sys/netinet/ip_carp.c

   1 /*      $FreeBSD$ */
   2
   3 /*
   4  * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
   5  * Copyright (c) 2003 Ryan McBride. All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
  20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  22  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  25  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  26  * THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include "opt_carp.h"
  30 #include "opt_bpf.h"
  31 #include "opt_inet.h"
  32 #include "opt_inet6.h"
  33
  34 #include <sys/types.h>
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/conf.h>
  38 #include <sys/kernel.h>
  39 #include <sys/limits.h>
  40 #include <sys/malloc.h>
  41 #include <sys/mbuf.h>
  42 #include <sys/module.h>
  43 #include <sys/time.h>
  44 #include <sys/proc.h>
  45 #include <sys/sysctl.h>
  46 #include <sys/syslog.h>
  47 #include <sys/signalvar.h>
  48 #include <sys/filio.h>
  49 #include <sys/sockio.h>
  50
  51 #include <sys/socket.h>
  52 #include <sys/vnode.h>
  53
  54 #include <machine/stdarg.h>
  55
  56 #include <net/bpf.h>
  57 #include <net/ethernet.h>
  58 #include <net/fddi.h>
  59 #include <net/iso88025.h>
  60 #include <net/if.h>
  61 #include <net/if_clone.h>
  62 #include <net/if_dl.h>
  63 #include <net/if_types.h>
  64 #include <net/route.h>
  65
  66 #ifdef INET
  67 #include <netinet/in.h>
  68 #include <netinet/in_var.h>
  69 #include <netinet/in_systm.h>
  70 #include <netinet/ip.h>
  71 #include <netinet/ip_var.h>
  72 #include <netinet/if_ether.h>
  73 #include <machine/in_cksum.h>
  74 #endif
  75
  76 #ifdef INET6
  77 #include <netinet/icmp6.h>
  78 #include <netinet/ip6.h>
  79 #include <netinet6/ip6_var.h>
  80 #include <netinet6/scope6_var.h>
  81 #include <netinet6/nd6.h>
  82 #endif
  83
  84 #include <crypto/sha1.h>
  85 #include <netinet/ip_carp.h>
  86
  87 #define CARP_IFNAME     "carp"
  88 static MALLOC_DEFINE(M_CARP, "CARP", "CARP interfaces");
  89 SYSCTL_DECL(_net_inet_carp);
  90
  91 struct carp_softc {
  92         struct ifnet            *sc_ifp;        /* Interface clue */
  93         struct ifnet            *sc_carpdev;    /* Pointer to parent interface */
  94         struct in_ifaddr        *sc_ia;         /* primary iface address */
  95         struct ip_moptions       sc_imo;
  96 #ifdef INET6
  97         struct in6_ifaddr       *sc_ia6;        /* primary iface address v6 */
  98         struct ip6_moptions      sc_im6o;
  99 #endif /* INET6 */
 100         TAILQ_ENTRY(carp_softc)  sc_list;
 101
 102         enum { INIT = 0, BACKUP, MASTER }       sc_state;
 103
 104         int                      sc_flags_backup;
 105         int                      sc_suppress;
 106
 107         int                      sc_sendad_errors;
 108 #define CARP_SENDAD_MAX_ERRORS  3
 109         int                      sc_sendad_success;
 110 #define CARP_SENDAD_MIN_SUCCESS 3
 111
 112         int                      sc_vhid;
 113         int                      sc_advskew;
 114         int                      sc_naddrs;
 115         int                      sc_naddrs6;
 116         int                      sc_advbase;    /* seconds */
 117         int                      sc_init_counter;
 118         u_int64_t                sc_counter;
 119
 120         /* authentication */
 121 #define CARP_HMAC_PAD   64
 122         unsigned char sc_key[CARP_KEY_LEN];
 123         unsigned char sc_pad[CARP_HMAC_PAD];
 124         SHA1_CTX sc_sha1;
 125
 126         struct callout           sc_ad_tmo;     /* advertisement timeout */
 127         struct callout           sc_md_tmo;     /* master down timeout */
 128         struct callout           sc_md6_tmo;    /* master down timeout */
 129
 130         LIST_ENTRY(carp_softc)   sc_next;       /* Interface clue */
 131 };
 132 #define SC2IFP(sc)      ((sc)->sc_ifp)
 133
 134 int carp_suppress_preempt = 0;
 135 int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 1, 0, 0 };    /* XXX for now */
 136 SYSCTL_INT(_net_inet_carp, CARPCTL_ALLOW, allow, CTLFLAG_RW,
 137     &carp_opts[CARPCTL_ALLOW], 0, "Accept incoming CARP packets");
 138 SYSCTL_INT(_net_inet_carp, CARPCTL_PREEMPT, preempt, CTLFLAG_RW,
 139     &carp_opts[CARPCTL_PREEMPT], 0, "high-priority backup preemption mode");
 140 SYSCTL_INT(_net_inet_carp, CARPCTL_LOG, log, CTLFLAG_RW,
 141     &carp_opts[CARPCTL_LOG], 0, "log bad carp packets");
 142 SYSCTL_INT(_net_inet_carp, CARPCTL_ARPBALANCE, arpbalance, CTLFLAG_RW,
 143     &carp_opts[CARPCTL_ARPBALANCE], 0, "balance arp responses");
 144 SYSCTL_INT(_net_inet_carp, OID_AUTO, suppress_preempt, CTLFLAG_RD,
 145     &carp_suppress_preempt, 0, "Preemption is suppressed");
 146
 147 struct carpstats carpstats;
 148 SYSCTL_STRUCT(_net_inet_carp, CARPCTL_STATS, stats, CTLFLAG_RW,
 149     &carpstats, carpstats,
 150     "CARP statistics (struct carpstats, netinet/ip_carp.h)");
 151
 152 struct carp_if {
 153         TAILQ_HEAD(, carp_softc) vhif_vrs;
 154         int vhif_nvrs;
 155
 156         struct ifnet    *vhif_ifp;
 157         struct mtx       vhif_mtx;
 158 };
 159
 160 /* Get carp_if from softc. Valid after carp_set_addr{,6}. */
 161 #define SC2CIF(sc)              ((struct carp_if *)(sc)->sc_carpdev->if_carp)
 162
 163 /* lock per carp_if queue */
 164 #define CARP_LOCK_INIT(cif)     mtx_init(&(cif)->vhif_mtx, "carp_if",   \
 165         NULL, MTX_DEF)
 166 #define CARP_LOCK_DESTROY(cif)  mtx_destroy(&(cif)->vhif_mtx)
 167 #define CARP_LOCK_ASSERT(cif)   mtx_assert(&(cif)->vhif_mtx, MA_OWNED)
 168 #define CARP_LOCK(cif)          mtx_lock(&(cif)->vhif_mtx)
 169 #define CARP_UNLOCK(cif)        mtx_unlock(&(cif)->vhif_mtx)
 170
 171 #define CARP_SCLOCK(sc)         mtx_lock(&SC2CIF(sc)->vhif_mtx)
 172 #define CARP_SCUNLOCK(sc)       mtx_unlock(&SC2CIF(sc)->vhif_mtx)
 173 #define CARP_SCLOCK_ASSERT(sc)  mtx_assert(&SC2CIF(sc)->vhif_mtx, MA_OWNED)
 174
 175 #define CARP_LOG(...)   do {                            \
 176         if (carp_opts[CARPCTL_LOG] > 0)                 \
 177                 log(LOG_INFO, __VA_ARGS__);             \
 178 } while (0)
 179
 180 #define CARP_DEBUG(...) do {                            \
 181         if (carp_opts[CARPCTL_LOG] > 1)                 \
 182                 log(LOG_DEBUG, __VA_ARGS__);            \
 183 } while (0)
 184
 185 static void     carp_hmac_prepare(struct carp_softc *);
 186 static void     carp_hmac_generate(struct carp_softc *, u_int32_t *,
 187                     unsigned char *);
 188 static int      carp_hmac_verify(struct carp_softc *, u_int32_t *,
 189                     unsigned char *);
 190 static void     carp_setroute(struct carp_softc *, int);
 191 static void     carp_input_c(struct mbuf *, struct carp_header *, sa_family_t);
 192 static int      carp_clone_create(struct if_clone *, int, caddr_t);
 193 static void     carp_clone_destroy(struct ifnet *);
 194 static void     carpdetach(struct carp_softc *);
 195 static int      carp_prepare_ad(struct mbuf *, struct carp_softc *,
 196                     struct carp_header *);
 197 static void     carp_send_ad_all(void);
 198 static void     carp_send_ad(void *);
 199 static void     carp_send_ad_locked(struct carp_softc *);
 200 static void     carp_send_arp(struct carp_softc *);
 201 static void     carp_master_down(void *);
 202 static void     carp_master_down_locked(struct carp_softc *);
 203 static int      carp_ioctl(struct ifnet *, u_long, caddr_t);
 204 static int      carp_looutput(struct ifnet *, struct mbuf *, struct sockaddr *,
 205                     struct rtentry *);
 206 static void     carp_start(struct ifnet *);
 207 static void     carp_setrun(struct carp_softc *, sa_family_t);
 208 static void     carp_set_state(struct carp_softc *, int);
 209 static int      carp_addrcount(struct carp_if *, struct in_ifaddr *, int);
 210 enum    { CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
 211
 212 static void     carp_multicast_cleanup(struct carp_softc *);
 213 static int      carp_set_addr(struct carp_softc *, struct sockaddr_in *);
 214 static int      carp_del_addr(struct carp_softc *, struct sockaddr_in *);
 215 static void     carp_carpdev_state_locked(struct carp_if *);
 216 static void     carp_sc_state_locked(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 #endif
 222
 223 static LIST_HEAD(, carp_softc) carpif_list;
 224 static struct mtx carp_mtx;
 225 IFC_SIMPLE_DECLARE(carp, 0);
 226
 227 static eventhandler_tag if_detach_event_tag;
 228
 229 static __inline u_int16_t
 230 carp_cksum(struct mbuf *m, int len)
 231 {
 232         return (in_cksum(m, len));
 233 }
 234
 235 static void
 236 carp_hmac_prepare(struct carp_softc *sc)
 237 {
 238         u_int8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
