lport == inp->inp_lport &&
                       memcmp(&grp->il_dependladdr,
                       &inp->inp_inc.inc_ie.ie_dependladdr,
                       sizeof(grp->il_dependladdr)) == 0)
                           break;
           }
           if (grp == NULL) {
                   /* Create new load balance group. */
                   grp = in_pcblbgroup_alloc(hdr, inp->inp_vflag,
                       inp->inp_lport, &inp->inp_inc.inc_ie.ie_dependladdr,
                       INPCBLBGROUP_SIZMIN);
                   if (grp == NULL)
                           return (ENOBUFS);
           } else if (grp->il_inpcnt == grp->il_inpsiz) {
                   if (grp->il_inpsiz >= INPCBLBGROUP_SIZMAX) {
                           if (ratecheck(&lastprint, &interval))
                                   printf("lb group port %d, limit reached\n",
                                       ntohs(grp->il_lport));
                           return (0);
                   }
   
                   /* Expand this local group. */
                   grp = in_pcblbgroup_resize(hdr, grp, grp->il_inpsiz * 2);
                   if (grp == NULL)
                           return (ENOBUFS);
           }
   
           KASSERT(grp->il_inpcnt < grp->il_inpsiz,
               ("invalid local group size %d and count %d", grp->il_inpsiz,
               grp->il_inpcnt));
   
           grp->il_inp[grp->il_inpcnt] = inp;
           grp->il_inpcnt++;
           return (0);
   }
   
   /*
    * Remove PCB from load balance group.
    */
   static void
   in_pcbremlbgrouphash(struct inpcb *inp)
   {
           struct inpcbinfo *pcbinfo;
           struct inpcblbgrouphead *hdr;
           struct inpcblbgroup *grp;
           int i;
   
           pcbinfo = inp->inp_pcbinfo;
   
           INP_WLOCK_ASSERT(inp);
           INP_HASH_WLOCK_ASSERT(pcbinfo);
   
           hdr = &pcbinfo->ipi_lbgrouphashbase[
               INP_PCBPORTHASH(inp->inp_lport, pcbinfo->ipi_lbgrouphashmask)];
           CK_LIST_FOREACH(grp, hdr, il_list) {
                   for (i = 0; i < grp->il_inpcnt; ++i) {
                           if (grp->il_inp[i] != inp)
                                   continue;
   
                           if (grp->il_inpcnt == 1) {
                                   /* We are the last, free this local group. */
                                   in_pcblbgroup_free(grp);
                           } else {
                                   /* Pull up inpcbs, shrink group if possible. */
                                   in_pcblbgroup_reorder(hdr, &grp, i);
                           }
                           return;
                   }
           }
   }
   
   /*
    * Different protocols initialize their inpcbs differently - giving
    * different name to the lock.  But they all are disposed the same.
    */
   static void
   inpcb_fini(void *mem, int size)
   {
           struct inpcb *inp = mem;
   
           INP_LOCK_DESTROY(inp);
   }
   
   /*
    * Initialize an inpcbinfo -- we should be able to reduce the number of
    * arguments in time.
    */
   void
   in_pcbinfo_init(struct inpcbinfo *pcbinfo, const char *name,
       struct inpcbhead *listhead, int hash_nelements, int porthash_nelements,
       char *inpcbzone_name, uma_init inpcbzone_init, u_int hashfields)
   {
   
           porthash_nelements = imin(porthash_nelements, IPPORT_MAX + 1);
   
           INP_INFO_LOCK_INIT(pcbinfo, name);
           INP_HASH_LOCK_INIT(pcbinfo, "pcbinfohash");     /* XXXRW: argument? */
           INP_LIST_LOCK_INIT(pcbinfo, "pcbinfolist");
   #ifdef VIMAGE
           pcbinfo->ipi_vnet = curvnet;
   #endif
           pcbinfo->ipi_listhead = listhead;
           CK_LIST_INIT(pcbinfo->ipi_listhead);
           pcbinfo->ipi_count = 0;
           pcbinfo->ipi_hashbase = hashinit(hash_nelements, M_PCB,
               &pcbinfo->ipi_hashmask);
           pcbinfo->ipi_porthashbase = hashinit(porthash_nelements, M_PCB,
               &pcbinfo->ipi_porthashmask);
           pcbinfo->ipi_lbgrouphashbase = hashinit(porthash_nelements, M_PCB,
               &pcbinfo->ipi_lbgrouphashmask);
   #ifdef PCBGROUP
           in_pcbgroup_init(pcbinfo, hashfields, hash_nelements);
   #endif
           pcbinfo->ipi_zone = uma_zcreate(inpcbzone_name, sizeof(struct inpcb),
               NULL, NULL, inpcbzone_init, inpcb_fini, UMA_ALIGN_PTR, 0);
           uma_zone_set_max(pcbinfo->ipi_zone, maxsockets);
           uma_zone_set_warning(pcbinfo->ipi_zone,
               "kern.ipc.maxsockets limit reached");
   }
   
   /*
    * Destroy an inpcbinfo.
    */
   void
   in_pcbinfo_destroy(struct inpcbinfo *pcbinfo)
   {
   
           KASSERT(pcbinfo->ipi_count == 0,
               ("%s: ipi_count = %u", __func__, pcbinfo->ipi_count));
   
           hashdestroy(pcbinfo->ipi_hashbase, M_PCB, pcbinfo->ipi_hashmask);
           hashdestroy(pcbinfo->ipi_porthashbase, M_PCB,
               pcbinfo->ipi_porthashmask);
           hashdestroy(pcbinfo->ipi_lbgrouphashbase, M_PCB,
               pcbinfo->ipi_lbgrouphashmask);
   #ifdef PCBGROUP
           in_pcbgroup_destroy(pcbinfo);
   #endif
           uma_zdestroy(pcbinfo->ipi_zone);
           INP_LIST_LOCK_DESTROY(pcbinfo);
           INP_HASH_LOCK_DESTROY(pcbinfo);
           INP_INFO_LOCK_DESTROY(pcbinfo);
   }
   
   /*
    * Allocate a PCB and associate it with the socket.
    * On success return with the PCB locked.
    */
   int
   in_pcballoc(struct socket *so, struct inpcbinfo *pcbinfo)
   {
           struct inpcb *inp;
           int error;
   
   #ifdef INVARIANTS
           if (pcbinfo == &V_tcbinfo) {
                   INP_INFO_RLOCK_ASSERT(pcbinfo);
           } else {
                   INP_INFO_WLOCK_ASSERT(pcbinfo);
           }
   #endif
   
           error = 0;
           inp = uma_zalloc(pcbinfo->ipi_zone, M_NOWAIT);
           if (inp == NULL)
                   return (ENOBUFS);
           bzero(&inp->inp_start_zero, inp_zero_size);
           inp->inp_pcbinfo = pcbinfo;
           inp->inp_socket = so;
           inp->inp_cred = crhold(so->so_cred);
           inp->inp_inc.inc_fibnum = so->so_fibnum;
   #ifdef MAC
           error = mac_inpcb_init(inp, M_NOWAIT);
           if (error != 0)
                   goto out;
           mac_inpcb_create(so, inp);
   #endif
   #if defined(IPSEC) || defined(IPSEC_SUPPORT)
           error = ipsec_init_pcbpolicy(inp);
           if (error != 0) {
   #ifdef MAC
                   mac_inpcb_destroy(inp);
   #endif
                   goto out;
           }
   #endif /*IPSEC*/
   #ifdef INET6
           if (INP_SOCKAF(so) == AF_INET6) {
                   inp->inp_vflag |= INP_IPV6PROTO;
                   if (V_ip6_v6only)
                           inp->inp_flags |= IN6P_IPV6_V6ONLY;
           }
   #endif
           INP_WLOCK(inp);
           INP_LIST_WLOCK(pcbinfo);
           CK_LIST_INSERT_HEAD(pcbinfo->ipi_listhead, inp, inp_list);
           pcbinfo->ipi_count++;
           so->so_pcb = (caddr_t)inp;
   #ifdef INET6
           if (V_ip6_auto_flowlabel)
                   inp->inp_flags |= IN6P_AUTOFLOWLABEL;
   #endif
           inp->inp_gencnt = ++pcbinfo->ipi_gencnt;
           refcount_init(&inp->inp_refcount, 1);   /* Reference from inpcbinfo */
   
           /*
            * Routes in inpcb's can cache L2 as well; they are guaranteed
            * to be cleaned up.
            */
           inp->inp_route.ro_flags = RT_LLE_CACHE;
           INP_LIST_WUNLOCK(pcbinfo);
   #if defined(IPSEC) || defined(IPSEC_SUPPORT) || defined(MAC)
   out:
           if (error != 0) {
                   crfree(inp->inp_cred);
                   uma_zfree(pcbinfo->ipi_zone, inp);
           }
   #endif
           return (error);
   }
   
   #ifdef INET
   int
   in_pcbbind(struct inpcb *inp, struct sockaddr *nam, struct ucred *cred)
   {
           int anonport, error;
   
           INP_WLOCK_ASSERT(inp);
           INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
   
           if (inp->inp_lport != 0 || inp->inp_laddr.s_addr != INADDR_ANY)
                   return (EINVAL);
           anonport = nam == NULL || ((struct sockaddr_in *)nam)->sin_port == 0;
           error = in_pcbbind_setup(inp, nam, &inp->inp_laddr.s_addr,
               &inp->inp_lport, cred);
           if (error)
                   return (error);
           if (in_pcbinshash(inp) != 0) {
                   inp->inp_laddr.s_addr = INADDR_ANY;
                   inp->inp_lport = 0;
                   return (EAGAIN);
           }
           if (anonport)
                   inp->inp_flags |= INP_ANONPORT;
           return (0);
   }
   #endif
   
   #if defined(INET) || defined(INET6)
   /*
    * Assign a local port like in_pcb_lport(), but also used with connect()
    * and a foreign address and port.  If fsa is non-NULL, choose a local port
    * that is unused with those, otherwise one that is completely unused.
    * lsa can be NULL for IPv6.
    */
   int
   in_pcb_lport_dest(struct inpcb *inp, struct sockaddr *lsa, u_short *lportp,
       struct sockaddr *fsa, u_short fport, struct ucred *cred, int lookupflags)
   {
           struct inpcbinfo *pcbinfo;
           struct inpcb *tmpinp;
           unsigned short *lastport;
           int count, dorandom, error;
           u_short aux, first, last, lport;
   #ifdef INET
           struct in_addr laddr, faddr;
   #endif
   #ifdef INET6
           struct in6_addr *laddr6, *faddr6;
   #endif
   
           pcbinfo = inp->inp_pcbinfo;
   
           /*
            * Because no actual state changes occur here, a global write lock on
            * the pcbinfo isn't required.
            */
           INP_LOCK_ASSERT(inp);
           INP_HASH_LOCK_ASSERT(pcbinfo);
   
           if (inp->inp_flags & INP_HIGHPORT) {
                   first = V_ipport_hifirstauto;   /* sysctl */
                   last  = V_ipport_hilastauto;
                   lastport = &pcbinfo->ipi_lasthi;
           } else if (inp->inp_flags & INP_LOWPORT) {
                   error = priv_check_cred(cred, PRIV_NETINET_RESERVEDPORT, 0);
                   if (error)
                           return (error);
                   first = V_ipport_lowfirstauto;  /* 1023 */
                   last  = V_ipport_lowlastauto;   /* 600 */
                   lastport = &pcbinfo->ipi_lastlow;
           } else {
                   first = V_ipport_firstauto;     /* sysctl */
                   last  = V_ipport_lastauto;
                   lastport = &pcbinfo->ipi_lastport;
           }
           /*
            * For UDP(-Lite), use random port allocation as long as the user
            * allows it.  For TCP (and as of yet unknown) connections,
            * use random port allocation only if the user allows it AND
            * ipport_tick() allows it.
            */
           if (V_ipport_randomized &&
                   (!V_ipport_stoprandom || pcbinfo == &V_udbinfo ||
                   pcbinfo == &V_ulitecbinfo))
                   dorandom = 1;
           else
                   dorandom = 0;
           /*
            * It makes no sense to do random port allocation if
            * we have the only port available.
            */
           if (first == last)
                   dorandom = 0;
           /* Make sure to not include UDP(-Lite) packets in the count. */
           if (pcbinfo != &V_udbinfo || pcbinfo != &V_ulitecbinfo)
                   V_ipport_tcpallocs++;
           /*
            * Instead of having two loops further down counting up or down
            * make sure that first is always <= last and go with only one
            * code path implementing all logic.
            */
           if (first > last) {
                   aux = first;
                   first = last;
                   last = aux;
           }
   
