xref: /netbsd-src/sys/netinet/ip_carp.c (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
1 /*	$NetBSD: ip_carp.c,v 1.4 2006/06/13 15:43:04 riz Exp $	*/
2 /*	$OpenBSD: ip_carp.c,v 1.113 2005/11/04 08:11:54 mcbride Exp $	*/
3 
4 /*
5  * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
6  * Copyright (c) 2003 Ryan McBride. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
26  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27  * THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 /*
31  * TODO:
32  *	- iface reconfigure
33  *	- support for hardware checksum calculations;
34  *
35  */
36 
37 #include <sys/param.h>
38 #include <sys/proc.h>
39 #include <sys/mbuf.h>
40 #include <sys/socket.h>
41 #include <sys/socketvar.h>
42 #include <sys/callout.h>
43 #include <sys/ioctl.h>
44 #include <sys/errno.h>
45 #include <sys/device.h>
46 #include <sys/time.h>
47 #include <sys/kernel.h>
48 #include <sys/kauth.h>
49 #include <sys/sysctl.h>
50 #include <sys/ucred.h>
51 #include <sys/syslog.h>
52 #include <sys/acct.h>
53 
54 #include <machine/cpu.h>
55 
56 #include <net/if.h>
57 #include <net/pfil.h>
58 #include <net/if_types.h>
59 #include <net/if_ether.h>
60 #include <net/route.h>
61 #include <net/netisr.h>
62 #include <netinet/if_inarp.h>
63 
64 #include <machine/stdarg.h>
65 
66 #if NFDDI > 0
67 #include <net/if_fddi.h>
68 #endif
69 #if NTOKEN > 0
70 #include <net/if_token.h>
71 #endif
72 
73 #ifdef INET
74 #include <netinet/in.h>
75 #include <netinet/in_systm.h>
76 #include <netinet/in_var.h>
77 #include <netinet/ip.h>
78 #include <netinet/ip_var.h>
79 
80 #include <net/if_dl.h>
81 #endif
82 
83 #ifdef INET6
84 #include <netinet/icmp6.h>
85 #include <netinet/ip6.h>
86 #include <netinet6/ip6_var.h>
87 #include <netinet6/nd6.h>
88 #endif
89 
90 #include "bpfilter.h"
91 #if NBPFILTER > 0
92 #include <net/bpf.h>
93 #endif
94 
95 #include <sys/sha1.h>
96 
97 #include <netinet/ip_carp.h>
98 
99 struct carp_mc_entry {
100 	LIST_ENTRY(carp_mc_entry)	mc_entries;
101 	union {
102 		struct ether_multi	*mcu_enm;
103 	} mc_u;
104 	struct sockaddr_storage		mc_addr;
105 };
106 #define	mc_enm	mc_u.mcu_enm
107 
108 struct carp_softc {
109 	struct ethercom sc_ac;
110 #define	sc_if		sc_ac.ec_if
111 #define	sc_carpdev	sc_ac.ec_if.if_carpdev
112 	int ah_cookie;
113 	int lh_cookie;
114 	struct ip_moptions sc_imo;
115 #ifdef INET6
116 	struct ip6_moptions sc_im6o;
117 #endif /* INET6 */
118 	TAILQ_ENTRY(carp_softc) sc_list;
119 
120 	enum { INIT = 0, BACKUP, MASTER }	sc_state;
121 
122 	int sc_suppress;
123 	int sc_bow_out;
124 
125 	int sc_sendad_errors;
126 #define CARP_SENDAD_MAX_ERRORS	3
127 	int sc_sendad_success;
128 #define CARP_SENDAD_MIN_SUCCESS 3
129 
130 	int sc_vhid;
131 	int sc_advskew;
132 	int sc_naddrs;
133 	int sc_naddrs6;
134 	int sc_advbase;		/* seconds */
135 	int sc_init_counter;
136 	u_int64_t sc_counter;
137 
138 	/* authentication */
139 #define CARP_HMAC_PAD	64
140 	unsigned char sc_key[CARP_KEY_LEN];
141 	unsigned char sc_pad[CARP_HMAC_PAD];
142 	SHA1_CTX sc_sha1;
143 	u_int32_t sc_hashkey[2];
144 
145 	struct callout sc_ad_tmo;	/* advertisement timeout */
146 	struct callout sc_md_tmo;	/* master down timeout */
147 	struct callout sc_md6_tmo;	/* master down timeout */
148 
149 	LIST_HEAD(__carp_mchead, carp_mc_entry)	carp_mc_listhead;
150 };
151 
152 int carp_suppress_preempt = 0;
153 int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 0, 0 };	/* XXX for now */
154 struct carpstats carpstats;
155 
156 struct carp_if {
157 	TAILQ_HEAD(, carp_softc) vhif_vrs;
158 	int vhif_nvrs;
159 
160 	struct ifnet *vhif_ifp;
161 };
162 
163 #define	CARP_LOG(sc, s)							\
164 	if (carp_opts[CARPCTL_LOG]) {					\
165 		if (sc)							\
166 			log(LOG_INFO, "%s: ",				\
167 			    (sc)->sc_if.if_xname);			\
168 		else							\
169 			log(LOG_INFO, "carp: ");			\
170 		addlog s;						\
171 		addlog("\n");						\
172 	}
173 
174 void	carp_hmac_prepare(struct carp_softc *);
175 void	carp_hmac_generate(struct carp_softc *, u_int32_t *,
176 	    unsigned char *);
177 int	carp_hmac_verify(struct carp_softc *, u_int32_t *,
178 	    unsigned char *);
179 void	carp_setroute(struct carp_softc *, int);
180 void	carp_proto_input_c(struct mbuf *, struct carp_header *, sa_family_t);
181 void	carpattach(int);
182 void	carpdetach(struct carp_softc *);
183 int	carp_prepare_ad(struct mbuf *, struct carp_softc *,
184 	    struct carp_header *);
185 void	carp_send_ad_all(void);
186 void	carp_send_ad(void *);
187 void	carp_send_arp(struct carp_softc *);
188 void	carp_master_down(void *);
189 int	carp_ioctl(struct ifnet *, u_long, caddr_t);
190 void	carp_start(struct ifnet *);
191 void	carp_setrun(struct carp_softc *, sa_family_t);
192 void	carp_set_state(struct carp_softc *, int);
193 int	carp_addrcount(struct carp_if *, struct in_ifaddr *, int);
194 enum	{ CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
195 
196 void	carp_multicast_cleanup(struct carp_softc *);
197 int	carp_set_ifp(struct carp_softc *, struct ifnet *);
198 void	carp_set_enaddr(struct carp_softc *);
199 void	carp_addr_updated(void *);
200 u_int32_t	carp_hash(struct carp_softc *, u_char *);
201 int	carp_set_addr(struct carp_softc *, struct sockaddr_in *);
202 int	carp_join_multicast(struct carp_softc *);
203 #ifdef INET6
204 void	carp_send_na(struct carp_softc *);
205 int	carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
206 int	carp_join_multicast6(struct carp_softc *);
207 #endif
208 int	carp_clone_create(struct if_clone *, int);
209 int	carp_clone_destroy(struct ifnet *);
210 int	carp_ether_addmulti(struct carp_softc *, struct ifreq *);
211 int	carp_ether_delmulti(struct carp_softc *, struct ifreq *);
212 void	carp_ether_purgemulti(struct carp_softc *);
213 
214 struct if_clone carp_cloner =
215     IF_CLONE_INITIALIZER("carp", carp_clone_create, carp_clone_destroy);
216 
217 static __inline u_int16_t
218 carp_cksum(struct mbuf *m, int len)
219 {
220 	return (in_cksum(m, len));
221 }
222 
223 void
224 carp_hmac_prepare(struct carp_softc *sc)
225 {
226 	u_int8_t carp_version = CARP_VERSION, type = CARP_ADVERTISEMENT;
227 	u_int8_t vhid = sc->sc_vhid & 0xff;
228 	SHA1_CTX sha1ctx;
229 	u_int32_t kmd[5];
230 	struct ifaddr *ifa;
231 	int i, found;
232 	struct in_addr last, cur, in;
233 #ifdef INET6
234 	struct in6_addr last6, cur6, in6;
235 #endif /* INET6 */
236 
237 	/* compute ipad from key */
238 	bzero(sc->sc_pad, sizeof(sc->sc_pad));
239 	bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
240 	for (i = 0; i < sizeof(sc->sc_pad); i++)
241 		sc->sc_pad[i] ^= 0x36;
242 
243 	/* precompute first part of inner hash */
244 	SHA1Init(&sc->sc_sha1);
245 	SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
246 	SHA1Update(&sc->sc_sha1, (void *)&carp_version, sizeof(carp_version));
247 	SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
248 
249 	/* generate a key for the arpbalance hash, before the vhid is hashed */
250 	bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
251 	SHA1Final((unsigned char *)kmd, &sha1ctx);
252 	sc->sc_hashkey[0] = kmd[0] ^ kmd[1];
253 	sc->sc_hashkey[1] = kmd[2] ^ kmd[3];
254 
255 	/* the rest of the precomputation */
256 	SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
257 
258 	/* Hash the addresses from smallest to largest, not interface order */
259 #ifdef INET
260 	cur.s_addr = 0;
261 	do {
262 		found = 0;
263 		last = cur;
264 		cur.s_addr = 0xffffffff;
265 		TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
266 			in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
267 			if (ifa->ifa_addr->sa_family == AF_INET &&
268 			    ntohl(in.s_addr) > ntohl(last.s_addr) &&
269 			    ntohl(in.s_addr) < ntohl(cur.s_addr)) {
270 				cur.s_addr = in.s_addr;
271 				found++;
272 			}
273 		}
274 		if (found)
275 			SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
276 	} while (found);
277 #endif /* INET */
278 
279 #ifdef INET6
280 	memset(&cur6, 0x00, sizeof(cur6));
281 	do {
282 		found = 0;
283 		last6 = cur6;
284 		memset(&cur6, 0xff, sizeof(cur6));
285 		TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
286 			in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
287 			if (IN6_IS_ADDR_LINKLOCAL(&in6))
288 				in6.s6_addr16[1] = 0;
289 			if (ifa->ifa_addr->sa_family == AF_INET6 &&
290 			    memcmp(&in6, &last6, sizeof(in6)) > 0 &&
291 			    memcmp(&in6, &cur6, sizeof(in6)) < 0) {
292 				cur6 = in6;
293 				found++;
294 			}
295 		}
296 		if (found)
297 			SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
298 	} while (found);
299 #endif /* INET6 */
300 
301 	/* convert ipad to opad */
302 	for (i = 0; i < sizeof(sc->sc_pad); i++)
303 		sc->sc_pad[i] ^= 0x36 ^ 0x5c;
304 }
305 
306 void
307 carp_hmac_generate(struct carp_softc *sc, u_int32_t counter[2],
308     unsigned char md[20])
309 {
310 	SHA1_CTX sha1ctx;
311 
312 	/* fetch first half of inner hash */
313 	bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
314 
315 	SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
316 	SHA1Final(md, &sha1ctx);
317 
318 	/* outer hash */
319 	SHA1Init(&sha1ctx);
320 	SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
321 	SHA1Update(&sha1ctx, md, 20);
322 	SHA1Final(md, &sha1ctx);
323 }
324 
325 int
326 carp_hmac_verify(struct carp_softc *sc, u_int32_t counter[2],
327     unsigned char md[20])
328 {
329 	unsigned char md2[20];
330 
331 	carp_hmac_generate(sc, counter, md2);
332 
333 	return (bcmp(md, md2, sizeof(md2)));
334 }
335 
336 void
337 carp_setroute(struct carp_softc *sc, int cmd)
338 {
339 	struct ifaddr *ifa;
340 	int s;
341 
342 	s = splsoftnet();
343 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
344 		switch (ifa->ifa_addr->sa_family) {
345 		case AF_INET: {
346 			int count = 0;
347 			struct sockaddr sa;
348 			struct rtentry *rt;
349 			struct radix_node_head *rnh =
350 			    rt_tables[ifa->ifa_addr->sa_family];
351 			struct radix_node *rn;
352 			int hr_otherif, nr_ourif;
353 
354 			/*
355 			 * Avoid screwing with the routes if there are other
356 			 * carp interfaces which are master and have the same
357 			 * address.
