xref: /dragonfly/sys/netinet/ip_carp.c (revision bc3d4063)
1 /*
2  * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
3  * Copyright (c) 2003 Ryan McBride. All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
18  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
20  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
23  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
24  * THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 /*
27  * $FreeBSD: src/sys/netinet/ip_carp.c,v 1.48 2007/02/02 09:39:09 glebius Exp $
28  * $DragonFly: src/sys/netinet/ip_carp.c,v 1.10 2008/07/27 10:06:57 sephe Exp $
29  */
30 
31 #include "opt_carp.h"
32 /*#include "opt_bpf.h"*/
33 #include "opt_inet.h"
34 #include "opt_inet6.h"
35 
36 #include <sys/types.h>
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/conf.h>
40 #include <sys/kernel.h>
41 #include <machine/limits.h>
42 #include <sys/malloc.h>
43 #include <sys/mbuf.h>
44 #include <sys/module.h>
45 #include <sys/time.h>
46 #include <sys/proc.h>
47 #include <sys/sysctl.h>
48 #include <sys/syslog.h>
49 #include <sys/signalvar.h>
50 #include <sys/filio.h>
51 #include <sys/sockio.h>
52 #include <sys/in_cksum.h>
53 #include <sys/socket.h>
54 #include <sys/vnode.h>
55 
56 #include <machine/stdarg.h>
57 
58 #include <net/bpf.h>
59 #include <net/ethernet.h>
60 #include <net/if.h>
61 #include <net/if_dl.h>
62 #include <net/if_types.h>
63 #include <net/route.h>
64 #include <net/if_clone.h>
65 
66 #ifdef INET
67 #include <netinet/in.h>
68 #include <netinet/in_var.h>
69 #include <netinet/in_systm.h>
70 #include <netinet/ip.h>
71 #include <netinet/ip_var.h>
72 #include <netinet/if_ether.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/scope6_var.h>
80 #include <netinet6/nd6.h>
81 #endif
82 
83 #include <crypto/sha1.h>
84 #include <netinet/ip_carp.h>
85 #include <sys/lock.h>
86 
87 #define	CARP_IFNAME	"carp"
88 static MALLOC_DEFINE(M_CARP, "CARP", "CARP interfaces");
89 static MALLOC_DEFINE(M_IFNET, "IFNET", "IFNET CARP?");
90 SYSCTL_DECL(_net_inet_carp);
91 
92 struct carp_softc {
93 	struct ifnet	 	*sc_ifp;	/* Interface clue */
94 	struct ifnet		*sc_carpdev;	/* Pointer to parent interface */
95 	struct in_ifaddr 	*sc_ia;		/* primary iface address */
96 	struct ip_moptions 	 sc_imo;
97 #ifdef INET6
98 	struct in6_ifaddr 	*sc_ia6;	/* primary iface address v6 */
99 	struct ip6_moptions 	 sc_im6o;
100 #endif /* INET6 */
101 	TAILQ_ENTRY(carp_softc)	 sc_list;
102 
103 	enum { INIT = 0, BACKUP, MASTER }	sc_state;
104 
105 	int			 sc_flags_backup;
106 	int			 sc_suppress;
107 
108 	int			 sc_sendad_errors;
109 #define	CARP_SENDAD_MAX_ERRORS	3
110 	int			 sc_sendad_success;
111 #define	CARP_SENDAD_MIN_SUCCESS 3
112 
113 	int			 sc_vhid;
114 	int			 sc_advskew;
115 	int			 sc_naddrs;
116 	int			 sc_naddrs6;
117 	int			 sc_advbase;	/* seconds */
118 	int			 sc_init_counter;
119 	u_int64_t		 sc_counter;
120 
121 	/* authentication */
122 #define CARP_HMAC_PAD	64
123 	unsigned char sc_key[CARP_KEY_LEN];
124 	unsigned char sc_pad[CARP_HMAC_PAD];
125 	SHA1_CTX sc_sha1;
126 
127 	struct callout		 sc_ad_tmo;	/* advertisement timeout */
128 	struct callout		 sc_md_tmo;	/* master down timeout */
129 	struct callout 		 sc_md6_tmo;	/* master down timeout */
130 
131 	LIST_ENTRY(carp_softc)	 sc_next;	/* Interface clue */
132 };
133 #define	SC2IFP(sc)	((sc)->sc_ifp)
134 
135 int carp_suppress_preempt = 0;
136 int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 1, 0, 0 };	/* XXX for now */
137 SYSCTL_INT(_net_inet_carp, CARPCTL_ALLOW, allow, CTLFLAG_RW,
138     &carp_opts[CARPCTL_ALLOW], 0, "Accept incoming CARP packets");
139 SYSCTL_INT(_net_inet_carp, CARPCTL_PREEMPT, preempt, CTLFLAG_RW,
140     &carp_opts[CARPCTL_PREEMPT], 0, "high-priority backup preemption mode");
141 SYSCTL_INT(_net_inet_carp, CARPCTL_LOG, log, CTLFLAG_RW,
142     &carp_opts[CARPCTL_LOG], 0, "log bad carp packets");
143 SYSCTL_INT(_net_inet_carp, CARPCTL_ARPBALANCE, arpbalance, CTLFLAG_RW,
144     &carp_opts[CARPCTL_ARPBALANCE], 0, "balance arp responses");
145 SYSCTL_INT(_net_inet_carp, OID_AUTO, suppress_preempt, CTLFLAG_RD,
146     &carp_suppress_preempt, 0, "Preemption is suppressed");
147 
148 struct carpstats carpstats;
149 SYSCTL_STRUCT(_net_inet_carp, CARPCTL_STATS, stats, CTLFLAG_RW,
150     &carpstats, carpstats,
151     "CARP statistics (struct carpstats, netinet/ip_carp.h)");
152 
153 struct carp_if {
154 	TAILQ_HEAD(, carp_softc) vhif_vrs;
155 	int vhif_nvrs;
156 
157 	struct ifnet 	*vhif_ifp;
158 	struct lock	vhif_lock;
159 };
160 
161 /* Get carp_if from softc. Valid after carp_set_addr{,6}. */
162 #define	SC2CIF(sc)		((struct carp_if *)(sc)->sc_carpdev->if_carp)
163 
164 #define	CARP_LOCK_INIT(cif)	lockinit(&(cif)->vhif_lock, "carp_if", 0, 0);
165 #define	CARP_LOCK_DESTROY(cif)	;
166 #define	CARP_LOCK_ASSERT(cif)	;
167 #define	CARP_LOCK(cif)		lockmgr(&(cif)->vhif_lock, LK_EXCLUSIVE);
168 #define	CARP_UNLOCK(cif)	lockmgr(&(cif)->vhif_lock, LK_RELEASE);
169 
170 #define	CARP_SCLOCK(sc)		lockmgr(&SC2CIF(sc)->vhif_lock, LK_EXCLUSIVE);
171 #define	CARP_SCUNLOCK(sc)	lockmgr(&SC2CIF(sc)->vhif_lock, LK_RELEASE);
172 #define	CARP_SCLOCK_ASSERT(sc)	;
173 
174 #define	CARP_LOG(...)	do {				\
175 	if (carp_opts[CARPCTL_LOG] > 0)			\
176 		log(LOG_INFO, __VA_ARGS__);		\
177 } while (0)
178 
179 #define	CARP_DEBUG(...)	do {				\
180 	if (carp_opts[CARPCTL_LOG] > 1)			\
181 		log(LOG_DEBUG, __VA_ARGS__);		\
182 } while (0)
183 
184 static void	carp_hmac_prepare(struct carp_softc *);
185 static void	carp_hmac_generate(struct carp_softc *, u_int32_t *,
186 		    unsigned char *);
187 static int	carp_hmac_verify(struct carp_softc *, u_int32_t *,
188 		    unsigned char *);
189 static void	carp_setroute(struct carp_softc *, int);
190 static void	carp_input_c(struct mbuf *, struct carp_header *, sa_family_t);
191 static int 	carp_clone_create(struct if_clone *, int);
192 static void 	carp_clone_destroy(struct ifnet *);
193 static void	carpdetach(struct carp_softc *, int);
194 static int	carp_prepare_ad(struct mbuf *, struct carp_softc *,
195 		    struct carp_header *);
196 static void	carp_send_ad_all(void);
197 static void	carp_send_ad(void *);
198 static void	carp_send_ad_locked(struct carp_softc *);
199 static void	carp_send_arp(struct carp_softc *);
200 static void	carp_master_down(void *);
201 static void	carp_master_down_locked(struct carp_softc *);
202 static int	carp_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
203 static int	carp_looutput(struct ifnet *, struct mbuf *, struct sockaddr *,
204 		    struct rtentry *);
205 static void	carp_start(struct ifnet *);
206 static void	carp_setrun(struct carp_softc *, sa_family_t);
207 static void	carp_set_state(struct carp_softc *, int);
208 static int	carp_addrcount(struct carp_if *, struct in_ifaddr *, int);
209 enum	{ CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
210 
211 static void	carp_multicast_cleanup(struct carp_softc *);
212 static int	carp_set_addr(struct carp_softc *, struct sockaddr_in *);
213 static int	carp_del_addr(struct carp_softc *, struct sockaddr_in *);
214 static void	carp_carpdev_state_locked(struct carp_if *);
215 static void	carp_sc_state_locked(struct carp_softc *);
216 #ifdef INET6
217 static void	carp_send_na(struct carp_softc *);
218 static int	carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
219 static int	carp_del_addr6(struct carp_softc *, struct sockaddr_in6 *);
220 static void	carp_multicast6_cleanup(struct carp_softc *);
221 #endif
222 
223 static LIST_HEAD(, carp_softc) carpif_list;
224 
225 struct if_clone carp_cloner = IF_CLONE_INITIALIZER(CARP_IFNAME, carp_clone_create, carp_clone_destroy, 0, IF_MAXUNIT);
226 
227 static eventhandler_tag if_detach_event_tag;
228 
229 static __inline u_int16_t
230 carp_cksum(struct mbuf *m, int len)
231 {
232 	return (in_cksum(m, len));
