xref: /netbsd-src/sys/netinet/ip_carp.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: ip_carp.c,v 1.30 2009/01/11 02:45:54 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 <sys/cdefs.h>
31 __KERNEL_RCSID(0, "$NetBSD: ip_carp.c,v 1.30 2009/01/11 02:45:54 christos Exp $");
32 
33 /*
34  * TODO:
35  *	- iface reconfigure
36  *	- support for hardware checksum calculations;
37  *
38  */
39 
40 #include <sys/param.h>
41 #include <sys/proc.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/socketvar.h>
45 #include <sys/callout.h>
46 #include <sys/ioctl.h>
47 #include <sys/errno.h>
48 #include <sys/device.h>
49 #include <sys/time.h>
50 #include <sys/kernel.h>
51 #include <sys/kauth.h>
52 #include <sys/sysctl.h>
53 #include <sys/ucred.h>
54 #include <sys/syslog.h>
55 #include <sys/acct.h>
56 
57 #include <sys/cpu.h>
58 
59 #include <net/if.h>
60 #include <net/pfil.h>
61 #include <net/if_types.h>
62 #include <net/if_ether.h>
63 #include <net/route.h>
64 #include <net/netisr.h>
65 #include <net/net_stats.h>
66 #include <netinet/if_inarp.h>
67 
68 #include <machine/stdarg.h>
69 
70 #if NFDDI > 0
71 #include <net/if_fddi.h>
72 #endif
73 #if NTOKEN > 0
74 #include <net/if_token.h>
75 #endif
76 
77 #ifdef INET
78 #include <netinet/in.h>
79 #include <netinet/in_systm.h>
80 #include <netinet/in_var.h>
81 #include <netinet/ip.h>
82 #include <netinet/ip_var.h>
83 
84 #include <net/if_dl.h>
85 #endif
86 
87 #ifdef INET6
88 #include <netinet/icmp6.h>
89 #include <netinet/ip6.h>
90 #include <netinet6/ip6_var.h>
91 #include <netinet6/nd6.h>
92 #include <netinet6/scope6_var.h>
93 #endif
94 
95 #include "bpfilter.h"
96 #if NBPFILTER > 0
97 #include <net/bpf.h>
98 #endif
99 
100 #include <sys/sha1.h>
101 
102 #include <netinet/ip_carp.h>
103 
104 struct carp_mc_entry {
105 	LIST_ENTRY(carp_mc_entry)	mc_entries;
106 	union {
107 		struct ether_multi	*mcu_enm;
108 	} mc_u;
109 	struct sockaddr_storage		mc_addr;
110 };
111 #define	mc_enm	mc_u.mcu_enm
112 
113 struct carp_softc {
114 	struct ethercom sc_ac;
115 #define	sc_if		sc_ac.ec_if
116 #define	sc_carpdev	sc_ac.ec_if.if_carpdev
117 	int ah_cookie;
118 	int lh_cookie;
119 	struct ip_moptions sc_imo;
120 #ifdef INET6
121 	struct ip6_moptions sc_im6o;
122 #endif /* INET6 */
123 	TAILQ_ENTRY(carp_softc) sc_list;
124 
125 	enum { INIT = 0, BACKUP, MASTER }	sc_state;
126 
127 	int sc_suppress;
128 	int sc_bow_out;
129 
130 	int sc_sendad_errors;
131 #define CARP_SENDAD_MAX_ERRORS	3
132 	int sc_sendad_success;
133 #define CARP_SENDAD_MIN_SUCCESS 3
134 
135 	int sc_vhid;
136 	int sc_advskew;
137 	int sc_naddrs;
138 	int sc_naddrs6;
139 	int sc_advbase;		/* seconds */
140 	int sc_init_counter;
141 	u_int64_t sc_counter;
142 
143 	/* authentication */
144 #define CARP_HMAC_PAD	64
145 	unsigned char sc_key[CARP_KEY_LEN];
146 	unsigned char sc_pad[CARP_HMAC_PAD];
147 	SHA1_CTX sc_sha1;
148 	u_int32_t sc_hashkey[2];
149 
150 	struct callout sc_ad_tmo;	/* advertisement timeout */
151 	struct callout sc_md_tmo;	/* master down timeout */
152 	struct callout sc_md6_tmo;	/* master down timeout */
153 
154 	LIST_HEAD(__carp_mchead, carp_mc_entry)	carp_mc_listhead;
155 };
156 
157 int carp_suppress_preempt = 0;
158 int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 0, 0 };	/* XXX for now */
159 
160 static percpu_t *carpstat_percpu;
161 
162 #define	CARP_STATINC(x)		_NET_STATINC(carpstat_percpu, x)
163 
164 struct carp_if {
165 	TAILQ_HEAD(, carp_softc) vhif_vrs;
166 	int vhif_nvrs;
167 
168 	struct ifnet *vhif_ifp;
169 };
170 
171 #define	CARP_LOG(sc, s)							\
172 	if (carp_opts[CARPCTL_LOG]) {					\
173 		if (sc)							\
174 			log(LOG_INFO, "%s: ",				\
175 			    (sc)->sc_if.if_xname);			\
176 		else							\
177 			log(LOG_INFO, "carp: ");			\
178 		addlog s;						\
179 		addlog("\n");						\
180 	}
181 
182 void	carp_hmac_prepare(struct carp_softc *);
183 void	carp_hmac_generate(struct carp_softc *, u_int32_t *,
184 	    unsigned char *);
185 int	carp_hmac_verify(struct carp_softc *, u_int32_t *,
186 	    unsigned char *);
187 void	carp_setroute(struct carp_softc *, int);
188 void	carp_proto_input_c(struct mbuf *, struct carp_header *, sa_family_t);
189 void	carpattach(int);
190 void	carpdetach(struct carp_softc *);
191 int	carp_prepare_ad(struct mbuf *, struct carp_softc *,
192 	    struct carp_header *);
193 void	carp_send_ad_all(void);
194 void	carp_send_ad(void *);
195 void	carp_send_arp(struct carp_softc *);
196 void	carp_master_down(void *);
197 int	carp_ioctl(struct ifnet *, u_long, void *);
198 void	carp_start(struct ifnet *);
199 void	carp_setrun(struct carp_softc *, sa_family_t);
200 void	carp_set_state(struct carp_softc *, int);
201 int	carp_addrcount(struct carp_if *, struct in_ifaddr *, int);
202 enum	{ CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
203 
204 void	carp_multicast_cleanup(struct carp_softc *);
205 int	carp_set_ifp(struct carp_softc *, struct ifnet *);
206 void	carp_set_enaddr(struct carp_softc *);
207 void	carp_addr_updated(void *);
208 u_int32_t	carp_hash(struct carp_softc *, u_char *);
209 int	carp_set_addr(struct carp_softc *, struct sockaddr_in *);
210 int	carp_join_multicast(struct carp_softc *);
211 #ifdef INET6
212 void	carp_send_na(struct carp_softc *);
213 int	carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
214 int	carp_join_multicast6(struct carp_softc *);
215 #endif
216 int	carp_clone_create(struct if_clone *, int);
217 int	carp_clone_destroy(struct ifnet *);
218 int	carp_ether_addmulti(struct carp_softc *, struct ifreq *);
219 int	carp_ether_delmulti(struct carp_softc *, struct ifreq *);
220 void	carp_ether_purgemulti(struct carp_softc *);
221 
222 struct if_clone carp_cloner =
223     IF_CLONE_INITIALIZER("carp", carp_clone_create, carp_clone_destroy);
224 
225 static __inline u_int16_t
226 carp_cksum(struct mbuf *m, int len)
227 {
228 	return (in_cksum(m, len));
229 }
230 
231 void
232 carp_hmac_prepare(struct carp_softc *sc)
233 {
234 	u_int8_t carp_version = CARP_VERSION, type = CARP_ADVERTISEMENT;
235 	u_int8_t vhid = sc->sc_vhid & 0xff;
236 	SHA1_CTX sha1ctx;
237 	u_int32_t kmd[5];
238 	struct ifaddr *ifa;
239 	int i, found;
240 	struct in_addr last, cur, in;
241 #ifdef INET6
242 	struct in6_addr last6, cur6, in6;
243 #endif /* INET6 */
244 
245 	/* compute ipad from key */
246 	bzero(sc->sc_pad, sizeof(sc->sc_pad));
247 	bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
248 	for (i = 0; i < sizeof(sc->sc_pad); i++)
249 		sc->sc_pad[i] ^= 0x36;
250 
251 	/* precompute first part of inner hash */
252 	SHA1Init(&sc->sc_sha1);
253 	SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
254 	SHA1Update(&sc->sc_sha1, (void *)&carp_version, sizeof(carp_version));
255 	SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
256 
257 	/* generate a key for the arpbalance hash, before the vhid is hashed */
258 	bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
259 	SHA1Final((unsigned char *)kmd, &sha1ctx);
260 	sc->sc_hashkey[0] = kmd[0] ^ kmd[1];
261 	sc->sc_hashkey[1] = kmd[2] ^ kmd[3];
262 
263 	/* the rest of the precomputation */
264 	SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
265 
266 	/* Hash the addresses from smallest to largest, not interface order */
267 #ifdef INET
268 	cur.s_addr = 0;
269 	do {
270 		found = 0;
271 		last = cur;
272 		cur.s_addr = 0xffffffff;
273 		IFADDR_FOREACH(ifa, &sc->sc_if) {
274 			in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
275 			if (ifa->ifa_addr->sa_family == AF_INET &&
276 			    ntohl(in.s_addr) > ntohl(last.s_addr) &&
277 			    ntohl(in.s_addr) < ntohl(cur.s_addr)) {
278 				cur.s_addr = in.s_addr;
279 				found++;
280 			}
281 		}
282 		if (found)
283 			SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
284 	} while (found);
285 #endif /* INET */
286 
287 #ifdef INET6
288 	memset(&cur6, 0x00, sizeof(cur6));
289 	do {
290 		found = 0;
291 		last6 = cur6;
292 		memset(&cur6, 0xff, sizeof(cur6));
293 		IFADDR_FOREACH(ifa, &sc->sc_if) {
294 			in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
295 			if (IN6_IS_ADDR_LINKLOCAL(&in6))
296 				in6.s6_addr16[1] = 0;
297 			if (ifa->ifa_addr->sa_family == AF_INET6 &&
298 			    memcmp(&in6, &last6, sizeof(in6)) > 0 &&
299 			    memcmp(&in6, &cur6, sizeof(in6)) < 0) {
300 				cur6 = in6;
301 				found++;
302 			}
303 		}
304 		if (found)
305 			SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
306 	} while (found);
307 #endif /* INET6 */
308 
309 	/* convert ipad to opad */
310 	for (i = 0; i < sizeof(sc->sc_pad); i++)
311 		sc->sc_pad[i] ^= 0x36 ^ 0x5c;
312 }
313 
314 void
315 carp_hmac_generate(struct carp_softc *sc, u_int32_t counter[2],
316     unsigned char md[20])
317 {
318 	SHA1_CTX sha1ctx;
319 
320 	/* fetch first half of inner hash */
321 	bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
322 
323 	SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
324 	SHA1Final(md, &sha1ctx);
325 
326 	/* outer hash */
327 	SHA1Init(&sha1ctx);
328 	SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
329 	SHA1Update(&sha1ctx, md, 20);
330 	SHA1Final(md, &sha1ctx);
331 }
332 
333 int
334 carp_hmac_verify(struct carp_softc *sc, u_int32_t counter[2],
335     unsigned char md[20])
336 {
337 	unsigned char md2[20];
338 
339 	carp_hmac_generate(sc, counter, md2);
340 
341 	return (bcmp(md, md2, sizeof(md2)));
342 }
343 
344 void
345 carp_setroute(struct carp_softc *sc, int cmd)
346 {
347 	struct ifaddr *ifa;
348 	int s;
349 
350 	s = splsoftnet();
351 	IFADDR_FOREACH(ifa, &sc->sc_if) {
352 		switch (ifa->ifa_addr->sa_family) {
353 		case AF_INET: {
354 			int count = 0;
355 			struct rtentry *rt;
356 			int hr_otherif, nr_ourif;
357 
358 			/*
359 			 * Avoid screwing with the routes if there are other
360 			 * carp interfaces which are master and have the same
361 			 * address.
