xref: /dragonfly/sys/netinet/ip_carp.c (revision 6700dd34)
1 /*
2  * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
3  * Copyright (c) 2003 Ryan McBride. All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
18  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
20  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
23  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
24  * THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 /*
27  * $FreeBSD: src/sys/netinet/ip_carp.c,v 1.48 2007/02/02 09:39:09 glebius Exp $
28  */
29 
30 #include "opt_carp.h"
31 #include "opt_inet.h"
32 #include "opt_inet6.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/in_cksum.h>
38 #include <sys/limits.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/msgport2.h>
42 #include <sys/time.h>
43 #include <sys/proc.h>
44 #include <sys/priv.h>
45 #include <sys/sockio.h>
46 #include <sys/socket.h>
47 #include <sys/sysctl.h>
48 #include <sys/syslog.h>
49 #include <sys/thread.h>
50 
51 #include <machine/stdarg.h>
52 #include <crypto/sha1.h>
53 
54 #include <net/bpf.h>
55 #include <net/ethernet.h>
56 #include <net/if.h>
57 #include <net/if_dl.h>
58 #include <net/if_types.h>
59 #include <net/route.h>
60 #include <net/if_clone.h>
61 #include <net/if_var.h>
62 #include <net/ifq_var.h>
63 #include <net/netmsg2.h>
64 #include <net/netisr2.h>
65 
66 #ifdef INET
67 #include <netinet/in.h>
68 #include <netinet/in_var.h>
69 #include <netinet/in_systm.h>
70 #include <netinet/ip.h>
71 #include <netinet/ip_var.h>
72 #include <netinet/if_ether.h>
73 #endif
74 
75 #ifdef INET6
76 #include <netinet/icmp6.h>
77 #include <netinet/ip6.h>
78 #include <netinet6/ip6_var.h>
79 #include <netinet6/scope6_var.h>
80 #include <netinet6/nd6.h>
81 #endif
82 
83 #include <netinet/ip_carp.h>
84 
85 /*
86  * Note about carp's MP safe approach:
87  *
88  * Brief: carp_softc (softc), carp_softc_container (scc)
89  *
90  * - All configuration operation, e.g. ioctl, add/delete inet addresses
91  *   is serialized by netisr0; not by carp's serializer
92  *
93  * - Backing interface's if_carp and carp_softc's relationship:
94  *
95  *                +---------+
96  *     if_carp -->| carp_if |
97  *                +---------+
98  *                     |
99  *                     |
100  *                     V      +---------+
101  *                  +-----+   |         |
102  *                  | scc |-->|  softc  |
103  *                  +-----+   |         |
104  *                     |      +---------+
105  *                     |
106  *                     V      +---------+
107  *                  +-----+   |         |
108  *                  | scc |-->|  softc  |
109  *                  +-----+   |         |
110  *                            +---------+
111  *
112  * - if_carp creation, modification and deletion all happen in netisr0,
113  *   as stated previously.  Since if_carp is accessed by multiple netisrs,
114  *   the modification to if_carp is conducted in the following way:
115  *
116  *   Adding carp_softc:
117  *
118  *   1) Duplicate the old carp_if to new carp_if (ncif), and insert the
119  *      to-be-added carp_softc to the new carp_if (ncif):
120  *
121  *        if_carp                     ncif
122  *           |                         |
123  *           V                         V
124  *      +---------+               +---------+
125  *      | carp_if |               | carp_if |
126  *      +---------+               +---------+
127  *           |                         |
128  *           |                         |
129  *           V        +-------+        V
130  *        +-----+     |       |     +-----+
131  *        | scc |---->| softc |<----| scc |
132  *        +-----+     |       |     +-----+
133  *           |        +-------+        |
134  *           |                         |
135  *           V        +-------+        V
136  *        +-----+     |       |     +-----+
137  *        | scc |---->| softc |<----| scc |
138  *        +-----+     |       |     +-----+
139  *                    +-------+        |
140  *                                     |
141  *                    +-------+        V
142  *                    |       |     +-----+
143  *                    | softc |<----| scc |
144  *                    |       |     +-----+
145  *                    +-------+
146  *
147  *   2) Switch save if_carp into ocif and switch if_carp to ncif:
148  *
149  *          ocif                    if_carp
150  *           |                         |
151  *           V                         V
152  *      +---------+               +---------+
153  *      | carp_if |               | carp_if |
154  *      +---------+               +---------+
155  *           |                         |
156  *           |                         |
157  *           V        +-------+        V
158  *        +-----+     |       |     +-----+
159  *        | scc |---->| softc |<----| scc |
160  *        +-----+     |       |     +-----+
161  *           |        +-------+        |
162  *           |                         |
163  *           V        +-------+        V
164  *        +-----+     |       |     +-----+
165  *        | scc |---->| softc |<----| scc |
166  *        +-----+     |       |     +-----+
167  *                    +-------+        |
168  *                                     |
169  *                    +-------+        V
170  *                    |       |     +-----+
171  *                    | softc |<----| scc |
172  *                    |       |     +-----+
173  *                    +-------+
174  *
175  *   3) Run netmsg_service_sync(), which will make sure that
176  *      ocif is no longer accessed (all network operations
177  *      are happened only in network threads).
178  *   4) Free ocif -- only carp_if and scc are freed.
179  *
180  *
181  *   Removing carp_softc:
182  *
183  *   1) Duplicate the old carp_if to new carp_if (ncif); the to-be-deleted
184  *      carp_softc will not be duplicated.
185  *
186  *        if_carp                     ncif
187  *           |                         |
188  *           V                         V
189  *      +---------+               +---------+
190  *      | carp_if |               | carp_if |
191  *      +---------+               +---------+
192  *           |                         |
193  *           |                         |
194  *           V        +-------+        V
195  *        +-----+     |       |     +-----+
196  *        | scc |---->| softc |<----| scc |
197  *        +-----+     |       |     +-----+
198  *           |        +-------+        |
199  *           |                         |
200  *           V        +-------+        |
201  *        +-----+     |       |        |
202  *        | scc |---->| softc |        |
203  *        +-----+     |       |        |
204  *           |        +-------+        |
205  *           |                         |
206  *           V        +-------+        V
207  *        +-----+     |       |     +-----+
208  *        | scc |---->| softc |<----| scc |
209  *        +-----+     |       |     +-----+
210  *                    +-------+
211  *
212  *   2) Switch save if_carp into ocif and switch if_carp to ncif:
213  *
214  *          ocif                    if_carp
215  *           |                         |
216  *           V                         V
217  *      +---------+               +---------+
218  *      | carp_if |               | carp_if |
219  *      +---------+               +---------+
220  *           |                         |
221  *           |                         |
222  *           V        +-------+        V
223  *        +-----+     |       |     +-----+
224  *        | scc |---->| softc |<----| scc |
225  *        +-----+     |       |     +-----+
226  *           |        +-------+        |
227  *           |                         |
228  *           V        +-------+        |
229  *        +-----+     |       |        |
230  *        | scc |---->| softc |        |
231  *        +-----+     |       |        |
232  *           |        +-------+        |
233  *           |                         |
234  *           V        +-------+        V
235  *        +-----+     |       |     +-----+
236  *        | scc |---->| softc |<----| scc |
237  *        +-----+     |       |     +-----+
238  *                    +-------+
239  *
240  *   3) Run netmsg_service_sync(), which will make sure that
241  *      ocif is no longer accessed (all network operations
242  *      are happened only in network threads).
243  *   4) Free ocif -- only carp_if and scc are freed.
244  *
245  * - if_carp accessing:
246  *   The accessing code should cache the if_carp in a local temporary
247  *   variable and accessing the temporary variable along the code path
248  *   instead of accessing if_carp later on.
249  */
250 
251 #define	CARP_IFNAME		"carp"
252 #define CARP_IS_RUNNING(ifp)	\
253 	(((ifp)->if_flags & (IFF_UP | IFF_RUNNING)) == (IFF_UP | IFF_RUNNING))
254 
255 struct carp_softc;
256 
257 struct carp_vhaddr {
258 	uint32_t		vha_flags;	/* CARP_VHAF_ */
259 	struct in_ifaddr	*vha_ia;	/* carp address */
260 	struct in_ifaddr	*vha_iaback;	/* backing address */
261 	TAILQ_ENTRY(carp_vhaddr) vha_link;
262 };
263 TAILQ_HEAD(carp_vhaddr_list, carp_vhaddr);
264 
265 struct netmsg_carp {
266 	struct netmsg_base	base;
267 	struct ifnet		*nc_carpdev;
268 	struct carp_softc	*nc_softc;
269 	void			*nc_data;
270 	size_t			nc_datalen;
271 };
272 
273 struct carp_softc {
274 	struct arpcom		 arpcom;
275 	struct ifnet		*sc_carpdev;	/* parent interface */
276 	struct carp_vhaddr_list	 sc_vha_list;	/* virtual addr list */
277 
278 	const struct in_ifaddr	*sc_ia;		/* primary iface address v4 */
279 	struct ip_moptions 	 sc_imo;
280 
281 #ifdef INET6
282 	struct in6_ifaddr 	*sc_ia6;	/* primary iface address v6 */
283 	struct ip6_moptions 	 sc_im6o;
284 #endif /* INET6 */
285 
286 	enum { INIT = 0, BACKUP, MASTER }
287 				 sc_state;
288 	boolean_t		 sc_dead;
289 
290 	int			 sc_suppress;
291 
292 	int			 sc_sendad_errors;
293 #define	CARP_SENDAD_MAX_ERRORS	3
294 	int			 sc_sendad_success;
295 #define	CARP_SENDAD_MIN_SUCCESS 3
296 
297 	int			 sc_vhid;
298 	int			 sc_advskew;
299 	int			 sc_naddrs;	/* actually used IPv4 vha */
300 	int			 sc_naddrs6;
301 	int			 sc_advbase;	/* seconds */
302 	int			 sc_init_counter;
303 	uint64_t		 sc_counter;
304 
305 	/* authentication */
306 #define CARP_HMAC_PAD	64
307 	unsigned char		 sc_key[CARP_KEY_LEN];
308 	unsigned char		 sc_pad[CARP_HMAC_PAD];
309 	SHA1_CTX		 sc_sha1;
310 
311 	struct callout		 sc_ad_tmo;	/* advertisement timeout */
312 	struct netmsg_carp	 sc_ad_msg;	/* adv timeout netmsg */
313 	struct callout		 sc_md_tmo;	/* ip4 master down timeout */
314 	struct callout 		 sc_md6_tmo;	/* ip6 master down timeout */
315 	struct netmsg_carp	 sc_md_msg;	/* master down timeout netmsg */
316 
317 	LIST_ENTRY(carp_softc)	 sc_next;	/* Interface clue */
318 };
319 
320 #define sc_if	arpcom.ac_if
321 
322 struct carp_softc_container {
323 	TAILQ_ENTRY(carp_softc_container) scc_link;
324 	struct carp_softc	*scc_softc;
325 };
326 TAILQ_HEAD(carp_if, carp_softc_container);
327 
328 SYSCTL_DECL(_net_inet_carp);
329 
330 static int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 1, 0, 0, 1 }; /* XXX for now */
331 SYSCTL_INT(_net_inet_carp, CARPCTL_ALLOW, allow, CTLFLAG_RW,
332     &carp_opts[CARPCTL_ALLOW], 0, "Accept incoming CARP packets");
333 SYSCTL_INT(_net_inet_carp, CARPCTL_PREEMPT, preempt, CTLFLAG_RW,
334     &carp_opts[CARPCTL_PREEMPT], 0, "high-priority backup preemption mode");
335 SYSCTL_INT(_net_inet_carp, CARPCTL_LOG, log, CTLFLAG_RW,
336     &carp_opts[CARPCTL_LOG], 0, "log bad carp packets");
337 SYSCTL_INT(_net_inet_carp, CARPCTL_ARPBALANCE, arpbalance, CTLFLAG_RW,
338     &carp_opts[CARPCTL_ARPBALANCE], 0, "balance arp responses");
339 SYSCTL_INT(_net_inet_carp, CARPCTL_SETROUTE, setroute, CTLFLAG_RW,
340     &carp_opts[CARPCTL_SETROUTE], 0, "set route");
341 
342 static int carp_suppress_preempt = 0;
343 SYSCTL_INT(_net_inet_carp, OID_AUTO, suppress_preempt, CTLFLAG_RD,
344     &carp_suppress_preempt, 0, "Preemption is suppressed");
345 
346 static int carp_prio_ad = 1;
347 SYSCTL_INT(_net_inet_carp, OID_AUTO, prio_ad, CTLFLAG_RD,
348     &carp_prio_ad, 0, "Prioritize advertisement packet");
349 
350 static struct carpstats carpstats;
351 SYSCTL_STRUCT(_net_inet_carp, CARPCTL_STATS, stats, CTLFLAG_RW,
352     &carpstats, carpstats,
353     "CARP statistics (struct carpstats, netinet/ip_carp.h)");
354 
355 #define	CARP_LOG(...)	do {				\
356 	if (carp_opts[CARPCTL_LOG] > 0)			\
357 		log(LOG_INFO, __VA_ARGS__);		\
358 } while (0)
359 
360 #define	CARP_DEBUG(...)	do {				\
361 	if (carp_opts[CARPCTL_LOG] > 1)			\
362 		log(LOG_DEBUG, __VA_ARGS__);		\
363 } while (0)
364 
365 static struct lwkt_token carp_listtok = LWKT_TOKEN_INITIALIZER(carp_list_token);
366 
367 static void	carp_hmac_prepare(struct carp_softc *);
368 static void	carp_hmac_generate(struct carp_softc *, uint32_t *,
369 		    unsigned char *);
370 static int	carp_hmac_verify(struct carp_softc *, uint32_t *,
371 		    unsigned char *);
372 static void	carp_setroute(struct carp_softc *, int);
373 static void	carp_proto_input_c(struct carp_softc *, struct mbuf *,
374 		    struct carp_header *, sa_family_t);
375 static int 	carp_clone_create(struct if_clone *, int, caddr_t);
376 static int 	carp_clone_destroy(struct ifnet *);
377 static void	carp_detach(struct carp_softc *, boolean_t, boolean_t);
378 static void	carp_prepare_ad(struct carp_softc *, struct carp_header *);
379 static void	carp_send_ad_all(void);
380 static void	carp_send_ad_timeout(void *);
381 static void	carp_send_ad(struct carp_softc *);
382 static void	carp_send_arp(struct carp_softc *);
383 static void	carp_master_down_timeout(void *);
384 static void	carp_master_down(struct carp_softc *);
385 static void	carp_setrun(struct carp_softc *, sa_family_t);
386 static void	carp_set_state(struct carp_softc *, int);
387 static struct ifnet *carp_forus(struct carp_if *, const uint8_t *);
388 
389 static void	carp_init(void *);
390 static int	carp_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
391 static int	carp_output(struct ifnet *, struct mbuf *, struct sockaddr *,
392 		    struct rtentry *);
393 static void	carp_start(struct ifnet *, struct ifaltq_subque *);
394 
395 static void	carp_multicast_cleanup(struct carp_softc *);
396 static void	carp_add_addr(struct carp_softc *, struct ifaddr *);
