sys/netinet/ip_carp.c

   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  * $DragonFly: src/sys/netinet/ip_carp.c,v 1.10 2008/07/27 10:06:57 sephe Exp $
  29  */
  30
  31 #include "opt_carp.h"
  32 #include "opt_inet.h"
  33 #include "opt_inet6.h"
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/kernel.h>
  38 #include <sys/in_cksum.h>
  39 #include <sys/limits.h>
  40 #include <sys/malloc.h>
  41 #include <sys/mbuf.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
  50 #include <machine/stdarg.h>
  51 #include <crypto/sha1.h>
  52
  53 #include <net/bpf.h>
  54 #include <net/ethernet.h>
  55 #include <net/if.h>
  56 #include <net/if_dl.h>
  57 #include <net/if_types.h>
  58 #include <net/route.h>
  59 #include <net/if_clone.h>
  60
  61 #ifdef INET
  62 #include <netinet/in.h>
  63 #include <netinet/in_var.h>
  64 #include <netinet/in_systm.h>
  65 #include <netinet/ip.h>
  66 #include <netinet/ip_var.h>
  67 #include <netinet/if_ether.h>
  68 #endif
  69
  70 #ifdef INET6
  71 #include <netinet/icmp6.h>
  72 #include <netinet/ip6.h>
  73 #include <netinet6/ip6_var.h>
  74 #include <netinet6/scope6_var.h>
  75 #include <netinet6/nd6.h>
  76 #endif
  77
  78 #include <netinet/ip_carp.h>
  79
  80 #define CARP_IFNAME             "carp"
  81 #define CARP_IS_RUNNING(ifp)    \
  82         (((ifp)->if_flags & (IFF_UP | IFF_RUNNING)) == (IFF_UP | IFF_RUNNING))
  83
  84 struct carp_vhaddr {
  85         uint32_t                vha_flags;      /* CARP_VHAF_ */
  86         const struct in_ifaddr  *vha_ia;        /* carp address */
  87         const struct in_ifaddr  *vha_iaback;    /* backing address */
  88         TAILQ_ENTRY(carp_vhaddr) vha_link;
  89 };
  90 TAILQ_HEAD(carp_vhaddr_list, carp_vhaddr);
  91
  92 struct carp_softc {
  93         struct ifnet             sc_if;
  94         struct ifnet            *sc_carpdev;    /* parent interface */
  95         struct carp_vhaddr_list  sc_vha_list;   /* virtual addr list */
  96
  97         const struct in_ifaddr  *sc_ia;         /* primary iface address v4 */
  98         struct ip_moptions       sc_imo;
  99
 100 #ifdef INET6
 101         struct in6_ifaddr       *sc_ia6;        /* primary iface address v6 */
 102         struct ip6_moptions      sc_im6o;
 103 #endif /* INET6 */
 104         TAILQ_ENTRY(carp_softc)  sc_list;
 105
 106         enum { INIT = 0, BACKUP, MASTER }
 107                                  sc_state;
 108         int                      sc_dead;
 109
 110         int                      sc_suppress;
 111
 112         int                      sc_sendad_errors;
 113 #define CARP_SENDAD_MAX_ERRORS  3
 114         int                      sc_sendad_success;
 115 #define CARP_SENDAD_MIN_SUCCESS 3
 116
 117         int                      sc_vhid;
 118         int                      sc_advskew;
 119         int                      sc_naddrs;     /* actually used IPv4 vha */
 120         int                      sc_naddrs6;
 121         int                      sc_advbase;    /* seconds */
 122         int                      sc_init_counter;
 123         uint64_t                 sc_counter;
 124
 125         /* authentication */
 126 #define CARP_HMAC_PAD   64
 127         unsigned char            sc_key[CARP_KEY_LEN];
 128         unsigned char            sc_pad[CARP_HMAC_PAD];
 129         SHA1_CTX                 sc_sha1;
 130
 131         struct callout           sc_ad_tmo;     /* advertisement timeout */
 132         struct callout           sc_md_tmo;     /* master down timeout */
 133         struct callout           sc_md6_tmo;    /* master down timeout */
 134
 135         LIST_ENTRY(carp_softc)   sc_next;       /* Interface clue */
 136 };
 137
 138 struct carp_if {
 139         TAILQ_HEAD(, carp_softc) vhif_vrs;
 140 };
 141
 142 enum    { CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
 143
 144 SYSCTL_DECL(_net_inet_carp);
 145
 146 static int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 1, 0, 0 }; /* XXX for now */
 147 SYSCTL_INT(_net_inet_carp, CARPCTL_ALLOW, allow, CTLFLAG_RW,
 148     &carp_opts[CARPCTL_ALLOW], 0, "Accept incoming CARP packets");
 149 SYSCTL_INT(_net_inet_carp, CARPCTL_PREEMPT, preempt, CTLFLAG_RW,
 150     &carp_opts[CARPCTL_PREEMPT], 0, "high-priority backup preemption mode");
 151 SYSCTL_INT(_net_inet_carp, CARPCTL_LOG, log, CTLFLAG_RW,
 152     &carp_opts[CARPCTL_LOG], 0, "log bad carp packets");
 153 SYSCTL_INT(_net_inet_carp, CARPCTL_ARPBALANCE, arpbalance, CTLFLAG_RW,
 154     &carp_opts[CARPCTL_ARPBALANCE], 0, "balance arp responses");
 155
 156 static int carp_suppress_preempt = 0;
 157 SYSCTL_INT(_net_inet_carp, OID_AUTO, suppress_preempt, CTLFLAG_RD,
 158     &carp_suppress_preempt, 0, "Preemption is suppressed");
 159
 160 static struct carpstats carpstats;
 161 SYSCTL_STRUCT(_net_inet_carp, CARPCTL_STATS, stats, CTLFLAG_RW,
 162     &carpstats, carpstats,
 163     "CARP statistics (struct carpstats, netinet/ip_carp.h)");
 164
 165 #define CARP_LOG(...)   do {                            \
 166         if (carp_opts[CARPCTL_LOG] > 0)                 \
 167                 log(LOG_INFO, __VA_ARGS__);             \
 168 } while (0)
 169
 170 #define CARP_DEBUG(...) do {                            \
 171         if (carp_opts[CARPCTL_LOG] > 1)                 \
 172                 log(LOG_DEBUG, __VA_ARGS__);            \
 173 } while (0)
 174
 175 static void     carp_hmac_prepare(struct carp_softc *);
 176 static void     carp_hmac_generate(struct carp_softc *, uint32_t *,
 177                     unsigned char *);
 178 static int      carp_hmac_verify(struct carp_softc *, uint32_t *,
 179                     unsigned char *);
 180 static void     carp_setroute(struct carp_softc *, int);
 181 static void     carp_input_c(struct mbuf *, struct carp_header *, sa_family_t);
 182 static int      carp_clone_create(struct if_clone *, int, caddr_t);
 183 static int      carp_clone_destroy(struct ifnet *);
 184 static void     carp_detach(struct carp_softc *, int);
 185 static int      carp_prepare_ad(struct mbuf *, struct carp_softc *,
 186                     struct carp_header *);
 187 static void     carp_send_ad_all(void);
 188 static void     carp_send_ad_timeout(void *);
 189 static void     carp_send_ad(struct carp_softc *);
 190 static void     carp_send_arp(struct carp_softc *);
 191 static void     carp_master_down_timeout(void *);
 192 static void     carp_master_down(struct carp_softc *);
 193 static int      carp_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
 194 static int      carp_looutput(struct ifnet *, struct mbuf *, struct sockaddr *,
 195                     struct rtentry *);
 196 static void     carp_start(struct ifnet *);
 197 static void     carp_setrun(struct carp_softc *, sa_family_t);
 198 static void     carp_set_state(struct carp_softc *, int);
 199
 200 static void     carp_multicast_cleanup(struct carp_softc *);
 201 static void     carp_add_addr(struct carp_softc *, struct ifaddr *);
 202 static void     carp_del_addr(struct carp_softc *, struct ifaddr *);
 203 static void     carp_config_addr(struct carp_softc *, struct ifaddr *);
 204 static void     carp_link_addrs(struct carp_softc *, struct ifnet *,
 205                     struct ifaddr *);
 206 static void     carp_unlink_addrs(struct carp_softc *, struct ifnet *,
 207                     struct ifaddr *);
 208
 209 static int      carp_get_vhaddr(struct carp_softc *, struct ifdrv *);
 210 static int      carp_config_vhaddr(struct carp_softc *, struct carp_vhaddr *);
 211 static int      carp_activate_vhaddr(struct carp_softc *, struct carp_vhaddr *,
 212                     struct ifnet *, const struct in_ifaddr *, int);
 213 static void     carp_deactivate_vhaddr(struct carp_softc *,
 214                     struct carp_vhaddr *);
 215
 216 static void     carp_sc_state(struct carp_softc *);
 217 #ifdef INET6
 218 static void     carp_send_na(struct carp_softc *);
 219 static int      carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
 220 static int      carp_del_addr6(struct carp_softc *, struct sockaddr_in6 *);
 221 static void     carp_multicast6_cleanup(struct carp_softc *);
 222 #endif
 223 static void     carp_stop(struct carp_softc *, int);
 224 static void     carp_reset(struct carp_softc *, int);
 225
 226 static void     carp_ifaddr(void *, struct ifnet *, enum ifaddr_event,
 227                             struct ifaddr *);
 228 static void     carp_ifdetach(void *, struct ifnet *);
 229
 230 static MALLOC_DEFINE(M_CARP, "CARP", "CARP interfaces");
 231
 232 static LIST_HEAD(, carp_softc) carpif_list;
 233
 234 static struct if_clone carp_cloner =
 235 IF_CLONE_INITIALIZER(CARP_IFNAME, carp_clone_create, carp_clone_destroy,
 236                      0, IF_MAXUNIT);
 237
 238 static eventhandler_tag carp_ifdetach_event;
 239 static eventhandler_tag carp_ifaddr_event;
 240
 241 static __inline void
 242 carp_insert_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha_new)
 243 {
 244         struct carp_vhaddr *vha;
 245         u_long new_addr, addr;
 246
 247         KKASSERT((vha_new->vha_flags & CARP_VHAF_ONLIST) == 0);
 248
 249         /*
 250          * Virtual address list is sorted; smaller one first
 251          */
 252         new_addr = ntohl(vha_new->vha_ia->ia_addr.sin_addr.s_addr);
 253
 254         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
 255                 addr = ntohl(vha->vha_ia->ia_addr.sin_addr.s_addr);
 256
 257                 if (addr > new_addr)
 258                         break;
 259         }
 260         if (vha == NULL)
 261                 TAILQ_INSERT_TAIL(&sc->sc_vha_list, vha_new, vha_link);
 262         else
 263                 TAILQ_INSERT_BEFORE(vha, vha_new, vha_link);
 264         vha_new->vha_flags |= CARP_VHAF_ONLIST;
 265 }
 266
 267 static __inline void
 268 carp_remove_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha)
 269 {
 270         KKASSERT(vha->vha_flags & CARP_VHAF_ONLIST);
 271         vha->vha_flags &= ~CARP_VHAF_ONLIST;
 272         TAILQ_REMOVE(&sc->sc_vha_list, vha, vha_link);
 273 }
 274
 275 static void
 276 carp_hmac_prepare(struct carp_softc *sc)
 277 {
 278         uint8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
 279         uint8_t vhid = sc->sc_vhid & 0xff;
 280         int i;
 281 #ifdef INET6
 282         struct ifaddr_container *ifac;
 283         struct in6_addr in6;
 284 #endif
 285 #ifdef INET
 286         struct carp_vhaddr *vha;
 287 #endif
 288
 289         /* XXX: possible race here */
 290
 291         /* compute ipad from key */
 292         bzero(sc->sc_pad, sizeof(sc->sc_pad));
 293         bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
 294         for (i = 0; i < sizeof(sc->sc_pad); i++)
 295                 sc->sc_pad[i] ^= 0x36;
 296
 297         /* precompute first part of inner hash */
 298         SHA1Init(&sc->sc_sha1);
 299         SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
 300         SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
 301         SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
