xref: /onnv-gate/usr/src/cmd/cmd-inet/usr.sbin/in.routed/rdisc.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
3*0Sstevel@tonic-gate  * Use is subject to license terms.
4*0Sstevel@tonic-gate  *
5*0Sstevel@tonic-gate  * Copyright (c) 1995
6*0Sstevel@tonic-gate  *	The Regents of the University of California.  All rights reserved.
7*0Sstevel@tonic-gate  *
8*0Sstevel@tonic-gate  * Redistribution and use in source and binary forms, with or without
9*0Sstevel@tonic-gate  * modification, are permitted provided that the following conditions
10*0Sstevel@tonic-gate  * are met:
11*0Sstevel@tonic-gate  * 1. Redistributions of source code must retain the above copyright
12*0Sstevel@tonic-gate  *    notice, this list of conditions and the following disclaimer.
13*0Sstevel@tonic-gate  * 2. Redistributions in binary form must reproduce the above copyright
14*0Sstevel@tonic-gate  *    notice, this list of conditions and the following disclaimer in the
15*0Sstevel@tonic-gate  *    documentation and/or other materials provided with the distribution.
16*0Sstevel@tonic-gate  * 3. All advertising materials mentioning features or use of this software
17*0Sstevel@tonic-gate  *    must display the following acknowledgment:
18*0Sstevel@tonic-gate  *	This product includes software developed by the University of
19*0Sstevel@tonic-gate  *	California, Berkeley and its contributors.
20*0Sstevel@tonic-gate  * 4. Neither the name of the University nor the names of its contributors
21*0Sstevel@tonic-gate  *    may be used to endorse or promote products derived from this software
22*0Sstevel@tonic-gate  *    without specific prior written permission.
23*0Sstevel@tonic-gate  *
24*0Sstevel@tonic-gate  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25*0Sstevel@tonic-gate  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26*0Sstevel@tonic-gate  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27*0Sstevel@tonic-gate  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28*0Sstevel@tonic-gate  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29*0Sstevel@tonic-gate  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30*0Sstevel@tonic-gate  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31*0Sstevel@tonic-gate  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32*0Sstevel@tonic-gate  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33*0Sstevel@tonic-gate  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34*0Sstevel@tonic-gate  * SUCH DAMAGE.
35*0Sstevel@tonic-gate  *
36*0Sstevel@tonic-gate  * $FreeBSD: src/sbin/routed/rdisc.c,v 1.8 2000/08/11 08:24:38 sheldonh Exp $
37*0Sstevel@tonic-gate  */
38*0Sstevel@tonic-gate 
39*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
40*0Sstevel@tonic-gate 
41*0Sstevel@tonic-gate #include "defs.h"
42*0Sstevel@tonic-gate #include <netinet/in_systm.h>
43*0Sstevel@tonic-gate #include <netinet/ip.h>
44*0Sstevel@tonic-gate #include <netinet/ip_icmp.h>
45*0Sstevel@tonic-gate 
46*0Sstevel@tonic-gate /*
47*0Sstevel@tonic-gate  * The size of the control buffer passed to recvmsg() used to receive
48*0Sstevel@tonic-gate  * ancillary data.
49*0Sstevel@tonic-gate  */
50*0Sstevel@tonic-gate #define	CONTROL_BUFSIZE	1024
51*0Sstevel@tonic-gate 
52*0Sstevel@tonic-gate /* router advertisement ICMP packet */
53*0Sstevel@tonic-gate struct icmp_ad {
54*0Sstevel@tonic-gate 	uint8_t    icmp_type;		/* type of message */
55*0Sstevel@tonic-gate 	uint8_t    icmp_code;		/* type sub code */
56*0Sstevel@tonic-gate 	uint16_t   icmp_cksum;		/* ones complement cksum of struct */
57*0Sstevel@tonic-gate 	uint8_t    icmp_ad_num;	/* # of following router addresses */
58*0Sstevel@tonic-gate 	uint8_t    icmp_ad_asize;	/* 2--words in each advertisement */
59*0Sstevel@tonic-gate 	uint16_t   icmp_ad_life;	/* seconds of validity */
60*0Sstevel@tonic-gate 	struct icmp_ad_info {
61*0Sstevel@tonic-gate 	    in_addr_t  icmp_ad_addr;
62*0Sstevel@tonic-gate 	    uint32_t  icmp_ad_pref;
63*0Sstevel@tonic-gate 	} icmp_ad_info[1];
64*0Sstevel@tonic-gate };
65*0Sstevel@tonic-gate 
66*0Sstevel@tonic-gate /* router solicitation ICMP packet */
67*0Sstevel@tonic-gate struct icmp_so {
68*0Sstevel@tonic-gate 	uint8_t    icmp_type;		/* type of message */
69*0Sstevel@tonic-gate 	uint8_t    icmp_code;		/* type sub code */
70*0Sstevel@tonic-gate 	uint16_t   icmp_cksum;		/* ones complement cksum of struct */
71*0Sstevel@tonic-gate 	uint32_t   icmp_so_rsvd;
72*0Sstevel@tonic-gate };
73*0Sstevel@tonic-gate 
74*0Sstevel@tonic-gate union ad_u {
75*0Sstevel@tonic-gate 	struct icmp icmp;
76*0Sstevel@tonic-gate 	struct icmp_ad ad;
77*0Sstevel@tonic-gate 	struct icmp_so so;
78*0Sstevel@tonic-gate };
79*0Sstevel@tonic-gate 
80*0Sstevel@tonic-gate 
81*0Sstevel@tonic-gate int	rdisc_sock = -1;		/* router-discovery raw socket */
82*0Sstevel@tonic-gate static struct interface *rdisc_sock_interface; /* current rdisc interface */
83*0Sstevel@tonic-gate 
84*0Sstevel@tonic-gate struct timeval rdisc_timer;
85*0Sstevel@tonic-gate boolean_t rdisc_ok;				/* using solicited route */
86*0Sstevel@tonic-gate 
87*0Sstevel@tonic-gate #define	MAX_ADS		16
88*0Sstevel@tonic-gate int max_ads; /* at least one per interface */
89*0Sstevel@tonic-gate /* accumulated advertisements */
90*0Sstevel@tonic-gate static struct dr *cur_drp, *drs;
91*0Sstevel@tonic-gate 
92*0Sstevel@tonic-gate /*
93*0Sstevel@tonic-gate  * adjust unsigned preference by interface metric,
94*0Sstevel@tonic-gate  * without driving it to infinity
95*0Sstevel@tonic-gate  */
96*0Sstevel@tonic-gate #define	PREF(p, ifp) ((p) <= (uint32_t)(ifp)->int_metric ? ((p) != 0 ? 1 : 0) \
97*0Sstevel@tonic-gate 	: (p) - ((ifp)->int_metric))
98*0Sstevel@tonic-gate 
99*0Sstevel@tonic-gate static void rdisc_sort(void);
100*0Sstevel@tonic-gate 
101*0Sstevel@tonic-gate typedef enum { unicast, bcast, mcast } dstaddr_t;
102*0Sstevel@tonic-gate 
103*0Sstevel@tonic-gate /* dump an ICMP Router Discovery Advertisement Message */
104*0Sstevel@tonic-gate static void
105*0Sstevel@tonic-gate trace_rdisc(const char	*act,
106*0Sstevel@tonic-gate     uint32_t from,
107*0Sstevel@tonic-gate     uint32_t to,
108*0Sstevel@tonic-gate     struct interface *ifp,
109*0Sstevel@tonic-gate     union ad_u	*p,
110*0Sstevel@tonic-gate     uint_t len)
111*0Sstevel@tonic-gate {
112*0Sstevel@tonic-gate 	int i;
113*0Sstevel@tonic-gate 	n_long *wp, *lim;
114*0Sstevel@tonic-gate 
115*0Sstevel@tonic-gate 
116*0Sstevel@tonic-gate 	if (!TRACEPACKETS || ftrace == 0)
117*0Sstevel@tonic-gate 		return;
118*0Sstevel@tonic-gate 
119*0Sstevel@tonic-gate 	lastlog();
120*0Sstevel@tonic-gate 
121*0Sstevel@tonic-gate 	if (p->icmp.icmp_type == ICMP_ROUTERADVERT) {
122*0Sstevel@tonic-gate 		(void) fprintf(ftrace, "%s Router Ad"
123*0Sstevel@tonic-gate 		    " from %s to %s via %s life=%d\n",
124*0Sstevel@tonic-gate 		    act, naddr_ntoa(from), naddr_ntoa(to),
125*0Sstevel@tonic-gate 		    ifp ? ifp->int_name : "?",
126*0Sstevel@tonic-gate 		    ntohs(p->ad.icmp_ad_life));
127*0Sstevel@tonic-gate 		if (!TRACECONTENTS)
128*0Sstevel@tonic-gate 			return;
129*0Sstevel@tonic-gate 
130*0Sstevel@tonic-gate 		wp = &p->ad.icmp_ad_info[0].icmp_ad_addr;
131*0Sstevel@tonic-gate 		lim = &wp[(len - sizeof (p->ad)) / sizeof (*wp)];
132*0Sstevel@tonic-gate 		for (i = 0; i < p->ad.icmp_ad_num && wp <= lim; i++) {
133*0Sstevel@tonic-gate 			(void) fprintf(ftrace, "\t%s preference=%ld",
134*0Sstevel@tonic-gate 			    naddr_ntoa(wp[0]), (long)ntohl(wp[1]));
135*0Sstevel@tonic-gate 			wp += p->ad.icmp_ad_asize;
136*0Sstevel@tonic-gate 		}
137*0Sstevel@tonic-gate 		(void) fputc('\n', ftrace);
138*0Sstevel@tonic-gate 
139*0Sstevel@tonic-gate 	} else {
140*0Sstevel@tonic-gate 		trace_act("%s Router Solic. from %s to %s via %s rsvd=%#x",
141*0Sstevel@tonic-gate 		    act, naddr_ntoa(from), naddr_ntoa(to),
142*0Sstevel@tonic-gate 		    ifp ? ifp->int_name : "?",
143*0Sstevel@tonic-gate 		    ntohl(p->so.icmp_so_rsvd));
144*0Sstevel@tonic-gate 	}
145*0Sstevel@tonic-gate }
146*0Sstevel@tonic-gate 
147*0Sstevel@tonic-gate /*
148*0Sstevel@tonic-gate  * Prepare Router Discovery socket.
149*0Sstevel@tonic-gate  */
150*0Sstevel@tonic-gate static void
151*0Sstevel@tonic-gate get_rdisc_sock(void)
152*0Sstevel@tonic-gate {
153*0Sstevel@tonic-gate 	int on = 1;
154*0Sstevel@tonic-gate 	unsigned char ttl = 1;
155*0Sstevel@tonic-gate 
156*0Sstevel@tonic-gate 	if (rdisc_sock < 0) {
157*0Sstevel@tonic-gate 		max_ads = MAX_ADS;
158*0Sstevel@tonic-gate 		drs = rtmalloc(max_ads * sizeof (struct dr), "get_rdisc_sock");
159*0Sstevel@tonic-gate 		(void) memset(drs, 0, max_ads * sizeof (struct dr));
160*0Sstevel@tonic-gate 		rdisc_sock = socket(PF_INET, SOCK_RAW, IPPROTO_ICMP);
161*0Sstevel@tonic-gate 		if (rdisc_sock < 0)
162*0Sstevel@tonic-gate 			BADERR(_B_TRUE, "rdisc_sock = socket()");
163*0Sstevel@tonic-gate 		fix_sock(rdisc_sock, "rdisc_sock");
164*0Sstevel@tonic-gate 
165*0Sstevel@tonic-gate 		if (setsockopt(rdisc_sock, IPPROTO_IP, IP_RECVIF, &on,
166*0Sstevel@tonic-gate 		    sizeof (on)))
167*0Sstevel@tonic-gate 			BADERR(_B_FALSE, "setsockopt(IP_RECVIF)");
168*0Sstevel@tonic-gate 
169*0Sstevel@tonic-gate 		if (setsockopt(rdisc_sock, IPPROTO_IP, IP_MULTICAST_TTL,
170*0Sstevel@tonic-gate 		    &ttl, sizeof (ttl)) < 0)
171*0Sstevel@tonic-gate 			DBGERR(_B_TRUE,
172*0Sstevel@tonic-gate 			    "rdisc_sock setsockopt(IP_MULTICAST_TTL)");
173*0Sstevel@tonic-gate 
174*0Sstevel@tonic-gate 		fix_select();
175*0Sstevel@tonic-gate 	}
176*0Sstevel@tonic-gate }
177*0Sstevel@tonic-gate 
178*0Sstevel@tonic-gate 
179*0Sstevel@tonic-gate /*
180*0Sstevel@tonic-gate  * Pick multicast group for router-discovery socket
181*0Sstevel@tonic-gate  */
182*0Sstevel@tonic-gate void
183*0Sstevel@tonic-gate set_rdisc_mg(struct interface *ifp,
184*0Sstevel@tonic-gate     int on)	/* 0=turn it off */
185*0Sstevel@tonic-gate {
186*0Sstevel@tonic-gate 	struct ip_mreq m;
187*0Sstevel@tonic-gate 	boolean_t dosupply;
188*0Sstevel@tonic-gate 
189*0Sstevel@tonic-gate 	if (rdisc_sock < 0) {
190*0Sstevel@tonic-gate 		/*
191*0Sstevel@tonic-gate 		 * Create the raw socket so that we can hear at least
192*0Sstevel@tonic-gate 		 * broadcast router discovery packets.
