17c478bd9Sstevel@tonic-gate /*
2*e704a8f2Smeem  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
37c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
47c478bd9Sstevel@tonic-gate  *
57c478bd9Sstevel@tonic-gate  * Copyright (c) 1995
67c478bd9Sstevel@tonic-gate  *	The Regents of the University of California.  All rights reserved.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * Redistribution and use in source and binary forms, with or without
97c478bd9Sstevel@tonic-gate  * modification, are permitted provided that the following conditions
107c478bd9Sstevel@tonic-gate  * are met:
117c478bd9Sstevel@tonic-gate  * 1. Redistributions of source code must retain the above copyright
127c478bd9Sstevel@tonic-gate  *    notice, this list of conditions and the following disclaimer.
137c478bd9Sstevel@tonic-gate  * 2. Redistributions in binary form must reproduce the above copyright
147c478bd9Sstevel@tonic-gate  *    notice, this list of conditions and the following disclaimer in the
157c478bd9Sstevel@tonic-gate  *    documentation and/or other materials provided with the distribution.
167c478bd9Sstevel@tonic-gate  * 3. All advertising materials mentioning features or use of this software
177c478bd9Sstevel@tonic-gate  *    must display the following acknowledgment:
187c478bd9Sstevel@tonic-gate  *	This product includes software developed by the University of
197c478bd9Sstevel@tonic-gate  *	California, Berkeley and its contributors.
207c478bd9Sstevel@tonic-gate  * 4. Neither the name of the University nor the names of its contributors
217c478bd9Sstevel@tonic-gate  *    may be used to endorse or promote products derived from this software
227c478bd9Sstevel@tonic-gate  *    without specific prior written permission.
237c478bd9Sstevel@tonic-gate  *
247c478bd9Sstevel@tonic-gate  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
257c478bd9Sstevel@tonic-gate  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
267c478bd9Sstevel@tonic-gate  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
277c478bd9Sstevel@tonic-gate  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
287c478bd9Sstevel@tonic-gate  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
297c478bd9Sstevel@tonic-gate  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
307c478bd9Sstevel@tonic-gate  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
317c478bd9Sstevel@tonic-gate  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
327c478bd9Sstevel@tonic-gate  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
337c478bd9Sstevel@tonic-gate  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
347c478bd9Sstevel@tonic-gate  * SUCH DAMAGE.
357c478bd9Sstevel@tonic-gate  *
367c478bd9Sstevel@tonic-gate  * $FreeBSD: src/sbin/routed/rdisc.c,v 1.8 2000/08/11 08:24:38 sheldonh Exp $
377c478bd9Sstevel@tonic-gate  */
387c478bd9Sstevel@tonic-gate 
397c478bd9Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
407c478bd9Sstevel@tonic-gate 
417c478bd9Sstevel@tonic-gate #include "defs.h"
427c478bd9Sstevel@tonic-gate #include <netinet/in_systm.h>
437c478bd9Sstevel@tonic-gate #include <netinet/ip.h>
447c478bd9Sstevel@tonic-gate #include <netinet/ip_icmp.h>
453173664eSapersson #include <fcntl.h>
463173664eSapersson #include <strings.h>
477c478bd9Sstevel@tonic-gate 
487c478bd9Sstevel@tonic-gate /*
497c478bd9Sstevel@tonic-gate  * The size of the control buffer passed to recvmsg() used to receive
507c478bd9Sstevel@tonic-gate  * ancillary data.
517c478bd9Sstevel@tonic-gate  */
527c478bd9Sstevel@tonic-gate #define	CONTROL_BUFSIZE	1024
537c478bd9Sstevel@tonic-gate 
547c478bd9Sstevel@tonic-gate /* router advertisement ICMP packet */
557c478bd9Sstevel@tonic-gate struct icmp_ad {
567c478bd9Sstevel@tonic-gate 	uint8_t    icmp_type;		/* type of message */
577c478bd9Sstevel@tonic-gate 	uint8_t    icmp_code;		/* type sub code */
587c478bd9Sstevel@tonic-gate 	uint16_t   icmp_cksum;		/* ones complement cksum of struct */
597c478bd9Sstevel@tonic-gate 	uint8_t    icmp_ad_num;	/* # of following router addresses */
607c478bd9Sstevel@tonic-gate 	uint8_t    icmp_ad_asize;	/* 2--words in each advertisement */
617c478bd9Sstevel@tonic-gate 	uint16_t   icmp_ad_life;	/* seconds of validity */
627c478bd9Sstevel@tonic-gate 	struct icmp_ad_info {
637c478bd9Sstevel@tonic-gate 	    in_addr_t  icmp_ad_addr;
647c478bd9Sstevel@tonic-gate 	    uint32_t  icmp_ad_pref;
657c478bd9Sstevel@tonic-gate 	} icmp_ad_info[1];
667c478bd9Sstevel@tonic-gate };
677c478bd9Sstevel@tonic-gate 
687c478bd9Sstevel@tonic-gate /* router solicitation ICMP packet */
697c478bd9Sstevel@tonic-gate struct icmp_so {
707c478bd9Sstevel@tonic-gate 	uint8_t    icmp_type;		/* type of message */
717c478bd9Sstevel@tonic-gate 	uint8_t    icmp_code;		/* type sub code */
727c478bd9Sstevel@tonic-gate 	uint16_t   icmp_cksum;		/* ones complement cksum of struct */
737c478bd9Sstevel@tonic-gate 	uint32_t   icmp_so_rsvd;
747c478bd9Sstevel@tonic-gate };
757c478bd9Sstevel@tonic-gate 
767c478bd9Sstevel@tonic-gate union ad_u {
777c478bd9Sstevel@tonic-gate 	struct icmp icmp;
787c478bd9Sstevel@tonic-gate 	struct icmp_ad ad;
797c478bd9Sstevel@tonic-gate 	struct icmp_so so;
807c478bd9Sstevel@tonic-gate };
817c478bd9Sstevel@tonic-gate 
827c478bd9Sstevel@tonic-gate 
837c478bd9Sstevel@tonic-gate int	rdisc_sock = -1;		/* router-discovery raw socket */
843173664eSapersson int	rdisc_mib_sock = -1;		/* AF_UNIX mib info socket */
857c478bd9Sstevel@tonic-gate static struct interface *rdisc_sock_interface; /* current rdisc interface */
867c478bd9Sstevel@tonic-gate 
877c478bd9Sstevel@tonic-gate struct timeval rdisc_timer;
887c478bd9Sstevel@tonic-gate boolean_t rdisc_ok;				/* using solicited route */
897c478bd9Sstevel@tonic-gate 
907c478bd9Sstevel@tonic-gate #define	MAX_ADS		16
917c478bd9Sstevel@tonic-gate int max_ads; /* at least one per interface */
927c478bd9Sstevel@tonic-gate /* accumulated advertisements */
933173664eSapersson static struct dr *cur_drp;
943173664eSapersson struct dr *drs;
957c478bd9Sstevel@tonic-gate 
967c478bd9Sstevel@tonic-gate /*
977c478bd9Sstevel@tonic-gate  * adjust unsigned preference by interface metric,
987c478bd9Sstevel@tonic-gate  * without driving it to infinity
997c478bd9Sstevel@tonic-gate  */
1007c478bd9Sstevel@tonic-gate #define	PREF(p, ifp) ((p) <= (uint32_t)(ifp)->int_metric ? ((p) != 0 ? 1 : 0) \
1017c478bd9Sstevel@tonic-gate 	: (p) - ((ifp)->int_metric))
1027c478bd9Sstevel@tonic-gate 
1037c478bd9Sstevel@tonic-gate static void rdisc_sort(void);
1047c478bd9Sstevel@tonic-gate 
1057c478bd9Sstevel@tonic-gate typedef enum { unicast, bcast, mcast } dstaddr_t;
1067c478bd9Sstevel@tonic-gate 
1077c478bd9Sstevel@tonic-gate /* dump an ICMP Router Discovery Advertisement Message */
1087c478bd9Sstevel@tonic-gate static void
trace_rdisc(const char * act,uint32_t from,uint32_t to,struct interface * ifp,union ad_u * p,uint_t len)1097c478bd9Sstevel@tonic-gate trace_rdisc(const char	*act,
1107c478bd9Sstevel@tonic-gate     uint32_t from,
1117c478bd9Sstevel@tonic-gate     uint32_t to,
1127c478bd9Sstevel@tonic-gate     struct interface *ifp,
1137c478bd9Sstevel@tonic-gate     union ad_u	*p,
1147c478bd9Sstevel@tonic-gate     uint_t len)
1157c478bd9Sstevel@tonic-gate {
1167c478bd9Sstevel@tonic-gate 	int i;
1177c478bd9Sstevel@tonic-gate 	n_long *wp, *lim;
1187c478bd9Sstevel@tonic-gate 
1197c478bd9Sstevel@tonic-gate 
1207c478bd9Sstevel@tonic-gate 	if (!TRACEPACKETS || ftrace == 0)
1217c478bd9Sstevel@tonic-gate 		return;
1227c478bd9Sstevel@tonic-gate 
1237c478bd9Sstevel@tonic-gate 	lastlog();
1247c478bd9Sstevel@tonic-gate 
1257c478bd9Sstevel@tonic-gate 	if (p->icmp.icmp_type == ICMP_ROUTERADVERT) {
1267c478bd9Sstevel@tonic-gate 		(void) fprintf(ftrace, "%s Router Ad"
1277c478bd9Sstevel@tonic-gate 		    " from %s to %s via %s life=%d\n",
1287c478bd9Sstevel@tonic-gate 		    act, naddr_ntoa(from), naddr_ntoa(to),
1297c478bd9Sstevel@tonic-gate 		    ifp ? ifp->int_name : "?",
1307c478bd9Sstevel@tonic-gate 		    ntohs(p->ad.icmp_ad_life));
1317c478bd9Sstevel@tonic-gate 		if (!TRACECONTENTS)
1327c478bd9Sstevel@tonic-gate 			return;
1337c478bd9Sstevel@tonic-gate 
1347c478bd9Sstevel@tonic-gate 		wp = &p->ad.icmp_ad_info[0].icmp_ad_addr;
1357c478bd9Sstevel@tonic-gate 		lim = &wp[(len - sizeof (p->ad)) / sizeof (*wp)];
1367c478bd9Sstevel@tonic-gate 		for (i = 0; i < p->ad.icmp_ad_num && wp <= lim; i++) {
1377c478bd9Sstevel@tonic-gate 			(void) fprintf(ftrace, "\t%s preference=%ld",
1387c478bd9Sstevel@tonic-gate 			    naddr_ntoa(wp[0]), (long)ntohl(wp[1]));
1397c478bd9Sstevel@tonic-gate 			wp += p->ad.icmp_ad_asize;
1407c478bd9Sstevel@tonic-gate 		}
1417c478bd9Sstevel@tonic-gate 		(void) fputc('\n', ftrace);
1427c478bd9Sstevel@tonic-gate 
1437c478bd9Sstevel@tonic-gate 	} else {
1447c478bd9Sstevel@tonic-gate 		trace_act("%s Router Solic. from %s to %s via %s rsvd=%#x",
1457c478bd9Sstevel@tonic-gate 		    act, naddr_ntoa(from), naddr_ntoa(to),
1467c478bd9Sstevel@tonic-gate 		    ifp ? ifp->int_name : "?",
1477c478bd9Sstevel@tonic-gate 		    ntohl(p->so.icmp_so_rsvd));
1487c478bd9Sstevel@tonic-gate 	}
1497c478bd9Sstevel@tonic-gate }
1507c478bd9Sstevel@tonic-gate 
1517c478bd9Sstevel@tonic-gate /*
1527c478bd9Sstevel@tonic-gate  * Prepare Router Discovery socket.
