xref: /freebsd/sys/net/rtsock.c (revision b8a6e03fac922677455d8e0977831506cf8212e8)

/*-
 * 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.
 *
 *	@(#)rtsock.c	8.7 (Berkeley) 10/12/95
 * $FreeBSD$
 */
#include "opt_ddb.h"
#include "opt_mpath.h"
#include "opt_inet.h"
#include "opt_inet6.h"

#include <sys/param.h>
#include <sys/jail.h>
#include <sys/kernel.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>

#ifdef DDB
#include <ddb/ddb.h>
#include <ddb/db_lex.h>
#endif

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/if_llatbl.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/raw_cb.h>
#include <net/route.h>
#include <net/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/ip6_var.h>
#include <netinet6/scope6_var.h>
#endif

#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 */

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/raw_input callback code to decide whether to filter the update
 * notification to a socket bound to a particular FIB.
 */
#define	RTS_FILTER_FIB	M_PROTO8

typedef struct {
	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)

static SYSCTL_NODE(_net, OID_AUTO, route, CTLFLAG_RD, 0, "");

struct walkarg {
	int	w_tmemsize;
	int	w_op, w_arg;
	caddr_t	w_tmem;
	struct sysctl_req *w_req;
};

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	sysctl_dumpentry(struct radix_node *rn, void *vw);
static int	sysctl_iflist(int af, struct walkarg *w);
static int	sysctl_ifmalist(int af, struct walkarg *w);
static int	route_output(struct mbuf *m, struct socket *so, ...);
static void	rt_getmetrics(const struct rtentry *rt, struct rt_metrics *out);
static void	rt_dispatch(struct mbuf *, sa_family_t);
static struct sockaddr	*rtsock_fix_netmask(struct sockaddr *dst,
			struct sockaddr *smask, struct sockaddr_storage *dmask);

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_RW,
    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, 0);

#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, 0);
#endif

static int
raw_input_rts_cb(struct mbuf *m, struct sockproto *proto, struct sockaddr *src,
    struct rawcb *rp)
{
	int fibnum;

	KASSERT(m != NULL, ("%s: m is NULL", __func__));
	KASSERT(proto != NULL, ("%s: proto is NULL", __func__));
	KASSERT(rp != NULL, ("%s: rp is NULL", __func__));

	/* No filtering requested. */
	if ((m->m_flags & RTS_FILTER_FIB) == 0)
		return (0);

	/* Check if it is a rts and the fib matches the one of the socket. */
	fibnum = M_GETFIB(m);
	if (proto->sp_family != PF_ROUTE ||
	    rp->rcb_socket == NULL ||
	    rp->rcb_socket->so_fibnum == fibnum)
		return (0);

	/* Filtering requested and no match, the socket shall be skipped. */
	return (1);
}

static void
rts_input(struct mbuf *m)
{
	struct sockproto route_proto;
	unsigned short *family;
	struct m_tag *tag;

	route_proto.sp_family = PF_ROUTE;
	tag = m_tag_find(m, PACKET_TAG_RTSOCKFAM, NULL);
	if (tag != NULL) {
		family = (unsigned short *)(tag + 1);
		route_proto.sp_protocol = *family;
		m_tag_delete(m, tag);
	} else
		route_proto.sp_protocol = 0;

	raw_input_ext(m, &route_proto, &route_src, raw_input_rts_cb);
}

/*
 * It really doesn't make any sense at all for this code to share much
 * with raw_usrreq.c, since its functionality is so restricted.  XXX
 */
static void
rts_abort(struct socket *so)
{

	raw_usrreqs.pru_abort(so);
}

static void
rts_close(struct socket *so)
{

	raw_usrreqs.pru_close(so);
}

/* pru_accept is EOPNOTSUPP */

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

	KASSERT(so->so_pcb == NULL, ("rts_attach: so_pcb != NULL"));

	/* XXX */
	rp = malloc(sizeof *rp, M_PCB, M_WAITOK | M_ZERO);

	so->so_pcb = (caddr_t)rp;
	so->so_fibnum = td->td_proc->p_fibnum;
	error = raw_attach(so, proto);
	rp = sotorawcb(so);
	if (error) {
		so->so_pcb = NULL;
		free(rp, M_PCB);
		return error;
	}
	RTSOCK_LOCK();
	switch(rp->rcb_proto.sp_protocol) {
	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);
	so->so_options |= SO_USELOOPBACK;
	return 0;
}

static int
rts_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
{

	return (raw_usrreqs.pru_bind(so, nam, td)); /* xxx just EINVAL */
}

static int
rts_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
{

	return (raw_usrreqs.pru_connect(so, nam, td)); /* XXX just EINVAL */
}

/* pru_connect2 is EOPNOTSUPP */
/* pru_control is EOPNOTSUPP */

static void
rts_detach(struct socket *so)
{
	struct rawcb *rp = sotorawcb(so);

