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/10.3/sys/netinet/ip_carp.c 278075 2015-02-02 11:42:35Z loos $");
   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_error(struct carp_softc *sc, int error)
  765 {
  766 
  767         if (error) {
  768                 if (sc->sc_sendad_errors < INT_MAX)
  769                         sc->sc_sendad_errors++;
  770                 if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
  771                         static const char fmt[] = "send error %d on %s";
  772                         char msg[sizeof(fmt) + IFNAMSIZ];
  773 
  774                         sprintf(msg, fmt, error, sc->sc_carpdev->if_xname);
  775                         carp_demote_adj(V_carp_senderr_adj, msg);
  776                 }
  777                 sc->sc_sendad_success = 0;
  778         } else {
  779                 if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS &&
  780                     ++sc->sc_sendad_success >= CARP_SENDAD_MIN_SUCCESS) {
  781                         static const char fmt[] = "send ok on %s";
  782                         char msg[sizeof(fmt) + IFNAMSIZ];
  783 
  784                         sprintf(msg, fmt, sc->sc_carpdev->if_xname);
  785                         carp_demote_adj(-V_carp_senderr_adj, msg);
  786                         sc->sc_sendad_errors = 0;
  787                 } else
  788                         sc->sc_sendad_errors = 0;
  789         }
  790 }
  791 
  792 static void
  793 carp_send_ad_locked(struct carp_softc *sc)
  794 {
  795         struct carp_header ch;
  796         struct timeval tv;
  797         struct sockaddr sa;
  798         struct ifaddr *ifa;
  799         struct carp_header *ch_ptr;
  800         struct mbuf *m;
  801         int len, advskew;
  802 
  803         CARP_LOCK_ASSERT(sc);
  804 
  805         advskew = DEMOTE_ADVSKEW(sc);
  806         tv.tv_sec = sc->sc_advbase;
  807         tv.tv_usec = advskew * 1000000 / 256;
  808 
  809         ch.carp_version = CARP_VERSION;
  810         ch.carp_type = CARP_ADVERTISEMENT;
  811         ch.carp_vhid = sc->sc_vhid;
  812         ch.carp_advbase = sc->sc_advbase;
  813         ch.carp_advskew = advskew;
  814         ch.carp_authlen = 7;    /* XXX DEFINE */
  815         ch.carp_pad1 = 0;       /* must be zero */
  816         ch.carp_cksum = 0;
  817 
  818         /* XXXGL: OpenBSD picks first ifaddr with needed family. */
  819 
  820 #ifdef INET
  821         if (sc->sc_naddrs) {
  822                 struct ip *ip;
  823 
  824                 m = m_gethdr(M_NOWAIT, MT_DATA);
  825                 if (m == NULL) {
  826                         CARPSTATS_INC(carps_onomem);
  827                         goto resched;
  828                 }
  829                 len = sizeof(*ip) + sizeof(ch);
  830                 m->m_pkthdr.len = len;
  831                 m->m_pkthdr.rcvif = NULL;
  832                 m->m_len = len;
  833                 MH_ALIGN(m, m->m_len);
  834                 m->m_flags |= M_MCAST;
  835                 ip = mtod(m, struct ip *);
  836                 ip->ip_v = IPVERSION;
  837                 ip->ip_hl = sizeof(*ip) >> 2;
  838                 ip->ip_tos = IPTOS_LOWDELAY;
  839                 ip->ip_len = htons(len);
  840                 ip->ip_id = ip_newid();
  841                 ip->ip_off = htons(IP_DF);
  842                 ip->ip_ttl = CARP_DFLTTL;
  843                 ip->ip_p = IPPROTO_CARP;
  844                 ip->ip_sum = 0;
  845 
  846                 bzero(&sa, sizeof(sa));
  847                 sa.sa_family = AF_INET;
  848                 ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
  849                 if (ifa != NULL) {
  850                         ip->ip_src.s_addr =
  851                             ifatoia(ifa)->ia_addr.sin_addr.s_addr;
  852                         ifa_free(ifa);
  853                 } else
  854                         ip->ip_src.s_addr = 0;
  855                 ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
  856 
  857                 ch_ptr = (struct carp_header *)(&ip[1]);
  858                 bcopy(&ch, ch_ptr, sizeof(ch));
  859                 if (carp_prepare_ad(m, sc, ch_ptr))
  860                         goto resched;
  861 
  862                 m->m_data += sizeof(*ip);
  863                 ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip));
  864                 m->m_data -= sizeof(*ip);
  865 
  866                 CARPSTATS_INC(carps_opackets);
  867 
  868                 carp_send_ad_error(sc, ip_output(m, NULL, NULL, IP_RAWOUTPUT,
  869                     &sc->sc_carpdev->if_carp->cif_imo, NULL));
  870         }
  871 #endif /* INET */
  872 #ifdef INET6
  873         if (sc->sc_naddrs6) {
  874                 struct ip6_hdr *ip6;
  875 
  876                 m = m_gethdr(M_NOWAIT, MT_DATA);
  877                 if (m == NULL) {
  878                         CARPSTATS_INC(carps_onomem);
  879                         goto resched;
  880                 }
  881                 len = sizeof(*ip6) + sizeof(ch);
  882                 m->m_pkthdr.len = len;
  883                 m->m_pkthdr.rcvif = NULL;
  884                 m->m_len = len;
  885                 MH_ALIGN(m, m->m_len);
  886                 m->m_flags |= M_MCAST;
  887                 ip6 = mtod(m, struct ip6_hdr *);
  888                 bzero(ip6, sizeof(*ip6));
  889                 ip6->ip6_vfc |= IPV6_VERSION;
  890                 ip6->ip6_hlim = CARP_DFLTTL;
  891                 ip6->ip6_nxt = IPPROTO_CARP;
  892                 bzero(&sa, sizeof(sa));
  893 
  894                 /* set the source address */
  895                 sa.sa_family = AF_INET6;
  896                 ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
  897                 if (ifa != NULL) {
  898                         bcopy(IFA_IN6(ifa), &ip6->ip6_src,
  899                             sizeof(struct in6_addr));
  900                         ifa_free(ifa);
  901                 } else
  902                         /* This should never happen with IPv6. */
  903                         bzero(&ip6->ip6_src, sizeof(struct in6_addr));
  904 
  905                 /* Set the multicast destination. */
  906                 ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
  907                 ip6->ip6_dst.s6_addr8[15] = 0x12;
  908                 if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
  909                         m_freem(m);