358 			 */
359 			if (sc->sc_carpdev != NULL &&
360 			    sc->sc_carpdev->if_carp != NULL) {
361 				count = carp_addrcount(
362 				    (struct carp_if *)sc->sc_carpdev->if_carp,
363 				    ifatoia(ifa), CARP_COUNT_MASTER);
364 				if ((cmd == RTM_ADD && count != 1) ||
365 				    (cmd == RTM_DELETE && count != 0))
366 					continue;
367 			}
368 
369 			/* Remove the existing host route, if any */
370 			rtrequest(RTM_DELETE, ifa->ifa_addr,
371 			    ifa->ifa_addr, ifa->ifa_netmask,
372 			    RTF_HOST, NULL);
373 
374 			/* Check for our address on another interface */
375 			rn = rnh->rnh_matchaddr(ifa->ifa_addr, rnh);
376 			rt = (struct rtentry *)rn;
377 			hr_otherif = (rt && rt->rt_ifp != &sc->sc_if &&
378 			    rt->rt_flags & (RTF_CLONING|RTF_CLONED));
379 
380 			/* Check for a network route on our interface */
381 			bcopy(ifa->ifa_addr, &sa, sizeof(sa));
382 			satosin(&sa)->sin_addr.s_addr = satosin(ifa->ifa_netmask
383 			    )->sin_addr.s_addr & satosin(&sa)->sin_addr.s_addr;
384 			rn = rnh->rnh_lookup(&sa, ifa->ifa_netmask, rnh);
385 			rt = (struct rtentry *)rn;
386 			nr_ourif = (rt && rt->rt_ifp == &sc->sc_if);
387 
388 			switch (cmd) {
389 			case RTM_ADD:
390 				if (hr_otherif) {
391 					ifa->ifa_rtrequest = NULL;
392 					ifa->ifa_flags &= ~RTF_CLONING;
393 
394 					rtrequest(RTM_ADD, ifa->ifa_addr,
395 					    ifa->ifa_addr, ifa->ifa_netmask,
396 					    RTF_UP | RTF_HOST, NULL);
397 				}
398 				if (!hr_otherif || nr_ourif || !rt) {
399 					if (nr_ourif && !(rt->rt_flags &
400 					    RTF_CLONING))
401 						rtrequest(RTM_DELETE, &sa,
402 						    ifa->ifa_addr,
403 						    ifa->ifa_netmask, 0, NULL);
404 
405 					ifa->ifa_rtrequest = arp_rtrequest;
406 					ifa->ifa_flags |= RTF_CLONING;
407 
408 					if (rtrequest(RTM_ADD, ifa->ifa_addr,
409 					    ifa->ifa_addr, ifa->ifa_netmask, 0,
410 					    NULL) == 0)
411 						ifa->ifa_flags |= IFA_ROUTE;
412 				}
413 				break;
414 			case RTM_DELETE:
415 				break;
416 			default:
417 				break;
418 			}
419 			break;
420 		}
421 
422 #ifdef INET6
423 		case AF_INET6:
424 			if (cmd == RTM_ADD)
425 				in6_ifaddloop(ifa);
426 			else
427 				in6_ifremloop(ifa);
428 			break;
429 #endif /* INET6 */
430 		default:
431 			break;
432 		}
433 	}
434 	splx(s);
435 }
436 
437 /*
438  * process input packet.
439  * we have rearranged checks order compared to the rfc,
440  * but it seems more efficient this way or not possible otherwise.
441  */
442 void
443 carp_proto_input(struct mbuf *m, ...)
444 {
445 	struct ip *ip = mtod(m, struct ip *);
446 	struct carp_softc *sc = NULL;
447 	struct carp_header *ch;
448 	int iplen, len, hlen;
449 	va_list ap;
450 
451 	va_start(ap, m);
452 	hlen = va_arg(ap, int);
453 	va_end(ap);
454 
455 	carpstats.carps_ipackets++;
456 
457 	if (!carp_opts[CARPCTL_ALLOW]) {
458 		m_freem(m);
459 		return;
460 	}
461 
462 	/* check if received on a valid carp interface */
463 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
464 		carpstats.carps_badif++;
465 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
466 		    m->m_pkthdr.rcvif->if_xname));
467 		m_freem(m);
468 		return;
469 	}
470 
471 	/* verify that the IP TTL is 255.  */
472 	if (ip->ip_ttl != CARP_DFLTTL) {
473 		carpstats.carps_badttl++;
474 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip->ip_ttl,
475 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
476 		m_freem(m);
477 		return;
478 	}
479 
480 	/*
481 	 * verify that the received packet length is
482 	 * equal to the CARP header
483 	 */
484 	iplen = ip->ip_hl << 2;
485 	len = iplen + sizeof(*ch);
486 	if (len > m->m_pkthdr.len) {
487 		carpstats.carps_badlen++;
488 		CARP_LOG(sc, ("packet too short %d on %s", m->m_pkthdr.len,
489 		    m->m_pkthdr.rcvif->if_xname));
490 		m_freem(m);
491 		return;
492 	}
493 
494 	if ((m = m_pullup(m, len)) == NULL) {
495 		carpstats.carps_hdrops++;
496 		return;
497 	}
498 	ip = mtod(m, struct ip *);
499 	ch = (struct carp_header *)((char *)ip + iplen);
500 	/* verify the CARP checksum */
501 	m->m_data += iplen;
502 	if (carp_cksum(m, len - iplen)) {
503 		carpstats.carps_badsum++;
504 		CARP_LOG(sc, ("checksum failed on %s",
505 		    m->m_pkthdr.rcvif->if_xname));
506 		m_freem(m);
507 		return;
508 	}
509 	m->m_data -= iplen;
510 
511 	carp_proto_input_c(m, ch, AF_INET);
512 }
513 
514 #ifdef INET6
515 int
516 carp6_proto_input(struct mbuf **mp, int *offp, int proto)
517 {
518 	struct mbuf *m = *mp;
519 	struct carp_softc *sc = NULL;
520 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
521 	struct carp_header *ch;
522 	u_int len;
523 
524 	carpstats.carps_ipackets6++;
525 
526 	if (!carp_opts[CARPCTL_ALLOW]) {
527 		m_freem(m);
528 		return (IPPROTO_DONE);
529 	}
530 
531 	/* check if received on a valid carp interface */
532 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
533 		carpstats.carps_badif++;
534 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
535 		    m->m_pkthdr.rcvif->if_xname));
536 		m_freem(m);
537 		return (IPPROTO_DONE);
538 	}
539 
540 	/* verify that the IP TTL is 255 */
541 	if (ip6->ip6_hlim != CARP_DFLTTL) {
542 		carpstats.carps_badttl++;
543 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip6->ip6_hlim,
544 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
545 		m_freem(m);
546 		return (IPPROTO_DONE);
547 	}
548 
549 	/* verify that we have a complete carp packet */
550 	len = m->m_len;
551 	IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
552 	if (ch == NULL) {
553 		carpstats.carps_badlen++;
554 		CARP_LOG(sc, ("packet size %u too small", len));
555 		return (IPPROTO_DONE);
556 	}
557 
558 
559 	/* verify the CARP checksum */
560 	m->m_data += *offp;
561 	if (carp_cksum(m, sizeof(*ch))) {
562 		carpstats.carps_badsum++;
563 		CARP_LOG(sc, ("checksum failed, on %s",
564 		    m->m_pkthdr.rcvif->if_xname));
565 		m_freem(m);
566 		return (IPPROTO_DONE);
567 	}
568 	m->m_data -= *offp;
569 
570 	carp_proto_input_c(m, ch, AF_INET6);
571 	return (IPPROTO_DONE);
572 }
573 #endif /* INET6 */
574 
575 void
576 carp_proto_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
577 {
578 	struct carp_softc *sc;
579 	u_int64_t tmp_counter;
580 	struct timeval sc_tv, ch_tv;
581 
582 	TAILQ_FOREACH(sc, &((struct carp_if *)
583 	    m->m_pkthdr.rcvif->if_carpdev->if_carp)->vhif_vrs, sc_list)
584 		if (sc->sc_vhid == ch->carp_vhid)
585 			break;
586 
587 	if (!sc || (sc->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) !=
588 	    (IFF_UP|IFF_RUNNING)) {
589 		carpstats.carps_badvhid++;
590 		m_freem(m);
591 		return;
592 	}
593 
594 	/*
595 	 * Check if our own advertisement was duplicated
596 	 * from a non simplex interface.
597 	 * XXX If there is no address on our physical interface
598 	 * there is no way to distinguish our ads from the ones
599 	 * another carp host might have sent us.
