xref: /freebsd/sys/netinet/ip_carp.c (revision 397e83df75e0fcd0d3fcb95ae4d794cb7600fc89)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2002 Michael Shalayeff.
5  * Copyright (c) 2003 Ryan McBride.
6  * Copyright (c) 2011 Gleb Smirnoff <glebius@FreeBSD.org>
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
22  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
28  * THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 #include "opt_bpf.h"
33 #include "opt_inet.h"
34 #include "opt_inet6.h"
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/devctl.h>
39 #include <sys/jail.h>
40 #include <sys/kassert.h>
41 #include <sys/kernel.h>
42 #include <sys/limits.h>
43 #include <sys/malloc.h>
44 #include <sys/mbuf.h>
45 #include <sys/module.h>
46 #include <sys/priv.h>
47 #include <sys/proc.h>
48 #include <sys/socket.h>
49 #include <sys/sockio.h>
50 #include <sys/sysctl.h>
51 #include <sys/syslog.h>
52 #include <sys/taskqueue.h>
53 #include <sys/counter.h>
54 
55 #include <net/ethernet.h>
56 #include <net/if.h>
57 #include <net/if_var.h>
58 #include <net/if_dl.h>
59 #include <net/if_llatbl.h>
60 #include <net/if_private.h>
61 #include <net/if_types.h>
62 #include <net/route.h>
63 #include <net/vnet.h>
64 
65 #if defined(INET) || defined(INET6)
66 #include <netinet/in.h>
67 #include <netinet/in_var.h>
68 #include <netinet/ip_carp.h>
69 #include <netinet/ip_carp_nl.h>
70 #include <netinet/ip.h>
71 #include <machine/in_cksum.h>
72 #endif
73 #ifdef INET
74 #include <netinet/ip_var.h>
75 #include <netinet/if_ether.h>
76 #endif
77 
78 #ifdef INET6
79 #include <netinet/icmp6.h>
80 #include <netinet/ip6.h>
81 #include <netinet6/in6_var.h>
82 #include <netinet6/ip6_var.h>
83 #include <netinet6/scope6_var.h>
84 #include <netinet6/nd6.h>
85 #endif
86 
87 #include <netlink/netlink.h>
88 #include <netlink/netlink_ctl.h>
89 #include <netlink/netlink_generic.h>
90 #include <netlink/netlink_message_parser.h>
91 
92 #include <crypto/sha1.h>
93 
94 static MALLOC_DEFINE(M_CARP, "CARP", "CARP addresses");
95 
96 struct carp_softc {
97 	struct ifnet		*sc_carpdev;	/* Pointer to parent ifnet. */
98 	struct ifaddr		**sc_ifas;	/* Our ifaddrs. */
99 	carp_version_t		sc_version;	/* carp or VRRPv3 */
100 	uint8_t			sc_addr[ETHER_ADDR_LEN];	/* Our link level address. */
101 	struct callout		sc_ad_tmo;	/* Advertising timeout. */
102 #ifdef INET
103 	struct callout		sc_md_tmo;	/* Master down timeout. */
104 #endif
105 #ifdef INET6
106 	struct callout 		sc_md6_tmo;	/* XXX: Master down timeout. */
107 #endif
108 	struct mtx		sc_mtx;
109 
110 	int			sc_vhid;
111 	union {
112 		struct { /* sc_version == CARP_VERSION_CARP */
113 			int		sc_advskew;
114 			int		sc_advbase;
115 			struct in_addr	sc_carpaddr;
116 			struct in6_addr	sc_carpaddr6;
117 			uint64_t	sc_counter;
118 			bool		sc_init_counter;
119 #define	CARP_HMAC_PAD	64
120 			unsigned char sc_key[CARP_KEY_LEN];
121 			unsigned char sc_pad[CARP_HMAC_PAD];
122 			SHA1_CTX sc_sha1;
123 		};
124 		struct { /* sc_version == CARP_VERSION_VRRPv3 */
125 			uint8_t		sc_vrrp_prio;
126 			uint16_t	sc_vrrp_adv_inter;
127 			uint16_t	sc_vrrp_master_inter;
128 		};
129 	};
130 	int			sc_naddrs;
131 	int			sc_naddrs6;
132 	int			sc_ifasiz;
133 	enum { INIT = 0, BACKUP, MASTER }	sc_state;
134 	int			sc_suppress;
135 	int			sc_sendad_errors;
136 #define	CARP_SENDAD_MAX_ERRORS	3
137 	int			sc_sendad_success;
138 #define	CARP_SENDAD_MIN_SUCCESS 3
139 
140 	TAILQ_ENTRY(carp_softc)	sc_list;	/* On the carp_if list. */
141 	LIST_ENTRY(carp_softc)	sc_next;	/* On the global list. */
142 };
143 
144 struct carp_if {
145 #ifdef INET
146 	int	cif_naddrs;
147 #endif
148 #ifdef INET6
149 	int	cif_naddrs6;
150 #endif
151 	TAILQ_HEAD(, carp_softc) cif_vrs;
152 #ifdef INET
153 	struct ip_moptions 	 cif_imo;
154 #endif
155 #ifdef INET6
156 	struct ip6_moptions 	 cif_im6o;
157 #endif
158 	struct ifnet	*cif_ifp;
159 	struct mtx	cif_mtx;
160 	uint32_t	cif_flags;
161 #define	CIF_PROMISC	0x00000001
162 };
163 
164 /* Kernel equivalent of struct carpreq, but with more fields for new features.
165  * */
166 struct carpkreq {
167 	int		carpr_count;
168 	int		carpr_vhid;
169 	int		carpr_state;
170 	int		carpr_advskew;
171 	int		carpr_advbase;
172 	unsigned char	carpr_key[CARP_KEY_LEN];
173 	/* Everything above this is identical to carpreq */
174 	struct in_addr	carpr_addr;
175 	struct in6_addr	carpr_addr6;
176 	carp_version_t	carpr_version;
177 	uint8_t		carpr_vrrp_priority;
178 	uint16_t	carpr_vrrp_adv_inter;
179 };
180 
181 /*
182  * Brief design of carp(4).
183  *
184  * Any carp-capable ifnet may have a list of carp softcs hanging off
185  * its ifp->if_carp pointer. Each softc represents one unique virtual
186  * host id, or vhid. The softc has a back pointer to the ifnet. All
187  * softcs are joined in a global list, which has quite limited use.
188  *
189  * Any interface address that takes part in CARP negotiation has a
190  * pointer to the softc of its vhid, ifa->ifa_carp. That could be either
191  * AF_INET or AF_INET6 address.
192  *
193  * Although, one can get the softc's backpointer to ifnet and traverse
194  * through its ifp->if_addrhead queue to find all interface addresses
195  * involved in CARP, we keep a growable array of ifaddr pointers. This
196  * allows us to avoid grabbing the IF_ADDR_LOCK() in many traversals that
197  * do calls into the network stack, thus avoiding LORs.
198  *
199  * Locking:
200  *
201  * Each softc has a lock sc_mtx. It is used to synchronise carp_input_c(),
202  * callout-driven events and ioctl()s.
203  *
204  * To traverse the list of softcs on an ifnet we use CIF_LOCK() or carp_sx.
205  * To traverse the global list we use the mutex carp_mtx.
206  *
207  * Known issues with locking:
208  *
209  * - Sending ad, we put the pointer to the softc in an mtag, and no reference
210  *   counting is done on the softc.
211  * - On module unload we may race (?) with packet processing thread
212  *   dereferencing our function pointers.
213  */
214 
215 /* Accept incoming CARP packets. */
216 VNET_DEFINE_STATIC(int, carp_allow) = 1;
217 #define	V_carp_allow	VNET(carp_allow)
218 
219 /* Set DSCP in outgoing CARP packets. */
220 VNET_DEFINE_STATIC(int, carp_dscp) = 56;
221 #define	V_carp_dscp	VNET(carp_dscp)
222 
223 /* Preempt slower nodes. */
224 VNET_DEFINE_STATIC(int, carp_preempt) = 0;
225 #define	V_carp_preempt	VNET(carp_preempt)
226 
227 /* Log level. */
228 VNET_DEFINE_STATIC(int, carp_log) = 1;
229 #define	V_carp_log	VNET(carp_log)
230 
231 /* Global advskew demotion. */
232 VNET_DEFINE_STATIC(int, carp_demotion) = 0;
233 #define	V_carp_demotion	VNET(carp_demotion)
234 
235 /* Send error demotion factor. */
236 VNET_DEFINE_STATIC(int, carp_senderr_adj) = CARP_MAXSKEW;
237 #define	V_carp_senderr_adj	VNET(carp_senderr_adj)
238 
239 /* Iface down demotion factor. */
240 VNET_DEFINE_STATIC(int, carp_ifdown_adj) = CARP_MAXSKEW;
241 #define	V_carp_ifdown_adj	VNET(carp_ifdown_adj)
242 
243 static int carp_allow_sysctl(SYSCTL_HANDLER_ARGS);
244 static int carp_dscp_sysctl(SYSCTL_HANDLER_ARGS);
245 static int carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS);
246 
247 SYSCTL_NODE(_net_inet, IPPROTO_CARP, carp, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
248     "CARP");
249 SYSCTL_PROC(_net_inet_carp, OID_AUTO, allow,
250     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE,
251     &VNET_NAME(carp_allow), 0, carp_allow_sysctl, "I",
252     "Accept incoming CARP packets");
253 SYSCTL_PROC(_net_inet_carp, OID_AUTO, dscp,
254     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
255     0, 0, carp_dscp_sysctl, "I",
256     "DSCP value for carp packets");
257 SYSCTL_INT(_net_inet_carp, OID_AUTO, preempt, CTLFLAG_VNET | CTLFLAG_RW,
258     &VNET_NAME(carp_preempt), 0, "High-priority backup preemption mode");
259 SYSCTL_INT(_net_inet_carp, OID_AUTO, log, CTLFLAG_VNET | CTLFLAG_RW,
260     &VNET_NAME(carp_log), 0, "CARP log level");
261 SYSCTL_PROC(_net_inet_carp, OID_AUTO, demotion,
262     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
263     0, 0, carp_demote_adj_sysctl, "I",
264     "Adjust demotion factor (skew of advskew)");
265 SYSCTL_INT(_net_inet_carp, OID_AUTO, senderr_demotion_factor,
266     CTLFLAG_VNET | CTLFLAG_RW,
267     &VNET_NAME(carp_senderr_adj), 0, "Send error demotion factor adjustment");
268 SYSCTL_INT(_net_inet_carp, OID_AUTO, ifdown_demotion_factor,
269     CTLFLAG_VNET | CTLFLAG_RW,
270     &VNET_NAME(carp_ifdown_adj), 0,
271     "Interface down demotion factor adjustment");
272 
273 VNET_PCPUSTAT_DEFINE(struct carpstats, carpstats);
274 VNET_PCPUSTAT_SYSINIT(carpstats);
275 VNET_PCPUSTAT_SYSUNINIT(carpstats);
276 
277 #define	CARPSTATS_ADD(name, val)	\
278     counter_u64_add(VNET(carpstats)[offsetof(struct carpstats, name) / \
279 	sizeof(uint64_t)], (val))
280 #define	CARPSTATS_INC(name)		CARPSTATS_ADD(name, 1)
281 
282 SYSCTL_VNET_PCPUSTAT(_net_inet_carp, OID_AUTO, stats, struct carpstats,
283     carpstats, "CARP statistics (struct carpstats, netinet/ip_carp.h)");
284 
285 #define	CARP_LOCK_INIT(sc)	mtx_init(&(sc)->sc_mtx, "carp_softc",   \
286 	NULL, MTX_DEF)
287 #define	CARP_LOCK_DESTROY(sc)	mtx_destroy(&(sc)->sc_mtx)
288 #define	CARP_LOCK_ASSERT(sc)	mtx_assert(&(sc)->sc_mtx, MA_OWNED)
289 #define	CARP_LOCK(sc)		mtx_lock(&(sc)->sc_mtx)
290 #define	CARP_UNLOCK(sc)		mtx_unlock(&(sc)->sc_mtx)
291 #define	CIF_LOCK_INIT(cif)	mtx_init(&(cif)->cif_mtx, "carp_if",   \
292 	NULL, MTX_DEF)
293 #define	CIF_LOCK_DESTROY(cif)	mtx_destroy(&(cif)->cif_mtx)
294 #define	CIF_LOCK_ASSERT(cif)	mtx_assert(&(cif)->cif_mtx, MA_OWNED)
295 #define	CIF_LOCK(cif)		mtx_lock(&(cif)->cif_mtx)
296 #define	CIF_UNLOCK(cif)		mtx_unlock(&(cif)->cif_mtx)
297 #define	CIF_FREE(cif)	do {				\
298 		CIF_LOCK(cif);				\
299 		if (TAILQ_EMPTY(&(cif)->cif_vrs))	\
300 			carp_free_if(cif);		\
301 		else					\
302 			CIF_UNLOCK(cif);		\
303 } while (0)
304 
305 #define	CARP_LOG(...)	do {				\
306 	if (V_carp_log > 0)				\
307 		log(LOG_INFO, "carp: " __VA_ARGS__);	\
308 } while (0)
309 
310 #define	CARP_DEBUG(...)	do {				\
311 	if (V_carp_log > 1)				\
312 		log(LOG_DEBUG, __VA_ARGS__);		\
313 } while (0)
314 
315 #define	IFNET_FOREACH_IFA(ifp, ifa)					\
316 	CK_STAILQ_FOREACH((ifa), &(ifp)->if_addrhead, ifa_link)	\
317 		if ((ifa)->ifa_carp != NULL)
318 
319 #define	CARP_FOREACH_IFA(sc, ifa)					\
320 	CARP_LOCK_ASSERT(sc);						\
321 	for (int _i = 0;						\
322 		_i < (sc)->sc_naddrs + (sc)->sc_naddrs6 &&		\
323 		((ifa) = sc->sc_ifas[_i]) != NULL;			\
324 		++_i)
325 
326 #define	IFNET_FOREACH_CARP(ifp, sc)					\
327 	KASSERT(mtx_owned(&ifp->if_carp->cif_mtx) ||			\
328 	    sx_xlocked(&carp_sx), ("cif_vrs not locked"));		\
329 	TAILQ_FOREACH((sc), &(ifp)->if_carp->cif_vrs, sc_list)
330 
331 #define	DEMOTE_ADVSKEW(sc)					\
332     (((sc)->sc_advskew + V_carp_demotion > CARP_MAXSKEW) ?	\
333     CARP_MAXSKEW :						\
334         (((sc)->sc_advskew + V_carp_demotion < 0) ?		\
335         0 : ((sc)->sc_advskew + V_carp_demotion)))
336 
337 static void	carp_input_c(struct mbuf *, struct carp_header *, sa_family_t, int);
338 static void	vrrp_input_c(struct mbuf *, int, sa_family_t, int, int, uint16_t);
339 static struct carp_softc
340 		*carp_alloc(struct ifnet *, carp_version_t, int);
341 static void	carp_destroy(struct carp_softc *);
342 static struct carp_if
343 		*carp_alloc_if(struct ifnet *);
344 static void	carp_free_if(struct carp_if *);
345 static void	carp_set_state(struct carp_softc *, int, const char* reason);
346 static void	carp_sc_state(struct carp_softc *);
347 static void	carp_setrun(struct carp_softc *, sa_family_t);
348 static void	carp_master_down(void *);
349 static void	carp_master_down_locked(struct carp_softc *,
350     		    const char* reason);
351 static void	carp_send_ad_locked(struct carp_softc *);
