xref: /src/sys/net/rtsock.c

/*	$NetBSD: rtsock.c,v 1.118 2008/12/17 20:51:37 cegger Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * 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 project 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 PROJECT 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 PROJECT 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.
 */

/*
 * 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
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rtsock.c,v 1.118 2008/12/17 20:51:37 cegger Exp $");

#include "opt_inet.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/sysctl.h>
#include <sys/kauth.h>
#include <sys/intr.h>
#ifdef RTSOCK_DEBUG
#include <netinet/in.h>
#endif /* RTSOCK_DEBUG */

#include <net/if.h>
#include <net/route.h>
#include <net/raw_cb.h>

#include <machine/stdarg.h>

DOMAIN_DEFINE(routedomain);	/* forward declare and add to link set */

struct	sockaddr route_dst = { .sa_len = 2, .sa_family = PF_ROUTE, };
struct	sockaddr route_src = { .sa_len = 2, .sa_family = PF_ROUTE, };

int	route_maxqlen = IFQ_MAXLEN;
static struct	ifqueue route_intrq;
static void	*route_sih;

struct walkarg {
	int	w_op;
	int	w_arg;
	int	w_given;
	int	w_needed;
	void *	w_where;
	int	w_tmemsize;
	int	w_tmemneeded;
	void *	w_tmem;
};

static struct mbuf *rt_msg1(int, struct rt_addrinfo *, void *, int);
static int rt_msg2(int, struct rt_addrinfo *, void *, struct walkarg *, int *);
static int rt_xaddrs(u_char, const char *, const char *, struct rt_addrinfo *);
static struct mbuf *rt_makeifannouncemsg(struct ifnet *, int, int,
    struct rt_addrinfo *);
static int sysctl_dumpentry(struct rtentry *, void *);
static int sysctl_iflist(int, struct walkarg *, int);
static int sysctl_rtable(SYSCTLFN_PROTO);
static inline void rt_adjustcount(int, int);
static void route_enqueue(struct mbuf *, int);

static inline void
rt_adjustcount(int af, int cnt)
{
	route_cb.any_count += cnt;
	switch (af) {
	case AF_INET:
		route_cb.ip_count += cnt;
		return;
#ifdef INET6
	case AF_INET6:
		route_cb.ip6_count += cnt;
		return;
#endif
	case AF_IPX:
		route_cb.ipx_count += cnt;
		return;
	case AF_NS:
		route_cb.ns_count += cnt;
		return;
	case AF_ISO:
		route_cb.iso_count += cnt;
		return;
	}
}

/*ARGSUSED*/
int
route_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
	struct mbuf *control, struct lwp *l)
{
	int error = 0;
	struct rawcb *rp = sotorawcb(so);
	int s;

	if (req == PRU_ATTACH) {
		sosetlock(so);
		rp = malloc(sizeof(*rp), M_PCB, M_WAITOK|M_ZERO);
		so->so_pcb = rp;
	}
	if (req == PRU_DETACH && rp)
		rt_adjustcount(rp->rcb_proto.sp_protocol, -1);
	s = splsoftnet();

	/*
	 * Don't call raw_usrreq() in the attach case, because
	 * we want to allow non-privileged processes to listen on
	 * and send "safe" commands to the routing socket.
	 */
	if (req == PRU_ATTACH) {
		if (l == NULL)
			error = EACCES;
		else
			error = raw_attach(so, (int)(long)nam);
	} else
		error = raw_usrreq(so, req, m, nam, control, l);

	rp = sotorawcb(so);
	if (req == PRU_ATTACH && rp) {
		if (error) {
			free(rp, M_PCB);
			splx(s);
			return error;
		}
		rt_adjustcount(rp->rcb_proto.sp_protocol, 1);
		rp->rcb_laddr = &route_src;
		rp->rcb_faddr = &route_dst;
		soisconnected(so);
		so->so_options |= SO_USELOOPBACK;
	}
	splx(s);
	return error;
}

static const struct sockaddr *
intern_netmask(const struct sockaddr *mask)
{
	struct radix_node *rn;
	extern struct radix_node_head *mask_rnhead;

	if (mask != NULL &&
	    (rn = rn_search(mask, mask_rnhead->rnh_treetop)))
		mask = (const struct sockaddr *)rn->rn_key;

	return mask;
}

/*ARGSUSED*/
int
route_output(struct mbuf *m, ...)
{
	struct sockproto proto = { .sp_family = PF_ROUTE, };
	struct rt_msghdr *rtm = NULL;
	struct rt_msghdr *old_rtm = NULL;
	struct rtentry *rt = NULL;
	struct rtentry *saved_nrt = NULL;
	struct rt_addrinfo info;
	int len, error = 0;
	struct ifnet *ifp = NULL;
	struct ifaddr *ifa = NULL;
	struct socket *so;
	va_list ap;
	sa_family_t family;

	va_start(ap, m);
	so = va_arg(ap, struct socket *);
	va_end(ap);