600 	 */
601 	if ((sc->sc_carpdev->if_flags & IFF_SIMPLEX) == 0) {
602 		struct sockaddr sa;
603 		struct ifaddr *ifa;
604 
605 		bzero(&sa, sizeof(sa));
606 		sa.sa_family = af;
607 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
608 
609 		if (ifa && af == AF_INET) {
610 			struct ip *ip = mtod(m, struct ip *);
611 			if (ip->ip_src.s_addr ==
612 					ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
613 				m_freem(m);
614 				return;
615 			}
616 		}
617 #ifdef INET6
618 		if (ifa && af == AF_INET6) {
619 			struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
620 			struct in6_addr in6_src, in6_found;
621 
622 			in6_src = ip6->ip6_src;
623 			in6_found = ifatoia6(ifa)->ia_addr.sin6_addr;
624 			if (IN6_IS_ADDR_LINKLOCAL(&in6_src))
625 				in6_src.s6_addr16[1] = 0;
626 			if (IN6_IS_ADDR_LINKLOCAL(&in6_found))
627 				in6_found.s6_addr16[1] = 0;
628 			if (IN6_ARE_ADDR_EQUAL(&in6_src, &in6_found)) {
629 				m_freem(m);
630 				return;
631 			}
632 		}
633 #endif /* INET6 */
634 	}
635 
636 	microtime(&sc->sc_if.if_lastchange);
637 	sc->sc_if.if_ipackets++;
638 	sc->sc_if.if_ibytes += m->m_pkthdr.len;
639 
640 	/* verify the CARP version. */
641 	if (ch->carp_version != CARP_VERSION) {
642 		carpstats.carps_badver++;
643 		sc->sc_if.if_ierrors++;
644 		CARP_LOG(sc, ("invalid version %d != %d",
645 		    ch->carp_version, CARP_VERSION));
646 		m_freem(m);
647 		return;
648 	}
649 
650 	/* verify the hash */
651 	if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
652 		carpstats.carps_badauth++;
653 		sc->sc_if.if_ierrors++;
654 		CARP_LOG(sc, ("incorrect hash"));
655 		m_freem(m);
656 		return;
657 	}
658 
659 	tmp_counter = ntohl(ch->carp_counter[0]);
660 	tmp_counter = tmp_counter<<32;
661 	tmp_counter += ntohl(ch->carp_counter[1]);
662 
663 	/* XXX Replay protection goes here */
664 
665 	sc->sc_init_counter = 0;
666 	sc->sc_counter = tmp_counter;
667 
668 
669 	sc_tv.tv_sec = sc->sc_advbase;
670 	if (carp_suppress_preempt && sc->sc_advskew <  240)
671 		sc_tv.tv_usec = 240 * 1000000 / 256;
672 	else
673 		sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
674 	ch_tv.tv_sec = ch->carp_advbase;
675 	ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
676 
677 	switch (sc->sc_state) {
678 	case INIT:
679 		break;
680 	case MASTER:
681 		/*
682 		 * If we receive an advertisement from a backup who's going to
683 		 * be more frequent than us, go into BACKUP state.
684 		 */
685 		if (timercmp(&sc_tv, &ch_tv, >) ||
686 		    timercmp(&sc_tv, &ch_tv, ==)) {
687 			callout_stop(&sc->sc_ad_tmo);
688 			carp_set_state(sc, BACKUP);
689 			carp_setrun(sc, 0);
690 			carp_setroute(sc, RTM_DELETE);
691 		}
692 		break;
693 	case BACKUP:
694 		/*
695 		 * If we're pre-empting masters who advertise slower than us,
696 		 * and this one claims to be slower, treat him as down.
697 		 */
698 		if (carp_opts[CARPCTL_PREEMPT] && timercmp(&sc_tv, &ch_tv, <)) {
699 			carp_master_down(sc);
700 			break;
701 		}
702 
703 		/*
704 		 *  If the master is going to advertise at such a low frequency
705 		 *  that he's guaranteed to time out, we'd might as well just
706 		 *  treat him as timed out now.
707 		 */
708 		sc_tv.tv_sec = sc->sc_advbase * 3;
709 		if (timercmp(&sc_tv, &ch_tv, <)) {
710 			carp_master_down(sc);
711 			break;
712 		}
713 
714 		/*
715 		 * Otherwise, we reset the counter and wait for the next
716 		 * advertisement.
717 		 */
718 		carp_setrun(sc, af);
719 		break;
720 	}
721 
722 	m_freem(m);
723 	return;
724 }
725 
726 /*
727  * Interface side of the CARP implementation.
728  */
729 
730 /* ARGSUSED */
731 void
732 carpattach(int n)
733 {
734 	if_clone_attach(&carp_cloner);
735 }
736 
737 int
738 carp_clone_create(struct if_clone *ifc, int unit)
739 {
740 	extern int ifqmaxlen;
741 	struct carp_softc *sc;
742 	struct ifnet *ifp;
743 
744 	sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT);
745 	if (!sc)
746 		return (ENOMEM);
747 	bzero(sc, sizeof(*sc));
748 
749 	sc->sc_suppress = 0;
750 	sc->sc_advbase = CARP_DFLTINTV;
751 	sc->sc_vhid = -1;	/* required setting */
752 	sc->sc_advskew = 0;
753 	sc->sc_init_counter = 1;
754 	sc->sc_naddrs = sc->sc_naddrs6 = 0;
755 #ifdef INET6
756 	sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
757 #endif /* INET6 */
758 
759 	callout_init(&sc->sc_ad_tmo);
760 	callout_init(&sc->sc_md_tmo);
761 	callout_init(&sc->sc_md6_tmo);
762 
763 	callout_setfunc(&sc->sc_ad_tmo, carp_send_ad, sc);
764 	callout_setfunc(&sc->sc_md_tmo, carp_master_down, sc);
765 	callout_setfunc(&sc->sc_md6_tmo, carp_master_down, sc);
766 
767 	LIST_INIT(&sc->carp_mc_listhead);
768 	ifp = &sc->sc_if;
769 	ifp->if_softc = sc;
770 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "%s%d", ifc->ifc_name,
771 	    unit);
772 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
773 	ifp->if_ioctl = carp_ioctl;
774 	ifp->if_start = carp_start;
775 	ifp->if_output = carp_output;
776 	ifp->if_type = IFT_CARP;
777 	ifp->if_addrlen = ETHER_ADDR_LEN;
778 	ifp->if_hdrlen = ETHER_HDR_LEN;
779 	ifp->if_mtu = ETHERMTU;
780 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
781 	IFQ_SET_READY(&ifp->if_snd);
782 	if_attach(ifp);
783 
784 	if_alloc_sadl(ifp);
785 	ifp->if_broadcastaddr = etherbroadcastaddr;
786 	carp_set_enaddr(sc);
787 	LIST_INIT(&sc->sc_ac.ec_multiaddrs);
788 #if NBPFILTER > 0
789 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
790 #endif
791 	return (0);
792 }
793 
794 int
795 carp_clone_destroy(struct ifnet *ifp)
796 {
797 	carpdetach(ifp->if_softc);
798 	ether_ifdetach(ifp);
799 	if_detach(ifp);
800 	free(ifp->if_softc, M_DEVBUF);
801 
802 	return (0);
803 }
804 
805 void
806 carpdetach(struct carp_softc *sc)
807 {
808 	struct carp_if *cif;
809 	int s;
810 
811 	callout_stop(&sc->sc_ad_tmo);
812 	callout_stop(&sc->sc_md_tmo);
813 	callout_stop(&sc->sc_md6_tmo);
814 
815 	if (sc->sc_suppress)
816 		carp_suppress_preempt--;
817 	sc->sc_suppress = 0;
818 
819 	if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
820 		carp_suppress_preempt--;
821 	sc->sc_sendad_errors = 0;
822 
823 	carp_set_state(sc, INIT);
824 	sc->sc_if.if_flags &= ~IFF_UP;
825 	carp_setrun(sc, 0);
826 	carp_multicast_cleanup(sc);
827 
828 	s = splnet();
829 	if (sc->sc_carpdev != NULL) {
830 		/* XXX linkstatehook removal */
831 		cif = (struct carp_if *)sc->sc_carpdev->if_carp;
832 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
833 		if (!--cif->vhif_nvrs) {
834 			ifpromisc(sc->sc_carpdev, 0);
835 			sc->sc_carpdev->if_carp = NULL;
836 			FREE(cif, M_IFADDR);
837 		}
838 	}
839 	sc->sc_carpdev = NULL;
840 	splx(s);
841 }
842 
843 /* Detach an interface from the carp. */
844 void
845 carp_ifdetach(struct ifnet *ifp)
846 {
847 	struct carp_softc *sc, *nextsc;
848 	struct carp_if *cif = (struct carp_if *)ifp->if_carp;
849 
850 	for (sc = TAILQ_FIRST(&cif->vhif_vrs); sc; sc = nextsc) {
851 		nextsc = TAILQ_NEXT(sc, sc_list);
852 		carpdetach(sc);
853 	}
854 }
855 
856 int
857 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
858 {
859 	if (sc->sc_init_counter) {
860 		/* this could also be seconds since unix epoch */
861 		sc->sc_counter = arc4random();
862 		sc->sc_counter = sc->sc_counter << 32;
863 		sc->sc_counter += arc4random();
864 	} else
865 		sc->sc_counter++;
866 
867 	ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
868 	ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
869 
870 	carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
871 
872 	return (0);
873 }
874 
875 void
876 carp_send_ad_all(void)
877 {
878 	struct ifnet *ifp;
879 	struct carp_if *cif;
880 	struct carp_softc *vh;
881 
882 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
883 		if (ifp->if_carp == NULL || ifp->if_type == IFT_CARP)
884 			continue;
885 
886 		cif = (struct carp_if *)ifp->if_carp;
887 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
888 			if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
889 			    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER)
890 				carp_send_ad(vh);
891 		}
892 	}
893 }
894 
895 
896 void
897 carp_send_ad(void *v)
898 {
899 	struct carp_header ch;
900 	struct timeval tv;
901 	struct carp_softc *sc = v;
902 	struct carp_header *ch_ptr;
903 	struct mbuf *m;
904 	int error, len, advbase, advskew, s;
905 	struct ifaddr *ifa;
906 	struct sockaddr sa;
907 
908 	s = splsoftnet();
909 
910 	advbase = advskew = 0; /* Sssssh compiler */
911 	if (sc->sc_carpdev == NULL) {
912 		sc->sc_if.if_oerrors++;
913 		goto retry_later;
914 	}
915 
916 	/* bow out if we've gone to backup (the carp interface is going down) */
917 	if (sc->sc_bow_out) {
918 		sc->sc_bow_out = 0;
919 		advbase = 255;
920 		advskew = 255;
921 	} else {
922 		advbase = sc->sc_advbase;
923 		if (!carp_suppress_preempt || sc->sc_advskew > 240)
924 			advskew = sc->sc_advskew;
925 		else
926 			advskew = 240;
927 		tv.tv_sec = advbase;