352 static void	vrrp_send_ad_locked(struct carp_softc *);
353 static void	carp_addroute(struct carp_softc *);
354 static void	carp_ifa_addroute(struct ifaddr *);
355 static void	carp_delroute(struct carp_softc *);
356 static void	carp_ifa_delroute(struct ifaddr *);
357 static void	carp_send_ad_all(void *, int);
358 static void	carp_demote_adj(int, char *);
359 
360 static LIST_HEAD(, carp_softc) carp_list;
361 static struct mtx carp_mtx;
362 static struct sx carp_sx;
363 static struct task carp_sendall_task =
364     TASK_INITIALIZER(0, carp_send_ad_all, NULL);
365 
366 static int
367 carp_is_supported_if(if_t ifp)
368 {
369 	if (ifp == NULL)
370 		return (ENXIO);
371 
372 	switch (ifp->if_type) {
373 	case IFT_ETHER:
374 	case IFT_L2VLAN:
375 	case IFT_BRIDGE:
376 		break;
377 	default:
378 		return (EOPNOTSUPP);
379 	}
380 
381 	return (0);
382 }
383 
384 static void
385 carp_hmac_prepare(struct carp_softc *sc)
386 {
387 	uint8_t version = CARP_VERSION_CARP, type = CARP_ADVERTISEMENT;
388 	uint8_t vhid = sc->sc_vhid & 0xff;
389 	struct ifaddr *ifa;
390 	int i, found;
391 #ifdef INET
392 	struct in_addr last, cur, in;
393 #endif
394 #ifdef INET6
395 	struct in6_addr last6, cur6, in6;
396 #endif
397 
398 	CARP_LOCK_ASSERT(sc);
399 	MPASS(sc->sc_version == CARP_VERSION_CARP);
400 
401 	/* Compute ipad from key. */
402 	bzero(sc->sc_pad, sizeof(sc->sc_pad));
403 	bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
404 	for (i = 0; i < sizeof(sc->sc_pad); i++)
405 		sc->sc_pad[i] ^= 0x36;
406 
407 	/* Precompute first part of inner hash. */
408 	SHA1Init(&sc->sc_sha1);
409 	SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
410 	SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
411 	SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
412 	SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
413 #ifdef INET
414 	cur.s_addr = 0;
415 	do {
416 		found = 0;
417 		last = cur;
418 		cur.s_addr = 0xffffffff;
419 		CARP_FOREACH_IFA(sc, ifa) {
420 			in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
421 			if (ifa->ifa_addr->sa_family == AF_INET &&
422 			    ntohl(in.s_addr) > ntohl(last.s_addr) &&
423 			    ntohl(in.s_addr) < ntohl(cur.s_addr)) {
424 				cur.s_addr = in.s_addr;
425 				found++;
426 			}
427 		}
428 		if (found)
429 			SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
430 	} while (found);
431 #endif /* INET */
432 #ifdef INET6
433 	memset(&cur6, 0, sizeof(cur6));
434 	do {
435 		found = 0;
436 		last6 = cur6;
437 		memset(&cur6, 0xff, sizeof(cur6));
438 		CARP_FOREACH_IFA(sc, ifa) {
439 			in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
440 			if (IN6_IS_SCOPE_EMBED(&in6))
441 				in6.s6_addr16[1] = 0;
442 			if (ifa->ifa_addr->sa_family == AF_INET6 &&
443 			    memcmp(&in6, &last6, sizeof(in6)) > 0 &&
444 			    memcmp(&in6, &cur6, sizeof(in6)) < 0) {
445 				cur6 = in6;
446 				found++;
447 			}
448 		}
449 		if (found)
450 			SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
451 	} while (found);
452 #endif /* INET6 */
453 
454 	/* convert ipad to opad */
455 	for (i = 0; i < sizeof(sc->sc_pad); i++)
456 		sc->sc_pad[i] ^= 0x36 ^ 0x5c;
457 }
458 
459 static void
460 carp_hmac_generate(struct carp_softc *sc, uint32_t counter[2],
461     unsigned char md[20])
462 {
463 	SHA1_CTX sha1ctx;
464 
465 	CARP_LOCK_ASSERT(sc);
466 
467 	/* fetch first half of inner hash */
468 	bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
469 
470 	SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
471 	SHA1Final(md, &sha1ctx);
472 
473 	/* outer hash */
474 	SHA1Init(&sha1ctx);
475 	SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
476 	SHA1Update(&sha1ctx, md, 20);
477 	SHA1Final(md, &sha1ctx);
478 }
479 
480 static int
481 carp_hmac_verify(struct carp_softc *sc, uint32_t counter[2],
482     unsigned char md[20])
483 {
484 	unsigned char md2[20];
485 
486 	CARP_LOCK_ASSERT(sc);
487 
488 	carp_hmac_generate(sc, counter, md2);
489 
490 	return (bcmp(md, md2, sizeof(md2)));
491 }
492 
493 static int
494 vrrp_checksum_verify(struct mbuf *m, int off, int len, uint16_t phdrcksum)
495 {
496 	uint16_t cksum;
497 
498 	/*
499 	 * Note that VRRPv3 checksums are different from CARP checksums.
500 	 * Carp just calculates the checksum over the packet.
501 	 * VRRPv3 includes the pseudo-header checksum as well.
502 	 */
503 	cksum = in_cksum_skip(m, off + len, off);
504 	cksum -= phdrcksum;
505 
506 	return (cksum);
507 }
508 
509 /*
510  * process input packet.
511  * we have rearranged checks order compared to the rfc,
512  * but it seems more efficient this way or not possible otherwise.
513  */
514 #ifdef INET
515 static int
516 carp_input(struct mbuf **mp, int *offp, int proto)
517 {
518 	struct mbuf *m = *mp;
519 	struct ip *ip = mtod(m, struct ip *);
520 	struct vrrpv3_header *vh;
521 	int iplen;
522 	int minlen;
523 	int totlen;
524 
525 	iplen = *offp;
526 	*mp = NULL;
527 
528 	CARPSTATS_INC(carps_ipackets);
529 
530 	if (!V_carp_allow) {
531 		m_freem(m);
532 		return (IPPROTO_DONE);
533 	}
534 
535 	iplen = ip->ip_hl << 2;
536 	totlen = ntohs(ip->ip_len);
537 
538 	/* Ensure we have enough header to figure out the version. */
539 	if (m->m_pkthdr.len < iplen + sizeof(*vh)) {
540 		CARPSTATS_INC(carps_badlen);
541 		CARP_DEBUG("%s: received len %zd < sizeof(struct vrrpv3_header) "
542 		    "on %s\n", __func__, m->m_len - sizeof(struct ip),
543 		    if_name(m->m_pkthdr.rcvif));
544 		m_freem(m);
545 		return (IPPROTO_DONE);
546 	}
547 
548 	if (iplen + sizeof(*vh) < m->m_len) {
549 		if ((m = m_pullup(m, iplen + sizeof(*vh))) == NULL) {
550 			CARPSTATS_INC(carps_hdrops);
551 			CARP_DEBUG("%s():%d: pullup failed\n", __func__, __LINE__);
552 			return (IPPROTO_DONE);
553 		}
554 		ip = mtod(m, struct ip *);
555 	}
556 	vh = (struct vrrpv3_header *)((char *)ip + iplen);
557 
558 	switch (vh->vrrp_version) {
559 	case CARP_VERSION_CARP:
560 		minlen = sizeof(struct carp_header);
561 		break;
562 	case CARP_VERSION_VRRPv3:
563 		minlen = sizeof(struct vrrpv3_header);
564 		break;
565 	default:
566 		CARPSTATS_INC(carps_badver);
567 		CARP_DEBUG("%s: unsupported version %d on %s\n", __func__,
568 		    vh->vrrp_version, if_name(m->m_pkthdr.rcvif));
569 		m_freem(m);
570 		return (IPPROTO_DONE);
571 	}
572 
573 	/* And now check the length again but with the real minimal length. */
574 	if (m->m_pkthdr.len < iplen + minlen) {
575 		CARPSTATS_INC(carps_badlen);
576 		CARP_DEBUG("%s: received len %zd < %d "
577 		    "on %s\n", __func__, m->m_len - sizeof(struct ip),
578 		    iplen + minlen,
579 		    if_name(m->m_pkthdr.rcvif));
580 		m_freem(m);
581 		return (IPPROTO_DONE);
582 	}
583 
584 	if (iplen + minlen < m->m_len) {
585 		if ((m = m_pullup(m, iplen + minlen)) == NULL) {
586 			CARPSTATS_INC(carps_hdrops);
587 			CARP_DEBUG("%s():%d: pullup failed\n", __func__, __LINE__);
588 			return (IPPROTO_DONE);
589 		}
590 		ip = mtod(m, struct ip *);
591 		vh = (struct vrrpv3_header *)((char *)ip + iplen);
592 	}
593 
594 	switch (vh->vrrp_version) {
595 	case CARP_VERSION_CARP: {
596 		struct carp_header *ch;
597 
598 		/* verify the CARP checksum */
599 		m->m_data += iplen;
600 		if (in_cksum(m, totlen - iplen)) {
601 			CARPSTATS_INC(carps_badsum);
602 			CARP_DEBUG("%s: checksum failed on %s\n", __func__,
603 			    if_name(m->m_pkthdr.rcvif));
604 			m_freem(m);
605 			break;
606 		}
607 		m->m_data -= iplen;
608 		ch = (struct carp_header *)((char *)ip + iplen);
609 		carp_input_c(m, ch, AF_INET, ip->ip_ttl);
610 		break;
611 	}
612 	case CARP_VERSION_VRRPv3: {
613 		uint16_t phdrcksum;
614 
615 		phdrcksum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
616 		    htonl((u_short)(totlen - iplen) + ip->ip_p));
617 		vrrp_input_c(m, iplen, AF_INET, ip->ip_ttl, totlen - iplen,
618 		    phdrcksum);
619 		break;
620 	}
621 	default:
622 		KASSERT(false, ("Unsupported version %d", vh->vrrp_version));
623 	}
624 
625 	return (IPPROTO_DONE);
626 }
627 #endif
628 
629 #ifdef INET6
630 static int
631 carp6_input(struct mbuf **mp, int *offp, int proto)
632 {
633 	struct mbuf *m = *mp;
634 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
635 	struct vrrpv3_header *vh;
636 	u_int len, minlen;
637 
638 	CARPSTATS_INC(carps_ipackets6);
639 
640 	if (!V_carp_allow) {
641 		m_freem(m);
642 		return (IPPROTO_DONE);
643 	}
644 
645 	/* check if received on a valid carp interface */
646 	if (m->m_pkthdr.rcvif->if_carp == NULL) {
647 		CARPSTATS_INC(carps_badif);
648 		CARP_DEBUG("%s: packet received on non-carp interface: %s\n",
649 		    __func__, if_name(m->m_pkthdr.rcvif));
650 		m_freem(m);
651 		return (IPPROTO_DONE);
652 	}
653 
654 	if (m->m_len < *offp + sizeof(*vh)) {
655 		len = m->m_len;
656 		m = m_pullup(m, *offp + sizeof(*vh));
657 		if (m == NULL) {
658 			CARPSTATS_INC(carps_badlen);
659 			CARP_DEBUG("%s: packet size %u too small\n", __func__, len);
660 			return (IPPROTO_DONE);
661 		}
662 		ip6 = mtod(m, struct ip6_hdr *);
663 	}
664 	vh = (struct vrrpv3_header *)(mtod(m, char *) + *offp);
665 
666 	switch (vh->vrrp_version) {
667 	case CARP_VERSION_CARP:
668 		minlen = sizeof(struct carp_header);
669 		break;
670 	case CARP_VERSION_VRRPv3:
671 		minlen = sizeof(struct vrrpv3_header);
672 		break;
673 	default:
674 		CARPSTATS_INC(carps_badver);
675 		CARP_DEBUG("%s: unsupported version %d on %s\n", __func__,
676 		    vh->vrrp_version, if_name(m->m_pkthdr.rcvif));
677 		m_freem(m);
678 		return (IPPROTO_DONE);
679 	}
680 
681 	/* And now check the length again but with the real minimal length. */
682 	if (m->m_pkthdr.len < sizeof(*ip6) + minlen) {
683 		CARPSTATS_INC(carps_badlen);
684 		CARP_DEBUG("%s: received len %zd < %zd "
685 		    "on %s\n", __func__, m->m_len - sizeof(struct ip),
686 		    sizeof(*ip6) + minlen,
687 		    if_name(m->m_pkthdr.rcvif));
688 		m_freem(m);
689 		return (IPPROTO_DONE);
690 	}
691 
692 	if (sizeof (*ip6) + minlen < m->m_len) {
693 		if ((m = m_pullup(m, sizeof(*ip6) + minlen)) == NULL) {
694 			CARPSTATS_INC(carps_hdrops);
695 			CARP_DEBUG("%s():%d: pullup failed\n", __func__, __LINE__);
696 			return (IPPROTO_DONE);
697 		}
698 		ip6 = mtod(m, struct ip6_hdr *);
699 		vh = (struct vrrpv3_header *)mtodo(m, sizeof(*ip6));
700 	}
701 
702 	switch (vh->vrrp_version) {
703 	case CARP_VERSION_CARP: {
704 		struct carp_header *ch;
705 
706 		/* verify the CARP checksum */
707 		m->m_data += *offp;
708 		if (in_cksum(m, sizeof(struct carp_header))) {
709 			CARPSTATS_INC(carps_badsum);
710 			CARP_DEBUG("%s: checksum failed, on %s\n", __func__,
711 			    if_name(m->m_pkthdr.rcvif));
712 			m_freem(m);
713 			break;
714 		}
715 		m->m_data -= *offp;
716 		ch = (struct carp_header *)((char *)ip6 + sizeof(*ip6));
717 		carp_input_c(m, ch, AF_INET6, ip6->ip6_hlim);
718 		break;
719 	}
720 	case CARP_VERSION_VRRPv3: {
721 		uint16_t phdrcksum;
722 
723 		phdrcksum = in6_cksum_pseudo(ip6, ntohs(ip6->ip6_plen),
724 		    ip6->ip6_nxt, 0);
725 		vrrp_input_c(m, sizeof(*ip6), AF_INET6, ip6->ip6_hlim,
726 		    ntohs(ip6->ip6_plen), phdrcksum);
727 		break;
728 	}
729 	default:
730 		KASSERT(false, ("Unsupported version %d", vh->vrrp_version));
731 	}
732 	return (IPPROTO_DONE);
733 }
734 #endif /* INET6 */
735 
736 /*
737  * This routine should not be necessary at all, but some switches
738  * (VMWare ESX vswitches) can echo our own packets back at us,
739  * and we must ignore them or they will cause us to drop out of
740  * MASTER mode.
741  *
742  * We cannot catch all cases of network loops.  Instead, what we
743  * do here is catch any packet that arrives with a carp header
744  * with a VHID of 0, that comes from an address that is our own.
745  * These packets are by definition "from us" (even if they are from
746  * a misconfigured host that is pretending to be us).
