xref: /netbsd-src/sys/netinet/ip_carp.c (revision 2980e352a13e8f0b545a366830c411e7a542ada8)
1 /*	$NetBSD: ip_carp.c,v 1.26 2008/05/04 07:22:14 thorpej 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 #include <sys/cdefs.h>
31 __KERNEL_RCSID(0, "$NetBSD: ip_carp.c,v 1.26 2008/05/04 07:22:14 thorpej Exp $");
32 
33 /*
34  * TODO:
35  *	- iface reconfigure
36  *	- support for hardware checksum calculations;
37  *
38  */
39 
40 #include <sys/param.h>
41 #include <sys/proc.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/socketvar.h>
45 #include <sys/callout.h>
46 #include <sys/ioctl.h>
47 #include <sys/errno.h>
48 #include <sys/device.h>
49 #include <sys/time.h>
50 #include <sys/kernel.h>
51 #include <sys/kauth.h>
52 #include <sys/sysctl.h>
53 #include <sys/ucred.h>
54 #include <sys/syslog.h>
55 #include <sys/acct.h>
56 
57 #include <sys/cpu.h>
58 
59 #include <net/if.h>
60 #include <net/pfil.h>
61 #include <net/if_types.h>
62 #include <net/if_ether.h>
63 #include <net/route.h>
64 #include <net/netisr.h>
65 #include <net/net_stats.h>
66 #include <netinet/if_inarp.h>
67 
68 #include <machine/stdarg.h>
69 
70 #if NFDDI > 0
71 #include <net/if_fddi.h>
72 #endif
73 #if NTOKEN > 0
74 #include <net/if_token.h>
75 #endif
76 
77 #ifdef INET
78 #include <netinet/in.h>
79 #include <netinet/in_systm.h>
80 #include <netinet/in_var.h>
81 #include <netinet/ip.h>
82 #include <netinet/ip_var.h>
83 
84 #include <net/if_dl.h>
85 #endif
86 
87 #ifdef INET6
88 #include <netinet/icmp6.h>
89 #include <netinet/ip6.h>
90 #include <netinet6/ip6_var.h>
91 #include <netinet6/nd6.h>
92 #include <netinet6/scope6_var.h>
93 #endif
94 
95 #include "bpfilter.h"
96 #if NBPFILTER > 0
97 #include <net/bpf.h>
98 #endif
99 
100 #include <sys/sha1.h>
101 
102 #include <netinet/ip_carp.h>
103 
104 struct carp_mc_entry {
105 	LIST_ENTRY(carp_mc_entry)	mc_entries;
106 	union {
107 		struct ether_multi	*mcu_enm;
108 	} mc_u;
109 	struct sockaddr_storage		mc_addr;
110 };
111 #define	mc_enm	mc_u.mcu_enm
112 
113 struct carp_softc {
114 	struct ethercom sc_ac;
115 #define	sc_if		sc_ac.ec_if
116 #define	sc_carpdev	sc_ac.ec_if.if_carpdev
117 	int ah_cookie;
118 	int lh_cookie;
119 	struct ip_moptions sc_imo;
120 #ifdef INET6
121 	struct ip6_moptions sc_im6o;
122 #endif /* INET6 */
123 	TAILQ_ENTRY(carp_softc) sc_list;
124 
125 	enum { INIT = 0, BACKUP, MASTER }	sc_state;
126 
127 	int sc_suppress;
128 	int sc_bow_out;
129 
130 	int sc_sendad_errors;
131 #define CARP_SENDAD_MAX_ERRORS	3
132 	int sc_sendad_success;
133 #define CARP_SENDAD_MIN_SUCCESS 3
134 
135 	int sc_vhid;
136 	int sc_advskew;
137 	int sc_naddrs;
138 	int sc_naddrs6;
139 	int sc_advbase;		/* seconds */
140 	int sc_init_counter;
141 	u_int64_t sc_counter;
142 
143 	/* authentication */
144 #define CARP_HMAC_PAD	64
145 	unsigned char sc_key[CARP_KEY_LEN];
146 	unsigned char sc_pad[CARP_HMAC_PAD];
147 	SHA1_CTX sc_sha1;
148 	u_int32_t sc_hashkey[2];
149 
150 	struct callout sc_ad_tmo;	/* advertisement timeout */
151 	struct callout sc_md_tmo;	/* master down timeout */
152 	struct callout sc_md6_tmo;	/* master down timeout */
153 
154 	LIST_HEAD(__carp_mchead, carp_mc_entry)	carp_mc_listhead;
155 };
156 
157 int carp_suppress_preempt = 0;
158 int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 0, 0 };	/* XXX for now */
159 
160 static percpu_t *carpstat_percpu;
161 
162 #define	CARP_STATINC(x)		_NET_STATINC(carpstat_percpu, x)
163 
164 struct carp_if {
165 	TAILQ_HEAD(, carp_softc) vhif_vrs;
166 	int vhif_nvrs;
167 
168 	struct ifnet *vhif_ifp;
169 };
170 
171 #define	CARP_LOG(sc, s)							\
172 	if (carp_opts[CARPCTL_LOG]) {					\
173 		if (sc)							\
174 			log(LOG_INFO, "%s: ",				\
175 			    (sc)->sc_if.if_xname);			\
176 		else							\
177 			log(LOG_INFO, "carp: ");			\
178 		addlog s;						\
179 		addlog("\n");						\
180 	}
181 
182 void	carp_hmac_prepare(struct carp_softc *);
183 void	carp_hmac_generate(struct carp_softc *, u_int32_t *,
184 	    unsigned char *);
185 int	carp_hmac_verify(struct carp_softc *, u_int32_t *,
186 	    unsigned char *);
187 void	carp_setroute(struct carp_softc *, int);
188 void	carp_proto_input_c(struct mbuf *, struct carp_header *, sa_family_t);
189 void	carpattach(int);
190 void	carpdetach(struct carp_softc *);
191 int	carp_prepare_ad(struct mbuf *, struct carp_softc *,
192 	    struct carp_header *);
193 void	carp_send_ad_all(void);
194 void	carp_send_ad(void *);
195 void	carp_send_arp(struct carp_softc *);
196 void	carp_master_down(void *);
197 int	carp_ioctl(struct ifnet *, u_long, void *);
198 void	carp_start(struct ifnet *);
199 void	carp_setrun(struct carp_softc *, sa_family_t);
200 void	carp_set_state(struct carp_softc *, int);
201 int	carp_addrcount(struct carp_if *, struct in_ifaddr *, int);
202 enum	{ CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
203 
204 void	carp_multicast_cleanup(struct carp_softc *);
205 int	carp_set_ifp(struct carp_softc *, struct ifnet *);
206 void	carp_set_enaddr(struct carp_softc *);
207 void	carp_addr_updated(void *);
208 u_int32_t	carp_hash(struct carp_softc *, u_char *);
209 int	carp_set_addr(struct carp_softc *, struct sockaddr_in *);
210 int	carp_join_multicast(struct carp_softc *);
211 #ifdef INET6
212 void	carp_send_na(struct carp_softc *);
213 int	carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
214 int	carp_join_multicast6(struct carp_softc *);
215 #endif
216 int	carp_clone_create(struct if_clone *, int);
217 int	carp_clone_destroy(struct ifnet *);
218 int	carp_ether_addmulti(struct carp_softc *, struct ifreq *);
219 int	carp_ether_delmulti(struct carp_softc *, struct ifreq *);
220 void	carp_ether_purgemulti(struct carp_softc *);
221 
222 struct if_clone carp_cloner =
223     IF_CLONE_INITIALIZER("carp", carp_clone_create, carp_clone_destroy);
224 
225 static __inline u_int16_t
226 carp_cksum(struct mbuf *m, int len)
227 {
228 	return (in_cksum(m, len));
229 }
230 
231 void
232 carp_hmac_prepare(struct carp_softc *sc)
233 {
234 	u_int8_t carp_version = CARP_VERSION, type = CARP_ADVERTISEMENT;
235 	u_int8_t vhid = sc->sc_vhid & 0xff;
236 	SHA1_CTX sha1ctx;
237 	u_int32_t kmd[5];
238 	struct ifaddr *ifa;
239 	int i, found;
240 	struct in_addr last, cur, in;
241 #ifdef INET6
242 	struct in6_addr last6, cur6, in6;
243 #endif /* INET6 */
244 
245 	/* compute ipad from key */
246 	bzero(sc->sc_pad, sizeof(sc->sc_pad));
247 	bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
248 	for (i = 0; i < sizeof(sc->sc_pad); i++)
249 		sc->sc_pad[i] ^= 0x36;
250 
251 	/* precompute first part of inner hash */
252 	SHA1Init(&sc->sc_sha1);
253 	SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
254 	SHA1Update(&sc->sc_sha1, (void *)&carp_version, sizeof(carp_version));
255 	SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
256 
257 	/* generate a key for the arpbalance hash, before the vhid is hashed */
258 	bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
259 	SHA1Final((unsigned char *)kmd, &sha1ctx);
260 	sc->sc_hashkey[0] = kmd[0] ^ kmd[1];
261 	sc->sc_hashkey[1] = kmd[2] ^ kmd[3];
262 
263 	/* the rest of the precomputation */
264 	SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
265 
266 	/* Hash the addresses from smallest to largest, not interface order */
267 #ifdef INET
268 	cur.s_addr = 0;
269 	do {
270 		found = 0;
271 		last = cur;
272 		cur.s_addr = 0xffffffff;
273 		IFADDR_FOREACH(ifa, &sc->sc_if) {
274 			in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
275 			if (ifa->ifa_addr->sa_family == AF_INET &&
276 			    ntohl(in.s_addr) > ntohl(last.s_addr) &&
277 			    ntohl(in.s_addr) < ntohl(cur.s_addr)) {
278 				cur.s_addr = in.s_addr;
279 				found++;
280 			}
281 		}
282 		if (found)
283 			SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
284 	} while (found);
285 #endif /* INET */
286 
287 #ifdef INET6
288 	memset(&cur6, 0x00, sizeof(cur6));
289 	do {
290 		found = 0;
291 		last6 = cur6;
292 		memset(&cur6, 0xff, sizeof(cur6));
293 		IFADDR_FOREACH(ifa, &sc->sc_if) {
294 			in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
295 			if (IN6_IS_ADDR_LINKLOCAL(&in6))
296 				in6.s6_addr16[1] = 0;
297 			if (ifa->ifa_addr->sa_family == AF_INET6 &&
298 			    memcmp(&in6, &last6, sizeof(in6)) > 0 &&
299 			    memcmp(&in6, &cur6, sizeof(in6)) < 0) {
300 				cur6 = in6;
301 				found++;
302 			}
303 		}
304 		if (found)
305 			SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
306 	} while (found);
307 #endif /* INET6 */
308 
309 	/* convert ipad to opad */
310 	for (i = 0; i < sizeof(sc->sc_pad); i++)
311 		sc->sc_pad[i] ^= 0x36 ^ 0x5c;
312 }
313 
314 void
315 carp_hmac_generate(struct carp_softc *sc, u_int32_t counter[2],
316     unsigned char md[20])
317 {
318 	SHA1_CTX sha1ctx;
319 
320 	/* fetch first half of inner hash */
321 	bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
322 
323 	SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
324 	SHA1Final(md, &sha1ctx);
325 
326 	/* outer hash */
327 	SHA1Init(&sha1ctx);
328 	SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
329 	SHA1Update(&sha1ctx, md, 20);
330 	SHA1Final(md, &sha1ctx);
331 }
332 
333 int
334 carp_hmac_verify(struct carp_softc *sc, u_int32_t counter[2],
335     unsigned char md[20])
336 {
337 	unsigned char md2[20];
338 
339 	carp_hmac_generate(sc, counter, md2);
340 
341 	return (bcmp(md, md2, sizeof(md2)));
342 }
343 
344 void
345 carp_setroute(struct carp_softc *sc, int cmd)
346 {
347 	struct ifaddr *ifa;
348 	int s;
349 
350 	s = splsoftnet();
351 	IFADDR_FOREACH(ifa, &sc->sc_if) {
352 		switch (ifa->ifa_addr->sa_family) {
353 		case AF_INET: {
354 			int count = 0;
355 			struct rtentry *rt;
356 			int hr_otherif, nr_ourif;
357 
358 			/*
359 			 * Avoid screwing with the routes if there are other
360 			 * carp interfaces which are master and have the same
361 			 * address.