928 		tv.tv_usec = advskew * 1000000 / 256;
929 	}
930 
931 	ch.carp_version = CARP_VERSION;
932 	ch.carp_type = CARP_ADVERTISEMENT;
933 	ch.carp_vhid = sc->sc_vhid;
934 	ch.carp_advbase = advbase;
935 	ch.carp_advskew = advskew;
936 	ch.carp_authlen = 7;	/* XXX DEFINE */
937 	ch.carp_pad1 = 0;	/* must be zero */
938 	ch.carp_cksum = 0;
939 
940 
941 #ifdef INET
942 	if (sc->sc_naddrs) {
943 		struct ip *ip;
944 
945 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
946 		if (m == NULL) {
947 			sc->sc_if.if_oerrors++;
948 			carpstats.carps_onomem++;
949 			/* XXX maybe less ? */
950 			goto retry_later;
951 		}
952 		len = sizeof(*ip) + sizeof(ch);
953 		m->m_pkthdr.len = len;
954 		m->m_pkthdr.rcvif = NULL;
955 		m->m_len = len;
956 		MH_ALIGN(m, m->m_len);
957 		m->m_flags |= M_MCAST;
958 		ip = mtod(m, struct ip *);
959 		ip->ip_v = IPVERSION;
960 		ip->ip_hl = sizeof(*ip) >> 2;
961 		ip->ip_tos = IPTOS_LOWDELAY;
962 		ip->ip_len = htons(len);
963 		ip->ip_id = htons(ip_randomid());
964 		ip->ip_off = htons(IP_DF);
965 		ip->ip_ttl = CARP_DFLTTL;
966 		ip->ip_p = IPPROTO_CARP;
967 		ip->ip_sum = 0;
968 
969 		bzero(&sa, sizeof(sa));
970 		sa.sa_family = AF_INET;
971 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
972 		if (ifa == NULL)
973 			ip->ip_src.s_addr = 0;
974 		else
975 			ip->ip_src.s_addr =
976 			    ifatoia(ifa)->ia_addr.sin_addr.s_addr;
977 		ip->ip_dst.s_addr = INADDR_CARP_GROUP;
978 
979 		ch_ptr = (struct carp_header *)(&ip[1]);
980 		bcopy(&ch, ch_ptr, sizeof(ch));
981 		if (carp_prepare_ad(m, sc, ch_ptr))
982 			goto retry_later;
983 
984 		m->m_data += sizeof(*ip);
985 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
986 		m->m_data -= sizeof(*ip);
987 
988 		microtime(&sc->sc_if.if_lastchange);
989 		sc->sc_if.if_opackets++;
990 		sc->sc_if.if_obytes += len;
991 		carpstats.carps_opackets++;
992 
993 		error = ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo,
994 		    NULL);
995 		if (error) {
996 			if (error == ENOBUFS)
997 				carpstats.carps_onomem++;
998 			else
999 				CARP_LOG(sc, ("ip_output failed: %d", error));
1000 			sc->sc_if.if_oerrors++;
1001 			if (sc->sc_sendad_errors < INT_MAX)
1002 				sc->sc_sendad_errors++;
1003 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1004 				carp_suppress_preempt++;
1005 				if (carp_suppress_preempt == 1)
1006 					carp_send_ad_all();
1007 			}
1008 			sc->sc_sendad_success = 0;
1009 		} else {
1010 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1011 				if (++sc->sc_sendad_success >=
1012 				    CARP_SENDAD_MIN_SUCCESS) {
1013 					carp_suppress_preempt--;
1014 					sc->sc_sendad_errors = 0;
1015 				}
1016 			} else
1017 				sc->sc_sendad_errors = 0;
1018 		}
1019 	}
1020 #endif /* INET */
1021 #ifdef INET6
1022 	if (sc->sc_naddrs6) {
1023 		struct ip6_hdr *ip6;
1024 
1025 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
1026 		if (m == NULL) {
1027 			sc->sc_if.if_oerrors++;
1028 			carpstats.carps_onomem++;
1029 			/* XXX maybe less ? */
1030 			goto retry_later;
1031 		}
1032 		len = sizeof(*ip6) + sizeof(ch);
1033 		m->m_pkthdr.len = len;
1034 		m->m_pkthdr.rcvif = NULL;
1035 		m->m_len = len;
1036 		MH_ALIGN(m, m->m_len);
1037 		m->m_flags |= M_MCAST;
1038 		ip6 = mtod(m, struct ip6_hdr *);
1039 		bzero(ip6, sizeof(*ip6));
1040 		ip6->ip6_vfc |= IPV6_VERSION;
1041 		ip6->ip6_hlim = CARP_DFLTTL;
1042 		ip6->ip6_nxt = IPPROTO_CARP;
1043 
1044 		/* set the source address */
1045 		bzero(&sa, sizeof(sa));
1046 		sa.sa_family = AF_INET6;
1047 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
1048 		if (ifa == NULL)	/* This should never happen with IPv6 */
1049 			bzero(&ip6->ip6_src, sizeof(struct in6_addr));
1050 		else
1051 			bcopy(ifatoia6(ifa)->ia_addr.sin6_addr.s6_addr,
1052 			    &ip6->ip6_src, sizeof(struct in6_addr));
1053 		/* set the multicast destination */
1054 
1055 		ip6->ip6_dst.s6_addr8[0] = 0xff;
1056 		ip6->ip6_dst.s6_addr8[1] = 0x02;
1057 		ip6->ip6_dst.s6_addr8[15] = 0x12;
1058 
1059 		ch_ptr = (struct carp_header *)(&ip6[1]);
1060 		bcopy(&ch, ch_ptr, sizeof(ch));
1061 		if (carp_prepare_ad(m, sc, ch_ptr))
1062 			goto retry_later;
1063 
1064 		m->m_data += sizeof(*ip6);
1065 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
1066 		m->m_data -= sizeof(*ip6);
1067 
1068 		microtime(&sc->sc_if.if_lastchange);
1069 		sc->sc_if.if_opackets++;
1070 		sc->sc_if.if_obytes += len;
1071 		carpstats.carps_opackets6++;
1072 
1073 		error = ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL);
1074 		if (error) {
1075 			if (error == ENOBUFS)
1076 				carpstats.carps_onomem++;
1077 			else
1078 				CARP_LOG(sc, ("ip6_output failed: %d", error));
1079 			sc->sc_if.if_oerrors++;
1080 			if (sc->sc_sendad_errors < INT_MAX)
1081 				sc->sc_sendad_errors++;
1082 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1083 				carp_suppress_preempt++;
1084 				if (carp_suppress_preempt == 1)
1085 					carp_send_ad_all();
1086 			}
1087 			sc->sc_sendad_success = 0;
1088 		} else {
1089 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1090 				if (++sc->sc_sendad_success >=
1091 				    CARP_SENDAD_MIN_SUCCESS) {
1092 					carp_suppress_preempt--;
1093 					sc->sc_sendad_errors = 0;
1094 				}
1095 			} else
1096 				sc->sc_sendad_errors = 0;
1097 		}
1098 	}
1099 #endif /* INET6 */
1100 
1101 retry_later:
1102 	splx(s);
1103 	if (advbase != 255 || advskew != 255)
1104 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1105 }
1106 
1107 /*
1108  * Broadcast a gratuitous ARP request containing
1109  * the virtual router MAC address for each IP address
1110  * associated with the virtual router.
1111  */
1112 void
1113 carp_send_arp(struct carp_softc *sc)
1114 {
1115 	struct ifaddr *ifa;
1116 	struct in_addr *in;
1117 	int s = splsoftnet();
1118 
1119 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
1120 
1121 		if (ifa->ifa_addr->sa_family != AF_INET)
1122 			continue;
1123 
1124 		in = &ifatoia(ifa)->ia_addr.sin_addr;
1125 		arprequest(sc->sc_carpdev, in, in, LLADDR(sc->sc_if.if_sadl));
1126 		DELAY(1000);	/* XXX */
1127 	}
1128 	splx(s);
1129 }
1130 
1131 #ifdef INET6
1132 void
1133 carp_send_na(struct carp_softc *sc)
1134 {
1135 	struct ifaddr *ifa;
1136 	struct in6_addr *in6;
1137 	static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1138 	int s = splsoftnet();
1139 
1140 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
1141 
1142 		if (ifa->ifa_addr->sa_family != AF_INET6)
1143 			continue;
1144 
1145 		in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1146 		nd6_na_output(sc->sc_carpdev, &mcast, in6,
1147 		    ND_NA_FLAG_OVERRIDE, 1, NULL);
1148 		DELAY(1000);	/* XXX */
1149 	}
1150 	splx(s);
1151 }
1152 #endif /* INET6 */
1153 
1154 /*
1155  * Based on bridge_hash() in if_bridge.c
1156  */
1157 #define	mix(a,b,c) \
1158 	do {						\
1159 		a -= b; a -= c; a ^= (c >> 13);		\
1160 		b -= c; b -= a; b ^= (a << 8);		\
1161 		c -= a; c -= b; c ^= (b >> 13);		\
1162 		a -= b; a -= c; a ^= (c >> 12);		\
1163 		b -= c; b -= a; b ^= (a << 16);		\
1164 		c -= a; c -= b; c ^= (b >> 5);		\
1165 		a -= b; a -= c; a ^= (c >> 3);		\
1166 		b -= c; b -= a; b ^= (a << 10);		\
1167 		c -= a; c -= b; c ^= (b >> 15);		\
1168 	} while (0)
1169 
1170 u_int32_t
1171 carp_hash(struct carp_softc *sc, u_char *src)
1172 {
1173 	u_int32_t a = 0x9e3779b9, b = sc->sc_hashkey[0], c = sc->sc_hashkey[1];
1174 
1175 	c += sc->sc_key[3] << 24;
1176 	c += sc->sc_key[2] << 16;
1177 	c += sc->sc_key[1] << 8;
1178 	c += sc->sc_key[0];
1179 	b += src[5] << 8;
1180 	b += src[4];
1181 	a += src[3] << 24;
1182 	a += src[2] << 16;
1183 	a += src[1] << 8;
1184 	a += src[0];
1185 
1186 	mix(a, b, c);
1187 	return (c);
1188 }
1189 
1190 int
1191 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
1192 {
1193 	struct carp_softc *vh;
1194 	struct ifaddr *ifa;
1195 	int count = 0;
1196 
1197 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1198 		if ((type == CARP_COUNT_RUNNING &&
1199 		    (vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1200 		    (IFF_UP|IFF_RUNNING)) ||
1201 		    (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
1202 			TAILQ_FOREACH(ifa, &vh->sc_if.if_addrlist, ifa_list) {
1203 				if (ifa->ifa_addr->sa_family == AF_INET &&
1204 				    ia->ia_addr.sin_addr.s_addr ==
1205 				    ifatoia(ifa)->ia_addr.sin_addr.s_addr)
1206 					count++;
1207 			}
1208 		}
1209 	}
1210 	return (count);
1211 }
1212 
1213 int
1214 carp_iamatch(struct in_ifaddr *ia, u_char *src,
1215     u_int32_t *count, u_int32_t index)
1216 {
1217 	struct carp_softc *sc = ia->ia_ifp->if_softc;
1218 
1219 	if (carp_opts[CARPCTL_ARPBALANCE]) {
1220 		/*
1221 		 * We use the source ip to decide which virtual host should
1222 		 * handle the request. If we're master of that virtual host,
1223 		 * then we respond, otherwise, just drop the arp packet on
1224 		 * the floor.
