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 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  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/priv.h>
  45 #include <sys/proc.h>
  46 #include <sys/protosw.h>
  47 #include <sys/sysctl.h>
  48 #include <sys/syslog.h>
  49 #include <sys/signalvar.h>
  50 #include <sys/filio.h>
  51 #include <sys/sockio.h>
  52
  53 #include <sys/socket.h>
  54 #include <sys/vnode.h>
  55
  56 #include <machine/stdarg.h>
  57
  58 #include <net/bpf.h>
  59 #include <net/ethernet.h>
  60 #include <net/fddi.h>
  61 #include <net/iso88025.h>
  62 #include <net/if.h>
  63 #include <net/if_clone.h>
  64 #include <net/if_dl.h>
  65 #include <net/if_types.h>
  66 #include <net/route.h>
  67 #include <net/vnet.h>
  68
  69 #if defined(INET) || defined(INET6)
  70 #include <netinet/in.h>
  71 #include <netinet/in_var.h>
  72 #include <netinet/ip_carp.h>
  73 #include <netinet/ip.h>
  74
  75 #include <machine/in_cksum.h>
  76 #endif
  77
  78 #ifdef INET
  79 #include <netinet/in_systm.h>
  80 #include <netinet/ip_var.h>
  81 #include <netinet/if_ether.h>
  82 #endif
  83
  84 #ifdef INET6
  85 #include <netinet/icmp6.h>
  86 #include <netinet/ip6.h>
  87 #include <netinet6/ip6protosw.h>
  88 #include <netinet6/ip6_var.h>
  89 #include <netinet6/scope6_var.h>
  90 #include <netinet6/in6_var.h>
  91 #include <netinet6/nd6.h>
  92 #endif
  93
  94 #include <crypto/sha1.h>
  95
  96 #define CARP_IFNAME     "carp"
  97 static MALLOC_DEFINE(M_CARP, "CARP", "CARP interfaces");
  98 SYSCTL_DECL(_net_inet_carp);
  99
 100 struct carp_softc {
 101         struct ifnet            *sc_ifp;        /* Interface clue */
 102         struct ifnet            *sc_carpdev;    /* Pointer to parent interface */
 103         struct in_ifaddr        *sc_ia;         /* primary iface address */
 104 #ifdef INET
 105         struct ip_moptions       sc_imo;
 106 #endif
 107 #ifdef INET6
 108         struct in6_ifaddr       *sc_ia6;        /* primary iface address v6 */
 109         struct ip6_moptions      sc_im6o;
 110 #endif /* INET6 */
 111         TAILQ_ENTRY(carp_softc)  sc_list;
 112
 113         enum { INIT = 0, BACKUP, MASTER }       sc_state;
 114
 115         int                      sc_flags_backup;
 116         int                      sc_suppress;
 117
 118         int                      sc_sendad_errors;
 119 #define CARP_SENDAD_MAX_ERRORS  3
 120         int                      sc_sendad_success;
 121 #define CARP_SENDAD_MIN_SUCCESS 3
 122
 123         int                      sc_vhid;
 124         int                      sc_advskew;
 125         int                      sc_naddrs;
 126         int                      sc_naddrs6;
 127         int                      sc_advbase;    /* seconds */
 128         int                      sc_init_counter;
 129         u_int64_t                sc_counter;
 130
 131         /* authentication */
 132 #define CARP_HMAC_PAD   64
 133         unsigned char sc_key[CARP_KEY_LEN];
 134         unsigned char sc_pad[CARP_HMAC_PAD];
 135         SHA1_CTX sc_sha1;
 136
 137         struct callout           sc_ad_tmo;     /* advertisement timeout */
 138         struct callout           sc_md_tmo;     /* master down timeout */
 139         struct callout           sc_md6_tmo;    /* master down timeout */
 140
 141         LIST_ENTRY(carp_softc)   sc_next;       /* Interface clue */
 142 };
 143 #define SC2IFP(sc)      ((sc)->sc_ifp)
 144
 145 int carp_suppress_preempt = 0;
 146 int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 1, 0, 0 };    /* XXX for now */
 147 SYSCTL_NODE(_net_inet, IPPROTO_CARP,    carp,   CTLFLAG_RW, 0,  "CARP");
 148 SYSCTL_INT(_net_inet_carp, CARPCTL_ALLOW, allow, CTLFLAG_RW,
 149     &carp_opts[CARPCTL_ALLOW], 0, "Accept incoming CARP packets");
 150 SYSCTL_INT(_net_inet_carp, CARPCTL_PREEMPT, preempt, CTLFLAG_RW,
 151     &carp_opts[CARPCTL_PREEMPT], 0, "high-priority backup preemption mode");
 152 SYSCTL_INT(_net_inet_carp, CARPCTL_LOG, log, CTLFLAG_RW,
 153     &carp_opts[CARPCTL_LOG], 0, "log bad carp packets");
 154 SYSCTL_INT(_net_inet_carp, CARPCTL_ARPBALANCE, arpbalance, CTLFLAG_RW,
 155     &carp_opts[CARPCTL_ARPBALANCE], 0, "balance arp responses");
 156 SYSCTL_INT(_net_inet_carp, OID_AUTO, suppress_preempt, CTLFLAG_RD,
 157     &carp_suppress_preempt, 0, "Preemption is suppressed");
 158
 159 struct carpstats carpstats;
 160 SYSCTL_STRUCT(_net_inet_carp, CARPCTL_STATS, stats, CTLFLAG_RW,
 161     &carpstats, carpstats,
 162     "CARP statistics (struct carpstats, netinet/ip_carp.h)");
 163
 164 struct carp_if {
 165         TAILQ_HEAD(, carp_softc) vhif_vrs;
 166         int vhif_nvrs;
 167
 168         struct ifnet    *vhif_ifp;
 169         struct mtx       vhif_mtx;
 170 };
 171
 172 #define CARP_INET       0
 173 #define CARP_INET6      1
 174 static int proto_reg[] = {-1, -1};
 175
 176 /* Get carp_if from softc. Valid after carp_set_addr{,6}. */
 177 #define SC2CIF(sc)              ((struct carp_if *)(sc)->sc_carpdev->if_carp)
 178
 179 /* lock per carp_if queue */
 180 #define CARP_LOCK_INIT(cif)     mtx_init(&(cif)->vhif_mtx, "carp_if",   \
 181         NULL, MTX_DEF)
 182 #define CARP_LOCK_DESTROY(cif)  mtx_destroy(&(cif)->vhif_mtx)
 183 #define CARP_LOCK_ASSERT(cif)   mtx_assert(&(cif)->vhif_mtx, MA_OWNED)
 184 #define CARP_LOCK(cif)          mtx_lock(&(cif)->vhif_mtx)
 185 #define CARP_UNLOCK(cif)        mtx_unlock(&(cif)->vhif_mtx)
 186
 187 #define CARP_SCLOCK(sc)         mtx_lock(&SC2CIF(sc)->vhif_mtx)
 188 #define CARP_SCUNLOCK(sc)       mtx_unlock(&SC2CIF(sc)->vhif_mtx)
 189 #define CARP_SCLOCK_ASSERT(sc)  mtx_assert(&SC2CIF(sc)->vhif_mtx, MA_OWNED)
 190
 191 #define CARP_LOG(...)   do {                            \
 192         if (carp_opts[CARPCTL_LOG] > 0)                 \
 193                 log(LOG_INFO, __VA_ARGS__);             \
 194 } while (0)
 195
 196 #define CARP_DEBUG(...) do {                            \
 197         if (carp_opts[CARPCTL_LOG] > 1)                 \
 198                 log(LOG_DEBUG, __VA_ARGS__);            \
 199 } while (0)
 200
 201 static void     carp_hmac_prepare(struct carp_softc *);
 202 static void     carp_hmac_generate(struct carp_softc *, u_int32_t *,
 203                     unsigned char *);
 204 static int      carp_hmac_verify(struct carp_softc *, u_int32_t *,
 205                     unsigned char *);
 206 static void     carp_setroute(struct carp_softc *, int);
 207 static void     carp_input_c(struct mbuf *, struct carp_header *, sa_family_t);
 208 static int      carp_clone_create(struct if_clone *, int, caddr_t);
 209 static void     carp_clone_destroy(struct ifnet *);
 210 static void     carpdetach(struct carp_softc *, int);
 211 static int      carp_prepare_ad(struct mbuf *, struct carp_softc *,
 212                     struct carp_header *);
 213 static void     carp_send_ad_all(void);
 214 static void     carp_send_ad(void *);
 215 static void     carp_send_ad_locked(struct carp_softc *);
 216 #ifdef INET
 217 static void     carp_send_arp(struct carp_softc *);
 218 #endif
 219 static void     carp_master_down(void *);
 220 static void     carp_master_down_locked(struct carp_softc *);
 221 static int      carp_ioctl(struct ifnet *, u_long, caddr_t);
 222 static int      carp_looutput(struct ifnet *, struct mbuf *, struct sockaddr *,
 223                     struct route *);
 224 static void     carp_start(struct ifnet *);
 225 static void     carp_setrun(struct carp_softc *, sa_family_t);
 226 static void     carp_set_state(struct carp_softc *, int);
 227 #ifdef INET
 228 static int      carp_addrcount(struct carp_if *, struct in_ifaddr *, int);
 229 #endif
 230 enum    { CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
 231
 232 #ifdef INET
 233 static void     carp_multicast_cleanup(struct carp_softc *, int dofree);
 234 static int      carp_set_addr(struct carp_softc *, struct sockaddr_in *);
 235 static int      carp_del_addr(struct carp_softc *, struct sockaddr_in *);
 236 #endif
 237 static void     carp_carpdev_state_locked(struct carp_if *);
 238 static void     carp_sc_state_locked(struct carp_softc *);
 239 #ifdef INET6
 240 static void     carp_send_na(struct carp_softc *);
 241 static int      carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
 242 static int      carp_del_addr6(struct carp_softc *, struct sockaddr_in6 *);
 243 static void     carp_multicast6_cleanup(struct carp_softc *, int dofree);
 244 #endif
 245
 246 static LIST_HEAD(, carp_softc) carpif_list;
 247 static struct mtx carp_mtx;
 248 IFC_SIMPLE_DECLARE(carp, 0);
 249
 250 static eventhandler_tag if_detach_event_tag;
 251
 252 static __inline u_int16_t
 253 carp_cksum(struct mbuf *m, int len)
 254 {
 255         return (in_cksum(m, len));
 256 }
 257
 258 static void
 259 carp_hmac_prepare(struct carp_softc *sc)
 260 {
 261         u_int8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
 262         u_int8_t vhid = sc->sc_vhid & 0xff;
 263         struct ifaddr *ifa;
 264         int i, found;
 265 #ifdef INET
 266         struct in_addr last, cur, in;
 267 #endif
 268 #ifdef INET6
 269         struct in6_addr last6, cur6, in6;
 270 #endif
 271
 272         if (sc->sc_carpdev)
 273                 CARP_SCLOCK(sc);
 274
 275         /* XXX: possible race here */
 276
 277         /* compute ipad from key */
 278         bzero(sc->sc_pad, sizeof(sc->sc_pad));
 279         bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
 280         for (i = 0; i < sizeof(sc->sc_pad); i++)
 281                 sc->sc_pad[i] ^= 0x36;
 282
 283         /* precompute first part of inner hash */
 284         SHA1Init(&sc->sc_sha1);
 285         SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
 286         SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
 287         SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
 288         SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
 289 #ifdef INET
 290         cur.s_addr = 0;
 291         do {
 292                 found = 0;
