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         if (m->m_len < *offp + sizeof(*ch)) {
 570                 len = m->m_len;
 571                 m = m_pullup(m, *offp + sizeof(*ch));
 572                 if (m == NULL) {
 573                         CARPSTATS_INC(carps_badlen);
 574                         CARP_DEBUG("%s: packet size %u too small\n", __func__, len);
 575                         return (IPPROTO_DONE);
 576                 }
 577         }
 578         ch = (struct carp_header *)(mtod(m, char *) + *offp);
 579
 580
 581         /* verify the CARP checksum */
 582         m->m_data += *offp;
 583         if (in_cksum(m, sizeof(*ch))) {
 584                 CARPSTATS_INC(carps_badsum);
 585                 CARP_DEBUG("%s: checksum failed, on %s\n", __func__,
 586                     m->m_pkthdr.rcvif->if_xname);
 587                 m_freem(m);
 588                 return (IPPROTO_DONE);
 589         }
 590         m->m_data -= *offp;
 591
 592         carp_input_c(m, ch, AF_INET6);
 593         return (IPPROTO_DONE);
 594 }
 595 #endif /* INET6 */
 596
 597 /*
 598  * This routine should not be necessary at all, but some switches
 599  * (VMWare ESX vswitches) can echo our own packets back at us,
 600  * and we must ignore them or they will cause us to drop out of
 601  * MASTER mode.
 602  *
 603  * We cannot catch all cases of network loops.  Instead, what we
 604  * do here is catch any packet that arrives with a carp header
 605  * with a VHID of 0, that comes from an address that is our own.
 606  * These packets are by definition "from us" (even if they are from
 607  * a misconfigured host that is pretending to be us).
 608  *
 609  * The VHID test is outside this mini-function.
 610  */
 611 static int
 612 carp_source_is_self(struct mbuf *m, struct ifaddr *ifa, sa_family_t af)
 613 {
 614 #ifdef INET
 615         struct ip *ip4;
 616         struct in_addr in4;
 617 #endif
 618 #ifdef INET6
 619         struct ip6_hdr *ip6;
 620         struct in6_addr in6;
 621 #endif
 622
 623         switch (af) {
 624 #ifdef INET
 625         case AF_INET:
 626                 ip4 = mtod(m, struct ip *);
 627                 in4 = ifatoia(ifa)->ia_addr.sin_addr;
 628                 return (in4.s_addr == ip4->ip_src.s_addr);
 629 #endif
 630 #ifdef INET6
 631         case AF_INET6:
 632                 ip6 = mtod(m, struct ip6_hdr *);
 633                 in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
 634                 return (memcmp(&in6, &ip6->ip6_src, sizeof(in6)) == 0);
 635 #endif
 636         default:
 637                 break;
 638         }
 639         return (0);
 640 }
 641
 642 static void
 643 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
 644 {
 645         struct ifnet *ifp = m->m_pkthdr.rcvif;
 646         struct ifaddr *ifa, *match;
 647         struct carp_softc *sc;
 648         uint64_t tmp_counter;
 649         struct timeval sc_tv, ch_tv;
 650         int error;
 651
 652         NET_EPOCH_ASSERT();
 653
 654         /*
 655          * Verify that the VHID is valid on the receiving interface.
 656          *
 657          * There should be just one match.  If there are none
 658          * the VHID is not valid and we drop the packet.  If
 659          * there are multiple VHID matches, take just the first
 660          * one, for compatibility with previous code.  While we're
 661          * scanning, check for obvious loops in the network topology
 662          * (these should never happen, and as noted above, we may
 663          * miss real loops; this is just a double-check).
 664          */
 665         error = 0;
 666         match = NULL;
 667         IFNET_FOREACH_IFA(ifp, ifa) {
 668                 if (match == NULL && ifa->ifa_carp != NULL &&
 669                     ifa->ifa_addr->sa_family == af &&
 670                     ifa->ifa_carp->sc_vhid == ch->carp_vhid)
 671                         match = ifa;
 672                 if (ch->carp_vhid == 0 && carp_source_is_self(m, ifa, af))
 673                         error = ELOOP;
 674         }
 675         ifa = error ? NULL : match;
 676         if (ifa != NULL)
 677                 ifa_ref(ifa);
 678
 679         if (ifa == NULL) {
 680                 if (error == ELOOP) {
 681                         CARP_DEBUG("dropping looped packet on interface %s\n",
 682                             ifp->if_xname);
 683                         CARPSTATS_INC(carps_badif);     /* ??? */
 684                 } else {
 685                         CARPSTATS_INC(carps_badvhid);
 686                 }
 687                 m_freem(m);
 688                 return;
 689         }
 690
 691         /* verify the CARP version. */
 692         if (ch->carp_version != CARP_VERSION) {
 693                 CARPSTATS_INC(carps_badver);
 694                 CARP_DEBUG("%s: invalid version %d\n", ifp->if_xname,
 695                     ch->carp_version);
 696                 ifa_free(ifa);
 697                 m_freem(m);
 698                 return;
 699         }
 700
 701         sc = ifa->ifa_carp;
 702         CARP_LOCK(sc);
 703         ifa_free(ifa);
 704
 705         if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
 706                 CARPSTATS_INC(carps_badauth);
 707                 CARP_DEBUG("%s: incorrect hash for VHID %u@%s\n", __func__,
 708                     sc->sc_vhid, ifp->if_xname);
 709                 goto out;
 710         }
 711
 712         tmp_counter = ntohl(ch->carp_counter[0]);
 713         tmp_counter = tmp_counter<<32;
 714         tmp_counter += ntohl(ch->carp_counter[1]);
 715
 716         /* XXX Replay protection goes here */
 717
 718         sc->sc_init_counter = 0;
 719         sc->sc_counter = tmp_counter;
 720
 721         sc_tv.tv_sec = sc->sc_advbase;
 722         sc_tv.tv_usec = DEMOTE_ADVSKEW(sc) * 1000000 / 256;
 723         ch_tv.tv_sec = ch->carp_advbase;
 724         ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
 725
 726         switch (sc->sc_state) {
 727         case INIT:
 728                 break;
 729         case MASTER:
 730                 /*
 731                  * If we receive an advertisement from a master who's going to
 732                  * be more frequent than us, go into BACKUP state.
 733                  */
 734                 if (timevalcmp(&sc_tv, &ch_tv, >) ||
 735                     timevalcmp(&sc_tv, &ch_tv, ==)) {
 736                         callout_stop(&sc->sc_ad_tmo);
 737                         carp_set_state(sc, BACKUP,
 738                             "more frequent advertisement received");
 739                         carp_setrun(sc, 0);
 740                         carp_delroute(sc);
 741                 }
 742                 break;
 743         case BACKUP:
 744                 /*
 745                  * If we're pre-empting masters who advertise slower than us,
 746                  * and this one claims to be slower, treat him as down.
 747                  */
 748                 if (V_carp_preempt && timevalcmp(&sc_tv, &ch_tv, <)) {
 749                         carp_master_down_locked(sc,
 750                             "preempting a slower master");
 751                         break;
 752                 }
 753
 754                 /*
 755                  *  If the master is going to advertise at such a low frequency
 756                  *  that he's guaranteed to time out, we'd might as well just
 757                  *  treat him as timed out now.
 758                  */
 759                 sc_tv.tv_sec = sc->sc_advbase * 3;
 760                 if (timevalcmp(&sc_tv, &ch_tv, <)) {
 761                         carp_master_down_locked(sc, "master will time out");
 762                         break;
 763                 }
 764
 765                 /*
 766                  * Otherwise, we reset the counter and wait for the next
 767                  * advertisement.
