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. All rights reserved.
    3  * Copyright (c) 2003 Ryan McBride. All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   17  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
   18  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   20  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
   23  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
   24  * THE POSSIBILITY OF SUCH DAMAGE.
   25  */
   26 
   27 #include <sys/cdefs.h>
   28 __FBSDID("$FreeBSD$");
   29 
   30 #include "opt_bpf.h"
   31 #include "opt_inet.h"
   32 #include "opt_inet6.h"
   33 
   34 #include <sys/types.h>
   35 #include <sys/param.h>
   36 #include <sys/systm.h>
   37 #include <sys/conf.h>
   38 #include <sys/kernel.h>
   39 #include <sys/limits.h>
   40 #include <sys/malloc.h>
   41 #include <sys/mbuf.h>
   42 #include <sys/module.h>
   43 #include <sys/time.h>
   44 #include <sys/priv.h>
   45 #include <sys/proc.h>
   46 #include <sys/protosw.h>
   47 #include <sys/sysctl.h>
   48 #include <sys/syslog.h>
   49 #include <sys/signalvar.h>
   50 #include <sys/filio.h>
   51 #include <sys/sockio.h>
   52 
   53 #include <sys/socket.h>
   54 #include <sys/vnode.h>
   55 
   56 #include <machine/stdarg.h>
   57 
   58 #include <net/bpf.h>
   59 #include <net/ethernet.h>
   60 #include <net/fddi.h>
   61 #include <net/iso88025.h>
   62 #include <net/if.h>
   63 #include <net/if_clone.h>
   64 #include <net/if_dl.h>
   65 #include <net/if_types.h>
   66 #include <net/route.h>
   67 #include <net/vnet.h>
   68 
   69 #if defined(INET) || defined(INET6)
   70 #include <netinet/in.h>
   71 #include <netinet/in_var.h>
   72 #include <netinet/ip_carp.h>
   73 #include <netinet/ip.h>
   74 
   75 #include <machine/in_cksum.h>
   76 #endif
   77 
   78 #ifdef INET
   79 #include <netinet/in_systm.h>
   80 #include <netinet/ip_var.h>
   81 #include <netinet/if_ether.h>
   82 #endif
   83 
   84 #ifdef INET6
   85 #include <netinet/icmp6.h>
   86 #include <netinet/ip6.h>
   87 #include <netinet6/ip6protosw.h>
   88 #include <netinet6/ip6_var.h>
   89 #include <netinet6/scope6_var.h>
   90 #include <netinet6/in6_var.h>
   91 #include <netinet6/nd6.h>
   92 #endif
   93 
   94 #include <crypto/sha1.h>
   95 
   96 #define CARP_IFNAME     "carp"
   97 static MALLOC_DEFINE(M_CARP, "CARP", "CARP interfaces");
   98 SYSCTL_DECL(_net_inet_carp);
   99 
  100 struct carp_softc {
  101         struct ifnet            *sc_ifp;        /* Interface clue */
  102         struct ifnet            *sc_carpdev;    /* Pointer to parent interface */
  103         struct in_ifaddr        *sc_ia;         /* primary iface address */
  104 #ifdef INET
  105         struct ip_moptions       sc_imo;
  106 #endif
  107 #ifdef INET6
  108         struct in6_ifaddr       *sc_ia6;        /* primary iface address v6 */
  109         struct ip6_moptions      sc_im6o;
  110 #endif /* INET6 */
  111         TAILQ_ENTRY(carp_softc)  sc_list;
  112 
  113         enum { INIT = 0, BACKUP, MASTER }       sc_state;
  114 
  115         int                      sc_flags_backup;
  116         int                      sc_suppress;
  117 
  118         int                      sc_sendad_errors;
  119 #define CARP_SENDAD_MAX_ERRORS  3
  120         int                      sc_sendad_success;
  121 #define CARP_SENDAD_MIN_SUCCESS 3
  122 
  123         int                      sc_vhid;
  124         int                      sc_advskew;
  125         int                      sc_naddrs;
  126         int                      sc_naddrs6;
  127         int                      sc_advbase;    /* seconds */
  128         int                      sc_init_counter;
  129         u_int64_t                sc_counter;
  130 
  131         /* authentication */
  132 #define CARP_HMAC_PAD   64
