/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1988, 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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.
 */
#include "opt_ddb.h"
#include "opt_inet.h"
#include "opt_inet6.h"

#include <sys/param.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/eventhandler.h>
#include <sys/domain.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/rmlock.h>
#include <sys/rwlock.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/systm.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/if_dl.h>
#include <net/if_llatbl.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#include <net/route/route_ctl.h>
#include <net/route/route_var.h>
#include <net/vnet.h>

#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netinet/ip_carp.h>
#ifdef INET6
#include <netinet6/in6_var.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#endif
#include <net/route/nhop.h>

#define DEBUG_MOD_NAME  rtsock
#define DEBUG_MAX_LEVEL LOG_DEBUG
#include <net/route/route_debug.h>
_DECLARE_DEBUG(LOG_INFO);

#ifdef COMPAT_FREEBSD32
#include <sys/mount.h>
#include <compat/freebsd32/freebsd32.h>

struct if_msghdr32 {
        uint16_t ifm_msglen;
        uint8_t ifm_version;
        uint8_t ifm_type;
        int32_t ifm_addrs;
        int32_t ifm_flags;
        uint16_t ifm_index;
        uint16_t _ifm_spare1;
        struct  if_data ifm_data;
};

struct if_msghdrl32 {
        uint16_t ifm_msglen;
        uint8_t ifm_version;
        uint8_t ifm_type;
        int32_t ifm_addrs;
        int32_t ifm_flags;
        uint16_t ifm_index;
        uint16_t _ifm_spare1;
        uint16_t ifm_len;
        uint16_t ifm_data_off;
        uint32_t _ifm_spare2;
        struct  if_data ifm_data;
};

struct ifa_msghdrl32 {
        uint16_t ifam_msglen;
        uint8_t ifam_version;
        uint8_t ifam_type;
        int32_t ifam_addrs;
        int32_t ifam_flags;
        uint16_t ifam_index;
        uint16_t _ifam_spare1;
        uint16_t ifam_len;
        uint16_t ifam_data_off;
        int32_t ifam_metric;
        struct  if_data ifam_data;
};

#define SA_SIZE32(sa)                                           \
    (  (((struct sockaddr *)(sa))->sa_len == 0) ?               \
        sizeof(int)             :                               \
        1 + ( (((struct sockaddr *)(sa))->sa_len - 1) | (sizeof(int) - 1) ) )

#endif /* COMPAT_FREEBSD32 */

struct linear_buffer {
        char            *base;  /* Base allocated memory pointer */
        uint32_t        offset; /* Currently used offset */
        uint32_t        size;   /* Total buffer size */
};
#define SCRATCH_BUFFER_SIZE     1024

#define RTS_PID_LOG(_l, _fmt, ...)                                      \
        RT_LOG_##_l(_l, "PID %d: " _fmt, curproc ? curproc->p_pid : 0,  \
            ## __VA_ARGS__)

MALLOC_DEFINE(M_RTABLE, "routetbl", "routing tables");

/* NB: these are not modified */
static struct   sockaddr route_src = { 2, PF_ROUTE, };
static struct   sockaddr sa_zero   = { sizeof(sa_zero), AF_INET, };

/* These are external hooks for CARP. */
int     (*carp_get_vhid_p)(struct ifaddr *);

/*
 * Used by rtsock callback code to decide whether to filter the update
 * notification to a socket bound to a particular FIB.
 */
#define RTS_FILTER_FIB  M_PROTO8
/*
 * Used to store address family of the notification.
 */
#define m_rtsock_family m_pkthdr.PH_loc.eight[0]

struct rcb {
        LIST_ENTRY(rcb) list;
        struct socket   *rcb_socket;
        sa_family_t     rcb_family;
};

typedef struct {
        LIST_HEAD(, rcb)        cblist;
        int     ip_count;       /* attached w/ AF_INET */
        int     ip6_count;      /* attached w/ AF_INET6 */
        int     any_count;      /* total attached */
} route_cb_t;
VNET_DEFINE_STATIC(route_cb_t, route_cb);
#define V_route_cb VNET(route_cb)

struct mtx rtsock_mtx;
MTX_SYSINIT(rtsock, &rtsock_mtx, "rtsock route_cb lock", MTX_DEF);

#define RTSOCK_LOCK()   mtx_lock(&rtsock_mtx)
#define RTSOCK_UNLOCK() mtx_unlock(&rtsock_mtx)
#define RTSOCK_LOCK_ASSERT()    mtx_assert(&rtsock_mtx, MA_OWNED)

SYSCTL_NODE(_net, OID_AUTO, route, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");

struct walkarg {
        int     family;
        int     w_tmemsize;
        int     w_op, w_arg;
        caddr_t w_tmem;
        struct sysctl_req *w_req;
        struct sockaddr *dst;
        struct sockaddr *mask;
};

static void     rts_input(struct mbuf *m);
static struct mbuf *rtsock_msg_mbuf(int type, struct rt_addrinfo *rtinfo);
static int      rtsock_msg_buffer(int type, struct rt_addrinfo *rtinfo,
                        struct walkarg *w, int *plen);
static int      rt_xaddrs(caddr_t cp, caddr_t cplim,
                        struct rt_addrinfo *rtinfo);
static int      cleanup_xaddrs(struct rt_addrinfo *info, struct linear_buffer *lb);
static int      sysctl_dumpentry(struct rtentry *rt, void *vw);
static int      sysctl_dumpnhop(struct rtentry *rt, struct nhop_object *nh,
                        uint32_t weight, struct walkarg *w);
static int      sysctl_iflist(int af, struct walkarg *w);
static int      sysctl_ifmalist(int af, struct walkarg *w);
static void     rt_getmetrics(const struct rtentry *rt,
                        const struct nhop_object *nh, struct rt_metrics *out);
static void     rt_dispatch(struct mbuf *, sa_family_t);
static void     rt_ifannouncemsg(struct ifnet *, int, const char *);
static int      handle_rtm_get(struct rt_addrinfo *info, u_int fibnum,
                        struct rt_msghdr *rtm, struct rib_cmd_info *rc);
static int      update_rtm_from_rc(struct rt_addrinfo *info,
                        struct rt_msghdr **prtm, int alloc_len,
                        struct rib_cmd_info *rc, struct nhop_object *nh);
static void     send_rtm_reply(struct socket *so, struct rt_msghdr *rtm,
                        struct mbuf *m, sa_family_t saf, u_int fibnum,
                        int rtm_errno);
static void     rtsock_notify_event(uint32_t fibnum, const struct rib_cmd_info *rc);
static void     rtsock_ifmsg(struct ifnet *ifp, int if_flags_mask);

static struct netisr_handler rtsock_nh = {
        .nh_name = "rtsock",
        .nh_handler = rts_input,
        .nh_proto = NETISR_ROUTE,
        .nh_policy = NETISR_POLICY_SOURCE,
};

static int
sysctl_route_netisr_maxqlen(SYSCTL_HANDLER_ARGS)
{
        int error, qlimit;

        netisr_getqlimit(&rtsock_nh, &qlimit);
        error = sysctl_handle_int(oidp, &qlimit, 0, req);
        if (error || !req->newptr)
                return (error);
        if (qlimit < 1)
                return (EINVAL);
        return (netisr_setqlimit(&rtsock_nh, qlimit));
}
SYSCTL_PROC(_net_route, OID_AUTO, netisr_maxqlen,
    CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE,
    0, 0, sysctl_route_netisr_maxqlen, "I",
    "maximum routing socket dispatch queue length");

static void
vnet_rts_init(void)
{
        int tmp;

        if (IS_DEFAULT_VNET(curvnet)) {
                if (TUNABLE_INT_FETCH("net.route.netisr_maxqlen", &tmp))
                        rtsock_nh.nh_qlimit = tmp;
                netisr_register(&rtsock_nh);
        }
#ifdef VIMAGE
         else
                netisr_register_vnet(&rtsock_nh);
#endif
}
VNET_SYSINIT(vnet_rtsock, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD,
    vnet_rts_init, NULL);

#ifdef VIMAGE
static void
vnet_rts_uninit(void)
{

        netisr_unregister_vnet(&rtsock_nh);
}
VNET_SYSUNINIT(vnet_rts_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD,
    vnet_rts_uninit, NULL);
#endif

static void
report_route_event(const struct rib_cmd_info *rc, void *_cbdata)
{
        uint32_t fibnum = (uint32_t)(uintptr_t)_cbdata;
        struct nhop_object *nh;

        nh = rc->rc_cmd == RTM_DELETE ? rc->rc_nh_old : rc->rc_nh_new;
        rt_routemsg(rc->rc_cmd, rc->rc_rt, nh, fibnum);
}

static void
rts_handle_route_event(uint32_t fibnum, const struct rib_cmd_info *rc)
{

        if ((rc->rc_nh_new && NH_IS_NHGRP(rc->rc_nh_new)) ||
            (rc->rc_nh_old && NH_IS_NHGRP(rc->rc_nh_old))) {
                rib_decompose_notification(rc, report_route_event,
                    (void *)(uintptr_t)fibnum);
        } else
                report_route_event(rc, (void *)(uintptr_t)fibnum);
}
static struct rtbridge rtsbridge = {
        .route_f = rts_handle_route_event,
        .ifmsg_f = rtsock_ifmsg,
};
static struct rtbridge *rtsbridge_orig_p;

static void
rtsock_notify_event(uint32_t fibnum, const struct rib_cmd_info *rc)
{
        netlink_callback_p->route_f(fibnum, rc);
}

static void
rtsock_init(void *dummy __unused)
{
        rtsbridge_orig_p = rtsock_callback_p;
        rtsock_callback_p = &rtsbridge;
}
SYSINIT(rtsock_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, rtsock_init, NULL);

static void
rts_ifnet_attached(void *arg __unused, struct ifnet *ifp)
{
        rt_ifannouncemsg(ifp, IFAN_ARRIVAL, NULL);
}
EVENTHANDLER_DEFINE(ifnet_attached_event, rts_ifnet_attached, NULL, 0);

static void
rts_handle_ifnet_departure(void *arg __unused, struct ifnet *ifp)
{
        rt_ifannouncemsg(ifp, IFAN_DEPARTURE, NULL);
}
EVENTHANDLER_DEFINE(ifnet_departure_event, rts_handle_ifnet_departure, NULL, 0);

static void
rts_handle_ifnet_rename(void *arg __unused, struct ifnet *ifp,
    const char *old_name)
{
        rt_ifannouncemsg(ifp, IFAN_DEPARTURE, old_name);
        rt_ifannouncemsg(ifp, IFAN_ARRIVAL, NULL);
}
EVENTHANDLER_DEFINE(ifnet_rename_event, rts_handle_ifnet_rename, NULL, 0);

static void
rts_append_data(struct socket *so, struct mbuf *m)
{

        if (sbappendaddr(&so->so_rcv, &route_src, m, NULL) == 0) {
                soroverflow(so);
                m_freem(m);
        } else
                sorwakeup(so);
}

static void
rts_input(struct mbuf *m)
{
        struct rcb *rcb;
        struct socket *last;

        last = NULL;
        RTSOCK_LOCK();
        LIST_FOREACH(rcb, &V_route_cb.cblist, list) {
                if (rcb->rcb_family != AF_UNSPEC &&
                    rcb->rcb_family != m->m_rtsock_family)
                        continue;
                if ((m->m_flags & RTS_FILTER_FIB) &&
                    M_GETFIB(m) != rcb->rcb_socket->so_fibnum)
                        continue;
                if (last != NULL) {
                        struct mbuf *n;