 293                 last = cur;
 294                 cur.s_addr = 0xffffffff;
 295                 IF_ADDR_RLOCK(SC2IFP(sc));
 296                 TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 297                         in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
 298                         if (ifa->ifa_addr->sa_family == AF_INET &&
 299                             ntohl(in.s_addr) > ntohl(last.s_addr) &&
 300                             ntohl(in.s_addr) < ntohl(cur.s_addr)) {
 301                                 cur.s_addr = in.s_addr;
 302                                 found++;
 303                         }
 304                 }
 305                 IF_ADDR_RUNLOCK(SC2IFP(sc));
 306                 if (found)
 307                         SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
 308         } while (found);
 309 #endif /* INET */
 310 #ifdef INET6
 311         memset(&cur6, 0, sizeof(cur6));
 312         do {
 313                 found = 0;
 314                 last6 = cur6;
 315                 memset(&cur6, 0xff, sizeof(cur6));
 316                 IF_ADDR_RLOCK(SC2IFP(sc));
 317                 TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 318                         in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
 319                         if (IN6_IS_SCOPE_EMBED(&in6))
 320                                 in6.s6_addr16[1] = 0;
 321                         if (ifa->ifa_addr->sa_family == AF_INET6 &&
 322                             memcmp(&in6, &last6, sizeof(in6)) > 0 &&
 323                             memcmp(&in6, &cur6, sizeof(in6)) < 0) {
 324                                 cur6 = in6;
 325                                 found++;
 326                         }
 327                 }
 328                 IF_ADDR_RUNLOCK(SC2IFP(sc));
 329                 if (found)
 330                         SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
 331         } while (found);
 332 #endif /* INET6 */
 333
 334         /* convert ipad to opad */
 335         for (i = 0; i < sizeof(sc->sc_pad); i++)
 336                 sc->sc_pad[i] ^= 0x36 ^ 0x5c;
 337
 338         if (sc->sc_carpdev)
 339                 CARP_SCUNLOCK(sc);
 340 }
 341
 342 static void
 343 carp_hmac_generate(struct carp_softc *sc, u_int32_t counter[2],
 344     unsigned char md[20])
 345 {
 346         SHA1_CTX sha1ctx;
 347
 348         /* fetch first half of inner hash */
 349         bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
 350
 351         SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
 352         SHA1Final(md, &sha1ctx);
 353
 354         /* outer hash */
 355         SHA1Init(&sha1ctx);
 356         SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
 357         SHA1Update(&sha1ctx, md, 20);
 358         SHA1Final(md, &sha1ctx);
 359 }
 360
 361 static int
 362 carp_hmac_verify(struct carp_softc *sc, u_int32_t counter[2],
 363     unsigned char md[20])
 364 {
 365         unsigned char md2[20];
 366
 367         CARP_SCLOCK_ASSERT(sc);
 368
 369         carp_hmac_generate(sc, counter, md2);
 370
 371         return (bcmp(md, md2, sizeof(md2)));
 372 }
 373
 374 static void
 375 carp_setroute(struct carp_softc *sc, int cmd)
 376 {
 377         struct ifaddr *ifa;
 378         int s;
 379
 380         if (sc->sc_carpdev)
 381                 CARP_SCLOCK_ASSERT(sc);
 382
 383         s = splnet();
 384         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 385 #ifdef INET
 386                 if (ifa->ifa_addr->sa_family == AF_INET &&
 387                     sc->sc_carpdev != NULL) {
 388                         int count = carp_addrcount(
 389                             (struct carp_if *)sc->sc_carpdev->if_carp,
 390                             ifatoia(ifa), CARP_COUNT_MASTER);
 391
 392                         if ((cmd == RTM_ADD && count == 1) ||
 393                             (cmd == RTM_DELETE && count == 0))
 394                                 rtinit(ifa, cmd, RTF_UP | RTF_HOST);
 395                 }
 396 #endif
 397         }
 398         splx(s);
 399 }
 400
 401 static int
 402 carp_clone_create(struct if_clone *ifc, int unit, caddr_t params)
 403 {
 404
 405         struct carp_softc *sc;
 406         struct ifnet *ifp;
 407
 408         sc = malloc(sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
 409         ifp = SC2IFP(sc) = if_alloc(IFT_ETHER);
 410         if (ifp == NULL) {
 411                 free(sc, M_CARP);
 412                 return (ENOSPC);
 413         }
 414
 415         sc->sc_flags_backup = 0;
 416         sc->sc_suppress = 0;
 417         sc->sc_advbase = CARP_DFLTINTV;
 418         sc->sc_vhid = -1;       /* required setting */
 419         sc->sc_advskew = 0;
 420         sc->sc_init_counter = 1;
 421         sc->sc_naddrs = sc->sc_naddrs6 = 0; /* M_ZERO? */
 422 #ifdef INET
 423         sc->sc_imo.imo_membership = (struct in_multi **)malloc(
 424             (sizeof(struct in_multi *) * IP_MIN_MEMBERSHIPS), M_CARP,
 425             M_WAITOK);
 426         sc->sc_imo.imo_mfilters = NULL;
 427         sc->sc_imo.imo_max_memberships = IP_MIN_MEMBERSHIPS;
 428         sc->sc_imo.imo_multicast_vif = -1;
 429 #endif
 430 #ifdef INET6
 431         sc->sc_im6o.im6o_membership = (struct in6_multi **)malloc(
 432             (sizeof(struct in6_multi *) * IPV6_MIN_MEMBERSHIPS), M_CARP,
 433             M_WAITOK);
 434         sc->sc_im6o.im6o_mfilters = NULL;
 435         sc->sc_im6o.im6o_max_memberships = IPV6_MIN_MEMBERSHIPS;
 436         sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
 437 #endif
 438
 439         callout_init(&sc->sc_ad_tmo, CALLOUT_MPSAFE);
 440         callout_init(&sc->sc_md_tmo, CALLOUT_MPSAFE);
 441         callout_init(&sc->sc_md6_tmo, CALLOUT_MPSAFE);
 442
 443         ifp->if_softc = sc;
 444         if_initname(ifp, CARP_IFNAME, unit);
 445         ifp->if_mtu = ETHERMTU;
 446         ifp->if_flags = IFF_LOOPBACK;
 447         ifp->if_ioctl = carp_ioctl;
 448         ifp->if_output = carp_looutput;
 449         ifp->if_start = carp_start;
 450         ifp->if_type = IFT_CARP;
 451         ifp->if_snd.ifq_maxlen = ifqmaxlen;
 452         ifp->if_hdrlen = 0;
 453         if_attach(ifp);
 454         bpfattach(SC2IFP(sc), DLT_NULL, sizeof(u_int32_t));
 455         mtx_lock(&carp_mtx);
 456         LIST_INSERT_HEAD(&carpif_list, sc, sc_next);
 457         mtx_unlock(&carp_mtx);
 458         return (0);
 459 }
 460
 461 static void
 462 carp_clone_destroy(struct ifnet *ifp)
 463 {
 464         struct carp_softc *sc = ifp->if_softc;
 465
 466         if (sc->sc_carpdev)
 467                 CARP_SCLOCK(sc);
 468         carpdetach(sc, 1);      /* Returns unlocked. */
 469
 470         mtx_lock(&carp_mtx);
 471         LIST_REMOVE(sc, sc_next);
 472         mtx_unlock(&carp_mtx);
 473         bpfdetach(ifp);
 474         if_detach(ifp);
 475         if_free_type(ifp, IFT_ETHER);
 476 #ifdef INET
 477         free(sc->sc_imo.imo_membership, M_CARP);
 478 #endif
 479 #ifdef INET6
 480         free(sc->sc_im6o.im6o_membership, M_CARP);
 481 #endif
 482         free(sc, M_CARP);
 483 }
 484
 485 /*
 486  * This function can be called on CARP interface destroy path,
 487  * and in case of the removal of the underlying interface as
 488  * well. We differentiate these two cases: in case of destruction
 489  * of the underlying interface, we do not cleanup our multicast
 490  * memberships, since they are already freed. But we purge pointers
 491  * to multicast structures, since they are no longer valid, to
 492  * avoid panic in future calls to carpdetach(). Also, we do not
 493  * release the lock on return, because the function will be
 494  * called once more, for another CARP instance on the same
 495  * interface.
 496  */
 497 static void
 498 carpdetach(struct carp_softc *sc, int unlock)
 499 {
 500         struct carp_if *cif;
 501
 502         callout_stop(&sc->sc_ad_tmo);
 503         callout_stop(&sc->sc_md_tmo);
 504         callout_stop(&sc->sc_md6_tmo);
 505
 506         if (sc->sc_suppress)
 507                 carp_suppress_preempt--;
 508         sc->sc_suppress = 0;
 509
 510         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
 511                 carp_suppress_preempt--;
 512         sc->sc_sendad_errors = 0;
 513
 514         carp_set_state(sc, INIT);
 515         SC2IFP(sc)->if_flags &= ~IFF_UP;
 516         carp_setrun(sc, 0);
 517 #ifdef INET
 518         carp_multicast_cleanup(sc, unlock);
 519 #endif
 520 #ifdef INET6
 521         carp_multicast6_cleanup(sc, unlock);
 522 #endif
 523
 524         if (sc->sc_carpdev != NULL) {
 525                 cif = (struct carp_if *)sc->sc_carpdev->if_carp;
 526                 CARP_LOCK_ASSERT(cif);
 527                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
 528                 if (!--cif->vhif_nvrs) {
 529                         ifpromisc(sc->sc_carpdev, 0);
 530                         sc->sc_carpdev->if_carp = NULL;
 531                         CARP_LOCK_DESTROY(cif);
 532                         free(cif, M_CARP);
 533                 } else if (unlock)
 534                         CARP_UNLOCK(cif);
 535                 sc->sc_carpdev = NULL;
 536         }
 537 }
 538
 539 /* Detach an interface from the carp. */
 540 static void
 541 carp_ifdetach(void *arg __unused, struct ifnet *ifp)
 542 {
 543         struct carp_if *cif = (struct carp_if *)ifp->if_carp;
 544         struct carp_softc *sc, *nextsc;
 545
 546         if (cif == NULL)
 547                 return;
 548
 549         /*
 550          * XXX: At the end of for() cycle the lock will be destroyed.
 551          */
 552         CARP_LOCK(cif);
 553         for (sc = TAILQ_FIRST(&cif->vhif_vrs); sc; sc = nextsc) {
 554                 nextsc = TAILQ_NEXT(sc, sc_list);
 555                 carpdetach(sc, 0);
 556         }
 557 }
 558
 559 /*
 560  * process input packet.
 561  * we have rearranged checks order compared to the rfc,
 562  * but it seems more efficient this way or not possible otherwise.