#define senderr(e) do { error = e; goto flush;} while (/*CONSTCOND*/ 0)
	if (m == NULL || ((m->m_len < sizeof(int32_t)) &&
	   (m = m_pullup(m, sizeof(int32_t))) == NULL))
		return ENOBUFS;
	if ((m->m_flags & M_PKTHDR) == 0)
		panic("route_output");
	len = m->m_pkthdr.len;
	if (len < sizeof(*rtm) ||
	    len != mtod(m, struct rt_msghdr *)->rtm_msglen) {
		info.rti_info[RTAX_DST] = NULL;
		senderr(EINVAL);
	}
	R_Malloc(rtm, struct rt_msghdr *, len);
	if (rtm == NULL) {
		info.rti_info[RTAX_DST] = NULL;
		senderr(ENOBUFS);
	}
	m_copydata(m, 0, len, rtm);
	if (rtm->rtm_version != RTM_VERSION) {
		info.rti_info[RTAX_DST] = NULL;
		senderr(EPROTONOSUPPORT);
	}
	rtm->rtm_pid = curproc->p_pid;
	memset(&info, 0, sizeof(info));
	info.rti_addrs = rtm->rtm_addrs;
	if (rt_xaddrs(rtm->rtm_type, (const char *)(rtm + 1), len + (char *)rtm,
	    &info))
		senderr(EINVAL);
	info.rti_flags = rtm->rtm_flags;
#ifdef RTSOCK_DEBUG
	if (info.rti_info[RTAX_DST]->sa_family == AF_INET) {
		printf("%s: extracted info.rti_info[RTAX_DST] %s\n", __func__,
		    inet_ntoa(((const struct sockaddr_in *)
		    info.rti_info[RTAX_DST])->sin_addr));
	}
#endif /* RTSOCK_DEBUG */
	if (info.rti_info[RTAX_DST] == NULL ||
	    (info.rti_info[RTAX_DST]->sa_family >= AF_MAX))
		senderr(EINVAL);
	if (info.rti_info[RTAX_GATEWAY] != NULL &&
	    (info.rti_info[RTAX_GATEWAY]->sa_family >= AF_MAX))
		senderr(EINVAL);

	/*
	 * Verify that the caller has the appropriate privilege; RTM_GET
	 * is the only operation the non-superuser is allowed.
	 */
	if (kauth_authorize_network(curlwp->l_cred, KAUTH_NETWORK_ROUTE,
	    0, rtm, NULL, NULL) != 0)
		senderr(EACCES);

	switch (rtm->rtm_type) {

	case RTM_ADD:
		if (info.rti_info[RTAX_GATEWAY] == NULL)
			senderr(EINVAL);
		error = rtrequest1(rtm->rtm_type, &info, &saved_nrt);
		if (error == 0 && saved_nrt) {
			rt_setmetrics(rtm->rtm_inits,
			    &rtm->rtm_rmx, &saved_nrt->rt_rmx);
			saved_nrt->rt_refcnt--;
		}
		break;

	case RTM_DELETE:
		error = rtrequest1(rtm->rtm_type, &info, &saved_nrt);
		if (error == 0) {
			(rt = saved_nrt)->rt_refcnt++;
			goto report;
		}
		break;

	case RTM_GET:
	case RTM_CHANGE:
	case RTM_LOCK:
                /* XXX This will mask info.rti_info[RTAX_DST] with
		 * info.rti_info[RTAX_NETMASK] before
                 * searching.  It did not used to do that.  --dyoung
		 */
		error = rtrequest1(RTM_GET, &info, &rt);
		if (error != 0)
			senderr(error);
		if (rtm->rtm_type != RTM_GET) {/* XXX: too grotty */
			struct radix_node *rn;

			if (memcmp(info.rti_info[RTAX_DST], rt_getkey(rt),
			    info.rti_info[RTAX_DST]->sa_len) != 0)
				senderr(ESRCH);
			info.rti_info[RTAX_NETMASK] = intern_netmask(
			    info.rti_info[RTAX_NETMASK]);
			for (rn = rt->rt_nodes; rn; rn = rn->rn_dupedkey)
				if (info.rti_info[RTAX_NETMASK] ==
				    (const struct sockaddr *)rn->rn_mask)
					break;
			if (rn == NULL)
				senderr(ETOOMANYREFS);
			rt = (struct rtentry *)rn;
		}

		switch (rtm->rtm_type) {
		case RTM_GET:
		report:
			info.rti_info[RTAX_DST] = rt_getkey(rt);
			info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
			info.rti_info[RTAX_NETMASK] = rt_mask(rt);
			if ((rtm->rtm_addrs & (RTA_IFP | RTA_IFA)) == 0)
				;
			else if ((ifp = rt->rt_ifp) != NULL) {
				const struct ifaddr *rtifa;
				info.rti_info[RTAX_IFP] = ifp->if_dl->ifa_addr;
                                /* rtifa used to be simply rt->rt_ifa.
                                 * If rt->rt_ifa != NULL, then
                                 * rt_get_ifa() != NULL.  So this
                                 * ought to still be safe. --dyoung
				 */
				rtifa = rt_get_ifa(rt);
				info.rti_info[RTAX_IFA] = rtifa->ifa_addr;
#ifdef RTSOCK_DEBUG
				if (info.rti_info[RTAX_IFA]->sa_family ==
				    AF_INET) {
					printf("%s: copying out RTAX_IFA %s ",
					    __func__, inet_ntoa(
					    (const struct sockaddr_in *)
					    info.rti_info[RTAX_IFA])->sin_addr);
					printf("for info.rti_info[RTAX_DST] %s "
					    "ifa_getifa %p ifa_seqno %p\n",
					    inet_ntoa(
					    (const struct sockaddr_in *)
					    info.rti_info[RTAX_DST])->sin_addr),
					    (void *)rtifa->ifa_getifa,
					    rtifa->ifa_seqno);
				}
#endif /* RTSOCK_DEBUG */
				if (ifp->if_flags & IFF_POINTOPOINT) {
					info.rti_info[RTAX_BRD] =
					    rtifa->ifa_dstaddr;
				} else
					info.rti_info[RTAX_BRD] = NULL;
				rtm->rtm_index = ifp->if_index;
			} else {
				info.rti_info[RTAX_IFP] = NULL;
				info.rti_info[RTAX_IFA] = NULL;
			}
			(void)rt_msg2(rtm->rtm_type, &info, NULL, NULL, &len);
			if (len > rtm->rtm_msglen) {
				old_rtm = rtm;
				R_Malloc(rtm, struct rt_msghdr *, len);
				if (rtm == NULL)
					senderr(ENOBUFS);
				(void)memcpy(rtm, old_rtm, old_rtm->rtm_msglen);
			}
			(void)rt_msg2(rtm->rtm_type, &info, rtm, NULL, 0);
			rtm->rtm_flags = rt->rt_flags;
			rtm->rtm_rmx = rt->rt_rmx;
			rtm->rtm_addrs = info.rti_addrs;
			break;