362 			 */
363 			if (sc->sc_carpdev != NULL &&
364 			    sc->sc_carpdev->if_carp != NULL) {
365 				count = carp_addrcount(
366 				    (struct carp_if *)sc->sc_carpdev->if_carp,
367 				    ifatoia(ifa), CARP_COUNT_MASTER);
368 				if ((cmd == RTM_ADD && count != 1) ||
369 				    (cmd == RTM_DELETE && count != 0))
370 					continue;
371 			}
372 
373 			/* Remove the existing host route, if any */
374 			rtrequest(RTM_DELETE, ifa->ifa_addr,
375 			    ifa->ifa_addr, ifa->ifa_netmask,
376 			    RTF_HOST, NULL);
377 
378 			rt = NULL;
379 			(void)rtrequest(RTM_GET, ifa->ifa_addr, ifa->ifa_addr,
380 			    ifa->ifa_netmask, RTF_HOST, &rt);
381 			hr_otherif = (rt && rt->rt_ifp != &sc->sc_if &&
382 			    rt->rt_flags & (RTF_CLONING|RTF_CLONED));
383 			if (rt != NULL) {
384 				RTFREE(rt);
385 				rt = NULL;
386 			}
387 
388 			/* Check for a network route on our interface */
389 
390 			rt = NULL;
391 			(void)rtrequest(RTM_GET, ifa->ifa_addr, ifa->ifa_addr,
392 			    ifa->ifa_netmask, 0, &rt);
393 			nr_ourif = (rt && rt->rt_ifp == &sc->sc_if);
394 
395 			switch (cmd) {
396 			case RTM_ADD:
397 				if (hr_otherif) {
398 					ifa->ifa_rtrequest = NULL;
399 					ifa->ifa_flags &= ~RTF_CLONING;
400 
401 					rtrequest(RTM_ADD, ifa->ifa_addr,
402 					    ifa->ifa_addr, ifa->ifa_netmask,
403 					    RTF_UP | RTF_HOST, NULL);
404 				}
405 				if (!hr_otherif || nr_ourif || !rt) {
406 					if (nr_ourif && !(rt->rt_flags &
407 					    RTF_CLONING))
408 						rtrequest(RTM_DELETE,
409 						    ifa->ifa_addr,
410 						    ifa->ifa_addr,
411 						    ifa->ifa_netmask, 0, NULL);
412 
413 					ifa->ifa_rtrequest = arp_rtrequest;
414 					ifa->ifa_flags |= RTF_CLONING;
415 
416 					if (rtrequest(RTM_ADD, ifa->ifa_addr,
417 					    ifa->ifa_addr, ifa->ifa_netmask, 0,
418 					    NULL) == 0)
419 						ifa->ifa_flags |= IFA_ROUTE;
420 				}
421 				break;
422 			case RTM_DELETE:
423 				break;
424 			default:
425 				break;
426 			}
427 			if (rt != NULL) {
428 				RTFREE(rt);
429 				rt = NULL;
430 			}
431 			break;
432 		}
433 
434 #ifdef INET6
435 		case AF_INET6:
436 			if (cmd == RTM_ADD)
437 				in6_ifaddloop(ifa);
438 			else
439 				in6_ifremloop(ifa);
440 			break;
441 #endif /* INET6 */
442 		default:
443 			break;
444 		}
445 	}
446 	splx(s);
447 }
448 
449 /*
450  * process input packet.
451  * we have rearranged checks order compared to the rfc,
452  * but it seems more efficient this way or not possible otherwise.
453  */
454 void
455 carp_proto_input(struct mbuf *m, ...)
456 {
457 	struct ip *ip = mtod(m, struct ip *);
458 	struct carp_softc *sc = NULL;
459 	struct carp_header *ch;
460 	int iplen, len, hlen;
461 	va_list ap;
462 
463 	va_start(ap, m);
464 	hlen = va_arg(ap, int);
465 	va_end(ap);
466 
467 	CARP_STATINC(CARP_STAT_IPACKETS);
468 
469 	if (!carp_opts[CARPCTL_ALLOW]) {
470 		m_freem(m);
471 		return;
472 	}
473 
474 	/* check if received on a valid carp interface */
475 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
476 		CARP_STATINC(CARP_STAT_BADIF);
477 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
478 		    m->m_pkthdr.rcvif->if_xname));
479 		m_freem(m);
480 		return;
481 	}
482 
483 	/* verify that the IP TTL is 255.  */
484 	if (ip->ip_ttl != CARP_DFLTTL) {
485 		CARP_STATINC(CARP_STAT_BADTTL);
486 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip->ip_ttl,
487 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
488 		m_freem(m);
489 		return;
490 	}
491 
492 	/*
493 	 * verify that the received packet length is
494 	 * equal to the CARP header
495 	 */
496 	iplen = ip->ip_hl << 2;
497 	len = iplen + sizeof(*ch);
498 	if (len > m->m_pkthdr.len) {
499 		CARP_STATINC(CARP_STAT_BADLEN);
500 		CARP_LOG(sc, ("packet too short %d on %s", m->m_pkthdr.len,
501 		    m->m_pkthdr.rcvif->if_xname));
502 		m_freem(m);
503 		return;
504 	}
505 
506 	if ((m = m_pullup(m, len)) == NULL) {
507 		CARP_STATINC(CARP_STAT_HDROPS);
508 		return;
509 	}
510 	ip = mtod(m, struct ip *);
511 	ch = (struct carp_header *)((char *)ip + iplen);
512 	/* verify the CARP checksum */
513 	m->m_data += iplen;
514 	if (carp_cksum(m, len - iplen)) {
515 		CARP_STATINC(CARP_STAT_BADSUM);
516 		CARP_LOG(sc, ("checksum failed on %s",
517 		    m->m_pkthdr.rcvif->if_xname));
518 		m_freem(m);
519 		return;
520 	}
521 	m->m_data -= iplen;
522 
523 	carp_proto_input_c(m, ch, AF_INET);
524 }
525 
526 #ifdef INET6
527 int
528 carp6_proto_input(struct mbuf **mp, int *offp, int proto)
529 {
530 	struct mbuf *m = *mp;
531 	struct carp_softc *sc = NULL;
532 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
533 	struct carp_header *ch;
534 	u_int len;
535 
536 	CARP_STATINC(CARP_STAT_IPACKETS6);
537 
538 	if (!carp_opts[CARPCTL_ALLOW]) {
539 		m_freem(m);
540 		return (IPPROTO_DONE);
541 	}
542 
543 	/* check if received on a valid carp interface */
544 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
545 		CARP_STATINC(CARP_STAT_BADIF);
546 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
547 		    m->m_pkthdr.rcvif->if_xname));
548 		m_freem(m);
549 		return (IPPROTO_DONE);
550 	}
551 
552 	/* verify that the IP TTL is 255 */
553 	if (ip6->ip6_hlim != CARP_DFLTTL) {
554 		CARP_STATINC(CARP_STAT_BADTTL);
555 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip6->ip6_hlim,
556 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
557 		m_freem(m);
558 		return (IPPROTO_DONE);
559 	}
560 
561 	/* verify that we have a complete carp packet */
562 	len = m->m_len;
563 	IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
564 	if (ch == NULL) {
565 		CARP_STATINC(CARP_STAT_BADLEN);
566 		CARP_LOG(sc, ("packet size %u too small", len));
567 		return (IPPROTO_DONE);
568 	}
569 
570 
571 	/* verify the CARP checksum */
572 	m->m_data += *offp;
573 	if (carp_cksum(m, sizeof(*ch))) {
574 		CARP_STATINC(CARP_STAT_BADSUM);
575 		CARP_LOG(sc, ("checksum failed, on %s",
576 		    m->m_pkthdr.rcvif->if_xname));
577 		m_freem(m);
578 		return (IPPROTO_DONE);
579 	}
580 	m->m_data -= *offp;
581 
582 	carp_proto_input_c(m, ch, AF_INET6);
583 	return (IPPROTO_DONE);
584 }
585 #endif /* INET6 */
586 
587 void
588 carp_proto_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
589 {
590 	struct carp_softc *sc;
591 	u_int64_t tmp_counter;
592 	struct timeval sc_tv, ch_tv;
593 
594 	TAILQ_FOREACH(sc, &((struct carp_if *)
595 	    m->m_pkthdr.rcvif->if_carpdev->if_carp)->vhif_vrs, sc_list)
596 		if (sc->sc_vhid == ch->carp_vhid)
597 			break;
598 
599 	if (!sc || (sc->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) !=
600 	    (IFF_UP|IFF_RUNNING)) {
601 		CARP_STATINC(CARP_STAT_BADVHID);
602 		m_freem(m);
603 		return;
604 	}
605 
606 	/*
607 	 * Check if our own advertisement was duplicated
608 	 * from a non simplex interface.