747  *
748  * The VHID test is outside this mini-function.
749  */
750 static int
751 carp_source_is_self(const struct mbuf *m, struct ifaddr *ifa, sa_family_t af)
752 {
753 #ifdef INET
754 	struct ip *ip4;
755 	struct in_addr in4;
756 #endif
757 #ifdef INET6
758 	struct ip6_hdr *ip6;
759 	struct in6_addr in6;
760 #endif
761 
762 	switch (af) {
763 #ifdef INET
764 	case AF_INET:
765 		ip4 = mtod(m, struct ip *);
766 		in4 = ifatoia(ifa)->ia_addr.sin_addr;
767 		return (in4.s_addr == ip4->ip_src.s_addr);
768 #endif
769 #ifdef INET6
770 	case AF_INET6:
771 		ip6 = mtod(m, struct ip6_hdr *);
772 		in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
773 		return (memcmp(&in6, &ip6->ip6_src, sizeof(in6)) == 0);
774 #endif
775 	default:
776 		break;
777 	}
778 	return (0);
779 }
780 
781 static struct ifaddr *
782 carp_find_ifa(const struct mbuf *m, sa_family_t af, uint8_t vhid)
783 {
784 	struct ifnet *ifp = m->m_pkthdr.rcvif;
785 	struct ifaddr *ifa, *match;
786 	int error;
787 
788 	NET_EPOCH_ASSERT();
789 
790 	/*
791 	 * Verify that the VHID is valid on the receiving interface.
792 	 *
793 	 * There should be just one match.  If there are none
794 	 * the VHID is not valid and we drop the packet.  If
795 	 * there are multiple VHID matches, take just the first
796 	 * one, for compatibility with previous code.  While we're
797 	 * scanning, check for obvious loops in the network topology
798 	 * (these should never happen, and as noted above, we may
799 	 * miss real loops; this is just a double-check).
800 	 */
801 	error = 0;
802 	match = NULL;
803 	IFNET_FOREACH_IFA(ifp, ifa) {
804 		if (match == NULL && ifa->ifa_carp != NULL &&
805 		    ifa->ifa_addr->sa_family == af &&
806 		    ifa->ifa_carp->sc_vhid == vhid)
807 			match = ifa;
808 		if (vhid == 0 && carp_source_is_self(m, ifa, af))
809 			error = ELOOP;
810 	}
811 	ifa = error ? NULL : match;
812 	if (ifa != NULL)
813 		ifa_ref(ifa);
814 
815 	if (ifa == NULL) {
816 		if (error == ELOOP) {
817 			CARP_DEBUG("dropping looped packet on interface %s\n",
818 			    if_name(ifp));
819 			CARPSTATS_INC(carps_badif);	/* ??? */
820 		} else {
821 			CARPSTATS_INC(carps_badvhid);
822 		}
823 	}
824 
825 	return (ifa);
826 }
827 
828 static void
829 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af, int ttl)
830 {
831 	struct ifnet *ifp = m->m_pkthdr.rcvif;
832 	struct ifaddr *ifa;
833 	struct carp_softc *sc;
834 	uint64_t tmp_counter;
835 	struct timeval sc_tv, ch_tv;
836 	bool multicast = false;
837 
838 	NET_EPOCH_ASSERT();
839 	MPASS(ch->carp_version == CARP_VERSION_CARP);
840 
841 	ifa = carp_find_ifa(m, af, ch->carp_vhid);
842 	if (ifa == NULL) {
843 		m_freem(m);
844 		return;
845 	}
846 
847 	sc = ifa->ifa_carp;
848 	CARP_LOCK(sc);
849 
850 	/* verify the CARP version. */
851 	if (sc->sc_version != CARP_VERSION_CARP) {
852 		CARP_UNLOCK(sc);
853 
854 		CARPSTATS_INC(carps_badver);
855 		CARP_DEBUG("%s: invalid version %d\n", if_name(ifp),
856 		    ch->carp_version);
857 		ifa_free(ifa);
858 		m_freem(m);
859 		return;
860 	}
861 
862 	if (ifa->ifa_addr->sa_family == AF_INET) {
863 		multicast = IN_MULTICAST(sc->sc_carpaddr.s_addr);
864 	} else {
865 		multicast = IN6_IS_ADDR_MULTICAST(&sc->sc_carpaddr6);
866 	}
867 	ifa_free(ifa);
868 
869 	/* verify that the IP TTL is 255, but only if we're not in unicast mode. */
870 	if (multicast && ttl != CARP_DFLTTL) {
871 		CARPSTATS_INC(carps_badttl);
872 		CARP_DEBUG("%s: received ttl %d != 255 on %s\n", __func__,
873 		    ttl, if_name(m->m_pkthdr.rcvif));
874 		goto out;
875 	}
876 
877 	if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
878 		CARPSTATS_INC(carps_badauth);
879 		CARP_DEBUG("%s: incorrect hash for VHID %u@%s\n", __func__,
880 		    sc->sc_vhid, if_name(ifp));
881 		goto out;
882 	}
883 
884 	tmp_counter = ntohl(ch->carp_counter[0]);
885 	tmp_counter = tmp_counter<<32;
886 	tmp_counter += ntohl(ch->carp_counter[1]);
887 
888 	/* XXX Replay protection goes here */
889 
890 	sc->sc_init_counter = false;
891 	sc->sc_counter = tmp_counter;
892 
893 	sc_tv.tv_sec = sc->sc_advbase;
894 	sc_tv.tv_usec = DEMOTE_ADVSKEW(sc) * 1000000 / 256;
895 	ch_tv.tv_sec = ch->carp_advbase;
896 	ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
897 
898 	switch (sc->sc_state) {
899 	case INIT:
900 		break;
901 	case MASTER:
902 		/*
903 		 * If we receive an advertisement from a master who's going to
904 		 * be more frequent than us, go into BACKUP state.
905 		 */
906 		if (timevalcmp(&sc_tv, &ch_tv, >) ||
907 		    timevalcmp(&sc_tv, &ch_tv, ==)) {
908 			callout_stop(&sc->sc_ad_tmo);
909 			carp_set_state(sc, BACKUP,
910 			    "more frequent advertisement received");
911 			carp_setrun(sc, 0);
912 			carp_delroute(sc);
913 		}
914 		break;
915 	case BACKUP:
916 		/*
917 		 * If we're pre-empting masters who advertise slower than us,
918 		 * and this one claims to be slower, treat him as down.
919 		 */
920 		if (V_carp_preempt && timevalcmp(&sc_tv, &ch_tv, <)) {
921 			carp_master_down_locked(sc,
922 			    "preempting a slower master");
923 			break;
924 		}
925 
926 		/*
927 		 *  If the master is going to advertise at such a low frequency
928 		 *  that he's guaranteed to time out, we'd might as well just
929 		 *  treat him as timed out now.
930 		 */
931 		sc_tv.tv_sec = sc->sc_advbase * 3;
932 		if (timevalcmp(&sc_tv, &ch_tv, <)) {
933 			carp_master_down_locked(sc, "master will time out");
934 			break;
935 		}
936 
937 		/*
938 		 * Otherwise, we reset the counter and wait for the next
939 		 * advertisement.
940 		 */
941 		carp_setrun(sc, af);
942 		break;
943 	}
944 
945 out:
946 	CARP_UNLOCK(sc);
947 	m_freem(m);
948 }
949 
950 static void
951 vrrp_input_c(struct mbuf *m, int off, sa_family_t af, int ttl,
952     int len, uint16_t phdrcksum)
953 {
954 	struct vrrpv3_header *vh = mtodo(m, off);
955 	struct ifnet *ifp = m->m_pkthdr.rcvif;
956 	struct ifaddr *ifa;
957 	struct carp_softc *sc;
958 
959 	NET_EPOCH_ASSERT();
960 	MPASS(vh->vrrp_version == CARP_VERSION_VRRPv3);
961 
962 	ifa = carp_find_ifa(m, af, vh->vrrp_vrtid);
963 	if (ifa == NULL) {
964 		m_freem(m);
965 		return;
966 	}
967 
968 	sc = ifa->ifa_carp;
969 	CARP_LOCK(sc);
970 
971 	ifa_free(ifa);
972 
973 	/* verify the CARP version. */
974 	if (sc->sc_version != CARP_VERSION_VRRPv3) {
975 		CARP_UNLOCK(sc);
976 
977 		CARPSTATS_INC(carps_badver);
978 		CARP_DEBUG("%s: invalid version %d\n", if_name(ifp),
979 		    vh->vrrp_version);
980 		m_freem(m);
981 		return;
982 	}
983 
984 	/* verify that the IP TTL is 255. */
985 	if (ttl != CARP_DFLTTL) {
986 		CARPSTATS_INC(carps_badttl);
987 		CARP_DEBUG("%s: received ttl %d != 255 on %s\n", __func__,
988 		    ttl, if_name(m->m_pkthdr.rcvif));
989 		goto out;
990 	}
991 
992 	if (vrrp_checksum_verify(m, off, len, phdrcksum)) {
993 		CARPSTATS_INC(carps_badsum);
994 		CARP_DEBUG("%s: incorrect checksum for VRID %u@%s\n", __func__,
995 		    sc->sc_vhid, if_name(ifp));
996 		goto out;
997 	}
998 
999 	/* RFC9568, 7.1 Receiving VRRP packets. */
1000 	if (sc->sc_vrrp_prio == 255) {
1001 		CARP_DEBUG("%s: our priority is 255. Ignore peer announcement.\n",
1002 		    __func__);
1003 		goto out;
1004 	}
1005 
1006 	/* XXX TODO Check IP address payload. */
1007 
1008 	sc->sc_vrrp_master_inter = ntohs(vh->vrrp_max_adver_int);
1009 
1010 	switch (sc->sc_state) {
1011 	case INIT:
1012 		break;
1013 	case MASTER:
1014 		/*
1015 		 * If we receive an advertisement from a master who's going to
1016 		 * be more frequent than us, go into BACKUP state.
1017 		 * Same if the peer has a higher priority than us.
1018 		 */
1019 		if (ntohs(vh->vrrp_max_adver_int) < sc->sc_vrrp_adv_inter ||
1020 		    vh->vrrp_priority > sc->sc_vrrp_prio) {
1021 			callout_stop(&sc->sc_ad_tmo);
1022 			carp_set_state(sc, BACKUP,
1023 			    "more frequent advertisement received");
1024 			carp_setrun(sc, 0);
1025 			carp_delroute(sc);
1026 		}
1027 		break;
1028 	case BACKUP:
1029 		/*
1030 		 * If we're pre-empting masters who advertise slower than us,
1031 		 * and this one claims to be slower, treat him as down.
1032 		 */
1033 		if (V_carp_preempt && (ntohs(vh->vrrp_max_adver_int) > sc->sc_vrrp_adv_inter
1034 		    || vh->vrrp_priority < sc->sc_vrrp_prio)) {
1035 			carp_master_down_locked(sc,
1036 			    "preempting a slower master");
1037 			break;
1038 		}
1039 
1040 		/*
1041 		 * Otherwise, we reset the counter and wait for the next
1042 		 * advertisement.
1043 		 */
1044 		carp_setrun(sc, af);
1045 		break;
1046 	}
1047 
1048 out:
1049 	CARP_UNLOCK(sc);
1050 	m_freem(m);
1051 }
1052 
1053 static int
1054 carp_tag(struct carp_softc *sc, struct mbuf *m)
1055 {
1056 	struct m_tag *mtag;
1057 
1058 	/* Tag packet for carp_output */
1059 	if ((mtag = m_tag_get(PACKET_TAG_CARP, sizeof(sc->sc_vhid),
1060 	    M_NOWAIT)) == NULL) {
1061 		m_freem(m);
1062 		CARPSTATS_INC(carps_onomem);
1063 		return (ENOMEM);
1064 	}
1065 	bcopy(&sc->sc_vhid, mtag + 1, sizeof(sc->sc_vhid));
1066 	m_tag_prepend(m, mtag);
1067 
1068 	return (0);
1069 }
1070 
1071 static void
1072 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
1073 {
1074 
1075 	MPASS(sc->sc_version == CARP_VERSION_CARP);
1076 
1077 	if (sc->sc_init_counter) {
1078 		/* this could also be seconds since unix epoch */
1079 		sc->sc_counter = arc4random();
1080 		sc->sc_counter = sc->sc_counter << 32;
1081 		sc->sc_counter += arc4random();
1082 	} else
1083 		sc->sc_counter++;
1084 
1085 	ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
1086 	ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
1087 
1088 	carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
1089 }
1090 
1091 static inline void
1092 send_ad_locked(struct carp_softc *sc)
1093 {
1094 	switch (sc->sc_version) {
1095 	case CARP_VERSION_CARP:
1096 		carp_send_ad_locked(sc);
1097 		break;
1098 	case CARP_VERSION_VRRPv3:
1099 		vrrp_send_ad_locked(sc);
1100 		break;
1101 	}
1102 }
1103 
1104 /*
1105  * To avoid LORs and possible recursions this function shouldn't
1106  * be called directly, but scheduled via taskqueue.
1107  */
1108 static void
1109 carp_send_ad_all(void *ctx __unused, int pending __unused)
1110 {
1111 	struct carp_softc *sc;
1112 	struct epoch_tracker et;
1113 
1114 	NET_EPOCH_ENTER(et);
1115 	mtx_lock(&carp_mtx);
1116 	LIST_FOREACH(sc, &carp_list, sc_next)
1117 		if (sc->sc_state == MASTER) {
1118 			CARP_LOCK(sc);
1119 			CURVNET_SET(sc->sc_carpdev->if_vnet);
1120 			send_ad_locked(sc);
1121 			CURVNET_RESTORE();
1122 			CARP_UNLOCK(sc);
1123 		}
1124 	mtx_unlock(&carp_mtx);
1125 	NET_EPOCH_EXIT(et);
1126 }
1127 
1128 /* Send a periodic advertisement, executed in callout context. */
1129 static void
1130 carp_callout(void *v)
1131 {
1132 	struct carp_softc *sc = v;
1133 	struct epoch_tracker et;
1134 
1135 	NET_EPOCH_ENTER(et);
1136 	CARP_LOCK_ASSERT(sc);
1137 	CURVNET_SET(sc->sc_carpdev->if_vnet);
1138 	send_ad_locked(sc);
1139 	CURVNET_RESTORE();
1140 	CARP_UNLOCK(sc);
1141 	NET_EPOCH_EXIT(et);
1142 }
1143 
1144 static void
1145 carp_send_ad_error(struct carp_softc *sc, int error)
1146 {
1147 
1148 	/*
1149 	 * We track errors and successful sends with this logic:
1150 	 * - Any error resets success counter to 0.
1151 	 * - MAX_ERRORS triggers demotion.
1152 	 * - MIN_SUCCESS successes resets error counter to 0.
1153 	 * - MIN_SUCCESS reverts demotion, if it was triggered before.