193*0Sstevel@tonic-gate 		 */
194*0Sstevel@tonic-gate 		if ((ifp->int_state & IS_NO_RDISC) == IS_NO_RDISC ||
195*0Sstevel@tonic-gate 		    !on)
196*0Sstevel@tonic-gate 			return;
197*0Sstevel@tonic-gate 		get_rdisc_sock();
198*0Sstevel@tonic-gate 	}
199*0Sstevel@tonic-gate 
200*0Sstevel@tonic-gate 	if (!(ifp->int_if_flags & IFF_MULTICAST)) {
201*0Sstevel@tonic-gate 		/* Can't multicast, so no groups could have been joined. */
202*0Sstevel@tonic-gate 		ifp->int_state &= ~(IS_ALL_HOSTS | IS_ALL_ROUTERS);
203*0Sstevel@tonic-gate 		return;
204*0Sstevel@tonic-gate 	}
205*0Sstevel@tonic-gate 
206*0Sstevel@tonic-gate 	dosupply = should_supply(ifp);
207*0Sstevel@tonic-gate 
208*0Sstevel@tonic-gate 	(void) memset(&m, 0, sizeof (m));
209*0Sstevel@tonic-gate 	m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT) &&
210*0Sstevel@tonic-gate 	    (ifp->int_dstaddr != 0) ? ifp->int_dstaddr : ifp->int_addr);
211*0Sstevel@tonic-gate 	if (dosupply || (ifp->int_state & IS_NO_ADV_IN) || !on) {
212*0Sstevel@tonic-gate 		/* stop listening to advertisements */
213*0Sstevel@tonic-gate 		if (ifp->int_state & IS_ALL_HOSTS) {
214*0Sstevel@tonic-gate 			m.imr_multiaddr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
215*0Sstevel@tonic-gate 			if (setsockopt(rdisc_sock, IPPROTO_IP,
216*0Sstevel@tonic-gate 			    IP_DROP_MEMBERSHIP, &m, sizeof (m)) < 0 &&
217*0Sstevel@tonic-gate 			    errno != EADDRNOTAVAIL && errno != ENOENT)
218*0Sstevel@tonic-gate 				LOGERR("IP_DROP_MEMBERSHIP ALLHOSTS");
219*0Sstevel@tonic-gate 			ifp->int_state &= ~IS_ALL_HOSTS;
220*0Sstevel@tonic-gate 		}
221*0Sstevel@tonic-gate 
222*0Sstevel@tonic-gate 	} else if (!(ifp->int_state & IS_ALL_HOSTS)) {
223*0Sstevel@tonic-gate 		/* start listening to advertisements */
224*0Sstevel@tonic-gate 		m.imr_multiaddr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
225*0Sstevel@tonic-gate 		if (setsockopt(rdisc_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
226*0Sstevel@tonic-gate 		    &m, sizeof (m)) < 0) {
227*0Sstevel@tonic-gate 			LOGERR("IP_ADD_MEMBERSHIP ALLHOSTS");
228*0Sstevel@tonic-gate 		} else {
229*0Sstevel@tonic-gate 			ifp->int_state |= IS_ALL_HOSTS;
230*0Sstevel@tonic-gate 		}
231*0Sstevel@tonic-gate 	}
232*0Sstevel@tonic-gate 
233*0Sstevel@tonic-gate 	if (!dosupply || (ifp->int_state & IS_NO_ADV_OUT) ||
234*0Sstevel@tonic-gate 	    !IS_IFF_ROUTING(ifp->int_if_flags) || !on) {
235*0Sstevel@tonic-gate 		/* stop listening to solicitations */
236*0Sstevel@tonic-gate 		if (ifp->int_state & IS_ALL_ROUTERS) {
237*0Sstevel@tonic-gate 			m.imr_multiaddr.s_addr = htonl(INADDR_ALLRTRS_GROUP);
238*0Sstevel@tonic-gate 			if (setsockopt(rdisc_sock, IPPROTO_IP,
239*0Sstevel@tonic-gate 			    IP_DROP_MEMBERSHIP, &m, sizeof (m)) < 0 &&
240*0Sstevel@tonic-gate 			    errno != EADDRNOTAVAIL && errno != ENOENT)
241*0Sstevel@tonic-gate 				LOGERR("IP_DROP_MEMBERSHIP ALLROUTERS");
242*0Sstevel@tonic-gate 			ifp->int_state &= ~IS_ALL_ROUTERS;
243*0Sstevel@tonic-gate 		}
244*0Sstevel@tonic-gate 
245*0Sstevel@tonic-gate 	} else if (!(ifp->int_state & IS_ALL_ROUTERS)) {
246*0Sstevel@tonic-gate 		/* start hearing solicitations */
247*0Sstevel@tonic-gate 		m.imr_multiaddr.s_addr = htonl(INADDR_ALLRTRS_GROUP);
248*0Sstevel@tonic-gate 		if (setsockopt(rdisc_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
249*0Sstevel@tonic-gate 		    &m, sizeof (m)) < 0) {
250*0Sstevel@tonic-gate 			LOGERR("IP_ADD_MEMBERSHIP ALLROUTERS");
251*0Sstevel@tonic-gate 		} else {
252*0Sstevel@tonic-gate 			ifp->int_state |= IS_ALL_ROUTERS;
253*0Sstevel@tonic-gate 		}
254*0Sstevel@tonic-gate 	}
255*0Sstevel@tonic-gate }
256*0Sstevel@tonic-gate 
257*0Sstevel@tonic-gate 
258*0Sstevel@tonic-gate /*
259*0Sstevel@tonic-gate  * start or stop supplying routes to other systems.
260*0Sstevel@tonic-gate  */
261*0Sstevel@tonic-gate void
262*0Sstevel@tonic-gate set_supplier(void)
263*0Sstevel@tonic-gate {
264*0Sstevel@tonic-gate 	struct interface *ifp;
265*0Sstevel@tonic-gate 	struct dr *drp;
266*0Sstevel@tonic-gate 	static boolean_t supplystate = _B_FALSE;
267*0Sstevel@tonic-gate 
268*0Sstevel@tonic-gate 	if (supplystate == (fwd_interfaces > 1))
269*0Sstevel@tonic-gate 		return;
270*0Sstevel@tonic-gate 	supplystate = fwd_interfaces > 1;
271*0Sstevel@tonic-gate 
272*0Sstevel@tonic-gate 	trace_act("%d forwarding interfaces present; becoming %ssupplier",
273*0Sstevel@tonic-gate 	    fwd_interfaces, supplystate ? "" : "non-");
274*0Sstevel@tonic-gate 
275*0Sstevel@tonic-gate 	if (supplystate) {
276*0Sstevel@tonic-gate 		/* Forget discovered routes. */
277*0Sstevel@tonic-gate 		for (drp = drs; drp < &drs[max_ads]; drp++) {
278*0Sstevel@tonic-gate 			drp->dr_recv_pref = DEF_PREFERENCELEVEL;
279*0Sstevel@tonic-gate 			drp->dr_life = 0;
280*0Sstevel@tonic-gate 		}
281*0Sstevel@tonic-gate 		rdisc_age(0);
282*0Sstevel@tonic-gate 
283*0Sstevel@tonic-gate 		/*
284*0Sstevel@tonic-gate 		 * Do not start advertising until we have heard some
285*0Sstevel@tonic-gate 		 * RIP routes.
286*0Sstevel@tonic-gate 		 */
287*0Sstevel@tonic-gate 		LIM_SEC(rdisc_timer, now.tv_sec+MIN_WAITTIME);
288*0Sstevel@tonic-gate 
289*0Sstevel@tonic-gate 		/* get rid of any redirects */
290*0Sstevel@tonic-gate 		del_redirects(0, 0);
291*0Sstevel@tonic-gate 	} else {
292*0Sstevel@tonic-gate 		/*
293*0Sstevel@tonic-gate 		 * Flush out all those advertisements we had sent by sending
294*0Sstevel@tonic-gate 		 * one with lifetime=0.
295*0Sstevel@tonic-gate 		 */
296*0Sstevel@tonic-gate 		rdisc_adv(_B_TRUE);
297*0Sstevel@tonic-gate 	}
298*0Sstevel@tonic-gate 
299*0Sstevel@tonic-gate 	/*
300*0Sstevel@tonic-gate 	 * Switch router discovery multicast groups from soliciting
301*0Sstevel@tonic-gate 	 * to advertising or back.
302*0Sstevel@tonic-gate 	 */
303*0Sstevel@tonic-gate 	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
304*0Sstevel@tonic-gate 		if (ifp->int_state & IS_BROKE)
305*0Sstevel@tonic-gate 			continue;
306*0Sstevel@tonic-gate 		ifp->int_rdisc_cnt = 0;
307*0Sstevel@tonic-gate 		ifp->int_rdisc_timer.tv_usec = rdisc_timer.tv_usec;
308*0Sstevel@tonic-gate 		ifp->int_rdisc_timer.tv_sec = now.tv_sec+MIN_WAITTIME;
309*0Sstevel@tonic-gate 		set_rdisc_mg(ifp, 1);
310*0Sstevel@tonic-gate 	}
311*0Sstevel@tonic-gate }
312*0Sstevel@tonic-gate 
313*0Sstevel@tonic-gate 
314*0Sstevel@tonic-gate /*
315*0Sstevel@tonic-gate  * Age discovered routes and find the best one
316*0Sstevel@tonic-gate  */
317*0Sstevel@tonic-gate void
318*0Sstevel@tonic-gate rdisc_age(in_addr_t bad_gate)
319*0Sstevel@tonic-gate {
320*0Sstevel@tonic-gate 	time_t sec;
321*0Sstevel@tonic-gate 	struct dr *drp;
322*0Sstevel@tonic-gate 	struct rt_spare new;
323*0Sstevel@tonic-gate 	struct rt_entry *rt;
324*0Sstevel@tonic-gate 
325*0Sstevel@tonic-gate 	/*
326*0Sstevel@tonic-gate 	 * If we are being told about a bad router,
327*0Sstevel@tonic-gate 	 * then age the discovered default route, and if there is
328*0Sstevel@tonic-gate 	 * no alternative, solicit a replacement.
329*0Sstevel@tonic-gate 	 */
330*0Sstevel@tonic-gate 	if (bad_gate != 0) {
331*0Sstevel@tonic-gate 		/*
332*0Sstevel@tonic-gate 		 * Look for the bad discovered default route.
333*0Sstevel@tonic-gate 		 * Age it and note its interface.
334*0Sstevel@tonic-gate 		 */
335*0Sstevel@tonic-gate 		for (drp = drs; drp < &drs[max_ads]; drp++) {
336*0Sstevel@tonic-gate 			if (drp->dr_ts == 0)
337*0Sstevel@tonic-gate 				continue;
338*0Sstevel@tonic-gate 
339*0Sstevel@tonic-gate 			/*
340*0Sstevel@tonic-gate 			 * When we find the bad router, age the route
341*0Sstevel@tonic-gate 			 * to at most SUPPLY_INTERVAL.
342*0Sstevel@tonic-gate 			 * This is contrary to RFC 1256, but defends against
343*0Sstevel@tonic-gate 			 * black holes.
344*0Sstevel@tonic-gate 			 */
345*0Sstevel@tonic-gate 			if (drp->dr_gate == bad_gate) {
346*0Sstevel@tonic-gate 				sec = (now.tv_sec - drp->dr_life +
347*0Sstevel@tonic-gate 				    SUPPLY_INTERVAL);
348*0Sstevel@tonic-gate 				if (drp->dr_ts > sec) {
349*0Sstevel@tonic-gate 					trace_act("age 0.0.0.0 --> %s via %s",
350*0Sstevel@tonic-gate 					    naddr_ntoa(drp->dr_gate),
351*0Sstevel@tonic-gate 					    drp->dr_ifp->int_name);
352*0Sstevel@tonic-gate 					drp->dr_ts = sec;
353*0Sstevel@tonic-gate 				}
354*0Sstevel@tonic-gate 				break;
355*0Sstevel@tonic-gate 			}
356*0Sstevel@tonic-gate 		}
357*0Sstevel@tonic-gate 	} else if (should_supply(NULL)) {
358*0Sstevel@tonic-gate 		/*
359*0Sstevel@tonic-gate 		 * If switching from client to server, get rid of old
360*0Sstevel@tonic-gate 		 * default routes.