362 			 */
363 			if (sc->sc_carpdev != NULL &&
364 			    sc->sc_carpdev->if_carp != NULL) {
365 				count = carp_addrcount(
366 				    (struct carp_if *)sc->sc_carpdev->if_carp,
367 				    ifatoia(ifa), CARP_COUNT_MASTER);
368 				if ((cmd == RTM_ADD && count != 1) ||
369 				    (cmd == RTM_DELETE && count != 0))
370 					continue;
371 			}
372 
373 			/* Remove the existing host route, if any */
374 			rtrequest(RTM_DELETE, ifa->ifa_addr,
375 			    ifa->ifa_addr, ifa->ifa_netmask,
376 			    RTF_HOST, NULL);
377 
378 			rt = NULL;
379 			(void)rtrequest(RTM_GET, ifa->ifa_addr, ifa->ifa_addr,
380 			    ifa->ifa_netmask, RTF_HOST, &rt);
381 			hr_otherif = (rt && rt->rt_ifp != &sc->sc_if &&
382 			    rt->rt_flags & (RTF_CLONING|RTF_CLONED));
383 			if (rt != NULL) {
384 				RTFREE(rt);
385 				rt = NULL;
386 			}
387 
388 			/* Check for a network route on our interface */
389 
390 			rt = NULL;
391 			(void)rtrequest(RTM_GET, ifa->ifa_addr, ifa->ifa_addr,
392 			    ifa->ifa_netmask, 0, &rt);
393 			nr_ourif = (rt && rt->rt_ifp == &sc->sc_if);
394 
395 			switch (cmd) {
396 			case RTM_ADD:
397 				if (hr_otherif) {
398 					ifa->ifa_rtrequest = NULL;
399 					ifa->ifa_flags &= ~RTF_CLONING;
400 
401 					rtrequest(RTM_ADD, ifa->ifa_addr,
402 					    ifa->ifa_addr, ifa->ifa_netmask,
403 					    RTF_UP | RTF_HOST, NULL);
404 				}
405 				if (!hr_otherif || nr_ourif || !rt) {
406 					if (nr_ourif && !(rt->rt_flags &
407 					    RTF_CLONING))
408 						rtrequest(RTM_DELETE,
409 						    ifa->ifa_addr,
410 						    ifa->ifa_addr,
411 						    ifa->ifa_netmask, 0, NULL);
412 
413 					ifa->ifa_rtrequest = arp_rtrequest;
414 					ifa->ifa_flags |= RTF_CLONING;
415 
416 					if (rtrequest(RTM_ADD, ifa->ifa_addr,
417 					    ifa->ifa_addr, ifa->ifa_netmask, 0,
418 					    NULL) == 0)
419 						ifa->ifa_flags |= IFA_ROUTE;
420 				}
421 				break;
422 			case RTM_DELETE:
423 				break;
424 			default:
425 				break;
426 			}
427 			if (rt != NULL) {
428 				RTFREE(rt);
429 				rt = NULL;
430 			}
431 			break;
432 		}
433 
434 #ifdef INET6
435 		case AF_INET6:
436 			if (cmd == RTM_ADD)
437 				in6_ifaddloop(ifa);
438 			else
439 				in6_ifremloop(ifa);
440 			break;
441 #endif /* INET6 */
442 		default:
443 			break;
444 		}
445 	}
446 	splx(s);
447 }
448 
449 /*
450  * process input packet.
451  * we have rearranged checks order compared to the rfc,
452  * but it seems more efficient this way or not possible otherwise.
453  */
454 void
455 carp_proto_input(struct mbuf *m, ...)
456 {
457 	struct ip *ip = mtod(m, struct ip *);
458 	struct carp_softc *sc = NULL;
459 	struct carp_header *ch;
460 	int iplen, len, hlen;
461 	va_list ap;
462 
463 	va_start(ap, m);
464 	hlen = va_arg(ap, int);
465 	va_end(ap);
466 
467 	CARP_STATINC(CARP_STAT_IPACKETS);
468 
469 	if (!carp_opts[CARPCTL_ALLOW]) {
470 		m_freem(m);
471 		return;
472 	}
473 
474 	/* check if received on a valid carp interface */
475 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
476 		CARP_STATINC(CARP_STAT_BADIF);
477 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
478 		    m->m_pkthdr.rcvif->if_xname));
479 		m_freem(m);
480 		return;
481 	}
482 
483 	/* verify that the IP TTL is 255.  */
484 	if (ip->ip_ttl != CARP_DFLTTL) {
485 		CARP_STATINC(CARP_STAT_BADTTL);
486 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip->ip_ttl,
487 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
488 		m_freem(m);
489 		return;
490 	}
491 
492 	/*
493 	 * verify that the received packet length is
494 	 * equal to the CARP header
495 	 */
496 	iplen = ip->ip_hl << 2;
497 	len = iplen + sizeof(*ch);
498 	if (len > m->m_pkthdr.len) {
499 		CARP_STATINC(CARP_STAT_BADLEN);
500 		CARP_LOG(sc, ("packet too short %d on %s", m->m_pkthdr.len,
501 		    m->m_pkthdr.rcvif->if_xname));
502 		m_freem(m);
503 		return;
504 	}
505 
506 	if ((m = m_pullup(m, len)) == NULL) {
507 		CARP_STATINC(CARP_STAT_HDROPS);
508 		return;
509 	}
510 	ip = mtod(m, struct ip *);
511 	ch = (struct carp_header *)((char *)ip + iplen);
512 	/* verify the CARP checksum */
513 	m->m_data += iplen;
514 	if (carp_cksum(m, len - iplen)) {
515 		CARP_STATINC(CARP_STAT_BADSUM);
516 		CARP_LOG(sc, ("checksum failed on %s",
517 		    m->m_pkthdr.rcvif->if_xname));
518 		m_freem(m);
519 		return;
520 	}
521 	m->m_data -= iplen;
522 
523 	carp_proto_input_c(m, ch, AF_INET);
524 }
525 
526 #ifdef INET6
527 int
528 carp6_proto_input(struct mbuf **mp, int *offp, int proto)
529 {
530 	struct mbuf *m = *mp;
531 	struct carp_softc *sc = NULL;
532 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
533 	struct carp_header *ch;
534 	u_int len;
535 
536 	CARP_STATINC(CARP_STAT_IPACKETS6);
537 
538 	if (!carp_opts[CARPCTL_ALLOW]) {
539 		m_freem(m);
540 		return (IPPROTO_DONE);
541 	}
542 
543 	/* check if received on a valid carp interface */
544 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
545 		CARP_STATINC(CARP_STAT_BADIF);
546 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
547 		    m->m_pkthdr.rcvif->if_xname));
548 		m_freem(m);
549 		return (IPPROTO_DONE);
550 	}
551 
552 	/* verify that the IP TTL is 255 */
553 	if (ip6->ip6_hlim != CARP_DFLTTL) {
554 		CARP_STATINC(CARP_STAT_BADTTL);
555 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip6->ip6_hlim,
556 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
557 		m_freem(m);
558 		return (IPPROTO_DONE);
559 	}
560 
561 	/* verify that we have a complete carp packet */
562 	len = m->m_len;
563 	IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
564 	if (ch == NULL) {
565 		CARP_STATINC(CARP_STAT_BADLEN);
566 		CARP_LOG(sc, ("packet size %u too small", len));
567 		return (IPPROTO_DONE);
568 	}
569 
570 
571 	/* verify the CARP checksum */
572 	m->m_data += *offp;
573 	if (carp_cksum(m, sizeof(*ch))) {
574 		CARP_STATINC(CARP_STAT_BADSUM);
575 		CARP_LOG(sc, ("checksum failed, on %s",
576 		    m->m_pkthdr.rcvif->if_xname));
577 		m_freem(m);
578 		return (IPPROTO_DONE);
579 	}
580 	m->m_data -= *offp;
581 
582 	carp_proto_input_c(m, ch, AF_INET6);
583 	return (IPPROTO_DONE);
584 }
585 #endif /* INET6 */
586 
587 void
588 carp_proto_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
589 {
590 	struct carp_softc *sc;
591 	u_int64_t tmp_counter;
592 	struct timeval sc_tv, ch_tv;
593 
594 	TAILQ_FOREACH(sc, &((struct carp_if *)
595 	    m->m_pkthdr.rcvif->if_carpdev->if_carp)->vhif_vrs, sc_list)
596 		if (sc->sc_vhid == ch->carp_vhid)
597 			break;
598 
599 	if (!sc || (sc->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) !=
600 	    (IFF_UP|IFF_RUNNING)) {
601 		CARP_STATINC(CARP_STAT_BADVHID);
602 		m_freem(m);
603 		return;
604 	}
605 
606 	/*
607 	 * Check if our own advertisement was duplicated
608 	 * from a non simplex interface.