 563  */
 564 #ifdef INET
 565 void
 566 carp_input(struct mbuf *m, int hlen)
 567 {
 568         struct ip *ip = mtod(m, struct ip *);
 569         struct carp_header *ch;
 570         int iplen, len;
 571
 572         CARPSTATS_INC(carps_ipackets);
 573
 574         if (!carp_opts[CARPCTL_ALLOW]) {
 575                 m_freem(m);
 576                 return;
 577         }
 578
 579         /* check if received on a valid carp interface */
 580         if (m->m_pkthdr.rcvif->if_carp == NULL) {
 581                 CARPSTATS_INC(carps_badif);
 582                 CARP_DEBUG("carp_input: packet received on non-carp "
 583                     "interface: %s\n",
 584                     m->m_pkthdr.rcvif->if_xname);
 585                 m_freem(m);
 586                 return;
 587         }
 588
 589         /* verify that the IP TTL is 255.  */
 590         if (ip->ip_ttl != CARP_DFLTTL) {
 591                 CARPSTATS_INC(carps_badttl);
 592                 CARP_DEBUG("carp_input: received ttl %d != 255 on %s\n",
 593                     ip->ip_ttl,
 594                     m->m_pkthdr.rcvif->if_xname);
 595                 m_freem(m);
 596                 return;
 597         }
 598
 599         iplen = ip->ip_hl << 2;
 600
 601         if (m->m_pkthdr.len < iplen + sizeof(*ch)) {
 602                 CARPSTATS_INC(carps_badlen);
 603                 CARP_DEBUG("carp_input: received len %zd < "
 604                     "sizeof(struct carp_header) on %s\n",
 605                     m->m_len - sizeof(struct ip),
 606                     m->m_pkthdr.rcvif->if_xname);
 607                 m_freem(m);
 608                 return;
 609         }
 610
 611         if (iplen + sizeof(*ch) < m->m_len) {
 612                 if ((m = m_pullup(m, iplen + sizeof(*ch))) == NULL) {
 613                         CARPSTATS_INC(carps_hdrops);
 614                         CARP_DEBUG("carp_input: pullup failed\n");
 615                         return;
 616                 }
 617                 ip = mtod(m, struct ip *);
 618         }
 619         ch = (struct carp_header *)((char *)ip + iplen);
 620
 621         /*
 622          * verify that the received packet length is
 623          * equal to the CARP header
 624          */
 625         len = iplen + sizeof(*ch);
 626         if (len > m->m_pkthdr.len) {
 627                 CARPSTATS_INC(carps_badlen);
 628                 CARP_DEBUG("carp_input: packet too short %d on %s\n",
 629                     m->m_pkthdr.len,
 630                     m->m_pkthdr.rcvif->if_xname);
 631                 m_freem(m);
 632                 return;
 633         }
 634
 635         if ((m = m_pullup(m, len)) == NULL) {
 636                 CARPSTATS_INC(carps_hdrops);
 637                 return;
 638         }
 639         ip = mtod(m, struct ip *);
 640         ch = (struct carp_header *)((char *)ip + iplen);
 641
 642         /* verify the CARP checksum */
 643         m->m_data += iplen;
 644         if (carp_cksum(m, len - iplen)) {
 645                 CARPSTATS_INC(carps_badsum);
 646                 CARP_DEBUG("carp_input: checksum failed on %s\n",
 647                     m->m_pkthdr.rcvif->if_xname);
 648                 m_freem(m);
 649                 return;
 650         }
 651         m->m_data -= iplen;
 652
 653         carp_input_c(m, ch, AF_INET);
 654 }
 655 #endif
 656
 657 #ifdef INET6
 658 int
 659 carp6_input(struct mbuf **mp, int *offp, int proto)
 660 {
 661         struct mbuf *m = *mp;
 662         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 663         struct carp_header *ch;
 664         u_int len;
 665
 666         CARPSTATS_INC(carps_ipackets6);
 667
 668         if (!carp_opts[CARPCTL_ALLOW]) {
 669                 m_freem(m);
 670                 return (IPPROTO_DONE);
 671         }
 672
 673         /* check if received on a valid carp interface */
 674         if (m->m_pkthdr.rcvif->if_carp == NULL) {
 675                 CARPSTATS_INC(carps_badif);
 676                 CARP_DEBUG("carp6_input: packet received on non-carp "
 677                     "interface: %s\n",
 678                     m->m_pkthdr.rcvif->if_xname);
 679                 m_freem(m);
 680                 return (IPPROTO_DONE);
 681         }
 682
 683         /* verify that the IP TTL is 255 */
 684         if (ip6->ip6_hlim != CARP_DFLTTL) {
 685                 CARPSTATS_INC(carps_badttl);
 686                 CARP_DEBUG("carp6_input: received ttl %d != 255 on %s\n",
 687                     ip6->ip6_hlim,
 688                     m->m_pkthdr.rcvif->if_xname);
 689                 m_freem(m);
 690                 return (IPPROTO_DONE);
 691         }
 692
 693         /* verify that we have a complete carp packet */
 694         len = m->m_len;
 695         IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
 696         if (ch == NULL) {
 697                 CARPSTATS_INC(carps_badlen);
 698                 CARP_DEBUG("carp6_input: packet size %u too small\n", len);
 699                 return (IPPROTO_DONE);
 700         }
 701
 702
 703         /* verify the CARP checksum */
 704         m->m_data += *offp;
 705         if (carp_cksum(m, sizeof(*ch))) {
 706                 CARPSTATS_INC(carps_badsum);
 707                 CARP_DEBUG("carp6_input: checksum failed, on %s\n",
 708                     m->m_pkthdr.rcvif->if_xname);
 709                 m_freem(m);
 710                 return (IPPROTO_DONE);
 711         }
 712         m->m_data -= *offp;
 713
 714         carp_input_c(m, ch, AF_INET6);
 715         return (IPPROTO_DONE);
 716 }
 717 #endif /* INET6 */
 718
 719 static void
 720 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
 721 {
 722         struct ifnet *ifp = m->m_pkthdr.rcvif;
 723         struct carp_softc *sc;
 724         u_int64_t tmp_counter;
 725         struct timeval sc_tv, ch_tv;
 726
 727         /* verify that the VHID is valid on the receiving interface */
 728         CARP_LOCK(ifp->if_carp);
 729         TAILQ_FOREACH(sc, &((struct carp_if *)ifp->if_carp)->vhif_vrs, sc_list)
 730                 if (sc->sc_vhid == ch->carp_vhid)
 731                         break;
 732
 733         if (!sc || !((SC2IFP(sc)->if_flags & IFF_UP) &&
 734             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING))) {
 735                 CARPSTATS_INC(carps_badvhid);
 736                 CARP_UNLOCK(ifp->if_carp);
 737                 m_freem(m);
 738                 return;
 739         }
 740
 741         getmicrotime(&SC2IFP(sc)->if_lastchange);
 742         SC2IFP(sc)->if_ipackets++;
 743         SC2IFP(sc)->if_ibytes += m->m_pkthdr.len;
 744
 745         if (bpf_peers_present(SC2IFP(sc)->if_bpf)) {
 746                 uint32_t af1 = af;
 747 #ifdef INET
 748                 struct ip *ip = mtod(m, struct ip *);
 749
 750                 /* BPF wants net byte order */
 751                 if (af == AF_INET) {
 752                         ip->ip_len = htons(ip->ip_len + (ip->ip_hl << 2));
 753                         ip->ip_off = htons(ip->ip_off);
 754                 }
 755 #endif
 756                 bpf_mtap2(SC2IFP(sc)->if_bpf, &af1, sizeof(af1), m);
 757         }
 758
 759         /* verify the CARP version. */
 760         if (ch->carp_version != CARP_VERSION) {
 761                 CARPSTATS_INC(carps_badver);
 762                 SC2IFP(sc)->if_ierrors++;
 763                 CARP_UNLOCK(ifp->if_carp);
 764                 CARP_DEBUG("%s; invalid version %d\n",
 765                     SC2IFP(sc)->if_xname,
 766                     ch->carp_version);
 767                 m_freem(m);
 768                 return;
 769         }
 770
 771         /* verify the hash */
 772         if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
 773                 CARPSTATS_INC(carps_badauth);
 774                 SC2IFP(sc)->if_ierrors++;
 775                 CARP_UNLOCK(ifp->if_carp);
 776                 CARP_DEBUG("%s: incorrect hash\n", SC2IFP(sc)->if_xname);
 777                 m_freem(m);
 778                 return;
 779         }
 780
 781         tmp_counter = ntohl(ch->carp_counter[0]);
 782         tmp_counter = tmp_counter<<32;
 783         tmp_counter += ntohl(ch->carp_counter[1]);
 784
 785         /* XXX Replay protection goes here */
 786
 787         sc->sc_init_counter = 0;
 788         sc->sc_counter = tmp_counter;
 789
 790         sc_tv.tv_sec = sc->sc_advbase;
 791         if (carp_suppress_preempt && sc->sc_advskew <  240)
 792                 sc_tv.tv_usec = 240 * 1000000 / 256;
 793         else
 794                 sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
 795         ch_tv.tv_sec = ch->carp_advbase;
 796         ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
 797
 798         switch (sc->sc_state) {
 799         case INIT:
 800                 break;
 801         case MASTER:
 802                 /*
 803                  * If we receive an advertisement from a master who's going to
 804                  * be more frequent than us, go into BACKUP state.
 805                  */
 806                 if (timevalcmp(&sc_tv, &ch_tv, >) ||
 807                     timevalcmp(&sc_tv, &ch_tv, ==)) {
 808                         callout_stop(&sc->sc_ad_tmo);
 809                         CARP_LOG("%s: MASTER -> BACKUP "
 810                            "(more frequent advertisement received)\n",
 811                            SC2IFP(sc)->if_xname);
 812                         carp_set_state(sc, BACKUP);
 813                         carp_setrun(sc, 0);
 814                         carp_setroute(sc, RTM_DELETE);
 815                 }
 816                 break;
 817         case BACKUP:
 818                 /*
 819                  * If we're pre-empting masters who advertise slower than us,
 820                  * and this one claims to be slower, treat him as down.
 821                  */
 822                 if (carp_opts[CARPCTL_PREEMPT] &&
 823                     timevalcmp(&sc_tv, &ch_tv, <)) {
 824                         CARP_LOG("%s: BACKUP -> MASTER "
 825                             "(preempting a slower master)\n",
 826                             SC2IFP(sc)->if_xname);
 827                         carp_master_down_locked(sc);
 828                         break;
 829                 }
 830
 831                 /*
 832                  *  If the master is going to advertise at such a low frequency
 833                  *  that he's guaranteed to time out, we'd might as well just
 834                  *  treat him as timed out now.
 835                  */
 836                 sc_tv.tv_sec = sc->sc_advbase * 3;
 837                 if (timevalcmp(&sc_tv, &ch_tv, <)) {
 838                         CARP_LOG("%s: BACKUP -> MASTER "
 839                             "(master timed out)\n",
 840                             SC2IFP(sc)->if_xname);
 841                         carp_master_down_locked(sc);
 842                         break;
 843                 }
 844
 845                 /*
 846                  * Otherwise, we reset the counter and wait for the next
 847                  * advertisement.