		case RTM_CHANGE:
			/*
			 * new gateway could require new ifaddr, ifp;
			 * flags may also be different; ifp may be specified
			 * by ll sockaddr when protocol address is ambiguous
			 */
			if ((error = rt_getifa(&info)) != 0)
				senderr(error);
			if (info.rti_info[RTAX_GATEWAY] &&
			    rt_setgate(rt, info.rti_info[RTAX_GATEWAY]))
				senderr(EDQUOT);
			/* new gateway could require new ifaddr, ifp;
			   flags may also be different; ifp may be specified
			   by ll sockaddr when protocol address is ambiguous */
			if (info.rti_info[RTAX_IFP] &&
			    (ifa = ifa_ifwithnet(info.rti_info[RTAX_IFP])) &&
			    (ifp = ifa->ifa_ifp) && (info.rti_info[RTAX_IFA] ||
			    info.rti_info[RTAX_GATEWAY])) {
				ifa = ifaof_ifpforaddr(info.rti_info[RTAX_IFA] ?
				    info.rti_info[RTAX_IFA] :
				    info.rti_info[RTAX_GATEWAY], ifp);
			} else if ((info.rti_info[RTAX_IFA] &&
			    (ifa = ifa_ifwithaddr(info.rti_info[RTAX_IFA]))) ||
			    (info.rti_info[RTAX_GATEWAY] &&
			    (ifa = ifa_ifwithroute(rt->rt_flags,
			    rt_getkey(rt), info.rti_info[RTAX_GATEWAY])))) {
				ifp = ifa->ifa_ifp;
			}
			if (ifa) {
				struct ifaddr *oifa = rt->rt_ifa;
				if (oifa != ifa) {
					if (oifa && oifa->ifa_rtrequest) {
						oifa->ifa_rtrequest(RTM_DELETE,
						    rt, &info);
					}
					rt_replace_ifa(rt, ifa);
					rt->rt_ifp = ifp;
				}
			}
			rt_setmetrics(rtm->rtm_inits, &rtm->rtm_rmx,
			    &rt->rt_rmx);
			if (rt->rt_ifa && rt->rt_ifa->ifa_rtrequest)
				rt->rt_ifa->ifa_rtrequest(RTM_ADD, rt, &info);
			/*FALLTHROUGH*/
		case RTM_LOCK:
			rt->rt_rmx.rmx_locks &= ~(rtm->rtm_inits);
			rt->rt_rmx.rmx_locks |=
			    (rtm->rtm_inits & rtm->rtm_rmx.rmx_locks);
			break;
		}
		break;

	default:
		senderr(EOPNOTSUPP);
	}

flush:
	if (rtm) {
		if (error)
			rtm->rtm_errno = error;
		else
			rtm->rtm_flags |= RTF_DONE;
	}
	family = info.rti_info[RTAX_DST] ? info.rti_info[RTAX_DST]->sa_family :
	    0;
	/* We cannot free old_rtm until we have stopped using the
	 * pointers in info, some of which may point to sockaddrs
	 * in old_rtm.
	 */
	if (old_rtm != NULL)
		Free(old_rtm);
	if (rt)
		rtfree(rt);
    {
	struct rawcb *rp = NULL;
	/*
	 * Check to see if we don't want our own messages.
	 */
	if ((so->so_options & SO_USELOOPBACK) == 0) {
		if (route_cb.any_count <= 1) {
			if (rtm)
				Free(rtm);
			m_freem(m);
			return error;
		}
		/* There is another listener, so construct message */
		rp = sotorawcb(so);
	}
	if (rtm) {
		m_copyback(m, 0, rtm->rtm_msglen, 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);
	}
	if (rp)
		rp->rcb_proto.sp_family = 0; /* Avoid us */
	if (family)
		proto.sp_protocol = family;
	if (m)
		raw_input(m, &proto, &route_src, &route_dst);
	if (rp)
		rp->rcb_proto.sp_family = PF_ROUTE;
    }
	return error;
}

void
rt_setmetrics(u_long which, const struct rt_metrics *in, struct rt_metrics *out)
{
#define metric(f, e) if (which & (f)) out->e = in->e;
	metric(RTV_RPIPE, rmx_recvpipe);
	metric(RTV_SPIPE, rmx_sendpipe);
	metric(RTV_SSTHRESH, rmx_ssthresh);
	metric(RTV_RTT, rmx_rtt);
	metric(RTV_RTTVAR, rmx_rttvar);
	metric(RTV_HOPCOUNT, rmx_hopcount);
	metric(RTV_MTU, rmx_mtu);
	metric(RTV_EXPIRE, rmx_expire);
#undef metric
}