361*0Sstevel@tonic-gate 		 */
362*0Sstevel@tonic-gate 		if (cur_drp != NULL) {
363*0Sstevel@tonic-gate 			rt = rtget(RIP_DEFAULT, 0);
364*0Sstevel@tonic-gate 			/*
365*0Sstevel@tonic-gate 			 * If there is a current default router, and the
366*0Sstevel@tonic-gate 			 * there is no rt_spare entry, create one
367*0Sstevel@tonic-gate 			 * for cur_drp to prevent segmentation fault
368*0Sstevel@tonic-gate 			 * at rdisc_sort.
369*0Sstevel@tonic-gate 			 */
370*0Sstevel@tonic-gate 			if (rt == NULL) {
371*0Sstevel@tonic-gate 				(void) memset(&new, 0, sizeof (new));
372*0Sstevel@tonic-gate 				new.rts_ifp = cur_drp->dr_ifp;
373*0Sstevel@tonic-gate 				new.rts_gate = cur_drp->dr_gate;
374*0Sstevel@tonic-gate 				new.rts_router = cur_drp->dr_gate;
375*0Sstevel@tonic-gate 				new.rts_metric = HOPCNT_INFINITY-1;
376*0Sstevel@tonic-gate 				new.rts_time = now.tv_sec;
377*0Sstevel@tonic-gate 				new.rts_origin = RO_RDISC;
378*0Sstevel@tonic-gate 				rtadd(RIP_DEFAULT, 0, RS_NOPROPAGATE, &new);
379*0Sstevel@tonic-gate 			}
380*0Sstevel@tonic-gate 
381*0Sstevel@tonic-gate 			rdisc_sort();
382*0Sstevel@tonic-gate 		}
383*0Sstevel@tonic-gate 		rdisc_adv(_B_FALSE);
384*0Sstevel@tonic-gate 	}
385*0Sstevel@tonic-gate 
386*0Sstevel@tonic-gate 	rdisc_sol();
387*0Sstevel@tonic-gate 	if (cur_drp != NULL) {
388*0Sstevel@tonic-gate 		rt = rtget(RIP_DEFAULT, 0);
389*0Sstevel@tonic-gate 		if (rt == NULL) {
390*0Sstevel@tonic-gate 			(void) memset(&new, 0, sizeof (new));
391*0Sstevel@tonic-gate 			new.rts_ifp = cur_drp->dr_ifp;
392*0Sstevel@tonic-gate 			new.rts_gate = cur_drp->dr_gate;
393*0Sstevel@tonic-gate 			new.rts_router = cur_drp->dr_gate;
394*0Sstevel@tonic-gate 			new.rts_metric = HOPCNT_INFINITY-1;
395*0Sstevel@tonic-gate 			new.rts_time = now.tv_sec;
396*0Sstevel@tonic-gate 			new.rts_origin = RO_RDISC;
397*0Sstevel@tonic-gate 			rtadd(RIP_DEFAULT, 0, RS_NOPROPAGATE, &new);
398*0Sstevel@tonic-gate 		}
399*0Sstevel@tonic-gate 	}
400*0Sstevel@tonic-gate 	rdisc_sort();
401*0Sstevel@tonic-gate 
402*0Sstevel@tonic-gate 	/*
403*0Sstevel@tonic-gate 	 * Delete old redirected routes to keep the kernel table small,
404*0Sstevel@tonic-gate 	 * and to prevent black holes.  Check that the kernel table
405*0Sstevel@tonic-gate 	 * matches the daemon table (i.e. has the default route).
406*0Sstevel@tonic-gate 	 * But only if RIP is not running and we are not dealing with
407*0Sstevel@tonic-gate 	 * a bad gateway, since otherwise age() will be called.
408*0Sstevel@tonic-gate 	 */
409*0Sstevel@tonic-gate 	if (rip_sock < 0 && bad_gate == 0)
410*0Sstevel@tonic-gate 		age(0);
411*0Sstevel@tonic-gate }
412*0Sstevel@tonic-gate 
413*0Sstevel@tonic-gate 
414*0Sstevel@tonic-gate /*
415*0Sstevel@tonic-gate  * Zap all routes discovered via an interface that has gone bad
416*0Sstevel@tonic-gate  * This should only be called when !(ifp->int_state & IS_DUP)
417*0Sstevel@tonic-gate  * This is called by if_del and if_bad, and the interface pointer
418*0Sstevel@tonic-gate  * might not be valid after this.
419*0Sstevel@tonic-gate  */
420*0Sstevel@tonic-gate void
421*0Sstevel@tonic-gate if_bad_rdisc(struct interface *ifp)
422*0Sstevel@tonic-gate {
423*0Sstevel@tonic-gate 	struct dr *drp;
424*0Sstevel@tonic-gate 
425*0Sstevel@tonic-gate 	for (drp = drs; drp < &drs[max_ads]; drp++) {
426*0Sstevel@tonic-gate 		if (drp->dr_ifp != ifp)
427*0Sstevel@tonic-gate 			continue;
428*0Sstevel@tonic-gate 		(void) memset(drp, 0, sizeof (*drp));
429*0Sstevel@tonic-gate 	}
430*0Sstevel@tonic-gate 
431*0Sstevel@tonic-gate 	/* make a note to re-solicit, turn RIP on or off, etc. */
432*0Sstevel@tonic-gate 	rdisc_timer.tv_sec = 0;
433*0Sstevel@tonic-gate }
434*0Sstevel@tonic-gate 
435*0Sstevel@tonic-gate /*
436*0Sstevel@tonic-gate  * Rewire all routes discovered via an interface that has gone bad
437*0Sstevel@tonic-gate  * This is only called by if_del.
438*0Sstevel@tonic-gate  */
439*0Sstevel@tonic-gate void
440*0Sstevel@tonic-gate if_rewire_rdisc(struct interface *oldifp, struct interface *newifp)
441*0Sstevel@tonic-gate {
442*0Sstevel@tonic-gate 	struct dr *drp;
443*0Sstevel@tonic-gate 
444*0Sstevel@tonic-gate 	for (drp = drs; drp < &drs[max_ads]; drp++) {
445*0Sstevel@tonic-gate 		if (drp->dr_ifp != oldifp)
446*0Sstevel@tonic-gate 			continue;
447*0Sstevel@tonic-gate 		drp->dr_ifp = newifp;
448*0Sstevel@tonic-gate 		drp->dr_pref += (newifp->int_metric - oldifp->int_metric);
449*0Sstevel@tonic-gate 		drp->dr_flags |= DR_CHANGED;
450*0Sstevel@tonic-gate 	}
451*0Sstevel@tonic-gate 
452*0Sstevel@tonic-gate 	/* make a note to re-solicit, turn RIP on or off, etc. */
453*0Sstevel@tonic-gate 	rdisc_timer.tv_sec = 0;
454*0Sstevel@tonic-gate }
455*0Sstevel@tonic-gate 
456*0Sstevel@tonic-gate /*
457*0Sstevel@tonic-gate  * Mark an interface ok for router discovering.
458*0Sstevel@tonic-gate  * This is called by if_ok and ifinit.
459*0Sstevel@tonic-gate  */
460*0Sstevel@tonic-gate void
461*0Sstevel@tonic-gate if_ok_rdisc(struct interface *ifp)
462*0Sstevel@tonic-gate {
463*0Sstevel@tonic-gate 	set_rdisc_mg(ifp, 1);
464*0Sstevel@tonic-gate 
465*0Sstevel@tonic-gate 	ifp->int_rdisc_cnt = 0;
466*0Sstevel@tonic-gate 	ifp->int_rdisc_timer.tv_sec = now.tv_sec +
467*0Sstevel@tonic-gate 	    ((ifp->int_state & IS_NO_ADV_OUT) ?
468*0Sstevel@tonic-gate 	    MAX_SOLICITATION_DELAY : MIN_WAITTIME);
469*0Sstevel@tonic-gate 	if (timercmp(&rdisc_timer, &ifp->int_rdisc_timer, > /* cstyle */))
470*0Sstevel@tonic-gate 		rdisc_timer = ifp->int_rdisc_timer;
471*0Sstevel@tonic-gate }
472*0Sstevel@tonic-gate 
473*0Sstevel@tonic-gate /*
474*0Sstevel@tonic-gate  * Get rid of a dead discovered router
475*0Sstevel@tonic-gate  */
476*0Sstevel@tonic-gate static void
477*0Sstevel@tonic-gate del_rdisc(struct dr *drp)
478*0Sstevel@tonic-gate {
479*0Sstevel@tonic-gate 	struct interface *ifp;
480*0Sstevel@tonic-gate 	uint32_t gate;
481*0Sstevel@tonic-gate 	int i;
482*0Sstevel@tonic-gate 	struct rt_entry *rt;
483*0Sstevel@tonic-gate 	struct rt_spare *rts = NULL;
484*0Sstevel@tonic-gate 
485*0Sstevel@tonic-gate 	del_redirects(gate = drp->dr_gate, 0);
486*0Sstevel@tonic-gate 	drp->dr_ts = 0;
487*0Sstevel@tonic-gate 	drp->dr_life = 0;
488*0Sstevel@tonic-gate 
489*0Sstevel@tonic-gate 	rt = rtget(RIP_DEFAULT, 0);
490*0Sstevel@tonic-gate 	if (rt == NULL) {
491*0Sstevel@tonic-gate 		trace_act("could not find default route in table");
492*0Sstevel@tonic-gate 	} else {
493*0Sstevel@tonic-gate 		for (i = 0; i < rt->rt_num_spares; i++) {
494*0Sstevel@tonic-gate 			if ((rt->rt_spares[i].rts_gate == drp->dr_gate) &&
495*0Sstevel@tonic-gate 			    (rt->rt_spares[i].rts_origin == RO_RDISC)) {
496*0Sstevel@tonic-gate 				rts = &rt->rt_spares[i];
497*0Sstevel@tonic-gate 				break;
498*0Sstevel@tonic-gate 			}
499*0Sstevel@tonic-gate 		}
500*0Sstevel@tonic-gate 		if (rts != NULL)
501*0Sstevel@tonic-gate 			rts_delete(rt, rts);
502*0Sstevel@tonic-gate 		else
503*0Sstevel@tonic-gate 			trace_act("could not find default route "
504*0Sstevel@tonic-gate 			    "through %s in table", naddr_ntoa(drp->dr_gate));
505*0Sstevel@tonic-gate 	}
506*0Sstevel@tonic-gate 
507*0Sstevel@tonic-gate 	/* Count the other discovered routers on the interface.  */
508*0Sstevel@tonic-gate 	i = 0;
509*0Sstevel@tonic-gate 	ifp = drp->dr_ifp;
510*0Sstevel@tonic-gate 	for (drp = drs; drp < &drs[max_ads]; drp++) {
511*0Sstevel@tonic-gate 		if (drp->dr_ts != 0 && drp->dr_ifp == ifp)
512*0Sstevel@tonic-gate 			i++;
513*0Sstevel@tonic-gate 	}
514*0Sstevel@tonic-gate 
515*0Sstevel@tonic-gate 	/*
516*0Sstevel@tonic-gate 	 * If that was the last good discovered router on the interface,
517*0Sstevel@tonic-gate 	 * then solicit a new one.
518*0Sstevel@tonic-gate 	 * This is contrary to RFC 1256, but defends against black holes.