                        n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
                        if (n != NULL)
                                rts_append_data(last, n);
                }
                last = rcb->rcb_socket;
        }
        if (last != NULL)
                rts_append_data(last, m);
        else
                m_freem(m);
        RTSOCK_UNLOCK();
}

static void
rts_close(struct socket *so)
{

        soisdisconnected(so);
}

static SYSCTL_NODE(_net, OID_AUTO, rtsock, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "Routing socket infrastructure");
static u_long rts_sendspace = 8192;
SYSCTL_ULONG(_net_rtsock, OID_AUTO, sendspace, CTLFLAG_RW, &rts_sendspace, 0,
    "Default routing socket send space");
static u_long rts_recvspace = 8192;
SYSCTL_ULONG(_net_rtsock, OID_AUTO, recvspace, CTLFLAG_RW, &rts_recvspace, 0,
    "Default routing socket receive space");

static int
rts_attach(struct socket *so, int proto, struct thread *td)
{
        struct rcb *rcb;
        int error;

        error = soreserve(so, rts_sendspace, rts_recvspace);
        if (error)
                return (error);

        rcb = malloc(sizeof(*rcb), M_PCB, M_WAITOK);
        rcb->rcb_socket = so;
        rcb->rcb_family = proto;

        so->so_pcb = rcb;
        so->so_fibnum = td->td_proc->p_fibnum;
        so->so_options |= SO_USELOOPBACK;

        RTSOCK_LOCK();
        LIST_INSERT_HEAD(&V_route_cb.cblist, rcb, list);
        switch (proto) {
        case AF_INET:
                V_route_cb.ip_count++;
                break;
        case AF_INET6:
                V_route_cb.ip6_count++;
                break;
        }
        V_route_cb.any_count++;
        RTSOCK_UNLOCK();
        soisconnected(so);

        return (0);
}

static int
rts_ctloutput(struct socket *so, struct sockopt *sopt)
{
        int error, optval;

        error = ENOPROTOOPT;
        if (sopt->sopt_dir == SOPT_SET) {
                switch (sopt->sopt_level) {
                case SOL_SOCKET:
                        switch (sopt->sopt_name) {
                        case SO_SETFIB:
                                error = sooptcopyin(sopt, &optval,
                                    sizeof(optval), sizeof(optval));
                                if (error != 0)
                                        break;
                                error = sosetfib(so, optval);
                                break;
                        }
                        break;
                }
        }
        return (error);
}

static void
rts_detach(struct socket *so)
{
        struct rcb *rcb = so->so_pcb;

        RTSOCK_LOCK();
        LIST_REMOVE(rcb, list);
        switch(rcb->rcb_family) {
        case AF_INET:
                V_route_cb.ip_count--;
                break;
        case AF_INET6:
                V_route_cb.ip6_count--;
                break;
        }
        V_route_cb.any_count--;
        RTSOCK_UNLOCK();
        free(rcb, M_PCB);
        so->so_pcb = NULL;
}

static int
rts_disconnect(struct socket *so)
{

        return (ENOTCONN);
}

static int
rts_shutdown(struct socket *so, enum shutdown_how how)
{
        /*
         * Note: route socket marks itself as connected through its lifetime.
         */
        switch (how) {
        case SHUT_RD:
                sorflush(so);
                break;
        case SHUT_RDWR:
                sorflush(so);
                /* FALLTHROUGH */
        case SHUT_WR:
                socantsendmore(so);
        }

        return (0);
}

#ifndef _SOCKADDR_UNION_DEFINED
#define _SOCKADDR_UNION_DEFINED
/*
 * The union of all possible address formats we handle.
 */
union sockaddr_union {
        struct sockaddr         sa;
        struct sockaddr_in      sin;
        struct sockaddr_in6     sin6;
};
#endif /* _SOCKADDR_UNION_DEFINED */

static int
rtm_get_jailed(struct rt_addrinfo *info, struct ifnet *ifp,
    struct nhop_object *nh, union sockaddr_union *saun, struct ucred *cred)
{
#if defined(INET) || defined(INET6)
        struct epoch_tracker et;
#endif

        /* First, see if the returned address is part of the jail. */
        if (prison_if(cred, nh->nh_ifa->ifa_addr) == 0) {
                info->rti_info[RTAX_IFA] = nh->nh_ifa->ifa_addr;
                return (0);
        }

        switch (info->rti_info[RTAX_DST]->sa_family) {
#ifdef INET
        case AF_INET:
        {
                struct in_addr ia;
                struct ifaddr *ifa;
                int found;

                found = 0;
                /*
                 * Try to find an address on the given outgoing interface
                 * that belongs to the jail.
                 */
                NET_EPOCH_ENTER(et);
                CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                        struct sockaddr *sa;
                        sa = ifa->ifa_addr;
                        if (sa->sa_family != AF_INET)
                                continue;
                        ia = ((struct sockaddr_in *)sa)->sin_addr;
                        if (prison_check_ip4(cred, &ia) == 0) {
                                found = 1;
                                break;
                        }
                }
                NET_EPOCH_EXIT(et);
                if (!found) {
                        /*
                         * As a last resort return the 'default' jail address.
                         */
                        ia = ((struct sockaddr_in *)nh->nh_ifa->ifa_addr)->
                            sin_addr;
                        if (prison_get_ip4(cred, &ia) != 0)
                                return (ESRCH);
                }
                bzero(&saun->sin, sizeof(struct sockaddr_in));
                saun->sin.sin_len = sizeof(struct sockaddr_in);
                saun->sin.sin_family = AF_INET;
                saun->sin.sin_addr.s_addr = ia.s_addr;
                info->rti_info[RTAX_IFA] = (struct sockaddr *)&saun->sin;
                break;
        }
#endif
#ifdef INET6
        case AF_INET6:
        {
                struct in6_addr ia6;
                struct ifaddr *ifa;
                int found;

                found = 0;
                /*
                 * Try to find an address on the given outgoing interface
                 * that belongs to the jail.
                 */
                NET_EPOCH_ENTER(et);
                CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                        struct sockaddr *sa;
                        sa = ifa->ifa_addr;
                        if (sa->sa_family != AF_INET6)
                                continue;
                        bcopy(&((struct sockaddr_in6 *)sa)->sin6_addr,
                            &ia6, sizeof(struct in6_addr));
                        if (prison_check_ip6(cred, &ia6) == 0) {
                                found = 1;
                                break;
                        }
                }
                NET_EPOCH_EXIT(et);
                if (!found) {
                        /*
                         * As a last resort return the 'default' jail address.
                         */
                        ia6 = ((struct sockaddr_in6 *)nh->nh_ifa->ifa_addr)->
                            sin6_addr;
                        if (prison_get_ip6(cred, &ia6) != 0)
                                return (ESRCH);
                }
                bzero(&saun->sin6, sizeof(struct sockaddr_in6));
                saun->sin6.sin6_len = sizeof(struct sockaddr_in6);
                saun->sin6.sin6_family = AF_INET6;
                bcopy(&ia6, &saun->sin6.sin6_addr, sizeof(struct in6_addr));
                if (sa6_recoverscope(&saun->sin6) != 0)
                        return (ESRCH);
                info->rti_info[RTAX_IFA] = (struct sockaddr *)&saun->sin6;
                break;
        }
#endif
        default:
                return (ESRCH);
        }
        return (0);
}

static int
fill_blackholeinfo(struct rt_addrinfo *info, union sockaddr_union *saun)
{
        struct ifaddr *ifa;
        sa_family_t saf;

        if (V_loif == NULL) {
                RTS_PID_LOG(LOG_INFO, "Unable to add blackhole/reject nhop without loopback");
                return (ENOTSUP);
        }
        info->rti_ifp = V_loif;

        saf = info->rti_info[RTAX_DST]->sa_family;

        CK_STAILQ_FOREACH(ifa, &info->rti_ifp->if_addrhead, ifa_link) {
                if (ifa->ifa_addr->sa_family == saf) {
                        info->rti_ifa = ifa;
                        break;
                }
        }
        if (info->rti_ifa == NULL) {
                RTS_PID_LOG(LOG_INFO, "Unable to find ifa for blackhole/reject nhop");
                return (ENOTSUP);
        }

        bzero(saun, sizeof(union sockaddr_union));
        switch (saf) {
#ifdef INET
        case AF_INET:
                saun->sin.sin_family = AF_INET;
                saun->sin.sin_len = sizeof(struct sockaddr_in);
                saun->sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
                break;
#endif
#ifdef INET6
        case AF_INET6:
                saun->sin6.sin6_family = AF_INET6;
                saun->sin6.sin6_len = sizeof(struct sockaddr_in6);
                saun->sin6.sin6_addr = in6addr_loopback;
                break;
#endif
        default:
                RTS_PID_LOG(LOG_INFO, "unsupported family: %d", saf);
                return (ENOTSUP);
        }
        info->rti_info[RTAX_GATEWAY] = &saun->sa;
        info->rti_flags |= RTF_GATEWAY;

        return (0);
}

/*
 * Fills in @info based on userland-provided @rtm message.
 *
 * Returns 0 on success.
 */
static int
fill_addrinfo(struct rt_msghdr *rtm, int len, struct linear_buffer *lb, u_int fibnum,
    struct rt_addrinfo *info)
{
        int error;

        rtm->rtm_pid = curproc->p_pid;
        info->rti_addrs = rtm->rtm_addrs;

        info->rti_mflags = rtm->rtm_inits;
        info->rti_rmx = &rtm->rtm_rmx;

        /*
         * rt_xaddrs() performs s6_addr[2] := sin6_scope_id for AF_INET6
         * link-local address because rtrequest requires addresses with
         * embedded scope id.
         */
        if (rt_xaddrs((caddr_t)(rtm + 1), len + (caddr_t)rtm, info))
                return (EINVAL);

        info->rti_flags = rtm->rtm_flags;
        error = cleanup_xaddrs(info, lb);
        if (error != 0)
                return (error);
        /*
         * Verify that the caller has the appropriate privilege; RTM_GET
         * is the only operation the non-superuser is allowed.
         */
        if (rtm->rtm_type != RTM_GET) {
                error = priv_check(curthread, PRIV_NET_ROUTE);
                if (error != 0)
                        return (error);
        }

        /*
         * The given gateway address may be an interface address.
         * For example, issuing a "route change" command on a route
         * entry that was created from a tunnel, and the gateway
         * address given is the local end point. In this case the 
         * RTF_GATEWAY flag must be cleared or the destination will
         * not be reachable even though there is no error message.
         */
        if (info->rti_info[RTAX_GATEWAY] != NULL &&
            info->rti_info[RTAX_GATEWAY]->sa_family != AF_LINK) {
                struct nhop_object *nh;

                /* 
                 * A host route through the loopback interface is 
                 * installed for each interface address. In pre 8.0
                 * releases the interface address of a PPP link type
                 * is not reachable locally. This behavior is fixed as 
                 * part of the new L2/L3 redesign and rewrite work. The
                 * signature of this interface address route is the
                 * AF_LINK sa_family type of the gateway, and the
                 * rt_ifp has the IFF_LOOPBACK flag set.
                 */
                nh = rib_lookup(fibnum, info->rti_info[RTAX_GATEWAY], NHR_NONE, 0);
                if (nh != NULL && nh->gw_sa.sa_family == AF_LINK &&
                    nh->nh_ifp->if_flags & IFF_LOOPBACK) {
                                info->rti_flags &= ~RTF_GATEWAY;
                                info->rti_flags |= RTF_GWFLAG_COMPAT;
                }
        }

        return (0);
}

static struct nhop_object *
select_nhop(struct nhop_object *nh, const struct sockaddr *gw)
{
        const struct weightened_nhop *wn;
        uint32_t num_nhops;

        if (!NH_IS_NHGRP(nh))
                return (nh);

        wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops);
        if (gw == NULL)
                return (wn[0].nh);
        for (int i = 0; i < num_nhops; i++) {
                if (match_nhop_gw(wn[i].nh, gw))
                        return (wn[i].nh);
        }

        return (NULL);
}

/*
 * Handles RTM_GET message from routing socket, returning matching rt.
 *
 * Returns:
 * 0 on success, with locked and referenced matching rt in @rt_nrt
 * errno of failure
 */
static int
handle_rtm_get(struct rt_addrinfo *info, u_int fibnum,
    struct rt_msghdr *rtm, struct rib_cmd_info *rc)
{
        RIB_RLOCK_TRACKER;
        struct rib_head *rnh;
        struct nhop_object *nh;
        sa_family_t saf;

        saf = info->rti_info[RTAX_DST]->sa_family;

        rnh = rt_tables_get_rnh(fibnum, saf);
        if (rnh == NULL)
                return (EAFNOSUPPORT);

