The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netinet/ip_carp.c

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    1 /*-
    2  * Copyright (c) 2002 Michael Shalayeff.
    3  * Copyright (c) 2003 Ryan McBride.
    4  * Copyright (c) 2011 Gleb Smirnoff <glebius@FreeBSD.org>
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  *
   16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   19  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
   20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   22  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
   25  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
   26  * THE POSSIBILITY OF SUCH DAMAGE.
   27  */
   28 
   29 #include <sys/cdefs.h>
   30 __FBSDID("$FreeBSD: releng/10.0/sys/netinet/ip_carp.c 255397 2013-09-08 18:19:40Z trociny $");
   31 
   32 #include "opt_bpf.h"
   33 #include "opt_inet.h"
   34 #include "opt_inet6.h"
   35 
   36 #include <sys/param.h>
   37 #include <sys/systm.h>
   38 #include <sys/bus.h>
   39 #include <sys/jail.h>
   40 #include <sys/kernel.h>
   41 #include <sys/limits.h>
   42 #include <sys/malloc.h>
   43 #include <sys/mbuf.h>
   44 #include <sys/module.h>
   45 #include <sys/priv.h>
   46 #include <sys/proc.h>
   47 #include <sys/protosw.h>
   48 #include <sys/socket.h>
   49 #include <sys/sockio.h>
   50 #include <sys/sysctl.h>
   51 #include <sys/syslog.h>
   52 #include <sys/taskqueue.h>
   53 #include <sys/counter.h>
   54 
   55 #include <net/ethernet.h>
   56 #include <net/fddi.h>
   57 #include <net/if.h>
   58 #include <net/if_dl.h>
   59 #include <net/if_llatbl.h>
   60 #include <net/if_types.h>
   61 #include <net/iso88025.h>
   62 #include <net/route.h>
   63 #include <net/vnet.h>
   64 
   65 #if defined(INET) || defined(INET6)
   66 #include <netinet/in.h>
   67 #include <netinet/in_var.h>
   68 #include <netinet/ip_carp.h>
   69 #include <netinet/ip.h>
   70 #include <machine/in_cksum.h>
   71 #endif
   72 #ifdef INET
   73 #include <netinet/ip_var.h>
   74 #include <netinet/if_ether.h>
   75 #endif
   76 
   77 #ifdef INET6
   78 #include <netinet/icmp6.h>
   79 #include <netinet/ip6.h>
   80 #include <netinet6/ip6protosw.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 };
  148 
  149 #define CARP_INET       0
  150 #define CARP_INET6      1
  151 static int proto_reg[] = {-1, -1};
  152 
  153 /*
  154  * Brief design of carp(4).
  155  *
  156  * Any carp-capable ifnet may have a list of carp softcs hanging off
  157  * its ifp->if_carp pointer. Each softc represents one unique virtual
  158  * host id, or vhid. The softc has a back pointer to the ifnet. All
  159  * softcs are joined in a global list, which has quite limited use.
  160  *
  161  * Any interface address that takes part in CARP negotiation has a
  162  * pointer to the softc of its vhid, ifa->ifa_carp. That could be either
  163  * AF_INET or AF_INET6 address.
  164  *
  165  * Although, one can get the softc's backpointer to ifnet and traverse
  166  * through its ifp->if_addrhead queue to find all interface addresses
  167  * involved in CARP, we keep a growable array of ifaddr pointers. This
  168  * allows us to avoid grabbing the IF_ADDR_LOCK() in many traversals that
  169  * do calls into the network stack, thus avoiding LORs.
  170  *
  171  * Locking:
  172  *
  173  * Each softc has a lock sc_mtx. It is used to synchronise carp_input_c(),
  174  * callout-driven events and ioctl()s.
  175  *
  176  * To traverse the list of softcs on an ifnet we use CIF_LOCK(), to
  177  * traverse the global list we use the mutex carp_mtx.
  178  *
  179  * Known issues with locking:
  180  *
  181  * - There is no protection for races between two ioctl() requests,
  182  *   neither SIOCSVH, nor SIOCAIFADDR & SIOCAIFADDR_IN6. I think that all
  183  *   interface ioctl()s should be serialized right in net/if.c.
  184  * - Sending ad, we put the pointer to the softc in an mtag, and no reference
  185  *   counting is done on the softc.
  186  * - On module unload we may race (?) with packet processing thread
  187  *   dereferencing our function pointers.
  188  */
  189 
  190 /* Accept incoming CARP packets. */
  191 static VNET_DEFINE(int, carp_allow) = 1;
  192 #define V_carp_allow    VNET(carp_allow)
  193 
  194 /* Preempt slower nodes. */
  195 static VNET_DEFINE(int, carp_preempt) = 0;
  196 #define V_carp_preempt  VNET(carp_preempt)
  197 
  198 /* Log level. */
  199 static VNET_DEFINE(int, carp_log) = 1;
  200 #define V_carp_log      VNET(carp_log)
  201 
  202 /* Global advskew demotion. */
  203 static VNET_DEFINE(int, carp_demotion) = 0;
  204 #define V_carp_demotion VNET(carp_demotion)
  205 
  206 /* Send error demotion factor. */
  207 static VNET_DEFINE(int, carp_senderr_adj) = CARP_MAXSKEW;
  208 #define V_carp_senderr_adj      VNET(carp_senderr_adj)
  209 
  210 /* Iface down demotion factor. */
  211 static VNET_DEFINE(int, carp_ifdown_adj) = CARP_MAXSKEW;
  212 #define V_carp_ifdown_adj       VNET(carp_ifdown_adj)
  213 
  214 static int carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS);
  215 
  216 SYSCTL_NODE(_net_inet, IPPROTO_CARP,    carp,   CTLFLAG_RW, 0,  "CARP");
  217 SYSCTL_VNET_INT(_net_inet_carp, OID_AUTO, allow, CTLFLAG_RW,
  218     &VNET_NAME(carp_allow), 0, "Accept incoming CARP packets");
  219 SYSCTL_VNET_INT(_net_inet_carp, OID_AUTO, preempt, CTLFLAG_RW,
  220     &VNET_NAME(carp_preempt), 0, "High-priority backup preemption mode");
  221 SYSCTL_VNET_INT(_net_inet_carp, OID_AUTO, log, CTLFLAG_RW,
  222     &VNET_NAME(carp_log), 0, "CARP log level");
  223 SYSCTL_VNET_PROC(_net_inet_carp, OID_AUTO, demotion, CTLTYPE_INT|CTLFLAG_RW,
  224     0, 0, carp_demote_adj_sysctl, "I",
  225     "Adjust demotion factor (skew of advskew)");
  226 SYSCTL_VNET_INT(_net_inet_carp, OID_AUTO, senderr_demotion_factor, CTLFLAG_RW,
  227     &VNET_NAME(carp_senderr_adj), 0, "Send error demotion factor adjustment");
  228 SYSCTL_VNET_INT(_net_inet_carp, OID_AUTO, ifdown_demotion_factor, CTLFLAG_RW,
  229     &VNET_NAME(carp_ifdown_adj), 0,
  230     "Interface down demotion factor adjustment");
  231 
  232 VNET_PCPUSTAT_DEFINE(struct carpstats, carpstats);
  233 VNET_PCPUSTAT_SYSINIT(carpstats);
  234 VNET_PCPUSTAT_SYSUNINIT(carpstats);
  235 
  236 #define CARPSTATS_ADD(name, val)        \
  237     counter_u64_add(VNET(carpstats)[offsetof(struct carpstats, name) / \
  238         sizeof(uint64_t)], (val))
  239 #define CARPSTATS_INC(name)             CARPSTATS_ADD(name, 1)
  240 
  241 SYSCTL_VNET_PCPUSTAT(_net_inet_carp, OID_AUTO, stats, struct carpstats,
  242     carpstats, "CARP statistics (struct carpstats, netinet/ip_carp.h)");
  243 
  244 #define CARP_LOCK_INIT(sc)      mtx_init(&(sc)->sc_mtx, "carp_softc",   \
  245         NULL, MTX_DEF)
  246 #define CARP_LOCK_DESTROY(sc)   mtx_destroy(&(sc)->sc_mtx)
  247 #define CARP_LOCK_ASSERT(sc)    mtx_assert(&(sc)->sc_mtx, MA_OWNED)
  248 #define CARP_LOCK(sc)           mtx_lock(&(sc)->sc_mtx)
  249 #define CARP_UNLOCK(sc)         mtx_unlock(&(sc)->sc_mtx)
  250 #define CIF_LOCK_INIT(cif)      mtx_init(&(cif)->cif_mtx, "carp_if",   \
  251         NULL, MTX_DEF)
  252 #define CIF_LOCK_DESTROY(cif)   mtx_destroy(&(cif)->cif_mtx)
  253 #define CIF_LOCK_ASSERT(cif)    mtx_assert(&(cif)->cif_mtx, MA_OWNED)
  254 #define CIF_LOCK(cif)           mtx_lock(&(cif)->cif_mtx)
  255 #define CIF_UNLOCK(cif)         mtx_unlock(&(cif)->cif_mtx)
  256 #define CIF_FREE(cif)   do {                            \
  257                 CIF_LOCK_ASSERT(cif);                   \
  258                 if (TAILQ_EMPTY(&(cif)->cif_vrs))       \
  259                         carp_free_if(cif);              \
  260                 else                                    \
  261                         CIF_UNLOCK(cif);                \
  262 } while (0)
  263 
  264 #define CARP_LOG(...)   do {                            \
  265         if (V_carp_log > 0)                             \
  266                 log(LOG_INFO, "carp: " __VA_ARGS__);    \
  267 } while (0)
  268 
  269 #define CARP_DEBUG(...) do {                            \
  270         if (V_carp_log > 1)                             \
  271                 log(LOG_DEBUG, __VA_ARGS__);            \
  272 } while (0)
  273 
  274 #define IFNET_FOREACH_IFA(ifp, ifa)                                     \
  275         IF_ADDR_LOCK_ASSERT(ifp);                                       \
  276         TAILQ_FOREACH((ifa), &(ifp)->if_addrhead, ifa_link)             \
  277                 if ((ifa)->ifa_carp != NULL)
  278 
  279 #define CARP_FOREACH_IFA(sc, ifa)                                       \
  280         CARP_LOCK_ASSERT(sc);                                           \
  281         for (int _i = 0;                                                \
  282                 _i < (sc)->sc_naddrs + (sc)->sc_naddrs6 &&              \
  283                 ((ifa) = sc->sc_ifas[_i]) != NULL;                      \
  284                 ++_i)
  285 
  286 #define IFNET_FOREACH_CARP(ifp, sc)                                     \
  287         CIF_LOCK_ASSERT(ifp->if_carp);                                  \
  288         TAILQ_FOREACH((sc), &(ifp)->if_carp->cif_vrs, sc_list)
  289 
  290 #define DEMOTE_ADVSKEW(sc)                                      \
  291     (((sc)->sc_advskew + V_carp_demotion > CARP_MAXSKEW) ?      \
  292     CARP_MAXSKEW : ((sc)->sc_advskew + V_carp_demotion))
  293 
  294 static void     carp_input_c(struct mbuf *, struct carp_header *, sa_family_t);
  295 static struct carp_softc
  296                 *carp_alloc(struct ifnet *);
  297 static void     carp_detach_locked(struct ifaddr *);
  298 static void     carp_destroy(struct carp_softc *);
  299 static struct carp_if
  300                 *carp_alloc_if(struct ifnet *);
