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_carp.h"
  31 #include "opt_bpf.h"
  32 #include "opt_inet.h"
  33 #include "opt_inet6.h"
  34
  35 #include <sys/types.h>
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/conf.h>
  39 #include <sys/kernel.h>
  40 #include <sys/limits.h>
  41 #include <sys/malloc.h>
  42 #include <sys/mbuf.h>
  43 #include <sys/module.h>
  44 #include <sys/time.h>
  45 #include <sys/priv.h>
  46 #include <sys/proc.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 #include <sys/vimage.h>
  56
  57 #include <machine/stdarg.h>
  58
  59 #include <net/bpf.h>
  60 #include <net/ethernet.h>
  61 #include <net/fddi.h>
  62 #include <net/iso88025.h>
  63 #include <net/if.h>
  64 #include <net/if_clone.h>
  65 #include <net/if_dl.h>
  66 #include <net/if_types.h>
  67 #include <net/route.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/ip6_var.h>
  83 #include <netinet6/scope6_var.h>
  84 #include <netinet6/nd6.h>
  85 #endif
  86
  87 #include <crypto/sha1.h>
  88 #include <netinet/ip_carp.h>
  89
  90 #define CARP_IFNAME     "carp"
  91 static MALLOC_DEFINE(M_CARP, "CARP", "CARP interfaces");
  92 SYSCTL_DECL(_net_inet_carp);
  93
  94 struct carp_softc {
  95         struct ifnet            *sc_ifp;        /* Interface clue */
  96         struct ifnet            *sc_carpdev;    /* Pointer to parent interface */
  97         struct in_ifaddr        *sc_ia;         /* primary iface address */
  98         struct ip_moptions       sc_imo;
  99 #ifdef INET6
 100         struct in6_ifaddr       *sc_ia6;        /* primary iface address v6 */
 101         struct ip6_moptions      sc_im6o;
 102 #endif /* INET6 */
 103         TAILQ_ENTRY(carp_softc)  sc_list;
 104
 105         enum { INIT = 0, BACKUP, MASTER }       sc_state;
 106
 107         int                      sc_flags_backup;
 108         int                      sc_suppress;
 109
 110         int                      sc_sendad_errors;
 111 #define CARP_SENDAD_MAX_ERRORS  3
 112         int                      sc_sendad_success;
 113 #define CARP_SENDAD_MIN_SUCCESS 3
 114
 115         int                      sc_vhid;
 116         int                      sc_advskew;
 117         int                      sc_naddrs;
 118         int                      sc_naddrs6;
 119         int                      sc_advbase;    /* seconds */
 120         int                      sc_init_counter;
 121         u_int64_t                sc_counter;
 122
 123         /* authentication */
 124 #define CARP_HMAC_PAD   64
 125         unsigned char sc_key[CARP_KEY_LEN];
 126         unsigned char sc_pad[CARP_HMAC_PAD];
 127         SHA1_CTX sc_sha1;
 128
 129         struct callout           sc_ad_tmo;     /* advertisement timeout */
 130         struct callout           sc_md_tmo;     /* master down timeout */
 131         struct callout           sc_md6_tmo;    /* master down timeout */
 132
 133         LIST_ENTRY(carp_softc)   sc_next;       /* Interface clue */
 134 };
 135 #define SC2IFP(sc)      ((sc)->sc_ifp)
 136
 137 int carp_suppress_preempt = 0;
 138 int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 1, 0, 0 };    /* XXX for now */
 139 SYSCTL_INT(_net_inet_carp, CARPCTL_ALLOW, allow, CTLFLAG_RW,
 140     &carp_opts[CARPCTL_ALLOW], 0, "Accept incoming CARP packets");
 141 SYSCTL_INT(_net_inet_carp, CARPCTL_PREEMPT, preempt, CTLFLAG_RW,
 142     &carp_opts[CARPCTL_PREEMPT], 0, "high-priority backup preemption mode");
 143 SYSCTL_INT(_net_inet_carp, CARPCTL_LOG, log, CTLFLAG_RW,
 144     &carp_opts[CARPCTL_LOG], 0, "log bad carp packets");
 145 SYSCTL_INT(_net_inet_carp, CARPCTL_ARPBALANCE, arpbalance, CTLFLAG_RW,
 146     &carp_opts[CARPCTL_ARPBALANCE], 0, "balance arp responses");
 147 SYSCTL_INT(_net_inet_carp, OID_AUTO, suppress_preempt, CTLFLAG_RD,
 148     &carp_suppress_preempt, 0, "Preemption is suppressed");
 149
 150 struct carpstats carpstats;
 151 SYSCTL_STRUCT(_net_inet_carp, CARPCTL_STATS, stats, CTLFLAG_RW,
 152     &carpstats, carpstats,
 153     "CARP statistics (struct carpstats, netinet/ip_carp.h)");
 154
 155 struct carp_if {
 156         TAILQ_HEAD(, carp_softc) vhif_vrs;
 157         int vhif_nvrs;
 158
 159         struct ifnet    *vhif_ifp;
 160         struct mtx       vhif_mtx;
 161 };
 162
 163 /* Get carp_if from softc. Valid after carp_set_addr{,6}. */
 164 #define SC2CIF(sc)              ((struct carp_if *)(sc)->sc_carpdev->if_carp)
 165
 166 /* lock per carp_if queue */
 167 #define CARP_LOCK_INIT(cif)     mtx_init(&(cif)->vhif_mtx, "carp_if",   \
 168         NULL, MTX_DEF)
 169 #define CARP_LOCK_DESTROY(cif)  mtx_destroy(&(cif)->vhif_mtx)
 170 #define CARP_LOCK_ASSERT(cif)   mtx_assert(&(cif)->vhif_mtx, MA_OWNED)
 171 #define CARP_LOCK(cif)          mtx_lock(&(cif)->vhif_mtx)
 172 #define CARP_UNLOCK(cif)        mtx_unlock(&(cif)->vhif_mtx)
 173
 174 #define CARP_SCLOCK(sc)         mtx_lock(&SC2CIF(sc)->vhif_mtx)
 175 #define CARP_SCUNLOCK(sc)       mtx_unlock(&SC2CIF(sc)->vhif_mtx)
 176 #define CARP_SCLOCK_ASSERT(sc)  mtx_assert(&SC2CIF(sc)->vhif_mtx, MA_OWNED)
 177
 178 #define CARP_LOG(...)   do {                            \
 179         if (carp_opts[CARPCTL_LOG] > 0)                 \
 180                 log(LOG_INFO, __VA_ARGS__);             \
 181 } while (0)
 182
 183 #define CARP_DEBUG(...) do {                            \
 184         if (carp_opts[CARPCTL_LOG] > 1)                 \
 185                 log(LOG_DEBUG, __VA_ARGS__);            \
 186 } while (0)
 187
 188 static void     carp_hmac_prepare(struct carp_softc *);
 189 static void     carp_hmac_generate(struct carp_softc *, u_int32_t *,
 190                     unsigned char *);
 191 static int      carp_hmac_verify(struct carp_softc *, u_int32_t *,
 192                     unsigned char *);
 193 static void     carp_setroute(struct carp_softc *, int);
 194 static void     carp_input_c(struct mbuf *, struct carp_header *, sa_family_t);
 195 static int      carp_clone_create(struct if_clone *, int, caddr_t);
 196 static void     carp_clone_destroy(struct ifnet *);
 197 static void     carpdetach(struct carp_softc *, int);
 198 static int      carp_prepare_ad(struct mbuf *, struct carp_softc *,
 199                     struct carp_header *);
 200 static void     carp_send_ad_all(void);
 201 static void     carp_send_ad(void *);
 202 static void     carp_send_ad_locked(struct carp_softc *);
 203 static void     carp_send_arp(struct carp_softc *);
 204 static void     carp_master_down(void *);
 205 static void     carp_master_down_locked(struct carp_softc *);
 206 static int      carp_ioctl(struct ifnet *, u_long, caddr_t);
 207 static int      carp_looutput(struct ifnet *, struct mbuf *, struct sockaddr *,
 208                     struct rtentry *);
 209 static void     carp_start(struct ifnet *);
 210 static void     carp_setrun(struct carp_softc *, sa_family_t);
 211 static void     carp_set_state(struct carp_softc *, int);
 212 static int      carp_addrcount(struct carp_if *, struct in_ifaddr *, int);
 213 enum    { CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
 214
 215 static void     carp_multicast_cleanup(struct carp_softc *);
 216 static int      carp_set_addr(struct carp_softc *, struct sockaddr_in *);
 217 static int      carp_del_addr(struct carp_softc *, struct sockaddr_in *);
 218 static void     carp_carpdev_state_locked(struct carp_if *);
 219 static void     carp_sc_state_locked(struct carp_softc *);
 220 #ifdef INET6
 221 static void     carp_send_na(struct carp_softc *);
 222 static int      carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
 223 static int      carp_del_addr6(struct carp_softc *, struct sockaddr_in6 *);
 224 static void     carp_multicast6_cleanup(struct carp_softc *);
 225 #endif
 226
 227 static LIST_HEAD(, carp_softc) carpif_list;
 228 static struct mtx carp_mtx;
 229 IFC_SIMPLE_DECLARE(carp, 0);
 230
 231 static eventhandler_tag if_detach_event_tag;
 232
 233 static __inline u_int16_t
 234 carp_cksum(struct mbuf *m, int len)
 235 {
 236         return (in_cksum(m, len));
 237 }
 238
 239 static void
 240 carp_hmac_prepare(struct carp_softc *sc)
 241 {
 242         u_int8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
 243         u_int8_t vhid = sc->sc_vhid & 0xff;
 244         struct ifaddr *ifa;
 245         int i, found;
 246 #ifdef INET
 247         struct in_addr last, cur, in;
 248 #endif
 249 #ifdef INET6
 250         struct in6_addr last6, cur6, in6;
 251 #endif
 252
 253         if (sc->sc_carpdev)
 254                 CARP_SCLOCK(sc);
 255
 256         /* XXX: possible race here */
 257
 258         /* compute ipad from key */
 259         bzero(sc->sc_pad, sizeof(sc->sc_pad));
 260         bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
 261         for (i = 0; i < sizeof(sc->sc_pad); i++)
 262                 sc->sc_pad[i] ^= 0x36;
 263
 264         /* precompute first part of inner hash */
 265         SHA1Init(&sc->sc_sha1);
 266         SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
 267         SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
 268         SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
 269         SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
 270 #ifdef INET
 271         cur.s_addr = 0;
 272         do {
 273                 found = 0;
 274                 last = cur;
 275                 cur.s_addr = 0xffffffff;