1537c478bd9Sstevel@tonic-gate  */
1547c478bd9Sstevel@tonic-gate static void
get_rdisc_sock(void)1557c478bd9Sstevel@tonic-gate get_rdisc_sock(void)
1567c478bd9Sstevel@tonic-gate {
1577c478bd9Sstevel@tonic-gate 	int on = 1;
1587c478bd9Sstevel@tonic-gate 	unsigned char ttl = 1;
1593173664eSapersson 	struct sockaddr_un laddr;
1603173664eSapersson 	int len;
1617c478bd9Sstevel@tonic-gate 
1627c478bd9Sstevel@tonic-gate 	if (rdisc_sock < 0) {
1637c478bd9Sstevel@tonic-gate 		max_ads = MAX_ADS;
1647c478bd9Sstevel@tonic-gate 		drs = rtmalloc(max_ads * sizeof (struct dr), "get_rdisc_sock");
1657c478bd9Sstevel@tonic-gate 		(void) memset(drs, 0, max_ads * sizeof (struct dr));
1667c478bd9Sstevel@tonic-gate 		rdisc_sock = socket(PF_INET, SOCK_RAW, IPPROTO_ICMP);
1677c478bd9Sstevel@tonic-gate 		if (rdisc_sock < 0)
1687c478bd9Sstevel@tonic-gate 			BADERR(_B_TRUE, "rdisc_sock = socket()");
1697c478bd9Sstevel@tonic-gate 		fix_sock(rdisc_sock, "rdisc_sock");
1707c478bd9Sstevel@tonic-gate 
1717c478bd9Sstevel@tonic-gate 		if (setsockopt(rdisc_sock, IPPROTO_IP, IP_RECVIF, &on,
1727c478bd9Sstevel@tonic-gate 		    sizeof (on)))
1737c478bd9Sstevel@tonic-gate 			BADERR(_B_FALSE, "setsockopt(IP_RECVIF)");
1747c478bd9Sstevel@tonic-gate 
1757c478bd9Sstevel@tonic-gate 		if (setsockopt(rdisc_sock, IPPROTO_IP, IP_MULTICAST_TTL,
1767c478bd9Sstevel@tonic-gate 		    &ttl, sizeof (ttl)) < 0)
1777c478bd9Sstevel@tonic-gate 			DBGERR(_B_TRUE,
1787c478bd9Sstevel@tonic-gate 			    "rdisc_sock setsockopt(IP_MULTICAST_TTL)");
1797c478bd9Sstevel@tonic-gate 
1803173664eSapersson 		/*
1813173664eSapersson 		 * On Solaris also open an AF_UNIX socket to
1823173664eSapersson 		 * pass default router information to mib agent
1833173664eSapersson 		 */
1843173664eSapersson 
1853173664eSapersson 		rdisc_mib_sock = socket(AF_UNIX, SOCK_DGRAM, 0);
1863173664eSapersson 		if (rdisc_mib_sock < 0) {
1873173664eSapersson 			BADERR(_B_TRUE, "rdisc_mib_sock = socket()");
1883173664eSapersson 		}
1893173664eSapersson 
1903173664eSapersson 		bzero(&laddr, sizeof (laddr));
1913173664eSapersson 		laddr.sun_family = AF_UNIX;
1923173664eSapersson 
1933173664eSapersson 		(void) strncpy(laddr.sun_path, RDISC_SNMP_SOCKET,
1943173664eSapersson 		    sizeof (laddr.sun_path));
1953173664eSapersson 		len = sizeof (struct sockaddr_un);
1963173664eSapersson 
1973173664eSapersson 		(void) unlink(RDISC_SNMP_SOCKET);
1983173664eSapersson 
1993173664eSapersson 		if (bind(rdisc_mib_sock, (struct sockaddr *)&laddr, len) < 0) {
2003173664eSapersson 			BADERR(_B_TRUE, "bind(rdisc_mib_sock)");
2013173664eSapersson 		}
2023173664eSapersson 
2033173664eSapersson 		if (fcntl(rdisc_mib_sock, F_SETFL, O_NONBLOCK) < 0) {
2043173664eSapersson 			BADERR(_B_TRUE, "rdisc_mib_sock fcntl O_NONBLOCK");
2053173664eSapersson 		}
2063173664eSapersson 
2077c478bd9Sstevel@tonic-gate 		fix_select();
2087c478bd9Sstevel@tonic-gate 	}
2097c478bd9Sstevel@tonic-gate }
2107c478bd9Sstevel@tonic-gate 
2117c478bd9Sstevel@tonic-gate 
2127c478bd9Sstevel@tonic-gate /*
2137c478bd9Sstevel@tonic-gate  * Pick multicast group for router-discovery socket
2147c478bd9Sstevel@tonic-gate  */
2157c478bd9Sstevel@tonic-gate void
set_rdisc_mg(struct interface * ifp,int on)2167c478bd9Sstevel@tonic-gate set_rdisc_mg(struct interface *ifp,
2177c478bd9Sstevel@tonic-gate     int on)	/* 0=turn it off */
2187c478bd9Sstevel@tonic-gate {
2197c478bd9Sstevel@tonic-gate 	struct ip_mreq m;
2207c478bd9Sstevel@tonic-gate 	boolean_t dosupply;
2217c478bd9Sstevel@tonic-gate 
2227c478bd9Sstevel@tonic-gate 	if (rdisc_sock < 0) {
2237c478bd9Sstevel@tonic-gate 		/*
2247c478bd9Sstevel@tonic-gate 		 * Create the raw socket so that we can hear at least
2257c478bd9Sstevel@tonic-gate 		 * broadcast router discovery packets.
2267c478bd9Sstevel@tonic-gate 		 */
2277c478bd9Sstevel@tonic-gate 		if ((ifp->int_state & IS_NO_RDISC) == IS_NO_RDISC ||
2287c478bd9Sstevel@tonic-gate 		    !on)
2297c478bd9Sstevel@tonic-gate 			return;
2307c478bd9Sstevel@tonic-gate 		get_rdisc_sock();
2317c478bd9Sstevel@tonic-gate 	}
2327c478bd9Sstevel@tonic-gate 
2337c478bd9Sstevel@tonic-gate 	if (!(ifp->int_if_flags & IFF_MULTICAST)) {
2347c478bd9Sstevel@tonic-gate 		/* Can't multicast, so no groups could have been joined. */
2357c478bd9Sstevel@tonic-gate 		ifp->int_state &= ~(IS_ALL_HOSTS | IS_ALL_ROUTERS);
2367c478bd9Sstevel@tonic-gate 		return;
2377c478bd9Sstevel@tonic-gate 	}
2387c478bd9Sstevel@tonic-gate 
2397c478bd9Sstevel@tonic-gate 	dosupply = should_supply(ifp);
2407c478bd9Sstevel@tonic-gate 
2417c478bd9Sstevel@tonic-gate 	(void) memset(&m, 0, sizeof (m));
2427c478bd9Sstevel@tonic-gate 	m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT) &&
2437c478bd9Sstevel@tonic-gate 	    (ifp->int_dstaddr != 0) ? ifp->int_dstaddr : ifp->int_addr);
2447c478bd9Sstevel@tonic-gate 	if (dosupply || (ifp->int_state & IS_NO_ADV_IN) || !on) {
2457c478bd9Sstevel@tonic-gate 		/* stop listening to advertisements */
2467c478bd9Sstevel@tonic-gate 		if (ifp->int_state & IS_ALL_HOSTS) {
2477c478bd9Sstevel@tonic-gate 			m.imr_multiaddr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
2487c478bd9Sstevel@tonic-gate 			if (setsockopt(rdisc_sock, IPPROTO_IP,
2497c478bd9Sstevel@tonic-gate 			    IP_DROP_MEMBERSHIP, &m, sizeof (m)) < 0 &&
2507c478bd9Sstevel@tonic-gate 			    errno != EADDRNOTAVAIL && errno != ENOENT)
2517c478bd9Sstevel@tonic-gate 				LOGERR("IP_DROP_MEMBERSHIP ALLHOSTS");
2527c478bd9Sstevel@tonic-gate 			ifp->int_state &= ~IS_ALL_HOSTS;
2537c478bd9Sstevel@tonic-gate 		}
2547c478bd9Sstevel@tonic-gate 
2557c478bd9Sstevel@tonic-gate 	} else if (!(ifp->int_state & IS_ALL_HOSTS)) {
2567c478bd9Sstevel@tonic-gate 		/* start listening to advertisements */
2577c478bd9Sstevel@tonic-gate 		m.imr_multiaddr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
2587c478bd9Sstevel@tonic-gate 		if (setsockopt(rdisc_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
2597c478bd9Sstevel@tonic-gate 		    &m, sizeof (m)) < 0) {
2607c478bd9Sstevel@tonic-gate 			LOGERR("IP_ADD_MEMBERSHIP ALLHOSTS");
2617c478bd9Sstevel@tonic-gate 		} else {
2627c478bd9Sstevel@tonic-gate 			ifp->int_state |= IS_ALL_HOSTS;
2637c478bd9Sstevel@tonic-gate 		}
2647c478bd9Sstevel@tonic-gate 	}
2657c478bd9Sstevel@tonic-gate 
2667c478bd9Sstevel@tonic-gate 	if (!dosupply || (ifp->int_state & IS_NO_ADV_OUT) ||
2677c478bd9Sstevel@tonic-gate 	    !IS_IFF_ROUTING(ifp->int_if_flags) || !on) {
2687c478bd9Sstevel@tonic-gate 		/* stop listening to solicitations */
2697c478bd9Sstevel@tonic-gate 		if (ifp->int_state & IS_ALL_ROUTERS) {
2707c478bd9Sstevel@tonic-gate 			m.imr_multiaddr.s_addr = htonl(INADDR_ALLRTRS_GROUP);
2717c478bd9Sstevel@tonic-gate 			if (setsockopt(rdisc_sock, IPPROTO_IP,
2727c478bd9Sstevel@tonic-gate 			    IP_DROP_MEMBERSHIP, &m, sizeof (m)) < 0 &&
2737c478bd9Sstevel@tonic-gate 			    errno != EADDRNOTAVAIL && errno != ENOENT)
2747c478bd9Sstevel@tonic-gate 				LOGERR("IP_DROP_MEMBERSHIP ALLROUTERS");
2757c478bd9Sstevel@tonic-gate 			ifp->int_state &= ~IS_ALL_ROUTERS;
2767c478bd9Sstevel@tonic-gate 		}
2777c478bd9Sstevel@tonic-gate 
2787c478bd9Sstevel@tonic-gate 	} else if (!(ifp->int_state & IS_ALL_ROUTERS)) {
2797c478bd9Sstevel@tonic-gate 		/* start hearing solicitations */
2807c478bd9Sstevel@tonic-gate 		m.imr_multiaddr.s_addr = htonl(INADDR_ALLRTRS_GROUP);
2817c478bd9Sstevel@tonic-gate 		if (setsockopt(rdisc_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
2827c478bd9Sstevel@tonic-gate 		    &m, sizeof (m)) < 0) {
2837c478bd9Sstevel@tonic-gate 			LOGERR("IP_ADD_MEMBERSHIP ALLROUTERS");
2847c478bd9Sstevel@tonic-gate 		} else {
2857c478bd9Sstevel@tonic-gate 			ifp->int_state |= IS_ALL_ROUTERS;
2867c478bd9Sstevel@tonic-gate 		}
2877c478bd9Sstevel@tonic-gate 	}
2887c478bd9Sstevel@tonic-gate }
2897c478bd9Sstevel@tonic-gate 
2907c478bd9Sstevel@tonic-gate 
2917c478bd9Sstevel@tonic-gate /*
2927c478bd9Sstevel@tonic-gate  * start or stop supplying routes to other systems.