  301 static void     carp_free_if(struct carp_if *);
  302 static void     carp_set_state(struct carp_softc *, int);
  303 static void     carp_sc_state(struct carp_softc *);
  304 static void     carp_setrun(struct carp_softc *, sa_family_t);
  305 static void     carp_master_down(void *);
  306 static void     carp_master_down_locked(struct carp_softc *);
  307 static void     carp_send_ad(void *);
  308 static void     carp_send_ad_locked(struct carp_softc *);
  309 static void     carp_addroute(struct carp_softc *);
  310 static void     carp_ifa_addroute(struct ifaddr *);
  311 static void     carp_delroute(struct carp_softc *);
  312 static void     carp_ifa_delroute(struct ifaddr *);
  313 static void     carp_send_ad_all(void *, int);
  314 static void     carp_demote_adj(int, char *);
  315 
  316 static LIST_HEAD(, carp_softc) carp_list;
  317 static struct mtx carp_mtx;
  318 static struct task carp_sendall_task =
  319     TASK_INITIALIZER(0, carp_send_ad_all, NULL);
  320 
  321 static void
  322 carp_hmac_prepare(struct carp_softc *sc)
  323 {
  324         uint8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
  325         uint8_t vhid = sc->sc_vhid & 0xff;
  326         struct ifaddr *ifa;
  327         int i, found;
  328 #ifdef INET
  329         struct in_addr last, cur, in;
  330 #endif
  331 #ifdef INET6
  332         struct in6_addr last6, cur6, in6;
  333 #endif
  334 
  335         CARP_LOCK_ASSERT(sc);
  336 
  337         /* Compute ipad from key. */
  338         bzero(sc->sc_pad, sizeof(sc->sc_pad));
  339         bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
  340         for (i = 0; i < sizeof(sc->sc_pad); i++)
  341                 sc->sc_pad[i] ^= 0x36;
  342 
  343         /* Precompute first part of inner hash. */
  344         SHA1Init(&sc->sc_sha1);
  345         SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
  346         SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
  347         SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
  348         SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
  349 #ifdef INET
  350         cur.s_addr = 0;
  351         do {
  352                 found = 0;
  353                 last = cur;
  354                 cur.s_addr = 0xffffffff;
  355                 CARP_FOREACH_IFA(sc, ifa) {
  356                         in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
  357                         if (ifa->ifa_addr->sa_family == AF_INET &&
  358                             ntohl(in.s_addr) > ntohl(last.s_addr) &&
  359                             ntohl(in.s_addr) < ntohl(cur.s_addr)) {
  360                                 cur.s_addr = in.s_addr;
  361                                 found++;
  362                         }
  363                 }
  364                 if (found)
  365                         SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
  366         } while (found);
  367 #endif /* INET */
  368 #ifdef INET6
  369         memset(&cur6, 0, sizeof(cur6));
  370         do {
  371                 found = 0;
  372                 last6 = cur6;
  373                 memset(&cur6, 0xff, sizeof(cur6));
  374                 CARP_FOREACH_IFA(sc, ifa) {
  375                         in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
  376                         if (IN6_IS_SCOPE_EMBED(&in6))
  377                                 in6.s6_addr16[1] = 0;
  378                         if (ifa->ifa_addr->sa_family == AF_INET6 &&
  379                             memcmp(&in6, &last6, sizeof(in6)) > 0 &&
  380                             memcmp(&in6, &cur6, sizeof(in6)) < 0) {
  381                                 cur6 = in6;
  382                                 found++;
  383                         }
  384                 }
  385                 if (found)
  386                         SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
  387         } while (found);
  388 #endif /* INET6 */
  389 
  390         /* convert ipad to opad */
  391         for (i = 0; i < sizeof(sc->sc_pad); i++)
  392                 sc->sc_pad[i] ^= 0x36 ^ 0x5c;
  393 }
  394 
  395 static void
  396 carp_hmac_generate(struct carp_softc *sc, uint32_t counter[2],
  397     unsigned char md[20])
  398 {
  399         SHA1_CTX sha1ctx;
  400 
  401         CARP_LOCK_ASSERT(sc);
  402 
  403         /* fetch first half of inner hash */
  404         bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
  405 
  406         SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
  407         SHA1Final(md, &sha1ctx);
  408 
  409         /* outer hash */
  410         SHA1Init(&sha1ctx);
  411         SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
  412         SHA1Update(&sha1ctx, md, 20);
  413         SHA1Final(md, &sha1ctx);
  414 }
  415 
  416 static int
  417 carp_hmac_verify(struct carp_softc *sc, uint32_t counter[2],
  418     unsigned char md[20])
  419 {
  420         unsigned char md2[20];
  421 
  422         CARP_LOCK_ASSERT(sc);
  423 
  424         carp_hmac_generate(sc, counter, md2);
  425 
  426         return (bcmp(md, md2, sizeof(md2)));
  427 }
  428 
  429 /*
  430  * process input packet.
  431  * we have rearranged checks order compared to the rfc,
  432  * but it seems more efficient this way or not possible otherwise.
  433  */
  434 #ifdef INET
  435 void
  436 carp_input(struct mbuf *m, int hlen)
  437 {
  438         struct ip *ip = mtod(m, struct ip *);
  439         struct carp_header *ch;
  440         int iplen, len;
  441 
  442         CARPSTATS_INC(carps_ipackets);
  443 
  444         if (!V_carp_allow) {
  445                 m_freem(m);
  446                 return;
  447         }
  448 
  449         /* verify that the IP TTL is 255.  */
  450         if (ip->ip_ttl != CARP_DFLTTL) {
  451                 CARPSTATS_INC(carps_badttl);
  452                 CARP_DEBUG("%s: received ttl %d != 255 on %s\n", __func__,
  453                     ip->ip_ttl,
  454                     m->m_pkthdr.rcvif->if_xname);
  455                 m_freem(m);
  456                 return;
  457         }
  458 
  459         iplen = ip->ip_hl << 2;
  460 
  461         if (m->m_pkthdr.len < iplen + sizeof(*ch)) {
  462                 CARPSTATS_INC(carps_badlen);
  463                 CARP_DEBUG("%s: received len %zd < sizeof(struct carp_header) "
  464                     "on %s\n", __func__, m->m_len - sizeof(struct ip),
  465                     m->m_pkthdr.rcvif->if_xname);
  466                 m_freem(m);
  467                 return;
  468         }
  469 
  470         if (iplen + sizeof(*ch) < m->m_len) {
  471                 if ((m = m_pullup(m, iplen + sizeof(*ch))) == NULL) {
  472                         CARPSTATS_INC(carps_hdrops);
  473                         CARP_DEBUG("%s: pullup failed\n", __func__);
  474                         return;
  475                 }
  476                 ip = mtod(m, struct ip *);
  477         }
  478         ch = (struct carp_header *)((char *)ip + iplen);
  479 
  480         /*
  481          * verify that the received packet length is
  482          * equal to the CARP header
  483          */
  484         len = iplen + sizeof(*ch);
  485         if (len > m->m_pkthdr.len) {
  486                 CARPSTATS_INC(carps_badlen);
  487                 CARP_DEBUG("%s: packet too short %d on %s\n", __func__,
  488                     m->m_pkthdr.len,
  489                     m->m_pkthdr.rcvif->if_xname);
  490                 m_freem(m);
  491                 return;
  492         }
  493 
  494         if ((m = m_pullup(m, len)) == NULL) {
  495                 CARPSTATS_INC(carps_hdrops);
  496                 return;
  497         }
  498         ip = mtod(m, struct ip *);
  499         ch = (struct carp_header *)((char *)ip + iplen);
  500 
  501         /* verify the CARP checksum */
  502         m->m_data += iplen;
  503         if (in_cksum(m, len - iplen)) {
  504                 CARPSTATS_INC(carps_badsum);
  505                 CARP_DEBUG("%s: checksum failed on %s\n", __func__,
  506                     m->m_pkthdr.rcvif->if_xname);
  507                 m_freem(m);
  508                 return;
  509         }
  510         m->m_data -= iplen;
  511 
  512         carp_input_c(m, ch, AF_INET);
  513 }
  514 #endif
  515 
  516 #ifdef INET6
  517 int
  518 carp6_input(struct mbuf **mp, int *offp, int proto)
  519 {
  520         struct mbuf *m = *mp;
  521         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  522         struct carp_header *ch;
  523         u_int len;
  524 
  525         CARPSTATS_INC(carps_ipackets6);
  526 
  527         if (!V_carp_allow) {
  528                 m_freem(m);
  529                 return (IPPROTO_DONE);
  530         }
  531 
  532         /* check if received on a valid carp interface */
  533         if (m->m_pkthdr.rcvif->if_carp == NULL) {
  534                 CARPSTATS_INC(carps_badif);
  535                 CARP_DEBUG("%s: packet received on non-carp interface: %s\n",
  536                     __func__, m->m_pkthdr.rcvif->if_xname);
  537                 m_freem(m);
  538                 return (IPPROTO_DONE);
  539         }
  540 
  541         /* verify that the IP TTL is 255 */
  542         if (ip6->ip6_hlim != CARP_DFLTTL) {
  543                 CARPSTATS_INC(carps_badttl);
  544                 CARP_DEBUG("%s: received ttl %d != 255 on %s\n", __func__,
  545                     ip6->ip6_hlim, m->m_pkthdr.rcvif->if_xname);
  546                 m_freem(m);
  547                 return (IPPROTO_DONE);
  548         }
  549 
  550         /* verify that we have a complete carp packet */
  551         len = m->m_len;
  552         IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
  553         if (ch == NULL) {