 276                 TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 277                         in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
 278                         if (ifa->ifa_addr->sa_family == AF_INET &&
 279                             ntohl(in.s_addr) > ntohl(last.s_addr) &&
 280                             ntohl(in.s_addr) < ntohl(cur.s_addr)) {
 281                                 cur.s_addr = in.s_addr;
 282                                 found++;
 283                         }
 284                 }
 285                 if (found)
 286                         SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
 287         } while (found);
 288 #endif /* INET */
 289 #ifdef INET6
 290         memset(&cur6, 0, sizeof(cur6));
 291         do {
 292                 found = 0;
 293                 last6 = cur6;
 294                 memset(&cur6, 0xff, sizeof(cur6));
 295                 TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 296                         in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
 297                         if (IN6_IS_SCOPE_EMBED(&in6))
 298                                 in6.s6_addr16[1] = 0;
 299                         if (ifa->ifa_addr->sa_family == AF_INET6 &&
 300                             memcmp(&in6, &last6, sizeof(in6)) > 0 &&
 301                             memcmp(&in6, &cur6, sizeof(in6)) < 0) {
 302                                 cur6 = in6;
 303                                 found++;
 304                         }
 305                 }
 306                 if (found)
 307                         SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
 308         } while (found);
 309 #endif /* INET6 */
 310
 311         /* convert ipad to opad */
 312         for (i = 0; i < sizeof(sc->sc_pad); i++)
 313                 sc->sc_pad[i] ^= 0x36 ^ 0x5c;
 314
 315         if (sc->sc_carpdev)
 316                 CARP_SCUNLOCK(sc);
 317 }
 318
 319 static void
 320 carp_hmac_generate(struct carp_softc *sc, u_int32_t counter[2],
 321     unsigned char md[20])
 322 {
 323         SHA1_CTX sha1ctx;
 324
 325         /* fetch first half of inner hash */
 326         bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
 327
 328         SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
 329         SHA1Final(md, &sha1ctx);
 330
 331         /* outer hash */
 332         SHA1Init(&sha1ctx);
 333         SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
 334         SHA1Update(&sha1ctx, md, 20);
 335         SHA1Final(md, &sha1ctx);
 336 }
 337
 338 static int
 339 carp_hmac_verify(struct carp_softc *sc, u_int32_t counter[2],
 340     unsigned char md[20])
 341 {
 342         unsigned char md2[20];
 343
 344         CARP_SCLOCK_ASSERT(sc);
 345
 346         carp_hmac_generate(sc, counter, md2);
 347
 348         return (bcmp(md, md2, sizeof(md2)));
 349 }
 350
 351 static void
 352 carp_setroute(struct carp_softc *sc, int cmd)
 353 {
 354         struct ifaddr *ifa;
 355         int s;
 356
 357         if (sc->sc_carpdev)
 358                 CARP_SCLOCK_ASSERT(sc);
 359
 360         s = splnet();
 361         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 362                 if (ifa->ifa_addr->sa_family == AF_INET &&
 363                     sc->sc_carpdev != NULL) {
 364                         int count = carp_addrcount(
 365                             (struct carp_if *)sc->sc_carpdev->if_carp,
 366                             ifatoia(ifa), CARP_COUNT_MASTER);
 367
 368                         if ((cmd == RTM_ADD && count == 1) ||
 369                             (cmd == RTM_DELETE && count == 0))
 370                                 rtinit(ifa, cmd, RTF_UP | RTF_HOST);
 371                 }
 372 #ifdef INET6
 373                 if (ifa->ifa_addr->sa_family == AF_INET6) {
 374                         if (cmd == RTM_ADD)
 375                                 in6_ifaddloop(ifa);
 376                         else
 377                                 in6_ifremloop(ifa);
 378                 }
 379 #endif /* INET6 */
 380         }
 381         splx(s);
 382 }
 383
 384 static int
 385 carp_clone_create(struct if_clone *ifc, int unit, caddr_t params)
 386 {
 387
 388         struct carp_softc *sc;
 389         struct ifnet *ifp;
 390
 391         MALLOC(sc, struct carp_softc *, sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
 392         ifp = SC2IFP(sc) = if_alloc(IFT_ETHER);
 393         if (ifp == NULL) {
 394                 FREE(sc, M_CARP);
 395                 return (ENOSPC);
 396         }
 397
 398         sc->sc_flags_backup = 0;
 399         sc->sc_suppress = 0;
 400         sc->sc_advbase = CARP_DFLTINTV;
 401         sc->sc_vhid = -1;       /* required setting */
 402         sc->sc_advskew = 0;
 403         sc->sc_init_counter = 1;
 404         sc->sc_naddrs = sc->sc_naddrs6 = 0; /* M_ZERO? */
 405 #ifdef INET6
 406         sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
 407 #endif
 408         sc->sc_imo.imo_membership = (struct in_multi **)malloc(
 409             (sizeof(struct in_multi *) * IP_MIN_MEMBERSHIPS), M_CARP,
 410             M_WAITOK);
 411         sc->sc_imo.imo_mfilters = NULL;
 412         sc->sc_imo.imo_max_memberships = IP_MIN_MEMBERSHIPS;
 413         sc->sc_imo.imo_multicast_vif = -1;
 414
 415         callout_init(&sc->sc_ad_tmo, CALLOUT_MPSAFE);
 416         callout_init(&sc->sc_md_tmo, CALLOUT_MPSAFE);
 417         callout_init(&sc->sc_md6_tmo, CALLOUT_MPSAFE);
 418
 419         ifp->if_softc = sc;
 420         if_initname(ifp, CARP_IFNAME, unit);
 421         ifp->if_mtu = ETHERMTU;
 422         ifp->if_flags = IFF_LOOPBACK;
 423         ifp->if_ioctl = carp_ioctl;
 424         ifp->if_output = carp_looutput;
 425         ifp->if_start = carp_start;
 426         ifp->if_type = IFT_CARP;
 427         ifp->if_snd.ifq_maxlen = ifqmaxlen;
 428         ifp->if_hdrlen = 0;
 429         if_attach(ifp);
 430         bpfattach(SC2IFP(sc), DLT_NULL, sizeof(u_int32_t));
 431         mtx_lock(&carp_mtx);
 432         LIST_INSERT_HEAD(&carpif_list, sc, sc_next);
 433         mtx_unlock(&carp_mtx);
 434         return (0);
 435 }
 436
 437 static void
 438 carp_clone_destroy(struct ifnet *ifp)
 439 {
 440         struct carp_softc *sc = ifp->if_softc;
 441
 442         if (sc->sc_carpdev)
 443                 CARP_SCLOCK(sc);
 444         carpdetach(sc, 1);      /* Returns unlocked. */
 445
 446         mtx_lock(&carp_mtx);
 447         LIST_REMOVE(sc, sc_next);
 448         mtx_unlock(&carp_mtx);
 449         bpfdetach(ifp);
 450         if_detach(ifp);
 451         if_free_type(ifp, IFT_ETHER);
 452         free(sc->sc_imo.imo_membership, M_CARP);
 453         free(sc, M_CARP);
 454 }
 455
 456 /*
 457  * This function can be called on CARP interface destroy path,
 458  * and in case of the removal of the underlying interface as
 459  * well. We differentiate these two cases. In the latter case
 460  * we do not cleanup our multicast memberships, since they
 461  * are already freed. Also, in the latter case we do not
 462  * release the lock on return, because the function will be
 463  * called once more, for another CARP instance on the same
 464  * interface.
 465  */
 466 static void
 467 carpdetach(struct carp_softc *sc, int unlock)
 468 {
 469         struct carp_if *cif;
 470
 471         callout_stop(&sc->sc_ad_tmo);
 472         callout_stop(&sc->sc_md_tmo);
 473         callout_stop(&sc->sc_md6_tmo);
 474
 475         if (sc->sc_suppress)
 476                 carp_suppress_preempt--;
 477         sc->sc_suppress = 0;
 478
 479         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
 480                 carp_suppress_preempt--;
 481         sc->sc_sendad_errors = 0;
 482
 483         carp_set_state(sc, INIT);
 484         SC2IFP(sc)->if_flags &= ~IFF_UP;
 485         carp_setrun(sc, 0);
 486         if (unlock)
 487                 carp_multicast_cleanup(sc);
 488 #ifdef INET6
 489         carp_multicast6_cleanup(sc);
 490 #endif
 491
 492         if (sc->sc_carpdev != NULL) {
 493                 cif = (struct carp_if *)sc->sc_carpdev->if_carp;
 494                 CARP_LOCK_ASSERT(cif);
 495                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
 496                 if (!--cif->vhif_nvrs) {
 497                         ifpromisc(sc->sc_carpdev, 0);
 498                         sc->sc_carpdev->if_carp = NULL;
 499                         CARP_LOCK_DESTROY(cif);
 500                         FREE(cif, M_IFADDR);
 501                 } else if (unlock)
 502                         CARP_UNLOCK(cif);
 503                 sc->sc_carpdev = NULL;
 504         }
 505 }
 506
 507 /* Detach an interface from the carp. */
 508 static void
 509 carp_ifdetach(void *arg __unused, struct ifnet *ifp)
 510 {
 511         struct carp_if *cif = (struct carp_if *)ifp->if_carp;
 512         struct carp_softc *sc, *nextsc;
 513
 514         if (cif == NULL)
 515                 return;
 516
 517         /*
 518          * XXX: At the end of for() cycle the lock will be destroyed.
 519          */
 520         CARP_LOCK(cif);
 521         for (sc = TAILQ_FIRST(&cif->vhif_vrs); sc; sc = nextsc) {
 522                 nextsc = TAILQ_NEXT(sc, sc_list);
 523                 carpdetach(sc, 0);
 524         }
 525 }
 526
 527 /*
 528  * process input packet.
 529  * we have rearranged checks order compared to the rfc,
 530  * but it seems more efficient this way or not possible otherwise.