609 	 * XXX If there is no address on our physical interface
610 	 * there is no way to distinguish our ads from the ones
611 	 * another carp host might have sent us.
612 	 */
613 	if ((sc->sc_carpdev->if_flags & IFF_SIMPLEX) == 0) {
614 		struct sockaddr sa;
615 		struct ifaddr *ifa;
616 
617 		bzero(&sa, sizeof(sa));
618 		sa.sa_family = af;
619 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
620 
621 		if (ifa && af == AF_INET) {
622 			struct ip *ip = mtod(m, struct ip *);
623 			if (ip->ip_src.s_addr ==
624 					ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
625 				m_freem(m);
626 				return;
627 			}
628 		}
629 #ifdef INET6
630 		if (ifa && af == AF_INET6) {
631 			struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
632 			struct in6_addr in6_src, in6_found;
633 
634 			in6_src = ip6->ip6_src;
635 			in6_found = ifatoia6(ifa)->ia_addr.sin6_addr;
636 			if (IN6_IS_ADDR_LINKLOCAL(&in6_src))
637 				in6_src.s6_addr16[1] = 0;
638 			if (IN6_IS_ADDR_LINKLOCAL(&in6_found))
639 				in6_found.s6_addr16[1] = 0;
640 			if (IN6_ARE_ADDR_EQUAL(&in6_src, &in6_found)) {
641 				m_freem(m);
642 				return;
643 			}
644 		}
645 #endif /* INET6 */
646 	}
647 
648 	nanotime(&sc->sc_if.if_lastchange);
649 	sc->sc_if.if_ipackets++;
650 	sc->sc_if.if_ibytes += m->m_pkthdr.len;
651 
652 	/* verify the CARP version. */
653 	if (ch->carp_version != CARP_VERSION) {
654 		CARP_STATINC(CARP_STAT_BADVER);
655 		sc->sc_if.if_ierrors++;
656 		CARP_LOG(sc, ("invalid version %d != %d",
657 		    ch->carp_version, CARP_VERSION));
658 		m_freem(m);
659 		return;
660 	}
661 
662 	/* verify the hash */
663 	if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
664 		CARP_STATINC(CARP_STAT_BADAUTH);
665 		sc->sc_if.if_ierrors++;
666 		CARP_LOG(sc, ("incorrect hash"));
667 		m_freem(m);
668 		return;
669 	}
670 
671 	tmp_counter = ntohl(ch->carp_counter[0]);
672 	tmp_counter = tmp_counter<<32;
673 	tmp_counter += ntohl(ch->carp_counter[1]);
674 
675 	/* XXX Replay protection goes here */
676 
677 	sc->sc_init_counter = 0;
678 	sc->sc_counter = tmp_counter;
679 
680 
681 	sc_tv.tv_sec = sc->sc_advbase;
682 	if (carp_suppress_preempt && sc->sc_advskew <  240)
683 		sc_tv.tv_usec = 240 * 1000000 / 256;
684 	else
685 		sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
686 	ch_tv.tv_sec = ch->carp_advbase;
687 	ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
688 
689 	switch (sc->sc_state) {
690 	case INIT:
691 		break;
692 	case MASTER:
693 		/*
694 		 * If we receive an advertisement from a backup who's going to
695 		 * be more frequent than us, go into BACKUP state.
696 		 */
697 		if (timercmp(&sc_tv, &ch_tv, >) ||
698 		    timercmp(&sc_tv, &ch_tv, ==)) {
699 			callout_stop(&sc->sc_ad_tmo);
700 			carp_set_state(sc, BACKUP);
701 			carp_setrun(sc, 0);
702 			carp_setroute(sc, RTM_DELETE);
703 		}
704 		break;
705 	case BACKUP:
706 		/*
707 		 * If we're pre-empting masters who advertise slower than us,
708 		 * and this one claims to be slower, treat him as down.
709 		 */
710 		if (carp_opts[CARPCTL_PREEMPT] && timercmp(&sc_tv, &ch_tv, <)) {
711 			carp_master_down(sc);
712 			break;
713 		}
714 
715 		/*
716 		 *  If the master is going to advertise at such a low frequency
717 		 *  that he's guaranteed to time out, we'd might as well just
718 		 *  treat him as timed out now.
719 		 */
720 		sc_tv.tv_sec = sc->sc_advbase * 3;
721 		if (timercmp(&sc_tv, &ch_tv, <)) {
722 			carp_master_down(sc);
723 			break;
724 		}
725 
726 		/*
727 		 * Otherwise, we reset the counter and wait for the next
728 		 * advertisement.
729 		 */
730 		carp_setrun(sc, af);
731 		break;
732 	}
733 
734 	m_freem(m);
735 	return;
736 }
737 
738 /*
739  * Interface side of the CARP implementation.
740  */
741 
742 /* ARGSUSED */
743 void
744 carpattach(int n)
745 {
746 	if_clone_attach(&carp_cloner);
747 
748 	carpstat_percpu = percpu_alloc(sizeof(uint64_t) * CARP_NSTATS);
749 }
750 
751 int
752 carp_clone_create(struct if_clone *ifc, int unit)
753 {
754 	extern int ifqmaxlen;
755 	struct carp_softc *sc;
756 	struct ifnet *ifp;
757 
758 	sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT|M_ZERO);
759 	if (!sc)
760 		return (ENOMEM);
761 
762 	sc->sc_suppress = 0;
763 	sc->sc_advbase = CARP_DFLTINTV;
764 	sc->sc_vhid = -1;	/* required setting */
765 	sc->sc_advskew = 0;
766 	sc->sc_init_counter = 1;
767 	sc->sc_naddrs = sc->sc_naddrs6 = 0;
768 #ifdef INET6
769 	sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
770 #endif /* INET6 */
771 
772 	callout_init(&sc->sc_ad_tmo, 0);
773 	callout_init(&sc->sc_md_tmo, 0);
774 	callout_init(&sc->sc_md6_tmo, 0);
775 
776 	callout_setfunc(&sc->sc_ad_tmo, carp_send_ad, sc);
777 	callout_setfunc(&sc->sc_md_tmo, carp_master_down, sc);
778 	callout_setfunc(&sc->sc_md6_tmo, carp_master_down, sc);
779 
780 	LIST_INIT(&sc->carp_mc_listhead);
781 	ifp = &sc->sc_if;
782 	ifp->if_softc = sc;
783 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "%s%d", ifc->ifc_name,
784 	    unit);
785 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
786 	ifp->if_ioctl = carp_ioctl;
787 	ifp->if_start = carp_start;
788 	ifp->if_output = carp_output;
789 	ifp->if_type = IFT_CARP;
790 	ifp->if_addrlen = ETHER_ADDR_LEN;
791 	ifp->if_hdrlen = ETHER_HDR_LEN;
792 	ifp->if_mtu = ETHERMTU;
793 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
794 	IFQ_SET_READY(&ifp->if_snd);
795 	if_attach(ifp);
796 
797 	if_alloc_sadl(ifp);
798 	ifp->if_broadcastaddr = etherbroadcastaddr;
799 	carp_set_enaddr(sc);
800 	LIST_INIT(&sc->sc_ac.ec_multiaddrs);
801 #if NBPFILTER > 0
802 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
803 #endif
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 = arc4random();
881 		sc->sc_counter = sc->sc_counter << 32;
882 		sc->sc_counter += arc4random();
883 	} else
884 		sc->sc_counter++;
885 
886 	ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
887 	ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
888 
889 	carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
890 
891 	return (0);
892 }
893 
894 void
895 carp_send_ad_all(void)
896 {
897 	struct ifnet *ifp;
898 	struct carp_if *cif;
899 	struct carp_softc *vh;
900 
901 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
902 		if (ifp->if_carp == NULL || ifp->if_type == IFT_CARP)
903 			continue;
904 
905 		cif = (struct carp_if *)ifp->if_carp;
906 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
907 			if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
908 			    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER)
909 				carp_send_ad(vh);
910 		}
911 	}
912 }
913 
914 
915 void
916 carp_send_ad(void *v)
917 {
918 	struct carp_header ch;
919 	struct timeval tv;
920 	struct carp_softc *sc = v;
921 	struct carp_header *ch_ptr;
922 	struct mbuf *m;
923 	int error, len, advbase, advskew, s;
924 	struct ifaddr *ifa;
925 	struct sockaddr sa;
926 
927 	s = splsoftnet();
928 
929 	advbase = advskew = 0; /* Sssssh compiler */
930 	if (sc->sc_carpdev == NULL) {
931 		sc->sc_if.if_oerrors++;
932 		goto retry_later;
933 	}
934 
935 	/* bow out if we've gone to backup (the carp interface is going down) */
936 	if (sc->sc_bow_out) {
937 		sc->sc_bow_out = 0;
938 		advbase = 255;
939 		advskew = 255;
940 	} else {
941 		advbase = sc->sc_advbase;
942 		if (!carp_suppress_preempt || sc->sc_advskew > 240)
943 			advskew = sc->sc_advskew;
944 		else
945 			advskew = 240;
946 		tv.tv_sec = advbase;
947 		tv.tv_usec = advskew * 1000000 / 256;
948 	}
949 
950 	ch.carp_version = CARP_VERSION;
951 	ch.carp_type = CARP_ADVERTISEMENT;
952 	ch.carp_vhid = sc->sc_vhid;
953 	ch.carp_advbase = advbase;
954 	ch.carp_advskew = advskew;
955 	ch.carp_authlen = 7;	/* XXX DEFINE */
956 	ch.carp_pad1 = 0;	/* must be zero */
957 	ch.carp_cksum = 0;
958 
959 
960 #ifdef INET
961 	if (sc->sc_naddrs) {
962 		struct ip *ip;
963 
964 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
965 		if (m == NULL) {
966 			sc->sc_if.if_oerrors++;
967 			CARP_STATINC(CARP_STAT_ONOMEM);
968 			/* XXX maybe less ? */
969 			goto retry_later;
970 		}
971 		len = sizeof(*ip) + sizeof(ch);
972 		m->m_pkthdr.len = len;
973 		m->m_pkthdr.rcvif = NULL;
974 		m->m_len = len;
975 		MH_ALIGN(m, m->m_len);
976 		m->m_flags |= M_MCAST;
977 		ip = mtod(m, struct ip *);
