xref: /netbsd-src/sys/netinet/ip_carp.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /*	$NetBSD: ip_carp.c,v 1.51 2013/10/18 19:48:36 christos Exp $	*/
2 /*	$OpenBSD: ip_carp.c,v 1.113 2005/11/04 08:11:54 mcbride Exp $	*/
3 
4 /*
5  * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
6  * Copyright (c) 2003 Ryan McBride. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
26  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27  * THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include "opt_inet.h"
31 
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: ip_carp.c,v 1.51 2013/10/18 19:48:36 christos Exp $");
34 
35 /*
36  * TODO:
37  *	- iface reconfigure
38  *	- support for hardware checksum calculations;
39  *
40  */
41 
42 #include <sys/param.h>
43 #include <sys/proc.h>
44 #include <sys/mbuf.h>
45 #include <sys/socket.h>
46 #include <sys/socketvar.h>
47 #include <sys/callout.h>
48 #include <sys/ioctl.h>
49 #include <sys/errno.h>
50 #include <sys/device.h>
51 #include <sys/time.h>
52 #include <sys/kernel.h>
53 #include <sys/kauth.h>
54 #include <sys/sysctl.h>
55 #include <sys/ucred.h>
56 #include <sys/syslog.h>
57 #include <sys/acct.h>
58 #include <sys/cprng.h>
59 
60 #include <sys/cpu.h>
61 
62 #include <net/if.h>
63 #include <net/pfil.h>
64 #include <net/if_types.h>
65 #include <net/if_ether.h>
66 #include <net/route.h>
67 #include <net/netisr.h>
68 #include <net/net_stats.h>
69 #include <netinet/if_inarp.h>
70 
71 #if NFDDI > 0
72 #include <net/if_fddi.h>
73 #endif
74 #if NTOKEN > 0
75 #include <net/if_token.h>
76 #endif
77 
78 #ifdef INET
79 #include <netinet/in.h>
80 #include <netinet/in_systm.h>
81 #include <netinet/in_var.h>
82 #include <netinet/ip.h>
83 #include <netinet/ip_var.h>
84 
85 #include <net/if_dl.h>
86 #endif
87 
88 #ifdef INET6
89 #include <netinet/icmp6.h>
90 #include <netinet/ip6.h>
91 #include <netinet6/ip6_var.h>
92 #include <netinet6/nd6.h>
93 #include <netinet6/scope6_var.h>
94 #endif
95 
96 #include <net/bpf.h>
97 
98 #include <sys/sha1.h>
99 
100 #include <netinet/ip_carp.h>
101 
102 struct carp_mc_entry {
103 	LIST_ENTRY(carp_mc_entry)	mc_entries;
104 	union {
105 		struct ether_multi	*mcu_enm;
106 	} mc_u;
107 	struct sockaddr_storage		mc_addr;
108 };
109 #define	mc_enm	mc_u.mcu_enm
110 
111 struct carp_softc {
112 	struct ethercom sc_ac;
113 #define	sc_if		sc_ac.ec_if
114 #define	sc_carpdev	sc_ac.ec_if.if_carpdev
115 	int ah_cookie;
116 	int lh_cookie;
117 	struct ip_moptions sc_imo;
118 #ifdef INET6
119 	struct ip6_moptions sc_im6o;
120 #endif /* INET6 */
121 	TAILQ_ENTRY(carp_softc) sc_list;
122 
123 	enum { INIT = 0, BACKUP, MASTER }	sc_state;
124 
125 	int sc_suppress;
126 	int sc_bow_out;
127 
128 	int sc_sendad_errors;
129 #define CARP_SENDAD_MAX_ERRORS	3
130 	int sc_sendad_success;
131 #define CARP_SENDAD_MIN_SUCCESS 3
132 
133 	int sc_vhid;
134 	int sc_advskew;
135 	int sc_naddrs;
136 	int sc_naddrs6;
137 	int sc_advbase;		/* seconds */
138 	int sc_init_counter;
139 	u_int64_t sc_counter;
140 
141 	/* authentication */
142 #define CARP_HMAC_PAD	64
143 	unsigned char sc_key[CARP_KEY_LEN];
144 	unsigned char sc_pad[CARP_HMAC_PAD];
145 	SHA1_CTX sc_sha1;
146 	u_int32_t sc_hashkey[2];
147 
148 	struct callout sc_ad_tmo;	/* advertisement timeout */
149 	struct callout sc_md_tmo;	/* master down timeout */
150 	struct callout sc_md6_tmo;	/* master down timeout */
151 
152 	LIST_HEAD(__carp_mchead, carp_mc_entry)	carp_mc_listhead;
153 };
154 
155 int carp_suppress_preempt = 0;
156 int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 0, 0 };	/* XXX for now */
157 
158 static percpu_t *carpstat_percpu;
159 
160 #define	CARP_STATINC(x)		_NET_STATINC(carpstat_percpu, x)
161 
162 struct carp_if {
163 	TAILQ_HEAD(, carp_softc) vhif_vrs;
164 	int vhif_nvrs;
165 
166 	struct ifnet *vhif_ifp;
167 };
168 
169 #define	CARP_LOG(sc, s)							\
170 	if (carp_opts[CARPCTL_LOG]) {					\
171 		if (sc)							\
172 			log(LOG_INFO, "%s: ",				\
173 			    (sc)->sc_if.if_xname);			\
174 		else							\
175 			log(LOG_INFO, "carp: ");			\
176 		addlog s;						\
177 		addlog("\n");						\
178 	}
179 
180 void	carp_hmac_prepare(struct carp_softc *);
181 void	carp_hmac_generate(struct carp_softc *, u_int32_t *,
182 	    unsigned char *);
183 int	carp_hmac_verify(struct carp_softc *, u_int32_t *,
184 	    unsigned char *);
185 void	carp_setroute(struct carp_softc *, int);
186 void	carp_proto_input_c(struct mbuf *, struct carp_header *, sa_family_t);
187 void	carpattach(int);
188 void	carpdetach(struct carp_softc *);
189 int	carp_prepare_ad(struct mbuf *, struct carp_softc *,
190 	    struct carp_header *);
191 void	carp_send_ad_all(void);
192 void	carp_send_ad(void *);
193 void	carp_send_arp(struct carp_softc *);
194 void	carp_master_down(void *);
195 int	carp_ioctl(struct ifnet *, u_long, void *);
196 void	carp_start(struct ifnet *);
197 void	carp_setrun(struct carp_softc *, sa_family_t);
198 void	carp_set_state(struct carp_softc *, int);
199 int	carp_addrcount(struct carp_if *, struct in_ifaddr *, int);
200 enum	{ CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
201 
202 void	carp_multicast_cleanup(struct carp_softc *);
203 int	carp_set_ifp(struct carp_softc *, struct ifnet *);
204 void	carp_set_enaddr(struct carp_softc *);
205 void	carp_addr_updated(void *);
206 u_int32_t	carp_hash(struct carp_softc *, u_char *);
207 int	carp_set_addr(struct carp_softc *, struct sockaddr_in *);
208 int	carp_join_multicast(struct carp_softc *);
209 #ifdef INET6
210 void	carp_send_na(struct carp_softc *);
211 int	carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
212 int	carp_join_multicast6(struct carp_softc *);
213 #endif
214 int	carp_clone_create(struct if_clone *, int);
215 int	carp_clone_destroy(struct ifnet *);
216 int	carp_ether_addmulti(struct carp_softc *, struct ifreq *);
217 int	carp_ether_delmulti(struct carp_softc *, struct ifreq *);
218 void	carp_ether_purgemulti(struct carp_softc *);
219 
220 static void sysctl_net_inet_carp_setup(struct sysctllog **);
221 
222 struct if_clone carp_cloner =
223     IF_CLONE_INITIALIZER("carp", carp_clone_create, carp_clone_destroy);
224 
225 static __inline u_int16_t
226 carp_cksum(struct mbuf *m, int len)
227 {
228 	return (in_cksum(m, len));
229 }
230 
231 void
232 carp_hmac_prepare(struct carp_softc *sc)
233 {
234 	u_int8_t carp_version = CARP_VERSION, type = CARP_ADVERTISEMENT;
235 	u_int8_t vhid = sc->sc_vhid & 0xff;
236 	SHA1_CTX sha1ctx;
237 	u_int32_t kmd[5];
238 	struct ifaddr *ifa;
239 	int i, found;
240 	struct in_addr last, cur, in;
241 #ifdef INET6
242 	struct in6_addr last6, cur6, in6;
243 #endif /* INET6 */
244 
245 	/* compute ipad from key */
246 	memset(sc->sc_pad, 0, sizeof(sc->sc_pad));
247 	memcpy(sc->sc_pad, sc->sc_key, sizeof(sc->sc_key));
248 	for (i = 0; i < sizeof(sc->sc_pad); i++)
249 		sc->sc_pad[i] ^= 0x36;
250 
251 	/* precompute first part of inner hash */
252 	SHA1Init(&sc->sc_sha1);
253 	SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
254 	SHA1Update(&sc->sc_sha1, (void *)&carp_version, sizeof(carp_version));
255 	SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
256 
257 	/* generate a key for the arpbalance hash, before the vhid is hashed */
258 	memcpy(&sha1ctx, &sc->sc_sha1, sizeof(sha1ctx));
259 	SHA1Final((unsigned char *)kmd, &sha1ctx);
260 	sc->sc_hashkey[0] = kmd[0] ^ kmd[1];
261 	sc->sc_hashkey[1] = kmd[2] ^ kmd[3];
262 
263 	/* the rest of the precomputation */
264 	SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
265 
266 	/* Hash the addresses from smallest to largest, not interface order */
267 #ifdef INET
268 	cur.s_addr = 0;
269 	do {
270 		found = 0;
271 		last = cur;
272 		cur.s_addr = 0xffffffff;
273 		IFADDR_FOREACH(ifa, &sc->sc_if) {
274 			in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
275 			if (ifa->ifa_addr->sa_family == AF_INET &&
276 			    ntohl(in.s_addr) > ntohl(last.s_addr) &&
277 			    ntohl(in.s_addr) < ntohl(cur.s_addr)) {
278 				cur.s_addr = in.s_addr;
279 				found++;
280 			}
281 		}
282 		if (found)
283 			SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
284 	} while (found);
285 #endif /* INET */
286 
287 #ifdef INET6
288 	memset(&cur6, 0x00, sizeof(cur6));
289 	do {
290 		found = 0;
291 		last6 = cur6;
292 		memset(&cur6, 0xff, sizeof(cur6));
293 		IFADDR_FOREACH(ifa, &sc->sc_if) {
294 			in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
295 			if (IN6_IS_ADDR_LINKLOCAL(&in6))
296 				in6.s6_addr16[1] = 0;
297 			if (ifa->ifa_addr->sa_family == AF_INET6 &&
298 			    memcmp(&in6, &last6, sizeof(in6)) > 0 &&
299 			    memcmp(&in6, &cur6, sizeof(in6)) < 0) {
300 				cur6 = in6;
301 				found++;
302 			}
303 		}
304 		if (found)
305 			SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
306 	} while (found);
307 #endif /* INET6 */
308 
309 	/* convert ipad to opad */
310 	for (i = 0; i < sizeof(sc->sc_pad); i++)
311 		sc->sc_pad[i] ^= 0x36 ^ 0x5c;
312 }
313 
314 void
315 carp_hmac_generate(struct carp_softc *sc, u_int32_t counter[2],
316     unsigned char md[20])
317 {
318 	SHA1_CTX sha1ctx;
319 
320 	/* fetch first half of inner hash */
321 	memcpy(&sha1ctx, &sc->sc_sha1, sizeof(sha1ctx));
322 
323 	SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
324 	SHA1Final(md, &sha1ctx);
325 
326 	/* outer hash */
327 	SHA1Init(&sha1ctx);
328 	SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
329 	SHA1Update(&sha1ctx, md, 20);
330 	SHA1Final(md, &sha1ctx);
331 }
332 
333 int
334 carp_hmac_verify(struct carp_softc *sc, u_int32_t counter[2],
335     unsigned char md[20])
336 {
337 	unsigned char md2[20];
338 
339 	carp_hmac_generate(sc, counter, md2);
340 
341 	return (memcmp(md, md2, sizeof(md2)));
342 }
343 
344 void
345 carp_setroute(struct carp_softc *sc, int cmd)
346 {
347 	struct ifaddr *ifa;
348 	int s;
349 
350 	s = splsoftnet();
351 	IFADDR_FOREACH(ifa, &sc->sc_if) {
352 		switch (ifa->ifa_addr->sa_family) {
353 		case AF_INET: {
354 			int count = 0;
355 			struct rtentry *rt;
356 			int hr_otherif, nr_ourif;
357 
358 			/*
359 			 * Avoid screwing with the routes if there are other
360 			 * carp interfaces which are master and have the same
361 			 * address.