 239         u_int8_t vhid = sc->sc_vhid & 0xff;
 240         struct ifaddr *ifa;
 241         int i;
 242 #ifdef INET6
 243         struct in6_addr in6;
 244 #endif
 245
 246         if (sc->sc_carpdev)
 247                 CARP_SCLOCK(sc);
 248
 249         /* XXX: possible race here */
 250
 251         /* compute ipad from key */
 252         bzero(sc->sc_pad, sizeof(sc->sc_pad));
 253         bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
 254         for (i = 0; i < sizeof(sc->sc_pad); i++)
 255                 sc->sc_pad[i] ^= 0x36;
 256
 257         /* precompute first part of inner hash */
 258         SHA1Init(&sc->sc_sha1);
 259         SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
 260         SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
 261         SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
 262         SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
 263 #ifdef INET
 264         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 265                 if (ifa->ifa_addr->sa_family == AF_INET)
 266                         SHA1Update(&sc->sc_sha1,
 267                             (void *)&ifatoia(ifa)->ia_addr.sin_addr.s_addr,
 268                             sizeof(struct in_addr));
 269         }
 270 #endif /* INET */
 271 #ifdef INET6
 272         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 273                 if (ifa->ifa_addr->sa_family == AF_INET6) {
 274                         in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
 275                         in6_clearscope(&in6);
 276                         SHA1Update(&sc->sc_sha1, (void *)&in6, sizeof(in6));
 277                 }
 278         }
 279 #endif /* INET6 */
 280
 281         /* convert ipad to opad */
 282         for (i = 0; i < sizeof(sc->sc_pad); i++)
 283                 sc->sc_pad[i] ^= 0x36 ^ 0x5c;
 284
 285         if (sc->sc_carpdev)
 286                 CARP_SCUNLOCK(sc);
 287 }
 288
 289 static void
 290 carp_hmac_generate(struct carp_softc *sc, u_int32_t counter[2],
 291     unsigned char md[20])
 292 {
 293         SHA1_CTX sha1ctx;
 294
 295         /* fetch first half of inner hash */
 296         bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
 297
 298         SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
 299         SHA1Final(md, &sha1ctx);
 300
 301         /* outer hash */
 302         SHA1Init(&sha1ctx);
 303         SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
 304         SHA1Update(&sha1ctx, md, 20);
 305         SHA1Final(md, &sha1ctx);
 306 }
 307
 308 static int
 309 carp_hmac_verify(struct carp_softc *sc, u_int32_t counter[2],
 310     unsigned char md[20])
 311 {
 312         unsigned char md2[20];
 313
 314         CARP_SCLOCK_ASSERT(sc);
 315
 316         carp_hmac_generate(sc, counter, md2);
 317
 318         return (bcmp(md, md2, sizeof(md2)));
 319 }
 320
 321 static void
 322 carp_setroute(struct carp_softc *sc, int cmd)
 323 {
 324         struct ifaddr *ifa;
 325         int s;
 326
 327         if (sc->sc_carpdev)
 328                 CARP_SCLOCK_ASSERT(sc);
 329
 330         s = splnet();
 331         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 332                 if (ifa->ifa_addr->sa_family == AF_INET &&
 333                     sc->sc_carpdev != NULL) {
 334                         int count = carp_addrcount(
 335                             (struct carp_if *)sc->sc_carpdev->if_carp,
 336                             ifatoia(ifa), CARP_COUNT_MASTER);
 337
 338                         if ((cmd == RTM_ADD && count == 1) ||
 339                             (cmd == RTM_DELETE && count == 0))
 340                                 rtinit(ifa, cmd, RTF_UP | RTF_HOST);
 341                 }
 342 #ifdef INET6
 343                 if (ifa->ifa_addr->sa_family == AF_INET6) {
 344                         if (cmd == RTM_ADD)
 345                                 in6_ifaddloop(ifa);
 346                         else
 347                                 in6_ifremloop(ifa);
 348                 }
 349 #endif /* INET6 */
 350         }
 351         splx(s);
 352 }
 353
 354 static int
 355 carp_clone_create(struct if_clone *ifc, int unit, caddr_t params)
 356 {
 357
 358         struct carp_softc *sc;
 359         struct ifnet *ifp;
 360
 361         MALLOC(sc, struct carp_softc *, sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
 362         ifp = SC2IFP(sc) = if_alloc(IFT_ETHER);
 363         if (ifp == NULL) {
 364                 FREE(sc, M_CARP);
 365                 return (ENOSPC);
 366         }
 367
 368         sc->sc_flags_backup = 0;
 369         sc->sc_suppress = 0;
 370         sc->sc_advbase = CARP_DFLTINTV;
 371         sc->sc_vhid = -1;       /* required setting */
 372         sc->sc_advskew = 0;
 373         sc->sc_init_counter = 1;
 374         sc->sc_naddrs = sc->sc_naddrs6 = 0; /* M_ZERO? */
 375 #ifdef INET6
 376         sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
 377 #endif
 378         sc->sc_imo.imo_membership = (struct in_multi **)malloc(
 379             (sizeof(struct in_multi *) * IP_MIN_MEMBERSHIPS), M_CARP,
 380             M_WAITOK);
 381         sc->sc_imo.imo_max_memberships = IP_MIN_MEMBERSHIPS;
 382
 383         callout_init(&sc->sc_ad_tmo, NET_CALLOUT_MPSAFE);
 384         callout_init(&sc->sc_md_tmo, NET_CALLOUT_MPSAFE);
 385         callout_init(&sc->sc_md6_tmo, NET_CALLOUT_MPSAFE);
 386
 387         ifp->if_softc = sc;
 388         if_initname(ifp, CARP_IFNAME, unit);
 389         ifp->if_mtu = ETHERMTU;
 390         ifp->if_flags = IFF_LOOPBACK;
 391         ifp->if_ioctl = carp_ioctl;
 392         ifp->if_output = carp_looutput;
 393         ifp->if_start = carp_start;
 394         ifp->if_type = IFT_CARP;
 395         ifp->if_snd.ifq_maxlen = ifqmaxlen;
 396         ifp->if_hdrlen = 0;
 397         if_attach(ifp);
 398         bpfattach(SC2IFP(sc), DLT_NULL, sizeof(u_int32_t));
 399         mtx_lock(&carp_mtx);
 400         LIST_INSERT_HEAD(&carpif_list, sc, sc_next);
 401         mtx_unlock(&carp_mtx);
 402         return (0);
 403 }
 404
 405 static void
 406 carp_clone_destroy(struct ifnet *ifp)
 407 {
 408         struct carp_softc *sc = ifp->if_softc;
 409
 410         if (sc->sc_carpdev)
 411                 CARP_SCLOCK(sc);
 412         carpdetach(sc);
 413         if (sc->sc_carpdev)
 414                 CARP_SCUNLOCK(sc);
 415
 416         mtx_lock(&carp_mtx);
 417         LIST_REMOVE(sc, sc_next);
 418         mtx_unlock(&carp_mtx);
 419         bpfdetach(ifp);
 420         if_detach(ifp);
 421         if_free_type(ifp, IFT_ETHER);
 422         free(sc->sc_imo.imo_membership, M_CARP);
 423         free(sc, M_CARP);
 424 }
 425
 426 static void
 427 carpdetach(struct carp_softc *sc)
 428 {
 429         struct carp_if *cif;
 430
 431         callout_stop(&sc->sc_ad_tmo);
 432         callout_stop(&sc->sc_md_tmo);
 433         callout_stop(&sc->sc_md6_tmo);
 434
 435         if (sc->sc_suppress)
 436                 carp_suppress_preempt--;
 437         sc->sc_suppress = 0;
 438
 439         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
 440                 carp_suppress_preempt--;
 441         sc->sc_sendad_errors = 0;
 442
 443         carp_set_state(sc, INIT);
 444         SC2IFP(sc)->if_flags &= ~IFF_UP;
 445         carp_setrun(sc, 0);
 446         carp_multicast_cleanup(sc);
 447
 448         if (sc->sc_carpdev != NULL) {
 449                 cif = (struct carp_if *)sc->sc_carpdev->if_carp;
 450                 CARP_LOCK_ASSERT(cif);
 451                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
 452                 if (!--cif->vhif_nvrs) {
 453                         ifpromisc(sc->sc_carpdev, 0);
 454                         sc->sc_carpdev->if_carp = NULL;
 455                         CARP_LOCK_DESTROY(cif);
 456                         FREE(cif, M_IFADDR);
 457                 }
 458         }
 459         sc->sc_carpdev = NULL;
 460 }
 461
 462 /* Detach an interface from the carp. */
 463 static void
 464 carp_ifdetach(void *arg __unused, struct ifnet *ifp)
 465 {
 466         struct carp_if *cif = (struct carp_if *)ifp->if_carp;
 467         struct carp_softc *sc, *nextsc;
 468
 469         if (cif == NULL)
 470                 return;
 471
 472         /*
 473          * XXX: At the end of for() cycle the lock will be destroyed.
 474          */
 475         CARP_LOCK(cif);
 476         for (sc = TAILQ_FIRST(&cif->vhif_vrs); sc; sc = nextsc) {
 477                 nextsc = TAILQ_NEXT(sc, sc_list);
 478                 carpdetach(sc);
 479         }
 480 }
 481
 482 /*
 483  * process input packet.
 484  * we have rearranged checks order compared to the rfc,
 485  * but it seems more efficient this way or not possible otherwise.