	KASSERT(rp != NULL, ("rts_detach: rp == NULL"));

	RTSOCK_LOCK();
	switch(rp->rcb_proto.sp_protocol) {
	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();
	raw_usrreqs.pru_detach(so);
}

static int
rts_disconnect(struct socket *so)
{

	return (raw_usrreqs.pru_disconnect(so));
}

/* pru_listen is EOPNOTSUPP */

static int
rts_peeraddr(struct socket *so, struct sockaddr **nam)
{

	return (raw_usrreqs.pru_peeraddr(so, nam));
}

/* pru_rcvd is EOPNOTSUPP */
/* pru_rcvoob is EOPNOTSUPP */

static int
rts_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
	 struct mbuf *control, struct thread *td)
{

	return (raw_usrreqs.pru_send(so, flags, m, nam, control, td));
}

/* pru_sense is null */

static int
rts_shutdown(struct socket *so)
{

	return (raw_usrreqs.pru_shutdown(so));
}

static int
rts_sockaddr(struct socket *so, struct sockaddr **nam)
{

	return (raw_usrreqs.pru_sockaddr(so, nam));
}

static struct pr_usrreqs route_usrreqs = {
	.pru_abort =		rts_abort,
	.pru_attach =		rts_attach,
	.pru_bind =		rts_bind,
	.pru_connect =		rts_connect,
	.pru_detach =		rts_detach,
	.pru_disconnect =	rts_disconnect,
	.pru_peeraddr =		rts_peeraddr,
	.pru_send =		rts_send,
	.pru_shutdown =		rts_shutdown,
	.pru_sockaddr =		rts_sockaddr,
	.pru_close =		rts_close,
};

#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 rtentry *rt, 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, rt->rt_ifa->ifa_addr) == 0) {
		info->rti_info[RTAX_IFA] = rt->rt_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 *)rt->rt_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 *)rt->rt_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);
}

/*ARGSUSED*/
static int
route_output(struct mbuf *m, struct socket *so, ...)
{
	RIB_RLOCK_TRACKER;
	struct rt_msghdr *rtm = NULL;
	struct rtentry *rt = NULL;
	struct rib_head *rnh;
	struct rt_addrinfo info;
	struct sockaddr_storage ss;
	struct epoch_tracker et;
#ifdef INET6
	struct sockaddr_in6 *sin6;
	int i, rti_need_deembed = 0;
#endif
	int alloc_len = 0, len, error = 0, fibnum;
	struct ifnet *ifp = NULL;
	union sockaddr_union saun;
	sa_family_t saf = AF_UNSPEC;
	struct rawcb *rp = NULL;
	struct walkarg w;

	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);
	if ((rtm = malloc(alloc_len, M_TEMP, M_NOWAIT)) == NULL)
		senderr(ENOBUFS);

	m_copydata(m, 0, len, (caddr_t)rtm);
	bzero(&info, sizeof(info));
	bzero(&w, sizeof(w));

	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.
	 */

	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))
		senderr(EINVAL);

	if (rtm->rtm_flags & RTF_RNH_LOCKED)
		senderr(EINVAL);
	info.rti_flags = rtm->rtm_flags;
	if (info.rti_info[RTAX_DST] == NULL ||
	    info.rti_info[RTAX_DST]->sa_family >= AF_MAX ||
	    (info.rti_info[RTAX_GATEWAY] != NULL &&
	     info.rti_info[RTAX_GATEWAY]->sa_family >= AF_MAX))
		senderr(EINVAL);
	saf = info.rti_info[RTAX_DST]->sa_family;
	/*
	 * 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)
			senderr(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 rt_addrinfo ginfo;
		struct sockaddr *gdst;

		bzero(&ginfo, sizeof(ginfo));
		bzero(&ss, sizeof(ss));
		ss.ss_len = sizeof(ss);

		ginfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&ss;
		gdst = info.rti_info[RTAX_GATEWAY];

		/*
		 * A host route through the loopback interface is
		 * installed for each interface adddress. 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 rt_gateway, and the
		 * rt_ifp has the IFF_LOOPBACK flag set.
		 */
		if (rib_lookup_info(fibnum, gdst, NHR_REF, 0, &ginfo) == 0) {
			if (ss.ss_family == AF_LINK &&
			    ginfo.rti_ifp->if_flags & IFF_LOOPBACK) {
				info.rti_flags &= ~RTF_GATEWAY;
				info.rti_flags |= RTF_GWFLAG_COMPAT;
			}
			rib_free_info(&ginfo);
		}
	}

	switch (rtm->rtm_type) {
		struct rtentry *saved_nrt;

	case RTM_ADD:
	case RTM_CHANGE:
		if (rtm->rtm_type == RTM_ADD) {
			if (info.rti_info[RTAX_GATEWAY] == NULL)
				senderr(EINVAL);
		}
		saved_nrt = NULL;