   #ifdef INET
           laddr.s_addr = INADDR_ANY;
           if ((inp->inp_vflag & (INP_IPV4|INP_IPV6)) == INP_IPV4) {
                   if (lsa != NULL)
                           laddr = ((struct sockaddr_in *)lsa)->sin_addr;
                   if (fsa != NULL)
                           faddr = ((struct sockaddr_in *)fsa)->sin_addr;
           }
   #endif
   #ifdef INET6
           laddr6 = NULL;
           if ((inp->inp_vflag & INP_IPV6) != 0) {
                   if (lsa != NULL)
                           laddr6 = &((struct sockaddr_in6 *)lsa)->sin6_addr;
                   if (fsa != NULL)
                           faddr6 = &((struct sockaddr_in6 *)fsa)->sin6_addr;
           }
   #endif
   
           tmpinp = NULL;
           lport = *lportp;
   
           if (dorandom)
                   *lastport = first + (arc4random() % (last - first));
   
           count = last - first;
   
           do {
                   if (count-- < 0)        /* completely used? */
                           return (EADDRNOTAVAIL);
                   ++*lastport;
                   if (*lastport < first || *lastport > last)
                           *lastport = first;
                   lport = htons(*lastport);
   
                   if (fsa != NULL) {
   
   #ifdef INET
                           if (lsa->sa_family == AF_INET) {
                                   tmpinp = in_pcblookup_hash_locked(pcbinfo,
                                       faddr, fport, laddr, lport, lookupflags,
                                       NULL);
                           }
   #endif
   #ifdef INET6
                           if (lsa->sa_family == AF_INET6) {
                                   tmpinp = in6_pcblookup_hash_locked(pcbinfo,
                                       faddr6, fport, laddr6, lport, lookupflags,
                                       NULL);
                           }
   #endif
                   } else {
   #ifdef INET6
                           if ((inp->inp_vflag & INP_IPV6) != 0)
                                   tmpinp = in6_pcblookup_local(pcbinfo,
                                       &inp->in6p_laddr, lport, lookupflags, cred);
   #endif
   #if defined(INET) && defined(INET6)
                           else
   #endif
   #ifdef INET
                                   tmpinp = in_pcblookup_local(pcbinfo, laddr,
                                       lport, lookupflags, cred);
   #endif
                   }
           } while (tmpinp != NULL);
   
           *lportp = lport;
   
           return (0);
   }
   
   /*
    * Select a local port (number) to use.
    */
   int
   in_pcb_lport(struct inpcb *inp, struct in_addr *laddrp, u_short *lportp,
       struct ucred *cred, int lookupflags)
   {
           struct sockaddr_in laddr;
   
           if (laddrp) {
                   bzero(&laddr, sizeof(laddr));
                   laddr.sin_family = AF_INET;
                   laddr.sin_addr = *laddrp;
           }
           return (in_pcb_lport_dest(inp, laddrp ? (struct sockaddr *) &laddr :
               NULL, lportp, NULL, 0, cred, lookupflags));
   }
   
   /*
    * Return cached socket options.
    */
   int
   inp_so_options(const struct inpcb *inp)
   {
           int so_options;
   
           so_options = 0;
   
           if ((inp->inp_flags2 & INP_REUSEPORT_LB) != 0)
                   so_options |= SO_REUSEPORT_LB;
           if ((inp->inp_flags2 & INP_REUSEPORT) != 0)
                   so_options |= SO_REUSEPORT;
           if ((inp->inp_flags2 & INP_REUSEADDR) != 0)
                   so_options |= SO_REUSEADDR;
           return (so_options);
   }
   #endif /* INET || INET6 */
   
   /*
    * Check if a new BINDMULTI socket is allowed to be created.
    *
    * ni points to the new inp.
    * oi points to the existing inp.
    *
    * This checks whether the existing inp also has BINDMULTI and
    * whether the credentials match.
    */
   int
   in_pcbbind_check_bindmulti(const struct inpcb *ni, const struct inpcb *oi)
   {
           /* Check permissions match */
           if ((ni->inp_flags2 & INP_BINDMULTI) &&
               (ni->inp_cred->cr_uid !=
               oi->inp_cred->cr_uid))
                   return (0);
   
           /* Check the existing inp has BINDMULTI set */
           if ((ni->inp_flags2 & INP_BINDMULTI) &&
               ((oi->inp_flags2 & INP_BINDMULTI) == 0))
                   return (0);
   
           /*
            * We're okay - either INP_BINDMULTI isn't set on ni, or
            * it is and it matches the checks.
            */
           return (1);
   }
   
   #ifdef INET
   /*
    * Set up a bind operation on a PCB, performing port allocation
    * as required, but do not actually modify the PCB. Callers can
    * either complete the bind by setting inp_laddr/inp_lport and
    * calling in_pcbinshash(), or they can just use the resulting
    * port and address to authorise the sending of a once-off packet.
    *
    * On error, the values of *laddrp and *lportp are not changed.
    */
   int
   in_pcbbind_setup(struct inpcb *inp, struct sockaddr *nam, in_addr_t *laddrp,
       u_short *lportp, struct ucred *cred)
   {
           struct socket *so = inp->inp_socket;
           struct sockaddr_in *sin;
           struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
           struct in_addr laddr;
           u_short lport = 0;
           int lookupflags = 0, reuseport = (so->so_options & SO_REUSEPORT);
           int error;
   
           /*
            * XXX: Maybe we could let SO_REUSEPORT_LB set SO_REUSEPORT bit here
            * so that we don't have to add to the (already messy) code below.
            */
           int reuseport_lb = (so->so_options & SO_REUSEPORT_LB);
   
           /*
            * No state changes, so read locks are sufficient here.
            */
           INP_LOCK_ASSERT(inp);
           INP_HASH_LOCK_ASSERT(pcbinfo);
   
           laddr.s_addr = *laddrp;
           if (nam != NULL && laddr.s_addr != INADDR_ANY)
                   return (EINVAL);
           if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT|SO_REUSEPORT_LB)) == 0)
                   lookupflags = INPLOOKUP_WILDCARD;
           if (nam == NULL) {
                   if ((error = prison_local_ip4(cred, &laddr)) != 0)
                           return (error);
           } else {
                   sin = (struct sockaddr_in *)nam;
                   if (nam->sa_len != sizeof (*sin))
                           return (EINVAL);
   #ifdef notdef
                   /*
                    * We should check the family, but old programs
                    * incorrectly fail to initialize it.
                    */
                   if (sin->sin_family != AF_INET)
                           return (EAFNOSUPPORT);
   #endif
                   error = prison_local_ip4(cred, &sin->sin_addr);
                   if (error)
                           return (error);
                   if (sin->sin_port != *lportp) {
                           /* Don't allow the port to change. */
                           if (*lportp != 0)
                                   return (EINVAL);
                           lport = sin->sin_port;
                   }
                   /* NB: lport is left as 0 if the port isn't being changed. */
                   if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) {
                           /*
                            * Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
                            * allow complete duplication of binding if
                            * SO_REUSEPORT is set, or if SO_REUSEADDR is set
                            * and a multicast address is bound on both
                            * new and duplicated sockets.
                            */
                           if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) != 0)
                                   reuseport = SO_REUSEADDR|SO_REUSEPORT;
                           /*
                            * XXX: How to deal with SO_REUSEPORT_LB here?
                            * Treat same as SO_REUSEPORT for now.
                            */
                           if ((so->so_options &
                               (SO_REUSEADDR|SO_REUSEPORT_LB)) != 0)
                                   reuseport_lb = SO_REUSEADDR|SO_REUSEPORT_LB;
                   } else if (sin->sin_addr.s_addr != INADDR_ANY) {
                           sin->sin_port = 0;              /* yech... */
                           bzero(&sin->sin_zero, sizeof(sin->sin_zero));
                           /*
                            * Is the address a local IP address?
                            * If INP_BINDANY is set, then the socket may be bound
                            * to any endpoint address, local or not.
                            */
                           if ((inp->inp_flags & INP_BINDANY) == 0 &&
                               ifa_ifwithaddr_check((struct sockaddr *)sin) == 0)
                                   return (EADDRNOTAVAIL);
                   }
                   laddr = sin->sin_addr;
                   if (lport) {
                           struct inpcb *t;
                           struct tcptw *tw;
   
                           /* GROSS */
                           if (ntohs(lport) <= V_ipport_reservedhigh &&
                               ntohs(lport) >= V_ipport_reservedlow &&
                               priv_check_cred(cred, PRIV_NETINET_RESERVEDPORT,
                               0))
                                   return (EACCES);
                           if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr)) &&
                               priv_check_cred(inp->inp_cred,
                               PRIV_NETINET_REUSEPORT, 0) != 0) {
                                   t = in_pcblookup_local(pcbinfo, sin->sin_addr,
                                       lport, INPLOOKUP_WILDCARD, cred);
           /*
            * XXX
            * This entire block sorely needs a rewrite.
            */
                                   if (t &&
                                       ((inp->inp_flags2 & INP_BINDMULTI) == 0) &&
                                       ((t->inp_flags & INP_TIMEWAIT) == 0) &&
                                       (so->so_type != SOCK_STREAM ||
                                        ntohl(t->inp_faddr.s_addr) == INADDR_ANY) &&
                                       (ntohl(sin->sin_addr.s_addr) != INADDR_ANY ||
                                        ntohl(t->inp_laddr.s_addr) != INADDR_ANY ||
                                        (t->inp_flags2 & INP_REUSEPORT) ||
                                        (t->inp_flags2 & INP_REUSEPORT_LB) == 0) &&
                                       (inp->inp_cred->cr_uid !=
                                        t->inp_cred->cr_uid))
                                           return (EADDRINUSE);
   
                                   /*
                                    * If the socket is a BINDMULTI socket, then
                                    * the credentials need to match and the
                                    * original socket also has to have been bound
                                    * with BINDMULTI.
                                    */
                                   if (t && (! in_pcbbind_check_bindmulti(inp, t)))
                                           return (EADDRINUSE);
                           }
                           t = in_pcblookup_local(pcbinfo, sin->sin_addr,
                               lport, lookupflags, cred);
                           if (t && (t->inp_flags & INP_TIMEWAIT)) {
                                   /*
                                    * XXXRW: If an incpb has had its timewait
                                    * state recycled, we treat the address as
                                    * being in use (for now).  This is better
                                    * than a panic, but not desirable.
                                    */
                                   tw = intotw(t);
                                   if (tw == NULL ||
                                       ((reuseport & tw->tw_so_options) == 0 &&
                                           (reuseport_lb &
                                               tw->tw_so_options) == 0)) {
                                           return (EADDRINUSE);
                                   }
                           } else if (t &&
                                      ((inp->inp_flags2 & INP_BINDMULTI) == 0) &&
                                      (reuseport & inp_so_options(t)) == 0 &&
                                      (reuseport_lb & inp_so_options(t)) == 0) {
   #ifdef INET6
                                   if (ntohl(sin->sin_addr.s_addr) !=
                                       INADDR_ANY ||
                                       ntohl(t->inp_laddr.s_addr) !=
                                       INADDR_ANY ||
                                       (inp->inp_vflag & INP_IPV6PROTO) == 0 ||
                                       (t->inp_vflag & INP_IPV6PROTO) == 0)
   #endif
                                                   return (EADDRINUSE);
                                   if (t && (! in_pcbbind_check_bindmulti(inp, t)))
                                           return (EADDRINUSE);
                           }
                   }
           }
           if (*lportp != 0)
                   lport = *lportp;
           if (lport == 0) {
                   error = in_pcb_lport(inp, &laddr, &lport, cred, lookupflags);
                   if (error != 0)
                           return (error);
   
           }
           *laddrp = laddr.s_addr;
           *lportp = lport;
           return (0);
   }
   
   /*
    * Connect from a socket to a specified address.
    * Both address and port must be specified in argument sin.
    * If don't have a local address for this socket yet,
   * then pick one.
   */
  int
  in_pcbconnect_mbuf(struct inpcb *inp, struct sockaddr *nam,
      struct ucred *cred, struct mbuf *m, bool rehash)
  {
          u_short lport, fport;
          in_addr_t laddr, faddr;
          int anonport, error;
  
          INP_WLOCK_ASSERT(inp);
          INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
  
          lport = inp->inp_lport;
          laddr = inp->inp_laddr.s_addr;
          anonport = (lport == 0);
          error = in_pcbconnect_setup(inp, nam, &laddr, &lport, &faddr, &fport,
              NULL, cred);
          if (error)
                  return (error);
  
          /* Do the initial binding of the local address if required. */
          if (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0) {
                  KASSERT(rehash == true,
                      ("Rehashing required for unbound inps"));
                  inp->inp_lport = lport;
                  inp->inp_laddr.s_addr = laddr;
                  if (in_pcbinshash(inp) != 0) {
                          inp->inp_laddr.s_addr = INADDR_ANY;
                          inp->inp_lport = 0;
                          return (EAGAIN);
                  }
          }
  
          /* Commit the remaining changes. */
          inp->inp_lport = lport;
          inp->inp_laddr.s_addr = laddr;
          inp->inp_faddr.s_addr = faddr;
          inp->inp_fport = fport;
          if (rehash) {
                  in_pcbrehash_mbuf(inp, m);
          } else {
                  in_pcbinshash_mbuf(inp, m);
          }
  
          if (anonport)
                  inp->inp_flags |= INP_ANONPORT;
          return (0);
  }
  
  int
  in_pcbconnect(struct inpcb *inp, struct sockaddr *nam, struct ucred *cred)
  {
  
          return (in_pcbconnect_mbuf(inp, nam, cred, NULL, true));
  }
  
  /*
   * Do proper source address selection on an unbound socket in case
   * of connect. Take jails into account as well.
   */
  int
  in_pcbladdr(struct inpcb *inp, struct in_addr *faddr, struct in_addr *laddr,
      struct ucred *cred)
  {
          struct ifaddr *ifa;
          struct sockaddr *sa;
          struct sockaddr_in *sin;
          struct route sro;
          int error;
  
          KASSERT(laddr != NULL, ("%s: laddr NULL", __func__));
          /*
           * Bypass source address selection and use the primary jail IP
           * if requested.
           */
          if (cred != NULL && !prison_saddrsel_ip4(cred, laddr))
                  return (0);
  
          error = 0;
          bzero(&sro, sizeof(sro));
  
          sin = (struct sockaddr_in *)&sro.ro_dst;
          sin->sin_family = AF_INET;
          sin->sin_len = sizeof(struct sockaddr_in);
          sin->sin_addr.s_addr = faddr->s_addr;
  
          /*
           * If route is known our src addr is taken from the i/f,
           * else punt.
           *
           * Find out route to destination.
           */
          if ((inp->inp_socket->so_options & SO_DONTROUTE) == 0)
                  in_rtalloc_ign(&sro, 0, inp->inp_inc.inc_fibnum);
  
