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