        RIB_RLOCK(rnh);

        /*
         * By (implicit) convention host route (one without netmask)
         * means longest-prefix-match request and the route with netmask
         * means exact-match lookup.
         * As cleanup_xaddrs() cleans up info flags&addrs for the /32,/128
         * prefixes, use original data to check for the netmask presence.
         */
        if ((rtm->rtm_addrs & RTA_NETMASK) == 0) {
                /*
                 * Provide longest prefix match for
                 * address lookup (no mask).
                 * 'route -n get addr'
                 */
                rc->rc_rt = (struct rtentry *) rnh->rnh_matchaddr(
                    info->rti_info[RTAX_DST], &rnh->head);
        } else
                rc->rc_rt = (struct rtentry *) rnh->rnh_lookup(
                    info->rti_info[RTAX_DST],
                    info->rti_info[RTAX_NETMASK], &rnh->head);

        if (rc->rc_rt == NULL) {
                RIB_RUNLOCK(rnh);
                return (ESRCH);
        }

        nh = select_nhop(rt_get_raw_nhop(rc->rc_rt), info->rti_info[RTAX_GATEWAY]);
        if (nh == NULL) {
                RIB_RUNLOCK(rnh);
                return (ESRCH);
        }
        /*
         * If performing proxied L2 entry insertion, and
         * the actual PPP host entry is found, perform
         * another search to retrieve the prefix route of
         * the local end point of the PPP link.
         * TODO: move this logic to userland.
         */
        if (rtm->rtm_flags & RTF_ANNOUNCE) {
                struct sockaddr_storage laddr;

                if (nh->nh_ifp != NULL &&
                    nh->nh_ifp->if_type == IFT_PROPVIRTUAL) {
                        struct ifaddr *ifa;

                        ifa = ifa_ifwithnet(info->rti_info[RTAX_DST], 1,
                                        RT_ALL_FIBS);
                        if (ifa != NULL)
                                rt_maskedcopy(ifa->ifa_addr,
                                              (struct sockaddr *)&laddr,
                                              ifa->ifa_netmask);
                } else
                        rt_maskedcopy(nh->nh_ifa->ifa_addr,
                                      (struct sockaddr *)&laddr,
                                      nh->nh_ifa->ifa_netmask);
                /* 
                 * refactor rt and no lock operation necessary
                 */
                rc->rc_rt = (struct rtentry *)rnh->rnh_matchaddr(
                    (struct sockaddr *)&laddr, &rnh->head);
                if (rc->rc_rt == NULL) {
                        RIB_RUNLOCK(rnh);
                        return (ESRCH);
                }
                nh = select_nhop(rt_get_raw_nhop(rc->rc_rt), info->rti_info[RTAX_GATEWAY]);
                if (nh == NULL) {
                        RIB_RUNLOCK(rnh);
                        return (ESRCH);
                }
        }
        rc->rc_nh_new = nh;
        rc->rc_nh_weight = rc->rc_rt->rt_weight;
        RIB_RUNLOCK(rnh);

        return (0);
}

static void
init_sockaddrs_family(int family, struct sockaddr *dst, struct sockaddr *mask)
{
#ifdef INET
        if (family == AF_INET) {
                struct sockaddr_in *dst4 = (struct sockaddr_in *)dst;
                struct sockaddr_in *mask4 = (struct sockaddr_in *)mask;

                bzero(dst4, sizeof(struct sockaddr_in));
                bzero(mask4, sizeof(struct sockaddr_in));

                dst4->sin_family = AF_INET;
                dst4->sin_len = sizeof(struct sockaddr_in);
                mask4->sin_family = AF_INET;
                mask4->sin_len = sizeof(struct sockaddr_in);
        }
#endif
#ifdef INET6
        if (family == AF_INET6) {
                struct sockaddr_in6 *dst6 = (struct sockaddr_in6 *)dst;
                struct sockaddr_in6 *mask6 = (struct sockaddr_in6 *)mask;

                bzero(dst6, sizeof(struct sockaddr_in6));
                bzero(mask6, sizeof(struct sockaddr_in6));

                dst6->sin6_family = AF_INET6;
                dst6->sin6_len = sizeof(struct sockaddr_in6);
                mask6->sin6_family = AF_INET6;
                mask6->sin6_len = sizeof(struct sockaddr_in6);
        }
#endif
}

static void
export_rtaddrs(const struct rtentry *rt, struct sockaddr *dst,
    struct sockaddr *mask)
{
#ifdef INET
        if (dst->sa_family == AF_INET) {
                struct sockaddr_in *dst4 = (struct sockaddr_in *)dst;
                struct sockaddr_in *mask4 = (struct sockaddr_in *)mask;
                uint32_t scopeid = 0;
                rt_get_inet_prefix_pmask(rt, &dst4->sin_addr, &mask4->sin_addr,
                    &scopeid);
                return;
        }
#endif
#ifdef INET6
        if (dst->sa_family == AF_INET6) {
                struct sockaddr_in6 *dst6 = (struct sockaddr_in6 *)dst;
                struct sockaddr_in6 *mask6 = (struct sockaddr_in6 *)mask;
                uint32_t scopeid = 0;
                rt_get_inet6_prefix_pmask(rt, &dst6->sin6_addr,
                    &mask6->sin6_addr, &scopeid);
                dst6->sin6_scope_id = scopeid;
                return;
        }
#endif
}

static int
update_rtm_from_info(struct rt_addrinfo *info, struct rt_msghdr **prtm,
    int alloc_len)
{
        struct rt_msghdr *rtm, *orig_rtm = NULL;
        struct walkarg w;
        int len;

        rtm = *prtm;
        /* Check if we need to realloc storage */
        rtsock_msg_buffer(rtm->rtm_type, info, NULL, &len);
        if (len > alloc_len) {
                struct rt_msghdr *tmp_rtm;

                tmp_rtm = malloc(len, M_TEMP, M_NOWAIT);
                if (tmp_rtm == NULL)
                        return (ENOBUFS);
                bcopy(rtm, tmp_rtm, rtm->rtm_msglen);
                orig_rtm = rtm;
                rtm = tmp_rtm;
                alloc_len = len;

                /*
                 * Delay freeing original rtm as info contains
                 * data referencing it.
                 */
        }

        w = (struct walkarg ){
                .w_tmem = (caddr_t)rtm,
                .w_tmemsize = alloc_len,
        };
        rtsock_msg_buffer(rtm->rtm_type, info, &w, &len);
        rtm->rtm_addrs = info->rti_addrs;

        if (orig_rtm != NULL)
                free(orig_rtm, M_TEMP);
        *prtm = rtm;
        return (0);
}


/*
 * Update sockaddrs, flags, etc in @prtm based on @rc data.
 * rtm can be reallocated.
 *
 * Returns 0 on success, along with pointer to (potentially reallocated)
 *  rtm.
 *
 */
static int
update_rtm_from_rc(struct rt_addrinfo *info, struct rt_msghdr **prtm,
    int alloc_len, struct rib_cmd_info *rc, struct nhop_object *nh)
{
        union sockaddr_union saun;
        struct rt_msghdr *rtm;
        struct ifnet *ifp;
        int error;

        rtm = *prtm;
        union sockaddr_union sa_dst, sa_mask;
        int family = info->rti_info[RTAX_DST]->sa_family;
        init_sockaddrs_family(family, &sa_dst.sa, &sa_mask.sa);
        export_rtaddrs(rc->rc_rt, &sa_dst.sa, &sa_mask.sa);

        info->rti_info[RTAX_DST] = &sa_dst.sa;
        info->rti_info[RTAX_NETMASK] = rt_is_host(rc->rc_rt) ? NULL : &sa_mask.sa;
        info->rti_info[RTAX_GATEWAY] = &nh->gw_sa;
        info->rti_info[RTAX_GENMASK] = 0;
        ifp = nh->nh_ifp;
        if (rtm->rtm_addrs & (RTA_IFP | RTA_IFA)) {
                if (ifp) {
                        info->rti_info[RTAX_IFP] =
                            ifp->if_addr->ifa_addr;
                        error = rtm_get_jailed(info, ifp, nh,
                            &saun, curthread->td_ucred);
                        if (error != 0)
                                return (error);
                        if (ifp->if_flags & IFF_POINTOPOINT)
                                info->rti_info[RTAX_BRD] =
                                    nh->nh_ifa->ifa_dstaddr;
                        rtm->rtm_index = ifp->if_index;
                } else {
                        info->rti_info[RTAX_IFP] = NULL;
                        info->rti_info[RTAX_IFA] = NULL;
                }
        } else if (ifp != NULL)
                rtm->rtm_index = ifp->if_index;

        if ((error = update_rtm_from_info(info, prtm, alloc_len)) != 0)
                return (error);

        rtm = *prtm;
        rtm->rtm_flags = rc->rc_rt->rte_flags | nhop_get_rtflags(nh);
        if (rtm->rtm_flags & RTF_GWFLAG_COMPAT)
                rtm->rtm_flags = RTF_GATEWAY | 
                        (rtm->rtm_flags & ~RTF_GWFLAG_COMPAT);
        rt_getmetrics(rc->rc_rt, nh, &rtm->rtm_rmx);
        rtm->rtm_rmx.rmx_weight = rc->rc_nh_weight;

        return (0);
}

static void
save_del_notification(const struct rib_cmd_info *rc, void *_cbdata)
{
        struct rib_cmd_info *rc_new = (struct rib_cmd_info *)_cbdata;

        if (rc->rc_cmd == RTM_DELETE)
                *rc_new = *rc;
}

static void
save_add_notification(const struct rib_cmd_info *rc, void *_cbdata)
{
        struct rib_cmd_info *rc_new = (struct rib_cmd_info *)_cbdata;

        if (rc->rc_cmd == RTM_ADD)
                *rc_new = *rc;
}

#if defined(INET6) || defined(INET)
static struct sockaddr *
alloc_sockaddr_aligned(struct linear_buffer *lb, int len)
{
        len = roundup2(len, sizeof(uint64_t));
        if (lb->offset + len > lb->size)
                return (NULL);
        struct sockaddr *sa = (struct sockaddr *)(lb->base + lb->offset);
        lb->offset += len;
        return (sa);
}
#endif

static int
rts_send(struct socket *so, int flags, struct mbuf *m,
    struct sockaddr *nam, struct mbuf *control, struct thread *td)
{
        struct rt_msghdr *rtm = NULL;
        struct rt_addrinfo info;
        struct epoch_tracker et;
#ifdef INET6
        struct sockaddr_storage ss;
        struct sockaddr_in6 *sin6;
        int i, rti_need_deembed = 0;
#endif
        int alloc_len = 0, len, error = 0, fibnum;
        sa_family_t saf = AF_UNSPEC;
        struct rib_cmd_info rc;
        struct nhop_object *nh;

        if ((flags & PRUS_OOB) || control != NULL) {
                m_freem(m);
                if (control != NULL)
                        m_freem(control);
                return (EOPNOTSUPP);
        }

        fibnum = so->so_fibnum;
#define senderr(e) { error = e; goto flush;}
        if (m == NULL || ((m->m_len < sizeof(long)) &&
                       (m = m_pullup(m, sizeof(long))) == NULL))
                return (ENOBUFS);
        if ((m->m_flags & M_PKTHDR) == 0)
                panic("route_output");
        NET_EPOCH_ENTER(et);
        len = m->m_pkthdr.len;
        if (len < sizeof(*rtm) ||
            len != mtod(m, struct rt_msghdr *)->rtm_msglen)
                senderr(EINVAL);