          /*
           * If we found a route, use the address corresponding to
           * the outgoing interface.
           * 
           * Otherwise assume faddr is reachable on a directly connected
           * network and try to find a corresponding interface to take
           * the source address from.
           */
          NET_EPOCH_ENTER();
          if (sro.ro_rt == NULL || sro.ro_rt->rt_ifp == NULL) {
                  struct in_ifaddr *ia;
                  struct ifnet *ifp;
  
                  ia = ifatoia(ifa_ifwithdstaddr((struct sockaddr *)sin,
                                          inp->inp_socket->so_fibnum));
                  if (ia == NULL) {
                          ia = ifatoia(ifa_ifwithnet((struct sockaddr *)sin, 0,
                                                  inp->inp_socket->so_fibnum));
  
                  }
                  if (ia == NULL) {
                          error = ENETUNREACH;
                          goto done;
                  }
  
                  if (cred == NULL || !prison_flag(cred, PR_IP4)) {
                          laddr->s_addr = ia->ia_addr.sin_addr.s_addr;
                          goto done;
                  }
  
                  ifp = ia->ia_ifp;
                  ia = NULL;
                  CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
  
                          sa = ifa->ifa_addr;
                          if (sa->sa_family != AF_INET)
                                  continue;
                          sin = (struct sockaddr_in *)sa;
                          if (prison_check_ip4(cred, &sin->sin_addr) == 0) {
                                  ia = (struct in_ifaddr *)ifa;
                                  break;
                          }
                  }
                  if (ia != NULL) {
                          laddr->s_addr = ia->ia_addr.sin_addr.s_addr;
                          goto done;
                  }
  
                  /* 3. As a last resort return the 'default' jail address. */
                  error = prison_get_ip4(cred, laddr);
                  goto done;
          }
  
          /*
           * If the outgoing interface on the route found is not
           * a loopback interface, use the address from that interface.
           * In case of jails do those three steps:
           * 1. check if the interface address belongs to the jail. If so use it.
           * 2. check if we have any address on the outgoing interface
           *    belonging to this jail. If so use it.
           * 3. as a last resort return the 'default' jail address.
           */
          if ((sro.ro_rt->rt_ifp->if_flags & IFF_LOOPBACK) == 0) {
                  struct in_ifaddr *ia;
                  struct ifnet *ifp;
  
                  /* If not jailed, use the default returned. */
                  if (cred == NULL || !prison_flag(cred, PR_IP4)) {
                          ia = (struct in_ifaddr *)sro.ro_rt->rt_ifa;
                          laddr->s_addr = ia->ia_addr.sin_addr.s_addr;
                          goto done;
                  }
  
                  /* Jailed. */
                  /* 1. Check if the iface address belongs to the jail. */
                  sin = (struct sockaddr_in *)sro.ro_rt->rt_ifa->ifa_addr;
                  if (prison_check_ip4(cred, &sin->sin_addr) == 0) {
                          ia = (struct in_ifaddr *)sro.ro_rt->rt_ifa;
                          laddr->s_addr = ia->ia_addr.sin_addr.s_addr;
                          goto done;
                  }
  
                  /*
                   * 2. Check if we have any address on the outgoing interface
                   *    belonging to this jail.
                   */
                  ia = NULL;
                  ifp = sro.ro_rt->rt_ifp;
                  CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                          sa = ifa->ifa_addr;
                          if (sa->sa_family != AF_INET)
                                  continue;
                          sin = (struct sockaddr_in *)sa;
                          if (prison_check_ip4(cred, &sin->sin_addr) == 0) {
                                  ia = (struct in_ifaddr *)ifa;
                                  break;
                          }
                  }
                  if (ia != NULL) {
                          laddr->s_addr = ia->ia_addr.sin_addr.s_addr;
                          goto done;
                  }
  
                  /* 3. As a last resort return the 'default' jail address. */
                  error = prison_get_ip4(cred, laddr);
                  goto done;
          }
  
          /*
           * The outgoing interface is marked with 'loopback net', so a route
           * to ourselves is here.
           * Try to find the interface of the destination address and then
           * take the address from there. That interface is not necessarily
           * a loopback interface.
           * In case of jails, check that it is an address of the jail
           * and if we cannot find, fall back to the 'default' jail address.
           */
          if ((sro.ro_rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) {
                  struct sockaddr_in sain;
                  struct in_ifaddr *ia;
  
                  bzero(&sain, sizeof(struct sockaddr_in));
                  sain.sin_family = AF_INET;
                  sain.sin_len = sizeof(struct sockaddr_in);
                  sain.sin_addr.s_addr = faddr->s_addr;
  
                  ia = ifatoia(ifa_ifwithdstaddr(sintosa(&sain),
                                          inp->inp_socket->so_fibnum));
                  if (ia == NULL)
                          ia = ifatoia(ifa_ifwithnet(sintosa(&sain), 0,
                                                  inp->inp_socket->so_fibnum));
                  if (ia == NULL)
                          ia = ifatoia(ifa_ifwithaddr(sintosa(&sain)));
  
                  if (cred == NULL || !prison_flag(cred, PR_IP4)) {
                          if (ia == NULL) {
                                  error = ENETUNREACH;
                                  goto done;
                          }
                          laddr->s_addr = ia->ia_addr.sin_addr.s_addr;
                          goto done;
                  }
  
                  /* Jailed. */
                  if (ia != NULL) {
                          struct ifnet *ifp;
  
                          ifp = ia->ia_ifp;
                          ia = NULL;
                          CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                                  sa = ifa->ifa_addr;
                                  if (sa->sa_family != AF_INET)
                                          continue;
                                  sin = (struct sockaddr_in *)sa;
                                  if (prison_check_ip4(cred,
                                      &sin->sin_addr) == 0) {
                                          ia = (struct in_ifaddr *)ifa;
                                          break;
                                  }
                          }
                          if (ia != NULL) {
                                  laddr->s_addr = ia->ia_addr.sin_addr.s_addr;
                                  goto done;
                          }
                  }
  
                  /* 3. As a last resort return the 'default' jail address. */
                  error = prison_get_ip4(cred, laddr);
                  goto done;
          }
  
  done:
          NET_EPOCH_EXIT();
          if (sro.ro_rt != NULL)
                  RTFREE(sro.ro_rt);
          return (error);
  }
  
  /*
   * Set up for a connect from a socket to the specified address.
   * On entry, *laddrp and *lportp should contain the current local
   * address and port for the PCB; these are updated to the values
   * that should be placed in inp_laddr and inp_lport to complete
   * the connect.
   *
   * On success, *faddrp and *fportp will be set to the remote address
   * and port. These are not updated in the error case.
   *
   * If the operation fails because the connection already exists,
   * *oinpp will be set to the PCB of that connection so that the
   * caller can decide to override it. In all other cases, *oinpp
   * is set to NULL.
   */
  int
  in_pcbconnect_setup(struct inpcb *inp, struct sockaddr *nam,
      in_addr_t *laddrp, u_short *lportp, in_addr_t *faddrp, u_short *fportp,
      struct inpcb **oinpp, struct ucred *cred)
  {
          struct rm_priotracker in_ifa_tracker;
          struct sockaddr_in *sin = (struct sockaddr_in *)nam;
          struct in_ifaddr *ia;
          struct inpcb *oinp;
          struct in_addr laddr, faddr;
          u_short lport, fport;
          int error;
  
          /*
           * Because a global state change doesn't actually occur here, a read
           * lock is sufficient.
           */
          INP_LOCK_ASSERT(inp);
          INP_HASH_LOCK_ASSERT(inp->inp_pcbinfo);
  
          if (oinpp != NULL)
                  *oinpp = NULL;
          if (nam->sa_len != sizeof (*sin))
                  return (EINVAL);
          if (sin->sin_family != AF_INET)
                  return (EAFNOSUPPORT);
          if (sin->sin_port == 0)
                  return (EADDRNOTAVAIL);
          laddr.s_addr = *laddrp;
          lport = *lportp;
          faddr = sin->sin_addr;
          fport = sin->sin_port;
  
          if (!CK_STAILQ_EMPTY(&V_in_ifaddrhead)) {
                  /*
                   * If the destination address is INADDR_ANY,
                   * use the primary local address.
                   * If the supplied address is INADDR_BROADCAST,
                   * and the primary interface supports broadcast,
                   * choose the broadcast address for that interface.
                   */
                  if (faddr.s_addr == INADDR_ANY) {
                          IN_IFADDR_RLOCK(&in_ifa_tracker);
                          faddr =
                              IA_SIN(CK_STAILQ_FIRST(&V_in_ifaddrhead))->sin_addr;
                          IN_IFADDR_RUNLOCK(&in_ifa_tracker);
                          if (cred != NULL &&
                              (error = prison_get_ip4(cred, &faddr)) != 0)
                                  return (error);
                  } else if (faddr.s_addr == (u_long)INADDR_BROADCAST) {
                          IN_IFADDR_RLOCK(&in_ifa_tracker);
                          if (CK_STAILQ_FIRST(&V_in_ifaddrhead)->ia_ifp->if_flags &
                              IFF_BROADCAST)
                                  faddr = satosin(&CK_STAILQ_FIRST(
                                      &V_in_ifaddrhead)->ia_broadaddr)->sin_addr;
                          IN_IFADDR_RUNLOCK(&in_ifa_tracker);
                  }
          }
          if (laddr.s_addr == INADDR_ANY) {
                  error = in_pcbladdr(inp, &faddr, &laddr, cred);
                  /*
                   * If the destination address is multicast and an outgoing
                   * interface has been set as a multicast option, prefer the
                   * address of that interface as our source address.
                   */
                  if (IN_MULTICAST(ntohl(faddr.s_addr)) &&
                      inp->inp_moptions != NULL) {
                          struct ip_moptions *imo;
                          struct ifnet *ifp;
  
                          imo = inp->inp_moptions;
                          if (imo->imo_multicast_ifp != NULL) {
                                  ifp = imo->imo_multicast_ifp;
                                  IN_IFADDR_RLOCK(&in_ifa_tracker);
                                  CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
                                          if ((ia->ia_ifp == ifp) &&
                                              (cred == NULL ||
                                              prison_check_ip4(cred,
                                              &ia->ia_addr.sin_addr) == 0))
                                                  break;
                                  }
                                  if (ia == NULL)
                                          error = EADDRNOTAVAIL;
                                  else {
                                          laddr = ia->ia_addr.sin_addr;
                                          error = 0;
                                  }
                                  IN_IFADDR_RUNLOCK(&in_ifa_tracker);
                          }
                  }
                  if (error)
                          return (error);
          }
          if (lport != 0) {
                  oinp = in_pcblookup_hash_locked(inp->inp_pcbinfo, faddr,
                      fport, laddr, lport, 0, NULL);
                  if (oinp != NULL) {
                          if (oinpp != NULL)
                                  *oinpp = oinp;
                          return (EADDRINUSE);
                  }
          } else {
                  struct sockaddr_in lsin, fsin;
  
                  bzero(&lsin, sizeof(lsin));
                  bzero(&fsin, sizeof(fsin));
                  lsin.sin_family = AF_INET;
                  lsin.sin_addr = laddr;
                  fsin.sin_family = AF_INET;
                  fsin.sin_addr = faddr;
                  error = in_pcb_lport_dest(inp, (struct sockaddr *) &lsin,
                      &lport, (struct sockaddr *)& fsin, fport, cred,
                      INPLOOKUP_WILDCARD);
                  if (error)
                          return (error);
          }
          *laddrp = laddr.s_addr;
          *lportp = lport;
          *faddrp = faddr.s_addr;
          *fportp = fport;
          return (0);
  }
  
  void
  in_pcbdisconnect(struct inpcb *inp)
  {
  
          INP_WLOCK_ASSERT(inp);
          INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
  
          inp->inp_faddr.s_addr = INADDR_ANY;
          inp->inp_fport = 0;
          in_pcbrehash(inp);
  }
  #endif /* INET */
  
  /*
   * in_pcbdetach() is responsibe for disassociating a socket from an inpcb.
   * For most protocols, this will be invoked immediately prior to calling
   * in_pcbfree().  However, with TCP the inpcb may significantly outlive the
   * socket, in which case in_pcbfree() is deferred.
   */
  void
  in_pcbdetach(struct inpcb *inp)
  {
  
          KASSERT(inp->inp_socket != NULL, ("%s: inp_socket == NULL", __func__));
  
  #ifdef RATELIMIT
          if (inp->inp_snd_tag != NULL)
                  in_pcbdetach_txrtlmt(inp);
  #endif
          inp->inp_socket->so_pcb = NULL;
          inp->inp_socket = NULL;
  }
  
  /*
   * in_pcbref() bumps the reference count on an inpcb in order to maintain
   * stability of an inpcb pointer despite the inpcb lock being released.  This
   * is used in TCP when the inpcbinfo lock needs to be acquired or upgraded,
   * but where the inpcb lock may already held, or when acquiring a reference
   * via a pcbgroup.
   *
   * in_pcbref() should be used only to provide brief memory stability, and
   * must always be followed by a call to INP_WLOCK() and in_pcbrele() to
   * garbage collect the inpcb if it has been in_pcbfree()'d from another
   * context.  Until in_pcbrele() has returned that the inpcb is still valid,
   * lock and rele are the *only* safe operations that may be performed on the
   * inpcb.
   *
   * While the inpcb will not be freed, releasing the inpcb lock means that the
   * connection's state may change, so the caller should be careful to
   * revalidate any cached state on reacquiring the lock.  Drop the reference
   * using in_pcbrele().
   */
  void
  in_pcbref(struct inpcb *inp)
  {
  