 848                  */
 849                 carp_setrun(sc, af);
 850                 break;
 851         }
 852
 853         CARP_UNLOCK(ifp->if_carp);
 854
 855         m_freem(m);
 856         return;
 857 }
 858
 859 static int
 860 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
 861 {
 862         struct m_tag *mtag;
 863         struct ifnet *ifp = SC2IFP(sc);
 864
 865         if (sc->sc_init_counter) {
 866                 /* this could also be seconds since unix epoch */
 867                 sc->sc_counter = arc4random();
 868                 sc->sc_counter = sc->sc_counter << 32;
 869                 sc->sc_counter += arc4random();
 870         } else
 871                 sc->sc_counter++;
 872
 873         ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
 874         ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
 875
 876         carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
 877
 878         /* Tag packet for carp_output */
 879         mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct ifnet *), M_NOWAIT);
 880         if (mtag == NULL) {
 881                 m_freem(m);
 882                 SC2IFP(sc)->if_oerrors++;
 883                 return (ENOMEM);
 884         }
 885         bcopy(&ifp, (caddr_t)(mtag + 1), sizeof(struct ifnet *));
 886         m_tag_prepend(m, mtag);
 887
 888         return (0);
 889 }
 890
 891 static void
 892 carp_send_ad_all(void)
 893 {
 894         struct carp_softc *sc;
 895
 896         mtx_lock(&carp_mtx);
 897         LIST_FOREACH(sc, &carpif_list, sc_next) {
 898                 if (sc->sc_carpdev == NULL)
 899                         continue;
 900                 CARP_SCLOCK(sc);
 901                 if ((SC2IFP(sc)->if_flags & IFF_UP) &&
 902                     (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING) &&
 903                      sc->sc_state == MASTER)
 904                         carp_send_ad_locked(sc);
 905                 CARP_SCUNLOCK(sc);
 906         }
 907         mtx_unlock(&carp_mtx);
 908 }
 909
 910 static void
 911 carp_send_ad(void *v)
 912 {
 913         struct carp_softc *sc = v;
 914
 915         CARP_SCLOCK(sc);
 916         carp_send_ad_locked(sc);
 917         CARP_SCUNLOCK(sc);
 918 }
 919
 920 static void
 921 carp_send_ad_locked(struct carp_softc *sc)
 922 {
 923         struct carp_header ch;
 924         struct timeval tv;
 925         struct carp_header *ch_ptr;
 926         struct mbuf *m;
 927         int len, advbase, advskew;
 928
 929         CARP_SCLOCK_ASSERT(sc);
 930
 931         /* bow out if we've lost our UPness or RUNNINGuiness */
 932         if (!((SC2IFP(sc)->if_flags & IFF_UP) &&
 933             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING))) {
 934                 advbase = 255;
 935                 advskew = 255;
 936         } else {
 937                 advbase = sc->sc_advbase;
 938                 if (!carp_suppress_preempt || sc->sc_advskew > 240)
 939                         advskew = sc->sc_advskew;
 940                 else
 941                         advskew = 240;
 942                 tv.tv_sec = advbase;
 943                 tv.tv_usec = advskew * 1000000 / 256;
 944         }
 945
 946         ch.carp_version = CARP_VERSION;
 947         ch.carp_type = CARP_ADVERTISEMENT;
 948         ch.carp_vhid = sc->sc_vhid;
 949         ch.carp_advbase = advbase;
 950         ch.carp_advskew = advskew;
 951         ch.carp_authlen = 7;    /* XXX DEFINE */
 952         ch.carp_pad1 = 0;       /* must be zero */
 953         ch.carp_cksum = 0;
 954
 955 #ifdef INET
 956         if (sc->sc_ia) {
 957                 struct ip *ip;
 958
 959                 MGETHDR(m, M_DONTWAIT, MT_HEADER);
 960                 if (m == NULL) {
 961                         SC2IFP(sc)->if_oerrors++;
 962                         CARPSTATS_INC(carps_onomem);
 963                         /* XXX maybe less ? */
 964                         if (advbase != 255 || advskew != 255)
 965                                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
 966                                     carp_send_ad, sc);
 967                         return;
 968                 }
 969                 len = sizeof(*ip) + sizeof(ch);
 970                 m->m_pkthdr.len = len;
 971                 m->m_pkthdr.rcvif = NULL;
 972                 m->m_len = len;
 973                 MH_ALIGN(m, m->m_len);
 974                 m->m_flags |= M_MCAST;
 975                 ip = mtod(m, struct ip *);
 976                 ip->ip_v = IPVERSION;
 977                 ip->ip_hl = sizeof(*ip) >> 2;
 978                 ip->ip_tos = IPTOS_LOWDELAY;
 979                 ip->ip_len = len;
 980                 ip->ip_id = ip_newid();
 981                 ip->ip_off = IP_DF;
 982                 ip->ip_ttl = CARP_DFLTTL;
 983                 ip->ip_p = IPPROTO_CARP;
 984                 ip->ip_sum = 0;
 985                 ip->ip_src.s_addr = sc->sc_ia->ia_addr.sin_addr.s_addr;
 986                 ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
 987
 988                 ch_ptr = (struct carp_header *)(&ip[1]);
 989                 bcopy(&ch, ch_ptr, sizeof(ch));
 990                 if (carp_prepare_ad(m, sc, ch_ptr))
 991                         return;
 992
 993                 m->m_data += sizeof(*ip);
 994                 ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
 995                 m->m_data -= sizeof(*ip);
 996
 997                 getmicrotime(&SC2IFP(sc)->if_lastchange);
 998                 SC2IFP(sc)->if_opackets++;
 999                 SC2IFP(sc)->if_obytes += len;
1000                 CARPSTATS_INC(carps_opackets);
1001
1002                 if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL)) {
1003                         SC2IFP(sc)->if_oerrors++;
1004                         if (sc->sc_sendad_errors < INT_MAX)
1005                                 sc->sc_sendad_errors++;
1006                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1007                                 carp_suppress_preempt++;
1008                                 if (carp_suppress_preempt == 1) {
1009                                         CARP_SCUNLOCK(sc);
1010                                         carp_send_ad_all();
1011                                         CARP_SCLOCK(sc);
1012                                 }
1013                         }
1014                         sc->sc_sendad_success = 0;
1015                 } else {
1016                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1017                                 if (++sc->sc_sendad_success >=
1018                                     CARP_SENDAD_MIN_SUCCESS) {
1019                                         carp_suppress_preempt--;
1020                                         sc->sc_sendad_errors = 0;
1021                                 }
1022                         } else
1023                                 sc->sc_sendad_errors = 0;
1024                 }
1025         }
1026 #endif /* INET */
1027 #ifdef INET6
1028         if (sc->sc_ia6) {
1029                 struct ip6_hdr *ip6;
1030
1031                 MGETHDR(m, M_DONTWAIT, MT_HEADER);
1032                 if (m == NULL) {
1033                         SC2IFP(sc)->if_oerrors++;
1034                         CARPSTATS_INC(carps_onomem);
1035                         /* XXX maybe less ? */
1036                         if (advbase != 255 || advskew != 255)
1037                                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1038                                     carp_send_ad, sc);
1039                         return;
1040                 }
1041                 len = sizeof(*ip6) + sizeof(ch);
1042                 m->m_pkthdr.len = len;
1043                 m->m_pkthdr.rcvif = NULL;
1044                 m->m_len = len;
1045                 MH_ALIGN(m, m->m_len);
1046                 m->m_flags |= M_MCAST;
1047                 ip6 = mtod(m, struct ip6_hdr *);
1048                 bzero(ip6, sizeof(*ip6));
1049                 ip6->ip6_vfc |= IPV6_VERSION;
1050                 ip6->ip6_hlim = CARP_DFLTTL;
1051                 ip6->ip6_nxt = IPPROTO_CARP;
1052                 bcopy(&sc->sc_ia6->ia_addr.sin6_addr, &ip6->ip6_src,
1053                     sizeof(struct in6_addr));
1054                 /* set the multicast destination */
1055
1056                 ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
1057                 ip6->ip6_dst.s6_addr8[15] = 0x12;
1058                 if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1059                         SC2IFP(sc)->if_oerrors++;
1060                         m_freem(m);
1061                         CARP_DEBUG("%s: in6_setscope failed\n", __func__);
1062                         return;
1063                 }
1064
1065                 ch_ptr = (struct carp_header *)(&ip6[1]);
1066                 bcopy(&ch, ch_ptr, sizeof(ch));
1067                 if (carp_prepare_ad(m, sc, ch_ptr))
1068                         return;
1069
1070                 m->m_data += sizeof(*ip6);
1071                 ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
1072                 m->m_data -= sizeof(*ip6);
1073
1074                 getmicrotime(&SC2IFP(sc)->if_lastchange);
1075                 SC2IFP(sc)->if_opackets++;
1076                 SC2IFP(sc)->if_obytes += len;
1077                 CARPSTATS_INC(carps_opackets6);
1078
1079                 if (ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL)) {
1080                         SC2IFP(sc)->if_oerrors++;
1081                         if (sc->sc_sendad_errors < INT_MAX)
1082                                 sc->sc_sendad_errors++;
1083                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1084                                 carp_suppress_preempt++;
1085                                 if (carp_suppress_preempt == 1) {
1086                                         CARP_SCUNLOCK(sc);
1087                                         carp_send_ad_all();
1088                                         CARP_SCLOCK(sc);
1089                                 }
1090                         }
1091                         sc->sc_sendad_success = 0;
1092                 } else {
1093                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1094                                 if (++sc->sc_sendad_success >=
1095                                     CARP_SENDAD_MIN_SUCCESS) {
1096                                         carp_suppress_preempt--;
1097                                         sc->sc_sendad_errors = 0;
1098                                 }
1099                         } else
1100                                 sc->sc_sendad_errors = 0;
1101                 }
1102         }
1103 #endif /* INET6 */
1104
1105         if (advbase != 255 || advskew != 255)
1106                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1107                     carp_send_ad, sc);
1108
1109 }
1110
1111 #ifdef INET
1112 /*
1113  * Broadcast a gratuitous ARP request containing
1114  * the virtual router MAC address for each IP address
1115  * associated with the virtual router.
1116  */
1117 static void
1118 carp_send_arp(struct carp_softc *sc)
1119 {
1120         struct ifaddr *ifa;
1121
1122         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
1123
1124                 if (ifa->ifa_addr->sa_family != AF_INET)
1125                         continue;
1126
1127 /*              arprequest(sc->sc_carpdev, &in, &in, IF_LLADDR(sc->sc_ifp)); */
1128                 arp_ifinit2(sc->sc_carpdev, ifa, IF_LLADDR(sc->sc_ifp));
1129
1130                 DELAY(1000);    /* XXX */
1131         }
1132 }
1133 #endif
1134
1135 #ifdef INET6
1136 static void
1137 carp_send_na(struct carp_softc *sc)
1138 {
1139         struct ifaddr *ifa;
1140         struct in6_addr *in6;
1141         static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1142
1143         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
1144
1145                 if (ifa->ifa_addr->sa_family != AF_INET6)
1146                         continue;
1147
1148                 in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1149                 nd6_na_output(sc->sc_carpdev, &mcast, in6,
1150                     ND_NA_FLAG_OVERRIDE, 1, NULL);
1151                 DELAY(1000);    /* XXX */
1152         }
1153 }
1154 #endif /* INET6 */
1155
1156 #ifdef INET
1157 static int
1158 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
1159 {
1160         struct carp_softc *vh;
1161         struct ifaddr *ifa;
1162         int count = 0;
1163
1164         CARP_LOCK_ASSERT(cif);
1165
1166         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1167                 if ((type == CARP_COUNT_RUNNING &&
1168                     (SC2IFP(vh)->if_flags & IFF_UP) &&
1169                     (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING)) ||
1170                     (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
1171                         IF_ADDR_RLOCK(SC2IFP(vh));
1172                         TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist,
1173                             ifa_list) {
1174                                 if (ifa->ifa_addr->sa_family == AF_INET &&
1175                                     ia->ia_addr.sin_addr.s_addr ==
1176                                     ifatoia(ifa)->ia_addr.sin_addr.s_addr)
1177                                         count++;
1178                         }
1179                         IF_ADDR_RUNLOCK(SC2IFP(vh));
1180                 }
1181         }
1182         return (count);
1183 }
1184
1185 int
1186 carp_iamatch(struct ifnet *ifp, struct in_ifaddr *ia,
1187     struct in_addr *isaddr, u_int8_t **enaddr)
1188 {
1189         struct carp_if *cif;
1190         struct carp_softc *vh;
1191         int index, count = 0;
1192         struct ifaddr *ifa;
1193
1194         cif = ifp->if_carp;
1195         CARP_LOCK(cif);
1196
1197         if (carp_opts[CARPCTL_ARPBALANCE]) {
1198                 /*
1199                  * XXX proof of concept implementation.