978 		ip->ip_v = IPVERSION;
979 		ip->ip_hl = sizeof(*ip) >> 2;
980 		ip->ip_tos = IPTOS_LOWDELAY;
981 		ip->ip_len = htons(len);
982 		ip->ip_id = 0;	/* no need for id, we don't support fragments */
983 		ip->ip_off = htons(IP_DF);
984 		ip->ip_ttl = CARP_DFLTTL;
985 		ip->ip_p = IPPROTO_CARP;
986 		ip->ip_sum = 0;
987 
988 		bzero(&sa, sizeof(sa));
989 		sa.sa_family = AF_INET;
990 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
991 		if (ifa == NULL)
992 			ip->ip_src.s_addr = 0;
993 		else
994 			ip->ip_src.s_addr =
995 			    ifatoia(ifa)->ia_addr.sin_addr.s_addr;
996 		ip->ip_dst.s_addr = INADDR_CARP_GROUP;
997 
998 		ch_ptr = (struct carp_header *)(&ip[1]);
999 		bcopy(&ch, ch_ptr, sizeof(ch));
1000 		if (carp_prepare_ad(m, sc, ch_ptr))
1001 			goto retry_later;
1002 
1003 		m->m_data += sizeof(*ip);
1004 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
1005 		m->m_data -= sizeof(*ip);
1006 
1007 		nanotime(&sc->sc_if.if_lastchange);
1008 		sc->sc_if.if_opackets++;
1009 		sc->sc_if.if_obytes += len;
1010 		CARP_STATINC(CARP_STAT_OPACKETS);
1011 
1012 		error = ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo,
1013 		    NULL);
1014 		if (error) {
1015 			if (error == ENOBUFS)
1016 				CARP_STATINC(CARP_STAT_ONOMEM);
1017 			else
1018 				CARP_LOG(sc, ("ip_output failed: %d", error));
1019 			sc->sc_if.if_oerrors++;
1020 			if (sc->sc_sendad_errors < INT_MAX)
1021 				sc->sc_sendad_errors++;
1022 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1023 				carp_suppress_preempt++;
1024 				if (carp_suppress_preempt == 1)
1025 					carp_send_ad_all();
1026 			}
1027 			sc->sc_sendad_success = 0;
1028 		} else {
1029 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1030 				if (++sc->sc_sendad_success >=
1031 				    CARP_SENDAD_MIN_SUCCESS) {
1032 					carp_suppress_preempt--;
1033 					sc->sc_sendad_errors = 0;
1034 				}
1035 			} else
1036 				sc->sc_sendad_errors = 0;
1037 		}
1038 	}
1039 #endif /* INET */
1040 #ifdef INET6
1041 	if (sc->sc_naddrs6) {
1042 		struct ip6_hdr *ip6;
1043 
1044 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
1045 		if (m == NULL) {
1046 			sc->sc_if.if_oerrors++;
1047 			CARP_STATINC(CARP_STAT_ONOMEM);
1048 			/* XXX maybe less ? */
1049 			goto retry_later;
1050 		}
1051 		len = sizeof(*ip6) + sizeof(ch);
1052 		m->m_pkthdr.len = len;
1053 		m->m_pkthdr.rcvif = NULL;
1054 		m->m_len = len;
1055 		MH_ALIGN(m, m->m_len);
1056 		m->m_flags |= M_MCAST;
1057 		ip6 = mtod(m, struct ip6_hdr *);
1058 		bzero(ip6, sizeof(*ip6));
1059 		ip6->ip6_vfc |= IPV6_VERSION;
1060 		ip6->ip6_hlim = CARP_DFLTTL;
1061 		ip6->ip6_nxt = IPPROTO_CARP;
1062 
1063 		/* set the source address */
1064 		bzero(&sa, sizeof(sa));
1065 		sa.sa_family = AF_INET6;
1066 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
1067 		if (ifa == NULL)	/* This should never happen with IPv6 */
1068 			bzero(&ip6->ip6_src, sizeof(struct in6_addr));
1069 		else
1070 			bcopy(ifatoia6(ifa)->ia_addr.sin6_addr.s6_addr,
1071 			    &ip6->ip6_src, sizeof(struct in6_addr));
1072 		/* set the multicast destination */
1073 
1074 		ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
1075 		ip6->ip6_dst.s6_addr8[15] = 0x12;
1076 		if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1077 			sc->sc_if.if_oerrors++;
1078 			m_freem(m);
1079 			CARP_LOG(sc, ("in6_setscope failed"));
1080 			goto retry_later;
1081 		}
1082 
1083 		ch_ptr = (struct carp_header *)(&ip6[1]);
1084 		bcopy(&ch, ch_ptr, sizeof(ch));
1085 		if (carp_prepare_ad(m, sc, ch_ptr))
1086 			goto retry_later;
1087 
1088 		m->m_data += sizeof(*ip6);
1089 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
1090 		m->m_data -= sizeof(*ip6);
1091 
1092 		nanotime(&sc->sc_if.if_lastchange);
1093 		sc->sc_if.if_opackets++;
1094 		sc->sc_if.if_obytes += len;
1095 		CARP_STATINC(CARP_STAT_OPACKETS6);
1096 
1097 		error = ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL);
1098 		if (error) {
1099 			if (error == ENOBUFS)
1100 				CARP_STATINC(CARP_STAT_ONOMEM);
1101 			else
1102 				CARP_LOG(sc, ("ip6_output failed: %d", error));
1103 			sc->sc_if.if_oerrors++;
1104 			if (sc->sc_sendad_errors < INT_MAX)
1105 				sc->sc_sendad_errors++;
1106 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1107 				carp_suppress_preempt++;
1108 				if (carp_suppress_preempt == 1)
1109 					carp_send_ad_all();
1110 			}
1111 			sc->sc_sendad_success = 0;
1112 		} else {
1113 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1114 				if (++sc->sc_sendad_success >=
1115 				    CARP_SENDAD_MIN_SUCCESS) {
1116 					carp_suppress_preempt--;
1117 					sc->sc_sendad_errors = 0;
1118 				}
1119 			} else
1120 				sc->sc_sendad_errors = 0;
1121 		}
1122 	}
1123 #endif /* INET6 */
1124 
1125 retry_later:
1126 	splx(s);
1127 	if (advbase != 255 || advskew != 255)
1128 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1129 }
1130 
1131 /*
1132  * Broadcast a gratuitous ARP request containing
1133  * the virtual router MAC address for each IP address
1134  * associated with the virtual router.
1135  */
1136 void
1137 carp_send_arp(struct carp_softc *sc)
1138 {
1139 	struct ifaddr *ifa;
1140 	struct in_addr *in;
1141 	int s = splsoftnet();
1142 
1143 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1144 
1145 		if (ifa->ifa_addr->sa_family != AF_INET)
1146 			continue;
1147 
1148 		in = &ifatoia(ifa)->ia_addr.sin_addr;
1149 		arprequest(sc->sc_carpdev, in, in, CLLADDR(sc->sc_if.if_sadl));
1150 		DELAY(1000);	/* XXX */
1151 	}
1152 	splx(s);
1153 }
1154 
1155 #ifdef INET6
1156 void
1157 carp_send_na(struct carp_softc *sc)
1158 {
1159 	struct ifaddr *ifa;
1160 	struct in6_addr *in6;
1161 	static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1162 	int s = splsoftnet();
1163 
1164 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1165 
1166 		if (ifa->ifa_addr->sa_family != AF_INET6)
1167 			continue;
1168 
1169 		in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1170 		nd6_na_output(sc->sc_carpdev, &mcast, in6,
1171 		    ND_NA_FLAG_OVERRIDE, 1, NULL);
1172 		DELAY(1000);	/* XXX */
1173 	}
1174 	splx(s);
1175 }
1176 #endif /* INET6 */
1177 
1178 /*
1179  * Based on bridge_hash() in if_bridge.c
1180  */
1181 #define	mix(a,b,c) \
1182 	do {						\
1183 		a -= b; a -= c; a ^= (c >> 13);		\
1184 		b -= c; b -= a; b ^= (a << 8);		\
1185 		c -= a; c -= b; c ^= (b >> 13);		\
1186 		a -= b; a -= c; a ^= (c >> 12);		\
1187 		b -= c; b -= a; b ^= (a << 16);		\
1188 		c -= a; c -= b; c ^= (b >> 5);		\
1189 		a -= b; a -= c; a ^= (c >> 3);		\
1190 		b -= c; b -= a; b ^= (a << 10);		\
1191 		c -= a; c -= b; c ^= (b >> 15);		\
1192 	} while (0)
1193 
1194 u_int32_t
1195 carp_hash(struct carp_softc *sc, u_char *src)
1196 {
1197 	u_int32_t a = 0x9e3779b9, b = sc->sc_hashkey[0], c = sc->sc_hashkey[1];
1198 
1199 	c += sc->sc_key[3] << 24;
1200 	c += sc->sc_key[2] << 16;
1201 	c += sc->sc_key[1] << 8;
1202 	c += sc->sc_key[0];
1203 	b += src[5] << 8;
1204 	b += src[4];
1205 	a += src[3] << 24;
1206 	a += src[2] << 16;
1207 	a += src[1] << 8;
1208 	a += src[0];
1209 
1210 	mix(a, b, c);
1211 	return (c);
1212 }
1213 
1214 int
1215 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
1216 {
1217 	struct carp_softc *vh;
1218 	struct ifaddr *ifa;
1219 	int count = 0;
1220 
1221 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1222 		if ((type == CARP_COUNT_RUNNING &&
1223 		    (vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1224 		    (IFF_UP|IFF_RUNNING)) ||
1225 		    (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
1226 			IFADDR_FOREACH(ifa, &vh->sc_if) {
1227 				if (ifa->ifa_addr->sa_family == AF_INET &&
1228 				    ia->ia_addr.sin_addr.s_addr ==
1229 				    ifatoia(ifa)->ia_addr.sin_addr.s_addr)
1230 					count++;
1231 			}
1232 		}
1233 	}
1234 	return (count);
1235 }
1236 
1237 int
1238 carp_iamatch(struct in_ifaddr *ia, u_char *src,
1239     u_int32_t *count, u_int32_t index)
1240 {
1241 	struct carp_softc *sc = ia->ia_ifp->if_softc;
1242 
1243 	if (carp_opts[CARPCTL_ARPBALANCE]) {
1244 		/*
1245 		 * We use the source ip to decide which virtual host should
1246 		 * handle the request. If we're master of that virtual host,
1247 		 * then we respond, otherwise, just drop the arp packet on
1248 		 * the floor.