1154 	 */
1155 	if (error) {
1156 		if (sc->sc_sendad_errors < INT_MAX)
1157 			sc->sc_sendad_errors++;
1158 		if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1159 			static const char fmt[] = "send error %d on %s";
1160 			char msg[sizeof(fmt) + IFNAMSIZ];
1161 
1162 			sprintf(msg, fmt, error, if_name(sc->sc_carpdev));
1163 			carp_demote_adj(V_carp_senderr_adj, msg);
1164 		}
1165 		sc->sc_sendad_success = 0;
1166 	} else if (sc->sc_sendad_errors > 0) {
1167 		if (++sc->sc_sendad_success >= CARP_SENDAD_MIN_SUCCESS) {
1168 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1169 				static const char fmt[] = "send ok on %s";
1170 				char msg[sizeof(fmt) + IFNAMSIZ];
1171 
1172 				sprintf(msg, fmt, if_name(sc->sc_carpdev));
1173 				carp_demote_adj(-V_carp_senderr_adj, msg);
1174 			}
1175 			sc->sc_sendad_errors = 0;
1176 		}
1177 	}
1178 }
1179 
1180 /*
1181  * Pick the best ifaddr on the given ifp for sending CARP
1182  * advertisements.
1183  *
1184  * "Best" here is defined by ifa_preferred().  This function is much
1185  * much like ifaof_ifpforaddr() except that we just use ifa_preferred().
1186  *
1187  * (This could be simplified to return the actual address, except that
1188  * it has a different format in AF_INET and AF_INET6.)
1189  */
1190 static struct ifaddr *
1191 carp_best_ifa(int af, struct ifnet *ifp)
1192 {
1193 	struct ifaddr *ifa, *best;
1194 
1195 	NET_EPOCH_ASSERT();
1196 
1197 	if (af >= AF_MAX)
1198 		return (NULL);
1199 	best = NULL;
1200 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1201 		if (ifa->ifa_addr->sa_family == af &&
1202 		    (best == NULL || ifa_preferred(best, ifa)))
1203 			best = ifa;
1204 	}
1205 	if (best != NULL)
1206 		ifa_ref(best);
1207 	return (best);
1208 }
1209 
1210 static void
1211 carp_send_ad_locked(struct carp_softc *sc)
1212 {
1213 	struct carp_header ch;
1214 	struct timeval tv;
1215 	struct ifaddr *ifa;
1216 	struct carp_header *ch_ptr;
1217 	struct mbuf *m;
1218 	int len, advskew;
1219 
1220 	NET_EPOCH_ASSERT();
1221 	CARP_LOCK_ASSERT(sc);
1222 	MPASS(sc->sc_version == CARP_VERSION_CARP);
1223 
1224 	advskew = DEMOTE_ADVSKEW(sc);
1225 	tv.tv_sec = sc->sc_advbase;
1226 	tv.tv_usec = advskew * 1000000 / 256;
1227 
1228 	ch.carp_version = CARP_VERSION_CARP;
1229 	ch.carp_type = CARP_ADVERTISEMENT;
1230 	ch.carp_vhid = sc->sc_vhid;
1231 	ch.carp_advbase = sc->sc_advbase;
1232 	ch.carp_advskew = advskew;
1233 	ch.carp_authlen = 7;	/* XXX DEFINE */
1234 	ch.carp_pad1 = 0;	/* must be zero */
1235 	ch.carp_cksum = 0;
1236 
1237 	/* XXXGL: OpenBSD picks first ifaddr with needed family. */
1238 
1239 #ifdef INET
1240 	if (sc->sc_naddrs) {
1241 		struct ip *ip;
1242 
1243 		m = m_gethdr(M_NOWAIT, MT_DATA);
1244 		if (m == NULL) {
1245 			CARPSTATS_INC(carps_onomem);
1246 			goto resched;
1247 		}
1248 		len = sizeof(*ip) + sizeof(ch);
1249 		m->m_pkthdr.len = len;
1250 		m->m_pkthdr.rcvif = NULL;
1251 		m->m_len = len;
1252 		M_ALIGN(m, m->m_len);
1253 		if (IN_MULTICAST(sc->sc_carpaddr.s_addr))
1254 			m->m_flags |= M_MCAST;
1255 		ip = mtod(m, struct ip *);
1256 		ip->ip_v = IPVERSION;
1257 		ip->ip_hl = sizeof(*ip) >> 2;
1258 		ip->ip_tos = V_carp_dscp << IPTOS_DSCP_OFFSET;
1259 		ip->ip_len = htons(len);
1260 		ip->ip_off = htons(IP_DF);
1261 		ip->ip_ttl = CARP_DFLTTL;
1262 		ip->ip_p = IPPROTO_CARP;
1263 		ip->ip_sum = 0;
1264 		ip_fillid(ip);
1265 
1266 		ifa = carp_best_ifa(AF_INET, sc->sc_carpdev);
1267 		if (ifa != NULL) {
1268 			ip->ip_src.s_addr =
1269 			    ifatoia(ifa)->ia_addr.sin_addr.s_addr;
1270 			ifa_free(ifa);
1271 		} else
1272 			ip->ip_src.s_addr = 0;
1273 		ip->ip_dst = sc->sc_carpaddr;
1274 
1275 		ch_ptr = (struct carp_header *)(&ip[1]);
1276 		bcopy(&ch, ch_ptr, sizeof(ch));
1277 		carp_prepare_ad(m, sc, ch_ptr);
1278 		if (IN_MULTICAST(ntohl(sc->sc_carpaddr.s_addr)) &&
1279 		    carp_tag(sc, m) != 0)
1280 			goto resched;
1281 
1282 		m->m_data += sizeof(*ip);
1283 		ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip));
1284 		m->m_data -= sizeof(*ip);
1285 
1286 		CARPSTATS_INC(carps_opackets);
1287 
1288 		carp_send_ad_error(sc, ip_output(m, NULL, NULL, IP_RAWOUTPUT,
1289 		    &sc->sc_carpdev->if_carp->cif_imo, NULL));
1290 	}
1291 #endif /* INET */
1292 #ifdef INET6
1293 	if (sc->sc_naddrs6) {
1294 		struct ip6_hdr *ip6;
1295 
1296 		m = m_gethdr(M_NOWAIT, MT_DATA);
1297 		if (m == NULL) {
1298 			CARPSTATS_INC(carps_onomem);
1299 			goto resched;
1300 		}
1301 		len = sizeof(*ip6) + sizeof(ch);
1302 		m->m_pkthdr.len = len;
1303 		m->m_pkthdr.rcvif = NULL;
1304 		m->m_len = len;
1305 		M_ALIGN(m, m->m_len);
1306 		ip6 = mtod(m, struct ip6_hdr *);
1307 		bzero(ip6, sizeof(*ip6));
1308 		ip6->ip6_vfc |= IPV6_VERSION;
1309 		/* Traffic class isn't defined in ip6 struct instead
1310 		 * it gets offset into flowid field */
1311 		ip6->ip6_flow |= htonl(V_carp_dscp << (IPV6_FLOWLABEL_LEN +
1312 		    IPTOS_DSCP_OFFSET));
1313 		ip6->ip6_hlim = CARP_DFLTTL;
1314 		ip6->ip6_nxt = IPPROTO_CARP;
1315 
1316 		/* set the source address */
1317 		ifa = carp_best_ifa(AF_INET6, sc->sc_carpdev);
1318 		if (ifa != NULL) {
1319 			bcopy(IFA_IN6(ifa), &ip6->ip6_src,
1320 			    sizeof(struct in6_addr));
1321 			ifa_free(ifa);
1322 		} else
1323 			/* This should never happen with IPv6. */
1324 			bzero(&ip6->ip6_src, sizeof(struct in6_addr));
1325 
1326 		/* Set the multicast destination. */
1327 		memcpy(&ip6->ip6_dst, &sc->sc_carpaddr6, sizeof(ip6->ip6_dst));
1328 		if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1329 		    IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) {
1330 			if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1331 				m_freem(m);
1332 				CARP_DEBUG("%s: in6_setscope failed\n", __func__);
1333 				goto resched;
1334 			}
1335 		}
1336 
1337 		ch_ptr = (struct carp_header *)(&ip6[1]);
1338 		bcopy(&ch, ch_ptr, sizeof(ch));
1339 		carp_prepare_ad(m, sc, ch_ptr);
1340 		if (IN6_IS_ADDR_MULTICAST(&sc->sc_carpaddr6) &&
1341 		    carp_tag(sc, m) != 0)
1342 			goto resched;
1343 
1344 		m->m_data += sizeof(*ip6);
1345 		ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip6));
1346 		m->m_data -= sizeof(*ip6);
1347 
1348 		CARPSTATS_INC(carps_opackets6);
1349 
1350 		carp_send_ad_error(sc, ip6_output(m, NULL, NULL, 0,
1351 		    &sc->sc_carpdev->if_carp->cif_im6o, NULL, NULL));
1352 	}
1353 #endif /* INET6 */
1354 
1355 resched:
1356 	callout_reset(&sc->sc_ad_tmo, tvtohz(&tv), carp_callout, sc);
1357 }
1358 
1359 static void
1360 vrrp_send_ad_locked(struct carp_softc *sc)
1361 {
1362 	struct vrrpv3_header *vh_ptr;
1363 	struct ifaddr *ifa;
1364 	struct mbuf *m;
1365 	int len;
1366 	struct vrrpv3_header vh = {
1367 	    .vrrp_version = CARP_VERSION_VRRPv3,
1368 	    .vrrp_type = VRRP_TYPE_ADVERTISEMENT,
1369 	    .vrrp_vrtid = sc->sc_vhid,
1370 	    .vrrp_priority = sc->sc_vrrp_prio,
1371 	    .vrrp_count_addr = 0,
1372 	    .vrrp_max_adver_int = htons(sc->sc_vrrp_adv_inter),
1373 	    .vrrp_checksum = 0,
1374 	};
1375 
1376 	NET_EPOCH_ASSERT();
1377 	CARP_LOCK_ASSERT(sc);
1378 	MPASS(sc->sc_version == CARP_VERSION_VRRPv3);
1379 
1380 #ifdef INET
1381 	if (sc->sc_naddrs) {
1382 		struct ip *ip;
1383 
1384 		m = m_gethdr(M_NOWAIT, MT_DATA);
1385 		if (m == NULL) {
1386 			CARPSTATS_INC(carps_onomem);
1387 			goto resched;
1388 		}
1389 		len = sizeof(*ip) + sizeof(vh);
1390 		m->m_pkthdr.len = len;
1391 		m->m_pkthdr.rcvif = NULL;
1392 		m->m_len = len;
1393 		M_ALIGN(m, m->m_len);
1394 		m->m_flags |= M_MCAST;
1395 		ip = mtod(m, struct ip *);
1396 		ip->ip_v = IPVERSION;
1397 		ip->ip_hl = sizeof(*ip) >> 2;
1398 		ip->ip_tos = V_carp_dscp << IPTOS_DSCP_OFFSET;
1399 		ip->ip_off = htons(IP_DF);
1400 		ip->ip_ttl = CARP_DFLTTL;
1401 		ip->ip_p = IPPROTO_CARP;
1402 		ip->ip_sum = 0;
1403 		ip_fillid(ip);
1404 
1405 		ifa = carp_best_ifa(AF_INET, sc->sc_carpdev);
1406 		if (ifa != NULL) {
1407 			ip->ip_src.s_addr =
1408 			    ifatoia(ifa)->ia_addr.sin_addr.s_addr;
1409 			ifa_free(ifa);
1410 		} else
1411 			ip->ip_src.s_addr = 0;
1412 		ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
1413 
1414 		/* Include the IP addresses in the announcement. */
1415 		for (int i = 0; i < (sc->sc_naddrs + sc->sc_naddrs6); i++) {
1416 			struct sockaddr_in *in;
1417 
1418 			MPASS(sc->sc_ifas[i] != NULL);
1419 			if (sc->sc_ifas[i]->ifa_addr->sa_family != AF_INET)
1420 				continue;
1421 
1422 			in = (struct sockaddr_in *)sc->sc_ifas[i]->ifa_addr;
1423 
1424 			if (m_append(m, sizeof(in->sin_addr),
1425 			    (caddr_t)&in->sin_addr) != 1) {
1426 				m_freem(m);
1427 				goto resched;
1428 			}
1429 
1430 			vh.vrrp_count_addr++;
1431 			len += sizeof(in->sin_addr);
1432 		}
1433 		ip->ip_len = htons(len);
1434 
1435 		vh_ptr = (struct vrrpv3_header *)mtodo(m, sizeof(*ip));
1436 		bcopy(&vh, vh_ptr, sizeof(vh));
1437 
1438 		vh_ptr->vrrp_checksum = in_pseudo(ip->ip_src.s_addr,
1439 		    ip->ip_dst.s_addr,
1440 		    htonl((uint16_t)(len - sizeof(*ip)) + ip->ip_p));
1441 		vh_ptr->vrrp_checksum = in_cksum_skip(m, len, sizeof(*ip));
1442 
1443 		if (carp_tag(sc, m))
1444 			goto resched;
1445 
1446 		CARPSTATS_INC(carps_opackets);
1447 
1448 		carp_send_ad_error(sc, ip_output(m, NULL, NULL, IP_RAWOUTPUT,
1449 		    &sc->sc_carpdev->if_carp->cif_imo, NULL));
1450 	}
1451 #endif
1452 #ifdef INET6
1453 	if (sc->sc_naddrs6) {
1454 		struct ip6_hdr *ip6;
1455 
1456 		m = m_gethdr(M_NOWAIT, MT_DATA);
1457 		if (m == NULL) {
1458 			CARPSTATS_INC(carps_onomem);
1459 			goto resched;
1460 		}
1461 		len = sizeof(*ip6) + sizeof(vh);
1462 		m->m_pkthdr.len = len;
1463 		m->m_pkthdr.rcvif = NULL;
1464 		m->m_len = len;
1465 		M_ALIGN(m, m->m_len);
1466 		m->m_flags |= M_MCAST;
1467 		ip6 = mtod(m, struct ip6_hdr *);
1468 		bzero(ip6, sizeof(*ip6));
1469 		ip6->ip6_vfc |= IPV6_VERSION;
1470 		/* Traffic class isn't defined in ip6 struct instead
1471 		 * it gets offset into flowid field */
1472 		ip6->ip6_flow |= htonl(V_carp_dscp << (IPV6_FLOWLABEL_LEN +
1473 		    IPTOS_DSCP_OFFSET));
1474 		ip6->ip6_hlim = CARP_DFLTTL;
1475 		ip6->ip6_nxt = IPPROTO_CARP;
1476 
1477 		/* set the source address */
1478 		ifa = carp_best_ifa(AF_INET6, sc->sc_carpdev);
1479 		if (ifa != NULL) {
1480 			bcopy(IFA_IN6(ifa), &ip6->ip6_src,
1481 			    sizeof(struct in6_addr));
1482 			ifa_free(ifa);
1483 		} else
1484 			/* This should never happen with IPv6. */
1485 			bzero(&ip6->ip6_src, sizeof(struct in6_addr));
1486 
1487 		/* Set the multicast destination. */
1488 		bzero(&ip6->ip6_dst, sizeof(ip6->ip6_dst));
1489 		ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
1490 		ip6->ip6_dst.s6_addr8[15] = 0x12;
1491 
1492 		/* Include the IP addresses in the announcement. */
1493 		len = sizeof(vh);
1494 		for (int i = 0; i < (sc->sc_naddrs + sc->sc_naddrs6); i++) {
1495 			struct sockaddr_in6 *in6;
1496 
1497 			MPASS(sc->sc_ifas[i] != NULL);
1498 			if (sc->sc_ifas[i]->ifa_addr->sa_family != AF_INET6)
1499 				continue;
1500 
1501 			in6 = (struct sockaddr_in6 *)sc->sc_ifas[i]->ifa_addr;
1502 
1503 			if (m_append(m, sizeof(in6->sin6_addr),
1504 			    (char *)&in6->sin6_addr) != 1) {
1505 				m_freem(m);
1506 				goto resched;
1507 			}
1508 
1509 			vh.vrrp_count_addr++;
1510 			len += sizeof(in6->sin6_addr);
1511 		}
1512 		ip6->ip6_plen = htonl(len);
1513 
1514 		vh_ptr = (struct vrrpv3_header *)mtodo(m, sizeof(*ip6));
1515 		bcopy(&vh, vh_ptr, sizeof(vh));
1516 
1517 		vh_ptr->vrrp_checksum = in6_cksum_pseudo(ip6, len, ip6->ip6_nxt, 0);
1518 		vh_ptr->vrrp_checksum = in_cksum_skip(m, len + sizeof(*ip6), sizeof(*ip6));
1519 
1520 		if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1521 			m_freem(m);
1522 			CARP_DEBUG("%s: in6_setscope failed\n", __func__);
1523 			goto resched;
1524 		}
1525 
1526 		if (carp_tag(sc, m))
1527 			goto resched;
1528 		CARPSTATS_INC(carps_opackets6);
1529 
1530 		carp_send_ad_error(sc, ip6_output(m, NULL, NULL, 0,
1531 		    &sc->sc_carpdev->if_carp->cif_im6o, NULL, NULL));
1532 	}
1533 #endif
1534 
1535 resched:
1536 	callout_reset(&sc->sc_ad_tmo, sc->sc_vrrp_adv_inter * hz / 100,
1537 	    carp_callout, sc);
1538 }
1539 
1540 static void
1541 carp_addroute(struct carp_softc *sc)
1542 {
1543 	struct ifaddr *ifa;
1544 
1545 	CARP_FOREACH_IFA(sc, ifa)
1546 		carp_ifa_addroute(ifa);
1547 }
1548 
1549 static void
1550 carp_ifa_addroute(struct ifaddr *ifa)
1551 {
1552 
1553 	switch (ifa->ifa_addr->sa_family) {
1554 #ifdef INET
1555 	case AF_INET:
1556 		in_addprefix(ifatoia(ifa));
1557 		ifa_add_loopback_route(ifa,
1558 		    (struct sockaddr *)&ifatoia(ifa)->ia_addr);
1559 		break;
1560 #endif
1561 #ifdef INET6
1562 	case AF_INET6:
1563 		ifa_add_loopback_route(ifa,
1564 		    (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
1565 		nd6_add_ifa_lle(ifatoia6(ifa));
1566 		break;
1567 #endif
1568 	}
1569 }
1570 
1571 static void
1572 carp_delroute(struct carp_softc *sc)
1573 {
1574 	struct ifaddr *ifa;
1575 
1576 	CARP_FOREACH_IFA(sc, ifa)
1577 		carp_ifa_delroute(ifa);
1578 }
1579 
1580 static void
1581 carp_ifa_delroute(struct ifaddr *ifa)
1582 {
1583 
1584 	switch (ifa->ifa_addr->sa_family) {
1585 #ifdef INET
1586 	case AF_INET:
1587 		ifa_del_loopback_route(ifa,
1588 		    (struct sockaddr *)&ifatoia(ifa)->ia_addr);
1589 		in_scrubprefix(ifatoia(ifa), LLE_STATIC);
1590 		break;
1591 #endif
1592 #ifdef INET6
1593 	case AF_INET6:
1594 		ifa_del_loopback_route(ifa,
1595 		    (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
1596 		nd6_rem_ifa_lle(ifatoia6(ifa), 1);
1597 		break;
1598 #endif
1599 	}
1600 }
1601 
1602 int
1603 carp_master(struct ifaddr *ifa)
1604 {
1605 	struct carp_softc *sc = ifa->ifa_carp;
1606 
1607 	return (sc->sc_state == MASTER);
1608 }
1609 
1610 #ifdef INET
1611 /*
1612  * Broadcast a gratuitous ARP request containing
1613  * the virtual router MAC address for each IP address
1614  * associated with the virtual router.