		/* support for new ARP code */
		if (info.rti_info[RTAX_GATEWAY] != NULL &&
		    info.rti_info[RTAX_GATEWAY]->sa_family == AF_LINK &&
		    (rtm->rtm_flags & RTF_LLDATA) != 0) {
			error = lla_rt_output(rtm, &info);
#ifdef INET6
			if (error == 0)
				rti_need_deembed = (V_deembed_scopeid) ? 1 : 0;
#endif
			break;
		}
		error = rtrequest1_fib(rtm->rtm_type, &info, &saved_nrt,
		    fibnum);
		if (error == 0 && saved_nrt != NULL) {
#ifdef INET6
			rti_need_deembed = (V_deembed_scopeid) ? 1 : 0;
#endif
			RT_LOCK(saved_nrt);
			rtm->rtm_index = saved_nrt->rt_ifp->if_index;
			RT_REMREF(saved_nrt);
			RT_UNLOCK(saved_nrt);
		}
		break;

	case RTM_DELETE:
		saved_nrt = NULL;
		/* support for new ARP code */
		if (info.rti_info[RTAX_GATEWAY] &&
		    (info.rti_info[RTAX_GATEWAY]->sa_family == AF_LINK) &&
		    (rtm->rtm_flags & RTF_LLDATA) != 0) {
			error = lla_rt_output(rtm, &info);
#ifdef INET6
			if (error == 0)
				rti_need_deembed = (V_deembed_scopeid) ? 1 : 0;
#endif
			break;
		}
		error = rtrequest1_fib(RTM_DELETE, &info, &saved_nrt, fibnum);
		if (error == 0) {
			RT_LOCK(saved_nrt);
			rt = saved_nrt;
			goto report;
		}
#ifdef INET6
		/* rt_msg2() will not be used when RTM_DELETE fails. */
		rti_need_deembed = (V_deembed_scopeid) ? 1 : 0;
#endif
		break;

	case RTM_GET:
		rnh = rt_tables_get_rnh(fibnum, saf);
		if (rnh == NULL)
			senderr(EAFNOSUPPORT);

		RIB_RLOCK(rnh);

		if (info.rti_info[RTAX_NETMASK] == NULL &&
		    rtm->rtm_type == RTM_GET) {
			/*
			 * Provide longest prefix match for
			 * address lookup (no mask).
			 * 'route -n get addr'
			 */
			rt = (struct rtentry *) rnh->rnh_matchaddr(
			    info.rti_info[RTAX_DST], &rnh->head);
		} else
			rt = (struct rtentry *) rnh->rnh_lookup(
			    info.rti_info[RTAX_DST],
			    info.rti_info[RTAX_NETMASK], &rnh->head);

		if (rt == NULL) {
			RIB_RUNLOCK(rnh);
			senderr(ESRCH);
		}
#ifdef RADIX_MPATH
		/*
		 * for RTM_CHANGE/LOCK, if we got multipath routes,
		 * we require users to specify a matching RTAX_GATEWAY.
		 *
		 * for RTM_GET, gate is optional even with multipath.
		 * if gate == NULL the first match is returned.
		 * (no need to call rt_mpath_matchgate if gate == NULL)
		 */
		if (rt_mpath_capable(rnh) &&
		    (rtm->rtm_type != RTM_GET || info.rti_info[RTAX_GATEWAY])) {
			rt = rt_mpath_matchgate(rt, info.rti_info[RTAX_GATEWAY]);
			if (!rt) {
				RIB_RUNLOCK(rnh);
				senderr(ESRCH);
			}
		}
#endif
		/*
		 * 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.
		 */
		if (rtm->rtm_flags & RTF_ANNOUNCE) {
			struct sockaddr laddr;

			if (rt->rt_ifp != NULL &&
			    rt->rt_ifp->if_type == IFT_PROPVIRTUAL) {
				struct epoch_tracker et;
				struct ifaddr *ifa;

				NET_EPOCH_ENTER(et);
				ifa = ifa_ifwithnet(info.rti_info[RTAX_DST], 1,
						RT_ALL_FIBS);
				NET_EPOCH_EXIT(et);
				if (ifa != NULL)
					rt_maskedcopy(ifa->ifa_addr,
						      &laddr,
						      ifa->ifa_netmask);
			} else
				rt_maskedcopy(rt->rt_ifa->ifa_addr,
					      &laddr,
					      rt->rt_ifa->ifa_netmask);
			/*
			 * refactor rt and no lock operation necessary
			 */
			rt = (struct rtentry *)rnh->rnh_matchaddr(&laddr,
			    &rnh->head);
			if (rt == NULL) {
				RIB_RUNLOCK(rnh);
				senderr(ESRCH);
			}
		}
		RT_LOCK(rt);
		RT_ADDREF(rt);
		RIB_RUNLOCK(rnh);