 486  */
 487 void
 488 carp_input(struct mbuf *m, int hlen)
 489 {
 490         struct ip *ip = mtod(m, struct ip *);
 491         struct carp_header *ch;
 492         int iplen, len;
 493
 494         carpstats.carps_ipackets++;
 495
 496         if (!carp_opts[CARPCTL_ALLOW]) {
 497                 m_freem(m);
 498                 return;
 499         }
 500
 501         /* check if received on a valid carp interface */
 502         if (m->m_pkthdr.rcvif->if_carp == NULL) {
 503                 carpstats.carps_badif++;
 504                 CARP_LOG("carp_input: packet received on non-carp "
 505                     "interface: %s\n",
 506                     m->m_pkthdr.rcvif->if_xname);
 507                 m_freem(m);
 508                 return;
 509         }
 510
 511         /* verify that the IP TTL is 255.  */
 512         if (ip->ip_ttl != CARP_DFLTTL) {
 513                 carpstats.carps_badttl++;
 514                 CARP_LOG("carp_input: received ttl %d != 255i on %s\n",
 515                     ip->ip_ttl,
 516                     m->m_pkthdr.rcvif->if_xname);
 517                 m_freem(m);
 518                 return;
 519         }
 520
 521         iplen = ip->ip_hl << 2;
 522
 523         if (m->m_pkthdr.len < iplen + sizeof(*ch)) {
 524                 carpstats.carps_badlen++;
 525                 CARP_LOG("carp_input: received len %zd < "
 526                     "sizeof(struct carp_header)\n",
 527                     m->m_len - sizeof(struct ip));
 528                 m_freem(m);
 529                 return;
 530         }
 531
 532         if (iplen + sizeof(*ch) < m->m_len) {
 533                 if ((m = m_pullup(m, iplen + sizeof(*ch))) == NULL) {
 534                         carpstats.carps_hdrops++;
 535                         CARP_LOG("carp_input: pullup failed\n");
 536                         return;
 537                 }
 538                 ip = mtod(m, struct ip *);
 539         }
 540         ch = (struct carp_header *)((char *)ip + iplen);
 541
 542         /*
 543          * verify that the received packet length is
 544          * equal to the CARP header
 545          */
 546         len = iplen + sizeof(*ch);
 547         if (len > m->m_pkthdr.len) {
 548                 carpstats.carps_badlen++;
 549                 CARP_LOG("carp_input: packet too short %d on %s\n",
 550                     m->m_pkthdr.len,
 551                     m->m_pkthdr.rcvif->if_xname);
 552                 m_freem(m);
 553                 return;
 554         }
 555
 556         if ((m = m_pullup(m, len)) == NULL) {
 557                 carpstats.carps_hdrops++;
 558                 return;
 559         }
 560         ip = mtod(m, struct ip *);
 561         ch = (struct carp_header *)((char *)ip + iplen);
 562
 563         /* verify the CARP checksum */
 564         m->m_data += iplen;
 565         if (carp_cksum(m, len - iplen)) {
 566                 carpstats.carps_badsum++;
 567                 CARP_LOG("carp_input: checksum failed on %s\n",
 568                     m->m_pkthdr.rcvif->if_xname);
 569                 m_freem(m);
 570                 return;
 571         }
 572         m->m_data -= iplen;
 573
 574         carp_input_c(m, ch, AF_INET);
 575 }
 576
 577 #ifdef INET6
 578 int
 579 carp6_input(struct mbuf **mp, int *offp, int proto)
 580 {
 581         struct mbuf *m = *mp;
 582         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 583         struct carp_header *ch;
 584         u_int len;
 585
 586         carpstats.carps_ipackets6++;
 587
 588         if (!carp_opts[CARPCTL_ALLOW]) {
 589                 m_freem(m);
 590                 return (IPPROTO_DONE);
 591         }
 592
 593         /* check if received on a valid carp interface */
 594         if (m->m_pkthdr.rcvif->if_carp == NULL) {
 595                 carpstats.carps_badif++;
 596                 CARP_LOG("carp6_input: packet received on non-carp "
 597                     "interface: %s\n",
 598                     m->m_pkthdr.rcvif->if_xname);
 599                 m_freem(m);
 600                 return (IPPROTO_DONE);
 601         }
 602
 603         /* verify that the IP TTL is 255 */
 604         if (ip6->ip6_hlim != CARP_DFLTTL) {
 605                 carpstats.carps_badttl++;
 606                 CARP_LOG("carp6_input: received ttl %d != 255 on %s\n",
 607                     ip6->ip6_hlim,
 608                     m->m_pkthdr.rcvif->if_xname);
 609                 m_freem(m);
 610                 return (IPPROTO_DONE);
 611         }
 612
 613         /* verify that we have a complete carp packet */
 614         len = m->m_len;
 615         IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
 616         if (ch == NULL) {
 617                 carpstats.carps_badlen++;
 618                 CARP_LOG("carp6_input: packet size %u too small\n", len);
 619                 return (IPPROTO_DONE);
 620         }
 621
 622
 623         /* verify the CARP checksum */
 624         m->m_data += *offp;
 625         if (carp_cksum(m, sizeof(*ch))) {
 626                 carpstats.carps_badsum++;
 627                 CARP_LOG("carp6_input: checksum failed, on %s\n",
 628                     m->m_pkthdr.rcvif->if_xname);
 629                 m_freem(m);
 630                 return (IPPROTO_DONE);
 631         }
 632         m->m_data -= *offp;
 633
 634         carp_input_c(m, ch, AF_INET6);
 635         return (IPPROTO_DONE);
 636 }
 637 #endif /* INET6 */
 638
 639 static void
 640 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
 641 {
 642         struct ifnet *ifp = m->m_pkthdr.rcvif;
 643         struct carp_softc *sc;
 644         u_int64_t tmp_counter;
 645         struct timeval sc_tv, ch_tv;
 646
 647         /* verify that the VHID is valid on the receiving interface */
 648         CARP_LOCK(ifp->if_carp);
 649         TAILQ_FOREACH(sc, &((struct carp_if *)ifp->if_carp)->vhif_vrs, sc_list)
 650                 if (sc->sc_vhid == ch->carp_vhid)
 651                         break;
 652
 653         if (!sc || !((SC2IFP(sc)->if_flags & IFF_UP) &&
 654             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING))) {
 655                 carpstats.carps_badvhid++;
 656                 CARP_UNLOCK(ifp->if_carp);
 657                 m_freem(m);
 658                 return;
 659         }
 660
 661         getmicrotime(&SC2IFP(sc)->if_lastchange);
 662         SC2IFP(sc)->if_ipackets++;
 663         SC2IFP(sc)->if_ibytes += m->m_pkthdr.len;
 664
 665         if (bpf_peers_present(SC2IFP(sc)->if_bpf)) {
 666                 struct ip *ip = mtod(m, struct ip *);
 667                 uint32_t af1 = af;
 668
 669                 /* BPF wants net byte order */
 670                 ip->ip_len = htons(ip->ip_len + (ip->ip_hl << 2));
 671                 ip->ip_off = htons(ip->ip_off);
 672                 bpf_mtap2(SC2IFP(sc)->if_bpf, &af1, sizeof(af1), m);
 673         }
 674
 675         /* verify the CARP version. */
 676         if (ch->carp_version != CARP_VERSION) {
 677                 carpstats.carps_badver++;
 678                 SC2IFP(sc)->if_ierrors++;
 679                 CARP_UNLOCK(ifp->if_carp);
 680                 CARP_LOG("%s; invalid version %d\n",
 681                     SC2IFP(sc)->if_xname,
 682                     ch->carp_version);
 683                 m_freem(m);
 684                 return;
 685         }
 686
 687         /* verify the hash */
 688         if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
 689                 carpstats.carps_badauth++;
 690                 SC2IFP(sc)->if_ierrors++;
 691                 CARP_UNLOCK(ifp->if_carp);
 692                 CARP_LOG("%s: incorrect hash\n", SC2IFP(sc)->if_xname);
 693                 m_freem(m);
 694                 return;
 695         }
 696
 697         tmp_counter = ntohl(ch->carp_counter[0]);
 698         tmp_counter = tmp_counter<<32;
 699         tmp_counter += ntohl(ch->carp_counter[1]);
 700
 701         /* XXX Replay protection goes here */
 702
 703         sc->sc_init_counter = 0;
 704         sc->sc_counter = tmp_counter;
 705
 706         sc_tv.tv_sec = sc->sc_advbase;
 707         if (carp_suppress_preempt && sc->sc_advskew <  240)
 708                 sc_tv.tv_usec = 240 * 1000000 / 256;
 709         else
 710                 sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
 711         ch_tv.tv_sec = ch->carp_advbase;
 712         ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
 713
 714         switch (sc->sc_state) {
 715         case INIT:
 716                 break;
 717         case MASTER:
 718                 /*
 719                  * If we receive an advertisement from a master who's going to
 720                  * be more frequent than us, go into BACKUP state.
 721                  */
 722                 if (timevalcmp(&sc_tv, &ch_tv, >) ||
 723                     timevalcmp(&sc_tv, &ch_tv, ==)) {
 724                         callout_stop(&sc->sc_ad_tmo);
 725                         CARP_DEBUG("%s: MASTER -> BACKUP "
 726                            "(more frequent advertisement received)\n",
 727                            SC2IFP(sc)->if_xname);
 728                         carp_set_state(sc, BACKUP);
 729                         carp_setrun(sc, 0);
 730                         carp_setroute(sc, RTM_DELETE);
 731                 }
 732                 break;
 733         case BACKUP:
 734                 /*
 735                  * If we're pre-empting masters who advertise slower than us,
 736                  * and this one claims to be slower, treat him as down.
 737                  */
 738                 if (carp_opts[CARPCTL_PREEMPT] &&
 739                     timevalcmp(&sc_tv, &ch_tv, <)) {
 740                         CARP_DEBUG("%s: BACKUP -> MASTER "
 741                             "(preempting a slower master)\n",
 742                             SC2IFP(sc)->if_xname);
 743                         carp_master_down_locked(sc);
 744                         break;
 745                 }
 746
 747                 /*
 748                  *  If the master is going to advertise at such a low frequency
 749                  *  that he's guaranteed to time out, we'd might as well just
 750                  *  treat him as timed out now.