609 	 * XXX If there is no address on our physical interface
610 	 * there is no way to distinguish our ads from the ones
611 	 * another carp host might have sent us.
612 	 */
613 	if ((sc->sc_carpdev->if_flags & IFF_SIMPLEX) == 0) {
614 		struct sockaddr sa;
615 		struct ifaddr *ifa;
616 
617 		bzero(&sa, sizeof(sa));
618 		sa.sa_family = af;
619 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
620 
621 		if (ifa && af == AF_INET) {
622 			struct ip *ip = mtod(m, struct ip *);
623 			if (ip->ip_src.s_addr ==
624 					ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
625 				m_freem(m);
626 				return;
627 			}
628 		}
629 #ifdef INET6
630 		if (ifa && af == AF_INET6) {
631 			struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
632 			struct in6_addr in6_src, in6_found;
633 
634 			in6_src = ip6->ip6_src;
635 			in6_found = ifatoia6(ifa)->ia_addr.sin6_addr;
636 			if (IN6_IS_ADDR_LINKLOCAL(&in6_src))
637 				in6_src.s6_addr16[1] = 0;
638 			if (IN6_IS_ADDR_LINKLOCAL(&in6_found))
639 				in6_found.s6_addr16[1] = 0;
640 			if (IN6_ARE_ADDR_EQUAL(&in6_src, &in6_found)) {
641 				m_freem(m);
642 				return;
643 			}
644 		}
645 #endif /* INET6 */
646 	}
647 
648 	microtime(&sc->sc_if.if_lastchange);
649 	sc->sc_if.if_ipackets++;
650 	sc->sc_if.if_ibytes += m->m_pkthdr.len;
651 
652 	/* verify the CARP version. */
653 	if (ch->carp_version != CARP_VERSION) {
654 		CARP_STATINC(CARP_STAT_BADVER);
655 		sc->sc_if.if_ierrors++;
656 		CARP_LOG(sc, ("invalid version %d != %d",
657 		    ch->carp_version, CARP_VERSION));
658 		m_freem(m);
659 		return;
660 	}
661 
662 	/* verify the hash */
663 	if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
664 		CARP_STATINC(CARP_STAT_BADAUTH);
665 		sc->sc_if.if_ierrors++;
666 		CARP_LOG(sc, ("incorrect hash"));
667 		m_freem(m);
668 		return;
669 	}
670 
671 	tmp_counter = ntohl(ch->carp_counter[0]);
672 	tmp_counter = tmp_counter<<32;
673 	tmp_counter += ntohl(ch->carp_counter[1]);
674 
675 	/* XXX Replay protection goes here */
676 
677 	sc->sc_init_counter = 0;
678 	sc->sc_counter = tmp_counter;
679 
680 
681 	sc_tv.tv_sec = sc->sc_advbase;
682 	if (carp_suppress_preempt && sc->sc_advskew <  240)
683 		sc_tv.tv_usec = 240 * 1000000 / 256;
684 	else
685 		sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
686 	ch_tv.tv_sec = ch->carp_advbase;
687 	ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
688 
689 	switch (sc->sc_state) {
690 	case INIT:
691 		break;
692 	case MASTER:
693 		/*
694 		 * If we receive an advertisement from a backup who's going to
695 		 * be more frequent than us, go into BACKUP state.
696 		 */
697 		if (timercmp(&sc_tv, &ch_tv, >) ||
698 		    timercmp(&sc_tv, &ch_tv, ==)) {
699 			callout_stop(&sc->sc_ad_tmo);
700 			carp_set_state(sc, BACKUP);
701 			carp_setrun(sc, 0);
702 			carp_setroute(sc, RTM_DELETE);
703 		}
704 		break;
705 	case BACKUP:
706 		/*
707 		 * If we're pre-empting masters who advertise slower than us,
708 		 * and this one claims to be slower, treat him as down.
709 		 */
710 		if (carp_opts[CARPCTL_PREEMPT] && timercmp(&sc_tv, &ch_tv, <)) {
711 			carp_master_down(sc);
712 			break;
713 		}
714 
715 		/*
716 		 *  If the master is going to advertise at such a low frequency
717 		 *  that he's guaranteed to time out, we'd might as well just
718 		 *  treat him as timed out now.
719 		 */
720 		sc_tv.tv_sec = sc->sc_advbase * 3;
721 		if (timercmp(&sc_tv, &ch_tv, <)) {
722 			carp_master_down(sc);
723 			break;
724 		}
725 
726 		/*
727 		 * Otherwise, we reset the counter and wait for the next
728 		 * advertisement.
729 		 */
730 		carp_setrun(sc, af);
731 		break;
732 	}
733 
734 	m_freem(m);
735 	return;
736 }
737 
738 /*
739  * Interface side of the CARP implementation.
740  */
741 
742 /* ARGSUSED */
743 void
744 carpattach(int n)
745 {
746 	if_clone_attach(&carp_cloner);
747 
748 	carpstat_percpu = percpu_alloc(sizeof(uint64_t) * CARP_NSTATS);
749 }
750 
751 int
752 carp_clone_create(struct if_clone *ifc, int unit)
753 {
754 	extern int ifqmaxlen;
755 	struct carp_softc *sc;
756 	struct ifnet *ifp;
757 
758 	sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT);
759 	if (!sc)
760 		return (ENOMEM);
761 	bzero(sc, sizeof(*sc));
762 
763 	sc->sc_suppress = 0;
764 	sc->sc_advbase = CARP_DFLTINTV;
765 	sc->sc_vhid = -1;	/* required setting */
766 	sc->sc_advskew = 0;
767 	sc->sc_init_counter = 1;
768 	sc->sc_naddrs = sc->sc_naddrs6 = 0;
769 #ifdef INET6
770 	sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
771 #endif /* INET6 */
772 
773 	callout_init(&sc->sc_ad_tmo, 0);
774 	callout_init(&sc->sc_md_tmo, 0);
775 	callout_init(&sc->sc_md6_tmo, 0);
776 
777 	callout_setfunc(&sc->sc_ad_tmo, carp_send_ad, sc);
778 	callout_setfunc(&sc->sc_md_tmo, carp_master_down, sc);
779 	callout_setfunc(&sc->sc_md6_tmo, carp_master_down, sc);
780 
781 	LIST_INIT(&sc->carp_mc_listhead);
782 	ifp = &sc->sc_if;
783 	ifp->if_softc = sc;
784 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "%s%d", ifc->ifc_name,
785 	    unit);
786 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
787 	ifp->if_ioctl = carp_ioctl;
788 	ifp->if_start = carp_start;
789 	ifp->if_output = carp_output;
790 	ifp->if_type = IFT_CARP;
791 	ifp->if_addrlen = ETHER_ADDR_LEN;
792 	ifp->if_hdrlen = ETHER_HDR_LEN;
793 	ifp->if_mtu = ETHERMTU;
794 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
795 	IFQ_SET_READY(&ifp->if_snd);
796 	if_attach(ifp);
797 
798 	if_alloc_sadl(ifp);
799 	ifp->if_broadcastaddr = etherbroadcastaddr;
800 	carp_set_enaddr(sc);
801 	LIST_INIT(&sc->sc_ac.ec_multiaddrs);
802 #if NBPFILTER > 0
803 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
804 #endif
805 	return (0);
806 }
807 
808 int
809 carp_clone_destroy(struct ifnet *ifp)
810 {
811 	struct carp_softc *sc = ifp->if_softc;
812 
813 	carpdetach(ifp->if_softc);
814 	ether_ifdetach(ifp);
815 	if_detach(ifp);
816 	callout_destroy(&sc->sc_ad_tmo);
817 	callout_destroy(&sc->sc_md_tmo);
818 	callout_destroy(&sc->sc_md6_tmo);
819 	free(ifp->if_softc, M_DEVBUF);
820 
821 	return (0);
822 }
823 
824 void
825 carpdetach(struct carp_softc *sc)
826 {
827 	struct carp_if *cif;
828 	int s;
829 
830 	callout_stop(&sc->sc_ad_tmo);
831 	callout_stop(&sc->sc_md_tmo);
832 	callout_stop(&sc->sc_md6_tmo);
833 
834 	if (sc->sc_suppress)
835 		carp_suppress_preempt--;
836 	sc->sc_suppress = 0;
837 
838 	if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
839 		carp_suppress_preempt--;
840 	sc->sc_sendad_errors = 0;
841 
842 	carp_set_state(sc, INIT);
843 	sc->sc_if.if_flags &= ~IFF_UP;
844 	carp_setrun(sc, 0);
845 	carp_multicast_cleanup(sc);
846 
847 	s = splnet();
848 	if (sc->sc_carpdev != NULL) {
849 		/* XXX linkstatehook removal */
850 		cif = (struct carp_if *)sc->sc_carpdev->if_carp;
851 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
852 		if (!--cif->vhif_nvrs) {
853 			ifpromisc(sc->sc_carpdev, 0);
854 			sc->sc_carpdev->if_carp = NULL;
855 			FREE(cif, M_IFADDR);
856 		}
857 	}
858 	sc->sc_carpdev = NULL;
859 	splx(s);
860 }
861 
862 /* Detach an interface from the carp. */
863 void
864 carp_ifdetach(struct ifnet *ifp)
865 {
866 	struct carp_softc *sc, *nextsc;
867 	struct carp_if *cif = (struct carp_if *)ifp->if_carp;
868 
869 	for (sc = TAILQ_FIRST(&cif->vhif_vrs); sc; sc = nextsc) {
870 		nextsc = TAILQ_NEXT(sc, sc_list);
871 		carpdetach(sc);
872 	}
873 }
874 
875 int
876 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc,
877     struct carp_header *ch)
878 {
879 	if (sc->sc_init_counter) {
880 		/* this could also be seconds since unix epoch */
881 		sc->sc_counter = arc4random();