519*0Sstevel@tonic-gate 	 */
520*0Sstevel@tonic-gate 	if (i != 0) {
521*0Sstevel@tonic-gate 		trace_act("discovered router %s via %s"
522*0Sstevel@tonic-gate 		    " is bad--have %d remaining",
523*0Sstevel@tonic-gate 		    naddr_ntoa(gate), ifp->int_name, i);
524*0Sstevel@tonic-gate 	} else if (ifp->int_rdisc_cnt >= MAX_SOLICITATIONS) {
525*0Sstevel@tonic-gate 		trace_act("last discovered router %s via %s"
526*0Sstevel@tonic-gate 		    " is bad--re-solicit",
527*0Sstevel@tonic-gate 		    naddr_ntoa(gate), ifp->int_name);
528*0Sstevel@tonic-gate 		ifp->int_rdisc_cnt = 0;
529*0Sstevel@tonic-gate 		ifp->int_rdisc_timer.tv_sec = 0;
530*0Sstevel@tonic-gate 		rdisc_sol();
531*0Sstevel@tonic-gate 	} else {
532*0Sstevel@tonic-gate 		trace_act("last discovered router %s via %s"
533*0Sstevel@tonic-gate 		    " is bad--wait to solicit",
534*0Sstevel@tonic-gate 		    naddr_ntoa(gate), ifp->int_name);
535*0Sstevel@tonic-gate 	}
536*0Sstevel@tonic-gate }
537*0Sstevel@tonic-gate 
538*0Sstevel@tonic-gate 
539*0Sstevel@tonic-gate /* Find the best discovered route, and discard stale routers. */
540*0Sstevel@tonic-gate static void
541*0Sstevel@tonic-gate rdisc_sort(void)
542*0Sstevel@tonic-gate {
543*0Sstevel@tonic-gate 	struct dr *drp, *new_drp;
544*0Sstevel@tonic-gate 	struct rt_entry *rt;
545*0Sstevel@tonic-gate 	struct rt_spare new, *rts;
546*0Sstevel@tonic-gate 	struct interface *ifp;
547*0Sstevel@tonic-gate 	uint_t new_st = 0;
548*0Sstevel@tonic-gate 	uint32_t new_pref = DEF_PREFERENCELEVEL;
549*0Sstevel@tonic-gate 	int first_rdisc_slot = 0;
550*0Sstevel@tonic-gate 	int j;
551*0Sstevel@tonic-gate 	boolean_t spares_avail;
552*0Sstevel@tonic-gate 	void *ptr;
553*0Sstevel@tonic-gate 	size_t ptrsize;
554*0Sstevel@tonic-gate 
555*0Sstevel@tonic-gate 	rt = rtget(RIP_DEFAULT, 0);
556*0Sstevel@tonic-gate 
557*0Sstevel@tonic-gate 	/*
558*0Sstevel@tonic-gate 	 * If all the rt_spare entries are taken up with with default routes
559*0Sstevel@tonic-gate 	 * learnt from RIP (ie rts_origin = RO_RIP), bail out.
560*0Sstevel@tonic-gate 	 * NOTE:
561*0Sstevel@tonic-gate 	 *	We *always* prefer default routes learned via RIP
562*0Sstevel@tonic-gate 	 *	(ie RO_RIP) over those learnt via RDISC (ie RO_RDISC).
563*0Sstevel@tonic-gate 	 *	The rdisc machinery should not modify, replace or
564*0Sstevel@tonic-gate 	 *	remove any existing default routes with RO_RIP set.
565*0Sstevel@tonic-gate 	 */
566*0Sstevel@tonic-gate 	if (rt != NULL) {
567*0Sstevel@tonic-gate 		spares_avail = _B_FALSE;
568*0Sstevel@tonic-gate 		for (j = 0; j < rt->rt_num_spares; j++)  {
569*0Sstevel@tonic-gate 			rts = &rt->rt_spares[j];
570*0Sstevel@tonic-gate 			if (rts->rts_gate == 0 || rts->rts_origin != RO_RIP) {
571*0Sstevel@tonic-gate 				spares_avail = _B_TRUE;
572*0Sstevel@tonic-gate 				break;
573*0Sstevel@tonic-gate 			}
574*0Sstevel@tonic-gate 		}
575*0Sstevel@tonic-gate 		if (!spares_avail) {
576*0Sstevel@tonic-gate 			ptrsize = (rt->rt_num_spares + SPARE_INC) *
577*0Sstevel@tonic-gate 			    sizeof (struct rt_spare);
578*0Sstevel@tonic-gate 			ptr = realloc(rt->rt_spares, ptrsize);
579*0Sstevel@tonic-gate 			if (ptr != NULL) {
580*0Sstevel@tonic-gate 				struct rt_spare *tmprts;
581*0Sstevel@tonic-gate 
582*0Sstevel@tonic-gate 				rt->rt_spares = ptr;
583*0Sstevel@tonic-gate 				rts = &rt->rt_spares[rt->rt_num_spares];
584*0Sstevel@tonic-gate 				(void) memset(rts, 0,
585*0Sstevel@tonic-gate 				    (SPARE_INC * sizeof (struct rt_spare)));
586*0Sstevel@tonic-gate 				rt->rt_num_spares += SPARE_INC;
587*0Sstevel@tonic-gate 				for (tmprts = rts, j = SPARE_INC;
588*0Sstevel@tonic-gate 				    j != 0; j--, tmprts++)
589*0Sstevel@tonic-gate 					tmprts->rts_metric = HOPCNT_INFINITY;
590*0Sstevel@tonic-gate 				spares_avail = _B_TRUE;
591*0Sstevel@tonic-gate 			} else {
592*0Sstevel@tonic-gate 				return;
593*0Sstevel@tonic-gate 			}
594*0Sstevel@tonic-gate 		}
595*0Sstevel@tonic-gate 	}
596*0Sstevel@tonic-gate 	/* Find the best RDISC advertiser */
597*0Sstevel@tonic-gate 	rt = NULL;
598*0Sstevel@tonic-gate 	new_drp = NULL;
599*0Sstevel@tonic-gate 	for (drp = drs; drp < &drs[max_ads]; drp++) {
600*0Sstevel@tonic-gate 		if (drp->dr_ts == 0)
601*0Sstevel@tonic-gate 			continue;
602*0Sstevel@tonic-gate 		ifp = drp->dr_ifp;
603*0Sstevel@tonic-gate 
604*0Sstevel@tonic-gate 		/* Get rid of expired discovered routers. */
605*0Sstevel@tonic-gate 		if (drp->dr_ts + drp->dr_life <= now.tv_sec) {
606*0Sstevel@tonic-gate 			del_rdisc(drp);
607*0Sstevel@tonic-gate 			continue;
608*0Sstevel@tonic-gate 		}
609*0Sstevel@tonic-gate 
610*0Sstevel@tonic-gate 		LIM_SEC(rdisc_timer, drp->dr_ts+drp->dr_life);
611*0Sstevel@tonic-gate 
612*0Sstevel@tonic-gate 		/*
613*0Sstevel@tonic-gate 		 * Update preference with possibly changed interface
614*0Sstevel@tonic-gate 		 * metric.
615*0Sstevel@tonic-gate 		 */
616*0Sstevel@tonic-gate 		drp->dr_pref = PREF(drp->dr_recv_pref, ifp);
617*0Sstevel@tonic-gate 
618*0Sstevel@tonic-gate 		/*
619*0Sstevel@tonic-gate 		 * Prefer the current route to prevent thrashing.
620*0Sstevel@tonic-gate 		 * Prefer shorter lifetimes to speed the detection of
621*0Sstevel@tonic-gate 		 * bad routers.
622*0Sstevel@tonic-gate 		 * Avoid sick interfaces.
623*0Sstevel@tonic-gate 		 */
624*0Sstevel@tonic-gate 		if (new_drp == NULL ||
625*0Sstevel@tonic-gate 		    (!((new_st ^ drp->dr_ifp->int_state) & IS_SICK) &&
626*0Sstevel@tonic-gate 		    (new_pref < drp->dr_pref ||
627*0Sstevel@tonic-gate 		    (new_pref == drp->dr_pref && (drp == cur_drp ||
628*0Sstevel@tonic-gate 		    (new_drp != cur_drp &&
629*0Sstevel@tonic-gate 		    new_drp->dr_life > drp->dr_life))))) ||
630*0Sstevel@tonic-gate 		    ((new_st & IS_SICK) &&
631*0Sstevel@tonic-gate 		    !(drp->dr_ifp->int_state & IS_SICK))) {
632*0Sstevel@tonic-gate 			    new_drp = drp;
633*0Sstevel@tonic-gate 			    new_st = drp->dr_ifp->int_state;
634*0Sstevel@tonic-gate 			    new_pref = drp->dr_pref;
635*0Sstevel@tonic-gate 		}
636*0Sstevel@tonic-gate 	}
637*0Sstevel@tonic-gate 
638*0Sstevel@tonic-gate 	/*
639*0Sstevel@tonic-gate 	 * switch to a better RDISC advertiser
640*0Sstevel@tonic-gate 	 */
641*0Sstevel@tonic-gate 	if ((new_drp != cur_drp) || (rt == NULL))  {
642*0Sstevel@tonic-gate 		rt = rtget(RIP_DEFAULT, 0);
643*0Sstevel@tonic-gate 
644*0Sstevel@tonic-gate 		/*
645*0Sstevel@tonic-gate 		 * Purge the table of all the default routes that were
646*0Sstevel@tonic-gate 		 * learnt via RDISC, while keeping an eye the first available
647*0Sstevel@tonic-gate 		 * slot for the spare entry of new_drp
648*0Sstevel@tonic-gate 		 */
649*0Sstevel@tonic-gate 		if (rt != NULL) {
650*0Sstevel@tonic-gate 			int i;
651*0Sstevel@tonic-gate 			for (i = 0; i < rt->rt_num_spares; i++)  {
652*0Sstevel@tonic-gate 				rts = &rt->rt_spares[i];
653*0Sstevel@tonic-gate 				if (rts->rts_gate == 0 && first_rdisc_slot == 0)
654*0Sstevel@tonic-gate 					first_rdisc_slot = i;
655*0Sstevel@tonic-gate 				if (rts->rts_origin == RO_RDISC) {
656*0Sstevel@tonic-gate 					rts_delete(rt, rts);
657*0Sstevel@tonic-gate 					if (first_rdisc_slot == 0) {
658*0Sstevel@tonic-gate 						first_rdisc_slot = i;
659*0Sstevel@tonic-gate 					}
660*0Sstevel@tonic-gate 				}
661*0Sstevel@tonic-gate 			}
662*0Sstevel@tonic-gate 		}
663*0Sstevel@tonic-gate 
664*0Sstevel@tonic-gate 		/* Stop using RDISC routes if they are all bad */
665*0Sstevel@tonic-gate 		if (new_drp == NULL) {
666*0Sstevel@tonic-gate 			trace_act("turn off Router Discovery client");
667*0Sstevel@tonic-gate 			rdisc_ok = _B_FALSE;
668*0Sstevel@tonic-gate 
669*0Sstevel@tonic-gate 		} else {
670*0Sstevel@tonic-gate 			if (cur_drp == NULL) {
671*0Sstevel@tonic-gate 				trace_act("turn on Router Discovery client"
672*0Sstevel@tonic-gate 				    " using %s via %s",
673*0Sstevel@tonic-gate 				    naddr_ntoa(new_drp->dr_gate),
674*0Sstevel@tonic-gate 				    new_drp->dr_ifp->int_name);
675*0Sstevel@tonic-gate 				rdisc_ok = _B_TRUE;
676*0Sstevel@tonic-gate 			}
677*0Sstevel@tonic-gate 
678*0Sstevel@tonic-gate 			/* Prepare a spare entry for the new_drp */
679*0Sstevel@tonic-gate 			(void) memset(&new, 0, sizeof (new));
680*0Sstevel@tonic-gate 			new.rts_ifp = new_drp->dr_ifp;
681*0Sstevel@tonic-gate 			new.rts_gate = new_drp->dr_gate;
682*0Sstevel@tonic-gate 			new.rts_router = new_drp->dr_gate;
683*0Sstevel@tonic-gate 			new.rts_metric = HOPCNT_INFINITY-1;
684*0Sstevel@tonic-gate 			new.rts_time = now.tv_sec;
685*0Sstevel@tonic-gate 			new.rts_origin = RO_RDISC;
686*0Sstevel@tonic-gate 			/*
687*0Sstevel@tonic-gate 			 * If there is no existing default route, add it
688*0Sstevel@tonic-gate 			 * to rts_spare[0].
689*0Sstevel@tonic-gate 			 */
690*0Sstevel@tonic-gate 			if (rt == NULL) {
691*0Sstevel@tonic-gate 				rtadd(RIP_DEFAULT, 0, RS_NOPROPAGATE, &new);
692*0Sstevel@tonic-gate 			} else {
693*0Sstevel@tonic-gate 
694*0Sstevel@tonic-gate 				/*
695*0Sstevel@tonic-gate 				 * Add the spare entry for the new_drp in
696*0Sstevel@tonic-gate 				 * the first available slot
697*0Sstevel@tonic-gate 				 */
698*0Sstevel@tonic-gate 				trace_act("Switching to "
699*0Sstevel@tonic-gate 				    "default router with better "
700*0Sstevel@tonic-gate 				    "preference %s via %s ",
701*0Sstevel@tonic-gate 				    naddr_ntoa(new_drp->dr_gate),
702*0Sstevel@tonic-gate 				    new_drp->dr_ifp->int_name);
703*0Sstevel@tonic-gate 				rt->rt_spares[first_rdisc_slot] = new;
704*0Sstevel@tonic-gate 				rt = NULL; /* redo rt_spares */
705*0Sstevel@tonic-gate 			}
706*0Sstevel@tonic-gate 		}
707*0Sstevel@tonic-gate 
708*0Sstevel@tonic-gate 		/*
709*0Sstevel@tonic-gate 		 * Get ready to redo the entire table. The table should
710*0Sstevel@tonic-gate 		 * only include :
711*0Sstevel@tonic-gate 		 * 	a. empty rt_spare slots
712*0Sstevel@tonic-gate 		 * 	b. default routes learnt via RIP
713*0Sstevel@tonic-gate 		 * 	c. default route for the latest best RDISC advertiser
714*0Sstevel@tonic-gate 		 * 	d. default routes of other RDISC advertisers whose
715*0Sstevel@tonic-gate 		 *	dr_pref == best RDISC advertiser->dr_pref
716*0Sstevel@tonic-gate 		 */
717*0Sstevel@tonic-gate 		cur_drp = new_drp;
718*0Sstevel@tonic-gate 	}
719*0Sstevel@tonic-gate 
720*0Sstevel@tonic-gate 	/* Redo the entire spare table (without touching RO_RIP entries) */
721*0Sstevel@tonic-gate 	if (rdisc_ok && rt == NULL) {
722*0Sstevel@tonic-gate 		int i;
723*0Sstevel@tonic-gate 		/*
724*0Sstevel@tonic-gate 		 * We've either just turned on router discovery,
725*0Sstevel@tonic-gate 		 * or switched to a router with better preference.