233 }
234 
235 static void
236 carp_hmac_prepare(struct carp_softc *sc)
237 {
238 	u_int8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
239 	u_int8_t vhid = sc->sc_vhid & 0xff;
240 	struct ifaddr_container *ifac;
241 	int i;
242 #ifdef INET6
243 	struct in6_addr in6;
244 #endif
245 
246 	if (sc->sc_carpdev)
247 		CARP_SCLOCK(sc);
248 
249 	/* XXX: possible race here */
250 
251 	/* compute ipad from key */
252 	bzero(sc->sc_pad, sizeof(sc->sc_pad));
253 	bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
254 	for (i = 0; i < sizeof(sc->sc_pad); i++)
255 		sc->sc_pad[i] ^= 0x36;
256 
257 	/* precompute first part of inner hash */
258 	SHA1Init(&sc->sc_sha1);
259 	SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
260 	SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
261 	SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
262 	SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
263 #ifdef INET
264 	TAILQ_FOREACH(ifac, &SC2IFP(sc)->if_addrheads[mycpuid], ifa_link) {
265 		struct ifaddr *ifa = ifac->ifa;
266 
267 		if (ifa->ifa_addr->sa_family == AF_INET)
268 			SHA1Update(&sc->sc_sha1,
269 			    (void *)&ifatoia(ifa)->ia_addr.sin_addr.s_addr,
270 			    sizeof(struct in_addr));
271 	}
272 #endif /* INET */
273 #ifdef INET6
274 	TAILQ_FOREACH(ifac, &SC2IFP(sc)->if_addrheads[mycpuid], ifa_link) {
275 		struct ifaddr *ifa = ifac->ifa;
276 
277 		if (ifa->ifa_addr->sa_family == AF_INET6) {
278 			in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
279 			in6_clearscope(&in6);
280 			SHA1Update(&sc->sc_sha1, (void *)&in6, sizeof(in6));
281 		}
282 	}
283 #endif /* INET6 */
284 
285 	/* convert ipad to opad */
286 	for (i = 0; i < sizeof(sc->sc_pad); i++)
287 		sc->sc_pad[i] ^= 0x36 ^ 0x5c;
288 
289 	if (sc->sc_carpdev)
290 		CARP_SCUNLOCK(sc);
291 }
292 
293 static void
294 carp_hmac_generate(struct carp_softc *sc, u_int32_t counter[2],
295     unsigned char md[20])
296 {
297 	SHA1_CTX sha1ctx;
298 
299 	/* fetch first half of inner hash */
300 	bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
301 
302 	SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
303 	SHA1Final(md, &sha1ctx);
304 
305 	/* outer hash */
306 	SHA1Init(&sha1ctx);
307 	SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
308 	SHA1Update(&sha1ctx, md, 20);
309 	SHA1Final(md, &sha1ctx);
310 }
311 
312 static int
313 carp_hmac_verify(struct carp_softc *sc, u_int32_t counter[2],
314     unsigned char md[20])
315 {
316 	unsigned char md2[20];
317 
318 	CARP_SCLOCK_ASSERT(sc);
319 
320 	carp_hmac_generate(sc, counter, md2);
321 
322 	return (bcmp(md, md2, sizeof(md2)));
323 }
324 
325 static void
326 carp_setroute(struct carp_softc *sc, int cmd)
327 {
328 	struct ifaddr_container *ifac;
329 
330 	if (sc->sc_carpdev)
331 		CARP_SCLOCK_ASSERT(sc);
332 
333 	crit_enter();
334 	TAILQ_FOREACH(ifac, &SC2IFP(sc)->if_addrheads[mycpuid], ifa_link) {
335 		struct ifaddr *ifa = ifac->ifa;
336 
337 		if (ifa->ifa_addr->sa_family == AF_INET &&
338 		    sc->sc_carpdev != NULL) {
339 			int count = carp_addrcount(
340 			    (struct carp_if *)sc->sc_carpdev->if_carp,
341 			    ifatoia(ifa), CARP_COUNT_MASTER);
342 
343 			if ((cmd == RTM_ADD && count == 1) ||
344 			    (cmd == RTM_DELETE && count == 0))
345 				rtinit(ifa, cmd, RTF_UP | RTF_HOST);
346 		}
347 #ifdef INET6
348 		if (ifa->ifa_addr->sa_family == AF_INET6) {
349 			if (cmd == RTM_ADD)
350 				in6_ifaddloop(ifa);
351 			else
352 				in6_ifremloop(ifa);
353 		}
354 #endif /* INET6 */
355 	}
356 	crit_exit();
357 
358 }
359 
360 static int
361 carp_clone_create(struct if_clone *ifc, int unit)
362 {
363 
364 	struct carp_softc *sc;
365 	struct ifnet *ifp;
366 
367         MALLOC(sc, struct carp_softc *, sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
368 	ifp = SC2IFP(sc) = kmalloc(sizeof(struct ifnet), M_IFNET, M_WAITOK|M_ZERO);
369 
370 	sc->sc_flags_backup = 0;
371 	sc->sc_suppress = 0;
372 	sc->sc_advbase = CARP_DFLTINTV;
373 	sc->sc_vhid = -1;	/* required setting */
374 	sc->sc_advskew = 0;
375 	sc->sc_init_counter = 1;
376 	sc->sc_naddrs = sc->sc_naddrs6 = 0; /* M_ZERO? */
377 
378 #ifdef INET6
379 	sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
380 #endif
381 
382 /*	sc->sc_imo.imo_membership = kmalloc((sizeof(struct in_multi) * IP_MAX_MEMBERSHIPS), M_CARP,M_WAITOK);*/
383 /*
384 	sc->sc_imo.imo_max_memberships = IP_MAX_MEMBERSHIPS;
385 	sc->sc_imo.imo_multicast_vif = -1;
386 */
387 	callout_init(&sc->sc_ad_tmo);
388 	callout_init(&sc->sc_md_tmo);
389 	callout_init(&sc->sc_md6_tmo);
390 
391 	ifp->if_softc = sc;
392         if_initname(ifp, CARP_IFNAME, unit);
393 	ifp->if_mtu = ETHERMTU;
394 	ifp->if_flags = IFF_LOOPBACK;
395 	ifp->if_ioctl = carp_ioctl;
396 	ifp->if_output = carp_looutput;
397 	ifp->if_start = carp_start;
398 	ifp->if_type = IFT_CARP;
399 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
400 	ifp->if_hdrlen = 0;
401 	if_attach(ifp, NULL);
402 	bpfattach(ifp, DLT_NULL, sizeof(u_int));
403 
404 	crit_enter();
405 	LIST_INSERT_HEAD(&carpif_list, sc, sc_next);
406 	crit_exit();
407 
408 	return (0);
409 }
410 
411 static void
412 carp_clone_destroy(struct ifnet *ifp)
413 {
414 	struct carp_softc *sc = ifp->if_softc;
415 
416 	if (sc->sc_carpdev)
417 		CARP_SCLOCK(sc);
418 	carpdetach(sc, 1);	/* Returns unlocked. */
419 
420 	crit_enter();
421 	LIST_REMOVE(sc, sc_next);
422 	crit_exit();
423 	bpfdetach(ifp);
424 	if_detach(ifp);
425 /*	if_free_type(ifp, IFT_ETHER);*/
426 /*	kfree(sc->sc_imo.imo_membership, M_CARP); */
427 	kfree(sc, M_CARP);
428 }
429 
430 /*
431  * This function can be called on CARP interface destroy path,
432  * and in case of the removal of the underlying interface as
433  * well. We differentiate these two cases. In the latter case
434  * we do not cleanup our multicast memberships, since they
435  * are already freed. Also, in the latter case we do not
436  * release the lock on return, because the function will be
437  * called once more, for another CARP instance on the same
438  * interface.
439  */
440 static void
441 carpdetach(struct carp_softc *sc, int unlock)
442 {
443 	struct carp_if *cif;
444 
445 	callout_stop(&sc->sc_ad_tmo);
446 	callout_stop(&sc->sc_md_tmo);
447 	callout_stop(&sc->sc_md6_tmo);
448 
449 	if (sc->sc_suppress)
450 		carp_suppress_preempt--;
451 	sc->sc_suppress = 0;
452 
453 	if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
454 		carp_suppress_preempt--;
455 	sc->sc_sendad_errors = 0;
456 
457 	carp_set_state(sc, INIT);
458 	SC2IFP(sc)->if_flags &= ~IFF_UP;
459 	carp_setrun(sc, 0);
460 	if (unlock)
461 		carp_multicast_cleanup(sc);
462 #ifdef INET6
463 	carp_multicast6_cleanup(sc);
464 #endif
465 
466 	if (sc->sc_carpdev != NULL) {
467 		cif = (struct carp_if *)sc->sc_carpdev->if_carp;
468 		CARP_LOCK_ASSERT(cif);
469 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
470 		if (!--cif->vhif_nvrs) {
471 			ifpromisc(sc->sc_carpdev, 0);
472 			sc->sc_carpdev->if_carp = NULL;
473 			CARP_LOCK_DESTROY(cif);
474 			FREE(cif, M_IFADDR);
475 		} else if (unlock)
476 			CARP_UNLOCK(cif);
477 		sc->sc_carpdev = NULL;
478 	}
479 }
480 
481 /* Detach an interface from the carp. */
482 static void
483 carp_ifdetach(void *arg __unused, struct ifnet *ifp)
484 {
485 	struct carp_if *cif = (struct carp_if *)ifp->if_carp;
486 	struct carp_softc *sc, *nextsc;
487 
488 	if (cif == NULL)
489 		return;
490 
491 	/*
492 	 * XXX: At the end of for() cycle the lock will be destroyed.
493 	 */
494 	CARP_LOCK(cif);
495 	for (sc = TAILQ_FIRST(&cif->vhif_vrs); sc; sc = nextsc) {
496 		nextsc = TAILQ_NEXT(sc, sc_list);
497 		carpdetach(sc, 0);
498 	}
499 	CARP_UNLOCK(cif);
500 }
501 
502 /*
503  * process input packet.
504  * we have rearranged checks order compared to the rfc,
505  * but it seems more efficient this way or not possible otherwise.