report:
		RT_LOCK_ASSERT(rt);
		if ((rt->rt_flags & RTF_HOST) == 0
		    ? jailed_without_vnet(curthread->td_ucred)
		    : prison_if(curthread->td_ucred,
		    rt_key(rt)) != 0) {
			RT_UNLOCK(rt);
			senderr(ESRCH);
		}
		info.rti_info[RTAX_DST] = rt_key(rt);
		info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
		info.rti_info[RTAX_NETMASK] = rtsock_fix_netmask(rt_key(rt),
		    rt_mask(rt), &ss);
		info.rti_info[RTAX_GENMASK] = 0;
		if (rtm->rtm_addrs & (RTA_IFP | RTA_IFA)) {
			ifp = rt->rt_ifp;
			if (ifp) {
				info.rti_info[RTAX_IFP] =
				    ifp->if_addr->ifa_addr;
				error = rtm_get_jailed(&info, ifp, rt,
				    &saun, curthread->td_ucred);
				if (error != 0) {
					RT_UNLOCK(rt);
					senderr(error);
				}
				if (ifp->if_flags & IFF_POINTOPOINT)
					info.rti_info[RTAX_BRD] =
					    rt->rt_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 = rt->rt_ifp) != NULL) {
			rtm->rtm_index = ifp->if_index;
		}

		/* Check if we need to realloc storage */
		rtsock_msg_buffer(rtm->rtm_type, &info, NULL, &len);
		if (len > alloc_len) {
			struct rt_msghdr *new_rtm;
			new_rtm = malloc(len, M_TEMP, M_NOWAIT);
			if (new_rtm == NULL) {
				RT_UNLOCK(rt);
				senderr(ENOBUFS);
			}
			bcopy(rtm, new_rtm, rtm->rtm_msglen);
			free(rtm, M_TEMP);
			rtm = new_rtm;
			alloc_len = len;
		}

		w.w_tmem = (caddr_t)rtm;
		w.w_tmemsize = alloc_len;
		rtsock_msg_buffer(rtm->rtm_type, &info, &w, &len);

		if (rt->rt_flags & RTF_GWFLAG_COMPAT)
			rtm->rtm_flags = RTF_GATEWAY |
				(rt->rt_flags & ~RTF_GWFLAG_COMPAT);
		else
			rtm->rtm_flags = rt->rt_flags;
		rt_getmetrics(rt, &rtm->rtm_rmx);
		rtm->rtm_addrs = info.rti_addrs;

		RT_UNLOCK(rt);
		break;

	default:
		senderr(EOPNOTSUPP);
	}

flush:
	NET_EPOCH_EXIT(et);
	if (rt != NULL)
		RTFREE(rt);
	/*
	 * 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 (error);
		}
		/* There is another listener, so construct message */
		rp = sotorawcb(so);
	}

	if (rtm != NULL) {
#ifdef INET6
		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));
			}
		}
#endif
		if (error != 0)
			rtm->rtm_errno = error;
		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 (rp) {
			/*
			 * XXX insure we don't get a copy by
			 * invalidating our protocol
			 */
			unsigned short family = rp->rcb_proto.sp_family;
			rp->rcb_proto.sp_family = 0;
			rt_dispatch(m, saf);
			rp->rcb_proto.sp_family = family;
		} else
			rt_dispatch(m, saf);
	}

	return (error);
}

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

	bzero(out, sizeof(*out));
	out->rmx_mtu = rt->rt_mtu;
	out->rmx_weight = rt->rt_weight;
	out->rmx_pksent = counter_u64_fetch(rt->rt_pksent);
	/* Kernel -> userland timebase conversion. */
	out->rmx_expire = rt->rt_expire ?
	    rt->rt_expire - 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)
			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);
}

/*
 * Fill in @dmask with valid netmask leaving original @smask
 * intact. Mostly used with radix netmasks.
 */
static struct sockaddr *
rtsock_fix_netmask(struct sockaddr *dst, 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 rt_msghdr *rtm;
	struct mbuf *m;
	int i;
	struct sockaddr *sa;
#ifdef INET6
	struct sockaddr_storage ss;
	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);
#ifdef INET6
		if (V_deembed_scopeid && sa->sa_family == AF_INET6) {
			sin6 = (struct sockaddr_in6 *)&ss;
			bcopy(sa, sin6, sizeof(*sin6));
			if (sa6_recoverscope(sin6) == 0)
				sa = (struct sockaddr *)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)
{
	int i;
	int len, buflen = 0, dlen;
	caddr_t cp = NULL;
	struct rt_msghdr *rtm = NULL;
#ifdef INET6
	struct sockaddr_storage ss;
	struct sockaddr_in6 *sin6;
#endif
#ifdef COMPAT_FREEBSD32
	bool compat32 = false;
#endif