          KASSERT(inp->inp_refcount > 0, ("%s: refcount 0", __func__));
  
          refcount_acquire(&inp->inp_refcount);
  }
  
  /*
   * Drop a refcount on an inpcb elevated using in_pcbref(); because a call to
   * in_pcbfree() may have been made between in_pcbref() and in_pcbrele(), we
   * return a flag indicating whether or not the inpcb remains valid.  If it is
   * valid, we return with the inpcb lock held.
   *
   * Notice that, unlike in_pcbref(), the inpcb lock must be held to drop a
   * reference on an inpcb.  Historically more work was done here (actually, in
   * in_pcbfree_internal()) but has been moved to in_pcbfree() to avoid the
   * need for the pcbinfo lock in in_pcbrele().  Deferring the free is entirely
   * about memory stability (and continued use of the write lock).
   */
  int
  in_pcbrele_rlocked(struct inpcb *inp)
  {
          struct inpcbinfo *pcbinfo;
  
          KASSERT(inp->inp_refcount > 0, ("%s: refcount 0", __func__));
  
          INP_RLOCK_ASSERT(inp);
  
          if (refcount_release(&inp->inp_refcount) == 0) {
                  /*
                   * If the inpcb has been freed, let the caller know, even if
                   * this isn't the last reference.
                   */
                  if (inp->inp_flags2 & INP_FREED) {
                          INP_RUNLOCK(inp);
                          return (1);
                  }
                  return (0);
          }
          
          KASSERT(inp->inp_socket == NULL, ("%s: inp_socket != NULL", __func__));
  #ifdef TCPHPTS
          if (inp->inp_in_hpts || inp->inp_in_input) {
                  struct tcp_hpts_entry *hpts;
                  /*
                   * We should not be on the hpts at 
                   * this point in any form. we must
                   * get the lock to be sure.
                   */
                  hpts = tcp_hpts_lock(inp);
                  if (inp->inp_in_hpts)
                          panic("Hpts:%p inp:%p at free still on hpts",
                                hpts, inp);
                  mtx_unlock(&hpts->p_mtx);
                  hpts = tcp_input_lock(inp);
                  if (inp->inp_in_input) 
                          panic("Hpts:%p inp:%p at free still on input hpts",
                                hpts, inp);
                  mtx_unlock(&hpts->p_mtx);
          }
  #endif
          INP_RUNLOCK(inp);
          pcbinfo = inp->inp_pcbinfo;
          uma_zfree(pcbinfo->ipi_zone, inp);
          return (1);
  }
  
  int
  in_pcbrele_wlocked(struct inpcb *inp)
  {
          struct inpcbinfo *pcbinfo;
  
          KASSERT(inp->inp_refcount > 0, ("%s: refcount 0", __func__));
  
          INP_WLOCK_ASSERT(inp);
  
          if (refcount_release(&inp->inp_refcount) == 0) {
                  /*
                   * If the inpcb has been freed, let the caller know, even if
                   * this isn't the last reference.
                   */
                  if (inp->inp_flags2 & INP_FREED) {
                          INP_WUNLOCK(inp);
                          return (1);
                  }
                  return (0);
          }
  
          KASSERT(inp->inp_socket == NULL, ("%s: inp_socket != NULL", __func__));
  #ifdef TCPHPTS
          if (inp->inp_in_hpts || inp->inp_in_input) {
                  struct tcp_hpts_entry *hpts;
                  /*
                   * We should not be on the hpts at 
                   * this point in any form. we must
                   * get the lock to be sure.
                   */
                  hpts = tcp_hpts_lock(inp);
                  if (inp->inp_in_hpts)
                          panic("Hpts:%p inp:%p at free still on hpts",
                                hpts, inp);
                  mtx_unlock(&hpts->p_mtx);
                  hpts = tcp_input_lock(inp);
                  if (inp->inp_in_input) 
                          panic("Hpts:%p inp:%p at free still on input hpts",
                                hpts, inp);
                  mtx_unlock(&hpts->p_mtx);
          }
  #endif
          INP_WUNLOCK(inp);
          pcbinfo = inp->inp_pcbinfo;
          uma_zfree(pcbinfo->ipi_zone, inp);
          return (1);
  }
  
  /*
   * Temporary wrapper.
   */
  int
  in_pcbrele(struct inpcb *inp)
  {
  
          return (in_pcbrele_wlocked(inp));
  }
  
  void
  in_pcblist_rele_rlocked(epoch_context_t ctx)
  {
          struct in_pcblist *il;
          struct inpcb *inp;
          struct inpcbinfo *pcbinfo;
          int i, n;
  
          il = __containerof(ctx, struct in_pcblist, il_epoch_ctx);
          pcbinfo = il->il_pcbinfo;
          n = il->il_count;
          INP_INFO_WLOCK(pcbinfo);
          for (i = 0; i < n; i++) {
                  inp = il->il_inp_list[i];
                  INP_RLOCK(inp);
                  if (!in_pcbrele_rlocked(inp))
                          INP_RUNLOCK(inp);
          }
          INP_INFO_WUNLOCK(pcbinfo);
          free(il, M_TEMP);
  }
  
  static void
  inpcbport_free(epoch_context_t ctx)
  {
          struct inpcbport *phd;
  
          phd = __containerof(ctx, struct inpcbport, phd_epoch_ctx);
          free(phd, M_PCB);
  }
  
  static void
  in_pcbfree_deferred(epoch_context_t ctx)
  {
          struct inpcb *inp;
          int released __unused;
  
          inp = __containerof(ctx, struct inpcb, inp_epoch_ctx);
  
          INP_WLOCK(inp);
          CURVNET_SET(inp->inp_vnet);
  #ifdef INET
          struct ip_moptions *imo = inp->inp_moptions;
          inp->inp_moptions = NULL;
  #endif
          /* XXXRW: Do as much as possible here. */
  #if defined(IPSEC) || defined(IPSEC_SUPPORT)
          if (inp->inp_sp != NULL)
                  ipsec_delete_pcbpolicy(inp);
  #endif
  #ifdef INET6
          struct ip6_moptions *im6o = NULL;
          if (inp->inp_vflag & INP_IPV6PROTO) {
                  ip6_freepcbopts(inp->in6p_outputopts);
                  im6o = inp->in6p_moptions;
                  inp->in6p_moptions = NULL;
          }
  #endif
          if (inp->inp_options)
                  (void)m_free(inp->inp_options);
          inp->inp_vflag = 0;
          crfree(inp->inp_cred);
  #ifdef MAC
          mac_inpcb_destroy(inp);
  #endif
          released = in_pcbrele_wlocked(inp);
          MPASS(released);
  #ifdef INET6
          ip6_freemoptions(im6o);
  #endif
  #ifdef INET
          inp_freemoptions(imo);
  #endif  
          CURVNET_RESTORE();
  }
  
  /*
   * Unconditionally schedule an inpcb to be freed by decrementing its
   * reference count, which should occur only after the inpcb has been detached
   * from its socket.  If another thread holds a temporary reference (acquired
   * using in_pcbref()) then the free is deferred until that reference is
   * released using in_pcbrele(), but the inpcb is still unlocked.  Almost all
   * work, including removal from global lists, is done in this context, where
   * the pcbinfo lock is held.
   */
  void
  in_pcbfree(struct inpcb *inp)
  {
          struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
  
          KASSERT(inp->inp_socket == NULL, ("%s: inp_socket != NULL", __func__));
          KASSERT((inp->inp_flags2 & INP_FREED) == 0,
              ("%s: called twice for pcb %p", __func__, inp));
          if (inp->inp_flags2 & INP_FREED) {
                  INP_WUNLOCK(inp);
                  return;
          }
  
  #ifdef INVARIANTS
          if (pcbinfo == &V_tcbinfo) {
                  INP_INFO_LOCK_ASSERT(pcbinfo);
          } else {
                  INP_INFO_WLOCK_ASSERT(pcbinfo);
          }
  #endif
          INP_WLOCK_ASSERT(inp);
          INP_LIST_WLOCK(pcbinfo);
          in_pcbremlists(inp);
          INP_LIST_WUNLOCK(pcbinfo);
          RO_INVALIDATE_CACHE(&inp->inp_route);
          /* mark as destruction in progress */
          inp->inp_flags2 |= INP_FREED;
          INP_WUNLOCK(inp);
          epoch_call(net_epoch_preempt, &inp->inp_epoch_ctx, in_pcbfree_deferred);
  }
  
  /*
   * in_pcbdrop() removes an inpcb from hashed lists, releasing its address and
   * port reservation, and preventing it from being returned by inpcb lookups.
   *
   * It is used by TCP to mark an inpcb as unused and avoid future packet
   * delivery or event notification when a socket remains open but TCP has
   * closed.  This might occur as a result of a shutdown()-initiated TCP close
   * or a RST on the wire, and allows the port binding to be reused while still
   * maintaining the invariant that so_pcb always points to a valid inpcb until
   * in_pcbdetach().
   *
   * XXXRW: Possibly in_pcbdrop() should also prevent future notifications by
   * in_pcbnotifyall() and in_pcbpurgeif0()?
   */
  void
  in_pcbdrop(struct inpcb *inp)
  {
  
          INP_WLOCK_ASSERT(inp);
  #ifdef INVARIANTS
          if (inp->inp_socket != NULL && inp->inp_ppcb != NULL)
                  MPASS(inp->inp_refcount > 1);
  #endif
  
          /*
           * XXXRW: Possibly we should protect the setting of INP_DROPPED with
           * the hash lock...?
           */
          inp->inp_flags |= INP_DROPPED;
          if (inp->inp_flags & INP_INHASHLIST) {
                  struct inpcbport *phd = inp->inp_phd;
  
                  INP_HASH_WLOCK(inp->inp_pcbinfo);
                  in_pcbremlbgrouphash(inp);
                  CK_LIST_REMOVE(inp, inp_hash);
                  CK_LIST_REMOVE(inp, inp_portlist);
                  if (CK_LIST_FIRST(&phd->phd_pcblist) == NULL) {
                          CK_LIST_REMOVE(phd, phd_hash);
                          epoch_call(net_epoch_preempt, &phd->phd_epoch_ctx, inpcbport_free);
                  }
                  INP_HASH_WUNLOCK(inp->inp_pcbinfo);
                  inp->inp_flags &= ~INP_INHASHLIST;
  #ifdef PCBGROUP
                  in_pcbgroup_remove(inp);
  #endif
          }
  }
  
  #ifdef INET
  /*
   * Common routines to return the socket addresses associated with inpcbs.
   */
  struct sockaddr *
  in_sockaddr(in_port_t port, struct in_addr *addr_p)
  {
          struct sockaddr_in *sin;
  
          sin = malloc(sizeof *sin, M_SONAME,
                  M_WAITOK | M_ZERO);
          sin->sin_family = AF_INET;
          sin->sin_len = sizeof(*sin);
          sin->sin_addr = *addr_p;
          sin->sin_port = port;
  
          return (struct sockaddr *)sin;
  }
  
  int
  in_getsockaddr(struct socket *so, struct sockaddr **nam)
  {
          struct inpcb *inp;
          struct in_addr addr;
          in_port_t port;
  
          inp = sotoinpcb(so);
          KASSERT(inp != NULL, ("in_getsockaddr: inp == NULL"));
  
          INP_RLOCK(inp);
          port = inp->inp_lport;
          addr = inp->inp_laddr;
          INP_RUNLOCK(inp);
  
          *nam = in_sockaddr(port, &addr);
          return 0;
  }
  
  int
  in_getpeeraddr(struct socket *so, struct sockaddr **nam)
  {
          struct inpcb *inp;
          struct in_addr addr;
          in_port_t port;
  
          inp = sotoinpcb(so);
          KASSERT(inp != NULL, ("in_getpeeraddr: inp == NULL"));
  
          INP_RLOCK(inp);
          port = inp->inp_fport;
          addr = inp->inp_faddr;
          INP_RUNLOCK(inp);
  
          *nam = in_sockaddr(port, &addr);
          return 0;
  }
  
  void
  in_pcbnotifyall(struct inpcbinfo *pcbinfo, struct in_addr faddr, int errno,
      struct inpcb *(*notify)(struct inpcb *, int))
  {
          struct inpcb *inp, *inp_temp;
  
          INP_INFO_WLOCK(pcbinfo);
          CK_LIST_FOREACH_SAFE(inp, pcbinfo->ipi_listhead, inp_list, inp_temp) {
                  INP_WLOCK(inp);
  #ifdef INET6
                  if ((inp->inp_vflag & INP_IPV4) == 0) {
                          INP_WUNLOCK(inp);
                          continue;
                  }
  #endif
                  if (inp->inp_faddr.s_addr != faddr.s_addr ||
                      inp->inp_socket == NULL) {
                          INP_WUNLOCK(inp);
                          continue;
                  }
                  if ((*notify)(inp, errno))
                          INP_WUNLOCK(inp);
          }
          INP_INFO_WUNLOCK(pcbinfo);
  }
  
  void
  in_pcbpurgeif0(struct inpcbinfo *pcbinfo, struct ifnet *ifp)
  {
          struct inpcb *inp;
          struct in_multi *inm;
          struct in_mfilter *imf;
          struct ip_moptions *imo;
  
          INP_INFO_WLOCK(pcbinfo);
          CK_LIST_FOREACH(inp, pcbinfo->ipi_listhead, inp_list) {
                  INP_WLOCK(inp);
                  imo = inp->inp_moptions;
                  if ((inp->inp_vflag & INP_IPV4) &&
                      imo != NULL) {
                          /*
                           * Unselect the outgoing interface if it is being
                           * detached.
                           */
                          if (imo->imo_multicast_ifp == ifp)
                                  imo->imo_multicast_ifp = NULL;
  