1615  */
1616 static void
1617 carp_send_arp(struct carp_softc *sc)
1618 {
1619 	struct ifaddr *ifa;
1620 	struct in_addr addr;
1621 
1622 	NET_EPOCH_ASSERT();
1623 
1624 	CARP_FOREACH_IFA(sc, ifa) {
1625 		if (ifa->ifa_addr->sa_family != AF_INET)
1626 			continue;
1627 		addr = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
1628 		arp_announce_ifaddr(sc->sc_carpdev, addr, sc->sc_addr);
1629 	}
1630 }
1631 
1632 int
1633 carp_iamatch(struct ifaddr *ifa, uint8_t **enaddr)
1634 {
1635 	struct carp_softc *sc = ifa->ifa_carp;
1636 
1637 	if (sc->sc_state == MASTER) {
1638 		*enaddr = sc->sc_addr;
1639 		return (1);
1640 	}
1641 
1642 	return (0);
1643 }
1644 #endif
1645 
1646 #ifdef INET6
1647 static void
1648 carp_send_na(struct carp_softc *sc)
1649 {
1650 	static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1651 	struct ifaddr *ifa;
1652 	struct in6_addr *in6;
1653 
1654 	CARP_FOREACH_IFA(sc, ifa) {
1655 		if (ifa->ifa_addr->sa_family != AF_INET6)
1656 			continue;
1657 
1658 		in6 = IFA_IN6(ifa);
1659 		nd6_na_output(sc->sc_carpdev, &mcast, in6,
1660 		    ND_NA_FLAG_OVERRIDE, 1, NULL);
1661 		DELAY(1000);	/* XXX */
1662 	}
1663 }
1664 
1665 /*
1666  * Returns ifa in case it's a carp address and it is MASTER, or if the address
1667  * matches and is not a carp address.  Returns NULL otherwise.
1668  */
1669 struct ifaddr *
1670 carp_iamatch6(struct ifnet *ifp, struct in6_addr *taddr)
1671 {
1672 	struct ifaddr *ifa;
1673 
1674 	NET_EPOCH_ASSERT();
1675 
1676 	ifa = NULL;
1677 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1678 		if (ifa->ifa_addr->sa_family != AF_INET6)
1679 			continue;
1680 		if (!IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa)))
1681 			continue;
1682 		if (ifa->ifa_carp && ifa->ifa_carp->sc_state != MASTER)
1683 			ifa = NULL;
1684 		else
1685 			ifa_ref(ifa);
1686 		break;
1687 	}
1688 
1689 	return (ifa);
1690 }
1691 
1692 char *
1693 carp_macmatch6(struct ifnet *ifp, struct mbuf *m, const struct in6_addr *taddr)
1694 {
1695 	struct ifaddr *ifa;
1696 
1697 	NET_EPOCH_ASSERT();
1698 
1699 	IFNET_FOREACH_IFA(ifp, ifa)
1700 		if (ifa->ifa_addr->sa_family == AF_INET6 &&
1701 		    IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa))) {
1702 			struct carp_softc *sc = ifa->ifa_carp;
1703 			struct m_tag *mtag;
1704 
1705 			mtag = m_tag_get(PACKET_TAG_CARP,
1706 			    sizeof(struct carp_softc *), M_NOWAIT);
1707 			if (mtag == NULL)
1708 				/* Better a bit than nothing. */
1709 				return (sc->sc_addr);
1710 
1711 			bcopy(&sc, mtag + 1, sizeof(sc));
1712 			m_tag_prepend(m, mtag);
1713 
1714 			return (sc->sc_addr);
1715 		}
1716 
1717 	return (NULL);
1718 }
1719 #endif /* INET6 */
1720 
1721 int
1722 carp_forus(struct ifnet *ifp, u_char *dhost)
1723 {
1724 	struct carp_softc *sc;
1725 	uint8_t *ena = dhost;
1726 
1727 	if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1728 		return (0);
1729 
1730 	CIF_LOCK(ifp->if_carp);
1731 	IFNET_FOREACH_CARP(ifp, sc) {
1732 		/*
1733 		 * CARP_LOCK() is not here, since would protect nothing, but
1734 		 * cause deadlock with if_bridge, calling this under its lock.
1735 		 */
1736 		if (sc->sc_state == MASTER && !bcmp(dhost, sc->sc_addr,
1737 		    ETHER_ADDR_LEN)) {
1738 			CIF_UNLOCK(ifp->if_carp);
1739 			return (1);
1740 		}
1741 	}
1742 	CIF_UNLOCK(ifp->if_carp);
1743 
1744 	return (0);
1745 }
1746 
1747 /* Master down timeout event, executed in callout context. */
1748 static void
1749 carp_master_down(void *v)
1750 {
1751 	struct carp_softc *sc = v;
1752 	struct epoch_tracker et;
1753 
1754 	NET_EPOCH_ENTER(et);
1755 	CARP_LOCK_ASSERT(sc);
1756 
1757 	CURVNET_SET(sc->sc_carpdev->if_vnet);
1758 	if (sc->sc_state == BACKUP) {
1759 		carp_master_down_locked(sc, "master timed out");
1760 	}
1761 	CURVNET_RESTORE();
1762 
1763 	CARP_UNLOCK(sc);
1764 	NET_EPOCH_EXIT(et);
1765 }
1766 
1767 static void
1768 carp_master_down_locked(struct carp_softc *sc, const char *reason)
1769 {
1770 
1771 	NET_EPOCH_ASSERT();
1772 	CARP_LOCK_ASSERT(sc);
1773 
1774 	switch (sc->sc_state) {
1775 	case BACKUP:
1776 		carp_set_state(sc, MASTER, reason);
1777 		send_ad_locked(sc);
1778 #ifdef INET
1779 		carp_send_arp(sc);
1780 #endif
1781 #ifdef INET6
1782 		carp_send_na(sc);
1783 #endif
1784 		carp_setrun(sc, 0);
1785 		carp_addroute(sc);
1786 		break;
1787 	case INIT:
1788 	case MASTER:
1789 #ifdef INVARIANTS
1790 		panic("carp: VHID %u@%s: master_down event in %s state\n",
1791 		    sc->sc_vhid,
1792 		    if_name(sc->sc_carpdev),
1793 		    sc->sc_state ? "MASTER" : "INIT");
1794 #endif
1795 		break;
1796 	}
1797 }
1798 
1799 /*
1800  * When in backup state, af indicates whether to reset the master down timer
1801  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1802  */
1803 static void
1804 carp_setrun(struct carp_softc *sc, sa_family_t af)
1805 {
1806 	struct timeval tv;
1807 	int timeout;
1808 
1809 	CARP_LOCK_ASSERT(sc);
1810 
1811 	if ((sc->sc_carpdev->if_flags & IFF_UP) == 0 ||
1812 	    sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
1813 	    (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) ||
1814 	    !V_carp_allow)
1815 		return;
1816 
1817 	switch (sc->sc_state) {
1818 	case INIT:
1819 		carp_set_state(sc, BACKUP, "initialization complete");
1820 		carp_setrun(sc, 0);
1821 		break;
1822 	case BACKUP:
1823 		callout_stop(&sc->sc_ad_tmo);
1824 
1825 		switch (sc->sc_version) {
1826 		case CARP_VERSION_CARP:
1827 			tv.tv_sec = 3 * sc->sc_advbase;
1828 			tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1829 			timeout = tvtohz(&tv);
1830 			break;
1831 		case CARP_VERSION_VRRPv3:
1832 			/* skew time */
1833 			timeout = (256 - sc->sc_vrrp_prio) *
1834 			    sc->sc_vrrp_master_inter / 256;
1835 			timeout += (3 * sc->sc_vrrp_master_inter);
1836 			timeout *= hz;
1837 			timeout /= 100; /* master interval is in centiseconds */
1838 			break;
1839 		}
1840 		switch (af) {
1841 #ifdef INET
1842 		case AF_INET:
1843 			callout_reset(&sc->sc_md_tmo, timeout,
1844 			    carp_master_down, sc);
1845 			break;
1846 #endif
1847 #ifdef INET6
1848 		case AF_INET6:
1849 			callout_reset(&sc->sc_md6_tmo, timeout,
1850 			    carp_master_down, sc);
1851 			break;
1852 #endif
1853 		default:
1854 #ifdef INET
1855 			if (sc->sc_naddrs)
1856 				callout_reset(&sc->sc_md_tmo, timeout,
1857 				    carp_master_down, sc);
1858 #endif
1859 #ifdef INET6
1860 			if (sc->sc_naddrs6)
1861 				callout_reset(&sc->sc_md6_tmo, timeout,
1862 				    carp_master_down, sc);
1863 #endif
1864 			break;
1865 		}
1866 		break;
1867 	case MASTER:
1868 		switch (sc->sc_version) {
1869 		case CARP_VERSION_CARP:
1870 			tv.tv_sec = sc->sc_advbase;
1871 			tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1872 			callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1873 			    carp_callout, sc);
1874 			break;
1875 		case CARP_VERSION_VRRPv3:
1876 			callout_reset(&sc->sc_ad_tmo,
1877 			    sc->sc_vrrp_adv_inter * hz / 100,
1878 			    carp_callout, sc);
1879 			break;
1880 		}
1881 		break;
1882 	}
1883 }
1884 
1885 /*
1886  * Setup multicast structures.