  554                 CARPSTATS_INC(carps_badlen);
  555                 CARP_DEBUG("%s: packet size %u too small\n", __func__, len);
  556                 return (IPPROTO_DONE);
  557         }
  558 
  559 
  560         /* verify the CARP checksum */
  561         m->m_data += *offp;
  562         if (in_cksum(m, sizeof(*ch))) {
  563                 CARPSTATS_INC(carps_badsum);
  564                 CARP_DEBUG("%s: checksum failed, on %s\n", __func__,
  565                     m->m_pkthdr.rcvif->if_xname);
  566                 m_freem(m);
  567                 return (IPPROTO_DONE);
  568         }
  569         m->m_data -= *offp;
  570 
  571         carp_input_c(m, ch, AF_INET6);
  572         return (IPPROTO_DONE);
  573 }
  574 #endif /* INET6 */
  575 
  576 static void
  577 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
  578 {
  579         struct ifnet *ifp = m->m_pkthdr.rcvif;
  580         struct ifaddr *ifa;
  581         struct carp_softc *sc;
  582         uint64_t tmp_counter;
  583         struct timeval sc_tv, ch_tv;
  584 
  585         /* verify that the VHID is valid on the receiving interface */
  586         IF_ADDR_RLOCK(ifp);
  587         IFNET_FOREACH_IFA(ifp, ifa)
  588                 if (ifa->ifa_addr->sa_family == af &&
  589                     ifa->ifa_carp->sc_vhid == ch->carp_vhid) {
  590                         ifa_ref(ifa);
  591                         break;
  592                 }
  593         IF_ADDR_RUNLOCK(ifp);
  594 
  595         if (ifa == NULL) {
  596                 CARPSTATS_INC(carps_badvhid);
  597                 m_freem(m);
  598                 return;
  599         }
  600 
  601         /* verify the CARP version. */
  602         if (ch->carp_version != CARP_VERSION) {
  603                 CARPSTATS_INC(carps_badver);
  604                 CARP_DEBUG("%s: invalid version %d\n", ifp->if_xname,
  605                     ch->carp_version);
  606                 ifa_free(ifa);
  607                 m_freem(m);
  608                 return;
  609         }
  610 
  611         sc = ifa->ifa_carp;
  612         CARP_LOCK(sc);
  613         ifa_free(ifa);
  614 
  615         if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
  616                 CARPSTATS_INC(carps_badauth);
  617                 CARP_DEBUG("%s: incorrect hash for VHID %u@%s\n", __func__,
  618                     sc->sc_vhid, ifp->if_xname);
  619                 goto out;
  620         }
  621 
  622         tmp_counter = ntohl(ch->carp_counter[0]);
  623         tmp_counter = tmp_counter<<32;
  624         tmp_counter += ntohl(ch->carp_counter[1]);
  625 
  626         /* XXX Replay protection goes here */
  627 
  628         sc->sc_init_counter = 0;
  629         sc->sc_counter = tmp_counter;
  630 
  631         sc_tv.tv_sec = sc->sc_advbase;
  632         sc_tv.tv_usec = DEMOTE_ADVSKEW(sc) * 1000000 / 256;
  633         ch_tv.tv_sec = ch->carp_advbase;
  634         ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
  635 
  636         switch (sc->sc_state) {
  637         case INIT:
  638                 break;
  639         case MASTER:
  640                 /*
  641                  * If we receive an advertisement from a master who's going to
  642                  * be more frequent than us, go into BACKUP state.
  643                  */
  644                 if (timevalcmp(&sc_tv, &ch_tv, >) ||
  645                     timevalcmp(&sc_tv, &ch_tv, ==)) {
  646                         callout_stop(&sc->sc_ad_tmo);
  647                         CARP_LOG("VHID %u@%s: MASTER -> BACKUP "
  648                             "(more frequent advertisement received)\n",
  649                             sc->sc_vhid,
  650                             sc->sc_carpdev->if_xname);
  651                         carp_set_state(sc, BACKUP);
  652                         carp_setrun(sc, 0);
  653                         carp_delroute(sc);
  654                 }
  655                 break;
  656         case BACKUP:
  657                 /*
  658                  * If we're pre-empting masters who advertise slower than us,
  659                  * and this one claims to be slower, treat him as down.
  660                  */
  661                 if (V_carp_preempt && timevalcmp(&sc_tv, &ch_tv, <)) {
  662                         CARP_LOG("VHID %u@%s: BACKUP -> MASTER "
  663                             "(preempting a slower master)\n",
  664                             sc->sc_vhid,
  665                             sc->sc_carpdev->if_xname);
  666                         carp_master_down_locked(sc);
  667                         break;
  668                 }
  669 
  670                 /*
  671                  *  If the master is going to advertise at such a low frequency
  672                  *  that he's guaranteed to time out, we'd might as well just
  673                  *  treat him as timed out now.
  674                  */
  675                 sc_tv.tv_sec = sc->sc_advbase * 3;
  676                 if (timevalcmp(&sc_tv, &ch_tv, <)) {
  677                         CARP_LOG("VHID %u@%s: BACKUP -> MASTER "
  678                             "(master timed out)\n",
  679                             sc->sc_vhid,
  680                             sc->sc_carpdev->if_xname);
  681                         carp_master_down_locked(sc);
  682                         break;
  683                 }
  684 
  685                 /*
  686                  * Otherwise, we reset the counter and wait for the next
  687                  * advertisement.
  688                  */
  689                 carp_setrun(sc, af);
  690                 break;
  691         }
  692 
  693 out:
  694         CARP_UNLOCK(sc);
  695         m_freem(m);
  696 }
  697 
  698 static int
  699 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
  700 {
  701         struct m_tag *mtag;
  702 
  703         if (sc->sc_init_counter) {
  704                 /* this could also be seconds since unix epoch */
  705                 sc->sc_counter = arc4random();
  706                 sc->sc_counter = sc->sc_counter << 32;
  707                 sc->sc_counter += arc4random();
  708         } else
  709                 sc->sc_counter++;
  710 
  711         ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
  712         ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
  713 
  714         carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
  715 
  716         /* Tag packet for carp_output */
  717         if ((mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct carp_softc *),
  718             M_NOWAIT)) == NULL) {
  719                 m_freem(m);
  720                 CARPSTATS_INC(carps_onomem);
  721                 return (ENOMEM);
  722         }
  723         bcopy(&sc, mtag + 1, sizeof(sc));
  724         m_tag_prepend(m, mtag);
  725 
  726         return (0);
  727 }
  728 
  729 /*
  730  * To avoid LORs and possible recursions this function shouldn't
  731  * be called directly, but scheduled via taskqueue.
  732  */
  733 static void
  734 carp_send_ad_all(void *ctx __unused, int pending __unused)
  735 {
  736         struct carp_softc *sc;
  737 
  738         mtx_lock(&carp_mtx);
  739         LIST_FOREACH(sc, &carp_list, sc_next)
  740                 if (sc->sc_state == MASTER) {
  741                         CARP_LOCK(sc);
  742                         CURVNET_SET(sc->sc_carpdev->if_vnet);
  743                         carp_send_ad_locked(sc);
  744                         CURVNET_RESTORE();
  745                         CARP_UNLOCK(sc);
  746                 }
  747         mtx_unlock(&carp_mtx);
  748 }
  749 
  750 /* Send a periodic advertisement, executed in callout context. */
  751 static void
  752 carp_send_ad(void *v)
  753 {
  754         struct carp_softc *sc = v;
  755 
  756         CARP_LOCK_ASSERT(sc);
  757         CURVNET_SET(sc->sc_carpdev->if_vnet);
  758         carp_send_ad_locked(sc);
  759         CURVNET_RESTORE();
  760         CARP_UNLOCK(sc);
  761 }
  762 
  763 static void
  764 carp_send_ad_locked(struct carp_softc *sc)
  765 {
  766         struct carp_header ch;
  767         struct timeval tv;
  768         struct sockaddr sa;
  769         struct ifaddr *ifa;
  770         struct carp_header *ch_ptr;
  771         struct mbuf *m;
  772         int len, advskew;
  773 
  774         CARP_LOCK_ASSERT(sc);
  775 
  776         advskew = DEMOTE_ADVSKEW(sc);
  777         tv.tv_sec = sc->sc_advbase;
  778         tv.tv_usec = advskew * 1000000 / 256;
  779 
  780         ch.carp_version = CARP_VERSION;
  781         ch.carp_type = CARP_ADVERTISEMENT;
  782         ch.carp_vhid = sc->sc_vhid;
  783         ch.carp_advbase = sc->sc_advbase;
  784         ch.carp_advskew = advskew;
  785         ch.carp_authlen = 7;    /* XXX DEFINE */
  786         ch.carp_pad1 = 0;       /* must be zero */
  787         ch.carp_cksum = 0;
  788 
  789         /* XXXGL: OpenBSD picks first ifaddr with needed family. */
  790 
  791 #ifdef INET
  792         if (sc->sc_naddrs) {
  793                 struct ip *ip;
  794 
  795                 m = m_gethdr(M_NOWAIT, MT_DATA);
  796                 if (m == NULL) {
  797                         CARPSTATS_INC(carps_onomem);
  798                         goto resched;
  799                 }
  800                 len = sizeof(*ip) + sizeof(ch);
  801                 m->m_pkthdr.len = len;
  802                 m->m_pkthdr.rcvif = NULL;
  803                 m->m_len = len;
  804                 MH_ALIGN(m, m->m_len);
  805                 m->m_flags |= M_MCAST;
  806                 ip = mtod(m, struct ip *);
  807                 ip->ip_v = IPVERSION;
  808                 ip->ip_hl = sizeof(*ip) >> 2;
  809                 ip->ip_tos = IPTOS_LOWDELAY;