2937c478bd9Sstevel@tonic-gate  */
2947c478bd9Sstevel@tonic-gate void
set_supplier(void)2957c478bd9Sstevel@tonic-gate set_supplier(void)
2967c478bd9Sstevel@tonic-gate {
2977c478bd9Sstevel@tonic-gate 	struct interface *ifp;
2987c478bd9Sstevel@tonic-gate 	struct dr *drp;
2997c478bd9Sstevel@tonic-gate 	static boolean_t supplystate = _B_FALSE;
3007c478bd9Sstevel@tonic-gate 
3017c478bd9Sstevel@tonic-gate 	if (supplystate == (fwd_interfaces > 1))
3027c478bd9Sstevel@tonic-gate 		return;
3037c478bd9Sstevel@tonic-gate 	supplystate = fwd_interfaces > 1;
3047c478bd9Sstevel@tonic-gate 
3057c478bd9Sstevel@tonic-gate 	trace_act("%d forwarding interfaces present; becoming %ssupplier",
3067c478bd9Sstevel@tonic-gate 	    fwd_interfaces, supplystate ? "" : "non-");
3077c478bd9Sstevel@tonic-gate 
3087c478bd9Sstevel@tonic-gate 	if (supplystate) {
3097c478bd9Sstevel@tonic-gate 		/* Forget discovered routes. */
3107c478bd9Sstevel@tonic-gate 		for (drp = drs; drp < &drs[max_ads]; drp++) {
3117c478bd9Sstevel@tonic-gate 			drp->dr_recv_pref = DEF_PREFERENCELEVEL;
3127c478bd9Sstevel@tonic-gate 			drp->dr_life = 0;
3137c478bd9Sstevel@tonic-gate 		}
3147c478bd9Sstevel@tonic-gate 		rdisc_age(0);
3157c478bd9Sstevel@tonic-gate 
3167c478bd9Sstevel@tonic-gate 		/*
3177c478bd9Sstevel@tonic-gate 		 * Do not start advertising until we have heard some
3187c478bd9Sstevel@tonic-gate 		 * RIP routes.
3197c478bd9Sstevel@tonic-gate 		 */
3207c478bd9Sstevel@tonic-gate 		LIM_SEC(rdisc_timer, now.tv_sec+MIN_WAITTIME);
3217c478bd9Sstevel@tonic-gate 
3227c478bd9Sstevel@tonic-gate 		/* get rid of any redirects */
3237c478bd9Sstevel@tonic-gate 		del_redirects(0, 0);
3247c478bd9Sstevel@tonic-gate 	} else {
3257c478bd9Sstevel@tonic-gate 		/*
3267c478bd9Sstevel@tonic-gate 		 * Flush out all those advertisements we had sent by sending
3277c478bd9Sstevel@tonic-gate 		 * one with lifetime=0.
3287c478bd9Sstevel@tonic-gate 		 */
3297c478bd9Sstevel@tonic-gate 		rdisc_adv(_B_TRUE);
3307c478bd9Sstevel@tonic-gate 	}
3317c478bd9Sstevel@tonic-gate 
3327c478bd9Sstevel@tonic-gate 	/*
3337c478bd9Sstevel@tonic-gate 	 * Switch router discovery multicast groups from soliciting
3347c478bd9Sstevel@tonic-gate 	 * to advertising or back.
3357c478bd9Sstevel@tonic-gate 	 */
3367c478bd9Sstevel@tonic-gate 	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
3377c478bd9Sstevel@tonic-gate 		if (ifp->int_state & IS_BROKE)
3387c478bd9Sstevel@tonic-gate 			continue;
3397c478bd9Sstevel@tonic-gate 		ifp->int_rdisc_cnt = 0;
3407c478bd9Sstevel@tonic-gate 		ifp->int_rdisc_timer.tv_usec = rdisc_timer.tv_usec;
3417c478bd9Sstevel@tonic-gate 		ifp->int_rdisc_timer.tv_sec = now.tv_sec+MIN_WAITTIME;
3427c478bd9Sstevel@tonic-gate 		set_rdisc_mg(ifp, 1);
3437c478bd9Sstevel@tonic-gate 	}
3447c478bd9Sstevel@tonic-gate }
3457c478bd9Sstevel@tonic-gate 
3467c478bd9Sstevel@tonic-gate 
3477c478bd9Sstevel@tonic-gate /*
3487c478bd9Sstevel@tonic-gate  * Age discovered routes and find the best one
3497c478bd9Sstevel@tonic-gate  */
3507c478bd9Sstevel@tonic-gate void
rdisc_age(in_addr_t bad_gate)3517c478bd9Sstevel@tonic-gate rdisc_age(in_addr_t bad_gate)
3527c478bd9Sstevel@tonic-gate {
3537c478bd9Sstevel@tonic-gate 	time_t sec;
3547c478bd9Sstevel@tonic-gate 	struct dr *drp;
3557c478bd9Sstevel@tonic-gate 	struct rt_spare new;
3567c478bd9Sstevel@tonic-gate 	struct rt_entry *rt;
3577c478bd9Sstevel@tonic-gate 
3587c478bd9Sstevel@tonic-gate 	/*
3597c478bd9Sstevel@tonic-gate 	 * If we are being told about a bad router,
3607c478bd9Sstevel@tonic-gate 	 * then age the discovered default route, and if there is
3617c478bd9Sstevel@tonic-gate 	 * no alternative, solicit a replacement.
3627c478bd9Sstevel@tonic-gate 	 */
3637c478bd9Sstevel@tonic-gate 	if (bad_gate != 0) {
3647c478bd9Sstevel@tonic-gate 		/*
3657c478bd9Sstevel@tonic-gate 		 * Look for the bad discovered default route.
3667c478bd9Sstevel@tonic-gate 		 * Age it and note its interface.
3677c478bd9Sstevel@tonic-gate 		 */
3687c478bd9Sstevel@tonic-gate 		for (drp = drs; drp < &drs[max_ads]; drp++) {
3697c478bd9Sstevel@tonic-gate 			if (drp->dr_ts == 0)
3707c478bd9Sstevel@tonic-gate 				continue;
3717c478bd9Sstevel@tonic-gate 
3727c478bd9Sstevel@tonic-gate 			/*
3737c478bd9Sstevel@tonic-gate 			 * When we find the bad router, age the route
3747c478bd9Sstevel@tonic-gate 			 * to at most SUPPLY_INTERVAL.
3757c478bd9Sstevel@tonic-gate 			 * This is contrary to RFC 1256, but defends against
3767c478bd9Sstevel@tonic-gate 			 * black holes.
3777c478bd9Sstevel@tonic-gate 			 */
3787c478bd9Sstevel@tonic-gate 			if (drp->dr_gate == bad_gate) {
3797c478bd9Sstevel@tonic-gate 				sec = (now.tv_sec - drp->dr_life +
3807c478bd9Sstevel@tonic-gate 				    SUPPLY_INTERVAL);
3817c478bd9Sstevel@tonic-gate 				if (drp->dr_ts > sec) {
3827c478bd9Sstevel@tonic-gate 					trace_act("age 0.0.0.0 --> %s via %s",
3837c478bd9Sstevel@tonic-gate 					    naddr_ntoa(drp->dr_gate),
3847c478bd9Sstevel@tonic-gate 					    drp->dr_ifp->int_name);
3857c478bd9Sstevel@tonic-gate 					drp->dr_ts = sec;
3867c478bd9Sstevel@tonic-gate 				}
3877c478bd9Sstevel@tonic-gate 				break;
3887c478bd9Sstevel@tonic-gate 			}
3897c478bd9Sstevel@tonic-gate 		}
3907c478bd9Sstevel@tonic-gate 	} else if (should_supply(NULL)) {
3917c478bd9Sstevel@tonic-gate 		/*
3927c478bd9Sstevel@tonic-gate 		 * If switching from client to server, get rid of old
3937c478bd9Sstevel@tonic-gate 		 * default routes.
3947c478bd9Sstevel@tonic-gate 		 */
3957c478bd9Sstevel@tonic-gate 		if (cur_drp != NULL) {
3967c478bd9Sstevel@tonic-gate 			rt = rtget(RIP_DEFAULT, 0);
3977c478bd9Sstevel@tonic-gate 			/*
3987c478bd9Sstevel@tonic-gate 			 * If there is a current default router, and the
3997c478bd9Sstevel@tonic-gate 			 * there is no rt_spare entry, create one
4007c478bd9Sstevel@tonic-gate 			 * for cur_drp to prevent segmentation fault
4017c478bd9Sstevel@tonic-gate 			 * at rdisc_sort.
4027c478bd9Sstevel@tonic-gate 			 */
4037c478bd9Sstevel@tonic-gate 			if (rt == NULL) {
4047c478bd9Sstevel@tonic-gate 				(void) memset(&new, 0, sizeof (new));
4057c478bd9Sstevel@tonic-gate 				new.rts_ifp = cur_drp->dr_ifp;
4067c478bd9Sstevel@tonic-gate 				new.rts_gate = cur_drp->dr_gate;
4077c478bd9Sstevel@tonic-gate 				new.rts_router = cur_drp->dr_gate;
4087c478bd9Sstevel@tonic-gate 				new.rts_metric = HOPCNT_INFINITY-1;
4097c478bd9Sstevel@tonic-gate 				new.rts_time = now.tv_sec;
4107c478bd9Sstevel@tonic-gate 				new.rts_origin = RO_RDISC;
4117c478bd9Sstevel@tonic-gate 				rtadd(RIP_DEFAULT, 0, RS_NOPROPAGATE, &new);
4127c478bd9Sstevel@tonic-gate 			}
4137c478bd9Sstevel@tonic-gate 
4147c478bd9Sstevel@tonic-gate 			rdisc_sort();
4157c478bd9Sstevel@tonic-gate 		}
4167c478bd9Sstevel@tonic-gate 		rdisc_adv(_B_FALSE);
4177c478bd9Sstevel@tonic-gate 	}
4187c478bd9Sstevel@tonic-gate 
4197c478bd9Sstevel@tonic-gate 	rdisc_sol();
4207c478bd9Sstevel@tonic-gate 	if (cur_drp != NULL) {
4217c478bd9Sstevel@tonic-gate 		rt = rtget(RIP_DEFAULT, 0);
4227c478bd9Sstevel@tonic-gate 		if (rt == NULL) {
4237c478bd9Sstevel@tonic-gate 			(void) memset(&new, 0, sizeof (new));
4247c478bd9Sstevel@tonic-gate 			new.rts_ifp = cur_drp->dr_ifp;
4257c478bd9Sstevel@tonic-gate 			new.rts_gate = cur_drp->dr_gate;
4267c478bd9Sstevel@tonic-gate 			new.rts_router = cur_drp->dr_gate;
4277c478bd9Sstevel@tonic-gate 			new.rts_metric = HOPCNT_INFINITY-1;
4287c478bd9Sstevel@tonic-gate 			new.rts_time = now.tv_sec;
4297c478bd9Sstevel@tonic-gate 			new.rts_origin = RO_RDISC;
4307c478bd9Sstevel@tonic-gate 			rtadd(RIP_DEFAULT, 0, RS_NOPROPAGATE, &new);
4317c478bd9Sstevel@tonic-gate 		}
4327c478bd9Sstevel@tonic-gate 	}
4337c478bd9Sstevel@tonic-gate 	rdisc_sort();
4347c478bd9Sstevel@tonic-gate 
4357c478bd9Sstevel@tonic-gate 	/*
4367c478bd9Sstevel@tonic-gate 	 * Delete old redirected routes to keep the kernel table small,
4377c478bd9Sstevel@tonic-gate 	 * and to prevent black holes.  Check that the kernel table
4387c478bd9Sstevel@tonic-gate 	 * matches the daemon table (i.e. has the default route).
