sys/netinet/ip_carp.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2002 Michael Shalayeff.
   5  * Copyright (c) 2003 Ryan McBride.
   6  * Copyright (c) 2011 Gleb Smirnoff <glebius@FreeBSD.org>
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
  22  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  24  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  28  * THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include "opt_bpf.h"
  35 #include "opt_inet.h"
  36 #include "opt_inet6.h"
  37
  38 #include <sys/param.h>
  39 #include <sys/systm.h>
  40 #include <sys/devctl.h>
  41 #include <sys/jail.h>
  42 #include <sys/kernel.h>
  43 #include <sys/limits.h>
  44 #include <sys/malloc.h>
  45 #include <sys/mbuf.h>
  46 #include <sys/module.h>
  47 #include <sys/priv.h>
  48 #include <sys/proc.h>
  49 #include <sys/protosw.h>
  50 #include <sys/socket.h>
  51 #include <sys/sockio.h>
  52 #include <sys/sysctl.h>
  53 #include <sys/syslog.h>
  54 #include <sys/taskqueue.h>
  55 #include <sys/counter.h>
  56
  57 #include <net/ethernet.h>
  58 #include <net/if.h>
  59 #include <net/if_var.h>
  60 #include <net/if_dl.h>
  61 #include <net/if_llatbl.h>
  62 #include <net/if_types.h>
  63 #include <net/route.h>
  64 #include <net/vnet.h>
  65
  66 #if defined(INET) || defined(INET6)
  67 #include <netinet/in.h>
  68 #include <netinet/in_var.h>
  69 #include <netinet/ip_carp.h>
  70 #include <netinet/ip.h>
  71 #include <machine/in_cksum.h>
  72 #endif
  73 #ifdef INET
  74 #include <netinet/ip_var.h>
  75 #include <netinet/if_ether.h>
  76 #endif
  77
  78 #ifdef INET6
  79 #include <netinet/icmp6.h>
  80 #include <netinet/ip6.h>
  81 #include <netinet6/in6_var.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
  89 static MALLOC_DEFINE(M_CARP, "CARP", "CARP addresses");
  90
  91 struct carp_softc {
  92         struct ifnet            *sc_carpdev;    /* Pointer to parent ifnet. */
  93         struct ifaddr           **sc_ifas;      /* Our ifaddrs. */
  94         struct sockaddr_dl      sc_addr;        /* Our link level address. */
  95         struct callout          sc_ad_tmo;      /* Advertising timeout. */
  96 #ifdef INET
  97         struct callout          sc_md_tmo;      /* Master down timeout. */
  98 #endif
  99 #ifdef INET6
 100         struct callout          sc_md6_tmo;     /* XXX: Master down timeout. */
 101 #endif
 102         struct mtx              sc_mtx;
 103
 104         int                     sc_vhid;
 105         int                     sc_advskew;
 106         int                     sc_advbase;
 107
 108         int                     sc_naddrs;
 109         int                     sc_naddrs6;
 110         int                     sc_ifasiz;
 111         enum { INIT = 0, BACKUP, MASTER }       sc_state;
 112         int                     sc_suppress;
 113         int                     sc_sendad_errors;
 114 #define CARP_SENDAD_MAX_ERRORS  3
 115         int                     sc_sendad_success;
 116 #define CARP_SENDAD_MIN_SUCCESS 3
 117
 118         int                     sc_init_counter;
 119         uint64_t                sc_counter;
 120
 121         /* authentication */
 122 #define CARP_HMAC_PAD   64
 123         unsigned char sc_key[CARP_KEY_LEN];
 124         unsigned char sc_pad[CARP_HMAC_PAD];
 125         SHA1_CTX sc_sha1;
 126
 127         TAILQ_ENTRY(carp_softc) sc_list;        /* On the carp_if list. */
 128         LIST_ENTRY(carp_softc)  sc_next;        /* On the global list. */
 129 };
 130
 131 struct carp_if {
 132 #ifdef INET
 133         int     cif_naddrs;
 134 #endif
 135 #ifdef INET6
 136         int     cif_naddrs6;
 137 #endif
 138         TAILQ_HEAD(, carp_softc) cif_vrs;
 139 #ifdef INET
 140         struct ip_moptions       cif_imo;
 141 #endif
 142 #ifdef INET6
 143         struct ip6_moptions      cif_im6o;
 144 #endif
 145         struct ifnet    *cif_ifp;
 146         struct mtx      cif_mtx;
 147         uint32_t        cif_flags;
 148 #define CIF_PROMISC     0x00000001
 149 };
 150
 151 #define CARP_INET       0
 152 #define CARP_INET6      1
 153 static int proto_reg[] = {-1, -1};
 154
 155 /*
 156  * Brief design of carp(4).
 157  *
 158  * Any carp-capable ifnet may have a list of carp softcs hanging off
 159  * its ifp->if_carp pointer. Each softc represents one unique virtual
 160  * host id, or vhid. The softc has a back pointer to the ifnet. All
 161  * softcs are joined in a global list, which has quite limited use.
 162  *
 163  * Any interface address that takes part in CARP negotiation has a
 164  * pointer to the softc of its vhid, ifa->ifa_carp. That could be either
 165  * AF_INET or AF_INET6 address.
 166  *
 167  * Although, one can get the softc's backpointer to ifnet and traverse
 168  * through its ifp->if_addrhead queue to find all interface addresses
 169  * involved in CARP, we keep a growable array of ifaddr pointers. This
 170  * allows us to avoid grabbing the IF_ADDR_LOCK() in many traversals that
 171  * do calls into the network stack, thus avoiding LORs.
 172  *
 173  * Locking:
 174  *
 175  * Each softc has a lock sc_mtx. It is used to synchronise carp_input_c(),
 176  * callout-driven events and ioctl()s.
 177  *
 178  * To traverse the list of softcs on an ifnet we use CIF_LOCK() or carp_sx.
 179  * To traverse the global list we use the mutex carp_mtx.
 180  *
 181  * Known issues with locking:
 182  *
 183  * - Sending ad, we put the pointer to the softc in an mtag, and no reference
 184  *   counting is done on the softc.
 185  * - On module unload we may race (?) with packet processing thread
 186  *   dereferencing our function pointers.
 187  */
 188
 189 /* Accept incoming CARP packets. */
 190 VNET_DEFINE_STATIC(int, carp_allow) = 1;
 191 #define V_carp_allow    VNET(carp_allow)
 192
 193 /* Set DSCP in outgoing CARP packets. */
 194 VNET_DEFINE_STATIC(int, carp_dscp) = 56;
 195 #define V_carp_dscp     VNET(carp_dscp)
 196
 197 /* Preempt slower nodes. */
 198 VNET_DEFINE_STATIC(int, carp_preempt) = 0;
 199 #define V_carp_preempt  VNET(carp_preempt)
 200
 201 /* Log level. */
 202 VNET_DEFINE_STATIC(int, carp_log) = 1;
 203 #define V_carp_log      VNET(carp_log)
 204
 205 /* Global advskew demotion. */
 206 VNET_DEFINE_STATIC(int, carp_demotion) = 0;
 207 #define V_carp_demotion VNET(carp_demotion)
 208
 209 /* Send error demotion factor. */
 210 VNET_DEFINE_STATIC(int, carp_senderr_adj) = CARP_MAXSKEW;
 211 #define V_carp_senderr_adj      VNET(carp_senderr_adj)
 212
 213 /* Iface down demotion factor. */
 214 VNET_DEFINE_STATIC(int, carp_ifdown_adj) = CARP_MAXSKEW;
 215 #define V_carp_ifdown_adj       VNET(carp_ifdown_adj)
 216
 217 static int carp_allow_sysctl(SYSCTL_HANDLER_ARGS);
 218 static int carp_dscp_sysctl(SYSCTL_HANDLER_ARGS);
 219 static int carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS);
 220
 221 SYSCTL_NODE(_net_inet, IPPROTO_CARP, carp, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
 222     "CARP");
 223 SYSCTL_PROC(_net_inet_carp, OID_AUTO, allow,
 224     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
 225     0, 0, carp_allow_sysctl, "I",
 226     "Accept incoming CARP packets");
 227 SYSCTL_PROC(_net_inet_carp, OID_AUTO, dscp,
 228     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
 229     0, 0, carp_dscp_sysctl, "I",
 230     "DSCP value for carp packets");
 231 SYSCTL_INT(_net_inet_carp, OID_AUTO, preempt, CTLFLAG_VNET | CTLFLAG_RW,
 232     &VNET_NAME(carp_preempt), 0, "High-priority backup preemption mode");
 233 SYSCTL_INT(_net_inet_carp, OID_AUTO, log, CTLFLAG_VNET | CTLFLAG_RW,
 234     &VNET_NAME(carp_log), 0, "CARP log level");
 235 SYSCTL_PROC(_net_inet_carp, OID_AUTO, demotion,
 236     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
 237     0, 0, carp_demote_adj_sysctl, "I",
 238     "Adjust demotion factor (skew of advskew)");
 239 SYSCTL_INT(_net_inet_carp, OID_AUTO, senderr_demotion_factor,
 240     CTLFLAG_VNET | CTLFLAG_RW,
 241     &VNET_NAME(carp_senderr_adj), 0, "Send error demotion factor adjustment");
 242 SYSCTL_INT(_net_inet_carp, OID_AUTO, ifdown_demotion_factor,
 243     CTLFLAG_VNET | CTLFLAG_RW,
 244     &VNET_NAME(carp_ifdown_adj), 0,
 245     "Interface down demotion factor adjustment");
 246
 247 VNET_PCPUSTAT_DEFINE(struct carpstats, carpstats);
 248 VNET_PCPUSTAT_SYSINIT(carpstats);
 249 VNET_PCPUSTAT_SYSUNINIT(carpstats);
 250
 251 #define CARPSTATS_ADD(name, val)        \
 252     counter_u64_add(VNET(carpstats)[offsetof(struct carpstats, name) / \
 253         sizeof(uint64_t)], (val))