1249 		 */
1250 
1251 		/* Count the elegible carp interfaces with this address */
1252 		if (*count == 0)
1253 			*count = carp_addrcount(
1254 			    (struct carp_if *)ia->ia_ifp->if_carpdev->if_carp,
1255 			    ia, CARP_COUNT_RUNNING);
1256 
1257 		/* This should never happen, but... */
1258 		if (*count == 0)
1259 			return (0);
1260 
1261 		if (carp_hash(sc, src) % *count == index - 1 &&
1262 		    sc->sc_state == MASTER) {
1263 			return (1);
1264 		}
1265 	} else {
1266 		if (sc->sc_state == MASTER)
1267 			return (1);
1268 	}
1269 
1270 	return (0);
1271 }
1272 
1273 #ifdef INET6
1274 struct ifaddr *
1275 carp_iamatch6(void *v, struct in6_addr *taddr)
1276 {
1277 	struct carp_if *cif = v;
1278 	struct carp_softc *vh;
1279 	struct ifaddr *ifa;
1280 
1281 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1282 		IFADDR_FOREACH(ifa, &vh->sc_if) {
1283 			if (IN6_ARE_ADDR_EQUAL(taddr,
1284 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1285 			    ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1286 			    (IFF_UP|IFF_RUNNING)) && vh->sc_state == MASTER)
1287 				return (ifa);
1288 		}
1289 	}
1290 
1291 	return (NULL);
1292 }
1293 #endif /* INET6 */
1294 
1295 struct ifnet *
1296 carp_ourether(void *v, struct ether_header *eh, u_char iftype, int src)
1297 {
1298 	struct carp_if *cif = (struct carp_if *)v;
1299 	struct carp_softc *vh;
1300 	u_int8_t *ena;
1301 
1302 	if (src)
1303 		ena = (u_int8_t *)&eh->ether_shost;
1304 	else
1305 		ena = (u_int8_t *)&eh->ether_dhost;
1306 
1307 	switch (iftype) {
1308 	case IFT_ETHER:
1309 	case IFT_FDDI:
1310 		if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1311 			return (NULL);
1312 		break;
1313 	case IFT_ISO88025:
1314 		if (ena[0] != 3 || ena[1] || ena[4] || ena[5])
1315 			return (NULL);
1316 		break;
1317 	default:
1318 		return (NULL);
1319 		break;
1320 	}
1321 
1322 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
1323 		if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1324 		    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER &&
1325 		    !bcmp(ena, CLLADDR(vh->sc_if.if_sadl),
1326 		    ETHER_ADDR_LEN)) {
1327 			return (&vh->sc_if);
1328 		    }
1329 
1330 	return (NULL);
1331 }
1332 
1333 int
1334 carp_input(struct mbuf *m, u_int8_t *shost, u_int8_t *dhost, u_int16_t etype)
1335 {
1336 	struct ether_header eh;
1337 	struct carp_if *cif = (struct carp_if *)m->m_pkthdr.rcvif->if_carp;
1338 	struct ifnet *ifp;
1339 
1340 	bcopy(shost, &eh.ether_shost, sizeof(eh.ether_shost));
1341 	bcopy(dhost, &eh.ether_dhost, sizeof(eh.ether_dhost));
1342 	eh.ether_type = etype;
1343 
1344 	if (m->m_flags & (M_BCAST|M_MCAST)) {
1345 		struct carp_softc *vh;
1346 		struct mbuf *m0;
1347 
1348 		/*
1349 		 * XXX Should really check the list of multicast addresses
1350 		 * for each CARP interface _before_ copying.
1351 		 */
1352 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1353 			m0 = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
1354 			if (m0 == NULL)
1355 				continue;
1356 			m0->m_pkthdr.rcvif = &vh->sc_if;
1357 			ether_input(&vh->sc_if, m0);
1358 		}
1359 		return (1);
1360 	}
1361 
1362 	ifp = carp_ourether(cif, &eh, m->m_pkthdr.rcvif->if_type, 0);
1363 	if (ifp == NULL) {
1364 		return (1);
1365 	}
1366 
1367 	m->m_pkthdr.rcvif = ifp;
1368 
1369 #if NBPFILTER > 0
1370 	if (ifp->if_bpf)
1371 		bpf_mtap(ifp->if_bpf, m);
1372 #endif
1373 	ifp->if_ipackets++;
1374 	ether_input(ifp, m);
1375 	return (0);
1376 }
1377 
1378 void
1379 carp_master_down(void *v)
1380 {
1381 	struct carp_softc *sc = v;
1382 
1383 	switch (sc->sc_state) {
1384 	case INIT:
1385 		printf("%s: master_down event in INIT state\n",
1386 		    sc->sc_if.if_xname);
1387 		break;
1388 	case MASTER:
1389 		break;
1390 	case BACKUP:
1391 		carp_set_state(sc, MASTER);
1392 		carp_send_ad(sc);
1393 		carp_send_arp(sc);
1394 #ifdef INET6
1395 		carp_send_na(sc);
1396 #endif /* INET6 */
1397 		carp_setrun(sc, 0);
1398 		carp_setroute(sc, RTM_ADD);
1399 		break;
1400 	}
1401 }
1402 
1403 /*
1404  * When in backup state, af indicates whether to reset the master down timer
1405  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1406  */
1407 void
1408 carp_setrun(struct carp_softc *sc, sa_family_t af)
1409 {
1410 	struct timeval tv;
1411 
1412 	if (sc->sc_carpdev == NULL) {
1413 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1414 		carp_set_state(sc, INIT);
1415 		return;
1416 	}
1417 
1418 	if (sc->sc_if.if_flags & IFF_UP && sc->sc_vhid > 0 &&
1419 	    (sc->sc_naddrs || sc->sc_naddrs6) && !sc->sc_suppress) {
1420 		sc->sc_if.if_flags |= IFF_RUNNING;
1421 	} else {
1422 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1423 		carp_setroute(sc, RTM_DELETE);
1424 		return;
1425 	}
1426 
1427 	switch (sc->sc_state) {
1428 	case INIT:
1429 		carp_set_state(sc, BACKUP);
1430 		carp_setroute(sc, RTM_DELETE);
1431 		carp_setrun(sc, 0);
1432 		break;
1433 	case BACKUP:
1434 		callout_stop(&sc->sc_ad_tmo);
1435 		tv.tv_sec = 3 * sc->sc_advbase;
1436 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1437 		switch (af) {
1438 #ifdef INET
1439 		case AF_INET:
1440 			callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1441 			break;
1442 #endif /* INET */
1443 #ifdef INET6
1444 		case AF_INET6:
1445 			callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1446 			break;
1447 #endif /* INET6 */
1448 		default:
1449 			if (sc->sc_naddrs)
1450 				callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1451 			if (sc->sc_naddrs6)
1452 				callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1453 			break;
1454 		}
1455 		break;
1456 	case MASTER:
1457 		tv.tv_sec = sc->sc_advbase;
1458 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1459 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1460 		break;
1461 	}
1462 }
1463 
1464 void
1465 carp_multicast_cleanup(struct carp_softc *sc)
1466 {
1467 	struct ip_moptions *imo = &sc->sc_imo;
1468 #ifdef INET6
1469 	struct ip6_moptions *im6o = &sc->sc_im6o;
1470 #endif
1471 	u_int16_t n = imo->imo_num_memberships;
1472 
1473 	/* Clean up our own multicast memberships */
1474 	while (n-- > 0) {
1475 		if (imo->imo_membership[n] != NULL) {
1476 			in_delmulti(imo->imo_membership[n]);
1477 			imo->imo_membership[n] = NULL;
1478 		}
1479 	}
1480 	imo->imo_num_memberships = 0;
1481 	imo->imo_multicast_ifp = NULL;
1482 
1483 #ifdef INET6
1484 	while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1485 		struct in6_multi_mship *imm =