726*0Sstevel@tonic-gate 		 * Find all other default routers whose
727*0Sstevel@tonic-gate 		 * pref == cur_drp->dr_pref and add them as spares
728*0Sstevel@tonic-gate 		 */
729*0Sstevel@tonic-gate 
730*0Sstevel@tonic-gate 		rt = rtget(RIP_DEFAULT, 0);
731*0Sstevel@tonic-gate 
732*0Sstevel@tonic-gate 		for (drp = drs; drp < &drs[max_ads]; drp++) {
733*0Sstevel@tonic-gate 			boolean_t dr_done = _B_FALSE;
734*0Sstevel@tonic-gate 			int slot = -1;
735*0Sstevel@tonic-gate 
736*0Sstevel@tonic-gate 			if (drp->dr_ts == 0)
737*0Sstevel@tonic-gate 				continue;
738*0Sstevel@tonic-gate 
739*0Sstevel@tonic-gate 			if (drp->dr_pref != cur_drp->dr_pref &&
740*0Sstevel@tonic-gate 			    ((drp->dr_flags & DR_CHANGED) == 0))
741*0Sstevel@tonic-gate 				continue;
742*0Sstevel@tonic-gate 
743*0Sstevel@tonic-gate 			/*
744*0Sstevel@tonic-gate 			 * Either pref matches cur_drp->dr_pref,
745*0Sstevel@tonic-gate 			 * or something has changed in this drp.
746*0Sstevel@tonic-gate 			 * In the former case, we may need to add
747*0Sstevel@tonic-gate 			 * this to rt_spares. In the latter case,
748*0Sstevel@tonic-gate 			 * if the pref has changed, need to take it
749*0Sstevel@tonic-gate 			 * out of rt_spares and the kernel.
750*0Sstevel@tonic-gate 			 *
751*0Sstevel@tonic-gate 			 * First, find an empty slot in rt_spares
752*0Sstevel@tonic-gate 			 * in case we have to add this drp to kernel.
753*0Sstevel@tonic-gate 			 * Also check if it is already there.
754*0Sstevel@tonic-gate 			 */
755*0Sstevel@tonic-gate 			for (i = 0; i < rt->rt_num_spares; i++) {
756*0Sstevel@tonic-gate 				if (rt->rt_spares[i].rts_gate == 0) {
757*0Sstevel@tonic-gate 					if (slot < 0)
758*0Sstevel@tonic-gate 						slot = i;
759*0Sstevel@tonic-gate 					continue;
760*0Sstevel@tonic-gate 				}
761*0Sstevel@tonic-gate 				if ((rt->rt_spares[i].rts_gate ==
762*0Sstevel@tonic-gate 				    drp->dr_gate) &&
763*0Sstevel@tonic-gate 				    (rt->rt_spares[i].rts_origin ==
764*0Sstevel@tonic-gate 				    RO_RDISC)) {
765*0Sstevel@tonic-gate 					/*
766*0Sstevel@tonic-gate 					 * a spare entry for this RDISC
767*0Sstevel@tonic-gate 					 * advertiser already exists. We need
768*0Sstevel@tonic-gate 					 * to check if this entry still belongs
769*0Sstevel@tonic-gate 					 * in the table
770*0Sstevel@tonic-gate 					 */
771*0Sstevel@tonic-gate 					dr_done = _B_TRUE;
772*0Sstevel@tonic-gate 					break;
773*0Sstevel@tonic-gate 				}
774*0Sstevel@tonic-gate 			}
775*0Sstevel@tonic-gate 
776*0Sstevel@tonic-gate 			drp->dr_flags &= ~DR_CHANGED;
777*0Sstevel@tonic-gate 
778*0Sstevel@tonic-gate 			if (drp->dr_pref != cur_drp->dr_pref) {
779*0Sstevel@tonic-gate 				if (dr_done) {
780*0Sstevel@tonic-gate 					/*
781*0Sstevel@tonic-gate 					 * The rt_spare of this RDISC advertiser
782*0Sstevel@tonic-gate 					 * needs to be removed as it no longer
783*0Sstevel@tonic-gate 					 * belongs in the table because its
784*0Sstevel@tonic-gate 					 * dr_pref is different than the latest
785*0Sstevel@tonic-gate 					 * RDISC advertiser's->dr_pref
786*0Sstevel@tonic-gate 					 */
787*0Sstevel@tonic-gate 					rts_delete(rt, &rt->rt_spares[i]);
788*0Sstevel@tonic-gate 				}
789*0Sstevel@tonic-gate 				continue;
790*0Sstevel@tonic-gate 			}
791*0Sstevel@tonic-gate 
792*0Sstevel@tonic-gate 			if (slot < 0)  {
793*0Sstevel@tonic-gate 				ptrsize = (rt->rt_num_spares + SPARE_INC) *
794*0Sstevel@tonic-gate 				    sizeof (struct rt_spare);
795*0Sstevel@tonic-gate 				ptr = realloc(rt->rt_spares, ptrsize);
796*0Sstevel@tonic-gate 				if (ptr != NULL) {
797*0Sstevel@tonic-gate 					struct rt_spare *tmprts;
798*0Sstevel@tonic-gate 
799*0Sstevel@tonic-gate 					rt->rt_spares = ptr;
800*0Sstevel@tonic-gate 					slot = rt->rt_num_spares;
801*0Sstevel@tonic-gate 					rts = &rt->rt_spares[rt->rt_num_spares];
802*0Sstevel@tonic-gate 					(void) memset(rts, 0, (SPARE_INC *
803*0Sstevel@tonic-gate 					    sizeof (struct rt_spare)));
804*0Sstevel@tonic-gate 					rt->rt_num_spares += SPARE_INC;
805*0Sstevel@tonic-gate 					for (tmprts = rts, i = SPARE_INC;
806*0Sstevel@tonic-gate 					    i != 0; i--, tmprts++)
807*0Sstevel@tonic-gate 						tmprts->rts_metric =
808*0Sstevel@tonic-gate 						    HOPCNT_INFINITY;
809*0Sstevel@tonic-gate 				}
810*0Sstevel@tonic-gate 			}
811*0Sstevel@tonic-gate 
812*0Sstevel@tonic-gate 			if (slot >= 0 && (dr_done != _B_TRUE)) {
813*0Sstevel@tonic-gate 				(void) memset(&new, 0, sizeof (new));
814*0Sstevel@tonic-gate 				new.rts_ifp = drp->dr_ifp;
815*0Sstevel@tonic-gate 				new.rts_gate = drp->dr_gate;
816*0Sstevel@tonic-gate 				new.rts_router = drp->dr_gate;
817*0Sstevel@tonic-gate 				new.rts_metric = HOPCNT_INFINITY-1;
818*0Sstevel@tonic-gate 				new.rts_time = now.tv_sec;
819*0Sstevel@tonic-gate 				new.rts_origin = RO_RDISC;
820*0Sstevel@tonic-gate 				rt->rt_spares[slot] = new;
821*0Sstevel@tonic-gate 				trace_act("spare default %s via %s",
822*0Sstevel@tonic-gate 				    naddr_ntoa(drp->dr_gate),
823*0Sstevel@tonic-gate 				    drp->dr_ifp->int_name);
824*0Sstevel@tonic-gate 			}
825*0Sstevel@tonic-gate 		}
826*0Sstevel@tonic-gate 	}
827*0Sstevel@tonic-gate 
828*0Sstevel@tonic-gate 	/* turn RIP on or off */
829*0Sstevel@tonic-gate 	if (!rdisc_ok || rip_interfaces > 1) {
830*0Sstevel@tonic-gate 		rip_on(0);
831*0Sstevel@tonic-gate 	} else {
832*0Sstevel@tonic-gate 		rip_off();
833*0Sstevel@tonic-gate 	}
834*0Sstevel@tonic-gate }
835*0Sstevel@tonic-gate 
836*0Sstevel@tonic-gate 
837*0Sstevel@tonic-gate /* Handle a single address in an advertisement */
838*0Sstevel@tonic-gate static void
839*0Sstevel@tonic-gate parse_ad(uint32_t from,
840*0Sstevel@tonic-gate     in_addr_t gate,
841*0Sstevel@tonic-gate     uint32_t pref,		/* signed and in network order */
842*0Sstevel@tonic-gate     ushort_t life,		/* in host byte order */
843*0Sstevel@tonic-gate     struct interface *ifp)
844*0Sstevel@tonic-gate {
845*0Sstevel@tonic-gate 	static struct msg_limit bad_gate;
846*0Sstevel@tonic-gate 	struct dr *drp, *new_drp;
847*0Sstevel@tonic-gate 	void *ptr;
848*0Sstevel@tonic-gate 	size_t ptrsize;
849*0Sstevel@tonic-gate 
850*0Sstevel@tonic-gate 	if (gate == RIP_DEFAULT || !check_dst(gate)) {
851*0Sstevel@tonic-gate 		msglim(&bad_gate, from, "router %s advertising bad gateway %s",
852*0Sstevel@tonic-gate 		    naddr_ntoa(from), naddr_ntoa(gate));
853*0Sstevel@tonic-gate 		return;
854*0Sstevel@tonic-gate 	}
855*0Sstevel@tonic-gate 
856*0Sstevel@tonic-gate 	/*
857*0Sstevel@tonic-gate 	 * ignore pointers to ourself and routes via unreachable networks
858*0Sstevel@tonic-gate 	 */
859*0Sstevel@tonic-gate 	if (ifwithaddr(gate, _B_TRUE, _B_FALSE) != 0) {
860*0Sstevel@tonic-gate 		trace_pkt("    discard Router Discovery Ad pointing at us");
861*0Sstevel@tonic-gate 		return;
862*0Sstevel@tonic-gate 	}
863*0Sstevel@tonic-gate 	if (!on_net(gate, ifp->int_net, ifp->int_mask)) {
864*0Sstevel@tonic-gate 		trace_pkt("    discard Router Discovery Ad"
865*0Sstevel@tonic-gate 		    " toward unreachable net");
866*0Sstevel@tonic-gate 		return;
867*0Sstevel@tonic-gate 	}
868*0Sstevel@tonic-gate 	/*
869*0Sstevel@tonic-gate 	 * Convert preference to an unsigned value
870*0Sstevel@tonic-gate 	 * and later bias it by the metric of the interface.