 254 #define CARPSTATS_INC(name)             CARPSTATS_ADD(name, 1)
 255
 256 SYSCTL_VNET_PCPUSTAT(_net_inet_carp, OID_AUTO, stats, struct carpstats,
 257     carpstats, "CARP statistics (struct carpstats, netinet/ip_carp.h)");
 258
 259 #define CARP_LOCK_INIT(sc)      mtx_init(&(sc)->sc_mtx, "carp_softc",   \
 260         NULL, MTX_DEF)
 261 #define CARP_LOCK_DESTROY(sc)   mtx_destroy(&(sc)->sc_mtx)
 262 #define CARP_LOCK_ASSERT(sc)    mtx_assert(&(sc)->sc_mtx, MA_OWNED)
 263 #define CARP_LOCK(sc)           mtx_lock(&(sc)->sc_mtx)
 264 #define CARP_UNLOCK(sc)         mtx_unlock(&(sc)->sc_mtx)
 265 #define CIF_LOCK_INIT(cif)      mtx_init(&(cif)->cif_mtx, "carp_if",   \
 266         NULL, MTX_DEF)
 267 #define CIF_LOCK_DESTROY(cif)   mtx_destroy(&(cif)->cif_mtx)
 268 #define CIF_LOCK_ASSERT(cif)    mtx_assert(&(cif)->cif_mtx, MA_OWNED)
 269 #define CIF_LOCK(cif)           mtx_lock(&(cif)->cif_mtx)
 270 #define CIF_UNLOCK(cif)         mtx_unlock(&(cif)->cif_mtx)
 271 #define CIF_FREE(cif)   do {                            \
 272                 CIF_LOCK(cif);                          \
 273                 if (TAILQ_EMPTY(&(cif)->cif_vrs))       \
 274                         carp_free_if(cif);              \
 275                 else                                    \
 276                         CIF_UNLOCK(cif);                \
 277 } while (0)
 278
 279 #define CARP_LOG(...)   do {                            \
 280         if (V_carp_log > 0)                             \
 281                 log(LOG_INFO, "carp: " __VA_ARGS__);    \
 282 } while (0)
 283
 284 #define CARP_DEBUG(...) do {                            \
 285         if (V_carp_log > 1)                             \
 286                 log(LOG_DEBUG, __VA_ARGS__);            \
 287 } while (0)
 288
 289 #define IFNET_FOREACH_IFA(ifp, ifa)                                     \
 290         CK_STAILQ_FOREACH((ifa), &(ifp)->if_addrhead, ifa_link) \
 291                 if ((ifa)->ifa_carp != NULL)
 292
 293 #define CARP_FOREACH_IFA(sc, ifa)                                       \
 294         CARP_LOCK_ASSERT(sc);                                           \
 295         for (int _i = 0;                                                \
 296                 _i < (sc)->sc_naddrs + (sc)->sc_naddrs6 &&              \
 297                 ((ifa) = sc->sc_ifas[_i]) != NULL;                      \
 298                 ++_i)
 299
 300 #define IFNET_FOREACH_CARP(ifp, sc)                                     \
 301         KASSERT(mtx_owned(&ifp->if_carp->cif_mtx) ||                    \
 302             sx_xlocked(&carp_sx), ("cif_vrs not locked"));              \
 303         TAILQ_FOREACH((sc), &(ifp)->if_carp->cif_vrs, sc_list)
 304
 305 #define DEMOTE_ADVSKEW(sc)                                      \
 306     (((sc)->sc_advskew + V_carp_demotion > CARP_MAXSKEW) ?      \
 307     CARP_MAXSKEW : ((sc)->sc_advskew + V_carp_demotion))
 308
 309 static void     carp_input_c(struct mbuf *, struct carp_header *, sa_family_t);
 310 static struct carp_softc
 311                 *carp_alloc(struct ifnet *);
 312 static void     carp_destroy(struct carp_softc *);
 313 static struct carp_if
 314                 *carp_alloc_if(struct ifnet *);
 315 static void     carp_free_if(struct carp_if *);
 316 static void     carp_set_state(struct carp_softc *, int, const char* reason);
 317 static void     carp_sc_state(struct carp_softc *);
 318 static void     carp_setrun(struct carp_softc *, sa_family_t);
 319 static void     carp_master_down(void *);
 320 static void     carp_master_down_locked(struct carp_softc *,
 321                     const char* reason);
 322 static void     carp_send_ad(void *);
 323 static void     carp_send_ad_locked(struct carp_softc *);
 324 static void     carp_addroute(struct carp_softc *);
 325 static void     carp_ifa_addroute(struct ifaddr *);
 326 static void     carp_delroute(struct carp_softc *);
 327 static void     carp_ifa_delroute(struct ifaddr *);
 328 static void     carp_send_ad_all(void *, int);
 329 static void     carp_demote_adj(int, char *);
 330
 331 static LIST_HEAD(, carp_softc) carp_list;
 332 static struct mtx carp_mtx;
 333 static struct sx carp_sx;
 334 static struct task carp_sendall_task =
 335     TASK_INITIALIZER(0, carp_send_ad_all, NULL);
 336
 337 static void
 338 carp_hmac_prepare(struct carp_softc *sc)
 339 {
 340         uint8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
 341         uint8_t vhid = sc->sc_vhid & 0xff;
 342         struct ifaddr *ifa;
 343         int i, found;
 344 #ifdef INET
 345         struct in_addr last, cur, in;
 346 #endif
 347 #ifdef INET6
 348         struct in6_addr last6, cur6, in6;
 349 #endif
 350
 351         CARP_LOCK_ASSERT(sc);
 352
 353         /* Compute ipad from key. */
 354         bzero(sc->sc_pad, sizeof(sc->sc_pad));
 355         bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
 356         for (i = 0; i < sizeof(sc->sc_pad); i++)
 357                 sc->sc_pad[i] ^= 0x36;
 358
 359         /* Precompute first part of inner hash. */
 360         SHA1Init(&sc->sc_sha1);
 361         SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
 362         SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
 363         SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
 364         SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
 365 #ifdef INET
 366         cur.s_addr = 0;
 367         do {
 368                 found = 0;
 369                 last = cur;
 370                 cur.s_addr = 0xffffffff;
 371                 CARP_FOREACH_IFA(sc, ifa) {
 372                         in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
 373                         if (ifa->ifa_addr->sa_family == AF_INET &&
 374                             ntohl(in.s_addr) > ntohl(last.s_addr) &&
 375                             ntohl(in.s_addr) < ntohl(cur.s_addr)) {
 376                                 cur.s_addr = in.s_addr;
 377                                 found++;
 378                         }
 379                 }
 380                 if (found)
 381                         SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
 382         } while (found);
 383 #endif /* INET */
 384 #ifdef INET6
 385         memset(&cur6, 0, sizeof(cur6));
 386         do {
 387                 found = 0;
 388                 last6 = cur6;
 389                 memset(&cur6, 0xff, sizeof(cur6));
 390                 CARP_FOREACH_IFA(sc, ifa) {
 391                         in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
 392                         if (IN6_IS_SCOPE_EMBED(&in6))
 393                                 in6.s6_addr16[1] = 0;
 394                         if (ifa->ifa_addr->sa_family == AF_INET6 &&
 395                             memcmp(&in6, &last6, sizeof(in6)) > 0 &&
 396                             memcmp(&in6, &cur6, sizeof(in6)) < 0) {
 397                                 cur6 = in6;
 398                                 found++;
 399                         }
 400                 }
 401                 if (found)
 402                         SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
 403         } while (found);
 404 #endif /* INET6 */
 405
 406         /* convert ipad to opad */
 407         for (i = 0; i < sizeof(sc->sc_pad); i++)
 408                 sc->sc_pad[i] ^= 0x36 ^ 0x5c;
 409 }
 410
 411 static void
 412 carp_hmac_generate(struct carp_softc *sc, uint32_t counter[2],
 413     unsigned char md[20])
 414 {
 415         SHA1_CTX sha1ctx;
 416
 417         CARP_LOCK_ASSERT(sc);
 418
 419         /* fetch first half of inner hash */
 420         bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
 421
 422         SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
 423         SHA1Final(md, &sha1ctx);
 424
 425         /* outer hash */
 426         SHA1Init(&sha1ctx);
 427         SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
 428         SHA1Update(&sha1ctx, md, 20);
 429         SHA1Final(md, &sha1ctx);
 430 }
 431
 432 static int
 433 carp_hmac_verify(struct carp_softc *sc, uint32_t counter[2],
 434     unsigned char md[20])
 435 {
 436         unsigned char md2[20];
 437
 438         CARP_LOCK_ASSERT(sc);
 439
 440         carp_hmac_generate(sc, counter, md2);
 441
 442         return (bcmp(md, md2, sizeof(md2)));
 443 }
 444
 445 /*
 446  * process input packet.
 447  * we have rearranged checks order compared to the rfc,
 448  * but it seems more efficient this way or not possible otherwise.