1486 		    LIST_FIRST(&im6o->im6o_memberships);
1487 
1488 		LIST_REMOVE(imm, i6mm_chain);
1489 		in6_leavegroup(imm);
1490 	}
1491 	im6o->im6o_multicast_ifp = NULL;
1492 #endif
1493 
1494 	/* And any other multicast memberships */
1495 	carp_ether_purgemulti(sc);
1496 }
1497 
1498 int
1499 carp_set_ifp(struct carp_softc *sc, struct ifnet *ifp)
1500 {
1501 	struct carp_if *cif, *ncif = NULL;
1502 	struct carp_softc *vr, *after = NULL;
1503 	int myself = 0, error = 0;
1504 	int s;
1505 
1506 	if (ifp == sc->sc_carpdev)
1507 		return (0);
1508 
1509 	if (ifp != NULL) {
1510 		if ((ifp->if_flags & IFF_MULTICAST) == 0)
1511 			return (EADDRNOTAVAIL);
1512 
1513 		if (ifp->if_type == IFT_CARP)
1514 			return (EINVAL);
1515 
1516 		if (ifp->if_carp == NULL) {
1517 			ncif = malloc(sizeof(*cif), M_IFADDR, M_NOWAIT);
1518 			if (ncif == NULL)
1519 				return (ENOBUFS);
1520 			if ((error = ifpromisc(ifp, 1))) {
1521 				free(ncif, M_IFADDR);
1522 				return (error);
1523 			}
1524 
1525 			ncif->vhif_ifp = ifp;
1526 			TAILQ_INIT(&ncif->vhif_vrs);
1527 		} else {
1528 			cif = (struct carp_if *)ifp->if_carp;
1529 			TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1530 				if (vr != sc && vr->sc_vhid == sc->sc_vhid)
1531 					return (EINVAL);
1532 		}
1533 
1534 		/* detach from old interface */
1535 		if (sc->sc_carpdev != NULL)
1536 			carpdetach(sc);
1537 
1538 		/* join multicast groups */
1539 		if (sc->sc_naddrs < 0 &&
1540 		    (error = carp_join_multicast(sc)) != 0) {
1541 			if (ncif != NULL)
1542 				free(ncif, M_IFADDR);
1543 			return (error);
1544 		}
1545 
1546 #ifdef INET6
1547 		if (sc->sc_naddrs6 < 0 &&
1548 		    (error = carp_join_multicast6(sc)) != 0) {
1549 			if (ncif != NULL)
1550 				free(ncif, M_IFADDR);
1551 			carp_multicast_cleanup(sc);
1552 			return (error);
1553 		}
1554 #endif
1555 
1556 		/* attach carp interface to physical interface */
1557 		if (ncif != NULL)
1558 			ifp->if_carp = (void *)ncif;
1559 		sc->sc_carpdev = ifp;
1560 		cif = (struct carp_if *)ifp->if_carp;
1561 		TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1562 			if (vr == sc)
1563 				myself = 1;
1564 			if (vr->sc_vhid < sc->sc_vhid)
1565 				after = vr;
1566 		}
1567 
1568 		if (!myself) {
1569 			/* We're trying to keep things in order */
1570 			if (after == NULL) {
1571 				TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1572 			} else {
1573 				TAILQ_INSERT_AFTER(&cif->vhif_vrs, after,
1574 				    sc, sc_list);
1575 			}
1576 			cif->vhif_nvrs++;
1577 		}
1578 		if (sc->sc_naddrs || sc->sc_naddrs6)
1579 			sc->sc_if.if_flags |= IFF_UP;
1580 		carp_set_enaddr(sc);
1581 		s = splnet();
1582 		/* XXX linkstatehooks establish */
1583 		carp_carpdev_state(ifp);
1584 		splx(s);
1585 	} else {
1586 		carpdetach(sc);
1587 		sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
1588 	}
1589 	return (0);
1590 }
1591 
1592 void
1593 carp_set_enaddr(struct carp_softc *sc)
1594 {
1595 	uint8_t enaddr[ETHER_ADDR_LEN];
1596 	if (sc->sc_carpdev && sc->sc_carpdev->if_type == IFT_ISO88025) {
1597 		enaddr[0] = 3;
1598 		enaddr[1] = 0;
1599 		enaddr[2] = 0x40 >> (sc->sc_vhid - 1);
1600 		enaddr[3] = 0x40000 >> (sc->sc_vhid - 1);
1601 		enaddr[4] = 0;
1602 		enaddr[5] = 0;
1603 	} else {
1604 		enaddr[0] = 0;
1605 		enaddr[1] = 0;
1606 		enaddr[2] = 0x5e;
1607 		enaddr[3] = 0;
1608 		enaddr[4] = 1;
1609 		enaddr[5] = sc->sc_vhid;
1610 	}
1611 	if_set_sadl(&sc->sc_if, enaddr, sizeof(enaddr), false);
1612 }
1613 
1614 void
1615 carp_addr_updated(void *v)
1616 {
1617 	struct carp_softc *sc = (struct carp_softc *) v;
1618 	struct ifaddr *ifa;
1619 	int new_naddrs = 0, new_naddrs6 = 0;
1620 
1621 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1622 		if (ifa->ifa_addr->sa_family == AF_INET)
1623 			new_naddrs++;
1624 		else if (ifa->ifa_addr->sa_family == AF_INET6)
1625 			new_naddrs6++;
1626 	}
1627 
1628 	/* Handle a callback after SIOCDIFADDR */
1629 	if (new_naddrs < sc->sc_naddrs || new_naddrs6 < sc->sc_naddrs6) {
1630 		struct in_addr mc_addr;
1631 		struct in_multi *inm;
1632 
1633 		sc->sc_naddrs = new_naddrs;
1634 		sc->sc_naddrs6 = new_naddrs6;
1635 
1636 		/* Re-establish multicast membership removed by in_control */
1637 		mc_addr.s_addr = INADDR_CARP_GROUP;
1638 		IN_LOOKUP_MULTI(mc_addr, &sc->sc_if, inm);
1639 		if (inm == NULL) {
1640 			bzero(&sc->sc_imo, sizeof(sc->sc_imo));
1641 
1642 			if (sc->sc_carpdev != NULL && sc->sc_naddrs > 0)
1643 				carp_join_multicast(sc);
1644 		}
1645 
1646 		if (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) {
1647 			sc->sc_if.if_flags &= ~IFF_UP;
1648 			carp_set_state(sc, INIT);
1649 		} else
1650 			carp_hmac_prepare(sc);
1651 	}
1652 
1653 	carp_setrun(sc, 0);
1654 }
1655 
1656 int
1657 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1658 {
1659 	struct ifnet *ifp = sc->sc_carpdev;
1660 	struct in_ifaddr *ia, *ia_if;
1661 	int error = 0;
1662 
1663 	if (sin->sin_addr.s_addr == 0) {
1664 		if (!(sc->sc_if.if_flags & IFF_UP))
1665 			carp_set_state(sc, INIT);
1666 		if (sc->sc_naddrs)
1667 			sc->sc_if.if_flags |= IFF_UP;
1668 		carp_setrun(sc, 0);
1669 		return (0);
1670 	}
1671 
1672 	/* we have to do this by hand to ensure we don't match on ourselves */
1673 	ia_if = NULL;
1674 	for (ia = TAILQ_FIRST(&in_ifaddrhead); ia;
1675 	    ia = TAILQ_NEXT(ia, ia_list)) {
1676 
1677 		/* and, yeah, we need a multicast-capable iface too */
1678 		if (ia->ia_ifp != &sc->sc_if &&
1679 		    ia->ia_ifp->if_type != IFT_CARP &&
1680 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1681 		    (sin->sin_addr.s_addr & ia->ia_subnetmask) ==
1682 		    ia->ia_subnet) {
1683 			if (!ia_if)
1684 				ia_if = ia;
1685 		}
1686 	}
1687 
1688 	if (ia_if) {
1689 		ia = ia_if;
1690 		if (ifp) {
1691 			if (ifp != ia->ia_ifp)
1692 				return (EADDRNOTAVAIL);
1693 		} else {
1694 			ifp = ia->ia_ifp;
1695 		}
1696 	}
1697 
1698 	if ((error = carp_set_ifp(sc, ifp)))
1699 		return (error);
1700 
1701 	if (sc->sc_carpdev == NULL)
1702 		return (EADDRNOTAVAIL);
1703 
1704 	if (sc->sc_naddrs == 0 && (error = carp_join_multicast(sc)) != 0)
1705 		return (error);
1706 
1707 	sc->sc_naddrs++;
1708 	if (sc->sc_carpdev != NULL)
1709 		sc->sc_if.if_flags |= IFF_UP;
1710 
1711 	carp_set_state(sc, INIT);
1712 	carp_setrun(sc, 0);
1713 
1714 	/*
1715 	 * Hook if_addrhooks so that we get a callback after in_ifinit has run,
1716 	 * to correct any inappropriate routes that it inserted.