4397c478bd9Sstevel@tonic-gate 	 * But only if RIP is not running and we are not dealing with
4407c478bd9Sstevel@tonic-gate 	 * a bad gateway, since otherwise age() will be called.
4417c478bd9Sstevel@tonic-gate 	 */
4427c478bd9Sstevel@tonic-gate 	if (rip_sock < 0 && bad_gate == 0)
4437c478bd9Sstevel@tonic-gate 		age(0);
4447c478bd9Sstevel@tonic-gate }
4457c478bd9Sstevel@tonic-gate 
4467c478bd9Sstevel@tonic-gate 
4477c478bd9Sstevel@tonic-gate /*
4487c478bd9Sstevel@tonic-gate  * Zap all routes discovered via an interface that has gone bad
4497c478bd9Sstevel@tonic-gate  * This should only be called when !(ifp->int_state & IS_DUP)
4507c478bd9Sstevel@tonic-gate  * This is called by if_del and if_bad, and the interface pointer
4517c478bd9Sstevel@tonic-gate  * might not be valid after this.
4527c478bd9Sstevel@tonic-gate  */
4537c478bd9Sstevel@tonic-gate void
if_bad_rdisc(struct interface * ifp)4547c478bd9Sstevel@tonic-gate if_bad_rdisc(struct interface *ifp)
4557c478bd9Sstevel@tonic-gate {
4567c478bd9Sstevel@tonic-gate 	struct dr *drp;
4577c478bd9Sstevel@tonic-gate 
4587c478bd9Sstevel@tonic-gate 	for (drp = drs; drp < &drs[max_ads]; drp++) {
4597c478bd9Sstevel@tonic-gate 		if (drp->dr_ifp != ifp)
4607c478bd9Sstevel@tonic-gate 			continue;
4617c478bd9Sstevel@tonic-gate 		(void) memset(drp, 0, sizeof (*drp));
4627c478bd9Sstevel@tonic-gate 	}
4637c478bd9Sstevel@tonic-gate 
4647c478bd9Sstevel@tonic-gate 	/* make a note to re-solicit, turn RIP on or off, etc. */
4657c478bd9Sstevel@tonic-gate 	rdisc_timer.tv_sec = 0;
4667c478bd9Sstevel@tonic-gate }
4677c478bd9Sstevel@tonic-gate 
4687c478bd9Sstevel@tonic-gate /*
4697c478bd9Sstevel@tonic-gate  * Rewire all routes discovered via an interface that has gone bad
4707c478bd9Sstevel@tonic-gate  * This is only called by if_del.
4717c478bd9Sstevel@tonic-gate  */
4727c478bd9Sstevel@tonic-gate void
if_rewire_rdisc(struct interface * oldifp,struct interface * newifp)4737c478bd9Sstevel@tonic-gate if_rewire_rdisc(struct interface *oldifp, struct interface *newifp)
4747c478bd9Sstevel@tonic-gate {
4757c478bd9Sstevel@tonic-gate 	struct dr *drp;
4767c478bd9Sstevel@tonic-gate 
4777c478bd9Sstevel@tonic-gate 	for (drp = drs; drp < &drs[max_ads]; drp++) {
4787c478bd9Sstevel@tonic-gate 		if (drp->dr_ifp != oldifp)
4797c478bd9Sstevel@tonic-gate 			continue;
4807c478bd9Sstevel@tonic-gate 		drp->dr_ifp = newifp;
4817c478bd9Sstevel@tonic-gate 		drp->dr_pref += (newifp->int_metric - oldifp->int_metric);
4827c478bd9Sstevel@tonic-gate 		drp->dr_flags |= DR_CHANGED;
4837c478bd9Sstevel@tonic-gate 	}
4847c478bd9Sstevel@tonic-gate 
4857c478bd9Sstevel@tonic-gate 	/* make a note to re-solicit, turn RIP on or off, etc. */
4867c478bd9Sstevel@tonic-gate 	rdisc_timer.tv_sec = 0;
4877c478bd9Sstevel@tonic-gate }
4887c478bd9Sstevel@tonic-gate 
4897c478bd9Sstevel@tonic-gate /*
4907c478bd9Sstevel@tonic-gate  * Mark an interface ok for router discovering.
4917c478bd9Sstevel@tonic-gate  * This is called by if_ok and ifinit.
4927c478bd9Sstevel@tonic-gate  */
4937c478bd9Sstevel@tonic-gate void
if_ok_rdisc(struct interface * ifp)4947c478bd9Sstevel@tonic-gate if_ok_rdisc(struct interface *ifp)
4957c478bd9Sstevel@tonic-gate {
4967c478bd9Sstevel@tonic-gate 	set_rdisc_mg(ifp, 1);
4977c478bd9Sstevel@tonic-gate 
4987c478bd9Sstevel@tonic-gate 	ifp->int_rdisc_cnt = 0;
4997c478bd9Sstevel@tonic-gate 	ifp->int_rdisc_timer.tv_sec = now.tv_sec +
5007c478bd9Sstevel@tonic-gate 	    ((ifp->int_state & IS_NO_ADV_OUT) ?
5017c478bd9Sstevel@tonic-gate 	    MAX_SOLICITATION_DELAY : MIN_WAITTIME);
5027c478bd9Sstevel@tonic-gate 	if (timercmp(&rdisc_timer, &ifp->int_rdisc_timer, > /* cstyle */))
5037c478bd9Sstevel@tonic-gate 		rdisc_timer = ifp->int_rdisc_timer;
5047c478bd9Sstevel@tonic-gate }
5057c478bd9Sstevel@tonic-gate 
5067c478bd9Sstevel@tonic-gate /*
5077c478bd9Sstevel@tonic-gate  * Get rid of a dead discovered router
5087c478bd9Sstevel@tonic-gate  */
5097c478bd9Sstevel@tonic-gate static void
del_rdisc(struct dr * drp)5107c478bd9Sstevel@tonic-gate del_rdisc(struct dr *drp)
5117c478bd9Sstevel@tonic-gate {
5127c478bd9Sstevel@tonic-gate 	struct interface *ifp;
5137c478bd9Sstevel@tonic-gate 	uint32_t gate;
5147c478bd9Sstevel@tonic-gate 	int i;
5157c478bd9Sstevel@tonic-gate 	struct rt_entry *rt;
5167c478bd9Sstevel@tonic-gate 	struct rt_spare *rts = NULL;
5177c478bd9Sstevel@tonic-gate 
5187c478bd9Sstevel@tonic-gate 	del_redirects(gate = drp->dr_gate, 0);
5197c478bd9Sstevel@tonic-gate 	drp->dr_ts = 0;
5207c478bd9Sstevel@tonic-gate 	drp->dr_life = 0;
5217c478bd9Sstevel@tonic-gate 
5227c478bd9Sstevel@tonic-gate 	rt = rtget(RIP_DEFAULT, 0);
5237c478bd9Sstevel@tonic-gate 	if (rt == NULL) {
5247c478bd9Sstevel@tonic-gate 		trace_act("could not find default route in table");
5257c478bd9Sstevel@tonic-gate 	} else {
5267c478bd9Sstevel@tonic-gate 		for (i = 0; i < rt->rt_num_spares; i++) {
5277c478bd9Sstevel@tonic-gate 			if ((rt->rt_spares[i].rts_gate == drp->dr_gate) &&
5287c478bd9Sstevel@tonic-gate 			    (rt->rt_spares[i].rts_origin == RO_RDISC)) {
5297c478bd9Sstevel@tonic-gate 				rts = &rt->rt_spares[i];
5307c478bd9Sstevel@tonic-gate 				break;
5317c478bd9Sstevel@tonic-gate 			}
5327c478bd9Sstevel@tonic-gate 		}
5337c478bd9Sstevel@tonic-gate 		if (rts != NULL)
5347c478bd9Sstevel@tonic-gate 			rts_delete(rt, rts);
5357c478bd9Sstevel@tonic-gate 		else
5367c478bd9Sstevel@tonic-gate 			trace_act("could not find default route "
5377c478bd9Sstevel@tonic-gate 			    "through %s in table", naddr_ntoa(drp->dr_gate));
5387c478bd9Sstevel@tonic-gate 	}
5397c478bd9Sstevel@tonic-gate 
5407c478bd9Sstevel@tonic-gate 	/* Count the other discovered routers on the interface.  */
5417c478bd9Sstevel@tonic-gate 	i = 0;
5427c478bd9Sstevel@tonic-gate 	ifp = drp->dr_ifp;
5437c478bd9Sstevel@tonic-gate 	for (drp = drs; drp < &drs[max_ads]; drp++) {
5447c478bd9Sstevel@tonic-gate 		if (drp->dr_ts != 0 && drp->dr_ifp == ifp)
5457c478bd9Sstevel@tonic-gate 			i++;
5467c478bd9Sstevel@tonic-gate 	}
5477c478bd9Sstevel@tonic-gate 
5487c478bd9Sstevel@tonic-gate 	/*
5497c478bd9Sstevel@tonic-gate 	 * If that was the last good discovered router on the interface,
5507c478bd9Sstevel@tonic-gate 	 * then solicit a new one.
5517c478bd9Sstevel@tonic-gate 	 * This is contrary to RFC 1256, but defends against black holes.
5527c478bd9Sstevel@tonic-gate 	 */
5537c478bd9Sstevel@tonic-gate 	if (i != 0) {
5547c478bd9Sstevel@tonic-gate 		trace_act("discovered router %s via %s"
5557c478bd9Sstevel@tonic-gate 		    " is bad--have %d remaining",
5567c478bd9Sstevel@tonic-gate 		    naddr_ntoa(gate), ifp->int_name, i);
5577c478bd9Sstevel@tonic-gate 	} else if (ifp->int_rdisc_cnt >= MAX_SOLICITATIONS) {
5587c478bd9Sstevel@tonic-gate 		trace_act("last discovered router %s via %s"
5597c478bd9Sstevel@tonic-gate 		    " is bad--re-solicit",
5607c478bd9Sstevel@tonic-gate 		    naddr_ntoa(gate), ifp->int_name);
5617c478bd9Sstevel@tonic-gate 		ifp->int_rdisc_cnt = 0;
5627c478bd9Sstevel@tonic-gate 		ifp->int_rdisc_timer.tv_sec = 0;
5637c478bd9Sstevel@tonic-gate 		rdisc_sol();
5647c478bd9Sstevel@tonic-gate 	} else {
5657c478bd9Sstevel@tonic-gate 		trace_act("last discovered router %s via %s"
5667c478bd9Sstevel@tonic-gate 		    " is bad--wait to solicit",
5677c478bd9Sstevel@tonic-gate 		    naddr_ntoa(gate), ifp->int_name);
5687c478bd9Sstevel@tonic-gate 	}
5697c478bd9Sstevel@tonic-gate }
5707c478bd9Sstevel@tonic-gate 
5717c478bd9Sstevel@tonic-gate 
5727c478bd9Sstevel@tonic-gate /* Find the best discovered route, and discard stale routers. */
5737c478bd9Sstevel@tonic-gate static void
rdisc_sort(void)5747c478bd9Sstevel@tonic-gate rdisc_sort(void)
5757c478bd9Sstevel@tonic-gate {
5767c478bd9Sstevel@tonic-gate 	struct dr *drp, *new_drp;
5777c478bd9Sstevel@tonic-gate 	struct rt_entry *rt;
5787c478bd9Sstevel@tonic-gate 	struct rt_spare new, *rts;
5797c478bd9Sstevel@tonic-gate 	struct interface *ifp;
5807c478bd9Sstevel@tonic-gate 	uint_t new_st = 0;
5817c478bd9Sstevel@tonic-gate 	uint32_t new_pref = DEF_PREFERENCELEVEL;
5827c478bd9Sstevel@tonic-gate 	int first_rdisc_slot = 0;
5837c478bd9Sstevel@tonic-gate 	int j;
5847c478bd9Sstevel@tonic-gate 	boolean_t spares_avail;
5857c478bd9Sstevel@tonic-gate 	void *ptr;
5867c478bd9Sstevel@tonic-gate 	size_t ptrsize;
5877c478bd9Sstevel@tonic-gate 
5887c478bd9Sstevel@tonic-gate 	rt = rtget(RIP_DEFAULT, 0);
5897c478bd9Sstevel@tonic-gate 
5907c478bd9Sstevel@tonic-gate 	/*
5917c478bd9Sstevel@tonic-gate 	 * If all the rt_spare entries are taken up with with default routes
5927c478bd9Sstevel@tonic-gate 	 * learnt from RIP (ie rts_origin = RO_RIP), bail out.