  910                         CARP_DEBUG("%s: in6_setscope failed\n", __func__);
  911                         goto resched;
  912                 }
  913 
  914                 ch_ptr = (struct carp_header *)(&ip6[1]);
  915                 bcopy(&ch, ch_ptr, sizeof(ch));
  916                 if (carp_prepare_ad(m, sc, ch_ptr))
  917                         goto resched;
  918 
  919                 m->m_data += sizeof(*ip6);
  920                 ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip6));
  921                 m->m_data -= sizeof(*ip6);
  922 
  923                 CARPSTATS_INC(carps_opackets6);
  924 
  925                 carp_send_ad_error(sc, ip6_output(m, NULL, NULL, 0,
  926                     &sc->sc_carpdev->if_carp->cif_im6o, NULL, NULL));
  927         }
  928 #endif /* INET6 */
  929 
  930 resched:
  931         callout_reset(&sc->sc_ad_tmo, tvtohz(&tv), carp_send_ad, sc);
  932 }
  933 
  934 static void
  935 carp_addroute(struct carp_softc *sc)
  936 {
  937         struct ifaddr *ifa;
  938 
  939         CARP_FOREACH_IFA(sc, ifa)
  940                 carp_ifa_addroute(ifa);
  941 }
  942 
  943 static void
  944 carp_ifa_addroute(struct ifaddr *ifa)
  945 {
  946 
  947         switch (ifa->ifa_addr->sa_family) {
  948 #ifdef INET
  949         case AF_INET:
  950                 in_addprefix(ifatoia(ifa), RTF_UP);
  951                 ifa_add_loopback_route(ifa,
  952                     (struct sockaddr *)&ifatoia(ifa)->ia_addr);
  953                 break;
  954 #endif
  955 #ifdef INET6
  956         case AF_INET6:
  957                 ifa_add_loopback_route(ifa,
  958                     (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
  959                 in6_ifaddloop(ifa);
  960                 break;
  961 #endif
  962         }
  963 }
  964 
  965 static void
  966 carp_delroute(struct carp_softc *sc)
  967 {
  968         struct ifaddr *ifa;
  969 
  970         CARP_FOREACH_IFA(sc, ifa)
  971                 carp_ifa_delroute(ifa);
  972 }
  973 
  974 static void
  975 carp_ifa_delroute(struct ifaddr *ifa)
  976 {
  977 
  978         switch (ifa->ifa_addr->sa_family) {
  979 #ifdef INET
  980         case AF_INET:
  981                 ifa_del_loopback_route(ifa,
  982                     (struct sockaddr *)&ifatoia(ifa)->ia_addr);
  983                 in_scrubprefix(ifatoia(ifa), LLE_STATIC);
  984                 break;
  985 #endif
  986 #ifdef INET6
  987         case AF_INET6:
  988                 ifa_del_loopback_route(ifa,
  989                     (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
  990                 in6_ifremloop(ifa);
  991                 break;
  992 #endif
  993         }
  994 }
  995 
  996 int
  997 carp_master(struct ifaddr *ifa)
  998 {
  999         struct carp_softc *sc = ifa->ifa_carp;
 1000 
 1001         return (sc->sc_state == MASTER);
 1002 }
 1003 
 1004 #ifdef INET
 1005 /*
 1006  * Broadcast a gratuitous ARP request containing
 1007  * the virtual router MAC address for each IP address
 1008  * associated with the virtual router.
 1009  */
 1010 static void
 1011 carp_send_arp(struct carp_softc *sc)
 1012 {
 1013         struct ifaddr *ifa;
 1014 
 1015         CARP_FOREACH_IFA(sc, ifa)
 1016                 if (ifa->ifa_addr->sa_family == AF_INET)
 1017                         arp_ifinit2(sc->sc_carpdev, ifa, LLADDR(&sc->sc_addr));
 1018 }
 1019 
 1020 int
 1021 carp_iamatch(struct ifaddr *ifa, uint8_t **enaddr)
 1022 {
 1023         struct carp_softc *sc = ifa->ifa_carp;
 1024 
 1025         if (sc->sc_state == MASTER) {
 1026                 *enaddr = LLADDR(&sc->sc_addr);
 1027                 return (1);
 1028         }
 1029 
 1030         return (0);
 1031 }
 1032 #endif
 1033 
 1034 #ifdef INET6
 1035 static void
 1036 carp_send_na(struct carp_softc *sc)
 1037 {
 1038         static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 1039         struct ifaddr *ifa;
 1040         struct in6_addr *in6;
 1041 
 1042         CARP_FOREACH_IFA(sc, ifa) {
 1043                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1044                         continue;
 1045 
 1046                 in6 = IFA_IN6(ifa);
 1047                 nd6_na_output(sc->sc_carpdev, &mcast, in6,
 1048                     ND_NA_FLAG_OVERRIDE, 1, NULL);
 1049                 DELAY(1000);    /* XXX */
 1050         }
 1051 }
 1052 
 1053 /*
 1054  * Returns ifa in case it's a carp address and it is MASTER, or if the address
 1055  * matches and is not a carp address.  Returns NULL otherwise.
 1056  */
 1057 struct ifaddr *
 1058 carp_iamatch6(struct ifnet *ifp, struct in6_addr *taddr)
 1059 {
 1060         struct ifaddr *ifa;
 1061 
 1062         ifa = NULL;
 1063         IF_ADDR_RLOCK(ifp);
 1064         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1065                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1066                         continue;
 1067                 if (!IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa)))
 1068                         continue;
 1069                 if (ifa->ifa_carp && ifa->ifa_carp->sc_state != MASTER)
 1070                         ifa = NULL;
 1071                 else
 1072                         ifa_ref(ifa);
 1073                 break;
 1074         }
 1075         IF_ADDR_RUNLOCK(ifp);
 1076 
 1077         return (ifa);
 1078 }
 1079 
 1080 caddr_t
 1081 carp_macmatch6(struct ifnet *ifp, struct mbuf *m, const struct in6_addr *taddr)
 1082 {
 1083         struct ifaddr *ifa;
 1084 
 1085         IF_ADDR_RLOCK(ifp);
 1086         IFNET_FOREACH_IFA(ifp, ifa)
 1087                 if (ifa->ifa_addr->sa_family == AF_INET6 &&
 1088                     IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa))) {
 1089                         struct carp_softc *sc = ifa->ifa_carp;
 1090                         struct m_tag *mtag;
 1091 
 1092                         IF_ADDR_RUNLOCK(ifp);
 1093 
 1094                         mtag = m_tag_get(PACKET_TAG_CARP,
 1095                             sizeof(struct carp_softc *), M_NOWAIT);
 1096                         if (mtag == NULL)
 1097                                 /* Better a bit than nothing. */
 1098                                 return (LLADDR(&sc->sc_addr));
 1099 
 1100                         bcopy(&sc, mtag + 1, sizeof(sc));
 1101                         m_tag_prepend(m, mtag);
 1102 
 1103                         return (LLADDR(&sc->sc_addr));
