xref: /netbsd-src/sys/netinet/ip_carp.c (revision 0df165c04d0a9ca1adde9ed2b890344c937954a6)
1 /*	$NetBSD: ip_carp.c,v 1.18 2007/10/19 12:16:46 ad 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 <sys/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, void *);
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 rtentry *rt;
348 			int hr_otherif, nr_ourif;
349 
350 			/*
351 			 * Avoid screwing with the routes if there are other
352 			 * carp interfaces which are master and have the same
353 			 * address.
354 			 */
355 			if (sc->sc_carpdev != NULL &&
356 			    sc->sc_carpdev->if_carp != NULL) {
357 				count = carp_addrcount(
358 				    (struct carp_if *)sc->sc_carpdev->if_carp,
359 				    ifatoia(ifa), CARP_COUNT_MASTER);
360 				if ((cmd == RTM_ADD && count != 1) ||
361 				    (cmd == RTM_DELETE && count != 0))
362 					continue;
363 			}
364 
365 			/* Remove the existing host route, if any */
366 			rtrequest(RTM_DELETE, ifa->ifa_addr,
367 			    ifa->ifa_addr, ifa->ifa_netmask,
368 			    RTF_HOST, NULL);
369 
370 			rt = NULL;
371 			(void)rtrequest(RTM_GET, ifa->ifa_addr, ifa->ifa_addr,
372 			    ifa->ifa_netmask, RTF_HOST, &rt);
373 			hr_otherif = (rt && rt->rt_ifp != &sc->sc_if &&
374 			    rt->rt_flags & (RTF_CLONING|RTF_CLONED));
375 			if (rt != NULL) {
376 				RTFREE(rt);
377 				rt = NULL;
378 			}
379 
380 			/* Check for a network route on our interface */
381 
382 			rt = NULL;
383 			(void)rtrequest(RTM_GET, ifa->ifa_addr, ifa->ifa_addr,
384 			    ifa->ifa_netmask, 0, &rt);
385 			nr_ourif = (rt && rt->rt_ifp == &sc->sc_if);
386 
387 			switch (cmd) {
388 			case RTM_ADD:
389 				if (hr_otherif) {
390 					ifa->ifa_rtrequest = NULL;
391 					ifa->ifa_flags &= ~RTF_CLONING;
392 
393 					rtrequest(RTM_ADD, ifa->ifa_addr,
394 					    ifa->ifa_addr, ifa->ifa_netmask,
395 					    RTF_UP | RTF_HOST, NULL);
396 				}
397 				if (!hr_otherif || nr_ourif || !rt) {
398 					if (nr_ourif && !(rt->rt_flags &
399 					    RTF_CLONING))
400 						rtrequest(RTM_DELETE,
401 						    ifa->ifa_addr,
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 			if (rt != NULL) {
420 				RTFREE(rt);
421 				rt = NULL;
422 			}
423 			break;
424 		}
425 
426 #ifdef INET6
427 		case AF_INET6:
428 			if (cmd == RTM_ADD)
429 				in6_ifaddloop(ifa);
430 			else
431 				in6_ifremloop(ifa);
432 			break;
433 #endif /* INET6 */
434 		default:
435 			break;
436 		}
437 	}
438 	splx(s);
439 }
440 
441 /*
442  * process input packet.
443  * we have rearranged checks order compared to the rfc,
444  * but it seems more efficient this way or not possible otherwise.
445  */
446 void
447 carp_proto_input(struct mbuf *m, ...)
448 {
449 	struct ip *ip = mtod(m, struct ip *);
450 	struct carp_softc *sc = NULL;
451 	struct carp_header *ch;
452 	int iplen, len, hlen;
453 	va_list ap;
454 
455 	va_start(ap, m);
456 	hlen = va_arg(ap, int);
457 	va_end(ap);
458 
459 	carpstats.carps_ipackets++;
460 
461 	if (!carp_opts[CARPCTL_ALLOW]) {
462 		m_freem(m);
463 		return;
464 	}
465 
466 	/* check if received on a valid carp interface */
467 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
468 		carpstats.carps_badif++;
469 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
470 		    m->m_pkthdr.rcvif->if_xname));
471 		m_freem(m);
472 		return;
473 	}
474 
475 	/* verify that the IP TTL is 255.  */
476 	if (ip->ip_ttl != CARP_DFLTTL) {
477 		carpstats.carps_badttl++;
478 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip->ip_ttl,
479 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
480 		m_freem(m);
481 		return;
482 	}
483 
484 	/*
485 	 * verify that the received packet length is
486 	 * equal to the CARP header
487 	 */
488 	iplen = ip->ip_hl << 2;
489 	len = iplen + sizeof(*ch);
490 	if (len > m->m_pkthdr.len) {
491 		carpstats.carps_badlen++;
492 		CARP_LOG(sc, ("packet too short %d on %s", m->m_pkthdr.len,
493 		    m->m_pkthdr.rcvif->if_xname));
494 		m_freem(m);
495 		return;
496 	}
497 
498 	if ((m = m_pullup(m, len)) == NULL) {
499 		carpstats.carps_hdrops++;
500 		return;
501 	}
502 	ip = mtod(m, struct ip *);
503 	ch = (struct carp_header *)((char *)ip + iplen);
504 	/* verify the CARP checksum */
505 	m->m_data += iplen;
506 	if (carp_cksum(m, len - iplen)) {
507 		carpstats.carps_badsum++;
508 		CARP_LOG(sc, ("checksum failed on %s",
509 		    m->m_pkthdr.rcvif->if_xname));
510 		m_freem(m);
511 		return;
512 	}
513 	m->m_data -= iplen;
514 
515 	carp_proto_input_c(m, ch, AF_INET);
516 }
517 
518 #ifdef INET6
519 int
520 carp6_proto_input(struct mbuf **mp, int *offp, int proto)
521 {
522 	struct mbuf *m = *mp;
523 	struct carp_softc *sc = NULL;
524 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
525 	struct carp_header *ch;
526 	u_int len;
527 
528 	carpstats.carps_ipackets6++;
529 
530 	if (!carp_opts[CARPCTL_ALLOW]) {
531 		m_freem(m);
532 		return (IPPROTO_DONE);
533 	}
534 
535 	/* check if received on a valid carp interface */
536 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
537 		carpstats.carps_badif++;
538 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
539 		    m->m_pkthdr.rcvif->if_xname));
540 		m_freem(m);
541 		return (IPPROTO_DONE);
542 	}
543 
544 	/* verify that the IP TTL is 255 */
545 	if (ip6->ip6_hlim != CARP_DFLTTL) {
546 		carpstats.carps_badttl++;
547 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip6->ip6_hlim,
548 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
549 		m_freem(m);
550 		return (IPPROTO_DONE);
551 	}
552 
553 	/* verify that we have a complete carp packet */
554 	len = m->m_len;
555 	IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
556 	if (ch == NULL) {
557 		carpstats.carps_badlen++;
558 		CARP_LOG(sc, ("packet size %u too small", len));
559 		return (IPPROTO_DONE);
560 	}
561 
562 
563 	/* verify the CARP checksum */
564 	m->m_data += *offp;
565 	if (carp_cksum(m, sizeof(*ch))) {
566 		carpstats.carps_badsum++;
567 		CARP_LOG(sc, ("checksum failed, on %s",
568 		    m->m_pkthdr.rcvif->if_xname));
569 		m_freem(m);
570 		return (IPPROTO_DONE);
571 	}
572 	m->m_data -= *offp;
573 
574 	carp_proto_input_c(m, ch, AF_INET6);
575 	return (IPPROTO_DONE);
576 }
577 #endif /* INET6 */
578 
579 void
580 carp_proto_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
581 {
582 	struct carp_softc *sc;
583 	u_int64_t tmp_counter;
584 	struct timeval sc_tv, ch_tv;
585 
586 	TAILQ_FOREACH(sc, &((struct carp_if *)
587 	    m->m_pkthdr.rcvif->if_carpdev->if_carp)->vhif_vrs, sc_list)
588 		if (sc->sc_vhid == ch->carp_vhid)
589 			break;
590 
591 	if (!sc || (sc->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) !=
592 	    (IFF_UP|IFF_RUNNING)) {
593 		carpstats.carps_badvhid++;
594 		m_freem(m);
595 		return;
596 	}
597 
598 	/*
599 	 * Check if our own advertisement was duplicated
600 	 * from a non simplex interface.
601 	 * XXX If there is no address on our physical interface
602 	 * there is no way to distinguish our ads from the ones
603 	 * another carp host might have sent us.