        /*
         * Most of current messages are in range 200-240 bytes,
         * minimize possible re-allocation on reply using larger size
         * buffer aligned on 1k boundaty.
         */
        alloc_len = roundup2(len, 1024);
        int total_len = alloc_len + SCRATCH_BUFFER_SIZE;
        if ((rtm = malloc(total_len, M_TEMP, M_NOWAIT)) == NULL)
                senderr(ENOBUFS);

        m_copydata(m, 0, len, (caddr_t)rtm);
        bzero(&info, sizeof(info));
        nh = NULL;
        struct linear_buffer lb = {
                .base = (char *)rtm + alloc_len,
                .size = SCRATCH_BUFFER_SIZE,
        };

        if (rtm->rtm_version != RTM_VERSION) {
                /* Do not touch message since format is unknown */
                free(rtm, M_TEMP);
                rtm = NULL;
                senderr(EPROTONOSUPPORT);
        }

        /*
         * Starting from here, it is possible
         * to alter original message and insert
         * caller PID and error value.
         */

        if ((error = fill_addrinfo(rtm, len, &lb, fibnum, &info)) != 0) {
                senderr(error);
        }
        /* fill_addringo() embeds scope into IPv6 addresses */
#ifdef INET6
        rti_need_deembed = 1;
#endif

        saf = info.rti_info[RTAX_DST]->sa_family;

        /* support for new ARP code */
        if (rtm->rtm_flags & RTF_LLDATA) {
                error = lla_rt_output(rtm, &info);
                goto flush;
        }

        union sockaddr_union gw_saun;
        int blackhole_flags = rtm->rtm_flags & (RTF_BLACKHOLE|RTF_REJECT);
        if (blackhole_flags != 0) {
                if (blackhole_flags != (RTF_BLACKHOLE | RTF_REJECT))
                        error = fill_blackholeinfo(&info, &gw_saun);
                else {
                        RTS_PID_LOG(LOG_DEBUG, "both BLACKHOLE and REJECT flags specifiied");
                        error = EINVAL;
                }
                if (error != 0)
                        senderr(error);
        }

        switch (rtm->rtm_type) {
        case RTM_ADD:
        case RTM_CHANGE:
                if (rtm->rtm_type == RTM_ADD) {
                        if (info.rti_info[RTAX_GATEWAY] == NULL) {
                                RTS_PID_LOG(LOG_DEBUG, "RTM_ADD w/o gateway");
                                senderr(EINVAL);
                        }
                }
                error = rib_action(fibnum, rtm->rtm_type, &info, &rc);
                if (error == 0) {
                        rtsock_notify_event(fibnum, &rc);
                        if (NH_IS_NHGRP(rc.rc_nh_new) ||
                            (rc.rc_nh_old && NH_IS_NHGRP(rc.rc_nh_old))) {
                                struct rib_cmd_info rc_simple = {};
                                rib_decompose_notification(&rc,
                                    save_add_notification, (void *)&rc_simple);
                                rc = rc_simple;
                        }

                        /* nh MAY be empty if RTM_CHANGE request is no-op */
                        nh = rc.rc_nh_new;
                        if (nh != NULL) {
                                rtm->rtm_index = nh->nh_ifp->if_index;
                                rtm->rtm_flags = rc.rc_rt->rte_flags | nhop_get_rtflags(nh);
                        }
                }
                break;

        case RTM_DELETE:
                error = rib_action(fibnum, RTM_DELETE, &info, &rc);
                if (error == 0) {
                        rtsock_notify_event(fibnum, &rc);
                        if (NH_IS_NHGRP(rc.rc_nh_old) ||
                            (rc.rc_nh_new && NH_IS_NHGRP(rc.rc_nh_new))) {
                                struct rib_cmd_info rc_simple = {};
                                rib_decompose_notification(&rc,
                                    save_del_notification, (void *)&rc_simple);
                                rc = rc_simple;
                        }
                        nh = rc.rc_nh_old;
                }
                break;

        case RTM_GET:
                error = handle_rtm_get(&info, fibnum, rtm, &rc);
                if (error != 0)
                        senderr(error);
                nh = rc.rc_nh_new;

                if (!rt_is_exportable(rc.rc_rt, curthread->td_ucred))
                        senderr(ESRCH);
                break;

        default:
                senderr(EOPNOTSUPP);
        }

        if (error == 0 && nh != NULL) {
                error = update_rtm_from_rc(&info, &rtm, alloc_len, &rc, nh);
                /*
                 * Note that some sockaddr pointers may have changed to
                 * point to memory outsize @rtm. Some may be pointing
                 * to the on-stack variables.
                 * Given that, any pointer in @info CANNOT BE USED.
                 */

                /*
                 * scopeid deembedding has been performed while
                 * writing updated rtm in rtsock_msg_buffer().
                 * With that in mind, skip deembedding procedure below.
                 */
#ifdef INET6
                rti_need_deembed = 0;
#endif
        }

flush:
        NET_EPOCH_EXIT(et);

#ifdef INET6
        if (rtm != NULL) {
                if (rti_need_deembed) {
                        /* sin6_scope_id is recovered before sending rtm. */
                        sin6 = (struct sockaddr_in6 *)&ss;
                        for (i = 0; i < RTAX_MAX; i++) {
                                if (info.rti_info[i] == NULL)
                                        continue;
                                if (info.rti_info[i]->sa_family != AF_INET6)
                                        continue;
                                bcopy(info.rti_info[i], sin6, sizeof(*sin6));
                                if (sa6_recoverscope(sin6) == 0)
                                        bcopy(sin6, info.rti_info[i],
                                                    sizeof(*sin6));
                        }
                        if (update_rtm_from_info(&info, &rtm, alloc_len) != 0) {
                                if (error != 0)
                                        error = ENOBUFS;
                        }
                }
        }
#endif
        send_rtm_reply(so, rtm, m, saf, fibnum, error);

        return (error);
}

/*
 * Sends the prepared reply message in @rtm to all rtsock clients.
 * Frees @m and @rtm.
 *
 */
static void
send_rtm_reply(struct socket *so, struct rt_msghdr *rtm, struct mbuf *m,
    sa_family_t saf, u_int fibnum, int rtm_errno)
{
        struct rcb *rcb = NULL;

        /*
         * Check to see if we don't want our own messages.
         */
        if ((so->so_options & SO_USELOOPBACK) == 0) {
                if (V_route_cb.any_count <= 1) {
                        if (rtm != NULL)
                                free(rtm, M_TEMP);
                        m_freem(m);
                        return;
                }
                /* There is another listener, so construct message */
                rcb = so->so_pcb;
        }

        if (rtm != NULL) {
                if (rtm_errno!= 0)
                        rtm->rtm_errno = rtm_errno;
                else
                        rtm->rtm_flags |= RTF_DONE;

                m_copyback(m, 0, rtm->rtm_msglen, (caddr_t)rtm);
                if (m->m_pkthdr.len < rtm->rtm_msglen) {
                        m_freem(m);
                        m = NULL;
                } else if (m->m_pkthdr.len > rtm->rtm_msglen)
                        m_adj(m, rtm->rtm_msglen - m->m_pkthdr.len);

                free(rtm, M_TEMP);
        }
        if (m != NULL) {
                M_SETFIB(m, fibnum);
                m->m_flags |= RTS_FILTER_FIB;
                if (rcb) {
                        /*
                         * XXX insure we don't get a copy by
                         * invalidating our protocol
                         */
                        sa_family_t family = rcb->rcb_family;
                        rcb->rcb_family = AF_UNSPEC;
                        rt_dispatch(m, saf);
                        rcb->rcb_family = family;
                } else
                        rt_dispatch(m, saf);
        }
}

static void
rt_getmetrics(const struct rtentry *rt, const struct nhop_object *nh,
    struct rt_metrics *out)
{

        bzero(out, sizeof(*out));
        out->rmx_mtu = nh->nh_mtu;
        out->rmx_weight = rt->rt_weight;
        out->rmx_nhidx = nhop_get_idx(nh);
        /* Kernel -> userland timebase conversion. */
        out->rmx_expire = nhop_get_expire(nh) ?
            nhop_get_expire(nh) - time_uptime + time_second : 0;
}

/*
 * Extract the addresses of the passed sockaddrs.
 * Do a little sanity checking so as to avoid bad memory references.
 * This data is derived straight from userland.
 */
static int
rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
{
        struct sockaddr *sa;
        int i;

        for (i = 0; i < RTAX_MAX && cp < cplim; i++) {
                if ((rtinfo->rti_addrs & (1 << i)) == 0)
                        continue;
                sa = (struct sockaddr *)cp;
                /*
                 * It won't fit.
                 */
                if (cp + sa->sa_len > cplim) {
                        RTS_PID_LOG(LOG_DEBUG, "sa_len too big for sa type %d", i);
                        return (EINVAL);
                }
                /*
                 * there are no more.. quit now
                 * If there are more bits, they are in error.
                 * I've seen this. route(1) can evidently generate these. 
                 * This causes kernel to core dump.
                 * for compatibility, If we see this, point to a safe address.
                 */
                if (sa->sa_len == 0) {
                        rtinfo->rti_info[i] = &sa_zero;
                        return (0); /* should be EINVAL but for compat */
                }
                /* accept it */
#ifdef INET6
                if (sa->sa_family == AF_INET6)
                        sa6_embedscope((struct sockaddr_in6 *)sa,
                            V_ip6_use_defzone);
#endif
                rtinfo->rti_info[i] = sa;
                cp += SA_SIZE(sa);
        }
        return (0);
}

#ifdef INET
static inline void
fill_sockaddr_inet(struct sockaddr_in *sin, struct in_addr addr)
{

        const struct sockaddr_in nsin = {
                .sin_family = AF_INET,
                .sin_len = sizeof(struct sockaddr_in),
                .sin_addr = addr,
        };
        *sin = nsin;
}
#endif

#ifdef INET6
static inline void
fill_sockaddr_inet6(struct sockaddr_in6 *sin6, const struct in6_addr *addr6,
    uint32_t scopeid)
{

        const struct sockaddr_in6 nsin6 = {
                .sin6_family = AF_INET6,
                .sin6_len = sizeof(struct sockaddr_in6),
                .sin6_addr = *addr6,
                .sin6_scope_id = scopeid,
        };
        *sin6 = nsin6;
}
#endif

#if defined(INET6) || defined(INET)
/*
 * Checks if gateway is suitable for lltable operations.
 * Lltable code requires AF_LINK gateway with ifindex
 *  and mac address specified.
 * Returns 0 on success.
 */
static int
cleanup_xaddrs_lladdr(struct rt_addrinfo *info)
{
        struct sockaddr_dl *sdl = (struct sockaddr_dl *)info->rti_info[RTAX_GATEWAY];

        if (sdl->sdl_family != AF_LINK)
                return (EINVAL);

        if (sdl->sdl_index == 0) {
                RTS_PID_LOG(LOG_DEBUG, "AF_LINK gateway w/o ifindex");
                return (EINVAL);
        }

        if (offsetof(struct sockaddr_dl, sdl_data) + sdl->sdl_nlen + sdl->sdl_alen > sdl->sdl_len) {
                RTS_PID_LOG(LOG_DEBUG, "AF_LINK gw: sdl_nlen/sdl_alen too large");
                return (EINVAL);
        }

        return (0);
}

static int
cleanup_xaddrs_gateway(struct rt_addrinfo *info, struct linear_buffer *lb)
{
        struct sockaddr *gw = info->rti_info[RTAX_GATEWAY];
        struct sockaddr *sa;

        if (info->rti_flags & RTF_LLDATA)
                return (cleanup_xaddrs_lladdr(info));

        switch (gw->sa_family) {
#ifdef INET
        case AF_INET:
                {
                        struct sockaddr_in *gw_sin = (struct sockaddr_in *)gw;