                          /*
                           * Drop multicast group membership if we joined
                           * through the interface being detached.
                           *
                           * XXX This can all be deferred to an epoch_call
                           */
  restart:
                          IP_MFILTER_FOREACH(imf, &imo->imo_head) {
                                  if ((inm = imf->imf_inm) == NULL)
                                          continue;
                                  if (inm->inm_ifp != ifp)
                                          continue;
                                  ip_mfilter_remove(&imo->imo_head, imf);
                                  IN_MULTI_LOCK_ASSERT();
                                  in_leavegroup_locked(inm, NULL);
                                  ip_mfilter_free(imf);
                                  goto restart;
                          }
                  }
                  INP_WUNLOCK(inp);
          }
          INP_INFO_WUNLOCK(pcbinfo);
  }
  
  /*
   * Lookup a PCB based on the local address and port.  Caller must hold the
   * hash lock.  No inpcb locks or references are acquired.
   */
  #define INP_LOOKUP_MAPPED_PCB_COST      3
  struct inpcb *
  in_pcblookup_local(struct inpcbinfo *pcbinfo, struct in_addr laddr,
      u_short lport, int lookupflags, struct ucred *cred)
  {
          struct inpcb *inp;
  #ifdef INET6
          int matchwild = 3 + INP_LOOKUP_MAPPED_PCB_COST;
  #else
          int matchwild = 3;
  #endif
          int wildcard;
  
          KASSERT((lookupflags & ~(INPLOOKUP_WILDCARD)) == 0,
              ("%s: invalid lookup flags %d", __func__, lookupflags));
  
          INP_HASH_LOCK_ASSERT(pcbinfo);
  
          if ((lookupflags & INPLOOKUP_WILDCARD) == 0) {
                  struct inpcbhead *head;
                  /*
                   * Look for an unconnected (wildcard foreign addr) PCB that
                   * matches the local address and port we're looking for.
                   */
                  head = &pcbinfo->ipi_hashbase[INP_PCBHASH(INADDR_ANY, lport,
                      0, pcbinfo->ipi_hashmask)];
                  CK_LIST_FOREACH(inp, head, inp_hash) {
  #ifdef INET6
                          /* XXX inp locking */
                          if ((inp->inp_vflag & INP_IPV4) == 0)
                                  continue;
  #endif
                          if (inp->inp_faddr.s_addr == INADDR_ANY &&
                              inp->inp_laddr.s_addr == laddr.s_addr &&
                              inp->inp_lport == lport) {
                                  /*
                                   * Found?
                                   */
                                  if (cred == NULL ||
                                      prison_equal_ip4(cred->cr_prison,
                                          inp->inp_cred->cr_prison))
                                          return (inp);
                          }
                  }
                  /*
                   * Not found.
                   */
                  return (NULL);
          } else {
                  struct inpcbporthead *porthash;
                  struct inpcbport *phd;
                  struct inpcb *match = NULL;
                  /*
                   * Best fit PCB lookup.
                   *
                   * First see if this local port is in use by looking on the
                   * port hash list.
                   */
                  porthash = &pcbinfo->ipi_porthashbase[INP_PCBPORTHASH(lport,
                      pcbinfo->ipi_porthashmask)];
                  CK_LIST_FOREACH(phd, porthash, phd_hash) {
                          if (phd->phd_port == lport)
                                  break;
                  }
                  if (phd != NULL) {
                          /*
                           * Port is in use by one or more PCBs. Look for best
                           * fit.
                           */
                          CK_LIST_FOREACH(inp, &phd->phd_pcblist, inp_portlist) {
                                  wildcard = 0;
                                  if (cred != NULL &&
                                      !prison_equal_ip4(inp->inp_cred->cr_prison,
                                          cred->cr_prison))
                                          continue;
  #ifdef INET6
                                  /* XXX inp locking */
                                  if ((inp->inp_vflag & INP_IPV4) == 0)
                                          continue;
                                  /*
                                   * We never select the PCB that has
                                   * INP_IPV6 flag and is bound to :: if
                                   * we have another PCB which is bound
                                   * to 0.0.0.0.  If a PCB has the
                                   * INP_IPV6 flag, then we set its cost
                                   * higher than IPv4 only PCBs.
                                   *
                                   * Note that the case only happens
                                   * when a socket is bound to ::, under
                                   * the condition that the use of the
                                   * mapped address is allowed.
                                   */
                                  if ((inp->inp_vflag & INP_IPV6) != 0)
                                          wildcard += INP_LOOKUP_MAPPED_PCB_COST;
  #endif
                                  if (inp->inp_faddr.s_addr != INADDR_ANY)
                                          wildcard++;
                                  if (inp->inp_laddr.s_addr != INADDR_ANY) {
                                          if (laddr.s_addr == INADDR_ANY)
                                                  wildcard++;
                                          else if (inp->inp_laddr.s_addr != laddr.s_addr)
                                                  continue;
                                  } else {
                                          if (laddr.s_addr != INADDR_ANY)
                                                  wildcard++;
                                  }
                                  if (wildcard < matchwild) {
                                          match = inp;
                                          matchwild = wildcard;
                                          if (matchwild == 0)
                                                  break;
                                  }
                          }
                  }
                  return (match);
          }
  }
  #undef INP_LOOKUP_MAPPED_PCB_COST
  
  static struct inpcb *
  in_pcblookup_lbgroup(const struct inpcbinfo *pcbinfo,
      const struct in_addr *laddr, uint16_t lport, const struct in_addr *faddr,
      uint16_t fport, int lookupflags)
  {
          struct inpcb *local_wild;
          const struct inpcblbgrouphead *hdr;
          struct inpcblbgroup *grp;
          uint32_t idx;
  
          INP_HASH_LOCK_ASSERT(pcbinfo);
  
          hdr = &pcbinfo->ipi_lbgrouphashbase[
              INP_PCBPORTHASH(lport, pcbinfo->ipi_lbgrouphashmask)];
  
          /*
           * Order of socket selection:
           * 1. non-wild.
           * 2. wild (if lookupflags contains INPLOOKUP_WILDCARD).
           *
           * NOTE:
           * - Load balanced group does not contain jailed sockets
           * - Load balanced group does not contain IPv4 mapped INET6 wild sockets
           */
          local_wild = NULL;
          CK_LIST_FOREACH(grp, hdr, il_list) {
  #ifdef INET6
                  if (!(grp->il_vflag & INP_IPV4))
                          continue;
  #endif
                  if (grp->il_lport != lport)
                          continue;
  
                  idx = INP_PCBLBGROUP_PKTHASH(faddr->s_addr, lport, fport) %
                      grp->il_inpcnt;
                  if (grp->il_laddr.s_addr == laddr->s_addr)
                          return (grp->il_inp[idx]);
                  if (grp->il_laddr.s_addr == INADDR_ANY &&
                      (lookupflags & INPLOOKUP_WILDCARD) != 0)
                          local_wild = grp->il_inp[idx];
          }
          return (local_wild);
  }
  
  #ifdef PCBGROUP
  /*
   * Lookup PCB in hash list, using pcbgroup tables.
   */
  static struct inpcb *
  in_pcblookup_group(struct inpcbinfo *pcbinfo, struct inpcbgroup *pcbgroup,
      struct in_addr faddr, u_int fport_arg, struct in_addr laddr,
      u_int lport_arg, int lookupflags, struct ifnet *ifp)
  {
          struct inpcbhead *head;
          struct inpcb *inp, *tmpinp;
          u_short fport = fport_arg, lport = lport_arg;
          bool locked;
  
          /*
           * First look for an exact match.
           */
          tmpinp = NULL;
          INP_GROUP_LOCK(pcbgroup);
          head = &pcbgroup->ipg_hashbase[INP_PCBHASH(faddr.s_addr, lport, fport,
              pcbgroup->ipg_hashmask)];
          CK_LIST_FOREACH(inp, head, inp_pcbgrouphash) {
  #ifdef INET6
                  /* XXX inp locking */
                  if ((inp->inp_vflag & INP_IPV4) == 0)
                          continue;
  #endif
                  if (inp->inp_faddr.s_addr == faddr.s_addr &&
                      inp->inp_laddr.s_addr == laddr.s_addr &&
                      inp->inp_fport == fport &&
                      inp->inp_lport == lport) {
                          /*
                           * XXX We should be able to directly return
                           * the inp here, without any checks.
                           * Well unless both bound with SO_REUSEPORT?
                           */
                          if (prison_flag(inp->inp_cred, PR_IP4))
                                  goto found;
                          if (tmpinp == NULL)
                                  tmpinp = inp;
                  }
          }
          if (tmpinp != NULL) {
                  inp = tmpinp;
                  goto found;
          }
  
  #ifdef  RSS
          /*
           * For incoming connections, we may wish to do a wildcard
           * match for an RSS-local socket.
           */
          if ((lookupflags & INPLOOKUP_WILDCARD) != 0) {
                  struct inpcb *local_wild = NULL, *local_exact = NULL;
  #ifdef INET6
                  struct inpcb *local_wild_mapped = NULL;
  #endif
                  struct inpcb *jail_wild = NULL;
                  struct inpcbhead *head;
                  int injail;
  
                  /*
                   * Order of socket selection - we always prefer jails.
                   *      1. jailed, non-wild.
                   *      2. jailed, wild.
                   *      3. non-jailed, non-wild.
                   *      4. non-jailed, wild.
                   */
  
                  head = &pcbgroup->ipg_hashbase[INP_PCBHASH(INADDR_ANY,
                      lport, 0, pcbgroup->ipg_hashmask)];
                  CK_LIST_FOREACH(inp, head, inp_pcbgrouphash) {
  #ifdef INET6
                          /* XXX inp locking */
                          if ((inp->inp_vflag & INP_IPV4) == 0)
                                  continue;
  #endif
                          if (inp->inp_faddr.s_addr != INADDR_ANY ||
                              inp->inp_lport != lport)
                                  continue;
  
                          injail = prison_flag(inp->inp_cred, PR_IP4);
                          if (injail) {
                                  if (prison_check_ip4(inp->inp_cred,
                                      &laddr) != 0)
                                          continue;
                          } else {
                                  if (local_exact != NULL)
                                          continue;
                          }
  
                          if (inp->inp_laddr.s_addr == laddr.s_addr) {
                                  if (injail)
                                          goto found;
                                  else
                                          local_exact = inp;
                          } else if (inp->inp_laddr.s_addr == INADDR_ANY) {
  #ifdef INET6
                                  /* XXX inp locking, NULL check */
                                  if (inp->inp_vflag & INP_IPV6PROTO)
                                          local_wild_mapped = inp;
                                  else
  #endif
                                          if (injail)
                                                  jail_wild = inp;
                                          else
                                                  local_wild = inp;
                          }
                  } /* LIST_FOREACH */
  
                  inp = jail_wild;
                  if (inp == NULL)
                          inp = local_exact;
                  if (inp == NULL)
                          inp = local_wild;
  #ifdef INET6
                  if (inp == NULL)
                          inp = local_wild_mapped;
  #endif
                  if (inp != NULL)
                          goto found;
          }
  #endif
  
          /*
           * Then look for a wildcard match, if requested.
           */
          if ((lookupflags & INPLOOKUP_WILDCARD) != 0) {
                  struct inpcb *local_wild = NULL, *local_exact = NULL;
  #ifdef INET6
                  struct inpcb *local_wild_mapped = NULL;
  #endif
                  struct inpcb *jail_wild = NULL;
                  struct inpcbhead *head;
                  int injail;
  
                  /*
                   * Order of socket selection - we always prefer jails.
                   *      1. jailed, non-wild.
                   *      2. jailed, wild.
                   *      3. non-jailed, non-wild.
                   *      4. non-jailed, wild.
                   */
                  head = &pcbinfo->ipi_wildbase[INP_PCBHASH(INADDR_ANY, lport,
                      0, pcbinfo->ipi_wildmask)];
                  CK_LIST_FOREACH(inp, head, inp_pcbgroup_wild) {
  #ifdef INET6
                          /* XXX inp locking */
                          if ((inp->inp_vflag & INP_IPV4) == 0)
                                  continue;
  #endif
                          if (inp->inp_faddr.s_addr != INADDR_ANY ||
                              inp->inp_lport != lport)
                                  continue;
  
                          injail = prison_flag(inp->inp_cred, PR_IP4);
                          if (injail) {
                                  if (prison_check_ip4(inp->inp_cred,
                                      &laddr) != 0)
                                          continue;
                          } else {
                                  if (local_exact != NULL)
                                          continue;
                          }
  