 768                  */
 769                 carp_setrun(sc, af);
 770                 break;
 771         }
 772
 773 out:
 774         CARP_UNLOCK(sc);
 775         m_freem(m);
 776 }
 777
 778 static int
 779 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
 780 {
 781         struct m_tag *mtag;
 782
 783         if (sc->sc_init_counter) {
 784                 /* this could also be seconds since unix epoch */
 785                 sc->sc_counter = arc4random();
 786                 sc->sc_counter = sc->sc_counter << 32;
 787                 sc->sc_counter += arc4random();
 788         } else
 789                 sc->sc_counter++;
 790
 791         ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
 792         ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
 793
 794         carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
 795
 796         /* Tag packet for carp_output */
 797         if ((mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct carp_softc *),
 798             M_NOWAIT)) == NULL) {
 799                 m_freem(m);
 800                 CARPSTATS_INC(carps_onomem);
 801                 return (ENOMEM);
 802         }
 803         bcopy(&sc, mtag + 1, sizeof(sc));
 804         m_tag_prepend(m, mtag);
 805
 806         return (0);
 807 }
 808
 809 /*
 810  * To avoid LORs and possible recursions this function shouldn't
 811  * be called directly, but scheduled via taskqueue.
 812  */
 813 static void
 814 carp_send_ad_all(void *ctx __unused, int pending __unused)
 815 {
 816         struct carp_softc *sc;
 817
 818         mtx_lock(&carp_mtx);
 819         LIST_FOREACH(sc, &carp_list, sc_next)
 820                 if (sc->sc_state == MASTER) {
 821                         CARP_LOCK(sc);
 822                         CURVNET_SET(sc->sc_carpdev->if_vnet);
 823                         carp_send_ad_locked(sc);
 824                         CURVNET_RESTORE();
 825                         CARP_UNLOCK(sc);
 826                 }
 827         mtx_unlock(&carp_mtx);
 828 }
 829
 830 /* Send a periodic advertisement, executed in callout context. */
 831 static void
 832 carp_send_ad(void *v)
 833 {
 834         struct carp_softc *sc = v;
 835
 836         CARP_LOCK_ASSERT(sc);
 837         CURVNET_SET(sc->sc_carpdev->if_vnet);
 838         carp_send_ad_locked(sc);
 839         CURVNET_RESTORE();
 840         CARP_UNLOCK(sc);
 841 }
 842
 843 static void
 844 carp_send_ad_error(struct carp_softc *sc, int error)
 845 {
 846
 847         if (error) {
 848                 if (sc->sc_sendad_errors < INT_MAX)
 849                         sc->sc_sendad_errors++;
 850                 if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
 851                         static const char fmt[] = "send error %d on %s";
 852                         char msg[sizeof(fmt) + IFNAMSIZ];
 853
 854                         sprintf(msg, fmt, error, sc->sc_carpdev->if_xname);
 855                         carp_demote_adj(V_carp_senderr_adj, msg);
 856                 }
 857                 sc->sc_sendad_success = 0;
 858         } else {
 859                 if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS &&
 860                     ++sc->sc_sendad_success >= CARP_SENDAD_MIN_SUCCESS) {
 861                         static const char fmt[] = "send ok on %s";
 862                         char msg[sizeof(fmt) + IFNAMSIZ];
 863
 864                         sprintf(msg, fmt, sc->sc_carpdev->if_xname);
 865                         carp_demote_adj(-V_carp_senderr_adj, msg);
 866                         sc->sc_sendad_errors = 0;
 867                 } else
 868                         sc->sc_sendad_errors = 0;
 869         }
 870 }
 871
 872 /*
 873  * Pick the best ifaddr on the given ifp for sending CARP
 874  * advertisements.
 875  *
 876  * "Best" here is defined by ifa_preferred().  This function is much
 877  * much like ifaof_ifpforaddr() except that we just use ifa_preferred().
 878  *
 879  * (This could be simplified to return the actual address, except that
 880  * it has a different format in AF_INET and AF_INET6.)
 881  */
 882 static struct ifaddr *
 883 carp_best_ifa(int af, struct ifnet *ifp)
 884 {
 885         struct ifaddr *ifa, *best;
 886
 887         NET_EPOCH_ASSERT();
 888
 889         if (af >= AF_MAX)
 890                 return (NULL);
 891         best = NULL;
 892         CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 893                 if (ifa->ifa_addr->sa_family == af &&
 894                     (best == NULL || ifa_preferred(best, ifa)))
 895                         best = ifa;
 896         }
 897         if (best != NULL)
 898                 ifa_ref(best);
 899         return (best);
 900 }
 901
 902 static void
 903 carp_send_ad_locked(struct carp_softc *sc)
 904 {
 905         struct carp_header ch;
 906         struct timeval tv;
 907         struct ifaddr *ifa;
 908         struct carp_header *ch_ptr;
 909         struct mbuf *m;
 910         int len, advskew;
 911
 912         CARP_LOCK_ASSERT(sc);
 913
 914         advskew = DEMOTE_ADVSKEW(sc);
 915         tv.tv_sec = sc->sc_advbase;
 916         tv.tv_usec = advskew * 1000000 / 256;
 917
 918         ch.carp_version = CARP_VERSION;
 919         ch.carp_type = CARP_ADVERTISEMENT;
 920         ch.carp_vhid = sc->sc_vhid;
 921         ch.carp_advbase = sc->sc_advbase;
 922         ch.carp_advskew = advskew;
 923         ch.carp_authlen = 7;    /* XXX DEFINE */
 924         ch.carp_pad1 = 0;       /* must be zero */
 925         ch.carp_cksum = 0;
 926
 927         /* XXXGL: OpenBSD picks first ifaddr with needed family. */
 928
 929 #ifdef INET
 930         if (sc->sc_naddrs) {
 931                 struct ip *ip;
 932
 933                 m = m_gethdr(M_NOWAIT, MT_DATA);
 934                 if (m == NULL) {
 935                         CARPSTATS_INC(carps_onomem);
 936                         goto resched;
 937                 }
 938                 len = sizeof(*ip) + sizeof(ch);
 939                 m->m_pkthdr.len = len;
 940                 m->m_pkthdr.rcvif = NULL;
 941                 m->m_len = len;
 942                 M_ALIGN(m, m->m_len);
 943                 m->m_flags |= M_MCAST;
 944                 ip = mtod(m, struct ip *);
 945                 ip->ip_v = IPVERSION;
 946                 ip->ip_hl = sizeof(*ip) >> 2;
 947                 ip->ip_tos = V_carp_dscp << IPTOS_DSCP_OFFSET;
 948                 ip->ip_len = htons(len);
 949                 ip->ip_off = htons(IP_DF);
 950                 ip->ip_ttl = CARP_DFLTTL;
 951                 ip->ip_p = IPPROTO_CARP;
 952                 ip->ip_sum = 0;
 953                 ip_fillid(ip);
 954
 955                 ifa = carp_best_ifa(AF_INET, sc->sc_carpdev);
 956                 if (ifa != NULL) {
 957                         ip->ip_src.s_addr =
 958                             ifatoia(ifa)->ia_addr.sin_addr.s_addr;
 959                         ifa_free(ifa);
 960                 } else
 961                         ip->ip_src.s_addr = 0;
 962                 ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
 963