 449  */
 450 #ifdef INET
 451 int
 452 carp_input(struct mbuf **mp, int *offp, int proto)
 453 {
 454         struct mbuf *m = *mp;
 455         struct ip *ip = mtod(m, struct ip *);
 456         struct carp_header *ch;
 457         int iplen, len;
 458
 459         iplen = *offp;
 460         *mp = NULL;
 461
 462         CARPSTATS_INC(carps_ipackets);
 463
 464         if (!V_carp_allow) {
 465                 m_freem(m);
 466                 return (IPPROTO_DONE);
 467         }
 468
 469         /* verify that the IP TTL is 255.  */
 470         if (ip->ip_ttl != CARP_DFLTTL) {
 471                 CARPSTATS_INC(carps_badttl);
 472                 CARP_DEBUG("%s: received ttl %d != 255 on %s\n", __func__,
 473                     ip->ip_ttl,
 474                     m->m_pkthdr.rcvif->if_xname);
 475                 m_freem(m);
 476                 return (IPPROTO_DONE);
 477         }
 478
 479         iplen = ip->ip_hl << 2;
 480
 481         if (m->m_pkthdr.len < iplen + sizeof(*ch)) {
 482                 CARPSTATS_INC(carps_badlen);
 483                 CARP_DEBUG("%s: received len %zd < sizeof(struct carp_header) "
 484                     "on %s\n", __func__, m->m_len - sizeof(struct ip),
 485                     m->m_pkthdr.rcvif->if_xname);
 486                 m_freem(m);
 487                 return (IPPROTO_DONE);
 488         }
 489
 490         if (iplen + sizeof(*ch) < m->m_len) {
 491                 if ((m = m_pullup(m, iplen + sizeof(*ch))) == NULL) {
 492                         CARPSTATS_INC(carps_hdrops);
 493                         CARP_DEBUG("%s: pullup failed\n", __func__);
 494                         return (IPPROTO_DONE);
 495                 }
 496                 ip = mtod(m, struct ip *);
 497         }
 498         ch = (struct carp_header *)((char *)ip + iplen);
 499
 500         /*
 501          * verify that the received packet length is
 502          * equal to the CARP header
 503          */
 504         len = iplen + sizeof(*ch);
 505         if (len > m->m_pkthdr.len) {
 506                 CARPSTATS_INC(carps_badlen);
 507                 CARP_DEBUG("%s: packet too short %d on %s\n", __func__,
 508                     m->m_pkthdr.len,
 509                     m->m_pkthdr.rcvif->if_xname);
 510                 m_freem(m);
 511                 return (IPPROTO_DONE);
 512         }
 513
 514         if ((m = m_pullup(m, len)) == NULL) {
 515                 CARPSTATS_INC(carps_hdrops);
 516                 return (IPPROTO_DONE);
 517         }
 518         ip = mtod(m, struct ip *);
 519         ch = (struct carp_header *)((char *)ip + iplen);
 520
 521         /* verify the CARP checksum */
 522         m->m_data += iplen;
 523         if (in_cksum(m, len - iplen)) {
 524                 CARPSTATS_INC(carps_badsum);
 525                 CARP_DEBUG("%s: checksum failed on %s\n", __func__,
 526                     m->m_pkthdr.rcvif->if_xname);
 527                 m_freem(m);
 528                 return (IPPROTO_DONE);
 529         }
 530         m->m_data -= iplen;
 531
 532         carp_input_c(m, ch, AF_INET);
 533         return (IPPROTO_DONE);
 534 }
 535 #endif
 536
 537 #ifdef INET6
 538 int
 539 carp6_input(struct mbuf **mp, int *offp, int proto)
 540 {
 541         struct mbuf *m = *mp;
 542         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 543         struct carp_header *ch;
 544         u_int len;
 545
 546         CARPSTATS_INC(carps_ipackets6);
 547
 548         if (!V_carp_allow) {
 549                 m_freem(m);
 550                 return (IPPROTO_DONE);
 551         }
 552
 553         /* check if received on a valid carp interface */
 554         if (m->m_pkthdr.rcvif->if_carp == NULL) {
 555                 CARPSTATS_INC(carps_badif);
 556                 CARP_DEBUG("%s: packet received on non-carp interface: %s\n",
 557                     __func__, m->m_pkthdr.rcvif->if_xname);
 558                 m_freem(m);
 559                 return (IPPROTO_DONE);
 560         }
 561
 562         /* verify that the IP TTL is 255 */
 563         if (ip6->ip6_hlim != CARP_DFLTTL) {
 564                 CARPSTATS_INC(carps_badttl);
 565                 CARP_DEBUG("%s: received ttl %d != 255 on %s\n", __func__,
 566                     ip6->ip6_hlim, m->m_pkthdr.rcvif->if_xname);
 567                 m_freem(m);
 568                 return (IPPROTO_DONE);
 569         }
 570
 571         /* verify that we have a complete carp packet */
 572         if (m->m_len < *offp + sizeof(*ch)) {
 573                 len = m->m_len;
 574                 m = m_pullup(m, *offp + sizeof(*ch));
 575                 if (m == NULL) {
 576                         CARPSTATS_INC(carps_badlen);
 577                         CARP_DEBUG("%s: packet size %u too small\n", __func__, len);
 578                         return (IPPROTO_DONE);
 579                 }
 580         }
 581         ch = (struct carp_header *)(mtod(m, char *) + *offp);
 582
 583         /* verify the CARP checksum */
 584         m->m_data += *offp;
 585         if (in_cksum(m, sizeof(*ch))) {
 586                 CARPSTATS_INC(carps_badsum);
 587                 CARP_DEBUG("%s: checksum failed, on %s\n", __func__,
 588                     m->m_pkthdr.rcvif->if_xname);
 589                 m_freem(m);
 590                 return (IPPROTO_DONE);
 591         }
 592         m->m_data -= *offp;
 593
 594         carp_input_c(m, ch, AF_INET6);
 595         return (IPPROTO_DONE);
 596 }
 597 #endif /* INET6 */
 598
 599 /*
 600  * This routine should not be necessary at all, but some switches
 601  * (VMWare ESX vswitches) can echo our own packets back at us,
 602  * and we must ignore them or they will cause us to drop out of
 603  * MASTER mode.
 604  *
 605  * We cannot catch all cases of network loops.  Instead, what we
 606  * do here is catch any packet that arrives with a carp header
 607  * with a VHID of 0, that comes from an address that is our own.
 608  * These packets are by definition "from us" (even if they are from
 609  * a misconfigured host that is pretending to be us).
 610  *
 611  * The VHID test is outside this mini-function.
 612  */
 613 static int
 614 carp_source_is_self(struct mbuf *m, struct ifaddr *ifa, sa_family_t af)
 615 {
 616 #ifdef INET
 617         struct ip *ip4;
 618         struct in_addr in4;
 619 #endif
 620 #ifdef INET6
 621         struct ip6_hdr *ip6;
 622         struct in6_addr in6;
 623 #endif
 624
 625         switch (af) {
 626 #ifdef INET
 627         case AF_INET:
 628                 ip4 = mtod(m, struct ip *);
 629                 in4 = ifatoia(ifa)->ia_addr.sin_addr;
 630                 return (in4.s_addr == ip4->ip_src.s_addr);
 631 #endif
 632 #ifdef INET6
 633         case AF_INET6:
 634                 ip6 = mtod(m, struct ip6_hdr *);
 635                 in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
 636                 return (memcmp(&in6, &ip6->ip6_src, sizeof(in6)) == 0);
 637 #endif
 638         default:
 639                 break;
 640         }
 641         return (0);
 642 }
 643
 644 static void
 645 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
 646 {
 647         struct ifnet *ifp = m->m_pkthdr.rcvif;
 648         struct ifaddr *ifa, *match;
 649         struct carp_softc *sc;
 650         uint64_t tmp_counter;
 651         struct timeval sc_tv, ch_tv;
 652         int error;
 653
 654         NET_EPOCH_ASSERT();
 655
 656         /*
 657          * Verify that the VHID is valid on the receiving interface.
 658          *
 659          * There should be just one match.  If there are none
 660          * the VHID is not valid and we drop the packet.  If
 661          * there are multiple VHID matches, take just the first
 662          * one, for compatibility with previous code.  While we're
 663          * scanning, check for obvious loops in the network topology
 664          * (these should never happen, and as noted above, we may
 665          * miss real loops; this is just a double-check).
 666          */
 667         error = 0;
 668         match = NULL;
 669         IFNET_FOREACH_IFA(ifp, ifa) {
 670                 if (match == NULL && ifa->ifa_carp != NULL &&
 671                     ifa->ifa_addr->sa_family == af &&
 672                     ifa->ifa_carp->sc_vhid == ch->carp_vhid)
 673                         match = ifa;
 674                 if (ch->carp_vhid == 0 && carp_source_is_self(m, ifa, af))
 675                         error = ELOOP;
 676         }
 677         ifa = error ? NULL : match;
 678         if (ifa != NULL)
 679                 ifa_ref(ifa);
 680
 681         if (ifa == NULL) {
 682                 if (error == ELOOP) {
 683                         CARP_DEBUG("dropping looped packet on interface %s\n",
 684                             ifp->if_xname);
 685                         CARPSTATS_INC(carps_badif);     /* ??? */
 686                 } else {
 687                         CARPSTATS_INC(carps_badvhid);
 688                 }
 689                 m_freem(m);
 690                 return;
 691         }
 692
 693         /* verify the CARP version. */
 694         if (ch->carp_version != CARP_VERSION) {
 695                 CARPSTATS_INC(carps_badver);
 696                 CARP_DEBUG("%s: invalid version %d\n", ifp->if_xname,
 697                     ch->carp_version);
 698                 ifa_free(ifa);
 699                 m_freem(m);
 700                 return;
 701         }
 702
 703         sc = ifa->ifa_carp;
 704         CARP_LOCK(sc);
 705         ifa_free(ifa);
 706
 707         if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
 708                 CARPSTATS_INC(carps_badauth);
 709                 CARP_DEBUG("%s: incorrect hash for VHID %u@%s\n", __func__,
 710                     sc->sc_vhid, ifp->if_xname);
 711                 goto out;
 712         }
 713
 714         tmp_counter = ntohl(ch->carp_counter[0]);
 715         tmp_counter = tmp_counter<<32;
 716         tmp_counter += ntohl(ch->carp_counter[1]);
 717
 718         /* XXX Replay protection goes here */
 719
 720         sc->sc_init_counter = 0;
 721         sc->sc_counter = tmp_counter;
 722
 723         sc_tv.tv_sec = sc->sc_advbase;
 724         sc_tv.tv_usec = DEMOTE_ADVSKEW(sc) * 1000000 / 256;
 725         ch_tv.tv_sec = ch->carp_advbase;
 726         ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
 727
 728         switch (sc->sc_state) {
 729         case INIT:
 730                 break;
 731         case MASTER:
 732                 /*
 733                  * If we receive an advertisement from a master who's going to
 734                  * be more frequent than us, go into BACKUP state.
 735                  */
 736                 if (timevalcmp(&sc_tv, &ch_tv, >) ||
 737                     timevalcmp(&sc_tv, &ch_tv, ==)) {
 738                         callout_stop(&sc->sc_ad_tmo);
 739                         carp_set_state(sc, BACKUP,
 740                             "more frequent advertisement received");
 741                         carp_setrun(sc, 0);
 742                         carp_delroute(sc);
 743                 }
 744                 break;
 745         case BACKUP:
 746                 /*
 747                  * If we're pre-empting masters who advertise slower than us,
 748                  * and this one claims to be slower, treat him as down.
 749                  */
 750                 if (V_carp_preempt && timevalcmp(&sc_tv, &ch_tv, <)) {
 751                         carp_master_down_locked(sc,
 752                             "preempting a slower master");
 753                         break;
 754                 }
 755
 756                 /*
 757                  *  If the master is going to advertise at such a low frequency
 758                  *  that he's guaranteed to time out, we'd might as well just
 759                  *  treat him as timed out now.
 760                  */
 761                 sc_tv.tv_sec = sc->sc_advbase * 3;
 762                 if (timevalcmp(&sc_tv, &ch_tv, <)) {
 763                         carp_master_down_locked(sc, "master will time out");
 764                         break;
 765                 }
 766
 767                 /*
 768                  * Otherwise, we reset the counter and wait for the next
 769                  * advertisement.
 770                  */
 771                 carp_setrun(sc, af);
 772                 break;
 773         }
 774
 775 out:
 776         CARP_UNLOCK(sc);
 777         m_freem(m);
 778 }
 779
 780 static int
 781 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
 782 {
 783         struct m_tag *mtag;
 784
 785         if (sc->sc_init_counter) {
 786                 /* this could also be seconds since unix epoch */
 787                 sc->sc_counter = arc4random();
 788                 sc->sc_counter = sc->sc_counter << 32;
 789                 sc->sc_counter += arc4random();
 790         } else
 791                 sc->sc_counter++;
 792
 793         ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
 794         ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
 795
 796         carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
 797
 798         /* Tag packet for carp_output */
 799         if ((mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct carp_softc *),
 800             M_NOWAIT)) == NULL) {
 801                 m_freem(m);
 802                 CARPSTATS_INC(carps_onomem);
 803                 return (ENOMEM);
 804         }
 805         bcopy(&sc, mtag + 1, sizeof(sc));
 806         m_tag_prepend(m, mtag);
 807
 808         return (0);
 809 }
 810
 811 /*
 812  * To avoid LORs and possible recursions this function shouldn't
 813  * be called directly, but scheduled via taskqueue.