 531  */
 532 void
 533 carp_input(struct mbuf *m, int hlen)
 534 {
 535         struct ip *ip = mtod(m, struct ip *);
 536         struct carp_header *ch;
 537         int iplen, len;
 538
 539         carpstats.carps_ipackets++;
 540
 541         if (!carp_opts[CARPCTL_ALLOW]) {
 542                 m_freem(m);
 543                 return;
 544         }
 545
 546         /* check if received on a valid carp interface */
 547         if (m->m_pkthdr.rcvif->if_carp == NULL) {
 548                 carpstats.carps_badif++;
 549                 CARP_LOG("carp_input: packet received on non-carp "
 550                     "interface: %s\n",
 551                     m->m_pkthdr.rcvif->if_xname);
 552                 m_freem(m);
 553                 return;
 554         }
 555
 556         /* verify that the IP TTL is 255.  */
 557         if (ip->ip_ttl != CARP_DFLTTL) {
 558                 carpstats.carps_badttl++;
 559                 CARP_LOG("carp_input: received ttl %d != 255i on %s\n",
 560                     ip->ip_ttl,
 561                     m->m_pkthdr.rcvif->if_xname);
 562                 m_freem(m);
 563                 return;
 564         }
 565
 566         iplen = ip->ip_hl << 2;
 567
 568         if (m->m_pkthdr.len < iplen + sizeof(*ch)) {
 569                 carpstats.carps_badlen++;
 570                 CARP_LOG("carp_input: received len %zd < "
 571                     "sizeof(struct carp_header)\n",
 572                     m->m_len - sizeof(struct ip));
 573                 m_freem(m);
 574                 return;
 575         }
 576
 577         if (iplen + sizeof(*ch) < m->m_len) {
 578                 if ((m = m_pullup(m, iplen + sizeof(*ch))) == NULL) {
 579                         carpstats.carps_hdrops++;
 580                         CARP_LOG("carp_input: pullup failed\n");
 581                         return;
 582                 }
 583                 ip = mtod(m, struct ip *);
 584         }
 585         ch = (struct carp_header *)((char *)ip + iplen);
 586
 587         /*
 588          * verify that the received packet length is
 589          * equal to the CARP header
 590          */
 591         len = iplen + sizeof(*ch);
 592         if (len > m->m_pkthdr.len) {
 593                 carpstats.carps_badlen++;
 594                 CARP_LOG("carp_input: packet too short %d on %s\n",
 595                     m->m_pkthdr.len,
 596                     m->m_pkthdr.rcvif->if_xname);
 597                 m_freem(m);
 598                 return;
 599         }
 600
 601         if ((m = m_pullup(m, len)) == NULL) {
 602                 carpstats.carps_hdrops++;
 603                 return;
 604         }
 605         ip = mtod(m, struct ip *);
 606         ch = (struct carp_header *)((char *)ip + iplen);
 607
 608         /* verify the CARP checksum */
 609         m->m_data += iplen;
 610         if (carp_cksum(m, len - iplen)) {
 611                 carpstats.carps_badsum++;
 612                 CARP_LOG("carp_input: checksum failed on %s\n",
 613                     m->m_pkthdr.rcvif->if_xname);
 614                 m_freem(m);
 615                 return;
 616         }
 617         m->m_data -= iplen;
 618
 619         carp_input_c(m, ch, AF_INET);
 620 }
 621
 622 #ifdef INET6
 623 int
 624 carp6_input(struct mbuf **mp, int *offp, int proto)
 625 {
 626         struct mbuf *m = *mp;
 627         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 628         struct carp_header *ch;
 629         u_int len;
 630
 631         carpstats.carps_ipackets6++;
 632
 633         if (!carp_opts[CARPCTL_ALLOW]) {
 634                 m_freem(m);
 635                 return (IPPROTO_DONE);
 636         }
 637
 638         /* check if received on a valid carp interface */
 639         if (m->m_pkthdr.rcvif->if_carp == NULL) {
 640                 carpstats.carps_badif++;
 641                 CARP_LOG("carp6_input: packet received on non-carp "
 642                     "interface: %s\n",
 643                     m->m_pkthdr.rcvif->if_xname);
 644                 m_freem(m);
 645                 return (IPPROTO_DONE);
 646         }
 647
 648         /* verify that the IP TTL is 255 */
 649         if (ip6->ip6_hlim != CARP_DFLTTL) {
 650                 carpstats.carps_badttl++;
 651                 CARP_LOG("carp6_input: received ttl %d != 255 on %s\n",
 652                     ip6->ip6_hlim,
 653                     m->m_pkthdr.rcvif->if_xname);
 654                 m_freem(m);
 655                 return (IPPROTO_DONE);
 656         }
 657
 658         /* verify that we have a complete carp packet */
 659         len = m->m_len;
 660         IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
 661         if (ch == NULL) {
 662                 carpstats.carps_badlen++;
 663                 CARP_LOG("carp6_input: packet size %u too small\n", len);
 664                 return (IPPROTO_DONE);
 665         }
 666
 667
 668         /* verify the CARP checksum */
 669         m->m_data += *offp;
 670         if (carp_cksum(m, sizeof(*ch))) {
 671                 carpstats.carps_badsum++;
 672                 CARP_LOG("carp6_input: checksum failed, on %s\n",
 673                     m->m_pkthdr.rcvif->if_xname);
 674                 m_freem(m);
 675                 return (IPPROTO_DONE);
 676         }
 677         m->m_data -= *offp;
 678
 679         carp_input_c(m, ch, AF_INET6);
 680         return (IPPROTO_DONE);
 681 }
 682 #endif /* INET6 */
 683
 684 static void
 685 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
 686 {
 687         struct ifnet *ifp = m->m_pkthdr.rcvif;
 688         struct carp_softc *sc;
 689         u_int64_t tmp_counter;
 690         struct timeval sc_tv, ch_tv;
 691
 692         /* verify that the VHID is valid on the receiving interface */
 693         CARP_LOCK(ifp->if_carp);
 694         TAILQ_FOREACH(sc, &((struct carp_if *)ifp->if_carp)->vhif_vrs, sc_list)
 695                 if (sc->sc_vhid == ch->carp_vhid)
 696                         break;
 697
 698         if (!sc || !((SC2IFP(sc)->if_flags & IFF_UP) &&
 699             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING))) {
 700                 carpstats.carps_badvhid++;
 701                 CARP_UNLOCK(ifp->if_carp);
 702                 m_freem(m);
 703                 return;
 704         }
 705
 706         getmicrotime(&SC2IFP(sc)->if_lastchange);
 707         SC2IFP(sc)->if_ipackets++;
 708         SC2IFP(sc)->if_ibytes += m->m_pkthdr.len;
 709
 710         if (bpf_peers_present(SC2IFP(sc)->if_bpf)) {
 711                 struct ip *ip = mtod(m, struct ip *);
 712                 uint32_t af1 = af;
 713
 714                 /* BPF wants net byte order */
 715                 ip->ip_len = htons(ip->ip_len + (ip->ip_hl << 2));
 716                 ip->ip_off = htons(ip->ip_off);
 717                 bpf_mtap2(SC2IFP(sc)->if_bpf, &af1, sizeof(af1), m);
 718         }
 719
 720         /* verify the CARP version. */
 721         if (ch->carp_version != CARP_VERSION) {
 722                 carpstats.carps_badver++;
 723                 SC2IFP(sc)->if_ierrors++;
 724                 CARP_UNLOCK(ifp->if_carp);
 725                 CARP_LOG("%s; invalid version %d\n",
 726                     SC2IFP(sc)->if_xname,
 727                     ch->carp_version);
 728                 m_freem(m);
 729                 return;
 730         }
 731
 732         /* verify the hash */
 733         if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
 734                 carpstats.carps_badauth++;
 735                 SC2IFP(sc)->if_ierrors++;
 736                 CARP_UNLOCK(ifp->if_carp);
 737                 CARP_LOG("%s: incorrect hash\n", SC2IFP(sc)->if_xname);
 738                 m_freem(m);
 739                 return;
 740         }
 741
 742         tmp_counter = ntohl(ch->carp_counter[0]);
 743         tmp_counter = tmp_counter<<32;
 744         tmp_counter += ntohl(ch->carp_counter[1]);
 745
 746         /* XXX Replay protection goes here */
 747
 748         sc->sc_init_counter = 0;
 749         sc->sc_counter = tmp_counter;
 750
 751         sc_tv.tv_sec = sc->sc_advbase;
 752         if (carp_suppress_preempt && sc->sc_advskew <  240)
 753                 sc_tv.tv_usec = 240 * 1000000 / 256;
 754         else
 755                 sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
 756         ch_tv.tv_sec = ch->carp_advbase;
 757         ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
 758
 759         switch (sc->sc_state) {
 760         case INIT:
 761                 break;
 762         case MASTER:
 763                 /*
 764                  * If we receive an advertisement from a master who's going to
 765                  * be more frequent than us, go into BACKUP state.
 766                  */
 767                 if (timevalcmp(&sc_tv, &ch_tv, >) ||
 768                     timevalcmp(&sc_tv, &ch_tv, ==)) {
 769                         callout_stop(&sc->sc_ad_tmo);
 770                         CARP_DEBUG("%s: MASTER -> BACKUP "
 771                            "(more frequent advertisement received)\n",
 772                            SC2IFP(sc)->if_xname);
 773                         carp_set_state(sc, BACKUP);
 774                         carp_setrun(sc, 0);
 775                         carp_setroute(sc, RTM_DELETE);
 776                 }
 777                 break;
 778         case BACKUP:
 779                 /*
 780                  * If we're pre-empting masters who advertise slower than us,
 781                  * and this one claims to be slower, treat him as down.
 782                  */
 783                 if (carp_opts[CARPCTL_PREEMPT] &&
 784                     timevalcmp(&sc_tv, &ch_tv, <)) {
 785                         CARP_DEBUG("%s: BACKUP -> MASTER "
 786                             "(preempting a slower master)\n",
 787                             SC2IFP(sc)->if_xname);
 788                         carp_master_down_locked(sc);
 789                         break;
 790                 }
 791
 792                 /*
 793                  *  If the master is going to advertise at such a low frequency
 794                  *  that he's guaranteed to time out, we'd might as well just
 795                  *  treat him as timed out now.