397 static void	carp_del_addr(struct carp_softc *, struct ifaddr *);
398 static void	carp_config_addr(struct carp_softc *, struct ifaddr *);
399 static void	carp_link_addrs(struct carp_softc *, struct ifnet *,
400 		    struct ifaddr *);
401 static void	carp_unlink_addrs(struct carp_softc *, struct ifnet *,
402 		    struct ifaddr *);
403 static void	carp_update_addrs(struct carp_softc *, struct ifaddr *);
404 
405 static int	carp_config_vhaddr(struct carp_softc *, struct carp_vhaddr *,
406 		    struct in_ifaddr *);
407 static int	carp_activate_vhaddr(struct carp_softc *, struct carp_vhaddr *,
408 		    struct ifnet *, struct in_ifaddr *, int);
409 static void	carp_deactivate_vhaddr(struct carp_softc *,
410 		    struct carp_vhaddr *, boolean_t);
411 static int	carp_addroute_vhaddr(struct carp_softc *, struct carp_vhaddr *);
412 static void	carp_delroute_vhaddr(struct carp_softc *, struct carp_vhaddr *,
413 		    boolean_t);
414 
415 #ifdef foo
416 static void	carp_sc_state(struct carp_softc *);
417 #endif
418 #ifdef INET6
419 static void	carp_send_na(struct carp_softc *);
420 #ifdef notyet
421 static int	carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
422 static int	carp_del_addr6(struct carp_softc *, struct sockaddr_in6 *);
423 #endif
424 static void	carp_multicast6_cleanup(struct carp_softc *);
425 #endif
426 static void	carp_stop(struct carp_softc *, boolean_t);
427 static void	carp_suspend(struct carp_softc *, boolean_t);
428 static void	carp_ioctl_stop(struct carp_softc *);
429 static int	carp_ioctl_setvh(struct carp_softc *, void *, struct ucred *);
430 static void	carp_ioctl_ifcap(struct carp_softc *, int);
431 static int	carp_ioctl_getvh(struct carp_softc *, void *, struct ucred *);
432 static int	carp_ioctl_getdevname(struct carp_softc *, struct ifdrv *);
433 static int	carp_ioctl_getvhaddr(struct carp_softc *, struct ifdrv *);
434 
435 static struct carp_if *carp_if_remove(struct carp_if *, struct carp_softc *);
436 static struct carp_if *carp_if_insert(struct carp_if *, struct carp_softc *);
437 static void	carp_if_free(struct carp_if *);
438 
439 static void	carp_ifaddr(void *, struct ifnet *, enum ifaddr_event,
440 			    struct ifaddr *);
441 static void	carp_ifdetach(void *, struct ifnet *);
442 
443 static void	carp_ifdetach_dispatch(netmsg_t);
444 static void	carp_clone_destroy_dispatch(netmsg_t);
445 static void	carp_init_dispatch(netmsg_t);
446 static void	carp_ioctl_stop_dispatch(netmsg_t);
447 static void	carp_ioctl_setvh_dispatch(netmsg_t);
448 static void	carp_ioctl_ifcap_dispatch(netmsg_t);
449 static void	carp_ioctl_getvh_dispatch(netmsg_t);
450 static void	carp_ioctl_getdevname_dispatch(netmsg_t);
451 static void	carp_ioctl_getvhaddr_dispatch(netmsg_t);
452 static void	carp_send_ad_timeout_dispatch(netmsg_t);
453 static void	carp_master_down_timeout_dispatch(netmsg_t);
454 
455 static MALLOC_DEFINE(M_CARP, "CARP", "CARP interfaces");
456 
457 static LIST_HEAD(, carp_softc) carpif_list;
458 
459 static struct if_clone carp_cloner =
460 IF_CLONE_INITIALIZER(CARP_IFNAME, carp_clone_create, carp_clone_destroy,
461 		     0, IF_MAXUNIT);
462 
463 static const uint8_t	carp_etheraddr[ETHER_ADDR_LEN] =
464 	{ 0, 0, 0x5e, 0, 1, 0 };
465 
466 static eventhandler_tag carp_ifdetach_event;
467 static eventhandler_tag carp_ifaddr_event;
468 
469 static __inline void
470 carp_insert_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha_new)
471 {
472 	struct carp_vhaddr *vha;
473 	u_long new_addr, addr;
474 
475 	KKASSERT((vha_new->vha_flags & CARP_VHAF_ONLIST) == 0);
476 
477 	/*
478 	 * Virtual address list is sorted; smaller one first
479 	 */
480 	new_addr = ntohl(vha_new->vha_ia->ia_addr.sin_addr.s_addr);
481 
482 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
483 		addr = ntohl(vha->vha_ia->ia_addr.sin_addr.s_addr);
484 
485 		if (addr > new_addr)
486 			break;
487 	}
488 	if (vha == NULL)
489 		TAILQ_INSERT_TAIL(&sc->sc_vha_list, vha_new, vha_link);
490 	else
491 		TAILQ_INSERT_BEFORE(vha, vha_new, vha_link);
492 	vha_new->vha_flags |= CARP_VHAF_ONLIST;
493 }
494 
495 static __inline void
496 carp_remove_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha)
497 {
498 	KKASSERT(vha->vha_flags & CARP_VHAF_ONLIST);
499 	vha->vha_flags &= ~CARP_VHAF_ONLIST;
500 	TAILQ_REMOVE(&sc->sc_vha_list, vha, vha_link);
501 }
502 
503 static void
504 carp_hmac_prepare(struct carp_softc *sc)
505 {
506 	uint8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
507 	uint8_t vhid = sc->sc_vhid & 0xff;
508 	int i;
509 #ifdef INET6
510 	struct ifaddr_container *ifac;
511 	struct in6_addr in6;
512 #endif
513 #ifdef INET
514 	struct carp_vhaddr *vha;
515 #endif
516 
517 	/* XXX: possible race here */
518 
519 	/* compute ipad from key */
520 	bzero(sc->sc_pad, sizeof(sc->sc_pad));
521 	bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
522 	for (i = 0; i < sizeof(sc->sc_pad); i++)
523 		sc->sc_pad[i] ^= 0x36;
524 
525 	/* precompute first part of inner hash */
526 	SHA1Init(&sc->sc_sha1);
527 	SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
528 	SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
529 	SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
530 	SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
531 #ifdef INET
532 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
533 		SHA1Update(&sc->sc_sha1,
534 		    (const uint8_t *)&vha->vha_ia->ia_addr.sin_addr,
535 		    sizeof(struct in_addr));
536 	}
537 #endif /* INET */
538 #ifdef INET6
539 	TAILQ_FOREACH(ifac, &sc->sc_if.if_addrheads[mycpuid], ifa_link) {
540 		struct ifaddr *ifa = ifac->ifa;
541 
542 		if (ifa->ifa_addr->sa_family == AF_INET6) {
543 			in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
544 			in6_clearscope(&in6);
545 			SHA1Update(&sc->sc_sha1, (void *)&in6, sizeof(in6));
546 		}
547 	}
548 #endif /* INET6 */
549 
550 	/* convert ipad to opad */
551 	for (i = 0; i < sizeof(sc->sc_pad); i++)
552 		sc->sc_pad[i] ^= 0x36 ^ 0x5c;
553 }
554 
555 static void
556 carp_hmac_generate(struct carp_softc *sc, uint32_t counter[2],
557     unsigned char md[20])
558 {
559 	SHA1_CTX sha1ctx;
560 
561 	/* fetch first half of inner hash */
562 	bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
563 
564 	SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
565 	SHA1Final(md, &sha1ctx);
566 
567 	/* outer hash */
568 	SHA1Init(&sha1ctx);
569 	SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
570 	SHA1Update(&sha1ctx, md, 20);
571 	SHA1Final(md, &sha1ctx);
572 }
573 
574 static int
575 carp_hmac_verify(struct carp_softc *sc, uint32_t counter[2],
576     unsigned char md[20])
577 {
578 	unsigned char md2[20];
579 
580 	carp_hmac_generate(sc, counter, md2);
581 	return (bcmp(md, md2, sizeof(md2)));
582 }
583 
584 static void
585 carp_setroute(struct carp_softc *sc, int cmd)
586 {
587 #ifdef INET6
588 	struct ifaddr_container *ifac;
589 #endif
590 	struct carp_vhaddr *vha;
591 
592 	KKASSERT(cmd == RTM_DELETE || cmd == RTM_ADD);
593 
594 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
595 		if (vha->vha_iaback == NULL)
596 			continue;
597 		if (cmd == RTM_DELETE)
598 			carp_delroute_vhaddr(sc, vha, FALSE);
599 		else
600 			carp_addroute_vhaddr(sc, vha);
601 	}
602 
603 #ifdef INET6
604 	TAILQ_FOREACH(ifac, &sc->sc_if.if_addrheads[mycpuid], ifa_link) {
605 		struct ifaddr *ifa = ifac->ifa;
606 
607 		if (ifa->ifa_addr->sa_family == AF_INET6) {
608 			if (cmd == RTM_ADD)
609 				in6_ifaddloop(ifa);
610 			else
611 				in6_ifremloop(ifa);
612 		}
613 	}
614 #endif /* INET6 */
615 }
616 
617 static int
618 carp_clone_create(struct if_clone *ifc, int unit, caddr_t param __unused)
619 {
620 	struct carp_softc *sc;
621 	struct ifnet *ifp;
622 
623 	sc = kmalloc(sizeof(*sc), M_CARP, M_WAITOK | M_ZERO);
624 	ifp = &sc->sc_if;
625 
626 	sc->sc_suppress = 0;
627 	sc->sc_advbase = CARP_DFLTINTV;
628 	sc->sc_vhid = -1;	/* required setting */
629 	sc->sc_advskew = 0;
630 	sc->sc_init_counter = 1;
631 	sc->sc_naddrs = 0;
632 	sc->sc_naddrs6 = 0;
633 
634 	TAILQ_INIT(&sc->sc_vha_list);
635 
636 #ifdef INET6
637 	sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
638 #endif
639 
640 	callout_init_mp(&sc->sc_ad_tmo);
641 	netmsg_init(&sc->sc_ad_msg.base, NULL, &netisr_adone_rport,
642 	    MSGF_DROPABLE | MSGF_PRIORITY, carp_send_ad_timeout_dispatch);
643 	sc->sc_ad_msg.nc_softc = sc;
644 
645 	callout_init_mp(&sc->sc_md_tmo);
646 	callout_init_mp(&sc->sc_md6_tmo);
647 	netmsg_init(&sc->sc_md_msg.base, NULL, &netisr_adone_rport,
648 	    MSGF_DROPABLE | MSGF_PRIORITY, carp_master_down_timeout_dispatch);
649 	sc->sc_md_msg.nc_softc = sc;
650 
651 	if_initname(ifp, CARP_IFNAME, unit);
652 	ifp->if_softc = sc;
653 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
654 	ifp->if_init = carp_init;
655 	ifp->if_ioctl = carp_ioctl;
656 	ifp->if_start = carp_start;
657 
658 	ifp->if_capabilities = IFCAP_TXCSUM | IFCAP_TSO;
659 	ifp->if_capenable = ifp->if_capabilities;
660 	/*
661 	 * Leave if_hwassist as it is; if_hwassist will be
662 	 * setup when this carp interface has parent.
663 	 */
664 
665 	ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
666 	ifq_set_ready(&ifp->if_snd);
667 
668 	ether_ifattach(ifp, carp_etheraddr, NULL);
669 
670 	ifp->if_type = IFT_CARP;
671 	ifp->if_output = carp_output;
672 
673 	lwkt_gettoken(&carp_listtok);
674 	LIST_INSERT_HEAD(&carpif_list, sc, sc_next);
675 	lwkt_reltoken(&carp_listtok);
676 
677 	return (0);
678 }
679 
680 static void
681 carp_clone_destroy_dispatch(netmsg_t msg)
682 {
683 	struct netmsg_carp *cmsg = (struct netmsg_carp *)msg;
684 	struct carp_softc *sc = cmsg->nc_softc;
685 
686 	sc->sc_dead = TRUE;
687 	carp_detach(sc, TRUE, FALSE);
688 
689 	callout_stop_sync(&sc->sc_ad_tmo);
690 	callout_stop_sync(&sc->sc_md_tmo);
691 	callout_stop_sync(&sc->sc_md6_tmo);
692 
693 	crit_enter();
694 	lwkt_dropmsg(&sc->sc_ad_msg.base.lmsg);
695 	lwkt_dropmsg(&sc->sc_md_msg.base.lmsg);
696 	crit_exit();
697 
698 	lwkt_replymsg(&cmsg->base.lmsg, 0);
699 }
700 
701 static int
702 carp_clone_destroy(struct ifnet *ifp)
703 {
704 	struct carp_softc *sc = ifp->if_softc;
705 	struct netmsg_carp cmsg;
706 
707 	bzero(&cmsg, sizeof(cmsg));
708 	netmsg_init(&cmsg.base, NULL, &curthread->td_msgport, 0,
709 	    carp_clone_destroy_dispatch);
710 	cmsg.nc_softc = sc;
711 
712 	lwkt_domsg(netisr_cpuport(0), &cmsg.base.lmsg, 0);
713 
714 	lwkt_gettoken(&carp_listtok);
715 	LIST_REMOVE(sc, sc_next);
716 	lwkt_reltoken(&carp_listtok);
717 
718 	bpfdetach(ifp);
719 	if_detach(ifp);
720 
721 	KASSERT(sc->sc_naddrs == 0, ("certain inet address is still active"));
722 	kfree(sc, M_CARP);
723 
724 	return 0;
725 }
726 
727 static struct carp_if *
728 carp_if_remove(struct carp_if *ocif, struct carp_softc *sc)
729 {
730 	struct carp_softc_container *oscc, *scc;
731 	struct carp_if *cif;
732 	int count = 0;
733 #ifdef INVARIANTS
734 	int found = 0;
735 #endif
736 
737 	TAILQ_FOREACH(oscc, ocif, scc_link) {
738 		++count;
739 #ifdef INVARIANTS
740 		if (oscc->scc_softc == sc)
741 			found = 1;
742 #endif
743 	}
744 	KASSERT(found, ("%s carp_softc is not on carp_if", __func__));
745 
746 	if (count == 1) {
747 		/* Last one is going to be unlinked */
748 		return NULL;
749 	}
750 
751 	cif = kmalloc(sizeof(*cif), M_CARP, M_WAITOK | M_ZERO);
752 	TAILQ_INIT(cif);
753 
754 	TAILQ_FOREACH(oscc, ocif, scc_link) {
755 		if (oscc->scc_softc == sc)
756 			continue;
757 
758 		scc = kmalloc(sizeof(*scc), M_CARP, M_WAITOK | M_ZERO);
759 		scc->scc_softc = oscc->scc_softc;
760 		TAILQ_INSERT_TAIL(cif, scc, scc_link);
761 	}
762 
763 	return cif;
764 }
765 
766 static struct carp_if *
767 carp_if_insert(struct carp_if *ocif, struct carp_softc *sc)
768 {
769 	struct carp_softc_container *oscc;
770 	int onlist;
771 
772 	onlist = 0;
773 	if (ocif != NULL) {
774 		TAILQ_FOREACH(oscc, ocif, scc_link) {
775 			if (oscc->scc_softc == sc)
776 				onlist = 1;
777 		}
778 	}
779 
780 #ifdef INVARIANTS
781 	if (sc->sc_carpdev != NULL) {
782 		KASSERT(onlist, ("%s is not on %s carp list",
783 		    sc->sc_if.if_xname, sc->sc_carpdev->if_xname));
784 	} else {
785 		KASSERT(!onlist, ("%s is already on carp list",
786 		    sc->sc_if.if_xname));
787 	}
788 #endif
789 
790 	if (!onlist) {
791 		struct carp_if *cif;
792 		struct carp_softc_container *new_scc, *scc;
793 		int inserted = 0;
794 
795 		cif = kmalloc(sizeof(*cif), M_CARP, M_WAITOK | M_ZERO);
796 		TAILQ_INIT(cif);
797 
798 		new_scc = kmalloc(sizeof(*new_scc), M_CARP, M_WAITOK | M_ZERO);
799 		new_scc->scc_softc = sc;
800 
801 		if (ocif != NULL) {
802 			TAILQ_FOREACH(oscc, ocif, scc_link) {
803 				if (!inserted &&
804 				    oscc->scc_softc->sc_vhid > sc->sc_vhid) {
805 					TAILQ_INSERT_TAIL(cif, new_scc,
806 					    scc_link);
807 					inserted = 1;
808 				}
809 
810 				scc = kmalloc(sizeof(*scc), M_CARP,
811 				    M_WAITOK | M_ZERO);
812 				scc->scc_softc = oscc->scc_softc;
813 				TAILQ_INSERT_TAIL(cif, scc, scc_link);
814 			}
815 		}
816 		if (!inserted)
817 			TAILQ_INSERT_TAIL(cif, new_scc, scc_link);
818 
819 		return cif;
820 	} else {
821 		return ocif;
822 	}
823 }
824 
825 static void
826 carp_if_free(struct carp_if *cif)
827 {
828 	struct carp_softc_container *scc;
829 
830 	while ((scc = TAILQ_FIRST(cif)) != NULL) {
831 		TAILQ_REMOVE(cif, scc, scc_link);
832 		kfree(scc, M_CARP);
833 	}
834 	kfree(cif, M_CARP);
835 }
836 
837 static void
838 carp_detach(struct carp_softc *sc, boolean_t detach, boolean_t del_iaback)
839 {
840 	carp_suspend(sc, detach);
841 
842 	carp_multicast_cleanup(sc);
843 #ifdef INET6
844 	carp_multicast6_cleanup(sc);
845 #endif
846 
847 	if (!sc->sc_dead && detach) {
848 		struct carp_vhaddr *vha;
849 
850 		TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link)
851 			carp_deactivate_vhaddr(sc, vha, del_iaback);
852 		KKASSERT(sc->sc_naddrs == 0);
853 	}
854 
855 	if (sc->sc_carpdev != NULL) {
856 		struct ifnet *ifp = sc->sc_carpdev;
857 		struct carp_if *ocif = ifp->if_carp;
858 
859 		ifp->if_carp = carp_if_remove(ocif, sc);
860 		KASSERT(ifp->if_carp != ocif,
861 		    ("%s carp_if_remove failed", __func__));
862 
863 		sc->sc_carpdev = NULL;
864 		sc->sc_ia = NULL;
865 		sc->arpcom.ac_if.if_hwassist = 0;
866 
867 		/*
868 		 * Make sure that all protocol threads see the
869 		 * sc_carpdev and if_carp changes
870 		 */
871 		netmsg_service_sync();
872 
873 		if (ifp->if_carp == NULL) {
874 			/*
875 			 * No more carp interfaces using
876 			 * ifp as the backing interface,
877 			 * move it out of promiscous mode.