	switch (type) {

	case RTM_DELADDR:
	case RTM_NEWADDR:
		if (w != NULL && w->w_op == NET_RT_IFLISTL) {
#ifdef COMPAT_FREEBSD32
			if (w->w_req->flags & SCTL_MASK32) {
				len = sizeof(struct ifa_msghdrl32);
				compat32 = true;
			} else
#endif
				len = sizeof(struct ifa_msghdrl);
		} else
			len = sizeof(struct ifa_msghdr);
		break;

	case RTM_IFINFO:
#ifdef COMPAT_FREEBSD32
		if (w != NULL && w->w_req->flags & SCTL_MASK32) {
			if (w->w_op == NET_RT_IFLISTL)
				len = sizeof(struct if_msghdrl32);
			else
				len = sizeof(struct if_msghdr32);
			compat32 = true;
			break;
		}
#endif
		if (w != NULL && w->w_op == NET_RT_IFLISTL)
			len = sizeof(struct if_msghdrl);
		else
			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) {
#ifdef INET6
			if (V_deembed_scopeid && sa->sa_family == AF_INET6) {
				sin6 = (struct sockaddr_in6 *)&ss;
				bcopy(sa, sin6, sizeof(*sin6));
				if (sa6_recoverscope(sin6) == 0)
					sa = (struct sockaddr *)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.
 */
void
rt_ifmsg(struct ifnet *ifp)
{
	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_IFP], 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.
 * Please do not call directly, use rt_routemsg().
 * Note that @rt data MAY be inconsistent/invalid:
 * if some userland app sends us "invalid" route message (invalid mask,
 * no dst, wrong address families, etc...) we need to pass it back
 * to app (and any other rtsock consumers) with rtm_errno field set to
 * non-zero value.
 *
 * Returns 0 on success.
 */
int
rtsock_routemsg(int cmd, struct ifnet *ifp, int error, struct rtentry *rt,
    int fibnum)
{
	struct rt_addrinfo info;
	struct sockaddr *sa;
	struct mbuf *m;
	struct rt_msghdr *rtm;
	struct sockaddr_storage ss;

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

	bzero((caddr_t)&info, sizeof(info));
	info.rti_info[RTAX_DST] = sa = rt_key(rt);
	info.rti_info[RTAX_NETMASK] = rtsock_fix_netmask(sa, rt_mask(rt), &ss);
	info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
	if ((m = rtsock_msg_mbuf(cmd, &info)) == NULL)
		return (ENOBUFS);
	rtm = mtod(m, struct rt_msghdr *);
	rtm->rtm_index = ifp->if_index;
	rtm->rtm_flags |= rt->rt_flags;
	rtm->rtm_errno = error;
	rtm->rtm_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);
}

/*
 * 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)
{
	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, 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);
	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.
 */
void
rt_ifannouncemsg(struct ifnet *ifp, int what)
{
	struct mbuf *m;
	struct rt_addrinfo info;

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

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

	/*
	 * Preserve the family from the sockaddr, if any, in an m_tag for
	 * use when injecting the mbuf into the routing socket buffer from
	 * the netisr.
	 */
	if (saf != AF_UNSPEC) {
		tag = m_tag_get(PACKET_TAG_RTSOCKFAM, sizeof(unsigned short),
		    M_NOWAIT);
		if (tag == NULL) {
			m_freem(m);
			return;
		}
		*(unsigned short *)(tag + 1) = saf;
		m_tag_prepend(m, tag);
	}
#ifdef VIMAGE
	if (V_loif)
		m->m_pkthdr.rcvif = V_loif;
	else {
		m_freem(m);
		return;
	}
#endif
	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 radix_node *rn, void *vw)
{
	struct walkarg *w = vw;
	struct rtentry *rt = (struct rtentry *)rn;
	int error = 0, size;
	struct rt_addrinfo info;
	struct sockaddr_storage ss;

	NET_EPOCH_ASSERT();