1200                  * We use the source ip to decide which virtual host should
1201                  * handle the request. If we're master of that virtual host,
1202                  * then we respond, otherwise, just drop the arp packet on
1203                  * the floor.
1204                  */
1205                 count = carp_addrcount(cif, ia, CARP_COUNT_RUNNING);
1206                 if (count == 0) {
1207                         /* should never reach this */
1208                         CARP_UNLOCK(cif);
1209                         return (0);
1210                 }
1211
1212                 /* this should be a hash, like pf_hash() */
1213                 index = ntohl(isaddr->s_addr) % count;
1214                 count = 0;
1215
1216                 TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1217                         if ((SC2IFP(vh)->if_flags & IFF_UP) &&
1218                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING)) {
1219                                 IF_ADDR_RLOCK(SC2IFP(vh));
1220                                 TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist,
1221                                     ifa_list) {
1222                                         if (ifa->ifa_addr->sa_family ==
1223                                             AF_INET &&
1224                                             ia->ia_addr.sin_addr.s_addr ==
1225                                             ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
1226                                                 if (count == index) {
1227                                                         if (vh->sc_state ==
1228                                                             MASTER) {
1229                                                                 *enaddr = IF_LLADDR(vh->sc_ifp);
1230                                                                 IF_ADDR_RUNLOCK(SC2IFP(vh));
1231                                                                 CARP_UNLOCK(cif);
1232                                                                 return (1);
1233                                                         } else {
1234                                                                 IF_ADDR_RUNLOCK(SC2IFP(vh));
1235                                                                 CARP_UNLOCK(cif);
1236                                                                 return (0);
1237                                                         }
1238                                                 }
1239                                                 count++;
1240                                         }
1241                                 }
1242                                 IF_ADDR_RUNLOCK(SC2IFP(vh));
1243                         }
1244                 }
1245         } else {
1246                 TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1247                         if ((SC2IFP(vh)->if_flags & IFF_UP) &&
1248                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
1249                             ia->ia_ifp == SC2IFP(vh) &&
1250                             vh->sc_state == MASTER) {
1251                                 *enaddr = IF_LLADDR(vh->sc_ifp);
1252                                 CARP_UNLOCK(cif);
1253                                 return (1);
1254                         }
1255                 }
1256         }
1257         CARP_UNLOCK(cif);
1258         return (0);
1259 }
1260 #endif
1261
1262 #ifdef INET6
1263 struct ifaddr *
1264 carp_iamatch6(struct ifnet *ifp, struct in6_addr *taddr)
1265 {
1266         struct carp_if *cif;
1267         struct carp_softc *vh;
1268         struct ifaddr *ifa;
1269
1270         cif = ifp->if_carp;
1271         CARP_LOCK(cif);
1272         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1273                 IF_ADDR_RLOCK(SC2IFP(vh));
1274                 TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist, ifa_list) {
1275                         if (IN6_ARE_ADDR_EQUAL(taddr,
1276                             &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1277                             (SC2IFP(vh)->if_flags & IFF_UP) &&
1278                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
1279                             vh->sc_state == MASTER) {
1280                                 ifa_ref(ifa);
1281                                 IF_ADDR_RUNLOCK(SC2IFP(vh));
1282                                 CARP_UNLOCK(cif);
1283                                 return (ifa);
1284                         }
1285                 }
1286                 IF_ADDR_RUNLOCK(SC2IFP(vh));
1287         }
1288         CARP_UNLOCK(cif);
1289
1290         return (NULL);
1291 }
1292
1293 caddr_t
1294 carp_macmatch6(struct ifnet *ifp, struct mbuf *m, const struct in6_addr *taddr)
1295 {
1296         struct m_tag *mtag;
1297         struct carp_if *cif;
1298         struct carp_softc *sc;
1299         struct ifaddr *ifa;
1300
1301         cif = ifp->if_carp;
1302         CARP_LOCK(cif);
1303         TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
1304                 IF_ADDR_RLOCK(SC2IFP(sc));
1305                 TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
1306                         if (IN6_ARE_ADDR_EQUAL(taddr,
1307                             &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1308                             (SC2IFP(sc)->if_flags & IFF_UP) &&
1309                             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING)) {
1310                                 struct ifnet *ifp = SC2IFP(sc);
1311                                 mtag = m_tag_get(PACKET_TAG_CARP,
1312                                     sizeof(struct ifnet *), M_NOWAIT);
1313                                 if (mtag == NULL) {
1314                                         /* better a bit than nothing */
1315                                         IF_ADDR_RUNLOCK(SC2IFP(sc));
1316                                         CARP_UNLOCK(cif);
1317                                         return (IF_LLADDR(sc->sc_ifp));
1318                                 }
1319                                 bcopy(&ifp, (caddr_t)(mtag + 1),
1320                                     sizeof(struct ifnet *));
1321                                 m_tag_prepend(m, mtag);
1322
1323                                 IF_ADDR_RUNLOCK(SC2IFP(sc));
1324                                 CARP_UNLOCK(cif);
1325                                 return (IF_LLADDR(sc->sc_ifp));
1326                         }
1327                 }
1328                 IF_ADDR_RUNLOCK(SC2IFP(sc));
1329         }
1330         CARP_UNLOCK(cif);
1331
1332         return (NULL);
1333 }
1334 #endif
1335
1336 struct ifnet *
1337 carp_forus(struct ifnet *ifp, u_char *dhost)
1338 {
1339         struct carp_if *cif;
1340         struct carp_softc *vh;
1341         u_int8_t *ena = dhost;
1342
1343         if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1344                 return (NULL);
1345
1346         cif = ifp->if_carp;
1347         CARP_LOCK(cif);
1348         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
1349                 if ((SC2IFP(vh)->if_flags & IFF_UP) &&
1350                     (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
1351                     vh->sc_state == MASTER &&
1352                     !bcmp(dhost, IF_LLADDR(vh->sc_ifp), ETHER_ADDR_LEN)) {
1353                         CARP_UNLOCK(cif);
1354                         return (SC2IFP(vh));
1355                 }
1356
1357         CARP_UNLOCK(cif);
1358         return (NULL);
1359 }
1360
1361 static void
1362 carp_master_down(void *v)
1363 {
1364         struct carp_softc *sc = v;
1365
1366         CARP_SCLOCK(sc);
1367         carp_master_down_locked(sc);
1368         CARP_SCUNLOCK(sc);
1369 }
1370
1371 static void
1372 carp_master_down_locked(struct carp_softc *sc)
1373 {
1374         if (sc->sc_carpdev)
1375                 CARP_SCLOCK_ASSERT(sc);
1376
1377         switch (sc->sc_state) {
1378         case INIT:
1379                 printf("%s: master_down event in INIT state\n",
1380                     SC2IFP(sc)->if_xname);
1381                 break;
1382         case MASTER:
1383                 break;
1384         case BACKUP:
1385                 carp_set_state(sc, MASTER);
1386                 carp_send_ad_locked(sc);
1387 #ifdef INET
1388                 carp_send_arp(sc);
1389 #endif
1390 #ifdef INET6
1391                 carp_send_na(sc);
1392 #endif /* INET6 */
1393                 carp_setrun(sc, 0);
1394                 carp_setroute(sc, RTM_ADD);
1395                 break;
1396         }
1397 }
1398
1399 /*
1400  * When in backup state, af indicates whether to reset the master down timer
1401  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1402  */
1403 static void
1404 carp_setrun(struct carp_softc *sc, sa_family_t af)
1405 {
1406         struct timeval tv;
1407
1408         if (sc->sc_carpdev == NULL) {
1409                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1410                 carp_set_state(sc, INIT);
1411                 return;
1412         } else
1413                 CARP_SCLOCK_ASSERT(sc);
1414
1415         if (SC2IFP(sc)->if_flags & IFF_UP &&
1416             sc->sc_vhid > 0 && (sc->sc_naddrs || sc->sc_naddrs6) &&
1417             sc->sc_carpdev->if_link_state == LINK_STATE_UP)
1418                 SC2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
1419         else {
1420                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1421                 carp_setroute(sc, RTM_DELETE);
1422                 return;
1423         }
1424
1425         switch (sc->sc_state) {
1426         case INIT:
1427                 CARP_LOG("%s: INIT -> BACKUP\n", SC2IFP(sc)->if_xname);
1428                 carp_set_state(sc, BACKUP);
1429                 carp_setroute(sc, RTM_DELETE);
1430                 carp_setrun(sc, 0);
1431                 break;
1432         case BACKUP:
1433                 callout_stop(&sc->sc_ad_tmo);
1434                 tv.tv_sec = 3 * sc->sc_advbase;
1435                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1436                 switch (af) {
1437 #ifdef INET
1438                 case AF_INET:
1439                         callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1440                             carp_master_down, sc);
1441                         break;
1442 #endif /* INET */
1443 #ifdef INET6
1444                 case AF_INET6:
1445                         callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1446                             carp_master_down, sc);
1447                         break;
1448 #endif /* INET6 */
1449                 default:
1450                         if (sc->sc_naddrs)
1451                                 callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1452                                     carp_master_down, sc);
1453                         if (sc->sc_naddrs6)
1454                                 callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1455                                     carp_master_down, sc);
1456                         break;
1457                 }
1458                 break;
1459         case MASTER:
1460                 tv.tv_sec = sc->sc_advbase;
1461                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1462                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1463                     carp_send_ad, sc);
1464                 break;
1465         }
1466 }
1467
1468 #ifdef INET
1469 static void
1470 carp_multicast_cleanup(struct carp_softc *sc, int dofree)
1471 {
1472         struct ip_moptions *imo = &sc->sc_imo;
1473         u_int16_t n = imo->imo_num_memberships;
1474
1475         /* Clean up our own multicast memberships */
1476         while (n-- > 0) {
1477                 if (imo->imo_membership[n] != NULL) {
1478                         if (dofree)
1479                                 in_delmulti(imo->imo_membership[n]);
1480                         imo->imo_membership[n] = NULL;
1481                 }
1482         }
1483         KASSERT(imo->imo_mfilters == NULL,
1484            ("%s: imo_mfilters != NULL", __func__));
1485         imo->imo_num_memberships = 0;
1486         imo->imo_multicast_ifp = NULL;
1487 }
1488 #endif
1489
1490 #ifdef INET6
1491 static void
1492 carp_multicast6_cleanup(struct carp_softc *sc, int dofree)
1493 {
1494         struct ip6_moptions *im6o = &sc->sc_im6o;
1495         u_int16_t n = im6o->im6o_num_memberships;
1496