  133         unsigned char sc_key[CARP_KEY_LEN];
  134         unsigned char sc_pad[CARP_HMAC_PAD];
  135         SHA1_CTX sc_sha1;
  136 
  137         struct callout           sc_ad_tmo;     /* advertisement timeout */
  138         struct callout           sc_md_tmo;     /* master down timeout */
  139         struct callout           sc_md6_tmo;    /* master down timeout */
  140         
  141         LIST_ENTRY(carp_softc)   sc_next;       /* Interface clue */
  142 };
  143 #define SC2IFP(sc)      ((sc)->sc_ifp)
  144 
  145 int carp_suppress_preempt = 0;
  146 int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 1, 0, 0 };    /* XXX for now */
  147 SYSCTL_NODE(_net_inet, IPPROTO_CARP,    carp,   CTLFLAG_RW, 0,  "CARP");
  148 SYSCTL_INT(_net_inet_carp, CARPCTL_ALLOW, allow, CTLFLAG_RW,
  149     &carp_opts[CARPCTL_ALLOW], 0, "Accept incoming CARP packets");
  150 SYSCTL_INT(_net_inet_carp, CARPCTL_PREEMPT, preempt, CTLFLAG_RW,
  151     &carp_opts[CARPCTL_PREEMPT], 0, "high-priority backup preemption mode");
  152 SYSCTL_INT(_net_inet_carp, CARPCTL_LOG, log, CTLFLAG_RW,
  153     &carp_opts[CARPCTL_LOG], 0, "log bad carp packets");
  154 SYSCTL_INT(_net_inet_carp, CARPCTL_ARPBALANCE, arpbalance, CTLFLAG_RW,
  155     &carp_opts[CARPCTL_ARPBALANCE], 0, "balance arp responses");
  156 SYSCTL_INT(_net_inet_carp, OID_AUTO, suppress_preempt, CTLFLAG_RD,
  157     &carp_suppress_preempt, 0, "Preemption is suppressed");
  158 
  159 struct carpstats carpstats;
  160 SYSCTL_STRUCT(_net_inet_carp, CARPCTL_STATS, stats, CTLFLAG_RW,
  161     &carpstats, carpstats,
  162     "CARP statistics (struct carpstats, netinet/ip_carp.h)");
  163 
  164 struct carp_if {
  165         TAILQ_HEAD(, carp_softc) vhif_vrs;
  166         int vhif_nvrs;
  167 
  168         struct ifnet    *vhif_ifp;
  169         struct mtx       vhif_mtx;
  170 };
  171 
  172 #define CARP_INET       0
  173 #define CARP_INET6      1
  174 static int proto_reg[] = {-1, -1};
  175 
  176 /* Get carp_if from softc. Valid after carp_set_addr{,6}. */
  177 #define SC2CIF(sc)              ((struct carp_if *)(sc)->sc_carpdev->if_carp)
  178 
  179 /* lock per carp_if queue */
  180 #define CARP_LOCK_INIT(cif)     mtx_init(&(cif)->vhif_mtx, "carp_if",   \
  181         NULL, MTX_DEF)
  182 #define CARP_LOCK_DESTROY(cif)  mtx_destroy(&(cif)->vhif_mtx)
  183 #define CARP_LOCK_ASSERT(cif)   mtx_assert(&(cif)->vhif_mtx, MA_OWNED)
  184 #define CARP_LOCK(cif)          mtx_lock(&(cif)->vhif_mtx)
  185 #define CARP_UNLOCK(cif)        mtx_unlock(&(cif)->vhif_mtx)
  186 
  187 #define CARP_SCLOCK(sc)         mtx_lock(&SC2CIF(sc)->vhif_mtx)
  188 #define CARP_SCUNLOCK(sc)       mtx_unlock(&SC2CIF(sc)->vhif_mtx)
  189 #define CARP_SCLOCK_ASSERT(sc)  mtx_assert(&SC2CIF(sc)->vhif_mtx, MA_OWNED)
  190 
  191 #define CARP_LOG(...)   do {                            \
  192         if (carp_opts[CARPCTL_LOG] > 0)                 \
  193                 log(LOG_INFO, __VA_ARGS__);             \
  194 } while (0)
  195 
  196 #define CARP_DEBUG(...) do {                            \
  197         if (carp_opts[CARPCTL_LOG] > 1)                 \
  198                 log(LOG_DEBUG, __VA_ARGS__);            \
  199 } while (0)
  200 
  201 static void     carp_hmac_prepare(struct carp_softc *);
  202 static void     carp_hmac_generate(struct carp_softc *, u_int32_t *,
  203                     unsigned char *);
  204 static int      carp_hmac_verify(struct carp_softc *, u_int32_t *,
  205                     unsigned char *);
  206 static void     carp_setroute(struct carp_softc *, int);
  207 static void     carp_input_c(struct mbuf *, struct carp_header *, sa_family_t);
  208 static int      carp_clone_create(struct if_clone *, int, caddr_t);
  209 static void     carp_clone_destroy(struct ifnet *);