 751                  */
 752                 sc_tv.tv_sec = sc->sc_advbase * 3;
 753                 if (timevalcmp(&sc_tv, &ch_tv, <)) {
 754                         CARP_DEBUG("%s: BACKUP -> MASTER "
 755                             "(master timed out)\n",
 756                             SC2IFP(sc)->if_xname);
 757                         carp_master_down_locked(sc);
 758                         break;
 759                 }
 760
 761                 /*
 762                  * Otherwise, we reset the counter and wait for the next
 763                  * advertisement.
 764                  */
 765                 carp_setrun(sc, af);
 766                 break;
 767         }
 768
 769         CARP_UNLOCK(ifp->if_carp);
 770
 771         m_freem(m);
 772         return;
 773 }
 774
 775 static int
 776 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
 777 {
 778         struct m_tag *mtag;
 779         struct ifnet *ifp = SC2IFP(sc);
 780
 781         if (sc->sc_init_counter) {
 782                 /* this could also be seconds since unix epoch */
 783                 sc->sc_counter = arc4random();
 784                 sc->sc_counter = sc->sc_counter << 32;
 785                 sc->sc_counter += arc4random();
 786         } else
 787                 sc->sc_counter++;
 788
 789         ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
 790         ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
 791
 792         carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
 793
 794         /* Tag packet for carp_output */
 795         mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct ifnet *), M_NOWAIT);
 796         if (mtag == NULL) {
 797                 m_freem(m);
 798                 SC2IFP(sc)->if_oerrors++;
 799                 return (ENOMEM);
 800         }
 801         bcopy(&ifp, (caddr_t)(mtag + 1), sizeof(struct ifnet *));
 802         m_tag_prepend(m, mtag);
 803
 804         return (0);
 805 }
 806
 807 static void
 808 carp_send_ad_all(void)
 809 {
 810         struct carp_softc *sc;
 811
 812         mtx_lock(&carp_mtx);
 813         LIST_FOREACH(sc, &carpif_list, sc_next) {
 814                 if (sc->sc_carpdev == NULL)
 815                         continue;
 816                 CARP_SCLOCK(sc);
 817                 if ((SC2IFP(sc)->if_flags & IFF_UP) &&
 818                     (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING) &&
 819                      sc->sc_state == MASTER)
 820                         carp_send_ad_locked(sc);
 821                 CARP_SCUNLOCK(sc);
 822         }
 823         mtx_unlock(&carp_mtx);
 824 }
 825
 826 static void
 827 carp_send_ad(void *v)
 828 {
 829         struct carp_softc *sc = v;
 830
 831         CARP_SCLOCK(sc);
 832         carp_send_ad_locked(sc);
 833         CARP_SCUNLOCK(sc);
 834 }
 835
 836 static void
 837 carp_send_ad_locked(struct carp_softc *sc)
 838 {
 839         struct carp_header ch;
 840         struct timeval tv;
 841         struct carp_header *ch_ptr;
 842         struct mbuf *m;
 843         int len, advbase, advskew;
 844
 845         CARP_SCLOCK_ASSERT(sc);
 846
 847         /* bow out if we've lost our UPness or RUNNINGuiness */
 848         if (!((SC2IFP(sc)->if_flags & IFF_UP) &&
 849             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING))) {
 850                 advbase = 255;
 851                 advskew = 255;
 852         } else {
 853                 advbase = sc->sc_advbase;
 854                 if (!carp_suppress_preempt || sc->sc_advskew > 240)
 855                         advskew = sc->sc_advskew;
 856                 else
 857                         advskew = 240;
 858                 tv.tv_sec = advbase;
 859                 tv.tv_usec = advskew * 1000000 / 256;
 860         }
 861
 862         ch.carp_version = CARP_VERSION;
 863         ch.carp_type = CARP_ADVERTISEMENT;
 864         ch.carp_vhid = sc->sc_vhid;
 865         ch.carp_advbase = advbase;
 866         ch.carp_advskew = advskew;
 867         ch.carp_authlen = 7;    /* XXX DEFINE */
 868         ch.carp_pad1 = 0;       /* must be zero */
 869         ch.carp_cksum = 0;
 870
 871 #ifdef INET
 872         if (sc->sc_ia) {
 873                 struct ip *ip;
 874
 875                 MGETHDR(m, M_DONTWAIT, MT_HEADER);
 876                 if (m == NULL) {
 877                         SC2IFP(sc)->if_oerrors++;
 878                         carpstats.carps_onomem++;
 879                         /* XXX maybe less ? */
 880                         if (advbase != 255 || advskew != 255)
 881                                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
 882                                     carp_send_ad, sc);
 883                         return;
 884                 }
 885                 len = sizeof(*ip) + sizeof(ch);
 886                 m->m_pkthdr.len = len;
 887                 m->m_pkthdr.rcvif = NULL;
 888                 m->m_len = len;
 889                 MH_ALIGN(m, m->m_len);
 890                 m->m_flags |= M_MCAST;
 891                 ip = mtod(m, struct ip *);
 892                 ip->ip_v = IPVERSION;
 893                 ip->ip_hl = sizeof(*ip) >> 2;
 894                 ip->ip_tos = IPTOS_LOWDELAY;
 895                 ip->ip_len = len;
 896                 ip->ip_id = ip_newid();
 897                 ip->ip_off = IP_DF;
 898                 ip->ip_ttl = CARP_DFLTTL;
 899                 ip->ip_p = IPPROTO_CARP;
 900                 ip->ip_sum = 0;
 901                 ip->ip_src.s_addr = sc->sc_ia->ia_addr.sin_addr.s_addr;
 902                 ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
 903
 904                 ch_ptr = (struct carp_header *)(&ip[1]);
 905                 bcopy(&ch, ch_ptr, sizeof(ch));
 906                 if (carp_prepare_ad(m, sc, ch_ptr))
 907                         return;
 908
 909                 m->m_data += sizeof(*ip);
 910                 ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
 911                 m->m_data -= sizeof(*ip);
 912
 913                 getmicrotime(&SC2IFP(sc)->if_lastchange);
 914                 SC2IFP(sc)->if_opackets++;
 915                 SC2IFP(sc)->if_obytes += len;
 916                 carpstats.carps_opackets++;
 917
 918                 if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL)) {
 919                         SC2IFP(sc)->if_oerrors++;
 920                         if (sc->sc_sendad_errors < INT_MAX)
 921                                 sc->sc_sendad_errors++;
 922                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
 923                                 carp_suppress_preempt++;
 924                                 if (carp_suppress_preempt == 1) {
 925                                         CARP_SCUNLOCK(sc);
 926                                         carp_send_ad_all();
 927                                         CARP_SCLOCK(sc);
 928                                 }
 929                         }
 930                         sc->sc_sendad_success = 0;
 931                 } else {
 932                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
 933                                 if (++sc->sc_sendad_success >=
 934                                     CARP_SENDAD_MIN_SUCCESS) {
 935                                         carp_suppress_preempt--;
 936                                         sc->sc_sendad_errors = 0;
 937                                 }
 938                         } else
 939                                 sc->sc_sendad_errors = 0;
 940                 }
 941         }
 942 #endif /* INET */
 943 #ifdef INET6
 944         if (sc->sc_ia6) {
 945                 struct ip6_hdr *ip6;
 946
 947                 MGETHDR(m, M_DONTWAIT, MT_HEADER);
 948                 if (m == NULL) {
 949                         SC2IFP(sc)->if_oerrors++;
 950                         carpstats.carps_onomem++;
 951                         /* XXX maybe less ? */
 952                         if (advbase != 255 || advskew != 255)
 953                                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
 954                                     carp_send_ad, sc);
 955                         return;
 956                 }
 957                 len = sizeof(*ip6) + sizeof(ch);
 958                 m->m_pkthdr.len = len;
 959                 m->m_pkthdr.rcvif = NULL;
 960                 m->m_len = len;
 961                 MH_ALIGN(m, m->m_len);
 962                 m->m_flags |= M_MCAST;
 963                 ip6 = mtod(m, struct ip6_hdr *);
 964                 bzero(ip6, sizeof(*ip6));
 965                 ip6->ip6_vfc |= IPV6_VERSION;
 966                 ip6->ip6_hlim = CARP_DFLTTL;
 967                 ip6->ip6_nxt = IPPROTO_CARP;
 968                 bcopy(&sc->sc_ia6->ia_addr.sin6_addr, &ip6->ip6_src,
 969                     sizeof(struct in6_addr));
 970                 /* set the multicast destination */
 971
 972                 ip6->ip6_dst.s6_addr8[0] = 0xff;
 973                 ip6->ip6_dst.s6_addr8[1] = 0x02;
 974                 ip6->ip6_dst.s6_addr8[15] = 0x12;
 975
 976                 ch_ptr = (struct carp_header *)(&ip6[1]);
 977                 bcopy(&ch, ch_ptr, sizeof(ch));
 978                 if (carp_prepare_ad(m, sc, ch_ptr))
 979                         return;
 980
 981                 m->m_data += sizeof(*ip6);
 982                 ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
 983                 m->m_data -= sizeof(*ip6);
 984
 985                 getmicrotime(&SC2IFP(sc)->if_lastchange);
 986                 SC2IFP(sc)->if_opackets++;
 987                 SC2IFP(sc)->if_obytes += len;
 988                 carpstats.carps_opackets6++;
 989
 990                 if (ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL)) {
 991                         SC2IFP(sc)->if_oerrors++;
 992                         if (sc->sc_sendad_errors < INT_MAX)
 993                                 sc->sc_sendad_errors++;
 994                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
 995                                 carp_suppress_preempt++;
 996                                 if (carp_suppress_preempt == 1) {
 997                                         CARP_SCUNLOCK(sc);
 998                                         carp_send_ad_all();
 999                                         CARP_SCLOCK(sc);
1000                                 }
1001                         }
1002                         sc->sc_sendad_success = 0;
1003                 } else {
1004                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1005                                 if (++sc->sc_sendad_success >=
1006                                     CARP_SENDAD_MIN_SUCCESS) {
1007                                         carp_suppress_preempt--;
1008                                         sc->sc_sendad_errors = 0;
1009                                 }
1010                         } else
1011                                 sc->sc_sendad_errors = 0;
1012                 }
1013         }
1014 #endif /* INET6 */
1015
1016         if (advbase != 255 || advskew != 255)
1017                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1018                     carp_send_ad, sc);
1019
1020 }
1021
1022 /*
1023  * Broadcast a gratuitous ARP request containing
1024  * the virtual router MAC address for each IP address
1025  * associated with the virtual router.