5937c478bd9Sstevel@tonic-gate 	 * NOTE:
5947c478bd9Sstevel@tonic-gate 	 *	We *always* prefer default routes learned via RIP
5957c478bd9Sstevel@tonic-gate 	 *	(ie RO_RIP) over those learnt via RDISC (ie RO_RDISC).
5967c478bd9Sstevel@tonic-gate 	 *	The rdisc machinery should not modify, replace or
5977c478bd9Sstevel@tonic-gate 	 *	remove any existing default routes with RO_RIP set.
5987c478bd9Sstevel@tonic-gate 	 */
5997c478bd9Sstevel@tonic-gate 	if (rt != NULL) {
6007c478bd9Sstevel@tonic-gate 		spares_avail = _B_FALSE;
6017c478bd9Sstevel@tonic-gate 		for (j = 0; j < rt->rt_num_spares; j++)  {
6027c478bd9Sstevel@tonic-gate 			rts = &rt->rt_spares[j];
60309f979dcSsowmini 			if (rts->rts_gate == 0 || rts->rts_origin != RO_RIP ||
60409f979dcSsowmini 			    rts->rts_ifp == &dummy_ifp) {
6057c478bd9Sstevel@tonic-gate 				spares_avail = _B_TRUE;
6067c478bd9Sstevel@tonic-gate 				break;
6077c478bd9Sstevel@tonic-gate 			}
6087c478bd9Sstevel@tonic-gate 		}
6097c478bd9Sstevel@tonic-gate 		if (!spares_avail) {
6107c478bd9Sstevel@tonic-gate 			ptrsize = (rt->rt_num_spares + SPARE_INC) *
6117c478bd9Sstevel@tonic-gate 			    sizeof (struct rt_spare);
6127c478bd9Sstevel@tonic-gate 			ptr = realloc(rt->rt_spares, ptrsize);
6137c478bd9Sstevel@tonic-gate 			if (ptr != NULL) {
6147c478bd9Sstevel@tonic-gate 				struct rt_spare *tmprts;
6157c478bd9Sstevel@tonic-gate 
6167c478bd9Sstevel@tonic-gate 				rt->rt_spares = ptr;
6177c478bd9Sstevel@tonic-gate 				rts = &rt->rt_spares[rt->rt_num_spares];
6187c478bd9Sstevel@tonic-gate 				(void) memset(rts, 0,
6197c478bd9Sstevel@tonic-gate 				    (SPARE_INC * sizeof (struct rt_spare)));
6207c478bd9Sstevel@tonic-gate 				rt->rt_num_spares += SPARE_INC;
6217c478bd9Sstevel@tonic-gate 				for (tmprts = rts, j = SPARE_INC;
6227c478bd9Sstevel@tonic-gate 				    j != 0; j--, tmprts++)
6237c478bd9Sstevel@tonic-gate 					tmprts->rts_metric = HOPCNT_INFINITY;
6247c478bd9Sstevel@tonic-gate 				spares_avail = _B_TRUE;
6257c478bd9Sstevel@tonic-gate 			} else {
6267c478bd9Sstevel@tonic-gate 				return;
6277c478bd9Sstevel@tonic-gate 			}
6287c478bd9Sstevel@tonic-gate 		}
6297c478bd9Sstevel@tonic-gate 	}
6307c478bd9Sstevel@tonic-gate 	/* Find the best RDISC advertiser */
6317c478bd9Sstevel@tonic-gate 	rt = NULL;
6327c478bd9Sstevel@tonic-gate 	new_drp = NULL;
6337c478bd9Sstevel@tonic-gate 	for (drp = drs; drp < &drs[max_ads]; drp++) {
6347c478bd9Sstevel@tonic-gate 		if (drp->dr_ts == 0)
6357c478bd9Sstevel@tonic-gate 			continue;
6367c478bd9Sstevel@tonic-gate 		ifp = drp->dr_ifp;
6377c478bd9Sstevel@tonic-gate 
6387c478bd9Sstevel@tonic-gate 		/* Get rid of expired discovered routers. */
6397c478bd9Sstevel@tonic-gate 		if (drp->dr_ts + drp->dr_life <= now.tv_sec) {
6407c478bd9Sstevel@tonic-gate 			del_rdisc(drp);
6417c478bd9Sstevel@tonic-gate 			continue;
6427c478bd9Sstevel@tonic-gate 		}
6437c478bd9Sstevel@tonic-gate 
6447c478bd9Sstevel@tonic-gate 		LIM_SEC(rdisc_timer, drp->dr_ts+drp->dr_life);
6457c478bd9Sstevel@tonic-gate 
6467c478bd9Sstevel@tonic-gate 		/*
6477c478bd9Sstevel@tonic-gate 		 * Update preference with possibly changed interface
6487c478bd9Sstevel@tonic-gate 		 * metric.
6497c478bd9Sstevel@tonic-gate 		 */
6507c478bd9Sstevel@tonic-gate 		drp->dr_pref = PREF(drp->dr_recv_pref, ifp);
6517c478bd9Sstevel@tonic-gate 
6527c478bd9Sstevel@tonic-gate 		/*
6537c478bd9Sstevel@tonic-gate 		 * Prefer the current route to prevent thrashing.
6547c478bd9Sstevel@tonic-gate 		 * Prefer shorter lifetimes to speed the detection of
6557c478bd9Sstevel@tonic-gate 		 * bad routers.
6567c478bd9Sstevel@tonic-gate 		 * Avoid sick interfaces.
6577c478bd9Sstevel@tonic-gate 		 */
6587c478bd9Sstevel@tonic-gate 		if (new_drp == NULL ||
6597c478bd9Sstevel@tonic-gate 		    (!((new_st ^ drp->dr_ifp->int_state) & IS_SICK) &&
6607c478bd9Sstevel@tonic-gate 		    (new_pref < drp->dr_pref ||
6617c478bd9Sstevel@tonic-gate 		    (new_pref == drp->dr_pref && (drp == cur_drp ||
6627c478bd9Sstevel@tonic-gate 		    (new_drp != cur_drp &&
6637c478bd9Sstevel@tonic-gate 		    new_drp->dr_life > drp->dr_life))))) ||
6647c478bd9Sstevel@tonic-gate 		    ((new_st & IS_SICK) &&
6657c478bd9Sstevel@tonic-gate 		    !(drp->dr_ifp->int_state & IS_SICK))) {
666*e704a8f2Smeem 			new_drp = drp;
667*e704a8f2Smeem 			new_st = drp->dr_ifp->int_state;
668*e704a8f2Smeem 			new_pref = drp->dr_pref;
6697c478bd9Sstevel@tonic-gate 		}
6707c478bd9Sstevel@tonic-gate 	}
6717c478bd9Sstevel@tonic-gate 
6727c478bd9Sstevel@tonic-gate 	/*
6737c478bd9Sstevel@tonic-gate 	 * switch to a better RDISC advertiser
6747c478bd9Sstevel@tonic-gate 	 */
6757c478bd9Sstevel@tonic-gate 	if ((new_drp != cur_drp) || (rt == NULL))  {
6767c478bd9Sstevel@tonic-gate 		rt = rtget(RIP_DEFAULT, 0);
6777c478bd9Sstevel@tonic-gate 
6787c478bd9Sstevel@tonic-gate 		/*
6797c478bd9Sstevel@tonic-gate 		 * Purge the table of all the default routes that were
6807c478bd9Sstevel@tonic-gate 		 * learnt via RDISC, while keeping an eye the first available
6817c478bd9Sstevel@tonic-gate 		 * slot for the spare entry of new_drp
6827c478bd9Sstevel@tonic-gate 		 */
6837c478bd9Sstevel@tonic-gate 		if (rt != NULL) {
6847c478bd9Sstevel@tonic-gate 			int i;
6857c478bd9Sstevel@tonic-gate 			for (i = 0; i < rt->rt_num_spares; i++)  {
6867c478bd9Sstevel@tonic-gate 				rts = &rt->rt_spares[i];
68709f979dcSsowmini 				if ((rts->rts_gate == 0 ||
68809f979dcSsowmini 				    rts->rts_ifp == &dummy_ifp) &&
68909f979dcSsowmini 				    first_rdisc_slot == 0)
6907c478bd9Sstevel@tonic-gate 					first_rdisc_slot = i;
6917c478bd9Sstevel@tonic-gate 				if (rts->rts_origin == RO_RDISC) {
6927c478bd9Sstevel@tonic-gate 					rts_delete(rt, rts);
6937c478bd9Sstevel@tonic-gate 					if (first_rdisc_slot == 0) {
6947c478bd9Sstevel@tonic-gate 						first_rdisc_slot = i;
6957c478bd9Sstevel@tonic-gate 					}
6967c478bd9Sstevel@tonic-gate 				}
6977c478bd9Sstevel@tonic-gate 			}
6987c478bd9Sstevel@tonic-gate 		}
6997c478bd9Sstevel@tonic-gate 
7007c478bd9Sstevel@tonic-gate 		/* Stop using RDISC routes if they are all bad */
7017c478bd9Sstevel@tonic-gate 		if (new_drp == NULL) {
7027c478bd9Sstevel@tonic-gate 			trace_act("turn off Router Discovery client");
7037c478bd9Sstevel@tonic-gate 			rdisc_ok = _B_FALSE;
7047c478bd9Sstevel@tonic-gate 
7057c478bd9Sstevel@tonic-gate 		} else {
7067c478bd9Sstevel@tonic-gate 			if (cur_drp == NULL) {
7077c478bd9Sstevel@tonic-gate 				trace_act("turn on Router Discovery client"
7087c478bd9Sstevel@tonic-gate 				    " using %s via %s",
7097c478bd9Sstevel@tonic-gate 				    naddr_ntoa(new_drp->dr_gate),
7107c478bd9Sstevel@tonic-gate 				    new_drp->dr_ifp->int_name);
7117c478bd9Sstevel@tonic-gate 				rdisc_ok = _B_TRUE;
7127c478bd9Sstevel@tonic-gate 			}
7137c478bd9Sstevel@tonic-gate 
7147c478bd9Sstevel@tonic-gate 			/* Prepare a spare entry for the new_drp */
7157c478bd9Sstevel@tonic-gate 			(void) memset(&new, 0, sizeof (new));
7167c478bd9Sstevel@tonic-gate 			new.rts_ifp = new_drp->dr_ifp;
7177c478bd9Sstevel@tonic-gate 			new.rts_gate = new_drp->dr_gate;
7187c478bd9Sstevel@tonic-gate 			new.rts_router = new_drp->dr_gate;
7197c478bd9Sstevel@tonic-gate 			new.rts_metric = HOPCNT_INFINITY-1;
7207c478bd9Sstevel@tonic-gate 			new.rts_time = now.tv_sec;
7217c478bd9Sstevel@tonic-gate 			new.rts_origin = RO_RDISC;
7227c478bd9Sstevel@tonic-gate 			/*
7237c478bd9Sstevel@tonic-gate 			 * If there is no existing default route, add it
7247c478bd9Sstevel@tonic-gate 			 * to rts_spare[0].