362 			 */
363 			if (sc->sc_carpdev != NULL &&
364 			    sc->sc_carpdev->if_carp != NULL) {
365 				count = carp_addrcount(
366 				    (struct carp_if *)sc->sc_carpdev->if_carp,
367 				    ifatoia(ifa), CARP_COUNT_MASTER);
368 				if ((cmd == RTM_ADD && count != 1) ||
369 				    (cmd == RTM_DELETE && count != 0))
370 					continue;
371 			}
372 
373 			/* Remove the existing host route, if any */
374 			rtrequest(RTM_DELETE, ifa->ifa_addr,
375 			    ifa->ifa_addr, ifa->ifa_netmask,
376 			    RTF_HOST, NULL);
377 
378 			rt = NULL;
379 			(void)rtrequest(RTM_GET, ifa->ifa_addr, ifa->ifa_addr,
380 			    ifa->ifa_netmask, RTF_HOST, &rt);
381 			hr_otherif = (rt && rt->rt_ifp != &sc->sc_if &&
382 			    rt->rt_flags & (RTF_CLONING|RTF_CLONED));
383 			if (rt != NULL) {
384 				RTFREE(rt);
385 				rt = NULL;
386 			}
387 
388 			/* Check for a network route on our interface */
389 
390 			rt = NULL;
391 			(void)rtrequest(RTM_GET, ifa->ifa_addr, ifa->ifa_addr,
392 			    ifa->ifa_netmask, 0, &rt);
393 			nr_ourif = (rt && rt->rt_ifp == &sc->sc_if);
394 
395 			switch (cmd) {
396 			case RTM_ADD:
397 				if (hr_otherif) {
398 					ifa->ifa_rtrequest = NULL;
399 					ifa->ifa_flags &= ~RTF_CLONING;
400 
401 					rtrequest(RTM_ADD, ifa->ifa_addr,
402 					    ifa->ifa_addr, ifa->ifa_netmask,
403 					    RTF_UP | RTF_HOST, NULL);
404 				}
405 				if (!hr_otherif || nr_ourif || !rt) {
406 					if (nr_ourif && !(rt->rt_flags &
407 					    RTF_CLONING))
408 						rtrequest(RTM_DELETE,
409 						    ifa->ifa_addr,
410 						    ifa->ifa_addr,
411 						    ifa->ifa_netmask, 0, NULL);
412 
413 					ifa->ifa_rtrequest = arp_rtrequest;
414 					ifa->ifa_flags |= RTF_CLONING;
415 
416 					if (rtrequest(RTM_ADD, ifa->ifa_addr,
417 					    ifa->ifa_addr, ifa->ifa_netmask, 0,
418 					    NULL) == 0)
419 						ifa->ifa_flags |= IFA_ROUTE;
420 				}
421 				break;
422 			case RTM_DELETE:
423 				break;
424 			default:
425 				break;
426 			}
427 			if (rt != NULL) {
428 				RTFREE(rt);
429 				rt = NULL;
430 			}
431 			break;
432 		}
433 
434 #ifdef INET6
435 		case AF_INET6:
436 			if (cmd == RTM_ADD)
437 				in6_ifaddloop(ifa);
438 			else
439 				in6_ifremloop(ifa);
440 			break;
441 #endif /* INET6 */
442 		default:
443 			break;
444 		}
445 	}
446 	splx(s);
447 }
448 
449 /*
450  * process input packet.
451  * we have rearranged checks order compared to the rfc,
452  * but it seems more efficient this way or not possible otherwise.
453  */
454 void
455 carp_proto_input(struct mbuf *m, ...)
456 {
457 	struct ip *ip = mtod(m, struct ip *);
458 	struct carp_softc *sc = NULL;
459 	struct carp_header *ch;
460 	int iplen, len;
461 	va_list ap;
462 
463 	va_start(ap, m);
464 	va_end(ap);
465 
466 	CARP_STATINC(CARP_STAT_IPACKETS);
467 
468 	if (!carp_opts[CARPCTL_ALLOW]) {
469 		m_freem(m);
470 		return;
471 	}
472 
473 	/* check if received on a valid carp interface */
474 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
475 		CARP_STATINC(CARP_STAT_BADIF);
476 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
477 		    m->m_pkthdr.rcvif->if_xname));
478 		m_freem(m);
479 		return;
480 	}
481 
482 	/* verify that the IP TTL is 255.  */
483 	if (ip->ip_ttl != CARP_DFLTTL) {
484 		CARP_STATINC(CARP_STAT_BADTTL);
485 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip->ip_ttl,
486 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
487 		m_freem(m);
488 		return;
489 	}
490 
491 	/*
492 	 * verify that the received packet length is
493 	 * equal to the CARP header
494 	 */
495 	iplen = ip->ip_hl << 2;
496 	len = iplen + sizeof(*ch);
497 	if (len > m->m_pkthdr.len) {
498 		CARP_STATINC(CARP_STAT_BADLEN);
499 		CARP_LOG(sc, ("packet too short %d on %s", m->m_pkthdr.len,
500 		    m->m_pkthdr.rcvif->if_xname));
501 		m_freem(m);
502 		return;
503 	}
504 
505 	if ((m = m_pullup(m, len)) == NULL) {
506 		CARP_STATINC(CARP_STAT_HDROPS);
507 		return;
508 	}
509 	ip = mtod(m, struct ip *);
510 	ch = (struct carp_header *)((char *)ip + iplen);
511 	/* verify the CARP checksum */
512 	m->m_data += iplen;
513 	if (carp_cksum(m, len - iplen)) {
514 		CARP_STATINC(CARP_STAT_BADSUM);
515 		CARP_LOG(sc, ("checksum failed on %s",
516 		    m->m_pkthdr.rcvif->if_xname));
517 		m_freem(m);
518 		return;
519 	}
520 	m->m_data -= iplen;
521 
522 	carp_proto_input_c(m, ch, AF_INET);
523 }
524 
525 #ifdef INET6
526 int
527 carp6_proto_input(struct mbuf **mp, int *offp, int proto)
528 {
529 	struct mbuf *m = *mp;
530 	struct carp_softc *sc = NULL;
531 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
532 	struct carp_header *ch;
533 	u_int len;
534 
535 	CARP_STATINC(CARP_STAT_IPACKETS6);
536 
537 	if (!carp_opts[CARPCTL_ALLOW]) {
538 		m_freem(m);
539 		return (IPPROTO_DONE);
540 	}
541 
542 	/* check if received on a valid carp interface */
543 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
544 		CARP_STATINC(CARP_STAT_BADIF);
545 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
546 		    m->m_pkthdr.rcvif->if_xname));
547 		m_freem(m);
548 		return (IPPROTO_DONE);
549 	}
550 
551 	/* verify that the IP TTL is 255 */
552 	if (ip6->ip6_hlim != CARP_DFLTTL) {
553 		CARP_STATINC(CARP_STAT_BADTTL);
554 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip6->ip6_hlim,
555 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
556 		m_freem(m);
557 		return (IPPROTO_DONE);
558 	}
559 
560 	/* verify that we have a complete carp packet */
561 	len = m->m_len;
562 	IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
563 	if (ch == NULL) {
564 		CARP_STATINC(CARP_STAT_BADLEN);
565 		CARP_LOG(sc, ("packet size %u too small", len));
566 		return (IPPROTO_DONE);
567 	}
568 
569 
570 	/* verify the CARP checksum */
571 	m->m_data += *offp;
572 	if (carp_cksum(m, sizeof(*ch))) {
573 		CARP_STATINC(CARP_STAT_BADSUM);
574 		CARP_LOG(sc, ("checksum failed, on %s",
575 		    m->m_pkthdr.rcvif->if_xname));
576 		m_freem(m);
577 		return (IPPROTO_DONE);
578 	}
579 	m->m_data -= *offp;
580 
581 	carp_proto_input_c(m, ch, AF_INET6);
582 	return (IPPROTO_DONE);
583 }
584 #endif /* INET6 */
585 
586 void
587 carp_proto_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
588 {
589 	struct carp_softc *sc;
590 	u_int64_t tmp_counter;
591 	struct timeval sc_tv, ch_tv;
592 
593 	TAILQ_FOREACH(sc, &((struct carp_if *)
594 	    m->m_pkthdr.rcvif->if_carpdev->if_carp)->vhif_vrs, sc_list)
595 		if (sc->sc_vhid == ch->carp_vhid)
596 			break;
597 
598 	if (!sc || (sc->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) !=
599 	    (IFF_UP|IFF_RUNNING)) {
600 		CARP_STATINC(CARP_STAT_BADVHID);
601 		m_freem(m);
602 		return;
603 	}
604 
605 	/*
606 	 * Check if our own advertisement was duplicated
607 	 * from a non simplex interface.