 796                  */
 797                 sc_tv.tv_sec = sc->sc_advbase * 3;
 798                 if (timevalcmp(&sc_tv, &ch_tv, <)) {
 799                         CARP_DEBUG("%s: BACKUP -> MASTER "
 800                             "(master timed out)\n",
 801                             SC2IFP(sc)->if_xname);
 802                         carp_master_down_locked(sc);
 803                         break;
 804                 }
 805
 806                 /*
 807                  * Otherwise, we reset the counter and wait for the next
 808                  * advertisement.
 809                  */
 810                 carp_setrun(sc, af);
 811                 break;
 812         }
 813
 814         CARP_UNLOCK(ifp->if_carp);
 815
 816         m_freem(m);
 817         return;
 818 }
 819
 820 static int
 821 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
 822 {
 823         struct m_tag *mtag;
 824         struct ifnet *ifp = SC2IFP(sc);
 825
 826         if (sc->sc_init_counter) {
 827                 /* this could also be seconds since unix epoch */
 828                 sc->sc_counter = arc4random();
 829                 sc->sc_counter = sc->sc_counter << 32;
 830                 sc->sc_counter += arc4random();
 831         } else
 832                 sc->sc_counter++;
 833
 834         ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
 835         ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
 836
 837         carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
 838
 839         /* Tag packet for carp_output */
 840         mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct ifnet *), M_NOWAIT);
 841         if (mtag == NULL) {
 842                 m_freem(m);
 843                 SC2IFP(sc)->if_oerrors++;
 844                 return (ENOMEM);
 845         }
 846         bcopy(&ifp, (caddr_t)(mtag + 1), sizeof(struct ifnet *));
 847         m_tag_prepend(m, mtag);
 848
 849         return (0);
 850 }
 851
 852 static void
 853 carp_send_ad_all(void)
 854 {
 855         struct carp_softc *sc;
 856
 857         mtx_lock(&carp_mtx);
 858         LIST_FOREACH(sc, &carpif_list, sc_next) {
 859                 if (sc->sc_carpdev == NULL)
 860                         continue;
 861                 CARP_SCLOCK(sc);
 862                 if ((SC2IFP(sc)->if_flags & IFF_UP) &&
 863                     (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING) &&
 864                      sc->sc_state == MASTER)
 865                         carp_send_ad_locked(sc);
 866                 CARP_SCUNLOCK(sc);
 867         }
 868         mtx_unlock(&carp_mtx);
 869 }
 870
 871 static void
 872 carp_send_ad(void *v)
 873 {
 874         struct carp_softc *sc = v;
 875
 876         CARP_SCLOCK(sc);
 877         carp_send_ad_locked(sc);
 878         CARP_SCUNLOCK(sc);
 879 }
 880
 881 static void
 882 carp_send_ad_locked(struct carp_softc *sc)
 883 {
 884         struct carp_header ch;
 885         struct timeval tv;
 886         struct carp_header *ch_ptr;
 887         struct mbuf *m;
 888         int len, advbase, advskew;
 889
 890         CARP_SCLOCK_ASSERT(sc);
 891
 892         /* bow out if we've lost our UPness or RUNNINGuiness */
 893         if (!((SC2IFP(sc)->if_flags & IFF_UP) &&
 894             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING))) {
 895                 advbase = 255;
 896                 advskew = 255;
 897         } else {
 898                 advbase = sc->sc_advbase;
 899                 if (!carp_suppress_preempt || sc->sc_advskew > 240)
 900                         advskew = sc->sc_advskew;
 901                 else
 902                         advskew = 240;
 903                 tv.tv_sec = advbase;
 904                 tv.tv_usec = advskew * 1000000 / 256;
 905         }
 906
 907         ch.carp_version = CARP_VERSION;
 908         ch.carp_type = CARP_ADVERTISEMENT;
 909         ch.carp_vhid = sc->sc_vhid;
 910         ch.carp_advbase = advbase;
 911         ch.carp_advskew = advskew;
 912         ch.carp_authlen = 7;    /* XXX DEFINE */
 913         ch.carp_pad1 = 0;       /* must be zero */
 914         ch.carp_cksum = 0;
 915
 916 #ifdef INET
 917         if (sc->sc_ia) {
 918                 struct ip *ip;
 919
 920                 MGETHDR(m, M_DONTWAIT, MT_HEADER);
 921                 if (m == NULL) {
 922                         SC2IFP(sc)->if_oerrors++;
 923                         carpstats.carps_onomem++;
 924                         /* XXX maybe less ? */
 925                         if (advbase != 255 || advskew != 255)
 926                                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
 927                                     carp_send_ad, sc);
 928                         return;
 929                 }
 930                 len = sizeof(*ip) + sizeof(ch);
 931                 m->m_pkthdr.len = len;
 932                 m->m_pkthdr.rcvif = NULL;
 933                 m->m_len = len;
 934                 MH_ALIGN(m, m->m_len);
 935                 m->m_flags |= M_MCAST;
 936                 ip = mtod(m, struct ip *);
 937                 ip->ip_v = IPVERSION;
 938                 ip->ip_hl = sizeof(*ip) >> 2;
 939                 ip->ip_tos = IPTOS_LOWDELAY;
 940                 ip->ip_len = len;
 941                 ip->ip_id = ip_newid();
 942                 ip->ip_off = IP_DF;
 943                 ip->ip_ttl = CARP_DFLTTL;
 944                 ip->ip_p = IPPROTO_CARP;
 945                 ip->ip_sum = 0;
 946                 ip->ip_src.s_addr = sc->sc_ia->ia_addr.sin_addr.s_addr;
 947                 ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
 948
 949                 ch_ptr = (struct carp_header *)(&ip[1]);
 950                 bcopy(&ch, ch_ptr, sizeof(ch));
 951                 if (carp_prepare_ad(m, sc, ch_ptr))
 952                         return;
 953
 954                 m->m_data += sizeof(*ip);
 955                 ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
 956                 m->m_data -= sizeof(*ip);
 957
 958                 getmicrotime(&SC2IFP(sc)->if_lastchange);
 959                 SC2IFP(sc)->if_opackets++;
 960                 SC2IFP(sc)->if_obytes += len;
 961                 carpstats.carps_opackets++;
 962
 963                 if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL)) {
 964                         SC2IFP(sc)->if_oerrors++;
 965                         if (sc->sc_sendad_errors < INT_MAX)
 966                                 sc->sc_sendad_errors++;
 967                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
 968                                 carp_suppress_preempt++;
 969                                 if (carp_suppress_preempt == 1) {
 970                                         CARP_SCUNLOCK(sc);
 971                                         carp_send_ad_all();
 972                                         CARP_SCLOCK(sc);
 973                                 }
 974                         }
 975                         sc->sc_sendad_success = 0;
 976                 } else {
 977                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
 978                                 if (++sc->sc_sendad_success >=
 979                                     CARP_SENDAD_MIN_SUCCESS) {
 980                                         carp_suppress_preempt--;
 981                                         sc->sc_sendad_errors = 0;
 982                                 }
 983                         } else
 984                                 sc->sc_sendad_errors = 0;
 985                 }
 986         }
 987 #endif /* INET */
 988 #ifdef INET6
 989         if (sc->sc_ia6) {
 990                 struct ip6_hdr *ip6;
 991
 992                 MGETHDR(m, M_DONTWAIT, MT_HEADER);
 993                 if (m == NULL) {
 994                         SC2IFP(sc)->if_oerrors++;
 995                         carpstats.carps_onomem++;
 996                         /* XXX maybe less ? */
 997                         if (advbase != 255 || advskew != 255)
 998                                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
 999                                     carp_send_ad, sc);
1000                         return;
1001                 }
1002                 len = sizeof(*ip6) + sizeof(ch);
1003                 m->m_pkthdr.len = len;
1004                 m->m_pkthdr.rcvif = NULL;
1005                 m->m_len = len;
1006                 MH_ALIGN(m, m->m_len);
1007                 m->m_flags |= M_MCAST;
1008                 ip6 = mtod(m, struct ip6_hdr *);
1009                 bzero(ip6, sizeof(*ip6));
1010                 ip6->ip6_vfc |= IPV6_VERSION;
1011                 ip6->ip6_hlim = CARP_DFLTTL;
1012                 ip6->ip6_nxt = IPPROTO_CARP;
1013                 bcopy(&sc->sc_ia6->ia_addr.sin6_addr, &ip6->ip6_src,
1014                     sizeof(struct in6_addr));
1015                 /* set the multicast destination */
1016
1017                 ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
1018                 ip6->ip6_dst.s6_addr8[15] = 0x12;
1019                 if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1020                         SC2IFP(sc)->if_oerrors++;
1021                         m_freem(m);
1022                         CARP_LOG("%s: in6_setscope failed\n", __func__);
1023                         return;
1024                 }
1025
1026                 ch_ptr = (struct carp_header *)(&ip6[1]);
1027                 bcopy(&ch, ch_ptr, sizeof(ch));
1028                 if (carp_prepare_ad(m, sc, ch_ptr))
1029                         return;
1030
1031                 m->m_data += sizeof(*ip6);
1032                 ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
1033                 m->m_data -= sizeof(*ip6);
1034
1035                 getmicrotime(&SC2IFP(sc)->if_lastchange);
1036                 SC2IFP(sc)->if_opackets++;
1037                 SC2IFP(sc)->if_obytes += len;
1038                 carpstats.carps_opackets6++;
1039
1040                 if (ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL)) {
1041                         SC2IFP(sc)->if_oerrors++;
1042                         if (sc->sc_sendad_errors < INT_MAX)
1043                                 sc->sc_sendad_errors++;
1044                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1045                                 carp_suppress_preempt++;
1046                                 if (carp_suppress_preempt == 1) {
1047                                         CARP_SCUNLOCK(sc);
1048                                         carp_send_ad_all();
1049                                         CARP_SCLOCK(sc);
1050                                 }
1051                         }
1052                         sc->sc_sendad_success = 0;
1053                 } else {
1054                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1055                                 if (++sc->sc_sendad_success >=
1056                                     CARP_SENDAD_MIN_SUCCESS) {
1057                                         carp_suppress_preempt--;
1058                                         sc->sc_sendad_errors = 0;
1059                                 }
1060                         } else
1061                                 sc->sc_sendad_errors = 0;
1062                 }
1063         }
1064 #endif /* INET6 */
1065
1066         if (advbase != 255 || advskew != 255)
1067                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1068                     carp_send_ad, sc);
1069
1070 }
1071
1072 /*
1073  * Broadcast a gratuitous ARP request containing
1074  * the virtual router MAC address for each IP address
1075  * associated with the virtual router.