1026  */
1027 static void
1028 carp_send_arp(struct carp_softc *sc)
1029 {
1030         struct ifaddr *ifa;
1031
1032         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
1033
1034                 if (ifa->ifa_addr->sa_family != AF_INET)
1035                         continue;
1036
1037 /*              arprequest(sc->sc_carpdev, &in, &in, IF_LLADDR(sc->sc_ifp)); */
1038                 arp_ifinit2(sc->sc_carpdev, ifa, IF_LLADDR(sc->sc_ifp));
1039
1040                 DELAY(1000);    /* XXX */
1041         }
1042 }
1043
1044 #ifdef INET6
1045 static void
1046 carp_send_na(struct carp_softc *sc)
1047 {
1048         struct ifaddr *ifa;
1049         struct in6_addr *in6;
1050         static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1051
1052         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
1053
1054                 if (ifa->ifa_addr->sa_family != AF_INET6)
1055                         continue;
1056
1057                 in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1058                 nd6_na_output(sc->sc_carpdev, &mcast, in6,
1059                     ND_NA_FLAG_OVERRIDE, 1, NULL);
1060                 DELAY(1000);    /* XXX */
1061         }
1062 }
1063 #endif /* INET6 */
1064
1065 static int
1066 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
1067 {
1068         struct carp_softc *vh;
1069         struct ifaddr *ifa;
1070         int count = 0;
1071
1072         CARP_LOCK_ASSERT(cif);
1073
1074         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1075                 if ((type == CARP_COUNT_RUNNING &&
1076                     (SC2IFP(vh)->if_flags & IFF_UP) &&
1077                     (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING)) ||
1078                     (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
1079                         TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist,
1080                             ifa_list) {
1081                                 if (ifa->ifa_addr->sa_family == AF_INET &&
1082                                     ia->ia_addr.sin_addr.s_addr ==
1083                                     ifatoia(ifa)->ia_addr.sin_addr.s_addr)
1084                                         count++;
1085                         }
1086                 }
1087         }
1088         return (count);
1089 }
1090
1091 int
1092 carp_iamatch(void *v, struct in_ifaddr *ia,
1093     struct in_addr *isaddr, u_int8_t **enaddr)
1094 {
1095         struct carp_if *cif = v;
1096         struct carp_softc *vh;
1097         int index, count = 0;
1098         struct ifaddr *ifa;
1099
1100         CARP_LOCK(cif);
1101
1102         if (carp_opts[CARPCTL_ARPBALANCE]) {
1103                 /*
1104                  * XXX proof of concept implementation.
1105                  * We use the source ip to decide which virtual host should
1106                  * handle the request. If we're master of that virtual host,
1107                  * then we respond, otherwise, just drop the arp packet on
1108                  * the floor.
1109                  */
1110                 count = carp_addrcount(cif, ia, CARP_COUNT_RUNNING);
1111                 if (count == 0) {
1112                         /* should never reach this */
1113                         CARP_UNLOCK(cif);
1114                         return (0);
1115                 }
1116
1117                 /* this should be a hash, like pf_hash() */
1118                 index = ntohl(isaddr->s_addr) % count;
1119                 count = 0;
1120
1121                 TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1122                         if ((SC2IFP(vh)->if_flags & IFF_UP) &&
1123                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING)) {
1124                                 TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist,
1125                                     ifa_list) {
1126                                         if (ifa->ifa_addr->sa_family ==
1127                                             AF_INET &&
1128                                             ia->ia_addr.sin_addr.s_addr ==
1129                                             ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
1130                                                 if (count == index) {
1131                                                         if (vh->sc_state ==
1132                                                             MASTER) {
1133                                                                 *enaddr = IF_LLADDR(vh->sc_ifp);
1134                                                                 CARP_UNLOCK(cif);
1135                                                                 return (1);
1136                                                         } else {
1137                                                                 CARP_UNLOCK(cif);
1138                                                                 return (0);
1139                                                         }
1140                                                 }
1141                                                 count++;
1142                                         }
1143                                 }
1144                         }
1145                 }
1146         } else {
1147                 TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1148                         if ((SC2IFP(vh)->if_flags & IFF_UP) &&
1149                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
1150                             ia->ia_ifp == SC2IFP(vh) &&
1151                             vh->sc_state == MASTER) {
1152                                 *enaddr = IF_LLADDR(vh->sc_ifp);
1153                                 CARP_UNLOCK(cif);
1154                                 return (1);
1155                         }
1156                 }
1157         }
1158         CARP_UNLOCK(cif);
1159         return (0);
1160 }
1161
1162 #ifdef INET6
1163 struct ifaddr *
1164 carp_iamatch6(void *v, struct in6_addr *taddr)
1165 {
1166         struct carp_if *cif = v;
1167         struct carp_softc *vh;
1168         struct ifaddr *ifa;
1169
1170         CARP_LOCK(cif);
1171         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1172                 TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist, ifa_list) {
1173                         if (IN6_ARE_ADDR_EQUAL(taddr,
1174                             &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1175                             (SC2IFP(vh)->if_flags & IFF_UP) &&
1176                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
1177                             vh->sc_state == MASTER) {
1178                                 CARP_UNLOCK(cif);
1179                                 return (ifa);
1180                         }
1181                 }
1182         }
1183         CARP_UNLOCK(cif);
1184
1185         return (NULL);
1186 }
1187
1188 void *
1189 carp_macmatch6(void *v, struct mbuf *m, const struct in6_addr *taddr)
1190 {
1191         struct m_tag *mtag;
1192         struct carp_if *cif = v;
1193         struct carp_softc *sc;
1194         struct ifaddr *ifa;
1195
1196         CARP_LOCK(cif);
1197         TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
1198                 TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
1199                         if (IN6_ARE_ADDR_EQUAL(taddr,
1200                             &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1201                             (SC2IFP(sc)->if_flags & IFF_UP) &&
1202                             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING)) {
1203                                 struct ifnet *ifp = SC2IFP(sc);
1204                                 mtag = m_tag_get(PACKET_TAG_CARP,
1205                                     sizeof(struct ifnet *), M_NOWAIT);
1206                                 if (mtag == NULL) {
1207                                         /* better a bit than nothing */
1208                                         CARP_UNLOCK(cif);
1209                                         return (IF_LLADDR(sc->sc_ifp));
1210                                 }
1211                                 bcopy(&ifp, (caddr_t)(mtag + 1),
1212                                     sizeof(struct ifnet *));
1213                                 m_tag_prepend(m, mtag);
1214
1215                                 CARP_UNLOCK(cif);
1216                                 return (IF_LLADDR(sc->sc_ifp));
1217                         }
1218                 }
1219         }
1220         CARP_UNLOCK(cif);
1221
1222         return (NULL);
1223 }
1224 #endif
1225
1226 struct ifnet *
1227 carp_forus(void *v, void *dhost)
1228 {
1229         struct carp_if *cif = v;
1230         struct carp_softc *vh;
1231         u_int8_t *ena = dhost;
1232
1233         if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1234                 return (NULL);
1235
1236         CARP_LOCK(cif);
1237         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
1238                 if ((SC2IFP(vh)->if_flags & IFF_UP) &&
1239                     (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
1240                     vh->sc_state == MASTER &&
1241                     !bcmp(dhost, IF_LLADDR(vh->sc_ifp), ETHER_ADDR_LEN)) {
1242                         CARP_UNLOCK(cif);
1243                         return (SC2IFP(vh));
1244                 }
1245
1246         CARP_UNLOCK(cif);
1247         return (NULL);
1248 }
1249
1250 static void
1251 carp_master_down(void *v)
1252 {
1253         struct carp_softc *sc = v;
1254
1255         CARP_SCLOCK(sc);
1256         carp_master_down_locked(sc);
1257         CARP_SCUNLOCK(sc);
1258 }
1259
1260 static void
1261 carp_master_down_locked(struct carp_softc *sc)
1262 {
1263         if (sc->sc_carpdev)
1264                 CARP_SCLOCK_ASSERT(sc);
1265
1266         switch (sc->sc_state) {
1267         case INIT:
1268                 printf("%s: master_down event in INIT state\n",
1269                     SC2IFP(sc)->if_xname);
1270                 break;
1271         case MASTER:
1272                 break;
1273         case BACKUP:
1274                 carp_set_state(sc, MASTER);
1275                 carp_send_ad_locked(sc);
1276                 carp_send_arp(sc);
1277 #ifdef INET6
1278                 carp_send_na(sc);
1279 #endif /* INET6 */
1280                 carp_setrun(sc, 0);
1281                 carp_setroute(sc, RTM_ADD);
1282                 break;
1283         }
1284 }
1285
1286 /*
1287  * When in backup state, af indicates whether to reset the master down timer
1288  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1289  */
1290 static void
1291 carp_setrun(struct carp_softc *sc, sa_family_t af)
1292 {
1293         struct timeval tv;
1294
1295         if (sc->sc_carpdev == NULL) {
1296                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1297                 carp_set_state(sc, INIT);
1298                 return;
1299         } else
1300                 CARP_SCLOCK_ASSERT(sc);
1301
1302         if (SC2IFP(sc)->if_flags & IFF_UP &&
1303             sc->sc_vhid > 0 && (sc->sc_naddrs || sc->sc_naddrs6))
1304                 SC2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
1305         else {
1306                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1307                 carp_setroute(sc, RTM_DELETE);
1308                 return;
1309         }
1310
1311         switch (sc->sc_state) {
1312         case INIT:
1313                 if (carp_opts[CARPCTL_PREEMPT] && !carp_suppress_preempt) {
1314                         carp_send_ad_locked(sc);
1315                         carp_send_arp(sc);
1316 #ifdef INET6
1317                         carp_send_na(sc);
1318 #endif /* INET6 */
1319                         CARP_DEBUG("%s: INIT -> MASTER (preempting)\n",
1320                             SC2IFP(sc)->if_xname);
1321                         carp_set_state(sc, MASTER);
1322                         carp_setroute(sc, RTM_ADD);
1323                 } else {
1324                         CARP_DEBUG("%s: INIT -> BACKUP\n", SC2IFP(sc)->if_xname);
1325                         carp_set_state(sc, BACKUP);
1326                         carp_setroute(sc, RTM_DELETE);
1327                         carp_setrun(sc, 0);
1328                 }
1329                 break;
1330         case BACKUP:
1331                 callout_stop(&sc->sc_ad_tmo);
1332                 tv.tv_sec = 3 * sc->sc_advbase;
1333                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1334                 switch (af) {
1335 #ifdef INET
1336                 case AF_INET:
1337                         callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1338                             carp_master_down, sc);
1339                         break;
1340 #endif /* INET */
1341 #ifdef INET6
1342                 case AF_INET6:
1343                         callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1344                             carp_master_down, sc);
1345                         break;
1346 #endif /* INET6 */
1347                 default:
1348                         if (sc->sc_naddrs)
1349                                 callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1350                                     carp_master_down, sc);
1351                         if (sc->sc_naddrs6)
1352                                 callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1353                                     carp_master_down, sc);
1354                         break;
1355                 }
1356                 break;
1357         case MASTER:
1358                 tv.tv_sec = sc->sc_advbase;
1359                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1360                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1361                     carp_send_ad, sc);
1362                 break;
1363         }
1364 }
1365
1366 void
1367 carp_multicast_cleanup(struct carp_softc *sc)
1368 {
1369         struct ip_moptions *imo = &sc->sc_imo;
1370 #ifdef INET6
1371         struct ip6_moptions *im6o = &sc->sc_im6o;
1372 #endif
1373         u_int16_t n = imo->imo_num_memberships;
1374
1375         /* Clean up our own multicast memberships */
1376         while (n-- > 0) {
1377                 if (imo->imo_membership[n] != NULL) {
1378                         in_delmulti(imo->imo_membership[n]);
1379                         imo->imo_membership[n] = NULL;
1380                 }
1381         }
1382         imo->imo_num_memberships = 0;
1383         imo->imo_multicast_ifp = NULL;
1384
1385 #ifdef INET6
1386         while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1387                 struct in6_multi_mship *imm =
1388                     LIST_FIRST(&im6o->im6o_memberships);
1389
1390                 LIST_REMOVE(imm, i6mm_chain);
1391                 in6_leavegroup(imm);
1392         }
1393         im6o->im6o_multicast_ifp = NULL;
1394 #endif
1395 }
1396
1397 static int
1398 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1399 {
1400         struct ifnet *ifp;
1401         struct carp_if *cif;
1402         struct in_ifaddr *ia, *ia_if;
1403         struct ip_moptions *imo = &sc->sc_imo;
1404         struct in_addr addr;
1405         u_long iaddr = htonl(sin->sin_addr.s_addr);
1406         int own, error;
1407
1408         if (sin->sin_addr.s_addr == 0) {
1409                 if (!(SC2IFP(sc)->if_flags & IFF_UP))
1410                         carp_set_state(sc, INIT);
1411                 if (sc->sc_naddrs)
1412                         SC2IFP(sc)->if_flags |= IFF_UP;
1413                 carp_setrun(sc, 0);
1414                 return (0);
1415         }
1416
1417         /* we have to do it by hands to check we won't match on us */
1418         ia_if = NULL; own = 0;
1419         TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) {
1420                 /* and, yeah, we need a multicast-capable iface too */
1421                 if (ia->ia_ifp != SC2IFP(sc) &&
1422                     (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1423                     (iaddr & ia->ia_subnetmask) == ia->ia_subnet) {
1424                         if (!ia_if)
1425                                 ia_if = ia;
1426                         if (sin->sin_addr.s_addr ==
1427                             ia->ia_addr.sin_addr.s_addr)
1428                                 own++;
1429                 }
1430         }
1431
1432         if (!ia_if)
1433                 return (EADDRNOTAVAIL);
1434
1435         ia = ia_if;
1436         ifp = ia->ia_ifp;
1437
1438         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
1439             (imo->imo_multicast_ifp && imo->imo_multicast_ifp != ifp))
1440                 return (EADDRNOTAVAIL);
1441
1442         if (imo->imo_num_memberships == 0) {
1443                 addr.s_addr = htonl(INADDR_CARP_GROUP);
1444                 if ((imo->imo_membership[0] = in_addmulti(&addr, ifp)) == NULL)
1445                         return (ENOBUFS);
1446                 imo->imo_num_memberships++;
1447                 imo->imo_multicast_ifp = ifp;
1448                 imo->imo_multicast_ttl = CARP_DFLTTL;
1449                 imo->imo_multicast_loop = 0;
1450         }
1451
1452         if (!ifp->if_carp) {
1453
1454                 MALLOC(cif, struct carp_if *, sizeof(*cif), M_CARP,
1455                     M_WAITOK|M_ZERO);
1456                 if (!cif) {
1457                         error = ENOBUFS;
1458                         goto cleanup;
1459                 }
1460                 if ((error = ifpromisc(ifp, 1))) {
1461                         FREE(cif, M_CARP);
1462                         goto cleanup;
1463                 }
1464
1465                 CARP_LOCK_INIT(cif);
1466                 CARP_LOCK(cif);
1467                 cif->vhif_ifp = ifp;
1468                 TAILQ_INIT(&cif->vhif_vrs);
1469                 ifp->if_carp = cif;
1470
1471         } else {
1472                 struct carp_softc *vr;
1473
1474                 cif = (struct carp_if *)ifp->if_carp;
1475                 CARP_LOCK(cif);
1476                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1477                         if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
1478                                 CARP_UNLOCK(cif);
1479                                 error = EINVAL;
1480                                 goto cleanup;
1481                         }
1482         }
1483         sc->sc_ia = ia;
1484         sc->sc_carpdev = ifp;
1485
1486         { /* XXX prevent endless loop if already in queue */
1487         struct carp_softc *vr, *after = NULL;
1488         int myself = 0;
1489         cif = (struct carp_if *)ifp->if_carp;
1490
1491         /* XXX: cif should not change, right? So we still hold the lock */
1492         CARP_LOCK_ASSERT(cif);
1493
1494         TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1495                 if (vr == sc)
1496                         myself = 1;
1497                 if (vr->sc_vhid < sc->sc_vhid)
1498                         after = vr;
1499         }
1500
1501         if (!myself) {
1502                 /* We're trying to keep things in order */
1503                 if (after == NULL) {
1504                         TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1505                 } else {
1506                         TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
1507                 }
1508                 cif->vhif_nvrs++;
1509         }
1510         }
1511
1512         sc->sc_naddrs++;
1513         SC2IFP(sc)->if_flags |= IFF_UP;
1514         if (own)
1515                 sc->sc_advskew = 0;
1516         carp_sc_state_locked(sc);
1517         carp_setrun(sc, 0);
1518
1519         CARP_UNLOCK(cif);
1520
1521         return (0);
1522
1523 cleanup:
1524         in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
1525         return (error);
1526 }
1527
1528 static int
1529 carp_del_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1530 {
1531         int error = 0;
1532
1533         if (!--sc->sc_naddrs) {
1534                 struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1535                 struct ip_moptions *imo = &sc->sc_imo;
1536
1537                 CARP_LOCK(cif);
1538                 callout_stop(&sc->sc_ad_tmo);
1539                 SC2IFP(sc)->if_flags &= ~IFF_UP;
1540                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1541                 sc->sc_vhid = -1;
1542                 in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
1543                 imo->imo_multicast_ifp = NULL;
1544                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
1545                 if (!--cif->vhif_nvrs) {
1546                         sc->sc_carpdev->if_carp = NULL;
1547                         CARP_LOCK_DESTROY(cif);
1548                         FREE(cif, M_IFADDR);
1549                 } else {
1550                         CARP_UNLOCK(cif);
1551                 }
1552         }
1553
1554         return (error);
1555 }
1556
1557 #ifdef INET6
1558 static int
1559 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1560 {
1561         struct ifnet *ifp;
1562         struct carp_if *cif;
1563         struct in6_ifaddr *ia, *ia_if;
1564         struct ip6_moptions *im6o = &sc->sc_im6o;
1565         struct in6_multi_mship *imm;
1566         struct in6_addr in6;
1567         int own, error;
1568
1569         if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1570                 if (!(SC2IFP(sc)->if_flags & IFF_UP))
1571                         carp_set_state(sc, INIT);
1572                 if (sc->sc_naddrs6)
1573                         SC2IFP(sc)->if_flags |= IFF_UP;
1574                 carp_setrun(sc, 0);
1575                 return (0);
1576         }
1577
1578         /* we have to do it by hands to check we won't match on us */
1579         ia_if = NULL; own = 0;
1580         for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1581                 int i;
1582
1583                 for (i = 0; i < 4; i++) {
1584                         if ((sin6->sin6_addr.s6_addr32[i] &
1585                             ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1586                             (ia->ia_addr.sin6_addr.s6_addr32[i] &
1587                             ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1588                                 break;
1589                 }
1590                 /* and, yeah, we need a multicast-capable iface too */
1591                 if (ia->ia_ifp != SC2IFP(sc) &&
1592                     (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1593                     (i == 4)) {
1594                         if (!ia_if)
1595                                 ia_if = ia;
1596                         if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr,
1597                             &ia->ia_addr.sin6_addr))
1598                                 own++;
1599                 }
1600         }
1601
1602         if (!ia_if)
1603                 return (EADDRNOTAVAIL);
1604         ia = ia_if;
1605         ifp = ia->ia_ifp;
1606
1607         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
1608             (im6o->im6o_multicast_ifp && im6o->im6o_multicast_ifp != ifp))
1609                 return (EADDRNOTAVAIL);
1610
1611         if (!sc->sc_naddrs6) {
1612                 im6o->im6o_multicast_ifp = ifp;
1613
1614                 /* join CARP multicast address */
1615                 bzero(&in6, sizeof(in6));
1616                 in6.s6_addr16[0] = htons(0xff02);
1617                 in6.s6_addr8[15] = 0x12;
1618                 if (in6_setscope(&in6, ifp, NULL) != 0)
1619                         goto cleanup;
1620                 if ((imm = in6_joingroup(ifp, &in6, &error, 0)) == NULL)
1621                         goto cleanup;
1622                 LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
1623
1624                 /* join solicited multicast address */
1625                 bzero(&in6, sizeof(in6));
1626                 in6.s6_addr16[0] = htons(0xff02);
1627                 in6.s6_addr32[1] = 0;
1628                 in6.s6_addr32[2] = htonl(1);
1629                 in6.s6_addr32[3] = sin6->sin6_addr.s6_addr32[3];
1630                 in6.s6_addr8[12] = 0xff;
1631                 if (in6_setscope(&in6, ifp, NULL) != 0)
1632                         goto cleanup;
1633                 if ((imm = in6_joingroup(ifp, &in6, &error, 0)) == NULL)
1634                         goto cleanup;
1635                 LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
1636         }
1637
1638         if (!ifp->if_carp) {
1639                 MALLOC(cif, struct carp_if *, sizeof(*cif), M_CARP,
1640                     M_WAITOK|M_ZERO);