1225 		 */
1226 
1227 		/* Count the elegible carp interfaces with this address */
1228 		if (*count == 0)
1229 			*count = carp_addrcount(
1230 			    (struct carp_if *)ia->ia_ifp->if_carpdev->if_carp,
1231 			    ia, CARP_COUNT_RUNNING);
1232 
1233 		/* This should never happen, but... */
1234 		if (*count == 0)
1235 			return (0);
1236 
1237 		if (carp_hash(sc, src) % *count == index - 1 &&
1238 		    sc->sc_state == MASTER) {
1239 			return (1);
1240 		}
1241 	} else {
1242 		if (sc->sc_state == MASTER)
1243 			return (1);
1244 	}
1245 
1246 	return (0);
1247 }
1248 
1249 #ifdef INET6
1250 struct ifaddr *
1251 carp_iamatch6(void *v, struct in6_addr *taddr)
1252 {
1253 	struct carp_if *cif = v;
1254 	struct carp_softc *vh;
1255 	struct ifaddr *ifa;
1256 
1257 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1258 		TAILQ_FOREACH(ifa, &vh->sc_if.if_addrlist, ifa_list) {
1259 			if (IN6_ARE_ADDR_EQUAL(taddr,
1260 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1261 			    ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1262 			    (IFF_UP|IFF_RUNNING)) && vh->sc_state == MASTER)
1263 				return (ifa);
1264 		}
1265 	}
1266 
1267 	return (NULL);
1268 }
1269 #endif /* INET6 */
1270 
1271 struct ifnet *
1272 carp_ourether(void *v, struct ether_header *eh, u_char iftype, int src)
1273 {
1274 	struct carp_if *cif = (struct carp_if *)v;
1275 	struct carp_softc *vh;
1276 	u_int8_t *ena;
1277 
1278 	if (src)
1279 		ena = (u_int8_t *)&eh->ether_shost;
1280 	else
1281 		ena = (u_int8_t *)&eh->ether_dhost;
1282 
1283 	switch (iftype) {
1284 	case IFT_ETHER:
1285 	case IFT_FDDI:
1286 		if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1287 			return (NULL);
1288 		break;
1289 	case IFT_ISO88025:
1290 		if (ena[0] != 3 || ena[1] || ena[4] || ena[5])
1291 			return (NULL);
1292 		break;
1293 	default:
1294 		return (NULL);
1295 		break;
1296 	}
1297 
1298 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
1299 		if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1300 		    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER &&
1301 		    !bcmp(ena, LLADDR(vh->sc_if.if_sadl),
1302 		    ETHER_ADDR_LEN)) {
1303 			return (&vh->sc_if);
1304 		    }
1305 
1306 	return (NULL);
1307 }
1308 
1309 int
1310 carp_input(struct mbuf *m, u_int8_t *shost, u_int8_t *dhost, u_int16_t etype)
1311 {
1312 	struct ether_header eh;
1313 	struct carp_if *cif = (struct carp_if *)m->m_pkthdr.rcvif->if_carp;
1314 	struct ifnet *ifp;
1315 
1316 	bcopy(shost, &eh.ether_shost, sizeof(eh.ether_shost));
1317 	bcopy(dhost, &eh.ether_dhost, sizeof(eh.ether_dhost));
1318 	eh.ether_type = etype;
1319 
1320 	if (m->m_flags & (M_BCAST|M_MCAST)) {
1321 		struct carp_softc *vh;
1322 		struct mbuf *m0;
1323 
1324 		/*
1325 		 * XXX Should really check the list of multicast addresses
1326 		 * for each CARP interface _before_ copying.
1327 		 */
1328 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1329 			m0 = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
1330 			if (m0 == NULL)
1331 				continue;
1332 			m0->m_pkthdr.rcvif = &vh->sc_if;
1333 			ether_input(&vh->sc_if, m0);
1334 		}
1335 		return (1);
1336 	}
1337 
1338 	ifp = carp_ourether(cif, &eh, m->m_pkthdr.rcvif->if_type, 0);
1339 	if (ifp == NULL) {
1340 		return (1);
1341 	}
1342 
1343 	m->m_pkthdr.rcvif = ifp;
1344 
1345 #if NBPFILTER > 0
1346 	if (ifp->if_bpf)
1347 		bpf_mtap(ifp->if_bpf, m);
1348 #endif
1349 	ifp->if_ipackets++;
1350 	ether_input(ifp, m);
1351 	return (0);
1352 }
1353 
1354 void
1355 carp_master_down(void *v)
1356 {
1357 	struct carp_softc *sc = v;
1358 
1359 	switch (sc->sc_state) {
1360 	case INIT:
1361 		printf("%s: master_down event in INIT state\n",
1362 		    sc->sc_if.if_xname);
1363 		break;
1364 	case MASTER:
1365 		break;
1366 	case BACKUP:
1367 		carp_set_state(sc, MASTER);
1368 		carp_send_ad(sc);
1369 		carp_send_arp(sc);
1370 #ifdef INET6
1371 		carp_send_na(sc);
1372 #endif /* INET6 */
1373 		carp_setrun(sc, 0);
1374 		carp_setroute(sc, RTM_ADD);
1375 		break;
1376 	}
1377 }
1378 
1379 /*
1380  * When in backup state, af indicates whether to reset the master down timer
1381  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1382  */
1383 void
1384 carp_setrun(struct carp_softc *sc, sa_family_t af)
1385 {
1386 	struct timeval tv;
1387 
1388 	if (sc->sc_carpdev == NULL) {
1389 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1390 		carp_set_state(sc, INIT);
1391 		return;
1392 	}
1393 
1394 	if (sc->sc_if.if_flags & IFF_UP && sc->sc_vhid > 0 &&
1395 	    (sc->sc_naddrs || sc->sc_naddrs6) && !sc->sc_suppress) {
1396 		sc->sc_if.if_flags |= IFF_RUNNING;
1397 	} else {
1398 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1399 		carp_setroute(sc, RTM_DELETE);
1400 		return;
1401 	}
1402 
1403 	switch (sc->sc_state) {
1404 	case INIT:
1405 		carp_set_state(sc, BACKUP);
1406 		carp_setroute(sc, RTM_DELETE);
1407 		carp_setrun(sc, 0);
1408 		break;
1409 	case BACKUP:
1410 		callout_stop(&sc->sc_ad_tmo);
1411 		tv.tv_sec = 3 * sc->sc_advbase;
1412 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1413 		switch (af) {
1414 #ifdef INET
1415 		case AF_INET:
1416 			callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1417 			break;
1418 #endif /* INET */
1419 #ifdef INET6
1420 		case AF_INET6:
1421 			callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1422 			break;
1423 #endif /* INET6 */
1424 		default:
1425 			if (sc->sc_naddrs)
1426 				callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1427 			if (sc->sc_naddrs6)
1428 				callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1429 			break;
1430 		}
1431 		break;
1432 	case MASTER:
1433 		tv.tv_sec = sc->sc_advbase;
1434 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1435 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1436 		break;
1437 	}
1438 }
1439 
1440 void
1441 carp_multicast_cleanup(struct carp_softc *sc)
1442 {
1443 	struct ip_moptions *imo = &sc->sc_imo;
1444 #ifdef INET6
1445 	struct ip6_moptions *im6o = &sc->sc_im6o;
1446 #endif
1447 	u_int16_t n = imo->imo_num_memberships;
1448 
1449 	/* Clean up our own multicast memberships */
1450 	while (n-- > 0) {
1451 		if (imo->imo_membership[n] != NULL) {
1452 			in_delmulti(imo->imo_membership[n]);
1453 			imo->imo_membership[n] = NULL;
1454 		}
1455 	}
1456 	imo->imo_num_memberships = 0;
1457 	imo->imo_multicast_ifp = NULL;
1458 
1459 #ifdef INET6
1460 	while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1461 		struct in6_multi_mship *imm =
1462 		    LIST_FIRST(&im6o->im6o_memberships);
1463 