                        /* Ensure reads do not go beyoud SA boundary */
                        if (SA_SIZE(gw) < offsetof(struct sockaddr_in, sin_zero)) {
                                RTS_PID_LOG(LOG_DEBUG, "gateway sin_len too small: %d",
                                    gw->sa_len);
                                return (EINVAL);
                        }
                        sa = alloc_sockaddr_aligned(lb, sizeof(struct sockaddr_in));
                        if (sa == NULL)
                                return (ENOBUFS);
                        fill_sockaddr_inet((struct sockaddr_in *)sa, gw_sin->sin_addr);
                        info->rti_info[RTAX_GATEWAY] = sa;
                }
                break;
#endif
#ifdef INET6
        case AF_INET6:
                {
                        struct sockaddr_in6 *gw_sin6 = (struct sockaddr_in6 *)gw;
                        if (gw_sin6->sin6_len < sizeof(struct sockaddr_in6)) {
                                RTS_PID_LOG(LOG_DEBUG, "gateway sin6_len too small: %d",
                                    gw->sa_len);
                                return (EINVAL);
                        }
                        fill_sockaddr_inet6(gw_sin6, &gw_sin6->sin6_addr, 0);
                        break;
                }
#endif
        case AF_LINK:
                {
                        struct sockaddr_dl *gw_sdl;

                        size_t sdl_min_len = offsetof(struct sockaddr_dl, sdl_data);
                        gw_sdl = (struct sockaddr_dl *)gw;
                        if (gw_sdl->sdl_len < sdl_min_len) {
                                RTS_PID_LOG(LOG_DEBUG, "gateway sdl_len too small: %d",
                                    gw_sdl->sdl_len);
                                return (EINVAL);
                        }
                        sa = alloc_sockaddr_aligned(lb, sizeof(struct sockaddr_dl_short));
                        if (sa == NULL)
                                return (ENOBUFS);

                        const struct sockaddr_dl_short sdl = {
                                .sdl_family = AF_LINK,
                                .sdl_len = sizeof(struct sockaddr_dl_short),
                                .sdl_index = gw_sdl->sdl_index,
                        };
                        *((struct sockaddr_dl_short *)sa) = sdl;
                        info->rti_info[RTAX_GATEWAY] = sa;
                        break;
                }
        }

        return (0);
}
#endif

static void
remove_netmask(struct rt_addrinfo *info)
{
        info->rti_info[RTAX_NETMASK] = NULL;
        info->rti_flags |= RTF_HOST;
        info->rti_addrs &= ~RTA_NETMASK;
}

#ifdef INET
static int
cleanup_xaddrs_inet(struct rt_addrinfo *info, struct linear_buffer *lb)
{
        struct sockaddr_in *dst_sa, *mask_sa;
        const int sa_len = sizeof(struct sockaddr_in);
        struct in_addr dst, mask;

        /* Check & fixup dst/netmask combination first */
        dst_sa = (struct sockaddr_in *)info->rti_info[RTAX_DST];
        mask_sa = (struct sockaddr_in *)info->rti_info[RTAX_NETMASK];

        /* Ensure reads do not go beyound the buffer size */
        if (SA_SIZE(dst_sa) < offsetof(struct sockaddr_in, sin_zero)) {
                RTS_PID_LOG(LOG_DEBUG, "prefix dst sin_len too small: %d",
                    dst_sa->sin_len);
                return (EINVAL);
        }

        if ((mask_sa != NULL) && mask_sa->sin_len < sizeof(struct sockaddr_in)) {
                /*
                 * Some older routing software encode mask length into the
                 * sin_len, thus resulting in "truncated" sockaddr.
                 */
                int len = mask_sa->sin_len - offsetof(struct sockaddr_in, sin_addr);
                if (len >= 0) {
                        mask.s_addr = 0;
                        if (len > sizeof(struct in_addr))
                                len = sizeof(struct in_addr);
                        memcpy(&mask, &mask_sa->sin_addr, len);
                } else {
                        RTS_PID_LOG(LOG_DEBUG, "prefix mask sin_len too small: %d",
                            mask_sa->sin_len);
                        return (EINVAL);
                }
        } else
                mask.s_addr = mask_sa ? mask_sa->sin_addr.s_addr : INADDR_BROADCAST;

        dst.s_addr = htonl(ntohl(dst_sa->sin_addr.s_addr) & ntohl(mask.s_addr));

        /* Construct new "clean" dst/mask sockaddresses */
        if ((dst_sa = (struct sockaddr_in *)alloc_sockaddr_aligned(lb, sa_len)) == NULL)
                return (ENOBUFS);
        fill_sockaddr_inet(dst_sa, dst);
        info->rti_info[RTAX_DST] = (struct sockaddr *)dst_sa;

        if (mask.s_addr != INADDR_BROADCAST) {
                if ((mask_sa = (struct sockaddr_in *)alloc_sockaddr_aligned(lb, sa_len)) == NULL)
                        return (ENOBUFS);
                fill_sockaddr_inet(mask_sa, mask);
                info->rti_info[RTAX_NETMASK] = (struct sockaddr *)mask_sa;
                info->rti_flags &= ~RTF_HOST;
        } else
                remove_netmask(info);

        /* Check gateway */
        if (info->rti_info[RTAX_GATEWAY] != NULL)
                return (cleanup_xaddrs_gateway(info, lb));

        return (0);
}
#endif

#ifdef INET6
static int
cleanup_xaddrs_inet6(struct rt_addrinfo *info, struct linear_buffer *lb)
{
        struct sockaddr *sa;
        struct sockaddr_in6 *dst_sa, *mask_sa;
        struct in6_addr mask, *dst;
        const int sa_len = sizeof(struct sockaddr_in6);

        /* Check & fixup dst/netmask combination first */
        dst_sa = (struct sockaddr_in6 *)info->rti_info[RTAX_DST];
        mask_sa = (struct sockaddr_in6 *)info->rti_info[RTAX_NETMASK];

        if (dst_sa->sin6_len < sizeof(struct sockaddr_in6)) {
                RTS_PID_LOG(LOG_DEBUG, "prefix dst sin6_len too small: %d",
                    dst_sa->sin6_len);
                return (EINVAL);
        }

        if (mask_sa && mask_sa->sin6_len < sizeof(struct sockaddr_in6)) {
                /*
                 * Some older routing software encode mask length into the
                 * sin6_len, thus resulting in "truncated" sockaddr.
                 */
                int len = mask_sa->sin6_len - offsetof(struct sockaddr_in6, sin6_addr);
                if (len >= 0) {
                        bzero(&mask, sizeof(mask));
                        if (len > sizeof(struct in6_addr))
                                len = sizeof(struct in6_addr);
                        memcpy(&mask, &mask_sa->sin6_addr, len);
                } else {
                        RTS_PID_LOG(LOG_DEBUG, "rtsock: prefix mask sin6_len too small: %d",
                            mask_sa->sin6_len);
                        return (EINVAL);
                }
        } else
                mask = mask_sa ? mask_sa->sin6_addr : in6mask128;

        dst = &dst_sa->sin6_addr;
        IN6_MASK_ADDR(dst, &mask);

        if ((sa = alloc_sockaddr_aligned(lb, sa_len)) == NULL)
                return (ENOBUFS);
        fill_sockaddr_inet6((struct sockaddr_in6 *)sa, dst, 0);
        info->rti_info[RTAX_DST] = sa;

        if (!IN6_ARE_ADDR_EQUAL(&mask, &in6mask128)) {
                if ((sa = alloc_sockaddr_aligned(lb, sa_len)) == NULL)
                        return (ENOBUFS);
                fill_sockaddr_inet6((struct sockaddr_in6 *)sa, &mask, 0);
                info->rti_info[RTAX_NETMASK] = sa;
                info->rti_flags &= ~RTF_HOST;
        } else
                remove_netmask(info);

        /* Check gateway */
        if (info->rti_info[RTAX_GATEWAY] != NULL)
                return (cleanup_xaddrs_gateway(info, lb));

        return (0);
}
#endif

static int
cleanup_xaddrs(struct rt_addrinfo *info, struct linear_buffer *lb)
{
        int error = EAFNOSUPPORT;

        if (info->rti_info[RTAX_DST] == NULL) {
                RTS_PID_LOG(LOG_DEBUG, "prefix dst is not set");
                return (EINVAL);
        }

        if (info->rti_flags & RTF_LLDATA) {
                /*
                 * arp(8)/ndp(8) sends RTA_NETMASK for the associated
                 * prefix along with the actual address in RTA_DST.
                 * Remove netmask to avoid unnecessary address masking.
                 */
                remove_netmask(info);
        }

        switch (info->rti_info[RTAX_DST]->sa_family) {
#ifdef INET
        case AF_INET:
                error = cleanup_xaddrs_inet(info, lb);
                break;
#endif
#ifdef INET6
        case AF_INET6:
                error = cleanup_xaddrs_inet6(info, lb);
                break;
#endif
        }

        return (error);
}

/*
 * Fill in @dmask with valid netmask leaving original @smask
 * intact. Mostly used with radix netmasks.
 */
struct sockaddr *
rtsock_fix_netmask(const struct sockaddr *dst, const struct sockaddr *smask,
    struct sockaddr_storage *dmask)
{
        if (dst == NULL || smask == NULL)
                return (NULL);

        memset(dmask, 0, dst->sa_len);
        memcpy(dmask, smask, smask->sa_len);
        dmask->ss_len = dst->sa_len;
        dmask->ss_family = dst->sa_family;

        return ((struct sockaddr *)dmask);
}

/*
 * Writes information related to @rtinfo object to newly-allocated mbuf.
 * Assumes MCLBYTES is enough to construct any message.
 * Used for OS notifications of vaious events (if/ifa announces,etc)
 *
 * Returns allocated mbuf or NULL on failure.
 */
static struct mbuf *
rtsock_msg_mbuf(int type, struct rt_addrinfo *rtinfo)
{
        struct sockaddr_storage ss;
        struct rt_msghdr *rtm;
        struct mbuf *m;
        int i;
        struct sockaddr *sa;
#ifdef INET6
        struct sockaddr_in6 *sin6;
#endif
        int len, dlen;

        switch (type) {
        case RTM_DELADDR:
        case RTM_NEWADDR:
                len = sizeof(struct ifa_msghdr);
                break;

        case RTM_DELMADDR:
        case RTM_NEWMADDR:
                len = sizeof(struct ifma_msghdr);
                break;

        case RTM_IFINFO:
                len = sizeof(struct if_msghdr);
                break;

        case RTM_IFANNOUNCE:
        case RTM_IEEE80211:
                len = sizeof(struct if_announcemsghdr);
                break;

        default:
                len = sizeof(struct rt_msghdr);
        }

        /* XXXGL: can we use MJUMPAGESIZE cluster here? */
        KASSERT(len <= MCLBYTES, ("%s: message too big", __func__));
        if (len > MHLEN)
                m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
        else
                m = m_gethdr(M_NOWAIT, MT_DATA);
        if (m == NULL)
                return (m);

        m->m_pkthdr.len = m->m_len = len;
        rtm = mtod(m, struct rt_msghdr *);
        bzero((caddr_t)rtm, len);
        for (i = 0; i < RTAX_MAX; i++) {
                if ((sa = rtinfo->rti_info[i]) == NULL)
                        continue;
                rtinfo->rti_addrs |= (1 << i);

                dlen = SA_SIZE(sa);
                KASSERT(dlen <= sizeof(ss),
                    ("%s: sockaddr size overflow", __func__));
                bzero(&ss, sizeof(ss));
                bcopy(sa, &ss, sa->sa_len);
                sa = (struct sockaddr *)&ss;
#ifdef INET6
                if (sa->sa_family == AF_INET6) {
                        sin6 = (struct sockaddr_in6 *)sa;
                        (void)sa6_recoverscope(sin6);
                }
#endif
                m_copyback(m, len, dlen, (caddr_t)sa);
                len += dlen;
        }
        if (m->m_pkthdr.len != len) {
                m_freem(m);
                return (NULL);
        }
        rtm->rtm_msglen = len;
        rtm->rtm_version = RTM_VERSION;
        rtm->rtm_type = type;
        return (m);
}