#define ROUNDUP(a) \
	((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))

static int
rt_xaddrs(u_char rtmtype, const char *cp, const char *cplim,
    struct rt_addrinfo *rtinfo)
{
	const struct sockaddr *sa = NULL;	/* Quell compiler warning */
	int i;

	for (i = 0; i < RTAX_MAX && cp < cplim; i++) {
		if ((rtinfo->rti_addrs & (1 << i)) == 0)
			continue;
		rtinfo->rti_info[i] = sa = (const struct sockaddr *)cp;
		ADVANCE(cp, sa);
	}

	/*
	 * Check for extra addresses specified, except RTM_GET asking
	 * for interface info.
	 */
	if (rtmtype == RTM_GET) {
		if (((rtinfo->rti_addrs &
		    (~((1 << RTAX_IFP) | (1 << RTAX_IFA)))) & (~0 << i)) != 0)
			return 1;
	} else if ((rtinfo->rti_addrs & (~0 << i)) != 0)
		return 1;
	/* Check for bad data length.  */
	if (cp != cplim) {
		if (i == RTAX_NETMASK + 1 && sa != NULL &&
		    cp - ROUNDUP(sa->sa_len) + sa->sa_len == cplim)
			/*
			 * The last sockaddr was info.rti_info[RTAX_NETMASK].
			 * We accept this for now for the sake of old
			 * binaries or third party softwares.
			 */
			;
		else
			return 1;
	}
	return 0;
}

static struct mbuf *
rt_msg1(int type, struct rt_addrinfo *rtinfo, void *data, int datalen)
{
	struct rt_msghdr *rtm;
	struct mbuf *m;
	int i;
	const struct sockaddr *sa;
	int len, dlen;

	m = m_gethdr(M_DONTWAIT, MT_DATA);
	if (m == NULL)
		return m;
	MCLAIM(m, &routedomain.dom_mowner);
	switch (type) {

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

#ifdef COMPAT_14
	case RTM_OIFINFO:
		len = sizeof(struct if_msghdr14);
		break;
#endif

	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);
	}
	if (len > MHLEN + MLEN)
		panic("rt_msg1: message too long");
	else if (len > MHLEN) {
		m->m_next = m_get(M_DONTWAIT, MT_DATA);
		if (m->m_next == NULL) {
			m_freem(m);
			return NULL;
		}
		MCLAIM(m->m_next, m->m_owner);
		m->m_pkthdr.len = len;
		m->m_len = MHLEN;
		m->m_next->m_len = len - MHLEN;
	} else {
		m->m_pkthdr.len = m->m_len = len;
	}
	m->m_pkthdr.rcvif = NULL;
	m_copyback(m, 0, datalen, data);
	if (len > datalen)
		(void)memset(mtod(m, char *) + datalen, 0, len - datalen);
	rtm = mtod(m, struct rt_msghdr *);
	for (i = 0; i < RTAX_MAX; i++) {
		if ((sa = rtinfo->rti_info[i]) == NULL)
			continue;
		rtinfo->rti_addrs |= (1 << i);
		dlen = ROUNDUP(sa->sa_len);
		m_copyback(m, len, dlen, 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;
}

/*
 * rt_msg2
 *
 *	 fills 'cp' or 'w'.w_tmem with the routing socket message and
 *		returns the length of the message in 'lenp'.
 *
 * if walkarg is 0, cp is expected to be 0 or a buffer large enough to hold
 *	the message
 * otherwise walkarg's w_needed is updated and if the user buffer is
 *	specified and w_needed indicates space exists the information is copied
 *	into the temp space (w_tmem). w_tmem is [re]allocated if necessary,
 *	if the allocation fails ENOBUFS is returned.
 */
static int
rt_msg2(int type, struct rt_addrinfo *rtinfo, void *cpv, struct walkarg *w,
	int *lenp)
{
	int i;
	int len, dlen, second_time = 0;
	char *cp0, *cp = cpv;

	rtinfo->rti_addrs = 0;
again:
	switch (type) {

	case RTM_DELADDR:
	case RTM_NEWADDR:
		len = sizeof(struct ifa_msghdr);
		break;
#ifdef COMPAT_14
	case RTM_OIFINFO:
		len = sizeof(struct if_msghdr14);
		break;
#endif