1464 		LIST_REMOVE(imm, i6mm_chain);
1465 		in6_leavegroup(imm);
1466 	}
1467 	im6o->im6o_multicast_ifp = NULL;
1468 #endif
1469 
1470 	/* And any other multicast memberships */
1471 	carp_ether_purgemulti(sc);
1472 }
1473 
1474 int
1475 carp_set_ifp(struct carp_softc *sc, struct ifnet *ifp)
1476 {
1477 	struct carp_if *cif, *ncif = NULL;
1478 	struct carp_softc *vr, *after = NULL;
1479 	int myself = 0, error = 0;
1480 	int s;
1481 
1482 	if (ifp == sc->sc_carpdev)
1483 		return (0);
1484 
1485 	if (ifp != NULL) {
1486 		if ((ifp->if_flags & IFF_MULTICAST) == 0)
1487 			return (EADDRNOTAVAIL);
1488 
1489 		if (ifp->if_type == IFT_CARP)
1490 			return (EINVAL);
1491 
1492 		if (ifp->if_carp == NULL) {
1493 			MALLOC(ncif, struct carp_if *, sizeof(*cif),
1494 			    M_IFADDR, M_NOWAIT);
1495 			if (ncif == NULL)
1496 				return (ENOBUFS);
1497 			if ((error = ifpromisc(ifp, 1))) {
1498 				FREE(ncif, M_IFADDR);
1499 				return (error);
1500 			}
1501 
1502 			ncif->vhif_ifp = ifp;
1503 			TAILQ_INIT(&ncif->vhif_vrs);
1504 		} else {
1505 			cif = (struct carp_if *)ifp->if_carp;
1506 			TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1507 				if (vr != sc && vr->sc_vhid == sc->sc_vhid)
1508 					return (EINVAL);
1509 		}
1510 
1511 		/* detach from old interface */
1512 		if (sc->sc_carpdev != NULL)
1513 			carpdetach(sc);
1514 
1515 		/* join multicast groups */
1516 		if (sc->sc_naddrs < 0 &&
1517 		    (error = carp_join_multicast(sc)) != 0) {
1518 			if (ncif != NULL)
1519 				FREE(ncif, M_IFADDR);
1520 			return (error);
1521 		}
1522 
1523 #ifdef INET6
1524 		if (sc->sc_naddrs6 < 0 &&
1525 		    (error = carp_join_multicast6(sc)) != 0) {
1526 			if (ncif != NULL)
1527 				FREE(ncif, M_IFADDR);
1528 			carp_multicast_cleanup(sc);
1529 			return (error);
1530 		}
1531 #endif
1532 
1533 		/* attach carp interface to physical interface */
1534 		if (ncif != NULL)
1535 			ifp->if_carp = (caddr_t)ncif;
1536 		sc->sc_carpdev = ifp;
1537 		cif = (struct carp_if *)ifp->if_carp;
1538 		TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1539 			if (vr == sc)
1540 				myself = 1;
1541 			if (vr->sc_vhid < sc->sc_vhid)
1542 				after = vr;
1543 		}
1544 
1545 		if (!myself) {
1546 			/* We're trying to keep things in order */
1547 			if (after == NULL) {
1548 				TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1549 			} else {
1550 				TAILQ_INSERT_AFTER(&cif->vhif_vrs, after,
1551 				    sc, sc_list);
1552 			}
1553 			cif->vhif_nvrs++;
1554 		}
1555 		if (sc->sc_naddrs || sc->sc_naddrs6)
1556 			sc->sc_if.if_flags |= IFF_UP;
1557 		carp_set_enaddr(sc);
1558 		s = splnet();
1559 		/* XXX linkstatehooks establish */
1560 		carp_carpdev_state(ifp);
1561 		splx(s);
1562 	} else {
1563 		carpdetach(sc);
1564 		sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
1565 	}
1566 	return (0);
1567 }
1568 
1569 void
1570 carp_set_enaddr(struct carp_softc *sc)
1571 {
1572 	if (sc->sc_carpdev && sc->sc_carpdev->if_type == IFT_ISO88025) {
1573 		LLADDR(sc->sc_if.if_sadl)[0] = 3;
1574 		LLADDR(sc->sc_if.if_sadl)[1] = 0;
1575 		LLADDR(sc->sc_if.if_sadl)[2] = 0x40 >> (sc->sc_vhid - 1);
1576 		LLADDR(sc->sc_if.if_sadl)[3] = 0x40000 >> (sc->sc_vhid - 1);
1577 		LLADDR(sc->sc_if.if_sadl)[4] = 0;
1578 		LLADDR(sc->sc_if.if_sadl)[5] = 0;
1579 	} else {
1580 		LLADDR(sc->sc_if.if_sadl)[0] = 0;
1581 		LLADDR(sc->sc_if.if_sadl)[1] = 0;
1582 		LLADDR(sc->sc_if.if_sadl)[2] = 0x5e;
1583 		LLADDR(sc->sc_if.if_sadl)[3] = 0;
1584 		LLADDR(sc->sc_if.if_sadl)[4] = 1;
1585 		LLADDR(sc->sc_if.if_sadl)[5] = sc->sc_vhid;
1586 	}
1587 }
1588 
1589 void
1590 carp_addr_updated(void *v)
1591 {
1592 	struct carp_softc *sc = (struct carp_softc *) v;
1593 	struct ifaddr *ifa;
1594 	int new_naddrs = 0, new_naddrs6 = 0;
1595 
1596 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
1597 		if (ifa->ifa_addr->sa_family == AF_INET)
1598 			new_naddrs++;
1599 		else if (ifa->ifa_addr->sa_family == AF_INET6)
1600 			new_naddrs6++;
1601 	}
1602 
1603 	/* Handle a callback after SIOCDIFADDR */
1604 	if (new_naddrs < sc->sc_naddrs || new_naddrs6 < sc->sc_naddrs6) {
1605 		struct in_addr mc_addr;
1606 		struct in_multi *inm;
1607 
1608 		sc->sc_naddrs = new_naddrs;
1609 		sc->sc_naddrs6 = new_naddrs6;
1610 
1611 		/* Re-establish multicast membership removed by in_control */
1612 		mc_addr.s_addr = INADDR_CARP_GROUP;
1613 		IN_LOOKUP_MULTI(mc_addr, &sc->sc_if, inm);
1614 		if (inm == NULL) {
1615 			bzero(&sc->sc_imo, sizeof(sc->sc_imo));
1616 
1617 			if (sc->sc_carpdev != NULL && sc->sc_naddrs > 0)
1618 				carp_join_multicast(sc);
1619 		}
1620 
1621 		if (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) {
1622 			sc->sc_if.if_flags &= ~IFF_UP;
1623 			carp_set_state(sc, INIT);
1624 		} else
1625 			carp_hmac_prepare(sc);
1626 	}
1627 
1628 	carp_setrun(sc, 0);
1629 }
1630 
1631 int
1632 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1633 {
1634 	struct ifnet *ifp = sc->sc_carpdev;
1635 	struct in_ifaddr *ia, *ia_if;
1636 	int error = 0;
1637 
1638 	if (sin->sin_addr.s_addr == 0) {
1639 		if (!(sc->sc_if.if_flags & IFF_UP))
1640 			carp_set_state(sc, INIT);
1641 		if (sc->sc_naddrs)
1642 			sc->sc_if.if_flags |= IFF_UP;
1643 		carp_setrun(sc, 0);
1644 		return (0);
1645 	}
1646 
1647 	/* we have to do this by hand to ensure we don't match on ourselves */
1648 	ia_if = NULL;
1649 	for (ia = TAILQ_FIRST(&in_ifaddrhead); ia;
1650 	    ia = TAILQ_NEXT(ia, ia_list)) {
1651 
1652 		/* and, yeah, we need a multicast-capable iface too */
1653 		if (ia->ia_ifp != &sc->sc_if &&
1654 		    ia->ia_ifp->if_type != IFT_CARP &&
1655 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1656 		    (sin->sin_addr.s_addr & ia->ia_subnetmask) ==
1657 		    ia->ia_subnet) {
1658 			if (!ia_if)
1659 				ia_if = ia;
1660 		}
1661 	}
1662 
1663 	if (ia_if) {
1664 		ia = ia_if;
1665 		if (ifp) {
1666 			if (ifp != ia->ia_ifp)
1667 				return (EADDRNOTAVAIL);
1668 		} else {
1669 			ifp = ia->ia_ifp;
1670 		}
1671 	}
1672 
1673 	if ((error = carp_set_ifp(sc, ifp)))
1674 		return (error);
1675 
1676 	if (sc->sc_carpdev == NULL)
1677 		return (EADDRNOTAVAIL);
1678 
1679 	if (sc->sc_naddrs == 0 && (error = carp_join_multicast(sc)) != 0)
1680 		return (error);
1681 
1682 	sc->sc_naddrs++;
1683 	if (sc->sc_carpdev != NULL)
1684 		sc->sc_if.if_flags |= IFF_UP;
1685 
1686 	carp_set_state(sc, INIT);
1687 	carp_setrun(sc, 0);
1688 
1689 	/*
1690 	 * Hook if_addrhooks so that we get a callback after in_ifinit has run,
1691 	 * to correct any inappropriate routes that it inserted.