506  */
507 void
508 carp_input(struct mbuf *m, int hlen)
509 {
510 	struct ip *ip = mtod(m, struct ip *);
511 	struct carp_header *ch;
512 	int iplen, len;
513 
514 	carpstats.carps_ipackets++;
515 
516 	if (!carp_opts[CARPCTL_ALLOW]) {
517 		m_freem(m);
518 		return;
519 	}
520 
521 	/* check if received on a valid carp interface */
522 	if (m->m_pkthdr.rcvif->if_carp == NULL) {
523 		carpstats.carps_badif++;
524 		CARP_LOG("carp_input: packet received on non-carp "
525 		    "interface: %s\n",
526 		    m->m_pkthdr.rcvif->if_xname);
527 		m_freem(m);
528 		return;
529 	}
530 
531 	/* verify that the IP TTL is 255.  */
532 	if (ip->ip_ttl != CARP_DFLTTL) {
533 		carpstats.carps_badttl++;
534 		CARP_LOG("carp_input: received ttl %d != 255i on %s\n",
535 		    ip->ip_ttl,
536 		    m->m_pkthdr.rcvif->if_xname);
537 		m_freem(m);
538 		return;
539 	}
540 
541 	iplen = ip->ip_hl << 2;
542 
543 	if (m->m_pkthdr.len < iplen + sizeof(*ch)) {
544 		carpstats.carps_badlen++;
545 		CARP_LOG("carp_input: received len %zd < "
546 		    "sizeof(struct carp_header)\n",
547 		    m->m_len - sizeof(struct ip));
548 		m_freem(m);
549 		return;
550 	}
551 
552 	if (iplen + sizeof(*ch) < m->m_len) {
553 		if ((m = m_pullup(m, iplen + sizeof(*ch))) == NULL) {
554 			carpstats.carps_hdrops++;
555 			CARP_LOG("carp_input: pullup failed\n");
556 			return;
557 		}
558 		ip = mtod(m, struct ip *);
559 	}
560 	ch = (struct carp_header *)((char *)ip + iplen);
561 
562 	/*
563 	 * verify that the received packet length is
564 	 * equal to the CARP header
565 	 */
566 	len = iplen + sizeof(*ch);
567 	if (len > m->m_pkthdr.len) {
568 		carpstats.carps_badlen++;
569 		CARP_LOG("carp_input: packet too short %d on %s\n",
570 		    m->m_pkthdr.len,
571 		    m->m_pkthdr.rcvif->if_xname);
572 		m_freem(m);
573 		return;
574 	}
575 
576 	if ((m = m_pullup(m, len)) == NULL) {
577 		carpstats.carps_hdrops++;
578 		return;
579 	}
580 	ip = mtod(m, struct ip *);
581 	ch = (struct carp_header *)((char *)ip + iplen);
582 
583 	/* verify the CARP checksum */
584 	m->m_data += iplen;
585 	if (carp_cksum(m, len - iplen)) {
586 		carpstats.carps_badsum++;
587 		CARP_LOG("carp_input: checksum failed on %s\n",
588 		    m->m_pkthdr.rcvif->if_xname);
589 		m_freem(m);
590 		return;
591 	}
592 	m->m_data -= iplen;
593 
594 	carp_input_c(m, ch, AF_INET);
595 }
596 
597 #ifdef INET6
598 int
599 carp6_input(struct mbuf **mp, int *offp, int proto)
600 {
601 	struct mbuf *m = *mp;
602 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
603 	struct carp_header *ch;
604 	u_int len;
605 
606 	carpstats.carps_ipackets6++;
607 
608 	if (!carp_opts[CARPCTL_ALLOW]) {
609 		m_freem(m);
610 		return (IPPROTO_DONE);
611 	}
612 
613 	/* check if received on a valid carp interface */
614 	if (m->m_pkthdr.rcvif->if_carp == NULL) {
615 		carpstats.carps_badif++;
616 		CARP_LOG("carp6_input: packet received on non-carp "
617 		    "interface: %s\n",
618 		    m->m_pkthdr.rcvif->if_xname);
619 		m_freem(m);
620 		return (IPPROTO_DONE);
621 	}
622 
623 	/* verify that the IP TTL is 255 */
624 	if (ip6->ip6_hlim != CARP_DFLTTL) {
625 		carpstats.carps_badttl++;
626 		CARP_LOG("carp6_input: received ttl %d != 255 on %s\n",
627 		    ip6->ip6_hlim,
628 		    m->m_pkthdr.rcvif->if_xname);
629 		m_freem(m);
630 		return (IPPROTO_DONE);
631 	}
632 
633 	/* verify that we have a complete carp packet */
634 	len = m->m_len;
635 	IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
636 	if (ch == NULL) {
637 		carpstats.carps_badlen++;
638 		CARP_LOG("carp6_input: packet size %u too small\n", len);
639 		return (IPPROTO_DONE);
640 	}
641 
642 
643 	/* verify the CARP checksum */
644 	m->m_data += *offp;
645 	if (carp_cksum(m, sizeof(*ch))) {
646 		carpstats.carps_badsum++;
647 		CARP_LOG("carp6_input: checksum failed, on %s\n",
648 		    m->m_pkthdr.rcvif->if_xname);
649 		m_freem(m);
650 		return (IPPROTO_DONE);
651 	}
652 	m->m_data -= *offp;
653 
654 	carp_input_c(m, ch, AF_INET6);
655 	return (IPPROTO_DONE);
656 }
657 #endif /* INET6 */
658 
659 static void
660 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
661 {
662 	struct ifnet *ifp = m->m_pkthdr.rcvif;
663 	struct carp_softc *sc;
664 	u_int64_t tmp_counter;
665 	struct timeval sc_tv, ch_tv;
666 
667 	/* verify that the VHID is valid on the receiving interface */
668 	CARP_LOCK(ifp->if_carp);
669 	TAILQ_FOREACH(sc, &((struct carp_if *)ifp->if_carp)->vhif_vrs, sc_list)
670 		if (sc->sc_vhid == ch->carp_vhid)
671 			break;
672 
673 	if (!sc || !((SC2IFP(sc)->if_flags & IFF_UP) && (SC2IFP(sc)->if_flags & IFF_RUNNING))) {
674 		carpstats.carps_badvhid++;
675 		CARP_UNLOCK(ifp->if_carp);
676 		m_freem(m);
677 		return;
678 	}
679 
680 	getmicrotime(&SC2IFP(sc)->if_lastchange);
681 	SC2IFP(sc)->if_ipackets++;
682 	SC2IFP(sc)->if_ibytes += m->m_pkthdr.len;
683 
684 	if (SC2IFP(sc)->if_bpf) {
685 		struct ip *ip = mtod(m, struct ip *);
686 
687 		/* BPF wants net byte order */
688 		ip->ip_len = htons(ip->ip_len + (ip->ip_hl << 2));
689 		ip->ip_off = htons(ip->ip_off);
690 		bpf_mtap(SC2IFP(sc)->if_bpf, m);
691 	}
692 
693 	/* verify the CARP version. */
694 	if (ch->carp_version != CARP_VERSION) {
695 		carpstats.carps_badver++;
696 		SC2IFP(sc)->if_ierrors++;
697 		CARP_UNLOCK(ifp->if_carp);
698 		CARP_LOG("%s; invalid version %d\n",
699 		    SC2IFP(sc)->if_xname,
700 		    ch->carp_version);
701 		m_freem(m);
702 		return;
703 	}
704 
705 	/* verify the hash */
706 	if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
707 		carpstats.carps_badauth++;
708 		SC2IFP(sc)->if_ierrors++;
709 		CARP_UNLOCK(ifp->if_carp);
710 		CARP_LOG("%s: incorrect hash\n", SC2IFP(sc)->if_xname);
711 		m_freem(m);
712 		return;
713 	}
714 
715 	tmp_counter = ntohl(ch->carp_counter[0]);
716 	tmp_counter = tmp_counter<<32;
717 	tmp_counter += ntohl(ch->carp_counter[1]);
718 
719 	/* XXX Replay protection goes here */
720 
721 	sc->sc_init_counter = 0;
722 	sc->sc_counter = tmp_counter;
723 
724 	sc_tv.tv_sec = sc->sc_advbase;
725 	if (carp_suppress_preempt && sc->sc_advskew <  240)
726 		sc_tv.tv_usec = 240 * 1000000 / 256;
727 	else
728 		sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
729 	ch_tv.tv_sec = ch->carp_advbase;
730 	ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
731 
732 	switch (sc->sc_state) {
733 	case INIT:
734 		break;
735 	case MASTER:
736 		/*
737 		 * If we receive an advertisement from a master who's going to
738 		 * be more frequent than us, go into BACKUP state.
739 		 */
740 		if (timevalcmp(&sc_tv, &ch_tv, >) ||
741 		    timevalcmp(&sc_tv, &ch_tv, ==)) {
742 			callout_stop(&sc->sc_ad_tmo);
743 			CARP_DEBUG("%s: MASTER -> BACKUP "
744 			   "(more frequent advertisement received)\n",
745 			   SC2IFP(sc)->if_xname);
746 			carp_set_state(sc, BACKUP);
747 			carp_setrun(sc, 0);
748 			carp_setroute(sc, RTM_DELETE);
749 		}
750 		break;
751 	case BACKUP:
752 		/*
753 		 * If we're pre-empting masters who advertise slower than us,
754 		 * and this one claims to be slower, treat him as down.
755 		 */
756 		if (carp_opts[CARPCTL_PREEMPT] &&
757 		    timevalcmp(&sc_tv, &ch_tv, <)) {
758 			CARP_DEBUG("%s: BACKUP -> MASTER "
759 			    "(preempting a slower master)\n",
760 			    SC2IFP(sc)->if_xname);
761 			carp_master_down_locked(sc);
762 			break;
763 		}
764 
765 		/*
766 		 *  If the master is going to advertise at such a low frequency
767 		 *  that he's guaranteed to time out, we'd might as well just
768 		 *  treat him as timed out now.
769 		 */
770 		sc_tv.tv_sec = sc->sc_advbase * 3;
771 		if (timevalcmp(&sc_tv, &ch_tv, <)) {
772 			CARP_DEBUG("%s: BACKUP -> MASTER "
773 			    "(master timed out)\n",
774 			    SC2IFP(sc)->if_xname);
775 			carp_master_down_locked(sc);
776 			break;
777 		}
778 
779 		/*
780 		 * Otherwise, we reset the counter and wait for the next
781 		 * advertisement.