878 			 */
879 			ifpromisc(ifp, 0);
880 		}
881 
882 		/*
883 		 * The old carp list could be safely free now,
884 		 * since no one can access it.
885 		 */
886 		carp_if_free(ocif);
887 	}
888 }
889 
890 static void
891 carp_ifdetach_dispatch(netmsg_t msg)
892 {
893 	struct netmsg_carp *cmsg = (struct netmsg_carp *)msg;
894 	struct ifnet *ifp = cmsg->nc_carpdev;
895 
896 	while (ifp->if_carp) {
897 		struct carp_softc_container *scc;
898 
899 		scc = TAILQ_FIRST((struct carp_if *)(ifp->if_carp));
900 		carp_detach(scc->scc_softc, TRUE, TRUE);
901 	}
902 	lwkt_replymsg(&cmsg->base.lmsg, 0);
903 }
904 
905 /* Detach an interface from the carp. */
906 static void
907 carp_ifdetach(void *arg __unused, struct ifnet *ifp)
908 {
909 	struct netmsg_carp cmsg;
910 
911 	ASSERT_IFNET_NOT_SERIALIZED_ALL(ifp);
912 
913 	bzero(&cmsg, sizeof(cmsg));
914 	netmsg_init(&cmsg.base, NULL, &curthread->td_msgport, 0,
915 	    carp_ifdetach_dispatch);
916 	cmsg.nc_carpdev = ifp;
917 
918 	lwkt_domsg(netisr_cpuport(0), &cmsg.base.lmsg, 0);
919 }
920 
921 /*
922  * process input packet.
923  * we have rearranged checks order compared to the rfc,
924  * but it seems more efficient this way or not possible otherwise.
925  */
926 int
927 carp_proto_input(struct mbuf **mp, int *offp, int proto)
928 {
929 	struct mbuf *m = *mp;
930 	struct ip *ip = mtod(m, struct ip *);
931 	struct ifnet *ifp = m->m_pkthdr.rcvif;
932 	struct carp_header *ch;
933 	struct carp_softc *sc;
934 	int len, iphlen;
935 
936 	iphlen = *offp;
937 	*mp = NULL;
938 
939 	carpstats.carps_ipackets++;
940 
941 	if (!carp_opts[CARPCTL_ALLOW]) {
942 		m_freem(m);
943 		goto back;
944 	}
945 
946 	/* Check if received on a valid carp interface */
947 	if (ifp->if_type != IFT_CARP) {
948 		carpstats.carps_badif++;
949 		CARP_LOG("carp_proto_input: packet received on non-carp "
950 		    "interface: %s\n", ifp->if_xname);
951 		m_freem(m);
952 		goto back;
953 	}
954 
955 	if (!CARP_IS_RUNNING(ifp)) {
956 		carpstats.carps_badif++;
957 		CARP_LOG("carp_proto_input: packet received on stopped carp "
958 		    "interface: %s\n", ifp->if_xname);
959 		m_freem(m);
960 		goto back;
961 	}
962 
963 	sc = ifp->if_softc;
964 	if (sc->sc_carpdev == NULL) {
965 		carpstats.carps_badif++;
966 		CARP_LOG("carp_proto_input: packet received on defunc carp "
967 		    "interface: %s\n", ifp->if_xname);
968 		m_freem(m);
969 		goto back;
970 	}
971 
972 	if (!IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
973 		carpstats.carps_badif++;
974 		CARP_LOG("carp_proto_input: non-mcast packet on "
975 		    "interface: %s\n", ifp->if_xname);
976 		m_freem(m);
977 		goto back;
978 	}
979 
980 	/* Verify that the IP TTL is CARP_DFLTTL. */
981 	if (ip->ip_ttl != CARP_DFLTTL) {
982 		carpstats.carps_badttl++;
983 		CARP_LOG("carp_proto_input: received ttl %d != %d on %s\n",
984 		    ip->ip_ttl, CARP_DFLTTL, ifp->if_xname);
985 		m_freem(m);
986 		goto back;
987 	}
988 
989 	/* Minimal CARP packet size */
990 	len = iphlen + sizeof(*ch);
991 
992 	/*
993 	 * Verify that the received packet length is
994 	 * not less than the CARP header
995 	 */
996 	if (m->m_pkthdr.len < len) {
997 		carpstats.carps_badlen++;
998 		CARP_LOG("packet too short %d on %s\n", m->m_pkthdr.len,
999 		    ifp->if_xname);
1000 		m_freem(m);
1001 		goto back;
1002 	}
1003 
1004 	/* Make sure that CARP header is contiguous */
1005 	if (len > m->m_len) {
1006 		m = m_pullup(m, len);
1007 		if (m == NULL) {
1008 			carpstats.carps_hdrops++;
1009 			CARP_LOG("carp_proto_input: m_pullup failed\n");
1010 			goto back;
1011 		}
1012 		ip = mtod(m, struct ip *);
1013 	}
1014 	ch = (struct carp_header *)((uint8_t *)ip + iphlen);
1015 
1016 	/* Verify the CARP checksum */
1017 	if (in_cksum_skip(m, len, iphlen)) {
1018 		carpstats.carps_badsum++;
1019 		CARP_LOG("carp_proto_input: checksum failed on %s\n",
1020 		    ifp->if_xname);
1021 		m_freem(m);
1022 		goto back;
1023 	}
1024 	carp_proto_input_c(sc, m, ch, AF_INET);
1025 back:
1026 	return(IPPROTO_DONE);
1027 }
1028 
1029 #ifdef INET6
1030 int
1031 carp6_proto_input(struct mbuf **mp, int *offp, int proto)
1032 {
1033 	struct mbuf *m = *mp;
1034 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1035 	struct ifnet *ifp = m->m_pkthdr.rcvif;
1036 	struct carp_header *ch;
1037 	struct carp_softc *sc;
1038 	u_int len;
1039 
1040 	carpstats.carps_ipackets6++;
1041 
1042 	if (!carp_opts[CARPCTL_ALLOW]) {
1043 		m_freem(m);
1044 		goto back;
1045 	}
1046 
1047 	/* check if received on a valid carp interface */
1048 	if (ifp->if_type != IFT_CARP) {
1049 		carpstats.carps_badif++;
1050 		CARP_LOG("carp6_proto_input: packet received on non-carp "
1051 		    "interface: %s\n", ifp->if_xname);
1052 		m_freem(m);
1053 		goto back;
1054 	}
1055 
1056 	if (!CARP_IS_RUNNING(ifp)) {
1057 		carpstats.carps_badif++;
1058 		CARP_LOG("carp_proto_input: packet received on stopped carp "
1059 		    "interface: %s\n", ifp->if_xname);
1060 		m_freem(m);
1061 		goto back;
1062 	}
1063 
1064 	sc = ifp->if_softc;
1065 	if (sc->sc_carpdev == NULL) {
1066 		carpstats.carps_badif++;
1067 		CARP_LOG("carp6_proto_input: packet received on defunc-carp "
1068 		    "interface: %s\n", ifp->if_xname);
1069 		m_freem(m);
1070 		goto back;
1071 	}
1072 
1073 	/* verify that the IP TTL is 255 */
1074 	if (ip6->ip6_hlim != CARP_DFLTTL) {
1075 		carpstats.carps_badttl++;
1076 		CARP_LOG("carp6_proto_input: received ttl %d != 255 on %s\n",
1077 		    ip6->ip6_hlim, ifp->if_xname);
1078 		m_freem(m);
1079 		goto back;
1080 	}
1081 
1082 	/* verify that we have a complete carp packet */
1083 	len = m->m_len;
1084 	IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
1085 	if (ch == NULL) {
1086 		carpstats.carps_badlen++;
1087 		CARP_LOG("carp6_proto_input: packet size %u too small\n", len);
1088 		goto back;
1089 	}
1090 
1091 	/* verify the CARP checksum */
1092 	if (in_cksum_range(m, 0, *offp, sizeof(*ch))) {
1093 		carpstats.carps_badsum++;
1094 		CARP_LOG("carp6_proto_input: checksum failed, on %s\n",
1095 		    ifp->if_xname);
1096 		m_freem(m);
1097 		goto back;
1098 	}
1099 
1100 	carp_proto_input_c(sc, m, ch, AF_INET6);
1101 back:
1102 	return (IPPROTO_DONE);
1103 }
1104 #endif /* INET6 */
1105 
1106 static void
1107 carp_proto_input_c(struct carp_softc *sc, struct mbuf *m,
1108     struct carp_header *ch, sa_family_t af)
1109 {
1110 	struct ifnet *cifp;
1111 	uint64_t tmp_counter;
1112 	struct timeval sc_tv, ch_tv;
1113 
1114 	if (sc->sc_vhid != ch->carp_vhid) {
1115 		/*
1116 		 * CARP uses multicast, however, multicast packets
1117 		 * are tapped to all CARP interfaces on the physical
1118 		 * interface receiving the CARP packets, so we don't
1119 		 * update any stats here.
1120 		 */
1121 		m_freem(m);
1122 		return;
1123 	}
1124 	cifp = &sc->sc_if;
1125 
1126 	/* verify the CARP version. */
1127 	if (ch->carp_version != CARP_VERSION) {
1128 		carpstats.carps_badver++;
1129 		CARP_LOG("%s; invalid version %d\n", cifp->if_xname,
1130 			 ch->carp_version);
1131 		m_freem(m);
1132 		return;
1133 	}
1134 
1135 	/* verify the hash */
1136 	if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
1137 		carpstats.carps_badauth++;
1138 		CARP_LOG("%s: incorrect hash\n", cifp->if_xname);
1139 		m_freem(m);
1140 		return;
1141 	}
1142 
1143 	tmp_counter = ntohl(ch->carp_counter[0]);
1144 	tmp_counter = tmp_counter<<32;
1145 	tmp_counter += ntohl(ch->carp_counter[1]);
1146 
1147 	/* XXX Replay protection goes here */
1148 
1149 	sc->sc_init_counter = 0;
1150 	sc->sc_counter = tmp_counter;
1151 
1152 	sc_tv.tv_sec = sc->sc_advbase;
1153 	if (carp_suppress_preempt && sc->sc_advskew <  240)
1154 		sc_tv.tv_usec = 240 * 1000000 / 256;
1155 	else
1156 		sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1157 	ch_tv.tv_sec = ch->carp_advbase;
1158 	ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
1159 
1160 	switch (sc->sc_state) {
1161 	case INIT:
1162 		break;
1163 
1164 	case MASTER:
1165 		/*
1166 		 * If we receive an advertisement from a master who's going to
1167 		 * be more frequent than us, go into BACKUP state.
1168 		 */
1169 		if (timevalcmp(&sc_tv, &ch_tv, >) ||
1170 		    timevalcmp(&sc_tv, &ch_tv, ==)) {
1171 			callout_stop(&sc->sc_ad_tmo);
1172 			CARP_DEBUG("%s: MASTER -> BACKUP "
1173 			   "(more frequent advertisement received)\n",
1174 			   cifp->if_xname);
1175 			carp_set_state(sc, BACKUP);
1176 			carp_setrun(sc, 0);
1177 			if (carp_opts[CARPCTL_SETROUTE])
1178 				carp_setroute(sc, RTM_DELETE);
1179 		}
1180 		break;
1181 
1182 	case BACKUP:
1183 		/*
1184 		 * If we're pre-empting masters who advertise slower than us,
1185 		 * and this one claims to be slower, treat him as down.
1186 		 */
1187 		if (carp_opts[CARPCTL_PREEMPT] &&
1188 		    timevalcmp(&sc_tv, &ch_tv, <)) {
1189 			CARP_DEBUG("%s: BACKUP -> MASTER "
1190 			    "(preempting a slower master)\n", cifp->if_xname);
1191 			carp_master_down(sc);
1192 			break;
1193 		}
1194 
1195 		/*
1196 		 *  If the master is going to advertise at such a low frequency
1197 		 *  that he's guaranteed to time out, we'd might as well just
1198 		 *  treat him as timed out now.
1199 		 */
1200 		sc_tv.tv_sec = sc->sc_advbase * 3;
1201 		if (timevalcmp(&sc_tv, &ch_tv, <)) {
1202 			CARP_DEBUG("%s: BACKUP -> MASTER (master timed out)\n",
1203 				   cifp->if_xname);
1204 			carp_master_down(sc);
1205 			break;
1206 		}
1207 
1208 		/*
1209 		 * Otherwise, we reset the counter and wait for the next
1210 		 * advertisement.
1211 		 */
1212 		carp_setrun(sc, af);
1213 		break;
1214 	}
1215 	m_freem(m);
1216 }
1217 
1218 struct mbuf *
1219 carp_input(void *v, struct mbuf *m)
1220 {
1221 	struct carp_if *cif = v;
1222 	struct ether_header *eh;
1223 	struct carp_softc_container *scc;
1224 	struct ifnet *ifp;
1225 
1226 	eh = mtod(m, struct ether_header *);
1227 
1228 	ifp = carp_forus(cif, eh->ether_dhost);
1229 	if (ifp != NULL) {
1230 		ether_reinput_oncpu(ifp, m, REINPUT_RUNBPF);
1231 		return NULL;
1232 	}
1233 
1234 	if ((m->m_flags & (M_BCAST | M_MCAST)) == 0)
1235 		return m;
1236 
1237 	/*
1238 	 * XXX Should really check the list of multicast addresses
1239 	 * for each CARP interface _before_ copying.