604 	 */
605 	if ((sc->sc_carpdev->if_flags & IFF_SIMPLEX) == 0) {
606 		struct sockaddr sa;
607 		struct ifaddr *ifa;
608 
609 		bzero(&sa, sizeof(sa));
610 		sa.sa_family = af;
611 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
612 
613 		if (ifa && af == AF_INET) {
614 			struct ip *ip = mtod(m, struct ip *);
615 			if (ip->ip_src.s_addr ==
616 					ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
617 				m_freem(m);
618 				return;
619 			}
620 		}
621 #ifdef INET6
622 		if (ifa && af == AF_INET6) {
623 			struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
624 			struct in6_addr in6_src, in6_found;
625 
626 			in6_src = ip6->ip6_src;
627 			in6_found = ifatoia6(ifa)->ia_addr.sin6_addr;
628 			if (IN6_IS_ADDR_LINKLOCAL(&in6_src))
629 				in6_src.s6_addr16[1] = 0;
630 			if (IN6_IS_ADDR_LINKLOCAL(&in6_found))
631 				in6_found.s6_addr16[1] = 0;
632 			if (IN6_ARE_ADDR_EQUAL(&in6_src, &in6_found)) {
633 				m_freem(m);
634 				return;
635 			}
636 		}
637 #endif /* INET6 */
638 	}
639 
640 	microtime(&sc->sc_if.if_lastchange);
641 	sc->sc_if.if_ipackets++;
642 	sc->sc_if.if_ibytes += m->m_pkthdr.len;
643 
644 	/* verify the CARP version. */
645 	if (ch->carp_version != CARP_VERSION) {
646 		carpstats.carps_badver++;
647 		sc->sc_if.if_ierrors++;
648 		CARP_LOG(sc, ("invalid version %d != %d",
649 		    ch->carp_version, CARP_VERSION));
650 		m_freem(m);
651 		return;
652 	}
653 
654 	/* verify the hash */
655 	if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
656 		carpstats.carps_badauth++;
657 		sc->sc_if.if_ierrors++;
658 		CARP_LOG(sc, ("incorrect hash"));
659 		m_freem(m);
660 		return;
661 	}
662 
663 	tmp_counter = ntohl(ch->carp_counter[0]);
664 	tmp_counter = tmp_counter<<32;
665 	tmp_counter += ntohl(ch->carp_counter[1]);
666 
667 	/* XXX Replay protection goes here */
668 
669 	sc->sc_init_counter = 0;
670 	sc->sc_counter = tmp_counter;
671 
672 
673 	sc_tv.tv_sec = sc->sc_advbase;
674 	if (carp_suppress_preempt && sc->sc_advskew <  240)
675 		sc_tv.tv_usec = 240 * 1000000 / 256;
676 	else
677 		sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
678 	ch_tv.tv_sec = ch->carp_advbase;
679 	ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
680 
681 	switch (sc->sc_state) {
682 	case INIT:
683 		break;
684 	case MASTER:
685 		/*
686 		 * If we receive an advertisement from a backup who's going to
687 		 * be more frequent than us, go into BACKUP state.
688 		 */
689 		if (timercmp(&sc_tv, &ch_tv, >) ||
690 		    timercmp(&sc_tv, &ch_tv, ==)) {
691 			callout_stop(&sc->sc_ad_tmo);
692 			carp_set_state(sc, BACKUP);
693 			carp_setrun(sc, 0);
694 			carp_setroute(sc, RTM_DELETE);
695 		}
696 		break;
697 	case BACKUP:
698 		/*
699 		 * If we're pre-empting masters who advertise slower than us,
700 		 * and this one claims to be slower, treat him as down.
701 		 */
702 		if (carp_opts[CARPCTL_PREEMPT] && timercmp(&sc_tv, &ch_tv, <)) {
703 			carp_master_down(sc);
704 			break;
705 		}
706 
707 		/*
708 		 *  If the master is going to advertise at such a low frequency
709 		 *  that he's guaranteed to time out, we'd might as well just
710 		 *  treat him as timed out now.
711 		 */
712 		sc_tv.tv_sec = sc->sc_advbase * 3;
713 		if (timercmp(&sc_tv, &ch_tv, <)) {
714 			carp_master_down(sc);
715 			break;
716 		}
717 
718 		/*
719 		 * Otherwise, we reset the counter and wait for the next
720 		 * advertisement.
721 		 */
722 		carp_setrun(sc, af);
723 		break;
724 	}
725 
726 	m_freem(m);
727 	return;
728 }
729 
730 /*
731  * Interface side of the CARP implementation.
732  */
733 
734 /* ARGSUSED */
735 void
736 carpattach(int n)
737 {
738 	if_clone_attach(&carp_cloner);
739 }
740 
741 int
742 carp_clone_create(struct if_clone *ifc, int unit)
743 {
744 	extern int ifqmaxlen;
745 	struct carp_softc *sc;
746 	struct ifnet *ifp;
747 
748 	sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT);
749 	if (!sc)
750 		return (ENOMEM);
751 	bzero(sc, sizeof(*sc));
752 
753 	sc->sc_suppress = 0;
754 	sc->sc_advbase = CARP_DFLTINTV;
755 	sc->sc_vhid = -1;	/* required setting */
756 	sc->sc_advskew = 0;
757 	sc->sc_init_counter = 1;
758 	sc->sc_naddrs = sc->sc_naddrs6 = 0;
759 #ifdef INET6
760 	sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
761 #endif /* INET6 */
762 
763 	callout_init(&sc->sc_ad_tmo, 0);
764 	callout_init(&sc->sc_md_tmo, 0);
765 	callout_init(&sc->sc_md6_tmo, 0);
766 
767 	callout_setfunc(&sc->sc_ad_tmo, carp_send_ad, sc);
768 	callout_setfunc(&sc->sc_md_tmo, carp_master_down, sc);
769 	callout_setfunc(&sc->sc_md6_tmo, carp_master_down, sc);
770 
771 	LIST_INIT(&sc->carp_mc_listhead);
772 	ifp = &sc->sc_if;
773 	ifp->if_softc = sc;
774 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "%s%d", ifc->ifc_name,
775 	    unit);
776 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
777 	ifp->if_ioctl = carp_ioctl;
778 	ifp->if_start = carp_start;
779 	ifp->if_output = carp_output;
780 	ifp->if_type = IFT_CARP;
781 	ifp->if_addrlen = ETHER_ADDR_LEN;
782 	ifp->if_hdrlen = ETHER_HDR_LEN;
783 	ifp->if_mtu = ETHERMTU;
784 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
785 	IFQ_SET_READY(&ifp->if_snd);
786 	if_attach(ifp);
787 
788 	if_alloc_sadl(ifp);
789 	ifp->if_broadcastaddr = etherbroadcastaddr;
790 	carp_set_enaddr(sc);
791 	LIST_INIT(&sc->sc_ac.ec_multiaddrs);
792 #if NBPFILTER > 0
793 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
794 #endif
795 	return (0);
796 }
797 
798 int
799 carp_clone_destroy(struct ifnet *ifp)
800 {
801 	struct carp_softc *sc = ifp->if_softc;
802 
803 	carpdetach(ifp->if_softc);
804 	ether_ifdetach(ifp);
805 	if_detach(ifp);
806 	callout_destroy(&sc->sc_ad_tmo);
807 	callout_destroy(&sc->sc_md_tmo);
808 	callout_destroy(&sc->sc_md6_tmo);
809 	free(ifp->if_softc, M_DEVBUF);
810 
811 	return (0);
812 }
813 
814 void
815 carpdetach(struct carp_softc *sc)
816 {
817 	struct carp_if *cif;
818 	int s;
819 
820 	callout_stop(&sc->sc_ad_tmo);
821 	callout_stop(&sc->sc_md_tmo);
822 	callout_stop(&sc->sc_md6_tmo);
823 
824 	if (sc->sc_suppress)
825 		carp_suppress_preempt--;
826 	sc->sc_suppress = 0;
827 
828 	if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
829 		carp_suppress_preempt--;
830 	sc->sc_sendad_errors = 0;
831 
832 	carp_set_state(sc, INIT);
833 	sc->sc_if.if_flags &= ~IFF_UP;
834 	carp_setrun(sc, 0);
835 	carp_multicast_cleanup(sc);
836 
837 	s = splnet();
838 	if (sc->sc_carpdev != NULL) {
839 		/* XXX linkstatehook removal */
840 		cif = (struct carp_if *)sc->sc_carpdev->if_carp;
841 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
842 		if (!--cif->vhif_nvrs) {
843 			ifpromisc(sc->sc_carpdev, 0);
844 			sc->sc_carpdev->if_carp = NULL;
845 			FREE(cif, M_IFADDR);
846 		}
847 	}
848 	sc->sc_carpdev = NULL;
849 	splx(s);
850 }
851 
852 /* Detach an interface from the carp. */
853 void
854 carp_ifdetach(struct ifnet *ifp)
855 {
856 	struct carp_softc *sc, *nextsc;
857 	struct carp_if *cif = (struct carp_if *)ifp->if_carp;
858 
859 	for (sc = TAILQ_FIRST(&cif->vhif_vrs); sc; sc = nextsc) {
860 		nextsc = TAILQ_NEXT(sc, sc_list);
861 		carpdetach(sc);
862 	}
863 }
864 
865 int
866 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc,
867     struct carp_header *ch)
868 {
869 	if (sc->sc_init_counter) {
870 		/* this could also be seconds since unix epoch */
871 		sc->sc_counter = arc4random();
