xref: /freebsd/sys/netinet/ip_carp.c (revision ebacd8013fe5f7fdf9f6a5b286f6680dd2891036)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 "opt_netlink.h"
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include "opt_bpf.h"
37 #include "opt_inet.h"
38 #include "opt_inet6.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/devctl.h>
43 #include <sys/jail.h>
44 #include <sys/kernel.h>
45 #include <sys/limits.h>
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/module.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/socket.h>
52 #include <sys/sockio.h>
53 #include <sys/sysctl.h>
54 #include <sys/syslog.h>
55 #include <sys/taskqueue.h>
56 #include <sys/counter.h>
57 
58 #include <net/ethernet.h>
59 #include <net/if.h>
60 #include <net/if_var.h>
61 #include <net/if_dl.h>
62 #include <net/if_llatbl.h>
63 #include <net/if_private.h>
64 #include <net/if_types.h>
65 #include <net/route.h>
66 #include <net/vnet.h>
67 
68 #if defined(INET) || defined(INET6)
69 #include <netinet/in.h>
70 #include <netinet/in_var.h>
71 #include <netinet/ip_carp.h>
72 #include <netinet/ip_carp_nl.h>
73 #include <netinet/ip.h>
74 #include <machine/in_cksum.h>
75 #endif
76 #ifdef INET
77 #include <netinet/ip_var.h>
78 #include <netinet/if_ether.h>
79 #endif
80 
81 #ifdef INET6
82 #include <netinet/icmp6.h>
83 #include <netinet/ip6.h>
84 #include <netinet6/in6_var.h>
85 #include <netinet6/ip6_var.h>
86 #include <netinet6/scope6_var.h>
87 #include <netinet6/nd6.h>
88 #endif
89 
90 #include <netlink/netlink.h>
91 #include <netlink/netlink_ctl.h>
92 #include <netlink/netlink_generic.h>
93 #include <netlink/netlink_message_parser.h>
94 
95 #include <crypto/sha1.h>
96 
97 static MALLOC_DEFINE(M_CARP, "CARP", "CARP addresses");
98 
99 struct carp_softc {
100 	struct ifnet		*sc_carpdev;	/* Pointer to parent ifnet. */
101 	struct ifaddr		**sc_ifas;	/* Our ifaddrs. */
102 	struct sockaddr_dl	sc_addr;	/* Our link level address. */
103 	struct callout		sc_ad_tmo;	/* Advertising timeout. */
104 #ifdef INET
105 	struct callout		sc_md_tmo;	/* Master down timeout. */
106 #endif
107 #ifdef INET6
108 	struct callout 		sc_md6_tmo;	/* XXX: Master down timeout. */
109 #endif
110 	struct mtx		sc_mtx;
111 
112 	int			sc_vhid;
113 	int			sc_advskew;
114 	int			sc_advbase;
115 	struct in_addr		sc_carpaddr;
116 	struct in6_addr		sc_carpaddr6;
117 
118 	int			sc_naddrs;
119 	int			sc_naddrs6;
120 	int			sc_ifasiz;
121 	enum { INIT = 0, BACKUP, MASTER }	sc_state;
122 	int			sc_suppress;
123 	int			sc_sendad_errors;
124 #define	CARP_SENDAD_MAX_ERRORS	3
125 	int			sc_sendad_success;
126 #define	CARP_SENDAD_MIN_SUCCESS 3
127 
128 	int			sc_init_counter;
129 	uint64_t		sc_counter;
130 
131 	/* authentication */
132 #define	CARP_HMAC_PAD	64
133 	unsigned char sc_key[CARP_KEY_LEN];
134 	unsigned char sc_pad[CARP_HMAC_PAD];
135 	SHA1_CTX sc_sha1;
136 
137 	TAILQ_ENTRY(carp_softc)	sc_list;	/* On the carp_if list. */
138 	LIST_ENTRY(carp_softc)	sc_next;	/* On the global list. */
139 };
140 
141 struct carp_if {
142 #ifdef INET
143 	int	cif_naddrs;
144 #endif
145 #ifdef INET6
146 	int	cif_naddrs6;
147 #endif
148 	TAILQ_HEAD(, carp_softc) cif_vrs;
149 #ifdef INET
150 	struct ip_moptions 	 cif_imo;
151 #endif
152 #ifdef INET6
153 	struct ip6_moptions 	 cif_im6o;
154 #endif
155 	struct ifnet	*cif_ifp;
156 	struct mtx	cif_mtx;
157 	uint32_t	cif_flags;
158 #define	CIF_PROMISC	0x00000001
159 };
160 
161 /* Kernel equivalent of struct carpreq, but with more fields for new features.
162  * */
163 struct carpkreq {
164 	int		carpr_count;
165 	int		carpr_vhid;
166 	int		carpr_state;
167 	int		carpr_advskew;
168 	int		carpr_advbase;
169 	unsigned char	carpr_key[CARP_KEY_LEN];
170 	/* Everything above this is identical to carpreq */
171 	struct in_addr	carpr_addr;
172 	struct in6_addr	carpr_addr6;
173 };
174 
175 /*
176  * Brief design of carp(4).
177  *
178  * Any carp-capable ifnet may have a list of carp softcs hanging off
179  * its ifp->if_carp pointer. Each softc represents one unique virtual
180  * host id, or vhid. The softc has a back pointer to the ifnet. All
181  * softcs are joined in a global list, which has quite limited use.
182  *
183  * Any interface address that takes part in CARP negotiation has a
184  * pointer to the softc of its vhid, ifa->ifa_carp. That could be either
185  * AF_INET or AF_INET6 address.
186  *
187  * Although, one can get the softc's backpointer to ifnet and traverse
188  * through its ifp->if_addrhead queue to find all interface addresses
189  * involved in CARP, we keep a growable array of ifaddr pointers. This
190  * allows us to avoid grabbing the IF_ADDR_LOCK() in many traversals that
191  * do calls into the network stack, thus avoiding LORs.
192  *
193  * Locking:
194  *
195  * Each softc has a lock sc_mtx. It is used to synchronise carp_input_c(),
196  * callout-driven events and ioctl()s.
197  *
198  * To traverse the list of softcs on an ifnet we use CIF_LOCK() or carp_sx.
199  * To traverse the global list we use the mutex carp_mtx.
200  *
201  * Known issues with locking:
202  *
203  * - Sending ad, we put the pointer to the softc in an mtag, and no reference
204  *   counting is done on the softc.
205  * - On module unload we may race (?) with packet processing thread
206  *   dereferencing our function pointers.
207  */
208 
209 /* Accept incoming CARP packets. */
210 VNET_DEFINE_STATIC(int, carp_allow) = 1;
211 #define	V_carp_allow	VNET(carp_allow)
212 
213 /* Set DSCP in outgoing CARP packets. */
214 VNET_DEFINE_STATIC(int, carp_dscp) = 56;
215 #define	V_carp_dscp	VNET(carp_dscp)
216 
217 /* Preempt slower nodes. */
218 VNET_DEFINE_STATIC(int, carp_preempt) = 0;
219 #define	V_carp_preempt	VNET(carp_preempt)
220 
221 /* Log level. */
222 VNET_DEFINE_STATIC(int, carp_log) = 1;
223 #define	V_carp_log	VNET(carp_log)
224 
225 /* Global advskew demotion. */
226 VNET_DEFINE_STATIC(int, carp_demotion) = 0;
227 #define	V_carp_demotion	VNET(carp_demotion)
228 
229 /* Send error demotion factor. */
230 VNET_DEFINE_STATIC(int, carp_senderr_adj) = CARP_MAXSKEW;
231 #define	V_carp_senderr_adj	VNET(carp_senderr_adj)
232 
233 /* Iface down demotion factor. */
234 VNET_DEFINE_STATIC(int, carp_ifdown_adj) = CARP_MAXSKEW;
235 #define	V_carp_ifdown_adj	VNET(carp_ifdown_adj)
236 
237 static int carp_allow_sysctl(SYSCTL_HANDLER_ARGS);
238 static int carp_dscp_sysctl(SYSCTL_HANDLER_ARGS);
239 static int carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS);
240 
241 SYSCTL_NODE(_net_inet, IPPROTO_CARP, carp, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
242     "CARP");
243 SYSCTL_PROC(_net_inet_carp, OID_AUTO, allow,
244     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE,
245     &VNET_NAME(carp_allow), 0, carp_allow_sysctl, "I",
246     "Accept incoming CARP packets");
247 SYSCTL_PROC(_net_inet_carp, OID_AUTO, dscp,
248     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
249     0, 0, carp_dscp_sysctl, "I",
250     "DSCP value for carp packets");
251 SYSCTL_INT(_net_inet_carp, OID_AUTO, preempt, CTLFLAG_VNET | CTLFLAG_RW,
252     &VNET_NAME(carp_preempt), 0, "High-priority backup preemption mode");
253 SYSCTL_INT(_net_inet_carp, OID_AUTO, log, CTLFLAG_VNET | CTLFLAG_RW,
254     &VNET_NAME(carp_log), 0, "CARP log level");
255 SYSCTL_PROC(_net_inet_carp, OID_AUTO, demotion,
256     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
257     0, 0, carp_demote_adj_sysctl, "I",
258     "Adjust demotion factor (skew of advskew)");
259 SYSCTL_INT(_net_inet_carp, OID_AUTO, senderr_demotion_factor,
260     CTLFLAG_VNET | CTLFLAG_RW,
261     &VNET_NAME(carp_senderr_adj), 0, "Send error demotion factor adjustment");
262 SYSCTL_INT(_net_inet_carp, OID_AUTO, ifdown_demotion_factor,
263     CTLFLAG_VNET | CTLFLAG_RW,
264     &VNET_NAME(carp_ifdown_adj), 0,
265     "Interface down demotion factor adjustment");
266 
267 VNET_PCPUSTAT_DEFINE(struct carpstats, carpstats);
268 VNET_PCPUSTAT_SYSINIT(carpstats);
269 VNET_PCPUSTAT_SYSUNINIT(carpstats);
270 
271 #define	CARPSTATS_ADD(name, val)	\
272     counter_u64_add(VNET(carpstats)[offsetof(struct carpstats, name) / \
273 	sizeof(uint64_t)], (val))
274 #define	CARPSTATS_INC(name)		CARPSTATS_ADD(name, 1)
275 
276 SYSCTL_VNET_PCPUSTAT(_net_inet_carp, OID_AUTO, stats, struct carpstats,
277     carpstats, "CARP statistics (struct carpstats, netinet/ip_carp.h)");
278 
279 #define	CARP_LOCK_INIT(sc)	mtx_init(&(sc)->sc_mtx, "carp_softc",   \
280 	NULL, MTX_DEF)
281 #define	CARP_LOCK_DESTROY(sc)	mtx_destroy(&(sc)->sc_mtx)
282 #define	CARP_LOCK_ASSERT(sc)	mtx_assert(&(sc)->sc_mtx, MA_OWNED)
283 #define	CARP_LOCK(sc)		mtx_lock(&(sc)->sc_mtx)
284 #define	CARP_UNLOCK(sc)		mtx_unlock(&(sc)->sc_mtx)
285 #define	CIF_LOCK_INIT(cif)	mtx_init(&(cif)->cif_mtx, "carp_if",   \
286 	NULL, MTX_DEF)
287 #define	CIF_LOCK_DESTROY(cif)	mtx_destroy(&(cif)->cif_mtx)
288 #define	CIF_LOCK_ASSERT(cif)	mtx_assert(&(cif)->cif_mtx, MA_OWNED)
289 #define	CIF_LOCK(cif)		mtx_lock(&(cif)->cif_mtx)
290 #define	CIF_UNLOCK(cif)		mtx_unlock(&(cif)->cif_mtx)
291 #define	CIF_FREE(cif)	do {				\
292 		CIF_LOCK(cif);				\
293 		if (TAILQ_EMPTY(&(cif)->cif_vrs))	\
294 			carp_free_if(cif);		\
295 		else					\
296 			CIF_UNLOCK(cif);		\
297 } while (0)
298 
299 #define	CARP_LOG(...)	do {				\
300 	if (V_carp_log > 0)				\
301 		log(LOG_INFO, "carp: " __VA_ARGS__);	\
302 } while (0)
303 
304 #define	CARP_DEBUG(...)	do {				\
305 	if (V_carp_log > 1)				\
306 		log(LOG_DEBUG, __VA_ARGS__);		\
307 } while (0)
308 