1240 	 */
1241 	TAILQ_FOREACH(scc, cif, scc_link) {
1242 		struct carp_softc *sc = scc->scc_softc;
1243 		struct mbuf *m0;
1244 
1245 		if ((sc->sc_if.if_flags & IFF_UP) == 0)
1246 			continue;
1247 
1248 		m0 = m_dup(m, M_NOWAIT);
1249 		if (m0 == NULL)
1250 			continue;
1251 
1252 		ether_reinput_oncpu(&sc->sc_if, m0, REINPUT_RUNBPF);
1253 	}
1254 	return m;
1255 }
1256 
1257 static void
1258 carp_prepare_ad(struct carp_softc *sc, struct carp_header *ch)
1259 {
1260 	if (sc->sc_init_counter) {
1261 		/* this could also be seconds since unix epoch */
1262 		sc->sc_counter = karc4random();
1263 		sc->sc_counter = sc->sc_counter << 32;
1264 		sc->sc_counter += karc4random();
1265 	} else {
1266 		sc->sc_counter++;
1267 	}
1268 
1269 	ch->carp_counter[0] = htonl((sc->sc_counter >> 32) & 0xffffffff);
1270 	ch->carp_counter[1] = htonl(sc->sc_counter & 0xffffffff);
1271 
1272 	carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
1273 }
1274 
1275 static void
1276 carp_send_ad_all(void)
1277 {
1278 	struct carp_softc *sc;
1279 
1280 	LIST_FOREACH(sc, &carpif_list, sc_next) {
1281 		if (sc->sc_carpdev == NULL)
1282 			continue;
1283 
1284 		if (CARP_IS_RUNNING(&sc->sc_if) && sc->sc_state == MASTER)
1285 			carp_send_ad(sc);
1286 	}
1287 }
1288 
1289 static void
1290 carp_send_ad_timeout(void *xsc)
1291 {
1292 	struct carp_softc *sc = xsc;
1293 	struct netmsg_carp *cmsg = &sc->sc_ad_msg;
1294 
1295 	KASSERT(mycpuid == 0, ("%s not on cpu0 but on cpu%d",
1296 	    __func__, mycpuid));
1297 
1298 	crit_enter();
1299 	if (cmsg->base.lmsg.ms_flags & MSGF_DONE)
1300 		lwkt_sendmsg_oncpu(netisr_cpuport(0), &cmsg->base.lmsg);
1301 	crit_exit();
1302 }
1303 
1304 static void
1305 carp_send_ad_timeout_dispatch(netmsg_t msg)
1306 {
1307 	struct netmsg_carp *cmsg = (struct netmsg_carp *)msg;
1308 	struct carp_softc *sc = cmsg->nc_softc;
1309 
1310 	/* Reply ASAP */
1311 	crit_enter();
1312 	lwkt_replymsg(&cmsg->base.lmsg, 0);
1313 	crit_exit();
1314 
1315 	carp_send_ad(sc);
1316 }
1317 
1318 static void
1319 carp_send_ad(struct carp_softc *sc)
1320 {
1321 	struct ifnet *cifp = &sc->sc_if;
1322 	struct carp_header ch;
1323 	struct timeval tv;
1324 	struct carp_header *ch_ptr;
1325 	struct mbuf *m;
1326 	int len, advbase, advskew;
1327 
1328 	if (!CARP_IS_RUNNING(cifp)) {
1329 		/* Bow out */
1330 		advbase = 255;
1331 		advskew = 255;
1332 	} else {
1333 		advbase = sc->sc_advbase;
1334 		if (!carp_suppress_preempt || sc->sc_advskew > 240)
1335 			advskew = sc->sc_advskew;
1336 		else
1337 			advskew = 240;
1338 		tv.tv_sec = advbase;
1339 		tv.tv_usec = advskew * 1000000 / 256;
1340 	}
1341 
1342 	ch.carp_version = CARP_VERSION;
1343 	ch.carp_type = CARP_ADVERTISEMENT;
1344 	ch.carp_vhid = sc->sc_vhid;
1345 	ch.carp_advbase = advbase;
1346 	ch.carp_advskew = advskew;
1347 	ch.carp_authlen = 7;	/* XXX DEFINE */
1348 	ch.carp_pad1 = 0;	/* must be zero */
1349 	ch.carp_cksum = 0;
1350 
1351 #ifdef INET
1352 	if (sc->sc_ia != NULL) {
1353 		struct ip *ip;
1354 
1355 		MGETHDR(m, M_NOWAIT, MT_HEADER);
1356 		if (m == NULL) {
1357 			IFNET_STAT_INC(cifp, oerrors, 1);
1358 			carpstats.carps_onomem++;
1359 			/* XXX maybe less ? */
1360 			if (advbase != 255 || advskew != 255)
1361 				callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
1362 				    carp_send_ad_timeout, sc);
1363 			return;
1364 		}
1365 		len = sizeof(*ip) + sizeof(ch);
1366 		m->m_pkthdr.len = len;
1367 		m->m_pkthdr.rcvif = NULL;
1368 		m->m_len = len;
1369 		MH_ALIGN(m, m->m_len);
1370 		m->m_flags |= M_MCAST;
1371 		if (carp_prio_ad)
1372 			m->m_flags |= M_PRIO;
1373 		ip = mtod(m, struct ip *);
1374 		ip->ip_v = IPVERSION;
1375 		ip->ip_hl = sizeof(*ip) >> 2;
1376 		ip->ip_tos = IPTOS_LOWDELAY;
1377 		ip->ip_len = len;
1378 		ip->ip_id = ip_newid();
1379 		ip->ip_off = IP_DF;
1380 		ip->ip_ttl = CARP_DFLTTL;
1381 		ip->ip_p = IPPROTO_CARP;
1382 		ip->ip_sum = 0;
1383 		ip->ip_src = sc->sc_ia->ia_addr.sin_addr;
1384 		ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
1385 
1386 		ch_ptr = (struct carp_header *)(&ip[1]);
1387 		bcopy(&ch, ch_ptr, sizeof(ch));
1388 		carp_prepare_ad(sc, ch_ptr);
1389 		ch_ptr->carp_cksum = in_cksum_skip(m, len, sizeof(*ip));
1390 
1391 		getmicrotime(&cifp->if_lastchange);
1392 		IFNET_STAT_INC(cifp, opackets, 1);
1393 		IFNET_STAT_INC(cifp, obytes, len);
1394 		carpstats.carps_opackets++;
1395 
1396 		if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL)) {
1397 			IFNET_STAT_INC(cifp, oerrors, 1);
1398 			if (sc->sc_sendad_errors < INT_MAX)
1399 				sc->sc_sendad_errors++;
1400 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1401 				carp_suppress_preempt++;
1402 				if (carp_suppress_preempt == 1) {
1403 					carp_send_ad_all();
1404 				}
1405 			}
1406 			sc->sc_sendad_success = 0;
1407 		} else {
1408 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1409 				if (++sc->sc_sendad_success >=
1410 				    CARP_SENDAD_MIN_SUCCESS) {
1411 					carp_suppress_preempt--;
1412 					sc->sc_sendad_errors = 0;
1413 				}
1414 			} else {
1415 				sc->sc_sendad_errors = 0;
1416 			}
1417 		}
1418 	}
1419 #endif /* INET */
1420 #ifdef INET6
1421 	if (sc->sc_ia6) {
1422 		struct ip6_hdr *ip6;
1423 
1424 		MGETHDR(m, M_NOWAIT, MT_HEADER);
1425 		if (m == NULL) {
1426 			IFNET_STAT_INC(cifp, oerrors, 1);
1427 			carpstats.carps_onomem++;
1428 			/* XXX maybe less ? */
1429 			if (advbase != 255 || advskew != 255)
1430 				callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
1431 				    carp_send_ad_timeout, sc);
1432 			return;
1433 		}
1434 		len = sizeof(*ip6) + sizeof(ch);
1435 		m->m_pkthdr.len = len;
1436 		m->m_pkthdr.rcvif = NULL;
1437 		m->m_len = len;
1438 		MH_ALIGN(m, m->m_len);
1439 		m->m_flags |= M_MCAST;
1440 		ip6 = mtod(m, struct ip6_hdr *);
1441 		bzero(ip6, sizeof(*ip6));
1442 		ip6->ip6_vfc |= IPV6_VERSION;
1443 		ip6->ip6_hlim = CARP_DFLTTL;
1444 		ip6->ip6_nxt = IPPROTO_CARP;
1445 		bcopy(&sc->sc_ia6->ia_addr.sin6_addr, &ip6->ip6_src,
1446 		    sizeof(struct in6_addr));
1447 		/* set the multicast destination */
1448 
1449 		ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
1450 		ip6->ip6_dst.s6_addr8[15] = 0x12;
1451 		if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1452 			IFNET_STAT_INC(cifp, oerrors, 1);
1453 			m_freem(m);
1454 			CARP_LOG("%s: in6_setscope failed\n", __func__);
1455 			return;
1456 		}
1457 
1458 		ch_ptr = (struct carp_header *)(&ip6[1]);
1459 		bcopy(&ch, ch_ptr, sizeof(ch));
1460 		carp_prepare_ad(sc, ch_ptr);
1461 		ch_ptr->carp_cksum = in_cksum_skip(m, len, sizeof(*ip6));
1462 
1463 		getmicrotime(&cifp->if_lastchange);
1464 		IFNET_STAT_INC(cifp, opackets, 1);
1465 		IFNET_STAT_INC(cifp, obytes, len);
1466 		carpstats.carps_opackets6++;
1467 
1468 		if (ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL)) {
1469 			IFNET_STAT_INC(cifp, oerrors, 1);
1470 			if (sc->sc_sendad_errors < INT_MAX)
1471 				sc->sc_sendad_errors++;
1472 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1473 				carp_suppress_preempt++;
1474 				if (carp_suppress_preempt == 1) {
1475 					carp_send_ad_all();
1476 				}
1477 			}
1478 			sc->sc_sendad_success = 0;
1479 		} else {
1480 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1481 				if (++sc->sc_sendad_success >=
1482 				    CARP_SENDAD_MIN_SUCCESS) {
1483 					carp_suppress_preempt--;
1484 					sc->sc_sendad_errors = 0;
1485 				}
1486 			} else {
1487 				sc->sc_sendad_errors = 0;
1488 			}
1489 		}
1490 	}
1491 #endif /* INET6 */
1492 
1493 	if (advbase != 255 || advskew != 255)
1494 		callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
1495 		    carp_send_ad_timeout, sc);
1496 }
1497 
1498 /*
1499  * Broadcast a gratuitous ARP request containing
1500  * the virtual router MAC address for each IP address
1501  * associated with the virtual router.
1502  */
1503 static void
1504 carp_send_arp(struct carp_softc *sc)
1505 {
1506 	const struct carp_vhaddr *vha;
1507 
1508 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
1509 		if (vha->vha_iaback == NULL)
1510 			continue;
1511 		arp_gratuitous(&sc->sc_if, &vha->vha_ia->ia_ifa);
1512 	}
1513 }
1514 
1515 #ifdef INET6
1516 static void
1517 carp_send_na(struct carp_softc *sc)
1518 {
1519 	struct ifaddr_container *ifac;
1520 	struct in6_addr *in6;
1521 	static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1522 
1523 	TAILQ_FOREACH(ifac, &sc->sc_if.if_addrheads[mycpuid], ifa_link) {
1524 		struct ifaddr *ifa = ifac->ifa;
1525 
1526 		if (ifa->ifa_addr->sa_family != AF_INET6)
1527 			continue;
1528 
1529 		in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1530 		nd6_na_output(sc->sc_carpdev, &mcast, in6,
1531 		    ND_NA_FLAG_OVERRIDE, 1, NULL);
1532 		DELAY(1000);	/* XXX */
1533 	}
1534 }
1535 #endif /* INET6 */
1536 
1537 static __inline const struct carp_vhaddr *
1538 carp_find_addr(const struct carp_softc *sc, const struct in_addr *addr)
1539 {
1540 	struct carp_vhaddr *vha;
1541 
1542 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
1543 		if (vha->vha_iaback == NULL)
1544 			continue;
1545 
1546 		if (vha->vha_ia->ia_addr.sin_addr.s_addr == addr->s_addr)
1547 			return vha;
1548 	}
1549 	return NULL;
1550 }
1551 
1552 #ifdef notyet
1553 static int
1554 carp_iamatch_balance(const struct carp_if *cif, const struct in_addr *itaddr,
1555 		     const struct in_addr *isaddr, uint8_t **enaddr)
1556 {
1557 	const struct carp_softc *vh;
1558 	int index, count = 0;
1559 
1560 	/*
1561 	 * XXX proof of concept implementation.
1562 	 * We use the source ip to decide which virtual host should
1563 	 * handle the request. If we're master of that virtual host,
1564 	 * then we respond, otherwise, just drop the arp packet on
1565 	 * the floor.