                          if (inp->inp_laddr.s_addr == laddr.s_addr) {
                                  if (injail)
                                          goto found;
                                  else
                                          local_exact = inp;
                          } else if (inp->inp_laddr.s_addr == INADDR_ANY) {
  #ifdef INET6
                                  /* XXX inp locking, NULL check */
                                  if (inp->inp_vflag & INP_IPV6PROTO)
                                          local_wild_mapped = inp;
                                  else
  #endif
                                          if (injail)
                                                  jail_wild = inp;
                                          else
                                                  local_wild = inp;
                          }
                  } /* LIST_FOREACH */
                  inp = jail_wild;
                  if (inp == NULL)
                          inp = local_exact;
                  if (inp == NULL)
                          inp = local_wild;
  #ifdef INET6
                  if (inp == NULL)
                          inp = local_wild_mapped;
  #endif
                  if (inp != NULL)
                          goto found;
          } /* if (lookupflags & INPLOOKUP_WILDCARD) */
          INP_GROUP_UNLOCK(pcbgroup);
          return (NULL);
  
  found:
          if (lookupflags & INPLOOKUP_WLOCKPCB)
                  locked = INP_TRY_WLOCK(inp);
          else if (lookupflags & INPLOOKUP_RLOCKPCB)
                  locked = INP_TRY_RLOCK(inp);
          else
                  panic("%s: locking bug", __func__);
          if (__predict_false(locked && (inp->inp_flags2 & INP_FREED))) {
                  if (lookupflags & INPLOOKUP_WLOCKPCB)
                          INP_WUNLOCK(inp);
                  else
                          INP_RUNLOCK(inp);
                  return (NULL);
          } else if (!locked)
                  in_pcbref(inp);
          INP_GROUP_UNLOCK(pcbgroup);
          if (!locked) {
                  if (lookupflags & INPLOOKUP_WLOCKPCB) {
                          INP_WLOCK(inp);
                          if (in_pcbrele_wlocked(inp))
                                  return (NULL);
                  } else {
                          INP_RLOCK(inp);
                          if (in_pcbrele_rlocked(inp))
                                  return (NULL);
                  }
          }
  #ifdef INVARIANTS
          if (lookupflags & INPLOOKUP_WLOCKPCB)
                  INP_WLOCK_ASSERT(inp);
          else
                  INP_RLOCK_ASSERT(inp);
  #endif
          return (inp);
  }
  #endif /* PCBGROUP */
  
  /*
   * Lookup PCB in hash list, using pcbinfo tables.  This variation assumes
   * that the caller has locked the hash list, and will not perform any further
   * locking or reference operations on either the hash list or the connection.
   */
  static struct inpcb *
  in_pcblookup_hash_locked(struct inpcbinfo *pcbinfo, struct in_addr faddr,
      u_int fport_arg, struct in_addr laddr, u_int lport_arg, int lookupflags,
      struct ifnet *ifp)
  {
          struct inpcbhead *head;
          struct inpcb *inp, *tmpinp;
          u_short fport = fport_arg, lport = lport_arg;
  
  #ifdef INVARIANTS
          KASSERT((lookupflags & ~(INPLOOKUP_WILDCARD)) == 0,
              ("%s: invalid lookup flags %d", __func__, lookupflags));
          if (!mtx_owned(&pcbinfo->ipi_hash_lock))
                  MPASS(in_epoch_verbose(net_epoch_preempt, 1));
  #endif
          /*
           * First look for an exact match.
           */
          tmpinp = NULL;
          head = &pcbinfo->ipi_hashbase[INP_PCBHASH(faddr.s_addr, lport, fport,
              pcbinfo->ipi_hashmask)];
          CK_LIST_FOREACH(inp, head, inp_hash) {
  #ifdef INET6
                  /* XXX inp locking */
                  if ((inp->inp_vflag & INP_IPV4) == 0)
                          continue;
  #endif
                  if (inp->inp_faddr.s_addr == faddr.s_addr &&
                      inp->inp_laddr.s_addr == laddr.s_addr &&
                      inp->inp_fport == fport &&
                      inp->inp_lport == lport) {
                          /*
                           * XXX We should be able to directly return
                           * the inp here, without any checks.
                           * Well unless both bound with SO_REUSEPORT?
                           */
                          if (prison_flag(inp->inp_cred, PR_IP4))
                                  return (inp);
                          if (tmpinp == NULL)
                                  tmpinp = inp;
                  }
          }
          if (tmpinp != NULL)
                  return (tmpinp);
  
          /*
           * Then look in lb group (for wildcard match).
           */
          if ((lookupflags & INPLOOKUP_WILDCARD) != 0) {
                  inp = in_pcblookup_lbgroup(pcbinfo, &laddr, lport, &faddr,
                      fport, lookupflags);
                  if (inp != NULL)
                          return (inp);
          }
  
          /*
           * Then look for a wildcard match, if requested.
           */
          if ((lookupflags & INPLOOKUP_WILDCARD) != 0) {
                  struct inpcb *local_wild = NULL, *local_exact = NULL;
  #ifdef INET6
                  struct inpcb *local_wild_mapped = NULL;
  #endif
                  struct inpcb *jail_wild = NULL;
                  int injail;
  
                  /*
                   * Order of socket selection - we always prefer jails.
                   *      1. jailed, non-wild.
                   *      2. jailed, wild.
                   *      3. non-jailed, non-wild.
                   *      4. non-jailed, wild.
                   */
  
                  head = &pcbinfo->ipi_hashbase[INP_PCBHASH(INADDR_ANY, lport,
                      0, pcbinfo->ipi_hashmask)];
                  CK_LIST_FOREACH(inp, head, inp_hash) {
  #ifdef INET6
                          /* XXX inp locking */
                          if ((inp->inp_vflag & INP_IPV4) == 0)
                                  continue;
  #endif
                          if (inp->inp_faddr.s_addr != INADDR_ANY ||
                              inp->inp_lport != lport)
                                  continue;
  
                          injail = prison_flag(inp->inp_cred, PR_IP4);
                          if (injail) {
                                  if (prison_check_ip4(inp->inp_cred,
                                      &laddr) != 0)
                                          continue;
                          } else {
                                  if (local_exact != NULL)
                                          continue;
                          }
  
                          if (inp->inp_laddr.s_addr == laddr.s_addr) {
                                  if (injail)
                                          return (inp);
                                  else
                                          local_exact = inp;
                          } else if (inp->inp_laddr.s_addr == INADDR_ANY) {
  #ifdef INET6
                                  /* XXX inp locking, NULL check */
                                  if (inp->inp_vflag & INP_IPV6PROTO)
                                          local_wild_mapped = inp;
                                  else
  #endif
                                          if (injail)
                                                  jail_wild = inp;
                                          else
                                                  local_wild = inp;
                          }
                  } /* LIST_FOREACH */
                  if (jail_wild != NULL)
                          return (jail_wild);
                  if (local_exact != NULL)
                          return (local_exact);
                  if (local_wild != NULL)
                          return (local_wild);
  #ifdef INET6
                  if (local_wild_mapped != NULL)
                          return (local_wild_mapped);
  #endif
          } /* if ((lookupflags & INPLOOKUP_WILDCARD) != 0) */
  
          return (NULL);
  }
  
  /*
   * Lookup PCB in hash list, using pcbinfo tables.  This variation locks the
   * hash list lock, and will return the inpcb locked (i.e., requires
   * INPLOOKUP_LOCKPCB).
   */
  static struct inpcb *
  in_pcblookup_hash(struct inpcbinfo *pcbinfo, struct in_addr faddr,
      u_int fport, struct in_addr laddr, u_int lport, int lookupflags,
      struct ifnet *ifp)
  {
          struct inpcb *inp;
  
          INP_HASH_RLOCK(pcbinfo);
          inp = in_pcblookup_hash_locked(pcbinfo, faddr, fport, laddr, lport,
              (lookupflags & ~(INPLOOKUP_RLOCKPCB | INPLOOKUP_WLOCKPCB)), ifp);
          if (inp != NULL) {
                  if (lookupflags & INPLOOKUP_WLOCKPCB) {
                          INP_WLOCK(inp);
                          if (__predict_false(inp->inp_flags2 & INP_FREED)) {
                                  INP_WUNLOCK(inp);
                                  inp = NULL;
                          }
                  } else if (lookupflags & INPLOOKUP_RLOCKPCB) {
                          INP_RLOCK(inp);
                          if (__predict_false(inp->inp_flags2 & INP_FREED)) {
                                  INP_RUNLOCK(inp);
                                  inp = NULL;
                          }
                  } else
                          panic("%s: locking bug", __func__);
  #ifdef INVARIANTS
                  if (inp != NULL) {
                          if (lookupflags & INPLOOKUP_WLOCKPCB)
                                  INP_WLOCK_ASSERT(inp);
                          else
                                  INP_RLOCK_ASSERT(inp);
                  }
  #endif
          }
          INP_HASH_RUNLOCK(pcbinfo);
          return (inp);
  }
  
  /*
   * Public inpcb lookup routines, accepting a 4-tuple, and optionally, an mbuf
   * from which a pre-calculated hash value may be extracted.
   *
   * Possibly more of this logic should be in in_pcbgroup.c.
   */
  struct inpcb *
  in_pcblookup(struct inpcbinfo *pcbinfo, struct in_addr faddr, u_int fport,
      struct in_addr laddr, u_int lport, int lookupflags, struct ifnet *ifp)
  {
  #if defined(PCBGROUP) && !defined(RSS)
          struct inpcbgroup *pcbgroup;
  #endif
  
          KASSERT((lookupflags & ~INPLOOKUP_MASK) == 0,
              ("%s: invalid lookup flags %d", __func__, lookupflags));
          KASSERT((lookupflags & (INPLOOKUP_RLOCKPCB | INPLOOKUP_WLOCKPCB)) != 0,
              ("%s: LOCKPCB not set", __func__));
  
          /*
           * When not using RSS, use connection groups in preference to the
           * reservation table when looking up 4-tuples.  When using RSS, just
           * use the reservation table, due to the cost of the Toeplitz hash
           * in software.
           *
           * XXXRW: This policy belongs in the pcbgroup code, as in principle
           * we could be doing RSS with a non-Toeplitz hash that is affordable
           * in software.
           */
  #if defined(PCBGROUP) && !defined(RSS)
          if (in_pcbgroup_enabled(pcbinfo)) {
                  pcbgroup = in_pcbgroup_bytuple(pcbinfo, laddr, lport, faddr,
                      fport);
                  return (in_pcblookup_group(pcbinfo, pcbgroup, faddr, fport,
                      laddr, lport, lookupflags, ifp));
          }
  #endif
          return (in_pcblookup_hash(pcbinfo, faddr, fport, laddr, lport,
              lookupflags, ifp));
  }
  
  struct inpcb *
  in_pcblookup_mbuf(struct inpcbinfo *pcbinfo, struct in_addr faddr,
      u_int fport, struct in_addr laddr, u_int lport, int lookupflags,
      struct ifnet *ifp, struct mbuf *m)
  {
  #ifdef PCBGROUP
          struct inpcbgroup *pcbgroup;
  #endif
  
          KASSERT((lookupflags & ~INPLOOKUP_MASK) == 0,
              ("%s: invalid lookup flags %d", __func__, lookupflags));
          KASSERT((lookupflags & (INPLOOKUP_RLOCKPCB | INPLOOKUP_WLOCKPCB)) != 0,
              ("%s: LOCKPCB not set", __func__));
  
  #ifdef PCBGROUP
          /*
           * If we can use a hardware-generated hash to look up the connection
           * group, use that connection group to find the inpcb.  Otherwise
           * fall back on a software hash -- or the reservation table if we're
           * using RSS.
           *
           * XXXRW: As above, that policy belongs in the pcbgroup code.
           */
          if (in_pcbgroup_enabled(pcbinfo) &&
              !(M_HASHTYPE_TEST(m, M_HASHTYPE_NONE))) {
                  pcbgroup = in_pcbgroup_byhash(pcbinfo, M_HASHTYPE_GET(m),
                      m->m_pkthdr.flowid);
                  if (pcbgroup != NULL)
                          return (in_pcblookup_group(pcbinfo, pcbgroup, faddr,
                              fport, laddr, lport, lookupflags, ifp));
  #ifndef RSS
                  pcbgroup = in_pcbgroup_bytuple(pcbinfo, laddr, lport, faddr,
                      fport);
                  return (in_pcblookup_group(pcbinfo, pcbgroup, faddr, fport,
                      laddr, lport, lookupflags, ifp));
  #endif
          }
  #endif
          return (in_pcblookup_hash(pcbinfo, faddr, fport, laddr, lport,
              lookupflags, ifp));
  }
  #endif /* INET */
  
  /*
   * Insert PCB onto various hash lists.
   */
  static int
  in_pcbinshash_internal(struct inpcb *inp, struct mbuf *m)
  {
          struct inpcbhead *pcbhash;
          struct inpcbporthead *pcbporthash;
          struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
          struct inpcbport *phd;
          u_int32_t hashkey_faddr;
          int so_options;
  
          INP_WLOCK_ASSERT(inp);
          INP_HASH_WLOCK_ASSERT(pcbinfo);
  
          KASSERT((inp->inp_flags & INP_INHASHLIST) == 0,
              ("in_pcbinshash: INP_INHASHLIST"));
  
  #ifdef INET6
          if (inp->inp_vflag & INP_IPV6)
                  hashkey_faddr = INP6_PCBHASHKEY(&inp->in6p_faddr);
          else
  #endif
          hashkey_faddr = inp->inp_faddr.s_addr;
  
          pcbhash = &pcbinfo->ipi_hashbase[INP_PCBHASH(hashkey_faddr,
                   inp->inp_lport, inp->inp_fport, pcbinfo->ipi_hashmask)];
  
          pcbporthash = &pcbinfo->ipi_porthashbase[
              INP_PCBPORTHASH(inp->inp_lport, pcbinfo->ipi_porthashmask)];
  
          /*
           * Add entry to load balance group.
           * Only do this if SO_REUSEPORT_LB is set.
           */
          so_options = inp_so_options(inp);
          if (so_options & SO_REUSEPORT_LB) {
                  int ret = in_pcbinslbgrouphash(inp);
                  if (ret) {
                          /* pcb lb group malloc fail (ret=ENOBUFS). */
                          return (ret);
                  }
          }
  