 302         SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
 303 #ifdef INET
 304         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
 305                 SHA1Update(&sc->sc_sha1,
 306                     (const uint8_t *)&vha->vha_ia->ia_addr.sin_addr,
 307                     sizeof(struct in_addr));
 308         }
 309 #endif /* INET */
 310 #ifdef INET6
 311         TAILQ_FOREACH(ifac, &sc->sc_if.if_addrheads[mycpuid], ifa_link) {
 312                 struct ifaddr *ifa = ifac->ifa;
 313
 314                 if (ifa->ifa_addr->sa_family == AF_INET6) {
 315                         in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
 316                         in6_clearscope(&in6);
 317                         SHA1Update(&sc->sc_sha1, (void *)&in6, sizeof(in6));
 318                 }
 319         }
 320 #endif /* INET6 */
 321
 322         /* convert ipad to opad */
 323         for (i = 0; i < sizeof(sc->sc_pad); i++)
 324                 sc->sc_pad[i] ^= 0x36 ^ 0x5c;
 325 }
 326
 327 static void
 328 carp_hmac_generate(struct carp_softc *sc, uint32_t counter[2],
 329     unsigned char md[20])
 330 {
 331         SHA1_CTX sha1ctx;
 332
 333         /* fetch first half of inner hash */
 334         bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
 335
 336         SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
 337         SHA1Final(md, &sha1ctx);
 338
 339         /* outer hash */
 340         SHA1Init(&sha1ctx);
 341         SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
 342         SHA1Update(&sha1ctx, md, 20);
 343         SHA1Final(md, &sha1ctx);
 344 }
 345
 346 static int
 347 carp_hmac_verify(struct carp_softc *sc, uint32_t counter[2],
 348     unsigned char md[20])
 349 {
 350         unsigned char md2[20];
 351
 352         carp_hmac_generate(sc, counter, md2);
 353         return (bcmp(md, md2, sizeof(md2)));
 354 }
 355
 356 static void
 357 carp_setroute(struct carp_softc *sc, int cmd)
 358 {
 359 #ifdef INET6
 360         struct ifaddr_container *ifac;
 361
 362         crit_enter();
 363         TAILQ_FOREACH(ifac, &sc->sc_if.if_addrheads[mycpuid], ifa_link) {
 364                 struct ifaddr *ifa = ifac->ifa;
 365
 366                 if (ifa->ifa_addr->sa_family == AF_INET6) {
 367                         if (cmd == RTM_ADD)
 368                                 in6_ifaddloop(ifa);
 369                         else
 370                                 in6_ifremloop(ifa);
 371                 }
 372         }
 373         crit_exit();
 374 #endif /* INET6 */
 375 }
 376
 377 static int
 378 carp_clone_create(struct if_clone *ifc, int unit, caddr_t param __unused)
 379 {
 380         struct carp_softc *sc;
 381         struct ifnet *ifp;
 382
 383         sc = kmalloc(sizeof(*sc), M_CARP, M_WAITOK | M_ZERO);
 384         ifp = &sc->sc_if;
 385
 386         sc->sc_suppress = 0;
 387         sc->sc_advbase = CARP_DFLTINTV;
 388         sc->sc_vhid = -1;       /* required setting */
 389         sc->sc_advskew = 0;
 390         sc->sc_init_counter = 1;
 391         sc->sc_naddrs = 0;
 392         sc->sc_naddrs6 = 0;
 393
 394         TAILQ_INIT(&sc->sc_vha_list);
 395
 396 #ifdef INET6
 397         sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
 398 #endif
 399
 400         callout_init(&sc->sc_ad_tmo);
 401         callout_init(&sc->sc_md_tmo);
 402         callout_init(&sc->sc_md6_tmo);
 403
 404         ifp->if_softc = sc;
 405         if_initname(ifp, CARP_IFNAME, unit);
 406         ifp->if_mtu = ETHERMTU;
 407         ifp->if_flags = IFF_LOOPBACK;
 408         ifp->if_ioctl = carp_ioctl;
 409         ifp->if_output = carp_looutput;
 410         ifp->if_start = carp_start;
 411         ifp->if_type = IFT_CARP;
 412         ifp->if_snd.ifq_maxlen = ifqmaxlen;
 413         ifp->if_hdrlen = 0;
 414         if_attach(ifp, NULL);
 415         bpfattach(ifp, DLT_NULL, sizeof(u_int));
 416
 417         crit_enter();
 418         LIST_INSERT_HEAD(&carpif_list, sc, sc_next);
 419         crit_exit();
 420
 421         return (0);
 422 }
 423
 424 static int
 425 carp_clone_destroy(struct ifnet *ifp)
 426 {
 427         struct carp_softc *sc = ifp->if_softc;
 428
 429         sc->sc_dead = 1;
 430         carp_detach(sc, 1);
 431
 432         crit_enter();
 433         LIST_REMOVE(sc, sc_next);
 434         crit_exit();
 435         bpfdetach(ifp);
 436         if_detach(ifp);
 437
 438         KASSERT(sc->sc_naddrs == 0, ("certain inet address is still active\n"));
 439         kfree(sc, M_CARP);
 440
 441         return 0;
 442 }
 443
 444 static void
 445 carp_detach(struct carp_softc *sc, int detach)
 446 {
 447         struct carp_if *cif;
 448
 449         carp_reset(sc, detach);
 450
 451         carp_multicast_cleanup(sc);
 452 #ifdef INET6
 453         carp_multicast6_cleanup(sc);
 454 #endif
 455
 456         if (!sc->sc_dead && detach) {
 457                 struct carp_vhaddr *vha;
 458
 459                 TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link)
 460                         carp_deactivate_vhaddr(sc, vha);
 461                 KKASSERT(sc->sc_naddrs == 0);
 462         }
 463
 464         if (sc->sc_carpdev != NULL) {
 465                 cif = sc->sc_carpdev->if_carp;
 466                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
 467                 if (TAILQ_EMPTY(&cif->vhif_vrs)) {
 468                         ifpromisc(sc->sc_carpdev, 0);
 469                         sc->sc_carpdev->if_carp = NULL;
 470                         kfree(cif, M_CARP);
 471                 }
 472                 sc->sc_carpdev = NULL;
 473                 sc->sc_ia = NULL;
 474         }
 475 }
 476
 477 /* Detach an interface from the carp. */
 478 static void
 479 carp_ifdetach(void *arg __unused, struct ifnet *ifp)
 480 {
 481         struct carp_if *cif = ifp->if_carp;
 482         struct carp_softc *sc;
 483
 484         while (ifp->if_carp &&
 485                (sc = TAILQ_FIRST(&cif->vhif_vrs)) != NULL)
 486                 carp_detach(sc, 1);
 487 }
 488
 489 /*
 490  * process input packet.
 491  * we have rearranged checks order compared to the rfc,
 492  * but it seems more efficient this way or not possible otherwise.
 493  */
 494 int
 495 carp_input(struct mbuf **mp, int *offp, int proto)
 496 {
 497         struct mbuf *m = *mp;
 498         struct ip *ip = mtod(m, struct ip *);
 499         struct carp_header *ch;
 500         int len, iphlen;
 501
 502         iphlen = *offp;
 503         *mp = NULL;
 504
 505         carpstats.carps_ipackets++;
 506
 507         if (!carp_opts[CARPCTL_ALLOW]) {
 508                 m_freem(m);
 509                 return(IPPROTO_DONE);
 510         }
 511
 512         /* Check if received on a valid carp interface */
 513         if (m->m_pkthdr.rcvif->if_carp == NULL) {
 514                 carpstats.carps_badif++;
 515                 CARP_LOG("carp_input: packet received on non-carp "
 516                     "interface: %s\n",
 517                     m->m_pkthdr.rcvif->if_xname);
 518                 m_freem(m);
 519                 return(IPPROTO_DONE);
 520         }
 521
 522         /* Verify that the IP TTL is CARP_DFLTTL. */
 523         if (ip->ip_ttl != CARP_DFLTTL) {
 524                 carpstats.carps_badttl++;
 525                 CARP_LOG("carp_input: received ttl %d != %d on %s\n",
 526                     ip->ip_ttl, CARP_DFLTTL,
 527                     m->m_pkthdr.rcvif->if_xname);
 528                 m_freem(m);
 529                 return(IPPROTO_DONE);
 530         }
 531
 532         /* Minimal CARP packet size */
 533         len = iphlen + sizeof(*ch);
 534
 535         /*
 536          * Verify that the received packet length is
 537          * not less than the CARP header
 538          */
 539         if (m->m_pkthdr.len < len) {
 540                 carpstats.carps_badlen++;
 541                 CARP_LOG("packet too short %d on %s\n", m->m_pkthdr.len,
 542                          m->m_pkthdr.rcvif->if_xname);
 543                 m_freem(m);
 544                 return(IPPROTO_DONE);
 545         }
 546
 547         /* Make sure that CARP header is contiguous */
 548         if (len > m->m_len) {
 549                 m = m_pullup(m, len);
 550                 if (m == NULL) {
 551                         carpstats.carps_hdrops++;
 552                         CARP_LOG("carp_input: m_pullup failed\n");
 553                         return(IPPROTO_DONE);
 554                 }
 555                 ip = mtod(m, struct ip *);
 556         }
 557         ch = (struct carp_header *)((uint8_t *)ip + iphlen);
 558
 559         /* Verify the CARP checksum */
 560         if (in_cksum_skip(m, len, iphlen)) {
 561                 carpstats.carps_badsum++;
 562                 CARP_LOG("carp_input: checksum failed on %s\n",
 563                     m->m_pkthdr.rcvif->if_xname);
 564                 m_freem(m);
 565                 return(IPPROTO_DONE);
 566         }
 567         carp_input_c(m, ch, AF_INET);
 568         return(IPPROTO_DONE);
 569 }
 570
 571 #ifdef INET6
 572 int
 573 carp6_input(struct mbuf **mp, int *offp, int proto)
 574 {
 575         struct mbuf *m = *mp;
 576         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 577         struct carp_header *ch;
 578         u_int len;
 579
 580         carpstats.carps_ipackets6++;
 581
 582         if (!carp_opts[CARPCTL_ALLOW]) {
 583                 m_freem(m);
 584                 return (IPPROTO_DONE);
 585         }
 586
 587         /* check if received on a valid carp interface */
 588         if (m->m_pkthdr.rcvif->if_carp == NULL) {
 589                 carpstats.carps_badif++;
 590                 CARP_LOG("carp6_input: packet received on non-carp "
 591                     "interface: %s\n",
 592                     m->m_pkthdr.rcvif->if_xname);
 593                 m_freem(m);
 594                 return (IPPROTO_DONE);
 595         }
 596
 597         /* verify that the IP TTL is 255 */
 598         if (ip6->ip6_hlim != CARP_DFLTTL) {
 599                 carpstats.carps_badttl++;
 600                 CARP_LOG("carp6_input: received ttl %d != 255 on %s\n",
 601                     ip6->ip6_hlim,
 602                     m->m_pkthdr.rcvif->if_xname);
 603                 m_freem(m);
 604                 return (IPPROTO_DONE);
 605         }
 606
 607         /* verify that we have a complete carp packet */
 608         len = m->m_len;
 609         IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
 610         if (ch == NULL) {
 611                 carpstats.carps_badlen++;
 612                 CARP_LOG("carp6_input: packet size %u too small\n", len);
 613                 return (IPPROTO_DONE);
 614         }
 615
 616         /* verify the CARP checksum */
 617         if (in_cksum_range(m, 0, *offp, sizeof(*ch))) {
 618                 carpstats.carps_badsum++;
 619                 CARP_LOG("carp6_input: checksum failed, on %s\n",
 620                     m->m_pkthdr.rcvif->if_xname);
 621                 m_freem(m);
 622                 return (IPPROTO_DONE);
 623         }
 624