1497         while (n-- > 0) {
1498                 if (im6o->im6o_membership[n] != NULL) {
1499                         if (dofree)
1500                                 in6_mc_leave(im6o->im6o_membership[n], NULL);
1501                         im6o->im6o_membership[n] = NULL;
1502                 }
1503         }
1504         KASSERT(im6o->im6o_mfilters == NULL,
1505            ("%s: im6o_mfilters != NULL", __func__));
1506         im6o->im6o_num_memberships = 0;
1507         im6o->im6o_multicast_ifp = NULL;
1508 }
1509 #endif
1510
1511 #ifdef INET
1512 static int
1513 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1514 {
1515         struct ifnet *ifp;
1516         struct carp_if *cif;
1517         struct in_ifaddr *ia, *ia_if;
1518         struct ip_moptions *imo = &sc->sc_imo;
1519         struct in_addr addr;
1520         u_long iaddr = htonl(sin->sin_addr.s_addr);
1521         int own, error;
1522
1523         if (sin->sin_addr.s_addr == 0) {
1524                 if (!(SC2IFP(sc)->if_flags & IFF_UP))
1525                         carp_set_state(sc, INIT);
1526                 if (sc->sc_naddrs)
1527                         SC2IFP(sc)->if_flags |= IFF_UP;
1528                 if (sc->sc_carpdev)
1529                         CARP_SCLOCK(sc);
1530                 carp_setrun(sc, 0);
1531                 if (sc->sc_carpdev)
1532                         CARP_SCUNLOCK(sc);
1533                 return (0);
1534         }
1535
1536         /* we have to do it by hands to check we won't match on us */
1537         ia_if = NULL; own = 0;
1538         IN_IFADDR_RLOCK();
1539         TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1540                 /* and, yeah, we need a multicast-capable iface too */
1541                 if (ia->ia_ifp != SC2IFP(sc) &&
1542                     (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1543                     (iaddr & ia->ia_subnetmask) == ia->ia_subnet) {
1544                         if (!ia_if)
1545                                 ia_if = ia;
1546                         if (sin->sin_addr.s_addr ==
1547                             ia->ia_addr.sin_addr.s_addr)
1548                                 own++;
1549                 }
1550         }
1551
1552         if (!ia_if) {
1553                 IN_IFADDR_RUNLOCK();
1554                 return (EADDRNOTAVAIL);
1555         }
1556
1557         ia = ia_if;
1558         ifa_ref(&ia->ia_ifa);
1559         IN_IFADDR_RUNLOCK();
1560
1561         ifp = ia->ia_ifp;
1562
1563         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
1564             (imo->imo_multicast_ifp && imo->imo_multicast_ifp != ifp)) {
1565                 ifa_free(&ia->ia_ifa);
1566                 return (EADDRNOTAVAIL);
1567         }
1568
1569         if (imo->imo_num_memberships == 0) {
1570                 addr.s_addr = htonl(INADDR_CARP_GROUP);
1571                 if ((imo->imo_membership[0] = in_addmulti(&addr, ifp)) ==
1572                     NULL) {
1573                         ifa_free(&ia->ia_ifa);
1574                         return (ENOBUFS);
1575                 }
1576                 imo->imo_num_memberships++;
1577                 imo->imo_multicast_ifp = ifp;
1578                 imo->imo_multicast_ttl = CARP_DFLTTL;
1579                 imo->imo_multicast_loop = 0;
1580         }
1581
1582         if (!ifp->if_carp) {
1583
1584                 cif = malloc(sizeof(*cif), M_CARP,
1585                     M_WAITOK|M_ZERO);
1586                 if (!cif) {
1587                         error = ENOBUFS;
1588                         goto cleanup;
1589                 }
1590                 if ((error = ifpromisc(ifp, 1))) {
1591                         free(cif, M_CARP);
1592                         goto cleanup;
1593                 }
1594
1595                 CARP_LOCK_INIT(cif);
1596                 CARP_LOCK(cif);
1597                 cif->vhif_ifp = ifp;
1598                 TAILQ_INIT(&cif->vhif_vrs);
1599                 ifp->if_carp = cif;
1600
1601         } else {
1602                 struct carp_softc *vr;
1603
1604                 cif = (struct carp_if *)ifp->if_carp;
1605                 CARP_LOCK(cif);
1606                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1607                         if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
1608                                 CARP_UNLOCK(cif);
1609                                 error = EEXIST;
1610                                 goto cleanup;
1611                         }
1612         }
1613         sc->sc_ia = ia;
1614         sc->sc_carpdev = ifp;
1615
1616         { /* XXX prevent endless loop if already in queue */
1617         struct carp_softc *vr, *after = NULL;
1618         int myself = 0;
1619         cif = (struct carp_if *)ifp->if_carp;
1620
1621         /* XXX: cif should not change, right? So we still hold the lock */
1622         CARP_LOCK_ASSERT(cif);
1623
1624         TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1625                 if (vr == sc)
1626                         myself = 1;
1627                 if (vr->sc_vhid < sc->sc_vhid)
1628                         after = vr;
1629         }
1630
1631         if (!myself) {
1632                 /* We're trying to keep things in order */
1633                 if (after == NULL) {
1634                         TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1635                 } else {
1636                         TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
1637                 }
1638                 cif->vhif_nvrs++;
1639         }
1640         }
1641
1642         sc->sc_naddrs++;
1643         SC2IFP(sc)->if_flags |= IFF_UP;
1644         if (own)
1645                 sc->sc_advskew = 0;
1646         carp_sc_state_locked(sc);
1647         carp_setrun(sc, 0);
1648
1649         CARP_UNLOCK(cif);
1650         ifa_free(&ia->ia_ifa);  /* XXXRW: should hold reference for softc. */
1651
1652         return (0);
1653
1654 cleanup:
1655         in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
1656         ifa_free(&ia->ia_ifa);
1657         return (error);
1658 }
1659
1660 static int
1661 carp_del_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1662 {
1663         int error = 0;
1664
1665         if (!--sc->sc_naddrs) {
1666                 struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1667                 struct ip_moptions *imo = &sc->sc_imo;
1668
1669                 CARP_LOCK(cif);
1670                 callout_stop(&sc->sc_ad_tmo);
1671                 SC2IFP(sc)->if_flags &= ~IFF_UP;
1672                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1673                 sc->sc_vhid = -1;
1674                 in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
1675                 imo->imo_multicast_ifp = NULL;
1676                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
1677                 if (!--cif->vhif_nvrs) {
1678                         sc->sc_carpdev->if_carp = NULL;
1679                         CARP_LOCK_DESTROY(cif);
1680                         free(cif, M_CARP);
1681                 } else {
1682                         CARP_UNLOCK(cif);
1683                 }
1684         }
1685
1686         return (error);
1687 }
1688 #endif
1689
1690 #ifdef INET6
1691 static int
1692 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1693 {
1694         struct ifnet *ifp;
1695         struct carp_if *cif;
1696         struct in6_ifaddr *ia, *ia_if;
1697         struct ip6_moptions *im6o = &sc->sc_im6o;
1698         struct in6_addr in6;
1699         int own, error;
1700
1701         error = 0;
1702
1703         if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1704                 if (!(SC2IFP(sc)->if_flags & IFF_UP))
1705                         carp_set_state(sc, INIT);
1706                 if (sc->sc_naddrs6)
1707                         SC2IFP(sc)->if_flags |= IFF_UP;
1708                 if (sc->sc_carpdev)
1709                         CARP_SCLOCK(sc);
1710                 carp_setrun(sc, 0);
1711                 if (sc->sc_carpdev)
1712                         CARP_SCUNLOCK(sc);
1713                 return (0);
1714         }
1715
1716         /* we have to do it by hands to check we won't match on us */
1717         ia_if = NULL; own = 0;
1718         IN6_IFADDR_RLOCK();
1719         TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
1720                 int i;
1721
1722                 for (i = 0; i < 4; i++) {
1723                         if ((sin6->sin6_addr.s6_addr32[i] &
1724                             ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1725                             (ia->ia_addr.sin6_addr.s6_addr32[i] &
1726                             ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1727                                 break;
1728                 }
1729                 /* and, yeah, we need a multicast-capable iface too */
1730                 if (ia->ia_ifp != SC2IFP(sc) &&
1731                     (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1732                     (i == 4)) {
1733                         if (!ia_if)
1734                                 ia_if = ia;
1735                         if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr,
1736                             &ia->ia_addr.sin6_addr))
1737                                 own++;
1738                 }
1739         }
1740
1741         if (!ia_if) {
1742                 IN6_IFADDR_RUNLOCK();
1743                 return (EADDRNOTAVAIL);
1744         }
1745         ia = ia_if;
1746         ifa_ref(&ia->ia_ifa);
1747         IN6_IFADDR_RUNLOCK();
1748         ifp = ia->ia_ifp;
1749
1750         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
1751             (im6o->im6o_multicast_ifp && im6o->im6o_multicast_ifp != ifp)) {
1752                 ifa_free(&ia->ia_ifa);
1753                 return (EADDRNOTAVAIL);
1754         }
1755
1756         if (!sc->sc_naddrs6) {
1757                 struct in6_multi *in6m;
1758
1759                 im6o->im6o_multicast_ifp = ifp;
1760
1761                 /* join CARP multicast address */
1762                 bzero(&in6, sizeof(in6));
1763                 in6.s6_addr16[0] = htons(0xff02);
1764                 in6.s6_addr8[15] = 0x12;
1765                 if (in6_setscope(&in6, ifp, NULL) != 0)
1766                         goto cleanup;
1767                 in6m = NULL;
1768                 error = in6_mc_join(ifp, &in6, NULL, &in6m, 0);
1769                 if (error)
1770                         goto cleanup;
1771                 im6o->im6o_membership[0] = in6m;
1772                 im6o->im6o_num_memberships++;
1773
1774                 /* join solicited multicast address */
1775                 bzero(&in6, sizeof(in6));
1776                 in6.s6_addr16[0] = htons(0xff02);
1777                 in6.s6_addr32[1] = 0;
1778                 in6.s6_addr32[2] = htonl(1);
1779                 in6.s6_addr32[3] = sin6->sin6_addr.s6_addr32[3];
1780                 in6.s6_addr8[12] = 0xff;
1781                 if (in6_setscope(&in6, ifp, NULL) != 0)
1782                         goto cleanup;
1783                 in6m = NULL;
1784                 error = in6_mc_join(ifp, &in6, NULL, &in6m, 0);
1785                 if (error)
1786                         goto cleanup;
1787                 im6o->im6o_membership[1] = in6m;
1788                 im6o->im6o_num_memberships++;
1789         }
1790
1791         if (!ifp->if_carp) {
1792                 cif = malloc(sizeof(*cif), M_CARP,
1793                     M_WAITOK|M_ZERO);
1794                 if (!cif) {
1795                         error = ENOBUFS;
1796                         goto cleanup;
1797                 }
1798                 if ((error = ifpromisc(ifp, 1))) {
1799                         free(cif, M_CARP);
1800                         goto cleanup;
1801                 }
1802
1803                 CARP_LOCK_INIT(cif);
1804                 CARP_LOCK(cif);
1805                 cif->vhif_ifp = ifp;
1806                 TAILQ_INIT(&cif->vhif_vrs);
1807                 ifp->if_carp = cif;
1808
1809         } else {
1810                 struct carp_softc *vr;
1811
1812                 cif = (struct carp_if *)ifp->if_carp;
1813                 CARP_LOCK(cif);
1814                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1815                         if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
1816                                 CARP_UNLOCK(cif);
1817                                 error = EINVAL;
1818                                 goto cleanup;
1819                         }