608 	 * XXX If there is no address on our physical interface
609 	 * there is no way to distinguish our ads from the ones
610 	 * another carp host might have sent us.
611 	 */
612 	if ((sc->sc_carpdev->if_flags & IFF_SIMPLEX) == 0) {
613 		struct sockaddr sa;
614 		struct ifaddr *ifa;
615 
616 		memset(&sa, 0, sizeof(sa));
617 		sa.sa_family = af;
618 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
619 
620 		if (ifa && af == AF_INET) {
621 			struct ip *ip = mtod(m, struct ip *);
622 			if (ip->ip_src.s_addr ==
623 					ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
624 				m_freem(m);
625 				return;
626 			}
627 		}
628 #ifdef INET6
629 		if (ifa && af == AF_INET6) {
630 			struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
631 			struct in6_addr in6_src, in6_found;
632 
633 			in6_src = ip6->ip6_src;
634 			in6_found = ifatoia6(ifa)->ia_addr.sin6_addr;
635 			if (IN6_IS_ADDR_LINKLOCAL(&in6_src))
636 				in6_src.s6_addr16[1] = 0;
637 			if (IN6_IS_ADDR_LINKLOCAL(&in6_found))
638 				in6_found.s6_addr16[1] = 0;
639 			if (IN6_ARE_ADDR_EQUAL(&in6_src, &in6_found)) {
640 				m_freem(m);
641 				return;
642 			}
643 		}
644 #endif /* INET6 */
645 	}
646 
647 	nanotime(&sc->sc_if.if_lastchange);
648 	sc->sc_if.if_ipackets++;
649 	sc->sc_if.if_ibytes += m->m_pkthdr.len;
650 
651 	/* verify the CARP version. */
652 	if (ch->carp_version != CARP_VERSION) {
653 		CARP_STATINC(CARP_STAT_BADVER);
654 		sc->sc_if.if_ierrors++;
655 		CARP_LOG(sc, ("invalid version %d != %d",
656 		    ch->carp_version, CARP_VERSION));
657 		m_freem(m);
658 		return;
659 	}
660 
661 	/* verify the hash */
662 	if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
663 		CARP_STATINC(CARP_STAT_BADAUTH);
664 		sc->sc_if.if_ierrors++;
665 		CARP_LOG(sc, ("incorrect hash"));
666 		m_freem(m);
667 		return;
668 	}
669 
670 	tmp_counter = ntohl(ch->carp_counter[0]);
671 	tmp_counter = tmp_counter<<32;
672 	tmp_counter += ntohl(ch->carp_counter[1]);
673 
674 	/* XXX Replay protection goes here */
675 
676 	sc->sc_init_counter = 0;
677 	sc->sc_counter = tmp_counter;
678 
679 
680 	sc_tv.tv_sec = sc->sc_advbase;
681 	if (carp_suppress_preempt && sc->sc_advskew <  240)
682 		sc_tv.tv_usec = 240 * 1000000 / 256;
683 	else
684 		sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
685 	ch_tv.tv_sec = ch->carp_advbase;
686 	ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
687 
688 	switch (sc->sc_state) {
689 	case INIT:
690 		break;
691 	case MASTER:
692 		/*
693 		 * If we receive an advertisement from a backup who's going to
694 		 * be more frequent than us, go into BACKUP state.
695 		 */
696 		if (timercmp(&sc_tv, &ch_tv, >) ||
697 		    timercmp(&sc_tv, &ch_tv, ==)) {
698 			callout_stop(&sc->sc_ad_tmo);
699 			CARP_LOG(sc, ("MASTER -> BACKUP (more frequent advertisement received)"));
700 			carp_set_state(sc, BACKUP);
701 			carp_setrun(sc, 0);
702 			carp_setroute(sc, RTM_DELETE);
703 		}
704 		break;
705 	case BACKUP:
706 		/*
707 		 * If we're pre-empting masters who advertise slower than us,
708 		 * and this one claims to be slower, treat him as down.
709 		 */
710 		if (carp_opts[CARPCTL_PREEMPT] && timercmp(&sc_tv, &ch_tv, <)) {
711 			CARP_LOG(sc, ("BACKUP -> MASTER (preempting a slower master)"));
712 			carp_master_down(sc);
713 			break;
714 		}
715 
716 		/*
717 		 *  If the master is going to advertise at such a low frequency
718 		 *  that he's guaranteed to time out, we'd might as well just
719 		 *  treat him as timed out now.
720 		 */
721 		sc_tv.tv_sec = sc->sc_advbase * 3;
722 		if (timercmp(&sc_tv, &ch_tv, <)) {
723 			CARP_LOG(sc, ("BACKUP -> MASTER (master timed out)"));
724 			carp_master_down(sc);
725 			break;
726 		}
727 
728 		/*
729 		 * Otherwise, we reset the counter and wait for the next
730 		 * advertisement.
731 		 */
732 		carp_setrun(sc, af);
733 		break;
734 	}
735 
736 	m_freem(m);
737 	return;
738 }
739 
740 /*
741  * Interface side of the CARP implementation.
742  */
743 
744 /* ARGSUSED */
745 void
746 carpattach(int n)
747 {
748 	if_clone_attach(&carp_cloner);
749 
750 	carpstat_percpu = percpu_alloc(sizeof(uint64_t) * CARP_NSTATS);
751 }
752 
753 int
754 carp_clone_create(struct if_clone *ifc, int unit)
755 {
756 	extern int ifqmaxlen;
757 	struct carp_softc *sc;
758 	struct ifnet *ifp;
759 
760 	sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT|M_ZERO);
761 	if (!sc)
762 		return (ENOMEM);
763 
764 	sc->sc_suppress = 0;
765 	sc->sc_advbase = CARP_DFLTINTV;
766 	sc->sc_vhid = -1;	/* required setting */
767 	sc->sc_advskew = 0;
768 	sc->sc_init_counter = 1;
769 	sc->sc_naddrs = sc->sc_naddrs6 = 0;
770 #ifdef INET6
771 	sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
772 #endif /* INET6 */
773 
774 	callout_init(&sc->sc_ad_tmo, 0);
775 	callout_init(&sc->sc_md_tmo, 0);
776 	callout_init(&sc->sc_md6_tmo, 0);
777 
778 	callout_setfunc(&sc->sc_ad_tmo, carp_send_ad, sc);
779 	callout_setfunc(&sc->sc_md_tmo, carp_master_down, sc);
780 	callout_setfunc(&sc->sc_md6_tmo, carp_master_down, sc);
781 
782 	LIST_INIT(&sc->carp_mc_listhead);
783 	ifp = &sc->sc_if;
784 	ifp->if_softc = sc;
785 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "%s%d", ifc->ifc_name,
786 	    unit);
787 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
788 	ifp->if_ioctl = carp_ioctl;
789 	ifp->if_start = carp_start;
790 	ifp->if_output = carp_output;
791 	ifp->if_type = IFT_CARP;
792 	ifp->if_addrlen = ETHER_ADDR_LEN;
793 	ifp->if_hdrlen = ETHER_HDR_LEN;
794 	ifp->if_mtu = ETHERMTU;
795 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
796 	IFQ_SET_READY(&ifp->if_snd);
797 	if_attach(ifp);
798 
799 	if_alloc_sadl(ifp);
800 	ifp->if_broadcastaddr = etherbroadcastaddr;
801 	carp_set_enaddr(sc);
802 	LIST_INIT(&sc->sc_ac.ec_multiaddrs);
803 	bpf_attach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
804 	return (0);
805 }
806 
807 int
808 carp_clone_destroy(struct ifnet *ifp)
809 {
810 	struct carp_softc *sc = ifp->if_softc;
811 
812 	carpdetach(ifp->if_softc);
813 	ether_ifdetach(ifp);
814 	if_detach(ifp);
815 	callout_destroy(&sc->sc_ad_tmo);
816 	callout_destroy(&sc->sc_md_tmo);
817 	callout_destroy(&sc->sc_md6_tmo);
818 	free(ifp->if_softc, M_DEVBUF);
819 
820 	return (0);
821 }
822 
823 void
824 carpdetach(struct carp_softc *sc)
825 {
826 	struct carp_if *cif;
827 	int s;
828 
829 	callout_stop(&sc->sc_ad_tmo);
830 	callout_stop(&sc->sc_md_tmo);
831 	callout_stop(&sc->sc_md6_tmo);
832 
833 	if (sc->sc_suppress)
834 		carp_suppress_preempt--;
835 	sc->sc_suppress = 0;
836 
837 	if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
838 		carp_suppress_preempt--;
839 	sc->sc_sendad_errors = 0;
840 
841 	carp_set_state(sc, INIT);
842 	sc->sc_if.if_flags &= ~IFF_UP;
843 	carp_setrun(sc, 0);
844 	carp_multicast_cleanup(sc);
845 
846 	s = splnet();
847 	if (sc->sc_carpdev != NULL) {
848 		/* XXX linkstatehook removal */
849 		cif = (struct carp_if *)sc->sc_carpdev->if_carp;
850 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
851 		if (!--cif->vhif_nvrs) {
852 			ifpromisc(sc->sc_carpdev, 0);
853 			sc->sc_carpdev->if_carp = NULL;
854 			free(cif, M_IFADDR);
855 		}
856 	}
857 	sc->sc_carpdev = NULL;
858 	splx(s);
859 }
860 
861 /* Detach an interface from the carp. */
862 void
863 carp_ifdetach(struct ifnet *ifp)
864 {
865 	struct carp_softc *sc, *nextsc;
866 	struct carp_if *cif = (struct carp_if *)ifp->if_carp;
867 
868 	for (sc = TAILQ_FIRST(&cif->vhif_vrs); sc; sc = nextsc) {
869 		nextsc = TAILQ_NEXT(sc, sc_list);
870 		carpdetach(sc);
871 	}
872 }
873 
874 int
875 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc,
876     struct carp_header *ch)
877 {
