xref: /freebsd/sys/netinet/ip_carp.c (revision ceaec73d406831b1251babb61675df0a1aa54a31)
1 /* 	$FreeBSD$ */
2 
3 /*
4  * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
5  * Copyright (c) 2003 Ryan McBride. All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
25  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
26  * THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "opt_carp.h"
30 #include "opt_bpf.h"
31 #include "opt_inet.h"
32 #include "opt_inet6.h"
33 
34 #include <sys/types.h>
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/conf.h>
38 #include <sys/kernel.h>
39 #include <sys/limits.h>
40 #include <sys/malloc.h>
41 #include <sys/mbuf.h>
42 #include <sys/module.h>
43 #include <sys/time.h>
44 #include <sys/proc.h>
45 #include <sys/sysctl.h>
46 #include <sys/syslog.h>
47 #include <sys/signalvar.h>
48 #include <sys/filio.h>
49 #include <sys/sockio.h>
50 
51 #include <sys/socket.h>
52 #include <sys/vnode.h>
53 
54 #include <machine/stdarg.h>
55 
56 #include <net/bpf.h>
57 #include <net/ethernet.h>
58 #include <net/fddi.h>
59 #include <net/iso88025.h>
60 #include <net/if.h>
61 #include <net/if_clone.h>
62 #include <net/if_types.h>
63 #include <net/route.h>
64 
65 #ifdef INET
66 #include <netinet/in.h>
67 #include <netinet/in_var.h>
68 #include <netinet/in_systm.h>
69 #include <netinet/ip.h>
70 #include <netinet/ip_var.h>
71 #include <netinet/if_ether.h>
72 #include <machine/in_cksum.h>
73 #endif
74 
75 #ifdef INET6
76 #include <netinet/icmp6.h>
77 #include <netinet/ip6.h>
78 #include <netinet6/ip6_var.h>
79 #include <netinet6/nd6.h>
80 #include <net/if_dl.h>
81 #endif
82 
83 #include <crypto/sha1.h>
84 #include <netinet/ip_carp.h>
85 
86 #define	CARP_IFNAME	"carp"
87 static MALLOC_DEFINE(M_CARP, "CARP", "CARP interfaces");
88 SYSCTL_DECL(_net_inet_carp);
89 
90 struct carp_softc {
91 	struct arpcom	 	 sc_ac;		/* Interface clue */
92 #define	sc_if			 sc_ac.ac_if
93 	struct ifnet		*sc_carpdev;	/* Pointer to parent interface */
94 	struct in_ifaddr 	*sc_ia;		/* primary iface address */
95 	struct ip_moptions 	 sc_imo;
96 #ifdef INET6
97 	struct in6_ifaddr 	*sc_ia6;	/* primary iface address v6 */
98 	struct ip6_moptions 	 sc_im6o;
99 #endif /* INET6 */
100 	TAILQ_ENTRY(carp_softc)	 sc_list;
101 
102 	enum { INIT = 0, BACKUP, MASTER }	sc_state;
103 
104 	int			 sc_flags_backup;
105 	int			 sc_suppress;
106 
107 	int			 sc_sendad_errors;
108 #define	CARP_SENDAD_MAX_ERRORS	3
109 	int			 sc_sendad_success;
110 #define	CARP_SENDAD_MIN_SUCCESS 3
111 
112 	int			 sc_vhid;
113 	int			 sc_advskew;
114 	int			 sc_naddrs;
115 	int			 sc_naddrs6;
116 	int			 sc_advbase;	/* seconds */
117 	int			 sc_init_counter;
118 	u_int64_t		 sc_counter;
119 
120 	/* authentication */
121 #define CARP_HMAC_PAD	64
122 	unsigned char sc_key[CARP_KEY_LEN];
123 	unsigned char sc_pad[CARP_HMAC_PAD];
124 	SHA1_CTX sc_sha1;
125 
126 	struct callout		 sc_ad_tmo;	/* advertisement timeout */
127 	struct callout		 sc_md_tmo;	/* master down timeout */
128 	struct callout 		 sc_md6_tmo;	/* master down timeout */
129 
130 	LIST_ENTRY(carp_softc)	 sc_next;	/* Interface clue */
131 };
132 
133 int carp_suppress_preempt = 0;
134 int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 1, 0, 0 };	/* XXX for now */
135 SYSCTL_INT(_net_inet_carp, CARPCTL_ALLOW, allow, CTLFLAG_RW,
136     &carp_opts[CARPCTL_ALLOW], 0, "Accept incoming CARP packets");
137 SYSCTL_INT(_net_inet_carp, CARPCTL_PREEMPT, preempt, CTLFLAG_RW,
138     &carp_opts[CARPCTL_PREEMPT], 0, "high-priority backup preemption mode");
139 SYSCTL_INT(_net_inet_carp, CARPCTL_LOG, log, CTLFLAG_RW,
140     &carp_opts[CARPCTL_LOG], 0, "log bad carp packets");
141 SYSCTL_INT(_net_inet_carp, CARPCTL_ARPBALANCE, arpbalance, CTLFLAG_RW,
142     &carp_opts[CARPCTL_ARPBALANCE], 0, "balance arp responses");
143 
144 struct carpstats carpstats;
145 SYSCTL_STRUCT(_net_inet_carp, CARPCTL_STATS, stats, CTLFLAG_RW,
146     &carpstats, carpstats,
147     "CARP statistics (struct carpstats, netinet/ip_carp.h)");
148 
149 struct carp_if {
150 	TAILQ_HEAD(, carp_softc) vhif_vrs;
151 	int vhif_nvrs;
152 
153 	struct callout	 cif_tmo;
154 	struct ifnet 	*vhif_ifp;
155 	struct mtx	 vhif_mtx;
156 };
157 
158 /* Get carp_if from softc. Valid after carp_set_addr{,6}. */
159 #define	SC2CIF(sc)		((struct carp_if *)(sc)->sc_carpdev->if_carp)
160 
161 /* lock per carp_if queue */
162 #define	CARP_LOCK_INIT(cif)	mtx_init(&(cif)->vhif_mtx, "carp_if", 	\
163 	NULL, MTX_DEF)
164 #define	CARP_LOCK_DESTROY(cif)	mtx_destroy(&(cif)->vhif_mtx)
165 #define	CARP_LOCK_ASSERT(cif)	mtx_assert(&(cif)->vhif_mtx, MA_OWNED)
166 #define	CARP_LOCK(cif)		mtx_lock(&(cif)->vhif_mtx)
167 #define	CARP_UNLOCK(cif)	mtx_unlock(&(cif)->vhif_mtx)
168 
169 #define	CARP_SCLOCK(sc)		mtx_lock(&SC2CIF(sc)->vhif_mtx)
170 #define	CARP_SCUNLOCK(sc)	mtx_unlock(&SC2CIF(sc)->vhif_mtx)
171 #define	CARP_SCLOCK_ASSERT(sc)	mtx_assert(&SC2CIF(sc)->vhif_mtx, MA_OWNED)
172 
173 #define	CARP_LOG(...)	do {				\
174 	if (carp_opts[CARPCTL_LOG] > 0)			\
175 		log(LOG_INFO, __VA_ARGS__);		\
176 } while (0)
177 
178 #define	CARP_DEBUG(...)	do {				\
179 	if (carp_opts[CARPCTL_LOG] > 1)			\
180 		log(LOG_DEBUG, __VA_ARGS__);		\
181 } while (0)
182 
183 static void	carp_hmac_prepare(struct carp_softc *);
184 static void	carp_hmac_generate(struct carp_softc *, u_int32_t *,
185 		    unsigned char *);
186 static int	carp_hmac_verify(struct carp_softc *, u_int32_t *,
187 		    unsigned char *);
188 static void	carp_setroute(struct carp_softc *, int);
189 static void	carp_input_c(struct mbuf *, struct carp_header *, sa_family_t);
190 static int 	carp_clone_create(struct if_clone *, int);
191 static void 	carp_clone_destroy(struct ifnet *);
192 static void	carpdetach(struct carp_softc *);
193 static int	carp_prepare_ad(struct mbuf *, struct carp_softc *,
194 		    struct carp_header *);
195 static void	carp_send_ad_all(void);
196 static void	carp_send_ad(void *);
197 static void	carp_send_ad_locked(struct carp_softc *);
198 static void	carp_send_arp(struct carp_softc *);
199 static void	carp_master_down(void *);
200 static void	carp_master_down_locked(struct carp_softc *);
201 static int	carp_ioctl(struct ifnet *, u_long, caddr_t);
202 static int	carp_looutput(struct ifnet *, struct mbuf *, struct sockaddr *,
203 		    struct rtentry *);
204 static void	carp_start(struct ifnet *);
205 static void	carp_setrun(struct carp_softc *, sa_family_t);
206 static void	carp_set_state(struct carp_softc *, int);
207 static int	carp_addrcount(struct carp_if *, struct in_ifaddr *, int);
208 enum	{ CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
209 
210 static int	carp_set_addr(struct carp_softc *, struct sockaddr_in *);
211 static int	carp_del_addr(struct carp_softc *, struct sockaddr_in *);
212 static void	carp_carpdev_state1(void *);