7257c478bd9Sstevel@tonic-gate 			 */
7267c478bd9Sstevel@tonic-gate 			if (rt == NULL) {
7277c478bd9Sstevel@tonic-gate 				rtadd(RIP_DEFAULT, 0, RS_NOPROPAGATE, &new);
7287c478bd9Sstevel@tonic-gate 			} else {
7297c478bd9Sstevel@tonic-gate 
7307c478bd9Sstevel@tonic-gate 				/*
7317c478bd9Sstevel@tonic-gate 				 * Add the spare entry for the new_drp in
7327c478bd9Sstevel@tonic-gate 				 * the first available slot
7337c478bd9Sstevel@tonic-gate 				 */
7347c478bd9Sstevel@tonic-gate 				trace_act("Switching to "
7357c478bd9Sstevel@tonic-gate 				    "default router with better "
7367c478bd9Sstevel@tonic-gate 				    "preference %s via %s ",
7377c478bd9Sstevel@tonic-gate 				    naddr_ntoa(new_drp->dr_gate),
7387c478bd9Sstevel@tonic-gate 				    new_drp->dr_ifp->int_name);
7397c478bd9Sstevel@tonic-gate 				rt->rt_spares[first_rdisc_slot] = new;
7407c478bd9Sstevel@tonic-gate 				rt = NULL; /* redo rt_spares */
7417c478bd9Sstevel@tonic-gate 			}
7427c478bd9Sstevel@tonic-gate 		}
7437c478bd9Sstevel@tonic-gate 
7447c478bd9Sstevel@tonic-gate 		/*
7457c478bd9Sstevel@tonic-gate 		 * Get ready to redo the entire table. The table should
7467c478bd9Sstevel@tonic-gate 		 * only include :
7477c478bd9Sstevel@tonic-gate 		 * 	a. empty rt_spare slots
7487c478bd9Sstevel@tonic-gate 		 * 	b. default routes learnt via RIP
7497c478bd9Sstevel@tonic-gate 		 * 	c. default route for the latest best RDISC advertiser
7507c478bd9Sstevel@tonic-gate 		 * 	d. default routes of other RDISC advertisers whose
7517c478bd9Sstevel@tonic-gate 		 *	dr_pref == best RDISC advertiser->dr_pref
7527c478bd9Sstevel@tonic-gate 		 */
7537c478bd9Sstevel@tonic-gate 		cur_drp = new_drp;
7547c478bd9Sstevel@tonic-gate 	}
7557c478bd9Sstevel@tonic-gate 
7567c478bd9Sstevel@tonic-gate 	/* Redo the entire spare table (without touching RO_RIP entries) */
7577c478bd9Sstevel@tonic-gate 	if (rdisc_ok && rt == NULL) {
7587c478bd9Sstevel@tonic-gate 		int i;
7597c478bd9Sstevel@tonic-gate 		/*
7607c478bd9Sstevel@tonic-gate 		 * We've either just turned on router discovery,
7617c478bd9Sstevel@tonic-gate 		 * or switched to a router with better preference.
7627c478bd9Sstevel@tonic-gate 		 * Find all other default routers whose
7637c478bd9Sstevel@tonic-gate 		 * pref == cur_drp->dr_pref and add them as spares
7647c478bd9Sstevel@tonic-gate 		 */
7657c478bd9Sstevel@tonic-gate 
7667c478bd9Sstevel@tonic-gate 		rt = rtget(RIP_DEFAULT, 0);
7677c478bd9Sstevel@tonic-gate 
7687c478bd9Sstevel@tonic-gate 		for (drp = drs; drp < &drs[max_ads]; drp++) {
7697c478bd9Sstevel@tonic-gate 			boolean_t dr_done = _B_FALSE;
7707c478bd9Sstevel@tonic-gate 			int slot = -1;
7717c478bd9Sstevel@tonic-gate 
7727c478bd9Sstevel@tonic-gate 			if (drp->dr_ts == 0)
7737c478bd9Sstevel@tonic-gate 				continue;
7747c478bd9Sstevel@tonic-gate 
7757c478bd9Sstevel@tonic-gate 			if (drp->dr_pref != cur_drp->dr_pref &&
7767c478bd9Sstevel@tonic-gate 			    ((drp->dr_flags & DR_CHANGED) == 0))
7777c478bd9Sstevel@tonic-gate 				continue;
7787c478bd9Sstevel@tonic-gate 
7797c478bd9Sstevel@tonic-gate 			/*
7807c478bd9Sstevel@tonic-gate 			 * Either pref matches cur_drp->dr_pref,
7817c478bd9Sstevel@tonic-gate 			 * or something has changed in this drp.
7827c478bd9Sstevel@tonic-gate 			 * In the former case, we may need to add
7837c478bd9Sstevel@tonic-gate 			 * this to rt_spares. In the latter case,
7847c478bd9Sstevel@tonic-gate 			 * if the pref has changed, need to take it
7857c478bd9Sstevel@tonic-gate 			 * out of rt_spares and the kernel.
7867c478bd9Sstevel@tonic-gate 			 *
7877c478bd9Sstevel@tonic-gate 			 * First, find an empty slot in rt_spares
7887c478bd9Sstevel@tonic-gate 			 * in case we have to add this drp to kernel.
7897c478bd9Sstevel@tonic-gate 			 * Also check if it is already there.
7907c478bd9Sstevel@tonic-gate 			 */
7917c478bd9Sstevel@tonic-gate 			for (i = 0; i < rt->rt_num_spares; i++) {
7927c478bd9Sstevel@tonic-gate 				if (rt->rt_spares[i].rts_gate == 0) {
7937c478bd9Sstevel@tonic-gate 					if (slot < 0)
7947c478bd9Sstevel@tonic-gate 						slot = i;
7957c478bd9Sstevel@tonic-gate 					continue;
7967c478bd9Sstevel@tonic-gate 				}
7977c478bd9Sstevel@tonic-gate 				if ((rt->rt_spares[i].rts_gate ==
7987c478bd9Sstevel@tonic-gate 				    drp->dr_gate) &&
7997c478bd9Sstevel@tonic-gate 				    (rt->rt_spares[i].rts_origin ==
8007c478bd9Sstevel@tonic-gate 				    RO_RDISC)) {
8017c478bd9Sstevel@tonic-gate 					/*
8027c478bd9Sstevel@tonic-gate 					 * a spare entry for this RDISC
8037c478bd9Sstevel@tonic-gate 					 * advertiser already exists. We need
8047c478bd9Sstevel@tonic-gate 					 * to check if this entry still belongs
8057c478bd9Sstevel@tonic-gate 					 * in the table
8067c478bd9Sstevel@tonic-gate 					 */
8077c478bd9Sstevel@tonic-gate 					dr_done = _B_TRUE;
8087c478bd9Sstevel@tonic-gate 					break;
8097c478bd9Sstevel@tonic-gate 				}
8107c478bd9Sstevel@tonic-gate 			}
8117c478bd9Sstevel@tonic-gate 
8127c478bd9Sstevel@tonic-gate 			drp->dr_flags &= ~DR_CHANGED;
8137c478bd9Sstevel@tonic-gate 
8147c478bd9Sstevel@tonic-gate 			if (drp->dr_pref != cur_drp->dr_pref) {
8157c478bd9Sstevel@tonic-gate 				if (dr_done) {
8167c478bd9Sstevel@tonic-gate 					/*
8177c478bd9Sstevel@tonic-gate 					 * The rt_spare of this RDISC advertiser
8187c478bd9Sstevel@tonic-gate 					 * needs to be removed as it no longer
8197c478bd9Sstevel@tonic-gate 					 * belongs in the table because its
8207c478bd9Sstevel@tonic-gate 					 * dr_pref is different than the latest
8217c478bd9Sstevel@tonic-gate 					 * RDISC advertiser's->dr_pref
8227c478bd9Sstevel@tonic-gate 					 */
8237c478bd9Sstevel@tonic-gate 					rts_delete(rt, &rt->rt_spares[i]);
8247c478bd9Sstevel@tonic-gate 				}
8257c478bd9Sstevel@tonic-gate 				continue;
8267c478bd9Sstevel@tonic-gate 			}
8277c478bd9Sstevel@tonic-gate 
82809f979dcSsowmini 			if (slot < 0 && !dr_done)  {
8297c478bd9Sstevel@tonic-gate 				ptrsize = (rt->rt_num_spares + SPARE_INC) *
8307c478bd9Sstevel@tonic-gate 				    sizeof (struct rt_spare);
8317c478bd9Sstevel@tonic-gate 				ptr = realloc(rt->rt_spares, ptrsize);
8327c478bd9Sstevel@tonic-gate 				if (ptr != NULL) {
8337c478bd9Sstevel@tonic-gate 					struct rt_spare *tmprts;
8347c478bd9Sstevel@tonic-gate 
8357c478bd9Sstevel@tonic-gate 					rt->rt_spares = ptr;
8367c478bd9Sstevel@tonic-gate 					slot = rt->rt_num_spares;
8377c478bd9Sstevel@tonic-gate 					rts = &rt->rt_spares[rt->rt_num_spares];
8387c478bd9Sstevel@tonic-gate 					(void) memset(rts, 0, (SPARE_INC *
8397c478bd9Sstevel@tonic-gate 					    sizeof (struct rt_spare)));
8407c478bd9Sstevel@tonic-gate 					rt->rt_num_spares += SPARE_INC;
8417c478bd9Sstevel@tonic-gate 					for (tmprts = rts, i = SPARE_INC;
8427c478bd9Sstevel@tonic-gate 					    i != 0; i--, tmprts++)
8437c478bd9Sstevel@tonic-gate 						tmprts->rts_metric =
8447c478bd9Sstevel@tonic-gate 						    HOPCNT_INFINITY;
8457c478bd9Sstevel@tonic-gate 				}
8467c478bd9Sstevel@tonic-gate 			}
8477c478bd9Sstevel@tonic-gate 
8487c478bd9Sstevel@tonic-gate 			if (slot >= 0 && (dr_done != _B_TRUE)) {
8497c478bd9Sstevel@tonic-gate 				(void) memset(&new, 0, sizeof (new));
8507c478bd9Sstevel@tonic-gate 				new.rts_ifp = drp->dr_ifp;
8517c478bd9Sstevel@tonic-gate 				new.rts_gate = drp->dr_gate;
8527c478bd9Sstevel@tonic-gate 				new.rts_router = drp->dr_gate;
8537c478bd9Sstevel@tonic-gate 				new.rts_metric = HOPCNT_INFINITY-1;
8547c478bd9Sstevel@tonic-gate 				new.rts_time = now.tv_sec;
8557c478bd9Sstevel@tonic-gate 				new.rts_origin = RO_RDISC;
8567c478bd9Sstevel@tonic-gate 				rt->rt_spares[slot] = new;
8577c478bd9Sstevel@tonic-gate 				trace_act("spare default %s via %s",
8587c478bd9Sstevel@tonic-gate 				    naddr_ntoa(drp->dr_gate),
8597c478bd9Sstevel@tonic-gate 				    drp->dr_ifp->int_name);
8607c478bd9Sstevel@tonic-gate 			}
8617c478bd9Sstevel@tonic-gate 		}
8627c478bd9Sstevel@tonic-gate 	}
8637c478bd9Sstevel@tonic-gate 
8647c478bd9Sstevel@tonic-gate 	/* turn RIP on or off */
8657c478bd9Sstevel@tonic-gate 	if (!rdisc_ok || rip_interfaces > 1) {
8667c478bd9Sstevel@tonic-gate 		rip_on(0);
8677c478bd9Sstevel@tonic-gate 	} else {
8687c478bd9Sstevel@tonic-gate 		rip_off();
8697c478bd9Sstevel@tonic-gate 	}
8707c478bd9Sstevel@tonic-gate }
8717c478bd9Sstevel@tonic-gate 
8727c478bd9Sstevel@tonic-gate 
8737c478bd9Sstevel@tonic-gate /* Handle a single address in an advertisement */
8747c478bd9Sstevel@tonic-gate static void
parse_ad(uint32_t from,in_addr_t gate,uint32_t pref,ushort_t life,struct interface * ifp)8757c478bd9Sstevel@tonic-gate parse_ad(uint32_t from,
8767c478bd9Sstevel@tonic-gate     in_addr_t gate,
8777c478bd9Sstevel@tonic-gate     uint32_t pref,		/* signed and in network order */
8787c478bd9Sstevel@tonic-gate     ushort_t life,		/* in host byte order */
8797c478bd9Sstevel@tonic-gate     struct interface *ifp)
8807c478bd9Sstevel@tonic-gate {
8817c478bd9Sstevel@tonic-gate 	static struct msg_limit bad_gate;
8827c478bd9Sstevel@tonic-gate 	struct dr *drp, *new_drp;
8837c478bd9Sstevel@tonic-gate 	void *ptr;
8847c478bd9Sstevel@tonic-gate 	size_t ptrsize;
8857c478bd9Sstevel@tonic-gate 
8867c478bd9Sstevel@tonic-gate 	if (gate == RIP_DEFAULT || !check_dst(gate)) {
8877c478bd9Sstevel@tonic-gate 		msglim(&bad_gate, from, "router %s advertising bad gateway %s",
8887c478bd9Sstevel@tonic-gate 		    naddr_ntoa(from), naddr_ntoa(gate));
8897c478bd9Sstevel@tonic-gate 		return;
8907c478bd9Sstevel@tonic-gate 	}
8917c478bd9Sstevel@tonic-gate 
8927c478bd9Sstevel@tonic-gate 	/*
8937c478bd9Sstevel@tonic-gate 	 * ignore pointers to ourself and routes via unreachable networks
8947c478bd9Sstevel@tonic-gate 	 */
8957c478bd9Sstevel@tonic-gate 	if (ifwithaddr(gate, _B_TRUE, _B_FALSE) != 0) {
8967c478bd9Sstevel@tonic-gate 		trace_pkt("    discard Router Discovery Ad pointing at us");
8977c478bd9Sstevel@tonic-gate 		return;
8987c478bd9Sstevel@tonic-gate 	}
8997c478bd9Sstevel@tonic-gate 	if (!on_net(gate, ifp->int_net, ifp->int_mask)) {
9007c478bd9Sstevel@tonic-gate 		trace_pkt("    discard Router Discovery Ad"
9017c478bd9Sstevel@tonic-gate 		    " toward unreachable net");
9027c478bd9Sstevel@tonic-gate 		return;
9037c478bd9Sstevel@tonic-gate 	}
9047c478bd9Sstevel@tonic-gate 	/*
9057c478bd9Sstevel@tonic-gate 	 * Convert preference to an unsigned value
9067c478bd9Sstevel@tonic-gate 	 * and later bias it by the metric of the interface.