1820         }
1821         sc->sc_ia6 = ia;
1822         sc->sc_carpdev = ifp;
1823
1824         { /* XXX prevent endless loop if already in queue */
1825         struct carp_softc *vr, *after = NULL;
1826         int myself = 0;
1827         cif = (struct carp_if *)ifp->if_carp;
1828         CARP_LOCK_ASSERT(cif);
1829
1830         TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1831                 if (vr == sc)
1832                         myself = 1;
1833                 if (vr->sc_vhid < sc->sc_vhid)
1834                         after = vr;
1835         }
1836
1837         if (!myself) {
1838                 /* We're trying to keep things in order */
1839                 if (after == NULL) {
1840                         TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1841                 } else {
1842                         TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
1843                 }
1844                 cif->vhif_nvrs++;
1845         }
1846         }
1847
1848         sc->sc_naddrs6++;
1849         SC2IFP(sc)->if_flags |= IFF_UP;
1850         if (own)
1851                 sc->sc_advskew = 0;
1852         carp_sc_state_locked(sc);
1853         carp_setrun(sc, 0);
1854
1855         CARP_UNLOCK(cif);
1856         ifa_free(&ia->ia_ifa);  /* XXXRW: should hold reference for softc. */
1857
1858         return (0);
1859
1860 cleanup:
1861         if (!sc->sc_naddrs6)
1862                 carp_multicast6_cleanup(sc, 1);
1863         ifa_free(&ia->ia_ifa);
1864         return (error);
1865 }
1866
1867 static int
1868 carp_del_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1869 {
1870         int error = 0;
1871
1872         if (!--sc->sc_naddrs6) {
1873                 struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1874
1875                 CARP_LOCK(cif);
1876                 callout_stop(&sc->sc_ad_tmo);
1877                 SC2IFP(sc)->if_flags &= ~IFF_UP;
1878                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1879                 sc->sc_vhid = -1;
1880                 carp_multicast6_cleanup(sc, 1);
1881                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
1882                 if (!--cif->vhif_nvrs) {
1883                         CARP_LOCK_DESTROY(cif);
1884                         sc->sc_carpdev->if_carp = NULL;
1885                         free(cif, M_CARP);
1886                 } else
1887                         CARP_UNLOCK(cif);
1888         }
1889
1890         return (error);
1891 }
1892 #endif /* INET6 */
1893
1894 static int
1895 carp_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
1896 {
1897         struct carp_softc *sc = ifp->if_softc, *vr;
1898         struct carpreq carpr;
1899         struct ifaddr *ifa;
1900         struct ifreq *ifr;
1901         struct ifaliasreq *ifra;
1902         int locked = 0, error = 0;
1903
1904         ifa = (struct ifaddr *)addr;
1905         ifra = (struct ifaliasreq *)addr;
1906         ifr = (struct ifreq *)addr;
1907
1908         switch (cmd) {
1909         case SIOCSIFADDR:
1910                 switch (ifa->ifa_addr->sa_family) {
1911 #ifdef INET
1912                 case AF_INET:
1913                         SC2IFP(sc)->if_flags |= IFF_UP;
1914                         bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1915                             sizeof(struct sockaddr));
1916                         error = carp_set_addr(sc, satosin(ifa->ifa_addr));
1917                         break;
1918 #endif /* INET */
1919 #ifdef INET6
1920                 case AF_INET6:
1921                         SC2IFP(sc)->if_flags |= IFF_UP;
1922                         error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1923                         break;
1924 #endif /* INET6 */
1925                 default:
1926                         error = EAFNOSUPPORT;
1927                         break;
1928                 }
1929                 break;
1930
1931         case SIOCAIFADDR:
1932                 switch (ifa->ifa_addr->sa_family) {
1933 #ifdef INET
1934                 case AF_INET:
1935                         SC2IFP(sc)->if_flags |= IFF_UP;
1936                         bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1937                             sizeof(struct sockaddr));
1938                         error = carp_set_addr(sc, satosin(&ifra->ifra_addr));
1939                         break;
1940 #endif /* INET */
1941 #ifdef INET6
1942                 case AF_INET6:
1943                         SC2IFP(sc)->if_flags |= IFF_UP;
1944                         error = carp_set_addr6(sc, satosin6(&ifra->ifra_addr));
1945                         break;
1946 #endif /* INET6 */
1947                 default:
1948                         error = EAFNOSUPPORT;
1949                         break;
1950                 }
1951                 break;
1952
1953         case SIOCDIFADDR:
1954                 switch (ifa->ifa_addr->sa_family) {
1955 #ifdef INET
1956                 case AF_INET:
1957                         error = carp_del_addr(sc, satosin(&ifra->ifra_addr));
1958                         break;
1959 #endif /* INET */
1960 #ifdef INET6
1961                 case AF_INET6:
1962                         error = carp_del_addr6(sc, satosin6(&ifra->ifra_addr));
1963                         break;
1964 #endif /* INET6 */
1965                 default:
1966                         error = EAFNOSUPPORT;
1967                         break;
1968                 }
1969                 break;
1970
1971         case SIOCSIFFLAGS:
1972                 if (sc->sc_carpdev) {
1973                         locked = 1;
1974                         CARP_SCLOCK(sc);
1975                 }
1976                 if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
1977                         callout_stop(&sc->sc_ad_tmo);
1978                         callout_stop(&sc->sc_md_tmo);
1979                         callout_stop(&sc->sc_md6_tmo);
1980                         if (sc->sc_state == MASTER)
1981                                 carp_send_ad_locked(sc);
1982                         carp_set_state(sc, INIT);
1983                         carp_setrun(sc, 0);
1984                 } else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
1985                         SC2IFP(sc)->if_flags |= IFF_UP;
1986                         carp_setrun(sc, 0);
1987                 }
1988                 break;
1989
1990         case SIOCSVH:
1991                 error = priv_check(curthread, PRIV_NETINET_CARP);
1992                 if (error)
1993                         break;
1994                 if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
1995                         break;
1996                 error = 1;
1997                 if (sc->sc_carpdev) {
1998                         locked = 1;
1999                         CARP_SCLOCK(sc);
2000                 }
2001                 if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
2002                         switch (carpr.carpr_state) {
2003                         case BACKUP:
2004                                 callout_stop(&sc->sc_ad_tmo);
2005                                 carp_set_state(sc, BACKUP);
2006                                 carp_setrun(sc, 0);
2007                                 carp_setroute(sc, RTM_DELETE);
2008                                 break;
2009                         case MASTER:
2010                                 carp_master_down_locked(sc);
2011                                 break;
2012                         default:
2013                                 break;
2014                         }
2015                 }
2016                 if (carpr.carpr_vhid > 0) {
2017                         if (carpr.carpr_vhid > 255) {
2018                                 error = EINVAL;
2019                                 break;
2020                         }
2021                         if (sc->sc_carpdev) {
2022                                 struct carp_if *cif;
2023                                 cif = (struct carp_if *)sc->sc_carpdev->if_carp;
2024                                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
2025                                         if (vr != sc &&
2026                                             vr->sc_vhid == carpr.carpr_vhid) {
2027                                                 error = EEXIST;
2028                                                 break;
2029                                         }
2030                                 if (error == EEXIST)
2031                                         break;
2032                         }
2033                         sc->sc_vhid = carpr.carpr_vhid;
2034                         IF_LLADDR(sc->sc_ifp)[0] = 0;
2035                         IF_LLADDR(sc->sc_ifp)[1] = 0;
2036                         IF_LLADDR(sc->sc_ifp)[2] = 0x5e;
2037                         IF_LLADDR(sc->sc_ifp)[3] = 0;
2038                         IF_LLADDR(sc->sc_ifp)[4] = 1;
2039                         IF_LLADDR(sc->sc_ifp)[5] = sc->sc_vhid;
2040                         error--;
2041                 }
2042                 if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
2043                         if (carpr.carpr_advskew >= 255) {
2044                                 error = EINVAL;
2045                                 break;
2046                         }
2047                         if (carpr.carpr_advbase > 255) {
2048                                 error = EINVAL;
2049                                 break;
2050                         }
2051                         sc->sc_advbase = carpr.carpr_advbase;
2052                         sc->sc_advskew = carpr.carpr_advskew;
2053                         error--;
2054                 }
2055                 bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
2056                 if (error > 0)
2057                         error = EINVAL;
2058                 else {
2059                         error = 0;
2060                         carp_setrun(sc, 0);
2061                 }
2062                 break;
2063
2064         case SIOCGVH:
2065                 /* XXX: lockless read */
2066                 bzero(&carpr, sizeof(carpr));
2067                 carpr.carpr_state = sc->sc_state;
2068                 carpr.carpr_vhid = sc->sc_vhid;
2069                 carpr.carpr_advbase = sc->sc_advbase;
2070                 carpr.carpr_advskew = sc->sc_advskew;
2071                 error = priv_check(curthread, PRIV_NETINET_CARP);
2072                 if (error == 0)
2073                         bcopy(sc->sc_key, carpr.carpr_key,
2074                             sizeof(carpr.carpr_key));
2075                 error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
2076                 break;
2077
2078         default:
2079                 error = EINVAL;
2080         }
2081
2082         if (locked)
2083                 CARP_SCUNLOCK(sc);
2084
2085         carp_hmac_prepare(sc);
2086
2087         return (error);
2088 }
2089
2090 /*
2091  * XXX: this is looutput. We should eventually use it from there.
2092  */
2093 static int
2094 carp_looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
2095     struct route *ro)
2096 {
2097         u_int32_t af;
2098         struct rtentry *rt = NULL;
2099
2100         M_ASSERTPKTHDR(m); /* check if we have the packet header */
2101
2102         if (ro != NULL)
2103                 rt = ro->ro_rt;
2104         if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
2105                 m_freem(m);
2106                 return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
2107                         rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
2108         }
2109
2110         ifp->if_opackets++;
2111         ifp->if_obytes += m->m_pkthdr.len;
2112
2113         /* BPF writes need to be handled specially. */
2114         if (dst->sa_family == AF_UNSPEC) {
2115                 bcopy(dst->sa_data, &af, sizeof(af));
2116                 dst->sa_family = af;
2117         }
2118
2119 #if 1   /* XXX */
2120         switch (dst->sa_family) {
2121         case AF_INET:
2122         case AF_INET6:
2123         case AF_IPX:
2124         case AF_APPLETALK:
2125                 break;
2126         default:
2127                 printf("carp_looutput: af=%d unexpected\n", dst->sa_family);
2128                 m_freem(m);
2129                 return (EAFNOSUPPORT);
2130         }
2131 #endif
2132         return(if_simloop(ifp, m, dst->sa_family, 0));
2133 }
2134
2135 /*
2136  * Start output on carp interface. This function should never be called.