213 static void	carp_carpdev_state_locked(struct carp_if *);
214 static void	carp_sc_state_locked(struct carp_softc *);
215 #ifdef INET6
216 static void	carp_send_na(struct carp_softc *);
217 static int	carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
218 static int	carp_del_addr6(struct carp_softc *, struct sockaddr_in6 *);
219 #endif
220 
221 static LIST_HEAD(, carp_softc) carpif_list;
222 static struct mtx carp_mtx;
223 IFC_SIMPLE_DECLARE(carp, 0);
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 static void
232 carp_hmac_prepare(struct carp_softc *sc)
233 {
234 	u_int8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
235 	u_int8_t vhid = sc->sc_vhid & 0xff;
236 	struct ifaddr *ifa;
237 	int i;
238 #ifdef INET6
239 	struct in6_addr in6;
240 #endif
241 
242 	if (sc->sc_carpdev)
243 		CARP_SCLOCK(sc);
244 
245 	/* XXX: possible race here */
246 
247 	/* compute ipad from key */
248 	bzero(sc->sc_pad, sizeof(sc->sc_pad));
249 	bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
250 	for (i = 0; i < sizeof(sc->sc_pad); i++)
251 		sc->sc_pad[i] ^= 0x36;
252 
253 	/* precompute first part of inner hash */
254 	SHA1Init(&sc->sc_sha1);
255 	SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
256 	SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
257 	SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
258 	SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
259 #ifdef INET
260 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
261 		if (ifa->ifa_addr->sa_family == AF_INET)
262 			SHA1Update(&sc->sc_sha1,
263 			    (void *)&ifatoia(ifa)->ia_addr.sin_addr.s_addr,
264 			    sizeof(struct in_addr));
265 	}
266 #endif /* INET */
267 #ifdef INET6
268 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
269 		if (ifa->ifa_addr->sa_family == AF_INET6) {
270 			in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
271 			if (IN6_IS_ADDR_LINKLOCAL(&in6))
272 				in6.s6_addr16[1] = 0;
273 			SHA1Update(&sc->sc_sha1, (void *)&in6, sizeof(in6));
274 		}
275 	}
276 #endif /* INET6 */
277 
278 	/* convert ipad to opad */
279 	for (i = 0; i < sizeof(sc->sc_pad); i++)
280 		sc->sc_pad[i] ^= 0x36 ^ 0x5c;
281 
282 	if (sc->sc_carpdev)
283 		CARP_SCUNLOCK(sc);
284 }
285 
286 static void
287 carp_hmac_generate(struct carp_softc *sc, u_int32_t counter[2],
288     unsigned char md[20])
289 {
290 	SHA1_CTX sha1ctx;
291 
292 	/* fetch first half of inner hash */
293 	bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
294 
295 	SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
296 	SHA1Final(md, &sha1ctx);
297 
298 	/* outer hash */
299 	SHA1Init(&sha1ctx);
300 	SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
301 	SHA1Update(&sha1ctx, md, 20);
302 	SHA1Final(md, &sha1ctx);
303 }
304 
305 static int
306 carp_hmac_verify(struct carp_softc *sc, u_int32_t counter[2],
307     unsigned char md[20])
308 {
309 	unsigned char md2[20];
310 
311 	CARP_SCLOCK_ASSERT(sc);
312 
313 	carp_hmac_generate(sc, counter, md2);
314 
315 	return (bcmp(md, md2, sizeof(md2)));
316 }
317 
318 static void
319 carp_setroute(struct carp_softc *sc, int cmd)
320 {
321 	struct ifaddr *ifa;
322 	int s;
323 
324 	if (sc->sc_carpdev)
325 		CARP_SCLOCK_ASSERT(sc);
326 
327 	s = splnet();
328 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
329 		if (ifa->ifa_addr->sa_family == AF_INET &&
330 		    sc->sc_carpdev != NULL) {
331 			int count = carp_addrcount(
332 			    (struct carp_if *)sc->sc_carpdev->if_carp,
333 			    ifatoia(ifa), CARP_COUNT_MASTER);
334 
335 			if ((cmd == RTM_ADD && count == 1) ||
336 			    (cmd == RTM_DELETE && count == 0))
337 				rtinit(ifa, cmd, RTF_UP | RTF_HOST);
338 		}
339 #ifdef INET6
340 		if (ifa->ifa_addr->sa_family == AF_INET6) {
341 			if (cmd == RTM_ADD)
342 				in6_ifaddloop(ifa);
343 			else
344 				in6_ifremloop(ifa);
345 		}
346 #endif /* INET6 */
347 	}
348 	splx(s);
349 }
350 
351 static int
352 carp_clone_create(struct if_clone *ifc, int unit)
353 {
354 
355 	struct carp_softc *sc;
356 	struct ifnet *ifp;
357 
358 	MALLOC(sc, struct carp_softc *, sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
359 
360 	sc->sc_flags_backup = 0;
361 	sc->sc_suppress = 0;
362 	sc->sc_advbase = CARP_DFLTINTV;
363 	sc->sc_vhid = -1;	/* required setting */
364 	sc->sc_advskew = 0;
365 	sc->sc_init_counter = 1;
366 	sc->sc_naddrs = sc->sc_naddrs6 = 0; /* M_ZERO? */
367 #ifdef INET6
368 	sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
369 #endif
370 
371 	callout_init(&sc->sc_ad_tmo, NET_CALLOUT_MPSAFE);
372 	callout_init(&sc->sc_md_tmo, NET_CALLOUT_MPSAFE);
373 	callout_init(&sc->sc_md6_tmo, NET_CALLOUT_MPSAFE);
374 
375 	ifp = &sc->sc_if;
376 	ifp->if_softc = sc;
377 	if_initname(ifp, CARP_IFNAME, unit);
378 	ifp->if_mtu = ETHERMTU;
379 	ifp->if_flags = 0;
380 	ifp->if_ioctl = carp_ioctl;
381 	ifp->if_output = carp_looutput;
382 	ifp->if_start = carp_start;
383 	ifp->if_type = IFT_CARP;
384 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
385 	ifp->if_hdrlen = 0;
386 	if_attach(ifp);
387 	bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t));
388 	mtx_lock(&carp_mtx);
389 	LIST_INSERT_HEAD(&carpif_list, sc, sc_next);
390 	mtx_unlock(&carp_mtx);
391 	return (0);
392 }
393 
394 static void
395 carp_clone_destroy(struct ifnet *ifp)
396 {
397 	struct carp_softc *sc = ifp->if_softc;
398 	struct carp_if *cif;
399 	struct ip_moptions *imo = &sc->sc_imo;
400 #ifdef INET6
401 	struct ip6_moptions *im6o = &sc->sc_im6o;
402 #endif
403 
404 /*	carpdetach(sc); */
405 
406 	callout_stop(&sc->sc_ad_tmo);
407 	callout_stop(&sc->sc_md_tmo);
408 	callout_stop(&sc->sc_md6_tmo);
409 
410 	if (imo->imo_num_memberships) {
411 		in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
412 		imo->imo_multicast_ifp = NULL;
413 	}
414 #ifdef INET6
415 	while (!LIST_EMPTY(&im6o->im6o_memberships)) {
416 		struct in6_multi_mship *imm =
417 		    LIST_FIRST(&im6o->im6o_memberships);
418 		LIST_REMOVE(imm, i6mm_chain);
419 		in6_leavegroup(imm);
420 	}
421 	im6o->im6o_multicast_ifp = NULL;
422 #endif
423 
424 	/* Remove ourself from parents if_carp queue */
425 	if (sc->sc_carpdev && (cif = sc->sc_carpdev->if_carp)) {
426 		CARP_LOCK(cif);
427 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
428 		if (!--cif->vhif_nvrs) {
429 			callout_drain(&cif->cif_tmo);
430 			sc->sc_carpdev->if_carp = NULL;
431 			CARP_LOCK_DESTROY(cif);
432 			FREE(cif, M_CARP);
433 			ifpromisc(sc->sc_carpdev, 0);
434 		} else {
435 			CARP_UNLOCK(cif);
436 		}
437 	}
438 
439 	mtx_lock(&carp_mtx);
440 	LIST_REMOVE(sc, sc_next);
441 	mtx_unlock(&carp_mtx);
442 	bpfdetach(ifp);
443 	if_detach(ifp);
444 	free(sc, M_CARP);
445 }
446 
447 /*
448  * process input packet.
449  * we have rearranged checks order compared to the rfc,
450  * but it seems more efficient this way or not possible otherwise.