1566 	 */
1567 
1568 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1569 		if (!CARP_IS_RUNNING(&vh->sc_if))
1570 			continue;
1571 
1572 		if (carp_find_addr(vh, itaddr) != NULL)
1573 			count++;
1574 	}
1575 	if (count == 0)
1576 		return 0;
1577 
1578 	/* this should be a hash, like pf_hash() */
1579 	index = ntohl(isaddr->s_addr) % count;
1580 	count = 0;
1581 
1582 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1583 		if (!CARP_IS_RUNNING(&vh->sc_if))
1584 			continue;
1585 
1586 		if (carp_find_addr(vh, itaddr) == NULL)
1587 			continue;
1588 
1589 		if (count == index) {
1590 			if (vh->sc_state == MASTER) {
1591 				*enaddr = IF_LLADDR(&vh->sc_if);
1592 				return 1;
1593 			} else {
1594 				return 0;
1595 			}
1596 		}
1597 		count++;
1598 	}
1599 	return 0;
1600 }
1601 #endif
1602 
1603 int
1604 carp_iamatch(const struct in_ifaddr *ia)
1605 {
1606 	const struct carp_softc *sc = ia->ia_ifp->if_softc;
1607 
1608 	ASSERT_NETISR0;
1609 
1610 #ifdef notyet
1611 	if (carp_opts[CARPCTL_ARPBALANCE])
1612 		return carp_iamatch_balance(cif, itaddr, isaddr, enaddr);
1613 #endif
1614 
1615 	if (!CARP_IS_RUNNING(&sc->sc_if) || sc->sc_state != MASTER)
1616 		return 0;
1617 
1618 	return 1;
1619 }
1620 
1621 #ifdef INET6
1622 struct ifaddr *
1623 carp_iamatch6(void *v, struct in6_addr *taddr)
1624 {
1625 #ifdef foo
1626 	struct carp_if *cif = v;
1627 	struct carp_softc *vh;
1628 
1629 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1630 		struct ifaddr_container *ifac;
1631 
1632 		TAILQ_FOREACH(ifac, &vh->sc_if.if_addrheads[mycpuid],
1633 			      ifa_link) {
1634 			struct ifaddr *ifa = ifac->ifa;
1635 
1636 			if (IN6_ARE_ADDR_EQUAL(taddr,
1637 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1638 			    CARP_IS_RUNNING(&vh->sc_if) &&
1639 			    vh->sc_state == MASTER) {
1640 				return (ifa);
1641 			}
1642 		}
1643 	}
1644 #endif
1645 	return (NULL);
1646 }
1647 
1648 void *
1649 carp_macmatch6(void *v, struct mbuf *m, const struct in6_addr *taddr)
1650 {
1651 #ifdef foo
1652 	struct m_tag *mtag;
1653 	struct carp_if *cif = v;
1654 	struct carp_softc *sc;
1655 
1656 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
1657 		struct ifaddr_container *ifac;
1658 
1659 		TAILQ_FOREACH(ifac, &sc->sc_if.if_addrheads[mycpuid],
1660 			      ifa_link) {
1661 			struct ifaddr *ifa = ifac->ifa;
1662 
1663 			if (IN6_ARE_ADDR_EQUAL(taddr,
1664 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1665 			    CARP_IS_RUNNING(&sc->sc_if)) {
1666 				struct ifnet *ifp = &sc->sc_if;
1667 
1668 				mtag = m_tag_get(PACKET_TAG_CARP,
1669 				    sizeof(struct ifnet *), M_NOWAIT);
1670 				if (mtag == NULL) {
1671 					/* better a bit than nothing */
1672 					return (IF_LLADDR(ifp));
1673 				}
1674 				bcopy(&ifp, (caddr_t)(mtag + 1),
1675 				    sizeof(struct ifnet *));
1676 				m_tag_prepend(m, mtag);
1677 
1678 				return (IF_LLADDR(ifp));
1679 			}
1680 		}
1681 	}
1682 #endif
1683 	return (NULL);
1684 }
1685 #endif
1686 
1687 static struct ifnet *
1688 carp_forus(struct carp_if *cif, const uint8_t *dhost)
1689 {
1690 	struct carp_softc_container *scc;
1691 
1692 	if (memcmp(dhost, carp_etheraddr, ETHER_ADDR_LEN - 1) != 0)
1693 		return NULL;
1694 
1695 	TAILQ_FOREACH(scc, cif, scc_link) {
1696 		struct carp_softc *sc = scc->scc_softc;
1697 		struct ifnet *ifp = &sc->sc_if;
1698 
1699 		if (CARP_IS_RUNNING(ifp) && sc->sc_state == MASTER &&
1700 		    !bcmp(dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN))
1701 			return ifp;
1702 	}
1703 	return NULL;
1704 }
1705 
1706 static void
1707 carp_master_down_timeout(void *xsc)
1708 {
1709 	struct carp_softc *sc = xsc;
1710 	struct netmsg_carp *cmsg = &sc->sc_md_msg;
1711 
1712 	KASSERT(mycpuid == 0, ("%s not on cpu0 but on cpu%d",
1713 	    __func__, mycpuid));
1714 
1715 	crit_enter();
1716 	if (cmsg->base.lmsg.ms_flags & MSGF_DONE)
1717 		lwkt_sendmsg_oncpu(netisr_cpuport(0), &cmsg->base.lmsg);
1718 	crit_exit();
1719 }
1720 
1721 static void
1722 carp_master_down_timeout_dispatch(netmsg_t msg)
1723 {
1724 	struct netmsg_carp *cmsg = (struct netmsg_carp *)msg;
1725 	struct carp_softc *sc = cmsg->nc_softc;
1726 
1727 	/* Reply ASAP */
1728 	crit_enter();
1729 	lwkt_replymsg(&cmsg->base.lmsg, 0);
1730 	crit_exit();
1731 
1732 	CARP_DEBUG("%s: BACKUP -> MASTER (master timed out)\n",
1733 		   sc->sc_if.if_xname);
1734 	carp_master_down(sc);
1735 }
1736 
1737 static void
1738 carp_master_down(struct carp_softc *sc)
1739 {
1740 	switch (sc->sc_state) {
1741 	case INIT:
1742 		kprintf("%s: master_down event in INIT state\n",
1743 			sc->sc_if.if_xname);
1744 		break;
1745 
1746 	case MASTER:
1747 		break;
1748 
1749 	case BACKUP:
1750 		carp_set_state(sc, MASTER);
1751 		carp_send_ad(sc);
1752 		carp_send_arp(sc);
1753 #ifdef INET6
1754 		carp_send_na(sc);
1755 #endif /* INET6 */
1756 		carp_setrun(sc, 0);
1757 		if (carp_opts[CARPCTL_SETROUTE])
1758 			carp_setroute(sc, RTM_ADD);
1759 		break;
1760 	}
1761 }
1762 
1763 /*
1764  * When in backup state, af indicates whether to reset the master down timer
1765  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1766  */
1767 static void
1768 carp_setrun(struct carp_softc *sc, sa_family_t af)
1769 {
1770 	struct ifnet *cifp = &sc->sc_if;
1771 	struct timeval tv;
1772 
1773 	if (sc->sc_carpdev == NULL) {
1774 		carp_set_state(sc, INIT);
1775 		return;
1776 	}
1777 
1778 	if ((cifp->if_flags & IFF_RUNNING) && sc->sc_vhid > 0 &&
1779 	    (sc->sc_naddrs || sc->sc_naddrs6)) {
1780 		/* Nothing */
1781 	} else {
1782 		if (carp_opts[CARPCTL_SETROUTE])
1783 			carp_setroute(sc, RTM_DELETE);
1784 		return;
1785 	}
1786 
1787 	switch (sc->sc_state) {
1788 	case INIT:
1789 		if (carp_opts[CARPCTL_PREEMPT] && !carp_suppress_preempt) {
1790 			carp_send_ad(sc);
1791 			carp_send_arp(sc);
1792 #ifdef INET6
1793 			carp_send_na(sc);
1794 #endif /* INET6 */
1795 			CARP_DEBUG("%s: INIT -> MASTER (preempting)\n",
1796 				   cifp->if_xname);
1797 			carp_set_state(sc, MASTER);
1798 			if (carp_opts[CARPCTL_SETROUTE])
1799 				carp_setroute(sc, RTM_ADD);
1800 		} else {
1801 			CARP_DEBUG("%s: INIT -> BACKUP\n", cifp->if_xname);
1802 			carp_set_state(sc, BACKUP);
1803 			if (carp_opts[CARPCTL_SETROUTE])
1804 				carp_setroute(sc, RTM_DELETE);
1805 			carp_setrun(sc, 0);
1806 		}
1807 		break;
1808 
1809 	case BACKUP:
1810 		callout_stop(&sc->sc_ad_tmo);
1811 		tv.tv_sec = 3 * sc->sc_advbase;
1812 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1813 		switch (af) {
1814 #ifdef INET
1815 		case AF_INET:
1816 			callout_reset(&sc->sc_md_tmo, tvtohz_high(&tv),
1817 			    carp_master_down_timeout, sc);
1818 			break;
1819 #endif /* INET */
1820 #ifdef INET6
1821 		case AF_INET6:
1822 			callout_reset(&sc->sc_md6_tmo, tvtohz_high(&tv),
1823 			    carp_master_down_timeout, sc);
1824 			break;
1825 #endif /* INET6 */
1826 		default:
1827 			if (sc->sc_naddrs)
1828 				callout_reset(&sc->sc_md_tmo, tvtohz_high(&tv),
1829 				    carp_master_down_timeout, sc);
1830 			if (sc->sc_naddrs6)
1831 				callout_reset(&sc->sc_md6_tmo, tvtohz_high(&tv),
1832 				    carp_master_down_timeout, sc);
1833 			break;
1834 		}
1835 		break;
1836 
1837 	case MASTER:
1838 		tv.tv_sec = sc->sc_advbase;
1839 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1840 		callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
1841 		    carp_send_ad_timeout, sc);
1842 		break;
1843 	}
1844 }
1845 
1846 static void
1847 carp_multicast_cleanup(struct carp_softc *sc)
1848 {
1849 	struct ip_moptions *imo = &sc->sc_imo;
1850 
1851 	if (imo->imo_num_memberships == 0)
1852 		return;
1853 	KKASSERT(imo->imo_num_memberships == 1);
1854 
1855 	in_delmulti(imo->imo_membership[0]);
1856 	imo->imo_membership[0] = NULL;
1857 	imo->imo_num_memberships = 0;
1858 	imo->imo_multicast_ifp = NULL;
1859 }
1860 
1861 #ifdef INET6
1862 static void
1863 carp_multicast6_cleanup(struct carp_softc *sc)
1864 {
1865 	struct ip6_moptions *im6o = &sc->sc_im6o;
1866 
1867 	while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1868 		struct in6_multi_mship *imm =
1869 		    LIST_FIRST(&im6o->im6o_memberships);
1870 
1871 		LIST_REMOVE(imm, i6mm_chain);
1872 		in6_leavegroup(imm);
1873 	}
1874 	im6o->im6o_multicast_ifp = NULL;
1875 }
1876 #endif
1877 
1878 static void
1879 carp_ioctl_getvhaddr_dispatch(netmsg_t msg)
1880 {
1881 	struct netmsg_carp *cmsg = (struct netmsg_carp *)msg;
1882 	struct carp_softc *sc = cmsg->nc_softc;
1883 	const struct carp_vhaddr *vha;
1884 	struct ifcarpvhaddr *carpa, *carpa0;
1885 	int count, len, error = 0;
1886 
1887 	count = 0;
1888 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link)
1889 		++count;
1890 
1891 	if (cmsg->nc_datalen == 0) {
1892 		cmsg->nc_datalen = count * sizeof(*carpa);
1893 		goto back;
1894 	} else if (count == 0 || cmsg->nc_datalen < sizeof(*carpa)) {
1895 		cmsg->nc_datalen = 0;
1896 		goto back;
1897 	}
1898 	len = min(cmsg->nc_datalen, sizeof(*carpa) * count);
1899 	KKASSERT(len >= sizeof(*carpa));
1900 
1901 	carpa0 = carpa = kmalloc(len, M_TEMP, M_WAITOK | M_NULLOK | M_ZERO);
1902 	if (carpa == NULL) {
1903 		error = ENOMEM;
1904 		goto back;
1905 	}
1906 
1907 	count = 0;
1908 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
1909 		if (len < sizeof(*carpa))
1910 			break;
1911 
1912 		carpa->carpa_flags = vha->vha_flags;
1913 		carpa->carpa_addr.sin_family = AF_INET;
1914 		carpa->carpa_addr.sin_addr = vha->vha_ia->ia_addr.sin_addr;
1915 
1916 		carpa->carpa_baddr.sin_family = AF_INET;
1917 		if (vha->vha_iaback == NULL) {
1918 			carpa->carpa_baddr.sin_addr.s_addr = INADDR_ANY;
1919 		} else {
1920 			carpa->carpa_baddr.sin_addr =
1921 			vha->vha_iaback->ia_addr.sin_addr;
1922 		}
1923 
1924 		++carpa;
1925 		++count;
1926 		len -= sizeof(*carpa);
1927 	}
1928 	cmsg->nc_datalen = sizeof(*carpa) * count;
1929 	KKASSERT(cmsg->nc_datalen > 0);
1930 
1931 	cmsg->nc_data = carpa0;
1932 
1933 back:
1934 	lwkt_replymsg(&cmsg->base.lmsg, error);
1935 }
1936 
1937 static int
1938 carp_ioctl_getvhaddr(struct carp_softc *sc, struct ifdrv *ifd)
1939 {
1940 	struct ifnet *ifp = &sc->arpcom.ac_if;
1941 	struct netmsg_carp cmsg;
1942 	int error;
1943 
1944 	ASSERT_IFNET_SERIALIZED_ALL(ifp);
1945 	ifnet_deserialize_all(ifp);
1946 
1947 	bzero(&cmsg, sizeof(cmsg));
1948 	netmsg_init(&cmsg.base, NULL, &curthread->td_msgport, 0,
1949 	    carp_ioctl_getvhaddr_dispatch);
1950 	cmsg.nc_softc = sc;
1951 	cmsg.nc_datalen = ifd->ifd_len;
1952 
1953 	error = lwkt_domsg(netisr_cpuport(0), &cmsg.base.lmsg, 0);
1954 
1955 	if (!error) {
1956 		if (cmsg.nc_data != NULL) {
1957 			error = copyout(cmsg.nc_data, ifd->ifd_data,
1958 			    cmsg.nc_datalen);
1959 			kfree(cmsg.nc_data, M_TEMP);
1960 		}
1961 		ifd->ifd_len = cmsg.nc_datalen;
1962 	} else {
1963 		KASSERT(cmsg.nc_data == NULL,
1964 		    ("%s temp vhaddr is alloc upon error", __func__));
1965 	}
1966 
1967 	ifnet_serialize_all(ifp);
1968 	return error;
1969 }
1970 
1971 static int
1972 carp_config_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha,
1973     struct in_ifaddr *ia_del)
1974 {
1975 	struct ifnet *ifp;
1976 	struct in_ifaddr *ia_if;
1977 	const struct in_ifaddr *ia_vha;
1978 	struct in_ifaddr_container *iac;
1979 	int own, ia_match_carpdev;
1980 
1981 	KKASSERT(vha->vha_ia != NULL);
1982 	ia_vha = vha->vha_ia;
1983 
1984 	ia_if = NULL;
1985 	own = 0;
1986 	ia_match_carpdev = 0;
1987 	TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
1988 		struct in_ifaddr *ia = iac->ia;
1989 
1990 		if (ia == ia_del)
1991 			continue;
1992 
1993 		if (ia->ia_ifp->if_type == IFT_CARP)
1994 			continue;
1995 
1996 		if ((ia->ia_ifp->if_flags & IFF_UP) == 0)
1997 			continue;
1998 
1999 		/* and, yeah, we need a multicast-capable iface too */
2000 		if ((ia->ia_ifp->if_flags & IFF_MULTICAST) == 0)
2001 			continue;
2002 
2003 		if (ia_vha->ia_subnetmask == ia->ia_subnetmask &&
2004 		    ia_vha->ia_subnet == ia->ia_subnet) {
2005 			if (ia_vha->ia_addr.sin_addr.s_addr ==
2006 			    ia->ia_addr.sin_addr.s_addr)
2007 				own = 1;
2008 			if (ia_if == NULL) {
2009 				ia_if = ia;
2010 			} else if (sc->sc_carpdev != NULL &&
2011 			    sc->sc_carpdev == ia->ia_ifp) {
2012 				ia_if = ia;
2013 				if (ia_if->ia_flags & IFA_ROUTE) {
2014 					/*
2015 					 * Address with prefix route
2016 					 * is prefered
2017 					 */
2018 					break;
2019 				}
2020 				ia_match_carpdev = 1;
2021 			} else if (!ia_match_carpdev) {
2022 				if (ia->ia_flags & IFA_ROUTE) {
2023 					/*
2024 					 * Address with prefix route
2025 					 * is prefered over others.
2026 					 */
2027 					ia_if = ia;
2028 				}
2029 			}
2030 		}
2031 	}
2032 
2033 	carp_deactivate_vhaddr(sc, vha, FALSE);
2034 	if (!ia_if)
2035 		return ENOENT;
2036 
2037 	ifp = ia_if->ia_ifp;
2038 
2039 	/* XXX Don't allow parent iface to be changed */
2040 	if (sc->sc_carpdev != NULL && sc->sc_carpdev != ifp)
2041 		return EEXIST;
2042 
2043 	return carp_activate_vhaddr(sc, vha, ifp, ia_if, own);
2044 }
2045 
2046 static void
2047 carp_add_addr(struct carp_softc *sc, struct ifaddr *carp_ifa)
2048 {
2049 	struct carp_vhaddr *vha_new;
2050 	struct in_ifaddr *carp_ia;
2051 #ifdef INVARIANTS
2052 	struct carp_vhaddr *vha;
2053 #endif
2054 
2055 	KKASSERT(carp_ifa->ifa_addr->sa_family == AF_INET);
2056 	carp_ia = ifatoia(carp_ifa);
2057 
2058 #ifdef INVARIANTS
2059 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link)
2060 		KKASSERT(vha->vha_ia != NULL && vha->vha_ia != carp_ia);
2061 #endif
2062 
2063 	vha_new = kmalloc(sizeof(*vha_new), M_CARP, M_WAITOK | M_ZERO);
2064 	vha_new->vha_ia = carp_ia;
2065 	carp_insert_vhaddr(sc, vha_new);
2066 
2067 	if (carp_config_vhaddr(sc, vha_new, NULL) != 0) {
2068 		/*
2069 		 * If the above configuration fails, it may only mean
2070 		 * that the new address is problematic.  However, the
2071 		 * carp(4) interface may already have several working
2072 		 * addresses.  Since the expected behaviour of
2073 		 * SIOC[AS]IFADDR is to put the NIC into working state,
2074 		 * we try starting the state machine manually here with
2075 		 * the hope that the carp(4)'s previously working
2076 		 * addresses still could be brought up.