871*0Sstevel@tonic-gate 	 */
872*0Sstevel@tonic-gate 	pref = UNSIGN_PREF(ntohl(pref));
873*0Sstevel@tonic-gate 
874*0Sstevel@tonic-gate 	if (pref == DEF_PREFERENCELEVEL || life < MIN_MAXADVERTISEINTERVAL) {
875*0Sstevel@tonic-gate 		pref = DEF_PREFERENCELEVEL;
876*0Sstevel@tonic-gate 		life = 0;
877*0Sstevel@tonic-gate 	}
878*0Sstevel@tonic-gate 
879*0Sstevel@tonic-gate 	for (new_drp = NULL, drp = drs; drp < &drs[max_ads]; drp++) {
880*0Sstevel@tonic-gate 		/* accept new info for a familiar entry */
881*0Sstevel@tonic-gate 		if ((drp->dr_gate == gate) && (drp->dr_ifp == ifp)) {
882*0Sstevel@tonic-gate 			new_drp = drp;
883*0Sstevel@tonic-gate 			drp->dr_flags |= DR_CHANGED;
884*0Sstevel@tonic-gate 			break;
885*0Sstevel@tonic-gate 		}
886*0Sstevel@tonic-gate 
887*0Sstevel@tonic-gate 		if (life == 0)
888*0Sstevel@tonic-gate 			continue;	/* do not worry about dead ads */
889*0Sstevel@tonic-gate 
890*0Sstevel@tonic-gate 		if (drp->dr_ts == 0) {
891*0Sstevel@tonic-gate 			new_drp = drp;	/* use unused entry */
892*0Sstevel@tonic-gate 
893*0Sstevel@tonic-gate 		} else if (new_drp == NULL) {
894*0Sstevel@tonic-gate 			/* look for an entry worse than the new one to reuse. */
895*0Sstevel@tonic-gate 			if ((!(ifp->int_state & IS_SICK) &&
896*0Sstevel@tonic-gate 			    (drp->dr_ifp->int_state & IS_SICK)) ||
897*0Sstevel@tonic-gate 			    (pref > drp->dr_pref &&
898*0Sstevel@tonic-gate 			    !((ifp->int_state ^ drp->dr_ifp->int_state) &
899*0Sstevel@tonic-gate 			    IS_SICK)))
900*0Sstevel@tonic-gate 				new_drp = drp;
901*0Sstevel@tonic-gate 
902*0Sstevel@tonic-gate 		} else if (new_drp->dr_ts != 0) {
903*0Sstevel@tonic-gate 			/* look for the least valuable entry to reuse */
904*0Sstevel@tonic-gate 			if ((!(new_drp->dr_ifp->int_state & IS_SICK) &&
905*0Sstevel@tonic-gate 			    (drp->dr_ifp->int_state & IS_SICK)) ||
906*0Sstevel@tonic-gate 			    (new_drp->dr_pref > drp->dr_pref &&
907*0Sstevel@tonic-gate 			    !((new_drp->dr_ifp->int_state ^
908*0Sstevel@tonic-gate 			    drp->dr_ifp->int_state) & IS_SICK)))
909*0Sstevel@tonic-gate 				new_drp = drp;
910*0Sstevel@tonic-gate 		}
911*0Sstevel@tonic-gate 	}
912*0Sstevel@tonic-gate 
913*0Sstevel@tonic-gate 	/* if all of the current entries are better, add more drs[] */
914*0Sstevel@tonic-gate 	if (new_drp == NULL) {
915*0Sstevel@tonic-gate 		ptrsize = (max_ads + MAX_ADS) * sizeof (struct dr);
916*0Sstevel@tonic-gate 		ptr = realloc(drs, ptrsize);
917*0Sstevel@tonic-gate 		if (ptr == NULL)
918*0Sstevel@tonic-gate 			return;
919*0Sstevel@tonic-gate 		drs = ptr;
920*0Sstevel@tonic-gate 		(void) memset(&drs[max_ads], 0, MAX_ADS * sizeof (struct dr));
921*0Sstevel@tonic-gate 		new_drp = &drs[max_ads];
922*0Sstevel@tonic-gate 		max_ads += MAX_ADS;
923*0Sstevel@tonic-gate 	}
924*0Sstevel@tonic-gate 
925*0Sstevel@tonic-gate 	/*
926*0Sstevel@tonic-gate 	 * Pointer copy is safe here because if_del
927*0Sstevel@tonic-gate 	 * calls if_bad_rdisc first, so a non-NULL df_ifp
928*0Sstevel@tonic-gate 	 * is always a valid pointer.
929*0Sstevel@tonic-gate 	 */
930*0Sstevel@tonic-gate 	new_drp->dr_ifp = ifp;
931*0Sstevel@tonic-gate 	new_drp->dr_gate = gate;
932*0Sstevel@tonic-gate 	new_drp->dr_ts = now.tv_sec;
933*0Sstevel@tonic-gate 	new_drp->dr_life = life;
934*0Sstevel@tonic-gate 	new_drp->dr_recv_pref = pref;
935*0Sstevel@tonic-gate 	/* bias functional preference by metric of the interface */
936*0Sstevel@tonic-gate 	new_drp->dr_pref = PREF(pref, ifp);
937*0Sstevel@tonic-gate 
938*0Sstevel@tonic-gate 	/* after hearing a good advertisement, stop asking */
939*0Sstevel@tonic-gate 	if (!(ifp->int_state & IS_SICK))
940*0Sstevel@tonic-gate 		ifp->int_rdisc_cnt = MAX_SOLICITATIONS;
941*0Sstevel@tonic-gate }
942*0Sstevel@tonic-gate 
943*0Sstevel@tonic-gate 
944*0Sstevel@tonic-gate /*
945*0Sstevel@tonic-gate  * Compute the IP checksum. This assumes the packet is less than 32K long.
946*0Sstevel@tonic-gate  */
947*0Sstevel@tonic-gate static uint16_t
948*0Sstevel@tonic-gate in_cksum(uint16_t *p, uint_t len)
949*0Sstevel@tonic-gate {
950*0Sstevel@tonic-gate 	uint32_t sum = 0;
951*0Sstevel@tonic-gate 	int nwords = len >> 1;
952*0Sstevel@tonic-gate 
953*0Sstevel@tonic-gate 	while (nwords-- != 0)
954*0Sstevel@tonic-gate 		sum += *p++;
955*0Sstevel@tonic-gate 
956*0Sstevel@tonic-gate 	if (len & 1)
957*0Sstevel@tonic-gate 		sum += *(uchar_t *)p;
958*0Sstevel@tonic-gate 
959*0Sstevel@tonic-gate 	/* end-around-carry */
960*0Sstevel@tonic-gate 	sum = (sum >> 16) + (sum & 0xffff);
961*0Sstevel@tonic-gate 	sum += (sum >> 16);
962*0Sstevel@tonic-gate 	return (~sum);
963*0Sstevel@tonic-gate }
964*0Sstevel@tonic-gate 
965*0Sstevel@tonic-gate 
966*0Sstevel@tonic-gate /* Send a router discovery advertisement or solicitation ICMP packet. */
967*0Sstevel@tonic-gate static void
968*0Sstevel@tonic-gate send_rdisc(union ad_u *p,
969*0Sstevel@tonic-gate     uint_t p_size,
970*0Sstevel@tonic-gate     struct interface *ifp,
971*0Sstevel@tonic-gate     in_addr_t dst,		/* 0 or unicast destination */
972*0Sstevel@tonic-gate     dstaddr_t type)
973*0Sstevel@tonic-gate {
974*0Sstevel@tonic-gate 	struct sockaddr_in sin;
975*0Sstevel@tonic-gate 	int flags = 0;
976*0Sstevel@tonic-gate 	const char *msg;
977*0Sstevel@tonic-gate 	int ifindex;
978*0Sstevel@tonic-gate 	struct in_addr addr;
979*0Sstevel@tonic-gate 
980*0Sstevel@tonic-gate 	/*
981*0Sstevel@tonic-gate 	 * Don't send Rdisc packets on duplicate interfaces, we
982*0Sstevel@tonic-gate 	 * don't want to generate duplicate packets.
983*0Sstevel@tonic-gate 	 */
984*0Sstevel@tonic-gate 	if (ifp->int_state & IS_DUP)
985*0Sstevel@tonic-gate 		return;
986*0Sstevel@tonic-gate 
987*0Sstevel@tonic-gate 	(void) memset(&sin, 0, sizeof (sin));
988*0Sstevel@tonic-gate 	sin.sin_addr.s_addr = dst;
989*0Sstevel@tonic-gate 	sin.sin_family = AF_INET;
990*0Sstevel@tonic-gate 
991*0Sstevel@tonic-gate 	switch (type) {
992*0Sstevel@tonic-gate 	case unicast:				/* unicast */
993*0Sstevel@tonic-gate 	default:
994*0Sstevel@tonic-gate 		flags = MSG_DONTROUTE;
995*0Sstevel@tonic-gate 		msg = "Send";
996*0Sstevel@tonic-gate 		break;
997*0Sstevel@tonic-gate 
998*0Sstevel@tonic-gate 	case bcast:				/* broadcast */
999*0Sstevel@tonic-gate 		if (ifp->int_if_flags & IFF_POINTOPOINT) {
1000*0Sstevel@tonic-gate 			msg = "Send pt-to-pt";
1001*0Sstevel@tonic-gate 			if (ifp->int_dstaddr == 0)
1002*0Sstevel@tonic-gate 				sin.sin_addr.s_addr = htonl(INADDR_BROADCAST);
1003*0Sstevel@tonic-gate 			else
1004*0Sstevel@tonic-gate 				sin.sin_addr.s_addr = ifp->int_dstaddr;
1005*0Sstevel@tonic-gate 		} else {
1006*0Sstevel@tonic-gate 			msg = "Send broadcast";
1007*0Sstevel@tonic-gate 			sin.sin_addr.s_addr = ifp->int_brdaddr;
1008*0Sstevel@tonic-gate 		}
1009*0Sstevel@tonic-gate 		break;
1010*0Sstevel@tonic-gate 
1011*0Sstevel@tonic-gate 	case mcast:				/* multicast */
1012*0Sstevel@tonic-gate 		msg = "Send multicast";
1013*0Sstevel@tonic-gate 		break;
1014*0Sstevel@tonic-gate 	}
1015*0Sstevel@tonic-gate 
1016*0Sstevel@tonic-gate 	if (rdisc_sock < 0)
1017*0Sstevel@tonic-gate 		get_rdisc_sock();
1018*0Sstevel@tonic-gate 
1019*0Sstevel@tonic-gate 	if (rdisc_sock_interface != ifp) {
1020*0Sstevel@tonic-gate 		/* select the right interface. */
1021*0Sstevel@tonic-gate 		ifindex = (type != mcast && ifp->int_phys != NULL) ?
1022*0Sstevel@tonic-gate 		    ifp->int_phys->phyi_index : 0;
1023*0Sstevel@tonic-gate 		if (setsockopt(rdisc_sock, IPPROTO_IP, IP_XMIT_IF, &ifindex,
1024*0Sstevel@tonic-gate 		    sizeof (ifindex)) == -1) {
1025*0Sstevel@tonic-gate 			LOGERR("setsockopt(rdisc_sock, IP_XMIT_IF)");
1026*0Sstevel@tonic-gate 			return;
1027*0Sstevel@tonic-gate 		}
1028*0Sstevel@tonic-gate 		/*
1029*0Sstevel@tonic-gate 		 * For multicast, we have to choose the source
1030*0Sstevel@tonic-gate 		 * address.  This is either the local address
1031*0Sstevel@tonic-gate 		 * (non-point-to-point) or the remote address.
1032*0Sstevel@tonic-gate 		 */
1033*0Sstevel@tonic-gate 		addr.s_addr = (ifp->int_if_flags & IFF_POINTOPOINT) ?