451  */
452 void
453 carp_input(struct mbuf *m, int hlen)
454 {
455 	struct ip *ip = mtod(m, struct ip *);
456 	struct carp_header *ch;
457 	int iplen, len;
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_carp == NULL) {
468 		carpstats.carps_badif++;
469 		CARP_LOG("carp_input: packet received on non-carp "
470 		    "interface: %s\n",
471 		    m->m_pkthdr.rcvif->if_xname);
472 		m_freem(m);
473 		return;
474 	}
475 
476 	/* verify that the IP TTL is 255.  */
477 	if (ip->ip_ttl != CARP_DFLTTL) {
478 		carpstats.carps_badttl++;
479 		CARP_LOG("carp_input: received ttl %d != 255i on %s\n",
480 		    ip->ip_ttl,
481 		    m->m_pkthdr.rcvif->if_xname);
482 		m_freem(m);
483 		return;
484 	}
485 
486 	iplen = ip->ip_hl << 2;
487 
488 	if (m->m_pkthdr.len < iplen + sizeof(*ch)) {
489 		carpstats.carps_badlen++;
490 		CARP_LOG("carp_input: received len %zd < "
491 		    "sizeof(struct carp_header)\n",
492 		    m->m_len - sizeof(struct ip));
493 		m_freem(m);
494 		return;
495 	}
496 
497 	if (iplen + sizeof(*ch) < m->m_len) {
498 		if ((m = m_pullup(m, iplen + sizeof(*ch))) == NULL) {
499 			carpstats.carps_hdrops++;
500 			CARP_LOG("carp_input: pullup failed\n");
501 			return;
502 		}
503 		ip = mtod(m, struct ip *);
504 	}
505 	ch = (struct carp_header *)((char *)ip + iplen);
506 
507 	/*
508 	 * verify that the received packet length is
509 	 * equal to the CARP header
510 	 */
511 	len = iplen + sizeof(*ch);
512 	if (len > m->m_pkthdr.len) {
513 		carpstats.carps_badlen++;
514 		CARP_LOG("carp_input: packet too short %d on %s\n",
515 		    m->m_pkthdr.len,
516 		    m->m_pkthdr.rcvif->if_xname);
517 		m_freem(m);
518 		return;
519 	}
520 
521 	if ((m = m_pullup(m, len)) == NULL) {
522 		carpstats.carps_hdrops++;
523 		return;
524 	}
525 	ip = mtod(m, struct ip *);
526 	ch = (struct carp_header *)((char *)ip + iplen);
527 
528 	/* verify the CARP checksum */
529 	m->m_data += iplen;
530 	if (carp_cksum(m, len - iplen)) {
531 		carpstats.carps_badsum++;
532 		CARP_LOG("carp_input: checksum failed on %s\n",
533 		    m->m_pkthdr.rcvif->if_xname);
534 		m_freem(m);
535 		return;
536 	}
537 	m->m_data -= iplen;
538 
539 	carp_input_c(m, ch, AF_INET);
540 }
541 
542 #ifdef INET6
543 int
544 carp6_input(struct mbuf **mp, int *offp, int proto)
545 {
546 	struct mbuf *m = *mp;
547 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
548 	struct carp_header *ch;
549 	u_int len;
550 
551 	carpstats.carps_ipackets6++;
552 
553 	if (!carp_opts[CARPCTL_ALLOW]) {
554 		m_freem(m);
555 		return (IPPROTO_DONE);
556 	}
557 
558 	/* check if received on a valid carp interface */
559 	if (m->m_pkthdr.rcvif->if_carp == NULL) {
560 		carpstats.carps_badif++;
561 		CARP_LOG("carp6_input: packet received on non-carp "
562 		    "interface: %s\n",
563 		    m->m_pkthdr.rcvif->if_xname);
564 		m_freem(m);
565 		return (IPPROTO_DONE);
566 	}
567 
568 	/* verify that the IP TTL is 255 */
569 	if (ip6->ip6_hlim != CARP_DFLTTL) {
570 		carpstats.carps_badttl++;
571 		CARP_LOG("carp6_input: received ttl %d != 255 on %s\n",
572 		    ip6->ip6_hlim,
573 		    m->m_pkthdr.rcvif->if_xname);
574 		m_freem(m);
575 		return (IPPROTO_DONE);
576 	}
577 
578 	/* verify that we have a complete carp packet */
579 	len = m->m_len;
580 	IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
581 	if (ch == NULL) {
582 		carpstats.carps_badlen++;
583 		CARP_LOG("carp6_input: packet size %u too small\n", len);
584 		return (IPPROTO_DONE);
585 	}
586 
587 
588 	/* verify the CARP checksum */
589 	m->m_data += *offp;
590 	if (carp_cksum(m, sizeof(*ch))) {
591 		carpstats.carps_badsum++;
592 		CARP_LOG("carp6_input: checksum failed, on %s\n",
593 		    m->m_pkthdr.rcvif->if_xname);
594 		m_freem(m);
595 		return (IPPROTO_DONE);
596 	}
597 	m->m_data -= *offp;
598 
599 	carp_input_c(m, ch, AF_INET6);
600 	return (IPPROTO_DONE);
601 }
602 #endif /* INET6 */
603 
604 static void
605 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
606 {
607 	struct ifnet *ifp = m->m_pkthdr.rcvif;
608 	struct carp_softc *sc;
609 	u_int64_t tmp_counter;
610 	struct timeval sc_tv, ch_tv;
611 
612 	/* verify that the VHID is valid on the receiving interface */
613 	CARP_LOCK(ifp->if_carp);
614 	TAILQ_FOREACH(sc, &((struct carp_if *)ifp->if_carp)->vhif_vrs, sc_list)
615 		if (sc->sc_vhid == ch->carp_vhid)
616 			break;
617 
618 	if (!sc || (sc->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) !=
619 	    (IFF_UP|IFF_RUNNING)) {
620 		carpstats.carps_badvhid++;
621 		CARP_UNLOCK(ifp->if_carp);
622 		m_freem(m);
623 		return;
624 	}
625 
626 	getmicrotime(&sc->sc_if.if_lastchange);
627 	sc->sc_if.if_ipackets++;
628 	sc->sc_if.if_ibytes += m->m_pkthdr.len;
629 
630 	if (sc->sc_if.if_bpf) {
631 		struct ip *ip = mtod(m, struct ip *);
632 		uint32_t af1 = af;
633 
634 		/* BPF wants net byte order */
635 		ip->ip_len = htons(ip->ip_len + (ip->ip_hl << 2));
636 		ip->ip_off = htons(ip->ip_off);
637 		bpf_mtap2(sc->sc_if.if_bpf, &af1, sizeof(af1), m);
638 	}
639 
640 	/* verify the CARP version. */
641 	if (ch->carp_version != CARP_VERSION) {
642 		carpstats.carps_badver++;
643 		sc->sc_if.if_ierrors++;
644 		CARP_UNLOCK(ifp->if_carp);
645 		CARP_LOG("%s; invalid version %d\n",
646 		    sc->sc_if.if_xname,
647 		    ch->carp_version);
648 		m_freem(m);
649 		return;
650 	}
651 
652 	/* verify the hash */
653 	if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
654 		carpstats.carps_badauth++;
655 		sc->sc_if.if_ierrors++;
656 		CARP_UNLOCK(ifp->if_carp);
657 		CARP_LOG("%s: incorrect hash\n", sc->sc_if.if_xname);
658 		m_freem(m);
659 		return;
660 	}
661 
662 	tmp_counter = ntohl(ch->carp_counter[0]);
663 	tmp_counter = tmp_counter<<32;
664 	tmp_counter += ntohl(ch->carp_counter[1]);
665 
666 	/* XXX Replay protection goes here */
667 
668 	sc->sc_init_counter = 0;
669 	sc->sc_counter = tmp_counter;
670 
671 	sc_tv.tv_sec = sc->sc_advbase;
672 	if (carp_suppress_preempt && sc->sc_advskew <  240)
673 		sc_tv.tv_usec = 240 * 1000000 / 256;
674 	else
675 		sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
676 	ch_tv.tv_sec = ch->carp_advbase;
677 	ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
678 
679 	switch (sc->sc_state) {
680 	case INIT:
681 		break;
682 	case MASTER:
683 		/*
684 		 * If we receive an advertisement from a master who's going to
685 		 * be more frequent than us, go into BACKUP state.
686 		 */
687 		if (timevalcmp(&sc_tv, &ch_tv, >) ||
688 		    timevalcmp(&sc_tv, &ch_tv, ==)) {
689 			callout_stop(&sc->sc_ad_tmo);
690 			CARP_DEBUG("%s: MASTER -> BACKUP "
691 			   "(more frequent advertisement received)\n",
692 			   sc->sc_if.if_xname);
693 			carp_set_state(sc, BACKUP);
694 			carp_setrun(sc, 0);
695 			carp_setroute(sc, RTM_DELETE);
696 		}
697 		break;
698 	case BACKUP:
699 		/*
700 		 * If we're pre-empting masters who advertise slower than us,
701 		 * and this one claims to be slower, treat him as down.
702 		 */
703 		if (carp_opts[CARPCTL_PREEMPT] &&
704 		    timevalcmp(&sc_tv, &ch_tv, <)) {
705 			CARP_DEBUG("%s: BACKUP -> MASTER "
706 			    "(preempting a slower master)\n",
707 			    sc->sc_if.if_xname);
708 			carp_master_down_locked(sc);
709 			break;
710 		}
711 
712 		/*
713 		 *  If the master is going to advertise at such a low frequency
714 		 *  that he's guaranteed to time out, we'd might as well just
715 		 *  treat him as timed out now.