2137  */
2138 static void
2139 carp_start(struct ifnet *ifp)
2140 {
2141 #ifdef DEBUG
2142         printf("%s: start called\n", ifp->if_xname);
2143 #endif
2144 }
2145
2146 int
2147 carp_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
2148     struct rtentry *rt)
2149 {
2150         struct m_tag *mtag;
2151         struct carp_softc *sc;
2152         struct ifnet *carp_ifp;
2153
2154         if (!sa)
2155                 return (0);
2156
2157         switch (sa->sa_family) {
2158 #ifdef INET
2159         case AF_INET:
2160                 break;
2161 #endif /* INET */
2162 #ifdef INET6
2163         case AF_INET6:
2164                 break;
2165 #endif /* INET6 */
2166         default:
2167                 return (0);
2168         }
2169
2170         mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
2171         if (mtag == NULL)
2172                 return (0);
2173
2174         bcopy(mtag + 1, &carp_ifp, sizeof(struct ifnet *));
2175         sc = carp_ifp->if_softc;
2176
2177         /* Set the source MAC address to Virtual Router MAC Address */
2178         switch (ifp->if_type) {
2179         case IFT_ETHER:
2180         case IFT_L2VLAN: {
2181                         struct ether_header *eh;
2182
2183                         eh = mtod(m, struct ether_header *);
2184                         eh->ether_shost[0] = 0;
2185                         eh->ether_shost[1] = 0;
2186                         eh->ether_shost[2] = 0x5e;
2187                         eh->ether_shost[3] = 0;
2188                         eh->ether_shost[4] = 1;
2189                         eh->ether_shost[5] = sc->sc_vhid;
2190                 }
2191                 break;
2192         case IFT_FDDI: {
2193                         struct fddi_header *fh;
2194
2195                         fh = mtod(m, struct fddi_header *);
2196                         fh->fddi_shost[0] = 0;
2197                         fh->fddi_shost[1] = 0;
2198                         fh->fddi_shost[2] = 0x5e;
2199                         fh->fddi_shost[3] = 0;
2200                         fh->fddi_shost[4] = 1;
2201                         fh->fddi_shost[5] = sc->sc_vhid;
2202                 }
2203                 break;
2204         case IFT_ISO88025: {
2205                         struct iso88025_header *th;
2206                         th = mtod(m, struct iso88025_header *);
2207                         th->iso88025_shost[0] = 3;
2208                         th->iso88025_shost[1] = 0;
2209                         th->iso88025_shost[2] = 0x40 >> (sc->sc_vhid - 1);
2210                         th->iso88025_shost[3] = 0x40000 >> (sc->sc_vhid - 1);
2211                         th->iso88025_shost[4] = 0;
2212                         th->iso88025_shost[5] = 0;
2213                 }
2214                 break;
2215         default:
2216                 printf("%s: carp is not supported for this interface type\n",
2217                     ifp->if_xname);
2218                 return (EOPNOTSUPP);
2219         }
2220
2221         return (0);
2222 }
2223
2224 static void
2225 carp_set_state(struct carp_softc *sc, int state)
2226 {
2227         int link_state;
2228
2229         if (sc->sc_carpdev)
2230                 CARP_SCLOCK_ASSERT(sc);
2231
2232         if (sc->sc_state == state)
2233                 return;
2234
2235         sc->sc_state = state;
2236         switch (state) {
2237         case BACKUP:
2238                 link_state = LINK_STATE_DOWN;
2239                 break;
2240         case MASTER:
2241                 link_state = LINK_STATE_UP;
2242                 break;
2243         default:
2244                 link_state = LINK_STATE_UNKNOWN;
2245                 break;
2246         }
2247         if_link_state_change(SC2IFP(sc), link_state);
2248 }
2249
2250 void
2251 carp_carpdev_state(struct ifnet *ifp)
2252 {
2253         struct carp_if *cif;
2254
2255         cif = ifp->if_carp;
2256         CARP_LOCK(cif);
2257         carp_carpdev_state_locked(cif);
2258         CARP_UNLOCK(cif);
2259 }
2260
2261 static void
2262 carp_carpdev_state_locked(struct carp_if *cif)
2263 {
2264         struct carp_softc *sc;
2265
2266         TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list)
2267                 carp_sc_state_locked(sc);
2268 }
2269
2270 static void
2271 carp_sc_state_locked(struct carp_softc *sc)
2272 {
2273         CARP_SCLOCK_ASSERT(sc);
2274
2275         if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
2276             !(sc->sc_carpdev->if_flags & IFF_UP)) {
2277                 sc->sc_flags_backup = SC2IFP(sc)->if_flags;
2278                 SC2IFP(sc)->if_flags &= ~IFF_UP;
2279                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
2280                 callout_stop(&sc->sc_ad_tmo);
2281                 callout_stop(&sc->sc_md_tmo);
2282                 callout_stop(&sc->sc_md6_tmo);
2283                 carp_set_state(sc, INIT);
2284                 carp_setrun(sc, 0);
2285                 if (!sc->sc_suppress) {
2286                         carp_suppress_preempt++;
2287                         if (carp_suppress_preempt == 1) {
2288                                 CARP_SCUNLOCK(sc);
2289                                 carp_send_ad_all();
2290                                 CARP_SCLOCK(sc);
2291                         }
2292                 }
2293                 sc->sc_suppress = 1;
2294         } else {
2295                 SC2IFP(sc)->if_flags |= sc->sc_flags_backup;
2296                 carp_set_state(sc, INIT);
2297                 carp_setrun(sc, 0);
2298                 if (sc->sc_suppress)
2299                         carp_suppress_preempt--;
2300                 sc->sc_suppress = 0;
2301         }
2302
2303         return;
2304 }
2305
2306 #ifdef INET
2307 extern  struct domain inetdomain;
2308 static struct protosw in_carp_protosw = {
2309         .pr_type =              SOCK_RAW,
2310         .pr_domain =            &inetdomain,
2311         .pr_protocol =          IPPROTO_CARP,
2312         .pr_flags =             PR_ATOMIC|PR_ADDR,
2313         .pr_input =             carp_input,
2314         .pr_output =            (pr_output_t *)rip_output,
2315         .pr_ctloutput =         rip_ctloutput,
2316         .pr_usrreqs =           &rip_usrreqs
2317 };
2318 #endif
2319
2320 #ifdef INET6
2321 extern  struct domain inet6domain;
2322 static struct ip6protosw in6_carp_protosw = {
2323         .pr_type =              SOCK_RAW,
2324         .pr_domain =            &inet6domain,
2325         .pr_protocol =          IPPROTO_CARP,
2326         .pr_flags =             PR_ATOMIC|PR_ADDR,
2327         .pr_input =             carp6_input,
2328         .pr_output =            rip6_output,
2329         .pr_ctloutput =         rip6_ctloutput,
2330         .pr_usrreqs =           &rip6_usrreqs
2331 };
2332 #endif
2333
2334 static void
2335 carp_mod_cleanup(void)
2336 {
2337
2338         if (if_detach_event_tag == NULL)
2339                 return;
2340         EVENTHANDLER_DEREGISTER(ifnet_departure_event, if_detach_event_tag);
2341         if_clone_detach(&carp_cloner);
2342 #ifdef INET
2343         if (proto_reg[CARP_INET] == 0) {
2344                 (void)ipproto_unregister(IPPROTO_CARP);
2345                 pf_proto_unregister(PF_INET, IPPROTO_CARP, SOCK_RAW);
2346                 proto_reg[CARP_INET] = -1;
2347         }
2348         carp_iamatch_p = NULL;
2349 #endif
2350 #ifdef INET6
2351         if (proto_reg[CARP_INET6] == 0) {
2352                 (void)ip6proto_unregister(IPPROTO_CARP);
2353                 pf_proto_unregister(PF_INET6, IPPROTO_CARP, SOCK_RAW);
2354                 proto_reg[CARP_INET6] = -1;
2355         }
2356         carp_iamatch6_p = NULL;
2357         carp_macmatch6_p = NULL;
2358 #endif
2359         carp_linkstate_p = NULL;
2360         carp_forus_p = NULL;
2361         carp_output_p = NULL;
2362         mtx_destroy(&carp_mtx);
2363 }
2364
2365 static int
2366 carp_mod_load(void)
2367 {
2368         int err;
2369
2370         if_detach_event_tag = EVENTHANDLER_REGISTER(ifnet_departure_event,
2371                 carp_ifdetach, NULL, EVENTHANDLER_PRI_ANY);
2372         if (if_detach_event_tag == NULL)
2373                 return (ENOMEM);
2374         mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
2375         LIST_INIT(&carpif_list);
2376         if_clone_attach(&carp_cloner);
2377         carp_linkstate_p = carp_carpdev_state;
2378         carp_forus_p = carp_forus;
2379         carp_output_p = carp_output;
2380 #ifdef INET6
2381         carp_iamatch6_p = carp_iamatch6;
2382         carp_macmatch6_p = carp_macmatch6;
2383         proto_reg[CARP_INET6] = pf_proto_register(PF_INET6,
2384             (struct protosw *)&in6_carp_protosw);
2385         if (proto_reg[CARP_INET6] != 0) {
2386                 printf("carp: error %d attaching to PF_INET6\n",
2387                     proto_reg[CARP_INET6]);
2388                 carp_mod_cleanup();
2389                 return (proto_reg[CARP_INET6]);
2390         }
2391         err = ip6proto_register(IPPROTO_CARP);
2392         if (err) {
2393                 printf("carp: error %d registering with INET6\n", err);
2394                 carp_mod_cleanup();
2395                 return (err);
2396         }
2397 #endif
2398 #ifdef INET
2399         carp_iamatch_p = carp_iamatch;
2400         proto_reg[CARP_INET] = pf_proto_register(PF_INET, &in_carp_protosw);
2401         if (proto_reg[CARP_INET] != 0) {
2402                 printf("carp: error %d attaching to PF_INET\n",
2403                     proto_reg[CARP_INET]);
2404                 carp_mod_cleanup();
2405                 return (proto_reg[CARP_INET]);
2406         }
2407         err = ipproto_register(IPPROTO_CARP);
2408         if (err) {
2409                 printf("carp: error %d registering with INET\n", err);
2410                 carp_mod_cleanup();
2411                 return (err);
2412         }
2413 #endif
2414         return 0;
2415 }
2416
2417 static int
2418 carp_modevent(module_t mod, int type, void *data)
2419 {
2420         switch (type) {
2421         case MOD_LOAD:
2422                 return carp_mod_load();
2423                 /* NOTREACHED */
2424         case MOD_UNLOAD:
2425                 /*
2426                  * XXX: For now, disallow module unloading by default due to
2427                  * a race condition where a thread may dereference one of the
2428                  * function pointer hooks after the module has been
2429                  * unloaded, during processing of a packet, causing a panic.
2430                  */
2431 #ifdef CARPMOD_CAN_UNLOAD
2432                 carp_mod_cleanup();
2433 #else
2434                 return (EBUSY);
2435 #endif
2436                 break;
2437
2438         default:
2439                 return (EINVAL);
2440         }
2441
2442         return (0);
2443 }
2444
2445 static moduledata_t carp_mod = {
2446         "carp",
2447         carp_modevent,
2448         0
2449 };
2450
2451 DECLARE_MODULE(carp, carp_mod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);