878 	if (sc->sc_init_counter) {
879 		/* this could also be seconds since unix epoch */
880 		sc->sc_counter = cprng_fast64();
881 	} else
882 		sc->sc_counter++;
883 
884 	ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
885 	ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
886 
887 	carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
888 
889 	return (0);
890 }
891 
892 void
893 carp_send_ad_all(void)
894 {
895 	struct ifnet *ifp;
896 	struct carp_if *cif;
897 	struct carp_softc *vh;
898 
899 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
900 		if (ifp->if_carp == NULL || ifp->if_type == IFT_CARP)
901 			continue;
902 
903 		cif = (struct carp_if *)ifp->if_carp;
904 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
905 			if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
906 			    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER)
907 				carp_send_ad(vh);
908 		}
909 	}
910 }
911 
912 
913 void
914 carp_send_ad(void *v)
915 {
916 	struct carp_header ch;
917 	struct timeval tv;
918 	struct carp_softc *sc = v;
919 	struct carp_header *ch_ptr;
920 	struct mbuf *m;
921 	int error, len, advbase, advskew, s;
922 	struct ifaddr *ifa;
923 	struct sockaddr sa;
924 
925 	s = splsoftnet();
926 
927 	advbase = advskew = 0; /* Sssssh compiler */
928 	if (sc->sc_carpdev == NULL) {
929 		sc->sc_if.if_oerrors++;
930 		goto retry_later;
931 	}
932 
933 	/* bow out if we've gone to backup (the carp interface is going down) */
934 	if (sc->sc_bow_out) {
935 		sc->sc_bow_out = 0;
936 		advbase = 255;
937 		advskew = 255;
938 	} else {
939 		advbase = sc->sc_advbase;
940 		if (!carp_suppress_preempt || sc->sc_advskew > 240)
941 			advskew = sc->sc_advskew;
942 		else
943 			advskew = 240;
944 		tv.tv_sec = advbase;
945 		tv.tv_usec = advskew * 1000000 / 256;
946 	}
947 
948 	ch.carp_version = CARP_VERSION;
949 	ch.carp_type = CARP_ADVERTISEMENT;
950 	ch.carp_vhid = sc->sc_vhid;
951 	ch.carp_advbase = advbase;
952 	ch.carp_advskew = advskew;
953 	ch.carp_authlen = 7;	/* XXX DEFINE */
954 	ch.carp_pad1 = 0;	/* must be zero */
955 	ch.carp_cksum = 0;
956 
957 
958 #ifdef INET
959 	if (sc->sc_naddrs) {
960 		struct ip *ip;
961 
962 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
963 		if (m == NULL) {
964 			sc->sc_if.if_oerrors++;
965 			CARP_STATINC(CARP_STAT_ONOMEM);
966 			/* XXX maybe less ? */
967 			goto retry_later;
968 		}
969 		len = sizeof(*ip) + sizeof(ch);
970 		m->m_pkthdr.len = len;
971 		m->m_pkthdr.rcvif = NULL;
972 		m->m_len = len;
973 		MH_ALIGN(m, m->m_len);
974 		m->m_flags |= M_MCAST;
975 		ip = mtod(m, struct ip *);
976 		ip->ip_v = IPVERSION;
977 		ip->ip_hl = sizeof(*ip) >> 2;
978 		ip->ip_tos = IPTOS_LOWDELAY;
979 		ip->ip_len = htons(len);
980 		ip->ip_id = 0;	/* no need for id, we don't support fragments */
981 		ip->ip_off = htons(IP_DF);
982 		ip->ip_ttl = CARP_DFLTTL;
983 		ip->ip_p = IPPROTO_CARP;
984 		ip->ip_sum = 0;
985 
986 		memset(&sa, 0, sizeof(sa));
987 		sa.sa_family = AF_INET;
988 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
989 		if (ifa == NULL)
990 			ip->ip_src.s_addr = 0;
991 		else
992 			ip->ip_src.s_addr =
993 			    ifatoia(ifa)->ia_addr.sin_addr.s_addr;
994 		ip->ip_dst.s_addr = INADDR_CARP_GROUP;
995 
996 		ch_ptr = (struct carp_header *)(&ip[1]);
997 		memcpy(ch_ptr, &ch, sizeof(ch));
998 		if (carp_prepare_ad(m, sc, ch_ptr))
999 			goto retry_later;
1000 
1001 		m->m_data += sizeof(*ip);
1002 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
1003 		m->m_data -= sizeof(*ip);
1004 
1005 		nanotime(&sc->sc_if.if_lastchange);
1006 		sc->sc_if.if_opackets++;
1007 		sc->sc_if.if_obytes += len;
1008 		CARP_STATINC(CARP_STAT_OPACKETS);
1009 
1010 		error = ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo,
1011 		    NULL);
1012 		if (error) {
1013 			if (error == ENOBUFS)
1014 				CARP_STATINC(CARP_STAT_ONOMEM);
1015 			else
1016 				CARP_LOG(sc, ("ip_output failed: %d", error));
1017 			sc->sc_if.if_oerrors++;
1018 			if (sc->sc_sendad_errors < INT_MAX)
1019 				sc->sc_sendad_errors++;
1020 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1021 				carp_suppress_preempt++;
1022 				if (carp_suppress_preempt == 1)
1023 					carp_send_ad_all();
1024 			}
1025 			sc->sc_sendad_success = 0;
1026 		} else {
1027 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1028 				if (++sc->sc_sendad_success >=
1029 				    CARP_SENDAD_MIN_SUCCESS) {
1030 					carp_suppress_preempt--;
1031 					sc->sc_sendad_errors = 0;
1032 				}
1033 			} else
1034 				sc->sc_sendad_errors = 0;
1035 		}
1036 	}
1037 #endif /* INET */
1038 #ifdef INET6
1039 	if (sc->sc_naddrs6) {
1040 		struct ip6_hdr *ip6;
1041 
1042 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
1043 		if (m == NULL) {
1044 			sc->sc_if.if_oerrors++;
1045 			CARP_STATINC(CARP_STAT_ONOMEM);
1046 			/* XXX maybe less ? */
1047 			goto retry_later;
1048 		}
1049 		len = sizeof(*ip6) + sizeof(ch);
1050 		m->m_pkthdr.len = len;
1051 		m->m_pkthdr.rcvif = NULL;
1052 		m->m_len = len;
1053 		MH_ALIGN(m, m->m_len);
1054 		m->m_flags |= M_MCAST;
1055 		ip6 = mtod(m, struct ip6_hdr *);
1056 		memset(ip6, 0, sizeof(*ip6));
1057 		ip6->ip6_vfc |= IPV6_VERSION;
1058 		ip6->ip6_hlim = CARP_DFLTTL;
1059 		ip6->ip6_nxt = IPPROTO_CARP;
1060 
1061 		/* set the source address */
1062 		memset(&sa, 0, sizeof(sa));
1063 		sa.sa_family = AF_INET6;
1064 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
1065 		if (ifa == NULL)	/* This should never happen with IPv6 */
1066 			memset(&ip6->ip6_src, 0, sizeof(struct in6_addr));
1067 		else
1068 			bcopy(ifatoia6(ifa)->ia_addr.sin6_addr.s6_addr,
1069 			    &ip6->ip6_src, sizeof(struct in6_addr));
1070 		/* set the multicast destination */
1071 
1072 		ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
1073 		ip6->ip6_dst.s6_addr8[15] = 0x12;
1074 		if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1075 			sc->sc_if.if_oerrors++;
1076 			m_freem(m);
1077 			CARP_LOG(sc, ("in6_setscope failed"));
1078 			goto retry_later;
1079 		}
1080 
1081 		ch_ptr = (struct carp_header *)(&ip6[1]);
1082 		memcpy(ch_ptr, &ch, sizeof(ch));
1083 		if (carp_prepare_ad(m, sc, ch_ptr))
1084 			goto retry_later;
1085 
1086 		m->m_data += sizeof(*ip6);
1087 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
1088 		m->m_data -= sizeof(*ip6);
1089 
1090 		nanotime(&sc->sc_if.if_lastchange);
1091 		sc->sc_if.if_opackets++;
1092 		sc->sc_if.if_obytes += len;
1093 		CARP_STATINC(CARP_STAT_OPACKETS6);
1094 
1095 		error = ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL);
1096 		if (error) {
1097 			if (error == ENOBUFS)
1098 				CARP_STATINC(CARP_STAT_ONOMEM);
1099 			else
1100 				CARP_LOG(sc, ("ip6_output failed: %d", error));
1101 			sc->sc_if.if_oerrors++;
1102 			if (sc->sc_sendad_errors < INT_MAX)
1103 				sc->sc_sendad_errors++;
1104 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1105 				carp_suppress_preempt++;
1106 				if (carp_suppress_preempt == 1)
1107 					carp_send_ad_all();
1108 			}
1109 			sc->sc_sendad_success = 0;
1110 		} else {
1111 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1112 				if (++sc->sc_sendad_success >=
1113 				    CARP_SENDAD_MIN_SUCCESS) {
1114 					carp_suppress_preempt--;
1115 					sc->sc_sendad_errors = 0;
1116 				}
1117 			} else
1118 				sc->sc_sendad_errors = 0;
1119 		}
1120 	}
1121 #endif /* INET6 */
1122 
1123 retry_later:
1124 	splx(s);
1125 	if (advbase != 255 || advskew != 255)
1126 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1127 }
1128 
1129 /*
1130  * Broadcast a gratuitous ARP request containing
1131  * the virtual router MAC address for each IP address
1132  * associated with the virtual router.