716 		 */
717 		sc_tv.tv_sec = sc->sc_advbase * 3;
718 		if (timevalcmp(&sc_tv, &ch_tv, <)) {
719 			CARP_DEBUG("%s: BACKUP -> MASTER "
720 			    "(master timed out)\n",
721 			    sc->sc_if.if_xname);
722 			carp_master_down_locked(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 	CARP_UNLOCK(ifp->if_carp);
735 
736 	m_freem(m);
737 	return;
738 }
739 
740 static void
741 carpdetach(struct carp_softc *sc)
742 {
743 	struct ifaddr *ifa;
744 
745 	callout_stop(&sc->sc_ad_tmo);
746 	callout_stop(&sc->sc_md_tmo);
747 	callout_stop(&sc->sc_md6_tmo);
748 
749 	while ((ifa = TAILQ_FIRST(&sc->sc_if.if_addrlist)) != NULL)
750 		if (ifa->ifa_addr->sa_family == AF_INET) {
751 			struct in_ifaddr *ia = ifatoia(ifa);
752 
753 			carp_del_addr(sc, &ia->ia_addr);
754 
755 			/* ripped screaming from in_control(SIOCDIFADDR) */
756 			in_ifscrub(&sc->sc_if, ia);
757 			TAILQ_REMOVE(&sc->sc_if.if_addrlist, ifa, ifa_link);
758 			TAILQ_REMOVE(&in_ifaddrhead, ia, ia_link);
759 			IFAFREE((&ia->ia_ifa));
760 		}
761 }
762 
763 /* Detach an interface from the carp.  */
764 void
765 carp_ifdetach(struct ifnet *ifp)
766 {
767 	struct carp_softc *sc;
768 	struct carp_if *cif = (struct carp_if *)ifp->if_carp;
769 
770 	CARP_LOCK(cif);
771 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list)
772 		carpdetach(sc);
773 	CARP_UNLOCK(cif);
774 }
775 
776 static int
777 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
778 {
779 	struct m_tag *mtag;
780 	struct ifnet *ifp = &sc->sc_if;
781 
782 	if (sc->sc_init_counter) {
783 		/* this could also be seconds since unix epoch */
784 		sc->sc_counter = arc4random();
785 		sc->sc_counter = sc->sc_counter << 32;
786 		sc->sc_counter += arc4random();
787 	} else
788 		sc->sc_counter++;
789 
790 	ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
791 	ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
792 
793 	carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
794 
795 	/* Tag packet for carp_output */
796 	mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct ifnet *), M_NOWAIT);
797 	if (mtag == NULL) {
798 		m_freem(m);
799 		sc->sc_if.if_oerrors++;
800 		return (ENOMEM);
801 	}
802 	bcopy(&ifp, (caddr_t)(mtag + 1), sizeof(struct ifnet *));
803 	m_tag_prepend(m, mtag);
804 
805 	return (0);
806 }
807 
808 static void
809 carp_send_ad_all(void)
810 {
811 	struct carp_softc *sc;
812 
813 	mtx_lock(&carp_mtx);
814 	LIST_FOREACH(sc, &carpif_list, sc_next) {
815 		if (sc->sc_carpdev == NULL)
816 			continue;
817 		CARP_SCLOCK(sc);
818 		if ((sc->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) &&
819 		     sc->sc_state == MASTER)
820 			carp_send_ad_locked(sc);
821 		CARP_SCUNLOCK(sc);
822 	}
823 	mtx_unlock(&carp_mtx);
824 }
825 
826 static void
827 carp_send_ad(void *v)
828 {
829 	struct carp_softc *sc = v;
830 
831 	CARP_SCLOCK(sc);
832 	carp_send_ad_locked(sc);
833 	CARP_SCUNLOCK(sc);
834 }
835 
836 static void
837 carp_send_ad_locked(struct carp_softc *sc)
838 {
839 	struct carp_header ch;
840 	struct timeval tv;
841 	struct carp_header *ch_ptr;
842 	struct mbuf *m;
843 	int len, advbase, advskew;
844 
845 	CARP_SCLOCK_ASSERT(sc);
846 
847 	/* bow out if we've lost our UPness or RUNNINGuiness */
848 	if ((sc->sc_if.if_flags &
849 	    (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
850 		advbase = 255;
851 		advskew = 255;
852 	} else {
853 		advbase = sc->sc_advbase;
854 		if (!carp_suppress_preempt || sc->sc_advskew > 240)
855 			advskew = sc->sc_advskew;
856 		else
857 			advskew = 240;
858 		tv.tv_sec = advbase;
859 		tv.tv_usec = advskew * 1000000 / 256;
860 	}
861 
862 	ch.carp_version = CARP_VERSION;
863 	ch.carp_type = CARP_ADVERTISEMENT;
864 	ch.carp_vhid = sc->sc_vhid;
865 	ch.carp_advbase = advbase;
866 	ch.carp_advskew = advskew;
867 	ch.carp_authlen = 7;	/* XXX DEFINE */
868 	ch.carp_pad1 = 0;	/* must be zero */
869 	ch.carp_cksum = 0;
870 
871 #ifdef INET
872 	if (sc->sc_ia) {
873 		struct ip *ip;
874 
875 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
876 		if (m == NULL) {
877 			sc->sc_ac.ac_if.if_oerrors++;
878 			carpstats.carps_onomem++;
879 			/* XXX maybe less ? */
880 			if (advbase != 255 || advskew != 255)
881 				callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
882 				    carp_send_ad, sc);
883 			return;
884 		}
885 		len = sizeof(*ip) + sizeof(ch);
886 		m->m_pkthdr.len = len;
887 		m->m_pkthdr.rcvif = NULL;
888 		m->m_len = len;
889 		MH_ALIGN(m, m->m_len);
890 		m->m_flags |= M_MCAST;
891 		ip = mtod(m, struct ip *);
892 		ip->ip_v = IPVERSION;
893 		ip->ip_hl = sizeof(*ip) >> 2;
894 		ip->ip_tos = IPTOS_LOWDELAY;
895 		ip->ip_len = len;
896 		ip->ip_id = ip_newid();
897 		ip->ip_off = IP_DF;
898 		ip->ip_ttl = CARP_DFLTTL;
899 		ip->ip_p = IPPROTO_CARP;
900 		ip->ip_sum = 0;
901 		ip->ip_src.s_addr = sc->sc_ia->ia_addr.sin_addr.s_addr;
902 		ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
903 
904 		ch_ptr = (struct carp_header *)(&ip[1]);
905 		bcopy(&ch, ch_ptr, sizeof(ch));
906 		if (carp_prepare_ad(m, sc, ch_ptr))
907 			return;
908 
909 		m->m_data += sizeof(*ip);
910 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
911 		m->m_data -= sizeof(*ip);
912 
913 		getmicrotime(&sc->sc_if.if_lastchange);
914 		sc->sc_ac.ac_if.if_opackets++;
915 		sc->sc_ac.ac_if.if_obytes += len;
916 		carpstats.carps_opackets++;
917 
918 		if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL)) {
919 			sc->sc_if.if_oerrors++;
920 			if (sc->sc_sendad_errors < INT_MAX)
921 				sc->sc_sendad_errors++;
922 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
923 				carp_suppress_preempt++;
924 				if (carp_suppress_preempt == 1) {
925 					CARP_SCUNLOCK(sc);
926 					carp_send_ad_all();
927 					CARP_SCLOCK(sc);
928 				}
929 			}
930 			sc->sc_sendad_success = 0;
931 		} else {
932 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
933 				if (++sc->sc_sendad_success >=
934 				    CARP_SENDAD_MIN_SUCCESS) {
935 					carp_suppress_preempt--;
936 					sc->sc_sendad_errors = 0;
937 				}
938 			} else
939 				sc->sc_sendad_errors = 0;
940 		}
941 	}
942 #endif /* INET */
943 #ifdef INET6
944 	if (sc->sc_ia6) {
945 		struct ip6_hdr *ip6;
946 
947 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
948 		if (m == NULL) {
949 			sc->sc_ac.ac_if.if_oerrors++;
950 			carpstats.carps_onomem++;
951 			/* XXX maybe less ? */
952 			if (advbase != 255 || advskew != 255)
953 				callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
954 				    carp_send_ad, sc);
955 			return;
956 		}
957 		len = sizeof(*ip6) + sizeof(ch);
958 		m->m_pkthdr.len = len;
959 		m->m_pkthdr.rcvif = NULL;
960 		m->m_len = len;
961 		MH_ALIGN(m, m->m_len);
962 		m->m_flags |= M_MCAST;
963 		ip6 = mtod(m, struct ip6_hdr *);
964 		bzero(ip6, sizeof(*ip6));
965 		ip6->ip6_vfc |= IPV6_VERSION;
966 		ip6->ip6_hlim = CARP_DFLTTL;
967 		ip6->ip6_nxt = IPPROTO_CARP;
968 		bcopy(&sc->sc_ia6->ia_addr.sin6_addr, &ip6->ip6_src,
969 		    sizeof(struct in6_addr));
970 		/* set the multicast destination */
971 
972 		ip6->ip6_dst.s6_addr8[0] = 0xff;
973 		ip6->ip6_dst.s6_addr8[1] = 0x02;
974 		ip6->ip6_dst.s6_addr8[15] = 0x12;
975 
976 		ch_ptr = (struct carp_header *)(&ip6[1]);
977 		bcopy(&ch, ch_ptr, sizeof(ch));
978 		if (carp_prepare_ad(m, sc, ch_ptr))
979 			return;
980 
981 		m->m_data += sizeof(*ip6);
982 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
983 		m->m_data -= sizeof(*ip6);
984 
985 		getmicrotime(&sc->sc_if.if_lastchange);
986 		sc->sc_if.if_opackets++;
987 		sc->sc_if.if_obytes += len;
988 		carpstats.carps_opackets6++;
989 
990 		if (ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL)) {
991 			sc->sc_if.if_oerrors++;
992 			if (sc->sc_sendad_errors < INT_MAX)
993 				sc->sc_sendad_errors++;
994 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
995 				carp_suppress_preempt++;
996 				if (carp_suppress_preempt == 1) {
997 					CARP_SCUNLOCK(sc);
998 					carp_send_ad_all();
999 					CARP_SCLOCK(sc);
1000 				}
1001 			}
1002 			sc->sc_sendad_success = 0;
1003 		} else {
1004 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1005 				if (++sc->sc_sendad_success >=
1006 				    CARP_SENDAD_MIN_SUCCESS) {
1007 					carp_suppress_preempt--;
1008 					sc->sc_sendad_errors = 0;
1009 				}
1010 			} else
1011 				sc->sc_sendad_errors = 0;
1012 		}
1013 	}
1014 #endif /* INET6 */
1015 
1016 	if (advbase != 255 || advskew != 255)
1017 		callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1018 		    carp_send_ad, sc);
1019 
1020 }
1021 
1022 /*
1023  * Broadcast a gratuitous ARP request containing
1024  * the virtual router MAC address for each IP address
1025  * associated with the virtual router.