782 		 */
783 		carp_setrun(sc, af);
784 		break;
785 	}
786 
787 	CARP_UNLOCK(ifp->if_carp);
788 
789 	m_freem(m);
790 	return;
791 }
792 
793 static int
794 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
795 {
796 	struct m_tag *mtag;
797 	struct ifnet *ifp = SC2IFP(sc);
798 
799 	if (sc->sc_init_counter) {
800 		/* this could also be seconds since unix epoch */
801 		sc->sc_counter = karc4random();
802 		sc->sc_counter = sc->sc_counter << 32;
803 		sc->sc_counter += karc4random();
804 	} else
805 		sc->sc_counter++;
806 
807 	ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
808 	ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
809 
810 	carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
811 
812 	/* Tag packet for carp_output */
813 	mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct ifnet *), MB_DONTWAIT);
814 	if (mtag == NULL) {
815 		m_freem(m);
816 		SC2IFP(sc)->if_oerrors++;
817 		return (ENOMEM);
818 	}
819 	bcopy(&ifp, (caddr_t)(mtag + 1), sizeof(struct ifnet *));
820 	m_tag_prepend(m, mtag);
821 
822 	return (0);
823 }
824 
825 static void
826 carp_send_ad_all(void)
827 {
828 	struct carp_softc *sc;
829 
830 	LIST_FOREACH(sc, &carpif_list, sc_next) {
831 		if (sc->sc_carpdev == NULL)
832 			continue;
833 		CARP_SCLOCK(sc);
834 		if ((SC2IFP(sc)->if_flags & IFF_UP) && (SC2IFP(sc)->if_flags & IFF_RUNNING) &&
835 		     sc->sc_state == MASTER)
836 			carp_send_ad_locked(sc);
837 		CARP_SCUNLOCK(sc);
838 	}
839 }
840 
841 static void
842 carp_send_ad(void *v)
843 {
844 	struct carp_softc *sc = v;
845 
846 	CARP_SCLOCK(sc);
847 	carp_send_ad_locked(sc);
848 	CARP_SCUNLOCK(sc);
849 }
850 
851 static void
852 carp_send_ad_locked(struct carp_softc *sc)
853 {
854 	struct carp_header ch;
855 	struct timeval tv;
856 	struct carp_header *ch_ptr;
857 	struct mbuf *m;
858 	int len, advbase, advskew;
859 
860 
861 	/* bow out if we've lost our UPness or RUNNINGuiness */
862 	if (!((SC2IFP(sc)->if_flags & IFF_UP) && (SC2IFP(sc)->if_flags & IFF_RUNNING))) {
863 		advbase = 255;
864 		advskew = 255;
865 	} else {
866 		advbase = sc->sc_advbase;
867 		if (!carp_suppress_preempt || sc->sc_advskew > 240)
868 			advskew = sc->sc_advskew;
869 		else
870 			advskew = 240;
871 		tv.tv_sec = advbase;
872 		tv.tv_usec = advskew * 1000000 / 256;
873 	}
874 
875 	ch.carp_version = CARP_VERSION;
876 	ch.carp_type = CARP_ADVERTISEMENT;
877 	ch.carp_vhid = sc->sc_vhid;
878 	ch.carp_advbase = advbase;
879 	ch.carp_advskew = advskew;
880 	ch.carp_authlen = 7;	/* XXX DEFINE */
881 	ch.carp_pad1 = 0;	/* must be zero */
882 	ch.carp_cksum = 0;
883 
884 #ifdef INET
885 	if (sc->sc_ia) {
886 		struct ip *ip;
887 
888 		MGETHDR(m, M_NOWAIT, MT_HEADER);
889 		if (m == NULL) {
890 			SC2IFP(sc)->if_oerrors++;
891 			carpstats.carps_onomem++;
892 			/* XXX maybe less ? */
893 			if (advbase != 255 || advskew != 255)
894 				callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
895 				    carp_send_ad, sc);
896 			return;
897 		}
898 		len = sizeof(*ip) + sizeof(ch);
899 		m->m_pkthdr.len = len;
900 		m->m_pkthdr.rcvif = NULL;
901 		m->m_len = len;
902 		MH_ALIGN(m, m->m_len);
903 		m->m_flags |= M_MCAST;
904 		ip = mtod(m, struct ip *);
905 		ip->ip_v = IPVERSION;
906 		ip->ip_hl = sizeof(*ip) >> 2;
907 		ip->ip_tos = IPTOS_LOWDELAY;
908 		ip->ip_len = len;
909 		ip->ip_id = ip_newid();
910 		ip->ip_off = IP_DF;
911 		ip->ip_ttl = CARP_DFLTTL;
912 		ip->ip_p = IPPROTO_CARP;
913 		ip->ip_sum = 0;
914 		ip->ip_src.s_addr = sc->sc_ia->ia_addr.sin_addr.s_addr;
915 		ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
916 
917 		ch_ptr = (struct carp_header *)(&ip[1]);
918 		bcopy(&ch, ch_ptr, sizeof(ch));
919 		if (carp_prepare_ad(m, sc, ch_ptr))
920 			return;
921 
922 		m->m_data += sizeof(*ip);
923 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
924 		m->m_data -= sizeof(*ip);
925 
926 		getmicrotime(&SC2IFP(sc)->if_lastchange);
927 		SC2IFP(sc)->if_opackets++;
928 		SC2IFP(sc)->if_obytes += len;
929 		carpstats.carps_opackets++;
930 
931 		if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL)) {
932 			SC2IFP(sc)->if_oerrors++;
933 			if (sc->sc_sendad_errors < INT_MAX)
934 				sc->sc_sendad_errors++;
935 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
936 				carp_suppress_preempt++;
937 				if (carp_suppress_preempt == 1) {
938 					CARP_SCUNLOCK(sc);
939 					carp_send_ad_all();
940 					CARP_SCLOCK(sc);
941 				}
942 			}
943 			sc->sc_sendad_success = 0;
944 		} else {
945 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
946 				if (++sc->sc_sendad_success >=
947 				    CARP_SENDAD_MIN_SUCCESS) {
948 					carp_suppress_preempt--;
949 					sc->sc_sendad_errors = 0;
950 				}
951 			} else
952 				sc->sc_sendad_errors = 0;
953 		}
954 	}
955 #endif /* INET */
956 #ifdef INET6
957 	if (sc->sc_ia6) {
958 		struct ip6_hdr *ip6;
959 
960 		MGETHDR(m, M_NOWAIT, MT_HEADER);
961 		if (m == NULL) {
962 			SC2IFP(sc)->if_oerrors++;
963 			carpstats.carps_onomem++;
964 			/* XXX maybe less ? */
965 			if (advbase != 255 || advskew != 255)
966 				callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
967 				    carp_send_ad, sc);
968 			return;
969 		}
970 		len = sizeof(*ip6) + sizeof(ch);
971 		m->m_pkthdr.len = len;
972 		m->m_pkthdr.rcvif = NULL;
973 		m->m_len = len;
974 		MH_ALIGN(m, m->m_len);
975 		m->m_flags |= M_MCAST;
976 		ip6 = mtod(m, struct ip6_hdr *);
977 		bzero(ip6, sizeof(*ip6));
978 		ip6->ip6_vfc |= IPV6_VERSION;
979 		ip6->ip6_hlim = CARP_DFLTTL;
980 		ip6->ip6_nxt = IPPROTO_CARP;
981 		bcopy(&sc->sc_ia6->ia_addr.sin6_addr, &ip6->ip6_src,
982 		    sizeof(struct in6_addr));
983 		/* set the multicast destination */
984 
985 		ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
986 		ip6->ip6_dst.s6_addr8[15] = 0x12;
987 		if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
988 			SC2IFP(sc)->if_oerrors++;
989 			m_freem(m);
990 			CARP_LOG("%s: in6_setscope failed\n", __func__);
991 			return;
992 		}
993 
994 		ch_ptr = (struct carp_header *)(&ip6[1]);
995 		bcopy(&ch, ch_ptr, sizeof(ch));
996 		if (carp_prepare_ad(m, sc, ch_ptr))
997 			return;
998 
999 		m->m_data += sizeof(*ip6);
1000 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
1001 		m->m_data -= sizeof(*ip6);
1002 
1003 		getmicrotime(&SC2IFP(sc)->if_lastchange);
1004 		SC2IFP(sc)->if_opackets++;
1005 		SC2IFP(sc)->if_obytes += len;
1006 		carpstats.carps_opackets6++;
1007 
1008 		if (ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL)) {
1009 			SC2IFP(sc)->if_oerrors++;
1010 			if (sc->sc_sendad_errors < INT_MAX)
1011 				sc->sc_sendad_errors++;
1012 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1013 				carp_suppress_preempt++;
1014 				if (carp_suppress_preempt == 1) {
1015 					CARP_SCUNLOCK(sc);
1016 					carp_send_ad_all();
1017 					CARP_SCLOCK(sc);
1018 				}
1019 			}
1020 			sc->sc_sendad_success = 0;
1021 		} else {
1022 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1023 				if (++sc->sc_sendad_success >=
1024 				    CARP_SENDAD_MIN_SUCCESS) {
1025 					carp_suppress_preempt--;
1026 					sc->sc_sendad_errors = 0;
1027 				}
1028 			} else
1029 				sc->sc_sendad_errors = 0;
1030 		}
1031 	}
1032 #endif /* INET6 */
1033 
1034 	if (advbase != 255 || advskew != 255)
1035 		callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
1036 		    carp_send_ad, sc);
1037 
1038 }
1039 
1040 /*
1041  * Broadcast a gratuitous ARP request containing
1042  * the virtual router MAC address for each IP address
1043  * associated with the virtual router.