1133  */
1134 void
1135 carp_send_arp(struct carp_softc *sc)
1136 {
1137 	struct ifaddr *ifa;
1138 	struct in_addr *in;
1139 	int s = splsoftnet();
1140 
1141 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1142 
1143 		if (ifa->ifa_addr->sa_family != AF_INET)
1144 			continue;
1145 
1146 		in = &ifatoia(ifa)->ia_addr.sin_addr;
1147 		arprequest(sc->sc_carpdev, in, in, CLLADDR(sc->sc_if.if_sadl));
1148 	}
1149 	splx(s);
1150 }
1151 
1152 #ifdef INET6
1153 void
1154 carp_send_na(struct carp_softc *sc)
1155 {
1156 	struct ifaddr *ifa;
1157 	struct in6_addr *in6;
1158 	static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1159 	int s = splsoftnet();
1160 
1161 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1162 
1163 		if (ifa->ifa_addr->sa_family != AF_INET6)
1164 			continue;
1165 
1166 		in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1167 		nd6_na_output(sc->sc_carpdev, &mcast, in6,
1168 		    ND_NA_FLAG_OVERRIDE, 1, NULL);
1169 	}
1170 	splx(s);
1171 }
1172 #endif /* INET6 */
1173 
1174 /*
1175  * Based on bridge_hash() in if_bridge.c
1176  */
1177 #define	mix(a,b,c) \
1178 	do {						\
1179 		a -= b; a -= c; a ^= (c >> 13);		\
1180 		b -= c; b -= a; b ^= (a << 8);		\
1181 		c -= a; c -= b; c ^= (b >> 13);		\
1182 		a -= b; a -= c; a ^= (c >> 12);		\
1183 		b -= c; b -= a; b ^= (a << 16);		\
1184 		c -= a; c -= b; c ^= (b >> 5);		\
1185 		a -= b; a -= c; a ^= (c >> 3);		\
1186 		b -= c; b -= a; b ^= (a << 10);		\
1187 		c -= a; c -= b; c ^= (b >> 15);		\
1188 	} while (0)
1189 
1190 u_int32_t
1191 carp_hash(struct carp_softc *sc, u_char *src)
1192 {
1193 	u_int32_t a = 0x9e3779b9, b = sc->sc_hashkey[0], c = sc->sc_hashkey[1];
1194 
1195 	c += sc->sc_key[3] << 24;
1196 	c += sc->sc_key[2] << 16;
1197 	c += sc->sc_key[1] << 8;
1198 	c += sc->sc_key[0];
1199 	b += src[5] << 8;
1200 	b += src[4];
1201 	a += src[3] << 24;
1202 	a += src[2] << 16;
1203 	a += src[1] << 8;
1204 	a += src[0];
1205 
1206 	mix(a, b, c);
1207 	return (c);
1208 }
1209 
1210 int
1211 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
1212 {
1213 	struct carp_softc *vh;
1214 	struct ifaddr *ifa;
1215 	int count = 0;
1216 
1217 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1218 		if ((type == CARP_COUNT_RUNNING &&
1219 		    (vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1220 		    (IFF_UP|IFF_RUNNING)) ||
1221 		    (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
1222 			IFADDR_FOREACH(ifa, &vh->sc_if) {
1223 				if (ifa->ifa_addr->sa_family == AF_INET &&
1224 				    ia->ia_addr.sin_addr.s_addr ==
1225 				    ifatoia(ifa)->ia_addr.sin_addr.s_addr)
1226 					count++;
1227 			}
1228 		}
1229 	}
1230 	return (count);
1231 }
1232 
1233 int
1234 carp_iamatch(struct in_ifaddr *ia, u_char *src,
1235     u_int32_t *count, u_int32_t index)
1236 {
1237 	struct carp_softc *sc = ia->ia_ifp->if_softc;
1238 
1239 	if (carp_opts[CARPCTL_ARPBALANCE]) {
1240 		/*
1241 		 * We use the source ip to decide which virtual host should
1242 		 * handle the request. If we're master of that virtual host,
1243 		 * then we respond, otherwise, just drop the arp packet on
1244 		 * the floor.
1245 		 */
1246 
1247 		/* Count the elegible carp interfaces with this address */
1248 		if (*count == 0)
1249 			*count = carp_addrcount(
1250 			    (struct carp_if *)ia->ia_ifp->if_carpdev->if_carp,
1251 			    ia, CARP_COUNT_RUNNING);
1252 
1253 		/* This should never happen, but... */
1254 		if (*count == 0)
1255 			return (0);
1256 
1257 		if (carp_hash(sc, src) % *count == index - 1 &&
1258 		    sc->sc_state == MASTER) {
1259 			return (1);
1260 		}
1261 	} else {
1262 		if (sc->sc_state == MASTER)
1263 			return (1);
1264 	}
1265 
1266 	return (0);
1267 }
1268 
1269 #ifdef INET6
1270 struct ifaddr *
1271 carp_iamatch6(void *v, struct in6_addr *taddr)
1272 {
1273 	struct carp_if *cif = v;
1274 	struct carp_softc *vh;
1275 	struct ifaddr *ifa;
1276 
1277 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1278 		IFADDR_FOREACH(ifa, &vh->sc_if) {
1279 			if (IN6_ARE_ADDR_EQUAL(taddr,
1280 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1281 			    ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1282 			    (IFF_UP|IFF_RUNNING)) && vh->sc_state == MASTER)
1283 				return (ifa);
1284 		}
1285 	}
1286 
1287 	return (NULL);
1288 }
1289 #endif /* INET6 */
1290 
1291 struct ifnet *
1292 carp_ourether(void *v, struct ether_header *eh, u_char iftype, int src)
1293 {
1294 	struct carp_if *cif = (struct carp_if *)v;
1295 	struct carp_softc *vh;
1296 	u_int8_t *ena;
1297 
1298 	if (src)
1299 		ena = (u_int8_t *)&eh->ether_shost;
1300 	else
1301 		ena = (u_int8_t *)&eh->ether_dhost;
1302 
1303 	switch (iftype) {
1304 	case IFT_ETHER:
1305 	case IFT_FDDI:
1306 		if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1307 			return (NULL);
1308 		break;
1309 	case IFT_ISO88025:
1310 		if (ena[0] != 3 || ena[1] || ena[4] || ena[5])
1311 			return (NULL);
1312 		break;
1313 	default:
1314 		return (NULL);
1315 		break;
1316 	}
1317 
1318 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
1319 		if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1320 		    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER &&
1321 		    !memcmp(ena, CLLADDR(vh->sc_if.if_sadl),
1322 		    ETHER_ADDR_LEN)) {
1323 			return (&vh->sc_if);
1324 		    }
1325 
1326 	return (NULL);
1327 }
1328 
1329 int
1330 carp_input(struct mbuf *m, u_int8_t *shost, u_int8_t *dhost, u_int16_t etype)
1331 {
1332 	struct ether_header eh;
1333 	struct carp_if *cif = (struct carp_if *)m->m_pkthdr.rcvif->if_carp;
1334 	struct ifnet *ifp;
1335 
1336 	memcpy(&eh.ether_shost, shost, sizeof(eh.ether_shost));
1337 	memcpy(&eh.ether_dhost, dhost, sizeof(eh.ether_dhost));
1338 	eh.ether_type = etype;
1339 
1340 	if (m->m_flags & (M_BCAST|M_MCAST)) {
1341 		struct carp_softc *vh;
1342 		struct mbuf *m0;
1343 
1344 		/*
1345 		 * XXX Should really check the list of multicast addresses
1346 		 * for each CARP interface _before_ copying.
1347 		 */
1348 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1349 			m0 = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
1350 			if (m0 == NULL)
1351 				continue;
1352 			m0->m_pkthdr.rcvif = &vh->sc_if;
1353 			ether_input(&vh->sc_if, m0);
1354 		}
1355 		return (1);
1356 	}
1357 
1358 	ifp = carp_ourether(cif, &eh, m->m_pkthdr.rcvif->if_type, 0);
1359 	if (ifp == NULL) {
1360 		return (1);
1361 	}
1362 
1363 	m->m_pkthdr.rcvif = ifp;
1364 
1365 	bpf_mtap(ifp, m);
1366 	ifp->if_ipackets++;
1367 	ether_input(ifp, m);
1368 	return (0);
1369 }
1370 
1371 void
1372 carp_master_down(void *v)
1373 {
1374 	struct carp_softc *sc = v;
1375 
1376 	switch (sc->sc_state) {
1377 	case INIT:
1378 		printf("%s: master_down event in INIT state\n",
1379 		    sc->sc_if.if_xname);
1380 		break;
1381 	case MASTER:
1382 		break;
1383 	case BACKUP:
1384 		CARP_LOG(sc, ("INIT -> MASTER (preempting)"));
1385 		carp_set_state(sc, MASTER);
1386 		carp_send_ad(sc);
1387 		carp_send_arp(sc);
1388 #ifdef INET6
1389 		carp_send_na(sc);
1390 #endif /* INET6 */
1391 		carp_setrun(sc, 0);
1392 		carp_setroute(sc, RTM_ADD);
1393 		break;
1394 	}
1395 }
1396 
1397 /*
1398  * When in backup state, af indicates whether to reset the master down timer
1399  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1400  */
1401 void
1402 carp_setrun(struct carp_softc *sc, sa_family_t af)
1403 {
1404 	struct timeval tv;
1405 
1406 	if (sc->sc_carpdev == NULL) {
1407 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1408 		carp_set_state(sc, INIT);
1409 		return;
1410 	}
1411 
1412 	if (sc->sc_if.if_flags & IFF_UP && sc->sc_vhid > 0 &&
1413 	    (sc->sc_naddrs || sc->sc_naddrs6) && !sc->sc_suppress) {
1414 		sc->sc_if.if_flags |= IFF_RUNNING;
1415 	} else {
1416 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1417 		carp_setroute(sc, RTM_DELETE);
1418 		return;
1419 	}
1420 
1421 	switch (sc->sc_state) {
1422 	case INIT:
1423 		carp_set_state(sc, BACKUP);
1424 		carp_setroute(sc, RTM_DELETE);
1425 		carp_setrun(sc, 0);
1426 		break;
1427 	case BACKUP:
1428 		callout_stop(&sc->sc_ad_tmo);
1429 		tv.tv_sec = 3 * sc->sc_advbase;
1430 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1431 		switch (af) {
1432 #ifdef INET
1433 		case AF_INET:
1434 			callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1435 			break;
1436 #endif /* INET */
1437 #ifdef INET6
1438 		case AF_INET6:
1439 			callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1440 			break;
1441 #endif /* INET6 */
1442 		default:
1443 			if (sc->sc_naddrs)
1444 				callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1445 			if (sc->sc_naddrs6)
1446 				callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1447 			break;
1448 		}
1449 		break;
1450 	case MASTER:
1451 		tv.tv_sec = sc->sc_advbase;
1452 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1453 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1454 		break;
1455 	}
1456 }
1457 
1458 void
1459 carp_multicast_cleanup(struct carp_softc *sc)
1460 {
1461 	struct ip_moptions *imo = &sc->sc_imo;
1462 #ifdef INET6
1463 	struct ip6_moptions *im6o = &sc->sc_im6o;
1464 #endif
1465 	u_int16_t n = imo->imo_num_memberships;
1466 
1467 	/* Clean up our own multicast memberships */
1468 	while (n-- > 0) {
1469 		if (imo->imo_membership[n] != NULL) {
1470 			in_delmulti(imo->imo_membership[n]);
1471 			imo->imo_membership[n] = NULL;
1472 		}
1473 	}
1474 	imo->imo_num_memberships = 0;
1475 	imo->imo_multicast_ifp = NULL;
1476 
1477 #ifdef INET6
1478 	while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1479 		struct in6_multi_mship *imm =
1480 		    LIST_FIRST(&im6o->im6o_memberships);
1481 
1482 		LIST_REMOVE(imm, i6mm_chain);
1483 		in6_leavegroup(imm);
1484 	}
1485 	im6o->im6o_multicast_ifp = NULL;
1486 #endif
1487 
1488 	/* And any other multicast memberships */
1489 	carp_ether_purgemulti(sc);
1490 }
1491 
1492 int
1493 carp_set_ifp(struct carp_softc *sc, struct ifnet *ifp)
1494 {
1495 	struct carp_if *cif, *ncif = NULL;
1496 	struct carp_softc *vr, *after = NULL;
1497 	int myself = 0, error = 0;
1498 	int s;
1499 
1500 	if (ifp == sc->sc_carpdev)
1501 		return (0);
1502 
1503 	if (ifp != NULL) {
1504 		if ((ifp->if_flags & IFF_MULTICAST) == 0)
1505 			return (EADDRNOTAVAIL);
1506 
1507 		if (ifp->if_type == IFT_CARP)
1508 			return (EINVAL);
1509 
1510 		if (ifp->if_carp == NULL) {
1511 			ncif = malloc(sizeof(*cif), M_IFADDR, M_NOWAIT);
1512 			if (ncif == NULL)
1513 				return (ENOBUFS);
1514 			if ((error = ifpromisc(ifp, 1))) {
1515 				free(ncif, M_IFADDR);
1516 				return (error);
1517 			}
1518 
1519 			ncif->vhif_ifp = ifp;
1520 			TAILQ_INIT(&ncif->vhif_vrs);
1521 		} else {
1522 			cif = (struct carp_if *)ifp->if_carp;
1523 			TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1524 				if (vr != sc && vr->sc_vhid == sc->sc_vhid)
1525 					return (EINVAL);
1526 		}
1527 
1528 		/* detach from old interface */
1529 		if (sc->sc_carpdev != NULL)
1530 			carpdetach(sc);
1531 
1532 		/* join multicast groups */
1533 		if (sc->sc_naddrs < 0 &&
1534 		    (error = carp_join_multicast(sc)) != 0) {
1535 			if (ncif != NULL)
1536 				free(ncif, M_IFADDR);
1537 			return (error);
1538 		}
1539 
1540 #ifdef INET6
1541 		if (sc->sc_naddrs6 < 0 &&
1542 		    (error = carp_join_multicast6(sc)) != 0) {
1543 			if (ncif != NULL)
1544 				free(ncif, M_IFADDR);
1545 			carp_multicast_cleanup(sc);
1546 			return (error);
1547 		}
1548 #endif
1549 
1550 		/* attach carp interface to physical interface */
1551 		if (ncif != NULL)
1552 			ifp->if_carp = (void *)ncif;
1553 		sc->sc_carpdev = ifp;
1554 		sc->sc_if.if_capabilities = ifp->if_capabilities &
1555 		             (IFCAP_TSOv4 | IFCAP_TSOv6 |
1556                              IFCAP_CSUM_IPv4_Tx|IFCAP_CSUM_IPv4_Rx|
1557                              IFCAP_CSUM_TCPv4_Tx|IFCAP_CSUM_TCPv4_Rx|
1558                              IFCAP_CSUM_UDPv4_Tx|IFCAP_CSUM_UDPv4_Rx|
1559                              IFCAP_CSUM_TCPv6_Tx|IFCAP_CSUM_TCPv6_Rx|
1560                              IFCAP_CSUM_UDPv6_Tx|IFCAP_CSUM_UDPv6_Rx);
1561 
1562 		cif = (struct carp_if *)ifp->if_carp;
1563 		TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1564 			if (vr == sc)
1565 				myself = 1;
1566 			if (vr->sc_vhid < sc->sc_vhid)
1567 				after = vr;
1568 		}
1569 
1570 		if (!myself) {
1571 			/* We're trying to keep things in order */
1572 			if (after == NULL) {
1573 				TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1574 			} else {
1575 				TAILQ_INSERT_AFTER(&cif->vhif_vrs, after,
1576 				    sc, sc_list);
1577 			}
1578 			cif->vhif_nvrs++;
1579 		}
1580 		if (sc->sc_naddrs || sc->sc_naddrs6)
1581 			sc->sc_if.if_flags |= IFF_UP;
1582 		carp_set_enaddr(sc);
1583 		s = splnet();
1584 		/* XXX linkstatehooks establish */
1585 		carp_carpdev_state(ifp);
1586 		splx(s);
1587 	} else {
1588 		carpdetach(sc);
1589 		sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
1590 	}
1591 	return (0);
1592 }
1593 
1594 void
1595 carp_set_enaddr(struct carp_softc *sc)
1596 {
1597 	uint8_t enaddr[ETHER_ADDR_LEN];
1598 	if (sc->sc_carpdev && sc->sc_carpdev->if_type == IFT_ISO88025) {
1599 		enaddr[0] = 3;
1600 		enaddr[1] = 0;
1601 		enaddr[2] = 0x40 >> (sc->sc_vhid - 1);
1602 		enaddr[3] = 0x40000 >> (sc->sc_vhid - 1);
1603 		enaddr[4] = 0;
1604 		enaddr[5] = 0;
1605 	} else {
1606 		enaddr[0] = 0;
1607 		enaddr[1] = 0;
1608 		enaddr[2] = 0x5e;
1609 		enaddr[3] = 0;
1610 		enaddr[4] = 1;
1611 		enaddr[5] = sc->sc_vhid;
1612 	}
1613 	if_set_sadl(&sc->sc_if, enaddr, sizeof(enaddr), false);
1614 }
1615 
1616 void
1617 carp_addr_updated(void *v)
1618 {
1619 	struct carp_softc *sc = (struct carp_softc *) v;
1620 	struct ifaddr *ifa;
1621 	int new_naddrs = 0, new_naddrs6 = 0;
1622 
1623 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1624 		if (ifa->ifa_addr->sa_family == AF_INET)
1625 			new_naddrs++;
1626 		else if (ifa->ifa_addr->sa_family == AF_INET6)
1627 			new_naddrs6++;
1628 	}
1629 
1630 	/* Handle a callback after SIOCDIFADDR */
1631 	if (new_naddrs < sc->sc_naddrs || new_naddrs6 < sc->sc_naddrs6) {
1632 		struct in_addr mc_addr;
1633 		struct in_multi *inm;
1634 
1635 		sc->sc_naddrs = new_naddrs;
1636 		sc->sc_naddrs6 = new_naddrs6;
1637 
1638 		/* Re-establish multicast membership removed by in_control */
1639 		mc_addr.s_addr = INADDR_CARP_GROUP;
1640 		IN_LOOKUP_MULTI(mc_addr, &sc->sc_if, inm);
1641 		if (inm == NULL) {
1642 			memset(&sc->sc_imo, 0, sizeof(sc->sc_imo));
1643 
1644 			if (sc->sc_carpdev != NULL && sc->sc_naddrs > 0)
1645 				carp_join_multicast(sc);
1646 		}
1647 
1648 		if (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) {
1649 			sc->sc_if.if_flags &= ~IFF_UP;
1650 			carp_set_state(sc, INIT);
1651 		} else
1652 			carp_hmac_prepare(sc);
1653 	}
1654 
1655 	carp_setrun(sc, 0);
1656 }
1657 
1658 int
1659 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1660 {
1661 	struct ifnet *ifp = sc->sc_carpdev;
1662 	struct in_ifaddr *ia, *ia_if;
1663 	int error = 0;
1664 
1665 	if (sin->sin_addr.s_addr == 0) {
1666 		if (!(sc->sc_if.if_flags & IFF_UP))
1667 			carp_set_state(sc, INIT);
1668 		if (sc->sc_naddrs)
1669 			sc->sc_if.if_flags |= IFF_UP;
1670 		carp_setrun(sc, 0);
1671 		return (0);
1672 	}
1673 
1674 	/* we have to do this by hand to ensure we don't match on ourselves */
1675 	ia_if = NULL;
1676 	for (ia = TAILQ_FIRST(&in_ifaddrhead); ia;
1677 	    ia = TAILQ_NEXT(ia, ia_list)) {
1678 
1679 		/* and, yeah, we need a multicast-capable iface too */
1680 		if (ia->ia_ifp != &sc->sc_if &&
1681 		    ia->ia_ifp->if_type != IFT_CARP &&
1682 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1683 		    (sin->sin_addr.s_addr & ia->ia_subnetmask) ==
1684 		    ia->ia_subnet) {
1685 			if (!ia_if)
1686 				ia_if = ia;
1687 		}
1688 	}
1689 
1690 	if (ia_if) {
1691 		ia = ia_if;
1692 		if (ifp) {
1693 			if (ifp != ia->ia_ifp)
1694 				return (EADDRNOTAVAIL);
1695 		} else {
1696 			ifp = ia->ia_ifp;
1697 		}
1698 	}
1699 
1700 	if ((error = carp_set_ifp(sc, ifp)))
1701 		return (error);
1702 
1703 	if (sc->sc_carpdev == NULL)
1704 		return (EADDRNOTAVAIL);
1705 
1706 	if (sc->sc_naddrs == 0 && (error = carp_join_multicast(sc)) != 0)
1707 		return (error);
1708 
1709 	sc->sc_naddrs++;
1710 	if (sc->sc_carpdev != NULL)
1711 		sc->sc_if.if_flags |= IFF_UP;
1712 
1713 	carp_set_state(sc, INIT);
1714 	carp_setrun(sc, 0);
1715 
1716 	/*
1717 	 * Hook if_addrhooks so that we get a callback after in_ifinit has run,
1718 	 * to correct any inappropriate routes that it inserted.