1076  */
1077 static void
1078 carp_send_arp(struct carp_softc *sc)
1079 {
1080         struct ifaddr *ifa;
1081
1082         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
1083
1084                 if (ifa->ifa_addr->sa_family != AF_INET)
1085                         continue;
1086
1087 /*              arprequest(sc->sc_carpdev, &in, &in, IF_LLADDR(sc->sc_ifp)); */
1088                 arp_ifinit2(sc->sc_carpdev, ifa, IF_LLADDR(sc->sc_ifp));
1089
1090                 DELAY(1000);    /* XXX */
1091         }
1092 }
1093
1094 #ifdef INET6
1095 static void
1096 carp_send_na(struct carp_softc *sc)
1097 {
1098         struct ifaddr *ifa;
1099         struct in6_addr *in6;
1100         static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1101
1102         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
1103
1104                 if (ifa->ifa_addr->sa_family != AF_INET6)
1105                         continue;
1106
1107                 in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1108                 nd6_na_output(sc->sc_carpdev, &mcast, in6,
1109                     ND_NA_FLAG_OVERRIDE, 1, NULL);
1110                 DELAY(1000);    /* XXX */
1111         }
1112 }
1113 #endif /* INET6 */
1114
1115 static int
1116 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
1117 {
1118         struct carp_softc *vh;
1119         struct ifaddr *ifa;
1120         int count = 0;
1121
1122         CARP_LOCK_ASSERT(cif);
1123
1124         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1125                 if ((type == CARP_COUNT_RUNNING &&
1126                     (SC2IFP(vh)->if_flags & IFF_UP) &&
1127                     (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING)) ||
1128                     (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
1129                         TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist,
1130                             ifa_list) {
1131                                 if (ifa->ifa_addr->sa_family == AF_INET &&
1132                                     ia->ia_addr.sin_addr.s_addr ==
1133                                     ifatoia(ifa)->ia_addr.sin_addr.s_addr)
1134                                         count++;
1135                         }
1136                 }
1137         }
1138         return (count);
1139 }
1140
1141 int
1142 carp_iamatch(void *v, struct in_ifaddr *ia,
1143     struct in_addr *isaddr, u_int8_t **enaddr)
1144 {
1145         struct carp_if *cif = v;
1146         struct carp_softc *vh;
1147         int index, count = 0;
1148         struct ifaddr *ifa;
1149
1150         CARP_LOCK(cif);
1151
1152         if (carp_opts[CARPCTL_ARPBALANCE]) {
1153                 /*
1154                  * XXX proof of concept implementation.
1155                  * We use the source ip to decide which virtual host should
1156                  * handle the request. If we're master of that virtual host,
1157                  * then we respond, otherwise, just drop the arp packet on
1158                  * the floor.
1159                  */
1160                 count = carp_addrcount(cif, ia, CARP_COUNT_RUNNING);
1161                 if (count == 0) {
1162                         /* should never reach this */
1163                         CARP_UNLOCK(cif);
1164                         return (0);
1165                 }
1166
1167                 /* this should be a hash, like pf_hash() */
1168                 index = ntohl(isaddr->s_addr) % count;
1169                 count = 0;
1170
1171                 TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1172                         if ((SC2IFP(vh)->if_flags & IFF_UP) &&
1173                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING)) {
1174                                 TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist,
1175                                     ifa_list) {
1176                                         if (ifa->ifa_addr->sa_family ==
1177                                             AF_INET &&
1178                                             ia->ia_addr.sin_addr.s_addr ==
1179                                             ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
1180                                                 if (count == index) {
1181                                                         if (vh->sc_state ==
1182                                                             MASTER) {
1183                                                                 *enaddr = IF_LLADDR(vh->sc_ifp);
1184                                                                 CARP_UNLOCK(cif);
1185                                                                 return (1);
1186                                                         } else {
1187                                                                 CARP_UNLOCK(cif);
1188                                                                 return (0);
1189                                                         }
1190                                                 }
1191                                                 count++;
1192                                         }
1193                                 }
1194                         }
1195                 }
1196         } else {
1197                 TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1198                         if ((SC2IFP(vh)->if_flags & IFF_UP) &&
1199                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
1200                             ia->ia_ifp == SC2IFP(vh) &&
1201                             vh->sc_state == MASTER) {
1202                                 *enaddr = IF_LLADDR(vh->sc_ifp);
1203                                 CARP_UNLOCK(cif);
1204                                 return (1);
1205                         }
1206                 }
1207         }
1208         CARP_UNLOCK(cif);
1209         return (0);
1210 }
1211
1212 #ifdef INET6
1213 struct ifaddr *
1214 carp_iamatch6(void *v, struct in6_addr *taddr)
1215 {
1216         struct carp_if *cif = v;
1217         struct carp_softc *vh;
1218         struct ifaddr *ifa;
1219
1220         CARP_LOCK(cif);
1221         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1222                 TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist, ifa_list) {
1223                         if (IN6_ARE_ADDR_EQUAL(taddr,
1224                             &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1225                             (SC2IFP(vh)->if_flags & IFF_UP) &&
1226                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
1227                             vh->sc_state == MASTER) {
1228                                 CARP_UNLOCK(cif);
1229                                 return (ifa);
1230                         }
1231                 }
1232         }
1233         CARP_UNLOCK(cif);
1234
1235         return (NULL);
1236 }
1237
1238 void *
1239 carp_macmatch6(void *v, struct mbuf *m, const struct in6_addr *taddr)
1240 {
1241         struct m_tag *mtag;
1242         struct carp_if *cif = v;
1243         struct carp_softc *sc;
1244         struct ifaddr *ifa;
1245
1246         CARP_LOCK(cif);
1247         TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
1248                 TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
1249                         if (IN6_ARE_ADDR_EQUAL(taddr,
1250                             &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1251                             (SC2IFP(sc)->if_flags & IFF_UP) &&
1252                             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING)) {
1253                                 struct ifnet *ifp = SC2IFP(sc);
1254                                 mtag = m_tag_get(PACKET_TAG_CARP,
1255                                     sizeof(struct ifnet *), M_NOWAIT);
1256                                 if (mtag == NULL) {
1257                                         /* better a bit than nothing */
1258                                         CARP_UNLOCK(cif);
1259                                         return (IF_LLADDR(sc->sc_ifp));
1260                                 }
1261                                 bcopy(&ifp, (caddr_t)(mtag + 1),
1262                                     sizeof(struct ifnet *));
1263                                 m_tag_prepend(m, mtag);
1264
1265                                 CARP_UNLOCK(cif);
1266                                 return (IF_LLADDR(sc->sc_ifp));
1267                         }
1268                 }
1269         }
1270         CARP_UNLOCK(cif);
1271
1272         return (NULL);
1273 }
1274 #endif
1275
1276 struct ifnet *
1277 carp_forus(void *v, void *dhost)
1278 {
1279         struct carp_if *cif = v;
1280         struct carp_softc *vh;
1281         u_int8_t *ena = dhost;
1282
1283         if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1284                 return (NULL);
1285
1286         CARP_LOCK(cif);
1287         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
1288                 if ((SC2IFP(vh)->if_flags & IFF_UP) &&
1289                     (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
1290                     vh->sc_state == MASTER &&
1291                     !bcmp(dhost, IF_LLADDR(vh->sc_ifp), ETHER_ADDR_LEN)) {
1292                         CARP_UNLOCK(cif);
1293                         return (SC2IFP(vh));
1294                 }
1295
1296         CARP_UNLOCK(cif);
1297         return (NULL);
1298 }
1299
1300 static void
1301 carp_master_down(void *v)
1302 {
1303         struct carp_softc *sc = v;
1304
1305         CARP_SCLOCK(sc);
1306         carp_master_down_locked(sc);
1307         CARP_SCUNLOCK(sc);
1308 }
1309
1310 static void
1311 carp_master_down_locked(struct carp_softc *sc)
1312 {
1313         if (sc->sc_carpdev)
1314                 CARP_SCLOCK_ASSERT(sc);
1315
1316         switch (sc->sc_state) {
1317         case INIT:
1318                 printf("%s: master_down event in INIT state\n",
1319                     SC2IFP(sc)->if_xname);
1320                 break;
1321         case MASTER:
1322                 break;
1323         case BACKUP:
1324                 carp_set_state(sc, MASTER);
1325                 carp_send_ad_locked(sc);
1326                 carp_send_arp(sc);
1327 #ifdef INET6
1328                 carp_send_na(sc);
1329 #endif /* INET6 */
1330                 carp_setrun(sc, 0);
1331                 carp_setroute(sc, RTM_ADD);
1332                 break;
1333         }
1334 }
1335
1336 /*
1337  * When in backup state, af indicates whether to reset the master down timer
1338  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1339  */
1340 static void
1341 carp_setrun(struct carp_softc *sc, sa_family_t af)
1342 {
1343         struct timeval tv;
1344
1345         if (sc->sc_carpdev == NULL) {
1346                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1347                 carp_set_state(sc, INIT);
1348                 return;
1349         } else
1350                 CARP_SCLOCK_ASSERT(sc);
1351
1352         if (SC2IFP(sc)->if_flags & IFF_UP &&
1353             sc->sc_vhid > 0 && (sc->sc_naddrs || sc->sc_naddrs6))
1354                 SC2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
1355         else {
1356                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1357                 carp_setroute(sc, RTM_DELETE);
1358                 return;
1359         }
1360
1361         switch (sc->sc_state) {
1362         case INIT:
1363                 if (carp_opts[CARPCTL_PREEMPT] && !carp_suppress_preempt) {
1364                         carp_send_ad_locked(sc);
1365                         carp_send_arp(sc);
1366 #ifdef INET6
1367                         carp_send_na(sc);
1368 #endif /* INET6 */
1369                         CARP_DEBUG("%s: INIT -> MASTER (preempting)\n",
1370                             SC2IFP(sc)->if_xname);
1371                         carp_set_state(sc, MASTER);
1372                         carp_setroute(sc, RTM_ADD);
1373                 } else {
1374                         CARP_DEBUG("%s: INIT -> BACKUP\n", SC2IFP(sc)->if_xname);
1375                         carp_set_state(sc, BACKUP);
1376                         carp_setroute(sc, RTM_DELETE);
1377                         carp_setrun(sc, 0);
1378                 }
1379                 break;
1380         case BACKUP:
1381                 callout_stop(&sc->sc_ad_tmo);
1382                 tv.tv_sec = 3 * sc->sc_advbase;
1383                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1384                 switch (af) {
1385 #ifdef INET
1386                 case AF_INET:
1387                         callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1388                             carp_master_down, sc);
1389                         break;
1390 #endif /* INET */
1391 #ifdef INET6
1392                 case AF_INET6:
1393                         callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1394                             carp_master_down, sc);
1395                         break;
1396 #endif /* INET6 */
1397                 default:
1398                         if (sc->sc_naddrs)
1399                                 callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1400                                     carp_master_down, sc);
1401                         if (sc->sc_naddrs6)
1402                                 callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1403                                     carp_master_down, sc);
1404                         break;
1405                 }
1406                 break;
1407         case MASTER:
1408                 tv.tv_sec = sc->sc_advbase;
1409                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1410                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1411                     carp_send_ad, sc);
1412                 break;
1413         }
1414 }
1415
1416 static void
1417 carp_multicast_cleanup(struct carp_softc *sc)
1418 {
1419         struct ip_moptions *imo = &sc->sc_imo;
1420         u_int16_t n = imo->imo_num_memberships;
1421
1422         /* Clean up our own multicast memberships */
1423         while (n-- > 0) {
1424                 if (imo->imo_membership[n] != NULL) {
1425                         in_delmulti(imo->imo_membership[n]);
1426                         imo->imo_membership[n] = NULL;
1427                 }
1428         }
1429         KASSERT(imo->imo_mfilters == NULL,
1430            ("%s: imo_mfilters != NULL", __func__));
1431         imo->imo_num_memberships = 0;
1432         imo->imo_multicast_ifp = NULL;
1433 }
1434
1435 #ifdef INET6
1436 static void
1437 carp_multicast6_cleanup(struct carp_softc *sc)
1438 {
1439         struct ip6_moptions *im6o = &sc->sc_im6o;
1440
1441         while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1442                 struct in6_multi_mship *imm =
1443                     LIST_FIRST(&im6o->im6o_memberships);
1444
1445                 LIST_REMOVE(imm, i6mm_chain);
1446                 in6_leavegroup(imm);
1447         }
1448         im6o->im6o_multicast_ifp = NULL;
1449 }
1450 #endif
1451
1452 static int
1453 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1454 {
1455         struct ifnet *ifp;
1456         struct carp_if *cif;
1457         struct in_ifaddr *ia, *ia_if;
1458         struct ip_moptions *imo = &sc->sc_imo;
1459         struct in_addr addr;
1460         u_long iaddr = htonl(sin->sin_addr.s_addr);
1461         int own, error;
1462
1463         if (sin->sin_addr.s_addr == 0) {
1464                 if (!(SC2IFP(sc)->if_flags & IFF_UP))
1465                         carp_set_state(sc, INIT);
1466                 if (sc->sc_naddrs)
1467                         SC2IFP(sc)->if_flags |= IFF_UP;
1468                 if (sc->sc_carpdev)
1469                         CARP_SCLOCK(sc);
1470                 carp_setrun(sc, 0);
1471                 if (sc->sc_carpdev)
1472                         CARP_SCUNLOCK(sc);
1473                 return (0);
1474         }
1475
1476         /* we have to do it by hands to check we won't match on us */
1477         ia_if = NULL; own = 0;
1478         TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1479                 /* and, yeah, we need a multicast-capable iface too */
1480                 if (ia->ia_ifp != SC2IFP(sc) &&
1481                     (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1482                     (iaddr & ia->ia_subnetmask) == ia->ia_subnet) {
1483                         if (!ia_if)
1484                                 ia_if = ia;
1485                         if (sin->sin_addr.s_addr ==
1486                             ia->ia_addr.sin_addr.s_addr)
1487                                 own++;
1488                 }
1489         }
1490
1491         if (!ia_if)
1492                 return (EADDRNOTAVAIL);
1493
1494         ia = ia_if;
1495         ifp = ia->ia_ifp;
1496
1497         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
1498             (imo->imo_multicast_ifp && imo->imo_multicast_ifp != ifp))
1499                 return (EADDRNOTAVAIL);
1500
1501         if (imo->imo_num_memberships == 0) {
1502                 addr.s_addr = htonl(INADDR_CARP_GROUP);
1503                 if ((imo->imo_membership[0] = in_addmulti(&addr, ifp)) == NULL)
1504                         return (ENOBUFS);
1505                 imo->imo_num_memberships++;
1506                 imo->imo_multicast_ifp = ifp;
1507                 imo->imo_multicast_ttl = CARP_DFLTTL;
1508                 imo->imo_multicast_loop = 0;
1509         }
1510
1511         if (!ifp->if_carp) {
1512
1513                 MALLOC(cif, struct carp_if *, sizeof(*cif), M_CARP,
1514                     M_WAITOK|M_ZERO);
1515                 if (!cif) {
1516                         error = ENOBUFS;
1517                         goto cleanup;
1518                 }
1519                 if ((error = ifpromisc(ifp, 1))) {
1520                         FREE(cif, M_CARP);
1521                         goto cleanup;
1522                 }
1523
1524                 CARP_LOCK_INIT(cif);
1525                 CARP_LOCK(cif);
1526                 cif->vhif_ifp = ifp;
1527                 TAILQ_INIT(&cif->vhif_vrs);
1528                 ifp->if_carp = cif;
1529
1530         } else {
1531                 struct carp_softc *vr;
1532
1533                 cif = (struct carp_if *)ifp->if_carp;
1534                 CARP_LOCK(cif);
1535                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1536                         if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
1537                                 CARP_UNLOCK(cif);
1538                                 error = EEXIST;
1539                                 goto cleanup;
1540                         }
1541         }
1542         sc->sc_ia = ia;
1543         sc->sc_carpdev = ifp;
1544
1545         { /* XXX prevent endless loop if already in queue */
1546         struct carp_softc *vr, *after = NULL;
1547         int myself = 0;
1548         cif = (struct carp_if *)ifp->if_carp;
1549
1550         /* XXX: cif should not change, right? So we still hold the lock */
1551         CARP_LOCK_ASSERT(cif);
1552
1553         TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1554                 if (vr == sc)
1555                         myself = 1;
1556                 if (vr->sc_vhid < sc->sc_vhid)
1557                         after = vr;
1558         }
1559
1560         if (!myself) {
1561                 /* We're trying to keep things in order */
1562                 if (after == NULL) {
1563                         TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1564                 } else {
1565                         TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
1566                 }
1567                 cif->vhif_nvrs++;
1568         }
1569         }
1570
1571         sc->sc_naddrs++;
1572         SC2IFP(sc)->if_flags |= IFF_UP;
1573         if (own)
1574                 sc->sc_advskew = 0;
1575         carp_sc_state_locked(sc);
1576         carp_setrun(sc, 0);
1577
1578         CARP_UNLOCK(cif);
1579
1580         return (0);
1581
1582 cleanup:
1583         in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
1584         return (error);
1585 }
1586
1587 static int
1588 carp_del_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1589 {
1590         int error = 0;
1591
1592         if (!--sc->sc_naddrs) {
1593                 struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1594                 struct ip_moptions *imo = &sc->sc_imo;
1595
1596                 CARP_LOCK(cif);
1597                 callout_stop(&sc->sc_ad_tmo);
1598                 SC2IFP(sc)->if_flags &= ~IFF_UP;
1599                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1600                 sc->sc_vhid = -1;
1601                 in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
1602                 imo->imo_multicast_ifp = NULL;
1603                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
1604                 if (!--cif->vhif_nvrs) {
1605                         sc->sc_carpdev->if_carp = NULL;
1606                         CARP_LOCK_DESTROY(cif);
1607                         FREE(cif, M_IFADDR);
1608                 } else {
1609                         CARP_UNLOCK(cif);
1610                 }
1611         }
1612
1613         return (error);
1614 }
1615
1616 #ifdef INET6
1617 static int
1618 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1619 {
1620         struct ifnet *ifp;
1621         struct carp_if *cif;
1622         struct in6_ifaddr *ia, *ia_if;
1623         struct ip6_moptions *im6o = &sc->sc_im6o;
1624         struct in6_multi_mship *imm;
1625         struct in6_addr in6;
1626         int own, error;
1627
1628         if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1629                 if (!(SC2IFP(sc)->if_flags & IFF_UP))
1630                         carp_set_state(sc, INIT);
1631                 if (sc->sc_naddrs6)
1632                         SC2IFP(sc)->if_flags |= IFF_UP;
1633                 if (sc->sc_carpdev)
1634                         CARP_SCLOCK(sc);
1635                 carp_setrun(sc, 0);
1636                 if (sc->sc_carpdev)
1637                         CARP_SCUNLOCK(sc);
1638                 return (0);
1639         }
1640
1641         /* we have to do it by hands to check we won't match on us */
1642         ia_if = NULL; own = 0;
1643         for (ia = V_in6_ifaddr; ia; ia = ia->ia_next) {
1644                 int i;
1645
1646                 for (i = 0; i < 4; i++) {
1647                         if ((sin6->sin6_addr.s6_addr32[i] &
1648                             ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1649                             (ia->ia_addr.sin6_addr.s6_addr32[i] &
1650                             ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1651                                 break;
1652                 }
1653                 /* and, yeah, we need a multicast-capable iface too */
1654                 if (ia->ia_ifp != SC2IFP(sc) &&
1655                     (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1656                     (i == 4)) {
1657                         if (!ia_if)
1658                                 ia_if = ia;
1659                         if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr,
1660                             &ia->ia_addr.sin6_addr))
1661                                 own++;
1662                 }
1663         }
1664
1665         if (!ia_if)
1666                 return (EADDRNOTAVAIL);
1667         ia = ia_if;
1668         ifp = ia->ia_ifp;
1669
1670         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
1671             (im6o->im6o_multicast_ifp && im6o->im6o_multicast_ifp != ifp))
1672                 return (EADDRNOTAVAIL);
1673
1674         if (!sc->sc_naddrs6) {
1675                 im6o->im6o_multicast_ifp = ifp;
1676
1677                 /* join CARP multicast address */
1678                 bzero(&in6, sizeof(in6));
1679                 in6.s6_addr16[0] = htons(0xff02);
1680                 in6.s6_addr8[15] = 0x12;
1681                 if (in6_setscope(&in6, ifp, NULL) != 0)
1682                         goto cleanup;
1683                 if ((imm = in6_joingroup(ifp, &in6, &error, 0)) == NULL)
1684                         goto cleanup;
1685                 LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
1686
1687                 /* join solicited multicast address */
1688                 bzero(&in6, sizeof(in6));
1689                 in6.s6_addr16[0] = htons(0xff02);
1690                 in6.s6_addr32[1] = 0;
1691                 in6.s6_addr32[2] = htonl(1);
1692                 in6.s6_addr32[3] = sin6->sin6_addr.s6_addr32[3];
1693                 in6.s6_addr8[12] = 0xff;
1694                 if (in6_setscope(&in6, ifp, NULL) != 0)
1695                         goto cleanup;
1696                 if ((imm = in6_joingroup(ifp, &in6, &error, 0)) == NULL)
1697                         goto cleanup;
1698                 LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
1699         }
1700
1701         if (!ifp->if_carp) {
1702                 MALLOC(cif, struct carp_if *, sizeof(*cif), M_CARP,
1703                     M_WAITOK|M_ZERO);
1704                 if (!cif) {