 964                 ch_ptr = (struct carp_header *)(&ip[1]);
 965                 bcopy(&ch, ch_ptr, sizeof(ch));
 966                 if (carp_prepare_ad(m, sc, ch_ptr))
 967                         goto resched;
 968
 969                 m->m_data += sizeof(*ip);
 970                 ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip));
 971                 m->m_data -= sizeof(*ip);
 972
 973                 CARPSTATS_INC(carps_opackets);
 974
 975                 carp_send_ad_error(sc, ip_output(m, NULL, NULL, IP_RAWOUTPUT,
 976                     &sc->sc_carpdev->if_carp->cif_imo, NULL));
 977         }
 978 #endif /* INET */
 979 #ifdef INET6
 980         if (sc->sc_naddrs6) {
 981                 struct ip6_hdr *ip6;
 982
 983                 m = m_gethdr(M_NOWAIT, MT_DATA);
 984                 if (m == NULL) {
 985                         CARPSTATS_INC(carps_onomem);
 986                         goto resched;
 987                 }
 988                 len = sizeof(*ip6) + sizeof(ch);
 989                 m->m_pkthdr.len = len;
 990                 m->m_pkthdr.rcvif = NULL;
 991                 m->m_len = len;
 992                 M_ALIGN(m, m->m_len);
 993                 m->m_flags |= M_MCAST;
 994                 ip6 = mtod(m, struct ip6_hdr *);
 995                 bzero(ip6, sizeof(*ip6));
 996                 ip6->ip6_vfc |= IPV6_VERSION;
 997                 /* Traffic class isn't defined in ip6 struct instead
 998                  * it gets offset into flowid field */
 999                 ip6->ip6_flow |= htonl(V_carp_dscp << (IPV6_FLOWLABEL_LEN +
1000                     IPTOS_DSCP_OFFSET));
1001                 ip6->ip6_hlim = CARP_DFLTTL;
1002                 ip6->ip6_nxt = IPPROTO_CARP;
1003
1004                 /* set the source address */
1005                 ifa = carp_best_ifa(AF_INET6, sc->sc_carpdev);
1006                 if (ifa != NULL) {
1007                         bcopy(IFA_IN6(ifa), &ip6->ip6_src,
1008                             sizeof(struct in6_addr));
1009                         ifa_free(ifa);
1010                 } else
1011                         /* This should never happen with IPv6. */
1012                         bzero(&ip6->ip6_src, sizeof(struct in6_addr));
1013
1014                 /* Set the multicast destination. */
1015                 ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
1016                 ip6->ip6_dst.s6_addr8[15] = 0x12;
1017                 if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1018                         m_freem(m);
1019                         CARP_DEBUG("%s: in6_setscope failed\n", __func__);
1020                         goto resched;
1021                 }
1022
1023                 ch_ptr = (struct carp_header *)(&ip6[1]);
1024                 bcopy(&ch, ch_ptr, sizeof(ch));
1025                 if (carp_prepare_ad(m, sc, ch_ptr))
1026                         goto resched;
1027
1028                 m->m_data += sizeof(*ip6);
1029                 ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip6));
1030                 m->m_data -= sizeof(*ip6);
1031
1032                 CARPSTATS_INC(carps_opackets6);
1033
1034                 carp_send_ad_error(sc, ip6_output(m, NULL, NULL, 0,
1035                     &sc->sc_carpdev->if_carp->cif_im6o, NULL, NULL));
1036         }
1037 #endif /* INET6 */
1038
1039 resched:
1040         callout_reset(&sc->sc_ad_tmo, tvtohz(&tv), carp_send_ad, sc);
1041 }
1042
1043 static void
1044 carp_addroute(struct carp_softc *sc)
1045 {
1046         struct ifaddr *ifa;
1047
1048         CARP_FOREACH_IFA(sc, ifa)
1049                 carp_ifa_addroute(ifa);
1050 }
1051
1052 static void
1053 carp_ifa_addroute(struct ifaddr *ifa)
1054 {
1055
1056         switch (ifa->ifa_addr->sa_family) {
1057 #ifdef INET
1058         case AF_INET:
1059                 in_addprefix(ifatoia(ifa), RTF_UP);
1060                 ifa_add_loopback_route(ifa,
1061                     (struct sockaddr *)&ifatoia(ifa)->ia_addr);
1062                 break;
1063 #endif
1064 #ifdef INET6
1065         case AF_INET6:
1066                 ifa_add_loopback_route(ifa,
1067                     (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
1068                 nd6_add_ifa_lle(ifatoia6(ifa));
1069                 break;
1070 #endif
1071         }
1072 }
1073
1074 static void
1075 carp_delroute(struct carp_softc *sc)
1076 {
1077         struct ifaddr *ifa;
1078
1079         CARP_FOREACH_IFA(sc, ifa)
1080                 carp_ifa_delroute(ifa);
1081 }
1082
1083 static void
1084 carp_ifa_delroute(struct ifaddr *ifa)
1085 {
1086
1087         switch (ifa->ifa_addr->sa_family) {
1088 #ifdef INET
1089         case AF_INET:
1090                 ifa_del_loopback_route(ifa,
1091                     (struct sockaddr *)&ifatoia(ifa)->ia_addr);
1092                 in_scrubprefix(ifatoia(ifa), LLE_STATIC);
1093                 break;
1094 #endif
1095 #ifdef INET6
1096         case AF_INET6:
1097                 ifa_del_loopback_route(ifa,
1098                     (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
1099                 nd6_rem_ifa_lle(ifatoia6(ifa), 1);
1100                 break;
1101 #endif
1102         }
1103 }
1104
1105 int
1106 carp_master(struct ifaddr *ifa)
1107 {
1108         struct carp_softc *sc = ifa->ifa_carp;
1109
1110         return (sc->sc_state == MASTER);
1111 }
1112
1113 #ifdef INET
1114 /*
1115  * Broadcast a gratuitous ARP request containing
1116  * the virtual router MAC address for each IP address
1117  * associated with the virtual router.
1118  */
1119 static void
1120 carp_send_arp(struct carp_softc *sc)
1121 {
1122         struct ifaddr *ifa;
1123         struct in_addr addr;
1124
1125         CARP_FOREACH_IFA(sc, ifa) {
1126                 if (ifa->ifa_addr->sa_family != AF_INET)
1127                         continue;
1128                 addr = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
1129                 arp_announce_ifaddr(sc->sc_carpdev, addr, LLADDR(&sc->sc_addr));
1130         }
1131 }
1132
1133 int
1134 carp_iamatch(struct ifaddr *ifa, uint8_t **enaddr)
1135 {
1136         struct carp_softc *sc = ifa->ifa_carp;
1137
1138         if (sc->sc_state == MASTER) {
1139                 *enaddr = LLADDR(&sc->sc_addr);
1140                 return (1);
1141         }
1142
1143         return (0);
1144 }
1145 #endif
1146
1147 #ifdef INET6
1148 static void
1149 carp_send_na(struct carp_softc *sc)
1150 {
1151         static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1152         struct ifaddr *ifa;
1153         struct in6_addr *in6;
1154
1155         CARP_FOREACH_IFA(sc, ifa) {
1156                 if (ifa->ifa_addr->sa_family != AF_INET6)
1157                         continue;
1158
1159                 in6 = IFA_IN6(ifa);
1160                 nd6_na_output(sc->sc_carpdev, &mcast, in6,
1161                     ND_NA_FLAG_OVERRIDE, 1, NULL);
1162                 DELAY(1000);    /* XXX */
1163         }
1164 }
1165
1166 /*
1167  * Returns ifa in case it's a carp address and it is MASTER, or if the address
1168  * matches and is not a carp address.  Returns NULL otherwise.