309 #define	IFNET_FOREACH_IFA(ifp, ifa)					\
310 	CK_STAILQ_FOREACH((ifa), &(ifp)->if_addrhead, ifa_link)	\
311 		if ((ifa)->ifa_carp != NULL)
312 
313 #define	CARP_FOREACH_IFA(sc, ifa)					\
314 	CARP_LOCK_ASSERT(sc);						\
315 	for (int _i = 0;						\
316 		_i < (sc)->sc_naddrs + (sc)->sc_naddrs6 &&		\
317 		((ifa) = sc->sc_ifas[_i]) != NULL;			\
318 		++_i)
319 
320 #define	IFNET_FOREACH_CARP(ifp, sc)					\
321 	KASSERT(mtx_owned(&ifp->if_carp->cif_mtx) ||			\
322 	    sx_xlocked(&carp_sx), ("cif_vrs not locked"));		\
323 	TAILQ_FOREACH((sc), &(ifp)->if_carp->cif_vrs, sc_list)
324 
325 #define	DEMOTE_ADVSKEW(sc)					\
326     (((sc)->sc_advskew + V_carp_demotion > CARP_MAXSKEW) ?	\
327     CARP_MAXSKEW :						\
328         (((sc)->sc_advskew + V_carp_demotion < 0) ?		\
329         0 : ((sc)->sc_advskew + V_carp_demotion)))
330 
331 static void	carp_input_c(struct mbuf *, struct carp_header *, sa_family_t, int);
332 static struct carp_softc
333 		*carp_alloc(struct ifnet *);
334 static void	carp_destroy(struct carp_softc *);
335 static struct carp_if
336 		*carp_alloc_if(struct ifnet *);
337 static void	carp_free_if(struct carp_if *);
338 static void	carp_set_state(struct carp_softc *, int, const char* reason);
339 static void	carp_sc_state(struct carp_softc *);
340 static void	carp_setrun(struct carp_softc *, sa_family_t);
341 static void	carp_master_down(void *);
342 static void	carp_master_down_locked(struct carp_softc *,
343     		    const char* reason);
344 static void	carp_send_ad(void *);
345 static void	carp_send_ad_locked(struct carp_softc *);
346 static void	carp_addroute(struct carp_softc *);
347 static void	carp_ifa_addroute(struct ifaddr *);
348 static void	carp_delroute(struct carp_softc *);
349 static void	carp_ifa_delroute(struct ifaddr *);
350 static void	carp_send_ad_all(void *, int);
351 static void	carp_demote_adj(int, char *);
352 
353 static LIST_HEAD(, carp_softc) carp_list;
354 static struct mtx carp_mtx;
355 static struct sx carp_sx;
356 static struct task carp_sendall_task =
357     TASK_INITIALIZER(0, carp_send_ad_all, NULL);
358 
359 static int
360 carp_is_supported_if(if_t ifp)
361 {
362 	if (ifp == NULL)
363 		return (ENXIO);
364 
365 	switch (ifp->if_type) {
366 	case IFT_ETHER:
367 	case IFT_L2VLAN:
368 	case IFT_BRIDGE:
369 		break;
370 	default:
371 		return (EOPNOTSUPP);
372 	}
373 
374 	return (0);
375 }
376 
377 static void
378 carp_hmac_prepare(struct carp_softc *sc)
379 {
380 	uint8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
381 	uint8_t vhid = sc->sc_vhid & 0xff;
382 	struct ifaddr *ifa;
383 	int i, found;
384 #ifdef INET
385 	struct in_addr last, cur, in;
386 #endif
387 #ifdef INET6
388 	struct in6_addr last6, cur6, in6;
389 #endif
390 
391 	CARP_LOCK_ASSERT(sc);
392 
393 	/* Compute ipad from key. */
394 	bzero(sc->sc_pad, sizeof(sc->sc_pad));
395 	bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
396 	for (i = 0; i < sizeof(sc->sc_pad); i++)
397 		sc->sc_pad[i] ^= 0x36;
398 
399 	/* Precompute first part of inner hash. */
400 	SHA1Init(&sc->sc_sha1);
401 	SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
402 	SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
403 	SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
404 	SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
405 #ifdef INET
406 	cur.s_addr = 0;
407 	do {
408 		found = 0;
409 		last = cur;
410 		cur.s_addr = 0xffffffff;
411 		CARP_FOREACH_IFA(sc, ifa) {
412 			in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
413 			if (ifa->ifa_addr->sa_family == AF_INET &&
414 			    ntohl(in.s_addr) > ntohl(last.s_addr) &&
415 			    ntohl(in.s_addr) < ntohl(cur.s_addr)) {
416 				cur.s_addr = in.s_addr;
417 				found++;
418 			}
419 		}
420 		if (found)
421 			SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
422 	} while (found);
423 #endif /* INET */
424 #ifdef INET6
425 	memset(&cur6, 0, sizeof(cur6));
426 	do {
427 		found = 0;
428 		last6 = cur6;
429 		memset(&cur6, 0xff, sizeof(cur6));
430 		CARP_FOREACH_IFA(sc, ifa) {
431 			in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
432 			if (IN6_IS_SCOPE_EMBED(&in6))
433 				in6.s6_addr16[1] = 0;
434 			if (ifa->ifa_addr->sa_family == AF_INET6 &&
435 			    memcmp(&in6, &last6, sizeof(in6)) > 0 &&
436 			    memcmp(&in6, &cur6, sizeof(in6)) < 0) {
437 				cur6 = in6;
438 				found++;
439 			}
440 		}
441 		if (found)
442 			SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
443 	} while (found);
444 #endif /* INET6 */
445 
446 	/* convert ipad to opad */
447 	for (i = 0; i < sizeof(sc->sc_pad); i++)
448 		sc->sc_pad[i] ^= 0x36 ^ 0x5c;
449 }
450 
451 static void
452 carp_hmac_generate(struct carp_softc *sc, uint32_t counter[2],
453     unsigned char md[20])
454 {
455 	SHA1_CTX sha1ctx;
456 
457 	CARP_LOCK_ASSERT(sc);
458 
459 	/* fetch first half of inner hash */
460 	bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
461 
462 	SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
463 	SHA1Final(md, &sha1ctx);
464 
465 	/* outer hash */
466 	SHA1Init(&sha1ctx);
467 	SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
468 	SHA1Update(&sha1ctx, md, 20);
469 	SHA1Final(md, &sha1ctx);
470 }
471 
472 static int
473 carp_hmac_verify(struct carp_softc *sc, uint32_t counter[2],
474     unsigned char md[20])
475 {
476 	unsigned char md2[20];
477 
478 	CARP_LOCK_ASSERT(sc);
479 
480 	carp_hmac_generate(sc, counter, md2);
481 
482 	return (bcmp(md, md2, sizeof(md2)));
483 }
484 
485 /*
486  * process input packet.
487  * we have rearranged checks order compared to the rfc,
488  * but it seems more efficient this way or not possible otherwise.
489  */
490 #ifdef INET
491 static int
492 carp_input(struct mbuf **mp, int *offp, int proto)
493 {
494 	struct mbuf *m = *mp;
495 	struct ip *ip = mtod(m, struct ip *);
496 	struct carp_header *ch;
497 	int iplen, len;
498 
499 	iplen = *offp;
500 	*mp = NULL;
501 
502 	CARPSTATS_INC(carps_ipackets);
503 
504 	if (!V_carp_allow) {
505 		m_freem(m);
506 		return (IPPROTO_DONE);
507 	}
508 
509 	iplen = ip->ip_hl << 2;
510 
511 	if (m->m_pkthdr.len < iplen + sizeof(*ch)) {
512 		CARPSTATS_INC(carps_badlen);
513 		CARP_DEBUG("%s: received len %zd < sizeof(struct carp_header) "
514 		    "on %s\n", __func__, m->m_len - sizeof(struct ip),
515 		    if_name(m->m_pkthdr.rcvif));
516 		m_freem(m);
517 		return (IPPROTO_DONE);
518 	}
519 
520 	if (iplen + sizeof(*ch) < m->m_len) {
521 		if ((m = m_pullup(m, iplen + sizeof(*ch))) == NULL) {
522 			CARPSTATS_INC(carps_hdrops);
523 			CARP_DEBUG("%s: pullup failed\n", __func__);
524 			return (IPPROTO_DONE);
525 		}
526 		ip = mtod(m, struct ip *);
527 	}
528 	ch = (struct carp_header *)((char *)ip + iplen);
529 
530 	/*
531 	 * verify that the received packet length is
532 	 * equal to the CARP header
533 	 */
534 	len = iplen + sizeof(*ch);
535 	if (len > m->m_pkthdr.len) {
536 		CARPSTATS_INC(carps_badlen);
537 		CARP_DEBUG("%s: packet too short %d on %s\n", __func__,
538 		    m->m_pkthdr.len,
539 		    if_name(m->m_pkthdr.rcvif));
540 		m_freem(m);
541 		return (IPPROTO_DONE);
542 	}
543 
544 	if ((m = m_pullup(m, len)) == NULL) {
545 		CARPSTATS_INC(carps_hdrops);
546 		return (IPPROTO_DONE);
547 	}
548 	ip = mtod(m, struct ip *);
549 	ch = (struct carp_header *)((char *)ip + iplen);
550 
551 	/* verify the CARP checksum */
552 	m->m_data += iplen;
553 	if (in_cksum(m, len - iplen)) {
554 		CARPSTATS_INC(carps_badsum);
555 		CARP_DEBUG("%s: checksum failed on %s\n", __func__,
556 		    if_name(m->m_pkthdr.rcvif));
557 		m_freem(m);
558 		return (IPPROTO_DONE);
559 	}
560 	m->m_data -= iplen;
561 
562 	carp_input_c(m, ch, AF_INET, ip->ip_ttl);
563 	return (IPPROTO_DONE);
564 }
565 #endif
566 
567 #ifdef INET6
568 static int
569 carp6_input(struct mbuf **mp, int *offp, int proto)
570 {
571 	struct mbuf *m = *mp;
572 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
573 	struct carp_header *ch;
574 	u_int len;
575 
576 	CARPSTATS_INC(carps_ipackets6);
577 
578 	if (!V_carp_allow) {
579 		m_freem(m);
580 		return (IPPROTO_DONE);
581 	}
582 
583 	/* check if received on a valid carp interface */
584 	if (m->m_pkthdr.rcvif->if_carp == NULL) {
585 		CARPSTATS_INC(carps_badif);
586 		CARP_DEBUG("%s: packet received on non-carp interface: %s\n",
587 		    __func__, if_name(m->m_pkthdr.rcvif));
588 		m_freem(m);
589 		return (IPPROTO_DONE);
590 	}
591 
592 	/* verify that we have a complete carp packet */
593 	if (m->m_len < *offp + sizeof(*ch)) {
594 		len = m->m_len;
595 		m = m_pullup(m, *offp + sizeof(*ch));
596 		if (m == NULL) {
597 			CARPSTATS_INC(carps_badlen);
598 			CARP_DEBUG("%s: packet size %u too small\n", __func__, len);
599 			return (IPPROTO_DONE);
600 		}
601 		ip6 = mtod(m, struct ip6_hdr *);
602 	}
603 	ch = (struct carp_header *)(mtod(m, char *) + *offp);
604 
605 	/* verify the CARP checksum */
606 	m->m_data += *offp;
607 	if (in_cksum(m, sizeof(*ch))) {
608 		CARPSTATS_INC(carps_badsum);
609 		CARP_DEBUG("%s: checksum failed, on %s\n", __func__,
610 		    if_name(m->m_pkthdr.rcvif));
611 		m_freem(m);
612 		return (IPPROTO_DONE);
613 	}
614 	m->m_data -= *offp;
615 
616 	carp_input_c(m, ch, AF_INET6, ip6->ip6_hlim);
617 	return (IPPROTO_DONE);
618 }
619 #endif /* INET6 */
620 
621 /*
622  * This routine should not be necessary at all, but some switches
623  * (VMWare ESX vswitches) can echo our own packets back at us,
624  * and we must ignore them or they will cause us to drop out of
625  * MASTER mode.