1705                         error = ENOBUFS;
1706                         goto cleanup;
1707                 }
1708                 if ((error = ifpromisc(ifp, 1))) {
1709                         FREE(cif, M_CARP);
1710                         goto cleanup;
1711                 }
1712
1713                 CARP_LOCK_INIT(cif);
1714                 CARP_LOCK(cif);
1715                 cif->vhif_ifp = ifp;
1716                 TAILQ_INIT(&cif->vhif_vrs);
1717                 ifp->if_carp = cif;
1718
1719         } else {
1720                 struct carp_softc *vr;
1721
1722                 cif = (struct carp_if *)ifp->if_carp;
1723                 CARP_LOCK(cif);
1724                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1725                         if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
1726                                 CARP_UNLOCK(cif);
1727                                 error = EINVAL;
1728                                 goto cleanup;
1729                         }
1730         }
1731         sc->sc_ia6 = ia;
1732         sc->sc_carpdev = ifp;
1733
1734         { /* XXX prevent endless loop if already in queue */
1735         struct carp_softc *vr, *after = NULL;
1736         int myself = 0;
1737         cif = (struct carp_if *)ifp->if_carp;
1738         CARP_LOCK_ASSERT(cif);
1739
1740         TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1741                 if (vr == sc)
1742                         myself = 1;
1743                 if (vr->sc_vhid < sc->sc_vhid)
1744                         after = vr;
1745         }
1746
1747         if (!myself) {
1748                 /* We're trying to keep things in order */
1749                 if (after == NULL) {
1750                         TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1751                 } else {
1752                         TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
1753                 }
1754                 cif->vhif_nvrs++;
1755         }
1756         }
1757
1758         sc->sc_naddrs6++;
1759         SC2IFP(sc)->if_flags |= IFF_UP;
1760         if (own)
1761                 sc->sc_advskew = 0;
1762         carp_sc_state_locked(sc);
1763         carp_setrun(sc, 0);
1764
1765         CARP_UNLOCK(cif);
1766
1767         return (0);
1768
1769 cleanup:
1770         /* clean up multicast memberships */
1771         if (!sc->sc_naddrs6) {
1772                 while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1773                         imm = LIST_FIRST(&im6o->im6o_memberships);
1774                         LIST_REMOVE(imm, i6mm_chain);
1775                         in6_leavegroup(imm);
1776                 }
1777         }
1778         return (error);
1779 }
1780
1781 static int
1782 carp_del_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1783 {
1784         int error = 0;
1785
1786         if (!--sc->sc_naddrs6) {
1787                 struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1788                 struct ip6_moptions *im6o = &sc->sc_im6o;
1789
1790                 CARP_LOCK(cif);
1791                 callout_stop(&sc->sc_ad_tmo);
1792                 SC2IFP(sc)->if_flags &= ~IFF_UP;
1793                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
1794                 sc->sc_vhid = -1;
1795                 while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1796                         struct in6_multi_mship *imm =
1797                             LIST_FIRST(&im6o->im6o_memberships);
1798
1799                         LIST_REMOVE(imm, i6mm_chain);
1800                         in6_leavegroup(imm);
1801                 }
1802                 im6o->im6o_multicast_ifp = NULL;
1803                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
1804                 if (!--cif->vhif_nvrs) {
1805                         CARP_LOCK_DESTROY(cif);
1806                         sc->sc_carpdev->if_carp = NULL;
1807                         FREE(cif, M_IFADDR);
1808                 } else
1809                         CARP_UNLOCK(cif);
1810         }
1811
1812         return (error);
1813 }
1814 #endif /* INET6 */
1815
1816 static int
1817 carp_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
1818 {
1819         struct carp_softc *sc = ifp->if_softc, *vr;
1820         struct carpreq carpr;
1821         struct ifaddr *ifa;
1822         struct ifreq *ifr;
1823         struct ifaliasreq *ifra;
1824         int locked = 0, error = 0;
1825
1826         ifa = (struct ifaddr *)addr;
1827         ifra = (struct ifaliasreq *)addr;
1828         ifr = (struct ifreq *)addr;
1829
1830         switch (cmd) {
1831         case SIOCSIFADDR:
1832                 switch (ifa->ifa_addr->sa_family) {
1833 #ifdef INET
1834                 case AF_INET:
1835                         SC2IFP(sc)->if_flags |= IFF_UP;
1836                         bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1837                             sizeof(struct sockaddr));
1838                         error = carp_set_addr(sc, satosin(ifa->ifa_addr));
1839                         break;
1840 #endif /* INET */
1841 #ifdef INET6
1842                 case AF_INET6:
1843                         SC2IFP(sc)->if_flags |= IFF_UP;
1844                         error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1845                         break;
1846 #endif /* INET6 */
1847                 default:
1848                         error = EAFNOSUPPORT;
1849                         break;
1850                 }
1851                 break;
1852
1853         case SIOCAIFADDR:
1854                 switch (ifa->ifa_addr->sa_family) {
1855 #ifdef INET
1856                 case AF_INET:
1857                         SC2IFP(sc)->if_flags |= IFF_UP;
1858                         bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
1859                             sizeof(struct sockaddr));
1860                         error = carp_set_addr(sc, satosin(&ifra->ifra_addr));
1861                         break;
1862 #endif /* INET */
1863 #ifdef INET6
1864                 case AF_INET6:
1865                         SC2IFP(sc)->if_flags |= IFF_UP;
1866                         error = carp_set_addr6(sc, satosin6(&ifra->ifra_addr));
1867                         break;
1868 #endif /* INET6 */
1869                 default:
1870                         error = EAFNOSUPPORT;
1871                         break;
1872                 }
1873                 break;
1874
1875         case SIOCDIFADDR:
1876                 switch (ifa->ifa_addr->sa_family) {
1877 #ifdef INET
1878                 case AF_INET:
1879                         error = carp_del_addr(sc, satosin(&ifra->ifra_addr));
1880                         break;
1881 #endif /* INET */
1882 #ifdef INET6
1883                 case AF_INET6:
1884                         error = carp_del_addr6(sc, satosin6(&ifra->ifra_addr));
1885                         break;
1886 #endif /* INET6 */
1887                 default:
1888                         error = EAFNOSUPPORT;
1889                         break;
1890                 }
1891                 break;
1892
1893         case SIOCSIFFLAGS:
1894                 if (sc->sc_carpdev) {
1895                         locked = 1;
1896                         CARP_SCLOCK(sc);
1897                 }
1898                 if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
1899                         callout_stop(&sc->sc_ad_tmo);
1900                         callout_stop(&sc->sc_md_tmo);
1901                         callout_stop(&sc->sc_md6_tmo);
1902                         if (sc->sc_state == MASTER)
1903                                 carp_send_ad_locked(sc);
1904                         carp_set_state(sc, INIT);
1905                         carp_setrun(sc, 0);
1906                 } else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
1907                         SC2IFP(sc)->if_flags |= IFF_UP;
1908                         carp_setrun(sc, 0);
1909                 }
1910                 break;
1911
1912         case SIOCSVH:
1913                 error = priv_check(curthread, PRIV_NETINET_CARP);
1914                 if (error)
1915                         break;
1916                 if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
1917                         break;
1918                 error = 1;
1919                 if (sc->sc_carpdev) {
1920                         locked = 1;
1921                         CARP_SCLOCK(sc);
1922                 }
1923                 if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
1924                         switch (carpr.carpr_state) {
1925                         case BACKUP:
1926                                 callout_stop(&sc->sc_ad_tmo);
1927                                 carp_set_state(sc, BACKUP);
1928                                 carp_setrun(sc, 0);
1929                                 carp_setroute(sc, RTM_DELETE);
1930                                 break;
1931                         case MASTER:
1932                                 carp_master_down_locked(sc);
1933                                 break;
1934                         default:
1935                                 break;
1936                         }
1937                 }
1938                 if (carpr.carpr_vhid > 0) {
1939                         if (carpr.carpr_vhid > 255) {
1940                                 error = EINVAL;
1941                                 break;
1942                         }
1943                         if (sc->sc_carpdev) {
1944                                 struct carp_if *cif;
1945                                 cif = (struct carp_if *)sc->sc_carpdev->if_carp;
1946                                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1947                                         if (vr != sc &&
1948                                             vr->sc_vhid == carpr.carpr_vhid) {
1949                                                 error = EEXIST;
1950                                                 break;
1951                                         }
1952                                 if (error == EEXIST)
1953                                         break;
1954                         }
1955                         sc->sc_vhid = carpr.carpr_vhid;
1956                         IF_LLADDR(sc->sc_ifp)[0] = 0;
1957                         IF_LLADDR(sc->sc_ifp)[1] = 0;
1958                         IF_LLADDR(sc->sc_ifp)[2] = 0x5e;
1959                         IF_LLADDR(sc->sc_ifp)[3] = 0;
1960                         IF_LLADDR(sc->sc_ifp)[4] = 1;
1961                         IF_LLADDR(sc->sc_ifp)[5] = sc->sc_vhid;
1962                         error--;
1963                 }
1964                 if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
1965                         if (carpr.carpr_advskew >= 255) {
1966                                 error = EINVAL;
1967                                 break;
1968                         }
1969                         if (carpr.carpr_advbase > 255) {
1970                                 error = EINVAL;
1971                                 break;
1972                         }
1973                         sc->sc_advbase = carpr.carpr_advbase;
1974                         sc->sc_advskew = carpr.carpr_advskew;
1975                         error--;
1976                 }
1977                 bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1978                 if (error > 0)
1979                         error = EINVAL;
1980                 else {
1981                         error = 0;
1982                         carp_setrun(sc, 0);
1983                 }
1984                 break;
1985
1986         case SIOCGVH:
1987                 /* XXX: lockless read */
1988                 bzero(&carpr, sizeof(carpr));
1989                 carpr.carpr_state = sc->sc_state;
1990                 carpr.carpr_vhid = sc->sc_vhid;
1991                 carpr.carpr_advbase = sc->sc_advbase;
1992                 carpr.carpr_advskew = sc->sc_advskew;
1993                 error = priv_check(curthread, PRIV_NETINET_CARP);
1994                 if (error == 0)
1995                         bcopy(sc->sc_key, carpr.carpr_key,
1996                             sizeof(carpr.carpr_key));
1997                 error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
1998                 break;
1999
2000         default:
2001                 error = EINVAL;
2002         }
2003
2004         if (locked)
2005                 CARP_SCUNLOCK(sc);
2006
2007         carp_hmac_prepare(sc);
2008
2009         return (error);
2010 }
2011
2012 /*
2013  * XXX: this is looutput. We should eventually use it from there.