1641                 if (!cif) {
1642                         error = ENOBUFS;
1643                         goto cleanup;
1644                 }
1645                 if ((error = ifpromisc(ifp, 1))) {
1646                         FREE(cif, M_CARP);
1647                         goto cleanup;
1648                 }
1649
1650                 CARP_LOCK_INIT(cif);
1651                 CARP_LOCK(cif);
1652                 cif->vhif_ifp = ifp;
1653                 TAILQ_INIT(&cif->vhif_vrs);
1654                 ifp->if_carp = cif;
1655
1656         } else {
1657                 struct carp_softc *vr;
1658
1659                 cif = (struct carp_if *)ifp->if_carp;
1660                 CARP_LOCK(cif);
1661                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1662                         if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
1663                                 CARP_UNLOCK(cif);
1664                                 error = EINVAL;
1665                                 goto cleanup;
1666                         }
1667         }
1668         sc->sc_ia6 = ia;
1669         sc->sc_carpdev = ifp;
1670
1671         { /* XXX prevent endless loop if already in queue */
1672         struct carp_softc *vr, *after = NULL;
1673         int myself = 0;
1674         cif = (struct carp_if *)ifp->if_carp;
1675         CARP_LOCK_ASSERT(cif);
1676
1677         TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1678                 if (vr == sc)
1679                         myself = 1;
1680                 if (vr->sc_vhid < sc->sc_vhid)
1681                         after = vr;
1682         }
1683
1684         if (!myself) {
1685                 /* We're trying to keep things in order */
1686                 if (after == NULL) {
1687                         TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1688                 } else {
1689                         TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
1690                 }
1691                 cif->vhif_nvrs++;
1692         }
1693         }
1694
1695         sc->sc_naddrs6++;
1696         SC2IFP(sc)->if_flags |= IFF_UP;
1697         if (own)
1698                 sc->sc_advskew = 0;
1699         carp_sc_state_locked(sc);
1700         carp_setrun(sc, 0);
1701
1702         CARP_UNLOCK(cif);
1703
1704         return (0);
1705
1706 cleanup:
1707         /* clean up multicast memberships */
1708         if (!sc->sc_naddrs6) {
1709                 while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1710                         imm = LIST_FIRST(&im6o->im6o_memberships);
1711                         LIST_REMOVE(imm, i6mm_chain);
1712                         in6_leavegroup(imm);
1713                 }
1714         }
1715         return (error);
1716 }
1717
1718 static int
1719 carp_del_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1720 {
1721         int error = 0;
1722
1723         if (!--sc->sc_naddrs6) {
1724                 struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1725                 struct ip6_moptions *im6o = &sc->sc_im6o;
1726
1727                 CARP_LOCK(cif);
1728                 callout_stop(&sc->sc_ad_tmo);
1729                 SC2IFP(sc)->if_flags &= ~IFF_UP;
1730                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1731                 sc->sc_vhid = -1;
1732                 while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1733                         struct in6_multi_mship *imm =
1734                             LIST_FIRST(&im6o->im6o_memberships);
1735
1736                         LIST_REMOVE(imm, i6mm_chain);
1737                         in6_leavegroup(imm);
1738                 }
1739                 im6o->im6o_multicast_ifp = NULL;
1740                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
1741                 if (!--cif->vhif_nvrs) {
1742                         CARP_LOCK_DESTROY(cif);
1743                         sc->sc_carpdev->if_carp = NULL;
1744                         FREE(cif, M_IFADDR);
1745                 } else
1746                         CARP_UNLOCK(cif);
1747         }
1748
1749         return (error);
1750 }
1751 #endif /* INET6 */
1752
1753 static int
1754 carp_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
1755 {
1756         struct carp_softc *sc = ifp->if_softc, *vr;
1757         struct carpreq carpr;
1758         struct ifaddr *ifa;
1759         struct ifreq *ifr;
1760         struct ifaliasreq *ifra;
1761         int locked = 0, error = 0;
1762
1763         ifa = (struct ifaddr *)addr;
1764         ifra = (struct ifaliasreq *)addr;
1765         ifr = (struct ifreq *)addr;
1766
1767         switch (cmd) {
1768         case SIOCSIFADDR:
1769                 switch (ifa->ifa_addr->sa_family) {
1770 #ifdef INET
1771                 case AF_INET:
1772                         SC2IFP(sc)->if_flags |= IFF_UP;
1773                         bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1774                             sizeof(struct sockaddr));
1775                         error = carp_set_addr(sc, satosin(ifa->ifa_addr));
1776                         break;
1777 #endif /* INET */
1778 #ifdef INET6
1779                 case AF_INET6:
1780                         SC2IFP(sc)->if_flags |= IFF_UP;
1781                         error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1782                         break;
1783 #endif /* INET6 */
1784                 default:
1785                         error = EAFNOSUPPORT;
1786                         break;
1787                 }
1788                 break;
1789
1790         case SIOCAIFADDR:
1791                 switch (ifa->ifa_addr->sa_family) {
1792 #ifdef INET
1793                 case AF_INET:
1794                         SC2IFP(sc)->if_flags |= IFF_UP;
1795                         bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1796                             sizeof(struct sockaddr));
1797                         error = carp_set_addr(sc, satosin(&ifra->ifra_addr));
1798                         break;
1799 #endif /* INET */
1800 #ifdef INET6
1801                 case AF_INET6:
1802                         SC2IFP(sc)->if_flags |= IFF_UP;
1803                         error = carp_set_addr6(sc, satosin6(&ifra->ifra_addr));
1804                         break;
1805 #endif /* INET6 */
1806                 default:
1807                         error = EAFNOSUPPORT;
1808                         break;
1809                 }
1810                 break;
1811
1812         case SIOCDIFADDR:
1813                 switch (ifa->ifa_addr->sa_family) {
1814 #ifdef INET
1815                 case AF_INET:
1816                         error = carp_del_addr(sc, satosin(&ifra->ifra_addr));
1817                         break;
1818 #endif /* INET */
1819 #ifdef INET6
1820                 case AF_INET6:
1821                         error = carp_del_addr6(sc, satosin6(&ifra->ifra_addr));
1822                         break;
1823 #endif /* INET6 */
1824                 default:
1825                         error = EAFNOSUPPORT;
1826                         break;
1827                 }
1828                 break;
1829
1830         case SIOCSIFFLAGS:
1831                 if (sc->sc_carpdev) {
1832                         locked = 1;
1833                         CARP_SCLOCK(sc);
1834                 }
1835                 if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
1836                         callout_stop(&sc->sc_ad_tmo);
1837                         callout_stop(&sc->sc_md_tmo);
1838                         callout_stop(&sc->sc_md6_tmo);
1839                         if (sc->sc_state == MASTER)
1840                                 carp_send_ad_locked(sc);
1841                         carp_set_state(sc, INIT);
1842                         carp_setrun(sc, 0);
1843                 } else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
1844                         SC2IFP(sc)->if_flags |= IFF_UP;
1845                         carp_setrun(sc, 0);
1846                 }
1847                 break;
1848
1849         case SIOCSVH:
1850                 if ((error = suser(curthread)) != 0)
1851                         break;
1852                 if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
1853                         break;
1854                 error = 1;
1855                 if (sc->sc_carpdev) {
1856                         locked = 1;
1857                         CARP_SCLOCK(sc);
1858                 }
1859                 if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
1860                         switch (carpr.carpr_state) {
1861                         case BACKUP:
1862                                 callout_stop(&sc->sc_ad_tmo);
1863                                 carp_set_state(sc, BACKUP);
1864                                 carp_setrun(sc, 0);
1865                                 carp_setroute(sc, RTM_DELETE);
1866                                 break;
1867                         case MASTER:
1868                                 carp_master_down_locked(sc);
1869                                 break;
1870                         default:
1871                                 break;
1872                         }
1873                 }
1874                 if (carpr.carpr_vhid > 0) {
1875                         if (carpr.carpr_vhid > 255) {
1876                                 error = EINVAL;
1877                                 break;
1878                         }
1879                         if (sc->sc_carpdev) {
1880                                 struct carp_if *cif;
1881                                 cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1882                                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1883                                         if (vr != sc &&
1884                                             vr->sc_vhid == carpr.carpr_vhid)
1885                                                 return EEXIST;
1886                         }
1887                         sc->sc_vhid = carpr.carpr_vhid;
1888                         IF_LLADDR(sc->sc_ifp)[0] = 0;
1889                         IF_LLADDR(sc->sc_ifp)[1] = 0;
1890                         IF_LLADDR(sc->sc_ifp)[2] = 0x5e;
1891                         IF_LLADDR(sc->sc_ifp)[3] = 0;
1892                         IF_LLADDR(sc->sc_ifp)[4] = 1;
1893                         IF_LLADDR(sc->sc_ifp)[5] = sc->sc_vhid;
1894                         error--;
1895                 }
1896                 if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
1897                         if (carpr.carpr_advskew >= 255) {
1898                                 error = EINVAL;
1899                                 break;
1900                         }
1901                         if (carpr.carpr_advbase > 255) {
1902                                 error = EINVAL;
1903                                 break;
1904                         }
1905                         sc->sc_advbase = carpr.carpr_advbase;
1906                         sc->sc_advskew = carpr.carpr_advskew;
1907                         error--;
1908                 }
1909                 bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1910                 if (error > 0)
1911                         error = EINVAL;
1912                 else {
1913                         error = 0;
1914                         carp_setrun(sc, 0);
1915                 }
1916                 break;
1917
1918         case SIOCGVH:
1919                 /* XXX: lockless read */
1920                 bzero(&carpr, sizeof(carpr));
1921                 carpr.carpr_state = sc->sc_state;
1922                 carpr.carpr_vhid = sc->sc_vhid;
1923                 carpr.carpr_advbase = sc->sc_advbase;
1924                 carpr.carpr_advskew = sc->sc_advskew;
1925                 if (suser(curthread) == 0)
1926                         bcopy(sc->sc_key, carpr.carpr_key,
1927                             sizeof(carpr.carpr_key));
1928                 error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
1929                 break;
1930
1931         default:
1932                 error = EINVAL;
1933         }
1934
1935         if (locked)
1936                 CARP_SCUNLOCK(sc);
1937
1938         carp_hmac_prepare(sc);
1939
1940         return (error);
1941 }
1942
1943 /*
1944  * XXX: this is looutput. We should eventually use it from there.