1717 	 */
1718 	if (sc->ah_cookie == 0) {
1719 		/* XXX link address hook */
1720 	}
1721 
1722 	return (0);
1723 }
1724 
1725 int
1726 carp_join_multicast(struct carp_softc *sc)
1727 {
1728 	struct ip_moptions *imo = &sc->sc_imo, tmpimo;
1729 	struct in_addr addr;
1730 
1731 	bzero(&tmpimo, sizeof(tmpimo));
1732 	addr.s_addr = INADDR_CARP_GROUP;
1733 	if ((tmpimo.imo_membership[0] =
1734 	    in_addmulti(&addr, &sc->sc_if)) == NULL) {
1735 		return (ENOBUFS);
1736 	}
1737 
1738 	imo->imo_membership[0] = tmpimo.imo_membership[0];
1739 	imo->imo_num_memberships = 1;
1740 	imo->imo_multicast_ifp = &sc->sc_if;
1741 	imo->imo_multicast_ttl = CARP_DFLTTL;
1742 	imo->imo_multicast_loop = 0;
1743 	return (0);
1744 }
1745 
1746 
1747 #ifdef INET6
1748 int
1749 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1750 {
1751 	struct ifnet *ifp = sc->sc_carpdev;
1752 	struct in6_ifaddr *ia, *ia_if;
1753 	int error = 0;
1754 
1755 	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1756 		if (!(sc->sc_if.if_flags & IFF_UP))
1757 			carp_set_state(sc, INIT);
1758 		if (sc->sc_naddrs6)
1759 			sc->sc_if.if_flags |= IFF_UP;
1760 		carp_setrun(sc, 0);
1761 		return (0);
1762 	}
1763 
1764 	/* we have to do this by hand to ensure we don't match on ourselves */
1765 	ia_if = NULL;
1766 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1767 		int i;
1768 
1769 		for (i = 0; i < 4; i++) {
1770 			if ((sin6->sin6_addr.s6_addr32[i] &
1771 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1772 			    (ia->ia_addr.sin6_addr.s6_addr32[i] &
1773 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1774 				break;
1775 		}
1776 		/* and, yeah, we need a multicast-capable iface too */
1777 		if (ia->ia_ifp != &sc->sc_if &&
1778 		    ia->ia_ifp->if_type != IFT_CARP &&
1779 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1780 		    (i == 4)) {
1781 			if (!ia_if)
1782 				ia_if = ia;
1783 		}
1784 	}
1785 
1786 	if (ia_if) {
1787 		ia = ia_if;
1788 		if (sc->sc_carpdev) {
1789 			if (sc->sc_carpdev != ia->ia_ifp)
1790 				return (EADDRNOTAVAIL);
1791 		} else {
1792 			ifp = ia->ia_ifp;
1793 		}
1794 	}
1795 
1796 	if ((error = carp_set_ifp(sc, ifp)))
1797 		return (error);
1798 
1799 	if (sc->sc_carpdev == NULL)
1800 		return (EADDRNOTAVAIL);
1801 
1802 	if (sc->sc_naddrs6 == 0 && (error = carp_join_multicast6(sc)) != 0)
1803 		return (error);
1804 
1805 	sc->sc_naddrs6++;
1806 	if (sc->sc_carpdev != NULL)
1807 		sc->sc_if.if_flags |= IFF_UP;
1808 	carp_set_state(sc, INIT);
1809 	carp_setrun(sc, 0);
1810 
1811 	return (0);
1812 }
1813 
1814 int
1815 carp_join_multicast6(struct carp_softc *sc)
1816 {
1817 	struct in6_multi_mship *imm, *imm2;
1818 	struct ip6_moptions *im6o = &sc->sc_im6o;
1819 	struct sockaddr_in6 addr6;
1820 	int error;
1821 
1822 	/* Join IPv6 CARP multicast group */
1823 	bzero(&addr6, sizeof(addr6));
1824 	addr6.sin6_family = AF_INET6;
1825 	addr6.sin6_len = sizeof(addr6);
1826 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1827 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1828 	addr6.sin6_addr.s6_addr8[15] = 0x12;
1829 	if ((imm = in6_joingroup(&sc->sc_if,
1830 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1831 		return (error);
1832 	}
1833 	/* join solicited multicast address */
1834 	bzero(&addr6.sin6_addr, sizeof(addr6.sin6_addr));
1835 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1836 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1837 	addr6.sin6_addr.s6_addr32[1] = 0;
1838 	addr6.sin6_addr.s6_addr32[2] = htonl(1);
1839 	addr6.sin6_addr.s6_addr32[3] = 0;
1840 	addr6.sin6_addr.s6_addr8[12] = 0xff;
1841 	if ((imm2 = in6_joingroup(&sc->sc_if,
1842 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1843 		in6_leavegroup(imm);
1844 		return (error);
1845 	}
1846 
1847 	/* apply v6 multicast membership */
1848 	im6o->im6o_multicast_ifp = &sc->sc_if;
1849 	if (imm)
1850 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm,
1851 		    i6mm_chain);
1852 	if (imm2)
1853 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm2,
1854 		    i6mm_chain);
1855 
1856 	return (0);
1857 }
1858 
1859 #endif /* INET6 */
1860 
1861 int
1862 carp_ioctl(struct ifnet *ifp, u_long cmd, void *data)
1863 {
1864 	struct lwp *l = curlwp;		/* XXX */
1865 	struct carp_softc *sc = ifp->if_softc, *vr;
1866 	struct carpreq carpr;
1867 	struct ifaddr *ifa;
1868 	struct ifreq *ifr;
1869 	struct ifnet *cdev = NULL;
1870 	int error = 0;
1871 
1872 	ifa = (struct ifaddr *)data;
1873 	ifr = (struct ifreq *)data;
1874 
1875 	switch (cmd) {
1876 	case SIOCINITIFADDR:
1877 		switch (ifa->ifa_addr->sa_family) {
1878 #ifdef INET
1879 		case AF_INET:
1880 			sc->sc_if.if_flags |= IFF_UP;
1881 			bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1882 			    sizeof(struct sockaddr));
1883 			error = carp_set_addr(sc, satosin(ifa->ifa_addr));
1884 			break;
1885 #endif /* INET */
1886 #ifdef INET6
1887 		case AF_INET6:
1888 			sc->sc_if.if_flags|= IFF_UP;
1889 			error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1890 			break;
1891 #endif /* INET6 */
1892 		default:
1893 			error = EAFNOSUPPORT;
1894 			break;
1895 		}
1896 		break;
1897 
1898 	case SIOCSIFFLAGS:
1899 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
1900 			break;
1901 		if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
1902 			callout_stop(&sc->sc_ad_tmo);
1903 			callout_stop(&sc->sc_md_tmo);
1904 			callout_stop(&sc->sc_md6_tmo);
1905 			if (sc->sc_state == MASTER) {
1906 				/* we need the interface up to bow out */
1907 				sc->sc_if.if_flags |= IFF_UP;
1908 				sc->sc_bow_out = 1;
1909 				carp_send_ad(sc);
1910 			}
1911 			sc->sc_if.if_flags &= ~IFF_UP;
1912 			carp_set_state(sc, INIT);
1913 			carp_setrun(sc, 0);
1914 		} else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
1915 			sc->sc_if.if_flags |= IFF_UP;
1916 			carp_setrun(sc, 0);
1917 		}
1918 		break;
1919 
1920 	case SIOCSVH:
1921 		if (l == NULL)
1922 			break;
1923 		if ((error = kauth_authorize_network(l->l_cred,
1924 		    KAUTH_NETWORK_INTERFACE,
1925 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
1926 		    NULL)) != 0)
1927 			break;
1928 		if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
1929 			break;
1930 		error = 1;
1931 		if (carpr.carpr_carpdev[0] != '\0' &&
1932 		    (cdev = ifunit(carpr.carpr_carpdev)) == NULL)
1933 			return (EINVAL);
1934 		if ((error = carp_set_ifp(sc, cdev)))
1935 			return (error);
1936 		if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
1937 			switch (carpr.carpr_state) {
1938 			case BACKUP:
1939 				callout_stop(&sc->sc_ad_tmo);
1940 				carp_set_state(sc, BACKUP);
1941 				carp_setrun(sc, 0);
1942 				carp_setroute(sc, RTM_DELETE);
1943 				break;
1944 			case MASTER:
1945 				carp_master_down(sc);
1946 				break;
1947 			default:
1948 				break;
1949 			}
1950 		}
1951 		if (carpr.carpr_vhid > 0) {
1952 			if (carpr.carpr_vhid > 255) {
1953 				error = EINVAL;
1954 				break;
1955 			}
1956 			if (sc->sc_carpdev) {
1957 				struct carp_if *cif;
1958 				cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1959 				TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1960 					if (vr != sc &&
1961 					    vr->sc_vhid == carpr.carpr_vhid)
1962 						return (EINVAL);
1963 			}
1964 			sc->sc_vhid = carpr.carpr_vhid;
1965 			carp_set_enaddr(sc);
1966 			carp_set_state(sc, INIT);
1967 			error--;
1968 		}
1969 		if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
1970 			if (carpr.carpr_advskew > 254) {
1971 				error = EINVAL;
1972 				break;
1973 			}
1974 			if (carpr.carpr_advbase > 255) {
1975 				error = EINVAL;
1976 				break;
1977 			}
1978 			sc->sc_advbase = carpr.carpr_advbase;
1979 			sc->sc_advskew = carpr.carpr_advskew;
1980 			error--;
1981 		}
1982 		bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1983 		if (error > 0)
1984 			error = EINVAL;
1985 		else {
1986 			error = 0;
1987 			carp_setrun(sc, 0);
1988 		}
1989 		break;
1990 
1991 	case SIOCGVH:
1992 		bzero(&carpr, sizeof(carpr));
1993 		if (sc->sc_carpdev != NULL)
1994 			strlcpy(carpr.carpr_carpdev, sc->sc_carpdev->if_xname,
1995 			    IFNAMSIZ);
1996 		carpr.carpr_state = sc->sc_state;
1997 		carpr.carpr_vhid = sc->sc_vhid;
1998 		carpr.carpr_advbase = sc->sc_advbase;
1999 		carpr.carpr_advskew = sc->sc_advskew;
2000 
2001 		if ((l == NULL) || (error = kauth_authorize_network(l->l_cred,
2002 		    KAUTH_NETWORK_INTERFACE,
2003 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
2004 		    NULL)) != 0)
2005 			bcopy(sc->sc_key, carpr.carpr_key,
2006 			    sizeof(carpr.carpr_key));
2007 		error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
2008 		break;
2009 
2010 	case SIOCADDMULTI:
2011 		error = carp_ether_addmulti(sc, ifr);
2012 		break;
2013 
2014 	case SIOCDELMULTI:
2015 		error = carp_ether_delmulti(sc, ifr);
2016 		break;
2017 
2018 	default:
2019 		error = ether_ioctl(ifp, cmd, data);
2020 	}
2021 
2022 	carp_hmac_prepare(sc);
2023 	return (error);
2024 }
2025 
2026 
2027 /*
2028  * Start output on carp interface. This function should never be called.