	if (w->w_op == NET_RT_FLAGS && !(rt->rt_flags & w->w_arg))
		return 0;
	if ((rt->rt_flags & RTF_HOST) == 0
	    ? jailed_without_vnet(w->w_req->td->td_ucred)
	    : prison_if(w->w_req->td->td_ucred, rt_key(rt)) != 0)
		return (0);
	bzero((caddr_t)&info, sizeof(info));
	info.rti_info[RTAX_DST] = rt_key(rt);
	info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
	info.rti_info[RTAX_NETMASK] = rtsock_fix_netmask(rt_key(rt),
	    rt_mask(rt), &ss);
	info.rti_info[RTAX_GENMASK] = 0;
	if (rt->rt_ifp && !(rt->rt_ifp->if_flags & IFF_DYING)) {
		info.rti_info[RTAX_IFP] = rt->rt_ifp->if_addr->ifa_addr;
		info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
		if (rt->rt_ifp->if_flags & IFF_POINTOPOINT)
			info.rti_info[RTAX_BRD] = rt->rt_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));
		if (rt->rt_flags & RTF_GWFLAG_COMPAT)
			rtm->rtm_flags = RTF_GATEWAY |
				(rt->rt_flags & ~RTF_GWFLAG_COMPAT);
		else
			rtm->rtm_flags = rt->rt_flags;
		rt_getmetrics(rt, &rtm->rtm_rmx);
		rtm->rtm_index = rt->rt_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 int
sysctl_rtsock(SYSCTL_HANDLER_ARGS)
{
	RIB_RLOCK_TRACKER;
	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;

	name ++;
	namelen--;
	if (req->newptr)
		return (EPERM);
	if (name[1] == NET_RT_DUMP) {
		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) {
				RIB_RLOCK(rnh);
			    	error = rnh->rnh_walktree(&rnh->head,
				    sysctl_dumpentry, &w);
				RIB_RUNLOCK(rnh);
			} else if (af != 0)
				error = EAFNOSUPPORT;
		}
		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, sysctl_rtsock, "");

/*
 * 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_domain =		&routedomain,
	.pr_flags =		PR_ATOMIC|PR_ADDR,
	.pr_output =		route_output,
	.pr_ctlinput =		raw_ctlinput,
	.pr_init =		raw_init,
	.pr_usrreqs =		&route_usrreqs
}
};

static struct domain routedomain = {
	.dom_family =		PF_ROUTE,
	.dom_name =		 "route",
	.dom_protosw =		routesw,
	.dom_protoswNPROTOSW =	&routesw[nitems(routesw)]
};

VNET_DOMAIN_SET(route);

#ifdef DDB
/*
 * Unfortunately, RTF_ values are expressed as raw masks rather than powers of
 * 2, so we cannot use them as nice C99 initializer indices below.
 */
static const char * const rtf_flag_strings[] = {
	"UP",
	"GATEWAY",
	"HOST",
	"REJECT",
	"DYNAMIC",
	"MODIFIED",
	"DONE",
	"UNUSED_0x80",
	"UNUSED_0x100",
	"XRESOLVE",
	"LLDATA",
	"STATIC",
	"BLACKHOLE",
	"UNUSED_0x2000",
	"PROTO2",
	"PROTO1",
	"UNUSED_0x10000",
	"UNUSED_0x20000",
	"PROTO3",
	"FIXEDMTU",
	"PINNED",
	"LOCAL",
	"BROADCAST",
	"MULTICAST",
	/* Big gap. */
	[28] = "STICKY",
	[30] = "RNH_LOCKED",
	[31] = "GWFLAG_COMPAT",
};

static const char * __pure
rt_flag_name(unsigned idx)
{
	if (idx >= nitems(rtf_flag_strings))
		return ("INVALID_FLAG");
	if (rtf_flag_strings[idx] == NULL)
		return ("UNKNOWN");
	return (rtf_flag_strings[idx]);
}

static void
rt_dumpaddr_ddb(const char *name, const struct sockaddr *sa)
{
	char buf[INET6_ADDRSTRLEN], *res;

	res = NULL;
	if (sa == NULL)
		res = "NULL";
	else if (sa->sa_family == AF_INET) {
		res = inet_ntop(AF_INET,
		    &((const struct sockaddr_in *)sa)->sin_addr,
		    buf, sizeof(buf));
	} else if (sa->sa_family == AF_INET6) {
		res = inet_ntop(AF_INET6,
		    &((const struct sockaddr_in6 *)sa)->sin6_addr,
		    buf, sizeof(buf));
	} else if (sa->sa_family == AF_LINK) {
		res = "on link";
	}

	if (res != NULL) {
		db_printf("%s <%s> ", name, res);
		return;
	}

	db_printf("%s <af:%d> ", name, sa->sa_family);
}

static int
rt_dumpentry_ddb(struct radix_node *rn, void *arg __unused)
{
	struct sockaddr_storage ss;
	struct rtentry *rt;
	int flags, idx;