626  *
627  * We cannot catch all cases of network loops.  Instead, what we
628  * do here is catch any packet that arrives with a carp header
629  * with a VHID of 0, that comes from an address that is our own.
630  * These packets are by definition "from us" (even if they are from
631  * a misconfigured host that is pretending to be us).
632  *
633  * The VHID test is outside this mini-function.
634  */
635 static int
636 carp_source_is_self(struct mbuf *m, struct ifaddr *ifa, sa_family_t af)
637 {
638 #ifdef INET
639 	struct ip *ip4;
640 	struct in_addr in4;
641 #endif
642 #ifdef INET6
643 	struct ip6_hdr *ip6;
644 	struct in6_addr in6;
645 #endif
646 
647 	switch (af) {
648 #ifdef INET
649 	case AF_INET:
650 		ip4 = mtod(m, struct ip *);
651 		in4 = ifatoia(ifa)->ia_addr.sin_addr;
652 		return (in4.s_addr == ip4->ip_src.s_addr);
653 #endif
654 #ifdef INET6
655 	case AF_INET6:
656 		ip6 = mtod(m, struct ip6_hdr *);
657 		in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
658 		return (memcmp(&in6, &ip6->ip6_src, sizeof(in6)) == 0);
659 #endif
660 	default:
661 		break;
662 	}
663 	return (0);
664 }
665 
666 static void
667 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af, int ttl)
668 {
669 	struct ifnet *ifp = m->m_pkthdr.rcvif;
670 	struct ifaddr *ifa, *match;
671 	struct carp_softc *sc;
672 	uint64_t tmp_counter;
673 	struct timeval sc_tv, ch_tv;
674 	int error;
675 	bool multicast = false;
676 
677 	NET_EPOCH_ASSERT();
678 
679 	/*
680 	 * Verify that the VHID is valid on the receiving interface.
681 	 *
682 	 * There should be just one match.  If there are none
683 	 * the VHID is not valid and we drop the packet.  If
684 	 * there are multiple VHID matches, take just the first
685 	 * one, for compatibility with previous code.  While we're
686 	 * scanning, check for obvious loops in the network topology
687 	 * (these should never happen, and as noted above, we may
688 	 * miss real loops; this is just a double-check).
689 	 */
690 	error = 0;
691 	match = NULL;
692 	IFNET_FOREACH_IFA(ifp, ifa) {
693 		if (match == NULL && ifa->ifa_carp != NULL &&
694 		    ifa->ifa_addr->sa_family == af &&
695 		    ifa->ifa_carp->sc_vhid == ch->carp_vhid)
696 			match = ifa;
697 		if (ch->carp_vhid == 0 && carp_source_is_self(m, ifa, af))
698 			error = ELOOP;
699 	}
700 	ifa = error ? NULL : match;
701 	if (ifa != NULL)
702 		ifa_ref(ifa);
703 
704 	if (ifa == NULL) {
705 		if (error == ELOOP) {
706 			CARP_DEBUG("dropping looped packet on interface %s\n",
707 			    if_name(ifp));
708 			CARPSTATS_INC(carps_badif);	/* ??? */
709 		} else {
710 			CARPSTATS_INC(carps_badvhid);
711 		}
712 		m_freem(m);
713 		return;
714 	}
715 
716 	/* verify the CARP version. */
717 	if (ch->carp_version != CARP_VERSION) {
718 		CARPSTATS_INC(carps_badver);
719 		CARP_DEBUG("%s: invalid version %d\n", if_name(ifp),
720 		    ch->carp_version);
721 		ifa_free(ifa);
722 		m_freem(m);
723 		return;
724 	}
725 
726 	sc = ifa->ifa_carp;
727 	CARP_LOCK(sc);
728 	if (ifa->ifa_addr->sa_family == AF_INET) {
729 		multicast = IN_MULTICAST(sc->sc_carpaddr.s_addr);
730 	} else {
731 		multicast = IN6_IS_ADDR_MULTICAST(&sc->sc_carpaddr6);
732 	}
733 	ifa_free(ifa);
734 
735 	/* verify that the IP TTL is 255, but only if we're not in unicast mode. */
736 	if (multicast && ttl != CARP_DFLTTL) {
737 		CARPSTATS_INC(carps_badttl);
738 		CARP_DEBUG("%s: received ttl %d != 255 on %s\n", __func__,
739 		    ttl, if_name(m->m_pkthdr.rcvif));
740 		goto out;
741 	}
742 
743 	if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
744 		CARPSTATS_INC(carps_badauth);
745 		CARP_DEBUG("%s: incorrect hash for VHID %u@%s\n", __func__,
746 		    sc->sc_vhid, if_name(ifp));
747 		goto out;
748 	}
749 
750 	tmp_counter = ntohl(ch->carp_counter[0]);
751 	tmp_counter = tmp_counter<<32;
752 	tmp_counter += ntohl(ch->carp_counter[1]);
753 
754 	/* XXX Replay protection goes here */
755 
756 	sc->sc_init_counter = 0;
757 	sc->sc_counter = tmp_counter;
758 
759 	sc_tv.tv_sec = sc->sc_advbase;
760 	sc_tv.tv_usec = DEMOTE_ADVSKEW(sc) * 1000000 / 256;
761 	ch_tv.tv_sec = ch->carp_advbase;
762 	ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
763 
764 	switch (sc->sc_state) {
765 	case INIT:
766 		break;
767 	case MASTER:
768 		/*
769 		 * If we receive an advertisement from a master who's going to
770 		 * be more frequent than us, go into BACKUP state.
771 		 */
772 		if (timevalcmp(&sc_tv, &ch_tv, >) ||
773 		    timevalcmp(&sc_tv, &ch_tv, ==)) {
774 			callout_stop(&sc->sc_ad_tmo);
775 			carp_set_state(sc, BACKUP,
776 			    "more frequent advertisement received");
777 			carp_setrun(sc, 0);
778 			carp_delroute(sc);
779 		}
780 		break;
781 	case BACKUP:
782 		/*
783 		 * If we're pre-empting masters who advertise slower than us,
784 		 * and this one claims to be slower, treat him as down.
785 		 */
786 		if (V_carp_preempt && timevalcmp(&sc_tv, &ch_tv, <)) {
787 			carp_master_down_locked(sc,
788 			    "preempting a slower master");
789 			break;
790 		}
791 
792 		/*
793 		 *  If the master is going to advertise at such a low frequency
794 		 *  that he's guaranteed to time out, we'd might as well just
795 		 *  treat him as timed out now.
796 		 */
797 		sc_tv.tv_sec = sc->sc_advbase * 3;
798 		if (timevalcmp(&sc_tv, &ch_tv, <)) {
799 			carp_master_down_locked(sc, "master will time out");
800 			break;
801 		}
802 
803 		/*
804 		 * Otherwise, we reset the counter and wait for the next
805 		 * advertisement.
806 		 */
807 		carp_setrun(sc, af);
808 		break;
809 	}
810 
811 out:
812 	CARP_UNLOCK(sc);
813 	m_freem(m);
814 }
815 
816 static int
817 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
818 {
819 	struct m_tag *mtag;
820 
821 	if (sc->sc_init_counter) {
822 		/* this could also be seconds since unix epoch */
823 		sc->sc_counter = arc4random();
824 		sc->sc_counter = sc->sc_counter << 32;
825 		sc->sc_counter += arc4random();
826 	} else
827 		sc->sc_counter++;
828 
829 	ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
830 	ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
831 
832 	carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
833 
834 	/* Tag packet for carp_output */
835 	if ((mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct carp_softc *),
836 	    M_NOWAIT)) == NULL) {
837 		m_freem(m);
838 		CARPSTATS_INC(carps_onomem);
839 		return (ENOMEM);
840 	}
841 	bcopy(&sc, mtag + 1, sizeof(sc));
842 	m_tag_prepend(m, mtag);
843 
844 	return (0);
845 }
846 
847 /*
848  * To avoid LORs and possible recursions this function shouldn't
849  * be called directly, but scheduled via taskqueue.
850  */
851 static void
852 carp_send_ad_all(void *ctx __unused, int pending __unused)
853 {
854 	struct carp_softc *sc;
855 	struct epoch_tracker et;
856 
857 	NET_EPOCH_ENTER(et);
858 	mtx_lock(&carp_mtx);
859 	LIST_FOREACH(sc, &carp_list, sc_next)
860 		if (sc->sc_state == MASTER) {
861 			CARP_LOCK(sc);
862 			CURVNET_SET(sc->sc_carpdev->if_vnet);
863 			carp_send_ad_locked(sc);
864 			CURVNET_RESTORE();
865 			CARP_UNLOCK(sc);
866 		}
867 	mtx_unlock(&carp_mtx);
868 	NET_EPOCH_EXIT(et);
869 }
870 
871 /* Send a periodic advertisement, executed in callout context. */
872 static void
873 carp_send_ad(void *v)
874 {
875 	struct carp_softc *sc = v;
876 	struct epoch_tracker et;
877 
878 	NET_EPOCH_ENTER(et);
879 	CARP_LOCK_ASSERT(sc);
880 	CURVNET_SET(sc->sc_carpdev->if_vnet);
881 	carp_send_ad_locked(sc);
882 	CURVNET_RESTORE();
883 	CARP_UNLOCK(sc);
884 	NET_EPOCH_EXIT(et);
885 }
886 
887 static void
888 carp_send_ad_error(struct carp_softc *sc, int error)
889 {
890 
891 	/*
892 	 * We track errors and successfull sends with this logic:
893 	 * - Any error resets success counter to 0.
894 	 * - MAX_ERRORS triggers demotion.
895 	 * - MIN_SUCCESS successes resets error counter to 0.
896 	 * - MIN_SUCCESS reverts demotion, if it was triggered before.
897 	 */
898 	if (error) {
899 		if (sc->sc_sendad_errors < INT_MAX)
900 			sc->sc_sendad_errors++;
901 		if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
902 			static const char fmt[] = "send error %d on %s";
903 			char msg[sizeof(fmt) + IFNAMSIZ];
904 
905 			sprintf(msg, fmt, error, if_name(sc->sc_carpdev));
906 			carp_demote_adj(V_carp_senderr_adj, msg);
907 		}
908 		sc->sc_sendad_success = 0;
909 	} else if (sc->sc_sendad_errors > 0) {
910 		if (++sc->sc_sendad_success >= CARP_SENDAD_MIN_SUCCESS) {
911 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
912 				static const char fmt[] = "send ok on %s";
913 				char msg[sizeof(fmt) + IFNAMSIZ];
914 
915 				sprintf(msg, fmt, if_name(sc->sc_carpdev));
916 				carp_demote_adj(-V_carp_senderr_adj, msg);
917 			}
918 			sc->sc_sendad_errors = 0;
919 		}
920 	}
921 }
922 
923 /*
924  * Pick the best ifaddr on the given ifp for sending CARP
925  * advertisements.
926  *
927  * "Best" here is defined by ifa_preferred().  This function is much
928  * much like ifaof_ifpforaddr() except that we just use ifa_preferred().
929  *
930  * (This could be simplified to return the actual address, except that
931  * it has a different format in AF_INET and AF_INET6.)