 1104                 }
 1105         IF_ADDR_RUNLOCK(ifp);
 1106 
 1107         return (NULL);
 1108 }
 1109 #endif /* INET6 */
 1110 
 1111 int
 1112 carp_forus(struct ifnet *ifp, u_char *dhost)
 1113 {
 1114         struct carp_softc *sc;
 1115         uint8_t *ena = dhost;
 1116 
 1117         if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
 1118                 return (0);
 1119 
 1120         CIF_LOCK(ifp->if_carp);
 1121         IFNET_FOREACH_CARP(ifp, sc) {
 1122                 CARP_LOCK(sc);
 1123                 if (sc->sc_state == MASTER && !bcmp(dhost, LLADDR(&sc->sc_addr),
 1124                     ETHER_ADDR_LEN)) {
 1125                         CARP_UNLOCK(sc);
 1126                         CIF_UNLOCK(ifp->if_carp);
 1127                         return (1);
 1128                 }
 1129                 CARP_UNLOCK(sc);
 1130         }
 1131         CIF_UNLOCK(ifp->if_carp);
 1132 
 1133         return (0);
 1134 }
 1135 
 1136 /* Master down timeout event, executed in callout context. */
 1137 static void
 1138 carp_master_down(void *v)
 1139 {
 1140         struct carp_softc *sc = v;
 1141 
 1142         CARP_LOCK_ASSERT(sc);
 1143 
 1144         CURVNET_SET(sc->sc_carpdev->if_vnet);
 1145         if (sc->sc_state == BACKUP) {
 1146                 CARP_LOG("VHID %u@%s: BACKUP -> MASTER (master down)\n",
 1147                     sc->sc_vhid,
 1148                     sc->sc_carpdev->if_xname);
 1149                 carp_master_down_locked(sc);
 1150         }
 1151         CURVNET_RESTORE();
 1152 
 1153         CARP_UNLOCK(sc);
 1154 }
 1155 
 1156 static void
 1157 carp_master_down_locked(struct carp_softc *sc)
 1158 {
 1159 
 1160         CARP_LOCK_ASSERT(sc);
 1161 
 1162         switch (sc->sc_state) {
 1163         case BACKUP:
 1164                 carp_set_state(sc, MASTER);
 1165                 carp_send_ad_locked(sc);
 1166 #ifdef INET
 1167                 carp_send_arp(sc);
 1168 #endif
 1169 #ifdef INET6
 1170                 carp_send_na(sc);
 1171 #endif
 1172                 carp_setrun(sc, 0);
 1173                 carp_addroute(sc);
 1174                 break;
 1175         case INIT:
 1176         case MASTER:
 1177 #ifdef INVARIANTS
 1178                 panic("carp: VHID %u@%s: master_down event in %s state\n",
 1179                     sc->sc_vhid,
 1180                     sc->sc_carpdev->if_xname,
 1181                     sc->sc_state ? "MASTER" : "INIT");
 1182 #endif
 1183                 break;
 1184         }
 1185 }
 1186 
 1187 /*
 1188  * When in backup state, af indicates whether to reset the master down timer
 1189  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
 1190  */
 1191 static void
 1192 carp_setrun(struct carp_softc *sc, sa_family_t af)
 1193 {
 1194         struct timeval tv;
 1195 
 1196         CARP_LOCK_ASSERT(sc);
 1197 
 1198         if ((sc->sc_carpdev->if_flags & IFF_UP) == 0 ||
 1199             sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
 1200             (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0))
 1201                 return;
 1202 
 1203         switch (sc->sc_state) {
 1204         case INIT:
 1205                 CARP_LOG("VHID %u@%s: INIT -> BACKUP\n",
 1206                     sc->sc_vhid,
 1207                     sc->sc_carpdev->if_xname);
 1208                 carp_set_state(sc, BACKUP);
 1209                 carp_setrun(sc, 0);
 1210                 break;
 1211         case BACKUP:
 1212                 callout_stop(&sc->sc_ad_tmo);
 1213                 tv.tv_sec = 3 * sc->sc_advbase;
 1214                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
 1215                 switch (af) {
 1216 #ifdef INET
 1217                 case AF_INET:
 1218                         callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
 1219                             carp_master_down, sc);
 1220                         break;
 1221 #endif
 1222 #ifdef INET6
 1223                 case AF_INET6:
 1224                         callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
 1225                             carp_master_down, sc);
 1226                         break;
 1227 #endif
 1228                 default:
 1229 #ifdef INET
 1230                         if (sc->sc_naddrs)
 1231                                 callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
 1232                                     carp_master_down, sc);
 1233 #endif
 1234 #ifdef INET6
 1235                         if (sc->sc_naddrs6)
 1236                                 callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
 1237                                     carp_master_down, sc);
 1238 #endif
 1239                         break;
 1240                 }
 1241                 break;
 1242         case MASTER:
 1243                 tv.tv_sec = sc->sc_advbase;
 1244                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
 1245                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
 1246                     carp_send_ad, sc);
 1247                 break;
 1248         }
 1249 }
 1250 
 1251 /*
 1252  * Setup multicast structures.
 1253  */
 1254 static int
 1255 carp_multicast_setup(struct carp_if *cif, sa_family_t sa)
 1256 {
 1257         struct ifnet *ifp = cif->cif_ifp;
 1258         int error = 0;
 1259 
 1260         CIF_LOCK_ASSERT(cif);
 1261 
 1262         switch (sa) {
 1263 #ifdef INET
 1264         case AF_INET:
 1265             {
 1266                 struct ip_moptions *imo = &cif->cif_imo;
 1267                 struct in_addr addr;
 1268 
 1269                 if (imo->imo_membership)
 1270                         return (0);
 1271 
 1272                 imo->imo_membership = (struct in_multi **)malloc(
 1273                     (sizeof(struct in_multi *) * IP_MIN_MEMBERSHIPS), M_CARP,
 1274                     M_NOWAIT);
 1275                 if (imo->imo_membership == NULL)
 1276                         return (ENOMEM);
 1277                 imo->imo_mfilters = NULL;
 1278                 imo->imo_max_memberships = IP_MIN_MEMBERSHIPS;
 1279                 imo->imo_multicast_vif = -1;
 1280 
 1281                 addr.s_addr = htonl(INADDR_CARP_GROUP);
 1282                 if ((error = in_joingroup(ifp, &addr, NULL,
 1283                     &imo->imo_membership[0])) != 0) {
 1284                         free(imo->imo_membership, M_CARP);
 1285                         break;
 1286                 }
 1287                 imo->imo_num_memberships++;