1945  */
1946 static int
1947 carp_looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
1948     struct rtentry *rt)
1949 {
1950         u_int32_t af;
1951
1952         M_ASSERTPKTHDR(m); /* check if we have the packet header */
1953
1954         if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
1955                 m_freem(m);
1956                 return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
1957                         rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
1958         }
1959
1960         ifp->if_opackets++;
1961         ifp->if_obytes += m->m_pkthdr.len;
1962
1963         /* BPF writes need to be handled specially. */
1964         if (dst->sa_family == AF_UNSPEC) {
1965                 bcopy(dst->sa_data, &af, sizeof(af));
1966                 dst->sa_family = af;
1967         }
1968
1969 #if 1   /* XXX */
1970         switch (dst->sa_family) {
1971         case AF_INET:
1972         case AF_INET6:
1973         case AF_IPX:
1974         case AF_APPLETALK:
1975                 break;
1976         default:
1977                 printf("carp_looutput: af=%d unexpected\n", dst->sa_family);
1978                 m_freem(m);
1979                 return (EAFNOSUPPORT);
1980         }
1981 #endif
1982         return(if_simloop(ifp, m, dst->sa_family, 0));
1983 }
1984
1985 /*
1986  * Start output on carp interface. This function should never be called.
1987  */
1988 static void
1989 carp_start(struct ifnet *ifp)
1990 {
1991 #ifdef DEBUG
1992         printf("%s: start called\n", ifp->if_xname);
1993 #endif
1994 }
1995
1996 int
1997 carp_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
1998     struct rtentry *rt)
1999 {
2000         struct m_tag *mtag;
2001         struct carp_softc *sc;
2002         struct ifnet *carp_ifp;
2003
2004         if (!sa)
2005                 return (0);
2006
2007         switch (sa->sa_family) {
2008 #ifdef INET
2009         case AF_INET:
2010                 break;
2011 #endif /* INET */
2012 #ifdef INET6
2013         case AF_INET6:
2014                 break;
2015 #endif /* INET6 */
2016         default:
2017                 return (0);
2018         }
2019
2020         mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
2021         if (mtag == NULL)
2022                 return (0);
2023
2024         bcopy(mtag + 1, &carp_ifp, sizeof(struct ifnet *));
2025         sc = carp_ifp->if_softc;
2026
2027         /* Set the source MAC address to Virtual Router MAC Address */
2028         switch (ifp->if_type) {
2029         case IFT_ETHER:
2030         case IFT_L2VLAN: {
2031                         struct ether_header *eh;
2032
2033                         eh = mtod(m, struct ether_header *);
2034                         eh->ether_shost[0] = 0;
2035                         eh->ether_shost[1] = 0;
2036                         eh->ether_shost[2] = 0x5e;
2037                         eh->ether_shost[3] = 0;
2038                         eh->ether_shost[4] = 1;
2039                         eh->ether_shost[5] = sc->sc_vhid;
2040                 }
2041                 break;
2042         case IFT_FDDI: {
2043                         struct fddi_header *fh;
2044
2045                         fh = mtod(m, struct fddi_header *);
2046                         fh->fddi_shost[0] = 0;
2047                         fh->fddi_shost[1] = 0;
2048                         fh->fddi_shost[2] = 0x5e;
2049                         fh->fddi_shost[3] = 0;
2050                         fh->fddi_shost[4] = 1;
2051                         fh->fddi_shost[5] = sc->sc_vhid;
2052                 }
2053                 break;
2054         case IFT_ISO88025: {
2055                         struct iso88025_header *th;
2056                         th = mtod(m, struct iso88025_header *);
2057                         th->iso88025_shost[0] = 3;
2058                         th->iso88025_shost[1] = 0;
2059                         th->iso88025_shost[2] = 0x40 >> (sc->sc_vhid - 1);
2060                         th->iso88025_shost[3] = 0x40000 >> (sc->sc_vhid - 1);
2061                         th->iso88025_shost[4] = 0;
2062                         th->iso88025_shost[5] = 0;
2063                 }
2064                 break;
2065         default:
2066                 printf("%s: carp is not supported for this interface type\n",
2067                     ifp->if_xname);
2068                 return (EOPNOTSUPP);
2069         }
2070
2071         return (0);
2072 }
2073
2074 static void
2075 carp_set_state(struct carp_softc *sc, int state)
2076 {
2077
2078         if (sc->sc_carpdev)
2079                 CARP_SCLOCK_ASSERT(sc);
2080
2081         if (sc->sc_state == state)
2082                 return;
2083
2084         sc->sc_state = state;
2085         switch (state) {
2086         case BACKUP:
2087                 SC2IFP(sc)->if_link_state = LINK_STATE_DOWN;
2088                 break;
2089         case MASTER:
2090                 SC2IFP(sc)->if_link_state = LINK_STATE_UP;
2091                 break;
2092         default:
2093                 SC2IFP(sc)->if_link_state = LINK_STATE_UNKNOWN;
2094                 break;
2095         }
2096         rt_ifmsg(SC2IFP(sc));
2097 }
2098
2099 void
2100 carp_carpdev_state(void *v)
2101 {
2102         struct carp_if *cif = v;
2103
2104         CARP_LOCK(cif);
2105         carp_carpdev_state_locked(cif);
2106         CARP_UNLOCK(cif);
2107 }
2108
2109 static void
2110 carp_carpdev_state_locked(struct carp_if *cif)
2111 {
2112         struct carp_softc *sc;
2113
2114         TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list)
2115                 carp_sc_state_locked(sc);
2116 }
2117
2118 static void
2119 carp_sc_state_locked(struct carp_softc *sc)
2120 {
2121         CARP_SCLOCK_ASSERT(sc);
2122
2123         if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
2124             !(sc->sc_carpdev->if_flags & IFF_UP)) {
2125                 sc->sc_flags_backup = SC2IFP(sc)->if_flags;
2126                 SC2IFP(sc)->if_flags &= ~IFF_UP;
2127                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
2128                 callout_stop(&sc->sc_ad_tmo);
2129                 callout_stop(&sc->sc_md_tmo);
2130                 callout_stop(&sc->sc_md6_tmo);
2131                 carp_set_state(sc, INIT);
2132                 carp_setrun(sc, 0);
2133                 if (!sc->sc_suppress) {
2134                         carp_suppress_preempt++;
2135                         if (carp_suppress_preempt == 1) {
2136                                 CARP_SCUNLOCK(sc);
2137                                 carp_send_ad_all();
2138                                 CARP_SCLOCK(sc);
2139                         }
2140                 }
2141                 sc->sc_suppress = 1;
2142         } else {
2143                 SC2IFP(sc)->if_flags |= sc->sc_flags_backup;
2144                 carp_set_state(sc, INIT);
2145                 carp_setrun(sc, 0);
2146                 if (sc->sc_suppress)
2147                         carp_suppress_preempt--;
2148                 sc->sc_suppress = 0;
2149         }
2150
2151         return;
2152 }
2153
2154 static int
2155 carp_modevent(module_t mod, int type, void *data)
2156 {
2157         switch (type) {
2158         case MOD_LOAD:
2159                 if_detach_event_tag = EVENTHANDLER_REGISTER(ifnet_departure_event,
2160                     carp_ifdetach, NULL, EVENTHANDLER_PRI_ANY);
2161                 if (if_detach_event_tag == NULL)
2162                         return (ENOMEM);
2163                 mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
2164                 LIST_INIT(&carpif_list);
2165                 if_clone_attach(&carp_cloner);
2166                 break;
2167
2168         case MOD_UNLOAD:
2169                 EVENTHANDLER_DEREGISTER(ifnet_departure_event, if_detach_event_tag);
2170                 if_clone_detach(&carp_cloner);
2171                 mtx_destroy(&carp_mtx);
2172                 break;
2173
2174         default:
2175                 return (EINVAL);
2176         }
2177
2178         return (0);
2179 }
2180
2181 static moduledata_t carp_mod = {
2182         "carp",
2183         carp_modevent,
2184         0
2185 };
2186
2187 DECLARE_MODULE(carp, carp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);