1692 	 */
1693 	if (sc->ah_cookie == 0) {
1694 		/* XXX link address hook */
1695 	}
1696 
1697 	return (0);
1698 }
1699 
1700 int
1701 carp_join_multicast(struct carp_softc *sc)
1702 {
1703 	struct ip_moptions *imo = &sc->sc_imo, tmpimo;
1704 	struct in_addr addr;
1705 
1706 	bzero(&tmpimo, sizeof(tmpimo));
1707 	addr.s_addr = INADDR_CARP_GROUP;
1708 	if ((tmpimo.imo_membership[0] =
1709 	    in_addmulti(&addr, &sc->sc_if)) == NULL) {
1710 		return (ENOBUFS);
1711 	}
1712 
1713 	imo->imo_membership[0] = tmpimo.imo_membership[0];
1714 	imo->imo_num_memberships = 1;
1715 	imo->imo_multicast_ifp = &sc->sc_if;
1716 	imo->imo_multicast_ttl = CARP_DFLTTL;
1717 	imo->imo_multicast_loop = 0;
1718 	return (0);
1719 }
1720 
1721 
1722 #ifdef INET6
1723 int
1724 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1725 {
1726 	struct ifnet *ifp = sc->sc_carpdev;
1727 	struct in6_ifaddr *ia, *ia_if;
1728 	int error = 0;
1729 
1730 	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1731 		if (!(sc->sc_if.if_flags & IFF_UP))
1732 			carp_set_state(sc, INIT);
1733 		if (sc->sc_naddrs6)
1734 			sc->sc_if.if_flags |= IFF_UP;
1735 		carp_setrun(sc, 0);
1736 		return (0);
1737 	}
1738 
1739 	/* we have to do this by hand to ensure we don't match on ourselves */
1740 	ia_if = NULL;
1741 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1742 		int i;
1743 
1744 		for (i = 0; i < 4; i++) {
1745 			if ((sin6->sin6_addr.s6_addr32[i] &
1746 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1747 			    (ia->ia_addr.sin6_addr.s6_addr32[i] &
1748 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1749 				break;
1750 		}
1751 		/* and, yeah, we need a multicast-capable iface too */
1752 		if (ia->ia_ifp != &sc->sc_if &&
1753 		    ia->ia_ifp->if_type != IFT_CARP &&
1754 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1755 		    (i == 4)) {
1756 			if (!ia_if)
1757 				ia_if = ia;
1758 		}
1759 	}
1760 
1761 	if (ia_if) {
1762 		ia = ia_if;
1763 		if (sc->sc_carpdev) {
1764 			if (sc->sc_carpdev != ia->ia_ifp)
1765 				return (EADDRNOTAVAIL);
1766 		} else {
1767 			ifp = ia->ia_ifp;
1768 		}
1769 	}
1770 
1771 	if ((error = carp_set_ifp(sc, ifp)))
1772 		return (error);
1773 
1774 	if (sc->sc_carpdev == NULL)
1775 		return (EADDRNOTAVAIL);
1776 
1777 	if (sc->sc_naddrs6 == 0 && (error = carp_join_multicast6(sc)) != 0)
1778 		return (error);
1779 
1780 	sc->sc_naddrs6++;
1781 	if (sc->sc_carpdev != NULL)
1782 		sc->sc_if.if_flags |= IFF_UP;
1783 	carp_set_state(sc, INIT);
1784 	carp_setrun(sc, 0);
1785 
1786 	return (0);
1787 }
1788 
1789 int
1790 carp_join_multicast6(struct carp_softc *sc)
1791 {
1792 	struct in6_multi_mship *imm, *imm2;
1793 	struct ip6_moptions *im6o = &sc->sc_im6o;
1794 	struct sockaddr_in6 addr6;
1795 	int error;
1796 
1797 	/* Join IPv6 CARP multicast group */
1798 	bzero(&addr6, sizeof(addr6));
1799 	addr6.sin6_family = AF_INET6;
1800 	addr6.sin6_len = sizeof(addr6);
1801 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1802 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1803 	addr6.sin6_addr.s6_addr8[15] = 0x12;
1804 	if ((imm = in6_joingroup(&sc->sc_if,
1805 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1806 		return (error);
1807 	}
1808 	/* join solicited multicast address */
1809 	bzero(&addr6.sin6_addr, sizeof(addr6.sin6_addr));
1810 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1811 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1812 	addr6.sin6_addr.s6_addr32[1] = 0;
1813 	addr6.sin6_addr.s6_addr32[2] = htonl(1);
1814 	addr6.sin6_addr.s6_addr32[3] = 0;
1815 	addr6.sin6_addr.s6_addr8[12] = 0xff;
1816 	if ((imm2 = in6_joingroup(&sc->sc_if,
1817 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1818 		in6_leavegroup(imm);
1819 		return (error);
1820 	}
1821 
1822 	/* apply v6 multicast membership */
1823 	im6o->im6o_multicast_ifp = &sc->sc_if;
1824 	if (imm)
1825 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm,
1826 		    i6mm_chain);
1827 	if (imm2)
1828 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm2,
1829 		    i6mm_chain);
1830 
1831 	return (0);
1832 }
1833 
1834 #endif /* INET6 */
1835 
1836 int
1837 carp_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
1838 {
1839 	struct proc *p = curlwp->l_proc;	/* XXX */
1840 	struct carp_softc *sc = ifp->if_softc, *vr;
1841 	struct carpreq carpr;
1842 	struct ifaddr *ifa;
1843 	struct ifreq *ifr;
1844 	struct ifaliasreq *ifra;
1845 	struct ifnet *cdev = NULL;
1846 	int error = 0;
1847 
1848 	ifa = (struct ifaddr *)addr;
1849 	ifra = (struct ifaliasreq *)addr;
1850 	ifr = (struct ifreq *)addr;
1851 
1852 	switch (cmd) {
1853 	case SIOCSIFADDR:
1854 		switch (ifa->ifa_addr->sa_family) {
1855 #ifdef INET
1856 		case AF_INET:
1857 			sc->sc_if.if_flags |= IFF_UP;
1858 			bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1859 			    sizeof(struct sockaddr));
1860 			error = carp_set_addr(sc, satosin(ifa->ifa_addr));
1861 			break;
1862 #endif /* INET */
1863 #ifdef INET6
1864 		case AF_INET6:
1865 			sc->sc_if.if_flags|= IFF_UP;
1866 			error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1867 			break;
1868 #endif /* INET6 */
1869 		default:
1870 			error = EAFNOSUPPORT;
1871 			break;
1872 		}
1873 		break;
1874 
1875 	case SIOCAIFADDR:
1876 		switch (ifa->ifa_addr->sa_family) {
1877 #ifdef INET
1878 		case AF_INET:
1879 			sc->sc_if.if_flags |= IFF_UP;
1880 			bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1881 			    sizeof(struct sockaddr));
1882 			error = carp_set_addr(sc, satosin(&ifra->ifra_addr));
1883 			break;
1884 #endif /* INET */
1885 #ifdef INET6
1886 		case AF_INET6:
1887 			sc->sc_if.if_flags |= IFF_UP;
1888 			error = carp_set_addr6(sc, satosin6(&ifra->ifra_addr));
1889 			break;
1890 #endif /* INET6 */
1891 		default:
1892 			error = EAFNOSUPPORT;
1893 			break;
1894 		}
1895 		break;
1896 
1897 	case SIOCSIFFLAGS:
1898 		if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
1899 			callout_stop(&sc->sc_ad_tmo);
1900 			callout_stop(&sc->sc_md_tmo);
1901 			callout_stop(&sc->sc_md6_tmo);
1902 			if (sc->sc_state == MASTER) {
1903 				/* we need the interface up to bow out */
1904 				sc->sc_if.if_flags |= IFF_UP;
1905 				sc->sc_bow_out = 1;
1906 				carp_send_ad(sc);
1907 			}
1908 			sc->sc_if.if_flags &= ~IFF_UP;
1909 			carp_set_state(sc, INIT);
1910 			carp_setrun(sc, 0);
1911 		} else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
1912 			sc->sc_if.if_flags |= IFF_UP;
1913 			carp_setrun(sc, 0);
1914 		}
1915 		break;
1916 
1917 	case SIOCSVH:
1918 		if (p == 0 || (error = kauth_authorize_generic(p->p_cred,
1919 		    KAUTH_GENERIC_ISSUSER, &p->p_acflag)))
1920 			break;
1921 		if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
1922 			break;
1923 		error = 1;
1924 		if (carpr.carpr_carpdev[0] != '\0' &&
1925 		    (cdev = ifunit(carpr.carpr_carpdev)) == NULL)
1926 			return (EINVAL);
1927 		if ((error = carp_set_ifp(sc, cdev)))
1928 			return (error);
1929 		if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
1930 			switch (carpr.carpr_state) {
1931 			case BACKUP:
1932 				callout_stop(&sc->sc_ad_tmo);
1933 				carp_set_state(sc, BACKUP);
1934 				carp_setrun(sc, 0);
1935 				carp_setroute(sc, RTM_DELETE);
1936 				break;
1937 			case MASTER:
1938 				carp_master_down(sc);
1939 				break;
1940 			default:
1941 				break;
1942 			}
1943 		}
1944 		if (carpr.carpr_vhid > 0) {
1945 			if (carpr.carpr_vhid > 255) {
1946 				error = EINVAL;
1947 				break;
1948 			}
1949 			if (sc->sc_carpdev) {
1950 				struct carp_if *cif;
1951 				cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1952 				TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1953 					if (vr != sc &&
1954 					    vr->sc_vhid == carpr.carpr_vhid)
1955 						return (EINVAL);
1956 			}
1957 			sc->sc_vhid = carpr.carpr_vhid;
1958 			carp_set_enaddr(sc);
1959 			carp_set_state(sc, INIT);
1960 			error--;
1961 		}
1962 		if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
1963 			if (carpr.carpr_advskew > 254) {
1964 				error = EINVAL;
1965 				break;
1966 			}
1967 			if (carpr.carpr_advbase > 255) {
1968 				error = EINVAL;
1969 				break;
1970 			}
1971 			sc->sc_advbase = carpr.carpr_advbase;
1972 			sc->sc_advskew = carpr.carpr_advskew;
1973 			error--;
1974 		}
1975 		bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1976 		if (error > 0)
1977 			error = EINVAL;
1978 		else {
1979 			error = 0;
1980 			carp_setrun(sc, 0);
1981 		}
1982 		break;
1983 
1984 	case SIOCGVH:
1985 		bzero(&carpr, sizeof(carpr));
1986 		if (sc->sc_carpdev != NULL)
1987 			strlcpy(carpr.carpr_carpdev, sc->sc_carpdev->if_xname,
1988 			    IFNAMSIZ);
1989 		carpr.carpr_state = sc->sc_state;
1990 		carpr.carpr_vhid = sc->sc_vhid;
1991 		carpr.carpr_advbase = sc->sc_advbase;
1992 		carpr.carpr_advskew = sc->sc_advskew;
1993 
1994 		if (p != 0 || !(error = kauth_authorize_generic(p->p_cred,
1995 		    KAUTH_GENERIC_ISSUSER, &p->p_acflag)))
1996 			bcopy(sc->sc_key, carpr.carpr_key,
1997 			    sizeof(carpr.carpr_key));
1998 		error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
1999 		break;
2000 
2001 	case SIOCADDMULTI:
2002 		error = carp_ether_addmulti(sc, ifr);
2003 		break;
2004 
2005 	case SIOCDELMULTI:
2006 		error = carp_ether_delmulti(sc, ifr);
2007 		break;
2008 
2009 	default:
2010 		error = EINVAL;
2011 	}
2012 
2013 	carp_hmac_prepare(sc);
2014 	return (error);
2015 }
2016 
2017 
2018 /*
2019  * Start output on carp interface. This function should never be called.