872 		sc->sc_counter = sc->sc_counter << 32;
873 		sc->sc_counter += arc4random();
874 	} else
875 		sc->sc_counter++;
876 
877 	ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
878 	ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
879 
880 	carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
881 
882 	return (0);
883 }
884 
885 void
886 carp_send_ad_all(void)
887 {
888 	struct ifnet *ifp;
889 	struct carp_if *cif;
890 	struct carp_softc *vh;
891 
892 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
893 		if (ifp->if_carp == NULL || ifp->if_type == IFT_CARP)
894 			continue;
895 
896 		cif = (struct carp_if *)ifp->if_carp;
897 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
898 			if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
899 			    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER)
900 				carp_send_ad(vh);
901 		}
902 	}
903 }
904 
905 
906 void
907 carp_send_ad(void *v)
908 {
909 	struct carp_header ch;
910 	struct timeval tv;
911 	struct carp_softc *sc = v;
912 	struct carp_header *ch_ptr;
913 	struct mbuf *m;
914 	int error, len, advbase, advskew, s;
915 	struct ifaddr *ifa;
916 	struct sockaddr sa;
917 
918 	s = splsoftnet();
919 
920 	advbase = advskew = 0; /* Sssssh compiler */
921 	if (sc->sc_carpdev == NULL) {
922 		sc->sc_if.if_oerrors++;
923 		goto retry_later;
924 	}
925 
926 	/* bow out if we've gone to backup (the carp interface is going down) */
927 	if (sc->sc_bow_out) {
928 		sc->sc_bow_out = 0;
929 		advbase = 255;
930 		advskew = 255;
931 	} else {
932 		advbase = sc->sc_advbase;
933 		if (!carp_suppress_preempt || sc->sc_advskew > 240)
934 			advskew = sc->sc_advskew;
935 		else
936 			advskew = 240;
937 		tv.tv_sec = advbase;
938 		tv.tv_usec = advskew * 1000000 / 256;
939 	}
940 
941 	ch.carp_version = CARP_VERSION;
942 	ch.carp_type = CARP_ADVERTISEMENT;
943 	ch.carp_vhid = sc->sc_vhid;
944 	ch.carp_advbase = advbase;
945 	ch.carp_advskew = advskew;
946 	ch.carp_authlen = 7;	/* XXX DEFINE */
947 	ch.carp_pad1 = 0;	/* must be zero */
948 	ch.carp_cksum = 0;
949 
950 
951 #ifdef INET
952 	if (sc->sc_naddrs) {
953 		struct ip *ip;
954 
955 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
956 		if (m == NULL) {
957 			sc->sc_if.if_oerrors++;
958 			carpstats.carps_onomem++;
959 			/* XXX maybe less ? */
960 			goto retry_later;
961 		}
962 		len = sizeof(*ip) + sizeof(ch);
963 		m->m_pkthdr.len = len;
964 		m->m_pkthdr.rcvif = NULL;
965 		m->m_len = len;
966 		MH_ALIGN(m, m->m_len);
967 		m->m_flags |= M_MCAST;
968 		ip = mtod(m, struct ip *);
969 		ip->ip_v = IPVERSION;
970 		ip->ip_hl = sizeof(*ip) >> 2;
971 		ip->ip_tos = IPTOS_LOWDELAY;
972 		ip->ip_len = htons(len);
973 		ip->ip_id = htons(ip_randomid());
974 		ip->ip_off = htons(IP_DF);
975 		ip->ip_ttl = CARP_DFLTTL;
976 		ip->ip_p = IPPROTO_CARP;
977 		ip->ip_sum = 0;
978 
979 		bzero(&sa, sizeof(sa));
980 		sa.sa_family = AF_INET;
981 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
982 		if (ifa == NULL)
983 			ip->ip_src.s_addr = 0;
984 		else
985 			ip->ip_src.s_addr =
986 			    ifatoia(ifa)->ia_addr.sin_addr.s_addr;
987 		ip->ip_dst.s_addr = INADDR_CARP_GROUP;
988 
989 		ch_ptr = (struct carp_header *)(&ip[1]);
990 		bcopy(&ch, ch_ptr, sizeof(ch));
991 		if (carp_prepare_ad(m, sc, ch_ptr))
992 			goto retry_later;
993 
994 		m->m_data += sizeof(*ip);
995 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
996 		m->m_data -= sizeof(*ip);
997 
998 		microtime(&sc->sc_if.if_lastchange);
999 		sc->sc_if.if_opackets++;
1000 		sc->sc_if.if_obytes += len;
1001 		carpstats.carps_opackets++;
1002 
1003 		error = ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo,
1004 		    NULL);
1005 		if (error) {
1006 			if (error == ENOBUFS)
1007 				carpstats.carps_onomem++;
1008 			else
1009 				CARP_LOG(sc, ("ip_output failed: %d", error));
1010 			sc->sc_if.if_oerrors++;
1011 			if (sc->sc_sendad_errors < INT_MAX)
1012 				sc->sc_sendad_errors++;
1013 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1014 				carp_suppress_preempt++;
1015 				if (carp_suppress_preempt == 1)
1016 					carp_send_ad_all();
1017 			}
1018 			sc->sc_sendad_success = 0;
1019 		} else {
1020 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1021 				if (++sc->sc_sendad_success >=
1022 				    CARP_SENDAD_MIN_SUCCESS) {
1023 					carp_suppress_preempt--;
1024 					sc->sc_sendad_errors = 0;
1025 				}
1026 			} else
1027 				sc->sc_sendad_errors = 0;
1028 		}
1029 	}
1030 #endif /* INET */
1031 #ifdef INET6
1032 	if (sc->sc_naddrs6) {
1033 		struct ip6_hdr *ip6;
1034 
1035 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
1036 		if (m == NULL) {
1037 			sc->sc_if.if_oerrors++;
1038 			carpstats.carps_onomem++;
1039 			/* XXX maybe less ? */
1040 			goto retry_later;
1041 		}
1042 		len = sizeof(*ip6) + sizeof(ch);
1043 		m->m_pkthdr.len = len;
1044 		m->m_pkthdr.rcvif = NULL;
1045 		m->m_len = len;
1046 		MH_ALIGN(m, m->m_len);
1047 		m->m_flags |= M_MCAST;
1048 		ip6 = mtod(m, struct ip6_hdr *);
1049 		bzero(ip6, sizeof(*ip6));
1050 		ip6->ip6_vfc |= IPV6_VERSION;
1051 		ip6->ip6_hlim = CARP_DFLTTL;
1052 		ip6->ip6_nxt = IPPROTO_CARP;
1053 
1054 		/* set the source address */
1055 		bzero(&sa, sizeof(sa));
1056 		sa.sa_family = AF_INET6;
1057 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
1058 		if (ifa == NULL)	/* This should never happen with IPv6 */
1059 			bzero(&ip6->ip6_src, sizeof(struct in6_addr));
1060 		else
1061 			bcopy(ifatoia6(ifa)->ia_addr.sin6_addr.s6_addr,
1062 			    &ip6->ip6_src, sizeof(struct in6_addr));
1063 		/* set the multicast destination */
1064 
1065 		ip6->ip6_dst.s6_addr8[0] = 0xff;
1066 		ip6->ip6_dst.s6_addr8[1] = 0x02;
1067 		ip6->ip6_dst.s6_addr8[15] = 0x12;
1068 
1069 		ch_ptr = (struct carp_header *)(&ip6[1]);
1070 		bcopy(&ch, ch_ptr, sizeof(ch));
1071 		if (carp_prepare_ad(m, sc, ch_ptr))
1072 			goto retry_later;
1073 
1074 		m->m_data += sizeof(*ip6);
1075 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
1076 		m->m_data -= sizeof(*ip6);
1077 
1078 		microtime(&sc->sc_if.if_lastchange);
1079 		sc->sc_if.if_opackets++;
1080 		sc->sc_if.if_obytes += len;
1081 		carpstats.carps_opackets6++;
1082 
1083 		error = ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL);
1084 		if (error) {
1085 			if (error == ENOBUFS)
1086 				carpstats.carps_onomem++;
1087 			else
1088 				CARP_LOG(sc, ("ip6_output failed: %d", error));
1089 			sc->sc_if.if_oerrors++;
1090 			if (sc->sc_sendad_errors < INT_MAX)
1091 				sc->sc_sendad_errors++;
1092 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1093 				carp_suppress_preempt++;
1094 				if (carp_suppress_preempt == 1)
1095 					carp_send_ad_all();
1096 			}
1097 			sc->sc_sendad_success = 0;
1098 		} else {
1099 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1100 				if (++sc->sc_sendad_success >=
1101 				    CARP_SENDAD_MIN_SUCCESS) {
1102 					carp_suppress_preempt--;
1103 					sc->sc_sendad_errors = 0;
1104 				}
1105 			} else
1106 				sc->sc_sendad_errors = 0;
1107 		}
1108 	}
1109 #endif /* INET6 */
1110 
1111 retry_later:
1112 	splx(s);
1113 	if (advbase != 255 || advskew != 255)
1114 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1115 }
1116 
1117 /*
1118  * Broadcast a gratuitous ARP request containing
1119  * the virtual router MAC address for each IP address
1120  * associated with the virtual router.