 1288                 imo->imo_multicast_ifp = ifp;
 1289                 imo->imo_multicast_ttl = CARP_DFLTTL;
 1290                 imo->imo_multicast_loop = 0;
 1291                 break;
 1292            }
 1293 #endif
 1294 #ifdef INET6
 1295         case AF_INET6:
 1296             {
 1297                 struct ip6_moptions *im6o = &cif->cif_im6o;
 1298                 struct in6_addr in6;
 1299                 struct in6_multi *in6m;
 1300 
 1301                 if (im6o->im6o_membership)
 1302                         return (0);
 1303 
 1304                 im6o->im6o_membership = (struct in6_multi **)malloc(
 1305                     (sizeof(struct in6_multi *) * IPV6_MIN_MEMBERSHIPS), M_CARP,
 1306                     M_ZERO | M_NOWAIT);
 1307                 if (im6o->im6o_membership == NULL)
 1308                         return (ENOMEM);
 1309                 im6o->im6o_mfilters = NULL;
 1310                 im6o->im6o_max_memberships = IPV6_MIN_MEMBERSHIPS;
 1311                 im6o->im6o_multicast_hlim = CARP_DFLTTL;
 1312                 im6o->im6o_multicast_ifp = ifp;
 1313 
 1314                 /* Join IPv6 CARP multicast group. */
 1315                 bzero(&in6, sizeof(in6));
 1316                 in6.s6_addr16[0] = htons(0xff02);
 1317                 in6.s6_addr8[15] = 0x12;
 1318                 if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
 1319                         free(im6o->im6o_membership, M_CARP);
 1320                         break;
 1321                 }
 1322                 in6m = NULL;
 1323                 if ((error = in6_mc_join(ifp, &in6, NULL, &in6m, 0)) != 0) {
 1324                         free(im6o->im6o_membership, M_CARP);
 1325                         break;
 1326                 }
 1327                 im6o->im6o_membership[0] = in6m;
 1328                 im6o->im6o_num_memberships++;
 1329 
 1330                 /* Join solicited multicast address. */
 1331                 bzero(&in6, sizeof(in6));
 1332                 in6.s6_addr16[0] = htons(0xff02);
 1333                 in6.s6_addr32[1] = 0;
 1334                 in6.s6_addr32[2] = htonl(1);
 1335                 in6.s6_addr32[3] = 0;
 1336                 in6.s6_addr8[12] = 0xff;
 1337                 if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
 1338                         in6_mc_leave(im6o->im6o_membership[0], NULL);
 1339                         free(im6o->im6o_membership, M_CARP);
 1340                         break;
 1341                 }
 1342                 in6m = NULL;
 1343                 if ((error = in6_mc_join(ifp, &in6, NULL, &in6m, 0)) != 0) {
 1344                         in6_mc_leave(im6o->im6o_membership[0], NULL);
 1345                         free(im6o->im6o_membership, M_CARP);
 1346                         break;
 1347                 }
 1348                 im6o->im6o_membership[1] = in6m;
 1349                 im6o->im6o_num_memberships++;
 1350                 break;
 1351             }
 1352 #endif
 1353         }
 1354 
 1355         return (error);
 1356 }
 1357 
 1358 /*
 1359  * Free multicast structures.
 1360  */
 1361 static void
 1362 carp_multicast_cleanup(struct carp_if *cif, sa_family_t sa)
 1363 {
 1364 
 1365         CIF_LOCK_ASSERT(cif);
 1366         switch (sa) {
 1367 #ifdef INET
 1368         case AF_INET:
 1369                 if (cif->cif_naddrs == 0) {
 1370                         struct ip_moptions *imo = &cif->cif_imo;
 1371 
 1372                         in_leavegroup(imo->imo_membership[0], NULL);
 1373                         KASSERT(imo->imo_mfilters == NULL,
 1374                             ("%s: imo_mfilters != NULL", __func__));
 1375                         free(imo->imo_membership, M_CARP);
 1376                         imo->imo_membership = NULL;
 1377 
 1378                 }
 1379                 break;
 1380 #endif
 1381 #ifdef INET6
 1382         case AF_INET6:
 1383                 if (cif->cif_naddrs6 == 0) {
 1384                         struct ip6_moptions *im6o = &cif->cif_im6o;
 1385 
 1386                         in6_mc_leave(im6o->im6o_membership[0], NULL);
 1387                         in6_mc_leave(im6o->im6o_membership[1], NULL);
 1388                         KASSERT(im6o->im6o_mfilters == NULL,
 1389                             ("%s: im6o_mfilters != NULL", __func__));
 1390                         free(im6o->im6o_membership, M_CARP);
 1391                         im6o->im6o_membership = NULL;
 1392                 }
 1393                 break;
 1394 #endif
 1395         }
 1396 }
 1397 
 1398 int
 1399 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa)
 1400 {
 1401         struct m_tag *mtag;
 1402         struct carp_softc *sc;
 1403 
 1404         if (!sa)
 1405                 return (0);
 1406 
 1407         switch (sa->sa_family) {
 1408 #ifdef INET
 1409         case AF_INET:
 1410                 break;
 1411 #endif
 1412 #ifdef INET6
 1413         case AF_INET6:
 1414                 break;
 1415 #endif
 1416         default:
 1417                 return (0);
 1418         }
 1419 
 1420         mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
 1421         if (mtag == NULL)
 1422                 return (0);
 1423 
 1424         bcopy(mtag + 1, &sc, sizeof(sc));
 1425 
 1426         /* Set the source MAC address to the Virtual Router MAC Address. */
 1427         switch (ifp->if_type) {
 1428         case IFT_ETHER:
 1429         case IFT_BRIDGE:
 1430         case IFT_L2VLAN: {
 1431                         struct ether_header *eh;
 1432 
 1433                         eh = mtod(m, struct ether_header *);
 1434                         eh->ether_shost[0] = 0;
 1435                         eh->ether_shost[1] = 0;
 1436                         eh->ether_shost[2] = 0x5e;
 1437                         eh->ether_shost[3] = 0;
 1438                         eh->ether_shost[4] = 1;
 1439                         eh->ether_shost[5] = sc->sc_vhid;
 1440                 }
 1441                 break;
 1442         case IFT_FDDI: {
 1443                         struct fddi_header *fh;
 1444 
 1445                         fh = mtod(m, struct fddi_header *);
 1446                         fh->fddi_shost[0] = 0;
 1447                         fh->fddi_shost[1] = 0;
 1448                         fh->fddi_shost[2] = 0x5e;
 1449                         fh->fddi_shost[3] = 0;
 1450                         fh->fddi_shost[4] = 1;