1044  */
1045 static void
1046 carp_send_arp(struct carp_softc *sc)
1047 {
1048 	struct ifaddr_container *ifac;
1049 
1050 	TAILQ_FOREACH(ifac, &SC2IFP(sc)->if_addrheads[mycpuid], ifa_link) {
1051 		struct ifaddr *ifa = ifac->ifa;
1052 
1053 		if (ifa->ifa_addr->sa_family != AF_INET)
1054 			continue;
1055 	        arp_ifinit2(sc->sc_carpdev, ifa, IF_LLADDR(sc->sc_ifp));
1056 
1057 		DELAY(1000);	/* XXX */
1058 	}
1059 }
1060 
1061 #ifdef INET6
1062 static void
1063 carp_send_na(struct carp_softc *sc)
1064 {
1065 	struct ifaddr_container *ifac;
1066 	struct in6_addr *in6;
1067 	static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1068 
1069 	TAILQ_FOREACH(ifac, &SC2IFP(sc)->if_addrheads[mycpuid], ifa_link) {
1070 		struct ifaddr *ifa = ifac->ifa;
1071 
1072 		if (ifa->ifa_addr->sa_family != AF_INET6)
1073 			continue;
1074 
1075 		in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1076 		nd6_na_output(sc->sc_carpdev, &mcast, in6,
1077 		    ND_NA_FLAG_OVERRIDE, 1, NULL);
1078 		DELAY(1000);	/* XXX */
1079 	}
1080 }
1081 #endif /* INET6 */
1082 
1083 static int
1084 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
1085 {
1086 	struct carp_softc *vh;
1087 	int count = 0;
1088 
1089 	CARP_LOCK_ASSERT(cif);
1090 
1091 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1092 		if ((type == CARP_COUNT_RUNNING &&
1093 		    (SC2IFP(vh)->if_flags & IFF_UP) && (SC2IFP(vh)->if_flags & IFF_RUNNING)) ||
1094 		    (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
1095 			struct ifaddr_container *ifac;
1096 
1097 			TAILQ_FOREACH(ifac, &SC2IFP(vh)->if_addrheads[mycpuid],
1098 				      ifa_link) {
1099 				struct ifaddr *ifa = ifac->ifa;
1100 
1101 				if (ifa->ifa_addr->sa_family == AF_INET &&
1102 				    ia->ia_addr.sin_addr.s_addr ==
1103 				    ifatoia(ifa)->ia_addr.sin_addr.s_addr)
1104 					count++;
1105 			}
1106 		}
1107 	}
1108 	return (count);
1109 }
1110 
1111 int
1112 carp_iamatch(void *v, struct in_ifaddr *ia,
1113     struct in_addr *isaddr, u_int8_t **enaddr)
1114 {
1115 	struct carp_if *cif = v;
1116 	struct carp_softc *vh;
1117 	int index, count = 0;
1118 
1119 	CARP_LOCK(cif);
1120 
1121 	if (carp_opts[CARPCTL_ARPBALANCE]) {
1122 		/*
1123 		 * XXX proof of concept implementation.
1124 		 * We use the source ip to decide which virtual host should
1125 		 * handle the request. If we're master of that virtual host,
1126 		 * then we respond, otherwise, just drop the arp packet on
1127 		 * the floor.
1128 		 */
1129 		count = carp_addrcount(cif, ia, CARP_COUNT_RUNNING);
1130 		if (count == 0) {
1131 			/* should never reach this */
1132 			CARP_UNLOCK(cif);
1133 			return (0);
1134 		}
1135 
1136 		/* this should be a hash, like pf_hash() */
1137 		index = ntohl(isaddr->s_addr) % count;
1138 		count = 0;
1139 
1140 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1141 			if ((SC2IFP(vh)->if_flags & IFF_UP) && (SC2IFP(vh)->if_flags & IFF_RUNNING)) {
1142 				struct ifaddr_container *ifac;
1143 
1144 				TAILQ_FOREACH(ifac, &SC2IFP(vh)->if_addrheads[mycpuid], ifa_link) {
1145 					struct ifaddr *ifa = ifac->ifa;
1146 
1147 					if (ifa->ifa_addr->sa_family ==
1148 					    AF_INET &&
1149 					    ia->ia_addr.sin_addr.s_addr ==
1150 					    ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
1151 						if (count == index) {
1152 							if (vh->sc_state ==
1153 							    MASTER) {
1154 								*enaddr = IF_LLADDR(vh->sc_ifp);
1155 								CARP_UNLOCK(cif);
1156 								return (1);
1157 							} else {
1158 								CARP_UNLOCK(cif);
1159 								return (0);
1160 							}
1161 						}
1162 						count++;
1163 					}
1164 				}
1165 			}
1166 		}
1167 	} else {
1168 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1169 			if ((SC2IFP(vh)->if_flags & IFF_UP) && (SC2IFP(vh)->if_flags & IFF_RUNNING) &&
1170 			    vh->sc_state == MASTER) {
1171 				*enaddr = IF_LLADDR(vh->sc_ifp);
1172 				CARP_UNLOCK(cif);
1173 				return (1);
1174 			}
1175 		}
1176 	}
1177 	CARP_UNLOCK(cif);
1178 	return(0);
1179 }
1180 
1181 #ifdef INET6
1182 struct ifaddr *
1183 carp_iamatch6(void *v, struct in6_addr *taddr)
1184 {
1185 	struct carp_if *cif = v;
1186 	struct carp_softc *vh;
1187 
1188 	CARP_LOCK(cif);
1189 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1190 		struct ifaddr_container *ifac;
1191 
1192 		TAILQ_FOREACH(ifac, &SC2IFP(vh)->if_addrheads[mycpuid], ifa_link) {
1193 			struct ifaddr *ifa = ifac->ifa;
1194 
1195 			if (IN6_ARE_ADDR_EQUAL(taddr,
1196 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1197  			    (SC2IFP(vh)->if_flags & IFF_UP) && (SC2IFP(vh)->if_flags & IFF_RUNNING) &&
1198 			    vh->sc_state == MASTER) {
1199 			    	CARP_UNLOCK(cif);
1200 				return (ifa);
1201 			}
1202 		}
1203 	}
1204 	CARP_UNLOCK(cif);
1205 
1206 	return (NULL);
1207 }
1208 
1209 void *
1210 carp_macmatch6(void *v, struct mbuf *m, const struct in6_addr *taddr)
1211 {
1212 	struct m_tag *mtag;
1213 	struct carp_if *cif = v;
1214 	struct carp_softc *sc;
1215 
1216 	CARP_LOCK(cif);
1217 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
1218 		struct ifaddr_container *ifac;
1219 
1220 		TAILQ_FOREACH(ifac, &SC2IFP(sc)->if_addrheads[mycpuid], ifa_link) {
1221 			struct ifaddr *ifa = ifac->ifa;
1222 
1223 			if (IN6_ARE_ADDR_EQUAL(taddr,
1224 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1225  			    (SC2IFP(sc)->if_flags & IFF_UP) && (SC2IFP(sc)->if_flags & IFF_RUNNING)) {
1226 				struct ifnet *ifp = SC2IFP(sc);
1227 				mtag = m_tag_get(PACKET_TAG_CARP,
1228 				    sizeof(struct ifnet *), MB_DONTWAIT);
1229 				if (mtag == NULL) {
1230 					/* better a bit than nothing */
1231 					CARP_UNLOCK(cif);
1232 					return (IF_LLADDR(sc->sc_ifp));
1233 				}
1234 				bcopy(&ifp, (caddr_t)(mtag + 1),
1235 				    sizeof(struct ifnet *));
1236 				m_tag_prepend(m, mtag);
1237 
1238 				CARP_UNLOCK(cif);
1239 				return (IF_LLADDR(sc->sc_ifp));
1240 			}
1241 		}
1242 	}
1243 	CARP_UNLOCK(cif);
1244 
1245 	return (NULL);
1246 }
1247 #endif
1248 
1249 struct ifnet *
1250 carp_forus(void *v, void *dhost)
1251 {
1252 	struct carp_if *cif = v;
1253 	struct carp_softc *vh;
1254 	u_int8_t *ena = dhost;
1255 
1256 	/**
1257          * XXX: See here for check on MAC adr is not for virtual use
1258          *
1259          **/
1260 
1261 	if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1262 	{
1263 		return (NULL);
1264 	}
1265 
1266 	CARP_LOCK(cif);
1267 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
1268 		if ((SC2IFP(vh)->if_flags & IFF_UP) && (SC2IFP(vh)->if_flags & IFF_RUNNING) &&
1269 		    vh->sc_state == MASTER &&
1270 		    !bcmp(dhost, IF_LLADDR(vh->sc_ifp), ETHER_ADDR_LEN)) {
1271 		    	CARP_UNLOCK(cif);
1272 			return (SC2IFP(vh));
1273 		}
1274 
1275     	CARP_UNLOCK(cif);
1276 	return (NULL);
1277 }
1278 
1279 static void
1280 carp_master_down(void *v)
1281 {
1282 	struct carp_softc *sc = v;
1283 
1284 	lwkt_serialize_enter(sc->sc_ifp->if_serializer);
1285 	carp_master_down_locked(sc);
1286 	lwkt_serialize_exit(sc->sc_ifp->if_serializer);
1287 }
1288 
1289 static void
1290 carp_master_down_locked(struct carp_softc *sc)
1291 {
1292 	if (sc->sc_carpdev)
1293 		CARP_SCLOCK_ASSERT(sc);
1294 
1295 	switch (sc->sc_state) {
1296 	case INIT:
1297 		kprintf("%s: master_down event in INIT state\n",
1298 		    SC2IFP(sc)->if_xname);
1299 		break;
1300 	case MASTER:
1301 		break;
1302 	case BACKUP:
1303 		carp_set_state(sc, MASTER);
1304 		carp_send_ad_locked(sc);
1305 		carp_send_arp(sc);
1306 #ifdef INET6
1307 		carp_send_na(sc);
1308 #endif /* INET6 */
1309 		carp_setrun(sc, 0);
1310 		carp_setroute(sc, RTM_ADD);
1311 		break;
1312 	}
1313 }
1314 
1315 /*
1316  * When in backup state, af indicates whether to reset the master down timer
1317  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1318  */
1319 static void
1320 carp_setrun(struct carp_softc *sc, sa_family_t af)
1321 {
1322 	struct timeval tv;
1323 
1324 	if (sc->sc_carpdev == NULL) {