  810                 ip->ip_len = htons(len);
  811                 ip->ip_id = ip_newid();
  812                 ip->ip_off = htons(IP_DF);
  813                 ip->ip_ttl = CARP_DFLTTL;
  814                 ip->ip_p = IPPROTO_CARP;
  815                 ip->ip_sum = 0;
  816 
  817                 bzero(&sa, sizeof(sa));
  818                 sa.sa_family = AF_INET;
  819                 ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
  820                 if (ifa != NULL) {
  821                         ip->ip_src.s_addr =
  822                             ifatoia(ifa)->ia_addr.sin_addr.s_addr;
  823                         ifa_free(ifa);
  824                 } else
  825                         ip->ip_src.s_addr = 0;
  826                 ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
  827 
  828                 ch_ptr = (struct carp_header *)(&ip[1]);
  829                 bcopy(&ch, ch_ptr, sizeof(ch));
  830                 if (carp_prepare_ad(m, sc, ch_ptr))
  831                         goto resched;
  832 
  833                 m->m_data += sizeof(*ip);
  834                 ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip));
  835                 m->m_data -= sizeof(*ip);
  836 
  837                 CARPSTATS_INC(carps_opackets);
  838 
  839                 if (ip_output(m, NULL, NULL, IP_RAWOUTPUT,
  840                     &sc->sc_carpdev->if_carp->cif_imo, NULL)) {
  841                         if (sc->sc_sendad_errors < INT_MAX)
  842                                 sc->sc_sendad_errors++;
  843                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS)
  844                                 carp_demote_adj(V_carp_senderr_adj,
  845                                     "send error");
  846                         sc->sc_sendad_success = 0;
  847                 } else {
  848                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
  849                                 if (++sc->sc_sendad_success >=
  850                                     CARP_SENDAD_MIN_SUCCESS) {
  851                                         carp_demote_adj(-V_carp_senderr_adj,
  852                                             "send ok");
  853                                         sc->sc_sendad_errors = 0;
  854                                 }
  855                         } else
  856                                 sc->sc_sendad_errors = 0;
  857                 }
  858         }
  859 #endif /* INET */
  860 #ifdef INET6
  861         if (sc->sc_naddrs6) {
  862                 struct ip6_hdr *ip6;
  863 
  864                 m = m_gethdr(M_NOWAIT, MT_DATA);
  865                 if (m == NULL) {
  866                         CARPSTATS_INC(carps_onomem);
  867                         goto resched;
  868                 }
  869                 len = sizeof(*ip6) + sizeof(ch);
  870                 m->m_pkthdr.len = len;
  871                 m->m_pkthdr.rcvif = NULL;
  872                 m->m_len = len;
  873                 MH_ALIGN(m, m->m_len);
  874                 m->m_flags |= M_MCAST;
  875                 ip6 = mtod(m, struct ip6_hdr *);
  876                 bzero(ip6, sizeof(*ip6));
  877                 ip6->ip6_vfc |= IPV6_VERSION;
  878                 ip6->ip6_hlim = CARP_DFLTTL;
  879                 ip6->ip6_nxt = IPPROTO_CARP;
  880                 bzero(&sa, sizeof(sa));
  881 
  882                 /* set the source address */
  883                 sa.sa_family = AF_INET6;
  884                 ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
  885                 if (ifa != NULL) {
  886                         bcopy(IFA_IN6(ifa), &ip6->ip6_src,
  887                             sizeof(struct in6_addr));
  888                         ifa_free(ifa);
  889                 } else
  890                         /* This should never happen with IPv6. */
  891                         bzero(&ip6->ip6_src, sizeof(struct in6_addr));
  892 
  893                 /* Set the multicast destination. */
  894                 ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
  895                 ip6->ip6_dst.s6_addr8[15] = 0x12;
  896                 if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
  897                         m_freem(m);
  898                         CARP_DEBUG("%s: in6_setscope failed\n", __func__);
  899                         goto resched;
  900                 }
  901 
  902                 ch_ptr = (struct carp_header *)(&ip6[1]);
  903                 bcopy(&ch, ch_ptr, sizeof(ch));
  904                 if (carp_prepare_ad(m, sc, ch_ptr))
  905                         goto resched;
  906 
  907                 m->m_data += sizeof(*ip6);
  908                 ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip6));
  909                 m->m_data -= sizeof(*ip6);
  910 
  911                 CARPSTATS_INC(carps_opackets6);
  912 
  913                 if (ip6_output(m, NULL, NULL, 0,
  914                     &sc->sc_carpdev->if_carp->cif_im6o, NULL, NULL)) {
  915                         if (sc->sc_sendad_errors < INT_MAX)
  916                                 sc->sc_sendad_errors++;
  917                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS)
  918                                 carp_demote_adj(V_carp_senderr_adj,
  919                                     "send6 error");
  920                         sc->sc_sendad_success = 0;
  921                 } else {
  922                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
  923                                 if (++sc->sc_sendad_success >=
  924                                     CARP_SENDAD_MIN_SUCCESS) {
  925                                         carp_demote_adj(-V_carp_senderr_adj,
  926                                             "send6 ok");
  927                                         sc->sc_sendad_errors = 0;
  928                                 }
  929                         } else
  930                                 sc->sc_sendad_errors = 0;
  931                 }
  932         }
  933 #endif /* INET6 */
  934 
  935 resched:
  936         callout_reset(&sc->sc_ad_tmo, tvtohz(&tv), carp_send_ad, sc);
  937 }
  938 
  939 static void
  940 carp_addroute(struct carp_softc *sc)
  941 {
  942         struct ifaddr *ifa;
  943 
  944         CARP_FOREACH_IFA(sc, ifa)
  945                 carp_ifa_addroute(ifa);
  946 }
  947 
  948 static void
  949 carp_ifa_addroute(struct ifaddr *ifa)
  950 {
  951 
  952         switch (ifa->ifa_addr->sa_family) {
  953 #ifdef INET
  954         case AF_INET:
  955                 in_addprefix(ifatoia(ifa), RTF_UP);
  956                 ifa_add_loopback_route(ifa,
  957                     (struct sockaddr *)&ifatoia(ifa)->ia_addr);
  958                 break;
  959 #endif
  960 #ifdef INET6
  961         case AF_INET6:
  962                 ifa_add_loopback_route(ifa,
  963                     (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
  964                 in6_ifaddloop(ifa);
  965                 break;
  966 #endif
  967         }
  968 }
  969 
  970 static void
  971 carp_delroute(struct carp_softc *sc)
  972 {
  973         struct ifaddr *ifa;
  974 
  975         CARP_FOREACH_IFA(sc, ifa)
  976                 carp_ifa_delroute(ifa);
  977 }
  978 
  979 static void
  980 carp_ifa_delroute(struct ifaddr *ifa)
  981 {
  982 
  983         switch (ifa->ifa_addr->sa_family) {
  984 #ifdef INET
  985         case AF_INET:
  986                 ifa_del_loopback_route(ifa,
  987                     (struct sockaddr *)&ifatoia(ifa)->ia_addr);
  988                 in_scrubprefix(ifatoia(ifa), LLE_STATIC);
  989                 break;
  990 #endif
  991 #ifdef INET6
  992         case AF_INET6:
  993                 ifa_del_loopback_route(ifa,
  994                     (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
  995                 in6_ifremloop(ifa);
  996                 break;
  997 #endif
  998         }
  999 }
 1000 
 1001 int
 1002 carp_master(struct ifaddr *ifa)
 1003 {
 1004         struct carp_softc *sc = ifa->ifa_carp;
 1005 
 1006         return (sc->sc_state == MASTER);
 1007 }
 1008 
 1009 #ifdef INET
 1010 /*
 1011  * Broadcast a gratuitous ARP request containing
 1012  * the virtual router MAC address for each IP address
 1013  * associated with the virtual router.
 1014  */
 1015 static void
 1016 carp_send_arp(struct carp_softc *sc)
 1017 {
 1018         struct ifaddr *ifa;
 1019 
 1020         CARP_FOREACH_IFA(sc, ifa)
 1021                 if (ifa->ifa_addr->sa_family == AF_INET)
 1022                         arp_ifinit2(sc->sc_carpdev, ifa, LLADDR(&sc->sc_addr));
 1023 }
 1024 
 1025 int
 1026 carp_iamatch(struct ifaddr *ifa, uint8_t **enaddr)
 1027 {
 1028         struct carp_softc *sc = ifa->ifa_carp;
 1029 
 1030         if (sc->sc_state == MASTER) {
 1031                 *enaddr = LLADDR(&sc->sc_addr);
 1032                 return (1);
 1033         }
 1034 
 1035         return (0);
 1036 }
 1037 #endif
 1038 
 1039 #ifdef INET6
 1040 static void
 1041 carp_send_na(struct carp_softc *sc)
 1042 {
 1043         static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 1044         struct ifaddr *ifa;
 1045         struct in6_addr *in6;
 1046 
 1047         CARP_FOREACH_IFA(sc, ifa) {
 1048                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1049                         continue;
 1050 
 1051                 in6 = IFA_IN6(ifa);
 1052                 nd6_na_output(sc->sc_carpdev, &mcast, in6,
 1053                     ND_NA_FLAG_OVERRIDE, 1, NULL);
 1054                 DELAY(1000);    /* XXX */
 1055         }
 1056 }
 1057 
 1058 /*
 1059  * Returns ifa in case it's a carp address and it is MASTER, or if the address
 1060  * matches and is not a carp address.  Returns NULL otherwise.