 1451                         fh->fddi_shost[5] = sc->sc_vhid;
 1452                 }
 1453                 break;
 1454         case IFT_ISO88025: {
 1455                         struct iso88025_header *th;
 1456                         th = mtod(m, struct iso88025_header *);
 1457                         th->iso88025_shost[0] = 3;
 1458                         th->iso88025_shost[1] = 0;
 1459                         th->iso88025_shost[2] = 0x40 >> (sc->sc_vhid - 1);
 1460                         th->iso88025_shost[3] = 0x40000 >> (sc->sc_vhid - 1);
 1461                         th->iso88025_shost[4] = 0;
 1462                         th->iso88025_shost[5] = 0;
 1463                 }
 1464                 break;
 1465         default:
 1466                 printf("%s: carp is not supported for the %d interface type\n",
 1467                     ifp->if_xname, ifp->if_type);
 1468                 return (EOPNOTSUPP);
 1469         }
 1470 
 1471         return (0);
 1472 }
 1473 
 1474 static struct carp_softc*
 1475 carp_alloc(struct ifnet *ifp)
 1476 {
 1477         struct carp_softc *sc;
 1478         struct carp_if *cif;
 1479 
 1480         if ((cif = ifp->if_carp) == NULL) {
 1481                 cif = carp_alloc_if(ifp);
 1482                 if (cif == NULL)
 1483                         return (NULL);
 1484         }
 1485 
 1486         sc = malloc(sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
 1487 
 1488         sc->sc_advbase = CARP_DFLTINTV;
 1489         sc->sc_vhid = -1;       /* required setting */
 1490         sc->sc_init_counter = 1;
 1491         sc->sc_state = INIT;
 1492 
 1493         sc->sc_ifasiz = sizeof(struct ifaddr *);
 1494         sc->sc_ifas = malloc(sc->sc_ifasiz, M_CARP, M_WAITOK|M_ZERO);
 1495         sc->sc_carpdev = ifp;
 1496 
 1497         CARP_LOCK_INIT(sc);
 1498 #ifdef INET
 1499         callout_init_mtx(&sc->sc_md_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
 1500 #endif
 1501 #ifdef INET6
 1502         callout_init_mtx(&sc->sc_md6_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
 1503 #endif
 1504         callout_init_mtx(&sc->sc_ad_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
 1505 
 1506         CIF_LOCK(cif);
 1507         TAILQ_INSERT_TAIL(&cif->cif_vrs, sc, sc_list);
 1508         CIF_UNLOCK(cif);
 1509 
 1510         mtx_lock(&carp_mtx);
 1511         LIST_INSERT_HEAD(&carp_list, sc, sc_next);
 1512         mtx_unlock(&carp_mtx);
 1513 
 1514         return (sc);
 1515 }
 1516 
 1517 static int
 1518 carp_grow_ifas(struct carp_softc *sc)
 1519 {
 1520         struct ifaddr **new;
 1521 
 1522         CARP_LOCK_ASSERT(sc);
 1523 
 1524         new = malloc(sc->sc_ifasiz * 2, M_CARP, M_NOWAIT|M_ZERO);
 1525         if (new == NULL)
 1526                 return (ENOMEM);
 1527         bcopy(sc->sc_ifas, new, sc->sc_ifasiz);
 1528         free(sc->sc_ifas, M_CARP);
 1529         sc->sc_ifas = new;
 1530         sc->sc_ifasiz *= 2;
 1531 
 1532         return (0);
 1533 }
 1534 
 1535 static void
 1536 carp_destroy(struct carp_softc *sc)
 1537 {
 1538         struct ifnet *ifp = sc->sc_carpdev;
 1539         struct carp_if *cif = ifp->if_carp;
 1540 
 1541         CIF_LOCK_ASSERT(cif);
 1542 
 1543         TAILQ_REMOVE(&cif->cif_vrs, sc, sc_list);
 1544 
 1545         mtx_lock(&carp_mtx);
 1546         LIST_REMOVE(sc, sc_next);
 1547         mtx_unlock(&carp_mtx);
 1548 
 1549         CARP_LOCK(sc);
 1550         if (sc->sc_suppress)
 1551                 carp_demote_adj(-V_carp_ifdown_adj, "vhid removed");
 1552         callout_drain(&sc->sc_ad_tmo);
 1553 #ifdef INET
 1554         callout_drain(&sc->sc_md_tmo);
 1555 #endif
 1556 #ifdef INET6
 1557         callout_drain(&sc->sc_md6_tmo);
 1558 #endif
 1559         CARP_LOCK_DESTROY(sc);
 1560 
 1561         free(sc->sc_ifas, M_CARP);
 1562         free(sc, M_CARP);
 1563 }
 1564 
 1565 static struct carp_if*
 1566 carp_alloc_if(struct ifnet *ifp)
 1567 {
 1568         struct carp_if *cif;
 1569 
 1570         cif = malloc(sizeof(*cif), M_CARP, M_WAITOK|M_ZERO);
 1571 
 1572         if (ifpromisc(ifp, 1) != 0)
 1573                 goto cleanup;
 1574 
 1575         CIF_LOCK_INIT(cif);
 1576         cif->cif_ifp = ifp;
 1577         TAILQ_INIT(&cif->cif_vrs);
 1578 
 1579         IF_ADDR_WLOCK(ifp);
 1580         ifp->if_carp = cif;
 1581         if_ref(ifp);
 1582         IF_ADDR_WUNLOCK(ifp);
 1583 
 1584         return (cif);
 1585 
 1586 cleanup:
 1587         free(cif, M_CARP);
 1588 
 1589         return (NULL);
 1590 }
 1591 
 1592 static void
 1593 carp_free_if(struct carp_if *cif)
 1594 {
 1595         struct ifnet *ifp = cif->cif_ifp;
 1596 
 1597         CIF_LOCK_ASSERT(cif);
 1598         KASSERT(TAILQ_EMPTY(&cif->cif_vrs), ("%s: softc list not empty",
 1599             __func__));
 1600 
 1601         IF_ADDR_WLOCK(ifp);
 1602         ifp->if_carp = NULL;
 1603         IF_ADDR_WUNLOCK(ifp);
 1604 
 1605         CIF_LOCK_DESTROY(cif);
 1606 
 1607         ifpromisc(ifp, 0);
 1608         if_rele(ifp);
 1609 
 1610         free(cif, M_CARP);
 1611 }
 1612 
 1613 static void
 1614 carp_carprcp(struct carpreq *carpr, struct carp_softc *sc, int priv)
 1615 {
 1616 
 1617         CARP_LOCK(sc);
 1618         carpr->carpr_state = sc->sc_state;
 1619         carpr->carpr_vhid = sc->sc_vhid;
 1620         carpr->carpr_advbase = sc->sc_advbase;
 1621         carpr->carpr_advskew = sc->sc_advskew;
 1622         if (priv)
 1623                 bcopy(sc->sc_key, carpr->carpr_key, sizeof(carpr->carpr_key));
 1624         else
 1625                 bzero(carpr->carpr_key, sizeof(carpr->carpr_key));
 1626         CARP_UNLOCK(sc);
 1627 }
 1628 
 1629 int
 1630 carp_ioctl(struct ifreq *ifr, u_long cmd, struct thread *td)
 1631 {
 1632         struct carpreq carpr;
 1633         struct ifnet *ifp;
 1634         struct carp_softc *sc = NULL;
 1635         int error = 0, locked = 0;
 1636 
 1637         if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
 1638                 return (error);
 1639 
 1640         ifp = ifunit_ref(ifr->ifr_name);
 1641         if (ifp == NULL)
 1642                 return (ENXIO);
 1643 
 1644         switch (ifp->if_type) {
 1645         case IFT_ETHER:
 1646         case IFT_L2VLAN:
 1647         case IFT_BRIDGE:
 1648         case IFT_FDDI:
 1649         case IFT_ISO88025:
 1650                 break;
 1651         default:
 1652                 error = EOPNOTSUPP;
 1653                 goto out;
 1654         }
 1655 