 625         carp_input_c(m, ch, AF_INET6);
 626         return (IPPROTO_DONE);
 627 }
 628 #endif /* INET6 */
 629
 630 static void
 631 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
 632 {
 633         struct ifnet *ifp = m->m_pkthdr.rcvif;
 634         struct ifnet *cifp;
 635         struct carp_softc *sc;
 636         uint64_t tmp_counter;
 637         struct timeval sc_tv, ch_tv;
 638
 639         /* verify that the VHID is valid on the receiving interface */
 640         TAILQ_FOREACH(sc, &((struct carp_if *)ifp->if_carp)->vhif_vrs, sc_list)
 641                 if (sc->sc_vhid == ch->carp_vhid)
 642                         break;
 643
 644         if (!sc || !CARP_IS_RUNNING(&sc->sc_if)) {
 645                 carpstats.carps_badvhid++;
 646                 m_freem(m);
 647                 return;
 648         }
 649         cifp = &sc->sc_if;
 650
 651         getmicrotime(&cifp->if_lastchange);
 652         cifp->if_ipackets++;
 653         cifp->if_ibytes += m->m_pkthdr.len;
 654
 655         if (cifp->if_bpf) {
 656                 struct ip *ip = mtod(m, struct ip *);
 657
 658                 /* BPF wants net byte order */
 659                 ip->ip_len = htons(ip->ip_len + (ip->ip_hl << 2));
 660                 ip->ip_off = htons(ip->ip_off);
 661                 bpf_mtap(cifp->if_bpf, m);
 662         }
 663
 664         /* verify the CARP version. */
 665         if (ch->carp_version != CARP_VERSION) {
 666                 carpstats.carps_badver++;
 667                 cifp->if_ierrors++;
 668                 CARP_LOG("%s; invalid version %d\n", cifp->if_xname,
 669                          ch->carp_version);
 670                 m_freem(m);
 671                 return;
 672         }
 673
 674         /* verify the hash */
 675         if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
 676                 carpstats.carps_badauth++;
 677                 cifp->if_ierrors++;
 678                 CARP_LOG("%s: incorrect hash\n", cifp->if_xname);
 679                 m_freem(m);
 680                 return;
 681         }
 682
 683         tmp_counter = ntohl(ch->carp_counter[0]);
 684         tmp_counter = tmp_counter<<32;
 685         tmp_counter += ntohl(ch->carp_counter[1]);
 686
 687         /* XXX Replay protection goes here */
 688
 689         sc->sc_init_counter = 0;
 690         sc->sc_counter = tmp_counter;
 691
 692         sc_tv.tv_sec = sc->sc_advbase;
 693         if (carp_suppress_preempt && sc->sc_advskew <  240)
 694                 sc_tv.tv_usec = 240 * 1000000 / 256;
 695         else
 696                 sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
 697         ch_tv.tv_sec = ch->carp_advbase;
 698         ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
 699
 700         switch (sc->sc_state) {
 701         case INIT:
 702                 break;
 703
 704         case MASTER:
 705                 /*
 706                  * If we receive an advertisement from a master who's going to
 707                  * be more frequent than us, go into BACKUP state.
 708                  */
 709                 if (timevalcmp(&sc_tv, &ch_tv, >) ||
 710                     timevalcmp(&sc_tv, &ch_tv, ==)) {
 711                         callout_stop(&sc->sc_ad_tmo);
 712                         CARP_DEBUG("%s: MASTER -> BACKUP "
 713                            "(more frequent advertisement received)\n",
 714                            cifp->if_xname);
 715                         carp_set_state(sc, BACKUP);
 716                         carp_setrun(sc, 0);
 717                         carp_setroute(sc, RTM_DELETE);
 718                 }
 719                 break;
 720
 721         case BACKUP:
 722                 /*
 723                  * If we're pre-empting masters who advertise slower than us,
 724                  * and this one claims to be slower, treat him as down.
 725                  */
 726                 if (carp_opts[CARPCTL_PREEMPT] &&
 727                     timevalcmp(&sc_tv, &ch_tv, <)) {
 728                         CARP_DEBUG("%s: BACKUP -> MASTER "
 729                             "(preempting a slower master)\n", cifp->if_xname);
 730                         carp_master_down(sc);
 731                         break;
 732                 }
 733
 734                 /*
 735                  *  If the master is going to advertise at such a low frequency
 736                  *  that he's guaranteed to time out, we'd might as well just
 737                  *  treat him as timed out now.
 738                  */
 739                 sc_tv.tv_sec = sc->sc_advbase * 3;
 740                 if (timevalcmp(&sc_tv, &ch_tv, <)) {
 741                         CARP_DEBUG("%s: BACKUP -> MASTER (master timed out)\n",
 742                                    cifp->if_xname);
 743                         carp_master_down(sc);
 744                         break;
 745                 }
 746
 747                 /*
 748                  * Otherwise, we reset the counter and wait for the next
 749                  * advertisement.
 750                  */
 751                 carp_setrun(sc, af);
 752                 break;
 753         }
 754         m_freem(m);
 755 }
 756
 757 static int
 758 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
 759 {
 760         struct ifnet *cifp = &sc->sc_if;
 761         struct m_tag *mtag;
 762
 763         if (sc->sc_init_counter) {
 764                 /* this could also be seconds since unix epoch */
 765                 sc->sc_counter = karc4random();
 766                 sc->sc_counter = sc->sc_counter << 32;
 767                 sc->sc_counter += karc4random();
 768         } else {
 769                 sc->sc_counter++;
 770         }
 771
 772         ch->carp_counter[0] = htonl((sc->sc_counter >> 32) & 0xffffffff);
 773         ch->carp_counter[1] = htonl(sc->sc_counter & 0xffffffff);
 774
 775         carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
 776
 777         /* Tag packet for carp_output */
 778         mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct ifnet *), MB_DONTWAIT);
 779         if (mtag == NULL) {
 780                 m_freem(m);
 781                 cifp->if_oerrors++;
 782                 return ENOMEM;
 783         }
 784         bcopy(&cifp, (caddr_t)(mtag + 1), sizeof(struct ifnet *));
 785         m_tag_prepend(m, mtag);
 786
 787         return 0;
 788 }
 789
 790 static void
 791 carp_send_ad_all(void)
 792 {
 793         struct carp_softc *sc;
 794
 795         LIST_FOREACH(sc, &carpif_list, sc_next) {
 796                 if (sc->sc_carpdev == NULL)
 797                         continue;
 798
 799                 if (CARP_IS_RUNNING(&sc->sc_if) && sc->sc_state == MASTER)
 800                         carp_send_ad(sc);
 801         }
 802 }
 803
 804 static void
 805 carp_send_ad_timeout(void *xsc)
 806 {
 807         carp_send_ad(xsc);
 808 }
 809
 810 static void
 811 carp_send_ad(struct carp_softc *sc)
 812 {
 813         struct ifnet *cifp = &sc->sc_if;
 814         struct carp_header ch;
 815         struct timeval tv;
 816         struct carp_header *ch_ptr;
 817         struct mbuf *m;
 818         int len, advbase, advskew;
 819
 820         if (!CARP_IS_RUNNING(cifp)) {
 821                 /* Bow out */
 822                 advbase = 255;
 823                 advskew = 255;
 824         } else {
 825                 advbase = sc->sc_advbase;
 826                 if (!carp_suppress_preempt || sc->sc_advskew > 240)
 827                         advskew = sc->sc_advskew;
 828                 else
 829                         advskew = 240;
 830                 tv.tv_sec = advbase;
 831                 tv.tv_usec = advskew * 1000000 / 256;
 832         }
 833
 834         ch.carp_version = CARP_VERSION;
 835         ch.carp_type = CARP_ADVERTISEMENT;
 836         ch.carp_vhid = sc->sc_vhid;
 837         ch.carp_advbase = advbase;
 838         ch.carp_advskew = advskew;
 839         ch.carp_authlen = 7;    /* XXX DEFINE */
 840         ch.carp_pad1 = 0;       /* must be zero */
 841         ch.carp_cksum = 0;
 842
 843 #ifdef INET
 844         if (sc->sc_ia != NULL) {
 845                 struct ip *ip;
 846
 847                 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
 848                 if (m == NULL) {
 849                         cifp->if_oerrors++;
 850                         carpstats.carps_onomem++;
 851                         /* XXX maybe less ? */
 852                         if (advbase != 255 || advskew != 255)
 853                                 callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
 854                                     carp_send_ad_timeout, sc);
 855                         return;
 856                 }
 857                 len = sizeof(*ip) + sizeof(ch);
 858                 m->m_pkthdr.len = len;
 859                 m->m_pkthdr.rcvif = NULL;
 860                 m->m_len = len;
 861                 MH_ALIGN(m, m->m_len);
 862                 m->m_flags |= M_MCAST;
 863                 ip = mtod(m, struct ip *);
 864                 ip->ip_v = IPVERSION;
 865                 ip->ip_hl = sizeof(*ip) >> 2;
 866                 ip->ip_tos = IPTOS_LOWDELAY;
 867                 ip->ip_len = len;
 868                 ip->ip_id = ip_newid();
 869                 ip->ip_off = IP_DF;
 870                 ip->ip_ttl = CARP_DFLTTL;
 871                 ip->ip_p = IPPROTO_CARP;
 872                 ip->ip_sum = 0;
 873                 ip->ip_src = sc->sc_ia->ia_addr.sin_addr;
 874                 ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
 875
 876                 ch_ptr = (struct carp_header *)(&ip[1]);
 877                 bcopy(&ch, ch_ptr, sizeof(ch));
 878                 if (carp_prepare_ad(m, sc, ch_ptr))
 879                         return;
 880                 ch_ptr->carp_cksum = in_cksum_skip(m, len, sizeof(*ip));
 881
 882                 getmicrotime(&cifp->if_lastchange);
 883                 cifp->if_opackets++;
 884                 cifp->if_obytes += len;
 885                 carpstats.carps_opackets++;
 886
 887                 if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL)) {
 888                         cifp->if_oerrors++;
 889                         if (sc->sc_sendad_errors < INT_MAX)
 890                                 sc->sc_sendad_errors++;
 891                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
 892                                 carp_suppress_preempt++;
 893                                 if (carp_suppress_preempt == 1) {
 894                                         carp_send_ad_all();
 895                                 }
 896                         }
 897                         sc->sc_sendad_success = 0;
 898                 } else {
 899                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
 900                                 if (++sc->sc_sendad_success >=
 901                                     CARP_SENDAD_MIN_SUCCESS) {
 902                                         carp_suppress_preempt--;
 903                                         sc->sc_sendad_errors = 0;