 1061  */
 1062 struct ifaddr *
 1063 carp_iamatch6(struct ifnet *ifp, struct in6_addr *taddr)
 1064 {
 1065         struct ifaddr *ifa;
 1066 
 1067         ifa = NULL;
 1068         IF_ADDR_RLOCK(ifp);
 1069         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1070                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1071                         continue;
 1072                 if (!IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa)))
 1073                         continue;
 1074                 if (ifa->ifa_carp && ifa->ifa_carp->sc_state != MASTER)
 1075                         ifa = NULL;
 1076                 else
 1077                         ifa_ref(ifa);
 1078                 break;
 1079         }
 1080         IF_ADDR_RUNLOCK(ifp);
 1081 
 1082         return (ifa);
 1083 }
 1084 
 1085 caddr_t
 1086 carp_macmatch6(struct ifnet *ifp, struct mbuf *m, const struct in6_addr *taddr)
 1087 {
 1088         struct ifaddr *ifa;
 1089 
 1090         IF_ADDR_RLOCK(ifp);
 1091         IFNET_FOREACH_IFA(ifp, ifa)
 1092                 if (ifa->ifa_addr->sa_family == AF_INET6 &&
 1093                     IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa))) {
 1094                         struct carp_softc *sc = ifa->ifa_carp;
 1095                         struct m_tag *mtag;
 1096 
 1097                         IF_ADDR_RUNLOCK(ifp);
 1098 
 1099                         mtag = m_tag_get(PACKET_TAG_CARP,
 1100                             sizeof(struct carp_softc *), M_NOWAIT);
 1101                         if (mtag == NULL)
 1102                                 /* Better a bit than nothing. */
 1103                                 return (LLADDR(&sc->sc_addr));
 1104 
 1105                         bcopy(&sc, mtag + 1, sizeof(sc));
 1106                         m_tag_prepend(m, mtag);
 1107 
 1108                         return (LLADDR(&sc->sc_addr));
 1109                 }
 1110         IF_ADDR_RUNLOCK(ifp);
 1111 
 1112         return (NULL);
 1113 }
 1114 #endif /* INET6 */
 1115 
 1116 int
 1117 carp_forus(struct ifnet *ifp, u_char *dhost)
 1118 {
 1119         struct carp_softc *sc;
 1120         uint8_t *ena = dhost;
 1121 
 1122         if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
 1123                 return (0);
 1124 
 1125         CIF_LOCK(ifp->if_carp);
 1126         IFNET_FOREACH_CARP(ifp, sc) {
 1127                 CARP_LOCK(sc);
 1128                 if (sc->sc_state == MASTER && !bcmp(dhost, LLADDR(&sc->sc_addr),
 1129                     ETHER_ADDR_LEN)) {
 1130                         CARP_UNLOCK(sc);
 1131                         CIF_UNLOCK(ifp->if_carp);
 1132                         return (1);
 1133                 }
 1134                 CARP_UNLOCK(sc);
 1135         }
 1136         CIF_UNLOCK(ifp->if_carp);
 1137 
 1138         return (0);
 1139 }
 1140 
 1141 /* Master down timeout event, executed in callout context. */
 1142 static void
 1143 carp_master_down(void *v)
 1144 {
 1145         struct carp_softc *sc = v;
 1146 
 1147         CARP_LOCK_ASSERT(sc);
 1148 
 1149         CURVNET_SET(sc->sc_carpdev->if_vnet);
 1150         if (sc->sc_state == BACKUP) {
 1151                 CARP_LOG("VHID %u@%s: BACKUP -> MASTER (master down)\n",
 1152                     sc->sc_vhid,
 1153                     sc->sc_carpdev->if_xname);
 1154                 carp_master_down_locked(sc);
 1155         }
 1156         CURVNET_RESTORE();
 1157 
 1158         CARP_UNLOCK(sc);
 1159 }
 1160 
 1161 static void
 1162 carp_master_down_locked(struct carp_softc *sc)
 1163 {
 1164 
 1165         CARP_LOCK_ASSERT(sc);
 1166 
 1167         switch (sc->sc_state) {
 1168         case BACKUP:
 1169                 carp_set_state(sc, MASTER);
 1170                 carp_send_ad_locked(sc);
 1171 #ifdef INET
 1172                 carp_send_arp(sc);
 1173 #endif
 1174 #ifdef INET6
 1175                 carp_send_na(sc);
 1176 #endif
 1177                 carp_setrun(sc, 0);
 1178                 carp_addroute(sc);
 1179                 break;
 1180         case INIT:
 1181         case MASTER:
 1182 #ifdef INVARIANTS
 1183                 panic("carp: VHID %u@%s: master_down event in %s state\n",
 1184                     sc->sc_vhid,
 1185                     sc->sc_carpdev->if_xname,
 1186                     sc->sc_state ? "MASTER" : "INIT");
 1187 #endif
 1188                 break;
 1189         }
 1190 }
 1191 
 1192 /*
 1193  * When in backup state, af indicates whether to reset the master down timer
 1194  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
 1195  */
 1196 static void
 1197 carp_setrun(struct carp_softc *sc, sa_family_t af)
 1198 {
 1199         struct timeval tv;
 1200 
 1201         CARP_LOCK_ASSERT(sc);
 1202 
 1203         if ((sc->sc_carpdev->if_flags & IFF_UP) == 0 ||
 1204             sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
 1205             (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0))
 1206                 return;
 1207 
 1208         switch (sc->sc_state) {
 1209         case INIT:
 1210                 CARP_LOG("VHID %u@%s: INIT -> BACKUP\n",
 1211                     sc->sc_vhid,
 1212                     sc->sc_carpdev->if_xname);
 1213                 carp_set_state(sc, BACKUP);
 1214                 carp_setrun(sc, 0);
 1215                 break;
 1216         case BACKUP:
 1217                 callout_stop(&sc->sc_ad_tmo);
 1218                 tv.tv_sec = 3 * sc->sc_advbase;
 1219                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
 1220                 switch (af) {
 1221 #ifdef INET
 1222                 case AF_INET:
 1223                         callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
 1224                             carp_master_down, sc);
 1225                         break;
 1226 #endif
 1227 #ifdef INET6
 1228                 case AF_INET6:
 1229                         callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
 1230                             carp_master_down, sc);
 1231                         break;
 1232 #endif
 1233                 default:
 1234 #ifdef INET
 1235                         if (sc->sc_naddrs)
 1236                                 callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
 1237                                     carp_master_down, sc);
 1238 #endif
 1239 #ifdef INET6
 1240                         if (sc->sc_naddrs6)
 1241                                 callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
 1242                                     carp_master_down, sc);
 1243 #endif
 1244                         break;
 1245                 }
 1246                 break;
 1247         case MASTER:
 1248                 tv.tv_sec = sc->sc_advbase;
 1249                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
 1250                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
 1251                     carp_send_ad, sc);
 1252                 break;
 1253         }
 1254 }
 1255 
 1256 /*
 1257  * Setup multicast structures.
 1258  */
 1259 static int
 1260 carp_multicast_setup(struct carp_if *cif, sa_family_t sa)
 1261 {
 1262         struct ifnet *ifp = cif->cif_ifp;
 1263         int error = 0;
 1264 
 1265         CIF_LOCK_ASSERT(cif);
 1266 
 1267         switch (sa) {
 1268 #ifdef INET
 1269         case AF_INET:
 1270             {
 1271                 struct ip_moptions *imo = &cif->cif_imo;
 1272                 struct in_addr addr;
 1273 
 1274                 if (imo->imo_membership)
 1275                         return (0);
 1276 
 1277                 imo->imo_membership = (struct in_multi **)malloc(
 1278                     (sizeof(struct in_multi *) * IP_MIN_MEMBERSHIPS), M_CARP,
 1279                     M_NOWAIT);
 1280                 if (imo->imo_membership == NULL)
 1281                         return (ENOMEM);
 1282                 imo->imo_mfilters = NULL;
 1283                 imo->imo_max_memberships = IP_MIN_MEMBERSHIPS;
 1284                 imo->imo_multicast_vif = -1;
 1285 
 1286                 addr.s_addr = htonl(INADDR_CARP_GROUP);
 1287                 if ((error = in_joingroup(ifp, &addr, NULL,
 1288                     &imo->imo_membership[0])) != 0) {
 1289                         free(imo->imo_membership, M_CARP);
 1290                         break;
 1291                 }
 1292                 imo->imo_num_memberships++;
 1293                 imo->imo_multicast_ifp = ifp;
 1294                 imo->imo_multicast_ttl = CARP_DFLTTL;
 1295                 imo->imo_multicast_loop = 0;
 1296                 break;
 1297            }
 1298 #endif
 1299 #ifdef INET6
 1300         case AF_INET6:
 1301             {
 1302                 struct ip6_moptions *im6o = &cif->cif_im6o;
 1303                 struct in6_addr in6;
 1304                 struct in6_multi *in6m;
 1305 
 1306                 if (im6o->im6o_membership)
 1307                         return (0);
 1308 
 1309                 im6o->im6o_membership = (struct in6_multi **)malloc(
 1310                     (sizeof(struct in6_multi *) * IPV6_MIN_MEMBERSHIPS), M_CARP,
 1311                     M_ZERO | M_NOWAIT);
 1312                 if (im6o->im6o_membership == NULL)
 1313                         return (ENOMEM);
 1314                 im6o->im6o_mfilters = NULL;
 1315                 im6o->im6o_max_memberships = IPV6_MIN_MEMBERSHIPS;
 1316                 im6o->im6o_multicast_hlim = CARP_DFLTTL;
 1317                 im6o->im6o_multicast_ifp = ifp;
 1318 
 1319                 /* Join IPv6 CARP multicast group. */
 1320                 bzero(&in6, sizeof(in6));
 1321                 in6.s6_addr16[0] = htons(0xff02);
 1322                 in6.s6_addr8[15] = 0x12;
 1323                 if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
 1324                         free(im6o->im6o_membership, M_CARP);
 1325                         break;
 1326                 }
 1327                 in6m = NULL;
 1328                 if ((error = in6_mc_join(ifp, &in6, NULL, &in6m, 0)) != 0) {
 1329                         free(im6o->im6o_membership, M_CARP);
 1330                         break;
 1331                 }
 1332                 im6o->im6o_membership[0] = in6m;
 1333                 im6o->im6o_num_memberships++;
 1334 
 1335                 /* Join solicited multicast address. */
 1336                 bzero(&in6, sizeof(in6));
 1337                 in6.s6_addr16[0] = htons(0xff02);
 1338                 in6.s6_addr32[1] = 0;
 1339                 in6.s6_addr32[2] = htonl(1);
 1340                 in6.s6_addr32[3] = 0;
 1341                 in6.s6_addr8[12] = 0xff;
 1342                 if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
 1343                         in6_mc_leave(im6o->im6o_membership[0], NULL);
 1344                         free(im6o->im6o_membership, M_CARP);
 1345                         break;
 1346                 }
 1347                 in6m = NULL;
 1348                 if ((error = in6_mc_join(ifp, &in6, NULL, &in6m, 0)) != 0) {
 1349                         in6_mc_leave(im6o->im6o_membership[0], NULL);
 1350                         free(im6o->im6o_membership, M_CARP);
 1351                         break;
 1352                 }
 1353                 im6o->im6o_membership[1] = in6m;
 1354                 im6o->im6o_num_memberships++;
 1355                 break;
 1356             }
 1357 #endif
 1358         }
 1359 
 1360         return (error);
 1361 }
 1362 
 1363 /*
 1364  * Free multicast structures.