1325 		SC2IFP(sc)->if_flags &= ~IFF_RUNNING;
1326 		carp_set_state(sc, INIT);
1327 		return;
1328 	}
1329 
1330 	if (SC2IFP(sc)->if_flags & IFF_UP &&
1331 	    sc->sc_vhid > 0 && (sc->sc_naddrs || sc->sc_naddrs6))
1332 		SC2IFP(sc)->if_flags |= IFF_RUNNING;
1333 	else {
1334 		SC2IFP(sc)->if_flags &= ~IFF_RUNNING;
1335 		carp_setroute(sc, RTM_DELETE);
1336 		return;
1337 	}
1338 
1339 	switch (sc->sc_state) {
1340 	case INIT:
1341 		if (carp_opts[CARPCTL_PREEMPT] && !carp_suppress_preempt) {
1342 			carp_send_ad_locked(sc);
1343 			carp_send_arp(sc);
1344 #ifdef INET6
1345 			carp_send_na(sc);
1346 #endif /* INET6 */
1347 			CARP_DEBUG("%s: INIT -> MASTER (preempting)\n",
1348 			    SC2IFP(sc)->if_xname);
1349 			carp_set_state(sc, MASTER);
1350 			carp_setroute(sc, RTM_ADD);
1351 		} else {
1352 			CARP_DEBUG("%s: INIT -> BACKUP\n", SC2IFP(sc)->if_xname);
1353 			carp_set_state(sc, BACKUP);
1354 			carp_setroute(sc, RTM_DELETE);
1355 			carp_setrun(sc, 0);
1356 		}
1357 		break;
1358 	case BACKUP:
1359 		callout_stop(&sc->sc_ad_tmo);
1360 		tv.tv_sec = 3 * sc->sc_advbase;
1361 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1362 		switch (af) {
1363 #ifdef INET
1364 		case AF_INET:
1365 			callout_reset(&sc->sc_md_tmo, tvtohz_high(&tv),
1366 			    carp_master_down, sc);
1367 			break;
1368 #endif /* INET */
1369 #ifdef INET6
1370 		case AF_INET6:
1371 			callout_reset(&sc->sc_md6_tmo, tvtohz_high(&tv),
1372 			    carp_master_down, sc);
1373 			break;
1374 #endif /* INET6 */
1375 		default:
1376 			if (sc->sc_naddrs)
1377 				callout_reset(&sc->sc_md_tmo, tvtohz_high(&tv),
1378 				    carp_master_down, sc);
1379 			if (sc->sc_naddrs6)
1380 				callout_reset(&sc->sc_md6_tmo, tvtohz_high(&tv),
1381 				    carp_master_down, sc);
1382 			break;
1383 		}
1384 		break;
1385 	case MASTER:
1386 		tv.tv_sec = sc->sc_advbase;
1387 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1388 		callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
1389 		    carp_send_ad, sc);
1390 		break;
1391 	}
1392 }
1393 
1394 static void
1395 carp_multicast_cleanup(struct carp_softc *sc)
1396 {
1397 	struct ip_moptions *imo = &sc->sc_imo;
1398 	u_int16_t n = imo->imo_num_memberships;
1399 
1400 	/* Clean up our own multicast memberships */
1401 	while (n-- > 0) {
1402 		if (imo->imo_membership[n] != NULL) {
1403 			in_delmulti(imo->imo_membership[n]);
1404 			imo->imo_membership[n] = NULL;
1405 		}
1406 	}
1407 	imo->imo_num_memberships = 0;
1408 	imo->imo_multicast_ifp = NULL;
1409 }
1410 
1411 #ifdef INET6
1412 static void
1413 carp_multicast6_cleanup(struct carp_softc *sc)
1414 {
1415 	struct ip6_moptions *im6o = &sc->sc_im6o;
1416 
1417 	while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1418 		struct in6_multi_mship *imm =
1419 		    LIST_FIRST(&im6o->im6o_memberships);
1420 
1421 		LIST_REMOVE(imm, i6mm_chain);
1422 		in6_leavegroup(imm);
1423 	}
1424 	im6o->im6o_multicast_ifp = NULL;
1425 }
1426 #endif
1427 
1428 static int
1429 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1430 {
1431 	struct ifnet *ifp;
1432 	struct carp_if *cif;
1433 	struct in_ifaddr *ia, *ia_if;
1434 	struct in_ifaddr_container *iac;
1435 	struct ip_moptions *imo = &sc->sc_imo;
1436 	struct in_addr addr;
1437 	u_long iaddr = htonl(sin->sin_addr.s_addr);
1438 	int own, error;
1439 
1440 	if (sin->sin_addr.s_addr == 0)
1441 	{
1442 		if (!(SC2IFP(sc)->if_flags & IFF_UP))
1443 		{
1444 			carp_set_state(sc, INIT);
1445 		}
1446 		if (sc->sc_naddrs)
1447 		{
1448 			SC2IFP(sc)->if_flags |= IFF_UP;
1449 		}
1450 		carp_setrun(sc, 0);
1451 		return (0);
1452 	}
1453 	/* we have to do it by hands to check we won't match on us */
1454 	ia_if = NULL; own = 0;
1455 	TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
1456 		ia = iac->ia;
1457 
1458 		/* and, yeah, we need a multicast-capable iface too */
1459 		if (ia->ia_ifp != SC2IFP(sc) &&
1460 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1461 		    (iaddr & ia->ia_subnetmask) == ia->ia_subnet) {
1462 			if (!ia_if)
1463 				ia_if = ia;
1464 			if (sin->sin_addr.s_addr ==
1465 			    ia->ia_addr.sin_addr.s_addr)
1466 				own++;
1467 		}
1468 	}
1469 
1470 
1471 	if (!ia_if)
1472 		return (EADDRNOTAVAIL);
1473 
1474 	ia = ia_if;
1475 	ifp = ia->ia_ifp;
1476 
1477 	if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
1478 	    (imo->imo_multicast_ifp && imo->imo_multicast_ifp != ifp))
1479 		return (EADDRNOTAVAIL);
1480 
1481 	if (imo->imo_num_memberships == 0) {
1482 		addr.s_addr = htonl(INADDR_CARP_GROUP);
1483 		if ((imo->imo_membership[0] = in_addmulti(&addr, ifp)) == NULL)
1484 			return (ENOBUFS);
1485 		imo->imo_num_memberships++;
1486 		imo->imo_multicast_ifp = ifp;
1487 		imo->imo_multicast_ttl = CARP_DFLTTL;
1488 		imo->imo_multicast_loop = 0;
1489 	}
1490 
1491 	if (!ifp->if_carp) {
1492 
1493 		MALLOC(cif, struct carp_if *, sizeof(*cif), M_CARP,
1494 		    M_WAITOK|M_ZERO);
1495 		if ((error = ifpromisc(ifp, 1))) {
1496 			FREE(cif, M_CARP);
1497 			goto cleanup;
1498 		}
1499 
1500 		CARP_LOCK_INIT(cif);
1501 		CARP_LOCK(cif);
1502 		cif->vhif_ifp = ifp;
1503 		TAILQ_INIT(&cif->vhif_vrs);
1504 		ifp->if_carp = cif;
1505 
1506 	} else {
1507 		struct carp_softc *vr;
1508 
1509 		cif = (struct carp_if *)ifp->if_carp;
1510 		CARP_LOCK(cif);
1511 		TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1512 			if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
1513 				CARP_UNLOCK(cif);
1514 				error = EINVAL;
1515 				goto cleanup;
1516 			}
1517 	}
1518 	sc->sc_ia = ia;
1519 	sc->sc_carpdev = ifp;
1520 
1521 	{ /* XXX prevent endless loop if already in queue */
1522 	struct carp_softc *vr, *after = NULL;
1523 	int myself = 0;
1524 	cif = (struct carp_if *)ifp->if_carp;
1525 
1526 	/* XXX: cif should not change, right? So we still hold the lock */
1527 	CARP_LOCK_ASSERT(cif);
1528 
1529 	TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1530 		if (vr == sc)
1531 			myself = 1;
1532 		if (vr->sc_vhid < sc->sc_vhid)
1533 			after = vr;
1534 	}
1535 
1536 	if (!myself) {
1537 		/* We're trying to keep things in order */
1538 		if (after == NULL) {
1539 			TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1540 		} else {
1541 			TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
1542 		}
1543 		cif->vhif_nvrs++;
1544 	}
1545 	}
1546 
1547 	sc->sc_naddrs++;
1548 	SC2IFP(sc)->if_flags |= IFF_UP;
1549 	if (own)
1550 		sc->sc_advskew = 0;
1551 
1552 
1553 	carp_sc_state_locked(sc);
1554 	carp_setrun(sc, 0);
1555 
1556 	CARP_UNLOCK(cif);
1557 
1558 	return (0);
1559 
1560 cleanup:
1561 	in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
1562 	return (error);
1563 
1564 }
1565 
1566 static int
1567 carp_del_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1568 {
1569 	int error = 0;
1570 
1571 	if (!--sc->sc_naddrs) {
1572 		struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1573 		struct ip_moptions *imo = &sc->sc_imo;
1574 
1575 		CARP_LOCK(cif);
1576 		callout_stop(&sc->sc_ad_tmo);
1577 		SC2IFP(sc)->if_flags &= ~IFF_UP;
1578 		SC2IFP(sc)->if_flags &= ~IFF_RUNNING;
1579 		sc->sc_vhid = -1;
1580 		in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
1581 		imo->imo_multicast_ifp = NULL;
1582 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
1583 		if (!--cif->vhif_nvrs) {
1584 			sc->sc_carpdev->if_carp = NULL;
1585 			CARP_LOCK_DESTROY(cif);
1586 			FREE(cif, M_IFADDR);
1587 		} else {
1588 			CARP_UNLOCK(cif);
1589 		}
1590 	}
1591 
1592 	return (error);
1593 }
1594 
1595 #ifdef INET6
1596 static int
1597 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1598 {
1599 	struct ifnet *ifp;
1600 	struct carp_if *cif;
1601 	struct in6_ifaddr *ia, *ia_if;
1602 	struct ip6_moptions *im6o = &sc->sc_im6o;
1603 	struct in6_multi_mship *imm;
1604 	struct in6_addr in6;
1605 	int own, error;
1606 
1607 	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1608 		if (!(SC2IFP(sc)->if_flags & IFF_UP))
1609 			carp_set_state(sc, INIT);