882 		sc->sc_counter = sc->sc_counter << 32;
883 		sc->sc_counter += arc4random();
884 	} else
885 		sc->sc_counter++;
886 
887 	ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
888 	ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
889 
890 	carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
891 
892 	return (0);
893 }
894 
895 void
896 carp_send_ad_all(void)
897 {
898 	struct ifnet *ifp;
899 	struct carp_if *cif;
900 	struct carp_softc *vh;
901 
902 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
903 		if (ifp->if_carp == NULL || ifp->if_type == IFT_CARP)
904 			continue;
905 
906 		cif = (struct carp_if *)ifp->if_carp;
907 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
908 			if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
909 			    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER)
910 				carp_send_ad(vh);
911 		}
912 	}
913 }
914 
915 
916 void
917 carp_send_ad(void *v)
918 {
919 	struct carp_header ch;
920 	struct timeval tv;
921 	struct carp_softc *sc = v;
922 	struct carp_header *ch_ptr;
923 	struct mbuf *m;
924 	int error, len, advbase, advskew, s;
925 	struct ifaddr *ifa;
926 	struct sockaddr sa;
927 
928 	s = splsoftnet();
929 
930 	advbase = advskew = 0; /* Sssssh compiler */
931 	if (sc->sc_carpdev == NULL) {
932 		sc->sc_if.if_oerrors++;
933 		goto retry_later;
934 	}
935 
936 	/* bow out if we've gone to backup (the carp interface is going down) */
937 	if (sc->sc_bow_out) {
938 		sc->sc_bow_out = 0;
939 		advbase = 255;
940 		advskew = 255;
941 	} else {
942 		advbase = sc->sc_advbase;
943 		if (!carp_suppress_preempt || sc->sc_advskew > 240)
944 			advskew = sc->sc_advskew;
945 		else
946 			advskew = 240;
947 		tv.tv_sec = advbase;
948 		tv.tv_usec = advskew * 1000000 / 256;
949 	}
950 
951 	ch.carp_version = CARP_VERSION;
952 	ch.carp_type = CARP_ADVERTISEMENT;
953 	ch.carp_vhid = sc->sc_vhid;
954 	ch.carp_advbase = advbase;
955 	ch.carp_advskew = advskew;
956 	ch.carp_authlen = 7;	/* XXX DEFINE */
957 	ch.carp_pad1 = 0;	/* must be zero */
958 	ch.carp_cksum = 0;
959 
960 
961 #ifdef INET
962 	if (sc->sc_naddrs) {
963 		struct ip *ip;
964 
965 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
966 		if (m == NULL) {
967 			sc->sc_if.if_oerrors++;
968 			CARP_STATINC(CARP_STAT_ONOMEM);
969 			/* XXX maybe less ? */
970 			goto retry_later;
971 		}
972 		len = sizeof(*ip) + sizeof(ch);
973 		m->m_pkthdr.len = len;
974 		m->m_pkthdr.rcvif = NULL;
975 		m->m_len = len;
976 		MH_ALIGN(m, m->m_len);
977 		m->m_flags |= M_MCAST;
978 		ip = mtod(m, struct ip *);
979 		ip->ip_v = IPVERSION;
980 		ip->ip_hl = sizeof(*ip) >> 2;
981 		ip->ip_tos = IPTOS_LOWDELAY;
982 		ip->ip_len = htons(len);
983 		ip->ip_id = 0;	/* no need for id, we don't support fragments */
984 		ip->ip_off = htons(IP_DF);
985 		ip->ip_ttl = CARP_DFLTTL;
986 		ip->ip_p = IPPROTO_CARP;
987 		ip->ip_sum = 0;
988 
989 		bzero(&sa, sizeof(sa));
990 		sa.sa_family = AF_INET;
991 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
992 		if (ifa == NULL)
993 			ip->ip_src.s_addr = 0;
994 		else
995 			ip->ip_src.s_addr =
996 			    ifatoia(ifa)->ia_addr.sin_addr.s_addr;
997 		ip->ip_dst.s_addr = INADDR_CARP_GROUP;
998 
999 		ch_ptr = (struct carp_header *)(&ip[1]);
1000 		bcopy(&ch, ch_ptr, sizeof(ch));
1001 		if (carp_prepare_ad(m, sc, ch_ptr))
1002 			goto retry_later;
1003 
1004 		m->m_data += sizeof(*ip);
1005 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
1006 		m->m_data -= sizeof(*ip);
1007 
1008 		microtime(&sc->sc_if.if_lastchange);
1009 		sc->sc_if.if_opackets++;
1010 		sc->sc_if.if_obytes += len;
1011 		CARP_STATINC(CARP_STAT_OPACKETS);
1012 
1013 		error = ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo,
1014 		    NULL);
1015 		if (error) {
1016 			if (error == ENOBUFS)
1017 				CARP_STATINC(CARP_STAT_ONOMEM);
1018 			else
1019 				CARP_LOG(sc, ("ip_output failed: %d", error));
1020 			sc->sc_if.if_oerrors++;
1021 			if (sc->sc_sendad_errors < INT_MAX)
1022 				sc->sc_sendad_errors++;
1023 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1024 				carp_suppress_preempt++;
1025 				if (carp_suppress_preempt == 1)
1026 					carp_send_ad_all();
1027 			}
1028 			sc->sc_sendad_success = 0;
1029 		} else {
1030 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1031 				if (++sc->sc_sendad_success >=
1032 				    CARP_SENDAD_MIN_SUCCESS) {
1033 					carp_suppress_preempt--;
1034 					sc->sc_sendad_errors = 0;
1035 				}
1036 			} else
1037 				sc->sc_sendad_errors = 0;
1038 		}
1039 	}
1040 #endif /* INET */
1041 #ifdef INET6
1042 	if (sc->sc_naddrs6) {
1043 		struct ip6_hdr *ip6;
1044 
1045 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
1046 		if (m == NULL) {
1047 			sc->sc_if.if_oerrors++;
1048 			CARP_STATINC(CARP_STAT_ONOMEM);
1049 			/* XXX maybe less ? */
1050 			goto retry_later;
1051 		}
1052 		len = sizeof(*ip6) + sizeof(ch);
1053 		m->m_pkthdr.len = len;
1054 		m->m_pkthdr.rcvif = NULL;
1055 		m->m_len = len;
1056 		MH_ALIGN(m, m->m_len);
1057 		m->m_flags |= M_MCAST;
1058 		ip6 = mtod(m, struct ip6_hdr *);
1059 		bzero(ip6, sizeof(*ip6));
1060 		ip6->ip6_vfc |= IPV6_VERSION;
1061 		ip6->ip6_hlim = CARP_DFLTTL;
1062 		ip6->ip6_nxt = IPPROTO_CARP;
1063 
1064 		/* set the source address */
1065 		bzero(&sa, sizeof(sa));
1066 		sa.sa_family = AF_INET6;
1067 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
1068 		if (ifa == NULL)	/* This should never happen with IPv6 */
1069 			bzero(&ip6->ip6_src, sizeof(struct in6_addr));
1070 		else
1071 			bcopy(ifatoia6(ifa)->ia_addr.sin6_addr.s6_addr,
1072 			    &ip6->ip6_src, sizeof(struct in6_addr));
1073 		/* set the multicast destination */
1074 
1075 		ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
1076 		ip6->ip6_dst.s6_addr8[15] = 0x12;
1077 		if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1078 			sc->sc_if.if_oerrors++;
1079 			m_freem(m);
1080 			CARP_LOG(sc, ("in6_setscope failed"));
1081 			goto retry_later;
1082 		}
1083 
1084 		ch_ptr = (struct carp_header *)(&ip6[1]);
1085 		bcopy(&ch, ch_ptr, sizeof(ch));
1086 		if (carp_prepare_ad(m, sc, ch_ptr))
1087 			goto retry_later;
1088 
1089 		m->m_data += sizeof(*ip6);
1090 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
1091 		m->m_data -= sizeof(*ip6);
1092 
1093 		microtime(&sc->sc_if.if_lastchange);
1094 		sc->sc_if.if_opackets++;
1095 		sc->sc_if.if_obytes += len;
1096 		CARP_STATINC(CARP_STAT_OPACKETS6);
1097 
1098 		error = ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL);
1099 		if (error) {
1100 			if (error == ENOBUFS)
1101 				CARP_STATINC(CARP_STAT_ONOMEM);
1102 			else
1103 				CARP_LOG(sc, ("ip6_output failed: %d", error));
1104 			sc->sc_if.if_oerrors++;
1105 			if (sc->sc_sendad_errors < INT_MAX)
1106 				sc->sc_sendad_errors++;
1107 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1108 				carp_suppress_preempt++;
1109 				if (carp_suppress_preempt == 1)
1110 					carp_send_ad_all();
1111 			}
1112 			sc->sc_sendad_success = 0;
1113 		} else {
1114 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1115 				if (++sc->sc_sendad_success >=
1116 				    CARP_SENDAD_MIN_SUCCESS) {
1117 					carp_suppress_preempt--;
1118 					sc->sc_sendad_errors = 0;
1119 				}
1120 			} else
1121 				sc->sc_sendad_errors = 0;
1122 		}
1123 	}
1124 #endif /* INET6 */
1125 
1126 retry_later:
1127 	splx(s);
1128 	if (advbase != 255 || advskew != 255)
1129 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1130 }
1131 
1132 /*
1133  * Broadcast a gratuitous ARP request containing
1134  * the virtual router MAC address for each IP address
1135  * associated with the virtual router.