 904                                 }
 905                         } else {
 906                                 sc->sc_sendad_errors = 0;
 907                         }
 908                 }
 909         }
 910 #endif /* INET */
 911 #ifdef INET6
 912         if (sc->sc_ia6) {
 913                 struct ip6_hdr *ip6;
 914
 915                 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
 916                 if (m == NULL) {
 917                         cifp->if_oerrors++;
 918                         carpstats.carps_onomem++;
 919                         /* XXX maybe less ? */
 920                         if (advbase != 255 || advskew != 255)
 921                                 callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
 922                                     carp_send_ad_timeout, sc);
 923                         return;
 924                 }
 925                 len = sizeof(*ip6) + sizeof(ch);
 926                 m->m_pkthdr.len = len;
 927                 m->m_pkthdr.rcvif = NULL;
 928                 m->m_len = len;
 929                 MH_ALIGN(m, m->m_len);
 930                 m->m_flags |= M_MCAST;
 931                 ip6 = mtod(m, struct ip6_hdr *);
 932                 bzero(ip6, sizeof(*ip6));
 933                 ip6->ip6_vfc |= IPV6_VERSION;
 934                 ip6->ip6_hlim = CARP_DFLTTL;
 935                 ip6->ip6_nxt = IPPROTO_CARP;
 936                 bcopy(&sc->sc_ia6->ia_addr.sin6_addr, &ip6->ip6_src,
 937                     sizeof(struct in6_addr));
 938                 /* set the multicast destination */
 939
 940                 ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
 941                 ip6->ip6_dst.s6_addr8[15] = 0x12;
 942                 if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
 943                         cifp->if_oerrors++;
 944                         m_freem(m);
 945                         CARP_LOG("%s: in6_setscope failed\n", __func__);
 946                         return;
 947                 }
 948
 949                 ch_ptr = (struct carp_header *)(&ip6[1]);
 950                 bcopy(&ch, ch_ptr, sizeof(ch));
 951                 if (carp_prepare_ad(m, sc, ch_ptr))
 952                         return;
 953                 ch_ptr->carp_cksum = in_cksum_skip(m, len, sizeof(*ip6));
 954
 955                 getmicrotime(&cifp->if_lastchange);
 956                 cifp->if_opackets++;
 957                 cifp->if_obytes += len;
 958                 carpstats.carps_opackets6++;
 959
 960                 if (ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL)) {
 961                         cifp->if_oerrors++;
 962                         if (sc->sc_sendad_errors < INT_MAX)
 963                                 sc->sc_sendad_errors++;
 964                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
 965                                 carp_suppress_preempt++;
 966                                 if (carp_suppress_preempt == 1) {
 967                                         carp_send_ad_all();
 968                                 }
 969                         }
 970                         sc->sc_sendad_success = 0;
 971                 } else {
 972                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
 973                                 if (++sc->sc_sendad_success >=
 974                                     CARP_SENDAD_MIN_SUCCESS) {
 975                                         carp_suppress_preempt--;
 976                                         sc->sc_sendad_errors = 0;
 977                                 }
 978                         } else {
 979                                 sc->sc_sendad_errors = 0;
 980                         }
 981                 }
 982         }
 983 #endif /* INET6 */
 984
 985         if (advbase != 255 || advskew != 255)
 986                 callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
 987                     carp_send_ad_timeout, sc);
 988 }
 989
 990 /*
 991  * Broadcast a gratuitous ARP request containing
 992  * the virtual router MAC address for each IP address
 993  * associated with the virtual router.
 994  */
 995 static void
 996 carp_send_arp(struct carp_softc *sc)
 997 {
 998         const struct carp_vhaddr *vha;
 999
1000         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
1001                 if (vha->vha_iaback == NULL)
1002                         continue;
1003
1004                 arp_iainit(sc->sc_carpdev, &vha->vha_ia->ia_addr.sin_addr,
1005                            IF_LLADDR(&sc->sc_if));
1006         }
1007 }
1008
1009 #ifdef INET6
1010 static void
1011 carp_send_na(struct carp_softc *sc)
1012 {
1013         struct ifaddr_container *ifac;
1014         struct in6_addr *in6;
1015         static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1016
1017         TAILQ_FOREACH(ifac, &sc->sc_if.if_addrheads[mycpuid], ifa_link) {
1018                 struct ifaddr *ifa = ifac->ifa;
1019
1020                 if (ifa->ifa_addr->sa_family != AF_INET6)
1021                         continue;
1022
1023                 in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1024                 nd6_na_output(sc->sc_carpdev, &mcast, in6,
1025                     ND_NA_FLAG_OVERRIDE, 1, NULL);
1026                 DELAY(1000);    /* XXX */
1027         }
1028 }
1029 #endif /* INET6 */
1030
1031 static __inline const struct carp_vhaddr *
1032 carp_find_addr(const struct carp_softc *sc, const struct in_addr *addr)
1033 {
1034         struct carp_vhaddr *vha;
1035
1036         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
1037                 if (vha->vha_iaback == NULL)
1038                         continue;
1039
1040                 if (vha->vha_ia->ia_addr.sin_addr.s_addr == addr->s_addr)
1041                         return vha;
1042         }
1043         return NULL;
1044 }
1045
1046 static int
1047 carp_iamatch_balance(const struct carp_if *cif, const struct in_addr *itaddr,
1048                      const struct in_addr *isaddr, uint8_t **enaddr)
1049 {
1050         const struct carp_softc *vh;
1051         int index, count = 0;
1052
1053         /*
1054          * XXX proof of concept implementation.
1055          * We use the source ip to decide which virtual host should
1056          * handle the request. If we're master of that virtual host,
1057          * then we respond, otherwise, just drop the arp packet on
1058          * the floor.
1059          */
1060
1061         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1062                 if (!CARP_IS_RUNNING(&vh->sc_if))
1063                         continue;
1064
1065                 if (carp_find_addr(vh, itaddr) != NULL)
1066                         count++;
1067         }
1068         if (count == 0)
1069                 return 0;
1070
1071         /* this should be a hash, like pf_hash() */
1072         index = ntohl(isaddr->s_addr) % count;
1073         count = 0;
1074
1075         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1076                 if (!CARP_IS_RUNNING(&vh->sc_if))
1077                         continue;
1078
1079                 if (carp_find_addr(vh, itaddr) == NULL)
1080                         continue;
1081
1082                 if (count == index) {
1083                         if (vh->sc_state == MASTER) {
1084                                 *enaddr = IF_LLADDR(&vh->sc_if);
1085                                 return 1;
1086                         } else {
1087                                 return 0;
1088                         }
1089                 }
1090                 count++;
1091         }
1092         return 0;
1093 }
1094
1095 int
1096 carp_iamatch(const void *v, const struct in_addr *itaddr,
1097              const struct in_addr *isaddr, uint8_t **enaddr)
1098 {
1099         const struct carp_if *cif = v;
1100         const struct carp_softc *vh;
1101
1102         if (carp_opts[CARPCTL_ARPBALANCE])
1103                 return carp_iamatch_balance(cif, itaddr, isaddr, enaddr);
1104
1105         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1106                 if (!CARP_IS_RUNNING(&vh->sc_if) || vh->sc_state != MASTER)
1107                         continue;
1108
1109                 if (carp_find_addr(vh, itaddr) != NULL) {
1110                         *enaddr = IF_LLADDR(&vh->sc_if);
1111                         return 1;
1112                 }
1113         }
1114         return 0;
1115 }
1116
1117 #ifdef INET6
1118 struct ifaddr *
1119 carp_iamatch6(void *v, struct in6_addr *taddr)
1120 {
1121         struct carp_if *cif = v;
1122         struct carp_softc *vh;
1123
1124         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1125                 struct ifaddr_container *ifac;
1126
1127                 TAILQ_FOREACH(ifac, &vh->sc_if.if_addrheads[mycpuid],
1128                               ifa_link) {
1129                         struct ifaddr *ifa = ifac->ifa;
1130
1131                         if (IN6_ARE_ADDR_EQUAL(taddr,
1132                             &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1133                             CARP_IS_RUNNING(&vh->sc_if) &&
1134                             vh->sc_state == MASTER) {
1135                                 return (ifa);
1136                         }
1137                 }
1138         }
1139         return (NULL);
1140 }
1141
1142 void *
1143 carp_macmatch6(void *v, struct mbuf *m, const struct in6_addr *taddr)
1144 {
1145         struct m_tag *mtag;
1146         struct carp_if *cif = v;
1147         struct carp_softc *sc;
1148
1149         TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
1150                 struct ifaddr_container *ifac;
1151
1152                 TAILQ_FOREACH(ifac, &sc->sc_if.if_addrheads[mycpuid],
1153                               ifa_link) {
1154                         struct ifaddr *ifa = ifac->ifa;
1155
1156                         if (IN6_ARE_ADDR_EQUAL(taddr,
1157                             &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1158                             CARP_IS_RUNNING(&sc->sc_if)) {
1159                                 struct ifnet *ifp = &sc->sc_if;
1160
1161                                 mtag = m_tag_get(PACKET_TAG_CARP,
1162                                     sizeof(struct ifnet *), MB_DONTWAIT);
1163                                 if (mtag == NULL) {
1164                                         /* better a bit than nothing */
1165                                         return (IF_LLADDR(ifp));
1166                                 }
1167                                 bcopy(&ifp, (caddr_t)(mtag + 1),
1168                                     sizeof(struct ifnet *));
1169                                 m_tag_prepend(m, mtag);
1170
1171                                 return (IF_LLADDR(ifp));
1172                         }
1173                 }
1174         }
1175         return (NULL);
1176 }
1177 #endif
1178
1179 int
1180 carp_forus(const void *v, const void *dhost)
1181 {
1182         const struct carp_if *cif = v;
1183         const struct carp_softc *vh;