1610 		if (sc->sc_naddrs6)
1611 			SC2IFP(sc)->if_flags |= IFF_UP;
1612 		carp_setrun(sc, 0);
1613 		return (0);
1614 	}
1615 
1616 	/* we have to do it by hands to check we won't match on us */
1617 	ia_if = NULL; own = 0;
1618 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1619 		int i;
1620 
1621 		for (i = 0; i < 4; i++) {
1622 			if ((sin6->sin6_addr.s6_addr32[i] &
1623 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1624 			    (ia->ia_addr.sin6_addr.s6_addr32[i] &
1625 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1626 				break;
1627 		}
1628 		/* and, yeah, we need a multicast-capable iface too */
1629 		if (ia->ia_ifp != SC2IFP(sc) &&
1630 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1631 		    (i == 4)) {
1632 			if (!ia_if)
1633 				ia_if = ia;
1634 			if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr,
1635 			    &ia->ia_addr.sin6_addr))
1636 				own++;
1637 		}
1638 	}
1639 
1640 	if (!ia_if)
1641 		return (EADDRNOTAVAIL);
1642 	ia = ia_if;
1643 	ifp = ia->ia_ifp;
1644 
1645 	if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
1646 	    (im6o->im6o_multicast_ifp && im6o->im6o_multicast_ifp != ifp))
1647 		return (EADDRNOTAVAIL);
1648 
1649 	if (!sc->sc_naddrs6) {
1650 		im6o->im6o_multicast_ifp = ifp;
1651 
1652 		/* join CARP multicast address */
1653 		bzero(&in6, sizeof(in6));
1654 		in6.s6_addr16[0] = htons(0xff02);
1655 		in6.s6_addr8[15] = 0x12;
1656 		if (in6_setscope(&in6, ifp, NULL) != 0)
1657 			goto cleanup;
1658 		if ((imm = in6_joingroup(ifp, &in6, &error)) == NULL)
1659 			goto cleanup;
1660 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
1661 
1662 		/* join solicited multicast address */
1663 		bzero(&in6, sizeof(in6));
1664 		in6.s6_addr16[0] = htons(0xff02);
1665 		in6.s6_addr32[1] = 0;
1666 		in6.s6_addr32[2] = htonl(1);
1667 		in6.s6_addr32[3] = sin6->sin6_addr.s6_addr32[3];
1668 		in6.s6_addr8[12] = 0xff;
1669 		if (in6_setscope(&in6, ifp, NULL) != 0)
1670 			goto cleanup;
1671 		if ((imm = in6_joingroup(ifp, &in6, &error)) == NULL)
1672 			goto cleanup;
1673 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
1674 	}
1675 
1676 	if (!ifp->if_carp) {
1677 		MALLOC(cif, struct carp_if *, sizeof(*cif), M_CARP,
1678 		    M_WAITOK|M_ZERO);
1679 		if ((error = ifpromisc(ifp, 1))) {
1680 			FREE(cif, M_CARP);
1681 			goto cleanup;
1682 		}
1683 
1684 		CARP_LOCK_INIT(cif);
1685 		CARP_LOCK(cif);
1686 		cif->vhif_ifp = ifp;
1687 		TAILQ_INIT(&cif->vhif_vrs);
1688 		ifp->if_carp = cif;
1689 
1690 	} else {
1691 		struct carp_softc *vr;
1692 
1693 		cif = (struct carp_if *)ifp->if_carp;
1694 		CARP_LOCK(cif);
1695 		TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1696 			if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
1697 				CARP_UNLOCK(cif);
1698 				error = EINVAL;
1699 				goto cleanup;
1700 			}
1701 	}
1702 	sc->sc_ia6 = ia;
1703 	sc->sc_carpdev = ifp;
1704 
1705 	{ /* XXX prevent endless loop if already in queue */
1706 	struct carp_softc *vr, *after = NULL;
1707 	int myself = 0;
1708 	cif = (struct carp_if *)ifp->if_carp;
1709 	CARP_LOCK_ASSERT(cif);
1710 
1711 	TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1712 		if (vr == sc)
1713 			myself = 1;
1714 		if (vr->sc_vhid < sc->sc_vhid)
1715 			after = vr;
1716 	}
1717 
1718 	if (!myself) {
1719 		/* We're trying to keep things in order */
1720 		if (after == NULL) {
1721 			TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1722 		} else {
1723 			TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
1724 		}
1725 		cif->vhif_nvrs++;
1726 	}
1727 	}
1728 
1729 	sc->sc_naddrs6++;
1730 	SC2IFP(sc)->if_flags |= IFF_UP;
1731 	if (own)
1732 		sc->sc_advskew = 0;
1733 	carp_sc_state_locked(sc);
1734 	carp_setrun(sc, 0);
1735 
1736 	CARP_UNLOCK(cif);
1737 
1738 	return (0);
1739 
1740 cleanup:
1741 	/* clean up multicast memberships */
1742 	if (!sc->sc_naddrs6) {
1743 		while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1744 			imm = LIST_FIRST(&im6o->im6o_memberships);
1745 			LIST_REMOVE(imm, i6mm_chain);
1746 			in6_leavegroup(imm);
1747 		}
1748 	}
1749 	return (error);
1750 }
1751 
1752 static int
1753 carp_del_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1754 {
1755 	int error = 0;
1756 
1757 	if (!--sc->sc_naddrs6) {
1758 		struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1759 		struct ip6_moptions *im6o = &sc->sc_im6o;
1760 
1761 		CARP_LOCK(cif);
1762 		callout_stop(&sc->sc_ad_tmo);
1763 		SC2IFP(sc)->if_flags &= ~IFF_UP;
1764 		SC2IFP(sc)->if_flags &= ~IFF_RUNNING;
1765 		sc->sc_vhid = -1;
1766 		while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1767 			struct in6_multi_mship *imm =
1768 			    LIST_FIRST(&im6o->im6o_memberships);
1769 
1770 			LIST_REMOVE(imm, i6mm_chain);
1771 			in6_leavegroup(imm);
1772 		}
1773 		im6o->im6o_multicast_ifp = NULL;
1774 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
1775 		if (!--cif->vhif_nvrs) {
1776 			CARP_LOCK_DESTROY(cif);
1777 			sc->sc_carpdev->if_carp = NULL;
1778 			FREE(cif, M_IFADDR);
1779 		} else
1780 			CARP_UNLOCK(cif);
1781 	}
1782 
1783 	return (error);
1784 }
1785 #endif /* INET6 */
1786 
1787 static int
1788 carp_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr, struct ucred *creds)
1789 {
1790 	struct carp_softc *sc = ifp->if_softc, *vr;
1791 	struct carpreq carpr;
1792 	struct ifaddr *ifa;
1793 	struct ifreq *ifr;
1794 	struct ifaliasreq *ifra;
1795 	int locked = 0, error = 0;
1796 
1797 	ifa = (struct ifaddr *)addr;
1798 	ifra = (struct ifaliasreq *)addr;
1799 	ifr = (struct ifreq *)addr;
1800 
1801 
1802 	switch (cmd) {
1803 	case SIOCSIFADDR:
1804 		switch (ifa->ifa_addr->sa_family) {
1805 #ifdef INET
1806 		case AF_INET:
1807 			SC2IFP(sc)->if_flags |= IFF_UP;
1808 			bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1809 			    sizeof(struct sockaddr));
1810 			error = carp_set_addr(sc, satosin(ifa->ifa_addr));
1811 			break;
1812 #endif /* INET */
1813 #ifdef INET6
1814 		case AF_INET6:
1815 			SC2IFP(sc)->if_flags |= IFF_UP;
1816 			error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1817 			break;
1818 #endif /* INET6 */
1819 		default:
1820 			error = EAFNOSUPPORT;
1821 			break;
1822 		}
1823 		break;
1824 
1825 	case SIOCAIFADDR:
1826 		switch (ifa->ifa_addr->sa_family) {
1827 #ifdef INET
1828 		case AF_INET:
1829 			SC2IFP(sc)->if_flags |= IFF_UP;
1830 			bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1831 			    sizeof(struct sockaddr));
1832 			error = carp_set_addr(sc, satosin(&ifra->ifra_addr));
1833 			break;
1834 #endif /* INET */
1835 #ifdef INET6
1836 		case AF_INET6:
1837 			SC2IFP(sc)->if_flags |= IFF_UP;
1838 			error = carp_set_addr6(sc, satosin6(&ifra->ifra_addr));
1839 			break;
1840 #endif /* INET6 */
1841 		default:
1842 			error = EAFNOSUPPORT;
1843 			break;
1844 		}
1845 		break;
1846 
1847 	case SIOCDIFADDR:
1848 		switch (ifa->ifa_addr->sa_family) {
1849 #ifdef INET
1850 		case AF_INET:
1851 			error = carp_del_addr(sc, satosin(&ifra->ifra_addr));
1852 			break;
1853 #endif /* INET */
1854 #ifdef INET6
1855 		case AF_INET6:
1856 			error = carp_del_addr6(sc, satosin6(&ifra->ifra_addr));
1857 			break;
1858 #endif /* INET6 */
1859 		default:
1860 			error = EAFNOSUPPORT;
1861 			break;
1862 		}
1863 		break;
1864 
1865 	case SIOCSIFFLAGS:
1866 		if (sc->sc_carpdev) {
1867 			locked = 1;
1868 			CARP_SCLOCK(sc);
1869 		}
1870 		if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
1871  			callout_stop(&sc->sc_ad_tmo);
1872  			callout_stop(&sc->sc_md_tmo);
1873  			callout_stop(&sc->sc_md6_tmo);
1874 			if (sc->sc_state == MASTER)
1875 				carp_send_ad_locked(sc);
1876 			carp_set_state(sc, INIT);
1877 			carp_setrun(sc, 0);
1878 		} else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
1879 			SC2IFP(sc)->if_flags |= IFF_UP;
1880 			carp_setrun(sc, 0);
1881 		}
1882 		break;
1883 
1884 	case SIOCSVH:
1885 		error = suser(curthread);
1886 		if (error)
1887 			break;