1034*0Sstevel@tonic-gate 		    ifp->int_dstaddr : ifp->int_addr;
1035*0Sstevel@tonic-gate 		if (type == mcast &&
1036*0Sstevel@tonic-gate 		    setsockopt(rdisc_sock, IPPROTO_IP, IP_MULTICAST_IF, &addr,
1037*0Sstevel@tonic-gate 			sizeof (addr)) == -1) {
1038*0Sstevel@tonic-gate 			LOGERR("setsockopt(rdisc_sock, IP_MULTICAST_IF)");
1039*0Sstevel@tonic-gate 			return;
1040*0Sstevel@tonic-gate 		}
1041*0Sstevel@tonic-gate 		rdisc_sock_interface = ifp;
1042*0Sstevel@tonic-gate 	}
1043*0Sstevel@tonic-gate 
1044*0Sstevel@tonic-gate 	trace_rdisc(msg, ifp->int_addr, sin.sin_addr.s_addr, ifp, p, p_size);
1045*0Sstevel@tonic-gate 
1046*0Sstevel@tonic-gate 	if (0 > sendto(rdisc_sock, p, p_size, flags,
1047*0Sstevel@tonic-gate 	    (struct sockaddr *)&sin, sizeof (sin))) {
1048*0Sstevel@tonic-gate 		if (!(ifp->int_state & IS_BROKE))
1049*0Sstevel@tonic-gate 			writelog(LOG_WARNING, "sendto(%s%s%s): %s",
1050*0Sstevel@tonic-gate 			    ifp->int_name, ", ",
1051*0Sstevel@tonic-gate 			    inet_ntoa(sin.sin_addr),
1052*0Sstevel@tonic-gate 			    rip_strerror(errno));
1053*0Sstevel@tonic-gate 		if (ifp != NULL)
1054*0Sstevel@tonic-gate 			if_sick(ifp, _B_FALSE);
1055*0Sstevel@tonic-gate 	}
1056*0Sstevel@tonic-gate }
1057*0Sstevel@tonic-gate 
1058*0Sstevel@tonic-gate 
1059*0Sstevel@tonic-gate /* Send an advertisement */
1060*0Sstevel@tonic-gate static void
1061*0Sstevel@tonic-gate send_adv(struct interface *ifp,
1062*0Sstevel@tonic-gate     in_addr_t dst,
1063*0Sstevel@tonic-gate     dstaddr_t type)
1064*0Sstevel@tonic-gate {
1065*0Sstevel@tonic-gate 	union ad_u u;
1066*0Sstevel@tonic-gate 
1067*0Sstevel@tonic-gate 	if ((ifp->int_state & (IS_SUPPRESS_RDISC|IS_FLUSH_RDISC)) ==
1068*0Sstevel@tonic-gate 	    IS_SUPPRESS_RDISC)
1069*0Sstevel@tonic-gate 		return;
1070*0Sstevel@tonic-gate 
1071*0Sstevel@tonic-gate 	(void) memset(&u, 0, sizeof (u.ad));
1072*0Sstevel@tonic-gate 
1073*0Sstevel@tonic-gate 	u.ad.icmp_type = ICMP_ROUTERADVERT;
1074*0Sstevel@tonic-gate 	u.ad.icmp_code = ICMP_ROUTERADVERT_COMMON;
1075*0Sstevel@tonic-gate 	u.ad.icmp_ad_num = 1;
1076*0Sstevel@tonic-gate 	u.ad.icmp_ad_asize = sizeof (u.ad.icmp_ad_info[0])/4;
1077*0Sstevel@tonic-gate 
1078*0Sstevel@tonic-gate 	u.ad.icmp_ad_life = (stopint || !should_supply(ifp) ||
1079*0Sstevel@tonic-gate 	    (ifp->int_state & IS_SUPPRESS_RDISC)) ? 0 :
1080*0Sstevel@tonic-gate 	    htons(ifp->int_rdisc_int*3);
1081*0Sstevel@tonic-gate 
1082*0Sstevel@tonic-gate 	/* Send the configured preference as a network byte order value */
1083*0Sstevel@tonic-gate 	u.ad.icmp_ad_info[0].icmp_ad_pref = htonl(ifp->int_rdisc_pref);
1084*0Sstevel@tonic-gate 
1085*0Sstevel@tonic-gate 	u.ad.icmp_ad_info[0].icmp_ad_addr = ifp->int_addr;
1086*0Sstevel@tonic-gate 
1087*0Sstevel@tonic-gate 	u.ad.icmp_cksum = in_cksum((uint16_t *)&u.ad, sizeof (u.ad));
1088*0Sstevel@tonic-gate 
1089*0Sstevel@tonic-gate 	send_rdisc(&u, sizeof (u.ad), ifp, dst, type);
1090*0Sstevel@tonic-gate 
1091*0Sstevel@tonic-gate 	if (ifp->int_state & IS_SUPPRESS_RDISC)
1092*0Sstevel@tonic-gate 		ifp->int_state &= ~IS_FLUSH_RDISC;
1093*0Sstevel@tonic-gate }
1094*0Sstevel@tonic-gate 
1095*0Sstevel@tonic-gate 
1096*0Sstevel@tonic-gate /* Advertise as a default router by way of router discovery. */
1097*0Sstevel@tonic-gate void
1098*0Sstevel@tonic-gate rdisc_adv(boolean_t forceadv)
1099*0Sstevel@tonic-gate {
1100*0Sstevel@tonic-gate 	struct interface *ifp;
1101*0Sstevel@tonic-gate 
1102*0Sstevel@tonic-gate 	if (!forceadv && !should_supply(NULL))
1103*0Sstevel@tonic-gate 		return;
1104*0Sstevel@tonic-gate 
1105*0Sstevel@tonic-gate 	rdisc_timer.tv_sec = now.tv_sec + NEVER;
1106*0Sstevel@tonic-gate 
1107*0Sstevel@tonic-gate 	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
1108*0Sstevel@tonic-gate 		if ((ifp->int_state & (IS_NO_ADV_OUT | IS_BROKE)) ||
1109*0Sstevel@tonic-gate 		    (!forceadv && !IS_IFF_ROUTING(ifp->int_if_flags)))
1110*0Sstevel@tonic-gate 			continue;
1111*0Sstevel@tonic-gate 
1112*0Sstevel@tonic-gate 		/* skip interfaces we shouldn't use */
1113*0Sstevel@tonic-gate 		if (IS_IFF_QUIET(ifp->int_if_flags))
1114*0Sstevel@tonic-gate 			continue;
1115*0Sstevel@tonic-gate 
1116*0Sstevel@tonic-gate 		if (!timercmp(&ifp->int_rdisc_timer, &now, > /* cstyle */) ||
1117*0Sstevel@tonic-gate 		    stopint != 0 || forceadv) {
1118*0Sstevel@tonic-gate 			send_adv(ifp, htonl(INADDR_ALLHOSTS_GROUP),
1119*0Sstevel@tonic-gate 			    (ifp->int_state & IS_BCAST_RDISC) ? 1 : 2);
1120*0Sstevel@tonic-gate 			ifp->int_rdisc_cnt++;
1121*0Sstevel@tonic-gate 
1122*0Sstevel@tonic-gate 			intvl_random(&ifp->int_rdisc_timer,
1123*0Sstevel@tonic-gate 			    (ifp->int_rdisc_int*3)/4, ifp->int_rdisc_int);
1124*0Sstevel@tonic-gate 			if (ifp->int_rdisc_cnt < MAX_INITIAL_ADVERTS &&
1125*0Sstevel@tonic-gate 			    (ifp->int_rdisc_timer.tv_sec >
1126*0Sstevel@tonic-gate 			    MAX_INITIAL_ADVERT_INTERVAL)) {
1127*0Sstevel@tonic-gate 				ifp->int_rdisc_timer.tv_sec =
1128*0Sstevel@tonic-gate 				    MAX_INITIAL_ADVERT_INTERVAL;
1129*0Sstevel@tonic-gate 			}
1130*0Sstevel@tonic-gate 			timevaladd(&ifp->int_rdisc_timer, &now);
1131*0Sstevel@tonic-gate 		}
1132*0Sstevel@tonic-gate 		if (timercmp(&rdisc_timer, &ifp->int_rdisc_timer,
1133*0Sstevel@tonic-gate 		    > /* cstyle */))
1134*0Sstevel@tonic-gate 			rdisc_timer = ifp->int_rdisc_timer;
1135*0Sstevel@tonic-gate 	}
1136*0Sstevel@tonic-gate }
1137*0Sstevel@tonic-gate 
1138*0Sstevel@tonic-gate 
1139*0Sstevel@tonic-gate /* Solicit for Router Discovery */
1140*0Sstevel@tonic-gate void
1141*0Sstevel@tonic-gate rdisc_sol(void)
1142*0Sstevel@tonic-gate {
1143*0Sstevel@tonic-gate 	struct interface *ifp;
1144*0Sstevel@tonic-gate 	union ad_u u;
1145*0Sstevel@tonic-gate 
1146*0Sstevel@tonic-gate 	if (should_supply(NULL))
1147*0Sstevel@tonic-gate 		return;
1148*0Sstevel@tonic-gate 
1149*0Sstevel@tonic-gate 	rdisc_timer.tv_sec = now.tv_sec + NEVER;
1150*0Sstevel@tonic-gate 
1151*0Sstevel@tonic-gate 	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
1152*0Sstevel@tonic-gate 		if (0 != (ifp->int_state & (IS_NO_SOL_OUT | IS_BROKE)) ||
1153*0Sstevel@tonic-gate 		    ifp->int_rdisc_cnt >= MAX_SOLICITATIONS)
1154*0Sstevel@tonic-gate 			continue;
1155*0Sstevel@tonic-gate 
1156*0Sstevel@tonic-gate 		/* skip interfaces we shouldn't use */
1157*0Sstevel@tonic-gate 		if (IS_IFF_QUIET(ifp->int_if_flags))
1158*0Sstevel@tonic-gate 			continue;
1159*0Sstevel@tonic-gate 
1160*0Sstevel@tonic-gate 		if (!timercmp(&ifp->int_rdisc_timer, &now, > /* cstyle */)) {
1161*0Sstevel@tonic-gate 			(void) memset(&u, 0, sizeof (u.so));
1162*0Sstevel@tonic-gate 			u.so.icmp_type = ICMP_ROUTERSOLICIT;
1163*0Sstevel@tonic-gate 			u.so.icmp_cksum = in_cksum((uint16_t *)&u.so,
1164*0Sstevel@tonic-gate 			    sizeof (u.so));
1165*0Sstevel@tonic-gate 			send_rdisc(&u, sizeof (u.so), ifp,
1166*0Sstevel@tonic-gate 			    htonl(INADDR_ALLRTRS_GROUP),
1167*0Sstevel@tonic-gate 			    ((ifp->int_state&IS_BCAST_RDISC) ? bcast : mcast));
1168*0Sstevel@tonic-gate 
1169*0Sstevel@tonic-gate 			if (++ifp->int_rdisc_cnt >= MAX_SOLICITATIONS)
1170*0Sstevel@tonic-gate 				continue;
1171*0Sstevel@tonic-gate 
1172*0Sstevel@tonic-gate 			ifp->int_rdisc_timer.tv_sec = SOLICITATION_INTERVAL;
1173*0Sstevel@tonic-gate 			ifp->int_rdisc_timer.tv_usec = 0;
1174*0Sstevel@tonic-gate 			timevaladd(&ifp->int_rdisc_timer, &now);
1175*0Sstevel@tonic-gate 		}
1176*0Sstevel@tonic-gate 
1177*0Sstevel@tonic-gate 		if (timercmp(&rdisc_timer, &ifp->int_rdisc_timer,
1178*0Sstevel@tonic-gate 		    > /* cstyle */))
1179*0Sstevel@tonic-gate 			rdisc_timer = ifp->int_rdisc_timer;
1180*0Sstevel@tonic-gate 	}
1181*0Sstevel@tonic-gate }
1182*0Sstevel@tonic-gate 
1183*0Sstevel@tonic-gate 
1184*0Sstevel@tonic-gate /*
1185*0Sstevel@tonic-gate  * check the IP header of a possible Router Discovery ICMP packet
1186*0Sstevel@tonic-gate  * Returns 0 if bad
1187*0Sstevel@tonic-gate  */
1188*0Sstevel@tonic-gate static struct interface *
1189*0Sstevel@tonic-gate ck_icmp(const char *act,
1190*0Sstevel@tonic-gate     in_addr_t	from,
1191*0Sstevel@tonic-gate     struct interface *ifp,
1192*0Sstevel@tonic-gate     in_addr_t	to,
1193*0Sstevel@tonic-gate     union ad_u *p,
1194*0Sstevel@tonic-gate     uint_t	len)
1195*0Sstevel@tonic-gate {
1196*0Sstevel@tonic-gate 	const char *type;
1197*0Sstevel@tonic-gate 
1198*0Sstevel@tonic-gate 
1199*0Sstevel@tonic-gate 	if (p->icmp.icmp_type == ICMP_ROUTERADVERT) {
1200*0Sstevel@tonic-gate 		type = "advertisement";
1201*0Sstevel@tonic-gate 		if (p->icmp.icmp_code == ICMP_ROUTERADVERT_NOCOMMON)
1202*0Sstevel@tonic-gate 			return (NULL); /* Mobile IP */
1203*0Sstevel@tonic-gate 	} else if (p->icmp.icmp_type == ICMP_ROUTERSOLICIT) {
1204*0Sstevel@tonic-gate 		type = "solicitation";
1205*0Sstevel@tonic-gate 	} else {
1206*0Sstevel@tonic-gate 		return (NULL);
1207*0Sstevel@tonic-gate 	}
1208*0Sstevel@tonic-gate 
1209*0Sstevel@tonic-gate 	if (p->icmp.icmp_code != ICMP_ROUTERADVERT_COMMON) {
1210*0Sstevel@tonic-gate 		trace_pkt("unrecognized ICMP Router %s code=%d from %s to %s",
1211*0Sstevel@tonic-gate 		    type, p->icmp.icmp_code, naddr_ntoa(from), naddr_ntoa(to));
1212*0Sstevel@tonic-gate 		return (NULL);
1213*0Sstevel@tonic-gate 	}
1214*0Sstevel@tonic-gate 
1215*0Sstevel@tonic-gate 	trace_rdisc(act, from, to, ifp, p, len);
1216*0Sstevel@tonic-gate 
1217*0Sstevel@tonic-gate 	if (ifp == NULL)
1218*0Sstevel@tonic-gate 		trace_pkt("unknown interface for router-discovery %s from %s "
1219*0Sstevel@tonic-gate 		    "to %s", type, naddr_ntoa(from), naddr_ntoa(to));
1220*0Sstevel@tonic-gate 
1221*0Sstevel@tonic-gate 	return (ifp);
1222*0Sstevel@tonic-gate }
1223*0Sstevel@tonic-gate 
1224*0Sstevel@tonic-gate 
1225*0Sstevel@tonic-gate /* Read packets from the router discovery socket */
1226*0Sstevel@tonic-gate void
1227*0Sstevel@tonic-gate read_d(void)
1228*0Sstevel@tonic-gate {
1229*0Sstevel@tonic-gate #define	PKTLEN	512
1230*0Sstevel@tonic-gate 	static struct msg_limit bad_asize, bad_len;
1231*0Sstevel@tonic-gate 	struct sockaddr_in from;
1232*0Sstevel@tonic-gate 	int n, cc, hlen;
1233*0Sstevel@tonic-gate 	struct {
1234*0Sstevel@tonic-gate 		union {
1235*0Sstevel@tonic-gate 			struct ip ip;
1236*0Sstevel@tonic-gate 			uint16_t s[PKTLEN/sizeof (uint16_t)];
1237*0Sstevel@tonic-gate 			uint8_t	b[PKTLEN/sizeof (uint8_t)];
1238*0Sstevel@tonic-gate 		} pkt;
1239*0Sstevel@tonic-gate 	} buf;
1240*0Sstevel@tonic-gate 	union ad_u *p;
1241*0Sstevel@tonic-gate 	n_long *wp;
1242*0Sstevel@tonic-gate 	struct interface *ifp;
1243*0Sstevel@tonic-gate 	boolean_t needsort = _B_FALSE;
1244*0Sstevel@tonic-gate 	struct msghdr msg;
1245*0Sstevel@tonic-gate 	struct iovec iov;
1246*0Sstevel@tonic-gate 	uint8_t ancillary_data[CONTROL_BUFSIZE];
1247*0Sstevel@tonic-gate 
1248*0Sstevel@tonic-gate 	iov.iov_base = &buf;
1249*0Sstevel@tonic-gate 	iov.iov_len = sizeof (buf);
1250*0Sstevel@tonic-gate 	msg.msg_iov = &iov;
1251*0Sstevel@tonic-gate 	msg.msg_iovlen = 1;
1252*0Sstevel@tonic-gate 	msg.msg_name = &from;
1253*0Sstevel@tonic-gate 	msg.msg_control = &ancillary_data;
1254*0Sstevel@tonic-gate 
1255*0Sstevel@tonic-gate 	for (;;) {
1256*0Sstevel@tonic-gate 		msg.msg_namelen = sizeof (from);
1257*0Sstevel@tonic-gate 		msg.msg_controllen = sizeof (ancillary_data);
1258*0Sstevel@tonic-gate 		cc = recvmsg(rdisc_sock, &msg, 0);
1259*0Sstevel@tonic-gate 		if (cc <= 0) {
1260*0Sstevel@tonic-gate 			if (cc < 0 && errno != EWOULDBLOCK)
1261*0Sstevel@tonic-gate 			    LOGERR("recvmsg(rdisc_sock)");
1262*0Sstevel@tonic-gate 			break;
1263*0Sstevel@tonic-gate 		}
1264*0Sstevel@tonic-gate 
1265*0Sstevel@tonic-gate 		hlen = buf.pkt.ip.ip_hl << 2;
1266*0Sstevel@tonic-gate 		if (cc < hlen + ICMP_MINLEN)
1267*0Sstevel@tonic-gate 			continue;
1268*0Sstevel@tonic-gate 		/* LINTED [alignment will be lw aligned] */
1269*0Sstevel@tonic-gate 		p = (union ad_u *)&buf.pkt.b[hlen];
1270*0Sstevel@tonic-gate 		cc -= hlen;
1271*0Sstevel@tonic-gate 
1272*0Sstevel@tonic-gate 		/*
1273*0Sstevel@tonic-gate 		 * If we could tell the interface on which a packet from
1274*0Sstevel@tonic-gate 		 * address 0 arrived, we could deal with such solicitations.