	/* If RNTORT is important, put it in a header. */
	rt = (void *)rn;

	rt_dumpaddr_ddb("dst", rt_key(rt));
	rt_dumpaddr_ddb("gateway", rt->rt_gateway);
	rt_dumpaddr_ddb("netmask", rtsock_fix_netmask(rt_key(rt), rt_mask(rt),
	    &ss));
	if (rt->rt_ifp != NULL && (rt->rt_ifp->if_flags & IFF_DYING) == 0) {
		rt_dumpaddr_ddb("ifp", rt->rt_ifp->if_addr->ifa_addr);
		rt_dumpaddr_ddb("ifa", rt->rt_ifa->ifa_addr);
	}

	db_printf("flags ");
	flags = rt->rt_flags;
	if (flags == 0)
		db_printf("none");

	while ((idx = ffs(flags)) > 0) {
		idx--;

		if (flags != rt->rt_flags)
			db_printf(",");
		db_printf("%s", rt_flag_name(idx));

		flags &= ~(1ul << idx);
	}

	db_printf("\n");
	return (0);
}

DB_SHOW_COMMAND(routetable, db_show_routetable_cmd)
{
	struct rib_head *rnh;
	int error, i, lim;

	if (have_addr)
		i = lim = addr;
	else {
		i = 1;
		lim = AF_MAX;
	}

	for (; i <= lim; i++) {
		rnh = rt_tables_get_rnh(0, i);
		if (rnh == NULL) {
			if (have_addr) {
				db_printf("%s: AF %d not supported?\n",
				    __func__, i);
				break;
			}
			continue;
		}

		if (!have_addr && i > 1)
			db_printf("\n");

		db_printf("Route table for AF %d%s%s%s:\n", i,
		    (i == AF_INET || i == AF_INET6) ? " (" : "",
		    (i == AF_INET) ? "INET" : (i == AF_INET6) ? "INET6" : "",
		    (i == AF_INET || i == AF_INET6) ? ")" : "");

		error = rnh->rnh_walktree(&rnh->head, rt_dumpentry_ddb, NULL);
		if (error != 0)
			db_printf("%s: walktree(%d): %d\n", __func__, i,
			    error);
	}
}

_DB_FUNC(_show, route, db_show_route_cmd, db_show_table, CS_OWN, NULL)
{
	char buf[INET6_ADDRSTRLEN], *bp;
	const void *dst_addrp;
	struct sockaddr *dstp;
	struct rtentry *rt;
	union {
		struct sockaddr_in dest_sin;
		struct sockaddr_in6 dest_sin6;
	} u;
	uint16_t hextets[8];
	unsigned i, tets;
	int t, af, exp, tokflags;

	/*
	 * Undecoded address family.  No double-colon expansion seen yet.
	 */
	af = -1;
	exp = -1;
	/* Assume INET6 to start; we can work back if guess was wrong. */
	tokflags = DRT_WSPACE | DRT_HEX | DRT_HEXADECIMAL;

	/*
	 * db_command has lexed 'show route' for us.
	 */
	t = db_read_token_flags(tokflags);
	if (t == tWSPACE)
		t = db_read_token_flags(tokflags);

	/*
	 * tEOL: Just 'show route' isn't a valid mode.
	 * tMINUS: It's either '-h' or some invalid option.  Regardless, usage.
	 */
	if (t == tEOL || t == tMINUS)
		goto usage;

	db_unread_token(t);

	tets = nitems(hextets);

	/*
	 * Each loop iteration, we expect to read one octet (v4) or hextet
	 * (v6), followed by an appropriate field separator ('.' or ':' or
	 * '::').
	 *
	 * At the start of each loop, we're looking for a number (octet or
	 * hextet).
	 *
	 * INET6 addresses have a special case where they may begin with '::'.
	 */
	for (i = 0; i < tets; i++) {
		t = db_read_token_flags(tokflags);

		if (t == tCOLONCOLON) {
			/* INET6 with leading '::' or invalid. */
			if (i != 0) {
				db_printf("Parse error: unexpected extra "
				    "colons.\n");
				goto exit;
			}

			af = AF_INET6;
			exp = i;
			hextets[i] = 0;
			continue;
		} else if (t == tNUMBER) {
			/*
			 * Lexer separates out '-' as tMINUS, but make the
			 * assumption explicit here.
			 */
			MPASS(db_tok_number >= 0);

			if (af == AF_INET && db_tok_number > UINT8_MAX) {
				db_printf("Not a valid v4 octet: %ld\n",
				    (long)db_tok_number);
				goto exit;
			}
			hextets[i] = db_tok_number;
		} else if (t == tEOL) {
			/*
			 * We can only detect the end of an IPv6 address in
			 * compact representation with EOL.
			 */
			if (af != AF_INET6 || exp < 0) {
				db_printf("Parse failed.  Got unexpected EOF "
				    "when the address is not a compact-"
				    "representation IPv6 address.\n");
				goto exit;
			}
			break;
		} else {
			db_printf("Parse failed.  Unexpected token %d.\n", t);
			goto exit;
		}