 1365  */
 1366 static void
 1367 carp_multicast_cleanup(struct carp_if *cif, sa_family_t sa)
 1368 {
 1369 
 1370         CIF_LOCK_ASSERT(cif);
 1371         switch (sa) {
 1372 #ifdef INET
 1373         case AF_INET:
 1374                 if (cif->cif_naddrs == 0) {
 1375                         struct ip_moptions *imo = &cif->cif_imo;
 1376 
 1377                         in_leavegroup(imo->imo_membership[0], NULL);
 1378                         KASSERT(imo->imo_mfilters == NULL,
 1379                             ("%s: imo_mfilters != NULL", __func__));
 1380                         free(imo->imo_membership, M_CARP);
 1381                         imo->imo_membership = NULL;
 1382 
 1383                 }
 1384                 break;
 1385 #endif
 1386 #ifdef INET6
 1387         case AF_INET6:
 1388                 if (cif->cif_naddrs6 == 0) {
 1389                         struct ip6_moptions *im6o = &cif->cif_im6o;
 1390 
 1391                         in6_mc_leave(im6o->im6o_membership[0], NULL);
 1392                         in6_mc_leave(im6o->im6o_membership[1], NULL);
 1393                         KASSERT(im6o->im6o_mfilters == NULL,
 1394                             ("%s: im6o_mfilters != NULL", __func__));
 1395                         free(im6o->im6o_membership, M_CARP);
 1396                         im6o->im6o_membership = NULL;
 1397                 }
 1398                 break;
 1399 #endif
 1400         }
 1401 }
 1402 
 1403 int
 1404 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa)
 1405 {
 1406         struct m_tag *mtag;
 1407         struct carp_softc *sc;
 1408 
 1409         if (!sa)
 1410                 return (0);
 1411 
 1412         switch (sa->sa_family) {
 1413 #ifdef INET
 1414         case AF_INET:
 1415                 break;
 1416 #endif
 1417 #ifdef INET6
 1418         case AF_INET6:
 1419                 break;
 1420 #endif
 1421         default:
 1422                 return (0);
 1423         }
 1424 
 1425         mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
 1426         if (mtag == NULL)
 1427                 return (0);
 1428 
 1429         bcopy(mtag + 1, &sc, sizeof(sc));
 1430 
 1431         /* Set the source MAC address to the Virtual Router MAC Address. */
 1432         switch (ifp->if_type) {
 1433         case IFT_ETHER:
 1434         case IFT_BRIDGE:
 1435         case IFT_L2VLAN: {
 1436                         struct ether_header *eh;
 1437 
 1438                         eh = mtod(m, struct ether_header *);
 1439                         eh->ether_shost[0] = 0;
 1440                         eh->ether_shost[1] = 0;
 1441                         eh->ether_shost[2] = 0x5e;
 1442                         eh->ether_shost[3] = 0;
 1443                         eh->ether_shost[4] = 1;
 1444                         eh->ether_shost[5] = sc->sc_vhid;
 1445                 }
 1446                 break;
 1447         case IFT_FDDI: {
 1448                         struct fddi_header *fh;
 1449 
 1450                         fh = mtod(m, struct fddi_header *);
 1451                         fh->fddi_shost[0] = 0;
 1452                         fh->fddi_shost[1] = 0;
 1453                         fh->fddi_shost[2] = 0x5e;
 1454                         fh->fddi_shost[3] = 0;
 1455                         fh->fddi_shost[4] = 1;
 1456                         fh->fddi_shost[5] = sc->sc_vhid;
 1457                 }
 1458                 break;
 1459         case IFT_ISO88025: {
 1460                         struct iso88025_header *th;
 1461                         th = mtod(m, struct iso88025_header *);
 1462                         th->iso88025_shost[0] = 3;
 1463                         th->iso88025_shost[1] = 0;
 1464                         th->iso88025_shost[2] = 0x40 >> (sc->sc_vhid - 1);
 1465                         th->iso88025_shost[3] = 0x40000 >> (sc->sc_vhid - 1);
 1466                         th->iso88025_shost[4] = 0;
 1467                         th->iso88025_shost[5] = 0;
 1468                 }
 1469                 break;
 1470         default:
 1471                 printf("%s: carp is not supported for the %d interface type\n",
 1472                     ifp->if_xname, ifp->if_type);
 1473                 return (EOPNOTSUPP);
 1474         }
 1475 
 1476         return (0);
 1477 }
 1478 
 1479 static struct carp_softc*
 1480 carp_alloc(struct ifnet *ifp)
 1481 {
 1482         struct carp_softc *sc;
 1483         struct carp_if *cif;
 1484 
 1485         if ((cif = ifp->if_carp) == NULL) {
 1486                 cif = carp_alloc_if(ifp);
 1487                 if (cif == NULL)
 1488                         return (NULL);
 1489         }
 1490 
 1491         sc = malloc(sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
 1492 
 1493         sc->sc_advbase = CARP_DFLTINTV;
 1494         sc->sc_vhid = -1;       /* required setting */
 1495         sc->sc_init_counter = 1;
 1496         sc->sc_state = INIT;
 1497 
 1498         sc->sc_ifasiz = sizeof(struct ifaddr *);
 1499         sc->sc_ifas = malloc(sc->sc_ifasiz, M_CARP, M_WAITOK|M_ZERO);
 1500         sc->sc_carpdev = ifp;
 1501 
 1502         CARP_LOCK_INIT(sc);
 1503 #ifdef INET
 1504         callout_init_mtx(&sc->sc_md_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
 1505 #endif
 1506 #ifdef INET6
 1507         callout_init_mtx(&sc->sc_md6_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
 1508 #endif
 1509         callout_init_mtx(&sc->sc_ad_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
 1510 
 1511         CIF_LOCK(cif);
 1512         TAILQ_INSERT_TAIL(&cif->cif_vrs, sc, sc_list);
 1513         CIF_UNLOCK(cif);
 1514 
 1515         mtx_lock(&carp_mtx);
 1516         LIST_INSERT_HEAD(&carp_list, sc, sc_next);
 1517         mtx_unlock(&carp_mtx);
 1518 
 1519         return (sc);
 1520 }
 1521 
 1522 static int
 1523 carp_grow_ifas(struct carp_softc *sc)
 1524 {
 1525         struct ifaddr **new;
 1526 
 1527         CARP_LOCK_ASSERT(sc);
 1528 
 1529         new = malloc(sc->sc_ifasiz * 2, M_CARP, M_NOWAIT|M_ZERO);
 1530         if (new == NULL)
 1531                 return (ENOMEM);
 1532         bcopy(sc->sc_ifas, new, sc->sc_ifasiz);
 1533         free(sc->sc_ifas, M_CARP);
 1534         sc->sc_ifas = new;
 1535         sc->sc_ifasiz *= 2;
 1536 
 1537         return (0);
 1538 }
 1539 
 1540 static void
 1541 carp_destroy(struct carp_softc *sc)
 1542 {
 1543         struct ifnet *ifp = sc->sc_carpdev;
 1544         struct carp_if *cif = ifp->if_carp;
 1545 
 1546         CIF_LOCK_ASSERT(cif);
 1547 
 1548         TAILQ_REMOVE(&cif->cif_vrs, sc, sc_list);
 1549 
 1550         mtx_lock(&carp_mtx);
 1551         LIST_REMOVE(sc, sc_next);
 1552         mtx_unlock(&carp_mtx);
 1553 
 1554         CARP_LOCK(sc);
 1555         if (sc->sc_suppress)
 1556                 carp_demote_adj(-V_carp_ifdown_adj, "vhid removed");
 1557         callout_drain(&sc->sc_ad_tmo);
 1558 #ifdef INET
 1559         callout_drain(&sc->sc_md_tmo);
 1560 #endif
 1561 #ifdef INET6
 1562         callout_drain(&sc->sc_md6_tmo);
 1563 #endif
 1564         CARP_LOCK_DESTROY(sc);
 1565 
 1566         free(sc->sc_ifas, M_CARP);
 1567         free(sc, M_CARP);
 1568 }
 1569 
 1570 static struct carp_if*
 1571 carp_alloc_if(struct ifnet *ifp)
 1572 {
 1573         struct carp_if *cif;
 1574 
 1575         cif = malloc(sizeof(*cif), M_CARP, M_WAITOK|M_ZERO);
 1576 
 1577         if (ifpromisc(ifp, 1) != 0)
 1578                 goto cleanup;
 1579 
 1580         CIF_LOCK_INIT(cif);
 1581         cif->cif_ifp = ifp;
 1582         TAILQ_INIT(&cif->cif_vrs);
 1583 
 1584         IF_ADDR_WLOCK(ifp);
 1585         ifp->if_carp = cif;
 1586         if_ref(ifp);
 1587         IF_ADDR_WUNLOCK(ifp);
 1588 
 1589         return (cif);
 1590 
 1591 cleanup:
 1592         free(cif, M_CARP);
 1593 
 1594         return (NULL);
 1595 }
 1596 
 1597 static void
 1598 carp_free_if(struct carp_if *cif)
 1599 {
 1600         struct ifnet *ifp = cif->cif_ifp;
 1601 
 1602         CIF_LOCK_ASSERT(cif);
 1603         KASSERT(TAILQ_EMPTY(&cif->cif_vrs), ("%s: softc list not empty",
 1604             __func__));
 1605 
 1606         IF_ADDR_WLOCK(ifp);
 1607         ifp->if_carp = NULL;
 1608         IF_ADDR_WUNLOCK(ifp);
 1609 
 1610         CIF_LOCK_DESTROY(cif);
 1611 
 1612         ifpromisc(ifp, 0);
 1613         if_rele(ifp);
 1614 
 1615         free(cif, M_CARP);
 1616 }
 1617 
 1618 static void
 1619 carp_carprcp(struct carpreq *carpr, struct carp_softc *sc, int priv)
 1620 {
 1621 
 1622         CARP_LOCK(sc);
 1623         carpr->carpr_state = sc->sc_state;
 1624         carpr->carpr_vhid = sc->sc_vhid;
 1625         carpr->carpr_advbase = sc->sc_advbase;
 1626         carpr->carpr_advskew = sc->sc_advskew;
 1627         if (priv)
 1628                 bcopy(sc->sc_key, carpr->carpr_key, sizeof(carpr->carpr_key));
 1629         else
 1630                 bzero(carpr->carpr_key, sizeof(carpr->carpr_key));
 1631         CARP_UNLOCK(sc);
 1632 }
 1633 
 1634 int
 1635 carp_ioctl(struct ifreq *ifr, u_long cmd, struct thread *td)
 1636 {
 1637         struct carpreq carpr;
 1638         struct ifnet *ifp;
 1639         struct carp_softc *sc = NULL;
 1640         int error = 0, locked = 0;
 1641 
 1642         if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
 1643                 return (error);
 1644 
 1645         ifp = ifunit_ref(ifr->ifr_name);
 1646         if (ifp == NULL)
 1647                 return (ENXIO);
 1648 
 1649         switch (ifp->if_type) {
 1650         case IFT_ETHER:
 1651         case IFT_L2VLAN:
 1652         case IFT_BRIDGE:
 1653         case IFT_FDDI:
 1654         case IFT_ISO88025:
 1655                 break;
 1656         default:
 1657                 error = EOPNOTSUPP;
 1658                 goto out;
 1659         }