932  */
933 static struct ifaddr *
934 carp_best_ifa(int af, struct ifnet *ifp)
935 {
936 	struct ifaddr *ifa, *best;
937 
938 	NET_EPOCH_ASSERT();
939 
940 	if (af >= AF_MAX)
941 		return (NULL);
942 	best = NULL;
943 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
944 		if (ifa->ifa_addr->sa_family == af &&
945 		    (best == NULL || ifa_preferred(best, ifa)))
946 			best = ifa;
947 	}
948 	if (best != NULL)
949 		ifa_ref(best);
950 	return (best);
951 }
952 
953 static void
954 carp_send_ad_locked(struct carp_softc *sc)
955 {
956 	struct carp_header ch;
957 	struct timeval tv;
958 	struct ifaddr *ifa;
959 	struct carp_header *ch_ptr;
960 	struct mbuf *m;
961 	int len, advskew;
962 
963 	NET_EPOCH_ASSERT();
964 	CARP_LOCK_ASSERT(sc);
965 
966 	advskew = DEMOTE_ADVSKEW(sc);
967 	tv.tv_sec = sc->sc_advbase;
968 	tv.tv_usec = advskew * 1000000 / 256;
969 
970 	ch.carp_version = CARP_VERSION;
971 	ch.carp_type = CARP_ADVERTISEMENT;
972 	ch.carp_vhid = sc->sc_vhid;
973 	ch.carp_advbase = sc->sc_advbase;
974 	ch.carp_advskew = advskew;
975 	ch.carp_authlen = 7;	/* XXX DEFINE */
976 	ch.carp_pad1 = 0;	/* must be zero */
977 	ch.carp_cksum = 0;
978 
979 	/* XXXGL: OpenBSD picks first ifaddr with needed family. */
980 
981 #ifdef INET
982 	if (sc->sc_naddrs) {
983 		struct ip *ip;
984 
985 		m = m_gethdr(M_NOWAIT, MT_DATA);
986 		if (m == NULL) {
987 			CARPSTATS_INC(carps_onomem);
988 			goto resched;
989 		}
990 		len = sizeof(*ip) + sizeof(ch);
991 		m->m_pkthdr.len = len;
992 		m->m_pkthdr.rcvif = NULL;
993 		m->m_len = len;
994 		M_ALIGN(m, m->m_len);
995 		if (IN_MULTICAST(sc->sc_carpaddr.s_addr))
996 			m->m_flags |= M_MCAST;
997 		ip = mtod(m, struct ip *);
998 		ip->ip_v = IPVERSION;
999 		ip->ip_hl = sizeof(*ip) >> 2;
1000 		ip->ip_tos = V_carp_dscp << IPTOS_DSCP_OFFSET;
1001 		ip->ip_len = htons(len);
1002 		ip->ip_off = htons(IP_DF);
1003 		ip->ip_ttl = CARP_DFLTTL;
1004 		ip->ip_p = IPPROTO_CARP;
1005 		ip->ip_sum = 0;
1006 		ip_fillid(ip);
1007 
1008 		ifa = carp_best_ifa(AF_INET, sc->sc_carpdev);
1009 		if (ifa != NULL) {
1010 			ip->ip_src.s_addr =
1011 			    ifatoia(ifa)->ia_addr.sin_addr.s_addr;
1012 			ifa_free(ifa);
1013 		} else
1014 			ip->ip_src.s_addr = 0;
1015 		ip->ip_dst = sc->sc_carpaddr;
1016 
1017 		ch_ptr = (struct carp_header *)(&ip[1]);
1018 		bcopy(&ch, ch_ptr, sizeof(ch));
1019 		if (carp_prepare_ad(m, sc, ch_ptr))
1020 			goto resched;
1021 
1022 		m->m_data += sizeof(*ip);
1023 		ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip));
1024 		m->m_data -= sizeof(*ip);
1025 
1026 		CARPSTATS_INC(carps_opackets);
1027 
1028 		carp_send_ad_error(sc, ip_output(m, NULL, NULL, IP_RAWOUTPUT,
1029 		    &sc->sc_carpdev->if_carp->cif_imo, NULL));
1030 	}
1031 #endif /* INET */
1032 #ifdef INET6
1033 	if (sc->sc_naddrs6) {
1034 		struct ip6_hdr *ip6;
1035 
1036 		m = m_gethdr(M_NOWAIT, MT_DATA);
1037 		if (m == NULL) {
1038 			CARPSTATS_INC(carps_onomem);
1039 			goto resched;
1040 		}
1041 		len = sizeof(*ip6) + sizeof(ch);
1042 		m->m_pkthdr.len = len;
1043 		m->m_pkthdr.rcvif = NULL;
1044 		m->m_len = len;
1045 		M_ALIGN(m, m->m_len);
1046 		ip6 = mtod(m, struct ip6_hdr *);
1047 		bzero(ip6, sizeof(*ip6));
1048 		ip6->ip6_vfc |= IPV6_VERSION;
1049 		/* Traffic class isn't defined in ip6 struct instead
1050 		 * it gets offset into flowid field */
1051 		ip6->ip6_flow |= htonl(V_carp_dscp << (IPV6_FLOWLABEL_LEN +
1052 		    IPTOS_DSCP_OFFSET));
1053 		ip6->ip6_hlim = CARP_DFLTTL;
1054 		ip6->ip6_nxt = IPPROTO_CARP;
1055 
1056 		/* set the source address */
1057 		ifa = carp_best_ifa(AF_INET6, sc->sc_carpdev);
1058 		if (ifa != NULL) {
1059 			bcopy(IFA_IN6(ifa), &ip6->ip6_src,
1060 			    sizeof(struct in6_addr));
1061 			ifa_free(ifa);
1062 		} else
1063 			/* This should never happen with IPv6. */
1064 			bzero(&ip6->ip6_src, sizeof(struct in6_addr));
1065 
1066 		/* Set the multicast destination. */
1067 		memcpy(&ip6->ip6_dst, &sc->sc_carpaddr6, sizeof(ip6->ip6_dst));
1068 		if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1069 			if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1070 				m_freem(m);
1071 				CARP_DEBUG("%s: in6_setscope failed\n", __func__);
1072 				goto resched;
1073 			}
1074 		}
1075 
1076 		ch_ptr = (struct carp_header *)(&ip6[1]);
1077 		bcopy(&ch, ch_ptr, sizeof(ch));
1078 		if (carp_prepare_ad(m, sc, ch_ptr))
1079 			goto resched;
1080 
1081 		m->m_data += sizeof(*ip6);
1082 		ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip6));
1083 		m->m_data -= sizeof(*ip6);
1084 
1085 		CARPSTATS_INC(carps_opackets6);
1086 
1087 		carp_send_ad_error(sc, ip6_output(m, NULL, NULL, 0,
1088 		    &sc->sc_carpdev->if_carp->cif_im6o, NULL, NULL));
1089 	}
1090 #endif /* INET6 */
1091 
1092 resched:
1093 	callout_reset(&sc->sc_ad_tmo, tvtohz(&tv), carp_send_ad, sc);
1094 }
1095 
1096 static void
1097 carp_addroute(struct carp_softc *sc)
1098 {
1099 	struct ifaddr *ifa;
1100 
1101 	CARP_FOREACH_IFA(sc, ifa)
1102 		carp_ifa_addroute(ifa);
1103 }
1104 
1105 static void
1106 carp_ifa_addroute(struct ifaddr *ifa)
1107 {
1108 
1109 	switch (ifa->ifa_addr->sa_family) {
1110 #ifdef INET
1111 	case AF_INET:
1112 		in_addprefix(ifatoia(ifa));
1113 		ifa_add_loopback_route(ifa,
1114 		    (struct sockaddr *)&ifatoia(ifa)->ia_addr);
1115 		break;
1116 #endif
1117 #ifdef INET6
1118 	case AF_INET6:
1119 		ifa_add_loopback_route(ifa,
1120 		    (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
1121 		nd6_add_ifa_lle(ifatoia6(ifa));
1122 		break;
1123 #endif
1124 	}
1125 }
1126 
1127 static void
1128 carp_delroute(struct carp_softc *sc)
1129 {
1130 	struct ifaddr *ifa;
1131 
1132 	CARP_FOREACH_IFA(sc, ifa)
1133 		carp_ifa_delroute(ifa);
1134 }
1135 
1136 static void
1137 carp_ifa_delroute(struct ifaddr *ifa)
1138 {
1139 
1140 	switch (ifa->ifa_addr->sa_family) {
1141 #ifdef INET
1142 	case AF_INET:
1143 		ifa_del_loopback_route(ifa,
1144 		    (struct sockaddr *)&ifatoia(ifa)->ia_addr);
1145 		in_scrubprefix(ifatoia(ifa), LLE_STATIC);
1146 		break;
1147 #endif
1148 #ifdef INET6
1149 	case AF_INET6:
1150 		ifa_del_loopback_route(ifa,
1151 		    (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
1152 		nd6_rem_ifa_lle(ifatoia6(ifa), 1);
1153 		break;
1154 #endif
1155 	}
1156 }
1157 
1158 int
1159 carp_master(struct ifaddr *ifa)
1160 {
1161 	struct carp_softc *sc = ifa->ifa_carp;
1162 
1163 	return (sc->sc_state == MASTER);
1164 }
1165 
1166 #ifdef INET
1167 /*
1168  * Broadcast a gratuitous ARP request containing
1169  * the virtual router MAC address for each IP address
1170  * associated with the virtual router.
1171  */
1172 static void
1173 carp_send_arp(struct carp_softc *sc)
1174 {
1175 	struct ifaddr *ifa;
1176 	struct in_addr addr;
1177 
1178 	NET_EPOCH_ASSERT();
1179 
1180 	CARP_FOREACH_IFA(sc, ifa) {
1181 		if (ifa->ifa_addr->sa_family != AF_INET)
1182 			continue;
1183 		addr = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
1184 		arp_announce_ifaddr(sc->sc_carpdev, addr, LLADDR(&sc->sc_addr));
1185 	}
1186 }
1187 
1188 int
1189 carp_iamatch(struct ifaddr *ifa, uint8_t **enaddr)
1190 {
1191 	struct carp_softc *sc = ifa->ifa_carp;
1192 
1193 	if (sc->sc_state == MASTER) {
1194 		*enaddr = LLADDR(&sc->sc_addr);
1195 		return (1);
1196 	}
1197 
1198 	return (0);
1199 }
1200 #endif
1201 
1202 #ifdef INET6
1203 static void
1204 carp_send_na(struct carp_softc *sc)
1205 {
1206 	static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1207 	struct ifaddr *ifa;
1208 	struct in6_addr *in6;
1209 
1210 	CARP_FOREACH_IFA(sc, ifa) {
1211 		if (ifa->ifa_addr->sa_family != AF_INET6)
1212 			continue;
1213 
1214 		in6 = IFA_IN6(ifa);
1215 		nd6_na_output(sc->sc_carpdev, &mcast, in6,
1216 		    ND_NA_FLAG_OVERRIDE, 1, NULL);
1217 		DELAY(1000);	/* XXX */
1218 	}
1219 }
1220 
1221 /*
1222  * Returns ifa in case it's a carp address and it is MASTER, or if the address
1223  * matches and is not a carp address.  Returns NULL otherwise.
1224  */
1225 struct ifaddr *
1226 carp_iamatch6(struct ifnet *ifp, struct in6_addr *taddr)
1227 {
1228 	struct ifaddr *ifa;
1229 
1230 	NET_EPOCH_ASSERT();
1231 
1232 	ifa = NULL;
1233 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1234 		if (ifa->ifa_addr->sa_family != AF_INET6)
1235 			continue;
1236 		if (!IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa)))
1237 			continue;
1238 		if (ifa->ifa_carp && ifa->ifa_carp->sc_state != MASTER)
1239 			ifa = NULL;
1240 		else
1241 			ifa_ref(ifa);
1242 		break;
1243 	}
1244 
1245 	return (ifa);
1246 }
1247 
1248 char *
1249 carp_macmatch6(struct ifnet *ifp, struct mbuf *m, const struct in6_addr *taddr)
1250 {
1251 	struct ifaddr *ifa;
1252 
1253 	NET_EPOCH_ASSERT();
1254 
1255 	IFNET_FOREACH_IFA(ifp, ifa)
1256 		if (ifa->ifa_addr->sa_family == AF_INET6 &&
1257 		    IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa))) {
1258 			struct carp_softc *sc = ifa->ifa_carp;
1259 			struct m_tag *mtag;
1260 
1261 			mtag = m_tag_get(PACKET_TAG_CARP,
1262 			    sizeof(struct carp_softc *), M_NOWAIT);
1263 			if (mtag == NULL)
1264 				/* Better a bit than nothing. */
1265 				return (LLADDR(&sc->sc_addr));
1266 
1267 			bcopy(&sc, mtag + 1, sizeof(sc));
1268 			m_tag_prepend(m, mtag);
1269 
1270 			return (LLADDR(&sc->sc_addr));
1271 		}
1272 
1273 	return (NULL);
1274 }
1275 #endif /* INET6 */
1276 
1277 int
1278 carp_forus(struct ifnet *ifp, u_char *dhost)
1279 {
1280 	struct carp_softc *sc;
1281 	uint8_t *ena = dhost;
1282 
1283 	if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1284 		return (0);
1285 
1286 	CIF_LOCK(ifp->if_carp);
1287 	IFNET_FOREACH_CARP(ifp, sc) {
1288 		/*
1289 		 * CARP_LOCK() is not here, since would protect nothing, but
1290 		 * cause deadlock with if_bridge, calling this under its lock.