1136  */
1137 void
1138 carp_send_arp(struct carp_softc *sc)
1139 {
1140 	struct ifaddr *ifa;
1141 	struct in_addr *in;
1142 	int s = splsoftnet();
1143 
1144 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1145 
1146 		if (ifa->ifa_addr->sa_family != AF_INET)
1147 			continue;
1148 
1149 		in = &ifatoia(ifa)->ia_addr.sin_addr;
1150 		arprequest(sc->sc_carpdev, in, in, CLLADDR(sc->sc_if.if_sadl));
1151 		DELAY(1000);	/* XXX */
1152 	}
1153 	splx(s);
1154 }
1155 
1156 #ifdef INET6
1157 void
1158 carp_send_na(struct carp_softc *sc)
1159 {
1160 	struct ifaddr *ifa;
1161 	struct in6_addr *in6;
1162 	static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1163 	int s = splsoftnet();
1164 
1165 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1166 
1167 		if (ifa->ifa_addr->sa_family != AF_INET6)
1168 			continue;
1169 
1170 		in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1171 		nd6_na_output(sc->sc_carpdev, &mcast, in6,
1172 		    ND_NA_FLAG_OVERRIDE, 1, NULL);
1173 		DELAY(1000);	/* XXX */
1174 	}
1175 	splx(s);
1176 }
1177 #endif /* INET6 */
1178 
1179 /*
1180  * Based on bridge_hash() in if_bridge.c
1181  */
1182 #define	mix(a,b,c) \
1183 	do {						\
1184 		a -= b; a -= c; a ^= (c >> 13);		\
1185 		b -= c; b -= a; b ^= (a << 8);		\
1186 		c -= a; c -= b; c ^= (b >> 13);		\
1187 		a -= b; a -= c; a ^= (c >> 12);		\
1188 		b -= c; b -= a; b ^= (a << 16);		\
1189 		c -= a; c -= b; c ^= (b >> 5);		\
1190 		a -= b; a -= c; a ^= (c >> 3);		\
1191 		b -= c; b -= a; b ^= (a << 10);		\
1192 		c -= a; c -= b; c ^= (b >> 15);		\
1193 	} while (0)
1194 
1195 u_int32_t
1196 carp_hash(struct carp_softc *sc, u_char *src)
1197 {
1198 	u_int32_t a = 0x9e3779b9, b = sc->sc_hashkey[0], c = sc->sc_hashkey[1];
1199 
1200 	c += sc->sc_key[3] << 24;
1201 	c += sc->sc_key[2] << 16;
1202 	c += sc->sc_key[1] << 8;
1203 	c += sc->sc_key[0];
1204 	b += src[5] << 8;
1205 	b += src[4];
1206 	a += src[3] << 24;
1207 	a += src[2] << 16;
1208 	a += src[1] << 8;
1209 	a += src[0];
1210 
1211 	mix(a, b, c);
1212 	return (c);
1213 }
1214 
1215 int
1216 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
1217 {
1218 	struct carp_softc *vh;
1219 	struct ifaddr *ifa;
1220 	int count = 0;
1221 
1222 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1223 		if ((type == CARP_COUNT_RUNNING &&
1224 		    (vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1225 		    (IFF_UP|IFF_RUNNING)) ||
1226 		    (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
1227 			IFADDR_FOREACH(ifa, &vh->sc_if) {
1228 				if (ifa->ifa_addr->sa_family == AF_INET &&
1229 				    ia->ia_addr.sin_addr.s_addr ==
1230 				    ifatoia(ifa)->ia_addr.sin_addr.s_addr)
1231 					count++;
1232 			}
1233 		}
1234 	}
1235 	return (count);
1236 }
1237 
1238 int
1239 carp_iamatch(struct in_ifaddr *ia, u_char *src,
1240     u_int32_t *count, u_int32_t index)
1241 {
1242 	struct carp_softc *sc = ia->ia_ifp->if_softc;
1243 
1244 	if (carp_opts[CARPCTL_ARPBALANCE]) {
1245 		/*
1246 		 * We use the source ip to decide which virtual host should
1247 		 * handle the request. If we're master of that virtual host,
1248 		 * then we respond, otherwise, just drop the arp packet on
1249 		 * the floor.
1250 		 */
1251 
1252 		/* Count the elegible carp interfaces with this address */
1253 		if (*count == 0)
1254 			*count = carp_addrcount(
1255 			    (struct carp_if *)ia->ia_ifp->if_carpdev->if_carp,
1256 			    ia, CARP_COUNT_RUNNING);
1257 
1258 		/* This should never happen, but... */
1259 		if (*count == 0)
1260 			return (0);
1261 
1262 		if (carp_hash(sc, src) % *count == index - 1 &&
1263 		    sc->sc_state == MASTER) {
1264 			return (1);
1265 		}
1266 	} else {
1267 		if (sc->sc_state == MASTER)
1268 			return (1);
1269 	}
1270 
1271 	return (0);
1272 }
1273 
1274 #ifdef INET6
1275 struct ifaddr *
1276 carp_iamatch6(void *v, struct in6_addr *taddr)
1277 {
1278 	struct carp_if *cif = v;
1279 	struct carp_softc *vh;
1280 	struct ifaddr *ifa;
1281 
1282 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1283 		IFADDR_FOREACH(ifa, &vh->sc_if) {
1284 			if (IN6_ARE_ADDR_EQUAL(taddr,
1285 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1286 			    ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1287 			    (IFF_UP|IFF_RUNNING)) && vh->sc_state == MASTER)
1288 				return (ifa);
1289 		}
1290 	}
1291 
1292 	return (NULL);
1293 }
1294 #endif /* INET6 */
1295 
1296 struct ifnet *
1297 carp_ourether(void *v, struct ether_header *eh, u_char iftype, int src)
1298 {
1299 	struct carp_if *cif = (struct carp_if *)v;
1300 	struct carp_softc *vh;
1301 	u_int8_t *ena;
1302 
1303 	if (src)
1304 		ena = (u_int8_t *)&eh->ether_shost;
1305 	else
1306 		ena = (u_int8_t *)&eh->ether_dhost;
1307 
1308 	switch (iftype) {
1309 	case IFT_ETHER:
1310 	case IFT_FDDI:
1311 		if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1312 			return (NULL);
1313 		break;
1314 	case IFT_ISO88025:
1315 		if (ena[0] != 3 || ena[1] || ena[4] || ena[5])
1316 			return (NULL);
1317 		break;
1318 	default:
1319 		return (NULL);
1320 		break;
1321 	}
1322 
1323 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
1324 		if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1325 		    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER &&
1326 		    !bcmp(ena, CLLADDR(vh->sc_if.if_sadl),
1327 		    ETHER_ADDR_LEN)) {
1328 			return (&vh->sc_if);
1329 		    }
1330 
1331 	return (NULL);
1332 }
1333 
1334 int
1335 carp_input(struct mbuf *m, u_int8_t *shost, u_int8_t *dhost, u_int16_t etype)
1336 {
1337 	struct ether_header eh;
1338 	struct carp_if *cif = (struct carp_if *)m->m_pkthdr.rcvif->if_carp;
1339 	struct ifnet *ifp;
1340 
1341 	bcopy(shost, &eh.ether_shost, sizeof(eh.ether_shost));
1342 	bcopy(dhost, &eh.ether_dhost, sizeof(eh.ether_dhost));
1343 	eh.ether_type = etype;
1344 
1345 	if (m->m_flags & (M_BCAST|M_MCAST)) {
1346 		struct carp_softc *vh;
1347 		struct mbuf *m0;
1348 
1349 		/*
1350 		 * XXX Should really check the list of multicast addresses
1351 		 * for each CARP interface _before_ copying.
1352 		 */
1353 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1354 			m0 = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
1355 			if (m0 == NULL)
1356 				continue;
1357 			m0->m_pkthdr.rcvif = &vh->sc_if;
1358 			ether_input(&vh->sc_if, m0);
1359 		}
1360 		return (1);
1361 	}
1362 
1363 	ifp = carp_ourether(cif, &eh, m->m_pkthdr.rcvif->if_type, 0);
1364 	if (ifp == NULL) {
1365 		return (1);
1366 	}
1367 
1368 	m->m_pkthdr.rcvif = ifp;
1369 
1370 #if NBPFILTER > 0
1371 	if (ifp->if_bpf)
1372 		bpf_mtap(ifp->if_bpf, m);
1373 #endif
1374 	ifp->if_ipackets++;
1375 	ether_input(ifp, m);
1376 	return (0);
1377 }
1378 
1379 void
1380 carp_master_down(void *v)
1381 {
1382 	struct carp_softc *sc = v;
1383 
1384 	switch (sc->sc_state) {
1385 	case INIT:
1386 		printf("%s: master_down event in INIT state\n",
1387 		    sc->sc_if.if_xname);
1388 		break;
1389 	case MASTER:
1390 		break;
1391 	case BACKUP:
1392 		carp_set_state(sc, MASTER);
1393 		carp_send_ad(sc);
1394 		carp_send_arp(sc);
1395 #ifdef INET6
1396 		carp_send_na(sc);
1397 #endif /* INET6 */
1398 		carp_setrun(sc, 0);
1399 		carp_setroute(sc, RTM_ADD);
1400 		break;
1401 	}
1402 }
1403 
1404 /*
1405  * When in backup state, af indicates whether to reset the master down timer
1406  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1407  */
1408 void
1409 carp_setrun(struct carp_softc *sc, sa_family_t af)
1410 {
1411 	struct timeval tv;
1412 
1413 	if (sc->sc_carpdev == NULL) {
1414 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1415 		carp_set_state(sc, INIT);
1416 		return;
1417 	}
1418 
1419 	if (sc->sc_if.if_flags & IFF_UP && sc->sc_vhid > 0 &&
1420 	    (sc->sc_naddrs || sc->sc_naddrs6) && !sc->sc_suppress) {
1421 		sc->sc_if.if_flags |= IFF_RUNNING;
1422 	} else {
1423 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1424 		carp_setroute(sc, RTM_DELETE);
1425 		return;
1426 	}
1427 
1428 	switch (sc->sc_state) {
1429 	case INIT:
1430 		carp_set_state(sc, BACKUP);
1431 		carp_setroute(sc, RTM_DELETE);