1184         const uint8_t *ena = dhost;
1185
1186         if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1187                 return 0;
1188
1189         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1190                 const struct ifnet *cifp = &vh->sc_if;
1191
1192                 if (CARP_IS_RUNNING(cifp) && vh->sc_state == MASTER &&
1193                     !bcmp(dhost, IF_LLADDR(cifp), ETHER_ADDR_LEN))
1194                         return 1;
1195         }
1196         return 0;
1197 }
1198
1199 static void
1200 carp_master_down_timeout(void *xsc)
1201 {
1202         struct carp_softc *sc = xsc;
1203
1204         CARP_DEBUG("%s: BACKUP -> MASTER (master timed out)\n",
1205                    sc->sc_if.if_xname);
1206         carp_master_down(sc);
1207 }
1208
1209 static void
1210 carp_master_down(struct carp_softc *sc)
1211 {
1212         switch (sc->sc_state) {
1213         case INIT:
1214                 kprintf("%s: master_down event in INIT state\n",
1215                         sc->sc_if.if_xname);
1216                 break;
1217
1218         case MASTER:
1219                 break;
1220
1221         case BACKUP:
1222                 carp_set_state(sc, MASTER);
1223                 carp_send_ad(sc);
1224                 carp_send_arp(sc);
1225 #ifdef INET6
1226                 carp_send_na(sc);
1227 #endif /* INET6 */
1228                 carp_setrun(sc, 0);
1229                 carp_setroute(sc, RTM_ADD);
1230                 break;
1231         }
1232 }
1233
1234 /*
1235  * When in backup state, af indicates whether to reset the master down timer
1236  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1237  */
1238 static void
1239 carp_setrun(struct carp_softc *sc, sa_family_t af)
1240 {
1241         struct ifnet *cifp = &sc->sc_if;
1242         struct timeval tv;
1243
1244         if (sc->sc_carpdev == NULL) {
1245                 carp_set_state(sc, INIT);
1246                 return;
1247         }
1248
1249         if ((cifp->if_flags & IFF_RUNNING) && sc->sc_vhid > 0 &&
1250             (sc->sc_naddrs || sc->sc_naddrs6)) {
1251                 /* Nothing */
1252         } else {
1253                 carp_setroute(sc, RTM_DELETE);
1254                 return;
1255         }
1256
1257         switch (sc->sc_state) {
1258         case INIT:
1259                 if (carp_opts[CARPCTL_PREEMPT] && !carp_suppress_preempt) {
1260                         carp_send_ad(sc);
1261                         carp_send_arp(sc);
1262 #ifdef INET6
1263                         carp_send_na(sc);
1264 #endif /* INET6 */
1265                         CARP_DEBUG("%s: INIT -> MASTER (preempting)\n",
1266                                    cifp->if_xname);
1267                         carp_set_state(sc, MASTER);
1268                         carp_setroute(sc, RTM_ADD);
1269                 } else {
1270                         CARP_DEBUG("%s: INIT -> BACKUP\n", cifp->if_xname);
1271                         carp_set_state(sc, BACKUP);
1272                         carp_setroute(sc, RTM_DELETE);
1273                         carp_setrun(sc, 0);
1274                 }
1275                 break;
1276
1277         case BACKUP:
1278                 callout_stop(&sc->sc_ad_tmo);
1279                 tv.tv_sec = 3 * sc->sc_advbase;
1280                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1281                 switch (af) {
1282 #ifdef INET
1283                 case AF_INET:
1284                         callout_reset(&sc->sc_md_tmo, tvtohz_high(&tv),
1285                             carp_master_down_timeout, sc);
1286                         break;
1287 #endif /* INET */
1288 #ifdef INET6
1289                 case AF_INET6:
1290                         callout_reset(&sc->sc_md6_tmo, tvtohz_high(&tv),
1291                             carp_master_down_timeout, sc);
1292                         break;
1293 #endif /* INET6 */
1294                 default:
1295                         if (sc->sc_naddrs)
1296                                 callout_reset(&sc->sc_md_tmo, tvtohz_high(&tv),
1297                                     carp_master_down_timeout, sc);
1298                         if (sc->sc_naddrs6)
1299                                 callout_reset(&sc->sc_md6_tmo, tvtohz_high(&tv),
1300                                     carp_master_down_timeout, sc);
1301                         break;
1302                 }
1303                 break;
1304
1305         case MASTER:
1306                 tv.tv_sec = sc->sc_advbase;
1307                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1308                 callout_reset(&sc->sc_ad_tmo, tvtohz_high(&tv),
1309                     carp_send_ad_timeout, sc);
1310                 break;
1311         }
1312 }
1313
1314 static void
1315 carp_multicast_cleanup(struct carp_softc *sc)
1316 {
1317         struct ip_moptions *imo = &sc->sc_imo;
1318
1319         if (imo->imo_num_memberships == 0)
1320                 return;
1321         KKASSERT(imo->imo_num_memberships == 1);
1322
1323         in_delmulti(imo->imo_membership[0]);
1324         imo->imo_membership[0] = NULL;
1325         imo->imo_num_memberships = 0;
1326         imo->imo_multicast_ifp = NULL;
1327 }
1328
1329 #ifdef INET6
1330 static void
1331 carp_multicast6_cleanup(struct carp_softc *sc)
1332 {
1333         struct ip6_moptions *im6o = &sc->sc_im6o;
1334
1335         while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1336                 struct in6_multi_mship *imm =
1337                     LIST_FIRST(&im6o->im6o_memberships);
1338
1339                 LIST_REMOVE(imm, i6mm_chain);
1340                 in6_leavegroup(imm);
1341         }
1342         im6o->im6o_multicast_ifp = NULL;
1343 }
1344 #endif
1345
1346 static int
1347 carp_get_vhaddr(struct carp_softc *sc, struct ifdrv *ifd)
1348 {
1349         const struct carp_vhaddr *vha;
1350         struct ifcarpvhaddr *carpa, *carpa0;
1351         int count, len, error;
1352
1353         count = 0;
1354         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link)
1355                 ++count;
1356
1357         if (ifd->ifd_len == 0) {
1358                 ifd->ifd_len = count * sizeof(*carpa);
1359                 return 0;
1360         } else if (count == 0 || ifd->ifd_len < sizeof(*carpa)) {
1361                 ifd->ifd_len = 0;
1362                 return 0;
1363         }
1364         len = min(ifd->ifd_len, sizeof(*carpa) * count);
1365         KKASSERT(len >= sizeof(*carpa));
1366
1367         carpa0 = carpa = kmalloc(len, M_TEMP, M_WAITOK | M_NULLOK | M_ZERO);
1368         if (carpa == NULL)
1369                 return ENOMEM;
1370
1371         count = 0;
1372         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
1373                 if (len < sizeof(*carpa))
1374                         break;
1375
1376                 carpa->carpa_flags = vha->vha_flags;
1377                 carpa->carpa_addr.sin_family = AF_INET;
1378                 carpa->carpa_addr.sin_addr = vha->vha_ia->ia_addr.sin_addr;
1379
1380                 carpa->carpa_baddr.sin_family = AF_INET;
1381                 if (vha->vha_iaback == NULL) {
1382                         carpa->carpa_baddr.sin_addr.s_addr = INADDR_ANY;
1383                 } else {
1384                         carpa->carpa_baddr.sin_addr =
1385                         vha->vha_iaback->ia_addr.sin_addr;
1386                 }
1387
1388                 ++carpa;
1389                 ++count;
1390                 len -= sizeof(*carpa);
1391         }
1392         ifd->ifd_len = sizeof(*carpa) * count;
1393         KKASSERT(ifd->ifd_len > 0);
1394
1395         error = copyout(carpa0, ifd->ifd_data, ifd->ifd_len);
1396         kfree(carpa0, M_TEMP);
1397         return error;
1398 }
1399
1400 static int
1401 carp_config_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha)
1402 {
1403         struct ifnet *ifp;
1404         struct in_ifaddr *ia_if;
1405         struct in_ifaddr_container *iac;
1406         const struct sockaddr_in *sin;
1407         u_long iaddr;
1408         int own;
1409
1410         KKASSERT(vha->vha_ia != NULL);
1411
1412         sin = &vha->vha_ia->ia_addr;
1413         iaddr = ntohl(sin->sin_addr.s_addr);
1414
1415         ia_if = NULL;
1416         own = 0;
1417         TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
1418                 struct in_ifaddr *ia = iac->ia;
1419
1420                 if ((ia->ia_flags & IFA_ROUTE) == 0)
1421                         continue;
1422
1423                 if (ia->ia_ifp->if_type == IFT_CARP)
1424                         continue;
1425
1426                 /* and, yeah, we need a multicast-capable iface too */
1427                 if ((ia->ia_ifp->if_flags & IFF_MULTICAST) == 0)
1428                         continue;
1429
1430                 if ((iaddr & ia->ia_subnetmask) == ia->ia_subnet) {
1431                         if (sin->sin_addr.s_addr ==
1432                             ia->ia_addr.sin_addr.s_addr)
1433                                 own = 1;
1434                         if (ia_if == NULL)
1435                                 ia_if = ia;
1436                         else if (sc->sc_carpdev != NULL &&
1437                                  sc->sc_carpdev == ia->ia_ifp)
1438                                 ia_if = ia;
1439                 }
1440         }
1441
1442         carp_deactivate_vhaddr(sc, vha);
1443         if (!ia_if)
1444                 return ENOENT;
1445
1446         ifp = ia_if->ia_ifp;
1447
1448         /* XXX Don't allow parent iface to be changed */
1449         if (sc->sc_carpdev != NULL && sc->sc_carpdev != ifp)
1450                 return EEXIST;
1451
1452         return carp_activate_vhaddr(sc, vha, ifp, ia_if, own);
1453 }
1454
1455 static void
1456 carp_add_addr(struct carp_softc *sc, struct ifaddr *carp_ifa)
1457 {
1458         struct carp_vhaddr *vha_new;
1459         struct in_ifaddr *carp_ia;
1460 #ifdef INVARIANTS
1461         struct carp_vhaddr *vha;
1462 #endif
1463
1464         KKASSERT(carp_ifa->ifa_addr->sa_family == AF_INET);
1465         carp_ia = ifatoia(carp_ifa);
1466
1467 #ifdef INVARIANTS
1468         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link)
1469                 KKASSERT(vha->vha_ia != NULL && vha->vha_ia != carp_ia);
1470 #endif
1471
1472         vha_new = kmalloc(sizeof(*vha_new), M_CARP, M_WAITOK | M_ZERO);
1473         vha_new->vha_ia = carp_ia;
1474         carp_insert_vhaddr(sc, vha_new);
1475
1476         if (carp_config_vhaddr(sc, vha_new) != 0) {
1477                 /*
1478                  * If the above configuration fails, it may only mean
1479                  * that the new address is problematic.  However, the
1480                  * carp(4) interface may already have several working
1481                  * addresses.  Since the expected behaviour of
1482                  * SIOC[AS]IFADDR is to put the NIC into working state,
1483                  * we try starting the state machine manually here with
1484                  * the hope that the carp(4)'s previously working
1485                  * addresses still could be brought up.