1169  */
1170 struct ifaddr *
1171 carp_iamatch6(struct ifnet *ifp, struct in6_addr *taddr)
1172 {
1173         struct ifaddr *ifa;
1174
1175         NET_EPOCH_ASSERT();
1176
1177         ifa = NULL;
1178         CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1179                 if (ifa->ifa_addr->sa_family != AF_INET6)
1180                         continue;
1181                 if (!IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa)))
1182                         continue;
1183                 if (ifa->ifa_carp && ifa->ifa_carp->sc_state != MASTER)
1184                         ifa = NULL;
1185                 else
1186                         ifa_ref(ifa);
1187                 break;
1188         }
1189
1190         return (ifa);
1191 }
1192
1193 char *
1194 carp_macmatch6(struct ifnet *ifp, struct mbuf *m, const struct in6_addr *taddr)
1195 {
1196         struct ifaddr *ifa;
1197
1198         NET_EPOCH_ASSERT();
1199
1200         IFNET_FOREACH_IFA(ifp, ifa)
1201                 if (ifa->ifa_addr->sa_family == AF_INET6 &&
1202                     IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa))) {
1203                         struct carp_softc *sc = ifa->ifa_carp;
1204                         struct m_tag *mtag;
1205
1206                         mtag = m_tag_get(PACKET_TAG_CARP,
1207                             sizeof(struct carp_softc *), M_NOWAIT);
1208                         if (mtag == NULL)
1209                                 /* Better a bit than nothing. */
1210                                 return (LLADDR(&sc->sc_addr));
1211
1212                         bcopy(&sc, mtag + 1, sizeof(sc));
1213                         m_tag_prepend(m, mtag);
1214
1215                         return (LLADDR(&sc->sc_addr));
1216                 }
1217
1218         return (NULL);
1219 }
1220 #endif /* INET6 */
1221
1222 int
1223 carp_forus(struct ifnet *ifp, u_char *dhost)
1224 {
1225         struct carp_softc *sc;
1226         uint8_t *ena = dhost;
1227
1228         if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1229                 return (0);
1230
1231         CIF_LOCK(ifp->if_carp);
1232         IFNET_FOREACH_CARP(ifp, sc) {
1233                 CARP_LOCK(sc);
1234                 if (sc->sc_state == MASTER && !bcmp(dhost, LLADDR(&sc->sc_addr),
1235                     ETHER_ADDR_LEN)) {
1236                         CARP_UNLOCK(sc);
1237                         CIF_UNLOCK(ifp->if_carp);
1238                         return (1);
1239                 }
1240                 CARP_UNLOCK(sc);
1241         }
1242         CIF_UNLOCK(ifp->if_carp);
1243
1244         return (0);
1245 }
1246
1247 /* Master down timeout event, executed in callout context. */
1248 static void
1249 carp_master_down(void *v)
1250 {
1251         struct carp_softc *sc = v;
1252
1253         CARP_LOCK_ASSERT(sc);
1254
1255         CURVNET_SET(sc->sc_carpdev->if_vnet);
1256         if (sc->sc_state == BACKUP) {
1257                 carp_master_down_locked(sc, "master timed out");
1258         }
1259         CURVNET_RESTORE();
1260
1261         CARP_UNLOCK(sc);
1262 }
1263
1264 static void
1265 carp_master_down_locked(struct carp_softc *sc, const char *reason)
1266 {
1267
1268         CARP_LOCK_ASSERT(sc);
1269
1270         switch (sc->sc_state) {
1271         case BACKUP:
1272                 carp_set_state(sc, MASTER, reason);
1273                 carp_send_ad_locked(sc);
1274 #ifdef INET
1275                 carp_send_arp(sc);
1276 #endif
1277 #ifdef INET6
1278                 carp_send_na(sc);
1279 #endif
1280                 carp_setrun(sc, 0);
1281                 carp_addroute(sc);
1282                 break;
1283         case INIT:
1284         case MASTER:
1285 #ifdef INVARIANTS
1286                 panic("carp: VHID %u@%s: master_down event in %s state\n",
1287                     sc->sc_vhid,
1288                     sc->sc_carpdev->if_xname,
1289                     sc->sc_state ? "MASTER" : "INIT");
1290 #endif
1291                 break;
1292         }
1293 }
1294
1295 /*
1296  * When in backup state, af indicates whether to reset the master down timer
1297  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1298  */
1299 static void
1300 carp_setrun(struct carp_softc *sc, sa_family_t af)
1301 {
1302         struct timeval tv;
1303
1304         CARP_LOCK_ASSERT(sc);
1305
1306         if ((sc->sc_carpdev->if_flags & IFF_UP) == 0 ||
1307             sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
1308             (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) ||
1309             !V_carp_allow)
1310                 return;
1311
1312         switch (sc->sc_state) {
1313         case INIT:
1314                 carp_set_state(sc, BACKUP, "initialization complete");
1315                 carp_setrun(sc, 0);
1316                 break;
1317         case BACKUP:
1318                 callout_stop(&sc->sc_ad_tmo);
1319                 tv.tv_sec = 3 * sc->sc_advbase;
1320                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1321                 switch (af) {
1322 #ifdef INET
1323                 case AF_INET:
1324                         callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1325                             carp_master_down, sc);
1326                         break;
1327 #endif
1328 #ifdef INET6
1329                 case AF_INET6:
1330                         callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1331                             carp_master_down, sc);
1332                         break;
1333 #endif
1334                 default:
1335 #ifdef INET
1336                         if (sc->sc_naddrs)
1337                                 callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1338                                     carp_master_down, sc);
1339 #endif
1340 #ifdef INET6
1341                         if (sc->sc_naddrs6)
1342                                 callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1343                                     carp_master_down, sc);
1344 #endif
1345                         break;
1346                 }
1347                 break;
1348         case MASTER:
1349                 tv.tv_sec = sc->sc_advbase;
1350                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1351                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1352                     carp_send_ad, sc);
1353                 break;
1354         }
1355 }
1356
1357 /*
1358  * Setup multicast structures.
1359  */
1360 static int
1361 carp_multicast_setup(struct carp_if *cif, sa_family_t sa)
1362 {
1363         struct ifnet *ifp = cif->cif_ifp;
1364         int error = 0;
1365
1366         switch (sa) {
1367 #ifdef INET
1368         case AF_INET:
1369             {
1370                 struct ip_moptions *imo = &cif->cif_imo;
1371                 struct in_mfilter *imf;
1372                 struct in_addr addr;
1373
1374                 if (ip_mfilter_first(&imo->imo_head) != NULL)
1375                         return (0);
1376
1377                 imf = ip_mfilter_alloc(M_WAITOK, 0, 0);
1378                 ip_mfilter_init(&imo->imo_head);
1379                 imo->imo_multicast_vif = -1;
1380
1381                 addr.s_addr = htonl(INADDR_CARP_GROUP);
1382                 if ((error = in_joingroup(ifp, &addr, NULL,
1383                     &imf->imf_inm)) != 0) {
1384                         ip_mfilter_free(imf);
1385                         break;
1386                 }
1387
1388                 ip_mfilter_insert(&imo->imo_head, imf);
1389                 imo->imo_multicast_ifp = ifp;
1390                 imo->imo_multicast_ttl = CARP_DFLTTL;
1391                 imo->imo_multicast_loop = 0;
1392                 break;
1393            }
1394 #endif
1395 #ifdef INET6
1396         case AF_INET6:
1397             {
1398                 struct ip6_moptions *im6o = &cif->cif_im6o;
1399                 struct in6_mfilter *im6f[2];
1400                 struct in6_addr in6;
1401
1402                 if (ip6_mfilter_first(&im6o->im6o_head))
1403                         return (0);
1404
1405                 im6f[0] = ip6_mfilter_alloc(M_WAITOK, 0, 0);
1406                 im6f[1] = ip6_mfilter_alloc(M_WAITOK, 0, 0);
1407
1408                 ip6_mfilter_init(&im6o->im6o_head);
1409                 im6o->im6o_multicast_hlim = CARP_DFLTTL;
1410                 im6o->im6o_multicast_ifp = ifp;
1411
1412                 /* Join IPv6 CARP multicast group. */
1413                 bzero(&in6, sizeof(in6));
1414                 in6.s6_addr16[0] = htons(0xff02);
1415                 in6.s6_addr8[15] = 0x12;
1416                 if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
1417                         ip6_mfilter_free(im6f[0]);
1418                         ip6_mfilter_free(im6f[1]);
1419                         break;
1420                 }
1421                 if ((error = in6_joingroup(ifp, &in6, NULL, &im6f[0]->im6f_in6m, 0)) != 0) {
1422                         ip6_mfilter_free(im6f[0]);
1423                         ip6_mfilter_free(im6f[1]);
1424                         break;
1425                 }
1426
1427                 /* Join solicited multicast address. */
1428                 bzero(&in6, sizeof(in6));
1429                 in6.s6_addr16[0] = htons(0xff02);
1430                 in6.s6_addr32[1] = 0;
1431                 in6.s6_addr32[2] = htonl(1);
1432                 in6.s6_addr32[3] = 0;
1433                 in6.s6_addr8[12] = 0xff;
1434
1435                 if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
1436                         ip6_mfilter_free(im6f[0]);
1437                         ip6_mfilter_free(im6f[1]);
1438                         break;
1439                 }
1440
1441                 if ((error = in6_joingroup(ifp, &in6, NULL, &im6f[1]->im6f_in6m, 0)) != 0) {
1442                         in6_leavegroup(im6f[0]->im6f_in6m, NULL);
1443                         ip6_mfilter_free(im6f[0]);
1444                         ip6_mfilter_free(im6f[1]);
1445                         break;
1446                 }
1447                 ip6_mfilter_insert(&im6o->im6o_head, im6f[0]);
1448                 ip6_mfilter_insert(&im6o->im6o_head, im6f[1]);
1449                 break;
1450             }
1451 #endif
1452         }
1453
1454         return (error);
1455 }
1456
1457 /*
1458  * Free multicast structures.