1432 		carp_setrun(sc, 0);
1433 		break;
1434 	case BACKUP:
1435 		callout_stop(&sc->sc_ad_tmo);
1436 		tv.tv_sec = 3 * sc->sc_advbase;
1437 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1438 		switch (af) {
1439 #ifdef INET
1440 		case AF_INET:
1441 			callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1442 			break;
1443 #endif /* INET */
1444 #ifdef INET6
1445 		case AF_INET6:
1446 			callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1447 			break;
1448 #endif /* INET6 */
1449 		default:
1450 			if (sc->sc_naddrs)
1451 				callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1452 			if (sc->sc_naddrs6)
1453 				callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1454 			break;
1455 		}
1456 		break;
1457 	case MASTER:
1458 		tv.tv_sec = sc->sc_advbase;
1459 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1460 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1461 		break;
1462 	}
1463 }
1464 
1465 void
1466 carp_multicast_cleanup(struct carp_softc *sc)
1467 {
1468 	struct ip_moptions *imo = &sc->sc_imo;
1469 #ifdef INET6
1470 	struct ip6_moptions *im6o = &sc->sc_im6o;
1471 #endif
1472 	u_int16_t n = imo->imo_num_memberships;
1473 
1474 	/* Clean up our own multicast memberships */
1475 	while (n-- > 0) {
1476 		if (imo->imo_membership[n] != NULL) {
1477 			in_delmulti(imo->imo_membership[n]);
1478 			imo->imo_membership[n] = NULL;
1479 		}
1480 	}
1481 	imo->imo_num_memberships = 0;
1482 	imo->imo_multicast_ifp = NULL;
1483 
1484 #ifdef INET6
1485 	while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1486 		struct in6_multi_mship *imm =
1487 		    LIST_FIRST(&im6o->im6o_memberships);
1488 
1489 		LIST_REMOVE(imm, i6mm_chain);
1490 		in6_leavegroup(imm);
1491 	}
1492 	im6o->im6o_multicast_ifp = NULL;
1493 #endif
1494 
1495 	/* And any other multicast memberships */
1496 	carp_ether_purgemulti(sc);
1497 }
1498 
1499 int
1500 carp_set_ifp(struct carp_softc *sc, struct ifnet *ifp)
1501 {
1502 	struct carp_if *cif, *ncif = NULL;
1503 	struct carp_softc *vr, *after = NULL;
1504 	int myself = 0, error = 0;
1505 	int s;
1506 
1507 	if (ifp == sc->sc_carpdev)
1508 		return (0);
1509 
1510 	if (ifp != NULL) {
1511 		if ((ifp->if_flags & IFF_MULTICAST) == 0)
1512 			return (EADDRNOTAVAIL);
1513 
1514 		if (ifp->if_type == IFT_CARP)
1515 			return (EINVAL);
1516 
1517 		if (ifp->if_carp == NULL) {
1518 			MALLOC(ncif, struct carp_if *, sizeof(*cif),
1519 			    M_IFADDR, M_NOWAIT);
1520 			if (ncif == NULL)
1521 				return (ENOBUFS);
1522 			if ((error = ifpromisc(ifp, 1))) {
1523 				FREE(ncif, M_IFADDR);
1524 				return (error);
1525 			}
1526 
1527 			ncif->vhif_ifp = ifp;
1528 			TAILQ_INIT(&ncif->vhif_vrs);
1529 		} else {
1530 			cif = (struct carp_if *)ifp->if_carp;
1531 			TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1532 				if (vr != sc && vr->sc_vhid == sc->sc_vhid)
1533 					return (EINVAL);
1534 		}
1535 
1536 		/* detach from old interface */
1537 		if (sc->sc_carpdev != NULL)
1538 			carpdetach(sc);
1539 
1540 		/* join multicast groups */
1541 		if (sc->sc_naddrs < 0 &&
1542 		    (error = carp_join_multicast(sc)) != 0) {
1543 			if (ncif != NULL)
1544 				FREE(ncif, M_IFADDR);
1545 			return (error);
1546 		}
1547 
1548 #ifdef INET6
1549 		if (sc->sc_naddrs6 < 0 &&
1550 		    (error = carp_join_multicast6(sc)) != 0) {
1551 			if (ncif != NULL)
1552 				FREE(ncif, M_IFADDR);
1553 			carp_multicast_cleanup(sc);
1554 			return (error);
1555 		}
1556 #endif
1557 
1558 		/* attach carp interface to physical interface */
1559 		if (ncif != NULL)
1560 			ifp->if_carp = (void *)ncif;
1561 		sc->sc_carpdev = ifp;
1562 		cif = (struct carp_if *)ifp->if_carp;
1563 		TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1564 			if (vr == sc)
1565 				myself = 1;
1566 			if (vr->sc_vhid < sc->sc_vhid)
1567 				after = vr;
1568 		}
1569 
1570 		if (!myself) {
1571 			/* We're trying to keep things in order */
1572 			if (after == NULL) {
1573 				TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1574 			} else {
1575 				TAILQ_INSERT_AFTER(&cif->vhif_vrs, after,
1576 				    sc, sc_list);
1577 			}
1578 			cif->vhif_nvrs++;
1579 		}
1580 		if (sc->sc_naddrs || sc->sc_naddrs6)
1581 			sc->sc_if.if_flags |= IFF_UP;
1582 		carp_set_enaddr(sc);
1583 		s = splnet();
1584 		/* XXX linkstatehooks establish */
1585 		carp_carpdev_state(ifp);
1586 		splx(s);
1587 	} else {
1588 		carpdetach(sc);
1589 		sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
1590 	}
1591 	return (0);
1592 }
1593 
1594 void
1595 carp_set_enaddr(struct carp_softc *sc)
1596 {
1597 	uint8_t enaddr[ETHER_ADDR_LEN];
1598 	if (sc->sc_carpdev && sc->sc_carpdev->if_type == IFT_ISO88025) {
1599 		enaddr[0] = 3;
1600 		enaddr[1] = 0;
1601 		enaddr[2] = 0x40 >> (sc->sc_vhid - 1);
1602 		enaddr[3] = 0x40000 >> (sc->sc_vhid - 1);
1603 		enaddr[4] = 0;
1604 		enaddr[5] = 0;
1605 	} else {
1606 		enaddr[0] = 0;
1607 		enaddr[1] = 0;
1608 		enaddr[2] = 0x5e;
1609 		enaddr[3] = 0;
1610 		enaddr[4] = 1;
1611 		enaddr[5] = sc->sc_vhid;
1612 	}
1613 	if_set_sadl(&sc->sc_if, enaddr, sizeof(enaddr));
1614 }
1615 
1616 void
1617 carp_addr_updated(void *v)
1618 {
1619 	struct carp_softc *sc = (struct carp_softc *) v;
1620 	struct ifaddr *ifa;
1621 	int new_naddrs = 0, new_naddrs6 = 0;
1622 
1623 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1624 		if (ifa->ifa_addr->sa_family == AF_INET)
1625 			new_naddrs++;
1626 		else if (ifa->ifa_addr->sa_family == AF_INET6)
1627 			new_naddrs6++;
1628 	}
1629 
1630 	/* Handle a callback after SIOCDIFADDR */
1631 	if (new_naddrs < sc->sc_naddrs || new_naddrs6 < sc->sc_naddrs6) {
1632 		struct in_addr mc_addr;
1633 		struct in_multi *inm;
1634 
1635 		sc->sc_naddrs = new_naddrs;
1636 		sc->sc_naddrs6 = new_naddrs6;
1637 
1638 		/* Re-establish multicast membership removed by in_control */
1639 		mc_addr.s_addr = INADDR_CARP_GROUP;
1640 		IN_LOOKUP_MULTI(mc_addr, &sc->sc_if, inm);
1641 		if (inm == NULL) {
1642 			bzero(&sc->sc_imo, sizeof(sc->sc_imo));
1643 
1644 			if (sc->sc_carpdev != NULL && sc->sc_naddrs > 0)
1645 				carp_join_multicast(sc);
1646 		}
1647 
1648 		if (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) {
1649 			sc->sc_if.if_flags &= ~IFF_UP;
1650 			carp_set_state(sc, INIT);
1651 		} else
1652 			carp_hmac_prepare(sc);
1653 	}
1654 
1655 	carp_setrun(sc, 0);
1656 }
1657 
1658 int
1659 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1660 {
1661 	struct ifnet *ifp = sc->sc_carpdev;
1662 	struct in_ifaddr *ia, *ia_if;
1663 	int error = 0;
1664 
1665 	if (sin->sin_addr.s_addr == 0) {
1666 		if (!(sc->sc_if.if_flags & IFF_UP))
1667 			carp_set_state(sc, INIT);
1668 		if (sc->sc_naddrs)
1669 			sc->sc_if.if_flags |= IFF_UP;
1670 		carp_setrun(sc, 0);
1671 		return (0);
1672 	}
1673 
1674 	/* we have to do this by hand to ensure we don't match on ourselves */
1675 	ia_if = NULL;
1676 	for (ia = TAILQ_FIRST(&in_ifaddrhead); ia;
1677 	    ia = TAILQ_NEXT(ia, ia_list)) {
1678 
1679 		/* and, yeah, we need a multicast-capable iface too */
1680 		if (ia->ia_ifp != &sc->sc_if &&
1681 		    ia->ia_ifp->if_type != IFT_CARP &&
1682 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1683 		    (sin->sin_addr.s_addr & ia->ia_subnetmask) ==
1684 		    ia->ia_subnet) {
1685 			if (!ia_if)
1686 				ia_if = ia;
1687 		}
1688 	}
1689 
1690 	if (ia_if) {
1691 		ia = ia_if;
1692 		if (ifp) {
1693 			if (ifp != ia->ia_ifp)
1694 				return (EADDRNOTAVAIL);
1695 		} else {
1696 			ifp = ia->ia_ifp;
1697 		}
1698 	}
1699 
1700 	if ((error = carp_set_ifp(sc, ifp)))
1701 		return (error);
1702 
1703 	if (sc->sc_carpdev == NULL)
1704 		return (EADDRNOTAVAIL);
1705 
1706 	if (sc->sc_naddrs == 0 && (error = carp_join_multicast(sc)) != 0)
1707 		return (error);
1708 
1709 	sc->sc_naddrs++;
1710 	if (sc->sc_carpdev != NULL)
1711 		sc->sc_if.if_flags |= IFF_UP;
1712 
1713 	carp_set_state(sc, INIT);
1714 	carp_setrun(sc, 0);
1715 
1716 	/*
1717 	 * Hook if_addrhooks so that we get a callback after in_ifinit has run,
1718 	 * to correct any inappropriate routes that it inserted.