1121  */
1122 void
1123 carp_send_arp(struct carp_softc *sc)
1124 {
1125 	struct ifaddr *ifa;
1126 	struct in_addr *in;
1127 	int s = splsoftnet();
1128 
1129 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
1130 
1131 		if (ifa->ifa_addr->sa_family != AF_INET)
1132 			continue;
1133 
1134 		in = &ifatoia(ifa)->ia_addr.sin_addr;
1135 		arprequest(sc->sc_carpdev, in, in, CLLADDR(sc->sc_if.if_sadl));
1136 		DELAY(1000);	/* XXX */
1137 	}
1138 	splx(s);
1139 }
1140 
1141 #ifdef INET6
1142 void
1143 carp_send_na(struct carp_softc *sc)
1144 {
1145 	struct ifaddr *ifa;
1146 	struct in6_addr *in6;
1147 	static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1148 	int s = splsoftnet();
1149 
1150 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
1151 
1152 		if (ifa->ifa_addr->sa_family != AF_INET6)
1153 			continue;
1154 
1155 		in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1156 		nd6_na_output(sc->sc_carpdev, &mcast, in6,
1157 		    ND_NA_FLAG_OVERRIDE, 1, NULL);
1158 		DELAY(1000);	/* XXX */
1159 	}
1160 	splx(s);
1161 }
1162 #endif /* INET6 */
1163 
1164 /*
1165  * Based on bridge_hash() in if_bridge.c
1166  */
1167 #define	mix(a,b,c) \
1168 	do {						\
1169 		a -= b; a -= c; a ^= (c >> 13);		\
1170 		b -= c; b -= a; b ^= (a << 8);		\
1171 		c -= a; c -= b; c ^= (b >> 13);		\
1172 		a -= b; a -= c; a ^= (c >> 12);		\
1173 		b -= c; b -= a; b ^= (a << 16);		\
1174 		c -= a; c -= b; c ^= (b >> 5);		\
1175 		a -= b; a -= c; a ^= (c >> 3);		\
1176 		b -= c; b -= a; b ^= (a << 10);		\
1177 		c -= a; c -= b; c ^= (b >> 15);		\
1178 	} while (0)
1179 
1180 u_int32_t
1181 carp_hash(struct carp_softc *sc, u_char *src)
1182 {
1183 	u_int32_t a = 0x9e3779b9, b = sc->sc_hashkey[0], c = sc->sc_hashkey[1];
1184 
1185 	c += sc->sc_key[3] << 24;
1186 	c += sc->sc_key[2] << 16;
1187 	c += sc->sc_key[1] << 8;
1188 	c += sc->sc_key[0];
1189 	b += src[5] << 8;
1190 	b += src[4];
1191 	a += src[3] << 24;
1192 	a += src[2] << 16;
1193 	a += src[1] << 8;
1194 	a += src[0];
1195 
1196 	mix(a, b, c);
1197 	return (c);
1198 }
1199 
1200 int
1201 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
1202 {
1203 	struct carp_softc *vh;
1204 	struct ifaddr *ifa;
1205 	int count = 0;
1206 
1207 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1208 		if ((type == CARP_COUNT_RUNNING &&
1209 		    (vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1210 		    (IFF_UP|IFF_RUNNING)) ||
1211 		    (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
1212 			TAILQ_FOREACH(ifa, &vh->sc_if.if_addrlist, ifa_list) {
1213 				if (ifa->ifa_addr->sa_family == AF_INET &&
1214 				    ia->ia_addr.sin_addr.s_addr ==
1215 				    ifatoia(ifa)->ia_addr.sin_addr.s_addr)
1216 					count++;
1217 			}
1218 		}
1219 	}
1220 	return (count);
1221 }
1222 
1223 int
1224 carp_iamatch(struct in_ifaddr *ia, u_char *src,
1225     u_int32_t *count, u_int32_t index)
1226 {
1227 	struct carp_softc *sc = ia->ia_ifp->if_softc;
1228 
1229 	if (carp_opts[CARPCTL_ARPBALANCE]) {
1230 		/*
1231 		 * We use the source ip to decide which virtual host should
1232 		 * handle the request. If we're master of that virtual host,
1233 		 * then we respond, otherwise, just drop the arp packet on
1234 		 * the floor.
1235 		 */
1236 
1237 		/* Count the elegible carp interfaces with this address */
1238 		if (*count == 0)
1239 			*count = carp_addrcount(
1240 			    (struct carp_if *)ia->ia_ifp->if_carpdev->if_carp,
1241 			    ia, CARP_COUNT_RUNNING);
1242 
1243 		/* This should never happen, but... */
1244 		if (*count == 0)
1245 			return (0);
1246 
1247 		if (carp_hash(sc, src) % *count == index - 1 &&
1248 		    sc->sc_state == MASTER) {
1249 			return (1);
1250 		}
1251 	} else {
1252 		if (sc->sc_state == MASTER)
1253 			return (1);
1254 	}
1255 
1256 	return (0);
1257 }
1258 
1259 #ifdef INET6
1260 struct ifaddr *
1261 carp_iamatch6(void *v, struct in6_addr *taddr)
1262 {
1263 	struct carp_if *cif = v;
1264 	struct carp_softc *vh;
1265 	struct ifaddr *ifa;
1266 
1267 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1268 		TAILQ_FOREACH(ifa, &vh->sc_if.if_addrlist, ifa_list) {
1269 			if (IN6_ARE_ADDR_EQUAL(taddr,
1270 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1271 			    ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1272 			    (IFF_UP|IFF_RUNNING)) && vh->sc_state == MASTER)
1273 				return (ifa);
1274 		}
1275 	}
1276 
1277 	return (NULL);
1278 }
1279 #endif /* INET6 */
1280 
1281 struct ifnet *
1282 carp_ourether(void *v, struct ether_header *eh, u_char iftype, int src)
1283 {
1284 	struct carp_if *cif = (struct carp_if *)v;
1285 	struct carp_softc *vh;
1286 	u_int8_t *ena;
1287 
1288 	if (src)
1289 		ena = (u_int8_t *)&eh->ether_shost;
1290 	else
1291 		ena = (u_int8_t *)&eh->ether_dhost;
1292 
1293 	switch (iftype) {
1294 	case IFT_ETHER:
1295 	case IFT_FDDI:
1296 		if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1297 			return (NULL);
1298 		break;
1299 	case IFT_ISO88025:
1300 		if (ena[0] != 3 || ena[1] || ena[4] || ena[5])
1301 			return (NULL);
1302 		break;
1303 	default:
1304 		return (NULL);
1305 		break;
1306 	}
1307 
1308 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
1309 		if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1310 		    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER &&
1311 		    !bcmp(ena, CLLADDR(vh->sc_if.if_sadl),
1312 		    ETHER_ADDR_LEN)) {
1313 			return (&vh->sc_if);
1314 		    }
1315 
1316 	return (NULL);
1317 }
1318 
1319 int
1320 carp_input(struct mbuf *m, u_int8_t *shost, u_int8_t *dhost, u_int16_t etype)
1321 {
1322 	struct ether_header eh;
1323 	struct carp_if *cif = (struct carp_if *)m->m_pkthdr.rcvif->if_carp;
1324 	struct ifnet *ifp;
1325 
1326 	bcopy(shost, &eh.ether_shost, sizeof(eh.ether_shost));
1327 	bcopy(dhost, &eh.ether_dhost, sizeof(eh.ether_dhost));
1328 	eh.ether_type = etype;
1329 
1330 	if (m->m_flags & (M_BCAST|M_MCAST)) {
1331 		struct carp_softc *vh;
1332 		struct mbuf *m0;
1333 
1334 		/*
1335 		 * XXX Should really check the list of multicast addresses
1336 		 * for each CARP interface _before_ copying.