1459  */
1460 static void
1461 carp_multicast_cleanup(struct carp_if *cif, sa_family_t sa)
1462 {
1463 #ifdef INET
1464         struct ip_moptions *imo = &cif->cif_imo;
1465         struct in_mfilter *imf;
1466 #endif
1467 #ifdef INET6
1468         struct ip6_moptions *im6o = &cif->cif_im6o;
1469         struct in6_mfilter *im6f;
1470 #endif
1471         sx_assert(&carp_sx, SA_XLOCKED);
1472
1473         switch (sa) {
1474 #ifdef INET
1475         case AF_INET:
1476                 if (cif->cif_naddrs != 0)
1477                         break;
1478
1479                 while ((imf = ip_mfilter_first(&imo->imo_head)) != NULL) {
1480                         ip_mfilter_remove(&imo->imo_head, imf);
1481                         in_leavegroup(imf->imf_inm, NULL);
1482                         ip_mfilter_free(imf);
1483                 }
1484                 break;
1485 #endif
1486 #ifdef INET6
1487         case AF_INET6:
1488                 if (cif->cif_naddrs6 != 0)
1489                         break;
1490
1491                 while ((im6f = ip6_mfilter_first(&im6o->im6o_head)) != NULL) {
1492                         ip6_mfilter_remove(&im6o->im6o_head, im6f);
1493                         in6_leavegroup(im6f->im6f_in6m, NULL);
1494                         ip6_mfilter_free(im6f);
1495                 }
1496                 break;
1497 #endif
1498         }
1499 }
1500
1501 int
1502 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa)
1503 {
1504         struct m_tag *mtag;
1505         struct carp_softc *sc;
1506
1507         if (!sa)
1508                 return (0);
1509
1510         switch (sa->sa_family) {
1511 #ifdef INET
1512         case AF_INET:
1513                 break;
1514 #endif
1515 #ifdef INET6
1516         case AF_INET6:
1517                 break;
1518 #endif
1519         default:
1520                 return (0);
1521         }
1522
1523         mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
1524         if (mtag == NULL)
1525                 return (0);
1526
1527         bcopy(mtag + 1, &sc, sizeof(sc));
1528
1529         /* Set the source MAC address to the Virtual Router MAC Address. */
1530         switch (ifp->if_type) {
1531         case IFT_ETHER:
1532         case IFT_BRIDGE:
1533         case IFT_L2VLAN: {
1534                         struct ether_header *eh;
1535
1536                         eh = mtod(m, struct ether_header *);
1537                         eh->ether_shost[0] = 0;
1538                         eh->ether_shost[1] = 0;
1539                         eh->ether_shost[2] = 0x5e;
1540                         eh->ether_shost[3] = 0;
1541                         eh->ether_shost[4] = 1;
1542                         eh->ether_shost[5] = sc->sc_vhid;
1543                 }
1544                 break;
1545         default:
1546                 printf("%s: carp is not supported for the %d interface type\n",
1547                     ifp->if_xname, ifp->if_type);
1548                 return (EOPNOTSUPP);
1549         }
1550
1551         return (0);
1552 }
1553
1554 static struct carp_softc*
1555 carp_alloc(struct ifnet *ifp)
1556 {
1557         struct carp_softc *sc;
1558         struct carp_if *cif;
1559
1560         sx_assert(&carp_sx, SA_XLOCKED);
1561
1562         if ((cif = ifp->if_carp) == NULL)
1563                 cif = carp_alloc_if(ifp);
1564
1565         sc = malloc(sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
1566
1567         sc->sc_advbase = CARP_DFLTINTV;
1568         sc->sc_vhid = -1;       /* required setting */
1569         sc->sc_init_counter = 1;
1570         sc->sc_state = INIT;
1571
1572         sc->sc_ifasiz = sizeof(struct ifaddr *);
1573         sc->sc_ifas = malloc(sc->sc_ifasiz, M_CARP, M_WAITOK|M_ZERO);
1574         sc->sc_carpdev = ifp;
1575
1576         CARP_LOCK_INIT(sc);
1577 #ifdef INET
1578         callout_init_mtx(&sc->sc_md_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1579 #endif
1580 #ifdef INET6
1581         callout_init_mtx(&sc->sc_md6_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1582 #endif
1583         callout_init_mtx(&sc->sc_ad_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1584
1585         CIF_LOCK(cif);
1586         TAILQ_INSERT_TAIL(&cif->cif_vrs, sc, sc_list);
1587         CIF_UNLOCK(cif);
1588
1589         mtx_lock(&carp_mtx);
1590         LIST_INSERT_HEAD(&carp_list, sc, sc_next);
1591         mtx_unlock(&carp_mtx);
1592
1593         return (sc);
1594 }
1595
1596 static void
1597 carp_grow_ifas(struct carp_softc *sc)
1598 {
1599         struct ifaddr **new;
1600
1601         new = malloc(sc->sc_ifasiz * 2, M_CARP, M_WAITOK | M_ZERO);
1602         CARP_LOCK(sc);
1603         bcopy(sc->sc_ifas, new, sc->sc_ifasiz);
1604         free(sc->sc_ifas, M_CARP);
1605         sc->sc_ifas = new;
1606         sc->sc_ifasiz *= 2;
1607         CARP_UNLOCK(sc);
1608 }
1609
1610 static void
1611 carp_destroy(struct carp_softc *sc)
1612 {
1613         struct ifnet *ifp = sc->sc_carpdev;
1614         struct carp_if *cif = ifp->if_carp;
1615
1616         sx_assert(&carp_sx, SA_XLOCKED);
1617
1618         if (sc->sc_suppress)
1619                 carp_demote_adj(-V_carp_ifdown_adj, "vhid removed");
1620         CARP_UNLOCK(sc);
1621
1622         CIF_LOCK(cif);
1623         TAILQ_REMOVE(&cif->cif_vrs, sc, sc_list);
1624         CIF_UNLOCK(cif);
1625
1626         mtx_lock(&carp_mtx);
1627         LIST_REMOVE(sc, sc_next);
1628         mtx_unlock(&carp_mtx);
1629
1630         callout_drain(&sc->sc_ad_tmo);
1631 #ifdef INET
1632         callout_drain(&sc->sc_md_tmo);
1633 #endif
1634 #ifdef INET6
1635         callout_drain(&sc->sc_md6_tmo);
1636 #endif
1637         CARP_LOCK_DESTROY(sc);
1638
1639         free(sc->sc_ifas, M_CARP);
1640         free(sc, M_CARP);
1641 }
1642
1643 static struct carp_if*
1644 carp_alloc_if(struct ifnet *ifp)
1645 {
1646         struct carp_if *cif;
1647         int error;
1648
1649         cif = malloc(sizeof(*cif), M_CARP, M_WAITOK|M_ZERO);
1650
1651         if ((error = ifpromisc(ifp, 1)) != 0)
1652                 printf("%s: ifpromisc(%s) failed: %d\n",
1653                     __func__, ifp->if_xname, error);
1654         else
1655                 cif->cif_flags |= CIF_PROMISC;
1656
1657         CIF_LOCK_INIT(cif);
1658         cif->cif_ifp = ifp;
1659         TAILQ_INIT(&cif->cif_vrs);
1660
1661         IF_ADDR_WLOCK(ifp);
1662         ifp->if_carp = cif;
1663         if_ref(ifp);
1664         IF_ADDR_WUNLOCK(ifp);
1665
1666         return (cif);
1667 }
1668
1669 static void
1670 carp_free_if(struct carp_if *cif)
1671 {
1672         struct ifnet *ifp = cif->cif_ifp;
1673
1674         CIF_LOCK_ASSERT(cif);
1675         KASSERT(TAILQ_EMPTY(&cif->cif_vrs), ("%s: softc list not empty",
1676             __func__));
1677
1678         IF_ADDR_WLOCK(ifp);
1679         ifp->if_carp = NULL;
1680         IF_ADDR_WUNLOCK(ifp);
1681
1682         CIF_LOCK_DESTROY(cif);
1683
1684         if (cif->cif_flags & CIF_PROMISC)
1685                 ifpromisc(ifp, 0);
1686         if_rele(ifp);