1275*0Sstevel@tonic-gate 		 */
1276*0Sstevel@tonic-gate 		ifp = receiving_interface(&msg, _B_FALSE);
1277*0Sstevel@tonic-gate 		ifp = ck_icmp("Recv", from.sin_addr.s_addr, ifp,
1278*0Sstevel@tonic-gate 		    buf.pkt.ip.ip_dst.s_addr, p, cc);
1279*0Sstevel@tonic-gate 		if (ifp == NULL)
1280*0Sstevel@tonic-gate 			continue;
1281*0Sstevel@tonic-gate 
1282*0Sstevel@tonic-gate 		if (IS_IFF_QUIET(ifp->int_if_flags)) {
1283*0Sstevel@tonic-gate 			trace_misc("discard RDISC packet received over %s, %X",
1284*0Sstevel@tonic-gate 			    ifp->int_name, ifp->int_if_flags);
1285*0Sstevel@tonic-gate 			continue;
1286*0Sstevel@tonic-gate 		}
1287*0Sstevel@tonic-gate 
1288*0Sstevel@tonic-gate 		if (from.sin_addr.s_addr != 0 &&
1289*0Sstevel@tonic-gate 		    ifwithaddr(from.sin_addr.s_addr, _B_FALSE, _B_FALSE)) {
1290*0Sstevel@tonic-gate 			trace_pkt("    "
1291*0Sstevel@tonic-gate 			    "discard our own Router Discovery message");
1292*0Sstevel@tonic-gate 			continue;
1293*0Sstevel@tonic-gate 		}
1294*0Sstevel@tonic-gate 
1295*0Sstevel@tonic-gate 		/* The remote address *must* be directly connected. */
1296*0Sstevel@tonic-gate 		if (!remote_address_ok(ifp, from.sin_addr.s_addr)) {
1297*0Sstevel@tonic-gate 			trace_misc("discard rdisc message; source %s not on "
1298*0Sstevel@tonic-gate 			    "interface %s", naddr_ntoa(from.sin_addr.s_addr),
1299*0Sstevel@tonic-gate 			    ifp->int_name);
1300*0Sstevel@tonic-gate 			continue;
1301*0Sstevel@tonic-gate 		}
1302*0Sstevel@tonic-gate 
1303*0Sstevel@tonic-gate 		switch (p->icmp.icmp_type) {
1304*0Sstevel@tonic-gate 		case ICMP_ROUTERADVERT:
1305*0Sstevel@tonic-gate 			if (ifp->int_state & IS_NO_ADV_IN)
1306*0Sstevel@tonic-gate 				continue;
1307*0Sstevel@tonic-gate 
1308*0Sstevel@tonic-gate 			if (p->ad.icmp_ad_asize*2*sizeof (wp[0]) <
1309*0Sstevel@tonic-gate 			    sizeof (p->ad.icmp_ad_info[0])) {
1310*0Sstevel@tonic-gate 				msglim(&bad_asize, from.sin_addr.s_addr,
1311*0Sstevel@tonic-gate 				    "intolerable rdisc address size=%d",
1312*0Sstevel@tonic-gate 				    p->ad.icmp_ad_asize);
1313*0Sstevel@tonic-gate 				continue;
1314*0Sstevel@tonic-gate 			}
1315*0Sstevel@tonic-gate 			if (p->ad.icmp_ad_num == 0) {
1316*0Sstevel@tonic-gate 				trace_pkt("    empty?");
1317*0Sstevel@tonic-gate 				continue;
1318*0Sstevel@tonic-gate 			}
1319*0Sstevel@tonic-gate 			if (cc < (sizeof (p->ad) -
1320*0Sstevel@tonic-gate 			    sizeof (p->ad.icmp_ad_info) +
1321*0Sstevel@tonic-gate 			    (p->ad.icmp_ad_num *
1322*0Sstevel@tonic-gate 			    sizeof (p->ad.icmp_ad_info[0])))) {
1323*0Sstevel@tonic-gate 				msglim(&bad_len, from.sin_addr.s_addr,
1324*0Sstevel@tonic-gate 				    "rdisc length %d does not match ad_num"
1325*0Sstevel@tonic-gate 				    " %d", cc, p->ad.icmp_ad_num);
1326*0Sstevel@tonic-gate 				continue;
1327*0Sstevel@tonic-gate 			}
1328*0Sstevel@tonic-gate 
1329*0Sstevel@tonic-gate 			needsort = _B_TRUE;
1330*0Sstevel@tonic-gate 			wp = &p->ad.icmp_ad_info[0].icmp_ad_addr;
1331*0Sstevel@tonic-gate 			for (n = 0; n < p->ad.icmp_ad_num; n++) {
1332*0Sstevel@tonic-gate 				parse_ad(from.sin_addr.s_addr,
1333*0Sstevel@tonic-gate 				    wp[0], wp[1],
1334*0Sstevel@tonic-gate 				    ntohs(p->ad.icmp_ad_life), ifp);
1335*0Sstevel@tonic-gate 				wp += p->ad.icmp_ad_asize;
1336*0Sstevel@tonic-gate 			}
1337*0Sstevel@tonic-gate 			break;
1338*0Sstevel@tonic-gate 
1339*0Sstevel@tonic-gate 
1340*0Sstevel@tonic-gate 		case ICMP_ROUTERSOLICIT:
1341*0Sstevel@tonic-gate 			if (!should_supply(ifp))
1342*0Sstevel@tonic-gate 				continue;
1343*0Sstevel@tonic-gate 			if ((ifp->int_state & IS_NO_ADV_OUT) ||
1344*0Sstevel@tonic-gate 			    !IS_IFF_ROUTING(ifp->int_if_flags))
1345*0Sstevel@tonic-gate 				continue;
1346*0Sstevel@tonic-gate 			if (stopint != 0)
1347*0Sstevel@tonic-gate 				continue;
1348*0Sstevel@tonic-gate 
1349*0Sstevel@tonic-gate 			/*
1350*0Sstevel@tonic-gate 			 * We should handle messages from address 0,
1351*0Sstevel@tonic-gate 			 * but cannot due to kernel limitations.
1352*0Sstevel@tonic-gate 			 */
1353*0Sstevel@tonic-gate 
1354*0Sstevel@tonic-gate 			/* Respond with a point-to-point advertisement */
1355*0Sstevel@tonic-gate 			send_adv(ifp, from.sin_addr.s_addr, 0);
1356*0Sstevel@tonic-gate 			break;
1357*0Sstevel@tonic-gate 		}
1358*0Sstevel@tonic-gate 	}
1359*0Sstevel@tonic-gate 
1360*0Sstevel@tonic-gate 	if (needsort)
1361*0Sstevel@tonic-gate 		rdisc_sort();
1362*0Sstevel@tonic-gate }
1363*0Sstevel@tonic-gate 
1364*0Sstevel@tonic-gate void
1365*0Sstevel@tonic-gate rdisc_dump(void)
1366*0Sstevel@tonic-gate {
1367*0Sstevel@tonic-gate 	struct dr *drp;
1368*0Sstevel@tonic-gate 
1369*0Sstevel@tonic-gate 	for (drp = drs; drp < &drs[max_ads]; drp++)
1370*0Sstevel@tonic-gate 		if (drp->dr_ts != 0)
1371*0Sstevel@tonic-gate 			trace_dr(drp);
1372*0Sstevel@tonic-gate }
1373*0Sstevel@tonic-gate 
1374*0Sstevel@tonic-gate void
1375*0Sstevel@tonic-gate rdisc_suppress(struct interface *ifp)
1376*0Sstevel@tonic-gate {
1377*0Sstevel@tonic-gate 	if (ifp->int_state & IS_ADV_OUT) {
1378*0Sstevel@tonic-gate 		msglog("%s \"rdisc_adv\" specified, will not "
1379*0Sstevel@tonic-gate 		    "suppress rdisc adv", ifp->int_name);
1380*0Sstevel@tonic-gate 	} else {
1381*0Sstevel@tonic-gate 		if (ifp->int_state & IS_SUPPRESS_RDISC)
1382*0Sstevel@tonic-gate 			return;
1383*0Sstevel@tonic-gate 		ifp->int_state |= (IS_SUPPRESS_RDISC|IS_FLUSH_RDISC);
1384*0Sstevel@tonic-gate 		trace_misc("suppress rdisc adv on %s", ifp->int_name);
1385*0Sstevel@tonic-gate 		rdisc_timer.tv_sec = 0;
1386*0Sstevel@tonic-gate 	}
1387*0Sstevel@tonic-gate }
1388*0Sstevel@tonic-gate 
1389*0Sstevel@tonic-gate void
1390*0Sstevel@tonic-gate rdisc_restore(struct interface *ifp)
1391*0Sstevel@tonic-gate {
1392*0Sstevel@tonic-gate 	if ((ifp->int_state & IS_SUPPRESS_RDISC) == 0)
1393*0Sstevel@tonic-gate 		return;
1394*0Sstevel@tonic-gate 	ifp->int_state &= ~(IS_SUPPRESS_RDISC|IS_FLUSH_RDISC);
1395*0Sstevel@tonic-gate 	trace_misc("restoring rdisc adv on %s", ifp->int_name);
1396*0Sstevel@tonic-gate 	rdisc_timer.tv_sec = 0;
1397*0Sstevel@tonic-gate }
1398