1291 		 */
1292 		if (sc->sc_state == MASTER && !bcmp(dhost, LLADDR(&sc->sc_addr),
1293 		    ETHER_ADDR_LEN)) {
1294 			CIF_UNLOCK(ifp->if_carp);
1295 			return (1);
1296 		}
1297 	}
1298 	CIF_UNLOCK(ifp->if_carp);
1299 
1300 	return (0);
1301 }
1302 
1303 /* Master down timeout event, executed in callout context. */
1304 static void
1305 carp_master_down(void *v)
1306 {
1307 	struct carp_softc *sc = v;
1308 	struct epoch_tracker et;
1309 
1310 	NET_EPOCH_ENTER(et);
1311 	CARP_LOCK_ASSERT(sc);
1312 
1313 	CURVNET_SET(sc->sc_carpdev->if_vnet);
1314 	if (sc->sc_state == BACKUP) {
1315 		carp_master_down_locked(sc, "master timed out");
1316 	}
1317 	CURVNET_RESTORE();
1318 
1319 	CARP_UNLOCK(sc);
1320 	NET_EPOCH_EXIT(et);
1321 }
1322 
1323 static void
1324 carp_master_down_locked(struct carp_softc *sc, const char *reason)
1325 {
1326 
1327 	NET_EPOCH_ASSERT();
1328 	CARP_LOCK_ASSERT(sc);
1329 
1330 	switch (sc->sc_state) {
1331 	case BACKUP:
1332 		carp_set_state(sc, MASTER, reason);
1333 		carp_send_ad_locked(sc);
1334 #ifdef INET
1335 		carp_send_arp(sc);
1336 #endif
1337 #ifdef INET6
1338 		carp_send_na(sc);
1339 #endif
1340 		carp_setrun(sc, 0);
1341 		carp_addroute(sc);
1342 		break;
1343 	case INIT:
1344 	case MASTER:
1345 #ifdef INVARIANTS
1346 		panic("carp: VHID %u@%s: master_down event in %s state\n",
1347 		    sc->sc_vhid,
1348 		    if_name(sc->sc_carpdev),
1349 		    sc->sc_state ? "MASTER" : "INIT");
1350 #endif
1351 		break;
1352 	}
1353 }
1354 
1355 /*
1356  * When in backup state, af indicates whether to reset the master down timer
1357  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1358  */
1359 static void
1360 carp_setrun(struct carp_softc *sc, sa_family_t af)
1361 {
1362 	struct timeval tv;
1363 
1364 	CARP_LOCK_ASSERT(sc);
1365 
1366 	if ((sc->sc_carpdev->if_flags & IFF_UP) == 0 ||
1367 	    sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
1368 	    (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) ||
1369 	    !V_carp_allow)
1370 		return;
1371 
1372 	switch (sc->sc_state) {
1373 	case INIT:
1374 		carp_set_state(sc, BACKUP, "initialization complete");
1375 		carp_setrun(sc, 0);
1376 		break;
1377 	case BACKUP:
1378 		callout_stop(&sc->sc_ad_tmo);
1379 		tv.tv_sec = 3 * sc->sc_advbase;
1380 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1381 		switch (af) {
1382 #ifdef INET
1383 		case AF_INET:
1384 			callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1385 			    carp_master_down, sc);
1386 			break;
1387 #endif
1388 #ifdef INET6
1389 		case AF_INET6:
1390 			callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1391 			    carp_master_down, sc);
1392 			break;
1393 #endif
1394 		default:
1395 #ifdef INET
1396 			if (sc->sc_naddrs)
1397 				callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1398 				    carp_master_down, sc);
1399 #endif
1400 #ifdef INET6
1401 			if (sc->sc_naddrs6)
1402 				callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1403 				    carp_master_down, sc);
1404 #endif
1405 			break;
1406 		}
1407 		break;
1408 	case MASTER:
1409 		tv.tv_sec = sc->sc_advbase;
1410 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1411 		callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1412 		    carp_send_ad, sc);
1413 		break;
1414 	}
1415 }
1416 
1417 /*
1418  * Setup multicast structures.
1419  */
1420 static int
1421 carp_multicast_setup(struct carp_if *cif, sa_family_t sa)
1422 {
1423 	struct ifnet *ifp = cif->cif_ifp;
1424 	int error = 0;
1425 
1426 	switch (sa) {
1427 #ifdef INET
1428 	case AF_INET:
1429 	    {
1430 		struct ip_moptions *imo = &cif->cif_imo;
1431 		struct in_mfilter *imf;
1432 		struct in_addr addr;
1433 
1434 		if (ip_mfilter_first(&imo->imo_head) != NULL)
1435 			return (0);
1436 
1437 		imf = ip_mfilter_alloc(M_WAITOK, 0, 0);
1438 		ip_mfilter_init(&imo->imo_head);
1439 		imo->imo_multicast_vif = -1;
1440 
1441 		addr.s_addr = htonl(INADDR_CARP_GROUP);
1442 		if ((error = in_joingroup(ifp, &addr, NULL,
1443 		    &imf->imf_inm)) != 0) {
1444 			ip_mfilter_free(imf);
1445 			break;
1446 		}
1447 
1448 		ip_mfilter_insert(&imo->imo_head, imf);
1449 		imo->imo_multicast_ifp = ifp;
1450 		imo->imo_multicast_ttl = CARP_DFLTTL;
1451 		imo->imo_multicast_loop = 0;
1452 		break;
1453 	   }
1454 #endif
1455 #ifdef INET6
1456 	case AF_INET6:
1457 	    {
1458 		struct ip6_moptions *im6o = &cif->cif_im6o;
1459 		struct in6_mfilter *im6f[2];
1460 		struct in6_addr in6;
1461 
1462 		if (ip6_mfilter_first(&im6o->im6o_head))
1463 			return (0);
1464 
1465 		im6f[0] = ip6_mfilter_alloc(M_WAITOK, 0, 0);
1466 		im6f[1] = ip6_mfilter_alloc(M_WAITOK, 0, 0);
1467 
1468 		ip6_mfilter_init(&im6o->im6o_head);
1469 		im6o->im6o_multicast_hlim = CARP_DFLTTL;
1470 		im6o->im6o_multicast_ifp = ifp;
1471 
1472 		/* Join IPv6 CARP multicast group. */
1473 		bzero(&in6, sizeof(in6));
1474 		in6.s6_addr16[0] = htons(0xff02);
1475 		in6.s6_addr8[15] = 0x12;
1476 		if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
1477 			ip6_mfilter_free(im6f[0]);
1478 			ip6_mfilter_free(im6f[1]);
1479 			break;
1480 		}
1481 		if ((error = in6_joingroup(ifp, &in6, NULL, &im6f[0]->im6f_in6m, 0)) != 0) {
1482 			ip6_mfilter_free(im6f[0]);
1483 			ip6_mfilter_free(im6f[1]);
1484 			break;
1485 		}
1486 
1487 		/* Join solicited multicast address. */
1488 		bzero(&in6, sizeof(in6));
1489 		in6.s6_addr16[0] = htons(0xff02);
1490 		in6.s6_addr32[1] = 0;
1491 		in6.s6_addr32[2] = htonl(1);
1492 		in6.s6_addr32[3] = 0;
1493 		in6.s6_addr8[12] = 0xff;
1494 
1495 		if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
1496 			ip6_mfilter_free(im6f[0]);
1497 			ip6_mfilter_free(im6f[1]);
1498 			break;
1499 		}
1500 
1501 		if ((error = in6_joingroup(ifp, &in6, NULL, &im6f[1]->im6f_in6m, 0)) != 0) {
1502 			in6_leavegroup(im6f[0]->im6f_in6m, NULL);
1503 			ip6_mfilter_free(im6f[0]);
1504 			ip6_mfilter_free(im6f[1]);
1505 			break;
1506 		}
1507 		ip6_mfilter_insert(&im6o->im6o_head, im6f[0]);
1508 		ip6_mfilter_insert(&im6o->im6o_head, im6f[1]);
1509 		break;
1510 	    }
1511 #endif
1512 	}
1513 
1514 	return (error);
1515 }
1516 
1517 /*
1518  * Free multicast structures.
1519  */
1520 static void
1521 carp_multicast_cleanup(struct carp_if *cif, sa_family_t sa)
1522 {
1523 #ifdef INET
1524 	struct ip_moptions *imo = &cif->cif_imo;
1525 	struct in_mfilter *imf;
1526 #endif
1527 #ifdef INET6
1528 	struct ip6_moptions *im6o = &cif->cif_im6o;
1529 	struct in6_mfilter *im6f;
1530 #endif
1531 	sx_assert(&carp_sx, SA_XLOCKED);
1532 
1533 	switch (sa) {
1534 #ifdef INET
1535 	case AF_INET:
1536 		if (cif->cif_naddrs != 0)
1537 			break;
1538 
1539 		while ((imf = ip_mfilter_first(&imo->imo_head)) != NULL) {
1540 			ip_mfilter_remove(&imo->imo_head, imf);
1541 			in_leavegroup(imf->imf_inm, NULL);
1542 			ip_mfilter_free(imf);
1543 		}
1544 		break;
1545 #endif
1546 #ifdef INET6
1547 	case AF_INET6:
1548 		if (cif->cif_naddrs6 != 0)
1549 			break;
1550 
1551 		while ((im6f = ip6_mfilter_first(&im6o->im6o_head)) != NULL) {
1552 			ip6_mfilter_remove(&im6o->im6o_head, im6f);
1553 			in6_leavegroup(im6f->im6f_in6m, NULL);
1554 			ip6_mfilter_free(im6f);
1555 		}
1556 		break;
1557 #endif
1558 	}
1559 }
1560 
1561 int
1562 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa)
1563 {
1564 	struct m_tag *mtag;
1565 	struct carp_softc *sc;
1566 
1567 	if (!sa)
1568 		return (0);
1569 
1570 	switch (sa->sa_family) {
1571 #ifdef INET
1572 	case AF_INET:
1573 		break;
1574 #endif
1575 #ifdef INET6
1576 	case AF_INET6:
1577 		break;
1578 #endif
1579 	default:
1580 		return (0);
1581 	}
1582 
1583 	mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
1584 	if (mtag == NULL)
1585 		return (0);
1586 
1587 	bcopy(mtag + 1, &sc, sizeof(sc));
1588 
1589 	switch (sa->sa_family) {
1590 	case AF_INET:
1591 		if (! IN_MULTICAST(ntohl(sc->sc_carpaddr.s_addr)))
1592 			return (0);
1593 		break;
1594 	case AF_INET6:
1595 		if (! IN6_IS_ADDR_MULTICAST(&sc->sc_carpaddr6))
1596 			return (0);
1597 		break;
1598 	default:
1599 		panic("Unknown af");
1600 	}
1601 
1602 	/* Set the source MAC address to the Virtual Router MAC Address. */
1603 	switch (ifp->if_type) {
1604 	case IFT_ETHER:
1605 	case IFT_BRIDGE:
1606 	case IFT_L2VLAN: {
1607 			struct ether_header *eh;
1608 
1609 			eh = mtod(m, struct ether_header *);
1610 			eh->ether_shost[0] = 0;
1611 			eh->ether_shost[1] = 0;
1612 			eh->ether_shost[2] = 0x5e;
1613 			eh->ether_shost[3] = 0;
1614 			eh->ether_shost[4] = 1;
1615 			eh->ether_shost[5] = sc->sc_vhid;
1616 		}