1337 		 */
1338 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1339 			m0 = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
1340 			if (m0 == NULL)
1341 				continue;
1342 			m0->m_pkthdr.rcvif = &vh->sc_if;
1343 			ether_input(&vh->sc_if, m0);
1344 		}
1345 		return (1);
1346 	}
1347 
1348 	ifp = carp_ourether(cif, &eh, m->m_pkthdr.rcvif->if_type, 0);
1349 	if (ifp == NULL) {
1350 		return (1);
1351 	}
1352 
1353 	m->m_pkthdr.rcvif = ifp;
1354 
1355 #if NBPFILTER > 0
1356 	if (ifp->if_bpf)
1357 		bpf_mtap(ifp->if_bpf, m);
1358 #endif
1359 	ifp->if_ipackets++;
1360 	ether_input(ifp, m);
1361 	return (0);
1362 }
1363 
1364 void
1365 carp_master_down(void *v)
1366 {
1367 	struct carp_softc *sc = v;
1368 
1369 	switch (sc->sc_state) {
1370 	case INIT:
1371 		printf("%s: master_down event in INIT state\n",
1372 		    sc->sc_if.if_xname);
1373 		break;
1374 	case MASTER:
1375 		break;
1376 	case BACKUP:
1377 		carp_set_state(sc, MASTER);
1378 		carp_send_ad(sc);
1379 		carp_send_arp(sc);
1380 #ifdef INET6
1381 		carp_send_na(sc);
1382 #endif /* INET6 */
1383 		carp_setrun(sc, 0);
1384 		carp_setroute(sc, RTM_ADD);
1385 		break;
1386 	}
1387 }
1388 
1389 /*
1390  * When in backup state, af indicates whether to reset the master down timer
1391  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1392  */
1393 void
1394 carp_setrun(struct carp_softc *sc, sa_family_t af)
1395 {
1396 	struct timeval tv;
1397 
1398 	if (sc->sc_carpdev == NULL) {
1399 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1400 		carp_set_state(sc, INIT);
1401 		return;
1402 	}
1403 
1404 	if (sc->sc_if.if_flags & IFF_UP && sc->sc_vhid > 0 &&
1405 	    (sc->sc_naddrs || sc->sc_naddrs6) && !sc->sc_suppress) {
1406 		sc->sc_if.if_flags |= IFF_RUNNING;
1407 	} else {
1408 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1409 		carp_setroute(sc, RTM_DELETE);
1410 		return;
1411 	}
1412 
1413 	switch (sc->sc_state) {
1414 	case INIT:
1415 		carp_set_state(sc, BACKUP);
1416 		carp_setroute(sc, RTM_DELETE);
1417 		carp_setrun(sc, 0);
1418 		break;
1419 	case BACKUP:
1420 		callout_stop(&sc->sc_ad_tmo);
1421 		tv.tv_sec = 3 * sc->sc_advbase;
1422 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1423 		switch (af) {
1424 #ifdef INET
1425 		case AF_INET:
1426 			callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1427 			break;
1428 #endif /* INET */
1429 #ifdef INET6
1430 		case AF_INET6:
1431 			callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1432 			break;
1433 #endif /* INET6 */
1434 		default:
1435 			if (sc->sc_naddrs)
1436 				callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1437 			if (sc->sc_naddrs6)
1438 				callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1439 			break;
1440 		}
1441 		break;
1442 	case MASTER:
1443 		tv.tv_sec = sc->sc_advbase;
1444 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1445 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1446 		break;
1447 	}
1448 }
1449 
1450 void
1451 carp_multicast_cleanup(struct carp_softc *sc)
1452 {
1453 	struct ip_moptions *imo = &sc->sc_imo;
1454 #ifdef INET6
1455 	struct ip6_moptions *im6o = &sc->sc_im6o;
1456 #endif
1457 	u_int16_t n = imo->imo_num_memberships;
1458 
1459 	/* Clean up our own multicast memberships */
1460 	while (n-- > 0) {
1461 		if (imo->imo_membership[n] != NULL) {
1462 			in_delmulti(imo->imo_membership[n]);
1463 			imo->imo_membership[n] = NULL;
1464 		}
1465 	}
1466 	imo->imo_num_memberships = 0;
1467 	imo->imo_multicast_ifp = NULL;
1468 
1469 #ifdef INET6
1470 	while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1471 		struct in6_multi_mship *imm =
1472 		    LIST_FIRST(&im6o->im6o_memberships);
1473 
1474 		LIST_REMOVE(imm, i6mm_chain);
1475 		in6_leavegroup(imm);
1476 	}
1477 	im6o->im6o_multicast_ifp = NULL;
1478 #endif
1479 
1480 	/* And any other multicast memberships */
1481 	carp_ether_purgemulti(sc);
1482 }
1483 
1484 int
1485 carp_set_ifp(struct carp_softc *sc, struct ifnet *ifp)
1486 {
1487 	struct carp_if *cif, *ncif = NULL;
1488 	struct carp_softc *vr, *after = NULL;
1489 	int myself = 0, error = 0;
1490 	int s;
1491 
1492 	if (ifp == sc->sc_carpdev)
1493 		return (0);
1494 
1495 	if (ifp != NULL) {
1496 		if ((ifp->if_flags & IFF_MULTICAST) == 0)
1497 			return (EADDRNOTAVAIL);
1498 
1499 		if (ifp->if_type == IFT_CARP)
1500 			return (EINVAL);
1501 
1502 		if (ifp->if_carp == NULL) {
1503 			MALLOC(ncif, struct carp_if *, sizeof(*cif),
1504 			    M_IFADDR, M_NOWAIT);
1505 			if (ncif == NULL)
1506 				return (ENOBUFS);
1507 			if ((error = ifpromisc(ifp, 1))) {
1508 				FREE(ncif, M_IFADDR);
1509 				return (error);
1510 			}
1511 
1512 			ncif->vhif_ifp = ifp;
1513 			TAILQ_INIT(&ncif->vhif_vrs);
1514 		} else {
1515 			cif = (struct carp_if *)ifp->if_carp;
1516 			TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1517 				if (vr != sc && vr->sc_vhid == sc->sc_vhid)
1518 					return (EINVAL);
1519 		}
1520 
1521 		/* detach from old interface */
1522 		if (sc->sc_carpdev != NULL)
1523 			carpdetach(sc);
1524 
1525 		/* join multicast groups */
1526 		if (sc->sc_naddrs < 0 &&
1527 		    (error = carp_join_multicast(sc)) != 0) {
1528 			if (ncif != NULL)
1529 				FREE(ncif, M_IFADDR);
1530 			return (error);
1531 		}
1532 
1533 #ifdef INET6
1534 		if (sc->sc_naddrs6 < 0 &&
1535 		    (error = carp_join_multicast6(sc)) != 0) {
1536 			if (ncif != NULL)
1537 				FREE(ncif, M_IFADDR);
1538 			carp_multicast_cleanup(sc);
1539 			return (error);
1540 		}
1541 #endif
1542 
1543 		/* attach carp interface to physical interface */
1544 		if (ncif != NULL)
1545 			ifp->if_carp = (void *)ncif;
1546 		sc->sc_carpdev = ifp;
1547 		cif = (struct carp_if *)ifp->if_carp;
1548 		TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1549 			if (vr == sc)
1550 				myself = 1;
1551 			if (vr->sc_vhid < sc->sc_vhid)
1552 				after = vr;
1553 		}
1554 
1555 		if (!myself) {
1556 			/* We're trying to keep things in order */
1557 			if (after == NULL) {
1558 				TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1559 			} else {
1560 				TAILQ_INSERT_AFTER(&cif->vhif_vrs, after,
1561 				    sc, sc_list);
1562 			}
1563 			cif->vhif_nvrs++;
1564 		}
1565 		if (sc->sc_naddrs || sc->sc_naddrs6)
1566 			sc->sc_if.if_flags |= IFF_UP;
1567 		carp_set_enaddr(sc);
1568 		s = splnet();
1569 		/* XXX linkstatehooks establish */
1570 		carp_carpdev_state(ifp);
1571 		splx(s);
1572 	} else {
1573 		carpdetach(sc);
1574 		sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
1575 	}
1576 	return (0);
1577 }
1578 
1579 void
1580 carp_set_enaddr(struct carp_softc *sc)
1581 {
1582 	uint8_t enaddr[ETHER_ADDR_LEN];
1583 	if (sc->sc_carpdev && sc->sc_carpdev->if_type == IFT_ISO88025) {
1584 		enaddr[0] = 3;
1585 		enaddr[1] = 0;
1586 		enaddr[2] = 0x40 >> (sc->sc_vhid - 1);
1587 		enaddr[3] = 0x40000 >> (sc->sc_vhid - 1);
1588 		enaddr[4] = 0;
1589 		enaddr[5] = 0;
1590 	} else {
1591 		enaddr[0] = 0;
1592 		enaddr[1] = 0;
1593 		enaddr[2] = 0x5e;
1594 		enaddr[3] = 0;
1595 		enaddr[4] = 1;
1596 		enaddr[5] = sc->sc_vhid;
1597 	}
1598 	(void)sockaddr_dl_setaddr(sc->sc_if.if_sadl, sc->sc_if.if_sadl->sdl_len,
1599 	    enaddr, sizeof(enaddr));
1600 }
1601 
1602 void
1603 carp_addr_updated(void *v)
1604 {
1605 	struct carp_softc *sc = (struct carp_softc *) v;