2020  */
2021 void
2022 carp_start(struct ifnet *ifp)
2023 {
2024 #ifdef DEBUG
2025 	printf("%s: start called\n", ifp->if_xname);
2026 #endif
2027 }
2028 
2029 int
2030 carp_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
2031     struct rtentry *rt)
2032 {
2033 	struct carp_softc *sc = ((struct carp_softc *)ifp->if_softc);
2034 
2035 	if (sc->sc_carpdev != NULL && sc->sc_state == MASTER) {
2036 		return (sc->sc_carpdev->if_output(ifp, m, sa, rt));
2037 	} else {
2038 		m_freem(m);
2039 		return (ENETUNREACH);
2040 	}
2041 }
2042 
2043 void
2044 carp_set_state(struct carp_softc *sc, int state)
2045 {
2046 	if (sc->sc_state == state)
2047 		return;
2048 
2049 	sc->sc_state = state;
2050 	switch (state) {
2051 	case BACKUP:
2052 		sc->sc_if.if_link_state = LINK_STATE_DOWN;
2053 		break;
2054 	case MASTER:
2055 		sc->sc_if.if_link_state = LINK_STATE_UP;
2056 		break;
2057 	default:
2058 		sc->sc_if.if_link_state = LINK_STATE_UNKNOWN;
2059 		break;
2060 	}
2061 	rt_ifmsg(&sc->sc_if);
2062 }
2063 
2064 void
2065 carp_carpdev_state(void *v)
2066 {
2067 	struct carp_if *cif;
2068 	struct carp_softc *sc;
2069 	struct ifnet *ifp = v;
2070 
2071 	if (ifp->if_type == IFT_CARP)
2072 		return;
2073 
2074 	cif = (struct carp_if *)ifp->if_carp;
2075 
2076 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
2077 		int suppressed = sc->sc_suppress;
2078 
2079 		if (sc->sc_carpdev->if_link_state == LINK_STATE_DOWN ||
2080 		    !(sc->sc_carpdev->if_flags & IFF_UP)) {
2081 			sc->sc_if.if_flags &= ~IFF_RUNNING;
2082 			callout_stop(&sc->sc_ad_tmo);
2083 			callout_stop(&sc->sc_md_tmo);
2084 			callout_stop(&sc->sc_md6_tmo);
2085 			carp_set_state(sc, INIT);
2086 			sc->sc_suppress = 1;
2087 			carp_setrun(sc, 0);
2088 			if (!suppressed) {
2089 				carp_suppress_preempt++;
2090 				if (carp_suppress_preempt == 1)
2091 					carp_send_ad_all();
2092 			}
2093 		} else {
2094 			carp_set_state(sc, INIT);
2095 			sc->sc_suppress = 0;
2096 			carp_setrun(sc, 0);
2097 			if (suppressed)
2098 				carp_suppress_preempt--;
2099 		}
2100 	}
2101 }
2102 
2103 int
2104 carp_ether_addmulti(struct carp_softc *sc, struct ifreq *ifr)
2105 {
2106 	struct ifnet *ifp;
2107 	struct carp_mc_entry *mc;
2108 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2109 	int error;
2110 
2111 	ifp = sc->sc_carpdev;
2112 	if (ifp == NULL)
2113 		return (EINVAL);
2114 
2115 	error = ether_addmulti(ifr, &sc->sc_ac);
2116 	if (error != ENETRESET)
2117 		return (error);
2118 
2119 	/*
2120 	 * This is new multicast address.  We have to tell parent
2121 	 * about it.  Also, remember this multicast address so that
2122 	 * we can delete them on unconfigure.
2123 	 */
2124 	MALLOC(mc, struct carp_mc_entry *, sizeof(struct carp_mc_entry),
2125 	    M_DEVBUF, M_NOWAIT);
2126 	if (mc == NULL) {
2127 		error = ENOMEM;
2128 		goto alloc_failed;
2129 	}
2130 
2131 	/*
2132 	 * As ether_addmulti() returns ENETRESET, following two
2133 	 * statement shouldn't fail.
2134 	 */
2135 	(void)ether_multiaddr(&ifr->ifr_addr, addrlo, addrhi);
2136 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, mc->mc_enm);
2137 	memcpy(&mc->mc_addr, &ifr->ifr_addr, ifr->ifr_addr.sa_len);
2138 	LIST_INSERT_HEAD(&sc->carp_mc_listhead, mc, mc_entries);
2139 
2140 	error = (*ifp->if_ioctl)(ifp, SIOCADDMULTI, (caddr_t)ifr);
2141 	if (error != 0)
2142 		goto ioctl_failed;
2143 
2144 	return (error);
2145 
2146  ioctl_failed:
2147 	LIST_REMOVE(mc, mc_entries);
2148 	FREE(mc, M_DEVBUF);
2149  alloc_failed:
2150 	(void)ether_delmulti(ifr, &sc->sc_ac);
2151 
2152 	return (error);
2153 }
2154 
2155 int
2156 carp_ether_delmulti(struct carp_softc *sc, struct ifreq *ifr)
2157 {
2158 	struct ifnet *ifp;
2159 	struct ether_multi *enm;
2160 	struct carp_mc_entry *mc;
2161 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2162 	int error;
2163 
2164 	ifp = sc->sc_carpdev;
2165 	if (ifp == NULL)
2166 		return (EINVAL);
2167 
2168 	/*
2169 	 * Find a key to lookup carp_mc_entry.  We have to do this
2170 	 * before calling ether_delmulti for obvious reason.
2171 	 */
2172 	if ((error = ether_multiaddr(&ifr->ifr_addr, addrlo, addrhi)) != 0)
2173 		return (error);
2174 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, enm);
2175 	if (enm == NULL)
2176 		return (EINVAL);
2177 
2178 	LIST_FOREACH(mc, &sc->carp_mc_listhead, mc_entries)
2179 		if (mc->mc_enm == enm)
2180 			break;
2181 
2182 	/* We won't delete entries we didn't add */
2183 	if (mc == NULL)
2184 		return (EINVAL);
2185 
2186 	error = ether_delmulti(ifr, &sc->sc_ac);
2187 	if (error != ENETRESET)
2188 		return (error);
2189 
2190 	/* We no longer use this multicast address.  Tell parent so. */
2191 	error = (*ifp->if_ioctl)(ifp, SIOCDELMULTI, (caddr_t)ifr);
2192 	if (error == 0) {
2193 		/* And forget about this address. */
2194 		LIST_REMOVE(mc, mc_entries);
2195 		FREE(mc, M_DEVBUF);
2196 	} else
2197 		(void)ether_addmulti(ifr, &sc->sc_ac);
2198 	return (error);
2199 }
2200 
2201 /*
2202  * Delete any multicast address we have asked to add from parent
2203  * interface.  Called when the carp is being unconfigured.
2204  */
2205 void
2206 carp_ether_purgemulti(struct carp_softc *sc)
2207 {
2208 	struct ifnet *ifp = sc->sc_carpdev;		/* Parent. */
2209 	struct carp_mc_entry *mc;
2210 	union {
2211 		struct ifreq ifreq;
2212 		struct {
2213 			char ifr_name[IFNAMSIZ];
2214 			struct sockaddr_storage ifr_ss;
2215 		} ifreq_storage;
2216 	} u;
2217 	struct ifreq *ifr = &u.ifreq;
2218 
2219 	if (ifp == NULL)
2220 		return;
2221 
2222 	memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
2223 	while ((mc = LIST_FIRST(&sc->carp_mc_listhead)) != NULL) {
2224 		memcpy(&ifr->ifr_addr, &mc->mc_addr, mc->mc_addr.ss_len);
2225 		(void)(*ifp->if_ioctl)(ifp, SIOCDELMULTI, (caddr_t)ifr);
2226 		LIST_REMOVE(mc, mc_entries);
2227 		FREE(mc, M_DEVBUF);
2228 	}
2229 }
2230 
2231 SYSCTL_SETUP(sysctl_net_inet_carp_setup, "sysctl net.inet.carp subtree setup")
2232 {
2233 
2234 	sysctl_createv(clog, 0, NULL, NULL,
2235 		       CTLFLAG_PERMANENT,
2236 		       CTLTYPE_NODE, "net", NULL,
2237 		       NULL, 0, NULL, 0,
2238 		       CTL_NET, CTL_EOL);
2239 	sysctl_createv(clog, 0, NULL, NULL,
2240 		       CTLFLAG_PERMANENT,
2241 		       CTLTYPE_NODE, "inet", NULL,
2242 		       NULL, 0, NULL, 0,
2243 		       CTL_NET, PF_INET, CTL_EOL);
2244 	sysctl_createv(clog, 0, NULL, NULL,
2245 		       CTLFLAG_PERMANENT,
2246 		       CTLTYPE_NODE, "carp",
2247 		       SYSCTL_DESCR("CARP related settings"),
2248 		       NULL, 0, NULL, 0,
2249 		       CTL_NET, PF_INET, IPPROTO_CARP, CTL_EOL);
2250 
2251 	sysctl_createv(clog, 0, NULL, NULL,
2252 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2253 		       CTLTYPE_INT, "preempt",
2254 		       SYSCTL_DESCR("Enable CARP Preempt"),
2255 		       NULL, 0, &carp_opts[CARPCTL_PREEMPT], 0,
2256 		       CTL_NET, PF_INET, IPPROTO_CARP,
2257 		       CTL_CREATE, CTL_EOL);
2258 	sysctl_createv(clog, 0, NULL, NULL,
2259 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2260 		       CTLTYPE_INT, "arpbalance",
2261 		       SYSCTL_DESCR("Enable ARP balancing"),
2262 		       NULL, 0, &carp_opts[CARPCTL_ARPBALANCE], 0,
2263 		       CTL_NET, PF_INET, IPPROTO_CARP,
2264 		       CTL_CREATE, CTL_EOL);
2265 	sysctl_createv(clog, 0, NULL, NULL,
2266 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2267 		       CTLTYPE_INT, "allow",
2268 		       SYSCTL_DESCR("Enable CARP"),
2269 		       NULL, 0, &carp_opts[CARPCTL_ALLOW], 0,
2270 		       CTL_NET, PF_INET, IPPROTO_CARP,
2271 		       CTL_CREATE, CTL_EOL);
2272 	sysctl_createv(clog, 0, NULL, NULL,
2273 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2274 		       CTLTYPE_INT, "log",
2275 		       SYSCTL_DESCR("CARP logging"),
2276 		       NULL, 0, &carp_opts[CARPCTL_LOG], 0,
2277 		       CTL_NET, PF_INET, IPPROTO_CARP,
2278 		       CTL_CREATE, CTL_EOL);
2279 	sysctl_createv(clog, 0, NULL, NULL,
2280 		       CTLFLAG_PERMANENT,
2281 		       CTLTYPE_STRUCT, "stats",
2282 		       SYSCTL_DESCR("CARP statistics"),
2283 		       NULL, 0, &carpstats, sizeof(carpstats),
2284 		       CTL_NET, PF_INET, IPPROTO_CARP, CARPCTL_STATS,
2285 		       CTL_EOL);
2286 }
2287