  210 static void     carpdetach(struct carp_softc *, int);
  211 static int      carp_prepare_ad(struct mbuf *, struct carp_softc *,
  212                     struct carp_header *);
  213 static void     carp_send_ad_all(void);
  214 static void     carp_send_ad(void *);
  215 static void     carp_send_ad_locked(struct carp_softc *);
  216 #ifdef INET
  217 static void     carp_send_arp(struct carp_softc *);
  218 #endif
  219 static void     carp_master_down(void *);
  220 static void     carp_master_down_locked(struct carp_softc *);
  221 static int      carp_ioctl(struct ifnet *, u_long, caddr_t);
  222 static int      carp_looutput(struct ifnet *, struct mbuf *, struct sockaddr *,
  223                     struct route *);
  224 static void     carp_start(struct ifnet *);
  225 static void     carp_setrun(struct carp_softc *, sa_family_t);
  226 static void     carp_set_state(struct carp_softc *, int);
  227 #ifdef INET
  228 static int      carp_addrcount(struct carp_if *, struct in_ifaddr *, int);
  229 #endif
  230 enum    { CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
  231 
  232 #ifdef INET
  233 static void     carp_multicast_cleanup(struct carp_softc *, int dofree);
  234 static int      carp_set_addr(struct carp_softc *, struct sockaddr_in *);
  235 static int      carp_del_addr(struct carp_softc *, struct sockaddr_in *);
  236 #endif
  237 static void     carp_carpdev_state_locked(struct carp_if *);
  238 static void     carp_sc_state_locked(struct carp_softc *);
  239 #ifdef INET6
  240 static void     carp_send_na(struct carp_softc *);
  241 static int      carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
  242 static int      carp_del_addr6(struct carp_softc *, struct sockaddr_in6 *);
  243 static void     carp_multicast6_cleanup(struct carp_softc *, int dofree);
  244 #endif
  245 
  246 static LIST_HEAD(, carp_softc) carpif_list;
  247 static struct mtx carp_mtx;
  248 IFC_SIMPLE_DECLARE(carp, 0);
  249 
  250 static eventhandler_tag if_detach_event_tag;
  251 
  252 static __inline u_int16_t
  253 carp_cksum(struct mbuf *m, int len)
  254 {
  255         return (in_cksum(m, len));
  256 }
  257 
  258 static void
  259 carp_hmac_prepare(struct carp_softc *sc)
  260 {
  261         u_int8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
  262         u_int8_t vhid = sc->sc_vhid & 0xff;
  263         struct ifaddr *ifa;
  264         int i, found;
  265 #ifdef INET
  266         struct in_addr last, cur, in;
  267 #endif
  268 #ifdef INET6
  269         struct in6_addr last6, cur6, in6;
  270 #endif
  271 
  272         if (sc->sc_carpdev)
  273                 CARP_SCLOCK(sc);
  274 
  275         /* XXX: possible race here */
  276 
  277         /* compute ipad from key */
  278         bzero(sc->sc_pad, sizeof(sc->sc_pad));
  279         bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
  280         for (i = 0; i < sizeof(sc->sc_pad); i++)
  281                 sc->sc_pad[i] ^= 0x36;
  282 
  283         /* precompute first part of inner hash */
  284         SHA1Init(&sc->sc_sha1);
  285         SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
  286         SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
  287         SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
  288         SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
  289 #ifdef INET
  290         cur.s_addr = 0;
  291         do {
  292                 found = 0;
  293                 last = cur;
  294                 cur.s_addr = 0xffffffff;
  295                 IF_ADDR_RLOCK(SC2IFP(sc));
  296                 TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
  297                         in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
  298                         if (ifa->ifa_addr->sa_family == AF_INET &&