 1656         if ((ifp->if_flags & IFF_MULTICAST) == 0) {
 1657                 error = EADDRNOTAVAIL;
 1658                 goto out;
 1659         }
 1660 
 1661         switch (cmd) {
 1662         case SIOCSVH:
 1663                 if ((error = priv_check(td, PRIV_NETINET_CARP)))
 1664                         break;
 1665                 if (carpr.carpr_vhid <= 0 || carpr.carpr_vhid > CARP_MAXVHID ||
 1666                     carpr.carpr_advbase < 0 || carpr.carpr_advskew < 0) {
 1667                         error = EINVAL;
 1668                         break;
 1669                 }
 1670 
 1671                 if (ifp->if_carp) {
 1672                         CIF_LOCK(ifp->if_carp);
 1673                         IFNET_FOREACH_CARP(ifp, sc)
 1674                                 if (sc->sc_vhid == carpr.carpr_vhid)
 1675                                         break;
 1676                         CIF_UNLOCK(ifp->if_carp);
 1677                 }
 1678                 if (sc == NULL) {
 1679                         sc = carp_alloc(ifp);
 1680                         if (sc == NULL) {
 1681                                 error = EINVAL; /* XXX: ifpromisc failed */
 1682                                 break;
 1683                         }
 1684 
 1685                         CARP_LOCK(sc);
 1686                         sc->sc_vhid = carpr.carpr_vhid;
 1687                         LLADDR(&sc->sc_addr)[0] = 0;
 1688                         LLADDR(&sc->sc_addr)[1] = 0;
 1689                         LLADDR(&sc->sc_addr)[2] = 0x5e;
 1690                         LLADDR(&sc->sc_addr)[3] = 0;
 1691                         LLADDR(&sc->sc_addr)[4] = 1;
 1692                         LLADDR(&sc->sc_addr)[5] = sc->sc_vhid;
 1693                 } else
 1694                         CARP_LOCK(sc);
 1695                 locked = 1;
 1696                 if (carpr.carpr_advbase > 0) {
 1697                         if (carpr.carpr_advbase > 255 ||
 1698                             carpr.carpr_advbase < CARP_DFLTINTV) {
 1699                                 error = EINVAL;
 1700                                 break;
 1701                         }
 1702                         sc->sc_advbase = carpr.carpr_advbase;
 1703                 }
 1704                 if (carpr.carpr_advskew >= 255) {
 1705                         error = EINVAL;
 1706                         break;
 1707                 }
 1708                 sc->sc_advskew = carpr.carpr_advskew;
 1709                 if (carpr.carpr_key[0] != '\0') {
 1710                         bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
 1711                         carp_hmac_prepare(sc);
 1712                 }
 1713                 if (sc->sc_state != INIT &&
 1714                     carpr.carpr_state != sc->sc_state) {
 1715                         switch (carpr.carpr_state) {
 1716                         case BACKUP:
 1717                                 callout_stop(&sc->sc_ad_tmo);
 1718                                 carp_set_state(sc, BACKUP);
 1719                                 carp_setrun(sc, 0);
 1720                                 carp_delroute(sc);
 1721                                 break;
 1722                         case MASTER:
 1723                                 carp_master_down_locked(sc);
 1724                                 break;
 1725                         default:
 1726                                 break;
 1727                         }
 1728                 }
 1729                 break;
 1730 
 1731         case SIOCGVH:
 1732             {
 1733                 int priveleged;
 1734 
 1735                 if (carpr.carpr_vhid < 0 || carpr.carpr_vhid > CARP_MAXVHID) {
 1736                         error = EINVAL;
 1737                         break;
 1738                 }
 1739                 if (carpr.carpr_count < 1) {
 1740                         error = EMSGSIZE;
 1741                         break;
 1742                 }
 1743                 if (ifp->if_carp == NULL) {
 1744                         error = ENOENT;
 1745                         break;
 1746                 }
 1747 
 1748                 priveleged = (priv_check(td, PRIV_NETINET_CARP) == 0);
 1749                 if (carpr.carpr_vhid != 0) {
 1750                         CIF_LOCK(ifp->if_carp);
 1751                         IFNET_FOREACH_CARP(ifp, sc)
 1752                                 if (sc->sc_vhid == carpr.carpr_vhid)
 1753                                         break;
 1754                         CIF_UNLOCK(ifp->if_carp);
 1755                         if (sc == NULL) {
 1756                                 error = ENOENT;
 1757                                 break;
 1758                         }
 1759                         carp_carprcp(&carpr, sc, priveleged);
 1760                         error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
 1761                 } else  {
 1762                         int i, count;
 1763 
 1764                         count = 0;
 1765                         CIF_LOCK(ifp->if_carp);
 1766                         IFNET_FOREACH_CARP(ifp, sc)
 1767                                 count++;
 1768 
 1769                         if (count > carpr.carpr_count) {
 1770                                 CIF_UNLOCK(ifp->if_carp);
 1771                                 error = EMSGSIZE;
 1772                                 break;
 1773                         }
 1774 
 1775                         i = 0;
 1776                         IFNET_FOREACH_CARP(ifp, sc) {
 1777                                 carp_carprcp(&carpr, sc, priveleged);
 1778                                 carpr.carpr_count = count;
 1779                                 error = copyout(&carpr, ifr->ifr_data +
 1780                                     (i * sizeof(carpr)), sizeof(carpr));
 1781                                 if (error) {
 1782                                         CIF_UNLOCK(ifp->if_carp);
 1783                                         break;
 1784                                 }
 1785                                 i++;
 1786                         }
 1787                         CIF_UNLOCK(ifp->if_carp);
 1788                 }
 1789                 break;
 1790             }
 1791         default:
 1792                 error = EINVAL;
 1793         }
 1794 
 1795 out:
 1796         if (locked)
 1797                 CARP_UNLOCK(sc);
 1798         if_rele(ifp);
 1799 
 1800         return (error);
 1801 }
 1802 