1719 	 */
1720 	if (sc->ah_cookie == 0) {
1721 		/* XXX link address hook */
1722 	}
1723 
1724 	return (0);
1725 }
1726 
1727 int
1728 carp_join_multicast(struct carp_softc *sc)
1729 {
1730 	struct ip_moptions *imo = &sc->sc_imo, tmpimo;
1731 	struct in_addr addr;
1732 
1733 	memset(&tmpimo, 0, sizeof(tmpimo));
1734 	addr.s_addr = INADDR_CARP_GROUP;
1735 	if ((tmpimo.imo_membership[0] =
1736 	    in_addmulti(&addr, &sc->sc_if)) == NULL) {
1737 		return (ENOBUFS);
1738 	}
1739 
1740 	imo->imo_membership[0] = tmpimo.imo_membership[0];
1741 	imo->imo_num_memberships = 1;
1742 	imo->imo_multicast_ifp = &sc->sc_if;
1743 	imo->imo_multicast_ttl = CARP_DFLTTL;
1744 	imo->imo_multicast_loop = 0;
1745 	return (0);
1746 }
1747 
1748 
1749 #ifdef INET6
1750 int
1751 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1752 {
1753 	struct ifnet *ifp = sc->sc_carpdev;
1754 	struct in6_ifaddr *ia, *ia_if;
1755 	int error = 0;
1756 
1757 	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1758 		if (!(sc->sc_if.if_flags & IFF_UP))
1759 			carp_set_state(sc, INIT);
1760 		if (sc->sc_naddrs6)
1761 			sc->sc_if.if_flags |= IFF_UP;
1762 		carp_setrun(sc, 0);
1763 		return (0);
1764 	}
1765 
1766 	/* we have to do this by hand to ensure we don't match on ourselves */
1767 	ia_if = NULL;
1768 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1769 		int i;
1770 
1771 		for (i = 0; i < 4; i++) {
1772 			if ((sin6->sin6_addr.s6_addr32[i] &
1773 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1774 			    (ia->ia_addr.sin6_addr.s6_addr32[i] &
1775 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1776 				break;
1777 		}
1778 		/* and, yeah, we need a multicast-capable iface too */
1779 		if (ia->ia_ifp != &sc->sc_if &&
1780 		    ia->ia_ifp->if_type != IFT_CARP &&
1781 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1782 		    (i == 4)) {
1783 			if (!ia_if)
1784 				ia_if = ia;
1785 		}
1786 	}
1787 
1788 	if (ia_if) {
1789 		ia = ia_if;
1790 		if (sc->sc_carpdev) {
1791 			if (sc->sc_carpdev != ia->ia_ifp)
1792 				return (EADDRNOTAVAIL);
1793 		} else {
1794 			ifp = ia->ia_ifp;
1795 		}
1796 	}
1797 
1798 	if ((error = carp_set_ifp(sc, ifp)))
1799 		return (error);
1800 
1801 	if (sc->sc_carpdev == NULL)
1802 		return (EADDRNOTAVAIL);
1803 
1804 	if (sc->sc_naddrs6 == 0 && (error = carp_join_multicast6(sc)) != 0)
1805 		return (error);
1806 
1807 	sc->sc_naddrs6++;
1808 	if (sc->sc_carpdev != NULL)
1809 		sc->sc_if.if_flags |= IFF_UP;
1810 	carp_set_state(sc, INIT);
1811 	carp_setrun(sc, 0);
1812 
1813 	return (0);
1814 }
1815 
1816 int
1817 carp_join_multicast6(struct carp_softc *sc)
1818 {
1819 	struct in6_multi_mship *imm, *imm2;
1820 	struct ip6_moptions *im6o = &sc->sc_im6o;
1821 	struct sockaddr_in6 addr6;
1822 	int error;
1823 
1824 	/* Join IPv6 CARP multicast group */
1825 	memset(&addr6, 0, sizeof(addr6));
1826 	addr6.sin6_family = AF_INET6;
1827 	addr6.sin6_len = sizeof(addr6);
1828 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1829 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1830 	addr6.sin6_addr.s6_addr8[15] = 0x12;
1831 	if ((imm = in6_joingroup(&sc->sc_if,
1832 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1833 		return (error);
1834 	}
1835 	/* join solicited multicast address */
1836 	memset(&addr6.sin6_addr, 0, sizeof(addr6.sin6_addr));
1837 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1838 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1839 	addr6.sin6_addr.s6_addr32[1] = 0;
1840 	addr6.sin6_addr.s6_addr32[2] = htonl(1);
1841 	addr6.sin6_addr.s6_addr32[3] = 0;
1842 	addr6.sin6_addr.s6_addr8[12] = 0xff;
1843 	if ((imm2 = in6_joingroup(&sc->sc_if,
1844 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1845 		in6_leavegroup(imm);
1846 		return (error);
1847 	}
1848 
1849 	/* apply v6 multicast membership */
1850 	im6o->im6o_multicast_ifp = &sc->sc_if;
1851 	if (imm)
1852 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm,
1853 		    i6mm_chain);
1854 	if (imm2)
1855 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm2,
1856 		    i6mm_chain);
1857 
1858 	return (0);
1859 }
1860 
1861 #endif /* INET6 */
1862 
1863 int
1864 carp_ioctl(struct ifnet *ifp, u_long cmd, void *data)
1865 {
1866 	struct lwp *l = curlwp;		/* XXX */
1867 	struct carp_softc *sc = ifp->if_softc, *vr;
1868 	struct carpreq carpr;
1869 	struct ifaddr *ifa;
1870 	struct ifreq *ifr;
1871 	struct ifnet *cdev = NULL;
1872 	int error = 0;
1873 
1874 	ifa = (struct ifaddr *)data;
1875 	ifr = (struct ifreq *)data;
1876 
1877 	switch (cmd) {
1878 	case SIOCINITIFADDR:
1879 		switch (ifa->ifa_addr->sa_family) {
1880 #ifdef INET
1881 		case AF_INET:
1882 			sc->sc_if.if_flags |= IFF_UP;
1883 			memcpy(ifa->ifa_dstaddr, ifa->ifa_addr,
1884 			    sizeof(struct sockaddr));
1885 			error = carp_set_addr(sc, satosin(ifa->ifa_addr));
1886 			break;
1887 #endif /* INET */
1888 #ifdef INET6
1889 		case AF_INET6:
1890 			sc->sc_if.if_flags|= IFF_UP;
1891 			error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1892 			break;
1893 #endif /* INET6 */
1894 		default:
1895 			error = EAFNOSUPPORT;
1896 			break;
1897 		}
1898 		break;
1899 
1900 	case SIOCSIFFLAGS:
1901 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
1902 			break;
1903 		if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
1904 			callout_stop(&sc->sc_ad_tmo);
1905 			callout_stop(&sc->sc_md_tmo);
1906 			callout_stop(&sc->sc_md6_tmo);
1907 			if (sc->sc_state == MASTER) {
1908 				/* we need the interface up to bow out */
1909 				sc->sc_if.if_flags |= IFF_UP;
1910 				sc->sc_bow_out = 1;
1911 				carp_send_ad(sc);
1912 			}
1913 			sc->sc_if.if_flags &= ~IFF_UP;
1914 			carp_set_state(sc, INIT);
1915 			carp_setrun(sc, 0);
1916 		} else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
1917 			sc->sc_if.if_flags |= IFF_UP;
1918 			carp_setrun(sc, 0);
1919 		}
1920 		break;
1921 
1922 	case SIOCSVH:
1923 		if (l == NULL)
1924 			break;
1925 		if ((error = kauth_authorize_network(l->l_cred,
1926 		    KAUTH_NETWORK_INTERFACE,
1927 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
1928 		    NULL)) != 0)
1929 			break;
1930 		if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
1931 			break;
1932 		error = 1;
1933 		if (carpr.carpr_carpdev[0] != '\0' &&
1934 		    (cdev = ifunit(carpr.carpr_carpdev)) == NULL)
1935 			return (EINVAL);
1936 		if ((error = carp_set_ifp(sc, cdev)))
1937 			return (error);
1938 		if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
1939 			switch (carpr.carpr_state) {
1940 			case BACKUP:
1941 				callout_stop(&sc->sc_ad_tmo);
1942 				carp_set_state(sc, BACKUP);
1943 				carp_setrun(sc, 0);
1944 				carp_setroute(sc, RTM_DELETE);
1945 				break;
1946 			case MASTER:
1947 				carp_master_down(sc);
1948 				break;
1949 			default:
1950 				break;
1951 			}
1952 		}
1953 		if (carpr.carpr_vhid > 0) {
1954 			if (carpr.carpr_vhid > 255) {
1955 				error = EINVAL;
1956 				break;
1957 			}
1958 			if (sc->sc_carpdev) {
1959 				struct carp_if *cif;
1960 				cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1961 				TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1962 					if (vr != sc &&
1963 					    vr->sc_vhid == carpr.carpr_vhid)
1964 						return (EINVAL);
1965 			}
1966 			sc->sc_vhid = carpr.carpr_vhid;
1967 			carp_set_enaddr(sc);
1968 			carp_set_state(sc, INIT);
1969 			error--;
1970 		}
1971 		if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
1972 			if (carpr.carpr_advskew > 254) {
1973 				error = EINVAL;
1974 				break;
1975 			}
1976 			if (carpr.carpr_advbase > 255) {
1977 				error = EINVAL;
1978 				break;
1979 			}
1980 			sc->sc_advbase = carpr.carpr_advbase;
1981 			sc->sc_advskew = carpr.carpr_advskew;
1982 			error--;
1983 		}
1984 		memcpy(sc->sc_key, carpr.carpr_key, sizeof(sc->sc_key));
1985 		if (error > 0)
1986 			error = EINVAL;
1987 		else {
1988 			error = 0;
1989 			carp_setrun(sc, 0);
1990 		}
1991 		break;
1992 
1993 	case SIOCGVH:
1994 		memset(&carpr, 0, sizeof(carpr));
1995 		if (sc->sc_carpdev != NULL)
1996 			strlcpy(carpr.carpr_carpdev, sc->sc_carpdev->if_xname,
1997 			    IFNAMSIZ);
1998 		carpr.carpr_state = sc->sc_state;
1999 		carpr.carpr_vhid = sc->sc_vhid;
2000 		carpr.carpr_advbase = sc->sc_advbase;
2001 		carpr.carpr_advskew = sc->sc_advskew;
2002 
2003 		if ((l != NULL) && (error = kauth_authorize_network(l->l_cred,
2004 		    KAUTH_NETWORK_INTERFACE,
2005 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
2006 		    NULL)) == 0)
2007 			memcpy(carpr.carpr_key, sc->sc_key,
2008 			    sizeof(carpr.carpr_key));
2009 		error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
2010 		break;
2011 
2012 	case SIOCADDMULTI:
2013 		error = carp_ether_addmulti(sc, ifr);
2014 		break;
2015 
2016 	case SIOCDELMULTI:
2017 		error = carp_ether_delmulti(sc, ifr);
2018 		break;
2019 
2020 	case SIOCSIFCAP:
2021 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
2022 			error = 0;
2023 		break;
2024 
2025 	default:
2026 		error = ether_ioctl(ifp, cmd, data);
2027 	}
2028 
2029 	carp_hmac_prepare(sc);
2030 	return (error);
2031 }
2032 
2033 
2034 /*
2035  * Start output on carp interface. This function should never be called.