 814  */
 815 static void
 816 carp_send_ad_all(void *ctx __unused, int pending __unused)
 817 {
 818         struct carp_softc *sc;
 819         struct epoch_tracker et;
 820
 821         NET_EPOCH_ENTER(et);
 822         mtx_lock(&carp_mtx);
 823         LIST_FOREACH(sc, &carp_list, sc_next)
 824                 if (sc->sc_state == MASTER) {
 825                         CARP_LOCK(sc);
 826                         CURVNET_SET(sc->sc_carpdev->if_vnet);
 827                         carp_send_ad_locked(sc);
 828                         CURVNET_RESTORE();
 829                         CARP_UNLOCK(sc);
 830                 }
 831         mtx_unlock(&carp_mtx);
 832         NET_EPOCH_EXIT(et);
 833 }
 834
 835 /* Send a periodic advertisement, executed in callout context. */
 836 static void
 837 carp_send_ad(void *v)
 838 {
 839         struct carp_softc *sc = v;
 840         struct epoch_tracker et;
 841
 842         NET_EPOCH_ENTER(et);
 843         CARP_LOCK_ASSERT(sc);
 844         CURVNET_SET(sc->sc_carpdev->if_vnet);
 845         carp_send_ad_locked(sc);
 846         CURVNET_RESTORE();
 847         CARP_UNLOCK(sc);
 848         NET_EPOCH_EXIT(et);
 849 }
 850
 851 static void
 852 carp_send_ad_error(struct carp_softc *sc, int error)
 853 {
 854
 855         if (error) {
 856                 if (sc->sc_sendad_errors < INT_MAX)
 857                         sc->sc_sendad_errors++;
 858                 if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
 859                         static const char fmt[] = "send error %d on %s";
 860                         char msg[sizeof(fmt) + IFNAMSIZ];
 861
 862                         sprintf(msg, fmt, error, sc->sc_carpdev->if_xname);
 863                         carp_demote_adj(V_carp_senderr_adj, msg);
 864                 }
 865                 sc->sc_sendad_success = 0;
 866         } else {
 867                 if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS &&
 868                     ++sc->sc_sendad_success >= CARP_SENDAD_MIN_SUCCESS) {
 869                         static const char fmt[] = "send ok on %s";
 870                         char msg[sizeof(fmt) + IFNAMSIZ];
 871
 872                         sprintf(msg, fmt, sc->sc_carpdev->if_xname);
 873                         carp_demote_adj(-V_carp_senderr_adj, msg);
 874                         sc->sc_sendad_errors = 0;
 875                 } else
 876                         sc->sc_sendad_errors = 0;
 877         }
 878 }
 879
 880 /*
 881  * Pick the best ifaddr on the given ifp for sending CARP
 882  * advertisements.
 883  *
 884  * "Best" here is defined by ifa_preferred().  This function is much
 885  * much like ifaof_ifpforaddr() except that we just use ifa_preferred().
 886  *
 887  * (This could be simplified to return the actual address, except that
 888  * it has a different format in AF_INET and AF_INET6.)
 889  */
 890 static struct ifaddr *
 891 carp_best_ifa(int af, struct ifnet *ifp)
 892 {
 893         struct ifaddr *ifa, *best;
 894
 895         NET_EPOCH_ASSERT();
 896
 897         if (af >= AF_MAX)
 898                 return (NULL);
 899         best = NULL;
 900         CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 901                 if (ifa->ifa_addr->sa_family == af &&
 902                     (best == NULL || ifa_preferred(best, ifa)))
 903                         best = ifa;
 904         }
 905         if (best != NULL)
 906                 ifa_ref(best);
 907         return (best);
 908 }
 909
 910 static void
 911 carp_send_ad_locked(struct carp_softc *sc)
 912 {
 913         struct carp_header ch;
 914         struct timeval tv;
 915         struct ifaddr *ifa;
 916         struct carp_header *ch_ptr;
 917         struct mbuf *m;
 918         int len, advskew;
 919
 920         NET_EPOCH_ASSERT();
 921         CARP_LOCK_ASSERT(sc);
 922
 923         advskew = DEMOTE_ADVSKEW(sc);
 924         tv.tv_sec = sc->sc_advbase;
 925         tv.tv_usec = advskew * 1000000 / 256;
 926
 927         ch.carp_version = CARP_VERSION;
 928         ch.carp_type = CARP_ADVERTISEMENT;
 929         ch.carp_vhid = sc->sc_vhid;
 930         ch.carp_advbase = sc->sc_advbase;
 931         ch.carp_advskew = advskew;
 932         ch.carp_authlen = 7;    /* XXX DEFINE */
 933         ch.carp_pad1 = 0;       /* must be zero */
 934         ch.carp_cksum = 0;
 935
 936         /* XXXGL: OpenBSD picks first ifaddr with needed family. */
 937
 938 #ifdef INET
 939         if (sc->sc_naddrs) {
 940                 struct ip *ip;
 941
 942                 m = m_gethdr(M_NOWAIT, MT_DATA);
 943                 if (m == NULL) {
 944                         CARPSTATS_INC(carps_onomem);
 945                         goto resched;
 946                 }
 947                 len = sizeof(*ip) + sizeof(ch);
 948                 m->m_pkthdr.len = len;
 949                 m->m_pkthdr.rcvif = NULL;
 950                 m->m_len = len;
 951                 M_ALIGN(m, m->m_len);
 952                 m->m_flags |= M_MCAST;
 953                 ip = mtod(m, struct ip *);
 954                 ip->ip_v = IPVERSION;
 955                 ip->ip_hl = sizeof(*ip) >> 2;
 956                 ip->ip_tos = V_carp_dscp << IPTOS_DSCP_OFFSET;
 957                 ip->ip_len = htons(len);
 958                 ip->ip_off = htons(IP_DF);
 959                 ip->ip_ttl = CARP_DFLTTL;
 960                 ip->ip_p = IPPROTO_CARP;
 961                 ip->ip_sum = 0;
 962                 ip_fillid(ip);
 963
 964                 ifa = carp_best_ifa(AF_INET, sc->sc_carpdev);
 965                 if (ifa != NULL) {
 966                         ip->ip_src.s_addr =
 967                             ifatoia(ifa)->ia_addr.sin_addr.s_addr;
 968                         ifa_free(ifa);
 969                 } else
 970                         ip->ip_src.s_addr = 0;
 971                 ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
 972
 973                 ch_ptr = (struct carp_header *)(&ip[1]);
 974                 bcopy(&ch, ch_ptr, sizeof(ch));
 975                 if (carp_prepare_ad(m, sc, ch_ptr))
 976                         goto resched;
 977
 978                 m->m_data += sizeof(*ip);
 979                 ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip));
 980                 m->m_data -= sizeof(*ip);
 981
 982                 CARPSTATS_INC(carps_opackets);
 983
 984                 carp_send_ad_error(sc, ip_output(m, NULL, NULL, IP_RAWOUTPUT,
 985                     &sc->sc_carpdev->if_carp->cif_imo, NULL));
 986         }
 987 #endif /* INET */
 988 #ifdef INET6
 989         if (sc->sc_naddrs6) {
 990                 struct ip6_hdr *ip6;
 991
 992                 m = m_gethdr(M_NOWAIT, MT_DATA);
 993                 if (m == NULL) {
 994                         CARPSTATS_INC(carps_onomem);
 995                         goto resched;
 996                 }
 997                 len = sizeof(*ip6) + sizeof(ch);
 998                 m->m_pkthdr.len = len;
 999                 m->m_pkthdr.rcvif = NULL;
1000                 m->m_len = len;
1001                 M_ALIGN(m, m->m_len);
1002                 m->m_flags |= M_MCAST;
1003                 ip6 = mtod(m, struct ip6_hdr *);
1004                 bzero(ip6, sizeof(*ip6));
1005                 ip6->ip6_vfc |= IPV6_VERSION;
1006                 /* Traffic class isn't defined in ip6 struct instead
1007                  * it gets offset into flowid field */
1008                 ip6->ip6_flow |= htonl(V_carp_dscp << (IPV6_FLOWLABEL_LEN +
1009                     IPTOS_DSCP_OFFSET));
1010                 ip6->ip6_hlim = CARP_DFLTTL;
1011                 ip6->ip6_nxt = IPPROTO_CARP;
1012
1013                 /* set the source address */
1014                 ifa = carp_best_ifa(AF_INET6, sc->sc_carpdev);
1015                 if (ifa != NULL) {
1016                         bcopy(IFA_IN6(ifa), &ip6->ip6_src,
1017                             sizeof(struct in6_addr));
1018                         ifa_free(ifa);
1019                 } else
1020                         /* This should never happen with IPv6. */
1021                         bzero(&ip6->ip6_src, sizeof(struct in6_addr));
1022
1023                 /* Set the multicast destination. */
1024                 ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
1025                 ip6->ip6_dst.s6_addr8[15] = 0x12;
1026                 if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1027                         m_freem(m);
1028                         CARP_DEBUG("%s: in6_setscope failed\n", __func__);
1029                         goto resched;
1030                 }
1031
1032                 ch_ptr = (struct carp_header *)(&ip6[1]);
1033                 bcopy(&ch, ch_ptr, sizeof(ch));
1034                 if (carp_prepare_ad(m, sc, ch_ptr))
1035                         goto resched;
1036
1037                 m->m_data += sizeof(*ip6);
1038                 ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip6));
1039                 m->m_data -= sizeof(*ip6);
1040
1041                 CARPSTATS_INC(carps_opackets6);
1042
1043                 carp_send_ad_error(sc, ip6_output(m, NULL, NULL, 0,
1044                     &sc->sc_carpdev->if_carp->cif_im6o, NULL, NULL));
1045         }
1046 #endif /* INET6 */
1047
1048 resched:
1049         callout_reset(&sc->sc_ad_tmo, tvtohz(&tv), carp_send_ad, sc);
1050 }
1051
1052 static void
1053 carp_addroute(struct carp_softc *sc)
1054 {
1055         struct ifaddr *ifa;
1056
1057         CARP_FOREACH_IFA(sc, ifa)
1058                 carp_ifa_addroute(ifa);
1059 }
1060
1061 static void
1062 carp_ifa_addroute(struct ifaddr *ifa)
1063 {
1064
1065         switch (ifa->ifa_addr->sa_family) {
1066 #ifdef INET
1067         case AF_INET:
1068                 in_addprefix(ifatoia(ifa), RTF_UP);
1069                 ifa_add_loopback_route(ifa,
1070                     (struct sockaddr *)&ifatoia(ifa)->ia_addr);
1071                 break;
1072 #endif
1073 #ifdef INET6
1074         case AF_INET6:
1075                 ifa_add_loopback_route(ifa,
1076                     (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
1077                 nd6_add_ifa_lle(ifatoia6(ifa));
1078                 break;
1079 #endif
1080         }
1081 }
1082
1083 static void
1084 carp_delroute(struct carp_softc *sc)
1085 {
1086         struct ifaddr *ifa;
1087
1088         CARP_FOREACH_IFA(sc, ifa)
1089                 carp_ifa_delroute(ifa);
1090 }
1091
1092 static void
1093 carp_ifa_delroute(struct ifaddr *ifa)
1094 {
1095
1096         switch (ifa->ifa_addr->sa_family) {
1097 #ifdef INET
1098         case AF_INET:
1099                 ifa_del_loopback_route(ifa,
1100                     (struct sockaddr *)&ifatoia(ifa)->ia_addr);
1101                 in_scrubprefix(ifatoia(ifa), LLE_STATIC);
1102                 break;
1103 #endif
1104 #ifdef INET6
1105         case AF_INET6:
1106                 ifa_del_loopback_route(ifa,
1107                     (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
1108                 nd6_rem_ifa_lle(ifatoia6(ifa), 1);
1109                 break;
1110 #endif
1111         }
1112 }
1113
1114 int
1115 carp_master(struct ifaddr *ifa)
1116 {
1117         struct carp_softc *sc = ifa->ifa_carp;
1118
1119         return (sc->sc_state == MASTER);
1120 }
1121
1122 #ifdef INET
1123 /*
1124  * Broadcast a gratuitous ARP request containing
1125  * the virtual router MAC address for each IP address
1126  * associated with the virtual router.