1719 	 */
1720 	if (sc->ah_cookie == 0) {
1721 		/* XXX link address hook */
1722 	}
1723 
1724 	return (0);
1725 }
1726 
1727 int
1728 carp_join_multicast(struct carp_softc *sc)
1729 {
1730 	struct ip_moptions *imo = &sc->sc_imo, tmpimo;
1731 	struct in_addr addr;
1732 
1733 	bzero(&tmpimo, sizeof(tmpimo));
1734 	addr.s_addr = INADDR_CARP_GROUP;
1735 	if ((tmpimo.imo_membership[0] =
1736 	    in_addmulti(&addr, &sc->sc_if)) == NULL) {
1737 		return (ENOBUFS);
1738 	}
1739 
1740 	imo->imo_membership[0] = tmpimo.imo_membership[0];
1741 	imo->imo_num_memberships = 1;
1742 	imo->imo_multicast_ifp = &sc->sc_if;
1743 	imo->imo_multicast_ttl = CARP_DFLTTL;
1744 	imo->imo_multicast_loop = 0;
1745 	return (0);
1746 }
1747 
1748 
1749 #ifdef INET6
1750 int
1751 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1752 {
1753 	struct ifnet *ifp = sc->sc_carpdev;
1754 	struct in6_ifaddr *ia, *ia_if;
1755 	int error = 0;
1756 
1757 	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1758 		if (!(sc->sc_if.if_flags & IFF_UP))
1759 			carp_set_state(sc, INIT);
1760 		if (sc->sc_naddrs6)
1761 			sc->sc_if.if_flags |= IFF_UP;
1762 		carp_setrun(sc, 0);
1763 		return (0);
1764 	}
1765 
1766 	/* we have to do this by hand to ensure we don't match on ourselves */
1767 	ia_if = NULL;
1768 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1769 		int i;
1770 
1771 		for (i = 0; i < 4; i++) {
1772 			if ((sin6->sin6_addr.s6_addr32[i] &
1773 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1774 			    (ia->ia_addr.sin6_addr.s6_addr32[i] &
1775 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1776 				break;
1777 		}
1778 		/* and, yeah, we need a multicast-capable iface too */
1779 		if (ia->ia_ifp != &sc->sc_if &&
1780 		    ia->ia_ifp->if_type != IFT_CARP &&
1781 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1782 		    (i == 4)) {
1783 			if (!ia_if)
1784 				ia_if = ia;
1785 		}
1786 	}
1787 
1788 	if (ia_if) {
1789 		ia = ia_if;
1790 		if (sc->sc_carpdev) {
1791 			if (sc->sc_carpdev != ia->ia_ifp)
1792 				return (EADDRNOTAVAIL);
1793 		} else {
1794 			ifp = ia->ia_ifp;
1795 		}
1796 	}
1797 
1798 	if ((error = carp_set_ifp(sc, ifp)))
1799 		return (error);
1800 
1801 	if (sc->sc_carpdev == NULL)
1802 		return (EADDRNOTAVAIL);
1803 
1804 	if (sc->sc_naddrs6 == 0 && (error = carp_join_multicast6(sc)) != 0)
1805 		return (error);
1806 
1807 	sc->sc_naddrs6++;
1808 	if (sc->sc_carpdev != NULL)
1809 		sc->sc_if.if_flags |= IFF_UP;
1810 	carp_set_state(sc, INIT);
1811 	carp_setrun(sc, 0);
1812 
1813 	return (0);
1814 }
1815 
1816 int
1817 carp_join_multicast6(struct carp_softc *sc)
1818 {
1819 	struct in6_multi_mship *imm, *imm2;
1820 	struct ip6_moptions *im6o = &sc->sc_im6o;
1821 	struct sockaddr_in6 addr6;
1822 	int error;
1823 
1824 	/* Join IPv6 CARP multicast group */
1825 	bzero(&addr6, sizeof(addr6));
1826 	addr6.sin6_family = AF_INET6;
1827 	addr6.sin6_len = sizeof(addr6);
1828 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1829 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1830 	addr6.sin6_addr.s6_addr8[15] = 0x12;
1831 	if ((imm = in6_joingroup(&sc->sc_if,
1832 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1833 		return (error);
1834 	}
1835 	/* join solicited multicast address */
1836 	bzero(&addr6.sin6_addr, sizeof(addr6.sin6_addr));
1837 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1838 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1839 	addr6.sin6_addr.s6_addr32[1] = 0;
1840 	addr6.sin6_addr.s6_addr32[2] = htonl(1);
1841 	addr6.sin6_addr.s6_addr32[3] = 0;
1842 	addr6.sin6_addr.s6_addr8[12] = 0xff;
1843 	if ((imm2 = in6_joingroup(&sc->sc_if,
1844 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1845 		in6_leavegroup(imm);
1846 		return (error);
1847 	}
1848 
1849 	/* apply v6 multicast membership */
1850 	im6o->im6o_multicast_ifp = &sc->sc_if;
1851 	if (imm)
1852 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm,
1853 		    i6mm_chain);
1854 	if (imm2)
1855 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm2,
1856 		    i6mm_chain);
1857 
1858 	return (0);
1859 }
1860 
1861 #endif /* INET6 */
1862 
1863 int
1864 carp_ioctl(struct ifnet *ifp, u_long cmd, void *addr)
1865 {
1866 	struct lwp *l = curlwp;		/* XXX */
1867 	struct carp_softc *sc = ifp->if_softc, *vr;
1868 	struct carpreq carpr;
1869 	struct ifaddr *ifa;
1870 	struct ifreq *ifr;
1871 	struct ifnet *cdev = NULL;
1872 	int error = 0;
1873 
1874 	ifa = (struct ifaddr *)addr;
1875 	ifr = (struct ifreq *)addr;
1876 
1877 	switch (cmd) {
1878 	case SIOCSIFADDR:
1879 		switch (ifa->ifa_addr->sa_family) {
1880 #ifdef INET
1881 		case AF_INET:
1882 			sc->sc_if.if_flags |= IFF_UP;
1883 			bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1884 			    sizeof(struct sockaddr));
1885 			error = carp_set_addr(sc, satosin(ifa->ifa_addr));
1886 			break;
1887 #endif /* INET */
1888 #ifdef INET6
1889 		case AF_INET6:
1890 			sc->sc_if.if_flags|= IFF_UP;
1891 			error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1892 			break;
1893 #endif /* INET6 */
1894 		default:
1895 			error = EAFNOSUPPORT;
1896 			break;
1897 		}
1898 		break;
1899 
1900 	case SIOCSIFFLAGS:
1901 		if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
1902 			callout_stop(&sc->sc_ad_tmo);
1903 			callout_stop(&sc->sc_md_tmo);
1904 			callout_stop(&sc->sc_md6_tmo);
1905 			if (sc->sc_state == MASTER) {
1906 				/* we need the interface up to bow out */
1907 				sc->sc_if.if_flags |= IFF_UP;
1908 				sc->sc_bow_out = 1;
1909 				carp_send_ad(sc);
1910 			}
1911 			sc->sc_if.if_flags &= ~IFF_UP;
1912 			carp_set_state(sc, INIT);
1913 			carp_setrun(sc, 0);
1914 		} else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
1915 			sc->sc_if.if_flags |= IFF_UP;
1916 			carp_setrun(sc, 0);
1917 		}
1918 		break;
1919 
1920 	case SIOCSVH:
1921 		if (l == NULL)
1922 			break;
1923 		if ((error = kauth_authorize_network(l->l_cred,
1924 		    KAUTH_NETWORK_INTERFACE,
1925 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
1926 		    NULL)) != 0)
1927 			break;
1928 		if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
1929 			break;
1930 		error = 1;
1931 		if (carpr.carpr_carpdev[0] != '\0' &&
1932 		    (cdev = ifunit(carpr.carpr_carpdev)) == NULL)
1933 			return (EINVAL);
1934 		if ((error = carp_set_ifp(sc, cdev)))
1935 			return (error);
1936 		if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
1937 			switch (carpr.carpr_state) {
1938 			case BACKUP:
1939 				callout_stop(&sc->sc_ad_tmo);
1940 				carp_set_state(sc, BACKUP);
1941 				carp_setrun(sc, 0);
1942 				carp_setroute(sc, RTM_DELETE);
1943 				break;
1944 			case MASTER:
1945 				carp_master_down(sc);
1946 				break;
1947 			default:
1948 				break;
1949 			}
1950 		}
1951 		if (carpr.carpr_vhid > 0) {
1952 			if (carpr.carpr_vhid > 255) {
1953 				error = EINVAL;
1954 				break;
1955 			}
1956 			if (sc->sc_carpdev) {
1957 				struct carp_if *cif;
1958 				cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1959 				TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1960 					if (vr != sc &&
1961 					    vr->sc_vhid == carpr.carpr_vhid)
1962 						return (EINVAL);
1963 			}
1964 			sc->sc_vhid = carpr.carpr_vhid;
1965 			carp_set_enaddr(sc);
1966 			carp_set_state(sc, INIT);
1967 			error--;
1968 		}
1969 		if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
1970 			if (carpr.carpr_advskew > 254) {
1971 				error = EINVAL;
1972 				break;
1973 			}
1974 			if (carpr.carpr_advbase > 255) {
1975 				error = EINVAL;
1976 				break;
1977 			}
1978 			sc->sc_advbase = carpr.carpr_advbase;
1979 			sc->sc_advskew = carpr.carpr_advskew;
1980 			error--;
1981 		}
1982 		bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1983 		if (error > 0)
1984 			error = EINVAL;
1985 		else {
1986 			error = 0;
1987 			carp_setrun(sc, 0);
1988 		}
1989 		break;
1990 
1991 	case SIOCGVH:
1992 		bzero(&carpr, sizeof(carpr));
1993 		if (sc->sc_carpdev != NULL)
1994 			strlcpy(carpr.carpr_carpdev, sc->sc_carpdev->if_xname,
1995 			    IFNAMSIZ);
1996 		carpr.carpr_state = sc->sc_state;
1997 		carpr.carpr_vhid = sc->sc_vhid;
1998 		carpr.carpr_advbase = sc->sc_advbase;
1999 		carpr.carpr_advskew = sc->sc_advskew;
2000 
2001 		if ((l == NULL) || (error = kauth_authorize_network(l->l_cred,
2002 		    KAUTH_NETWORK_INTERFACE,
2003 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
2004 		    NULL)) != 0)
2005 			bcopy(sc->sc_key, carpr.carpr_key,
2006 			    sizeof(carpr.carpr_key));
2007 		error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
2008 		break;
2009 
2010 	case SIOCADDMULTI:
2011 		error = carp_ether_addmulti(sc, ifr);
2012 		break;
2013 
2014 	case SIOCDELMULTI:
2015 		error = carp_ether_delmulti(sc, ifr);
2016 		break;
2017 
2018 	default:
2019 		error = EINVAL;
2020 	}
2021 
2022 	carp_hmac_prepare(sc);
2023 	return (error);
2024 }
2025 
2026 
2027 /*
2028  * Start output on carp interface. This function should never be called.