 1803 static int
 1804 carp_get_vhid(struct ifaddr *ifa)
 1805 {
 1806 
 1807         if (ifa == NULL || ifa->ifa_carp == NULL)
 1808                 return (0);
 1809 
 1810         return (ifa->ifa_carp->sc_vhid);
 1811 }
 1812 
 1813 int
 1814 carp_attach(struct ifaddr *ifa, int vhid)
 1815 {
 1816         struct ifnet *ifp = ifa->ifa_ifp;
 1817         struct carp_if *cif = ifp->if_carp;
 1818         struct carp_softc *sc;
 1819         int index, error;
 1820 
 1821         if (ifp->if_carp == NULL)
 1822                 return (ENOPROTOOPT);
 1823 
 1824         switch (ifa->ifa_addr->sa_family) {
 1825 #ifdef INET
 1826         case AF_INET:
 1827 #endif
 1828 #ifdef INET6
 1829         case AF_INET6:
 1830 #endif
 1831                 break;
 1832         default:
 1833                 return (EPROTOTYPE);
 1834         }
 1835 
 1836         CIF_LOCK(cif);
 1837         IFNET_FOREACH_CARP(ifp, sc)
 1838                 if (sc->sc_vhid == vhid)
 1839                         break;
 1840         if (sc == NULL) {
 1841                 CIF_UNLOCK(cif);
 1842                 return (ENOENT);
 1843         }
 1844 
 1845         if (ifa->ifa_carp) {
 1846                 if (ifa->ifa_carp->sc_vhid != vhid)
 1847                         carp_detach_locked(ifa);
 1848                 else {
 1849                         CIF_UNLOCK(cif);
 1850                         return (0);
 1851                 }
 1852         }
 1853 
 1854         error = carp_multicast_setup(cif, ifa->ifa_addr->sa_family);
 1855         if (error) {
 1856                 CIF_FREE(cif);
 1857                 return (error);
 1858         }
 1859 
 1860         CARP_LOCK(sc);
 1861         index = sc->sc_naddrs + sc->sc_naddrs6 + 1;
 1862         if (index > sc->sc_ifasiz / sizeof(struct ifaddr *))
 1863                 if ((error = carp_grow_ifas(sc)) != 0) {
 1864                         carp_multicast_cleanup(cif,
 1865                             ifa->ifa_addr->sa_family);
 1866                         CARP_UNLOCK(sc);
 1867                         CIF_FREE(cif);
 1868                         return (error);
 1869                 }
 1870 
 1871         switch (ifa->ifa_addr->sa_family) {
 1872 #ifdef INET
 1873         case AF_INET:
 1874                 cif->cif_naddrs++;
 1875                 sc->sc_naddrs++;
 1876                 break;
 1877 #endif
 1878 #ifdef INET6
 1879         case AF_INET6:
 1880                 cif->cif_naddrs6++;
 1881                 sc->sc_naddrs6++;
 1882                 break;
 1883 #endif
 1884         }
 1885 
 1886         ifa_ref(ifa);
 1887         sc->sc_ifas[index - 1] = ifa;
 1888         ifa->ifa_carp = sc;
 1889 
 1890         carp_hmac_prepare(sc);
 1891         carp_sc_state(sc);
 1892 
 1893         CARP_UNLOCK(sc);
 1894         CIF_UNLOCK(cif);
 1895 
 1896         return (0);
 1897 }
 1898 
 1899 void
 1900 carp_detach(struct ifaddr *ifa)
 1901 {
 1902         struct ifnet *ifp = ifa->ifa_ifp;
 1903         struct carp_if *cif = ifp->if_carp;
 1904 
 1905         CIF_LOCK(cif);
 1906         carp_detach_locked(ifa);
 1907         CIF_FREE(cif);
 1908 }
 1909 
 1910 static void
 1911 carp_detach_locked(struct ifaddr *ifa)
 1912 {
 1913         struct ifnet *ifp = ifa->ifa_ifp;
 1914         struct carp_if *cif = ifp->if_carp;
 1915         struct carp_softc *sc = ifa->ifa_carp;
 1916         int i, index;
 1917 
 1918         KASSERT(sc != NULL, ("%s: %p not attached", __func__, ifa));
 1919 
 1920         CIF_LOCK_ASSERT(cif);
 1921         CARP_LOCK(sc);
 1922 
 1923         /* Shift array. */
 1924         index = sc->sc_naddrs + sc->sc_naddrs6;
 1925         for (i = 0; i < index; i++)
 1926                 if (sc->sc_ifas[i] == ifa)
 1927                         break;
 1928         KASSERT(i < index, ("%s: %p no backref", __func__, ifa));
 1929         for (; i < index - 1; i++)
 1930                 sc->sc_ifas[i] = sc->sc_ifas[i+1];
 1931         sc->sc_ifas[index - 1] = NULL;
 1932 
 1933         switch (ifa->ifa_addr->sa_family) {
 1934 #ifdef INET
 1935         case AF_INET:
 1936                 cif->cif_naddrs--;
 1937                 sc->sc_naddrs--;
 1938                 break;
 1939 #endif
 1940 #ifdef INET6
 1941         case AF_INET6:
 1942                 cif->cif_naddrs6--;
 1943                 sc->sc_naddrs6--;
 1944                 break;
 1945 #endif
 1946         }
 1947 
 1948         carp_ifa_delroute(ifa);
 1949         carp_multicast_cleanup(cif, ifa->ifa_addr->sa_family);
 1950 
 1951         ifa->ifa_carp = NULL;
 1952         ifa_free(ifa);
 1953 
 1954         carp_hmac_prepare(sc);
 1955         carp_sc_state(sc);
 1956 
 1957         if (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) {
 1958                 CARP_UNLOCK(sc);
 1959                 carp_destroy(sc);
 1960         } else
 1961                 CARP_UNLOCK(sc);
 1962 }
 1963 
 1964 static void
 1965 carp_set_state(struct carp_softc *sc, int state)
 1966 {
 1967 
 1968         CARP_LOCK_ASSERT(sc);
 1969 
 1970         if (sc->sc_state != state) {
 1971                 const char *carp_states[] = { CARP_STATES };
 1972                 char subsys[IFNAMSIZ+5];
 1973 
 1974                 sc->sc_state = state;
 1975 
 1976                 snprintf(subsys, IFNAMSIZ+5, "%u@%s", sc->sc_vhid,
 1977                     sc->sc_carpdev->if_xname);
 1978                 devctl_notify("CARP", subsys, carp_states[state], NULL);
 1979         }
 1980 }
 1981 
 1982 static void
 1983 carp_linkstate(struct ifnet *ifp)
 1984 {
 1985         struct carp_softc *sc;
 1986 
 1987         CIF_LOCK(ifp->if_carp);
 1988         IFNET_FOREACH_CARP(ifp, sc) {
 1989                 CARP_LOCK(sc);
 1990                 carp_sc_state(sc);
 1991                 CARP_UNLOCK(sc);
 1992         }
 1993         CIF_UNLOCK(ifp->if_carp);
 1994 }
 1995 
 1996 static void
 1997 carp_sc_state(struct carp_softc *sc)
 1998 {
 1999 
 2000         CARP_LOCK_ASSERT(sc);
 2001 
 2002         if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
 2003             !(sc->sc_carpdev->if_flags & IFF_UP)) {
 2004                 callout_stop(&sc->sc_ad_tmo);
 2005 #ifdef INET
 2006                 callout_stop(&sc->sc_md_tmo);
 2007 #endif
 2008 #ifdef INET6
 2009                 callout_stop(&sc->sc_md6_tmo);
 2010 #endif
 2011                 carp_set_state(sc, INIT);
 2012                 carp_setrun(sc, 0);
 2013                 if (!sc->sc_suppress)
 2014                         carp_demote_adj(V_carp_ifdown_adj, "interface down");