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

	default:
		len = sizeof(struct rt_msghdr);
	}
	if ((cp0 = cp) != NULL)
		cp += len;
	for (i = 0; i < RTAX_MAX; i++) {
		const struct sockaddr *sa;

		if ((sa = rtinfo->rti_info[i]) == NULL)
			continue;
		rtinfo->rti_addrs |= (1 << i);
		dlen = ROUNDUP(sa->sa_len);
		if (cp) {
			(void)memcpy(cp, sa, (size_t)dlen);
			cp += dlen;
		}
		len += dlen;
	}
	if (cp == NULL && w != NULL && !second_time) {
		struct walkarg *rw = w;

		rw->w_needed += len;
		if (rw->w_needed <= 0 && rw->w_where) {
			if (rw->w_tmemsize < len) {
				if (rw->w_tmem)
					free(rw->w_tmem, M_RTABLE);
				rw->w_tmem = malloc(len, M_RTABLE, M_NOWAIT);
				if (rw->w_tmem)
					rw->w_tmemsize = len;
				else
					rw->w_tmemsize = 0;
			}
			if (rw->w_tmem) {
				cp = rw->w_tmem;
				second_time = 1;
				goto again;
			} else {
				rw->w_tmemneeded = len;
				return ENOBUFS;
			}
		}
	}
	if (cp) {
		struct rt_msghdr *rtm = (struct rt_msghdr *)cp0;

		rtm->rtm_version = RTM_VERSION;
		rtm->rtm_type = type;
		rtm->rtm_msglen = len;
	}
	if (lenp)
		*lenp = len;
	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(int type, struct rt_addrinfo *rtinfo, int flags, int error)
{
	struct rt_msghdr rtm;
	struct mbuf *m;
	const struct sockaddr *sa = rtinfo->rti_info[RTAX_DST];

	if (route_cb.any_count == 0)
		return;
	memset(&rtm, 0, sizeof(rtm));
	rtm.rtm_flags = RTF_DONE | flags;
	rtm.rtm_errno = error;
	m = rt_msg1(type, rtinfo, &rtm, sizeof(rtm));
	if (m == NULL)
		return;
	mtod(m, struct rt_msghdr *)->rtm_addrs = rtinfo->rti_addrs;
	route_enqueue(m, sa ? sa->sa_family : 0);
}

/*
 * 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;
#ifdef COMPAT_14
	struct if_msghdr14 oifm;
#endif
	struct mbuf *m;
	struct rt_addrinfo info;

	if (route_cb.any_count == 0)
		return;
	memset(&info, 0, sizeof(info));
	memset(&ifm, 0, sizeof(ifm));
	ifm.ifm_index = ifp->if_index;
	ifm.ifm_flags = ifp->if_flags;
	ifm.ifm_data = ifp->if_data;
	ifm.ifm_addrs = 0;
	m = rt_msg1(RTM_IFINFO, &info, &ifm, sizeof(ifm));
	if (m == NULL)
		return;
	route_enqueue(m, 0);
#ifdef COMPAT_14
	memset(&info, 0, sizeof(info));
	memset(&oifm, 0, sizeof(oifm));
	oifm.ifm_index = ifp->if_index;
	oifm.ifm_flags = ifp->if_flags;
	oifm.ifm_data.ifi_type = ifp->if_data.ifi_type;
	oifm.ifm_data.ifi_addrlen = ifp->if_data.ifi_addrlen;
	oifm.ifm_data.ifi_hdrlen = ifp->if_data.ifi_hdrlen;
	oifm.ifm_data.ifi_mtu = ifp->if_data.ifi_mtu;
	oifm.ifm_data.ifi_metric = ifp->if_data.ifi_metric;
	oifm.ifm_data.ifi_baudrate = ifp->if_data.ifi_baudrate;
	oifm.ifm_data.ifi_ipackets = ifp->if_data.ifi_ipackets;
	oifm.ifm_data.ifi_ierrors = ifp->if_data.ifi_ierrors;
	oifm.ifm_data.ifi_opackets = ifp->if_data.ifi_opackets;
	oifm.ifm_data.ifi_oerrors = ifp->if_data.ifi_oerrors;
	oifm.ifm_data.ifi_collisions = ifp->if_data.ifi_collisions;
	oifm.ifm_data.ifi_ibytes = ifp->if_data.ifi_ibytes;
	oifm.ifm_data.ifi_obytes = ifp->if_data.ifi_obytes;
	oifm.ifm_data.ifi_imcasts = ifp->if_data.ifi_imcasts;
	oifm.ifm_data.ifi_omcasts = ifp->if_data.ifi_omcasts;
	oifm.ifm_data.ifi_iqdrops = ifp->if_data.ifi_iqdrops;
	oifm.ifm_data.ifi_noproto = ifp->if_data.ifi_noproto;
	oifm.ifm_data.ifi_lastchange = ifp->if_data.ifi_lastchange;
	oifm.ifm_addrs = 0;
	m = rt_msg1(RTM_OIFINFO, &info, &oifm, sizeof(oifm));
	if (m == NULL)
		return;
	route_enqueue(m, 0);
#endif
}

/*
 * This is called to generate messages from the routing socket
 * indicating a network interface has had addresses associated with it.
 * if we ever reverse the logic and replace messages TO the routing
 * socket indicate a request to configure interfaces, then it will
 * be unnecessary as the routing socket will automatically generate
 * copies of it.
 */
void
rt_newaddrmsg(int cmd, struct ifaddr *ifa, int error, struct rtentry *rt)
{
#define	cmdpass(__cmd, __pass)	(((__cmd) << 2) | (__pass))
	struct rt_addrinfo info;
	const struct sockaddr *sa;
	int pass;
	struct mbuf *m;
	struct ifnet *ifp = ifa->ifa_ifp;
	struct rt_msghdr rtm;
	struct ifa_msghdr ifam;
	int ncmd;