/*
 * Writes information related to @rtinfo object to preallocated buffer.
 * Stores needed size in @plen. If @w is NULL, calculates size without
 * writing.
 * Used for sysctl dumps and rtsock answers (RTM_DEL/RTM_GET) generation.
 *
 * Returns 0 on success.
 *
 */
static int
rtsock_msg_buffer(int type, struct rt_addrinfo *rtinfo, struct walkarg *w, int *plen)
{
        struct sockaddr_storage ss;
        int len, buflen = 0, dlen, i;
        caddr_t cp = NULL;
        struct rt_msghdr *rtm = NULL;
#ifdef INET6
        struct sockaddr_in6 *sin6;
#endif
#ifdef COMPAT_FREEBSD32
        bool compat32;

        compat32 = w != NULL && w->w_req != NULL &&
            (w->w_req->flags & SCTL_MASK32);
#endif

        switch (type) {
        case RTM_DELADDR:
        case RTM_NEWADDR:
                if (w != NULL && w->w_op == NET_RT_IFLISTL) {
#ifdef COMPAT_FREEBSD32
                        if (compat32)
                                len = sizeof(struct ifa_msghdrl32);
                        else
#endif
                                len = sizeof(struct ifa_msghdrl);
                } else
                        len = sizeof(struct ifa_msghdr);
                break;

        case RTM_IFINFO:
                if (w != NULL && w->w_op == NET_RT_IFLISTL) {
#ifdef COMPAT_FREEBSD32
                        if (compat32)
                                len = sizeof(struct if_msghdrl32);
                        else
#endif
                                len = sizeof(struct if_msghdrl);
                } else {
#ifdef COMPAT_FREEBSD32
                        if (compat32)
                                len = sizeof(struct if_msghdr32);
                        else
#endif
                                len = sizeof(struct if_msghdr);
                }
                break;

        case RTM_NEWMADDR:
                len = sizeof(struct ifma_msghdr);
                break;

        default:
                len = sizeof(struct rt_msghdr);
        }

        if (w != NULL) {
                rtm = (struct rt_msghdr *)w->w_tmem;
                buflen = w->w_tmemsize - len;
                cp = (caddr_t)w->w_tmem + len;
        }

        rtinfo->rti_addrs = 0;
        for (i = 0; i < RTAX_MAX; i++) {
                struct sockaddr *sa;

                if ((sa = rtinfo->rti_info[i]) == NULL)
                        continue;
                rtinfo->rti_addrs |= (1 << i);
#ifdef COMPAT_FREEBSD32
                if (compat32)
                        dlen = SA_SIZE32(sa);
                else
#endif
                        dlen = SA_SIZE(sa);
                if (cp != NULL && buflen >= dlen) {
                        if (sa->sa_len > sizeof(ss))
                                return (EINVAL);
                        bzero(&ss, sizeof(ss));
                        bcopy(sa, &ss, sa->sa_len);
                        sa = (struct sockaddr *)&ss;
#ifdef INET6
                        if (sa->sa_family == AF_INET6) {
                                sin6 = (struct sockaddr_in6 *)sa;
                                (void)sa6_recoverscope(sin6);
                        }
#endif
                        bcopy((caddr_t)sa, cp, (unsigned)dlen);
                        cp += dlen;
                        buflen -= dlen;
                } else if (cp != NULL) {
                        /*
                         * Buffer too small. Count needed size
                         * and return with error.
                         */
                        cp = NULL;
                }

                len += dlen;
        }

        if (cp != NULL) {
                dlen = ALIGN(len) - len;
                if (buflen < dlen)
                        cp = NULL;
                else {
                        bzero(cp, dlen);
                        cp += dlen;
                        buflen -= dlen;
                }
        }
        len = ALIGN(len);

        if (cp != NULL) {
                /* fill header iff buffer is large enough */
                rtm->rtm_version = RTM_VERSION;
                rtm->rtm_type = type;
                rtm->rtm_msglen = len;
        }

        *plen = len;

        if (w != NULL && cp == NULL)
                return (ENOBUFS);

        return (0);
}

/*
 * This routine is called to generate a message from the routing
 * socket indicating that a redirect has occurred, a routing lookup
 * has failed, or that a protocol has detected timeouts to a particular
 * destination.
 */
void
rt_missmsg_fib(int type, struct rt_addrinfo *rtinfo, int flags, int error,
    int fibnum)
{
        struct rt_msghdr *rtm;
        struct mbuf *m;
        struct sockaddr *sa = rtinfo->rti_info[RTAX_DST];

        if (V_route_cb.any_count == 0)
                return;
        m = rtsock_msg_mbuf(type, rtinfo);
        if (m == NULL)
                return;

        if (fibnum != RT_ALL_FIBS) {
                KASSERT(fibnum >= 0 && fibnum < rt_numfibs, ("%s: fibnum out "
                    "of range 0 <= %d < %d", __func__, fibnum, rt_numfibs));
                M_SETFIB(m, fibnum);
                m->m_flags |= RTS_FILTER_FIB;
        }

        rtm = mtod(m, struct rt_msghdr *);
        rtm->rtm_flags = RTF_DONE | flags;
        rtm->rtm_errno = error;
        rtm->rtm_addrs = rtinfo->rti_addrs;
        rt_dispatch(m, sa ? sa->sa_family : AF_UNSPEC);
}

void
rt_missmsg(int type, struct rt_addrinfo *rtinfo, int flags, int error)
{

        rt_missmsg_fib(type, rtinfo, flags, error, RT_ALL_FIBS);
}

/*
 * This routine is called to generate a message from the routing
 * socket indicating that the status of a network interface has changed.
 */
static void
rtsock_ifmsg(struct ifnet *ifp, int if_flags_mask __unused)
{
        struct if_msghdr *ifm;
        struct mbuf *m;
        struct rt_addrinfo info;

        if (V_route_cb.any_count == 0)
                return;
        bzero((caddr_t)&info, sizeof(info));
        m = rtsock_msg_mbuf(RTM_IFINFO, &info);
        if (m == NULL)
                return;
        ifm = mtod(m, struct if_msghdr *);
        ifm->ifm_index = ifp->if_index;
        ifm->ifm_flags = ifp->if_flags | ifp->if_drv_flags;
        if_data_copy(ifp, &ifm->ifm_data);
        ifm->ifm_addrs = 0;
        rt_dispatch(m, AF_UNSPEC);
}

/*
 * Announce interface address arrival/withdraw.
 * Please do not call directly, use rt_addrmsg().
 * Assume input data to be valid.
 * Returns 0 on success.
 */
int
rtsock_addrmsg(int cmd, struct ifaddr *ifa, int fibnum)
{
        struct rt_addrinfo info;
        struct sockaddr *sa;
        int ncmd;
        struct mbuf *m;
        struct ifa_msghdr *ifam;
        struct ifnet *ifp = ifa->ifa_ifp;
        struct sockaddr_storage ss;

        if (V_route_cb.any_count == 0)
                return (0);

        ncmd = cmd == RTM_ADD ? RTM_NEWADDR : RTM_DELADDR;

        bzero((caddr_t)&info, sizeof(info));
        info.rti_info[RTAX_IFA] = sa = ifa->ifa_addr;
        info.rti_info[RTAX_IFP] = ifp->if_addr->ifa_addr;
        info.rti_info[RTAX_NETMASK] = rtsock_fix_netmask(
            info.rti_info[RTAX_IFA], ifa->ifa_netmask, &ss);
        info.rti_info[RTAX_BRD] = ifa->ifa_dstaddr;
        if ((m = rtsock_msg_mbuf(ncmd, &info)) == NULL)
                return (ENOBUFS);
        ifam = mtod(m, struct ifa_msghdr *);
        ifam->ifam_index = ifp->if_index;
        ifam->ifam_metric = ifa->ifa_ifp->if_metric;
        ifam->ifam_flags = ifa->ifa_flags;
        ifam->ifam_addrs = info.rti_addrs;

        if (fibnum != RT_ALL_FIBS) {
                M_SETFIB(m, fibnum);
                m->m_flags |= RTS_FILTER_FIB;
        }

        rt_dispatch(m, sa ? sa->sa_family : AF_UNSPEC);

        return (0);
}

/*
 * Announce route addition/removal to rtsock based on @rt data.
 * Callers are advives to use rt_routemsg() instead of using this
 *  function directly.
 * Assume @rt data is consistent.
 *
 * Returns 0 on success.
 */
int
rtsock_routemsg(int cmd, struct rtentry *rt, struct nhop_object *nh,
    int fibnum)
{
        union sockaddr_union dst, mask;
        struct rt_addrinfo info;

        if (V_route_cb.any_count == 0)
                return (0);

        int family = rt_get_family(rt);
        init_sockaddrs_family(family, &dst.sa, &mask.sa);
        export_rtaddrs(rt, &dst.sa, &mask.sa);

        bzero((caddr_t)&info, sizeof(info));
        info.rti_info[RTAX_DST] = &dst.sa;
        info.rti_info[RTAX_NETMASK] = &mask.sa;
        info.rti_info[RTAX_GATEWAY] = &nh->gw_sa;
        info.rti_flags = rt->rte_flags | nhop_get_rtflags(nh);
        info.rti_ifp = nh->nh_ifp;

        return (rtsock_routemsg_info(cmd, &info, fibnum));
}

int
rtsock_routemsg_info(int cmd, struct rt_addrinfo *info, int fibnum)
{
        struct rt_msghdr *rtm;
        struct sockaddr *sa;
        struct mbuf *m;

        if (V_route_cb.any_count == 0)
                return (0);

        if (info->rti_flags & RTF_HOST)
                info->rti_info[RTAX_NETMASK] = NULL;

        m = rtsock_msg_mbuf(cmd, info);
        if (m == NULL)
                return (ENOBUFS);

        if (fibnum != RT_ALL_FIBS) {
                KASSERT(fibnum >= 0 && fibnum < rt_numfibs, ("%s: fibnum out "
                    "of range 0 <= %d < %d", __func__, fibnum, rt_numfibs));
                M_SETFIB(m, fibnum);
                m->m_flags |= RTS_FILTER_FIB;
        }

        rtm = mtod(m, struct rt_msghdr *);
        rtm->rtm_addrs = info->rti_addrs;
        if (info->rti_ifp != NULL)
                rtm->rtm_index = info->rti_ifp->if_index;
        /* Add RTF_DONE to indicate command 'completion' required by API */
        info->rti_flags |= RTF_DONE;
        /* Reported routes has to be up */
        if (cmd == RTM_ADD || cmd == RTM_CHANGE)
                info->rti_flags |= RTF_UP;
        rtm->rtm_flags = info->rti_flags;