1127  */
1128 static void
1129 carp_send_arp(struct carp_softc *sc)
1130 {
1131         struct ifaddr *ifa;
1132         struct in_addr addr;
1133
1134         NET_EPOCH_ASSERT();
1135
1136         CARP_FOREACH_IFA(sc, ifa) {
1137                 if (ifa->ifa_addr->sa_family != AF_INET)
1138                         continue;
1139                 addr = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
1140                 arp_announce_ifaddr(sc->sc_carpdev, addr, LLADDR(&sc->sc_addr));
1141         }
1142 }
1143
1144 int
1145 carp_iamatch(struct ifaddr *ifa, uint8_t **enaddr)
1146 {
1147         struct carp_softc *sc = ifa->ifa_carp;
1148
1149         if (sc->sc_state == MASTER) {
1150                 *enaddr = LLADDR(&sc->sc_addr);
1151                 return (1);
1152         }
1153
1154         return (0);
1155 }
1156 #endif
1157
1158 #ifdef INET6
1159 static void
1160 carp_send_na(struct carp_softc *sc)
1161 {
1162         static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1163         struct ifaddr *ifa;
1164         struct in6_addr *in6;
1165
1166         CARP_FOREACH_IFA(sc, ifa) {
1167                 if (ifa->ifa_addr->sa_family != AF_INET6)
1168                         continue;
1169
1170                 in6 = IFA_IN6(ifa);
1171                 nd6_na_output(sc->sc_carpdev, &mcast, in6,
1172                     ND_NA_FLAG_OVERRIDE, 1, NULL);
1173                 DELAY(1000);    /* XXX */
1174         }
1175 }
1176
1177 /*
1178  * Returns ifa in case it's a carp address and it is MASTER, or if the address
1179  * matches and is not a carp address.  Returns NULL otherwise.
1180  */
1181 struct ifaddr *
1182 carp_iamatch6(struct ifnet *ifp, struct in6_addr *taddr)
1183 {
1184         struct ifaddr *ifa;
1185
1186         NET_EPOCH_ASSERT();
1187
1188         ifa = NULL;
1189         CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1190                 if (ifa->ifa_addr->sa_family != AF_INET6)
1191                         continue;
1192                 if (!IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa)))
1193                         continue;
1194                 if (ifa->ifa_carp && ifa->ifa_carp->sc_state != MASTER)
1195                         ifa = NULL;
1196                 else
1197                         ifa_ref(ifa);
1198                 break;
1199         }
1200
1201         return (ifa);
1202 }
1203
1204 char *
1205 carp_macmatch6(struct ifnet *ifp, struct mbuf *m, const struct in6_addr *taddr)
1206 {
1207         struct ifaddr *ifa;
1208
1209         NET_EPOCH_ASSERT();
1210
1211         IFNET_FOREACH_IFA(ifp, ifa)
1212                 if (ifa->ifa_addr->sa_family == AF_INET6 &&
1213                     IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa))) {
1214                         struct carp_softc *sc = ifa->ifa_carp;
1215                         struct m_tag *mtag;
1216
1217                         mtag = m_tag_get(PACKET_TAG_CARP,
1218                             sizeof(struct carp_softc *), M_NOWAIT);
1219                         if (mtag == NULL)
1220                                 /* Better a bit than nothing. */
1221                                 return (LLADDR(&sc->sc_addr));
1222
1223                         bcopy(&sc, mtag + 1, sizeof(sc));
1224                         m_tag_prepend(m, mtag);
1225
1226                         return (LLADDR(&sc->sc_addr));
1227                 }
1228
1229         return (NULL);
1230 }
1231 #endif /* INET6 */
1232
1233 int
1234 carp_forus(struct ifnet *ifp, u_char *dhost)
1235 {
1236         struct carp_softc *sc;
1237         uint8_t *ena = dhost;
1238
1239         if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1240                 return (0);
1241
1242         CIF_LOCK(ifp->if_carp);
1243         IFNET_FOREACH_CARP(ifp, sc) {
1244                 /*
1245                  * CARP_LOCK() is not here, since would protect nothing, but
1246                  * cause deadlock with if_bridge, calling this under its lock.
1247                  */
1248                 if (sc->sc_state == MASTER && !bcmp(dhost, LLADDR(&sc->sc_addr),
1249                     ETHER_ADDR_LEN)) {
1250                         CIF_UNLOCK(ifp->if_carp);
1251                         return (1);
1252                 }
1253         }
1254         CIF_UNLOCK(ifp->if_carp);
1255
1256         return (0);
1257 }
1258
1259 /* Master down timeout event, executed in callout context. */
1260 static void
1261 carp_master_down(void *v)
1262 {
1263         struct carp_softc *sc = v;
1264         struct epoch_tracker et;
1265
1266         NET_EPOCH_ENTER(et);
1267         CARP_LOCK_ASSERT(sc);
1268
1269         CURVNET_SET(sc->sc_carpdev->if_vnet);
1270         if (sc->sc_state == BACKUP) {
1271                 carp_master_down_locked(sc, "master timed out");
1272         }
1273         CURVNET_RESTORE();
1274
1275         CARP_UNLOCK(sc);
1276         NET_EPOCH_EXIT(et);
1277 }
1278
1279 static void
1280 carp_master_down_locked(struct carp_softc *sc, const char *reason)
1281 {
1282
1283         NET_EPOCH_ASSERT();
1284         CARP_LOCK_ASSERT(sc);
1285
1286         switch (sc->sc_state) {
1287         case BACKUP:
1288                 carp_set_state(sc, MASTER, reason);
1289                 carp_send_ad_locked(sc);
1290 #ifdef INET
1291                 carp_send_arp(sc);
1292 #endif
1293 #ifdef INET6
1294                 carp_send_na(sc);
1295 #endif
1296                 carp_setrun(sc, 0);
1297                 carp_addroute(sc);
1298                 break;
1299         case INIT:
1300         case MASTER:
1301 #ifdef INVARIANTS
1302                 panic("carp: VHID %u@%s: master_down event in %s state\n",
1303                     sc->sc_vhid,
1304                     sc->sc_carpdev->if_xname,
1305                     sc->sc_state ? "MASTER" : "INIT");
1306 #endif
1307                 break;
1308         }
1309 }
1310
1311 /*
1312  * When in backup state, af indicates whether to reset the master down timer
1313  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1314  */
1315 static void
1316 carp_setrun(struct carp_softc *sc, sa_family_t af)
1317 {
1318         struct timeval tv;
1319
1320         CARP_LOCK_ASSERT(sc);
1321
1322         if ((sc->sc_carpdev->if_flags & IFF_UP) == 0 ||
1323             sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
1324             (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) ||
1325             !V_carp_allow)
1326                 return;
1327
1328         switch (sc->sc_state) {
1329         case INIT:
1330                 carp_set_state(sc, BACKUP, "initialization complete");
1331                 carp_setrun(sc, 0);
1332                 break;
1333         case BACKUP:
1334                 callout_stop(&sc->sc_ad_tmo);
1335                 tv.tv_sec = 3 * sc->sc_advbase;
1336                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1337                 switch (af) {
1338 #ifdef INET
1339                 case AF_INET:
1340                         callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1341                             carp_master_down, sc);
1342                         break;
1343 #endif
1344 #ifdef INET6
1345                 case AF_INET6:
1346                         callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1347                             carp_master_down, sc);
1348                         break;
1349 #endif
1350                 default:
1351 #ifdef INET
1352                         if (sc->sc_naddrs)
1353                                 callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1354                                     carp_master_down, sc);
1355 #endif
1356 #ifdef INET6
1357                         if (sc->sc_naddrs6)
1358                                 callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1359                                     carp_master_down, sc);
1360 #endif
1361                         break;
1362                 }
1363                 break;
1364         case MASTER:
1365                 tv.tv_sec = sc->sc_advbase;
1366                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1367                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1368                     carp_send_ad, sc);
1369                 break;
1370         }
1371 }
1372
1373 /*
1374  * Setup multicast structures.
