MFV r330102: ntp 4.2.8p11

[FreeBSD/FreeBSD.git] / 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/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>
#include <netinet/ip_var.h>
#include <netinet/tcp_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#endif
#ifdef INET
#include <netinet/in_var.h>
#endif
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/in6_var.h>
#include <netinet6/ip6_var.h>
#endif /* INET6 */

#include <netipsec/ipsec_support.h>

#include <security/mac/mac_framework.h>

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);
static VNET_DEFINE(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 sequental one");
SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, randomtime,
        CTLFLAG_VNET | CTLFLAG_RW,
        &VNET_NAME(ipport_randomtime), 0,
        "Minimum time to keep sequental 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.
 */

/*
 * 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)
{

        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;
        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);
#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);
#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);
        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

/*
 * Select a local port (number) to use.
 */
#if defined(INET) || defined(INET6)
int
in_pcb_lport(struct inpcb *inp, struct in_addr *laddrp, u_short *lportp,
    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;
#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
        /* Make the compiler happy. */
        laddr.s_addr = 0;
        if ((inp->inp_vflag & (INP_IPV4|INP_IPV6)) == INP_IPV4) {
                KASSERT(laddrp != NULL, ("%s: laddrp NULL for v4 inp %p",
                    __func__, inp));
                laddr = *laddrp;
        }
#endif
        tmpinp = NULL;  /* Make compiler happy. */
        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);

#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);

#ifdef INET
        if ((inp->inp_vflag & (INP_IPV4|INP_IPV6)) == INP_IPV4)
                laddrp->s_addr = laddr.s_addr;
#endif
        *lportp = lport;

        return (0);
}

/*
 * Return cached socket options.
 */
short
inp_so_options(const struct inpcb *inp)
{
   short so_options;

   so_options = 0;

   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 exisitng 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;

        /*
         * No state changes, so read locks are sufficient here.
         */
        INP_LOCK_ASSERT(inp);
        INP_HASH_LOCK_ASSERT(pcbinfo);

        if (TAILQ_EMPTY(&V_in_ifaddrhead)) /* XXX broken! */
                return (EADDRNOTAVAIL);
        laddr.s_addr = *laddrp;
        if (nam != NULL && laddr.s_addr != INADDR_ANY)
                return (EINVAL);
        if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 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;
                } 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) == 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)
                                        return (EADDRINUSE);
                        } else if (t &&
                            ((inp->inp_flags2 & INP_BINDMULTI) == 0) &&
                            (reuseport & 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)
{
        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) {
                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;
        in_pcbrehash_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));
}

/*
 * 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.
         */
        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;
                        ifa_free(&ia->ia_ifa);
                        goto done;
                }

                ifp = ia->ia_ifp;
                ifa_free(&ia->ia_ifa);
                ia = NULL;
                IF_ADDR_RLOCK(ifp);
                TAILQ_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;
                        IF_ADDR_RUNLOCK(ifp);
                        goto done;
                }
                IF_ADDR_RUNLOCK(ifp);

                /* 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;
                IF_ADDR_RLOCK(ifp);
                TAILQ_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;
                        IF_ADDR_RUNLOCK(ifp);
                        goto done;
                }
                IF_ADDR_RUNLOCK(ifp);

                /* 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;
                        ifa_free(&ia->ia_ifa);
                        goto done;
                }

                /* Jailed. */
                if (ia != NULL) {
                        struct ifnet *ifp;

                        ifp = ia->ia_ifp;
                        ifa_free(&ia->ia_ifa);
                        ia = NULL;
                        IF_ADDR_RLOCK(ifp);
                        TAILQ_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;
                                IF_ADDR_RUNLOCK(ifp);
                                goto done;
                        }
                        IF_ADDR_RUNLOCK(ifp);
                }