9077c478bd9Sstevel@tonic-gate 	 */
9087c478bd9Sstevel@tonic-gate 	pref = UNSIGN_PREF(ntohl(pref));
9097c478bd9Sstevel@tonic-gate 
9107c478bd9Sstevel@tonic-gate 	if (pref == DEF_PREFERENCELEVEL || life < MIN_MAXADVERTISEINTERVAL) {
9117c478bd9Sstevel@tonic-gate 		pref = DEF_PREFERENCELEVEL;
9127c478bd9Sstevel@tonic-gate 		life = 0;
9137c478bd9Sstevel@tonic-gate 	}
9147c478bd9Sstevel@tonic-gate 
9157c478bd9Sstevel@tonic-gate 	for (new_drp = NULL, drp = drs; drp < &drs[max_ads]; drp++) {
9167c478bd9Sstevel@tonic-gate 		/* accept new info for a familiar entry */
9177c478bd9Sstevel@tonic-gate 		if ((drp->dr_gate == gate) && (drp->dr_ifp == ifp)) {
9187c478bd9Sstevel@tonic-gate 			new_drp = drp;
9197c478bd9Sstevel@tonic-gate 			drp->dr_flags |= DR_CHANGED;
9207c478bd9Sstevel@tonic-gate 			break;
9217c478bd9Sstevel@tonic-gate 		}
9227c478bd9Sstevel@tonic-gate 
9237c478bd9Sstevel@tonic-gate 		if (life == 0)
9247c478bd9Sstevel@tonic-gate 			continue;	/* do not worry about dead ads */
9257c478bd9Sstevel@tonic-gate 
9267c478bd9Sstevel@tonic-gate 		if (drp->dr_ts == 0) {
9277c478bd9Sstevel@tonic-gate 			new_drp = drp;	/* use unused entry */
9287c478bd9Sstevel@tonic-gate 
9297c478bd9Sstevel@tonic-gate 		} else if (new_drp == NULL) {
9307c478bd9Sstevel@tonic-gate 			/* look for an entry worse than the new one to reuse. */
9317c478bd9Sstevel@tonic-gate 			if ((!(ifp->int_state & IS_SICK) &&
9327c478bd9Sstevel@tonic-gate 			    (drp->dr_ifp->int_state & IS_SICK)) ||
9337c478bd9Sstevel@tonic-gate 			    (pref > drp->dr_pref &&
9347c478bd9Sstevel@tonic-gate 			    !((ifp->int_state ^ drp->dr_ifp->int_state) &
9357c478bd9Sstevel@tonic-gate 			    IS_SICK)))
9367c478bd9Sstevel@tonic-gate 				new_drp = drp;
9377c478bd9Sstevel@tonic-gate 
9387c478bd9Sstevel@tonic-gate 		} else if (new_drp->dr_ts != 0) {
9397c478bd9Sstevel@tonic-gate 			/* look for the least valuable entry to reuse */
9407c478bd9Sstevel@tonic-gate 			if ((!(new_drp->dr_ifp->int_state & IS_SICK) &&
9417c478bd9Sstevel@tonic-gate 			    (drp->dr_ifp->int_state & IS_SICK)) ||
9427c478bd9Sstevel@tonic-gate 			    (new_drp->dr_pref > drp->dr_pref &&
9437c478bd9Sstevel@tonic-gate 			    !((new_drp->dr_ifp->int_state ^
9447c478bd9Sstevel@tonic-gate 			    drp->dr_ifp->int_state) & IS_SICK)))
9457c478bd9Sstevel@tonic-gate 				new_drp = drp;
9467c478bd9Sstevel@tonic-gate 		}
9477c478bd9Sstevel@tonic-gate 	}
9487c478bd9Sstevel@tonic-gate 
9497c478bd9Sstevel@tonic-gate 	/* if all of the current entries are better, add more drs[] */
9507c478bd9Sstevel@tonic-gate 	if (new_drp == NULL) {
9517c478bd9Sstevel@tonic-gate 		ptrsize = (max_ads + MAX_ADS) * sizeof (struct dr);
9527c478bd9Sstevel@tonic-gate 		ptr = realloc(drs, ptrsize);
9537c478bd9Sstevel@tonic-gate 		if (ptr == NULL)
9547c478bd9Sstevel@tonic-gate 			return;
9557c478bd9Sstevel@tonic-gate 		drs = ptr;
9567c478bd9Sstevel@tonic-gate 		(void) memset(&drs[max_ads], 0, MAX_ADS * sizeof (struct dr));
9577c478bd9Sstevel@tonic-gate 		new_drp = &drs[max_ads];
9587c478bd9Sstevel@tonic-gate 		max_ads += MAX_ADS;
9597c478bd9Sstevel@tonic-gate 	}
9607c478bd9Sstevel@tonic-gate 
9617c478bd9Sstevel@tonic-gate 	/*
9627c478bd9Sstevel@tonic-gate 	 * Pointer copy is safe here because if_del
9637c478bd9Sstevel@tonic-gate 	 * calls if_bad_rdisc first, so a non-NULL df_ifp
9647c478bd9Sstevel@tonic-gate 	 * is always a valid pointer.
9657c478bd9Sstevel@tonic-gate 	 */
9667c478bd9Sstevel@tonic-gate 	new_drp->dr_ifp = ifp;
9677c478bd9Sstevel@tonic-gate 	new_drp->dr_gate = gate;
9687c478bd9Sstevel@tonic-gate 	new_drp->dr_ts = now.tv_sec;
9697c478bd9Sstevel@tonic-gate 	new_drp->dr_life = life;
9707c478bd9Sstevel@tonic-gate 	new_drp->dr_recv_pref = pref;
9717c478bd9Sstevel@tonic-gate 	/* bias functional preference by metric of the interface */
9727c478bd9Sstevel@tonic-gate 	new_drp->dr_pref = PREF(pref, ifp);
9737c478bd9Sstevel@tonic-gate 
9747c478bd9Sstevel@tonic-gate 	/* after hearing a good advertisement, stop asking */
9757c478bd9Sstevel@tonic-gate 	if (!(ifp->int_state & IS_SICK))
9767c478bd9Sstevel@tonic-gate 		ifp->int_rdisc_cnt = MAX_SOLICITATIONS;
9777c478bd9Sstevel@tonic-gate }
9787c478bd9Sstevel@tonic-gate 
9797c478bd9Sstevel@tonic-gate 
9807c478bd9Sstevel@tonic-gate /*
9817c478bd9Sstevel@tonic-gate  * Compute the IP checksum. This assumes the packet is less than 32K long.
9827c478bd9Sstevel@tonic-gate  */
9837c478bd9Sstevel@tonic-gate static uint16_t
in_cksum(uint16_t * p,uint_t len)9847c478bd9Sstevel@tonic-gate in_cksum(uint16_t *p, uint_t len)
9857c478bd9Sstevel@tonic-gate {
9867c478bd9Sstevel@tonic-gate 	uint32_t sum = 0;
9877c478bd9Sstevel@tonic-gate 	int nwords = len >> 1;
9887c478bd9Sstevel@tonic-gate 
9897c478bd9Sstevel@tonic-gate 	while (nwords-- != 0)
9907c478bd9Sstevel@tonic-gate 		sum += *p++;
9917c478bd9Sstevel@tonic-gate 
9927c478bd9Sstevel@tonic-gate 	if (len & 1)
9937c478bd9Sstevel@tonic-gate 		sum += *(uchar_t *)p;
9947c478bd9Sstevel@tonic-gate 
9957c478bd9Sstevel@tonic-gate 	/* end-around-carry */
9967c478bd9Sstevel@tonic-gate 	sum = (sum >> 16) + (sum & 0xffff);
9977c478bd9Sstevel@tonic-gate 	sum += (sum >> 16);
9987c478bd9Sstevel@tonic-gate 	return (~sum);
9997c478bd9Sstevel@tonic-gate }
10007c478bd9Sstevel@tonic-gate 
10017c478bd9Sstevel@tonic-gate 
10027c478bd9Sstevel@tonic-gate /* Send a router discovery advertisement or solicitation ICMP packet. */
10037c478bd9Sstevel@tonic-gate static void
send_rdisc(union ad_u * p,uint_t p_size,struct interface * ifp,in_addr_t dst,dstaddr_t type)10047c478bd9Sstevel@tonic-gate send_rdisc(union ad_u *p,
10057c478bd9Sstevel@tonic-gate     uint_t p_size,
10067c478bd9Sstevel@tonic-gate     struct interface *ifp,
10077c478bd9Sstevel@tonic-gate     in_addr_t dst,		/* 0 or unicast destination */
10087c478bd9Sstevel@tonic-gate     dstaddr_t type)
10097c478bd9Sstevel@tonic-gate {
10107c478bd9Sstevel@tonic-gate 	struct sockaddr_in sin;
10117c478bd9Sstevel@tonic-gate 	int flags = 0;
10127c478bd9Sstevel@tonic-gate 	const char *msg;
1013*e704a8f2Smeem 	int ifindex = 0;
10147c478bd9Sstevel@tonic-gate 	struct in_addr addr;
10157c478bd9Sstevel@tonic-gate 
10167c478bd9Sstevel@tonic-gate 	/*
10177c478bd9Sstevel@tonic-gate 	 * Don't send Rdisc packets on duplicate interfaces, we
10187c478bd9Sstevel@tonic-gate 	 * don't want to generate duplicate packets.