2036  */
2037 void
2038 carp_start(struct ifnet *ifp)
2039 {
2040 #ifdef DEBUG
2041 	printf("%s: start called\n", ifp->if_xname);
2042 #endif
2043 }
2044 
2045 int
2046 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa,
2047     struct rtentry *rt)
2048 {
2049 	struct carp_softc *sc = ((struct carp_softc *)ifp->if_softc);
2050 
2051 	if (sc->sc_carpdev != NULL && sc->sc_state == MASTER) {
2052 		return (sc->sc_carpdev->if_output(ifp, m, sa, rt));
2053 	} else {
2054 		m_freem(m);
2055 		return (ENETUNREACH);
2056 	}
2057 }
2058 
2059 void
2060 carp_set_state(struct carp_softc *sc, int state)
2061 {
2062 	static const char *carp_states[] = { CARP_STATES };
2063 	if (sc->sc_state == state)
2064 		return;
2065 
2066 	CARP_LOG(sc, ("state transition from: %s -> to: %s", carp_states[sc->sc_state], carp_states[state]));
2067 
2068 	sc->sc_state = state;
2069 	switch (state) {
2070 	case BACKUP:
2071 		sc->sc_if.if_link_state = LINK_STATE_DOWN;
2072 		break;
2073 	case MASTER:
2074 		sc->sc_if.if_link_state = LINK_STATE_UP;
2075 		break;
2076 	default:
2077 		sc->sc_if.if_link_state = LINK_STATE_UNKNOWN;
2078 		break;
2079 	}
2080 	rt_ifmsg(&sc->sc_if);
2081 }
2082 
2083 void
2084 carp_carpdev_state(void *v)
2085 {
2086 	struct carp_if *cif;
2087 	struct carp_softc *sc;
2088 	struct ifnet *ifp = v;
2089 
2090 	if (ifp->if_type == IFT_CARP)
2091 		return;
2092 
2093 	cif = (struct carp_if *)ifp->if_carp;
2094 
2095 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
2096 		int suppressed = sc->sc_suppress;
2097 
2098 		if (sc->sc_carpdev->if_link_state == LINK_STATE_DOWN ||
2099 		    !(sc->sc_carpdev->if_flags & IFF_UP)) {
2100 			sc->sc_if.if_flags &= ~IFF_RUNNING;
2101 			callout_stop(&sc->sc_ad_tmo);
2102 			callout_stop(&sc->sc_md_tmo);
2103 			callout_stop(&sc->sc_md6_tmo);
2104 			carp_set_state(sc, INIT);
2105 			sc->sc_suppress = 1;
2106 			carp_setrun(sc, 0);
2107 			if (!suppressed) {
2108 				carp_suppress_preempt++;
2109 				if (carp_suppress_preempt == 1)
2110 					carp_send_ad_all();
2111 			}
2112 		} else {
2113 			carp_set_state(sc, INIT);
2114 			sc->sc_suppress = 0;
2115 			carp_setrun(sc, 0);
2116 			if (suppressed)
2117 				carp_suppress_preempt--;
2118 		}
2119 	}
2120 }
2121 
2122 int
2123 carp_ether_addmulti(struct carp_softc *sc, struct ifreq *ifr)
2124 {
2125 	const struct sockaddr *sa = ifreq_getaddr(SIOCADDMULTI, ifr);
2126 	struct ifnet *ifp;
2127 	struct carp_mc_entry *mc;
2128 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2129 	int error;
2130 
2131 	ifp = sc->sc_carpdev;
2132 	if (ifp == NULL)
2133 		return (EINVAL);
2134 
2135 	error = ether_addmulti(sa, &sc->sc_ac);
2136 	if (error != ENETRESET)
2137 		return (error);
2138 
2139 	/*
2140 	 * This is new multicast address.  We have to tell parent
2141 	 * about it.  Also, remember this multicast address so that
2142 	 * we can delete them on unconfigure.
2143 	 */
2144 	mc = malloc(sizeof(struct carp_mc_entry), M_DEVBUF, M_NOWAIT);
2145 	if (mc == NULL) {
2146 		error = ENOMEM;
2147 		goto alloc_failed;
2148 	}
2149 
2150 	/*
2151 	 * As ether_addmulti() returns ENETRESET, following two
2152 	 * statement shouldn't fail.
2153 	 */
2154 	(void)ether_multiaddr(sa, addrlo, addrhi);
2155 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, mc->mc_enm);
2156 	memcpy(&mc->mc_addr, sa, sa->sa_len);
2157 	LIST_INSERT_HEAD(&sc->carp_mc_listhead, mc, mc_entries);
2158 
2159 	error = if_mcast_op(ifp, SIOCADDMULTI, sa);
2160 	if (error != 0)
2161 		goto ioctl_failed;
2162 
2163 	return (error);
2164 
2165  ioctl_failed:
2166 	LIST_REMOVE(mc, mc_entries);
2167 	free(mc, M_DEVBUF);
2168  alloc_failed:
2169 	(void)ether_delmulti(sa, &sc->sc_ac);
2170 
2171 	return (error);
2172 }
2173 
2174 int
2175 carp_ether_delmulti(struct carp_softc *sc, struct ifreq *ifr)
2176 {
2177 	const struct sockaddr *sa = ifreq_getaddr(SIOCDELMULTI, ifr);
2178 	struct ifnet *ifp;
2179 	struct ether_multi *enm;
2180 	struct carp_mc_entry *mc;
2181 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2182 	int error;
2183 
2184 	ifp = sc->sc_carpdev;
2185 	if (ifp == NULL)
2186 		return (EINVAL);
2187 
2188 	/*
2189 	 * Find a key to lookup carp_mc_entry.  We have to do this
2190 	 * before calling ether_delmulti for obvious reason.
2191 	 */
2192 	if ((error = ether_multiaddr(sa, addrlo, addrhi)) != 0)
2193 		return (error);
2194 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, enm);
2195 	if (enm == NULL)
2196 		return (EINVAL);
2197 
2198 	LIST_FOREACH(mc, &sc->carp_mc_listhead, mc_entries)
2199 		if (mc->mc_enm == enm)
2200 			break;
2201 
2202 	/* We won't delete entries we didn't add */
2203 	if (mc == NULL)
2204 		return (EINVAL);
2205 
2206 	error = ether_delmulti(sa, &sc->sc_ac);
2207 	if (error != ENETRESET)
2208 		return (error);
2209 
2210 	/* We no longer use this multicast address.  Tell parent so. */
2211 	error = if_mcast_op(ifp, SIOCDELMULTI, sa);
2212 	if (error == 0) {
2213 		/* And forget about this address. */
2214 		LIST_REMOVE(mc, mc_entries);
2215 		free(mc, M_DEVBUF);
2216 	} else
2217 		(void)ether_addmulti(sa, &sc->sc_ac);
2218 	return (error);
2219 }
2220 
2221 /*
2222  * Delete any multicast address we have asked to add from parent
2223  * interface.  Called when the carp is being unconfigured.
2224  */
2225 void
2226 carp_ether_purgemulti(struct carp_softc *sc)
2227 {
2228 	struct ifnet *ifp = sc->sc_carpdev;		/* Parent. */
2229 	struct carp_mc_entry *mc;
2230 
2231 	if (ifp == NULL)
2232 		return;
2233 
2234 	while ((mc = LIST_FIRST(&sc->carp_mc_listhead)) != NULL) {
2235 		(void)if_mcast_op(ifp, SIOCDELMULTI, sstosa(&mc->mc_addr));
2236 		LIST_REMOVE(mc, mc_entries);
2237 		free(mc, M_DEVBUF);
2238 	}
2239 }
2240 
2241 static int
2242 sysctl_net_inet_carp_stats(SYSCTLFN_ARGS)
2243 {
2244 
2245 	return (NETSTAT_SYSCTL(carpstat_percpu, CARP_NSTATS));
2246 }
2247 
2248 void
2249 carp_init(void)
2250 {
2251 
2252 	sysctl_net_inet_carp_setup(NULL);
2253 }
2254 
2255 static void
2256 sysctl_net_inet_carp_setup(struct sysctllog **clog)
2257 {
2258 
2259 	sysctl_createv(clog, 0, NULL, NULL,
2260 		       CTLFLAG_PERMANENT,
2261 		       CTLTYPE_NODE, "net", NULL,
2262 		       NULL, 0, NULL, 0,
2263 		       CTL_NET, CTL_EOL);
2264 	sysctl_createv(clog, 0, NULL, NULL,
2265 		       CTLFLAG_PERMANENT,
2266 		       CTLTYPE_NODE, "inet", NULL,
2267 		       NULL, 0, NULL, 0,
2268 		       CTL_NET, PF_INET, CTL_EOL);
2269 	sysctl_createv(clog, 0, NULL, NULL,
2270 		       CTLFLAG_PERMANENT,
2271 		       CTLTYPE_NODE, "carp",
2272 		       SYSCTL_DESCR("CARP related settings"),
2273 		       NULL, 0, NULL, 0,
2274 		       CTL_NET, PF_INET, IPPROTO_CARP, CTL_EOL);
2275 
2276 	sysctl_createv(clog, 0, NULL, NULL,
2277 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2278 		       CTLTYPE_INT, "preempt",
2279 		       SYSCTL_DESCR("Enable CARP Preempt"),
2280 		       NULL, 0, &carp_opts[CARPCTL_PREEMPT], 0,
2281 		       CTL_NET, PF_INET, IPPROTO_CARP,
2282 		       CTL_CREATE, CTL_EOL);
2283 	sysctl_createv(clog, 0, NULL, NULL,
2284 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2285 		       CTLTYPE_INT, "arpbalance",
2286 		       SYSCTL_DESCR("Enable ARP balancing"),
2287 		       NULL, 0, &carp_opts[CARPCTL_ARPBALANCE], 0,
2288 		       CTL_NET, PF_INET, IPPROTO_CARP,
2289 		       CTL_CREATE, CTL_EOL);
2290 	sysctl_createv(clog, 0, NULL, NULL,
2291 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2292 		       CTLTYPE_INT, "allow",
2293 		       SYSCTL_DESCR("Enable CARP"),
2294 		       NULL, 0, &carp_opts[CARPCTL_ALLOW], 0,
2295 		       CTL_NET, PF_INET, IPPROTO_CARP,
2296 		       CTL_CREATE, CTL_EOL);
2297 	sysctl_createv(clog, 0, NULL, NULL,
2298 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2299 		       CTLTYPE_INT, "log",
2300 		       SYSCTL_DESCR("CARP logging"),
2301 		       NULL, 0, &carp_opts[CARPCTL_LOG], 0,
2302 		       CTL_NET, PF_INET, IPPROTO_CARP,
2303 		       CTL_CREATE, CTL_EOL);
2304 	sysctl_createv(clog, 0, NULL, NULL,
2305 		       CTLFLAG_PERMANENT,
2306 		       CTLTYPE_STRUCT, "stats",
2307 		       SYSCTL_DESCR("CARP statistics"),
2308 		       sysctl_net_inet_carp_stats, 0, NULL, 0,
2309 		       CTL_NET, PF_INET, IPPROTO_CARP, CARPCTL_STATS,
2310 		       CTL_EOL);
2311 }
2312