        sa = info->rti_info[RTAX_DST];
        rt_dispatch(m, sa ? sa->sa_family : AF_UNSPEC);

        return (0);
}

/*
 * This is the analogue to the rt_newaddrmsg which performs the same
 * function but for multicast group memberhips.  This is easier since
 * there is no route state to worry about.
 */
void
rt_newmaddrmsg(int cmd, struct ifmultiaddr *ifma)
{
        struct rt_addrinfo info;
        struct mbuf *m = NULL;
        struct ifnet *ifp = ifma->ifma_ifp;
        struct ifma_msghdr *ifmam;

        if (V_route_cb.any_count == 0)
                return;

        bzero((caddr_t)&info, sizeof(info));
        info.rti_info[RTAX_IFA] = ifma->ifma_addr;
        if (ifp && ifp->if_addr)
                info.rti_info[RTAX_IFP] = ifp->if_addr->ifa_addr;
        else
                info.rti_info[RTAX_IFP] = NULL;
        /*
         * If a link-layer address is present, present it as a ``gateway''
         * (similarly to how ARP entries, e.g., are presented).
         */
        info.rti_info[RTAX_GATEWAY] = ifma->ifma_lladdr;
        m = rtsock_msg_mbuf(cmd, &info);
        if (m == NULL)
                return;
        ifmam = mtod(m, struct ifma_msghdr *);
        KASSERT(ifp != NULL, ("%s: link-layer multicast address w/o ifp\n",
            __func__));
        ifmam->ifmam_index = ifp->if_index;
        ifmam->ifmam_addrs = info.rti_addrs;
        rt_dispatch(m, ifma->ifma_addr ? ifma->ifma_addr->sa_family : AF_UNSPEC);
}

static struct mbuf *
rt_makeifannouncemsg(struct ifnet *ifp, int type, int what,
    struct rt_addrinfo *info, const char *ifname)
{
        struct if_announcemsghdr *ifan;
        struct mbuf *m;

        if (V_route_cb.any_count == 0)
                return NULL;
        bzero((caddr_t)info, sizeof(*info));
        m = rtsock_msg_mbuf(type, info);
        if (m != NULL) {
                ifan = mtod(m, struct if_announcemsghdr *);
                ifan->ifan_index = ifp->if_index;
                strlcpy(ifan->ifan_name,
                    ifname != NULL ? ifname : ifp->if_xname,
                    sizeof(ifan->ifan_name));
                ifan->ifan_what = what;
        }
        return m;
}

/*
 * This is called to generate routing socket messages indicating
 * IEEE80211 wireless events.
 * XXX we piggyback on the RTM_IFANNOUNCE msg format in a clumsy way.
 */
void
rt_ieee80211msg(struct ifnet *ifp, int what, void *data, size_t data_len)
{
        struct mbuf *m;
        struct rt_addrinfo info;

        m = rt_makeifannouncemsg(ifp, RTM_IEEE80211, what, &info, NULL);
        if (m != NULL) {
                /*
                 * Append the ieee80211 data.  Try to stick it in the
                 * mbuf containing the ifannounce msg; otherwise allocate
                 * a new mbuf and append.
                 *
                 * NB: we assume m is a single mbuf.
                 */
                if (data_len > M_TRAILINGSPACE(m)) {
                        struct mbuf *n = m_get(M_NOWAIT, MT_DATA);
                        if (n == NULL) {
                                m_freem(m);
                                return;
                        }
                        bcopy(data, mtod(n, void *), data_len);
                        n->m_len = data_len;
                        m->m_next = n;
                } else if (data_len > 0) {
                        bcopy(data, mtod(m, u_int8_t *) + m->m_len, data_len);
                        m->m_len += data_len;
                }
                if (m->m_flags & M_PKTHDR)
                        m->m_pkthdr.len += data_len;
                mtod(m, struct if_announcemsghdr *)->ifan_msglen += data_len;
                rt_dispatch(m, AF_UNSPEC);
        }
}

/*
 * This is called to generate routing socket messages indicating
 * network interface arrival and departure.
 */
static void
rt_ifannouncemsg(struct ifnet *ifp, int what, const char *ifname)
{
        struct mbuf *m;
        struct rt_addrinfo info;

        m = rt_makeifannouncemsg(ifp, RTM_IFANNOUNCE, what, &info, ifname);
        if (m != NULL)
                rt_dispatch(m, AF_UNSPEC);
}

static void
rt_dispatch(struct mbuf *m, sa_family_t saf)
{

        M_ASSERTPKTHDR(m);

        m->m_rtsock_family = saf;
        if (V_loif)
                m->m_pkthdr.rcvif = V_loif;
        else {
                m_freem(m);
                return;
        }
        netisr_queue(NETISR_ROUTE, m);  /* mbuf is free'd on failure. */
}

/*
 * This is used in dumping the kernel table via sysctl().
 */
static int
sysctl_dumpentry(struct rtentry *rt, void *vw)
{
        const struct weightened_nhop *wn;
        struct walkarg *w = vw;
        struct nhop_object *nh;
        int error;
        uint32_t num_nhops;

        NET_EPOCH_ASSERT();

        if (!rt_is_exportable(rt, w->w_req->td->td_ucred))
                return (0);

        export_rtaddrs(rt, w->dst, w->mask);
        nh = rt_get_raw_nhop(rt);
        if (NH_IS_NHGRP(nh)) {
                wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops);
                for (int i = 0; i < num_nhops; i++) {
                        error = sysctl_dumpnhop(rt, wn[i].nh, wn[i].weight, w);
                        if (error != 0)
                                return (error);
                }
        } else
                sysctl_dumpnhop(rt, nh, rt->rt_weight, w);

        return (0);
}


static int
sysctl_dumpnhop(struct rtentry *rt, struct nhop_object *nh, uint32_t weight,
    struct walkarg *w)
{
        struct rt_addrinfo info;
        int error = 0, size;
        uint32_t rtflags;

        rtflags = nhop_get_rtflags(nh);

        if (w->w_op == NET_RT_FLAGS && !(rtflags & w->w_arg))
                return (0);

        bzero((caddr_t)&info, sizeof(info));
        info.rti_info[RTAX_DST] = w->dst;
        info.rti_info[RTAX_GATEWAY] = &nh->gw_sa;
        info.rti_info[RTAX_NETMASK] = (rtflags & RTF_HOST) ? NULL : w->mask;
        info.rti_info[RTAX_GENMASK] = 0;
        if (nh->nh_ifp && !(nh->nh_ifp->if_flags & IFF_DYING)) {
                info.rti_info[RTAX_IFP] = nh->nh_ifp->if_addr->ifa_addr;
                info.rti_info[RTAX_IFA] = nh->nh_ifa->ifa_addr;
                if (nh->nh_ifp->if_flags & IFF_POINTOPOINT)
                        info.rti_info[RTAX_BRD] = nh->nh_ifa->ifa_dstaddr;
        }
        if ((error = rtsock_msg_buffer(RTM_GET, &info, w, &size)) != 0)
                return (error);
        if (w->w_req && w->w_tmem) {
                struct rt_msghdr *rtm = (struct rt_msghdr *)w->w_tmem;

                bzero(&rtm->rtm_index,
                    sizeof(*rtm) - offsetof(struct rt_msghdr, rtm_index));

                /*
                 * rte flags may consist of RTF_HOST (duplicated in nhop rtflags)
                 * and RTF_UP (if entry is linked, which is always true here).
                 * Given that, use nhop rtflags & add RTF_UP.
                 */
                rtm->rtm_flags = rtflags | RTF_UP;
                if (rtm->rtm_flags & RTF_GWFLAG_COMPAT)
                        rtm->rtm_flags = RTF_GATEWAY | 
                                (rtm->rtm_flags & ~RTF_GWFLAG_COMPAT);
                rt_getmetrics(rt, nh, &rtm->rtm_rmx);
                rtm->rtm_rmx.rmx_weight = weight;
                rtm->rtm_index = nh->nh_ifp->if_index;
                rtm->rtm_addrs = info.rti_addrs;
                error = SYSCTL_OUT(w->w_req, (caddr_t)rtm, size);
                return (error);
        }
        return (error);
}

static int
sysctl_iflist_ifml(struct ifnet *ifp, const struct if_data *src_ifd,
    struct rt_addrinfo *info, struct walkarg *w, int len)
{
        struct if_msghdrl *ifm;
        struct if_data *ifd;

        ifm = (struct if_msghdrl *)w->w_tmem;

#ifdef COMPAT_FREEBSD32
        if (w->w_req->flags & SCTL_MASK32) {
                struct if_msghdrl32 *ifm32;

                ifm32 = (struct if_msghdrl32 *)ifm;
                ifm32->ifm_addrs = info->rti_addrs;
                ifm32->ifm_flags = ifp->if_flags | ifp->if_drv_flags;
                ifm32->ifm_index = ifp->if_index;
                ifm32->_ifm_spare1 = 0;
                ifm32->ifm_len = sizeof(*ifm32);
                ifm32->ifm_data_off = offsetof(struct if_msghdrl32, ifm_data);
                ifm32->_ifm_spare2 = 0;
                ifd = &ifm32->ifm_data;
        } else
#endif
        {
                ifm->ifm_addrs = info->rti_addrs;
                ifm->ifm_flags = ifp->if_flags | ifp->if_drv_flags;
                ifm->ifm_index = ifp->if_index;
                ifm->_ifm_spare1 = 0;
                ifm->ifm_len = sizeof(*ifm);
                ifm->ifm_data_off = offsetof(struct if_msghdrl, ifm_data);
                ifm->_ifm_spare2 = 0;
                ifd = &ifm->ifm_data;
        }

        memcpy(ifd, src_ifd, sizeof(*ifd));

        return (SYSCTL_OUT(w->w_req, (caddr_t)ifm, len));
}

static int
sysctl_iflist_ifm(struct ifnet *ifp, const struct if_data *src_ifd,
    struct rt_addrinfo *info, struct walkarg *w, int len)
{
        struct if_msghdr *ifm;
        struct if_data *ifd;

        ifm = (struct if_msghdr *)w->w_tmem;

#ifdef COMPAT_FREEBSD32
        if (w->w_req->flags & SCTL_MASK32) {
                struct if_msghdr32 *ifm32;

                ifm32 = (struct if_msghdr32 *)ifm;
                ifm32->ifm_addrs = info->rti_addrs;
                ifm32->ifm_flags = ifp->if_flags | ifp->if_drv_flags;
                ifm32->ifm_index = ifp->if_index;
                ifm32->_ifm_spare1 = 0;
                ifd = &ifm32->ifm_data;
        } else
#endif
        {
                ifm->ifm_addrs = info->rti_addrs;
                ifm->ifm_flags = ifp->if_flags | ifp->if_drv_flags;
                ifm->ifm_index = ifp->if_index;
                ifm->_ifm_spare1 = 0;
                ifd = &ifm->ifm_data;
        }

        memcpy(ifd, src_ifd, sizeof(*ifd));

        return (SYSCTL_OUT(w->w_req, (caddr_t)ifm, len));
}

static int
sysctl_iflist_ifaml(struct ifaddr *ifa, struct rt_addrinfo *info,
    struct walkarg *w, int len)
{
        struct ifa_msghdrl *ifam;
        struct if_data *ifd;

        ifam = (struct ifa_msghdrl *)w->w_tmem;