2014  */
2015 static int
2016 carp_looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
2017     struct rtentry *rt)
2018 {
2019         u_int32_t af;
2020
2021         M_ASSERTPKTHDR(m); /* check if we have the packet header */
2022
2023         if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
2024                 m_freem(m);
2025                 return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
2026                         rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
2027         }
2028
2029         ifp->if_opackets++;
2030         ifp->if_obytes += m->m_pkthdr.len;
2031
2032         /* BPF writes need to be handled specially. */
2033         if (dst->sa_family == AF_UNSPEC) {
2034                 bcopy(dst->sa_data, &af, sizeof(af));
2035                 dst->sa_family = af;
2036         }
2037
2038 #if 1   /* XXX */
2039         switch (dst->sa_family) {
2040         case AF_INET:
2041         case AF_INET6:
2042         case AF_IPX:
2043         case AF_APPLETALK:
2044                 break;
2045         default:
2046                 printf("carp_looutput: af=%d unexpected\n", dst->sa_family);
2047                 m_freem(m);
2048                 return (EAFNOSUPPORT);
2049         }
2050 #endif
2051         return(if_simloop(ifp, m, dst->sa_family, 0));
2052 }
2053
2054 /*
2055  * Start output on carp interface. This function should never be called.
2056  */
2057 static void
2058 carp_start(struct ifnet *ifp)
2059 {
2060 #ifdef DEBUG
2061         printf("%s: start called\n", ifp->if_xname);
2062 #endif
2063 }
2064
2065 int
2066 carp_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
2067     struct rtentry *rt)
2068 {
2069         struct m_tag *mtag;
2070         struct carp_softc *sc;
2071         struct ifnet *carp_ifp;
2072
2073         if (!sa)
2074                 return (0);
2075
2076         switch (sa->sa_family) {
2077 #ifdef INET
2078         case AF_INET:
2079                 break;
2080 #endif /* INET */
2081 #ifdef INET6
2082         case AF_INET6:
2083                 break;
2084 #endif /* INET6 */
2085         default:
2086                 return (0);
2087         }
2088
2089         mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
2090         if (mtag == NULL)
2091                 return (0);
2092
2093         bcopy(mtag + 1, &carp_ifp, sizeof(struct ifnet *));
2094         sc = carp_ifp->if_softc;
2095
2096         /* Set the source MAC address to Virtual Router MAC Address */
2097         switch (ifp->if_type) {
2098         case IFT_ETHER:
2099         case IFT_L2VLAN: {
2100                         struct ether_header *eh;
2101
2102                         eh = mtod(m, struct ether_header *);
2103                         eh->ether_shost[0] = 0;
2104                         eh->ether_shost[1] = 0;
2105                         eh->ether_shost[2] = 0x5e;
2106                         eh->ether_shost[3] = 0;
2107                         eh->ether_shost[4] = 1;
2108                         eh->ether_shost[5] = sc->sc_vhid;
2109                 }
2110                 break;
2111         case IFT_FDDI: {
2112                         struct fddi_header *fh;
2113
2114                         fh = mtod(m, struct fddi_header *);
2115                         fh->fddi_shost[0] = 0;
2116                         fh->fddi_shost[1] = 0;
2117                         fh->fddi_shost[2] = 0x5e;
2118                         fh->fddi_shost[3] = 0;
2119                         fh->fddi_shost[4] = 1;
2120                         fh->fddi_shost[5] = sc->sc_vhid;
2121                 }
2122                 break;
2123         case IFT_ISO88025: {
2124                         struct iso88025_header *th;
2125                         th = mtod(m, struct iso88025_header *);
2126                         th->iso88025_shost[0] = 3;
2127                         th->iso88025_shost[1] = 0;
2128                         th->iso88025_shost[2] = 0x40 >> (sc->sc_vhid - 1);
2129                         th->iso88025_shost[3] = 0x40000 >> (sc->sc_vhid - 1);
2130                         th->iso88025_shost[4] = 0;
2131                         th->iso88025_shost[5] = 0;
2132                 }
2133                 break;
2134         default:
2135                 printf("%s: carp is not supported for this interface type\n",
2136                     ifp->if_xname);
2137                 return (EOPNOTSUPP);
2138         }
2139
2140         return (0);
2141 }
2142
2143 static void
2144 carp_set_state(struct carp_softc *sc, int state)
2145 {
2146
2147         if (sc->sc_carpdev)
2148                 CARP_SCLOCK_ASSERT(sc);
2149
2150         if (sc->sc_state == state)
2151                 return;
2152
2153         sc->sc_state = state;
2154         switch (state) {
2155         case BACKUP:
2156                 SC2IFP(sc)->if_link_state = LINK_STATE_DOWN;
2157                 break;
2158         case MASTER:
2159                 SC2IFP(sc)->if_link_state = LINK_STATE_UP;
2160                 break;
2161         default:
2162                 SC2IFP(sc)->if_link_state = LINK_STATE_UNKNOWN;
2163                 break;
2164         }
2165         rt_ifmsg(SC2IFP(sc));
2166 }
2167
2168 void
2169 carp_carpdev_state(void *v)
2170 {
2171         struct carp_if *cif = v;
2172
2173         CARP_LOCK(cif);
2174         carp_carpdev_state_locked(cif);
2175         CARP_UNLOCK(cif);
2176 }
2177
2178 static void
2179 carp_carpdev_state_locked(struct carp_if *cif)
2180 {
2181         struct carp_softc *sc;
2182
2183         TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list)
2184                 carp_sc_state_locked(sc);
2185 }
2186
2187 static void
2188 carp_sc_state_locked(struct carp_softc *sc)
2189 {
2190         CARP_SCLOCK_ASSERT(sc);
2191
2192         if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
2193             !(sc->sc_carpdev->if_flags & IFF_UP)) {
2194                 sc->sc_flags_backup = SC2IFP(sc)->if_flags;
2195                 SC2IFP(sc)->if_flags &= ~IFF_UP;
2196                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
2197                 callout_stop(&sc->sc_ad_tmo);
2198                 callout_stop(&sc->sc_md_tmo);
2199                 callout_stop(&sc->sc_md6_tmo);
2200                 carp_set_state(sc, INIT);
2201                 carp_setrun(sc, 0);
2202                 if (!sc->sc_suppress) {
2203                         carp_suppress_preempt++;
2204                         if (carp_suppress_preempt == 1) {
2205                                 CARP_SCUNLOCK(sc);
2206                                 carp_send_ad_all();
2207                                 CARP_SCLOCK(sc);
2208                         }
2209                 }
2210                 sc->sc_suppress = 1;
2211         } else {
2212                 SC2IFP(sc)->if_flags |= sc->sc_flags_backup;
2213                 carp_set_state(sc, INIT);
2214                 carp_setrun(sc, 0);
2215                 if (sc->sc_suppress)
2216                         carp_suppress_preempt--;
2217                 sc->sc_suppress = 0;
2218         }
2219
2220         return;
2221 }
2222
2223 static int
2224 carp_modevent(module_t mod, int type, void *data)
2225 {
2226         switch (type) {
2227         case MOD_LOAD:
2228                 if_detach_event_tag = EVENTHANDLER_REGISTER(ifnet_departure_event,
2229                     carp_ifdetach, NULL, EVENTHANDLER_PRI_ANY);
2230                 if (if_detach_event_tag == NULL)
2231                         return (ENOMEM);
2232                 mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
2233                 LIST_INIT(&carpif_list);
2234                 if_clone_attach(&carp_cloner);
2235                 break;
2236
2237         case MOD_UNLOAD:
2238                 EVENTHANDLER_DEREGISTER(ifnet_departure_event, if_detach_event_tag);
2239                 if_clone_detach(&carp_cloner);
2240                 mtx_destroy(&carp_mtx);
2241                 break;
2242
2243         default:
2244                 return (EINVAL);
2245         }
2246
2247         return (0);
2248 }
2249
2250 static moduledata_t carp_mod = {
2251         "carp",
2252         carp_modevent,
2253         0
2254 };
2255
2256 DECLARE_MODULE(carp, carp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);