                /* 3. As a last resort return the 'default' jail address. */
                error = prison_get_ip4(cred, laddr);
                goto done;
        }

done:
        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 (!TAILQ_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(TAILQ_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 (TAILQ_FIRST(&V_in_ifaddrhead)->ia_ifp->if_flags &
                            IFF_BROADCAST)
                                faddr = satosin(&TAILQ_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);
                                TAILQ_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);
        }
        oinp = in_pcblookup_hash_locked(inp->inp_pcbinfo, faddr, fport,
            laddr, lport, 0, NULL);
        if (oinp != NULL) {
                if (oinpp != NULL)
                        *oinpp = oinp;
                return (EADDRINUSE);
        }
        if (lport == 0) {
                error = in_pcbbind_setup(inp, NULL, &laddr.s_addr, &lport,
                    cred);
                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__));

        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__));

        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));
}

/*
 * 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__));

#ifdef INVARIANTS
        if (pcbinfo == &V_tcbinfo) {
                INP_INFO_LOCK_ASSERT(pcbinfo);
        } else {
                INP_INFO_WLOCK_ASSERT(pcbinfo);
        }
#endif
        INP_WLOCK_ASSERT(inp);

        /* XXXRW: Do as much as possible here. */
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
        if (inp->inp_sp != NULL)
                ipsec_delete_pcbpolicy(inp);
#endif
        INP_LIST_WLOCK(pcbinfo);
        inp->inp_gencnt = ++pcbinfo->ipi_gencnt;
        in_pcbremlists(inp);
        INP_LIST_WUNLOCK(pcbinfo);
#ifdef INET6
        if (inp->inp_vflag & INP_IPV6PROTO) {
                ip6_freepcbopts(inp->in6p_outputopts);
                if (inp->in6p_moptions != NULL)
                        ip6_freemoptions(inp->in6p_moptions);
        }
#endif
        if (inp->inp_options)
                (void)m_free(inp->inp_options);
#ifdef INET
        if (inp->inp_moptions != NULL)
                inp_freemoptions(inp->inp_moptions);
#endif
        RO_INVALIDATE_CACHE(&inp->inp_route);

        inp->inp_vflag = 0;
        inp->inp_flags2 |= INP_FREED;
        crfree(inp->inp_cred);
#ifdef MAC
        mac_inpcb_destroy(inp);
#endif
        if (!in_pcbrele_wlocked(inp))
                INP_WUNLOCK(inp);
}

/*
 * 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);

        /*
         * 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);
                LIST_REMOVE(inp, inp_hash);
                LIST_REMOVE(inp, inp_portlist);
                if (LIST_FIRST(&phd->phd_pcblist) == NULL) {
                        LIST_REMOVE(phd, phd_hash);
                        free(phd, M_PCB);
                }
                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);
        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 ip_moptions *imo;
        int i, gap;

        INP_INFO_WLOCK(pcbinfo);
        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.
                         */
                        for (i = 0, gap = 0; i < imo->imo_num_memberships;
                            i++) {
                                if (imo->imo_membership[i]->inm_ifp == ifp) {
                                        in_delmulti(imo->imo_membership[i]);
                                        gap++;
                                } else if (gap != 0)
                                        imo->imo_membership[i - gap] =
                                            imo->imo_membership[i];
                        }
                        imo->imo_num_memberships -= gap;
                }
                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)];
                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)];
                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.
                         */
                        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

#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;

        /*
         * 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)];
        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)];
                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)];
                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:
        in_pcbref(inp);
        INP_GROUP_UNLOCK(pcbgroup);
        if (lookupflags & INPLOOKUP_WLOCKPCB) {
                INP_WLOCK(inp);
                if (in_pcbrele_wlocked(inp))
                        return (NULL);
        } else if (lookupflags & INPLOOKUP_RLOCKPCB) {
                INP_RLOCK(inp);
                if (in_pcbrele_rlocked(inp))
                        return (NULL);
        } else
                panic("%s: locking bug", __func__);
        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;