1375  */
1376 static int
1377 carp_multicast_setup(struct carp_if *cif, sa_family_t sa)
1378 {
1379         struct ifnet *ifp = cif->cif_ifp;
1380         int error = 0;
1381
1382         switch (sa) {
1383 #ifdef INET
1384         case AF_INET:
1385             {
1386                 struct ip_moptions *imo = &cif->cif_imo;
1387                 struct in_mfilter *imf;
1388                 struct in_addr addr;
1389
1390                 if (ip_mfilter_first(&imo->imo_head) != NULL)
1391                         return (0);
1392
1393                 imf = ip_mfilter_alloc(M_WAITOK, 0, 0);
1394                 ip_mfilter_init(&imo->imo_head);
1395                 imo->imo_multicast_vif = -1;
1396
1397                 addr.s_addr = htonl(INADDR_CARP_GROUP);
1398                 if ((error = in_joingroup(ifp, &addr, NULL,
1399                     &imf->imf_inm)) != 0) {
1400                         ip_mfilter_free(imf);
1401                         break;
1402                 }
1403
1404                 ip_mfilter_insert(&imo->imo_head, imf);
1405                 imo->imo_multicast_ifp = ifp;
1406                 imo->imo_multicast_ttl = CARP_DFLTTL;
1407                 imo->imo_multicast_loop = 0;
1408                 break;
1409            }
1410 #endif
1411 #ifdef INET6
1412         case AF_INET6:
1413             {
1414                 struct ip6_moptions *im6o = &cif->cif_im6o;
1415                 struct in6_mfilter *im6f[2];
1416                 struct in6_addr in6;
1417
1418                 if (ip6_mfilter_first(&im6o->im6o_head))
1419                         return (0);
1420
1421                 im6f[0] = ip6_mfilter_alloc(M_WAITOK, 0, 0);
1422                 im6f[1] = ip6_mfilter_alloc(M_WAITOK, 0, 0);
1423
1424                 ip6_mfilter_init(&im6o->im6o_head);
1425                 im6o->im6o_multicast_hlim = CARP_DFLTTL;
1426                 im6o->im6o_multicast_ifp = ifp;
1427
1428                 /* Join IPv6 CARP multicast group. */
1429                 bzero(&in6, sizeof(in6));
1430                 in6.s6_addr16[0] = htons(0xff02);
1431                 in6.s6_addr8[15] = 0x12;
1432                 if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
1433                         ip6_mfilter_free(im6f[0]);
1434                         ip6_mfilter_free(im6f[1]);
1435                         break;
1436                 }
1437                 if ((error = in6_joingroup(ifp, &in6, NULL, &im6f[0]->im6f_in6m, 0)) != 0) {
1438                         ip6_mfilter_free(im6f[0]);
1439                         ip6_mfilter_free(im6f[1]);
1440                         break;
1441                 }
1442
1443                 /* Join solicited multicast address. */
1444                 bzero(&in6, sizeof(in6));
1445                 in6.s6_addr16[0] = htons(0xff02);
1446                 in6.s6_addr32[1] = 0;
1447                 in6.s6_addr32[2] = htonl(1);
1448                 in6.s6_addr32[3] = 0;
1449                 in6.s6_addr8[12] = 0xff;
1450
1451                 if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
1452                         ip6_mfilter_free(im6f[0]);
1453                         ip6_mfilter_free(im6f[1]);
1454                         break;
1455                 }
1456
1457                 if ((error = in6_joingroup(ifp, &in6, NULL, &im6f[1]->im6f_in6m, 0)) != 0) {
1458                         in6_leavegroup(im6f[0]->im6f_in6m, NULL);
1459                         ip6_mfilter_free(im6f[0]);
1460                         ip6_mfilter_free(im6f[1]);
1461                         break;
1462                 }
1463                 ip6_mfilter_insert(&im6o->im6o_head, im6f[0]);
1464                 ip6_mfilter_insert(&im6o->im6o_head, im6f[1]);
1465                 break;
1466             }
1467 #endif
1468         }
1469
1470         return (error);
1471 }
1472
1473 /*
1474  * Free multicast structures.
1475  */
1476 static void
1477 carp_multicast_cleanup(struct carp_if *cif, sa_family_t sa)
1478 {
1479 #ifdef INET
1480         struct ip_moptions *imo = &cif->cif_imo;
1481         struct in_mfilter *imf;
1482 #endif
1483 #ifdef INET6
1484         struct ip6_moptions *im6o = &cif->cif_im6o;
1485         struct in6_mfilter *im6f;
1486 #endif
1487         sx_assert(&carp_sx, SA_XLOCKED);
1488
1489         switch (sa) {
1490 #ifdef INET
1491         case AF_INET:
1492                 if (cif->cif_naddrs != 0)
1493                         break;
1494
1495                 while ((imf = ip_mfilter_first(&imo->imo_head)) != NULL) {
1496                         ip_mfilter_remove(&imo->imo_head, imf);
1497                         in_leavegroup(imf->imf_inm, NULL);
1498                         ip_mfilter_free(imf);
1499                 }
1500                 break;
1501 #endif
1502 #ifdef INET6
1503         case AF_INET6:
1504                 if (cif->cif_naddrs6 != 0)
1505                         break;
1506
1507                 while ((im6f = ip6_mfilter_first(&im6o->im6o_head)) != NULL) {
1508                         ip6_mfilter_remove(&im6o->im6o_head, im6f);
1509                         in6_leavegroup(im6f->im6f_in6m, NULL);
1510                         ip6_mfilter_free(im6f);
1511                 }
1512                 break;
1513 #endif
1514         }
1515 }
1516
1517 int
1518 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa)
1519 {
1520         struct m_tag *mtag;
1521         struct carp_softc *sc;
1522
1523         if (!sa)
1524                 return (0);
1525
1526         switch (sa->sa_family) {
1527 #ifdef INET
1528         case AF_INET:
1529                 break;
1530 #endif
1531 #ifdef INET6
1532         case AF_INET6:
1533                 break;
1534 #endif
1535         default:
1536                 return (0);
1537         }
1538
1539         mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
1540         if (mtag == NULL)
1541                 return (0);
1542
1543         bcopy(mtag + 1, &sc, sizeof(sc));
1544
1545         /* Set the source MAC address to the Virtual Router MAC Address. */
1546         switch (ifp->if_type) {
1547         case IFT_ETHER:
1548         case IFT_BRIDGE:
1549         case IFT_L2VLAN: {
1550                         struct ether_header *eh;
1551
1552                         eh = mtod(m, struct ether_header *);
1553                         eh->ether_shost[0] = 0;
1554                         eh->ether_shost[1] = 0;
1555                         eh->ether_shost[2] = 0x5e;
1556                         eh->ether_shost[3] = 0;
1557                         eh->ether_shost[4] = 1;
1558                         eh->ether_shost[5] = sc->sc_vhid;
1559                 }
1560                 break;
1561         default:
1562                 printf("%s: carp is not supported for the %d interface type\n",
1563                     ifp->if_xname, ifp->if_type);
1564                 return (EOPNOTSUPP);
1565         }
1566
1567         return (0);
1568 }
1569
1570 static struct carp_softc*
1571 carp_alloc(struct ifnet *ifp)
1572 {
1573         struct carp_softc *sc;
1574         struct carp_if *cif;
1575
1576         sx_assert(&carp_sx, SA_XLOCKED);
1577
1578         if ((cif = ifp->if_carp) == NULL)
1579                 cif = carp_alloc_if(ifp);
1580
1581         sc = malloc(sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
1582
1583         sc->sc_advbase = CARP_DFLTINTV;
1584         sc->sc_vhid = -1;       /* required setting */
1585         sc->sc_init_counter = 1;
1586         sc->sc_state = INIT;
1587
1588         sc->sc_ifasiz = sizeof(struct ifaddr *);
1589         sc->sc_ifas = malloc(sc->sc_ifasiz, M_CARP, M_WAITOK|M_ZERO);
1590         sc->sc_carpdev = ifp;
1591
1592         CARP_LOCK_INIT(sc);
1593 #ifdef INET
1594         callout_init_mtx(&sc->sc_md_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1595 #endif
1596 #ifdef INET6
1597         callout_init_mtx(&sc->sc_md6_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1598 #endif
1599         callout_init_mtx(&sc->sc_ad_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1600
1601         CIF_LOCK(cif);
1602         TAILQ_INSERT_TAIL(&cif->cif_vrs, sc, sc_list);
1603         CIF_UNLOCK(cif);
1604
1605         mtx_lock(&carp_mtx);
1606         LIST_INSERT_HEAD(&carp_list, sc, sc_next);
1607         mtx_unlock(&carp_mtx);
1608
1609         return (sc);
1610 }
1611
1612 static void
1613 carp_grow_ifas(struct carp_softc *sc)
1614 {
1615         struct ifaddr **new;
1616
1617         new = malloc(sc->sc_ifasiz * 2, M_CARP, M_WAITOK | M_ZERO);
1618         CARP_LOCK(sc);
1619         bcopy(sc->sc_ifas, new, sc->sc_ifasiz);
1620         free(sc->sc_ifas, M_CARP);
1621         sc->sc_ifas = new;
1622         sc->sc_ifasiz *= 2;
1623         CARP_UNLOCK(sc);
1624 }
1625
1626 static void
1627 carp_destroy(struct carp_softc *sc)
1628 {
1629         struct ifnet *ifp = sc->sc_carpdev;
1630         struct carp_if *cif = ifp->if_carp;
1631
1632         sx_assert(&carp_sx, SA_XLOCKED);
1633
1634         if (sc->sc_suppress)
1635                 carp_demote_adj(-V_carp_ifdown_adj, "vhid removed");
1636         CARP_UNLOCK(sc);
1637
1638         CIF_LOCK(cif);
1639         TAILQ_REMOVE(&cif->cif_vrs, sc, sc_list);
1640         CIF_UNLOCK(cif);
1641
1642         mtx_lock(&carp_mtx);
1643         LIST_REMOVE(sc, sc_next);
1644         mtx_unlock(&carp_mtx);
1645
1646         callout_drain(&sc->sc_ad_tmo);
1647 #ifdef INET
1648         callout_drain(&sc->sc_md_tmo);
1649 #endif
1650 #ifdef INET6
1651         callout_drain(&sc->sc_md6_tmo);
1652 #endif
1653         CARP_LOCK_DESTROY(sc);
1654
1655         free(sc->sc_ifas, M_CARP);
1656         free(sc, M_CARP);
1657 }
1658
1659 static struct carp_if*
1660 carp_alloc_if(struct ifnet *ifp)
1661 {
1662         struct carp_if *cif;
1663         int error;
1664
1665         cif = malloc(sizeof(*cif), M_CARP, M_WAITOK|M_ZERO);
1666
1667         if ((error = ifpromisc(ifp, 1)) != 0)
1668                 printf("%s: ifpromisc(%s) failed: %d\n",
1669                     __func__, ifp->if_xname, error);
1670         else
1671                 cif->cif_flags |= CIF_PROMISC;
1672
1673         CIF_LOCK_INIT(cif);
1674         cif->cif_ifp = ifp;
1675         TAILQ_INIT(&cif->cif_vrs);
1676
1677         IF_ADDR_WLOCK(ifp);
1678         ifp->if_carp = cif;
1679         if_ref(ifp);
1680         IF_ADDR_WUNLOCK(ifp);
1681
1682         return (cif);
1683 }
1684
1685 static void
1686 carp_free_if(struct carp_if *cif)
1687 {
1688         struct ifnet *ifp = cif->cif_ifp;
1689
1690         CIF_LOCK_ASSERT(cif);
1691         KASSERT(TAILQ_EMPTY(&cif->cif_vrs), ("%s: softc list not empty",
1692             __func__));