1888 		if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
1889 			break;
1890 		error = 1;
1891 		if (sc->sc_carpdev) {
1892 			locked = 1;
1893 			CARP_SCLOCK(sc);
1894 		}
1895 		if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
1896 			switch (carpr.carpr_state) {
1897 			case BACKUP:
1898 				callout_stop(&sc->sc_ad_tmo);
1899 				carp_set_state(sc, BACKUP);
1900 				carp_setrun(sc, 0);
1901 				carp_setroute(sc, RTM_DELETE);
1902 				break;
1903 			case MASTER:
1904 				carp_master_down_locked(sc);
1905 				break;
1906 			default:
1907 				break;
1908 			}
1909 		}
1910 		if (carpr.carpr_vhid > 0) {
1911 			if (carpr.carpr_vhid > 255) {
1912 				error = EINVAL;
1913 				break;
1914 			}
1915 			if (sc->sc_carpdev) {
1916 				struct carp_if *cif;
1917 				cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1918 				TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1919 					if (vr != sc &&
1920 					    vr->sc_vhid == carpr.carpr_vhid)
1921 						return EEXIST;
1922 			}
1923 			sc->sc_vhid = carpr.carpr_vhid;
1924 			IF_LLADDR(sc->sc_ifp)[0] = 0;
1925 			IF_LLADDR(sc->sc_ifp)[1] = 0;
1926 			IF_LLADDR(sc->sc_ifp)[2] = 0x5e;
1927 			IF_LLADDR(sc->sc_ifp)[3] = 0;
1928 			IF_LLADDR(sc->sc_ifp)[4] = 1;
1929 			IF_LLADDR(sc->sc_ifp)[5] = sc->sc_vhid;
1930 			error--;
1931 		}
1932 		if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
1933 			if (carpr.carpr_advskew >= 255) {
1934 				error = EINVAL;
1935 				break;
1936 			}
1937 			if (carpr.carpr_advbase > 255) {
1938 				error = EINVAL;
1939 				break;
1940 			}
1941 			sc->sc_advbase = carpr.carpr_advbase;
1942 			sc->sc_advskew = carpr.carpr_advskew;
1943 			error--;
1944 		}
1945 		bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1946 		if (error > 0)
1947 			error = EINVAL;
1948 		else {
1949 			error = 0;
1950 			carp_setrun(sc, 0);
1951 		}
1952 		break;
1953 
1954 	case SIOCGVH:
1955 		/* XXX: lockless read */
1956 		bzero(&carpr, sizeof(carpr));
1957 		carpr.carpr_state = sc->sc_state;
1958 		carpr.carpr_vhid = sc->sc_vhid;
1959 		carpr.carpr_advbase = sc->sc_advbase;
1960 		carpr.carpr_advskew = sc->sc_advskew;
1961 		error = suser(curthread);
1962 		if (error == 0)
1963 			bcopy(sc->sc_key, carpr.carpr_key,
1964 			    sizeof(carpr.carpr_key));
1965 		error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
1966 		break;
1967 
1968 	default:
1969 		error = EINVAL;
1970 	}
1971 
1972 	if (locked)
1973 		CARP_SCUNLOCK(sc);
1974 
1975 	carp_hmac_prepare(sc);
1976 
1977 	return (error);
1978 }
1979 
1980 /*
1981  * XXX: this is looutput. We should eventually use it from there.
1982  */
1983 static int
1984 carp_looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
1985     struct rtentry *rt)
1986 {
1987 	u_int32_t af;
1988 
1989 	M_ASSERTPKTHDR(m); /* check if we have the packet header */
1990 
1991 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
1992 		m_freem(m);
1993 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
1994 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
1995 	}
1996 
1997 	ifp->if_opackets++;
1998 	ifp->if_obytes += m->m_pkthdr.len;
1999 
2000 	/* BPF writes need to be handled specially. */
2001 	if (dst->sa_family == AF_UNSPEC) {
2002 		bcopy(dst->sa_data, &af, sizeof(af));
2003 		dst->sa_family = af;
2004 	}
2005 
2006 #if 1	/* XXX */
2007 	switch (dst->sa_family) {
2008 	case AF_INET:
2009 	case AF_INET6:
2010 	case AF_IPX:
2011 	case AF_APPLETALK:
2012 		break;
2013 	default:
2014 		m_freem(m);
2015 		return (EAFNOSUPPORT);
2016 	}
2017 #endif
2018 	return(if_simloop(ifp, m, dst->sa_family, 0));
2019 }
2020 
2021 /*
2022  * Start output on carp interface. This function should never be called.
2023  */
2024 static void
2025 carp_start(struct ifnet *ifp)
2026 {
2027 #ifdef DEBUG
2028 	kprintf("%s: start called\n", ifp->if_xname);
2029 #endif
2030 }
2031 
2032 int
2033 carp_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
2034     struct rtentry *rt)
2035 {
2036 	struct m_tag *mtag;
2037 	struct carp_softc *sc;
2038 	struct ifnet *carp_ifp;
2039 
2040 	if (!sa)
2041 		return (0);
2042 
2043 	switch (sa->sa_family) {
2044 #ifdef INET
2045 	case AF_INET:
2046 		break;
2047 #endif /* INET */
2048 #ifdef INET6
2049 	case AF_INET6:
2050 		break;
2051 #endif /* INET6 */
2052 	default:
2053 		return (0);
2054 	}
2055 
2056 	mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
2057 	if (mtag == NULL)
2058 		return (0);
2059 
2060 	bcopy(mtag + 1, &carp_ifp, sizeof(struct ifnet *));
2061 	sc = carp_ifp->if_softc;
2062 
2063 	/* Set the source MAC address to Virtual Router MAC Address */
2064 	switch (ifp->if_type) {
2065 	case IFT_ETHER:
2066 	case IFT_L2VLAN: {
2067 			struct ether_header *eh;
2068 
2069 			eh = mtod(m, struct ether_header *);
2070 			eh->ether_shost[0] = 0;
2071 			eh->ether_shost[1] = 0;
2072 			eh->ether_shost[2] = 0x5e;
2073 			eh->ether_shost[3] = 0;
2074 			eh->ether_shost[4] = 1;
2075 			eh->ether_shost[5] = sc->sc_vhid;
2076 		}
2077 		break;
2078 	default:
2079 		kprintf("%s: carp is not supported for this interface type\n",
2080 		    ifp->if_xname);
2081 		return (EOPNOTSUPP);
2082 	}
2083 
2084 	return (0);
2085 
2086 }
2087 
2088 static void
2089 carp_set_state(struct carp_softc *sc, int state)
2090 {
2091 
2092 	if (sc->sc_carpdev)
2093 		CARP_SCLOCK_ASSERT(sc);
2094 
2095 	if (sc->sc_state == state)
2096 		return;
2097 
2098 	sc->sc_state = state;
2099 	switch (state) {
2100 	case BACKUP:
2101 		SC2IFP(sc)->if_link_state = LINK_STATE_DOWN;
2102 		break;
2103 	case MASTER:
2104 		SC2IFP(sc)->if_link_state = LINK_STATE_UP;
2105 		break;
2106 	default:
2107 		SC2IFP(sc)->if_link_state = LINK_STATE_UNKNOWN;
2108 		break;
2109 	}
2110 	rt_ifmsg(SC2IFP(sc));
2111 }
2112 
2113 void
2114 carp_carpdev_state(void *v)
2115 {
2116 	struct carp_if *cif = v;
2117 
2118 	CARP_LOCK(cif);
2119 	carp_carpdev_state_locked(cif);
2120 	CARP_UNLOCK(cif);
2121 }
2122 
2123 static void
2124 carp_carpdev_state_locked(struct carp_if *cif)
2125 {
2126 	struct carp_softc *sc;
2127 
2128 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list)
2129 		carp_sc_state_locked(sc);
2130 }
2131 
2132 static void
2133 carp_sc_state_locked(struct carp_softc *sc)
2134 {
2135 	CARP_SCLOCK_ASSERT(sc);
2136 
2137 	if ( !(sc->sc_carpdev->if_flags & IFF_UP)) {
2138 		sc->sc_flags_backup = SC2IFP(sc)->if_flags;
2139 		SC2IFP(sc)->if_flags &= ~IFF_UP;
2140 		SC2IFP(sc)->if_flags &= ~IFF_RUNNING;
2141 		callout_stop(&sc->sc_ad_tmo);
2142 		callout_stop(&sc->sc_md_tmo);
2143 		callout_stop(&sc->sc_md6_tmo);
2144 		carp_set_state(sc, INIT);
2145 		carp_setrun(sc, 0);
2146 		if (!sc->sc_suppress) {
2147 			carp_suppress_preempt++;
2148 			if (carp_suppress_preempt == 1) {
2149 				CARP_SCUNLOCK(sc);
2150 				carp_send_ad_all();
2151 				CARP_SCLOCK(sc);
2152 			}
2153 		}
2154 		sc->sc_suppress = 1;
2155 	} else {
2156 		SC2IFP(sc)->if_flags |= sc->sc_flags_backup;
2157 		carp_set_state(sc, INIT);
2158 		carp_setrun(sc, 0);
2159 		if (sc->sc_suppress)
2160 			carp_suppress_preempt--;
2161 		sc->sc_suppress = 0;
2162 	}
2163 
2164 	return;
2165 }
2166 
2167 static int
2168 carp_modevent(module_t mod, int type, void *data)
2169 {
2170 	switch (type) {
2171 	case MOD_LOAD:
2172 		if_detach_event_tag = EVENTHANDLER_REGISTER(ifnet_departure_event,
2173 		    carp_ifdetach, NULL, EVENTHANDLER_PRI_ANY);
2174 		if (if_detach_event_tag == NULL)
2175 			return (ENOMEM);
2176 
2177 		LIST_INIT(&carpif_list);
2178 		if_clone_attach(&carp_cloner);
2179 		break;
2180 
2181 	case MOD_UNLOAD:
2182 		EVENTHANDLER_DEREGISTER(ifnet_departure_event, if_detach_event_tag);
2183 		if_clone_detach(&carp_cloner);
2184 		break;
2185 
2186 	default:
2187 		return (EINVAL);
2188 	}
2189 
2190 	return (0);
2191 }
2192 
2193 static moduledata_t carp_mod = {
2194 	"carp",
2195 	carp_modevent,
2196 	0
2197 };
2198 
2199 DECLARE_MODULE(carp, carp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2200