1486                  */
1487                 carp_hmac_prepare(sc);
1488                 carp_set_state(sc, INIT);
1489                 carp_setrun(sc, 0);
1490         }
1491 }
1492
1493 static void
1494 carp_del_addr(struct carp_softc *sc, struct ifaddr *carp_ifa)
1495 {
1496         struct carp_vhaddr *vha;
1497         struct in_ifaddr *carp_ia;
1498
1499         KKASSERT(carp_ifa->ifa_addr->sa_family == AF_INET);
1500         carp_ia = ifatoia(carp_ifa);
1501
1502         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
1503                 KKASSERT(vha->vha_ia != NULL);
1504                 if (vha->vha_ia == carp_ia)
1505                         break;
1506         }
1507         KASSERT(vha != NULL, ("no corresponding vhaddr %p\n", carp_ifa));
1508
1509         /*
1510          * Remove the vhaddr from the list before deactivating
1511          * the vhaddr, so that the HMAC could be correctly
1512          * updated in carp_deactivate_vhaddr()
1513          */
1514         carp_remove_vhaddr(sc, vha);
1515
1516         carp_deactivate_vhaddr(sc, vha);
1517         kfree(vha, M_CARP);
1518 }
1519
1520 static void
1521 carp_config_addr(struct carp_softc *sc, struct ifaddr *carp_ifa)
1522 {
1523         struct carp_vhaddr *vha;
1524         struct in_ifaddr *carp_ia;
1525
1526         KKASSERT(carp_ifa->ifa_addr->sa_family == AF_INET);
1527         carp_ia = ifatoia(carp_ifa);
1528
1529         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
1530                 KKASSERT(vha->vha_ia != NULL);
1531                 if (vha->vha_ia == carp_ia)
1532                         break;
1533         }
1534         KASSERT(vha != NULL, ("no corresponding vhaddr %p\n", carp_ifa));
1535
1536         /* Remove then reinsert, to keep the vhaddr list sorted */
1537         carp_remove_vhaddr(sc, vha);
1538         carp_insert_vhaddr(sc, vha);
1539
1540         if (carp_config_vhaddr(sc, vha) != 0) {
1541                 /* See the comment in carp_add_addr() */
1542                 carp_hmac_prepare(sc);
1543                 carp_set_state(sc, INIT);
1544                 carp_setrun(sc, 0);
1545         }
1546 }
1547
1548 #ifdef INET6
1549 static int
1550 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1551 {
1552         struct ifnet *ifp;
1553         struct carp_if *cif;
1554         struct in6_ifaddr *ia, *ia_if;
1555         struct ip6_moptions *im6o = &sc->sc_im6o;
1556         struct in6_multi_mship *imm;
1557         struct in6_addr in6;
1558         int own, error;
1559
1560         if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1561                 carp_setrun(sc, 0);
1562                 return (0);
1563         }
1564
1565         /* we have to do it by hands to check we won't match on us */
1566         ia_if = NULL; own = 0;
1567         for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1568                 int i;
1569
1570                 for (i = 0; i < 4; i++) {
1571                         if ((sin6->sin6_addr.s6_addr32[i] &
1572                             ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1573                             (ia->ia_addr.sin6_addr.s6_addr32[i] &
1574                             ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1575                                 break;
1576                 }
1577                 /* and, yeah, we need a multicast-capable iface too */
1578                 if (ia->ia_ifp != &sc->sc_if &&
1579                     (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1580                     (i == 4)) {
1581                         if (!ia_if)
1582                                 ia_if = ia;
1583                         if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr,
1584                             &ia->ia_addr.sin6_addr))
1585                                 own++;
1586                 }
1587         }
1588
1589         if (!ia_if)
1590                 return (EADDRNOTAVAIL);
1591         ia = ia_if;
1592         ifp = ia->ia_ifp;
1593
1594         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
1595             (im6o->im6o_multicast_ifp && im6o->im6o_multicast_ifp != ifp))
1596                 return (EADDRNOTAVAIL);
1597
1598         if (!sc->sc_naddrs6) {
1599                 im6o->im6o_multicast_ifp = ifp;
1600
1601                 /* join CARP multicast address */
1602                 bzero(&in6, sizeof(in6));
1603                 in6.s6_addr16[0] = htons(0xff02);
1604                 in6.s6_addr8[15] = 0x12;
1605                 if (in6_setscope(&in6, ifp, NULL) != 0)
1606                         goto cleanup;
1607                 if ((imm = in6_joingroup(ifp, &in6, &error)) == NULL)
1608                         goto cleanup;
1609                 LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
1610
1611                 /* join solicited multicast address */
1612                 bzero(&in6, sizeof(in6));
1613                 in6.s6_addr16[0] = htons(0xff02);
1614                 in6.s6_addr32[1] = 0;
1615                 in6.s6_addr32[2] = htonl(1);
1616                 in6.s6_addr32[3] = sin6->sin6_addr.s6_addr32[3];
1617                 in6.s6_addr8[12] = 0xff;
1618                 if (in6_setscope(&in6, ifp, NULL) != 0)
1619                         goto cleanup;
1620                 if ((imm = in6_joingroup(ifp, &in6, &error)) == NULL)
1621                         goto cleanup;
1622                 LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
1623         }
1624
1625         if (!ifp->if_carp) {
1626                 cif = kmalloc(sizeof(*cif), M_CARP, M_WAITOK | M_ZERO);
1627
1628                 if ((error = ifpromisc(ifp, 1))) {
1629                         kfree(cif, M_CARP);
1630                         goto cleanup;
1631                 }
1632
1633                 TAILQ_INIT(&cif->vhif_vrs);
1634                 ifp->if_carp = cif;
1635         } else {
1636                 struct carp_softc *vr;
1637
1638                 cif = ifp->if_carp;
1639                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1640                         if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
1641                                 error = EINVAL;
1642                                 goto cleanup;
1643                         }
1644                 }
1645         }
1646         sc->sc_ia6 = ia;
1647         sc->sc_carpdev = ifp;
1648
1649         { /* XXX prevent endless loop if already in queue */
1650         struct carp_softc *vr, *after = NULL;
1651         int myself = 0;
1652         cif = ifp->if_carp;
1653
1654         TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1655                 if (vr == sc)
1656                         myself = 1;
1657                 if (vr->sc_vhid < sc->sc_vhid)
1658                         after = vr;
1659         }
1660
1661         if (!myself) {
1662                 /* We're trying to keep things in order */
1663                 if (after == NULL)
1664                         TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1665                 else
1666                         TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
1667         }
1668         }
1669
1670         sc->sc_naddrs6++;
1671         if (own)
1672                 sc->sc_advskew = 0;
1673         carp_sc_state(sc);
1674         carp_setrun(sc, 0);
1675
1676         return (0);
1677
1678 cleanup:
1679         /* clean up multicast memberships */
1680         if (!sc->sc_naddrs6) {
1681                 while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1682                         imm = LIST_FIRST(&im6o->im6o_memberships);
1683                         LIST_REMOVE(imm, i6mm_chain);
1684                         in6_leavegroup(imm);
1685                 }
1686         }
1687         return (error);
1688 }
1689
1690 static int
1691 carp_del_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1692 {
1693         int error = 0;
1694
1695         if (!--sc->sc_naddrs6) {
1696                 struct carp_if *cif = sc->sc_carpdev->if_carp;
1697                 struct ip6_moptions *im6o = &sc->sc_im6o;
1698
1699                 callout_stop(&sc->sc_ad_tmo);
1700                 sc->sc_vhid = -1;
1701                 while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1702                         struct in6_multi_mship *imm =
1703                             LIST_FIRST(&im6o->im6o_memberships);
1704
1705                         LIST_REMOVE(imm, i6mm_chain);
1706                         in6_leavegroup(imm);
1707                 }
1708                 im6o->im6o_multicast_ifp = NULL;
1709                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
1710                 if (TAILQ_EMPTY(&cif->vhif_vrs)) {
1711                         sc->sc_carpdev->if_carp = NULL;
1712                         kfree(cif, M_IFADDR);
1713                 }
1714         }
1715         return (error);
1716 }
1717 #endif /* INET6 */
1718
1719 static int
1720 carp_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr, struct ucred *cr)
1721 {
1722         struct carp_softc *sc = ifp->if_softc, *vr;
1723         struct carpreq carpr;
1724         struct ifaddr *ifa;
1725         struct ifreq *ifr;
1726         struct ifaliasreq *ifra;
1727         struct ifdrv *ifd;
1728         char devname[IFNAMSIZ];
1729         int error = 0;
1730
1731         ifa = (struct ifaddr *)addr;
1732         ifra = (struct ifaliasreq *)addr;
1733         ifr = (struct ifreq *)addr;
1734         ifd = (struct ifdrv *)addr;
1735
1736         switch (cmd) {
1737         case SIOCSIFADDR:
1738                 switch (ifa->ifa_addr->sa_family) {
1739 #ifdef INET
1740                 case AF_INET:
1741                         ifp->if_flags |= IFF_UP | IFF_RUNNING;
1742                         break;
1743 #endif /* INET */
1744 #ifdef INET6
1745                 case AF_INET6:
1746                         ifp->if_flags |= IFF_UP | IFF_RUNNING;
1747                         error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1748                         break;
1749 #endif /* INET6 */
1750                 default:
1751                         error = EAFNOSUPPORT;
1752                         break;
1753                 }
1754                 break;
1755
1756         case SIOCAIFADDR:
1757                 switch (ifa->ifa_addr->sa_family) {
1758 #ifdef INET
1759                 case AF_INET:
1760                         panic("SIOCAIFADDR should never be seen\n");
1761 #endif /* INET */
1762 #ifdef INET6
1763                 case AF_INET6:
1764                         ifp->if_flags |= IFF_UP | IFF_RUNNING;
1765                         error = carp_set_addr6(sc, satosin6(&ifra->ifra_addr));
1766                         break;
1767 #endif /* INET6 */
1768                 default:
1769                         error = EAFNOSUPPORT;
1770                         break;
1771                 }
1772                 break;
1773
1774         case SIOCDIFADDR:
1775                 switch (ifa->ifa_addr->sa_family) {
1776 #ifdef INET
1777                 case AF_INET:
1778                         panic("SIOCDIFADDR should never be seen\n");
1779 #endif /* INET */
1780 #ifdef INET6
1781                 case AF_INET6:
1782                         error = carp_del_addr6(sc, satosin6(&ifra->ifra_addr));
1783                         break;
1784 #endif /* INET6 */
1785                 default:
1786                         error = EAFNOSUPPORT;
1787                         break;
1788                 }
1789                 break;
1790
1791         case SIOCSIFFLAGS:
1792                 if (ifp->if_flags & IFF_UP) {
1793                         if ((ifp->if_flags & IFF_RUNNING) == 0) {
1794                                 ifp->if_flags |= IFF_RUNNING;
1795                                 carp_set_state(sc, INIT);
1796                                 carp_setrun(sc, 0);
1797                         }
1798                 } else if (ifp->if_flags & IFF_RUNNING) {
1799                         carp_stop(sc, 0);
1800                 }
1801                 break;
1802
1803         case SIOCSVH:
1804                 error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY);
1805                 if (error)
1806                         break;
1807                 error = copyin(ifr->ifr_data, &carpr, sizeof(carpr));
1808                 if (error)
1809                         break;
1810
1811                 error = 1;
1812                 if ((ifp->if_flags & IFF_RUNNING) &&
1813                     sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
1814                         switch (carpr.carpr_state) {
1815                         case BACKUP:
1816                                 callout_stop(&sc->sc_ad_tmo);
1817                                 carp_set_state(sc, BACKUP);
1818                                 carp_setrun(sc, 0);
1819                                 carp_setroute(sc, RTM_DELETE);
1820                                 break;
1821
1822                         case MASTER:
1823                                 carp_master_down(sc);
1824                                 break;
1825
1826                         default:
1827                                 break;
1828                         }
1829                 }
1830                 if (carpr.carpr_vhid > 0) {
1831                         if (carpr.carpr_vhid > 255) {
1832                                 error = EINVAL;
1833                                 break;
1834                         }
1835                         if (sc->sc_carpdev) {
1836                                 struct carp_if *cif = sc->sc_carpdev->if_carp;
1837
1838                                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1839                                         if (vr != sc &&
1840                                             vr->sc_vhid == carpr.carpr_vhid)
1841                                                 return EEXIST;
1842                                 }
1843                         }
1844                         sc->sc_vhid = carpr.carpr_vhid;
1845                         IF_LLADDR(ifp)[0] = 0;
1846                         IF_LLADDR(ifp)[1] = 0;
1847                         IF_LLADDR(ifp)[2] = 0x5e;
1848                         IF_LLADDR(ifp)[3] = 0;
1849                         IF_LLADDR(ifp)[4] = 1;
1850                         IF_LLADDR(ifp)[5] = sc->sc_vhid;
1851                         error--;
1852                 }
1853                 if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
1854                         if (carpr.carpr_advskew >= 255) {
1855                                 error = EINVAL;
1856                                 break;
1857                         }
1858                         if (carpr.carpr_advbase > 255) {
1859                                 error = EINVAL;
1860                                 break;
1861                         }
1862                         sc->sc_advbase = carpr.carpr_advbase;
1863                         sc->sc_advskew = carpr.carpr_advskew;
1864                         error--;
1865                 }
1866                 bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1867                 if (error > 0) {
1868                         error = EINVAL;
1869                 } else {
1870                         error = 0;
1871                         carp_setrun(sc, 0);
1872                 }
1873                 break;
1874
1875         case SIOCGVH:
1876                 bzero(&carpr, sizeof(carpr));
1877                 carpr.carpr_state = sc->sc_state;
1878                 carpr.carpr_vhid = sc->sc_vhid;
1879                 carpr.carpr_advbase = sc->sc_advbase;
1880                 carpr.carpr_advskew = sc->sc_advskew;
1881                 error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY);
1882                 if (error == 0) {
1883                         bcopy(sc->sc_key, carpr.carpr_key,
1884                               sizeof(carpr.carpr_key));
1885                 }
1886
1887                 error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
1888                 break;
1889
1890         case SIOCGDRVSPEC:
1891                 switch (ifd->ifd_cmd) {
1892                 case CARPGDEVNAME:
1893                         if (ifd->ifd_len != sizeof(devname))
1894                                 error = EINVAL;
1895                         break;
1896
1897                 case CARPGVHADDR:
1898                         break;
1899
1900                 default:
1901                         error = EINVAL;
1902                         break;
1903                 }
1904                 if (error)
1905                         break;
1906
1907                 switch (ifd->ifd_cmd) {
1908                 case CARPGVHADDR:
1909                         error = carp_get_vhaddr(sc, ifd);
1910                         break;
1911
1912                 case CARPGDEVNAME:
1913                         bzero(devname, sizeof(devname));
1914                         if (sc->sc_carpdev != NULL) {
1915                                 strlcpy(devname, sc->sc_carpdev->if_xname,
1916                                         sizeof(devname));
1917                         }
1918                         error = copyout(devname, ifd->ifd_data,
1919                                         sizeof(devname));
1920                         break;
1921                 }
1922                 break;
1923
1924         default:
1925                 error = EINVAL;
1926                 break;
1927         }
1928         carp_hmac_prepare(sc);
1929         return error;
1930 }
1931
1932 /*
1933  * XXX: this is looutput. We should eventually use it from there.