1617 		break;
1618 	default:
1619 		printf("%s: carp is not supported for the %d interface type\n",
1620 		    if_name(ifp), ifp->if_type);
1621 		return (EOPNOTSUPP);
1622 	}
1623 
1624 	return (0);
1625 }
1626 
1627 static struct carp_softc*
1628 carp_alloc(struct ifnet *ifp)
1629 {
1630 	struct carp_softc *sc;
1631 	struct carp_if *cif;
1632 
1633 	sx_assert(&carp_sx, SA_XLOCKED);
1634 
1635 	if ((cif = ifp->if_carp) == NULL)
1636 		cif = carp_alloc_if(ifp);
1637 
1638 	sc = malloc(sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
1639 
1640 	sc->sc_advbase = CARP_DFLTINTV;
1641 	sc->sc_vhid = -1;	/* required setting */
1642 	sc->sc_init_counter = 1;
1643 	sc->sc_state = INIT;
1644 
1645 	sc->sc_ifasiz = sizeof(struct ifaddr *);
1646 	sc->sc_ifas = malloc(sc->sc_ifasiz, M_CARP, M_WAITOK|M_ZERO);
1647 	sc->sc_carpdev = ifp;
1648 
1649 	sc->sc_carpaddr.s_addr = htonl(INADDR_CARP_GROUP);
1650 	sc->sc_carpaddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
1651 	sc->sc_carpaddr6.s6_addr8[15] = 0x12;
1652 
1653 	CARP_LOCK_INIT(sc);
1654 #ifdef INET
1655 	callout_init_mtx(&sc->sc_md_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1656 #endif
1657 #ifdef INET6
1658 	callout_init_mtx(&sc->sc_md6_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1659 #endif
1660 	callout_init_mtx(&sc->sc_ad_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1661 
1662 	CIF_LOCK(cif);
1663 	TAILQ_INSERT_TAIL(&cif->cif_vrs, sc, sc_list);
1664 	CIF_UNLOCK(cif);
1665 
1666 	mtx_lock(&carp_mtx);
1667 	LIST_INSERT_HEAD(&carp_list, sc, sc_next);
1668 	mtx_unlock(&carp_mtx);
1669 
1670 	return (sc);
1671 }
1672 
1673 static void
1674 carp_grow_ifas(struct carp_softc *sc)
1675 {
1676 	struct ifaddr **new;
1677 
1678 	new = malloc(sc->sc_ifasiz * 2, M_CARP, M_WAITOK | M_ZERO);
1679 	CARP_LOCK(sc);
1680 	bcopy(sc->sc_ifas, new, sc->sc_ifasiz);
1681 	free(sc->sc_ifas, M_CARP);
1682 	sc->sc_ifas = new;
1683 	sc->sc_ifasiz *= 2;
1684 	CARP_UNLOCK(sc);
1685 }
1686 
1687 static void
1688 carp_destroy(struct carp_softc *sc)
1689 {
1690 	struct ifnet *ifp = sc->sc_carpdev;
1691 	struct carp_if *cif = ifp->if_carp;
1692 
1693 	sx_assert(&carp_sx, SA_XLOCKED);
1694 
1695 	if (sc->sc_suppress)
1696 		carp_demote_adj(-V_carp_ifdown_adj, "vhid removed");
1697 	CARP_UNLOCK(sc);
1698 
1699 	CIF_LOCK(cif);
1700 	TAILQ_REMOVE(&cif->cif_vrs, sc, sc_list);
1701 	CIF_UNLOCK(cif);
1702 
1703 	mtx_lock(&carp_mtx);
1704 	LIST_REMOVE(sc, sc_next);
1705 	mtx_unlock(&carp_mtx);
1706 
1707 	callout_drain(&sc->sc_ad_tmo);
1708 #ifdef INET
1709 	callout_drain(&sc->sc_md_tmo);
1710 #endif
1711 #ifdef INET6
1712 	callout_drain(&sc->sc_md6_tmo);
1713 #endif
1714 	CARP_LOCK_DESTROY(sc);
1715 
1716 	free(sc->sc_ifas, M_CARP);
1717 	free(sc, M_CARP);
1718 }
1719 
1720 static struct carp_if*
1721 carp_alloc_if(struct ifnet *ifp)
1722 {
1723 	struct carp_if *cif;
1724 	int error;
1725 
1726 	cif = malloc(sizeof(*cif), M_CARP, M_WAITOK|M_ZERO);
1727 
1728 	if ((error = ifpromisc(ifp, 1)) != 0)
1729 		printf("%s: ifpromisc(%s) failed: %d\n",
1730 		    __func__, if_name(ifp), error);
1731 	else
1732 		cif->cif_flags |= CIF_PROMISC;
1733 
1734 	CIF_LOCK_INIT(cif);
1735 	cif->cif_ifp = ifp;
1736 	TAILQ_INIT(&cif->cif_vrs);
1737 
1738 	IF_ADDR_WLOCK(ifp);
1739 	ifp->if_carp = cif;
1740 	if_ref(ifp);
1741 	IF_ADDR_WUNLOCK(ifp);
1742 
1743 	return (cif);
1744 }
1745 
1746 static void
1747 carp_free_if(struct carp_if *cif)
1748 {
1749 	struct ifnet *ifp = cif->cif_ifp;
1750 
1751 	CIF_LOCK_ASSERT(cif);
1752 	KASSERT(TAILQ_EMPTY(&cif->cif_vrs), ("%s: softc list not empty",
1753 	    __func__));
1754 
1755 	IF_ADDR_WLOCK(ifp);
1756 	ifp->if_carp = NULL;
1757 	IF_ADDR_WUNLOCK(ifp);
1758 
1759 	CIF_LOCK_DESTROY(cif);
1760 
1761 	if (cif->cif_flags & CIF_PROMISC)
1762 		ifpromisc(ifp, 0);
1763 	if_rele(ifp);
1764 
1765 	free(cif, M_CARP);
1766 }
1767 
1768 static bool
1769 carp_carprcp(void *arg, struct carp_softc *sc, int priv)
1770 {
1771 	struct carpreq *carpr = arg;
1772 
1773 	CARP_LOCK(sc);
1774 	carpr->carpr_state = sc->sc_state;
1775 	carpr->carpr_vhid = sc->sc_vhid;
1776 	carpr->carpr_advbase = sc->sc_advbase;
1777 	carpr->carpr_advskew = sc->sc_advskew;
1778 	if (priv)
1779 		bcopy(sc->sc_key, carpr->carpr_key, sizeof(carpr->carpr_key));
1780 	else
1781 		bzero(carpr->carpr_key, sizeof(carpr->carpr_key));
1782 	CARP_UNLOCK(sc);
1783 
1784 	return (true);
1785 }
1786 
1787 static int
1788 carp_ioctl_set(if_t ifp, struct carpkreq *carpr)
1789 {
1790 	struct epoch_tracker et;
1791 	struct carp_softc *sc = NULL;
1792 	int error = 0;
1793 
1794 
1795 	if (carpr->carpr_vhid <= 0 || carpr->carpr_vhid > CARP_MAXVHID ||
1796 	    carpr->carpr_advbase < 0 || carpr->carpr_advskew < 0) {
1797 		return (EINVAL);
1798 	}
1799 
1800 	if (ifp->if_carp) {
1801 		IFNET_FOREACH_CARP(ifp, sc)
1802 			if (sc->sc_vhid == carpr->carpr_vhid)
1803 				break;
1804 	}
1805 	if (sc == NULL) {
1806 		sc = carp_alloc(ifp);
1807 		CARP_LOCK(sc);
1808 		sc->sc_vhid = carpr->carpr_vhid;
1809 		LLADDR(&sc->sc_addr)[0] = 0;
1810 		LLADDR(&sc->sc_addr)[1] = 0;
1811 		LLADDR(&sc->sc_addr)[2] = 0x5e;
1812 		LLADDR(&sc->sc_addr)[3] = 0;
1813 		LLADDR(&sc->sc_addr)[4] = 1;
1814 		LLADDR(&sc->sc_addr)[5] = sc->sc_vhid;
1815 	} else
1816 		CARP_LOCK(sc);
1817 	if (carpr->carpr_advbase > 0) {
1818 		if (carpr->carpr_advbase > 255 ||
1819 		    carpr->carpr_advbase < CARP_DFLTINTV) {
1820 			error = EINVAL;
1821 			goto out;
1822 		}
1823 		sc->sc_advbase = carpr->carpr_advbase;
1824 	}
1825 	if (carpr->carpr_advskew >= 255) {
1826 		error = EINVAL;
1827 		goto out;
1828 	}
1829 	sc->sc_advskew = carpr->carpr_advskew;
1830 	if (carpr->carpr_addr.s_addr != INADDR_ANY)
1831 		sc->sc_carpaddr = carpr->carpr_addr;
1832 	if (! IN6_IS_ADDR_UNSPECIFIED(&carpr->carpr_addr6)) {
1833 		memcpy(&sc->sc_carpaddr6, &carpr->carpr_addr6,
1834 		    sizeof(sc->sc_carpaddr6));
1835 	}
1836 	if (carpr->carpr_key[0] != '\0') {
1837 		bcopy(carpr->carpr_key, sc->sc_key, sizeof(sc->sc_key));
1838 		carp_hmac_prepare(sc);
1839 	}
1840 	if (sc->sc_state != INIT &&
1841 	    carpr->carpr_state != sc->sc_state) {
1842 		switch (carpr->carpr_state) {
1843 		case BACKUP:
1844 			callout_stop(&sc->sc_ad_tmo);
1845 			carp_set_state(sc, BACKUP,
1846 			    "user requested via ifconfig");
1847 			carp_setrun(sc, 0);
1848 			carp_delroute(sc);
1849 			break;
1850 		case MASTER:
1851 			NET_EPOCH_ENTER(et);
1852 			carp_master_down_locked(sc,
1853 			    "user requested via ifconfig");
1854 			NET_EPOCH_EXIT(et);
1855 			break;
1856 		default:
1857 			break;
1858 		}
1859 	}
1860 
1861 out:
1862 	CARP_UNLOCK(sc);
1863 
1864 	return (error);
1865 }
1866 
1867 static int
1868 carp_ioctl_get(if_t ifp, struct ucred *cred, struct carpreq *carpr,
1869     bool (*outfn)(void *, struct carp_softc *, int), void *arg)
1870 {
1871 	int priveleged;
1872 	struct carp_softc *sc;
1873 
1874 	if (carpr->carpr_vhid < 0 || carpr->carpr_vhid > CARP_MAXVHID)
1875 		return (EINVAL);
1876 	if (carpr->carpr_count < 1)
1877 		return (EMSGSIZE);
1878 	if (ifp->if_carp == NULL)
1879 		return (ENOENT);
1880 
1881 	priveleged = (priv_check_cred(cred, PRIV_NETINET_CARP) == 0);
1882 	if (carpr->carpr_vhid != 0) {
1883 		IFNET_FOREACH_CARP(ifp, sc)
1884 			if (sc->sc_vhid == carpr->carpr_vhid)
1885 				break;
1886 		if (sc == NULL)
1887 			return (ENOENT);
1888 
1889 		if (! outfn(arg, sc, priveleged))
1890 			return (ENOMEM);
1891 		carpr->carpr_count = 1;
1892 	} else  {
1893 		int count;
1894 
1895 		count = 0;
1896 		IFNET_FOREACH_CARP(ifp, sc)
1897 			count++;
1898 
1899 		if (count > carpr->carpr_count)
1900 			return (EMSGSIZE);
1901 
1902 		IFNET_FOREACH_CARP(ifp, sc) {
1903 			if (! outfn(arg, sc, priveleged))
1904 				return (ENOMEM);
1905 			carpr->carpr_count = count;
1906 		}
1907 	}
1908 
1909 	return (0);
1910 }
1911 
1912 int
1913 carp_ioctl(struct ifreq *ifr, u_long cmd, struct thread *td)
1914 {
1915 	struct carpreq carpr;
1916 	struct carpkreq carprk = { };
1917 	struct ifnet *ifp;
1918 	int error = 0;
1919 
1920 	if ((error = copyin(ifr_data_get_ptr(ifr), &carpr, sizeof carpr)))
1921 		return (error);
1922 
1923 	ifp = ifunit_ref(ifr->ifr_name);
1924 	if ((error = carp_is_supported_if(ifp)) != 0)
1925 		goto out;
1926 
1927 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
1928 		error = EADDRNOTAVAIL;
1929 		goto out;
1930 	}
1931 
1932 	sx_xlock(&carp_sx);
1933 	switch (cmd) {
1934 	case SIOCSVH:
1935 		if ((error = priv_check(td, PRIV_NETINET_CARP)))
1936 			break;
1937 