1026  */
1027 static void
1028 carp_send_arp(struct carp_softc *sc)
1029 {
1030 	struct ifaddr *ifa;
1031 
1032 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
1033 
1034 		if (ifa->ifa_addr->sa_family != AF_INET)
1035 			continue;
1036 
1037 /*		arprequest(sc->sc_carpdev, &in, &in, sc->sc_ac.ac_enaddr); */
1038 		arp_ifinit2(sc->sc_carpdev, ifa, sc->sc_ac.ac_enaddr);
1039 
1040 		DELAY(1000);	/* XXX */
1041 	}
1042 }
1043 
1044 #ifdef INET6
1045 static void
1046 carp_send_na(struct carp_softc *sc)
1047 {
1048 	struct ifaddr *ifa;
1049 	struct in6_addr *in6;
1050 	static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1051 
1052 	TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
1053 
1054 		if (ifa->ifa_addr->sa_family != AF_INET6)
1055 			continue;
1056 
1057 		in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1058 		nd6_na_output(sc->sc_carpdev, &mcast, in6,
1059 		    ND_NA_FLAG_OVERRIDE, 1, NULL);
1060 		DELAY(1000);	/* XXX */
1061 	}
1062 }
1063 #endif /* INET6 */
1064 
1065 static int
1066 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
1067 {
1068 	struct carp_softc *vh;
1069 	struct ifaddr *ifa;
1070 	int count = 0;
1071 
1072 	CARP_LOCK_ASSERT(cif);
1073 
1074 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1075 		if ((type == CARP_COUNT_RUNNING &&
1076 		    (vh->sc_ac.ac_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1077 		    (IFF_UP|IFF_RUNNING)) ||
1078 		    (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
1079 			TAILQ_FOREACH(ifa, &vh->sc_ac.ac_if.if_addrlist,
1080 			    ifa_list) {
1081 				if (ifa->ifa_addr->sa_family == AF_INET &&
1082 				    ia->ia_addr.sin_addr.s_addr ==
1083 				    ifatoia(ifa)->ia_addr.sin_addr.s_addr)
1084 					count++;
1085 			}
1086 		}
1087 	}
1088 	return (count);
1089 }
1090 
1091 int
1092 carp_iamatch(void *v, struct in_ifaddr *ia,
1093     struct in_addr *isaddr, u_int8_t **enaddr)
1094 {
1095 	struct carp_if *cif = v;
1096 	struct carp_softc *vh;
1097 	int index, count = 0;
1098 	struct ifaddr *ifa;
1099 
1100 	CARP_LOCK(cif);
1101 
1102 	if (carp_opts[CARPCTL_ARPBALANCE]) {
1103 		/*
1104 		 * XXX proof of concept implementation.
1105 		 * We use the source ip to decide which virtual host should
1106 		 * handle the request. If we're master of that virtual host,
1107 		 * then we respond, otherwise, just drop the arp packet on
1108 		 * the floor.
1109 		 */
1110 		count = carp_addrcount(cif, ia, CARP_COUNT_RUNNING);
1111 		if (count == 0) {
1112 			/* should never reach this */
1113 			CARP_UNLOCK(cif);
1114 			return (0);
1115 		}
1116 
1117 		/* this should be a hash, like pf_hash() */
1118 		index = isaddr->s_addr % count;
1119 		count = 0;
1120 
1121 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1122 			if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1123 			    (IFF_UP|IFF_RUNNING)) {
1124 				TAILQ_FOREACH(ifa, &vh->sc_if.if_addrlist,
1125 				    ifa_list) {
1126 					if (ifa->ifa_addr->sa_family ==
1127 					    AF_INET &&
1128 					    ia->ia_addr.sin_addr.s_addr ==
1129 					    ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
1130 						if (count == index) {
1131 							if (vh->sc_state ==
1132 							    MASTER) {
1133 								*enaddr = vh->sc_ac.ac_enaddr;
1134 								CARP_UNLOCK(cif);
1135 								return (1);
1136 							} else {
1137 								CARP_UNLOCK(cif);
1138 								return (0);
1139 							}
1140 						}
1141 						count++;
1142 					}
1143 				}
1144 			}
1145 		}
1146 	} else {
1147 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1148 			if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1149 			    (IFF_UP|IFF_RUNNING) && ia->ia_ifp ==
1150 			    &vh->sc_if) {
1151 				*enaddr = vh->sc_ac.ac_enaddr;
1152 				CARP_UNLOCK(cif);
1153 				return (1);
1154 			}
1155 		}
1156 	}
1157 	CARP_UNLOCK(cif);
1158 	return (0);
1159 }
1160 
1161 #ifdef INET6
1162 struct ifaddr *
1163 carp_iamatch6(void *v, struct in6_addr *taddr)
1164 {
1165 	struct carp_if *cif = v;
1166 	struct carp_softc *vh;
1167 	struct ifaddr *ifa;
1168 
1169 	CARP_LOCK(cif);
1170 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1171 		TAILQ_FOREACH(ifa, &vh->sc_if.if_addrlist, ifa_list) {
1172 			if (IN6_ARE_ADDR_EQUAL(taddr,
1173 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1174  			    ((vh->sc_if.if_flags &
1175 			    (IFF_UP|IFF_RUNNING)) == (IFF_UP|IFF_RUNNING))) {
1176 			    	CARP_UNLOCK(cif);
1177 				return (ifa);
1178 			}
1179 		}
1180 	}
1181 	CARP_UNLOCK(cif);
1182 
1183 	return (NULL);
1184 }
1185 
1186 void *
1187 carp_macmatch6(void *v, struct mbuf *m, const struct in6_addr *taddr)
1188 {
1189 	struct m_tag *mtag;
1190 	struct carp_if *cif = v;
1191 	struct carp_softc *sc;
1192 	struct ifaddr *ifa;
1193 
1194 	CARP_LOCK(cif);
1195 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
1196 		TAILQ_FOREACH(ifa, &sc->sc_if.if_addrlist, ifa_list) {
1197 			if (IN6_ARE_ADDR_EQUAL(taddr,
1198 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1199  			    ((sc->sc_if.if_flags &
1200 			    (IFF_UP|IFF_RUNNING)) == (IFF_UP|IFF_RUNNING))) {
1201 				struct ifnet *ifp = &sc->sc_if;
1202 				mtag = m_tag_get(PACKET_TAG_CARP,
1203 				    sizeof(struct ifnet *), M_NOWAIT);
1204 				if (mtag == NULL) {
1205 					/* better a bit than nothing */
1206 					CARP_UNLOCK(cif);
1207 					return (sc->sc_ac.ac_enaddr);
1208 				}
1209 				bcopy(&ifp, (caddr_t)(mtag + 1),
1210 				    sizeof(struct ifnet *));
1211 				m_tag_prepend(m, mtag);
1212 
1213 				CARP_UNLOCK(cif);
1214 				return (sc->sc_ac.ac_enaddr);
1215 			}
1216 		}
1217 	}
1218 	CARP_UNLOCK(cif);
1219 
1220 	return (NULL);
1221 }
1222 #endif
1223 
1224 struct ifnet *
1225 carp_forus(void *v, void *dhost)
1226 {
1227 	struct carp_if *cif = v;
1228 	struct carp_softc *vh;
1229 	u_int8_t *ena = dhost;
1230 
1231 	if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1232 		return (NULL);
1233 
1234 	CARP_LOCK(cif);
1235 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
1236 		if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1237 		    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER &&
1238 		    !bcmp(dhost, vh->sc_ac.ac_enaddr, ETHER_ADDR_LEN)) {
1239 		    	CARP_UNLOCK(cif);
1240 			return (&vh->sc_if);
1241 		}
1242 
1243     	CARP_UNLOCK(cif);
1244 	return (NULL);
1245 }
1246 
1247 static void
1248 carp_master_down(void *v)
1249 {
1250 	struct carp_softc *sc = v;
1251 
1252 	CARP_SCLOCK(sc);
1253 	carp_master_down_locked(sc);
1254 	CARP_SCUNLOCK(sc);
1255 }
1256 
1257 static void
1258 carp_master_down_locked(struct carp_softc *sc)
1259 {
1260 	if (sc->sc_carpdev)
1261 		CARP_SCLOCK_ASSERT(sc);
1262 
1263 	switch (sc->sc_state) {
1264 	case INIT:
1265 		printf("%s: master_down event in INIT state\n",
1266 		    sc->sc_if.if_xname);
1267 		break;
1268 	case MASTER:
1269 		break;
1270 	case BACKUP:
1271 		carp_set_state(sc, MASTER);
1272 		carp_send_ad_locked(sc);
1273 		carp_send_arp(sc);
1274 #ifdef INET6
1275 		carp_send_na(sc);
1276 #endif /* INET6 */
1277 		carp_setrun(sc, 0);
1278 		carp_setroute(sc, RTM_ADD);
1279 		break;
1280 	}
1281 }
1282 
1283 /*
1284  * When in backup state, af indicates whether to reset the master down timer
1285  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1286  */
1287 static void
1288 carp_setrun(struct carp_softc *sc, sa_family_t af)
1289 {
1290 	struct timeval tv;
1291 
1292 	if (sc->sc_carpdev)
1293 		CARP_SCLOCK_ASSERT(sc);
1294 
1295 	if (sc->sc_if.if_flags & IFF_UP &&
1296 	    sc->sc_vhid > 0 && (sc->sc_naddrs || sc->sc_naddrs6))
1297 		sc->sc_if.if_flags |= IFF_RUNNING;
1298 	else {
1299 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1300 		carp_setroute(sc, RTM_DELETE);
1301 		return;
1302 	}
1303 
1304 	switch (sc->sc_state) {
1305 	case INIT:
1306 		if (carp_opts[CARPCTL_PREEMPT] && !carp_suppress_preempt) {
1307 			carp_send_ad_locked(sc);
1308 			carp_send_arp(sc);
1309 #ifdef INET6
1310 			carp_send_na(sc);
1311 #endif /* INET6 */
1312 			CARP_DEBUG("%s: INIT -> MASTER (preempting)\n",
1313 			    sc->sc_if.if_xname);
1314 			carp_set_state(sc, MASTER);
1315 			carp_setroute(sc, RTM_ADD);
1316 		} else {
1317 			CARP_DEBUG("%s: INIT -> BACKUP\n", sc->sc_if.if_xname);
1318 			carp_set_state(sc, BACKUP);
1319 			carp_setroute(sc, RTM_DELETE);
1320 			carp_setrun(sc, 0);
1321 		}
1322 		break;
1323 	case BACKUP:
1324 		callout_stop(&sc->sc_ad_tmo);
1325 		tv.tv_sec = 3 * sc->sc_advbase;