2077 		 */
2078 		carp_hmac_prepare(sc);
2079 		carp_set_state(sc, INIT);
2080 		carp_setrun(sc, 0);
2081 	}
2082 }
2083 
2084 static void
2085 carp_del_addr(struct carp_softc *sc, struct ifaddr *carp_ifa)
2086 {
2087 	struct carp_vhaddr *vha;
2088 	struct in_ifaddr *carp_ia;
2089 
2090 	KKASSERT(carp_ifa->ifa_addr->sa_family == AF_INET);
2091 	carp_ia = ifatoia(carp_ifa);
2092 
2093 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
2094 		KKASSERT(vha->vha_ia != NULL);
2095 		if (vha->vha_ia == carp_ia)
2096 			break;
2097 	}
2098 	KASSERT(vha != NULL, ("no corresponding vhaddr %p", carp_ifa));
2099 
2100 	/*
2101 	 * Remove the vhaddr from the list before deactivating
2102 	 * the vhaddr, so that the HMAC could be correctly
2103 	 * updated in carp_deactivate_vhaddr()
2104 	 */
2105 	carp_remove_vhaddr(sc, vha);
2106 
2107 	carp_deactivate_vhaddr(sc, vha, FALSE);
2108 	kfree(vha, M_CARP);
2109 }
2110 
2111 static void
2112 carp_config_addr(struct carp_softc *sc, struct ifaddr *carp_ifa)
2113 {
2114 	struct carp_vhaddr *vha;
2115 	struct in_ifaddr *carp_ia;
2116 
2117 	KKASSERT(carp_ifa->ifa_addr->sa_family == AF_INET);
2118 	carp_ia = ifatoia(carp_ifa);
2119 
2120 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
2121 		KKASSERT(vha->vha_ia != NULL);
2122 		if (vha->vha_ia == carp_ia)
2123 			break;
2124 	}
2125 	KASSERT(vha != NULL, ("no corresponding vhaddr %p", carp_ifa));
2126 
2127 	/* Remove then reinsert, to keep the vhaddr list sorted */
2128 	carp_remove_vhaddr(sc, vha);
2129 	carp_insert_vhaddr(sc, vha);
2130 
2131 	if (carp_config_vhaddr(sc, vha, NULL) != 0) {
2132 		/* See the comment in carp_add_addr() */
2133 		carp_hmac_prepare(sc);
2134 		carp_set_state(sc, INIT);
2135 		carp_setrun(sc, 0);
2136 	}
2137 }
2138 
2139 #ifdef notyet
2140 
2141 #ifdef INET6
2142 static int
2143 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
2144 {
2145 	struct ifnet *ifp;
2146 	struct carp_if *cif;
2147 	struct in6_ifaddr *ia, *ia_if;
2148 	struct ip6_moptions *im6o = &sc->sc_im6o;
2149 	struct in6_multi_mship *imm;
2150 	struct in6_addr in6;
2151 	int own, error;
2152 
2153 	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
2154 		carp_setrun(sc, 0);
2155 		return (0);
2156 	}
2157 
2158 	/* we have to do it by hands to check we won't match on us */
2159 	ia_if = NULL; own = 0;
2160 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
2161 		int i;
2162 
2163 		for (i = 0; i < 4; i++) {
2164 			if ((sin6->sin6_addr.s6_addr32[i] &
2165 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
2166 			    (ia->ia_addr.sin6_addr.s6_addr32[i] &
2167 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
2168 				break;
2169 		}
2170 		/* and, yeah, we need a multicast-capable iface too */
2171 		if (ia->ia_ifp != &sc->sc_if &&
2172 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
2173 		    (i == 4)) {
2174 			if (!ia_if)
2175 				ia_if = ia;
2176 			if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr,
2177 			    &ia->ia_addr.sin6_addr))
2178 				own++;
2179 		}
2180 	}
2181 
2182 	if (!ia_if)
2183 		return (EADDRNOTAVAIL);
2184 	ia = ia_if;
2185 	ifp = ia->ia_ifp;
2186 
2187 	if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
2188 	    (im6o->im6o_multicast_ifp && im6o->im6o_multicast_ifp != ifp))
2189 		return (EADDRNOTAVAIL);
2190 
2191 	if (!sc->sc_naddrs6) {
2192 		im6o->im6o_multicast_ifp = ifp;
2193 
2194 		/* join CARP multicast address */
2195 		bzero(&in6, sizeof(in6));
2196 		in6.s6_addr16[0] = htons(0xff02);
2197 		in6.s6_addr8[15] = 0x12;
2198 		if (in6_setscope(&in6, ifp, NULL) != 0)
2199 			goto cleanup;
2200 		if ((imm = in6_joingroup(ifp, &in6, &error)) == NULL)
2201 			goto cleanup;
2202 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
2203 
2204 		/* join solicited multicast address */
2205 		bzero(&in6, sizeof(in6));
2206 		in6.s6_addr16[0] = htons(0xff02);
2207 		in6.s6_addr32[1] = 0;
2208 		in6.s6_addr32[2] = htonl(1);
2209 		in6.s6_addr32[3] = sin6->sin6_addr.s6_addr32[3];
2210 		in6.s6_addr8[12] = 0xff;
2211 		if (in6_setscope(&in6, ifp, NULL) != 0)
2212 			goto cleanup;
2213 		if ((imm = in6_joingroup(ifp, &in6, &error)) == NULL)
2214 			goto cleanup;
2215 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
2216 	}
2217 
2218 #ifdef foo
2219 	if (!ifp->if_carp) {
2220 		cif = kmalloc(sizeof(*cif), M_CARP, M_WAITOK | M_ZERO);
2221 
2222 		if ((error = ifpromisc(ifp, 1))) {
2223 			kfree(cif, M_CARP);
2224 			goto cleanup;
2225 		}
2226 
2227 		TAILQ_INIT(&cif->vhif_vrs);
2228 		ifp->if_carp = cif;
2229 	} else {
2230 		struct carp_softc *vr;
2231 
2232 		cif = ifp->if_carp;
2233 		TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
2234 			if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
2235 				error = EINVAL;
2236 				goto cleanup;
2237 			}
2238 		}
2239 	}
2240 #endif
2241 	sc->sc_ia6 = ia;
2242 	sc->sc_carpdev = ifp;
2243 
2244 #ifdef foo
2245 	{ /* XXX prevent endless loop if already in queue */
2246 	struct carp_softc *vr, *after = NULL;
2247 	int myself = 0;
2248 	cif = ifp->if_carp;
2249 
2250 	TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
2251 		if (vr == sc)
2252 			myself = 1;
2253 		if (vr->sc_vhid < sc->sc_vhid)
2254 			after = vr;
2255 	}
2256 
2257 	if (!myself) {
2258 		/* We're trying to keep things in order */
2259 		if (after == NULL)
2260 			TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
2261 		else
2262 			TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
2263 	}
2264 	}
2265 #endif
2266 
2267 	sc->sc_naddrs6++;
2268 	if (own)
2269 		sc->sc_advskew = 0;
2270 	carp_sc_state(sc);
2271 	carp_setrun(sc, 0);
2272 
2273 	return (0);
2274 
2275 cleanup:
2276 	/* clean up multicast memberships */
2277 	if (!sc->sc_naddrs6) {
2278 		while (!LIST_EMPTY(&im6o->im6o_memberships)) {
2279 			imm = LIST_FIRST(&im6o->im6o_memberships);
2280 			LIST_REMOVE(imm, i6mm_chain);
2281 			in6_leavegroup(imm);
2282 		}
2283 	}
2284 	return (error);
2285 }
2286 
2287 static int
2288 carp_del_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
2289 {
2290 	int error = 0;
2291 
2292 	if (!--sc->sc_naddrs6) {
2293 		struct carp_if *cif = sc->sc_carpdev->if_carp;
2294 		struct ip6_moptions *im6o = &sc->sc_im6o;
2295 
2296 		callout_stop(&sc->sc_ad_tmo);
2297 		sc->sc_vhid = -1;
2298 		while (!LIST_EMPTY(&im6o->im6o_memberships)) {
2299 			struct in6_multi_mship *imm =
2300 			    LIST_FIRST(&im6o->im6o_memberships);
2301 
2302 			LIST_REMOVE(imm, i6mm_chain);
2303 			in6_leavegroup(imm);
2304 		}
2305 		im6o->im6o_multicast_ifp = NULL;
2306 #ifdef foo
2307 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
2308 		if (TAILQ_EMPTY(&cif->vhif_vrs)) {
2309 			sc->sc_carpdev->if_carp = NULL;
2310 			kfree(cif, M_IFADDR);
2311 		}
2312 #endif
2313 	}
2314 	return (error);
2315 }
2316 #endif /* INET6 */
2317 
2318 #endif
2319 
2320 static int
2321 carp_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr, struct ucred *cr)
2322 {
2323 	struct carp_softc *sc = ifp->if_softc;
2324 	struct ifreq *ifr = (struct ifreq *)addr;
2325 	struct ifdrv *ifd = (struct ifdrv *)addr;
2326 	int error = 0;
2327 
2328 	ASSERT_IFNET_SERIALIZED_ALL(ifp);
2329 
2330 	switch (cmd) {
2331 	case SIOCSIFFLAGS:
2332 		if (ifp->if_flags & IFF_UP) {
2333 			if ((ifp->if_flags & IFF_RUNNING) == 0)
2334 				carp_init(sc);
2335 		} else if (ifp->if_flags & IFF_RUNNING) {
2336 			carp_ioctl_stop(sc);
2337 		}
2338 		break;
2339 
2340 	case SIOCSIFCAP:
2341 		carp_ioctl_ifcap(sc, ifr->ifr_reqcap);
2342 		break;
2343 
2344 	case SIOCSVH:
2345 		error = carp_ioctl_setvh(sc, ifr->ifr_data, cr);
2346 		break;
2347 
2348 	case SIOCGVH:
2349 		error = carp_ioctl_getvh(sc, ifr->ifr_data, cr);
2350 		break;
2351 
2352 	case SIOCGDRVSPEC:
2353 		switch (ifd->ifd_cmd) {
2354 		case CARPGDEVNAME:
2355 			error = carp_ioctl_getdevname(sc, ifd);
2356 			break;
2357 
2358 		case CARPGVHADDR:
2359 			error = carp_ioctl_getvhaddr(sc, ifd);
2360 			break;
2361 
2362 		default:
2363 			error = EINVAL;
2364 			break;
2365 		}
2366 		break;
2367 
2368 	default:
2369 		error = ether_ioctl(ifp, cmd, addr);
2370 		break;
2371 	}
2372 
2373 	return error;
2374 }
2375 
2376 static void
2377 carp_ioctl_stop_dispatch(netmsg_t msg)
2378 {
2379 	struct netmsg_carp *cmsg = (struct netmsg_carp *)msg;
2380 	struct carp_softc *sc = cmsg->nc_softc;
2381 
2382 	carp_stop(sc, FALSE);
2383 	lwkt_replymsg(&cmsg->base.lmsg, 0);
2384 }
2385 
2386 static void
2387 carp_ioctl_stop(struct carp_softc *sc)
2388 {
2389 	struct ifnet *ifp = &sc->arpcom.ac_if;
2390 	struct netmsg_carp cmsg;
2391 
2392 	ASSERT_IFNET_SERIALIZED_ALL(ifp);
2393 
2394 	ifnet_deserialize_all(ifp);
2395 
2396 	bzero(&cmsg, sizeof(cmsg));
2397 	netmsg_init(&cmsg.base, NULL, &curthread->td_msgport, 0,
2398 	    carp_ioctl_stop_dispatch);
2399 	cmsg.nc_softc = sc;
2400 
2401 	lwkt_domsg(netisr_cpuport(0), &cmsg.base.lmsg, 0);
2402 
2403 	ifnet_serialize_all(ifp);
2404 }
2405 
2406 static void
2407 carp_ioctl_setvh_dispatch(netmsg_t msg)
2408 {
2409 	struct netmsg_carp *cmsg = (struct netmsg_carp *)msg;
2410 	struct carp_softc *sc = cmsg->nc_softc;
2411 	struct ifnet *ifp = &sc->arpcom.ac_if;
2412 	const struct carpreq *carpr = cmsg->nc_data;
2413 	int error;
2414 
2415 	error = 1;
2416 	if ((ifp->if_flags & IFF_RUNNING) &&
2417 	    sc->sc_state != INIT && carpr->carpr_state != sc->sc_state) {
2418 		switch (carpr->carpr_state) {
2419 		case BACKUP:
2420 			callout_stop(&sc->sc_ad_tmo);
2421 			carp_set_state(sc, BACKUP);
2422 			carp_setrun(sc, 0);
2423 			if (carp_opts[CARPCTL_SETROUTE])
2424 				carp_setroute(sc, RTM_DELETE);
2425 			break;
2426 
2427 		case MASTER:
2428 			carp_master_down(sc);
2429 			break;
2430 
2431 		default:
2432 			break;
2433 		}
2434 	}
2435 	if (carpr->carpr_vhid > 0) {
2436 		if (carpr->carpr_vhid > 255) {
2437 			error = EINVAL;
2438 			goto back;
2439 		}
2440 		if (sc->sc_carpdev) {
2441 			struct carp_if *cif = sc->sc_carpdev->if_carp;
2442 			struct carp_softc_container *scc;
2443 
2444 			TAILQ_FOREACH(scc, cif, scc_link) {
2445 				struct carp_softc *vr = scc->scc_softc;
2446 
2447 				if (vr != sc &&
2448 				    vr->sc_vhid == carpr->carpr_vhid) {
2449 					error = EEXIST;
2450 					goto back;
2451 				}
2452 			}
2453 		}
2454 		sc->sc_vhid = carpr->carpr_vhid;
2455 
2456 		IF_LLADDR(ifp)[5] = sc->sc_vhid;
2457 		bcopy(IF_LLADDR(ifp), sc->arpcom.ac_enaddr,
2458 		    ETHER_ADDR_LEN);
2459 
2460 		error--;
2461 	}
2462 	if (carpr->carpr_advbase > 0 || carpr->carpr_advskew > 0) {
2463 		if (carpr->carpr_advskew >= 255) {
2464 			error = EINVAL;
2465 			goto back;
2466 		}
2467 		if (carpr->carpr_advbase > 255) {
2468 			error = EINVAL;
2469 			goto back;
2470 		}
2471 		sc->sc_advbase = carpr->carpr_advbase;
2472 		sc->sc_advskew = carpr->carpr_advskew;
2473 		error--;
2474 	}
2475 	bcopy(carpr->carpr_key, sc->sc_key, sizeof(sc->sc_key));
2476 	if (error > 0) {
2477 		error = EINVAL;
2478 	} else {
2479 		error = 0;
2480 		carp_setrun(sc, 0);
2481 	}
2482 back:
2483 	carp_hmac_prepare(sc);
2484 
2485 	lwkt_replymsg(&cmsg->base.lmsg, error);
2486 }
2487 
2488 static int
2489 carp_ioctl_setvh(struct carp_softc *sc, void *udata, struct ucred *cr)
2490 {
2491 	struct ifnet *ifp = &sc->arpcom.ac_if;
2492 	struct netmsg_carp cmsg;
2493 	struct carpreq carpr;
2494 	int error;
2495 
2496 	ASSERT_IFNET_SERIALIZED_ALL(ifp);
2497 	ifnet_deserialize_all(ifp);
2498 
2499 	error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY);
2500 	if (error)
2501 		goto back;
2502 
2503 	error = copyin(udata, &carpr, sizeof(carpr));