1693
1694         IF_ADDR_WLOCK(ifp);
1695         ifp->if_carp = NULL;
1696         IF_ADDR_WUNLOCK(ifp);
1697
1698         CIF_LOCK_DESTROY(cif);
1699
1700         if (cif->cif_flags & CIF_PROMISC)
1701                 ifpromisc(ifp, 0);
1702         if_rele(ifp);
1703
1704         free(cif, M_CARP);
1705 }
1706
1707 static void
1708 carp_carprcp(struct carpreq *carpr, struct carp_softc *sc, int priv)
1709 {
1710
1711         CARP_LOCK(sc);
1712         carpr->carpr_state = sc->sc_state;
1713         carpr->carpr_vhid = sc->sc_vhid;
1714         carpr->carpr_advbase = sc->sc_advbase;
1715         carpr->carpr_advskew = sc->sc_advskew;
1716         if (priv)
1717                 bcopy(sc->sc_key, carpr->carpr_key, sizeof(carpr->carpr_key));
1718         else
1719                 bzero(carpr->carpr_key, sizeof(carpr->carpr_key));
1720         CARP_UNLOCK(sc);
1721 }
1722
1723 int
1724 carp_ioctl(struct ifreq *ifr, u_long cmd, struct thread *td)
1725 {
1726         struct carpreq carpr;
1727         struct ifnet *ifp;
1728         struct carp_softc *sc = NULL;
1729         int error = 0, locked = 0;
1730
1731         if ((error = copyin(ifr_data_get_ptr(ifr), &carpr, sizeof carpr)))
1732                 return (error);
1733
1734         ifp = ifunit_ref(ifr->ifr_name);
1735         if (ifp == NULL)
1736                 return (ENXIO);
1737
1738         switch (ifp->if_type) {
1739         case IFT_ETHER:
1740         case IFT_L2VLAN:
1741         case IFT_BRIDGE:
1742                 break;
1743         default:
1744                 error = EOPNOTSUPP;
1745                 goto out;
1746         }
1747
1748         if ((ifp->if_flags & IFF_MULTICAST) == 0) {
1749                 error = EADDRNOTAVAIL;
1750                 goto out;
1751         }
1752
1753         sx_xlock(&carp_sx);
1754         switch (cmd) {
1755         case SIOCSVH:
1756                 if ((error = priv_check(td, PRIV_NETINET_CARP)))
1757                         break;
1758                 if (carpr.carpr_vhid <= 0 || carpr.carpr_vhid > CARP_MAXVHID ||
1759                     carpr.carpr_advbase < 0 || carpr.carpr_advskew < 0) {
1760                         error = EINVAL;
1761                         break;
1762                 }
1763
1764                 if (ifp->if_carp) {
1765                         IFNET_FOREACH_CARP(ifp, sc)
1766                                 if (sc->sc_vhid == carpr.carpr_vhid)
1767                                         break;
1768                 }
1769                 if (sc == NULL) {
1770                         sc = carp_alloc(ifp);
1771                         CARP_LOCK(sc);
1772                         sc->sc_vhid = carpr.carpr_vhid;
1773                         LLADDR(&sc->sc_addr)[0] = 0;
1774                         LLADDR(&sc->sc_addr)[1] = 0;
1775                         LLADDR(&sc->sc_addr)[2] = 0x5e;
1776                         LLADDR(&sc->sc_addr)[3] = 0;
1777                         LLADDR(&sc->sc_addr)[4] = 1;
1778                         LLADDR(&sc->sc_addr)[5] = sc->sc_vhid;
1779                 } else
1780                         CARP_LOCK(sc);
1781                 locked = 1;
1782                 if (carpr.carpr_advbase > 0) {
1783                         if (carpr.carpr_advbase > 255 ||
1784                             carpr.carpr_advbase < CARP_DFLTINTV) {
1785                                 error = EINVAL;
1786                                 break;
1787                         }
1788                         sc->sc_advbase = carpr.carpr_advbase;
1789                 }
1790                 if (carpr.carpr_advskew >= 255) {
1791                         error = EINVAL;
1792                         break;
1793                 }
1794                 sc->sc_advskew = carpr.carpr_advskew;
1795                 if (carpr.carpr_key[0] != '\0') {
1796                         bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1797                         carp_hmac_prepare(sc);
1798                 }
1799                 if (sc->sc_state != INIT &&
1800                     carpr.carpr_state != sc->sc_state) {
1801                         switch (carpr.carpr_state) {
1802                         case BACKUP:
1803                                 callout_stop(&sc->sc_ad_tmo);
1804                                 carp_set_state(sc, BACKUP,
1805                                     "user requested via ifconfig");
1806                                 carp_setrun(sc, 0);
1807                                 carp_delroute(sc);
1808                                 break;
1809                         case MASTER:
1810                                 carp_master_down_locked(sc,
1811                                     "user requested via ifconfig");
1812                                 break;
1813                         default:
1814                                 break;
1815                         }
1816                 }
1817                 break;
1818
1819         case SIOCGVH:
1820             {
1821                 int priveleged;
1822
1823                 if (carpr.carpr_vhid < 0 || carpr.carpr_vhid > CARP_MAXVHID) {
1824                         error = EINVAL;
1825                         break;
1826                 }
1827                 if (carpr.carpr_count < 1) {
1828                         error = EMSGSIZE;
1829                         break;
1830                 }
1831                 if (ifp->if_carp == NULL) {
1832                         error = ENOENT;
1833                         break;
1834                 }
1835
1836                 priveleged = (priv_check(td, PRIV_NETINET_CARP) == 0);
1837                 if (carpr.carpr_vhid != 0) {
1838                         IFNET_FOREACH_CARP(ifp, sc)
1839                                 if (sc->sc_vhid == carpr.carpr_vhid)
1840                                         break;
1841                         if (sc == NULL) {
1842                                 error = ENOENT;
1843                                 break;
1844                         }
1845                         carp_carprcp(&carpr, sc, priveleged);
1846                         error = copyout(&carpr, ifr_data_get_ptr(ifr),
1847                             sizeof(carpr));
1848                 } else  {
1849                         int i, count;
1850
1851                         count = 0;
1852                         IFNET_FOREACH_CARP(ifp, sc)
1853                                 count++;
1854
1855                         if (count > carpr.carpr_count) {
1856                                 CIF_UNLOCK(ifp->if_carp);
1857                                 error = EMSGSIZE;
1858                                 break;
1859                         }
1860
1861                         i = 0;
1862                         IFNET_FOREACH_CARP(ifp, sc) {
1863                                 carp_carprcp(&carpr, sc, priveleged);
1864                                 carpr.carpr_count = count;
1865                                 error = copyout(&carpr,
1866                                     (char *)ifr_data_get_ptr(ifr) +
1867                                     (i * sizeof(carpr)), sizeof(carpr));
1868                                 if (error) {
1869                                         CIF_UNLOCK(ifp->if_carp);
1870                                         break;
1871                                 }
1872                                 i++;
1873                         }
1874                 }
1875                 break;
1876             }
1877         default:
1878                 error = EINVAL;
1879         }
1880         sx_xunlock(&carp_sx);
1881
1882 out:
1883         if (locked)
1884                 CARP_UNLOCK(sc);
1885         if_rele(ifp);
1886
1887         return (error);
1888 }
1889
1890 static int
1891 carp_get_vhid(struct ifaddr *ifa)
1892 {
1893
1894         if (ifa == NULL || ifa->ifa_carp == NULL)
1895                 return (0);
1896
1897         return (ifa->ifa_carp->sc_vhid);
1898 }
1899
1900 int
1901 carp_attach(struct ifaddr *ifa, int vhid)
1902 {
1903         struct ifnet *ifp = ifa->ifa_ifp;
1904         struct carp_if *cif = ifp->if_carp;
1905         struct carp_softc *sc;
1906         int index, error;
1907
1908         KASSERT(ifa->ifa_carp == NULL, ("%s: ifa %p attached", __func__, ifa));
1909
1910         switch (ifa->ifa_addr->sa_family) {
1911 #ifdef INET
1912         case AF_INET:
1913 #endif
1914 #ifdef INET6
1915         case AF_INET6:
1916 #endif
1917                 break;
1918         default:
1919                 return (EPROTOTYPE);
1920         }
1921
1922         sx_xlock(&carp_sx);
1923         if (ifp->if_carp == NULL) {
1924                 sx_xunlock(&carp_sx);
1925                 return (ENOPROTOOPT);
1926         }
1927
1928         IFNET_FOREACH_CARP(ifp, sc)
1929                 if (sc->sc_vhid == vhid)
1930                         break;
1931         if (sc == NULL) {
1932                 sx_xunlock(&carp_sx);
1933                 return (ENOENT);
1934         }
1935
1936         error = carp_multicast_setup(cif, ifa->ifa_addr->sa_family);
1937         if (error) {
1938                 CIF_FREE(cif);
1939                 sx_xunlock(&carp_sx);
1940                 return (error);
1941         }
1942
1943         index = sc->sc_naddrs + sc->sc_naddrs6 + 1;
1944         if (index > sc->sc_ifasiz / sizeof(struct ifaddr *))
1945                 carp_grow_ifas(sc);
1946
1947         switch (ifa->ifa_addr->sa_family) {
1948 #ifdef INET
1949         case AF_INET:
1950                 cif->cif_naddrs++;
1951                 sc->sc_naddrs++;
1952                 break;
1953 #endif
1954 #ifdef INET6
1955         case AF_INET6:
1956                 cif->cif_naddrs6++;
1957                 sc->sc_naddrs6++;
1958                 break;
1959 #endif
1960         }
1961
1962         ifa_ref(ifa);
1963
1964         CARP_LOCK(sc);
1965         sc->sc_ifas[index - 1] = ifa;
1966         ifa->ifa_carp = sc;
1967         carp_hmac_prepare(sc);
1968         carp_sc_state(sc);
1969         CARP_UNLOCK(sc);
1970
1971         sx_xunlock(&carp_sx);
1972
1973         return (0);
1974 }
1975
1976 void
1977 carp_detach(struct ifaddr *ifa, bool keep_cif)
1978 {
1979         struct ifnet *ifp = ifa->ifa_ifp;
1980         struct carp_if *cif = ifp->if_carp;
1981         struct carp_softc *sc = ifa->ifa_carp;
1982         int i, index;
1983
1984         KASSERT(sc != NULL, ("%s: %p not attached", __func__, ifa));
1985
1986         sx_xlock(&carp_sx);
1987
1988         CARP_LOCK(sc);
1989         /* Shift array. */
1990         index = sc->sc_naddrs + sc->sc_naddrs6;
1991         for (i = 0; i < index; i++)
