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