  299                             ntohl(in.s_addr) > ntohl(last.s_addr) &&
  300                             ntohl(in.s_addr) < ntohl(cur.s_addr)) {
  301                                 cur.s_addr = in.s_addr;
  302                                 found++;
  303                         }
  304                 }
  305                 IF_ADDR_RUNLOCK(SC2IFP(sc));
  306                 if (found)
  307                         SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
  308         } while (found);
  309 #endif /* INET */
  310 #ifdef INET6
  311         memset(&cur6, 0, sizeof(cur6));
  312         do {
  313                 found = 0;
  314                 last6 = cur6;
  315                 memset(&cur6, 0xff, sizeof(cur6));
  316                 IF_ADDR_RLOCK(SC2IFP(sc));
  317                 TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
  318                         in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
  319                         if (IN6_IS_SCOPE_EMBED(&in6))
  320                                 in6.s6_addr16[1] = 0;
  321                         if (ifa->ifa_addr->sa_family == AF_INET6 &&
  322                             memcmp(&in6, &last6, sizeof(in6)) > 0 &&
  323                             memcmp(&in6, &cur6, sizeof(in6)) < 0) {
  324                                 cur6 = in6;
  325                                 found++;
  326                         }
  327                 }
  328                 IF_ADDR_RUNLOCK(SC2IFP(sc));
  329                 if (found)
  330                         SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
  331         } while (found);
  332 #endif /* INET6 */
  333 
  334         /* convert ipad to opad */
  335         for (i = 0; i < sizeof(sc->sc_pad); i++)
  336                 sc->sc_pad[i] ^= 0x36 ^ 0x5c;
  337 
  338         if (sc->sc_carpdev)
  339                 CARP_SCUNLOCK(sc);
  340 }
  341 
  342 static void
  343 carp_hmac_generate(struct carp_softc *sc, u_int32_t counter[2],
  344     unsigned char md[20])
  345 {
  346         SHA1_CTX sha1ctx;
  347 
  348         /* fetch first half of inner hash */
  349         bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
  350 
  351         SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
  352         SHA1Final(md, &sha1ctx);
  353 
  354         /* outer hash */
  355         SHA1Init(&sha1ctx);
  356         SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
  357         SHA1Update(&sha1ctx, md, 20);
  358         SHA1Final(md, &sha1ctx);
  359 }
  360 
  361 static int
  362 carp_hmac_verify(struct carp_softc *sc, u_int32_t counter[2],
  363     unsigned char md[20])
  364 {
  365         unsigned char md2[20];
  366 
  367         CARP_SCLOCK_ASSERT(sc);
  368 
  369         carp_hmac_generate(sc, counter, md2);
  370 
  371         return (bcmp(md, md2, sizeof(md2)));
  372 }
  373 
  374 static void
  375 carp_setroute(struct carp_softc *sc, int cmd)
  376 {
  377         struct ifaddr *ifa;
  378         int s;
  379 
  380         if (sc->sc_carpdev)
  381                 CARP_SCLOCK_ASSERT(sc);
  382 
  383         s = splnet();
  384         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
  385 #ifdef INET
  386                 if (ifa->ifa_addr->sa_family == AF_INET &&
  387                     sc->sc_carpdev != NULL) {
  388                         int count = carp_addrcount(
  389                             (struct carp_if *)sc->sc_carpdev->if_carp,
  390                             ifatoia(ifa), CARP_COUNT_MASTER);
  391 
  392                         if ((cmd == RTM_ADD && count == 1) ||
  393                             (cmd == RTM_DELETE && count == 0))
  394                                 rtinit(ifa, cmd, RTF_UP | RTF_HOST);
  395                 }
  396 #endif
  397         }