1887  */
1888 static int
1889 carp_multicast_setup(struct carp_if *cif, sa_family_t sa)
1890 {
1891 	struct ifnet *ifp = cif->cif_ifp;
1892 	int error = 0;
1893 
1894 	switch (sa) {
1895 #ifdef INET
1896 	case AF_INET:
1897 	    {
1898 		struct ip_moptions *imo = &cif->cif_imo;
1899 		struct in_mfilter *imf;
1900 		struct in_addr addr;
1901 
1902 		if (ip_mfilter_first(&imo->imo_head) != NULL)
1903 			return (0);
1904 
1905 		imf = ip_mfilter_alloc(M_WAITOK, 0, 0);
1906 		ip_mfilter_init(&imo->imo_head);
1907 		imo->imo_multicast_vif = -1;
1908 
1909 		addr.s_addr = htonl(INADDR_CARP_GROUP);
1910 		if ((error = in_joingroup(ifp, &addr, NULL,
1911 		    &imf->imf_inm)) != 0) {
1912 			ip_mfilter_free(imf);
1913 			break;
1914 		}
1915 
1916 		ip_mfilter_insert(&imo->imo_head, imf);
1917 		imo->imo_multicast_ifp = ifp;
1918 		imo->imo_multicast_ttl = CARP_DFLTTL;
1919 		imo->imo_multicast_loop = 0;
1920 		break;
1921 	   }
1922 #endif
1923 #ifdef INET6
1924 	case AF_INET6:
1925 	    {
1926 		struct ip6_moptions *im6o = &cif->cif_im6o;
1927 		struct in6_mfilter *im6f[2];
1928 		struct in6_addr in6;
1929 
1930 		if (ip6_mfilter_first(&im6o->im6o_head))
1931 			return (0);
1932 
1933 		im6f[0] = ip6_mfilter_alloc(M_WAITOK, 0, 0);
1934 		im6f[1] = ip6_mfilter_alloc(M_WAITOK, 0, 0);
1935 
1936 		ip6_mfilter_init(&im6o->im6o_head);
1937 		im6o->im6o_multicast_hlim = CARP_DFLTTL;
1938 		im6o->im6o_multicast_ifp = ifp;
1939 
1940 		/* Join IPv6 CARP multicast group. */
1941 		bzero(&in6, sizeof(in6));
1942 		in6.s6_addr16[0] = htons(0xff02);
1943 		in6.s6_addr8[15] = 0x12;
1944 		if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
1945 			ip6_mfilter_free(im6f[0]);
1946 			ip6_mfilter_free(im6f[1]);
1947 			break;
1948 		}
1949 		if ((error = in6_joingroup(ifp, &in6, NULL, &im6f[0]->im6f_in6m, 0)) != 0) {
1950 			ip6_mfilter_free(im6f[0]);
1951 			ip6_mfilter_free(im6f[1]);
1952 			break;
1953 		}
1954 
1955 		/* Join solicited multicast address. */
1956 		bzero(&in6, sizeof(in6));
1957 		in6.s6_addr16[0] = htons(0xff02);
1958 		in6.s6_addr32[1] = 0;
1959 		in6.s6_addr32[2] = htonl(1);
1960 		in6.s6_addr32[3] = 0;
1961 		in6.s6_addr8[12] = 0xff;
1962 
1963 		if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
1964 			ip6_mfilter_free(im6f[0]);
1965 			ip6_mfilter_free(im6f[1]);
1966 			break;
1967 		}
1968 
1969 		if ((error = in6_joingroup(ifp, &in6, NULL, &im6f[1]->im6f_in6m, 0)) != 0) {
1970 			in6_leavegroup(im6f[0]->im6f_in6m, NULL);
1971 			ip6_mfilter_free(im6f[0]);
1972 			ip6_mfilter_free(im6f[1]);
1973 			break;
1974 		}
1975 		ip6_mfilter_insert(&im6o->im6o_head, im6f[0]);
1976 		ip6_mfilter_insert(&im6o->im6o_head, im6f[1]);
1977 		break;
1978 	    }
1979 #endif
1980 	}
1981 
1982 	return (error);
1983 }
1984 
1985 /*
1986  * Free multicast structures.
1987  */
1988 static void
1989 carp_multicast_cleanup(struct carp_if *cif, sa_family_t sa)
1990 {
1991 #ifdef INET
1992 	struct ip_moptions *imo = &cif->cif_imo;
1993 	struct in_mfilter *imf;
1994 #endif
1995 #ifdef INET6
1996 	struct ip6_moptions *im6o = &cif->cif_im6o;
1997 	struct in6_mfilter *im6f;
1998 #endif
1999 	sx_assert(&carp_sx, SA_XLOCKED);
2000 
2001 	switch (sa) {
2002 #ifdef INET
2003 	case AF_INET:
2004 		if (cif->cif_naddrs != 0)
2005 			break;
2006 
2007 		while ((imf = ip_mfilter_first(&imo->imo_head)) != NULL) {
2008 			ip_mfilter_remove(&imo->imo_head, imf);
2009 			in_leavegroup(imf->imf_inm, NULL);
2010 			ip_mfilter_free(imf);
2011 		}
2012 		break;
2013 #endif
2014 #ifdef INET6
2015 	case AF_INET6:
2016 		if (cif->cif_naddrs6 != 0)
2017 			break;
2018 
2019 		while ((im6f = ip6_mfilter_first(&im6o->im6o_head)) != NULL) {
2020 			ip6_mfilter_remove(&im6o->im6o_head, im6f);
2021 			in6_leavegroup(im6f->im6f_in6m, NULL);
2022 			ip6_mfilter_free(im6f);
2023 		}
2024 		break;
2025 #endif
2026 	}
2027 }
2028 
2029 int
2030 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa)
2031 {
2032 	struct m_tag *mtag;
2033 	int vhid;
2034 
2035 	if (!sa)
2036 		return (0);
2037 
2038 	switch (sa->sa_family) {
2039 #ifdef INET
2040 	case AF_INET:
2041 		break;
2042 #endif
2043 #ifdef INET6
2044 	case AF_INET6:
2045 		break;
2046 #endif
2047 	default:
2048 		return (0);
2049 	}
2050 
2051 	mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
2052 	if (mtag == NULL)
2053 		return (0);
2054 
2055 	bcopy(mtag + 1, &vhid, sizeof(vhid));
2056 
2057 	/* Set the source MAC address to the Virtual Router MAC Address. */
2058 	switch (ifp->if_type) {
2059 	case IFT_ETHER:
2060 	case IFT_BRIDGE:
2061 	case IFT_L2VLAN: {
2062 			struct ether_header *eh;
2063 
2064 			eh = mtod(m, struct ether_header *);
2065 			eh->ether_shost[0] = 0;
2066 			eh->ether_shost[1] = 0;
2067 			eh->ether_shost[2] = 0x5e;
2068 			eh->ether_shost[3] = 0;
2069 			eh->ether_shost[4] = 1;
2070 			eh->ether_shost[5] = vhid;
2071 		}
2072 		break;
2073 	default:
2074 		printf("%s: carp is not supported for the %d interface type\n",
2075 		    if_name(ifp), ifp->if_type);
2076 		return (EOPNOTSUPP);
2077 	}
2078 
2079 	return (0);
2080 }
2081 
2082 static struct carp_softc*
2083 carp_alloc(struct ifnet *ifp, carp_version_t version, int vhid)
2084 {
2085 	struct carp_softc *sc;
2086 	struct carp_if *cif;
2087 
2088 	sx_assert(&carp_sx, SA_XLOCKED);
2089 
2090 	if ((cif = ifp->if_carp) == NULL)
2091 		cif = carp_alloc_if(ifp);
2092 
2093 	sc = malloc(sizeof(*sc), M_CARP, M_WAITOK);
2094 	*sc = (struct carp_softc ){
2095 		.sc_vhid = vhid,
2096 		.sc_version = version,
2097 		.sc_state = INIT,
2098 		.sc_carpdev = ifp,
2099 		.sc_ifasiz = sizeof(struct ifaddr *),
2100 		.sc_addr = { 0, 0, 0x5e, 0, 1, vhid },
2101 	};
2102 	sc->sc_ifas = malloc(sc->sc_ifasiz, M_CARP, M_WAITOK|M_ZERO);
2103 
2104 	switch (version) {
2105 	case CARP_VERSION_CARP:
2106 		sc->sc_advbase = CARP_DFLTINTV;
2107 		sc->sc_init_counter = true;
2108 		sc->sc_carpaddr.s_addr = htonl(INADDR_CARP_GROUP);
2109 		sc->sc_carpaddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
2110 		sc->sc_carpaddr6.s6_addr8[15] = 0x12;
2111 		break;
2112 	case CARP_VERSION_VRRPv3:
2113 		sc->sc_vrrp_adv_inter = 100;
2114 		sc->sc_vrrp_master_inter = sc->sc_vrrp_adv_inter;
2115 		sc->sc_vrrp_prio = 100;
2116 		break;
2117 	}
2118 
2119 	CARP_LOCK_INIT(sc);
2120 #ifdef INET
2121 	callout_init_mtx(&sc->sc_md_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
2122 #endif
2123 #ifdef INET6
2124 	callout_init_mtx(&sc->sc_md6_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
2125 #endif
2126 	callout_init_mtx(&sc->sc_ad_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
2127 
2128 	CIF_LOCK(cif);
2129 	TAILQ_INSERT_TAIL(&cif->cif_vrs, sc, sc_list);
2130 	CIF_UNLOCK(cif);
2131 
2132 	mtx_lock(&carp_mtx);
2133 	LIST_INSERT_HEAD(&carp_list, sc, sc_next);
2134 	mtx_unlock(&carp_mtx);
2135 
2136 	return (sc);
2137 }
2138 
2139 static void
2140 carp_grow_ifas(struct carp_softc *sc)
2141 {
2142 	struct ifaddr **new;
2143 
2144 	new = malloc(sc->sc_ifasiz * 2, M_CARP, M_WAITOK | M_ZERO);
2145 	CARP_LOCK(sc);
2146 	bcopy(sc->sc_ifas, new, sc->sc_ifasiz);
2147 	free(sc->sc_ifas, M_CARP);
2148 	sc->sc_ifas = new;
2149 	sc->sc_ifasiz *= 2;
2150 	CARP_UNLOCK(sc);
2151 }
2152 
2153 static void
2154 carp_destroy(struct carp_softc *sc)
2155 {
2156 	struct ifnet *ifp = sc->sc_carpdev;
2157 	struct carp_if *cif = ifp->if_carp;
2158 
2159 	sx_assert(&carp_sx, SA_XLOCKED);
2160 
2161 	if (sc->sc_suppress)
2162 		carp_demote_adj(-V_carp_ifdown_adj, "vhid removed");
2163 	CARP_UNLOCK(sc);
2164 
2165 	CIF_LOCK(cif);
2166 	TAILQ_REMOVE(&cif->cif_vrs, sc, sc_list);
2167 	CIF_UNLOCK(cif);
2168 
2169 	mtx_lock(&carp_mtx);
2170 	LIST_REMOVE(sc, sc_next);
2171 	mtx_unlock(&carp_mtx);
2172 
2173 	callout_drain(&sc->sc_ad_tmo);
2174 #ifdef INET
2175 	callout_drain(&sc->sc_md_tmo);
2176 #endif
2177 #ifdef INET6
2178 	callout_drain(&sc->sc_md6_tmo);
2179 #endif
2180 	CARP_LOCK_DESTROY(sc);
2181 
2182 	free(sc->sc_ifas, M_CARP);
2183 	free(sc, M_CARP);
2184 }
2185 
2186 static struct carp_if*
2187 carp_alloc_if(struct ifnet *ifp)
2188 {
2189 	struct carp_if *cif;
2190 	int error;
2191 
2192 	cif = malloc(sizeof(*cif), M_CARP, M_WAITOK|M_ZERO);
2193 
2194 	if ((error = ifpromisc(ifp, 1)) != 0)
2195 		printf("%s: ifpromisc(%s) failed: %d\n",
2196 		    __func__, if_name(ifp), error);
2197 	else
2198 		cif->cif_flags |= CIF_PROMISC;
2199 
2200 	CIF_LOCK_INIT(cif);
2201 	cif->cif_ifp = ifp;
2202 	TAILQ_INIT(&cif->cif_vrs);
2203 
2204 	IF_ADDR_WLOCK(ifp);
2205 	ifp->if_carp = cif;
2206 	if_ref(ifp);
2207 	IF_ADDR_WUNLOCK(ifp);
2208 
2209 	return (cif);
2210 }
2211 
2212 static void
2213 carp_free_if(struct carp_if *cif)
2214 {
2215 	struct ifnet *ifp = cif->cif_ifp;
2216 
2217 	CIF_LOCK_ASSERT(cif);
2218 	KASSERT(TAILQ_EMPTY(&cif->cif_vrs), ("%s: softc list not empty",
2219 	    __func__));
2220 
2221 	IF_ADDR_WLOCK(ifp);
2222 	ifp->if_carp = NULL;
2223 	IF_ADDR_WUNLOCK(ifp);
2224 
2225 	CIF_LOCK_DESTROY(cif);
2226 
2227 	if (cif->cif_flags & CIF_PROMISC)
2228 		ifpromisc(ifp, 0);
2229 	if_rele(ifp);
2230 
2231 	free(cif, M_CARP);
2232 }
2233 
2234 static bool
2235 carp_carprcp(void *arg, struct carp_softc *sc, int priv)
2236 {
2237 	struct carpreq *carpr = arg;
2238 
2239 	CARP_LOCK(sc);
2240 	carpr->carpr_state = sc->sc_state;
2241 	carpr->carpr_vhid = sc->sc_vhid;
2242 	switch (sc->sc_version) {
2243 	case CARP_VERSION_CARP:
2244 		carpr->carpr_advbase = sc->sc_advbase;
2245 		carpr->carpr_advskew = sc->sc_advskew;
2246 		if (priv)
2247 			bcopy(sc->sc_key, carpr->carpr_key,
2248 			    sizeof(carpr->carpr_key));
2249 		else
2250 			bzero(carpr->carpr_key, sizeof(carpr->carpr_key));
2251 		break;
2252 	case CARP_VERSION_VRRPv3:
2253 		break;
2254 	}
2255 	CARP_UNLOCK(sc);
2256 
2257 	return (true);
2258 }
2259 
2260 static int
2261 carp_ioctl_set(if_t ifp, struct carpkreq *carpr)
2262 {
2263 	struct epoch_tracker et;
2264 	struct carp_softc *sc = NULL;
2265 	int error = 0;
2266 
2267 	if (carpr->carpr_vhid <= 0 || carpr->carpr_vhid > CARP_MAXVHID)
2268 		return (EINVAL);
2269 
2270 	switch (carpr->carpr_version) {
2271 	case CARP_VERSION_CARP:
2272 		if (carpr->carpr_advbase != 0 && (carpr->carpr_advbase > 255 ||
2273 		    carpr->carpr_advbase < CARP_DFLTINTV))
2274 			return (EINVAL);
2275 		if (carpr->carpr_advskew < 0 || carpr->carpr_advskew >= 255)
2276 			return (EINVAL);
2277 		break;
2278 	case CARP_VERSION_VRRPv3:
2279 		/* XXXGL: shouldn't we check anything? */
2280 		break;
2281 	default:
2282 		return (EINVAL);
2283 	}
2284 
2285 	if (ifp->if_carp) {
2286 		IFNET_FOREACH_CARP(ifp, sc)
2287 			if (sc->sc_vhid == carpr->carpr_vhid)
2288 				break;
2289 	}
2290 
2291 	if (sc == NULL)
2292 		sc = carp_alloc(ifp, carpr->carpr_version, carpr->carpr_vhid);
2293 	else if (sc->sc_version != carpr->carpr_version)
2294 		return (EINVAL);
2295 
2296 	CARP_LOCK(sc);
2297 	switch (sc->sc_version) {
2298 	case CARP_VERSION_CARP:
2299 		if (carpr->carpr_advbase != 0)
2300 			sc->sc_advbase = carpr->carpr_advbase;
2301 		sc->sc_advskew = carpr->carpr_advskew;
2302 		if (carpr->carpr_addr.s_addr != INADDR_ANY)
2303 			sc->sc_carpaddr = carpr->carpr_addr;
2304 		if (!IN6_IS_ADDR_UNSPECIFIED(&carpr->carpr_addr6)) {
2305 			memcpy(&sc->sc_carpaddr6, &carpr->carpr_addr6,
2306 			    sizeof(sc->sc_carpaddr6));
2307 		}
2308 		if (carpr->carpr_key[0] != '\0') {
2309 			bcopy(carpr->carpr_key, sc->sc_key, sizeof(sc->sc_key));
2310 			carp_hmac_prepare(sc);
2311 		}
2312 		break;
2313 	case CARP_VERSION_VRRPv3:
2314 		if (carpr->carpr_vrrp_priority != 0)
2315 			sc->sc_vrrp_prio = carpr->carpr_vrrp_priority;
2316 		if (carpr->carpr_vrrp_adv_inter)
2317 			sc->sc_vrrp_adv_inter = carpr->carpr_vrrp_adv_inter;
2318 		break;
2319 	}
2320 
2321 	if (sc->sc_state != INIT &&
2322 	    carpr->carpr_state != sc->sc_state) {
2323 		switch (carpr->carpr_state) {
2324 		case BACKUP:
2325 			callout_stop(&sc->sc_ad_tmo);
2326 			carp_set_state(sc, BACKUP,
2327 			    "user requested via ifconfig");
2328 			carp_setrun(sc, 0);
2329 			carp_delroute(sc);
2330 			break;
2331 		case MASTER:
2332 			NET_EPOCH_ENTER(et);
2333 			carp_master_down_locked(sc,
2334 			    "user requested via ifconfig");
2335 			NET_EPOCH_EXIT(et);
2336 			break;
2337 		default:
2338 			break;
2339 		}
2340 	}
2341 	CARP_UNLOCK(sc);
2342 
2343 	return (error);
2344 }
2345 
2346 static int
2347 carp_ioctl_get(if_t ifp, struct ucred *cred, struct carpreq *carpr,
2348     bool (*outfn)(void *, struct carp_softc *, int), void *arg)
2349 {
2350 	int priveleged;
2351 	struct carp_softc *sc;
2352 
2353 	if (carpr->carpr_vhid < 0 || carpr->carpr_vhid > CARP_MAXVHID)
2354 		return (EINVAL);
2355 	if (carpr->carpr_count < 1)
2356 		return (EMSGSIZE);
2357 	if (ifp->if_carp == NULL)
2358 		return (ENOENT);
2359 
2360 	priveleged = (priv_check_cred(cred, PRIV_NETINET_CARP) == 0);
2361 	if (carpr->carpr_vhid != 0) {
2362 		IFNET_FOREACH_CARP(ifp, sc)
2363 			if (sc->sc_vhid == carpr->carpr_vhid)
2364 				break;
2365 		if (sc == NULL)
2366 			return (ENOENT);
2367 
2368 		if (! outfn(arg, sc, priveleged))
2369 			return (ENOMEM);
2370 		carpr->carpr_count = 1;
2371 	} else  {
2372 		int count;
2373 
2374 		count = 0;
2375 		IFNET_FOREACH_CARP(ifp, sc)
2376 			count++;
2377 
2378 		if (count > carpr->carpr_count)
2379 			return (EMSGSIZE);
2380 
2381 		IFNET_FOREACH_CARP(ifp, sc) {
2382 			if (! outfn(arg, sc, priveleged))
2383 				return (ENOMEM);
2384 			carpr->carpr_count = count;
2385 		}
2386 	}
2387 
2388 	return (0);
2389 }
2390 
2391 int
2392 carp_ioctl(struct ifreq *ifr, u_long cmd, struct thread *td)
2393 {
2394 	struct carpreq carpr;
2395 	struct carpkreq carprk = {
2396 		.carpr_version = CARP_VERSION_CARP,
2397 	};
2398 	struct ifnet *ifp;
2399 	int error = 0;
2400 
2401 	if ((error = copyin(ifr_data_get_ptr(ifr), &carpr, sizeof carpr)))
2402 		return (error);
2403 
2404 	ifp = ifunit_ref(ifr->ifr_name);
2405 	if ((error = carp_is_supported_if(ifp)) != 0)
2406 		goto out;
2407 
2408 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
2409 		error = EADDRNOTAVAIL;
2410 		goto out;
2411 	}
2412 
2413 	sx_xlock(&carp_sx);
2414 	switch (cmd) {
2415 	case SIOCSVH:
2416 		if ((error = priv_check(td, PRIV_NETINET_CARP)))
2417 			break;
2418 
2419 		memcpy(&carprk, &carpr, sizeof(carpr));
2420 		error = carp_ioctl_set(ifp, &carprk);
2421 		break;
2422 
2423 	case SIOCGVH:
2424 		error = carp_ioctl_get(ifp, td->td_ucred, &carpr,
2425 		    carp_carprcp, &carpr);
2426 		if (error == 0) {
2427 			error = copyout(&carpr,
2428 			    (char *)ifr_data_get_ptr(ifr),
2429 			    carpr.carpr_count * sizeof(carpr));
2430 		}
2431 		break;
2432 	default:
2433 		error = EINVAL;
2434 	}
2435 	sx_xunlock(&carp_sx);
2436 
2437 out:
2438 	if (ifp != NULL)
2439 		if_rele(ifp);
2440 
2441 	return (error);
2442 }
2443 
2444 static int
2445 carp_get_vhid(struct ifaddr *ifa)
2446 {
2447 
2448 	if (ifa == NULL || ifa->ifa_carp == NULL)
2449 		return (0);
2450 
2451 	return (ifa->ifa_carp->sc_vhid);
2452 }
2453 
2454 int
2455 carp_attach(struct ifaddr *ifa, int vhid)
2456 {
2457 	struct ifnet *ifp = ifa->ifa_ifp;
2458 	struct carp_if *cif = ifp->if_carp;
2459 	struct carp_softc *sc;
2460 	int index, error;
2461 
2462 	KASSERT(ifa->ifa_carp == NULL, ("%s: ifa %p attached", __func__, ifa));
2463 
2464 	switch (ifa->ifa_addr->sa_family) {
2465 #ifdef INET
2466 	case AF_INET:
2467 #endif
2468 #ifdef INET6
2469 	case AF_INET6:
2470 #endif
2471 		break;
2472 	default:
2473 		return (EPROTOTYPE);
2474 	}
2475 
2476 	sx_xlock(&carp_sx);
2477 	if (ifp->if_carp == NULL) {
2478 		sx_xunlock(&carp_sx);
2479 		return (ENOPROTOOPT);
2480 	}
2481 
2482 	IFNET_FOREACH_CARP(ifp, sc)
2483 		if (sc->sc_vhid == vhid)
2484 			break;
2485 	if (sc == NULL) {
2486 		sx_xunlock(&carp_sx);
2487 		return (ENOENT);
2488 	}
2489 
2490 	error = carp_multicast_setup(cif, ifa->ifa_addr->sa_family);
2491 	if (error) {
2492 		CIF_FREE(cif);
2493 		sx_xunlock(&carp_sx);
2494 		return (error);
2495 	}
2496 
2497 	index = sc->sc_naddrs + sc->sc_naddrs6 + 1;
2498 	if (index > sc->sc_ifasiz / sizeof(struct ifaddr *))
2499 		carp_grow_ifas(sc);
2500 
2501 	switch (ifa->ifa_addr->sa_family) {
2502 #ifdef INET
2503 	case AF_INET:
2504 		cif->cif_naddrs++;
2505 		sc->sc_naddrs++;
2506 		break;
2507 #endif
2508 #ifdef INET6
2509 	case AF_INET6:
2510 		cif->cif_naddrs6++;
2511 		sc->sc_naddrs6++;
2512 		break;
2513 #endif
2514 	}
2515 
2516 	ifa_ref(ifa);
2517 
2518 	CARP_LOCK(sc);
2519 	sc->sc_ifas[index - 1] = ifa;
2520 	ifa->ifa_carp = sc;
2521 	if (sc->sc_version == CARP_VERSION_CARP)
2522 		carp_hmac_prepare(sc);
2523 	carp_sc_state(sc);
2524 	CARP_UNLOCK(sc);
2525 
2526 	sx_xunlock(&carp_sx);
2527 
2528 	return (0);
2529 }
2530 
2531 void
2532 carp_detach(struct ifaddr *ifa, bool keep_cif)
2533 {
2534 	struct ifnet *ifp = ifa->ifa_ifp;
2535 	struct carp_if *cif = ifp->if_carp;
2536 	struct carp_softc *sc = ifa->ifa_carp;
2537 	int i, index;
2538 
2539 	KASSERT(sc != NULL, ("%s: %p not attached", __func__, ifa));
2540 
2541 	sx_xlock(&carp_sx);
2542 
2543 	CARP_LOCK(sc);
2544 	/* Shift array. */
2545 	index = sc->sc_naddrs + sc->sc_naddrs6;
2546 	for (i = 0; i < index; i++)
2547 		if (sc->sc_ifas[i] == ifa)
2548 			break;
2549 	KASSERT(i < index, ("%s: %p no backref", __func__, ifa));
2550 	for (; i < index - 1; i++)
2551 		sc->sc_ifas[i] = sc->sc_ifas[i+1];
2552 	sc->sc_ifas[index - 1] = NULL;
2553 
2554 	switch (ifa->ifa_addr->sa_family) {
2555 #ifdef INET
2556 	case AF_INET:
2557 		cif->cif_naddrs--;
2558 		sc->sc_naddrs--;
2559 		break;
2560 #endif
2561 #ifdef INET6
2562 	case AF_INET6:
2563 		cif->cif_naddrs6--;
2564 		sc->sc_naddrs6--;
2565 		break;
2566 #endif
2567 	}
2568 
2569 	carp_ifa_delroute(ifa);
2570 	carp_multicast_cleanup(cif, ifa->ifa_addr->sa_family);
2571 
2572 	ifa->ifa_carp = NULL;
2573 	ifa_free(ifa);
2574 
2575 	if (sc->sc_version == CARP_VERSION_CARP)
2576 		carp_hmac_prepare(sc);
2577 	carp_sc_state(sc);
2578 
2579 	if (!keep_cif && sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0)
2580 		carp_destroy(sc);
2581 	else
2582 		CARP_UNLOCK(sc);
2583 
2584 	if (!keep_cif)
2585 		CIF_FREE(cif);
2586 
2587 	sx_xunlock(&carp_sx);
2588 }
2589 
2590 static void
2591 carp_set_state(struct carp_softc *sc, int state, const char *reason)
2592 {
2593 
2594 	CARP_LOCK_ASSERT(sc);
2595 
2596 	if (sc->sc_state != state) {
2597 		const char *carp_states[] = { CARP_STATES };
2598 		char subsys[IFNAMSIZ+5];
2599 
2600 		snprintf(subsys, IFNAMSIZ+5, "%u@%s", sc->sc_vhid,
2601 		    if_name(sc->sc_carpdev));
2602 
2603 		CARP_LOG("%s: %s -> %s (%s)\n", subsys,
2604 		    carp_states[sc->sc_state], carp_states[state], reason);
2605 
2606 		sc->sc_state = state;
2607 
2608 		devctl_notify("CARP", subsys, carp_states[state], NULL);
2609 	}
2610 }
2611 
2612 static void
2613 carp_linkstate(struct ifnet *ifp)
2614 {
2615 	struct carp_softc *sc;
2616 
2617 	CIF_LOCK(ifp->if_carp);
2618 	IFNET_FOREACH_CARP(ifp, sc) {
2619 		CARP_LOCK(sc);
2620 		carp_sc_state(sc);
2621 		CARP_UNLOCK(sc);
2622 	}
2623 	CIF_UNLOCK(ifp->if_carp);
2624 }
2625 
2626 static void
2627 carp_sc_state(struct carp_softc *sc)
2628 {
2629 
2630 	CARP_LOCK_ASSERT(sc);
2631 
2632 	if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
2633 	    !(sc->sc_carpdev->if_flags & IFF_UP) ||
2634 	    !V_carp_allow) {
2635 		callout_stop(&sc->sc_ad_tmo);
2636 #ifdef INET
2637 		callout_stop(&sc->sc_md_tmo);
2638 #endif
2639 #ifdef INET6
2640 		callout_stop(&sc->sc_md6_tmo);
2641 #endif
2642 		carp_set_state(sc, INIT, "hardware interface down");
2643 		carp_setrun(sc, 0);
2644 		carp_delroute(sc);
2645 		if (!sc->sc_suppress)
2646 			carp_demote_adj(V_carp_ifdown_adj, "interface down");
2647 		sc->sc_suppress = 1;
2648 	} else {
2649 		carp_set_state(sc, INIT, "hardware interface up");
2650 		carp_setrun(sc, 0);
2651 		if (sc->sc_suppress)
2652 			carp_demote_adj(-V_carp_ifdown_adj, "interface up");
2653 		sc->sc_suppress = 0;
2654 	}
2655 }
2656 
2657 static void
2658 carp_demote_adj(int adj, char *reason)
2659 {
2660 	atomic_add_int(&V_carp_demotion, adj);
2661 	CARP_LOG("demoted by %d to %d (%s)\n", adj, V_carp_demotion, reason);
2662 	taskqueue_enqueue(taskqueue_swi, &carp_sendall_task);
2663 }
2664 
2665 static int
2666 carp_allow_sysctl(SYSCTL_HANDLER_ARGS)
2667 {
2668 	int new, error;
2669 	struct carp_softc *sc;
2670 
2671 	new = V_carp_allow;
2672 	error = sysctl_handle_int(oidp, &new, 0, req);
2673 	if (error || !req->newptr)
2674 		return (error);
2675 
2676 	if (V_carp_allow != new) {
2677 		V_carp_allow = new;
2678 
2679 		mtx_lock(&carp_mtx);
2680 		LIST_FOREACH(sc, &carp_list, sc_next) {
2681 			CARP_LOCK(sc);
2682 			if (curvnet == sc->sc_carpdev->if_vnet)
2683 				carp_sc_state(sc);
2684 			CARP_UNLOCK(sc);
2685 		}
2686 		mtx_unlock(&carp_mtx);
2687 	}
2688 
2689 	return (0);
2690 }
2691 
2692 static int
2693 carp_dscp_sysctl(SYSCTL_HANDLER_ARGS)
2694 {
2695 	int new, error;
2696 
2697 	new = V_carp_dscp;
2698 	error = sysctl_handle_int(oidp, &new, 0, req);
2699 	if (error || !req->newptr)
2700 		return (error);
2701 
2702 	if (new < 0 || new > 63)
2703 		return (EINVAL);
2704 
2705 	V_carp_dscp = new;
2706 
2707 	return (0);
2708 }
2709 
2710 static int
2711 carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS)
2712 {
2713 	int new, error;
2714 
2715 	new = V_carp_demotion;
2716 	error = sysctl_handle_int(oidp, &new, 0, req);
2717 	if (error || !req->newptr)
2718 		return (error);
2719 
2720 	carp_demote_adj(new, "sysctl");
2721 
2722 	return (0);
2723 }
2724 
2725 static int
2726 nlattr_get_carp_key(struct nlattr *nla, struct nl_pstate *npt, const void *arg, void *target)
2727 {
2728 	if (__predict_false(NLA_DATA_LEN(nla) > CARP_KEY_LEN))
2729 		return (EINVAL);
2730 
2731 	memcpy(target, NLA_DATA_CONST(nla), NLA_DATA_LEN(nla));
2732 	return (0);
2733 }
2734 