        KASSERT((lookupflags & ~(INPLOOKUP_WILDCARD)) == 0,
            ("%s: invalid lookup flags %d", __func__, lookupflags));

        INP_HASH_LOCK_ASSERT(pcbinfo);

        /*
         * First look for an exact match.
         */
        tmpinp = NULL;
        head = &pcbinfo->ipi_hashbase[INP_PCBHASH(faddr.s_addr, lport, fport,
            pcbinfo->ipi_hashmask)];
        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 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)];
                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) {
                in_pcbref(inp);
                INP_HASH_RUNLOCK(pcbinfo);
                if (lookupflags & INPLOOKUP_WLOCKPCB) {
                        INP_WLOCK(inp);
                        if (in_pcbrele_wlocked(inp))
                                return (NULL);
                } else if (lookupflags & INPLOOKUP_RLOCKPCB) {
                        INP_RLOCK(inp);
                        if (in_pcbrele_rlocked(inp))
                                return (NULL);
                } else
                        panic("%s: locking bug", __func__);
        } else
                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, int do_pcbgroup_update)
{
        struct inpcbhead *pcbhash;
        struct inpcbporthead *pcbporthash;
        struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
        struct inpcbport *phd;
        u_int32_t hashkey_faddr;

        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)];

        /*
         * Go through port list and look for a head for this lport.
         */
        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 */
                }
                phd->phd_port = inp->inp_lport;
                LIST_INIT(&phd->phd_pcblist);
                LIST_INSERT_HEAD(pcbporthash, phd, phd_hash);
        }
        inp->inp_phd = phd;
        LIST_INSERT_HEAD(&phd->phd_pcblist, inp, inp_portlist);
        LIST_INSERT_HEAD(pcbhash, inp, inp_hash);
        inp->inp_flags |= INP_INHASHLIST;
#ifdef PCBGROUP
        if (do_pcbgroup_update)
                in_pcbgroup_update(inp);
#endif
        return (0);
}

/*
 * For now, there are two public interfaces to insert an inpcb into the hash
 * lists -- one that does update pcbgroups, and one that doesn't.  The latter
 * is used only in the TCP syncache, where in_pcbinshash is called before the
 * full 4-tuple is set for the inpcb, and we don't want to install in the
 * pcbgroup until later.
 *
 * XXXRW: This seems like a misfeature.  in_pcbinshash should always update
 * connection groups, and partially initialised inpcbs should not be exposed
 * to either reservation hash tables or pcbgroups.
 */
int
in_pcbinshash(struct inpcb *inp)
{

        return (in_pcbinshash_internal(inp, 1));
}

int
in_pcbinshash_nopcbgroup(struct inpcb *inp)
{

        return (in_pcbinshash_internal(inp, 0));
}

/*
 * 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)];

        LIST_REMOVE(inp, inp_hash);
        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);
                LIST_REMOVE(inp, inp_hash);
                LIST_REMOVE(inp, inp_portlist);
                if (LIST_FIRST(&phd->phd_pcblist) == NULL) {
                        LIST_REMOVE(phd, phd_hash);
                        free(phd, M_PCB);
                }
                INP_HASH_WUNLOCK(pcbinfo);
                inp->inp_flags &= ~INP_INHASHLIST;
        }
        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);
        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)
{

        xi->xi_len = sizeof(struct xinpcb);
        if (inp->inp_socket)
                sotoxsocket(inp->inp_socket, &xi->xi_socket);
        else
                bzero(&xi->xi_socket, sizeof(struct xsocket));
        bcopy(&inp->inp_inc, &xi->inp_inc, sizeof(struct in_conninfo));
        xi->inp_gencnt = inp->inp_gencnt;
        xi->inp_ppcb = 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 (inp->inp_snd_tag != NULL)
                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)
{
        struct socket *socket;
        bool did_upgrade;

        if (inp == NULL)
                return;

        socket = inp->inp_socket;
        if (socket == 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 */