1934  */
1935 static int
1936 carp_looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
1937     struct rtentry *rt)
1938 {
1939         uint32_t af;
1940
1941         M_ASSERTPKTHDR(m); /* check if we have the packet header */
1942
1943         if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
1944                 m_freem(m);
1945                 return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
1946                         rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
1947         }
1948
1949         ifp->if_opackets++;
1950         ifp->if_obytes += m->m_pkthdr.len;
1951
1952         /* BPF writes need to be handled specially. */
1953         if (dst->sa_family == AF_UNSPEC) {
1954                 bcopy(dst->sa_data, &af, sizeof(af));
1955                 dst->sa_family = af;
1956         }
1957
1958 #if 1   /* XXX */
1959         switch (dst->sa_family) {
1960         case AF_INET:
1961         case AF_INET6:
1962         case AF_IPX:
1963         case AF_APPLETALK:
1964                 break;
1965
1966         default:
1967                 m_freem(m);
1968                 return (EAFNOSUPPORT);
1969         }
1970 #endif
1971         return (if_simloop(ifp, m, dst->sa_family, 0));
1972 }
1973
1974 /*
1975  * Start output on carp interface. This function should never be called.
1976  */
1977 static void
1978 carp_start(struct ifnet *ifp)
1979 {
1980 #ifdef DEBUG
1981         kprintf("%s: start called\n", ifp->if_xname);
1982 #endif
1983 }
1984
1985 int
1986 carp_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
1987     struct rtentry *rt)
1988 {
1989         struct m_tag *mtag;
1990         struct carp_softc *sc;
1991         struct ifnet *carp_ifp;
1992         struct ether_header *eh;
1993
1994         if (!sa)
1995                 return (0);
1996
1997         switch (sa->sa_family) {
1998 #ifdef INET
1999         case AF_INET:
2000                 break;
2001 #endif /* INET */
2002 #ifdef INET6
2003         case AF_INET6:
2004                 break;
2005 #endif /* INET6 */
2006         default:
2007                 return (0);
2008         }
2009
2010         mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
2011         if (mtag == NULL)
2012                 return (0);
2013
2014         bcopy(mtag + 1, &carp_ifp, sizeof(struct ifnet *));
2015         sc = carp_ifp->if_softc;
2016
2017         /* Set the source MAC address to Virtual Router MAC Address */
2018         switch (ifp->if_type) {
2019         case IFT_ETHER:
2020         case IFT_L2VLAN:
2021                 eh = mtod(m, struct ether_header *);
2022                 eh->ether_shost[0] = 0;
2023                 eh->ether_shost[1] = 0;
2024                 eh->ether_shost[2] = 0x5e;
2025                 eh->ether_shost[3] = 0;
2026                 eh->ether_shost[4] = 1;
2027                 eh->ether_shost[5] = sc->sc_vhid;
2028                 break;
2029
2030         default:
2031                 if_printf(ifp, "carp is not supported for this "
2032                           "interface type\n");
2033                 return (EOPNOTSUPP);
2034         }
2035         return (0);
2036 }
2037
2038 static void
2039 carp_set_state(struct carp_softc *sc, int state)
2040 {
2041         struct ifnet *cifp = &sc->sc_if;
2042
2043         if (sc->sc_state == state)
2044                 return;
2045         sc->sc_state = state;
2046
2047         switch (sc->sc_state) {
2048         case BACKUP:
2049                 cifp->if_link_state = LINK_STATE_DOWN;
2050                 break;
2051
2052         case MASTER:
2053                 cifp->if_link_state = LINK_STATE_UP;
2054                 break;
2055
2056         default:
2057                 cifp->if_link_state = LINK_STATE_UNKNOWN;
2058                 break;
2059         }
2060         rt_ifmsg(cifp);
2061 }
2062
2063 void
2064 carp_group_demote_adj(struct ifnet *ifp, int adj)
2065 {
2066         struct ifg_list *ifgl;
2067         int *dm;
2068
2069         TAILQ_FOREACH(ifgl, &ifp->if_groups, ifgl_next) {
2070                 if (!strcmp(ifgl->ifgl_group->ifg_group, IFG_ALL))
2071                         continue;
2072                 dm = &ifgl->ifgl_group->ifg_carp_demoted;
2073
2074                 if (*dm + adj >= 0)
2075                         *dm += adj;
2076                 else
2077                         *dm = 0;
2078
2079                 if (adj > 0 && *dm == 1)
2080                         carp_send_ad_all();
2081                 CARP_LOG("%s demoted group %s to %d", ifp->if_xname,
2082                     ifgl->ifgl_group->ifg_group, *dm);
2083         }
2084 }
2085
2086 void
2087 carp_carpdev_state(void *v)
2088 {
2089         struct carp_if *cif = v;
2090         struct carp_softc *sc;
2091
2092         TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list)
2093                 carp_sc_state(sc);
2094 }
2095
2096 static void
2097 carp_sc_state(struct carp_softc *sc)
2098 {
2099         if (!(sc->sc_carpdev->if_flags & IFF_UP)) {
2100                 callout_stop(&sc->sc_ad_tmo);
2101                 callout_stop(&sc->sc_md_tmo);
2102                 callout_stop(&sc->sc_md6_tmo);
2103                 carp_set_state(sc, INIT);
2104                 carp_setrun(sc, 0);
2105                 if (!sc->sc_suppress) {
2106                         carp_suppress_preempt++;
2107                         if (carp_suppress_preempt == 1)
2108                                 carp_send_ad_all();
2109                 }
2110                 sc->sc_suppress = 1;
2111         } else {
2112                 carp_set_state(sc, INIT);
2113                 carp_setrun(sc, 0);
2114                 if (sc->sc_suppress)
2115                         carp_suppress_preempt--;
2116                 sc->sc_suppress = 0;
2117         }
2118 }
2119
2120 static void
2121 carp_stop(struct carp_softc *sc, int detach)
2122 {
2123         sc->sc_if.if_flags &= ~IFF_RUNNING;
2124
2125         callout_stop(&sc->sc_ad_tmo);
2126         callout_stop(&sc->sc_md_tmo);
2127         callout_stop(&sc->sc_md6_tmo);
2128
2129         if (!detach && sc->sc_state == MASTER)
2130                 carp_send_ad(sc);
2131
2132         if (sc->sc_suppress)
2133                 carp_suppress_preempt--;
2134         sc->sc_suppress = 0;
2135
2136         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
2137                 carp_suppress_preempt--;
2138         sc->sc_sendad_errors = 0;
2139         sc->sc_sendad_success = 0;
2140
2141         carp_set_state(sc, INIT);
2142         carp_setrun(sc, 0);
2143 }
2144
2145 static void
2146 carp_reset(struct carp_softc *sc, int detach)
2147 {
2148         struct ifnet *cifp = &sc->sc_if;
2149
2150         carp_stop(sc, detach);
2151         if (!sc->sc_dead && (cifp->if_flags & IFF_UP))
2152                 cifp->if_flags |= IFF_RUNNING;
2153 }
2154
2155 static int
2156 carp_activate_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha,
2157                      struct ifnet *ifp, const struct in_ifaddr *ia_if, int own)
2158 {
2159         struct ip_moptions *imo = &sc->sc_imo;
2160         struct carp_if *cif;
2161         struct carp_softc *vr, *after = NULL;
2162         int onlist, error;
2163 #ifdef INVARIANTS
2164         int assert_onlist;
2165 #endif
2166
2167         KKASSERT(vha->vha_ia != NULL);
2168
2169         KASSERT(ia_if != NULL, ("NULL backing address\n"));
2170         KASSERT(vha->vha_iaback == NULL, ("%p is already activated\n", vha));
2171         KASSERT((vha->vha_flags & CARP_VHAF_OWNER) == 0,
2172                 ("inactive vhaddr %p is the address owner\n", vha));
2173
2174         KASSERT(sc->sc_carpdev == NULL || sc->sc_carpdev == ifp,
2175                 ("%s is already on %s\n", sc->sc_if.if_xname,
2176                  sc->sc_carpdev->if_xname));
2177
2178         KASSERT(imo->imo_multicast_ifp == NULL ||
2179                 imo->imo_multicast_ifp == ifp,
2180                 ("%s didn't leave mcast group on %s\n",
2181                  sc->sc_if.if_xname, imo->imo_multicast_ifp->if_xname));
2182
2183         if (imo->imo_num_memberships == 0) {
2184                 struct in_addr addr;
2185
2186                 addr.s_addr = htonl(INADDR_CARP_GROUP);
2187                 if ((imo->imo_membership[0] = in_addmulti(&addr, ifp)) == NULL)
2188                         return ENOBUFS;
2189                 imo->imo_num_memberships++;
2190                 imo->imo_multicast_ifp = ifp;
2191                 imo->imo_multicast_ttl = CARP_DFLTTL;
2192                 imo->imo_multicast_loop = 0;
2193         }
2194
2195         if (!ifp->if_carp) {
2196                 KASSERT(sc->sc_carpdev == NULL,
2197                         ("%s is already on %s\n", sc->sc_if.if_xname,
2198                          sc->sc_carpdev->if_xname));
2199
2200                 cif = kmalloc(sizeof(*cif), M_CARP, M_WAITOK | M_ZERO);
2201
2202                 error = ifpromisc(ifp, 1);
2203                 if (error) {
2204                         kfree(cif, M_CARP);
2205                         goto cleanup;
2206                 }
2207
2208                 TAILQ_INIT(&cif->vhif_vrs);
2209                 ifp->if_carp = cif;
2210         } else {
2211                 cif = ifp->if_carp;
2212                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
2213                         if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
2214                                 error = EINVAL;
2215                                 goto cleanup;
2216                         }
2217                 }
2218         }
2219
2220 #ifdef INVARIANTS
2221         if (sc->sc_carpdev != NULL)
2222                 assert_onlist = 1;
2223         else
2224                 assert_onlist = 0;
2225 #endif
2226         sc->sc_ia = ia_if;
2227         sc->sc_carpdev = ifp;
2228
2229         cif = ifp->if_carp;
2230         onlist = 0;
2231         TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
2232                 if (vr == sc)
2233                         onlist = 1;
2234                 if (vr->sc_vhid < sc->sc_vhid)
2235                         after = vr;
2236         }
2237
2238 #ifdef INVARIANTS
2239         if (assert_onlist) {
2240                 KASSERT(onlist, ("%s is not on %s carp list\n",