1992                 if (sc->sc_ifas[i] == ifa)
1993                         break;
1994         KASSERT(i < index, ("%s: %p no backref", __func__, ifa));
1995         for (; i < index - 1; i++)
1996                 sc->sc_ifas[i] = sc->sc_ifas[i+1];
1997         sc->sc_ifas[index - 1] = NULL;
1998
1999         switch (ifa->ifa_addr->sa_family) {
2000 #ifdef INET
2001         case AF_INET:
2002                 cif->cif_naddrs--;
2003                 sc->sc_naddrs--;
2004                 break;
2005 #endif
2006 #ifdef INET6
2007         case AF_INET6:
2008                 cif->cif_naddrs6--;
2009                 sc->sc_naddrs6--;
2010                 break;
2011 #endif
2012         }
2013
2014         carp_ifa_delroute(ifa);
2015         carp_multicast_cleanup(cif, ifa->ifa_addr->sa_family);
2016
2017         ifa->ifa_carp = NULL;
2018         ifa_free(ifa);
2019
2020         carp_hmac_prepare(sc);
2021         carp_sc_state(sc);
2022
2023         if (!keep_cif && sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0)
2024                 carp_destroy(sc);
2025         else
2026                 CARP_UNLOCK(sc);
2027
2028         if (!keep_cif)
2029                 CIF_FREE(cif);
2030
2031         sx_xunlock(&carp_sx);
2032 }
2033
2034 static void
2035 carp_set_state(struct carp_softc *sc, int state, const char *reason)
2036 {
2037
2038         CARP_LOCK_ASSERT(sc);
2039
2040         if (sc->sc_state != state) {
2041                 const char *carp_states[] = { CARP_STATES };
2042                 char subsys[IFNAMSIZ+5];
2043
2044                 snprintf(subsys, IFNAMSIZ+5, "%u@%s", sc->sc_vhid,
2045                     sc->sc_carpdev->if_xname);
2046
2047                 CARP_LOG("%s: %s -> %s (%s)\n", subsys,
2048                     carp_states[sc->sc_state], carp_states[state], reason);
2049
2050                 sc->sc_state = state;
2051
2052                 devctl_notify("CARP", subsys, carp_states[state], NULL);
2053         }
2054 }
2055
2056 static void
2057 carp_linkstate(struct ifnet *ifp)
2058 {
2059         struct carp_softc *sc;
2060
2061         CIF_LOCK(ifp->if_carp);
2062         IFNET_FOREACH_CARP(ifp, sc) {
2063                 CARP_LOCK(sc);
2064                 carp_sc_state(sc);
2065                 CARP_UNLOCK(sc);
2066         }
2067         CIF_UNLOCK(ifp->if_carp);
2068 }
2069
2070 static void
2071 carp_sc_state(struct carp_softc *sc)
2072 {
2073
2074         CARP_LOCK_ASSERT(sc);
2075
2076         if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
2077             !(sc->sc_carpdev->if_flags & IFF_UP) ||
2078             !V_carp_allow) {
2079                 callout_stop(&sc->sc_ad_tmo);
2080 #ifdef INET
2081                 callout_stop(&sc->sc_md_tmo);
2082 #endif
2083 #ifdef INET6
2084                 callout_stop(&sc->sc_md6_tmo);
2085 #endif
2086                 carp_set_state(sc, INIT, "hardware interface down");
2087                 carp_setrun(sc, 0);
2088                 if (!sc->sc_suppress)
2089                         carp_demote_adj(V_carp_ifdown_adj, "interface down");
2090                 sc->sc_suppress = 1;
2091         } else {
2092                 carp_set_state(sc, INIT, "hardware interface up");
2093                 carp_setrun(sc, 0);
2094                 if (sc->sc_suppress)
2095                         carp_demote_adj(-V_carp_ifdown_adj, "interface up");
2096                 sc->sc_suppress = 0;
2097         }
2098 }
2099
2100 static void
2101 carp_demote_adj(int adj, char *reason)
2102 {
2103         atomic_add_int(&V_carp_demotion, adj);
2104         CARP_LOG("demoted by %d to %d (%s)\n", adj, V_carp_demotion, reason);
2105         taskqueue_enqueue(taskqueue_swi, &carp_sendall_task);
2106 }
2107
2108 static int
2109 carp_allow_sysctl(SYSCTL_HANDLER_ARGS)
2110 {
2111         int new, error;
2112         struct carp_softc *sc;
2113
2114         new = V_carp_allow;
2115         error = sysctl_handle_int(oidp, &new, 0, req);
2116         if (error || !req->newptr)
2117                 return (error);
2118
2119         if (V_carp_allow != new) {
2120                 V_carp_allow = new;
2121
2122                 mtx_lock(&carp_mtx);
2123                 LIST_FOREACH(sc, &carp_list, sc_next) {
2124                         CARP_LOCK(sc);
2125                         if (curvnet == sc->sc_carpdev->if_vnet)
2126                                 carp_sc_state(sc);
2127                         CARP_UNLOCK(sc);
2128                 }
2129                 mtx_unlock(&carp_mtx);
2130         }
2131
2132         return (0);
2133 }
2134
2135 static int
2136 carp_dscp_sysctl(SYSCTL_HANDLER_ARGS)
2137 {
2138         int new, error;
2139
2140         new = V_carp_dscp;
2141         error = sysctl_handle_int(oidp, &new, 0, req);
2142         if (error || !req->newptr)
2143                 return (error);
2144
2145         if (new < 0 || new > 63)
2146                 return (EINVAL);
2147
2148         V_carp_dscp = new;
2149
2150         return (0);
2151 }
2152
2153 static int
2154 carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS)
2155 {
2156         int new, error;
2157
2158         new = V_carp_demotion;
2159         error = sysctl_handle_int(oidp, &new, 0, req);
2160         if (error || !req->newptr)
2161                 return (error);
2162
2163         carp_demote_adj(new, "sysctl");
2164
2165         return (0);
2166 }
2167
2168 #ifdef INET
2169 extern  struct domain inetdomain;
2170 static struct protosw in_carp_protosw = {
2171         .pr_type =              SOCK_RAW,
2172         .pr_domain =            &inetdomain,
2173         .pr_protocol =          IPPROTO_CARP,
2174         .pr_flags =             PR_ATOMIC|PR_ADDR,
2175         .pr_input =             carp_input,
2176         .pr_output =            rip_output,
2177         .pr_ctloutput =         rip_ctloutput,
2178         .pr_usrreqs =           &rip_usrreqs
2179 };
2180 #endif
2181
2182 #ifdef INET6
2183 extern  struct domain inet6domain;
2184 static struct protosw in6_carp_protosw = {
2185         .pr_type =              SOCK_RAW,
2186         .pr_domain =            &inet6domain,
2187         .pr_protocol =          IPPROTO_CARP,
2188         .pr_flags =             PR_ATOMIC|PR_ADDR,
2189         .pr_input =             carp6_input,
2190         .pr_output =            rip6_output,
2191         .pr_ctloutput =         rip6_ctloutput,
2192         .pr_usrreqs =           &rip6_usrreqs
2193 };
2194 #endif
2195
2196 static void
2197 carp_mod_cleanup(void)
2198 {
2199
2200 #ifdef INET
2201         if (proto_reg[CARP_INET] == 0) {
2202                 (void)ipproto_unregister(IPPROTO_CARP);
2203                 pf_proto_unregister(PF_INET, IPPROTO_CARP, SOCK_RAW);
2204                 proto_reg[CARP_INET] = -1;
2205         }
2206         carp_iamatch_p = NULL;
2207 #endif
2208 #ifdef INET6
2209         if (proto_reg[CARP_INET6] == 0) {
2210                 (void)ip6proto_unregister(IPPROTO_CARP);
2211                 pf_proto_unregister(PF_INET6, IPPROTO_CARP, SOCK_RAW);
2212                 proto_reg[CARP_INET6] = -1;
2213         }
2214         carp_iamatch6_p = NULL;
2215         carp_macmatch6_p = NULL;
2216 #endif
2217         carp_ioctl_p = NULL;
2218         carp_attach_p = NULL;
2219         carp_detach_p = NULL;
2220         carp_get_vhid_p = NULL;
2221         carp_linkstate_p = NULL;
2222         carp_forus_p = NULL;
2223         carp_output_p = NULL;
2224         carp_demote_adj_p = NULL;
2225         carp_master_p = NULL;
2226         mtx_unlock(&carp_mtx);
2227         taskqueue_drain(taskqueue_swi, &carp_sendall_task);
2228         mtx_destroy(&carp_mtx);
2229         sx_destroy(&carp_sx);
2230 }
2231
2232 static int
2233 carp_mod_load(void)
2234 {
2235         int err;
2236
2237         mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
2238         sx_init(&carp_sx, "carp_sx");
2239         LIST_INIT(&carp_list);
2240         carp_get_vhid_p = carp_get_vhid;
2241         carp_forus_p = carp_forus;
2242         carp_output_p = carp_output;
2243         carp_linkstate_p = carp_linkstate;
2244         carp_ioctl_p = carp_ioctl;
2245         carp_attach_p = carp_attach;
2246         carp_detach_p = carp_detach;
2247         carp_demote_adj_p = carp_demote_adj;
2248         carp_master_p = carp_master;
2249 #ifdef INET6
2250         carp_iamatch6_p = carp_iamatch6;
2251         carp_macmatch6_p = carp_macmatch6;
2252         proto_reg[CARP_INET6] = pf_proto_register(PF_INET6,
2253             (struct protosw *)&in6_carp_protosw);
2254         if (proto_reg[CARP_INET6]) {
2255                 printf("carp: error %d attaching to PF_INET6\n",
2256                     proto_reg[CARP_INET6]);
2257                 carp_mod_cleanup();
2258                 return (proto_reg[CARP_INET6]);
2259         }
2260         err = ip6proto_register(IPPROTO_CARP);
2261         if (err) {
2262                 printf("carp: error %d registering with INET6\n", err);
2263                 carp_mod_cleanup();
2264                 return (err);
2265         }
2266 #endif
2267 #ifdef INET
2268         carp_iamatch_p = carp_iamatch;
2269         proto_reg[CARP_INET] = pf_proto_register(PF_INET, &in_carp_protosw);
2270         if (proto_reg[CARP_INET]) {
2271                 printf("carp: error %d attaching to PF_INET\n",
2272                     proto_reg[CARP_INET]);
2273                 carp_mod_cleanup();
2274                 return (proto_reg[CARP_INET]);
2275         }
2276         err = ipproto_register(IPPROTO_CARP);
2277         if (err) {
2278                 printf("carp: error %d registering with INET\n", err);
2279                 carp_mod_cleanup();
2280                 return (err);
2281         }
2282 #endif
2283         return (0);
2284 }
2285
2286 static int
2287 carp_modevent(module_t mod, int type, void *data)
2288 {
2289         switch (type) {
2290         case MOD_LOAD:
2291                 return carp_mod_load();
2292                 /* NOTREACHED */
2293         case MOD_UNLOAD:
2294                 mtx_lock(&carp_mtx);
2295                 if (LIST_EMPTY(&carp_list))
2296                         carp_mod_cleanup();
2297                 else {
2298                         mtx_unlock(&carp_mtx);
2299                         return (EBUSY);
2300                 }
2301                 break;
2302
2303         default:
2304                 return (EINVAL);
2305         }
2306
2307         return (0);
2308 }
2309
2310 static moduledata_t carp_mod = {
2311         "carp",
2312         carp_modevent,
2313         0
2314 };
2315
2316 DECLARE_MODULE(carp, carp_mod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);