1938 		memcpy(&carprk, &carpr, sizeof(carpr));
1939 		error = carp_ioctl_set(ifp, &carprk);
1940 		break;
1941 
1942 	case SIOCGVH:
1943 		error = carp_ioctl_get(ifp, td->td_ucred, &carpr,
1944 		    carp_carprcp, &carpr);
1945 		if (error == 0) {
1946 			error = copyout(&carpr,
1947 			    (char *)ifr_data_get_ptr(ifr),
1948 			    carpr.carpr_count * sizeof(carpr));
1949 		}
1950 		break;
1951 	default:
1952 		error = EINVAL;
1953 	}
1954 	sx_xunlock(&carp_sx);
1955 
1956 out:
1957 	if (ifp != NULL)
1958 		if_rele(ifp);
1959 
1960 	return (error);
1961 }
1962 
1963 static int
1964 carp_get_vhid(struct ifaddr *ifa)
1965 {
1966 
1967 	if (ifa == NULL || ifa->ifa_carp == NULL)
1968 		return (0);
1969 
1970 	return (ifa->ifa_carp->sc_vhid);
1971 }
1972 
1973 int
1974 carp_attach(struct ifaddr *ifa, int vhid)
1975 {
1976 	struct ifnet *ifp = ifa->ifa_ifp;
1977 	struct carp_if *cif = ifp->if_carp;
1978 	struct carp_softc *sc;
1979 	int index, error;
1980 
1981 	KASSERT(ifa->ifa_carp == NULL, ("%s: ifa %p attached", __func__, ifa));
1982 
1983 	switch (ifa->ifa_addr->sa_family) {
1984 #ifdef INET
1985 	case AF_INET:
1986 #endif
1987 #ifdef INET6
1988 	case AF_INET6:
1989 #endif
1990 		break;
1991 	default:
1992 		return (EPROTOTYPE);
1993 	}
1994 
1995 	sx_xlock(&carp_sx);
1996 	if (ifp->if_carp == NULL) {
1997 		sx_xunlock(&carp_sx);
1998 		return (ENOPROTOOPT);
1999 	}
2000 
2001 	IFNET_FOREACH_CARP(ifp, sc)
2002 		if (sc->sc_vhid == vhid)
2003 			break;
2004 	if (sc == NULL) {
2005 		sx_xunlock(&carp_sx);
2006 		return (ENOENT);
2007 	}
2008 
2009 	error = carp_multicast_setup(cif, ifa->ifa_addr->sa_family);
2010 	if (error) {
2011 		CIF_FREE(cif);
2012 		sx_xunlock(&carp_sx);
2013 		return (error);
2014 	}
2015 
2016 	index = sc->sc_naddrs + sc->sc_naddrs6 + 1;
2017 	if (index > sc->sc_ifasiz / sizeof(struct ifaddr *))
2018 		carp_grow_ifas(sc);
2019 
2020 	switch (ifa->ifa_addr->sa_family) {
2021 #ifdef INET
2022 	case AF_INET:
2023 		cif->cif_naddrs++;
2024 		sc->sc_naddrs++;
2025 		break;
2026 #endif
2027 #ifdef INET6
2028 	case AF_INET6:
2029 		cif->cif_naddrs6++;
2030 		sc->sc_naddrs6++;
2031 		break;
2032 #endif
2033 	}
2034 
2035 	ifa_ref(ifa);
2036 
2037 	CARP_LOCK(sc);
2038 	sc->sc_ifas[index - 1] = ifa;
2039 	ifa->ifa_carp = sc;
2040 	carp_hmac_prepare(sc);
2041 	carp_sc_state(sc);
2042 	CARP_UNLOCK(sc);
2043 
2044 	sx_xunlock(&carp_sx);
2045 
2046 	return (0);
2047 }
2048 
2049 void
2050 carp_detach(struct ifaddr *ifa, bool keep_cif)
2051 {
2052 	struct ifnet *ifp = ifa->ifa_ifp;
2053 	struct carp_if *cif = ifp->if_carp;
2054 	struct carp_softc *sc = ifa->ifa_carp;
2055 	int i, index;
2056 
2057 	KASSERT(sc != NULL, ("%s: %p not attached", __func__, ifa));
2058 
2059 	sx_xlock(&carp_sx);
2060 
2061 	CARP_LOCK(sc);
2062 	/* Shift array. */
2063 	index = sc->sc_naddrs + sc->sc_naddrs6;
2064 	for (i = 0; i < index; i++)
2065 		if (sc->sc_ifas[i] == ifa)
2066 			break;
2067 	KASSERT(i < index, ("%s: %p no backref", __func__, ifa));
2068 	for (; i < index - 1; i++)
2069 		sc->sc_ifas[i] = sc->sc_ifas[i+1];
2070 	sc->sc_ifas[index - 1] = NULL;
2071 
2072 	switch (ifa->ifa_addr->sa_family) {
2073 #ifdef INET
2074 	case AF_INET:
2075 		cif->cif_naddrs--;
2076 		sc->sc_naddrs--;
2077 		break;
2078 #endif
2079 #ifdef INET6
2080 	case AF_INET6:
2081 		cif->cif_naddrs6--;
2082 		sc->sc_naddrs6--;
2083 		break;
2084 #endif
2085 	}
2086 
2087 	carp_ifa_delroute(ifa);
2088 	carp_multicast_cleanup(cif, ifa->ifa_addr->sa_family);
2089 
2090 	ifa->ifa_carp = NULL;
2091 	ifa_free(ifa);
2092 
2093 	carp_hmac_prepare(sc);
2094 	carp_sc_state(sc);
2095 
2096 	if (!keep_cif && sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0)
2097 		carp_destroy(sc);
2098 	else
2099 		CARP_UNLOCK(sc);
2100 
2101 	if (!keep_cif)
2102 		CIF_FREE(cif);
2103 
2104 	sx_xunlock(&carp_sx);
2105 }
2106 
2107 static void
2108 carp_set_state(struct carp_softc *sc, int state, const char *reason)
2109 {
2110 
2111 	CARP_LOCK_ASSERT(sc);
2112 
2113 	if (sc->sc_state != state) {
2114 		const char *carp_states[] = { CARP_STATES };
2115 		char subsys[IFNAMSIZ+5];
2116 
2117 		snprintf(subsys, IFNAMSIZ+5, "%u@%s", sc->sc_vhid,
2118 		    if_name(sc->sc_carpdev));
2119 
2120 		CARP_LOG("%s: %s -> %s (%s)\n", subsys,
2121 		    carp_states[sc->sc_state], carp_states[state], reason);
2122 
2123 		sc->sc_state = state;
2124 
2125 		devctl_notify("CARP", subsys, carp_states[state], NULL);
2126 	}
2127 }
2128 
2129 static void
2130 carp_linkstate(struct ifnet *ifp)
2131 {
2132 	struct carp_softc *sc;
2133 
2134 	CIF_LOCK(ifp->if_carp);
2135 	IFNET_FOREACH_CARP(ifp, sc) {
2136 		CARP_LOCK(sc);
2137 		carp_sc_state(sc);
2138 		CARP_UNLOCK(sc);
2139 	}
2140 	CIF_UNLOCK(ifp->if_carp);
2141 }
2142 
2143 static void
2144 carp_sc_state(struct carp_softc *sc)
2145 {
2146 
2147 	CARP_LOCK_ASSERT(sc);
2148 
2149 	if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
2150 	    !(sc->sc_carpdev->if_flags & IFF_UP) ||
2151 	    !V_carp_allow) {
2152 		callout_stop(&sc->sc_ad_tmo);
2153 #ifdef INET
2154 		callout_stop(&sc->sc_md_tmo);
2155 #endif
2156 #ifdef INET6
2157 		callout_stop(&sc->sc_md6_tmo);
2158 #endif
2159 		carp_set_state(sc, INIT, "hardware interface down");
2160 		carp_setrun(sc, 0);
2161 		if (!sc->sc_suppress)
2162 			carp_demote_adj(V_carp_ifdown_adj, "interface down");
2163 		sc->sc_suppress = 1;
2164 	} else {
2165 		carp_set_state(sc, INIT, "hardware interface up");
2166 		carp_setrun(sc, 0);
2167 		if (sc->sc_suppress)
2168 			carp_demote_adj(-V_carp_ifdown_adj, "interface up");
2169 		sc->sc_suppress = 0;
2170 	}
2171 }
2172 
2173 static void
2174 carp_demote_adj(int adj, char *reason)
2175 {
2176 	atomic_add_int(&V_carp_demotion, adj);
2177 	CARP_LOG("demoted by %d to %d (%s)\n", adj, V_carp_demotion, reason);
2178 	taskqueue_enqueue(taskqueue_swi, &carp_sendall_task);
2179 }
2180 
2181 static int
2182 carp_allow_sysctl(SYSCTL_HANDLER_ARGS)
2183 {
2184 	int new, error;
2185 	struct carp_softc *sc;
2186 
2187 	new = V_carp_allow;
2188 	error = sysctl_handle_int(oidp, &new, 0, req);
2189 	if (error || !req->newptr)
2190 		return (error);
2191 
2192 	if (V_carp_allow != new) {
2193 		V_carp_allow = new;
2194 
2195 		mtx_lock(&carp_mtx);
2196 		LIST_FOREACH(sc, &carp_list, sc_next) {
2197 			CARP_LOCK(sc);
2198 			if (curvnet == sc->sc_carpdev->if_vnet)
2199 				carp_sc_state(sc);
2200 			CARP_UNLOCK(sc);
2201 		}
2202 		mtx_unlock(&carp_mtx);
2203 	}
2204 
2205 	return (0);
2206 }
2207 
2208 static int
2209 carp_dscp_sysctl(SYSCTL_HANDLER_ARGS)
2210 {
2211 	int new, error;
2212 
2213 	new = V_carp_dscp;
2214 	error = sysctl_handle_int(oidp, &new, 0, req);
2215 	if (error || !req->newptr)
2216 		return (error);
2217 
2218 	if (new < 0 || new > 63)
2219 		return (EINVAL);
2220 
2221 	V_carp_dscp = new;
2222 
2223 	return (0);
2224 }
2225 
2226 static int
2227 carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS)
2228 {
2229 	int new, error;
2230 
2231 	new = V_carp_demotion;
2232 	error = sysctl_handle_int(oidp, &new, 0, req);
2233 	if (error || !req->newptr)
2234 		return (error);
2235 
2236 	carp_demote_adj(new, "sysctl");
2237 
2238 	return (0);
2239 }
2240 
2241 static int
2242 nlattr_get_carp_key(struct nlattr *nla, struct nl_pstate *npt, const void *arg, void *target)
2243 {
2244 	if (__predict_false(NLA_DATA_LEN(nla) > CARP_KEY_LEN))
2245 		return (EINVAL);
2246 
2247 	memcpy(target, NLA_DATA_CONST(nla), NLA_DATA_LEN(nla));
2248 	return (0);
2249 }
2250 
2251 struct carp_nl_send_args {
2252 	struct nlmsghdr *hdr;
2253 	struct nl_pstate *npt;
2254 };
2255 
2256 static bool
2257 carp_nl_send(void *arg, struct carp_softc *sc, int priv)
2258 {
2259 	struct carp_nl_send_args *nlsa = arg;
2260 	struct nlmsghdr *hdr = nlsa->hdr;
2261 	struct nl_pstate *npt = nlsa->npt;
2262 	struct nl_writer *nw = npt->nw;
2263 	struct genlmsghdr *ghdr_new;
2264 
2265 	if (!nlmsg_reply(nw, hdr, sizeof(struct genlmsghdr))) {
2266 		nlmsg_abort(nw);
2267 		return (false);
2268 	}
2269 
2270 	ghdr_new = nlmsg_reserve_object(nw, struct genlmsghdr);
2271 	if (ghdr_new == NULL) {
2272 		nlmsg_abort(nw);
2273 		return (false);
2274 	}
2275 
2276 	ghdr_new->cmd = CARP_NL_CMD_GET;
2277 	ghdr_new->version = 0;
2278 	ghdr_new->reserved = 0;
2279 
2280 	CARP_LOCK(sc);
2281 
2282 	nlattr_add_u32(nw, CARP_NL_VHID, sc->sc_vhid);
2283 	nlattr_add_u32(nw, CARP_NL_STATE, sc->sc_state);
2284 	nlattr_add_s32(nw, CARP_NL_ADVBASE, sc->sc_advbase);
2285 	nlattr_add_s32(nw, CARP_NL_ADVSKEW, sc->sc_advskew);