	if (route_cb.any_count == 0)
		return;
	for (pass = 1; pass < 3; pass++) {
		memset(&info, 0, sizeof(info));
		switch (cmdpass(cmd, pass)) {
		case cmdpass(RTM_ADD, 1):
		case cmdpass(RTM_CHANGE, 1):
		case cmdpass(RTM_DELETE, 2):
			if (cmd == RTM_ADD)
				ncmd = RTM_NEWADDR;
			else
				ncmd = RTM_DELADDR;

			info.rti_info[RTAX_IFA] = sa = ifa->ifa_addr;
			info.rti_info[RTAX_IFP] = ifp->if_dl->ifa_addr;
			info.rti_info[RTAX_NETMASK] = ifa->ifa_netmask;
			info.rti_info[RTAX_BRD] = ifa->ifa_dstaddr;
			memset(&ifam, 0, sizeof(ifam));
			ifam.ifam_index = ifp->if_index;
			ifam.ifam_metric = ifa->ifa_metric;
			ifam.ifam_flags = ifa->ifa_flags;
			m = rt_msg1(ncmd, &info, &ifam, sizeof(ifam));
			if (m == NULL)
				continue;
			mtod(m, struct ifa_msghdr *)->ifam_addrs =
			    info.rti_addrs;
			break;
		case cmdpass(RTM_ADD, 2):
		case cmdpass(RTM_CHANGE, 2):
		case cmdpass(RTM_DELETE, 1):
			if (rt == NULL)
				continue;
			info.rti_info[RTAX_NETMASK] = rt_mask(rt);
			info.rti_info[RTAX_DST] = sa = rt_getkey(rt);
			info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
			memset(&rtm, 0, sizeof(rtm));
			rtm.rtm_index = ifp->if_index;
			rtm.rtm_flags |= rt->rt_flags;
			rtm.rtm_errno = error;
			m = rt_msg1(cmd, &info, &rtm, sizeof(rtm));
			if (m == NULL)
				continue;
			mtod(m, struct rt_msghdr *)->rtm_addrs = info.rti_addrs;
			break;
		default:
			continue;
		}
#ifdef DIAGNOSTIC
		if (m == NULL)
			panic("%s: called with wrong command", __func__);
#endif
		route_enqueue(m, sa ? sa->sa_family : 0);
	}
#undef cmdpass
}

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

	memset(info, 0, sizeof(*info));
	memset(&ifan, 0, sizeof(ifan));
	ifan.ifan_index = ifp->if_index;
	strlcpy(ifan.ifan_name, ifp->if_xname, sizeof(ifan.ifan_name));
	ifan.ifan_what = what;
	return rt_msg1(type, info, &ifan, sizeof(ifan));
}

/*
 * 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;

	if (route_cb.any_count == 0)
		return;
	m = rt_makeifannouncemsg(ifp, RTM_IFANNOUNCE, what, &info);
	if (m == NULL)
		return;
	route_enqueue(m, 0);
}

/*
 * 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;

	if (route_cb.any_count == 0)
		return;
	m = rt_makeifannouncemsg(ifp, RTM_IEEE80211, what, &info);
	if (m == NULL)
		return;
	/*
	 * 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;
		}
		(void)memcpy(mtod(n, void *), data, data_len);
		n->m_len = data_len;
		m->m_next = n;
	} else if (data_len > 0) {
		(void)memcpy(mtod(m, uint8_t *) + m->m_len, data, 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;
	route_enqueue(m, 0);
}

/*
 * This is used in dumping the kernel table via sysctl().
 */
static int
sysctl_dumpentry(struct rtentry *rt, void *v)
{
	struct walkarg *w = v;
	int error = 0, size;
	struct rt_addrinfo info;

	if (w->w_op == NET_RT_FLAGS && !(rt->rt_flags & w->w_arg))
		return 0;
	memset(&info, 0, sizeof(info));
	info.rti_info[RTAX_DST] = rt_getkey(rt);
	info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
	info.rti_info[RTAX_NETMASK] = rt_mask(rt);
	if (rt->rt_ifp) {
		const struct ifaddr *rtifa;
		info.rti_info[RTAX_IFP] = rt->rt_ifp->if_dl->ifa_addr;
		/* rtifa used to be simply rt->rt_ifa.  If rt->rt_ifa != NULL,
		 * then rt_get_ifa() != NULL.  So this ought to still be safe.
		 * --dyoung
		 */
		rtifa = rt_get_ifa(rt);
		info.rti_info[RTAX_IFA] = rtifa->ifa_addr;
		if (rt->rt_ifp->if_flags & IFF_POINTOPOINT)
			info.rti_info[RTAX_BRD] = rtifa->ifa_dstaddr;
	}
	if ((error = rt_msg2(RTM_GET, &info, 0, w, &size)))
		return error;
	if (w->w_where && w->w_tmem && w->w_needed <= 0) {
		struct rt_msghdr *rtm = (struct rt_msghdr *)w->w_tmem;

		rtm->rtm_flags = rt->rt_flags;
		rtm->rtm_use = rt->rt_use;
		rtm->rtm_rmx = rt->rt_rmx;
		KASSERT(rt->rt_ifp != NULL);
		rtm->rtm_index = rt->rt_ifp->if_index;
		rtm->rtm_errno = rtm->rtm_pid = rtm->rtm_seq = 0;
		rtm->rtm_addrs = info.rti_addrs;
		if ((error = copyout(rtm, w->w_where, size)) != 0)
			w->w_where = NULL;
		else
			w->w_where = (char *)w->w_where + size;
	}
	return error;
}