2029  */
2030 void
2031 carp_start(struct ifnet *ifp)
2032 {
2033 #ifdef DEBUG
2034 	printf("%s: start called\n", ifp->if_xname);
2035 #endif
2036 }
2037 
2038 int
2039 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa,
2040     struct rtentry *rt)
2041 {
2042 	struct carp_softc *sc = ((struct carp_softc *)ifp->if_softc);
2043 
2044 	if (sc->sc_carpdev != NULL && sc->sc_state == MASTER) {
2045 		return (sc->sc_carpdev->if_output(ifp, m, sa, rt));
2046 	} else {
2047 		m_freem(m);
2048 		return (ENETUNREACH);
2049 	}
2050 }
2051 
2052 void
2053 carp_set_state(struct carp_softc *sc, int state)
2054 {
2055 	if (sc->sc_state == state)
2056 		return;
2057 
2058 	sc->sc_state = state;
2059 	switch (state) {
2060 	case BACKUP:
2061 		sc->sc_if.if_link_state = LINK_STATE_DOWN;
2062 		break;
2063 	case MASTER:
2064 		sc->sc_if.if_link_state = LINK_STATE_UP;
2065 		break;
2066 	default:
2067 		sc->sc_if.if_link_state = LINK_STATE_UNKNOWN;
2068 		break;
2069 	}
2070 	rt_ifmsg(&sc->sc_if);
2071 }
2072 
2073 void
2074 carp_carpdev_state(void *v)
2075 {
2076 	struct carp_if *cif;
2077 	struct carp_softc *sc;
2078 	struct ifnet *ifp = v;
2079 
2080 	if (ifp->if_type == IFT_CARP)
2081 		return;
2082 
2083 	cif = (struct carp_if *)ifp->if_carp;
2084 
2085 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
2086 		int suppressed = sc->sc_suppress;
2087 
2088 		if (sc->sc_carpdev->if_link_state == LINK_STATE_DOWN ||
2089 		    !(sc->sc_carpdev->if_flags & IFF_UP)) {
2090 			sc->sc_if.if_flags &= ~IFF_RUNNING;
2091 			callout_stop(&sc->sc_ad_tmo);
2092 			callout_stop(&sc->sc_md_tmo);
2093 			callout_stop(&sc->sc_md6_tmo);
2094 			carp_set_state(sc, INIT);
2095 			sc->sc_suppress = 1;
2096 			carp_setrun(sc, 0);
2097 			if (!suppressed) {
2098 				carp_suppress_preempt++;
2099 				if (carp_suppress_preempt == 1)
2100 					carp_send_ad_all();
2101 			}
2102 		} else {
2103 			carp_set_state(sc, INIT);
2104 			sc->sc_suppress = 0;
2105 			carp_setrun(sc, 0);
2106 			if (suppressed)
2107 				carp_suppress_preempt--;
2108 		}
2109 	}
2110 }
2111 
2112 int
2113 carp_ether_addmulti(struct carp_softc *sc, struct ifreq *ifr)
2114 {
2115 	const struct sockaddr *sa = ifreq_getaddr(SIOCADDMULTI, ifr);
2116 	struct ifnet *ifp;
2117 	struct carp_mc_entry *mc;
2118 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2119 	int error;
2120 
2121 	ifp = sc->sc_carpdev;
2122 	if (ifp == NULL)
2123 		return (EINVAL);
2124 
2125 	error = ether_addmulti(sa, &sc->sc_ac);
2126 	if (error != ENETRESET)
2127 		return (error);
2128 
2129 	/*
2130 	 * This is new multicast address.  We have to tell parent
2131 	 * about it.  Also, remember this multicast address so that
2132 	 * we can delete them on unconfigure.
2133 	 */
2134 	mc = malloc(sizeof(struct carp_mc_entry), M_DEVBUF, M_NOWAIT);
2135 	if (mc == NULL) {
2136 		error = ENOMEM;
2137 		goto alloc_failed;
2138 	}
2139 
2140 	/*
2141 	 * As ether_addmulti() returns ENETRESET, following two
2142 	 * statement shouldn't fail.
2143 	 */
2144 	(void)ether_multiaddr(sa, addrlo, addrhi);
2145 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, mc->mc_enm);
2146 	memcpy(&mc->mc_addr, sa, sa->sa_len);
2147 	LIST_INSERT_HEAD(&sc->carp_mc_listhead, mc, mc_entries);
2148 
2149 	error = (*ifp->if_ioctl)(ifp, SIOCADDMULTI, ifr);
2150 	if (error != 0)
2151 		goto ioctl_failed;
2152 
2153 	return (error);
2154 
2155  ioctl_failed:
2156 	LIST_REMOVE(mc, mc_entries);
2157 	free(mc, M_DEVBUF);
2158  alloc_failed:
2159 	(void)ether_delmulti(sa, &sc->sc_ac);
2160 
2161 	return (error);
2162 }
2163 
2164 int
2165 carp_ether_delmulti(struct carp_softc *sc, struct ifreq *ifr)
2166 {
2167 	const struct sockaddr *sa = ifreq_getaddr(SIOCDELMULTI, ifr);
2168 	struct ifnet *ifp;
2169 	struct ether_multi *enm;
2170 	struct carp_mc_entry *mc;
2171 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2172 	int error;
2173 
2174 	ifp = sc->sc_carpdev;
2175 	if (ifp == NULL)
2176 		return (EINVAL);
2177 
2178 	/*
2179 	 * Find a key to lookup carp_mc_entry.  We have to do this
2180 	 * before calling ether_delmulti for obvious reason.
2181 	 */
2182 	if ((error = ether_multiaddr(sa, addrlo, addrhi)) != 0)
2183 		return (error);
2184 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, enm);
2185 	if (enm == NULL)
2186 		return (EINVAL);
2187 
2188 	LIST_FOREACH(mc, &sc->carp_mc_listhead, mc_entries)
2189 		if (mc->mc_enm == enm)
2190 			break;
2191 
2192 	/* We won't delete entries we didn't add */
2193 	if (mc == NULL)
2194 		return (EINVAL);
2195 
2196 	error = ether_delmulti(sa, &sc->sc_ac);
2197 	if (error != ENETRESET)
2198 		return (error);
2199 
2200 	/* We no longer use this multicast address.  Tell parent so. */
2201 	error = (*ifp->if_ioctl)(ifp, SIOCDELMULTI, ifr);
2202 	if (error == 0) {
2203 		/* And forget about this address. */
2204 		LIST_REMOVE(mc, mc_entries);
2205 		free(mc, M_DEVBUF);
2206 	} else
2207 		(void)ether_addmulti(sa, &sc->sc_ac);
2208 	return (error);
2209 }
2210 
2211 /*
2212  * Delete any multicast address we have asked to add from parent
2213  * interface.  Called when the carp is being unconfigured.
2214  */
2215 void
2216 carp_ether_purgemulti(struct carp_softc *sc)
2217 {
2218 	struct ifnet *ifp = sc->sc_carpdev;		/* Parent. */
2219 	struct carp_mc_entry *mc;
2220 	union {
2221 		struct ifreq ifreq;
2222 		struct {
2223 			char ifr_name[IFNAMSIZ];
2224 			struct sockaddr_storage ifr_ss;
2225 		} ifreq_storage;
2226 	} u;
2227 	struct ifreq *ifr = &u.ifreq;
2228 
2229 	if (ifp == NULL)
2230 		return;
2231 
2232 	memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
2233 	while ((mc = LIST_FIRST(&sc->carp_mc_listhead)) != NULL) {
2234 		memcpy(&ifr->ifr_addr, &mc->mc_addr, mc->mc_addr.ss_len);
2235 		(void)(*ifp->if_ioctl)(ifp, SIOCDELMULTI, ifr);
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 SYSCTL_SETUP(sysctl_net_inet_carp_setup, "sysctl net.inet.carp subtree setup")
2249 {
2250 
2251 	sysctl_createv(clog, 0, NULL, NULL,
2252 		       CTLFLAG_PERMANENT,
2253 		       CTLTYPE_NODE, "net", NULL,
2254 		       NULL, 0, NULL, 0,
2255 		       CTL_NET, CTL_EOL);
2256 	sysctl_createv(clog, 0, NULL, NULL,
2257 		       CTLFLAG_PERMANENT,
2258 		       CTLTYPE_NODE, "inet", NULL,
2259 		       NULL, 0, NULL, 0,
2260 		       CTL_NET, PF_INET, CTL_EOL);
2261 	sysctl_createv(clog, 0, NULL, NULL,
2262 		       CTLFLAG_PERMANENT,
2263 		       CTLTYPE_NODE, "carp",
2264 		       SYSCTL_DESCR("CARP related settings"),
2265 		       NULL, 0, NULL, 0,
2266 		       CTL_NET, PF_INET, IPPROTO_CARP, CTL_EOL);
2267 
2268 	sysctl_createv(clog, 0, NULL, NULL,
2269 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2270 		       CTLTYPE_INT, "preempt",
2271 		       SYSCTL_DESCR("Enable CARP Preempt"),
2272 		       NULL, 0, &carp_opts[CARPCTL_PREEMPT], 0,
2273 		       CTL_NET, PF_INET, IPPROTO_CARP,
2274 		       CTL_CREATE, CTL_EOL);
2275 	sysctl_createv(clog, 0, NULL, NULL,
2276 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2277 		       CTLTYPE_INT, "arpbalance",
2278 		       SYSCTL_DESCR("Enable ARP balancing"),
2279 		       NULL, 0, &carp_opts[CARPCTL_ARPBALANCE], 0,
2280 		       CTL_NET, PF_INET, IPPROTO_CARP,
2281 		       CTL_CREATE, CTL_EOL);
2282 	sysctl_createv(clog, 0, NULL, NULL,
2283 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2284 		       CTLTYPE_INT, "allow",
2285 		       SYSCTL_DESCR("Enable CARP"),
2286 		       NULL, 0, &carp_opts[CARPCTL_ALLOW], 0,
2287 		       CTL_NET, PF_INET, IPPROTO_CARP,
2288 		       CTL_CREATE, CTL_EOL);
2289 	sysctl_createv(clog, 0, NULL, NULL,
2290 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2291 		       CTLTYPE_INT, "log",
2292 		       SYSCTL_DESCR("CARP logging"),
2293 		       NULL, 0, &carp_opts[CARPCTL_LOG], 0,
2294 		       CTL_NET, PF_INET, IPPROTO_CARP,
2295 		       CTL_CREATE, CTL_EOL);
2296 	sysctl_createv(clog, 0, NULL, NULL,
2297 		       CTLFLAG_PERMANENT,
2298 		       CTLTYPE_STRUCT, "stats",
2299 		       SYSCTL_DESCR("CARP statistics"),
2300 		       sysctl_net_inet_carp_stats, 0, NULL, 0,
2301 		       CTL_NET, PF_INET, IPPROTO_CARP, CARPCTL_STATS,
2302 		       CTL_EOL);
2303 }
2304