 1660 
 1661         if ((ifp->if_flags & IFF_MULTICAST) == 0) {
 1662                 error = EADDRNOTAVAIL;
 1663                 goto out;
 1664         }
 1665 
 1666         switch (cmd) {
 1667         case SIOCSVH:
 1668                 if ((error = priv_check(td, PRIV_NETINET_CARP)))
 1669                         break;
 1670                 if (carpr.carpr_vhid <= 0 || carpr.carpr_vhid > CARP_MAXVHID ||
 1671                     carpr.carpr_advbase < 0 || carpr.carpr_advskew < 0) {
 1672                         error = EINVAL;
 1673                         break;
 1674                 }
 1675 
 1676                 if (ifp->if_carp) {
 1677                         CIF_LOCK(ifp->if_carp);
 1678                         IFNET_FOREACH_CARP(ifp, sc)
 1679                                 if (sc->sc_vhid == carpr.carpr_vhid)
 1680                                         break;
 1681                         CIF_UNLOCK(ifp->if_carp);
 1682                 }
 1683                 if (sc == NULL) {
 1684                         sc = carp_alloc(ifp);
 1685                         if (sc == NULL) {
 1686                                 error = EINVAL; /* XXX: ifpromisc failed */
 1687                                 break;
 1688                         }
 1689 
 1690                         CARP_LOCK(sc);
 1691                         sc->sc_vhid = carpr.carpr_vhid;
 1692                         LLADDR(&sc->sc_addr)[0] = 0;
 1693                         LLADDR(&sc->sc_addr)[1] = 0;
 1694                         LLADDR(&sc->sc_addr)[2] = 0x5e;
 1695                         LLADDR(&sc->sc_addr)[3] = 0;
 1696                         LLADDR(&sc->sc_addr)[4] = 1;
 1697                         LLADDR(&sc->sc_addr)[5] = sc->sc_vhid;
 1698                 } else
 1699                         CARP_LOCK(sc);
 1700                 locked = 1;
 1701                 if (carpr.carpr_advbase > 0) {
 1702                         if (carpr.carpr_advbase > 255 ||
 1703                             carpr.carpr_advbase < CARP_DFLTINTV) {
 1704                                 error = EINVAL;
 1705                                 break;
 1706                         }
 1707                         sc->sc_advbase = carpr.carpr_advbase;
 1708                 }
 1709                 if (carpr.carpr_advskew > 0) {
 1710                         if (carpr.carpr_advskew >= 255) {
 1711                                 error = EINVAL;
 1712                                 break;
 1713                         }
 1714                         sc->sc_advskew = carpr.carpr_advskew;
 1715                 }
 1716                 if (carpr.carpr_key[0] != '\0') {
 1717                         bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
 1718                         carp_hmac_prepare(sc);
 1719                 }
 1720                 if (sc->sc_state != INIT &&
 1721                     carpr.carpr_state != sc->sc_state) {
 1722                         switch (carpr.carpr_state) {
 1723                         case BACKUP:
 1724                                 callout_stop(&sc->sc_ad_tmo);
 1725                                 carp_set_state(sc, BACKUP);
 1726                                 carp_setrun(sc, 0);
 1727                                 carp_delroute(sc);
 1728                                 break;
 1729                         case MASTER:
 1730                                 carp_master_down_locked(sc);
 1731                                 break;
 1732                         default:
 1733                                 break;
 1734                         }
 1735                 }
 1736                 break;
 1737 
 1738         case SIOCGVH:
 1739             {
 1740                 int priveleged;
 1741 
 1742                 if (carpr.carpr_vhid < 0 || carpr.carpr_vhid > CARP_MAXVHID) {
 1743                         error = EINVAL;
 1744                         break;
 1745                 }
 1746                 if (carpr.carpr_count < 1) {
 1747                         error = EMSGSIZE;
 1748                         break;
 1749                 }
 1750                 if (ifp->if_carp == NULL) {
 1751                         error = ENOENT;
 1752                         break;
 1753                 }
 1754 
 1755                 priveleged = (priv_check(td, PRIV_NETINET_CARP) == 0);
 1756                 if (carpr.carpr_vhid != 0) {
 1757                         CIF_LOCK(ifp->if_carp);
 1758                         IFNET_FOREACH_CARP(ifp, sc)
 1759                                 if (sc->sc_vhid == carpr.carpr_vhid)
 1760                                         break;
 1761                         CIF_UNLOCK(ifp->if_carp);
 1762                         if (sc == NULL) {
 1763                                 error = ENOENT;
 1764                                 break;
 1765                         }
 1766                         carp_carprcp(&carpr, sc, priveleged);
 1767                         error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
 1768                 } else  {
 1769                         int i, count;
 1770 
 1771                         count = 0;
 1772                         CIF_LOCK(ifp->if_carp);
 1773                         IFNET_FOREACH_CARP(ifp, sc)
 1774                                 count++;
 1775 
 1776                         if (count > carpr.carpr_count) {
 1777                                 CIF_UNLOCK(ifp->if_carp);
 1778                                 error = EMSGSIZE;
 1779                                 break;
 1780                         }
 1781 
 1782                         i = 0;
 1783                         IFNET_FOREACH_CARP(ifp, sc) {
 1784                                 carp_carprcp(&carpr, sc, priveleged);
 1785                                 carpr.carpr_count = count;
 1786                                 error = copyout(&carpr, ifr->ifr_data +
 1787                                     (i * sizeof(carpr)), sizeof(carpr));
 1788                                 if (error) {
 1789                                         CIF_UNLOCK(ifp->if_carp);
 1790                                         break;
 1791                                 }
 1792                                 i++;
 1793                         }
 1794                         CIF_UNLOCK(ifp->if_carp);
 1795                 }
 1796                 break;
 1797             }
 1798         default:
 1799                 error = EINVAL;
 1800         }
 1801 
 1802 out:
 1803         if (locked)
 1804                 CARP_UNLOCK(sc);
 1805         if_rele(ifp);
 1806 
 1807         return (error);
 1808 }
 1809 
 1810 static int
 1811 carp_get_vhid(struct ifaddr *ifa)
 1812 {
 1813 
 1814         if (ifa == NULL || ifa->ifa_carp == NULL)
 1815                 return (0);
 1816 
 1817         return (ifa->ifa_carp->sc_vhid);
 1818 }
 1819 
 1820 int
 1821 carp_attach(struct ifaddr *ifa, int vhid)
 1822 {
 1823         struct ifnet *ifp = ifa->ifa_ifp;
 1824         struct carp_if *cif = ifp->if_carp;
 1825         struct carp_softc *sc;
 1826         int index, error;
 1827 
 1828         if (ifp->if_carp == NULL)
 1829                 return (ENOPROTOOPT);
 1830 
 1831         switch (ifa->ifa_addr->sa_family) {
 1832 #ifdef INET
 1833         case AF_INET:
 1834 #endif
 1835 #ifdef INET6
 1836         case AF_INET6:
 1837 #endif
 1838                 break;
 1839         default:
 1840                 return (EPROTOTYPE);
 1841         }
 1842 
 1843         CIF_LOCK(cif);
 1844         IFNET_FOREACH_CARP(ifp, sc)
 1845                 if (sc->sc_vhid == vhid)
 1846                         break;
 1847         if (sc == NULL) {
 1848                 CIF_UNLOCK(cif);
 1849                 return (ENOENT);
 1850         }
 1851 
 1852         if (ifa->ifa_carp) {
 1853                 if (ifa->ifa_carp->sc_vhid != vhid)
 1854                         carp_detach_locked(ifa);
 1855                 else {
 1856                         CIF_UNLOCK(cif);
 1857                         return (0);
 1858                 }
 1859         }
 1860 
 1861         error = carp_multicast_setup(cif, ifa->ifa_addr->sa_family);
 1862         if (error) {
 1863                 CIF_FREE(cif);
 1864                 return (error);
 1865         }
 1866 
 1867         CARP_LOCK(sc);
 1868         index = sc->sc_naddrs + sc->sc_naddrs6 + 1;
 1869         if (index > sc->sc_ifasiz / sizeof(struct ifaddr *))
 1870                 if ((error = carp_grow_ifas(sc)) != 0) {
 1871                         carp_multicast_cleanup(cif,
 1872                             ifa->ifa_addr->sa_family);
 1873                         CARP_UNLOCK(sc);
 1874                         CIF_FREE(cif);
 1875                         return (error);
 1876                 }
 1877 
 1878         switch (ifa->ifa_addr->sa_family) {
 1879 #ifdef INET
 1880         case AF_INET:
 1881                 cif->cif_naddrs++;
 1882                 sc->sc_naddrs++;
 1883                 break;
 1884 #endif
 1885 #ifdef INET6
 1886         case AF_INET6:
 1887                 cif->cif_naddrs6++;
 1888                 sc->sc_naddrs6++;
 1889                 break;
 1890 #endif
 1891         }
 1892 
 1893         ifa_ref(ifa);
 1894         sc->sc_ifas[index - 1] = ifa;
 1895         ifa->ifa_carp = sc;
 1896 
 1897         carp_hmac_prepare(sc);
 1898         carp_sc_state(sc);
 1899 
 1900         CARP_UNLOCK(sc);
 1901         CIF_UNLOCK(cif);
 1902 
 1903         return (0);
 1904 }
 1905 
 1906 void
 1907 carp_detach(struct ifaddr *ifa)
 1908 {
 1909         struct ifnet *ifp = ifa->ifa_ifp;
 1910         struct carp_if *cif = ifp->if_carp;
 1911 
 1912         CIF_LOCK(cif);
 1913         carp_detach_locked(ifa);
 1914         CIF_FREE(cif);
 1915 }
 1916 
 1917 static void