1687
1688         free(cif, M_CARP);
1689 }
1690
1691 static void
1692 carp_carprcp(struct carpreq *carpr, struct carp_softc *sc, int priv)
1693 {
1694
1695         CARP_LOCK(sc);
1696         carpr->carpr_state = sc->sc_state;
1697         carpr->carpr_vhid = sc->sc_vhid;
1698         carpr->carpr_advbase = sc->sc_advbase;
1699         carpr->carpr_advskew = sc->sc_advskew;
1700         if (priv)
1701                 bcopy(sc->sc_key, carpr->carpr_key, sizeof(carpr->carpr_key));
1702         else
1703                 bzero(carpr->carpr_key, sizeof(carpr->carpr_key));
1704         CARP_UNLOCK(sc);
1705 }
1706
1707 int
1708 carp_ioctl(struct ifreq *ifr, u_long cmd, struct thread *td)
1709 {
1710         struct carpreq carpr;
1711         struct ifnet *ifp;
1712         struct carp_softc *sc = NULL;
1713         int error = 0, locked = 0;
1714
1715         if ((error = copyin(ifr_data_get_ptr(ifr), &carpr, sizeof carpr)))
1716                 return (error);
1717
1718         ifp = ifunit_ref(ifr->ifr_name);
1719         if (ifp == NULL)
1720                 return (ENXIO);
1721
1722         switch (ifp->if_type) {
1723         case IFT_ETHER:
1724         case IFT_L2VLAN:
1725         case IFT_BRIDGE:
1726                 break;
1727         default:
1728                 error = EOPNOTSUPP;
1729                 goto out;
1730         }
1731
1732         if ((ifp->if_flags & IFF_MULTICAST) == 0) {
1733                 error = EADDRNOTAVAIL;
1734                 goto out;
1735         }
1736
1737         sx_xlock(&carp_sx);
1738         switch (cmd) {
1739         case SIOCSVH:
1740                 if ((error = priv_check(td, PRIV_NETINET_CARP)))
1741                         break;
1742                 if (carpr.carpr_vhid <= 0 || carpr.carpr_vhid > CARP_MAXVHID ||
1743                     carpr.carpr_advbase < 0 || carpr.carpr_advskew < 0) {
1744                         error = EINVAL;
1745                         break;
1746                 }
1747
1748                 if (ifp->if_carp) {
1749                         IFNET_FOREACH_CARP(ifp, sc)
1750                                 if (sc->sc_vhid == carpr.carpr_vhid)
1751                                         break;
1752                 }
1753                 if (sc == NULL) {
1754                         sc = carp_alloc(ifp);
1755                         CARP_LOCK(sc);
1756                         sc->sc_vhid = carpr.carpr_vhid;
1757                         LLADDR(&sc->sc_addr)[0] = 0;
1758                         LLADDR(&sc->sc_addr)[1] = 0;
1759                         LLADDR(&sc->sc_addr)[2] = 0x5e;
1760                         LLADDR(&sc->sc_addr)[3] = 0;
1761                         LLADDR(&sc->sc_addr)[4] = 1;
1762                         LLADDR(&sc->sc_addr)[5] = sc->sc_vhid;
1763                 } else
1764                         CARP_LOCK(sc);
1765                 locked = 1;
1766                 if (carpr.carpr_advbase > 0) {
1767                         if (carpr.carpr_advbase > 255 ||
1768                             carpr.carpr_advbase < CARP_DFLTINTV) {
1769                                 error = EINVAL;
1770                                 break;
1771                         }
1772                         sc->sc_advbase = carpr.carpr_advbase;
1773                 }
1774                 if (carpr.carpr_advskew >= 255) {
1775                         error = EINVAL;
1776                         break;
1777                 }
1778                 sc->sc_advskew = carpr.carpr_advskew;
1779                 if (carpr.carpr_key[0] != '\0') {
1780                         bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1781                         carp_hmac_prepare(sc);
1782                 }
1783                 if (sc->sc_state != INIT &&
1784                     carpr.carpr_state != sc->sc_state) {
1785                         switch (carpr.carpr_state) {
1786                         case BACKUP:
1787                                 callout_stop(&sc->sc_ad_tmo);
1788                                 carp_set_state(sc, BACKUP,
1789                                     "user requested via ifconfig");
1790                                 carp_setrun(sc, 0);
1791                                 carp_delroute(sc);
1792                                 break;
1793                         case MASTER:
1794                                 carp_master_down_locked(sc,
1795                                     "user requested via ifconfig");
1796                                 break;
1797                         default:
1798                                 break;
1799                         }
1800                 }
1801                 break;
1802
1803         case SIOCGVH:
1804             {
1805                 int priveleged;
1806
1807                 if (carpr.carpr_vhid < 0 || carpr.carpr_vhid > CARP_MAXVHID) {
1808                         error = EINVAL;
1809                         break;
1810                 }
1811                 if (carpr.carpr_count < 1) {
1812                         error = EMSGSIZE;
1813                         break;
1814                 }
1815                 if (ifp->if_carp == NULL) {
1816                         error = ENOENT;
1817                         break;
1818                 }
1819
1820                 priveleged = (priv_check(td, PRIV_NETINET_CARP) == 0);
1821                 if (carpr.carpr_vhid != 0) {
1822                         IFNET_FOREACH_CARP(ifp, sc)
1823                                 if (sc->sc_vhid == carpr.carpr_vhid)
1824                                         break;
1825                         if (sc == NULL) {
1826                                 error = ENOENT;
1827                                 break;
1828                         }
1829                         carp_carprcp(&carpr, sc, priveleged);
1830                         error = copyout(&carpr, ifr_data_get_ptr(ifr),
1831                             sizeof(carpr));
1832                 } else  {
1833                         int i, count;
1834
1835                         count = 0;
1836                         IFNET_FOREACH_CARP(ifp, sc)
1837                                 count++;
1838
1839                         if (count > carpr.carpr_count) {
1840                                 CIF_UNLOCK(ifp->if_carp);
1841                                 error = EMSGSIZE;
1842                                 break;
1843                         }
1844
1845                         i = 0;
1846                         IFNET_FOREACH_CARP(ifp, sc) {
1847                                 carp_carprcp(&carpr, sc, priveleged);
1848                                 carpr.carpr_count = count;
1849                                 error = copyout(&carpr,
1850                                     (char *)ifr_data_get_ptr(ifr) +
1851                                     (i * sizeof(carpr)), sizeof(carpr));
1852                                 if (error) {
1853                                         CIF_UNLOCK(ifp->if_carp);