  398         splx(s);
  399 }
  400 
  401 static int
  402 carp_clone_create(struct if_clone *ifc, int unit, caddr_t params)
  403 {
  404 
  405         struct carp_softc *sc;
  406         struct ifnet *ifp;
  407 
  408         sc = malloc(sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
  409         ifp = SC2IFP(sc) = if_alloc(IFT_ETHER);
  410         if (ifp == NULL) {
  411                 free(sc, M_CARP);
  412                 return (ENOSPC);
  413         }
  414         
  415         sc->sc_flags_backup = 0;
  416         sc->sc_suppress = 0;
  417         sc->sc_advbase = CARP_DFLTINTV;
  418         sc->sc_vhid = -1;       /* required setting */
  419         sc->sc_advskew = 0;
  420         sc->sc_init_counter = 1;
  421         sc->sc_naddrs = sc->sc_naddrs6 = 0; /* M_ZERO? */
  422 #ifdef INET
  423         sc->sc_imo.imo_membership = (struct in_multi **)malloc(
  424             (sizeof(struct in_multi *) * IP_MIN_MEMBERSHIPS), M_CARP,
  425             M_WAITOK);
  426         sc->sc_imo.imo_mfilters = NULL;
  427         sc->sc_imo.imo_max_memberships = IP_MIN_MEMBERSHIPS;
  428         sc->sc_imo.imo_multicast_vif = -1;
  429 #endif
  430 #ifdef INET6
  431         sc->sc_im6o.im6o_membership = (struct in6_multi **)malloc(
  432             (sizeof(struct in6_multi *) * IPV6_MIN_MEMBERSHIPS), M_CARP,
  433             M_WAITOK);
  434         sc->sc_im6o.im6o_mfilters = NULL;
  435         sc->sc_im6o.im6o_max_memberships = IPV6_MIN_MEMBERSHIPS;
  436         sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
  437 #endif
  438 
  439         callout_init(&sc->sc_ad_tmo, CALLOUT_MPSAFE);
  440         callout_init(&sc->sc_md_tmo, CALLOUT_MPSAFE);
  441         callout_init(&sc->sc_md6_tmo, CALLOUT_MPSAFE);
  442         
  443         ifp->if_softc = sc;
  444         if_initname(ifp, CARP_IFNAME, unit);
  445         ifp->if_mtu = ETHERMTU;
  446         ifp->if_flags = IFF_LOOPBACK;
  447         ifp->if_ioctl = carp_ioctl;
  448         ifp->if_output = carp_looutput;
  449         ifp->if_start = carp_start;
  450         ifp->if_type = IFT_CARP;
  451         ifp->if_snd.ifq_maxlen = ifqmaxlen;
  452         ifp->if_hdrlen = 0;
  453         if_attach(ifp);
  454         bpfattach(SC2IFP(sc), DLT_NULL, sizeof(u_int32_t));
  455         mtx_lock(&carp_mtx);
  456         LIST_INSERT_HEAD(&carpif_list, sc, sc_next);
  457         mtx_unlock(&carp_mtx);
  458         return (0);
  459 }
  460 
  461 static void
  462 carp_clone_destroy(struct ifnet *ifp)
  463 {
  464         struct carp_softc *sc = ifp->if_softc;
  465 
  466         if (sc->sc_carpdev)
  467                 CARP_SCLOCK(sc);
  468         carpdetach(sc, 1);      /* Returns unlocked. */
  469 
  470         mtx_lock(&carp_mtx);
  471         LIST_REMOVE(sc, sc_next);
  472         mtx_unlock(&carp_mtx);
  473         bpfdetach(ifp);
  474         if_detach(ifp);
  475         if_free_type(ifp, IFT_ETHER);
  476 #ifdef INET
  477         free(sc->sc_imo.imo_membership, M_CARP);
  478 #endif
  479 #ifdef INET6
  480         free(sc->sc_im6o.im6o_membership, M_CARP);
  481 #endif
  482         free(sc, M_CARP);
  483 }
  484 
  485 /*
  486  * This function can be called on CARP interface destroy path,
  487  * and in case of the removal of the underlying interface as
  488  * well. We differentiate these two cases: in case of destruction
  489  * of the underlying interface, we do not cleanup our multicast
  490  * memberships, since they are already freed. But we purge pointers
  491  * to multicast structures, since they are no longer valid, to
  492  * avoid panic in future calls to carpdetach(). Also, we do not
  493  * release the lock on return, because the function will be
  494  * called once more, for another CARP instance on the same
  495  * interface.