 1918 carp_detach_locked(struct ifaddr *ifa)
 1919 {
 1920         struct ifnet *ifp = ifa->ifa_ifp;
 1921         struct carp_if *cif = ifp->if_carp;
 1922         struct carp_softc *sc = ifa->ifa_carp;
 1923         int i, index;
 1924 
 1925         KASSERT(sc != NULL, ("%s: %p not attached", __func__, ifa));
 1926 
 1927         CIF_LOCK_ASSERT(cif);
 1928         CARP_LOCK(sc);
 1929 
 1930         /* Shift array. */
 1931         index = sc->sc_naddrs + sc->sc_naddrs6;
 1932         for (i = 0; i < index; i++)
 1933                 if (sc->sc_ifas[i] == ifa)
 1934                         break;
 1935         KASSERT(i < index, ("%s: %p no backref", __func__, ifa));
 1936         for (; i < index - 1; i++)
 1937                 sc->sc_ifas[i] = sc->sc_ifas[i+1];
 1938         sc->sc_ifas[index - 1] = NULL;
 1939 
 1940         switch (ifa->ifa_addr->sa_family) {
 1941 #ifdef INET
 1942         case AF_INET:
 1943                 cif->cif_naddrs--;
 1944                 sc->sc_naddrs--;
 1945                 break;
 1946 #endif
 1947 #ifdef INET6
 1948         case AF_INET6:
 1949                 cif->cif_naddrs6--;
 1950                 sc->sc_naddrs6--;
 1951                 break;
 1952 #endif
 1953         }
 1954 
 1955         carp_ifa_delroute(ifa);
 1956         carp_multicast_cleanup(cif, ifa->ifa_addr->sa_family);
 1957 
 1958         ifa->ifa_carp = NULL;
 1959         ifa_free(ifa);
 1960 
 1961         carp_hmac_prepare(sc);
 1962         carp_sc_state(sc);
 1963 
 1964         if (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) {
 1965                 CARP_UNLOCK(sc);
 1966                 carp_destroy(sc);
 1967         } else
 1968                 CARP_UNLOCK(sc);
 1969 }
 1970 
 1971 static void
 1972 carp_set_state(struct carp_softc *sc, int state)
 1973 {
 1974 
 1975         CARP_LOCK_ASSERT(sc);
 1976 
 1977         if (sc->sc_state != state) {
 1978                 const char *carp_states[] = { CARP_STATES };
 1979                 char subsys[IFNAMSIZ+5];
 1980 
 1981                 sc->sc_state = state;
 1982 
 1983                 snprintf(subsys, IFNAMSIZ+5, "%u@%s", sc->sc_vhid,
 1984                     sc->sc_carpdev->if_xname);
 1985                 devctl_notify("CARP", subsys, carp_states[state], NULL);
 1986         }
 1987 }
 1988 
 1989 static void
 1990 carp_linkstate(struct ifnet *ifp)
 1991 {
 1992         struct carp_softc *sc;
 1993 
 1994         CIF_LOCK(ifp->if_carp);
 1995         IFNET_FOREACH_CARP(ifp, sc) {
 1996                 CARP_LOCK(sc);
 1997                 carp_sc_state(sc);
 1998                 CARP_UNLOCK(sc);
 1999         }
 2000         CIF_UNLOCK(ifp->if_carp);
 2001 }
 2002 
 2003 static void
 2004 carp_sc_state(struct carp_softc *sc)
 2005 {
 2006 
 2007         CARP_LOCK_ASSERT(sc);
 2008 
 2009         if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
 2010             !(sc->sc_carpdev->if_flags & IFF_UP)) {
 2011                 callout_stop(&sc->sc_ad_tmo);
 2012 #ifdef INET
 2013                 callout_stop(&sc->sc_md_tmo);
 2014 #endif
 2015 #ifdef INET6
 2016                 callout_stop(&sc->sc_md6_tmo);
 2017 #endif
 2018                 carp_set_state(sc, INIT);
 2019                 carp_setrun(sc, 0);
 2020                 if (!sc->sc_suppress)
 2021                         carp_demote_adj(V_carp_ifdown_adj, "interface down");
 2022                 sc->sc_suppress = 1;
 2023         } else {
 2024                 carp_set_state(sc, INIT);
 2025                 carp_setrun(sc, 0);
 2026                 if (sc->sc_suppress)
 2027                         carp_demote_adj(-V_carp_ifdown_adj, "interface up");
 2028                 sc->sc_suppress = 0;
 2029         }
 2030 }
 2031 
 2032 static void
 2033 carp_demote_adj(int adj, char *reason)
 2034 {
 2035         atomic_add_int(&V_carp_demotion, adj);
 2036         CARP_LOG("demoted by %d to %d (%s)\n", adj, V_carp_demotion, reason);
 2037         taskqueue_enqueue(taskqueue_swi, &carp_sendall_task);
 2038 }
 2039 
 2040 static int
 2041 carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS)
 2042 {
 2043         int new, error;
 2044 
 2045         new = V_carp_demotion;
 2046         error = sysctl_handle_int(oidp, &new, 0, req);
 2047         if (error || !req->newptr)
 2048                 return (error);
 2049 
 2050         carp_demote_adj(new, "sysctl");
 2051 
 2052         return (0);
 2053 }
 2054 
 2055 #ifdef INET
 2056 extern  struct domain inetdomain;
 2057 static struct protosw in_carp_protosw = {
 2058         .pr_type =              SOCK_RAW,
 2059         .pr_domain =            &inetdomain,
 2060         .pr_protocol =          IPPROTO_CARP,
 2061         .pr_flags =             PR_ATOMIC|PR_ADDR,
 2062         .pr_input =             carp_input,
 2063         .pr_output =            (pr_output_t *)rip_output,
 2064         .pr_ctloutput =         rip_ctloutput,
 2065         .pr_usrreqs =           &rip_usrreqs
 2066 };
 2067 #endif
 2068 
 2069 #ifdef INET6
 2070 extern  struct domain inet6domain;
 2071 static struct ip6protosw in6_carp_protosw = {
 2072         .pr_type =              SOCK_RAW,
 2073         .pr_domain =            &inet6domain,
 2074         .pr_protocol =          IPPROTO_CARP,
 2075         .pr_flags =             PR_ATOMIC|PR_ADDR,
 2076         .pr_input =             carp6_input,
 2077         .pr_output =            rip6_output,
 2078         .pr_ctloutput =         rip6_ctloutput,
 2079         .pr_usrreqs =           &rip6_usrreqs
 2080 };
 2081 #endif
 2082 
 2083 static void
 2084 carp_mod_cleanup(void)
 2085 {
 2086 
 2087 #ifdef INET
 2088         if (proto_reg[CARP_INET] == 0) {
 2089                 (void)ipproto_unregister(IPPROTO_CARP);
 2090                 pf_proto_unregister(PF_INET, IPPROTO_CARP, SOCK_RAW);
 2091                 proto_reg[CARP_INET] = -1;
 2092         }
 2093         carp_iamatch_p = NULL;
 2094 #endif
 2095 #ifdef INET6
 2096         if (proto_reg[CARP_INET6] == 0) {
 2097                 (void)ip6proto_unregister(IPPROTO_CARP);
 2098                 pf_proto_unregister(PF_INET6, IPPROTO_CARP, SOCK_RAW);
 2099                 proto_reg[CARP_INET6] = -1;
 2100         }
 2101         carp_iamatch6_p = NULL;
 2102         carp_macmatch6_p = NULL;
 2103 #endif
 2104         carp_ioctl_p = NULL;
 2105         carp_attach_p = NULL;
 2106         carp_detach_p = NULL;
 2107         carp_get_vhid_p = NULL;
 2108         carp_linkstate_p = NULL;
 2109         carp_forus_p = NULL;
 2110         carp_output_p = NULL;
 2111         carp_demote_adj_p = NULL;
 2112         carp_master_p = NULL;
 2113         mtx_unlock(&carp_mtx);
 2114         taskqueue_drain(taskqueue_swi, &carp_sendall_task);
 2115         mtx_destroy(&carp_mtx);
 2116 }
 2117 
 2118 static int
 2119 carp_mod_load(void)
 2120 {
 2121         int err;
 2122 
 2123         mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
 2124         LIST_INIT(&carp_list);
 2125         carp_get_vhid_p = carp_get_vhid;
 2126         carp_forus_p = carp_forus;
 2127         carp_output_p = carp_output;
 2128         carp_linkstate_p = carp_linkstate;
 2129         carp_ioctl_p = carp_ioctl;
 2130         carp_attach_p = carp_attach;
 2131         carp_detach_p = carp_detach;
 2132         carp_demote_adj_p = carp_demote_adj;
 2133         carp_master_p = carp_master;
 2134 #ifdef INET6
 2135         carp_iamatch6_p = carp_iamatch6;
 2136         carp_macmatch6_p = carp_macmatch6;
 2137         proto_reg[CARP_INET6] = pf_proto_register(PF_INET6,
 2138             (struct protosw *)&in6_carp_protosw);
 2139         if (proto_reg[CARP_INET6]) {
 2140                 printf("carp: error %d attaching to PF_INET6\n",
 2141                     proto_reg[CARP_INET6]);
 2142                 carp_mod_cleanup();
 2143                 return (proto_reg[CARP_INET6]);
 2144         }
 2145         err = ip6proto_register(IPPROTO_CARP);
 2146         if (err) {
 2147                 printf("carp: error %d registering with INET6\n", err);
 2148                 carp_mod_cleanup();
 2149                 return (err);
 2150         }
 2151 #endif
 2152 #ifdef INET
 2153         carp_iamatch_p = carp_iamatch;
 2154         proto_reg[CARP_INET] = pf_proto_register(PF_INET, &in_carp_protosw);
 2155         if (proto_reg[CARP_INET]) {
 2156                 printf("carp: error %d attaching to PF_INET\n",
 2157                     proto_reg[CARP_INET]);
 2158                 carp_mod_cleanup();
 2159                 return (proto_reg[CARP_INET]);
 2160         }
 2161         err = ipproto_register(IPPROTO_CARP);
 2162         if (err) {
 2163                 printf("carp: error %d registering with INET\n", err);
 2164                 carp_mod_cleanup();
 2165                 return (err);
 2166         }
 2167 #endif
 2168         return (0);
 2169 }
 2170 
 2171 static int
 2172 carp_modevent(module_t mod, int type, void *data)
 2173 {
 2174         switch (type) {
 2175         case MOD_LOAD:
 2176                 return carp_mod_load();
 2177                 /* NOTREACHED */
 2178         case MOD_UNLOAD:
 2179                 mtx_lock(&carp_mtx);
 2180                 if (LIST_EMPTY(&carp_list))
 2181                         carp_mod_cleanup();
 2182                 else {
 2183                         mtx_unlock(&carp_mtx);
 2184                         return (EBUSY);
 2185                 }
 2186                 break;
 2187 
 2188         default:
 2189                 return (EINVAL);
 2190         }
 2191 
 2192         return (0);
 2193 }
 2194 
 2195 static moduledata_t carp_mod = {
 2196         "carp",
 2197         carp_modevent,
 2198         0
 2199 };
 2200 
 2201 DECLARE_MODULE(carp, carp_mod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);

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