1326 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1327 		switch (af) {
1328 #ifdef INET
1329 		case AF_INET:
1330 			callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1331 			    carp_master_down, sc);
1332 			break;
1333 #endif /* INET */
1334 #ifdef INET6
1335 		case AF_INET6:
1336 			callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1337 			    carp_master_down, sc);
1338 			break;
1339 #endif /* INET6 */
1340 		default:
1341 			if (sc->sc_naddrs)
1342 				callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1343 				    carp_master_down, sc);
1344 			if (sc->sc_naddrs6)
1345 				callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1346 				    carp_master_down, sc);
1347 			break;
1348 		}
1349 		break;
1350 	case MASTER:
1351 		tv.tv_sec = sc->sc_advbase;
1352 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1353 		callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1354 		    carp_send_ad, sc);
1355 		break;
1356 	}
1357 }
1358 
1359 static int
1360 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1361 {
1362 	struct ifnet *ifp;
1363 	struct carp_if *cif;
1364 	struct in_ifaddr *ia, *ia_if;
1365 	struct ip_moptions *imo = &sc->sc_imo;
1366 	struct in_addr addr;
1367 	u_long iaddr = htonl(sin->sin_addr.s_addr);
1368 	int own, error;
1369 
1370 	if (sin->sin_addr.s_addr == 0) {
1371 		if (!(sc->sc_if.if_flags & IFF_UP))
1372 			carp_set_state(sc, INIT);
1373 		if (sc->sc_naddrs)
1374 			sc->sc_if.if_flags |= IFF_UP;
1375 		carp_setrun(sc, 0);
1376 		return (0);
1377 	}
1378 
1379 	/* we have to do it by hands to check we won't match on us */
1380 	ia_if = NULL; own = 0;
1381 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) {
1382 		/* and, yeah, we need a multicast-capable iface too */
1383 		if (ia->ia_ifp != &sc->sc_if &&
1384 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1385 		    (iaddr & ia->ia_subnetmask) == ia->ia_subnet) {
1386 			if (!ia_if)
1387 				ia_if = ia;
1388 			if (sin->sin_addr.s_addr ==
1389 			    ia->ia_addr.sin_addr.s_addr)
1390 				own++;
1391 		}
1392 	}
1393 
1394 	if (!ia_if)
1395 		return (EADDRNOTAVAIL);
1396 
1397 	ia = ia_if;
1398 	ifp = ia->ia_ifp;
1399 
1400 	if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
1401 	    (imo->imo_multicast_ifp && imo->imo_multicast_ifp != ifp))
1402 		return (EADDRNOTAVAIL);
1403 
1404 	if (imo->imo_num_memberships == 0) {
1405 		addr.s_addr = htonl(INADDR_CARP_GROUP);
1406 		if ((imo->imo_membership[0] = in_addmulti(&addr, ifp)) == NULL)
1407 			return (ENOBUFS);
1408 		imo->imo_num_memberships++;
1409 		imo->imo_multicast_ifp = ifp;
1410 		imo->imo_multicast_ttl = CARP_DFLTTL;
1411 		imo->imo_multicast_loop = 0;
1412 	}
1413 
1414 	if (!ifp->if_carp) {
1415 
1416 		MALLOC(cif, struct carp_if *, sizeof(*cif), M_CARP,
1417 		    M_WAITOK|M_ZERO);
1418 		if (!cif) {
1419 			error = ENOBUFS;
1420 			goto cleanup;
1421 		}
1422 		if ((error = ifpromisc(ifp, 1))) {
1423 			FREE(cif, M_CARP);
1424 			goto cleanup;
1425 		}
1426 
1427 		CARP_LOCK_INIT(cif);
1428 		CARP_LOCK(cif);
1429 		cif->vhif_ifp = ifp;
1430 		TAILQ_INIT(&cif->vhif_vrs);
1431 		callout_init(&cif->cif_tmo, NET_CALLOUT_MPSAFE);
1432 		ifp->if_carp = cif;
1433 
1434 	} else {
1435 		struct carp_softc *vr;
1436 
1437 		cif = (struct carp_if *)ifp->if_carp;
1438 		CARP_LOCK(cif);
1439 		TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1440 			if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
1441 				CARP_UNLOCK(cif);
1442 				error = EINVAL;
1443 				goto cleanup;
1444 			}
1445 	}
1446 	sc->sc_ia = ia;
1447 	sc->sc_carpdev = ifp;
1448 
1449 	{ /* XXX prevent endless loop if already in queue */
1450 	struct carp_softc *vr, *after = NULL;
1451 	int myself = 0;
1452 	cif = (struct carp_if *)ifp->if_carp;
1453 
1454 	/* XXX: cif should not change, right? So we still hold the lock */
1455 	CARP_LOCK_ASSERT(cif);
1456 
1457 	TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1458 		if (vr == sc)
1459 			myself = 1;
1460 		if (vr->sc_vhid < sc->sc_vhid)
1461 			after = vr;
1462 	}
1463 
1464 	if (!myself) {
1465 		/* We're trying to keep things in order */
1466 		if (after == NULL) {
1467 			TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1468 		} else {
1469 			TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
1470 		}
1471 		cif->vhif_nvrs++;
1472 	}
1473 	}
1474 
1475 	sc->sc_naddrs++;
1476 	sc->sc_if.if_flags |= IFF_UP;
1477 	if (own)
1478 		sc->sc_advskew = 0;
1479 	carp_sc_state_locked(sc);
1480 	carp_setrun(sc, 0);
1481 
1482 	CARP_UNLOCK(cif);
1483 
1484 	return (0);
1485 
1486 cleanup:
1487 	in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
1488 	return (error);
1489 }
1490 
1491 static int
1492 carp_del_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1493 {
1494 	int error = 0;
1495 
1496 	if (!--sc->sc_naddrs) {
1497 		struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1498 		struct ip_moptions *imo = &sc->sc_imo;
1499 
1500 		CARP_LOCK(cif);
1501 		callout_stop(&sc->sc_ad_tmo);
1502 		sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
1503 		sc->sc_vhid = -1;
1504 		in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
1505 		imo->imo_multicast_ifp = NULL;
1506 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
1507 		if (!--cif->vhif_nvrs) {
1508 			callout_drain(&cif->cif_tmo);
1509 			sc->sc_carpdev->if_carp = NULL;
1510 			CARP_LOCK_DESTROY(cif);
1511 			FREE(cif, M_IFADDR);
1512 		} else {
1513 			CARP_UNLOCK(cif);
1514 		}
1515 	}
1516 
1517 	return (error);
1518 }
1519 
1520 #ifdef INET6
1521 static int
1522 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1523 {
1524 	struct ifnet *ifp;
1525 	struct carp_if *cif;
1526 	struct in6_ifaddr *ia, *ia_if;
1527 	struct ip6_moptions *im6o = &sc->sc_im6o;
1528 	struct in6_multi_mship *imm;
1529 	struct sockaddr_in6 addr;
1530 	int own, error;
1531 
1532 	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1533 		if (!(sc->sc_if.if_flags & IFF_UP))
1534 			carp_set_state(sc, INIT);
1535 		if (sc->sc_naddrs6)
1536 			sc->sc_if.if_flags |= IFF_UP;
1537 		carp_setrun(sc, 0);
1538 		return (0);
1539 	}
1540 
1541 	/* we have to do it by hands to check we won't match on us */
1542 	ia_if = NULL; own = 0;
1543 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1544 		int i;
1545 
1546 		for (i = 0; i < 4; i++) {
1547 			if ((sin6->sin6_addr.s6_addr32[i] &
1548 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1549 			    (ia->ia_addr.sin6_addr.s6_addr32[i] &
1550 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1551 				break;
1552 		}
1553 		/* and, yeah, we need a multicast-capable iface too */
1554 		if (ia->ia_ifp != &sc->sc_ac.ac_if &&
1555 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1556 		    (i == 4)) {
1557 			if (!ia_if)
1558 				ia_if = ia;
1559 			if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr,
1560 			    &ia->ia_addr.sin6_addr))
1561 				own++;
1562 		}
1563 	}
1564 
1565 	if (!ia_if)
1566 		return (EADDRNOTAVAIL);
1567 	ia = ia_if;
1568 	ifp = ia->ia_ifp;
1569 
1570 	if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
1571 	    (im6o->im6o_multicast_ifp && im6o->im6o_multicast_ifp != ifp))
1572 		return (EADDRNOTAVAIL);
1573 
1574 	if (!sc->sc_naddrs6) {
1575 		im6o->im6o_multicast_ifp = ifp;
1576 
1577 		/* join CARP multicast address */
1578 		bzero(&addr, sizeof(addr));
1579 		addr.sin6_family = AF_INET6;
1580 		addr.sin6_len = sizeof(addr);
1581 		addr.sin6_addr.s6_addr16[0] = htons(0xff02);
1582 		addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
1583 		addr.sin6_addr.s6_addr8[15] = 0x12;
1584 		if ((imm = in6_joingroup(ifp, &addr.sin6_addr, &error)) == NULL)
1585 			goto cleanup;
1586 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
1587 
1588 		/* join solicited multicast address */
1589 		bzero(&addr.sin6_addr, sizeof(addr.sin6_addr));
1590 		addr.sin6_addr.s6_addr16[0] = htons(0xff02);
1591 		addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
1592 		addr.sin6_addr.s6_addr32[1] = 0;
1593 		addr.sin6_addr.s6_addr32[2] = htonl(1);
1594 		addr.sin6_addr.s6_addr32[3] = sin6->sin6_addr.s6_addr32[3];
1595 		addr.sin6_addr.s6_addr8[12] = 0xff;
1596 		if ((imm = in6_joingroup(ifp, &addr.sin6_addr, &error)) == NULL)
1597 			goto cleanup;
1598 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
1599 	}
1600 
1601 	if (!ifp->if_carp) {
1602 		MALLOC(cif, struct carp_if *, sizeof(*cif), M_CARP,