2241                         sc->sc_if.if_xname, ifp->if_xname));
2242         } else {
2243                 KASSERT(!onlist, ("%s is already on %s carp list\n",
2244                         sc->sc_if.if_xname, ifp->if_xname));
2245         }
2246 #endif
2247
2248         if (!onlist) {
2249                 /* We're trying to keep things in order */
2250                 if (after == NULL)
2251                         TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
2252                 else
2253                         TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
2254         }
2255
2256         vha->vha_iaback = ia_if;
2257         sc->sc_naddrs++;
2258
2259         if (own) {
2260                 vha->vha_flags |= CARP_VHAF_OWNER;
2261
2262                 /* XXX save user configured advskew? */
2263                 sc->sc_advskew = 0;
2264         }
2265
2266         carp_hmac_prepare(sc);
2267         carp_set_state(sc, INIT);
2268         carp_setrun(sc, 0);
2269         return 0;
2270 cleanup:
2271         carp_multicast_cleanup(sc);
2272         return error;
2273 }
2274
2275 static void
2276 carp_deactivate_vhaddr(struct carp_softc *sc, struct carp_vhaddr *vha)
2277 {
2278         KKASSERT(vha->vha_ia != NULL);
2279
2280         carp_hmac_prepare(sc);
2281
2282         if (vha->vha_iaback == NULL) {
2283                 KASSERT((vha->vha_flags & CARP_VHAF_OWNER) == 0,
2284                         ("inactive vhaddr %p is the address owner\n", vha));
2285                 return;
2286         }
2287
2288         vha->vha_flags &= ~CARP_VHAF_OWNER;
2289
2290         KKASSERT(sc->sc_naddrs > 0);
2291         vha->vha_iaback = NULL;
2292         sc->sc_naddrs--;
2293         if (!sc->sc_naddrs) {
2294                 if (sc->sc_naddrs6) {
2295                         carp_multicast_cleanup(sc);
2296                         sc->sc_ia = NULL;
2297                 } else {
2298                         carp_detach(sc, 0);
2299                 }
2300         }
2301 }
2302
2303 static void
2304 carp_link_addrs(struct carp_softc *sc, struct ifnet *ifp, struct ifaddr *ifa_if)
2305 {
2306         struct carp_vhaddr *vha;
2307         struct in_ifaddr *ia_if;
2308
2309         KKASSERT(ifa_if->ifa_addr->sa_family == AF_INET);
2310         ia_if = ifatoia(ifa_if);
2311
2312         if ((ia_if->ia_flags & IFA_ROUTE) == 0)
2313                 return;
2314
2315         /*
2316          * Test each inactive vhaddr against the newly added address.
2317          * If the newly added address could be the backing address,
2318          * then activate the matching vhaddr.
2319          */
2320         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
2321                 const struct in_ifaddr *ia;
2322                 u_long iaddr;
2323                 int own;
2324
2325                 if (vha->vha_iaback != NULL)
2326                         continue;
2327
2328                 ia = vha->vha_ia;
2329                 iaddr = ntohl(ia->ia_addr.sin_addr.s_addr);
2330
2331                 if ((iaddr & ia_if->ia_subnetmask) != ia_if->ia_subnet)
2332                         continue;
2333
2334                 own = 0;
2335                 if (ia->ia_addr.sin_addr.s_addr ==
2336                     ia_if->ia_addr.sin_addr.s_addr)
2337                         own = 1;
2338
2339                 carp_activate_vhaddr(sc, vha, ifp, ia_if, own);
2340         }
2341 }
2342
2343 static void
2344 carp_unlink_addrs(struct carp_softc *sc, struct ifnet *ifp,
2345                   struct ifaddr *ifa_if)
2346 {
2347         struct carp_vhaddr *vha;
2348         struct in_ifaddr *ia_if;
2349
2350         KKASSERT(ifa_if->ifa_addr->sa_family == AF_INET);
2351         ia_if = ifatoia(ifa_if);
2352
2353         /*
2354          * Ad src address is deleted; set it to NULL.
2355          * Following loop will try pick up a new ad src address
2356          * if one of the vhaddr could retain its backing address.
2357          */
2358         if (sc->sc_ia == ia_if)
2359                 sc->sc_ia = NULL;
2360
2361         /*
2362          * Test each active vhaddr against the deleted address.
2363          * If the deleted address is vhaddr address's backing
2364          * address, then deactivate the vhaddr.
2365          */
2366         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link) {
2367                 if (vha->vha_iaback == NULL)
2368                         continue;
2369
2370                 if (vha->vha_iaback == ia_if)
2371                         carp_deactivate_vhaddr(sc, vha);
2372                 else if (sc->sc_ia == NULL)
2373                         sc->sc_ia = vha->vha_iaback;
2374         }
2375 }
2376
2377 static void
2378 carp_update_addrs(struct carp_softc *sc)
2379 {
2380         struct carp_vhaddr *vha;
2381
2382         KKASSERT(sc->sc_carpdev == NULL);
2383
2384         TAILQ_FOREACH(vha, &sc->sc_vha_list, vha_link)
2385                 carp_config_vhaddr(sc, vha);
2386 }
2387
2388 static void
2389 carp_ifaddr(void *arg __unused, struct ifnet *ifp,
2390             enum ifaddr_event event, struct ifaddr *ifa)
2391 {
2392         struct carp_softc *sc;
2393
2394         if (ifa->ifa_addr->sa_family != AF_INET)
2395                 return;
2396
2397         if (ifp->if_type == IFT_CARP) {
2398                 /*
2399                  * Address is changed on carp(4) interface
2400                  */
2401                 switch (event) {
2402                 case IFADDR_EVENT_ADD:
2403                         carp_add_addr(ifp->if_softc, ifa);
2404                         break;
2405
2406                 case IFADDR_EVENT_CHANGE:
2407                         carp_config_addr(ifp->if_softc, ifa);
2408                         break;
2409
2410                 case IFADDR_EVENT_DELETE:
2411                         carp_del_addr(ifp->if_softc, ifa);
2412                         break;
2413                 }
2414                 return;
2415         }
2416
2417         /*
2418          * Address is changed on non-carp(4) interface
2419          */
2420         if ((ifp->if_flags & IFF_MULTICAST) == 0)
2421                 return;
2422
2423         crit_enter();
2424         LIST_FOREACH(sc, &carpif_list, sc_next) {
2425                 if (sc->sc_carpdev != NULL && sc->sc_carpdev != ifp) {
2426                         /* Not the parent iface; skip */
2427                         continue;
2428                 }
2429
2430                 switch (event) {
2431                 case IFADDR_EVENT_ADD:
2432                         carp_link_addrs(sc, ifp, ifa);
2433                         break;
2434
2435                 case IFADDR_EVENT_DELETE:
2436                         if (sc->sc_carpdev != NULL) {
2437                                 carp_unlink_addrs(sc, ifp, ifa);
2438                                 if (sc->sc_carpdev == NULL)
2439                                         carp_update_addrs(sc);
2440                         } else {
2441                                 /*
2442                                  * The carp(4) interface didn't have a
2443                                  * parent iface, so it is not possible
2444                                  * that it will contain any address to
2445                                  * be unlinked.
2446                                  */
2447                         }
2448                         break;
2449
2450                 case IFADDR_EVENT_CHANGE:
2451                         if (sc->sc_carpdev == NULL) {
2452                                 /*
2453                                  * The carp(4) interface didn't have a
2454                                  * parent iface, so it is not possible
2455                                  * that it will contain any address to
2456                                  * be updated.
2457                                  */
2458                                 carp_link_addrs(sc, ifp, ifa);
2459                         } else {
2460                                 /*
2461                                  * First try breaking tie with the old
2462                                  * address.  Then see whether we could
2463                                  * link certain vhaddr to the new address.
2464                                  * If that fails, i.e. carpdev is NULL,
2465                                  * we try a global update.
2466                                  *
2467                                  * NOTE: The above order is critical.
2468                                  */
2469                                 carp_unlink_addrs(sc, ifp, ifa);
2470                                 carp_link_addrs(sc, ifp, ifa);
2471                                 if (sc->sc_carpdev == NULL)
2472                                         carp_update_addrs(sc);
2473                         }
2474                         break;
2475                 }
2476         }
2477         crit_exit();
2478 }
2479
2480 static int
2481 carp_modevent(module_t mod, int type, void *data)
2482 {
2483         switch (type) {
2484         case MOD_LOAD:
2485                 LIST_INIT(&carpif_list);
2486                 carp_ifdetach_event =
2487                 EVENTHANDLER_REGISTER(ifnet_detach_event, carp_ifdetach, NULL,
2488                                       EVENTHANDLER_PRI_ANY);
2489                 carp_ifaddr_event =
2490                 EVENTHANDLER_REGISTER(ifaddr_event, carp_ifaddr, NULL,
2491                                       EVENTHANDLER_PRI_ANY);
2492                 if_clone_attach(&carp_cloner);
2493                 break;
2494
2495         case MOD_UNLOAD:
2496                 EVENTHANDLER_DEREGISTER(ifnet_detach_event,
2497                                         carp_ifdetach_event);
2498                 EVENTHANDLER_DEREGISTER(ifaddr_event,
2499                                         carp_ifaddr_event);
2500                 if_clone_detach(&carp_cloner);
2501                 break;
2502
2503         default:
2504                 return (EINVAL);
2505         }
2506         return (0);
2507 }
2508
2509 static moduledata_t carp_mod = {
2510         "carp",
2511         carp_modevent,
2512         0
2513 };
2514 DECLARE_MODULE(carp, carp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);