2286 	nlattr_add_in_addr(nw, CARP_NL_ADDR, &sc->sc_carpaddr);
2287 	nlattr_add_in6_addr(nw, CARP_NL_ADDR6, &sc->sc_carpaddr6);
2288 
2289 	if (priv)
2290 		nlattr_add(nw, CARP_NL_KEY, sizeof(sc->sc_key), sc->sc_key);
2291 
2292 	CARP_UNLOCK(sc);
2293 
2294 	if (! nlmsg_end(nw)) {
2295 		nlmsg_abort(nw);
2296 		return (false);
2297 	}
2298 
2299 	return (true);
2300 }
2301 
2302 struct nl_carp_parsed {
2303 	unsigned int	ifindex;
2304 	char		*ifname;
2305 	uint32_t	state;
2306 	uint32_t	vhid;
2307 	int32_t		advbase;
2308 	int32_t		advskew;
2309 	char		key[CARP_KEY_LEN];
2310 	struct in_addr	addr;
2311 	struct in6_addr	addr6;
2312 };
2313 
2314 #define	_IN(_field)	offsetof(struct genlmsghdr, _field)
2315 #define	_OUT(_field)	offsetof(struct nl_carp_parsed, _field)
2316 
2317 static const struct nlattr_parser nla_p_set[] = {
2318 	{ .type = CARP_NL_VHID, .off = _OUT(vhid), .cb = nlattr_get_uint32 },
2319 	{ .type = CARP_NL_STATE, .off = _OUT(state), .cb = nlattr_get_uint32 },
2320 	{ .type = CARP_NL_ADVBASE, .off = _OUT(advbase), .cb = nlattr_get_uint32 },
2321 	{ .type = CARP_NL_ADVSKEW, .off = _OUT(advskew), .cb = nlattr_get_uint32 },
2322 	{ .type = CARP_NL_KEY, .off = _OUT(key), .cb = nlattr_get_carp_key },
2323 	{ .type = CARP_NL_IFINDEX, .off = _OUT(ifindex), .cb = nlattr_get_uint32 },
2324 	{ .type = CARP_NL_ADDR, .off = _OUT(addr), .cb = nlattr_get_in_addr },
2325 	{ .type = CARP_NL_ADDR6, .off = _OUT(addr6), .cb = nlattr_get_in6_addr },
2326 	{ .type = CARP_NL_IFNAME, .off = _OUT(ifname), .cb = nlattr_get_string },
2327 };
2328 static const struct nlfield_parser nlf_p_set[] = {
2329 };
2330 NL_DECLARE_PARSER(carp_parser, struct genlmsghdr, nlf_p_set, nla_p_set);
2331 #undef _IN
2332 #undef _OUT
2333 
2334 
2335 static int
2336 carp_nl_get(struct nlmsghdr *hdr, struct nl_pstate *npt)
2337 {
2338 	struct nl_carp_parsed attrs = { };
2339 	struct carp_nl_send_args args;
2340 	struct carpreq carpr = { };
2341 	struct epoch_tracker et;
2342 	if_t ifp = NULL;
2343 	int error;
2344 
2345 	error = nl_parse_nlmsg(hdr, &carp_parser, npt, &attrs);
2346 	if (error != 0)
2347 		return (error);
2348 
2349 	NET_EPOCH_ENTER(et);
2350 	if (attrs.ifname != NULL)
2351 		ifp = ifunit_ref(attrs.ifname);
2352 	else if (attrs.ifindex != 0)
2353 		ifp = ifnet_byindex_ref(attrs.ifindex);
2354 	NET_EPOCH_EXIT(et);
2355 
2356 	if ((error = carp_is_supported_if(ifp)) != 0)
2357 		goto out;
2358 
2359 	hdr->nlmsg_flags |= NLM_F_MULTI;
2360 	args.hdr = hdr;
2361 	args.npt = npt;
2362 
2363 	carpr.carpr_vhid = attrs.vhid;
2364 	carpr.carpr_count = CARP_MAXVHID;
2365 
2366 	sx_xlock(&carp_sx);
2367 	error = carp_ioctl_get(ifp, nlp_get_cred(npt->nlp), &carpr,
2368 	    carp_nl_send, &args);
2369 	sx_xunlock(&carp_sx);
2370 
2371 	if (! nlmsg_end_dump(npt->nw, error, hdr))
2372 		error = ENOMEM;
2373 
2374 out:
2375 	if (ifp != NULL)
2376 		if_rele(ifp);
2377 
2378 	return (error);
2379 }
2380 
2381 static int
2382 carp_nl_set(struct nlmsghdr *hdr, struct nl_pstate *npt)
2383 {
2384 	struct nl_carp_parsed attrs = { };
2385 	struct carpkreq carpr;
2386 	struct epoch_tracker et;
2387 	if_t ifp = NULL;
2388 	int error;
2389 
2390 	error = nl_parse_nlmsg(hdr, &carp_parser, npt, &attrs);
2391 	if (error != 0)
2392 		return (error);
2393 
2394 	if (attrs.vhid <= 0 || attrs.vhid > CARP_MAXVHID)
2395 		return (EINVAL);
2396 	if (attrs.state > CARP_MAXSTATE)
2397 		return (EINVAL);
2398 	if (attrs.advbase < 0 || attrs.advskew < 0)
2399 		return (EINVAL);
2400 	if (attrs.advbase > 255)
2401 		return (EINVAL);
2402 	if (attrs.advskew >= 255)
2403 		return (EINVAL);
2404 
2405 	NET_EPOCH_ENTER(et);
2406 	if (attrs.ifname != NULL)
2407 		ifp = ifunit_ref(attrs.ifname);
2408 	else if (attrs.ifindex != 0)
2409 		ifp = ifnet_byindex_ref(attrs.ifindex);
2410 	NET_EPOCH_EXIT(et);
2411 
2412 	if ((error = carp_is_supported_if(ifp)) != 0)
2413 		goto out;
2414 
2415 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
2416 		error = EADDRNOTAVAIL;
2417 		goto out;
2418 	}
2419 
2420 	carpr.carpr_count = 1;
2421 	carpr.carpr_vhid = attrs.vhid;
2422 	carpr.carpr_state = attrs.state;
2423 	carpr.carpr_advbase = attrs.advbase;
2424 	carpr.carpr_advskew = attrs.advskew;
2425 	carpr.carpr_addr = attrs.addr;
2426 	carpr.carpr_addr6 = attrs.addr6;
2427 
2428 	memcpy(&carpr.carpr_key, &attrs.key, sizeof(attrs.key));
2429 
2430 	sx_xlock(&carp_sx);
2431 	error = carp_ioctl_set(ifp, &carpr);
2432 	sx_xunlock(&carp_sx);
2433 
2434 out:
2435 	if (ifp != NULL)
2436 		if_rele(ifp);
2437 
2438 	return (error);
2439 }
2440 
2441 static const struct nlhdr_parser *all_parsers[] = {
2442 	&carp_parser
2443 };
2444 
2445 static const struct genl_cmd carp_cmds[] = {
2446 	{
2447 		.cmd_num = CARP_NL_CMD_GET,
2448 		.cmd_name = "SIOCGVH",
2449 		.cmd_cb = carp_nl_get,
2450 		.cmd_flags = GENL_CMD_CAP_DO | GENL_CMD_CAP_DUMP |
2451 		    GENL_CMD_CAP_HASPOL,
2452 	},
2453 	{
2454 		.cmd_num = CARP_NL_CMD_SET,
2455 		.cmd_name = "SIOCSVH",
2456 		.cmd_cb = carp_nl_set,
2457 		.cmd_flags = GENL_CMD_CAP_DO | GENL_CMD_CAP_HASPOL,
2458 		.cmd_priv = PRIV_NETINET_CARP,
2459 	},
2460 };
2461 
2462 static void
2463 carp_nl_register(void)
2464 {
2465 	bool ret __diagused;
2466 	int family_id __diagused;
2467 
2468 	NL_VERIFY_PARSERS(all_parsers);
2469 	family_id = genl_register_family(CARP_NL_FAMILY_NAME, 0, 2,
2470 	    CARP_NL_CMD_MAX);
2471 	MPASS(family_id != 0);
2472 
2473 	ret = genl_register_cmds(CARP_NL_FAMILY_NAME, carp_cmds,
2474 	    NL_ARRAY_LEN(carp_cmds));
2475 	MPASS(ret);
2476 }
2477 
2478 static void
2479 carp_nl_unregister(void)
2480 {
2481 	genl_unregister_family(CARP_NL_FAMILY_NAME);
2482 }
2483 
2484 static void
2485 carp_mod_cleanup(void)
2486 {
2487 
2488 	carp_nl_unregister();
2489 
2490 #ifdef INET
2491 	(void)ipproto_unregister(IPPROTO_CARP);
2492 	carp_iamatch_p = NULL;
2493 #endif
2494 #ifdef INET6
2495 	(void)ip6proto_unregister(IPPROTO_CARP);
2496 	carp_iamatch6_p = NULL;
2497 	carp_macmatch6_p = NULL;
2498 #endif
2499 	carp_ioctl_p = NULL;
2500 	carp_attach_p = NULL;
2501 	carp_detach_p = NULL;
2502 	carp_get_vhid_p = NULL;
2503 	carp_linkstate_p = NULL;
2504 	carp_forus_p = NULL;
2505 	carp_output_p = NULL;
2506 	carp_demote_adj_p = NULL;
2507 	carp_master_p = NULL;
2508 	mtx_unlock(&carp_mtx);
2509 	taskqueue_drain(taskqueue_swi, &carp_sendall_task);
2510 	mtx_destroy(&carp_mtx);
2511 	sx_destroy(&carp_sx);
2512 }
2513 
2514 static void
2515 ipcarp_sysinit(void)
2516 {
2517 
2518 	/* Load allow as tunable so to postpone carp start after module load */
2519 	TUNABLE_INT_FETCH("net.inet.carp.allow", &V_carp_allow);
2520 }
2521 VNET_SYSINIT(ip_carp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, ipcarp_sysinit, NULL);
2522 
2523 static int
2524 carp_mod_load(void)
2525 {
2526 	int err;
2527 
2528 	mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
2529 	sx_init(&carp_sx, "carp_sx");
2530 	LIST_INIT(&carp_list);
2531 	carp_get_vhid_p = carp_get_vhid;
2532 	carp_forus_p = carp_forus;
2533 	carp_output_p = carp_output;
2534 	carp_linkstate_p = carp_linkstate;
2535 	carp_ioctl_p = carp_ioctl;
2536 	carp_attach_p = carp_attach;
2537 	carp_detach_p = carp_detach;
2538 	carp_demote_adj_p = carp_demote_adj;
2539 	carp_master_p = carp_master;
2540 #ifdef INET6
2541 	carp_iamatch6_p = carp_iamatch6;
2542 	carp_macmatch6_p = carp_macmatch6;
2543 	err = ip6proto_register(IPPROTO_CARP, carp6_input, NULL);
2544 	if (err) {
2545 		printf("carp: error %d registering with INET6\n", err);
2546 		carp_mod_cleanup();
2547 		return (err);
2548 	}
2549 #endif
2550 #ifdef INET
2551 	carp_iamatch_p = carp_iamatch;
2552 	err = ipproto_register(IPPROTO_CARP, carp_input, NULL);
2553 	if (err) {
2554 		printf("carp: error %d registering with INET\n", err);
2555 		carp_mod_cleanup();
2556 		return (err);
2557 	}
2558 #endif
2559 
2560 	carp_nl_register();
2561 
2562 	return (0);
2563 }
2564 
2565 static int
2566 carp_modevent(module_t mod, int type, void *data)
2567 {
2568 	switch (type) {
2569 	case MOD_LOAD:
2570 		return carp_mod_load();
2571 		/* NOTREACHED */
2572 	case MOD_UNLOAD:
2573 		mtx_lock(&carp_mtx);
2574 		if (LIST_EMPTY(&carp_list))
2575 			carp_mod_cleanup();
2576 		else {
2577 			mtx_unlock(&carp_mtx);
2578 			return (EBUSY);
2579 		}
2580 		break;
2581 
2582 	default:
2583 		return (EINVAL);
2584 	}
2585 
2586 	return (0);
2587 }
2588 
2589 static moduledata_t carp_mod = {
2590 	"carp",
2591 	carp_modevent,
2592 	0
2593 };
2594 
2595 DECLARE_MODULE(carp, carp_mod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
2596