1603 		    M_WAITOK|M_ZERO);
1604 		if (!cif) {
1605 			error = ENOBUFS;
1606 			goto cleanup;
1607 		}
1608 		if ((error = ifpromisc(ifp, 1))) {
1609 			FREE(cif, M_CARP);
1610 			goto cleanup;
1611 		}
1612 
1613 		CARP_LOCK_INIT(cif);
1614 		CARP_LOCK(cif);
1615 		cif->vhif_ifp = ifp;
1616 		TAILQ_INIT(&cif->vhif_vrs);
1617 		callout_init(&cif->cif_tmo, NET_CALLOUT_MPSAFE);
1618 		ifp->if_carp = cif;
1619 
1620 	} else {
1621 		struct carp_softc *vr;
1622 
1623 		cif = (struct carp_if *)ifp->if_carp;
1624 		CARP_LOCK(cif);
1625 		TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1626 			if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
1627 				CARP_UNLOCK(cif);
1628 				error = EINVAL;
1629 				goto cleanup;
1630 			}
1631 	}
1632 	sc->sc_ia6 = ia;
1633 	sc->sc_carpdev = ifp;
1634 
1635 	{ /* XXX prevent endless loop if already in queue */
1636 	struct carp_softc *vr, *after = NULL;
1637 	int myself = 0;
1638 	cif = (struct carp_if *)ifp->if_carp;
1639 	CARP_LOCK_ASSERT(cif);
1640 
1641 	TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1642 		if (vr == sc)
1643 			myself = 1;
1644 		if (vr->sc_vhid < sc->sc_vhid)
1645 			after = vr;
1646 	}
1647 
1648 	if (!myself) {
1649 		/* We're trying to keep things in order */
1650 		if (after == NULL) {
1651 			TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1652 		} else {
1653 			TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
1654 		}
1655 		cif->vhif_nvrs++;
1656 	}
1657 	}
1658 
1659 	sc->sc_naddrs6++;
1660 	sc->sc_ac.ac_if.if_flags |= IFF_UP;
1661 	if (own)
1662 		sc->sc_advskew = 0;
1663 	carp_sc_state_locked(sc);
1664 	carp_setrun(sc, 0);
1665 
1666 	CARP_UNLOCK(cif);
1667 
1668 	return (0);
1669 
1670 cleanup:
1671 	/* clean up multicast memberships */
1672 	if (!sc->sc_naddrs6) {
1673 		while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1674 			imm = LIST_FIRST(&im6o->im6o_memberships);
1675 			LIST_REMOVE(imm, i6mm_chain);
1676 			in6_leavegroup(imm);
1677 		}
1678 	}
1679 	return (error);
1680 }
1681 
1682 static int
1683 carp_del_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1684 {
1685 	int error = 0;
1686 
1687 	if (!--sc->sc_naddrs6) {
1688 		struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1689 		struct ip6_moptions *im6o = &sc->sc_im6o;
1690 
1691 		CARP_LOCK(cif);
1692 		callout_stop(&sc->sc_ad_tmo);
1693 		sc->sc_ac.ac_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
1694 		sc->sc_vhid = -1;
1695 		while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1696 			struct in6_multi_mship *imm =
1697 			    LIST_FIRST(&im6o->im6o_memberships);
1698 
1699 			LIST_REMOVE(imm, i6mm_chain);
1700 			in6_leavegroup(imm);
1701 		}
1702 		im6o->im6o_multicast_ifp = NULL;
1703 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
1704 		if (!--cif->vhif_nvrs) {
1705 			callout_drain(&cif->cif_tmo);
1706 			CARP_LOCK_DESTROY(cif);
1707 			sc->sc_carpdev->if_carp = NULL;
1708 			FREE(cif, M_IFADDR);
1709 		} else
1710 			CARP_UNLOCK(cif);
1711 	}
1712 
1713 	return (error);
1714 }
1715 #endif /* INET6 */
1716 
1717 static int
1718 carp_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
1719 {
1720 	struct carp_softc *sc = ifp->if_softc, *vr;
1721 	struct carpreq carpr;
1722 	struct ifaddr *ifa;
1723 	struct ifreq *ifr;
1724 	struct ifaliasreq *ifra;
1725 	int locked = 0, error = 0;
1726 
1727 	ifa = (struct ifaddr *)addr;
1728 	ifra = (struct ifaliasreq *)addr;
1729 	ifr = (struct ifreq *)addr;
1730 
1731 	switch (cmd) {
1732 	case SIOCSIFADDR:
1733 		switch (ifa->ifa_addr->sa_family) {
1734 #ifdef INET
1735 		case AF_INET:
1736 			sc->sc_if.if_flags |= IFF_UP;
1737 			bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1738 			    sizeof(struct sockaddr));
1739 			error = carp_set_addr(sc, satosin(ifa->ifa_addr));
1740 			break;
1741 #endif /* INET */
1742 #ifdef INET6
1743 		case AF_INET6:
1744 			sc->sc_if.if_flags |= IFF_UP;
1745 			error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1746 			break;
1747 #endif /* INET6 */
1748 		default:
1749 			error = EAFNOSUPPORT;
1750 			break;
1751 		}
1752 		break;
1753 
1754 	case SIOCAIFADDR:
1755 		switch (ifa->ifa_addr->sa_family) {
1756 #ifdef INET
1757 		case AF_INET:
1758 			sc->sc_if.if_flags |= IFF_UP;
1759 			bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1760 			    sizeof(struct sockaddr));
1761 			error = carp_set_addr(sc, satosin(&ifra->ifra_addr));
1762 			break;
1763 #endif /* INET */
1764 #ifdef INET6
1765 		case AF_INET6:
1766 			sc->sc_if.if_flags |= IFF_UP;
1767 			error = carp_set_addr6(sc, satosin6(&ifra->ifra_addr));
1768 			break;
1769 #endif /* INET6 */
1770 		default:
1771 			error = EAFNOSUPPORT;
1772 			break;
1773 		}
1774 		break;
1775 
1776 	case SIOCDIFADDR:
1777 		switch (ifa->ifa_addr->sa_family) {
1778 #ifdef INET
1779 		case AF_INET:
1780 			error = carp_del_addr(sc, satosin(&ifra->ifra_addr));
1781 			break;
1782 #endif /* INET */
1783 #ifdef INET6
1784 		case AF_INET6:
1785 			error = carp_del_addr6(sc, satosin6(&ifra->ifra_addr));
1786 			break;
1787 #endif /* INET6 */
1788 		default:
1789 			error = EAFNOSUPPORT;
1790 			break;
1791 		}
1792 		break;
1793 
1794 	case SIOCSIFFLAGS:
1795 		if (sc->sc_carpdev) {
1796 			locked = 1;
1797 			CARP_SCLOCK(sc);
1798 		}
1799 		if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
1800  			callout_stop(&sc->sc_ad_tmo);
1801  			callout_stop(&sc->sc_md_tmo);
1802  			callout_stop(&sc->sc_md6_tmo);
1803 			if (sc->sc_state == MASTER)
1804 				carp_send_ad_locked(sc);
1805 			carp_set_state(sc, INIT);
1806 			carp_setrun(sc, 0);
1807 		} else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
1808 			sc->sc_if.if_flags |= IFF_UP;
1809 			carp_setrun(sc, 0);
1810 		}
1811 		break;
1812 
1813 	case SIOCSVH:
1814 		if ((error = suser(curthread)) != 0)
1815 			break;
1816 		if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
1817 			break;
1818 		error = 1;
1819 		if (sc->sc_carpdev) {
1820 			locked = 1;
1821 			CARP_SCLOCK(sc);
1822 		}
1823 		if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
1824 			switch (carpr.carpr_state) {
1825 			case BACKUP:
1826 				callout_stop(&sc->sc_ad_tmo);
1827 				carp_set_state(sc, BACKUP);
1828 				carp_setrun(sc, 0);
1829 				carp_setroute(sc, RTM_DELETE);
1830 				break;
1831 			case MASTER:
1832 				carp_master_down_locked(sc);
1833 				break;
1834 			default:
1835 				break;
1836 			}
1837 		}
1838 		if (carpr.carpr_vhid > 0) {
1839 			if (carpr.carpr_vhid > 255) {
1840 				error = EINVAL;
1841 				break;
1842 			}
1843 			if (sc->sc_carpdev) {
1844 				struct carp_if *cif;
1845 				cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1846 				TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1847 					if (vr != sc &&
1848 					    vr->sc_vhid == carpr.carpr_vhid)
1849 						return EEXIST;
1850 			}
1851 			sc->sc_vhid = carpr.carpr_vhid;
1852 			sc->sc_ac.ac_enaddr[0] = 0;
1853 			sc->sc_ac.ac_enaddr[1] = 0;
1854 			sc->sc_ac.ac_enaddr[2] = 0x5e;
1855 			sc->sc_ac.ac_enaddr[3] = 0;
1856 			sc->sc_ac.ac_enaddr[4] = 1;
1857 			sc->sc_ac.ac_enaddr[5] = sc->sc_vhid;
1858 			error--;
1859 		}
1860 		if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
1861 			if (carpr.carpr_advskew >= 255) {
1862 				error = EINVAL;
1863 				break;
1864 			}
1865 			if (carpr.carpr_advbase > 255) {
1866 				error = EINVAL;
1867 				break;
1868 			}
1869 			sc->sc_advbase = carpr.carpr_advbase;
1870 			sc->sc_advskew = carpr.carpr_advskew;
1871 			error--;
1872 		}
1873 		bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1874 		if (error > 0)
1875 			error = EINVAL;
1876 		else {
1877 			error = 0;
1878 			carp_setrun(sc, 0);
1879 		}
1880 		break;
1881 
1882 	case SIOCGVH:
1883 		/* XXX: lockless read */
1884 		bzero(&carpr, sizeof(carpr));
1885 		carpr.carpr_state = sc->sc_state;
1886 		carpr.carpr_vhid = sc->sc_vhid;
1887 		carpr.carpr_advbase = sc->sc_advbase;
1888 		carpr.carpr_advskew = sc->sc_advskew;
1889 		if (suser(curthread) == 0)
1890 			bcopy(sc->sc_key, carpr.carpr_key,
1891 			    sizeof(carpr.carpr_key));
1892 		error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
1893 		break;
1894 
1895 	default:
1896 		error = EINVAL;
1897 	}
1898 
1899 	if (locked)
1900 		CARP_SCUNLOCK(sc);
1901 
1902 	carp_hmac_prepare(sc);
1903 
1904 	return (error);
1905 }
1906 
1907 /*
1908  * XXX: this is looutput. We should eventually use it from there.