1606 	struct ifaddr *ifa;
1607 	int new_naddrs = 0, new_naddrs6 = 0;
1608 
1609 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
1610 		if (ifa->ifa_addr->sa_family == AF_INET)
1611 			new_naddrs++;
1612 		else if (ifa->ifa_addr->sa_family == AF_INET6)
1613 			new_naddrs6++;
1614 	}
1615 
1616 	/* Handle a callback after SIOCDIFADDR */
1617 	if (new_naddrs < sc->sc_naddrs || new_naddrs6 < sc->sc_naddrs6) {
1618 		struct in_addr mc_addr;
1619 		struct in_multi *inm;
1620 
1621 		sc->sc_naddrs = new_naddrs;
1622 		sc->sc_naddrs6 = new_naddrs6;
1623 
1624 		/* Re-establish multicast membership removed by in_control */
1625 		mc_addr.s_addr = INADDR_CARP_GROUP;
1626 		IN_LOOKUP_MULTI(mc_addr, &sc->sc_if, inm);
1627 		if (inm == NULL) {
1628 			bzero(&sc->sc_imo, sizeof(sc->sc_imo));
1629 
1630 			if (sc->sc_carpdev != NULL && sc->sc_naddrs > 0)
1631 				carp_join_multicast(sc);
1632 		}
1633 
1634 		if (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) {
1635 			sc->sc_if.if_flags &= ~IFF_UP;
1636 			carp_set_state(sc, INIT);
1637 		} else
1638 			carp_hmac_prepare(sc);
1639 	}
1640 
1641 	carp_setrun(sc, 0);
1642 }
1643 
1644 int
1645 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1646 {
1647 	struct ifnet *ifp = sc->sc_carpdev;
1648 	struct in_ifaddr *ia, *ia_if;
1649 	int error = 0;
1650 
1651 	if (sin->sin_addr.s_addr == 0) {
1652 		if (!(sc->sc_if.if_flags & IFF_UP))
1653 			carp_set_state(sc, INIT);
1654 		if (sc->sc_naddrs)
1655 			sc->sc_if.if_flags |= IFF_UP;
1656 		carp_setrun(sc, 0);
1657 		return (0);
1658 	}
1659 
1660 	/* we have to do this by hand to ensure we don't match on ourselves */
1661 	ia_if = NULL;
1662 	for (ia = TAILQ_FIRST(&in_ifaddrhead); ia;
1663 	    ia = TAILQ_NEXT(ia, ia_list)) {
1664 
1665 		/* and, yeah, we need a multicast-capable iface too */
1666 		if (ia->ia_ifp != &sc->sc_if &&
1667 		    ia->ia_ifp->if_type != IFT_CARP &&
1668 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1669 		    (sin->sin_addr.s_addr & ia->ia_subnetmask) ==
1670 		    ia->ia_subnet) {
1671 			if (!ia_if)
1672 				ia_if = ia;
1673 		}
1674 	}
1675 
1676 	if (ia_if) {
1677 		ia = ia_if;
1678 		if (ifp) {
1679 			if (ifp != ia->ia_ifp)
1680 				return (EADDRNOTAVAIL);
1681 		} else {
1682 			ifp = ia->ia_ifp;
1683 		}
1684 	}
1685 
1686 	if ((error = carp_set_ifp(sc, ifp)))
1687 		return (error);
1688 
1689 	if (sc->sc_carpdev == NULL)
1690 		return (EADDRNOTAVAIL);
1691 
1692 	if (sc->sc_naddrs == 0 && (error = carp_join_multicast(sc)) != 0)
1693 		return (error);
1694 
1695 	sc->sc_naddrs++;
1696 	if (sc->sc_carpdev != NULL)
1697 		sc->sc_if.if_flags |= IFF_UP;
1698 
1699 	carp_set_state(sc, INIT);
1700 	carp_setrun(sc, 0);
1701 
1702 	/*
1703 	 * Hook if_addrhooks so that we get a callback after in_ifinit has run,
1704 	 * to correct any inappropriate routes that it inserted.
1705 	 */
1706 	if (sc->ah_cookie == 0) {
1707 		/* XXX link address hook */
1708 	}
1709 
1710 	return (0);
1711 }
1712 
1713 int
1714 carp_join_multicast(struct carp_softc *sc)
1715 {
1716 	struct ip_moptions *imo = &sc->sc_imo, tmpimo;
1717 	struct in_addr addr;
1718 
1719 	bzero(&tmpimo, sizeof(tmpimo));
1720 	addr.s_addr = INADDR_CARP_GROUP;
1721 	if ((tmpimo.imo_membership[0] =
1722 	    in_addmulti(&addr, &sc->sc_if)) == NULL) {
1723 		return (ENOBUFS);
1724 	}
1725 
1726 	imo->imo_membership[0] = tmpimo.imo_membership[0];
1727 	imo->imo_num_memberships = 1;
1728 	imo->imo_multicast_ifp = &sc->sc_if;
1729 	imo->imo_multicast_ttl = CARP_DFLTTL;
1730 	imo->imo_multicast_loop = 0;
1731 	return (0);
1732 }
1733 
1734 
1735 #ifdef INET6
1736 int
1737 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1738 {
1739 	struct ifnet *ifp = sc->sc_carpdev;
1740 	struct in6_ifaddr *ia, *ia_if;
1741 	int error = 0;
1742 
1743 	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1744 		if (!(sc->sc_if.if_flags & IFF_UP))
1745 			carp_set_state(sc, INIT);
1746 		if (sc->sc_naddrs6)
1747 			sc->sc_if.if_flags |= IFF_UP;
1748 		carp_setrun(sc, 0);
1749 		return (0);
1750 	}
1751 
1752 	/* we have to do this by hand to ensure we don't match on ourselves */
1753 	ia_if = NULL;
1754 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1755 		int i;
1756 
1757 		for (i = 0; i < 4; i++) {
1758 			if ((sin6->sin6_addr.s6_addr32[i] &
1759 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1760 			    (ia->ia_addr.sin6_addr.s6_addr32[i] &
1761 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1762 				break;
1763 		}
1764 		/* and, yeah, we need a multicast-capable iface too */
1765 		if (ia->ia_ifp != &sc->sc_if &&
1766 		    ia->ia_ifp->if_type != IFT_CARP &&
1767 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1768 		    (i == 4)) {
1769 			if (!ia_if)
1770 				ia_if = ia;
1771 		}
1772 	}
1773 
1774 	if (ia_if) {
1775 		ia = ia_if;
1776 		if (sc->sc_carpdev) {
1777 			if (sc->sc_carpdev != ia->ia_ifp)
1778 				return (EADDRNOTAVAIL);
1779 		} else {
1780 			ifp = ia->ia_ifp;
1781 		}
1782 	}
1783 
1784 	if ((error = carp_set_ifp(sc, ifp)))
1785 		return (error);
1786 
1787 	if (sc->sc_carpdev == NULL)
1788 		return (EADDRNOTAVAIL);
1789 
1790 	if (sc->sc_naddrs6 == 0 && (error = carp_join_multicast6(sc)) != 0)
1791 		return (error);
1792 
1793 	sc->sc_naddrs6++;
1794 	if (sc->sc_carpdev != NULL)
1795 		sc->sc_if.if_flags |= IFF_UP;
1796 	carp_set_state(sc, INIT);
1797 	carp_setrun(sc, 0);
1798 
1799 	return (0);
1800 }
1801 
1802 int
1803 carp_join_multicast6(struct carp_softc *sc)
1804 {
1805 	struct in6_multi_mship *imm, *imm2;
1806 	struct ip6_moptions *im6o = &sc->sc_im6o;
1807 	struct sockaddr_in6 addr6;
1808 	int error;
1809 
1810 	/* Join IPv6 CARP multicast group */
1811 	bzero(&addr6, sizeof(addr6));
1812 	addr6.sin6_family = AF_INET6;
1813 	addr6.sin6_len = sizeof(addr6);
1814 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1815 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1816 	addr6.sin6_addr.s6_addr8[15] = 0x12;
1817 	if ((imm = in6_joingroup(&sc->sc_if,
1818 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1819 		return (error);
1820 	}
1821 	/* join solicited multicast address */
1822 	bzero(&addr6.sin6_addr, sizeof(addr6.sin6_addr));
1823 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1824 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1825 	addr6.sin6_addr.s6_addr32[1] = 0;
1826 	addr6.sin6_addr.s6_addr32[2] = htonl(1);
1827 	addr6.sin6_addr.s6_addr32[3] = 0;
1828 	addr6.sin6_addr.s6_addr8[12] = 0xff;
1829 	if ((imm2 = in6_joingroup(&sc->sc_if,
1830 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1831 		in6_leavegroup(imm);
1832 		return (error);
1833 	}
1834 
1835 	/* apply v6 multicast membership */
1836 	im6o->im6o_multicast_ifp = &sc->sc_if;
1837 	if (imm)
1838 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm,
1839 		    i6mm_chain);
1840 	if (imm2)
1841 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm2,
1842 		    i6mm_chain);
1843 
1844 	return (0);
1845 }
1846 
1847 #endif /* INET6 */
1848 
1849 int
1850 carp_ioctl(struct ifnet *ifp, u_long cmd, void *addr)
1851 {
1852 	struct lwp *l = curlwp;		/* XXX */
1853 	struct carp_softc *sc = ifp->if_softc, *vr;
1854 	struct carpreq carpr;
1855 	struct ifaddr *ifa;
1856 	struct ifreq *ifr;
1857 	struct ifnet *cdev = NULL;