          /*
           * Go through port list and look for a head for this lport.
           */
          CK_LIST_FOREACH(phd, pcbporthash, phd_hash) {
                  if (phd->phd_port == inp->inp_lport)
                          break;
          }
          /*
           * If none exists, malloc one and tack it on.
           */
          if (phd == NULL) {
                  phd = malloc(sizeof(struct inpcbport), M_PCB, M_NOWAIT);
                  if (phd == NULL) {
                          return (ENOBUFS); /* XXX */
                  }
                  bzero(&phd->phd_epoch_ctx, sizeof(struct epoch_context));
                  phd->phd_port = inp->inp_lport;
                  CK_LIST_INIT(&phd->phd_pcblist);
                  CK_LIST_INSERT_HEAD(pcbporthash, phd, phd_hash);
          }
          inp->inp_phd = phd;
          CK_LIST_INSERT_HEAD(&phd->phd_pcblist, inp, inp_portlist);
          CK_LIST_INSERT_HEAD(pcbhash, inp, inp_hash);
          inp->inp_flags |= INP_INHASHLIST;
  #ifdef PCBGROUP
          if (m != NULL) {
                  in_pcbgroup_update_mbuf(inp, m);
          } else {
                  in_pcbgroup_update(inp);
          }
  #endif
          return (0);
  }
  
  int
  in_pcbinshash(struct inpcb *inp)
  {
  
          return (in_pcbinshash_internal(inp, NULL));
  }
  
  int
  in_pcbinshash_mbuf(struct inpcb *inp, struct mbuf *m)
  {
  
          return (in_pcbinshash_internal(inp, m));
  }
  
  /*
   * Move PCB to the proper hash bucket when { faddr, fport } have  been
   * changed. NOTE: This does not handle the case of the lport changing (the
   * hashed port list would have to be updated as well), so the lport must
   * not change after in_pcbinshash() has been called.
   */
  void
  in_pcbrehash_mbuf(struct inpcb *inp, struct mbuf *m)
  {
          struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
          struct inpcbhead *head;
          u_int32_t hashkey_faddr;
  
          INP_WLOCK_ASSERT(inp);
          INP_HASH_WLOCK_ASSERT(pcbinfo);
  
          KASSERT(inp->inp_flags & INP_INHASHLIST,
              ("in_pcbrehash: !INP_INHASHLIST"));
  
  #ifdef INET6
          if (inp->inp_vflag & INP_IPV6)
                  hashkey_faddr = INP6_PCBHASHKEY(&inp->in6p_faddr);
          else
  #endif
          hashkey_faddr = inp->inp_faddr.s_addr;
  
          head = &pcbinfo->ipi_hashbase[INP_PCBHASH(hashkey_faddr,
                  inp->inp_lport, inp->inp_fport, pcbinfo->ipi_hashmask)];
  
          CK_LIST_REMOVE(inp, inp_hash);
          CK_LIST_INSERT_HEAD(head, inp, inp_hash);
  
  #ifdef PCBGROUP
          if (m != NULL)
                  in_pcbgroup_update_mbuf(inp, m);
          else
                  in_pcbgroup_update(inp);
  #endif
  }
  
  void
  in_pcbrehash(struct inpcb *inp)
  {
  
          in_pcbrehash_mbuf(inp, NULL);
  }
  
  /*
   * Remove PCB from various lists.
   */
  static void
  in_pcbremlists(struct inpcb *inp)
  {
          struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
  
  #ifdef INVARIANTS
          if (pcbinfo == &V_tcbinfo) {
                  INP_INFO_RLOCK_ASSERT(pcbinfo);
          } else {
                  INP_INFO_WLOCK_ASSERT(pcbinfo);
          }
  #endif
  
          INP_WLOCK_ASSERT(inp);
          INP_LIST_WLOCK_ASSERT(pcbinfo);
  
          inp->inp_gencnt = ++pcbinfo->ipi_gencnt;
          if (inp->inp_flags & INP_INHASHLIST) {
                  struct inpcbport *phd = inp->inp_phd;
  
                  INP_HASH_WLOCK(pcbinfo);
  
                  /* XXX: Only do if SO_REUSEPORT_LB set? */
                  in_pcbremlbgrouphash(inp);
  
                  CK_LIST_REMOVE(inp, inp_hash);
                  CK_LIST_REMOVE(inp, inp_portlist);
                  if (CK_LIST_FIRST(&phd->phd_pcblist) == NULL) {
                          CK_LIST_REMOVE(phd, phd_hash);
                          epoch_call(net_epoch_preempt, &phd->phd_epoch_ctx, inpcbport_free);
                  }
                  INP_HASH_WUNLOCK(pcbinfo);
                  inp->inp_flags &= ~INP_INHASHLIST;
          }
          CK_LIST_REMOVE(inp, inp_list);
          pcbinfo->ipi_count--;
  #ifdef PCBGROUP
          in_pcbgroup_remove(inp);
  #endif
  }
  
  /*
   * Check for alternatives when higher level complains
   * about service problems.  For now, invalidate cached
   * routing information.  If the route was created dynamically
   * (by a redirect), time to try a default gateway again.
   */
  void
  in_losing(struct inpcb *inp)
  {
  
          RO_INVALIDATE_CACHE(&inp->inp_route);
          return;
  }
  
  /*
   * A set label operation has occurred at the socket layer, propagate the
   * label change into the in_pcb for the socket.
   */
  void
  in_pcbsosetlabel(struct socket *so)
  {
  #ifdef MAC
          struct inpcb *inp;
  
          inp = sotoinpcb(so);
          KASSERT(inp != NULL, ("in_pcbsosetlabel: so->so_pcb == NULL"));
  
          INP_WLOCK(inp);
          SOCK_LOCK(so);
          mac_inpcb_sosetlabel(so, inp);
          SOCK_UNLOCK(so);
          INP_WUNLOCK(inp);
  #endif
  }
  
  /*
   * ipport_tick runs once per second, determining if random port allocation
   * should be continued.  If more than ipport_randomcps ports have been
   * allocated in the last second, then we return to sequential port
   * allocation. We return to random allocation only once we drop below
   * ipport_randomcps for at least ipport_randomtime seconds.
   */
  static void
  ipport_tick(void *xtp)
  {
          VNET_ITERATOR_DECL(vnet_iter);
  
          VNET_LIST_RLOCK_NOSLEEP();
          VNET_FOREACH(vnet_iter) {
                  CURVNET_SET(vnet_iter); /* XXX appease INVARIANTS here */
                  if (V_ipport_tcpallocs <=
                      V_ipport_tcplastcount + V_ipport_randomcps) {
                          if (V_ipport_stoprandom > 0)
                                  V_ipport_stoprandom--;
                  } else
                          V_ipport_stoprandom = V_ipport_randomtime;
                  V_ipport_tcplastcount = V_ipport_tcpallocs;
                  CURVNET_RESTORE();
          }
          VNET_LIST_RUNLOCK_NOSLEEP();
          callout_reset(&ipport_tick_callout, hz, ipport_tick, NULL);
  }
  
  static void
  ip_fini(void *xtp)
  {
  
          callout_stop(&ipport_tick_callout);
  }
  
  /* 
   * The ipport_callout should start running at about the time we attach the
   * inet or inet6 domains.
   */
  static void
  ipport_tick_init(const void *unused __unused)
  {
  
          /* Start ipport_tick. */
          callout_init(&ipport_tick_callout, 1);
          callout_reset(&ipport_tick_callout, 1, ipport_tick, NULL);
          EVENTHANDLER_REGISTER(shutdown_pre_sync, ip_fini, NULL,
                  SHUTDOWN_PRI_DEFAULT);
  }
  SYSINIT(ipport_tick_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, 
      ipport_tick_init, NULL);
  
  void
  inp_wlock(struct inpcb *inp)
  {
  
          INP_WLOCK(inp);
  }
  
  void
  inp_wunlock(struct inpcb *inp)
  {
  
          INP_WUNLOCK(inp);
  }
  
  void
  inp_rlock(struct inpcb *inp)
  {
  
          INP_RLOCK(inp);
  }
  
  void
  inp_runlock(struct inpcb *inp)
  {
  
          INP_RUNLOCK(inp);
  }
  
  #ifdef INVARIANT_SUPPORT
  void
  inp_lock_assert(struct inpcb *inp)
  {
  
          INP_WLOCK_ASSERT(inp);
  }
  
  void
  inp_unlock_assert(struct inpcb *inp)
  {
  
          INP_UNLOCK_ASSERT(inp);
  }
  #endif
  
  void
  inp_apply_all(void (*func)(struct inpcb *, void *), void *arg)
  {
          struct inpcb *inp;
  
          INP_INFO_WLOCK(&V_tcbinfo);
          CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) {
                  INP_WLOCK(inp);
                  func(inp, arg);
                  INP_WUNLOCK(inp);
          }
          INP_INFO_WUNLOCK(&V_tcbinfo);
  }
  
  struct socket *
  inp_inpcbtosocket(struct inpcb *inp)
  {
  
          INP_WLOCK_ASSERT(inp);
          return (inp->inp_socket);
  }
  
  struct tcpcb *
  inp_inpcbtotcpcb(struct inpcb *inp)
  {
  
          INP_WLOCK_ASSERT(inp);
          return ((struct tcpcb *)inp->inp_ppcb);
  }
  
  int
  inp_ip_tos_get(const struct inpcb *inp)
  {
  
          return (inp->inp_ip_tos);
  }
  
  void
  inp_ip_tos_set(struct inpcb *inp, int val)
  {
  
          inp->inp_ip_tos = val;
  }
  
  void
  inp_4tuple_get(struct inpcb *inp, uint32_t *laddr, uint16_t *lp,
      uint32_t *faddr, uint16_t *fp)
  {
  
          INP_LOCK_ASSERT(inp);
          *laddr = inp->inp_laddr.s_addr;
          *faddr = inp->inp_faddr.s_addr;
          *lp = inp->inp_lport;
          *fp = inp->inp_fport;
  }
  
  struct inpcb *
  so_sotoinpcb(struct socket *so)
  {
  
          return (sotoinpcb(so));
  }
  
  struct tcpcb *
  so_sototcpcb(struct socket *so)
  {
  
          return (sototcpcb(so));
  }
  
  /*
   * Create an external-format (``xinpcb'') structure using the information in
   * the kernel-format in_pcb structure pointed to by inp.  This is done to
   * reduce the spew of irrelevant information over this interface, to isolate
   * user code from changes in the kernel structure, and potentially to provide
   * information-hiding if we decide that some of this information should be
   * hidden from users.
   */
  void
  in_pcbtoxinpcb(const struct inpcb *inp, struct xinpcb *xi)
  {
  
          bzero(xi, sizeof(*xi));
          xi->xi_len = sizeof(struct xinpcb);
          if (inp->inp_socket)
                  sotoxsocket(inp->inp_socket, &xi->xi_socket);
          bcopy(&inp->inp_inc, &xi->inp_inc, sizeof(struct in_conninfo));
          xi->inp_gencnt = inp->inp_gencnt;
          xi->inp_ppcb = (uintptr_t)inp->inp_ppcb;
          xi->inp_flow = inp->inp_flow;
          xi->inp_flowid = inp->inp_flowid;
          xi->inp_flowtype = inp->inp_flowtype;
          xi->inp_flags = inp->inp_flags;
          xi->inp_flags2 = inp->inp_flags2;
          xi->inp_rss_listen_bucket = inp->inp_rss_listen_bucket;
          xi->in6p_cksum = inp->in6p_cksum;
          xi->in6p_hops = inp->in6p_hops;
          xi->inp_ip_tos = inp->inp_ip_tos;
          xi->inp_vflag = inp->inp_vflag;
          xi->inp_ip_ttl = inp->inp_ip_ttl;
          xi->inp_ip_p = inp->inp_ip_p;
          xi->inp_ip_minttl = inp->inp_ip_minttl;
  }
  
  #ifdef DDB
  static void
  db_print_indent(int indent)
  {
          int i;
  
          for (i = 0; i < indent; i++)
                  db_printf(" ");
  }
  
  static void
  db_print_inconninfo(struct in_conninfo *inc, const char *name, int indent)
  {
          char faddr_str[48], laddr_str[48];
  
          db_print_indent(indent);
          db_printf("%s at %p\n", name, inc);
  
          indent += 2;
  