1909  */
1910 static int
1911 carp_looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
1912     struct rtentry *rt)
1913 {
1914 	M_ASSERTPKTHDR(m); /* check if we have the packet header */
1915 
1916 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
1917 		m_freem(m);
1918 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
1919 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
1920 	}
1921 
1922 	ifp->if_opackets++;
1923 	ifp->if_obytes += m->m_pkthdr.len;
1924 #if 1	/* XXX */
1925 	switch (dst->sa_family) {
1926 	case AF_INET:
1927 	case AF_INET6:
1928 	case AF_IPX:
1929 	case AF_APPLETALK:
1930 		break;
1931 	default:
1932 		printf("carp_looutput: af=%d unexpected\n", dst->sa_family);
1933 		m_freem(m);
1934 		return (EAFNOSUPPORT);
1935 	}
1936 #endif
1937 	return(if_simloop(ifp, m, dst->sa_family, 0));
1938 }
1939 
1940 /*
1941  * Start output on carp interface. This function should never be called.
1942  */
1943 static void
1944 carp_start(struct ifnet *ifp)
1945 {
1946 #ifdef DEBUG
1947 	printf("%s: start called\n", ifp->if_xname);
1948 #endif
1949 }
1950 
1951 int
1952 carp_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
1953     struct rtentry *rt)
1954 {
1955 	struct m_tag *mtag;
1956 	struct carp_softc *sc;
1957 	struct ifnet *carp_ifp;
1958 
1959 	if (!sa)
1960 		return (0);
1961 
1962 	switch (sa->sa_family) {
1963 #ifdef INET
1964 	case AF_INET:
1965 		break;
1966 #endif /* INET */
1967 #ifdef INET6
1968 	case AF_INET6:
1969 		break;
1970 #endif /* INET6 */
1971 	default:
1972 		return (0);
1973 	}
1974 
1975 	mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
1976 	if (mtag == NULL)
1977 		return (0);
1978 
1979 	bcopy(mtag + 1, &carp_ifp, sizeof(struct ifnet *));
1980 	sc = carp_ifp->if_softc;
1981 
1982 	/* Set the source MAC address to Virtual Router MAC Address */
1983 	switch (ifp->if_type) {
1984 	case IFT_ETHER:
1985 	case IFT_L2VLAN: {
1986 			struct ether_header *eh;
1987 
1988 			eh = mtod(m, struct ether_header *);
1989 			eh->ether_shost[0] = 0;
1990 			eh->ether_shost[1] = 0;
1991 			eh->ether_shost[2] = 0x5e;
1992 			eh->ether_shost[3] = 0;
1993 			eh->ether_shost[4] = 1;
1994 			eh->ether_shost[5] = sc->sc_vhid;
1995 		}
1996 		break;
1997 	case IFT_FDDI: {
1998 			struct fddi_header *fh;
1999 
2000 			fh = mtod(m, struct fddi_header *);
2001 			fh->fddi_shost[0] = 0;
2002 			fh->fddi_shost[1] = 0;
2003 			fh->fddi_shost[2] = 0x5e;
2004 			fh->fddi_shost[3] = 0;
2005 			fh->fddi_shost[4] = 1;
2006 			fh->fddi_shost[5] = sc->sc_vhid;
2007 		}
2008 		break;
2009 	case IFT_ISO88025: {
2010  			struct iso88025_header *th;
2011  			th = mtod(m, struct iso88025_header *);
2012 			th->iso88025_shost[0] = 3;
2013 			th->iso88025_shost[1] = 0;
2014 			th->iso88025_shost[2] = 0x40 >> (sc->sc_vhid - 1);
2015 			th->iso88025_shost[3] = 0x40000 >> (sc->sc_vhid - 1);
2016 			th->iso88025_shost[4] = 0;
2017 			th->iso88025_shost[5] = 0;
2018 		}
2019 		break;
2020 	default:
2021 		printf("%s: carp is not supported for this interface type\n",
2022 		    ifp->if_xname);
2023 		return (EOPNOTSUPP);
2024 	}
2025 
2026 	return (0);
2027 }
2028 
2029 static void
2030 carp_set_state(struct carp_softc *sc, int state)
2031 {
2032 
2033 	if (sc->sc_carpdev)
2034 		CARP_SCLOCK_ASSERT(sc);
2035 
2036 	if (sc->sc_state == state)
2037 		return;
2038 
2039 	sc->sc_state = state;
2040 	switch (state) {
2041 	case BACKUP:
2042 		sc->sc_ac.ac_if.if_link_state = LINK_STATE_DOWN;
2043 		break;
2044 	case MASTER:
2045 		sc->sc_ac.ac_if.if_link_state = LINK_STATE_UP;
2046 		break;
2047 	default:
2048 		sc->sc_ac.ac_if.if_link_state = LINK_STATE_UNKNOWN;
2049 		break;
2050 	}
2051 	rt_ifmsg(&sc->sc_ac.ac_if);
2052 }
2053 
2054 void
2055 carp_carpdev_state(void *v)
2056 {
2057 	struct carp_if *cif = v;
2058 
2059 	/*
2060 	 * We came here from interrupt handler of network
2061 	 * card. To avoid multiple LORs, we will queue function
2062 	 * for later.
2063 	 */
2064 
2065 	callout_reset(&cif->cif_tmo, 1, carp_carpdev_state1, v);
2066 }
2067 
2068 void
2069 carp_carpdev_state1(void *v)
2070 {
2071 	struct carp_if *cif = v;
2072 
2073 	CARP_LOCK(cif);
2074 	carp_carpdev_state_locked(cif);
2075 	CARP_UNLOCK(cif);
2076 }
2077 
2078 static void
2079 carp_carpdev_state_locked(struct carp_if *cif)
2080 {
2081 	struct carp_softc *sc;
2082 
2083 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list)
2084 		carp_sc_state_locked(sc);
2085 }
2086 
2087 static void
2088 carp_sc_state_locked(struct carp_softc *sc)
2089 {
2090 	CARP_SCLOCK_ASSERT(sc);
2091 
2092 	if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
2093 	    !(sc->sc_carpdev->if_flags & IFF_UP)) {
2094 		sc->sc_flags_backup = sc->sc_if.if_flags;
2095 		sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
2096 		callout_stop(&sc->sc_ad_tmo);
2097 		callout_stop(&sc->sc_md_tmo);
2098 		callout_stop(&sc->sc_md6_tmo);
2099 		carp_set_state(sc, INIT);
2100 		carp_setrun(sc, 0);
2101 		if (!sc->sc_suppress) {
2102 			carp_suppress_preempt++;
2103 			if (carp_suppress_preempt == 1) {
2104 				CARP_SCUNLOCK(sc);
2105 				carp_send_ad_all();
2106 				CARP_SCLOCK(sc);
2107 			}
2108 		}
2109 		sc->sc_suppress = 1;
2110 	} else {
2111 		sc->sc_if.if_flags |= sc->sc_flags_backup;
2112 		carp_set_state(sc, INIT);
2113 		carp_setrun(sc, 0);
2114 		if (sc->sc_suppress)
2115 			carp_suppress_preempt--;
2116 		sc->sc_suppress = 0;
2117 	}
2118 
2119 	return;
2120 }
2121 
2122 static int
2123 carp_modevent(module_t mod, int type, void *data)
2124 {
2125 	int error = 0;
2126 
2127 	switch (type) {
2128 	case MOD_LOAD:
2129 		mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
2130 		LIST_INIT(&carpif_list);
2131 		if_clone_attach(&carp_cloner);
2132 		break;
2133 
2134 	case MOD_UNLOAD:
2135 		if_clone_detach(&carp_cloner);
2136 		while (!LIST_EMPTY(&carpif_list))
2137 			carp_clone_destroy(&LIST_FIRST(&carpif_list)->sc_if);
2138 		mtx_destroy(&carp_mtx);
2139 		break;
2140 
2141 	default:
2142 		error = EINVAL;
2143 		break;
2144 	}
2145 
2146 	return error;
2147 }
2148 
2149 static moduledata_t carp_mod = {
2150 	"carp",
2151 	carp_modevent,
2152 	0
2153 };
2154 
2155 DECLARE_MODULE(carp, carp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2156