  496  */
  497 static void
  498 carpdetach(struct carp_softc *sc, int unlock)
  499 {
  500         struct carp_if *cif;
  501 
  502         callout_stop(&sc->sc_ad_tmo);
  503         callout_stop(&sc->sc_md_tmo);
  504         callout_stop(&sc->sc_md6_tmo);
  505 
  506         if (sc->sc_suppress)
  507                 carp_suppress_preempt--;
  508         sc->sc_suppress = 0;
  509 
  510         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
  511                 carp_suppress_preempt--;
  512         sc->sc_sendad_errors = 0;
  513 
  514         carp_set_state(sc, INIT);
  515         SC2IFP(sc)->if_flags &= ~IFF_UP;
  516         carp_setrun(sc, 0);
  517 #ifdef INET
  518         carp_multicast_cleanup(sc, unlock);
  519 #endif
  520 #ifdef INET6
  521         carp_multicast6_cleanup(sc, unlock);
  522 #endif
  523 
  524         if (sc->sc_carpdev != NULL) {
  525                 cif = (struct carp_if *)sc->sc_carpdev->if_carp;
  526                 CARP_LOCK_ASSERT(cif);
  527                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
  528                 if (!--cif->vhif_nvrs) {
  529                         ifpromisc(sc->sc_carpdev, 0);
  530                         sc->sc_carpdev->if_carp = NULL;
  531                         CARP_LOCK_DESTROY(cif);
  532                         free(cif, M_CARP);
  533                 } else if (unlock)
  534                         CARP_UNLOCK(cif);
  535                 sc->sc_carpdev = NULL;
  536         }
  537 }
  538 
  539 /* Detach an interface from the carp. */
  540 static void
  541 carp_ifdetach(void *arg __unused, struct ifnet *ifp)
  542 {
  543         struct carp_if *cif = (struct carp_if *)ifp->if_carp;
  544         struct carp_softc *sc, *nextsc;
  545 
  546         if (cif == NULL)
  547                 return;
  548 
  549         /*
  550          * XXX: At the end of for() cycle the lock will be destroyed.
  551          */
  552         CARP_LOCK(cif);
  553         for (sc = TAILQ_FIRST(&cif->vhif_vrs); sc; sc = nextsc) {
  554                 nextsc = TAILQ_NEXT(sc, sc_list);
  555                 carpdetach(sc, 0);
  556         }
  557 }
  558 
  559 /*
  560  * process input packet.
  561  * we have rearranged checks order compared to the rfc,
  562  * but it seems more efficient this way or not possible otherwise.
  563  */
  564 #ifdef INET
  565 void
  566 carp_input(struct mbuf *m, int hlen)
  567 {
  568         struct ip *ip = mtod(m, struct ip *);
  569         struct carp_header *ch;
  570         int iplen, len;
  571 
  572         CARPSTATS_INC(carps_ipackets);
  573 
  574         if (!carp_opts[CARPCTL_ALLOW]) {
  575                 m_freem(m);
  576                 return;
  577         }
  578 
  579         /* check if received on a valid carp interface */
  580         if (m->m_pkthdr.rcvif->if_carp == NULL) {
  581                 CARPSTATS_INC(carps_badif);
  582                 CARP_DEBUG("carp_input: packet received on non-carp "
  583                     "interface: %s\n",
  584                     m->m_pkthdr.rcvif->if_xname);
  585                 m_freem(m);
  586                 return;
  587         }
  588 
  589         /* verify that the IP TTL is 255.  */
  590         if (ip->ip_ttl != CARP_DFLTTL) {
  591                 CARPSTATS_INC(carps_badttl);
  592                 CARP_DEBUG("carp_input: received ttl %d != 255 on %s\n",
  593                     ip->ip_ttl,
  594                     m->m_pkthdr.rcvif->if_xname);
  595                 m_freem(m);
  596                 return;
  597         }
  598 
  599         iplen = ip->ip_hl << 2;
  600 
  601         if (m->m_pkthdr.len < iplen + sizeof(*ch)) {
  602                 CARPSTATS_INC(carps_badlen);
  603                 CARP_DEBUG("carp_input: received len %zd < "
  604                     "sizeof(struct carp_header) on %s\n",
  605                     m->m_len - sizeof(struct ip),
  606                     m->m_pkthdr.rcvif->if_xname);
  607                 m_freem(m);
  608                 return;