#ifdef COMPAT_FREEBSD32
        if (w->w_req->flags & SCTL_MASK32) {
                struct ifa_msghdrl32 *ifam32;

                ifam32 = (struct ifa_msghdrl32 *)ifam;
                ifam32->ifam_addrs = info->rti_addrs;
                ifam32->ifam_flags = ifa->ifa_flags;
                ifam32->ifam_index = ifa->ifa_ifp->if_index;
                ifam32->_ifam_spare1 = 0;
                ifam32->ifam_len = sizeof(*ifam32);
                ifam32->ifam_data_off =
                    offsetof(struct ifa_msghdrl32, ifam_data);
                ifam32->ifam_metric = ifa->ifa_ifp->if_metric;
                ifd = &ifam32->ifam_data;
        } else
#endif
        {
                ifam->ifam_addrs = info->rti_addrs;
                ifam->ifam_flags = ifa->ifa_flags;
                ifam->ifam_index = ifa->ifa_ifp->if_index;
                ifam->_ifam_spare1 = 0;
                ifam->ifam_len = sizeof(*ifam);
                ifam->ifam_data_off = offsetof(struct ifa_msghdrl, ifam_data);
                ifam->ifam_metric = ifa->ifa_ifp->if_metric;
                ifd = &ifam->ifam_data;
        }

        bzero(ifd, sizeof(*ifd));
        ifd->ifi_datalen = sizeof(struct if_data);
        ifd->ifi_ipackets = counter_u64_fetch(ifa->ifa_ipackets);
        ifd->ifi_opackets = counter_u64_fetch(ifa->ifa_opackets);
        ifd->ifi_ibytes = counter_u64_fetch(ifa->ifa_ibytes);
        ifd->ifi_obytes = counter_u64_fetch(ifa->ifa_obytes);

        /* Fixup if_data carp(4) vhid. */
        if (carp_get_vhid_p != NULL)
                ifd->ifi_vhid = (*carp_get_vhid_p)(ifa);

        return (SYSCTL_OUT(w->w_req, w->w_tmem, len));
}

static int
sysctl_iflist_ifam(struct ifaddr *ifa, struct rt_addrinfo *info,
    struct walkarg *w, int len)
{
        struct ifa_msghdr *ifam;

        ifam = (struct ifa_msghdr *)w->w_tmem;
        ifam->ifam_addrs = info->rti_addrs;
        ifam->ifam_flags = ifa->ifa_flags;
        ifam->ifam_index = ifa->ifa_ifp->if_index;
        ifam->_ifam_spare1 = 0;
        ifam->ifam_metric = ifa->ifa_ifp->if_metric;

        return (SYSCTL_OUT(w->w_req, w->w_tmem, len));
}

static int
sysctl_iflist(int af, struct walkarg *w)
{
        struct ifnet *ifp;
        struct ifaddr *ifa;
        struct if_data ifd;
        struct rt_addrinfo info;
        int len, error = 0;
        struct sockaddr_storage ss;

        bzero((caddr_t)&info, sizeof(info));
        bzero(&ifd, sizeof(ifd));
        CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
                if (w->w_arg && w->w_arg != ifp->if_index)
                        continue;
                if_data_copy(ifp, &ifd);
                ifa = ifp->if_addr;
                info.rti_info[RTAX_IFP] = ifa->ifa_addr;
                error = rtsock_msg_buffer(RTM_IFINFO, &info, w, &len);
                if (error != 0)
                        goto done;
                info.rti_info[RTAX_IFP] = NULL;
                if (w->w_req && w->w_tmem) {
                        if (w->w_op == NET_RT_IFLISTL)
                                error = sysctl_iflist_ifml(ifp, &ifd, &info, w,
                                    len);
                        else
                                error = sysctl_iflist_ifm(ifp, &ifd, &info, w,
                                    len);
                        if (error)
                                goto done;
                }
                while ((ifa = CK_STAILQ_NEXT(ifa, ifa_link)) != NULL) {
                        if (af && af != ifa->ifa_addr->sa_family)
                                continue;
                        if (prison_if(w->w_req->td->td_ucred,
                            ifa->ifa_addr) != 0)
                                continue;
                        info.rti_info[RTAX_IFA] = ifa->ifa_addr;
                        info.rti_info[RTAX_NETMASK] = rtsock_fix_netmask(
                            ifa->ifa_addr, ifa->ifa_netmask, &ss);
                        info.rti_info[RTAX_BRD] = ifa->ifa_dstaddr;
                        error = rtsock_msg_buffer(RTM_NEWADDR, &info, w, &len);
                        if (error != 0)
                                goto done;
                        if (w->w_req && w->w_tmem) {
                                if (w->w_op == NET_RT_IFLISTL)
                                        error = sysctl_iflist_ifaml(ifa, &info,
                                            w, len);
                                else
                                        error = sysctl_iflist_ifam(ifa, &info,
                                            w, len);
                                if (error)
                                        goto done;
                        }
                }
                info.rti_info[RTAX_IFA] = NULL;
                info.rti_info[RTAX_NETMASK] = NULL;
                info.rti_info[RTAX_BRD] = NULL;
        }
done:
        return (error);
}

static int
sysctl_ifmalist(int af, struct walkarg *w)
{
        struct rt_addrinfo info;
        struct ifaddr *ifa;
        struct ifmultiaddr *ifma;
        struct ifnet *ifp;
        int error, len;

        NET_EPOCH_ASSERT();

        error = 0;
        bzero((caddr_t)&info, sizeof(info));

        CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
                if (w->w_arg && w->w_arg != ifp->if_index)
                        continue;
                ifa = ifp->if_addr;
                info.rti_info[RTAX_IFP] = ifa ? ifa->ifa_addr : NULL;
                CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                        if (af && af != ifma->ifma_addr->sa_family)
                                continue;
                        if (prison_if(w->w_req->td->td_ucred,
                            ifma->ifma_addr) != 0)
                                continue;
                        info.rti_info[RTAX_IFA] = ifma->ifma_addr;
                        info.rti_info[RTAX_GATEWAY] =
                            (ifma->ifma_addr->sa_family != AF_LINK) ?
                            ifma->ifma_lladdr : NULL;
                        error = rtsock_msg_buffer(RTM_NEWMADDR, &info, w, &len);
                        if (error != 0)
                                break;
                        if (w->w_req && w->w_tmem) {
                                struct ifma_msghdr *ifmam;

                                ifmam = (struct ifma_msghdr *)w->w_tmem;
                                ifmam->ifmam_index = ifma->ifma_ifp->if_index;
                                ifmam->ifmam_flags = 0;
                                ifmam->ifmam_addrs = info.rti_addrs;
                                ifmam->_ifmam_spare1 = 0;
                                error = SYSCTL_OUT(w->w_req, w->w_tmem, len);
                                if (error != 0)
                                        break;
                        }
                }
                if (error != 0)
                        break;
        }
        return (error);
}

static void
rtable_sysctl_dump(uint32_t fibnum, int family, struct walkarg *w)
{
        union sockaddr_union sa_dst, sa_mask;

        w->family = family;
        w->dst = (struct sockaddr *)&sa_dst;
        w->mask = (struct sockaddr *)&sa_mask;

        init_sockaddrs_family(family, w->dst, w->mask);

        rib_walk(fibnum, family, false, sysctl_dumpentry, w);
}

static int
sysctl_rtsock(SYSCTL_HANDLER_ARGS)
{
        struct epoch_tracker et;
        int     *name = (int *)arg1;
        u_int   namelen = arg2;
        struct rib_head *rnh = NULL; /* silence compiler. */
        int     i, lim, error = EINVAL;
        int     fib = 0;
        u_char  af;
        struct  walkarg w;

        if (namelen < 3)
                return (EINVAL);

        name++;
        namelen--;
        if (req->newptr)
                return (EPERM);
        if (name[1] == NET_RT_DUMP || name[1] == NET_RT_NHOP || name[1] == NET_RT_NHGRP) {
                if (namelen == 3)
                        fib = req->td->td_proc->p_fibnum;
                else if (namelen == 4)
                        fib = (name[3] == RT_ALL_FIBS) ?
                            req->td->td_proc->p_fibnum : name[3];
                else
                        return ((namelen < 3) ? EISDIR : ENOTDIR);
                if (fib < 0 || fib >= rt_numfibs)
                        return (EINVAL);
        } else if (namelen != 3)
                return ((namelen < 3) ? EISDIR : ENOTDIR);
        af = name[0];
        if (af > AF_MAX)
                return (EINVAL);
        bzero(&w, sizeof(w));
        w.w_op = name[1];
        w.w_arg = name[2];
        w.w_req = req;

        error = sysctl_wire_old_buffer(req, 0);
        if (error)
                return (error);

        /*
         * Allocate reply buffer in advance.
         * All rtsock messages has maximum length of u_short.
         */
        w.w_tmemsize = 65536;
        w.w_tmem = malloc(w.w_tmemsize, M_TEMP, M_WAITOK);

        NET_EPOCH_ENTER(et);
        switch (w.w_op) {
        case NET_RT_DUMP:
        case NET_RT_FLAGS:
                if (af == 0) {                  /* dump all tables */
                        i = 1;
                        lim = AF_MAX;
                } else                          /* dump only one table */
                        i = lim = af;

                /*
                 * take care of llinfo entries, the caller must
                 * specify an AF
                 */
                if (w.w_op == NET_RT_FLAGS &&
                    (w.w_arg == 0 || w.w_arg & RTF_LLINFO)) {
                        if (af != 0)
                                error = lltable_sysctl_dumparp(af, w.w_req);
                        else
                                error = EINVAL;
                        break;
                }
                /*
                 * take care of routing entries
                 */
                for (error = 0; error == 0 && i <= lim; i++) {
                        rnh = rt_tables_get_rnh(fib, i);
                        if (rnh != NULL) {
                                rtable_sysctl_dump(fib, i, &w);
                        } else if (af != 0)
                                error = EAFNOSUPPORT;
                }
                break;
        case NET_RT_NHOP:
        case NET_RT_NHGRP:
                /* Allow dumping one specific af/fib at a time */
                if (namelen < 4) {
                        error = EINVAL;
                        break;
                }
                fib = name[3];
                if (fib < 0 || fib > rt_numfibs) {
                        error = EINVAL;
                        break;
                }
                rnh = rt_tables_get_rnh(fib, af);
                if (rnh == NULL) {
                        error = EAFNOSUPPORT;
                        break;
                }
                if (w.w_op == NET_RT_NHOP)
                        error = nhops_dump_sysctl(rnh, w.w_req);
                else
                        error = nhgrp_dump_sysctl(rnh, w.w_req);
                break;
        case NET_RT_IFLIST:
        case NET_RT_IFLISTL:
                error = sysctl_iflist(af, &w);
                break;

        case NET_RT_IFMALIST:
                error = sysctl_ifmalist(af, &w);
                break;
        }
        NET_EPOCH_EXIT(et);

        free(w.w_tmem, M_TEMP);
        return (error);
}

static SYSCTL_NODE(_net, PF_ROUTE, routetable, CTLFLAG_RD | CTLFLAG_MPSAFE,
    sysctl_rtsock, "Return route tables and interface/address lists");

/*
 * Definitions of protocols supported in the ROUTE domain.
 */

static struct domain routedomain;               /* or at least forward */

static struct protosw routesw = {
        .pr_type =              SOCK_RAW,
        .pr_flags =             PR_ATOMIC|PR_ADDR,
        .pr_abort =             rts_close,
        .pr_attach =            rts_attach,
        .pr_ctloutput =         rts_ctloutput,
        .pr_detach =            rts_detach,
        .pr_send =              rts_send,
        .pr_shutdown =          rts_shutdown,
        .pr_disconnect =        rts_disconnect,
        .pr_close =             rts_close,
};

static struct domain routedomain = {
        .dom_family =           PF_ROUTE,
        .dom_name =             "route",
        .dom_nprotosw =         1,
        .dom_protosw =          { &routesw },
};

DOMAIN_SET(route);