		/* Next, look for a separator, if appropriate. */
		if (i == tets - 1)
			continue;

		t = db_read_token_flags(tokflags);
		if (af < 0) {
			if (t == tCOLON) {
				af = AF_INET6;
				continue;
			}
			if (t == tCOLONCOLON) {
				af = AF_INET6;
				i++;
				hextets[i] = 0;
				exp = i;
				continue;
			}
			if (t == tDOT) {
				unsigned hn, dn;

				af = AF_INET;
				/* Need to fixup the first parsed number. */
				if (hextets[0] > 0x255 ||
				    (hextets[0] & 0xf0) > 0x90 ||
				    (hextets[0] & 0xf) > 9) {
					db_printf("Not a valid v4 octet: %x\n",
					    hextets[0]);
					goto exit;
				}

				hn = hextets[0];
				dn = (hn >> 8) * 100 +
				    ((hn >> 4) & 0xf) * 10 +
				    (hn & 0xf);

				hextets[0] = dn;

				/* Switch to decimal for remaining octets. */
				tokflags &= ~DRT_RADIX_MASK;
				tokflags |= DRT_DECIMAL;

				tets = 4;
				continue;
			}

			db_printf("Parse error.  Unexpected token %d.\n", t);
			goto exit;
		} else if (af == AF_INET) {
			if (t == tDOT)
				continue;
			db_printf("Expected '.' (%d) between octets but got "
			    "(%d).\n", tDOT, t);
			goto exit;

		} else if (af == AF_INET6) {
			if (t == tCOLON)
				continue;
			if (t == tCOLONCOLON) {
				if (exp < 0) {
					i++;
					hextets[i] = 0;
					exp = i;
					continue;
				}
				db_printf("Got bogus second '::' in v6 "
				    "address.\n");
				goto exit;
			}
			if (t == tEOL) {
				/*
				 * Handle in the earlier part of the loop
				 * because we need to handle trailing :: too.
				 */
				db_unread_token(t);
				continue;
			}

			db_printf("Expected ':' (%d) or '::' (%d) between "
			    "hextets but got (%d).\n", tCOLON, tCOLONCOLON, t);
			goto exit;
		}
	}

	/* Check for trailing garbage. */
	if (i == tets) {
		t = db_read_token_flags(tokflags);
		if (t != tEOL) {
			db_printf("Got unexpected garbage after address "
			    "(%d).\n", t);
			goto exit;
		}
	}

	/*
	 * Need to expand compact INET6 addresses.
	 *
	 * Technically '::' for a single ':0:' is MUST NOT but just in case,
	 * don't bother expanding that form (exp >= 0 && i == tets case).
	 */
	if (af == AF_INET6 && exp >= 0 && i < tets) {
		if (exp + 1 < i) {
			memmove(&hextets[exp + 1 + (nitems(hextets) - i)],
			    &hextets[exp + 1],
			    (i - (exp + 1)) * sizeof(hextets[0]));
		}
		memset(&hextets[exp + 1], 0, (nitems(hextets) - i) *
		    sizeof(hextets[0]));
	}

	memset(&u, 0, sizeof(u));
	if (af == AF_INET) {
		u.dest_sin.sin_family = AF_INET;
		u.dest_sin.sin_len = sizeof(u.dest_sin);
		u.dest_sin.sin_addr.s_addr = htonl(
		    ((uint32_t)hextets[0] << 24) |
		    ((uint32_t)hextets[1] << 16) |
		    ((uint32_t)hextets[2] << 8) |
		    (uint32_t)hextets[3]);
		dstp = (void *)&u.dest_sin;
		dst_addrp = &u.dest_sin.sin_addr;
	} else if (af == AF_INET6) {
		u.dest_sin6.sin6_family = AF_INET6;
		u.dest_sin6.sin6_len = sizeof(u.dest_sin6);
		for (i = 0; i < nitems(hextets); i++)
			u.dest_sin6.sin6_addr.s6_addr16[i] = htons(hextets[i]);
		dstp = (void *)&u.dest_sin6;
		dst_addrp = &u.dest_sin6.sin6_addr;
	} else {
		MPASS(false);
		/* UNREACHABLE */
		/* Appease Clang false positive: */
		dstp = NULL;
	}

	bp = inet_ntop(af, dst_addrp, buf, sizeof(buf));
	if (bp != NULL)
		db_printf("Looking up route to destination '%s'\n", bp);

	CURVNET_SET(vnet0);
	rt = rtalloc1(dstp, 0, RTF_RNH_LOCKED);
	CURVNET_RESTORE();

	if (rt == NULL) {
		db_printf("Could not get route for that server.\n");
		return;
	}

	rt_dumpentry_ddb((void *)rt, NULL);
	RTFREE_LOCKED(rt);

	return;
usage:
	db_printf("Usage: 'show route <address>'\n"
	    "  Currently accepts only dotted-decimal INET or colon-separated\n"
	    "  hextet INET6 addresses.\n");
exit:
	db_skip_to_eol();
}
#endif