2504 	if (error)
2505 		goto back;
2506 
2507 	bzero(&cmsg, sizeof(cmsg));
2508 	netmsg_init(&cmsg.base, NULL, &curthread->td_msgport, 0,
2509 	    carp_ioctl_setvh_dispatch);
2510 	cmsg.nc_softc = sc;
2511 	cmsg.nc_data = &carpr;
2512 
2513 	error = lwkt_domsg(netisr_cpuport(0), &cmsg.base.lmsg, 0);
2514 
2515 back:
2516 	ifnet_serialize_all(ifp);
2517 	return error;
2518 }
2519 
2520 static void
2521 carp_ioctl_ifcap_dispatch(netmsg_t msg)
2522 {
2523 	struct netmsg_carp *cmsg = (struct netmsg_carp *)msg;
2524 	struct carp_softc *sc = cmsg->nc_softc;
2525 	struct ifnet *ifp = &sc->arpcom.ac_if;
2526 	int reqcap = *((const int *)(cmsg->nc_data));
2527 	int mask;
2528 
2529 	mask = reqcap ^ ifp->if_capenable;
2530 	if (mask & IFCAP_TXCSUM) {
2531 		ifp->if_capenable ^= IFCAP_TXCSUM;
2532 		if ((ifp->if_capenable & IFCAP_TXCSUM) &&
2533 		    sc->sc_carpdev != NULL) {
2534 			ifp->if_hwassist |=
2535 			    (sc->sc_carpdev->if_hwassist &
2536 			     (CSUM_IP | CSUM_UDP | CSUM_TCP));
2537 		} else {
2538 			ifp->if_hwassist &= ~(CSUM_IP | CSUM_UDP | CSUM_TCP);
2539 		}
2540 	}
2541 	if (mask & IFCAP_TSO) {
2542 		ifp->if_capenable ^= IFCAP_TSO;
2543 		if ((ifp->if_capenable & IFCAP_TSO) &&
2544 		    sc->sc_carpdev != NULL) {
2545 			ifp->if_hwassist |=
2546 			    (sc->sc_carpdev->if_hwassist & CSUM_TSO);
2547 		} else {
2548 			ifp->if_hwassist &= ~CSUM_TSO;
2549 		}
2550 	}
2551 
2552 	lwkt_replymsg(&cmsg->base.lmsg, 0);
2553 }
2554 
2555 static void
2556 carp_ioctl_ifcap(struct carp_softc *sc, int reqcap)
2557 {
2558 	struct ifnet *ifp = &sc->arpcom.ac_if;
2559 	struct netmsg_carp cmsg;
2560 
2561 	ASSERT_IFNET_SERIALIZED_ALL(ifp);
2562 	ifnet_deserialize_all(ifp);
2563 
2564 	bzero(&cmsg, sizeof(cmsg));
2565 	netmsg_init(&cmsg.base, NULL, &curthread->td_msgport, 0,
2566 	    carp_ioctl_ifcap_dispatch);
2567 	cmsg.nc_softc = sc;
2568 	cmsg.nc_data = &reqcap;
2569 
2570 	lwkt_domsg(netisr_cpuport(0), &cmsg.base.lmsg, 0);
2571 
2572 	ifnet_serialize_all(ifp);
2573 }
2574 
2575 static void
2576 carp_ioctl_getvh_dispatch(netmsg_t msg)
2577 {
2578 	struct netmsg_carp *cmsg = (struct netmsg_carp *)msg;
2579 	struct carp_softc *sc = cmsg->nc_softc;
2580 	struct carpreq *carpr = cmsg->nc_data;
2581 
2582 	carpr->carpr_state = sc->sc_state;
2583 	carpr->carpr_vhid = sc->sc_vhid;
2584 	carpr->carpr_advbase = sc->sc_advbase;
2585 	carpr->carpr_advskew = sc->sc_advskew;
2586 	bcopy(sc->sc_key, carpr->carpr_key, sizeof(carpr->carpr_key));
2587 
2588 	lwkt_replymsg(&cmsg->base.lmsg, 0);
2589 }
2590 
2591 static int
2592 carp_ioctl_getvh(struct carp_softc *sc, void *udata, struct ucred *cr)
2593 {
2594 	struct ifnet *ifp = &sc->arpcom.ac_if;
2595 	struct netmsg_carp cmsg;
2596 	struct carpreq carpr;
2597 	int error;
2598 
2599 	ASSERT_IFNET_SERIALIZED_ALL(ifp);
2600 	ifnet_deserialize_all(ifp);
2601 
2602 	bzero(&cmsg, sizeof(cmsg));
2603 	netmsg_init(&cmsg.base, NULL, &curthread->td_msgport, 0,
2604 	    carp_ioctl_getvh_dispatch);
2605 	cmsg.nc_softc = sc;
2606 	cmsg.nc_data = &carpr;
2607 
2608 	lwkt_domsg(netisr_cpuport(0), &cmsg.base.lmsg, 0);
2609 
2610 	error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY);
2611 	if (error)
2612 		bzero(carpr.carpr_key, sizeof(carpr.carpr_key));
2613 
2614 	error = copyout(&carpr, udata, sizeof(carpr));
2615 
2616 	ifnet_serialize_all(ifp);
2617 	return error;
2618 }
2619 
2620 static void
2621 carp_ioctl_getdevname_dispatch(netmsg_t msg)
2622 {
2623 	struct netmsg_carp *cmsg = (struct netmsg_carp *)msg;
2624 	struct carp_softc *sc = cmsg->nc_softc;
2625 	char *devname = cmsg->nc_data;
2626 
2627 	bzero(devname, IFNAMSIZ);
2628 	if (sc->sc_carpdev != NULL)
2629 		strlcpy(devname, sc->sc_carpdev->if_xname, IFNAMSIZ);
2630 
2631 	lwkt_replymsg(&cmsg->base.lmsg, 0);
2632 }
2633 
2634 static int
2635 carp_ioctl_getdevname(struct carp_softc *sc, struct ifdrv *ifd)
2636 {
2637 	struct ifnet *ifp = &sc->arpcom.ac_if;
2638 	struct netmsg_carp cmsg;
2639 	char devname[IFNAMSIZ];
2640 	int error;
2641 
2642 	ASSERT_IFNET_SERIALIZED_ALL(ifp);
2643 
2644 	if (ifd->ifd_len != sizeof(devname))
2645 		return EINVAL;
2646 
2647 	ifnet_deserialize_all(ifp);
2648 
2649 	bzero(&cmsg, sizeof(cmsg));
2650 	netmsg_init(&cmsg.base, NULL, &curthread->td_msgport, 0,
2651 	    carp_ioctl_getdevname_dispatch);
2652 	cmsg.nc_softc = sc;
2653 	cmsg.nc_data = devname;
2654 
2655 	lwkt_domsg(netisr_cpuport(0), &cmsg.base.lmsg, 0);
2656 
2657 	error = copyout(devname, ifd->ifd_data, sizeof(devname));
2658 
2659 	ifnet_serialize_all(ifp);
2660 	return error;
2661 }
2662 
2663 static void
2664 carp_init_dispatch(netmsg_t msg)
2665 {
2666 	struct netmsg_carp *cmsg = (struct netmsg_carp *)msg;
2667 	struct carp_softc *sc = cmsg->nc_softc;
2668 
2669 	sc->sc_if.if_flags |= IFF_RUNNING;
2670 	carp_hmac_prepare(sc);
2671 	carp_set_state(sc, INIT);
2672 	carp_setrun(sc, 0);
2673 
2674 	lwkt_replymsg(&cmsg->base.lmsg, 0);
2675 }
2676 
2677 static void
2678 carp_init(void *xsc)
2679 {
2680 	struct carp_softc *sc = xsc;
2681 	struct ifnet *ifp = &sc->arpcom.ac_if;
2682 	struct netmsg_carp cmsg;
2683 
2684 	ASSERT_IFNET_SERIALIZED_ALL(ifp);
2685 
2686 	ifnet_deserialize_all(ifp);
2687 
2688 	bzero(&cmsg, sizeof(cmsg));
2689 	netmsg_init(&cmsg.base, NULL, &curthread->td_msgport, 0,
2690 	    carp_init_dispatch);
2691 	cmsg.nc_softc = sc;
2692 
2693 	lwkt_domsg(netisr_cpuport(0), &cmsg.base.lmsg, 0);
2694 
2695 	ifnet_serialize_all(ifp);
2696 }
2697 
2698 static int
2699 carp_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
2700     struct rtentry *rt)
2701 {
2702 	struct carp_softc *sc = ifp->if_softc;
2703 	struct ifnet *carpdev;
2704 	int error = 0;
2705 
2706 	carpdev = sc->sc_carpdev;
2707 	if (carpdev != NULL) {
2708 		if (m->m_flags & M_MCAST)
2709 			IFNET_STAT_INC(ifp, omcasts, 1);
2710 		IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len + ETHER_HDR_LEN);
2711 		IFNET_STAT_INC(ifp, opackets, 1);
2712 
2713 		/*
2714 		 * NOTE:
2715 		 * CARP's ifp is passed to backing device's
2716 		 * if_output method.
2717 		 */
2718 		carpdev->if_output(ifp, m, dst, rt);
2719 	} else {
2720 		IFNET_STAT_INC(ifp, oerrors, 1);
2721 		m_freem(m);
2722 		error = ENETUNREACH;
2723 	}
2724 	return error;
2725 }
2726 
2727 /*
2728  * Start output on carp interface. This function should never be called.
2729  */
2730 static void
2731 carp_start(struct ifnet *ifp, struct ifaltq_subque *ifsq __unused)
2732 {
2733 	panic("%s: start called", ifp->if_xname);
2734 }
2735 
2736 static void
2737 carp_set_state(struct carp_softc *sc, int state)
2738 {
2739 	struct ifnet *cifp = &sc->sc_if;
2740 
2741 	if (sc->sc_state == state)
2742 		return;
2743 	sc->sc_state = state;
2744 
2745 	switch (sc->sc_state) {
2746 	case BACKUP:
2747 		cifp->if_link_state = LINK_STATE_DOWN;
2748 		break;
2749 
2750 	case MASTER:
2751 		cifp->if_link_state = LINK_STATE_UP;
2752 		break;
2753 
2754 	default:
2755 		cifp->if_link_state = LINK_STATE_UNKNOWN;
2756 		break;
2757 	}
2758 	rt_ifmsg(cifp);
2759 }
2760 
2761 void
2762 carp_group_demote_adj(struct ifnet *ifp, int adj)
2763 {
2764 	struct ifg_list	*ifgl;
2765 	int *dm;
2766 
2767 	TAILQ_FOREACH(ifgl, &ifp->if_groups, ifgl_next) {
2768 		if (!strcmp(ifgl->ifgl_group->ifg_group, IFG_ALL))
2769 			continue;
2770 		dm = &ifgl->ifgl_group->ifg_carp_demoted;
2771 
2772 		if (*dm + adj >= 0)
2773 			*dm += adj;
2774 		else
2775 			*dm = 0;
2776 
2777 		if (adj > 0 && *dm == 1)
2778 			carp_send_ad_all();
2779 		CARP_LOG("%s demoted group %s to %d", ifp->if_xname,
2780                     ifgl->ifgl_group->ifg_group, *dm);
2781 	}
2782 }
2783 
2784 #ifdef foo
2785 void
2786 carp_carpdev_state(void *v)
2787 {
2788 	struct carp_if *cif = v;
2789 	struct carp_softc *sc;
2790 
2791 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list)
2792 		carp_sc_state(sc);
2793 }
2794 
2795 static void
2796 carp_sc_state(struct carp_softc *sc)
2797 {
2798 	if (!(sc->sc_carpdev->if_flags & IFF_UP)) {
2799 		callout_stop(&sc->sc_ad_tmo);
2800 		callout_stop(&sc->sc_md_tmo);
2801 		callout_stop(&sc->sc_md6_tmo);
2802 		carp_set_state(sc, INIT);
2803 		carp_setrun(sc, 0);
2804 		if (!sc->sc_suppress) {
2805 			carp_suppress_preempt++;
2806 			if (carp_suppress_preempt == 1)
2807 				carp_send_ad_all();
2808 		}
2809 		sc->sc_suppress = 1;
2810 	} else {
2811 		carp_set_state(sc, INIT);
2812 		carp_setrun(sc, 0);
2813 		if (sc->sc_suppress)
2814 			carp_suppress_preempt--;
2815 		sc->sc_suppress = 0;
2816 	}
2817 }
2818 #endif
2819 
2820 static void
2821 carp_stop(struct carp_softc *sc, boolean_t detach)
2822 {
2823 	sc->sc_if.if_flags &= ~IFF_RUNNING;
2824 
2825 	callout_stop(&sc->sc_ad_tmo);
2826 	callout_stop(&sc->sc_md_tmo);
2827 	callout_stop(&sc->sc_md6_tmo);
2828 
2829 	if (!detach && sc->sc_state == MASTER)
2830 		carp_send_ad(sc);
2831 
2832 	if (sc->sc_suppress)
2833 		carp_suppress_preempt--;
2834 	sc->sc_suppress = 0;
2835 
2836 	if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
2837 		carp_suppress_preempt--;
2838 	sc->sc_sendad_errors = 0;
2839 	sc->sc_sendad_success = 0;
2840 
2841 	carp_set_state(sc, INIT);
2842 	carp_setrun(sc, 0);
2843 }
2844 
2845 static void
2846 carp_suspend(struct carp_softc *sc, boolean_t detach)
2847 {
2848 	struct ifnet *cifp = &sc->sc_if;
2849 
2850 	carp_stop(sc, detach);
2851 
2852 	/* Retain the running state, if we are not dead yet */
2853 	if (!sc->sc_dead && (cifp->if_flags & IFF_UP))
2854 		cifp->if_flags |= IFF_RUNNING;
2855 }
2856 
2857 static int
2858 carp_activate_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha,
2859     struct ifnet *ifp, struct in_ifaddr *ia_if, int own)
2860 {
2861 	struct ip_moptions *imo = &sc->sc_imo;
2862 	struct carp_if *ocif = ifp->if_carp;
2863 	int error;
2864 
2865 	KKASSERT(vha->vha_ia != NULL);
2866 
2867 	KASSERT(ia_if != NULL, ("NULL backing address"));
2868 	KASSERT(vha->vha_iaback == NULL, ("%p is already activated", vha));
2869 	KASSERT((vha->vha_flags & CARP_VHAF_OWNER) == 0,
2870 		("inactive vhaddr %p is the address owner", vha));
2871 
2872 	KASSERT(sc->sc_carpdev == NULL || sc->sc_carpdev == ifp,
2873 		("%s is already on %s", sc->sc_if.if_xname,
2874 		 sc->sc_carpdev->if_xname));
2875 
2876 	if (ocif == NULL) {
2877 		KASSERT(sc->sc_carpdev == NULL,
2878 			("%s is already on %s", sc->sc_if.if_xname,
2879 			 sc->sc_carpdev->if_xname));
2880 
2881 		error = ifpromisc(ifp, 1);
2882 		if (error)
2883 			return error;
2884 	} else {
2885 		struct carp_softc_container *scc;
2886 
2887 		TAILQ_FOREACH(scc, ocif, scc_link) {
2888 			struct carp_softc *vr = scc->scc_softc;
2889 
2890 			if (vr != sc && vr->sc_vhid == sc->sc_vhid)
2891 				return EINVAL;
2892 		}
2893 	}
2894 
2895 	ifp->if_carp = carp_if_insert(ocif, sc);
2896 	KASSERT(ifp->if_carp != NULL, ("%s carp_if_insert failed", __func__));
2897 
2898 	sc->sc_ia = ia_if;
2899 	sc->sc_carpdev = ifp;
2900 	sc->arpcom.ac_if.if_hwassist = 0;
2901 	if (sc->arpcom.ac_if.if_capenable & IFCAP_TXCSUM) {
2902 		sc->arpcom.ac_if.if_hwassist |=
2903 		    (ifp->if_hwassist & (CSUM_IP | CSUM_UDP | CSUM_TCP));
2904 	}
2905 	if (sc->arpcom.ac_if.if_capenable & IFCAP_TSO)
2906 		sc->arpcom.ac_if.if_hwassist |= (ifp->if_hwassist & CSUM_TSO);
2907 
2908 	/*
2909 	 * Make sure that all protocol threads see the sc_carpdev and
2910 	 * if_carp changes
2911 	 */
2912 	netmsg_service_sync();
2913 
2914 	if (ocif != NULL && ifp->if_carp != ocif) {
2915 		/*
2916 		 * The old carp list could be safely free now,
2917 		 * since no one can access it.