1854                                         break;
1855                                 }
1856                                 i++;
1857                         }
1858                 }
1859                 break;
1860             }
1861         default:
1862                 error = EINVAL;
1863         }
1864         sx_xunlock(&carp_sx);
1865
1866 out:
1867         if (locked)
1868                 CARP_UNLOCK(sc);
1869         if_rele(ifp);
1870
1871         return (error);
1872 }
1873
1874 static int
1875 carp_get_vhid(struct ifaddr *ifa)
1876 {
1877
1878         if (ifa == NULL || ifa->ifa_carp == NULL)
1879                 return (0);
1880
1881         return (ifa->ifa_carp->sc_vhid);
1882 }
1883
1884 int
1885 carp_attach(struct ifaddr *ifa, int vhid)
1886 {
1887         struct ifnet *ifp = ifa->ifa_ifp;
1888         struct carp_if *cif = ifp->if_carp;
1889         struct carp_softc *sc;
1890         int index, error;
1891
1892         KASSERT(ifa->ifa_carp == NULL, ("%s: ifa %p attached", __func__, ifa));
1893
1894         switch (ifa->ifa_addr->sa_family) {
1895 #ifdef INET
1896         case AF_INET:
1897 #endif
1898 #ifdef INET6
1899         case AF_INET6:
1900 #endif
1901                 break;
1902         default:
1903                 return (EPROTOTYPE);
1904         }
1905
1906         sx_xlock(&carp_sx);
1907         if (ifp->if_carp == NULL) {
1908                 sx_xunlock(&carp_sx);
1909                 return (ENOPROTOOPT);
1910         }
1911
1912         IFNET_FOREACH_CARP(ifp, sc)
1913                 if (sc->sc_vhid == vhid)
1914                         break;
1915         if (sc == NULL) {
1916                 sx_xunlock(&carp_sx);
1917                 return (ENOENT);
1918         }
1919
1920         error = carp_multicast_setup(cif, ifa->ifa_addr->sa_family);
1921         if (error) {
1922                 CIF_FREE(cif);
1923                 sx_xunlock(&carp_sx);
1924                 return (error);
1925         }
1926
1927         index = sc->sc_naddrs + sc->sc_naddrs6 + 1;
1928         if (index > sc->sc_ifasiz / sizeof(struct ifaddr *))
1929                 carp_grow_ifas(sc);
1930
1931         switch (ifa->ifa_addr->sa_family) {
1932 #ifdef INET
1933         case AF_INET:
1934                 cif->cif_naddrs++;
1935                 sc->sc_naddrs++;
1936                 break;
1937 #endif
1938 #ifdef INET6
1939         case AF_INET6:
1940                 cif->cif_naddrs6++;
1941                 sc->sc_naddrs6++;
1942                 break;
1943 #endif
1944         }
1945
1946         ifa_ref(ifa);
1947
1948         CARP_LOCK(sc);
1949         sc->sc_ifas[index - 1] = ifa;
1950         ifa->ifa_carp = sc;
1951         carp_hmac_prepare(sc);
1952         carp_sc_state(sc);
1953         CARP_UNLOCK(sc);
1954
1955         sx_xunlock(&carp_sx);
1956
1957         return (0);
1958 }
1959
1960 void
1961 carp_detach(struct ifaddr *ifa, bool keep_cif)
1962 {
1963         struct ifnet *ifp = ifa->ifa_ifp;
1964         struct carp_if *cif = ifp->if_carp;
1965         struct carp_softc *sc = ifa->ifa_carp;
1966         int i, index;
1967
1968         KASSERT(sc != NULL, ("%s: %p not attached", __func__, ifa));
1969
1970         sx_xlock(&carp_sx);
1971
1972         CARP_LOCK(sc);
1973         /* Shift array. */
1974         index = sc->sc_naddrs + sc->sc_naddrs6;
1975         for (i = 0; i < index; i++)
1976                 if (sc->sc_ifas[i] == ifa)
1977                         break;
1978         KASSERT(i < index, ("%s: %p no backref", __func__, ifa));
1979         for (; i < index - 1; i++)
1980                 sc->sc_ifas[i] = sc->sc_ifas[i+1];
1981         sc->sc_ifas[index - 1] = NULL;
1982
1983         switch (ifa->ifa_addr->sa_family) {
1984 #ifdef INET
1985         case AF_INET:
1986                 cif->cif_naddrs--;
1987                 sc->sc_naddrs--;
1988                 break;
1989 #endif
1990 #ifdef INET6
1991         case AF_INET6:
1992                 cif->cif_naddrs6--;
1993                 sc->sc_naddrs6--;
1994                 break;
1995 #endif
1996         }
1997
1998         carp_ifa_delroute(ifa);
1999         carp_multicast_cleanup(cif, ifa->ifa_addr->sa_family);
2000
2001         ifa->ifa_carp = NULL;
2002         ifa_free(ifa);
2003
2004         carp_hmac_prepare(sc);
2005         carp_sc_state(sc);
2006
2007         if (!keep_cif && sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0)
2008                 carp_destroy(sc);
2009         else
2010                 CARP_UNLOCK(sc);
2011
2012         if (!keep_cif)
2013                 CIF_FREE(cif);
2014
2015         sx_xunlock(&carp_sx);
2016 }
2017
2018 static void
2019 carp_set_state(struct carp_softc *sc, int state, const char *reason)
2020 {
2021
2022         CARP_LOCK_ASSERT(sc);
2023
2024         if (sc->sc_state != state) {
2025                 const char *carp_states[] = { CARP_STATES };
2026                 char subsys[IFNAMSIZ+5];
2027
2028                 snprintf(subsys, IFNAMSIZ+5, "%u@%s", sc->sc_vhid,
2029                     sc->sc_carpdev->if_xname);
2030
2031                 CARP_LOG("%s: %s -> %s (%s)\n", subsys,
2032                     carp_states[sc->sc_state], carp_states[state], reason);
2033
2034                 sc->sc_state = state;
2035
2036                 devctl_notify("CARP", subsys, carp_states[state], NULL);
2037         }
2038 }
2039
2040 static void
2041 carp_linkstate(struct ifnet *ifp)
2042 {
2043         struct carp_softc *sc;
2044
2045         CIF_LOCK(ifp->if_carp);
2046         IFNET_FOREACH_CARP(ifp, sc) {
2047                 CARP_LOCK(sc);
2048                 carp_sc_state(sc);
2049                 CARP_UNLOCK(sc);
2050         }
2051         CIF_UNLOCK(ifp->if_carp);
2052 }
2053
2054 static void
2055 carp_sc_state(struct carp_softc *sc)
2056 {
2057
2058         CARP_LOCK_ASSERT(sc);
2059
2060         if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
2061             !(sc->sc_carpdev->if_flags & IFF_UP) ||
2062             !V_carp_allow) {
2063                 callout_stop(&sc->sc_ad_tmo);
2064 #ifdef INET
2065                 callout_stop(&sc->sc_md_tmo);
2066 #endif
2067 #ifdef INET6
2068                 callout_stop(&sc->sc_md6_tmo);
2069 #endif
2070                 carp_set_state(sc, INIT, "hardware interface down");
2071                 carp_setrun(sc, 0);
2072                 if (!sc->sc_suppress)
2073                         carp_demote_adj(V_carp_ifdown_adj, "interface down");
2074                 sc->sc_suppress = 1;
2075         } else {
2076                 carp_set_state(sc, INIT, "hardware interface up");
2077                 carp_setrun(sc, 0);
2078                 if (sc->sc_suppress)
2079                         carp_demote_adj(-V_carp_ifdown_adj, "interface up");
2080                 sc->sc_suppress = 0;
2081         }
2082 }
2083
2084 static void
2085 carp_demote_adj(int adj, char *reason)
2086 {
2087         atomic_add_int(&V_carp_demotion, adj);
2088         CARP_LOG("demoted by %d to %d (%s)\n", adj, V_carp_demotion, reason);