10197c478bd9Sstevel@tonic-gate 	 */
10207c478bd9Sstevel@tonic-gate 	if (ifp->int_state & IS_DUP)
10217c478bd9Sstevel@tonic-gate 		return;
10227c478bd9Sstevel@tonic-gate 
10237c478bd9Sstevel@tonic-gate 	(void) memset(&sin, 0, sizeof (sin));
10247c478bd9Sstevel@tonic-gate 	sin.sin_addr.s_addr = dst;
10257c478bd9Sstevel@tonic-gate 	sin.sin_family = AF_INET;
10267c478bd9Sstevel@tonic-gate 
10277c478bd9Sstevel@tonic-gate 	switch (type) {
10287c478bd9Sstevel@tonic-gate 	case unicast:				/* unicast */
10297c478bd9Sstevel@tonic-gate 	default:
10307c478bd9Sstevel@tonic-gate 		flags = MSG_DONTROUTE;
10317c478bd9Sstevel@tonic-gate 		msg = "Send";
10327c478bd9Sstevel@tonic-gate 		break;
10337c478bd9Sstevel@tonic-gate 
10347c478bd9Sstevel@tonic-gate 	case bcast:				/* broadcast */
10357c478bd9Sstevel@tonic-gate 		if (ifp->int_if_flags & IFF_POINTOPOINT) {
10367c478bd9Sstevel@tonic-gate 			msg = "Send pt-to-pt";
10377c478bd9Sstevel@tonic-gate 			if (ifp->int_dstaddr == 0)
10387c478bd9Sstevel@tonic-gate 				sin.sin_addr.s_addr = htonl(INADDR_BROADCAST);
10397c478bd9Sstevel@tonic-gate 			else
10407c478bd9Sstevel@tonic-gate 				sin.sin_addr.s_addr = ifp->int_dstaddr;
10417c478bd9Sstevel@tonic-gate 		} else {
10427c478bd9Sstevel@tonic-gate 			msg = "Send broadcast";
10437c478bd9Sstevel@tonic-gate 			sin.sin_addr.s_addr = ifp->int_brdaddr;
10447c478bd9Sstevel@tonic-gate 		}
10457c478bd9Sstevel@tonic-gate 		break;
10467c478bd9Sstevel@tonic-gate 
10477c478bd9Sstevel@tonic-gate 	case mcast:				/* multicast */
10487c478bd9Sstevel@tonic-gate 		msg = "Send multicast";
10497c478bd9Sstevel@tonic-gate 		break;
10507c478bd9Sstevel@tonic-gate 	}
10517c478bd9Sstevel@tonic-gate 
10527c478bd9Sstevel@tonic-gate 	if (rdisc_sock < 0)
10537c478bd9Sstevel@tonic-gate 		get_rdisc_sock();
10547c478bd9Sstevel@tonic-gate 
1055*e704a8f2Smeem 	/* select the right interface. */
1056*e704a8f2Smeem 	ifindex = (type != mcast && ifp->int_phys != NULL) ?
1057*e704a8f2Smeem 	    ifp->int_phys->phyi_index : 0;
1058*e704a8f2Smeem 
10597c478bd9Sstevel@tonic-gate 	if (rdisc_sock_interface != ifp) {
10607c478bd9Sstevel@tonic-gate 		/*
10617c478bd9Sstevel@tonic-gate 		 * For multicast, we have to choose the source
10627c478bd9Sstevel@tonic-gate 		 * address.  This is either the local address
10637c478bd9Sstevel@tonic-gate 		 * (non-point-to-point) or the remote address.
10647c478bd9Sstevel@tonic-gate 		 */
10657c478bd9Sstevel@tonic-gate 		addr.s_addr = (ifp->int_if_flags & IFF_POINTOPOINT) ?
10667c478bd9Sstevel@tonic-gate 		    ifp->int_dstaddr : ifp->int_addr;
10677c478bd9Sstevel@tonic-gate 		if (type == mcast &&
10687c478bd9Sstevel@tonic-gate 		    setsockopt(rdisc_sock, IPPROTO_IP, IP_MULTICAST_IF, &addr,
1069*e704a8f2Smeem 		    sizeof (addr)) == -1) {
10707c478bd9Sstevel@tonic-gate 			LOGERR("setsockopt(rdisc_sock, IP_MULTICAST_IF)");
10717c478bd9Sstevel@tonic-gate 			return;
10727c478bd9Sstevel@tonic-gate 		}
10737c478bd9Sstevel@tonic-gate 		rdisc_sock_interface = ifp;
10747c478bd9Sstevel@tonic-gate 	}
10757c478bd9Sstevel@tonic-gate 
10767c478bd9Sstevel@tonic-gate 	trace_rdisc(msg, ifp->int_addr, sin.sin_addr.s_addr, ifp, p, p_size);
10777c478bd9Sstevel@tonic-gate 
1078*e704a8f2Smeem 	if (0 > sendtoif(rdisc_sock, p, p_size, flags, &sin, ifindex)) {
10797c478bd9Sstevel@tonic-gate 		if (!(ifp->int_state & IS_BROKE))
10807c478bd9Sstevel@tonic-gate 			writelog(LOG_WARNING, "sendto(%s%s%s): %s",
10817c478bd9Sstevel@tonic-gate 			    ifp->int_name, ", ",
10827c478bd9Sstevel@tonic-gate 			    inet_ntoa(sin.sin_addr),
10837c478bd9Sstevel@tonic-gate 			    rip_strerror(errno));
10847c478bd9Sstevel@tonic-gate 		if (ifp != NULL)
10857c478bd9Sstevel@tonic-gate 			if_sick(ifp, _B_FALSE);
10867c478bd9Sstevel@tonic-gate 	}
10877c478bd9Sstevel@tonic-gate }
10887c478bd9Sstevel@tonic-gate 
10897c478bd9Sstevel@tonic-gate 
10907c478bd9Sstevel@tonic-gate /* Send an advertisement */
10917c478bd9Sstevel@tonic-gate static void
send_adv(struct interface * ifp,in_addr_t dst,dstaddr_t type)10927c478bd9Sstevel@tonic-gate send_adv(struct interface *ifp,
10937c478bd9Sstevel@tonic-gate     in_addr_t dst,
10947c478bd9Sstevel@tonic-gate     dstaddr_t type)
10957c478bd9Sstevel@tonic-gate {
10967c478bd9Sstevel@tonic-gate 	union ad_u u;
10977c478bd9Sstevel@tonic-gate 
10987c478bd9Sstevel@tonic-gate 	if ((ifp->int_state & (IS_SUPPRESS_RDISC|IS_FLUSH_RDISC)) ==
10997c478bd9Sstevel@tonic-gate 	    IS_SUPPRESS_RDISC)
11007c478bd9Sstevel@tonic-gate 		return;
11017c478bd9Sstevel@tonic-gate 
11027c478bd9Sstevel@tonic-gate 	(void) memset(&u, 0, sizeof (u.ad));
11037c478bd9Sstevel@tonic-gate 
11047c478bd9Sstevel@tonic-gate 	u.ad.icmp_type = ICMP_ROUTERADVERT;
11057c478bd9Sstevel@tonic-gate 	u.ad.icmp_code = ICMP_ROUTERADVERT_COMMON;
11067c478bd9Sstevel@tonic-gate 	u.ad.icmp_ad_num = 1;
11077c478bd9Sstevel@tonic-gate 	u.ad.icmp_ad_asize = sizeof (u.ad.icmp_ad_info[0])/4;
11087c478bd9Sstevel@tonic-gate 
11097c478bd9Sstevel@tonic-gate 	u.ad.icmp_ad_life = (stopint || !should_supply(ifp) ||
11107c478bd9Sstevel@tonic-gate 	    (ifp->int_state & IS_SUPPRESS_RDISC)) ? 0 :
11117c478bd9Sstevel@tonic-gate 	    htons(ifp->int_rdisc_int*3);
11127c478bd9Sstevel@tonic-gate 
11137c478bd9Sstevel@tonic-gate 	/* Send the configured preference as a network byte order value */
11147c478bd9Sstevel@tonic-gate 	u.ad.icmp_ad_info[0].icmp_ad_pref = htonl(ifp->int_rdisc_pref);
11157c478bd9Sstevel@tonic-gate 
11167c478bd9Sstevel@tonic-gate 	u.ad.icmp_ad_info[0].icmp_ad_addr = ifp->int_addr;
11177c478bd9Sstevel@tonic-gate 
11187c478bd9Sstevel@tonic-gate 	u.ad.icmp_cksum = in_cksum((uint16_t *)&u.ad, sizeof (u.ad));
11197c478bd9Sstevel@tonic-gate 
11207c478bd9Sstevel@tonic-gate 	send_rdisc(&u, sizeof (u.ad), ifp, dst, type);
11217c478bd9Sstevel@tonic-gate 
11227c478bd9Sstevel@tonic-gate 	if (ifp->int_state & IS_SUPPRESS_RDISC)
11237c478bd9Sstevel@tonic-gate 		ifp->int_state &= ~IS_FLUSH_RDISC;
11247c478bd9Sstevel@tonic-gate }
11257c478bd9Sstevel@tonic-gate 
11267c478bd9Sstevel@tonic-gate 
11277c478bd9Sstevel@tonic-gate /* Advertise as a default router by way of router discovery. */
11287c478bd9Sstevel@tonic-gate void
rdisc_adv(boolean_t forceadv)11297c478bd9Sstevel@tonic-gate rdisc_adv(boolean_t forceadv)
11307c478bd9Sstevel@tonic-gate {
11317c478bd9Sstevel@tonic-gate 	struct interface *ifp;
11327c478bd9Sstevel@tonic-gate 
11337c478bd9Sstevel@tonic-gate 	if (!forceadv && !should_supply(NULL))
11347c478bd9Sstevel@tonic-gate 		return;
11357c478bd9Sstevel@tonic-gate 
11367c478bd9Sstevel@tonic-gate 	rdisc_timer.tv_sec = now.tv_sec + NEVER;
11377c478bd9Sstevel@tonic-gate 
11387c478bd9Sstevel@tonic-gate 	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
11397c478bd9Sstevel@tonic-gate 		if ((ifp->int_state & (IS_NO_ADV_OUT | IS_BROKE)) ||
11407c478bd9Sstevel@tonic-gate 		    (!forceadv && !IS_IFF_ROUTING(ifp->int_if_flags)))
11417c478bd9Sstevel@tonic-gate 			continue;
11427c478bd9Sstevel@tonic-gate 
11437c478bd9Sstevel@tonic-gate 		/* skip interfaces we shouldn't use */
11447c478bd9Sstevel@tonic-gate 		if (IS_IFF_QUIET(ifp->int_if_flags))
11457c478bd9Sstevel@tonic-gate 			continue;
11467c478bd9Sstevel@tonic-gate 
11477c478bd9Sstevel@tonic-gate 		if (!timercmp(&ifp->int_rdisc_timer, &now, > /* cstyle */) ||
11487c478bd9Sstevel@tonic-gate 		    stopint != 0 || forceadv) {
11497c478bd9Sstevel@tonic-gate 			send_adv(ifp, htonl(INADDR_