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

	memset(&info, 0, sizeof(info));
	IFNET_FOREACH(ifp) {
		if (w->w_arg && w->w_arg != ifp->if_index)
			continue;
		if (IFADDR_EMPTY(ifp))
			continue;
		info.rti_info[RTAX_IFP] = ifp->if_dl->ifa_addr;
		switch (type) {
		case NET_RT_IFLIST:
			error = rt_msg2(RTM_IFINFO, &info, NULL, w, &len);
			break;
#ifdef COMPAT_14
		case NET_RT_OIFLIST:
			error = rt_msg2(RTM_OIFINFO, &info, NULL, w, &len);
			break;
#endif
		default:
			panic("sysctl_iflist(1)");
		}
		if (error)
			return error;
		info.rti_info[RTAX_IFP] = NULL;
		if (w->w_where && w->w_tmem && w->w_needed <= 0) {
			switch (type) {
			case NET_RT_IFLIST: {
				struct if_msghdr *ifm;

				ifm = (struct if_msghdr *)w->w_tmem;
				ifm->ifm_index = ifp->if_index;
				ifm->ifm_flags = ifp->if_flags;
				ifm->ifm_data = ifp->if_data;
				ifm->ifm_addrs = info.rti_addrs;
				error = copyout(ifm, w->w_where, len);
				if (error)
					return error;
				w->w_where = (char *)w->w_where + len;
				break;
			}

#ifdef COMPAT_14
			case NET_RT_OIFLIST: {
				struct if_msghdr14 *ifm;

				ifm = (struct if_msghdr14 *)w->w_tmem;
				ifm->ifm_index = ifp->if_index;
				ifm->ifm_flags = ifp->if_flags;
				ifm->ifm_data.ifi_type = ifp->if_data.ifi_type;
				ifm->ifm_data.ifi_addrlen =
				    ifp->if_data.ifi_addrlen;
				ifm->ifm_data.ifi_hdrlen =
				    ifp->if_data.ifi_hdrlen;
				ifm->ifm_data.ifi_mtu = ifp->if_data.ifi_mtu;
				ifm->ifm_data.ifi_metric =
				    ifp->if_data.ifi_metric;
				ifm->ifm_data.ifi_baudrate =
				    ifp->if_data.ifi_baudrate;
				ifm->ifm_data.ifi_ipackets =
				    ifp->if_data.ifi_ipackets;
				ifm->ifm_data.ifi_ierrors =
				    ifp->if_data.ifi_ierrors;
				ifm->ifm_data.ifi_opackets =
				    ifp->if_data.ifi_opackets;
				ifm->ifm_data.ifi_oerrors =
				    ifp->if_data.ifi_oerrors;
				ifm->ifm_data.ifi_collisions =
				    ifp->if_data.ifi_collisions;
				ifm->ifm_data.ifi_ibytes =
				    ifp->if_data.ifi_ibytes;
				ifm->ifm_data.ifi_obytes =
				    ifp->if_data.ifi_obytes;
				ifm->ifm_data.ifi_imcasts =
				    ifp->if_data.ifi_imcasts;
				ifm->ifm_data.ifi_omcasts =
				    ifp->if_data.ifi_omcasts;
				ifm->ifm_data.ifi_iqdrops =
				    ifp->if_data.ifi_iqdrops;
				ifm->ifm_data.ifi_noproto =
				    ifp->if_data.ifi_noproto;
				ifm->ifm_data.ifi_lastchange =
				    ifp->if_data.ifi_lastchange;
				ifm->ifm_addrs = info.rti_addrs;
				error = copyout(ifm, w->w_where, len);
				if (error)
					return error;
				w->w_where = (char *)w->w_where + len;
				break;
			}
#endif
			default:
				panic("sysctl_iflist(2)");
			}
		}
		IFADDR_FOREACH(ifa, ifp) {
			if (af && af != ifa->ifa_addr->sa_family)
				continue;
			info.rti_info[RTAX_IFA] = ifa->ifa_addr;
			info.rti_info[RTAX_NETMASK] = ifa->ifa_netmask;
			info.rti_info[RTAX_BRD] = ifa->ifa_dstaddr;
			if ((error = rt_msg2(RTM_NEWADDR, &info, 0, w, &len)))
				return error;
			if (w->w_where && w->w_tmem && w->w_needed <= 0) {
				struct ifa_msghdr *ifam;

				ifam = (struct ifa_msghdr *)w->w_tmem;
				ifam->ifam_index = ifa->ifa_ifp->if_index;
				ifam->ifam_flags = ifa->ifa_flags;
				ifam->ifam_metric = ifa->ifa_metric;
				ifam->ifam_addrs = info.rti_addrs;
				error = copyout(w->w_tmem, w->w_where, len);
				if (error)
					return error;
				w->w_where = (char *)w->w_where + len;
			}
		}
		info.rti_info[RTAX_IFA] = info.rti_info[RTAX_NETMASK] =
		    info.rti_info[RTAX_BRD] = NULL;
	}
	return 0;
}

static int
sysctl_rtable(SYSCTLFN_ARGS)
{
	void 	*where = oldp;
	size_t	*given = oldlenp;
	const void *new = newp;
	int	i, s, error = EINVAL;
	u_char  af;
	struct	walkarg w;

	if (namelen == 1 && name[0] == CTL_QUERY)
		return sysctl_query(SYSCTLFN_CALL(rnode));