2918 		 */
2919 		carp_if_free(ocif);
2920 	}
2921 
2922 	vha->vha_iaback = ia_if;
2923 	sc->sc_naddrs++;
2924 
2925 	if (own) {
2926 		vha->vha_flags |= CARP_VHAF_OWNER;
2927 
2928 		/* XXX save user configured advskew? */
2929 		sc->sc_advskew = 0;
2930 	}
2931 
2932 	carp_addroute_vhaddr(sc, vha);
2933 
2934 	/*
2935 	 * Join the multicast group only after the backing interface
2936 	 * has been hooked with the CARP interface.
2937 	 */
2938 	KASSERT(imo->imo_multicast_ifp == NULL ||
2939 		imo->imo_multicast_ifp == &sc->sc_if,
2940 		("%s didn't leave mcast group on %s",
2941 		 sc->sc_if.if_xname, imo->imo_multicast_ifp->if_xname));
2942 
2943 	if (imo->imo_num_memberships == 0) {
2944 		struct in_addr addr;
2945 
2946 		addr.s_addr = htonl(INADDR_CARP_GROUP);
2947 		imo->imo_membership[0] = in_addmulti(&addr, &sc->sc_if);
2948 		if (imo->imo_membership[0] == NULL) {
2949 			carp_deactivate_vhaddr(sc, vha, FALSE);
2950 			return ENOBUFS;
2951 		}
2952 
2953 		imo->imo_num_memberships++;
2954 		imo->imo_multicast_ifp = &sc->sc_if;
2955 		imo->imo_multicast_ttl = CARP_DFLTTL;
2956 		imo->imo_multicast_loop = 0;
2957 	}
2958 
2959 	carp_hmac_prepare(sc);
2960 	carp_set_state(sc, INIT);
2961 	carp_setrun(sc, 0);
2962 	return 0;
2963 }
2964 
2965 static void
2966 carp_deactivate_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha,
2967     boolean_t del_iaback)
2968 {
2969 	KKASSERT(vha->vha_ia != NULL);
2970 
2971 	carp_hmac_prepare(sc);
2972 
2973 	if (vha->vha_iaback == NULL) {
2974 		KASSERT((vha->vha_flags & CARP_VHAF_OWNER) == 0,
2975 			("inactive vhaddr %p is the address owner", vha));
2976 		return;
2977 	}
2978 
2979 	vha->vha_flags &= ~CARP_VHAF_OWNER;
2980 	carp_delroute_vhaddr(sc, vha, del_iaback);
2981 
2982 	KKASSERT(sc->sc_naddrs > 0);
2983 	vha->vha_iaback = NULL;
2984 	sc->sc_naddrs--;
2985 	if (!sc->sc_naddrs) {
2986 		if (sc->sc_naddrs6) {
2987 			carp_multicast_cleanup(sc);
2988 			sc->sc_ia = NULL;
2989 		} else {
2990 			carp_detach(sc, FALSE, del_iaback);
2991 		}
2992 	}
2993 }
2994 
2995 static void
2996 carp_link_addrs(struct carp_softc *sc, struct ifnet *ifp, struct ifaddr *ifa_if)
2997 {
2998 	struct carp_vhaddr *vha;
2999 	struct in_ifaddr *ia_if;
3000 
3001 	KKASSERT(ifa_if->ifa_addr->sa_family == AF_INET);
3002 	ia_if = ifatoia(ifa_if);
3003 
3004 	/*
3005 	 * Test each inactive vhaddr against the newly added address.
3006 	 * If the newly added address could be the backing address,
3007 	 * then activate the matching vhaddr.
3008 	 */
3009 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
3010 		const struct in_ifaddr *ia;
3011 		int own;
3012 
3013 		if (vha->vha_iaback != NULL)
3014 			continue;
3015 
3016 		ia = vha->vha_ia;
3017 		if (ia->ia_subnetmask != ia_if->ia_subnetmask ||
3018 		    ia->ia_subnet != ia_if->ia_subnet)
3019 			continue;
3020 
3021 		own = 0;
3022 		if (ia->ia_addr.sin_addr.s_addr ==
3023 		    ia_if->ia_addr.sin_addr.s_addr)
3024 			own = 1;
3025 
3026 		carp_activate_vhaddr(sc, vha, ifp, ia_if, own);
3027 	}
3028 }
3029 
3030 static void
3031 carp_unlink_addrs(struct carp_softc *sc, struct ifnet *ifp,
3032 		  struct ifaddr *ifa_if)
3033 {
3034 	struct carp_vhaddr *vha;
3035 	struct in_ifaddr *ia_if;
3036 
3037 	KKASSERT(ifa_if->ifa_addr->sa_family == AF_INET);
3038 	ia_if = ifatoia(ifa_if);
3039 
3040 	/*
3041 	 * Ad src address is deleted; set it to NULL.
3042 	 * Following loop will try pick up a new ad src address
3043 	 * if one of the vhaddr could retain its backing address.
3044 	 */
3045 	if (sc->sc_ia == ia_if)
3046 		sc->sc_ia = NULL;
3047 
3048 	/*
3049 	 * Test each active vhaddr against the deleted address.
3050 	 * If the deleted address is vhaddr address's backing
3051 	 * address, then deactivate the vhaddr.
3052 	 */
3053 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
3054 		if (vha->vha_iaback == NULL)
3055 			continue;
3056 
3057 		if (vha->vha_iaback == ia_if)
3058 			carp_deactivate_vhaddr(sc, vha, TRUE);
3059 		else if (sc->sc_ia == NULL)
3060 			sc->sc_ia = vha->vha_iaback;
3061 	}
3062 }
3063 
3064 static void
3065 carp_update_addrs(struct carp_softc *sc, struct ifaddr *ifa_del)
3066 {
3067 	struct carp_vhaddr *vha;
3068 
3069 	KKASSERT(sc->sc_carpdev == NULL);
3070 
3071 	TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link)
3072 		carp_config_vhaddr(sc, vha, ifatoia(ifa_del));
3073 }
3074 
3075 static void
3076 carp_ifaddr(void *arg __unused, struct ifnet *ifp,
3077 	    enum ifaddr_event event, struct ifaddr *ifa)
3078 {
3079 	struct carp_softc *sc;
3080 
3081 	if (ifa->ifa_addr->sa_family != AF_INET)
3082 		return;
3083 
3084 	ASSERT_NETISR0;
3085 
3086 	if (ifp->if_type == IFT_CARP) {
3087 		/*
3088 		 * Address is changed on carp(4) interface
3089 		 */
3090 		switch (event) {
3091 		case IFADDR_EVENT_ADD:
3092 			carp_add_addr(ifp->if_softc, ifa);
3093 			break;
3094 
3095 		case IFADDR_EVENT_CHANGE:
3096 			carp_config_addr(ifp->if_softc, ifa);
3097 			break;
3098 
3099 		case IFADDR_EVENT_DELETE:
3100 			carp_del_addr(ifp->if_softc, ifa);
3101 			break;
3102 		}
3103 		return;
3104 	}
3105 
3106 	/*
3107 	 * Address is changed on non-carp(4) interface
3108 	 */
3109 	if ((ifp->if_flags & IFF_MULTICAST) == 0)
3110 		return;
3111 
3112 	LIST_FOREACH(sc, &carpif_list, sc_next) {
3113 		if (sc->sc_carpdev != NULL && sc->sc_carpdev != ifp) {
3114 			/* Not the parent iface; skip */
3115 			continue;
3116 		}
3117 
3118 		switch (event) {
3119 		case IFADDR_EVENT_ADD:
3120 			carp_link_addrs(sc, ifp, ifa);
3121 			break;
3122 
3123 		case IFADDR_EVENT_DELETE:
3124 			if (sc->sc_carpdev != NULL) {
3125 				carp_unlink_addrs(sc, ifp, ifa);
3126 				if (sc->sc_carpdev == NULL) {
3127 					/*
3128 					 * We no longer have the parent
3129 					 * interface, however, certain
3130 					 * virtual addresses, which are
3131 					 * not used because they can't
3132 					 * match the previous parent
3133 					 * interface's addresses, may now
3134 					 * match different interface's
3135 					 * addresses.
3136 					 */
3137 					carp_update_addrs(sc, ifa);
3138 				}
3139 			} else {
3140 				/*
3141 				 * The carp(4) interface didn't have a
3142 				 * parent iface, so it is not possible
3143 				 * that it will contain any address to
3144 				 * be unlinked.
3145 				 */
3146 			}
3147 			break;
3148 
3149 		case IFADDR_EVENT_CHANGE:
3150 			if (sc->sc_carpdev == NULL) {
3151 				/*
3152 				 * The carp(4) interface didn't have a
3153 				 * parent iface, so it is not possible
3154 				 * that it will contain any address to
3155 				 * be updated.
3156 				 */
3157 				carp_link_addrs(sc, ifp, ifa);
3158 			} else {
3159 				/*
3160 				 * First try breaking tie with the old
3161 				 * address.  Then see whether we could
3162 				 * link certain vhaddr to the new address.
3163 				 * If that fails, i.e. carpdev is NULL,
3164 				 * we try a global update.
3165 				 *
3166 				 * NOTE: The above order is critical.
3167 				 */
3168 				carp_unlink_addrs(sc, ifp, ifa);
3169 				carp_link_addrs(sc, ifp, ifa);
3170 				if (sc->sc_carpdev == NULL) {
3171 					/*
3172 					 * See the comment in the above
3173 					 * IFADDR_EVENT_DELETE block.
3174 					 */
3175 					carp_update_addrs(sc, NULL);
3176 				}
3177 			}
3178 			break;
3179 		}
3180 	}
3181 }
3182 
3183 void
3184 carp_proto_ctlinput(netmsg_t msg)
3185 {
3186 	int cmd = msg->ctlinput.nm_cmd;
3187 	struct sockaddr *sa = msg->ctlinput.nm_arg;
3188 	struct in_ifaddr_container *iac;
3189 
3190 	/* We only process PRC_IFDOWN and PRC_IFUP commands */
3191 	if (cmd != PRC_IFDOWN && cmd != PRC_IFUP)
3192 		goto done;
3193 
3194 	TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
3195 		struct in_ifaddr *ia = iac->ia;
3196 		struct ifnet *ifp = ia->ia_ifp;
3197 
3198 		if (ifp->if_type == IFT_CARP)
3199 			continue;
3200 
3201 		if (ia->ia_ifa.ifa_addr == sa) {
3202 			if (cmd == PRC_IFDOWN) {
3203 				carp_ifaddr(NULL, ifp, IFADDR_EVENT_DELETE,
3204 				    &ia->ia_ifa);
3205 			} else if (cmd == PRC_IFUP) {
3206 				carp_ifaddr(NULL, ifp, IFADDR_EVENT_ADD,
3207 				    &ia->ia_ifa);
3208 			}
3209 			break;
3210 		}
3211 	}
3212 done:
3213 	lwkt_replymsg(&msg->lmsg, 0);
3214 }
3215 
3216 struct ifnet *
3217 carp_parent(struct ifnet *cifp)
3218 {
3219 	struct carp_softc *sc;
3220 
3221 	KKASSERT(cifp->if_type == IFT_CARP);
3222 	sc = cifp->if_softc;
3223 
3224 	return sc->sc_carpdev;
3225 }
3226 
3227 #define rtinitflags(x) \
3228 	(((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) \
3229 		 ? RTF_HOST : 0)
3230 
3231 static int
3232 carp_addroute_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha)
3233 {
3234 	struct in_ifaddr *ia, *iaback;
3235 
3236 	if (sc->sc_state != MASTER)
3237 		return 0;
3238 
3239 	ia = vha->vha_ia;
3240 	KKASSERT(ia != NULL);
3241 
3242 	iaback = vha->vha_iaback;
3243 	KKASSERT(iaback != NULL);
3244 
3245 	return rtchange(&iaback->ia_ifa, &ia->ia_ifa);
3246 }
3247 
3248 static void
3249 carp_delroute_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha,
3250     boolean_t del_iaback)
3251 {
3252 	struct in_ifaddr *ia, *iaback;
3253 
3254 	ia = vha->vha_ia;
3255 	KKASSERT(ia != NULL);
3256 
3257 	iaback = vha->vha_iaback;
3258 	KKASSERT(iaback != NULL);
3259 
3260 	if (!del_iaback && (iaback->ia_ifp->if_flags & IFF_UP)) {
3261 		rtchange(&ia->ia_ifa, &iaback->ia_ifa);
3262 		return;
3263 	}
3264 
3265 	rtinit(&ia->ia_ifa, RTM_DELETE, rtinitflags(ia));
3266 	in_ifadown_force(&ia->ia_ifa, 1);
3267 	ia->ia_flags &= ~IFA_ROUTE;
3268 }
3269 
3270 static int
3271 carp_modevent(module_t mod, int type, void *data)
3272 {
3273 	switch (type) {
3274 	case MOD_LOAD:
3275 		LIST_INIT(&carpif_list);
3276 		carp_ifdetach_event =
3277 		EVENTHANDLER_REGISTER(ifnet_detach_event, carp_ifdetach, NULL,
3278 				      EVENTHANDLER_PRI_ANY);
3279 		carp_ifaddr_event =
3280 		EVENTHANDLER_REGISTER(ifaddr_event, carp_ifaddr, NULL,
3281 				      EVENTHANDLER_PRI_FIRST);
3282 		if_clone_attach(&carp_cloner);
3283 		break;
3284 
3285 	case MOD_UNLOAD:
3286 		EVENTHANDLER_DEREGISTER(ifnet_detach_event,
3287 					carp_ifdetach_event);
3288 		EVENTHANDLER_DEREGISTER(ifaddr_event,
3289 					carp_ifaddr_event);
3290 		if_clone_detach(&carp_cloner);
3291 		break;
3292 
3293 	default:
3294 		return (EINVAL);
3295 	}
3296 	return (0);
3297 }
3298 
3299 static moduledata_t carp_mod = {
3300 	"carp",
3301 	carp_modevent,
3302 	0
3303 };
3304 DECLARE_MODULE(carp, carp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
3305