2029  */
2030 void
2031 carp_start(struct ifnet *ifp)
2032 {
2033 #ifdef DEBUG
2034 	printf("%s: start called\n", ifp->if_xname);
2035 #endif
2036 }
2037 
2038 int
2039 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa,
2040     struct rtentry *rt)
2041 {
2042 	struct carp_softc *sc = ((struct carp_softc *)ifp->if_softc);
2043 
2044 	if (sc->sc_carpdev != NULL && sc->sc_state == MASTER) {
2045 		return (sc->sc_carpdev->if_output(ifp, m, sa, rt));
2046 	} else {
2047 		m_freem(m);
2048 		return (ENETUNREACH);
2049 	}
2050 }
2051 
2052 void
2053 carp_set_state(struct carp_softc *sc, int state)
2054 {
2055 	if (sc->sc_state == state)
2056 		return;
2057 
2058 	sc->sc_state = state;
2059 	switch (state) {
2060 	case BACKUP:
2061 		sc->sc_if.if_link_state = LINK_STATE_DOWN;
2062 		break;
2063 	case MASTER:
2064 		sc->sc_if.if_link_state = LINK_STATE_UP;
2065 		break;
2066 	default:
2067 		sc->sc_if.if_link_state = LINK_STATE_UNKNOWN;
2068 		break;
2069 	}
2070 	rt_ifmsg(&sc->sc_if);
2071 }
2072 
2073 void
2074 carp_carpdev_state(void *v)
2075 {
2076 	struct carp_if *cif;
2077 	struct carp_softc *sc;
2078 	struct ifnet *ifp = v;
2079 
2080 	if (ifp->if_type == IFT_CARP)
2081 		return;
2082 
2083 	cif = (struct carp_if *)ifp->if_carp;
2084 
2085 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
2086 		int suppressed = sc->sc_suppress;
2087 
2088 		if (sc->sc_carpdev->if_link_state == LINK_STATE_DOWN ||
2089 		    !(sc->sc_carpdev->if_flags & IFF_UP)) {
2090 			sc->sc_if.if_flags &= ~IFF_RUNNING;
2091 			callout_stop(&sc->sc_ad_tmo);
2092 			callout_stop(&sc->sc_md_tmo);
2093 			callout_stop(&sc->sc_md6_tmo);
2094 			carp_set_state(sc, INIT);
2095 			sc->sc_suppress = 1;
2096 			carp_setrun(sc, 0);
2097 			if (!suppressed) {
2098 				carp_suppress_preempt++;
2099 				if (carp_suppress_preempt == 1)
2100 					carp_send_ad_all();
2101 			}
2102 		} else {
2103 			carp_set_state(sc, INIT);
2104 			sc->sc_suppress = 0;
2105 			carp_setrun(sc, 0);
2106 			if (suppressed)
2107 				carp_suppress_preempt--;
2108 		}
2109 	}
2110 }
2111 
2112 int
2113 carp_ether_addmulti(struct carp_softc *sc, struct ifreq *ifr)
2114 {
2115 	const struct sockaddr *sa = ifreq_getaddr(SIOCADDMULTI, ifr);
2116 	struct ifnet *ifp;
2117 	struct carp_mc_entry *mc;
2118 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2119 	int error;
2120 
2121 	ifp = sc->sc_carpdev;
2122 	if (ifp == NULL)
2123 		return (EINVAL);
2124 
2125 	error = ether_addmulti(sa, &sc->sc_ac);
2126 	if (error != ENETRESET)
2127 		return (error);
2128 
2129 	/*
2130 	 * This is new multicast address.  We have to tell parent
2131 	 * about it.  Also, remember this multicast address so that
2132 	 * we can delete them on unconfigure.
2133 	 */
2134 	MALLOC(mc, struct carp_mc_entry *, sizeof(struct carp_mc_entry),
2135 	    M_DEVBUF, M_NOWAIT);
2136 	if (mc == NULL) {
2137 		error = ENOMEM;
2138 		goto alloc_failed;
2139 	}
2140 
2141 	/*
2142 	 * As ether_addmulti() returns ENETRESET, following two
2143 	 * statement shouldn't fail.
2144 	 */
2145 	(void)ether_multiaddr(sa, addrlo, addrhi);
2146 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, mc->mc_enm);
2147 	memcpy(&mc->mc_addr, sa, sa->sa_len);
2148 	LIST_INSERT_HEAD(&sc->carp_mc_listhead, mc, mc_entries);
2149 
2150 	error = (*ifp->if_ioctl)(ifp, SIOCADDMULTI, (void *)ifr);
2151 	if (error != 0)
2152 		goto ioctl_failed;
2153 
2154 	return (error);
2155 
2156  ioctl_failed:
2157 	LIST_REMOVE(mc, mc_entries);
2158 	FREE(mc, M_DEVBUF);
2159  alloc_failed:
2160 	(void)ether_delmulti(sa, &sc->sc_ac);
2161 
2162 	return (error);
2163 }
2164 
2165 int
2166 carp_ether_delmulti(struct carp_softc *sc, struct ifreq *ifr)
2167 {
2168 	const struct sockaddr *sa = ifreq_getaddr(SIOCDELMULTI, ifr);
2169 	struct ifnet *ifp;
2170 	struct ether_multi *enm;
2171 	struct carp_mc_entry *mc;
2172 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2173 	int error;
2174 
2175 	ifp = sc->sc_carpdev;
2176 	if (ifp == NULL)
2177 		return (EINVAL);
2178 
2179 	/*
2180 	 * Find a key to lookup carp_mc_entry.  We have to do this
2181 	 * before calling ether_delmulti for obvious reason.
2182 	 */
2183 	if ((error = ether_multiaddr(sa, addrlo, addrhi)) != 0)
2184 		return (error);
2185 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, enm);
2186 	if (enm == NULL)
2187 		return (EINVAL);
2188 
2189 	LIST_FOREACH(mc, &sc->carp_mc_listhead, mc_entries)
2190 		if (mc->mc_enm == enm)
2191 			break;
2192 
2193 	/* We won't delete entries we didn't add */
2194 	if (mc == NULL)
2195 		return (EINVAL);
2196 
2197 	error = ether_delmulti(sa, &sc->sc_ac);
2198 	if (error != ENETRESET)
2199 		return (error);
2200 
2201 	/* We no longer use this multicast address.  Tell parent so. */
2202 	error = (*ifp->if_ioctl)(ifp, SIOCDELMULTI, (void *)ifr);
2203 	if (error == 0) {
2204 		/* And forget about this address. */
2205 		LIST_REMOVE(mc, mc_entries);
2206 		FREE(mc, M_DEVBUF);
2207 	} else
2208 		(void)ether_addmulti(sa, &sc->sc_ac);
2209 	return (error);
2210 }
2211 
2212 /*
2213  * Delete any multicast address we have asked to add from parent
2214  * interface.  Called when the carp is being unconfigured.
2215  */
2216 void
2217 carp_ether_purgemulti(struct carp_softc *sc)
2218 {
2219 	struct ifnet *ifp = sc->sc_carpdev;		/* Parent. */
2220 	struct carp_mc_entry *mc;
2221 	union {
2222 		struct ifreq ifreq;
2223 		struct {
2224 			char ifr_name[IFNAMSIZ];
2225 			struct sockaddr_storage ifr_ss;
2226 		} ifreq_storage;
2227 	} u;
2228 	struct ifreq *ifr = &u.ifreq;
2229 
2230 	if (ifp == NULL)
2231 		return;
2232 
2233 	memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
2234 	while ((mc = LIST_FIRST(&sc->carp_mc_listhead)) != NULL) {
2235 		memcpy(&ifr->ifr_addr, &mc->mc_addr, mc->mc_addr.ss_len);
2236 		(void)(*ifp->if_ioctl)(ifp, SIOCDELMULTI, (void *)ifr);
2237 		LIST_REMOVE(mc, mc_entries);
2238 		FREE(mc, M_DEVBUF);
2239 	}
2240 }
2241 
2242 static int
2243 sysctl_net_inet_carp_stats(SYSCTLFN_ARGS)
2244 {
2245 
2246 	return (NETSTAT_SYSCTL(carpstat_percpu, CARP_NSTATS));
2247 }
2248 
2249 SYSCTL_SETUP(sysctl_net_inet_carp_setup, "sysctl net.inet.carp subtree setup")
2250 {
2251 
2252 	sysctl_createv(clog, 0, NULL, NULL,
2253 		       CTLFLAG_PERMANENT,
2254 		       CTLTYPE_NODE, "net", NULL,
2255 		       NULL, 0, NULL, 0,
2256 		       CTL_NET, CTL_EOL);
2257 	sysctl_createv(clog, 0, NULL, NULL,
2258 		       CTLFLAG_PERMANENT,
2259 		       CTLTYPE_NODE, "inet", NULL,
2260 		       NULL, 0, NULL, 0,
2261 		       CTL_NET, PF_INET, CTL_EOL);
2262 	sysctl_createv(clog, 0, NULL, NULL,
2263 		       CTLFLAG_PERMANENT,
2264 		       CTLTYPE_NODE, "carp",
2265 		       SYSCTL_DESCR("CARP related settings"),
2266 		       NULL, 0, NULL, 0,
2267 		       CTL_NET, PF_INET, IPPROTO_CARP, CTL_EOL);
2268 
2269 	sysctl_createv(clog, 0, NULL, NULL,
2270 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2271 		       CTLTYPE_INT, "preempt",
2272 		       SYSCTL_DESCR("Enable CARP Preempt"),
2273 		       NULL, 0, &carp_opts[CARPCTL_PREEMPT], 0,
2274 		       CTL_NET, PF_INET, IPPROTO_CARP,
2275 		       CTL_CREATE, CTL_EOL);
2276 	sysctl_createv(clog, 0, NULL, NULL,
2277 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2278 		       CTLTYPE_INT, "arpbalance",
2279 		       SYSCTL_DESCR("Enable ARP balancing"),
2280 		       NULL, 0, &carp_opts[CARPCTL_ARPBALANCE], 0,
2281 		       CTL_NET, PF_INET, IPPROTO_CARP,
2282 		       CTL_CREATE, CTL_EOL);
2283 	sysctl_createv(clog, 0, NULL, NULL,
2284 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2285 		       CTLTYPE_INT, "allow",
2286 		       SYSCTL_DESCR("Enable CARP"),
2287 		       NULL, 0, &carp_opts[CARPCTL_ALLOW], 0,
2288 		       CTL_NET, PF_INET, IPPROTO_CARP,
2289 		       CTL_CREATE, CTL_EOL);
2290 	sysctl_createv(clog, 0, NULL, NULL,
2291 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2292 		       CTLTYPE_INT, "log",
2293 		       SYSCTL_DESCR("CARP logging"),
2294 		       NULL, 0, &carp_opts[CARPCTL_LOG], 0,
2295 		       CTL_NET, PF_INET, IPPROTO_CARP,
2296 		       CTL_CREATE, CTL_EOL);
2297 	sysctl_createv(clog, 0, NULL, NULL,
2298 		       CTLFLAG_PERMANENT,
2299 		       CTLTYPE_STRUCT, "stats",
2300 		       SYSCTL_DESCR("CARP statistics"),
2301 		       sysctl_net_inet_carp_stats, 0, NULL, 0,
2302 		       CTL_NET, PF_INET, IPPROTO_CARP, CARPCTL_STATS,
2303 		       CTL_EOL);
2304 }
2305