2089         taskqueue_enqueue(taskqueue_swi, &carp_sendall_task);
2090 }
2091
2092 static int
2093 carp_allow_sysctl(SYSCTL_HANDLER_ARGS)
2094 {
2095         int new, error;
2096         struct carp_softc *sc;
2097
2098         new = V_carp_allow;
2099         error = sysctl_handle_int(oidp, &new, 0, req);
2100         if (error || !req->newptr)
2101                 return (error);
2102
2103         if (V_carp_allow != new) {
2104                 V_carp_allow = new;
2105
2106                 mtx_lock(&carp_mtx);
2107                 LIST_FOREACH(sc, &carp_list, sc_next) {
2108                         CARP_LOCK(sc);
2109                         if (curvnet == sc->sc_carpdev->if_vnet)
2110                                 carp_sc_state(sc);
2111                         CARP_UNLOCK(sc);
2112                 }
2113                 mtx_unlock(&carp_mtx);
2114         }
2115
2116         return (0);
2117 }
2118
2119 static int
2120 carp_dscp_sysctl(SYSCTL_HANDLER_ARGS)
2121 {
2122         int new, error;
2123
2124         new = V_carp_dscp;
2125         error = sysctl_handle_int(oidp, &new, 0, req);
2126         if (error || !req->newptr)
2127                 return (error);
2128
2129         if (new < 0 || new > 63)
2130                 return (EINVAL);
2131
2132         V_carp_dscp = new;
2133
2134         return (0);
2135 }
2136
2137 static int
2138 carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS)
2139 {
2140         int new, error;
2141
2142         new = V_carp_demotion;
2143         error = sysctl_handle_int(oidp, &new, 0, req);
2144         if (error || !req->newptr)
2145                 return (error);
2146
2147         carp_demote_adj(new, "sysctl");
2148
2149         return (0);
2150 }
2151
2152 #ifdef INET
2153 extern  struct domain inetdomain;
2154 static struct protosw in_carp_protosw = {
2155         .pr_type =              SOCK_RAW,
2156         .pr_domain =            &inetdomain,
2157         .pr_protocol =          IPPROTO_CARP,
2158         .pr_flags =             PR_ATOMIC|PR_ADDR,
2159         .pr_input =             carp_input,
2160         .pr_output =            rip_output,
2161         .pr_ctloutput =         rip_ctloutput,
2162         .pr_usrreqs =           &rip_usrreqs
2163 };
2164 #endif
2165
2166 #ifdef INET6
2167 extern  struct domain inet6domain;
2168 static struct protosw in6_carp_protosw = {
2169         .pr_type =              SOCK_RAW,
2170         .pr_domain =            &inet6domain,
2171         .pr_protocol =          IPPROTO_CARP,
2172         .pr_flags =             PR_ATOMIC|PR_ADDR,
2173         .pr_input =             carp6_input,
2174         .pr_output =            rip6_output,
2175         .pr_ctloutput =         rip6_ctloutput,
2176         .pr_usrreqs =           &rip6_usrreqs
2177 };
2178 #endif
2179
2180 static void
2181 carp_mod_cleanup(void)
2182 {
2183
2184 #ifdef INET
2185         if (proto_reg[CARP_INET] == 0) {
2186                 (void)ipproto_unregister(IPPROTO_CARP);
2187                 pf_proto_unregister(PF_INET, IPPROTO_CARP, SOCK_RAW);
2188                 proto_reg[CARP_INET] = -1;
2189         }
2190         carp_iamatch_p = NULL;
2191 #endif
2192 #ifdef INET6
2193         if (proto_reg[CARP_INET6] == 0) {
2194                 (void)ip6proto_unregister(IPPROTO_CARP);
2195                 pf_proto_unregister(PF_INET6, IPPROTO_CARP, SOCK_RAW);
2196                 proto_reg[CARP_INET6] = -1;
2197         }
2198         carp_iamatch6_p = NULL;
2199         carp_macmatch6_p = NULL;
2200 #endif
2201         carp_ioctl_p = NULL;
2202         carp_attach_p = NULL;
2203         carp_detach_p = NULL;
2204         carp_get_vhid_p = NULL;
2205         carp_linkstate_p = NULL;
2206         carp_forus_p = NULL;
2207         carp_output_p = NULL;
2208         carp_demote_adj_p = NULL;
2209         carp_master_p = NULL;
2210         mtx_unlock(&carp_mtx);
2211         taskqueue_drain(taskqueue_swi, &carp_sendall_task);
2212         mtx_destroy(&carp_mtx);
2213         sx_destroy(&carp_sx);
2214 }
2215
2216 static int
2217 carp_mod_load(void)
2218 {
2219         int err;
2220
2221         mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
2222         sx_init(&carp_sx, "carp_sx");
2223         LIST_INIT(&carp_list);
2224         carp_get_vhid_p = carp_get_vhid;
2225         carp_forus_p = carp_forus;
2226         carp_output_p = carp_output;
2227         carp_linkstate_p = carp_linkstate;
2228         carp_ioctl_p = carp_ioctl;
2229         carp_attach_p = carp_attach;
2230         carp_detach_p = carp_detach;
2231         carp_demote_adj_p = carp_demote_adj;
2232         carp_master_p = carp_master;
2233 #ifdef INET6
2234         carp_iamatch6_p = carp_iamatch6;
2235         carp_macmatch6_p = carp_macmatch6;
2236         proto_reg[CARP_INET6] = pf_proto_register(PF_INET6,
2237             (struct protosw *)&in6_carp_protosw);
2238         if (proto_reg[CARP_INET6]) {
2239                 printf("carp: error %d attaching to PF_INET6\n",
2240                     proto_reg[CARP_INET6]);
2241                 carp_mod_cleanup();
2242                 return (proto_reg[CARP_INET6]);
2243         }
2244         err = ip6proto_register(IPPROTO_CARP);
2245         if (err) {
2246                 printf("carp: error %d registering with INET6\n", err);
2247                 carp_mod_cleanup();
2248                 return (err);
2249         }
2250 #endif
2251 #ifdef INET
2252         carp_iamatch_p = carp_iamatch;
2253         proto_reg[CARP_INET] = pf_proto_register(PF_INET, &in_carp_protosw);
2254         if (proto_reg[CARP_INET]) {
2255                 printf("carp: error %d attaching to PF_INET\n",
2256                     proto_reg[CARP_INET]);
2257                 carp_mod_cleanup();
2258                 return (proto_reg[CARP_INET]);
2259         }
2260         err = ipproto_register(IPPROTO_CARP);
2261         if (err) {
2262                 printf("carp: error %d registering with INET\n", err);
2263                 carp_mod_cleanup();
2264                 return (err);
2265         }
2266 #endif
2267         return (0);
2268 }
2269
2270 static int
2271 carp_modevent(module_t mod, int type, void *data)
2272 {
2273         switch (type) {
2274         case MOD_LOAD:
2275                 return carp_mod_load();
2276                 /* NOTREACHED */
2277         case MOD_UNLOAD:
2278                 mtx_lock(&carp_mtx);
2279                 if (LIST_EMPTY(&carp_list))
2280                         carp_mod_cleanup();
2281                 else {
2282                         mtx_unlock(&carp_mtx);
2283                         return (EBUSY);
2284                 }
2285                 break;
2286
2287         default:
2288                 return (EINVAL);
2289         }
2290
2291         return (0);
2292 }
2293
2294 static moduledata_t carp_mod = {
2295         "carp",
2296         carp_modevent,
2297         0
2298 };
2299
2300 DECLARE_MODULE(carp, carp_mod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);