1858 	int error = 0;
1859 
1860 	ifa = (struct ifaddr *)addr;
1861 	ifr = (struct ifreq *)addr;
1862 
1863 	switch (cmd) {
1864 	case SIOCSIFADDR:
1865 		switch (ifa->ifa_addr->sa_family) {
1866 #ifdef INET
1867 		case AF_INET:
1868 			sc->sc_if.if_flags |= IFF_UP;
1869 			bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1870 			    sizeof(struct sockaddr));
1871 			error = carp_set_addr(sc, satosin(ifa->ifa_addr));
1872 			break;
1873 #endif /* INET */
1874 #ifdef INET6
1875 		case AF_INET6:
1876 			sc->sc_if.if_flags|= IFF_UP;
1877 			error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1878 			break;
1879 #endif /* INET6 */
1880 		default:
1881 			error = EAFNOSUPPORT;
1882 			break;
1883 		}
1884 		break;
1885 
1886 	case SIOCSIFFLAGS:
1887 		if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
1888 			callout_stop(&sc->sc_ad_tmo);
1889 			callout_stop(&sc->sc_md_tmo);
1890 			callout_stop(&sc->sc_md6_tmo);
1891 			if (sc->sc_state == MASTER) {
1892 				/* we need the interface up to bow out */
1893 				sc->sc_if.if_flags |= IFF_UP;
1894 				sc->sc_bow_out = 1;
1895 				carp_send_ad(sc);
1896 			}
1897 			sc->sc_if.if_flags &= ~IFF_UP;
1898 			carp_set_state(sc, INIT);
1899 			carp_setrun(sc, 0);
1900 		} else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
1901 			sc->sc_if.if_flags |= IFF_UP;
1902 			carp_setrun(sc, 0);
1903 		}
1904 		break;
1905 
1906 	case SIOCSVH:
1907 		if (l == NULL)
1908 			break;
1909 		if ((error = kauth_authorize_network(l->l_cred,
1910 		    KAUTH_NETWORK_INTERFACE,
1911 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
1912 		    NULL)) != 0)
1913 			break;
1914 		if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
1915 			break;
1916 		error = 1;
1917 		if (carpr.carpr_carpdev[0] != '\0' &&
1918 		    (cdev = ifunit(carpr.carpr_carpdev)) == NULL)
1919 			return (EINVAL);
1920 		if ((error = carp_set_ifp(sc, cdev)))
1921 			return (error);
1922 		if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
1923 			switch (carpr.carpr_state) {
1924 			case BACKUP:
1925 				callout_stop(&sc->sc_ad_tmo);
1926 				carp_set_state(sc, BACKUP);
1927 				carp_setrun(sc, 0);
1928 				carp_setroute(sc, RTM_DELETE);
1929 				break;
1930 			case MASTER:
1931 				carp_master_down(sc);
1932 				break;
1933 			default:
1934 				break;
1935 			}
1936 		}
1937 		if (carpr.carpr_vhid > 0) {
1938 			if (carpr.carpr_vhid > 255) {
1939 				error = EINVAL;
1940 				break;
1941 			}
1942 			if (sc->sc_carpdev) {
1943 				struct carp_if *cif;
1944 				cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1945 				TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1946 					if (vr != sc &&
1947 					    vr->sc_vhid == carpr.carpr_vhid)
1948 						return (EINVAL);
1949 			}
1950 			sc->sc_vhid = carpr.carpr_vhid;
1951 			carp_set_enaddr(sc);
1952 			carp_set_state(sc, INIT);
1953 			error--;
1954 		}
1955 		if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
1956 			if (carpr.carpr_advskew > 254) {
1957 				error = EINVAL;
1958 				break;
1959 			}
1960 			if (carpr.carpr_advbase > 255) {
1961 				error = EINVAL;
1962 				break;
1963 			}
1964 			sc->sc_advbase = carpr.carpr_advbase;
1965 			sc->sc_advskew = carpr.carpr_advskew;
1966 			error--;
1967 		}
1968 		bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1969 		if (error > 0)
1970 			error = EINVAL;
1971 		else {
1972 			error = 0;
1973 			carp_setrun(sc, 0);
1974 		}
1975 		break;
1976 
1977 	case SIOCGVH:
1978 		bzero(&carpr, sizeof(carpr));
1979 		if (sc->sc_carpdev != NULL)
1980 			strlcpy(carpr.carpr_carpdev, sc->sc_carpdev->if_xname,
1981 			    IFNAMSIZ);
1982 		carpr.carpr_state = sc->sc_state;
1983 		carpr.carpr_vhid = sc->sc_vhid;
1984 		carpr.carpr_advbase = sc->sc_advbase;
1985 		carpr.carpr_advskew = sc->sc_advskew;
1986 
1987 		if ((l == NULL) || (error = kauth_authorize_network(l->l_cred,
1988 		    KAUTH_NETWORK_INTERFACE,
1989 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
1990 		    NULL)) != 0)
1991 			bcopy(sc->sc_key, carpr.carpr_key,
1992 			    sizeof(carpr.carpr_key));
1993 		error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
1994 		break;
1995 
1996 	case SIOCADDMULTI:
1997 		error = carp_ether_addmulti(sc, ifr);
1998 		break;
1999 
2000 	case SIOCDELMULTI:
2001 		error = carp_ether_delmulti(sc, ifr);
2002 		break;
2003 
2004 	default:
2005 		error = EINVAL;
2006 	}
2007 
2008 	carp_hmac_prepare(sc);
2009 	return (error);
2010 }
2011 
2012 
2013 /*
2014  * Start output on carp interface. This function should never be called.
2015  */
2016 void
2017 carp_start(struct ifnet *ifp)
2018 {
2019 #ifdef DEBUG
2020 	printf("%s: start called\n", ifp->if_xname);
2021 #endif
2022 }
2023 
2024 int
2025 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa,
2026     struct rtentry *rt)
2027 {
2028 	struct carp_softc *sc = ((struct carp_softc *)ifp->if_softc);
2029 
2030 	if (sc->sc_carpdev != NULL && sc->sc_state == MASTER) {
2031 		return (sc->sc_carpdev->if_output(ifp, m, sa, rt));
2032 	} else {
2033 		m_freem(m);
2034 		return (ENETUNREACH);
2035 	}
2036 }
2037 
2038 void
2039 carp_set_state(struct carp_softc *sc, int state)
2040 {
2041 	if (sc->sc_state == state)
2042 		return;
2043 
2044 	sc->sc_state = state;
2045 	switch (state) {
2046 	case BACKUP:
2047 		sc->sc_if.if_link_state = LINK_STATE_DOWN;
2048 		break;
2049 	case MASTER:
2050 		sc->sc_if.if_link_state = LINK_STATE_UP;
2051 		break;
2052 	default:
2053 		sc->sc_if.if_link_state = LINK_STATE_UNKNOWN;
2054 		break;
2055 	}
2056 	rt_ifmsg(&sc->sc_if);
2057 }
2058 
2059 void
2060 carp_carpdev_state(void *v)
2061 {
2062 	struct carp_if *cif;
2063 	struct carp_softc *sc;
2064 	struct ifnet *ifp = v;
2065 
2066 	if (ifp->if_type == IFT_CARP)
2067 		return;
2068 
2069 	cif = (struct carp_if *)ifp->if_carp;
2070 
2071 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
2072 		int suppressed = sc->sc_suppress;
2073 
2074 		if (sc->sc_carpdev->if_link_state == LINK_STATE_DOWN ||
2075 		    !(sc->sc_carpdev->if_flags & IFF_UP)) {
2076 			sc->sc_if.if_flags &= ~IFF_RUNNING;
2077 			callout_stop(&sc->sc_ad_tmo);
2078 			callout_stop(&sc->sc_md_tmo);
2079 			callout_stop(&sc->sc_md6_tmo);
2080 			carp_set_state(sc, INIT);
2081 			sc->sc_suppress = 1;
2082 			carp_setrun(sc, 0);
2083 			if (!suppressed) {
2084 				carp_suppress_preempt++;
2085 				if (carp_suppress_preempt == 1)
2086 					carp_send_ad_all();
2087 			}
2088 		} else {
2089 			carp_set_state(sc, INIT);
2090 			sc->sc_suppress = 0;
2091 			carp_setrun(sc, 0);
2092 			if (suppressed)
2093 				carp_suppress_preempt--;
2094 		}
2095 	}
2096 }
2097 
2098 int
2099 carp_ether_addmulti(struct carp_softc *sc, struct ifreq *ifr)
2100 {
2101 	const struct sockaddr *sa = ifreq_getaddr(SIOCADDMULTI, ifr);
2102 	struct ifnet *ifp;
2103 	struct carp_mc_entry *mc;
2104 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2105 	int error;
2106 
2107 	ifp = sc->sc_carpdev;
2108 	if (ifp == NULL)
2109 		return (EINVAL);
2110 
2111 	error = ether_addmulti(sa, &sc->sc_ac);
2112 	if (error != ENETRESET)
2113 		return (error);
2114 
2115 	/*
2116 	 * This is new multicast address.  We have to tell parent
2117 	 * about it.  Also, remember this multicast address so that
2118 	 * we can delete them on unconfigure.