  #ifdef INET6
          if (inc->inc_flags & INC_ISIPV6) {
                  /* IPv6. */
                  ip6_sprintf(laddr_str, &inc->inc6_laddr);
                  ip6_sprintf(faddr_str, &inc->inc6_faddr);
          } else
  #endif
          {
                  /* IPv4. */
                  inet_ntoa_r(inc->inc_laddr, laddr_str);
                  inet_ntoa_r(inc->inc_faddr, faddr_str);
          }
          db_print_indent(indent);
          db_printf("inc_laddr %s   inc_lport %u\n", laddr_str,
              ntohs(inc->inc_lport));
          db_print_indent(indent);
          db_printf("inc_faddr %s   inc_fport %u\n", faddr_str,
              ntohs(inc->inc_fport));
  }
  
  static void
  db_print_inpflags(int inp_flags)
  {
          int comma;
  
          comma = 0;
          if (inp_flags & INP_RECVOPTS) {
                  db_printf("%sINP_RECVOPTS", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_RECVRETOPTS) {
                  db_printf("%sINP_RECVRETOPTS", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_RECVDSTADDR) {
                  db_printf("%sINP_RECVDSTADDR", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_ORIGDSTADDR) {
                  db_printf("%sINP_ORIGDSTADDR", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_HDRINCL) {
                  db_printf("%sINP_HDRINCL", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_HIGHPORT) {
                  db_printf("%sINP_HIGHPORT", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_LOWPORT) {
                  db_printf("%sINP_LOWPORT", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_ANONPORT) {
                  db_printf("%sINP_ANONPORT", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_RECVIF) {
                  db_printf("%sINP_RECVIF", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_MTUDISC) {
                  db_printf("%sINP_MTUDISC", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_RECVTTL) {
                  db_printf("%sINP_RECVTTL", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_DONTFRAG) {
                  db_printf("%sINP_DONTFRAG", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_RECVTOS) {
                  db_printf("%sINP_RECVTOS", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & IN6P_IPV6_V6ONLY) {
                  db_printf("%sIN6P_IPV6_V6ONLY", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & IN6P_PKTINFO) {
                  db_printf("%sIN6P_PKTINFO", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & IN6P_HOPLIMIT) {
                  db_printf("%sIN6P_HOPLIMIT", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & IN6P_HOPOPTS) {
                  db_printf("%sIN6P_HOPOPTS", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & IN6P_DSTOPTS) {
                  db_printf("%sIN6P_DSTOPTS", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & IN6P_RTHDR) {
                  db_printf("%sIN6P_RTHDR", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & IN6P_RTHDRDSTOPTS) {
                  db_printf("%sIN6P_RTHDRDSTOPTS", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & IN6P_TCLASS) {
                  db_printf("%sIN6P_TCLASS", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & IN6P_AUTOFLOWLABEL) {
                  db_printf("%sIN6P_AUTOFLOWLABEL", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & INP_TIMEWAIT) {
                  db_printf("%sINP_TIMEWAIT", comma ? ", " : "");
                  comma  = 1;
          }
          if (inp_flags & INP_ONESBCAST) {
                  db_printf("%sINP_ONESBCAST", comma ? ", " : "");
                  comma  = 1;
          }
          if (inp_flags & INP_DROPPED) {
                  db_printf("%sINP_DROPPED", comma ? ", " : "");
                  comma  = 1;
          }
          if (inp_flags & INP_SOCKREF) {
                  db_printf("%sINP_SOCKREF", comma ? ", " : "");
                  comma  = 1;
          }
          if (inp_flags & IN6P_RFC2292) {
                  db_printf("%sIN6P_RFC2292", comma ? ", " : "");
                  comma = 1;
          }
          if (inp_flags & IN6P_MTU) {
                  db_printf("IN6P_MTU%s", comma ? ", " : "");
                  comma = 1;
          }
  }
  
  static void
  db_print_inpvflag(u_char inp_vflag)
  {
          int comma;
  
          comma = 0;
          if (inp_vflag & INP_IPV4) {
                  db_printf("%sINP_IPV4", comma ? ", " : "");
                  comma  = 1;
          }
          if (inp_vflag & INP_IPV6) {
                  db_printf("%sINP_IPV6", comma ? ", " : "");
                  comma  = 1;
          }
          if (inp_vflag & INP_IPV6PROTO) {
                  db_printf("%sINP_IPV6PROTO", comma ? ", " : "");
                  comma  = 1;
          }
  }
  
  static void
  db_print_inpcb(struct inpcb *inp, const char *name, int indent)
  {
  
          db_print_indent(indent);
          db_printf("%s at %p\n", name, inp);
  
          indent += 2;
  
          db_print_indent(indent);
          db_printf("inp_flow: 0x%x\n", inp->inp_flow);
  
          db_print_inconninfo(&inp->inp_inc, "inp_conninfo", indent);
  
          db_print_indent(indent);
          db_printf("inp_ppcb: %p   inp_pcbinfo: %p   inp_socket: %p\n",
              inp->inp_ppcb, inp->inp_pcbinfo, inp->inp_socket);
  
          db_print_indent(indent);
          db_printf("inp_label: %p   inp_flags: 0x%x (",
             inp->inp_label, inp->inp_flags);
          db_print_inpflags(inp->inp_flags);
          db_printf(")\n");
  
          db_print_indent(indent);
          db_printf("inp_sp: %p   inp_vflag: 0x%x (", inp->inp_sp,
              inp->inp_vflag);
          db_print_inpvflag(inp->inp_vflag);
          db_printf(")\n");
  
          db_print_indent(indent);
          db_printf("inp_ip_ttl: %d   inp_ip_p: %d   inp_ip_minttl: %d\n",
              inp->inp_ip_ttl, inp->inp_ip_p, inp->inp_ip_minttl);
  
          db_print_indent(indent);
  #ifdef INET6
          if (inp->inp_vflag & INP_IPV6) {
                  db_printf("in6p_options: %p   in6p_outputopts: %p   "
                      "in6p_moptions: %p\n", inp->in6p_options,
                      inp->in6p_outputopts, inp->in6p_moptions);
                  db_printf("in6p_icmp6filt: %p   in6p_cksum %d   "
                      "in6p_hops %u\n", inp->in6p_icmp6filt, inp->in6p_cksum,
                      inp->in6p_hops);
          } else
  #endif
          {
                  db_printf("inp_ip_tos: %d   inp_ip_options: %p   "
                      "inp_ip_moptions: %p\n", inp->inp_ip_tos,
                      inp->inp_options, inp->inp_moptions);
          }
  
          db_print_indent(indent);
          db_printf("inp_phd: %p   inp_gencnt: %ju\n", inp->inp_phd,
              (uintmax_t)inp->inp_gencnt);
  }
  
  DB_SHOW_COMMAND(inpcb, db_show_inpcb)
  {
          struct inpcb *inp;
  
          if (!have_addr) {
                  db_printf("usage: show inpcb <addr>\n");
                  return;
          }
          inp = (struct inpcb *)addr;
  
          db_print_inpcb(inp, "inpcb", 0);
  }
  #endif /* DDB */
  
  #ifdef RATELIMIT
  /*
   * Modify TX rate limit based on the existing "inp->inp_snd_tag",
   * if any.
   */
  int
  in_pcbmodify_txrtlmt(struct inpcb *inp, uint32_t max_pacing_rate)
  {
          union if_snd_tag_modify_params params = {
                  .rate_limit.max_rate = max_pacing_rate,
          };
          struct m_snd_tag *mst;
          struct ifnet *ifp;
          int error;
  
          mst = inp->inp_snd_tag;
          if (mst == NULL)
                  return (EINVAL);
  
          ifp = mst->ifp;
          if (ifp == NULL)
                  return (EINVAL);
  
          if (ifp->if_snd_tag_modify == NULL) {
                  error = EOPNOTSUPP;
          } else {
                  error = ifp->if_snd_tag_modify(mst, &params);
          }
          return (error);
  }
  
  /*
   * Query existing TX rate limit based on the existing
   * "inp->inp_snd_tag", if any.
   */
  int
  in_pcbquery_txrtlmt(struct inpcb *inp, uint32_t *p_max_pacing_rate)
  {
          union if_snd_tag_query_params params = { };
          struct m_snd_tag *mst;
          struct ifnet *ifp;
          int error;
  
          mst = inp->inp_snd_tag;
          if (mst == NULL)
                  return (EINVAL);
  
          ifp = mst->ifp;
          if (ifp == NULL)
                  return (EINVAL);
  
          if (ifp->if_snd_tag_query == NULL) {
                  error = EOPNOTSUPP;
          } else {
                  error = ifp->if_snd_tag_query(mst, &params);
                  if (error == 0 &&  p_max_pacing_rate != NULL)
                          *p_max_pacing_rate = params.rate_limit.max_rate;
          }
          return (error);
  }
  
  /*
   * Query existing TX queue level based on the existing
   * "inp->inp_snd_tag", if any.
   */
  int
  in_pcbquery_txrlevel(struct inpcb *inp, uint32_t *p_txqueue_level)
  {
          union if_snd_tag_query_params params = { };
          struct m_snd_tag *mst;
          struct ifnet *ifp;
          int error;
  
          mst = inp->inp_snd_tag;
          if (mst == NULL)
                  return (EINVAL);
  
          ifp = mst->ifp;
          if (ifp == NULL)
                  return (EINVAL);
  
          if (ifp->if_snd_tag_query == NULL)
                  return (EOPNOTSUPP);
  
          error = ifp->if_snd_tag_query(mst, &params);
          if (error == 0 &&  p_txqueue_level != NULL)
                  *p_txqueue_level = params.rate_limit.queue_level;
          return (error);
  }
  
  /*
   * Allocate a new TX rate limit send tag from the network interface
   * given by the "ifp" argument and save it in "inp->inp_snd_tag":
   */
  int
  in_pcbattach_txrtlmt(struct inpcb *inp, struct ifnet *ifp,
      uint32_t flowtype, uint32_t flowid, uint32_t max_pacing_rate)
  {
          union if_snd_tag_alloc_params params = {
                  .rate_limit.hdr.type = (max_pacing_rate == -1U) ?
                      IF_SND_TAG_TYPE_UNLIMITED : IF_SND_TAG_TYPE_RATE_LIMIT,
                  .rate_limit.hdr.flowid = flowid,
                  .rate_limit.hdr.flowtype = flowtype,
                  .rate_limit.max_rate = max_pacing_rate,
          };
          int error;
  
          INP_WLOCK_ASSERT(inp);
  
          /*
           * If there is already a send tag, or the INP is being torn
           * down, allocating a new send tag is not allowed. Else send
           * tags may leak.
           */
          if (inp->inp_snd_tag != NULL || (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0)
                  return (EINVAL);
  
          if (ifp->if_snd_tag_alloc == NULL) {
                  error = EOPNOTSUPP;
          } else {
                  error = ifp->if_snd_tag_alloc(ifp, &params, &inp->inp_snd_tag);
  
                  /*
                   * At success increment the refcount on
                   * the send tag's network interface:
                   */
                  if (error == 0)
                          if_ref(inp->inp_snd_tag->ifp);
          }
          return (error);
  }
  
  /*
   * Free an existing TX rate limit tag based on the "inp->inp_snd_tag",
   * if any:
   */
  void
  in_pcbdetach_txrtlmt(struct inpcb *inp)
  {
          struct m_snd_tag *mst;
          struct ifnet *ifp;
  
          INP_WLOCK_ASSERT(inp);
  
          mst = inp->inp_snd_tag;
          inp->inp_snd_tag = NULL;
  
          if (mst == NULL)
                  return;
  
          ifp = mst->ifp;
          if (ifp == NULL)
                  return;
  
          /*
           * If the device was detached while we still had reference(s)
           * on the ifp, we assume if_snd_tag_free() was replaced with
           * stubs.
           */
          ifp->if_snd_tag_free(mst);
  
          /* release reference count on network interface */
          if_rele(ifp);
  }
  
  /*
   * This function should be called when the INP_RATE_LIMIT_CHANGED flag
   * is set in the fast path and will attach/detach/modify the TX rate
   * limit send tag based on the socket's so_max_pacing_rate value.
   */
  void
  in_pcboutput_txrtlmt(struct inpcb *inp, struct ifnet *ifp, struct mbuf *mb)
  {
          struct socket *socket;
          uint32_t max_pacing_rate;
          bool did_upgrade;
          int error;
  
          if (inp == NULL)
                  return;
  
          socket = inp->inp_socket;
          if (socket == NULL)
                  return;
  
          if (!INP_WLOCKED(inp)) {
                  /*
                   * NOTE: If the write locking fails, we need to bail
                   * out and use the non-ratelimited ring for the
                   * transmit until there is a new chance to get the
                   * write lock.
                   */
                  if (!INP_TRY_UPGRADE(inp))
                          return;
                  did_upgrade = 1;
          } else {
                  did_upgrade = 0;
          }
  
          /*
           * NOTE: The so_max_pacing_rate value is read unlocked,
           * because atomic updates are not required since the variable
           * is checked at every mbuf we send. It is assumed that the
           * variable read itself will be atomic.
           */
          max_pacing_rate = socket->so_max_pacing_rate;
  
          /*
           * NOTE: When attaching to a network interface a reference is
           * made to ensure the network interface doesn't go away until
           * all ratelimit connections are gone. The network interface
           * pointers compared below represent valid network interfaces,
           * except when comparing towards NULL.
           */
          if (max_pacing_rate == 0 && inp->inp_snd_tag == NULL) {
                  error = 0;
          } else if (!(ifp->if_capenable & IFCAP_TXRTLMT)) {
                  if (inp->inp_snd_tag != NULL)
                          in_pcbdetach_txrtlmt(inp);
                  error = 0;
          } else if (inp->inp_snd_tag == NULL) {
                  /*
                   * In order to utilize packet pacing with RSS, we need
                   * to wait until there is a valid RSS hash before we
                   * can proceed:
                   */
                  if (M_HASHTYPE_GET(mb) == M_HASHTYPE_NONE) {
                          error = EAGAIN;
                  } else {
                          error = in_pcbattach_txrtlmt(inp, ifp, M_HASHTYPE_GET(mb),
                              mb->m_pkthdr.flowid, max_pacing_rate);
                  }
          } else {
                  error = in_pcbmodify_txrtlmt(inp, max_pacing_rate);
          }
          if (error == 0 || error == EOPNOTSUPP)
                  inp->inp_flags2 &= ~INP_RATE_LIMIT_CHANGED;
          if (did_upgrade)
                  INP_DOWNGRADE(inp);
  }
  
  /*
   * Track route changes for TX rate limiting.
   */
  void
  in_pcboutput_eagain(struct inpcb *inp)
  {
          bool did_upgrade;
  
          if (inp == NULL)
                  return;
  
          if (inp->inp_snd_tag == NULL)
                  return;
  
          if (!INP_WLOCKED(inp)) {
                  /*
                   * NOTE: If the write locking fails, we need to bail
                   * out and use the non-ratelimited ring for the
                   * transmit until there is a new chance to get the
                   * write lock.
                   */
                  if (!INP_TRY_UPGRADE(inp))
                          return;
                  did_upgrade = 1;
          } else {
                  did_upgrade = 0;
          }
  
          /* detach rate limiting */
          in_pcbdetach_txrtlmt(inp);
  
          /* make sure new mbuf send tag allocation is made */
          inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
  
          if (did_upgrade)
                  INP_DOWNGRADE(inp);
  }
  #endif /* RATELIMIT */

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