	if (new)
		return EPERM;
	if (namelen != 3)
		return EINVAL;
	af = name[0];
	w.w_tmemneeded = 0;
	w.w_tmemsize = 0;
	w.w_tmem = NULL;
again:
	/* we may return here if a later [re]alloc of the t_mem buffer fails */
	if (w.w_tmemneeded) {
		w.w_tmem = malloc(w.w_tmemneeded, M_RTABLE, M_WAITOK);
		w.w_tmemsize = w.w_tmemneeded;
		w.w_tmemneeded = 0;
	}
	w.w_op = name[1];
	w.w_arg = name[2];
	w.w_given = *given;
	w.w_needed = 0 - w.w_given;
	w.w_where = where;

	s = splsoftnet();
	switch (w.w_op) {

	case NET_RT_DUMP:
	case NET_RT_FLAGS:
		for (i = 1; i <= AF_MAX; i++)
			if ((af == 0 || af == i) &&
			    (error = rt_walktree(i, sysctl_dumpentry, &w)))
				break;
		break;

#ifdef COMPAT_14
	case NET_RT_OIFLIST:
		error = sysctl_iflist(af, &w, w.w_op);
		break;
#endif

	case NET_RT_IFLIST:
		error = sysctl_iflist(af, &w, w.w_op);
	}
	splx(s);

	/* check to see if we couldn't allocate memory with NOWAIT */
	if (error == ENOBUFS && w.w_tmem == 0 && w.w_tmemneeded)
		goto again;

	if (w.w_tmem)
		free(w.w_tmem, M_RTABLE);
	w.w_needed += w.w_given;
	if (where) {
		*given = (char *)w.w_where - (char *)where;
		if (*given < w.w_needed)
			return ENOMEM;
	} else {
		*given = (11 * w.w_needed) / 10;
	}
	return error;
}

/*
 * Routing message software interrupt routine
 */
static void
route_intr(void *cookie)
{
	struct sockproto proto = { .sp_family = PF_ROUTE, };
	struct mbuf *m;
	int s;

	mutex_enter(softnet_lock);
	KERNEL_LOCK(1, NULL);
	while (!IF_IS_EMPTY(&route_intrq)) {
		s = splnet();
		IF_DEQUEUE(&route_intrq, m);
		splx(s);
		if (m == NULL)
			break;
		proto.sp_protocol = M_GETCTX(m, uintptr_t);
		raw_input(m, &proto, &route_src, &route_dst);
	}
	KERNEL_UNLOCK_ONE(NULL);
	mutex_exit(softnet_lock);
}

/*
 * Enqueue a message to the software interrupt routine.
 */
static void
route_enqueue(struct mbuf *m, int family)
{
	int s, wasempty;

	s = splnet();
	if (IF_QFULL(&route_intrq)) {
		IF_DROP(&route_intrq);
		m_freem(m);
	} else {
		wasempty = IF_IS_EMPTY(&route_intrq);
		M_SETCTX(m, (uintptr_t)family);
		IF_ENQUEUE(&route_intrq, m);
		if (wasempty)
			softint_schedule(route_sih);
	}
	splx(s);
}

void
rt_init(void)
{

	route_intrq.ifq_maxlen = route_maxqlen;
	route_sih = softint_establish(SOFTINT_NET | SOFTINT_MPSAFE,
	    route_intr, NULL);
}

/*
 * Definitions of protocols supported in the ROUTE domain.
 */
PR_WRAP_USRREQ(route_usrreq)
#define	route_usrreq	route_usrreq_wrapper

const struct protosw routesw[] = {
	{
		.pr_type = SOCK_RAW,
		.pr_domain = &routedomain,
		.pr_flags = PR_ATOMIC|PR_ADDR,
		.pr_input = raw_input,
		.pr_output = route_output,
		.pr_ctlinput = raw_ctlinput,
		.pr_usrreq = route_usrreq,
		.pr_init = raw_init,
	},
};

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

SYSCTL_SETUP(sysctl_net_route_setup, "sysctl net.route subtree setup")
{
	const struct sysctlnode *rnode = NULL;

	sysctl_createv(clog, 0, NULL, NULL,
		       CTLFLAG_PERMANENT,
		       CTLTYPE_NODE, "net", NULL,
		       NULL, 0, NULL, 0,
		       CTL_NET, CTL_EOL);

	sysctl_createv(clog, 0, NULL, &rnode,
		       CTLFLAG_PERMANENT,
		       CTLTYPE_NODE, "route",
		       SYSCTL_DESCR("PF_ROUTE information"),
		       NULL, 0, NULL, 0,
		       CTL_NET, PF_ROUTE, CTL_EOL);
	sysctl_createv(clog, 0, NULL, NULL,
		       CTLFLAG_PERMANENT,
		       CTLTYPE_NODE, "rtable",
		       SYSCTL_DESCR("Routing table information"),
		       sysctl_rtable, 0, NULL, 0,
		       CTL_NET, PF_ROUTE, 0 /* any protocol */, CTL_EOL);
	sysctl_createv(clog, 0, &rnode, NULL,
		       CTLFLAG_PERMANENT,
		       CTLTYPE_STRUCT, "stats",
		       SYSCTL_DESCR("Routing statistics"),
		       NULL, 0, &rtstat, sizeof(rtstat),
		       CTL_CREATE, CTL_EOL);
}