2735 struct carp_nl_send_args {
2736 	struct nlmsghdr *hdr;
2737 	struct nl_pstate *npt;
2738 };
2739 
2740 static bool
2741 carp_nl_send(void *arg, struct carp_softc *sc, int priv)
2742 {
2743 	struct carp_nl_send_args *nlsa = arg;
2744 	struct nlmsghdr *hdr = nlsa->hdr;
2745 	struct nl_pstate *npt = nlsa->npt;
2746 	struct nl_writer *nw = npt->nw;
2747 	struct genlmsghdr *ghdr_new;
2748 
2749 	if (!nlmsg_reply(nw, hdr, sizeof(struct genlmsghdr))) {
2750 		nlmsg_abort(nw);
2751 		return (false);
2752 	}
2753 
2754 	ghdr_new = nlmsg_reserve_object(nw, struct genlmsghdr);
2755 	if (ghdr_new == NULL) {
2756 		nlmsg_abort(nw);
2757 		return (false);
2758 	}
2759 
2760 	ghdr_new->cmd = CARP_NL_CMD_GET;
2761 	ghdr_new->version = 0;
2762 	ghdr_new->reserved = 0;
2763 
2764 	CARP_LOCK(sc);
2765 
2766 	nlattr_add_u32(nw, CARP_NL_VHID, sc->sc_vhid);
2767 	nlattr_add_u32(nw, CARP_NL_STATE, sc->sc_state);
2768 	nlattr_add_u8(nw, CARP_NL_VERSION, sc->sc_version);
2769 	switch (sc->sc_version) {
2770 	case CARP_VERSION_CARP:
2771 		nlattr_add_s32(nw, CARP_NL_ADVBASE, sc->sc_advbase);
2772 		nlattr_add_s32(nw, CARP_NL_ADVSKEW, sc->sc_advskew);
2773 		nlattr_add_in_addr(nw, CARP_NL_ADDR, &sc->sc_carpaddr);
2774 		nlattr_add_in6_addr(nw, CARP_NL_ADDR6, &sc->sc_carpaddr6);
2775 		if (priv)
2776 			nlattr_add(nw, CARP_NL_KEY, sizeof(sc->sc_key),
2777 			    sc->sc_key);
2778 		break;
2779 	case CARP_VERSION_VRRPv3:
2780 		nlattr_add_u8(nw, CARP_NL_VRRP_PRIORITY, sc->sc_vrrp_prio);
2781 		nlattr_add_u16(nw, CARP_NL_VRRP_ADV_INTER,
2782 		    sc->sc_vrrp_adv_inter);
2783 		break;
2784 	}
2785 
2786 	CARP_UNLOCK(sc);
2787 
2788 	if (! nlmsg_end(nw)) {
2789 		nlmsg_abort(nw);
2790 		return (false);
2791 	}
2792 
2793 	return (true);
2794 }
2795 
2796 struct nl_carp_parsed {
2797 	unsigned int	ifindex;
2798 	char		*ifname;
2799 	uint32_t	state;
2800 	uint32_t	vhid;
2801 	int32_t		advbase;
2802 	int32_t		advskew;
2803 	char		key[CARP_KEY_LEN];
2804 	struct in_addr	addr;
2805 	struct in6_addr	addr6;
2806 	carp_version_t	version;
2807 	uint8_t		vrrp_prio;
2808 	uint16_t	vrrp_adv_inter;
2809 };
2810 
2811 #define	_IN(_field)	offsetof(struct genlmsghdr, _field)
2812 #define	_OUT(_field)	offsetof(struct nl_carp_parsed, _field)
2813 
2814 static const struct nlattr_parser nla_p_set[] = {
2815 	{ .type = CARP_NL_VHID, .off = _OUT(vhid), .cb = nlattr_get_uint32 },
2816 	{ .type = CARP_NL_STATE, .off = _OUT(state), .cb = nlattr_get_uint32 },
2817 	{ .type = CARP_NL_ADVBASE, .off = _OUT(advbase), .cb = nlattr_get_uint32 },
2818 	{ .type = CARP_NL_ADVSKEW, .off = _OUT(advskew), .cb = nlattr_get_uint32 },
2819 	{ .type = CARP_NL_KEY, .off = _OUT(key), .cb = nlattr_get_carp_key },
2820 	{ .type = CARP_NL_IFINDEX, .off = _OUT(ifindex), .cb = nlattr_get_uint32 },
2821 	{ .type = CARP_NL_ADDR, .off = _OUT(addr), .cb = nlattr_get_in_addr },
2822 	{ .type = CARP_NL_ADDR6, .off = _OUT(addr6), .cb = nlattr_get_in6_addr },
2823 	{ .type = CARP_NL_IFNAME, .off = _OUT(ifname), .cb = nlattr_get_string },
2824 	{ .type = CARP_NL_VERSION, .off = _OUT(version), .cb = nlattr_get_uint8 },
2825 	{ .type = CARP_NL_VRRP_PRIORITY, .off = _OUT(vrrp_prio), .cb = nlattr_get_uint8 },
2826 	{ .type = CARP_NL_VRRP_ADV_INTER, .off = _OUT(vrrp_adv_inter), .cb = nlattr_get_uint16 },
2827 };
2828 static const struct nlfield_parser nlf_p_set[] = {
2829 };
2830 NL_DECLARE_PARSER(carp_parser, struct genlmsghdr, nlf_p_set, nla_p_set);
2831 #undef _IN
2832 #undef _OUT
2833 
2834 
2835 static int
2836 carp_nl_get(struct nlmsghdr *hdr, struct nl_pstate *npt)
2837 {
2838 	struct nl_carp_parsed attrs = { };
2839 	struct carp_nl_send_args args;
2840 	struct carpreq carpr = { };
2841 	struct epoch_tracker et;
2842 	if_t ifp = NULL;
2843 	int error;
2844 
2845 	error = nl_parse_nlmsg(hdr, &carp_parser, npt, &attrs);
2846 	if (error != 0)
2847 		return (error);
2848 
2849 	NET_EPOCH_ENTER(et);
2850 	if (attrs.ifname != NULL)
2851 		ifp = ifunit_ref(attrs.ifname);
2852 	else if (attrs.ifindex != 0)
2853 		ifp = ifnet_byindex_ref(attrs.ifindex);
2854 	NET_EPOCH_EXIT(et);
2855 
2856 	if ((error = carp_is_supported_if(ifp)) != 0)
2857 		goto out;
2858 
2859 	hdr->nlmsg_flags |= NLM_F_MULTI;
2860 	args.hdr = hdr;
2861 	args.npt = npt;
2862 
2863 	carpr.carpr_vhid = attrs.vhid;
2864 	carpr.carpr_count = CARP_MAXVHID;
2865 
2866 	sx_xlock(&carp_sx);
2867 	error = carp_ioctl_get(ifp, nlp_get_cred(npt->nlp), &carpr,
2868 	    carp_nl_send, &args);
2869 	sx_xunlock(&carp_sx);
2870 
2871 	if (! nlmsg_end_dump(npt->nw, error, hdr))
2872 		error = ENOMEM;
2873 
2874 out:
2875 	if (ifp != NULL)
2876 		if_rele(ifp);
2877 
2878 	return (error);
2879 }
2880 
2881 static int
2882 carp_nl_set(struct nlmsghdr *hdr, struct nl_pstate *npt)
2883 {
2884 	struct nl_carp_parsed attrs = { };
2885 	struct carpkreq carpr;
2886 	struct epoch_tracker et;
2887 	if_t ifp = NULL;
2888 	int error;
2889 
2890 	error = nl_parse_nlmsg(hdr, &carp_parser, npt, &attrs);
2891 	if (error != 0)
2892 		return (error);
2893 
2894 	if (attrs.vhid <= 0 || attrs.vhid > CARP_MAXVHID)
2895 		return (EINVAL);
2896 	if (attrs.state > CARP_MAXSTATE)
2897 		return (EINVAL);
2898 	if (attrs.version == 0)	/* compat with pre-VRRPv3 */
2899 		attrs.version = CARP_VERSION_CARP;
2900 	switch (attrs.version) {
2901 	case CARP_VERSION_CARP:
2902 		if (attrs.advbase < 0 || attrs.advskew < 0)
2903 			return (EINVAL);
2904 		if (attrs.advbase > 255)
2905 			return (EINVAL);
2906 		if (attrs.advskew >= 255)
2907 			return (EINVAL);
2908 		break;
2909 	case CARP_VERSION_VRRPv3:
2910 		if (attrs.vrrp_adv_inter > VRRP_MAX_INTERVAL)
2911 			return (EINVAL);
2912 		break;
2913 	default:
2914 		return (EINVAL);
2915 	}
2916 
2917 	NET_EPOCH_ENTER(et);
2918 	if (attrs.ifname != NULL)
2919 		ifp = ifunit_ref(attrs.ifname);
2920 	else if (attrs.ifindex != 0)
2921 		ifp = ifnet_byindex_ref(attrs.ifindex);
2922 	NET_EPOCH_EXIT(et);
2923 
2924 	if ((error = carp_is_supported_if(ifp)) != 0)
2925 		goto out;
2926 
2927 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
2928 		error = EADDRNOTAVAIL;
2929 		goto out;
2930 	}
2931 
2932 	carpr.carpr_count = 1;
2933 	carpr.carpr_vhid = attrs.vhid;
2934 	carpr.carpr_state = attrs.state;
2935 	carpr.carpr_version = attrs.version;
2936 	switch (attrs.version) {
2937 	case CARP_VERSION_CARP:
2938 		carpr.carpr_advbase = attrs.advbase;
2939 		carpr.carpr_advskew = attrs.advskew;
2940 		carpr.carpr_addr = attrs.addr;
2941 		carpr.carpr_addr6 = attrs.addr6;
2942 		memcpy(&carpr.carpr_key, &attrs.key, sizeof(attrs.key));
2943 		break;
2944 	case CARP_VERSION_VRRPv3:
2945 		carpr.carpr_vrrp_priority = attrs.vrrp_prio;
2946 		carpr.carpr_vrrp_adv_inter = attrs.vrrp_adv_inter;
2947 		break;
2948 	}
2949 
2950 	sx_xlock(&carp_sx);
2951 	error = carp_ioctl_set(ifp, &carpr);
2952 	sx_xunlock(&carp_sx);
2953 
2954 out:
2955 	if (ifp != NULL)
2956 		if_rele(ifp);
2957 
2958 	return (error);
2959 }
2960 
2961 static const struct nlhdr_parser *all_parsers[] = {
2962 	&carp_parser
2963 };
2964 
2965 static const struct genl_cmd carp_cmds[] = {
2966 	{
2967 		.cmd_num = CARP_NL_CMD_GET,
2968 		.cmd_name = "SIOCGVH",
2969 		.cmd_cb = carp_nl_get,
2970 		.cmd_flags = GENL_CMD_CAP_DO | GENL_CMD_CAP_DUMP |
2971 		    GENL_CMD_CAP_HASPOL,
2972 	},
2973 	{
2974 		.cmd_num = CARP_NL_CMD_SET,
2975 		.cmd_name = "SIOCSVH",
2976 		.cmd_cb = carp_nl_set,
2977 		.cmd_flags = GENL_CMD_CAP_DO | GENL_CMD_CAP_HASPOL,
2978 		.cmd_priv = PRIV_NETINET_CARP,
2979 	},
2980 };
2981 
2982 static void
2983 carp_nl_register(void)
2984 {
2985 	bool ret __diagused;
2986 	int family_id __diagused;
2987 
2988 	NL_VERIFY_PARSERS(all_parsers);
2989 	family_id = genl_register_family(CARP_NL_FAMILY_NAME, 0, 2,
2990 	    CARP_NL_CMD_MAX);
2991 	MPASS(family_id != 0);
2992 
2993 	ret = genl_register_cmds(CARP_NL_FAMILY_NAME, carp_cmds,
2994 	    NL_ARRAY_LEN(carp_cmds));
2995 	MPASS(ret);
2996 }
2997 
2998 static void
2999 carp_nl_unregister(void)
3000 {
3001 	genl_unregister_family(CARP_NL_FAMILY_NAME);
3002 }
3003 
3004 static void
3005 carp_mod_cleanup(void)
3006 {
3007 
3008 	carp_nl_unregister();
3009 
3010 #ifdef INET
3011 	(void)ipproto_unregister(IPPROTO_CARP);
3012 	carp_iamatch_p = NULL;
3013 #endif
3014 #ifdef INET6
3015 	(void)ip6proto_unregister(IPPROTO_CARP);
3016 	carp_iamatch6_p = NULL;
3017 	carp_macmatch6_p = NULL;
3018 #endif
3019 	carp_ioctl_p = NULL;
3020 	carp_attach_p = NULL;
3021 	carp_detach_p = NULL;
3022 	carp_get_vhid_p = NULL;
3023 	carp_linkstate_p = NULL;
3024 	carp_forus_p = NULL;
3025 	carp_output_p = NULL;
3026 	carp_demote_adj_p = NULL;
3027 	carp_master_p = NULL;
3028 	mtx_unlock(&carp_mtx);
3029 	taskqueue_drain(taskqueue_swi, &carp_sendall_task);
3030 	mtx_destroy(&carp_mtx);
3031 	sx_destroy(&carp_sx);
3032 }
3033 
3034 static void
3035 ipcarp_sysinit(void)
3036 {
3037 
3038 	/* Load allow as tunable so to postpone carp start after module load */
3039 	TUNABLE_INT_FETCH("net.inet.carp.allow", &V_carp_allow);
3040 }
3041 VNET_SYSINIT(ip_carp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, ipcarp_sysinit, NULL);
3042 
3043 static int
3044 carp_mod_load(void)
3045 {
3046 	int err;
3047 
3048 	mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
3049 	sx_init(&carp_sx, "carp_sx");
3050 	LIST_INIT(&carp_list);
3051 	carp_get_vhid_p = carp_get_vhid;
3052 	carp_forus_p = carp_forus;
3053 	carp_output_p = carp_output;
3054 	carp_linkstate_p = carp_linkstate;
3055 	carp_ioctl_p = carp_ioctl;
3056 	carp_attach_p = carp_attach;
3057 	carp_detach_p = carp_detach;
3058 	carp_demote_adj_p = carp_demote_adj;
3059 	carp_master_p = carp_master;
3060 #ifdef INET6
3061 	carp_iamatch6_p = carp_iamatch6;
3062 	carp_macmatch6_p = carp_macmatch6;
3063 	err = ip6proto_register(IPPROTO_CARP, carp6_input, NULL);
3064 	if (err) {
3065 		printf("carp: error %d registering with INET6\n", err);
3066 		carp_mod_cleanup();
3067 		return (err);
3068 	}
3069 #endif
3070 #ifdef INET
3071 	carp_iamatch_p = carp_iamatch;
3072 	err = ipproto_register(IPPROTO_CARP, carp_input, NULL);
3073 	if (err) {
3074 		printf("carp: error %d registering with INET\n", err);
3075 		carp_mod_cleanup();
3076 		return (err);
3077 	}
3078 #endif
3079 
3080 	carp_nl_register();
3081 
3082 	return (0);
3083 }
3084 
3085 static int
3086 carp_modevent(module_t mod, int type, void *data)
3087 {
3088 	switch (type) {
3089 	case MOD_LOAD:
3090 		return carp_mod_load();
3091 		/* NOTREACHED */
3092 	case MOD_UNLOAD:
3093 		mtx_lock(&carp_mtx);
3094 		if (LIST_EMPTY(&carp_list))
3095 			carp_mod_cleanup();
3096 		else {
3097 			mtx_unlock(&carp_mtx);
3098 			return (EBUSY);
3099 		}
3100 		break;
3101 
3102 	default:
3103 		return (EINVAL);
3104 	}
3105 
3106 	return (0);
3107 }
3108 
3109 static moduledata_t carp_mod = {
3110 	"carp",
3111 	carp_modevent,
3112 	0
3113 };
3114 
3115 DECLARE_MODULE(carp, carp_mod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
3116