 2015                 sc->sc_suppress = 1;
 2016         } else {
 2017                 carp_set_state(sc, INIT);
 2018                 carp_setrun(sc, 0);
 2019                 if (sc->sc_suppress)
 2020                         carp_demote_adj(-V_carp_ifdown_adj, "interface up");
 2021                 sc->sc_suppress = 0;
 2022         }
 2023 }
 2024 
 2025 static void
 2026 carp_demote_adj(int adj, char *reason)
 2027 {
 2028         atomic_add_int(&V_carp_demotion, adj);
 2029         CARP_LOG("demoted by %d to %d (%s)\n", adj, V_carp_demotion, reason);
 2030         taskqueue_enqueue(taskqueue_swi, &carp_sendall_task);
 2031 }
 2032 
 2033 static int
 2034 carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS)
 2035 {
 2036         int new, error;
 2037 
 2038         new = V_carp_demotion;
 2039         error = sysctl_handle_int(oidp, &new, 0, req);
 2040         if (error || !req->newptr)
 2041                 return (error);
 2042 
 2043         carp_demote_adj(new, "sysctl");
 2044 
 2045         return (0);
 2046 }
 2047 
 2048 #ifdef INET
 2049 extern  struct domain inetdomain;
 2050 static struct protosw in_carp_protosw = {
 2051         .pr_type =              SOCK_RAW,
 2052         .pr_domain =            &inetdomain,
 2053         .pr_protocol =          IPPROTO_CARP,
 2054         .pr_flags =             PR_ATOMIC|PR_ADDR,
 2055         .pr_input =             carp_input,
 2056         .pr_output =            (pr_output_t *)rip_output,
 2057         .pr_ctloutput =         rip_ctloutput,
 2058         .pr_usrreqs =           &rip_usrreqs
 2059 };
 2060 #endif
 2061 
 2062 #ifdef INET6
 2063 extern  struct domain inet6domain;
 2064 static struct ip6protosw in6_carp_protosw = {
 2065         .pr_type =              SOCK_RAW,
 2066         .pr_domain =            &inet6domain,
 2067         .pr_protocol =          IPPROTO_CARP,
 2068         .pr_flags =             PR_ATOMIC|PR_ADDR,
 2069         .pr_input =             carp6_input,
 2070         .pr_output =            rip6_output,
 2071         .pr_ctloutput =         rip6_ctloutput,
 2072         .pr_usrreqs =           &rip6_usrreqs
 2073 };
 2074 #endif
 2075 
 2076 static void
 2077 carp_mod_cleanup(void)
 2078 {
 2079 
 2080 #ifdef INET
 2081         if (proto_reg[CARP_INET] == 0) {
 2082                 (void)ipproto_unregister(IPPROTO_CARP);
 2083                 pf_proto_unregister(PF_INET, IPPROTO_CARP, SOCK_RAW);
 2084                 proto_reg[CARP_INET] = -1;
 2085         }
 2086         carp_iamatch_p = NULL;
 2087 #endif
 2088 #ifdef INET6
 2089         if (proto_reg[CARP_INET6] == 0) {
 2090                 (void)ip6proto_unregister(IPPROTO_CARP);
 2091                 pf_proto_unregister(PF_INET6, IPPROTO_CARP, SOCK_RAW);
 2092                 proto_reg[CARP_INET6] = -1;
 2093         }
 2094         carp_iamatch6_p = NULL;
 2095         carp_macmatch6_p = NULL;
 2096 #endif
 2097         carp_ioctl_p = NULL;
 2098         carp_attach_p = NULL;
 2099         carp_detach_p = NULL;
 2100         carp_get_vhid_p = NULL;
 2101         carp_linkstate_p = NULL;
 2102         carp_forus_p = NULL;
 2103         carp_output_p = NULL;
 2104         carp_demote_adj_p = NULL;
 2105         carp_master_p = NULL;
 2106         mtx_unlock(&carp_mtx);
 2107         taskqueue_drain(taskqueue_swi, &carp_sendall_task);
 2108         mtx_destroy(&carp_mtx);
 2109 }
 2110 
 2111 static int
 2112 carp_mod_load(void)
 2113 {
 2114         int err;
 2115 
 2116         mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
 2117         LIST_INIT(&carp_list);
 2118         carp_get_vhid_p = carp_get_vhid;
 2119         carp_forus_p = carp_forus;
 2120         carp_output_p = carp_output;
 2121         carp_linkstate_p = carp_linkstate;
 2122         carp_ioctl_p = carp_ioctl;
 2123         carp_attach_p = carp_attach;
 2124         carp_detach_p = carp_detach;
 2125         carp_demote_adj_p = carp_demote_adj;
 2126         carp_master_p = carp_master;
 2127 #ifdef INET6
 2128         carp_iamatch6_p = carp_iamatch6;
 2129         carp_macmatch6_p = carp_macmatch6;
 2130         proto_reg[CARP_INET6] = pf_proto_register(PF_INET6,
 2131             (struct protosw *)&in6_carp_protosw);
 2132         if (proto_reg[CARP_INET6]) {
 2133                 printf("carp: error %d attaching to PF_INET6\n",
 2134                     proto_reg[CARP_INET6]);
 2135                 carp_mod_cleanup();
 2136                 return (proto_reg[CARP_INET6]);
 2137         }
 2138         err = ip6proto_register(IPPROTO_CARP);
 2139         if (err) {
 2140                 printf("carp: error %d registering with INET6\n", err);
 2141                 carp_mod_cleanup();
 2142                 return (err);
 2143         }
 2144 #endif
 2145 #ifdef INET
 2146         carp_iamatch_p = carp_iamatch;
 2147         proto_reg[CARP_INET] = pf_proto_register(PF_INET, &in_carp_protosw);
 2148         if (proto_reg[CARP_INET]) {
 2149                 printf("carp: error %d attaching to PF_INET\n",
 2150                     proto_reg[CARP_INET]);
 2151                 carp_mod_cleanup();
 2152                 return (proto_reg[CARP_INET]);
 2153         }
 2154         err = ipproto_register(IPPROTO_CARP);
 2155         if (err) {
 2156                 printf("carp: error %d registering with INET\n", err);
 2157                 carp_mod_cleanup();
 2158                 return (err);
 2159         }
 2160 #endif
 2161         return (0);
 2162 }
 2163 
 2164 static int
 2165 carp_modevent(module_t mod, int type, void *data)
 2166 {
 2167         switch (type) {
 2168         case MOD_LOAD:
 2169                 return carp_mod_load();
 2170                 /* NOTREACHED */
 2171         case MOD_UNLOAD:
 2172                 mtx_lock(&carp_mtx);
 2173                 if (LIST_EMPTY(&carp_list))
 2174                         carp_mod_cleanup();
 2175                 else {
 2176                         mtx_unlock(&carp_mtx);
 2177                         return (EBUSY);
 2178                 }
 2179                 break;
 2180 
 2181         default:
 2182                 return (EINVAL);
 2183         }
 2184 
 2185         return (0);
 2186 }
 2187 
 2188 static moduledata_t carp_mod = {
 2189         "carp",
 2190         carp_modevent,
 2191         0
 2192 };
 2193 
 2194 DECLARE_MODULE(carp, carp_mod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);

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