2119 	 */
2120 	MALLOC(mc, struct carp_mc_entry *, sizeof(struct carp_mc_entry),
2121 	    M_DEVBUF, M_NOWAIT);
2122 	if (mc == NULL) {
2123 		error = ENOMEM;
2124 		goto alloc_failed;
2125 	}
2126 
2127 	/*
2128 	 * As ether_addmulti() returns ENETRESET, following two
2129 	 * statement shouldn't fail.
2130 	 */
2131 	(void)ether_multiaddr(sa, addrlo, addrhi);
2132 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, mc->mc_enm);
2133 	memcpy(&mc->mc_addr, sa, sa->sa_len);
2134 	LIST_INSERT_HEAD(&sc->carp_mc_listhead, mc, mc_entries);
2135 
2136 	error = (*ifp->if_ioctl)(ifp, SIOCADDMULTI, (void *)ifr);
2137 	if (error != 0)
2138 		goto ioctl_failed;
2139 
2140 	return (error);
2141 
2142  ioctl_failed:
2143 	LIST_REMOVE(mc, mc_entries);
2144 	FREE(mc, M_DEVBUF);
2145  alloc_failed:
2146 	(void)ether_delmulti(sa, &sc->sc_ac);
2147 
2148 	return (error);
2149 }
2150 
2151 int
2152 carp_ether_delmulti(struct carp_softc *sc, struct ifreq *ifr)
2153 {
2154 	const struct sockaddr *sa = ifreq_getaddr(SIOCDELMULTI, ifr);
2155 	struct ifnet *ifp;
2156 	struct ether_multi *enm;
2157 	struct carp_mc_entry *mc;
2158 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2159 	int error;
2160 
2161 	ifp = sc->sc_carpdev;
2162 	if (ifp == NULL)
2163 		return (EINVAL);
2164 
2165 	/*
2166 	 * Find a key to lookup carp_mc_entry.  We have to do this
2167 	 * before calling ether_delmulti for obvious reason.
2168 	 */
2169 	if ((error = ether_multiaddr(sa, addrlo, addrhi)) != 0)
2170 		return (error);
2171 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, enm);
2172 	if (enm == NULL)
2173 		return (EINVAL);
2174 
2175 	LIST_FOREACH(mc, &sc->carp_mc_listhead, mc_entries)
2176 		if (mc->mc_enm == enm)
2177 			break;
2178 
2179 	/* We won't delete entries we didn't add */
2180 	if (mc == NULL)
2181 		return (EINVAL);
2182 
2183 	error = ether_delmulti(sa, &sc->sc_ac);
2184 	if (error != ENETRESET)
2185 		return (error);
2186 
2187 	/* We no longer use this multicast address.  Tell parent so. */
2188 	error = (*ifp->if_ioctl)(ifp, SIOCDELMULTI, (void *)ifr);
2189 	if (error == 0) {
2190 		/* And forget about this address. */
2191 		LIST_REMOVE(mc, mc_entries);
2192 		FREE(mc, M_DEVBUF);
2193 	} else
2194 		(void)ether_addmulti(sa, &sc->sc_ac);
2195 	return (error);
2196 }
2197 
2198 /*
2199  * Delete any multicast address we have asked to add from parent
2200  * interface.  Called when the carp is being unconfigured.
2201  */
2202 void
2203 carp_ether_purgemulti(struct carp_softc *sc)
2204 {
2205 	struct ifnet *ifp = sc->sc_carpdev;		/* Parent. */
2206 	struct carp_mc_entry *mc;
2207 	union {
2208 		struct ifreq ifreq;
2209 		struct {
2210 			char ifr_name[IFNAMSIZ];
2211 			struct sockaddr_storage ifr_ss;
2212 		} ifreq_storage;
2213 	} u;
2214 	struct ifreq *ifr = &u.ifreq;
2215 
2216 	if (ifp == NULL)
2217 		return;
2218 
2219 	memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
2220 	while ((mc = LIST_FIRST(&sc->carp_mc_listhead)) != NULL) {
2221 		memcpy(&ifr->ifr_addr, &mc->mc_addr, mc->mc_addr.ss_len);
2222 		(void)(*ifp->if_ioctl)(ifp, SIOCDELMULTI, (void *)ifr);
2223 		LIST_REMOVE(mc, mc_entries);
2224 		FREE(mc, M_DEVBUF);
2225 	}
2226 }
2227 
2228 SYSCTL_SETUP(sysctl_net_inet_carp_setup, "sysctl net.inet.carp subtree setup")
2229 {
2230 
2231 	sysctl_createv(clog, 0, NULL, NULL,
2232 		       CTLFLAG_PERMANENT,
2233 		       CTLTYPE_NODE, "net", NULL,
2234 		       NULL, 0, NULL, 0,
2235 		       CTL_NET, CTL_EOL);
2236 	sysctl_createv(clog, 0, NULL, NULL,
2237 		       CTLFLAG_PERMANENT,
2238 		       CTLTYPE_NODE, "inet", NULL,
2239 		       NULL, 0, NULL, 0,
2240 		       CTL_NET, PF_INET, CTL_EOL);
2241 	sysctl_createv(clog, 0, NULL, NULL,
2242 		       CTLFLAG_PERMANENT,
2243 		       CTLTYPE_NODE, "carp",
2244 		       SYSCTL_DESCR("CARP related settings"),
2245 		       NULL, 0, NULL, 0,
2246 		       CTL_NET, PF_INET, IPPROTO_CARP, CTL_EOL);
2247 
2248 	sysctl_createv(clog, 0, NULL, NULL,
2249 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2250 		       CTLTYPE_INT, "preempt",
2251 		       SYSCTL_DESCR("Enable CARP Preempt"),
2252 		       NULL, 0, &carp_opts[CARPCTL_PREEMPT], 0,
2253 		       CTL_NET, PF_INET, IPPROTO_CARP,
2254 		       CTL_CREATE, CTL_EOL);
2255 	sysctl_createv(clog, 0, NULL, NULL,
2256 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2257 		       CTLTYPE_INT, "arpbalance",
2258 		       SYSCTL_DESCR("Enable ARP balancing"),
2259 		       NULL, 0, &carp_opts[CARPCTL_ARPBALANCE], 0,
2260 		       CTL_NET, PF_INET, IPPROTO_CARP,
2261 		       CTL_CREATE, CTL_EOL);
2262 	sysctl_createv(clog, 0, NULL, NULL,
2263 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2264 		       CTLTYPE_INT, "allow",
2265 		       SYSCTL_DESCR("Enable CARP"),
2266 		       NULL, 0, &carp_opts[CARPCTL_ALLOW], 0,
2267 		       CTL_NET, PF_INET, IPPROTO_CARP,
2268 		       CTL_CREATE, CTL_EOL);
2269 	sysctl_createv(clog, 0, NULL, NULL,
2270 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2271 		       CTLTYPE_INT, "log",
2272 		       SYSCTL_DESCR("CARP logging"),
2273 		       NULL, 0, &carp_opts[CARPCTL_LOG], 0,
2274 		       CTL_NET, PF_INET, IPPROTO_CARP,
2275 		       CTL_CREATE, CTL_EOL);
2276 	sysctl_createv(clog, 0, NULL, NULL,
2277 		       CTLFLAG_PERMANENT,
2278 		       CTLTYPE_STRUCT, "stats",
2279 		       SYSCTL_DESCR("CARP statistics"),
2280 		       NULL, 0, &carpstats, sizeof(carpstats),
2281 		       CTL_NET, PF_INET, IPPROTO_CARP, CARPCTL_STATS,
2282 		       CTL_EOL);
2283 }
2284