  609         }
  610 
  611         if (iplen + sizeof(*ch) < m->m_len) {
  612                 if ((m = m_pullup(m, iplen + sizeof(*ch))) == NULL) {
  613                         CARPSTATS_INC(carps_hdrops);
  614                         CARP_DEBUG("carp_input: pullup failed\n");
  615                         return;
  616                 }
  617                 ip = mtod(m, struct ip *);
  618         }
  619         ch = (struct carp_header *)((char *)ip + iplen);
  620 
  621         /*
  622          * verify that the received packet length is
  623          * equal to the CARP header
  624          */
  625         len = iplen + sizeof(*ch);
  626         if (len > m->m_pkthdr.len) {
  627                 CARPSTATS_INC(carps_badlen);
  628                 CARP_DEBUG("carp_input: packet too short %d on %s\n",
  629                     m->m_pkthdr.len,
  630                     m->m_pkthdr.rcvif->if_xname);
  631                 m_freem(m);
  632                 return;
  633         }
  634 
  635         if ((m = m_pullup(m, len)) == NULL) {
  636                 CARPSTATS_INC(carps_hdrops);
  637                 return;
  638         }
  639         ip = mtod(m, struct ip *);
  640         ch = (struct carp_header *)((char *)ip + iplen);
  641 
  642         /* verify the CARP checksum */
  643         m->m_data += iplen;
  644         if (carp_cksum(m, len - iplen)) {
  645                 CARPSTATS_INC(carps_badsum);
  646                 CARP_DEBUG("carp_input: checksum failed on %s\n",
  647                     m->m_pkthdr.rcvif->if_xname);
  648                 m_freem(m);
  649                 return;
  650         }
  651         m->m_data -= iplen;
  652 
  653         carp_input_c(m, ch, AF_INET);
  654 }
  655 #endif
  656 
  657 #ifdef INET6
  658 int
  659 carp6_input(struct mbuf **mp, int *offp, int proto)
  660 {
  661         struct mbuf *m = *mp;
  662         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  663         struct carp_header *ch;
  664         u_int len;
  665 
  666         CARPSTATS_INC(carps_ipackets6);
  667 
  668         if (!carp_opts[CARPCTL_ALLOW]) {
  669                 m_freem(m);
  670                 return (IPPROTO_DONE);
  671         }
  672 
  673         /* check if received on a valid carp interface */
  674         if (m->m_pkthdr.rcvif->if_carp == NULL) {
  675                 CARPSTATS_INC(carps_badif);
  676                 CARP_DEBUG("carp6_input: packet received on non-carp "
  677                     "interface: %s\n",
  678                     m->m_pkthdr.rcvif->if_xname);
  679                 m_freem(m);
  680                 return (IPPROTO_DONE);
  681         }
  682 
  683         /* verify that the IP TTL is 255 */
  684         if (ip6->ip6_hlim != CARP_DFLTTL) {
  685                 CARPSTATS_INC(carps_badttl);
  686                 CARP_DEBUG("carp6_input: received ttl %d != 255 on %s\n",
  687                     ip6->ip6_hlim,
  688                     m->m_pkthdr.rcvif->if_xname);
  689                 m_freem(m);
  690                 return (IPPROTO_DONE);
  691         }
  692 
  693         /* verify that we have a complete carp packet */
  694         len = m->m_len;
  695         IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
  696         if (ch == NULL) {
  697                 CARPSTATS_INC(carps_badlen);
  698                 CARP_DEBUG("carp6_input: packet size %u too small\n", len);
  699                 return (IPPROTO_DONE);
  700         }
  701 
  702 
  703         /* verify the CARP checksum */
  704         m->m_data += *offp;
  705         if (carp_cksum(m, sizeof(*ch))) {
  706                 CARPSTATS_INC(carps_badsum);
  707                 CARP_DEBUG("carp6_input: checksum failed, on %s\n",
  708                     m->m_pkthdr.rcvif->if_xname);
  709                 m_freem(m);
  710                 return (IPPROTO_DONE);
  711         }
  712         m->m_data -= *offp;
  713 
  714         carp_input_c(m, ch, AF_INET6);
  715         return (IPPROTO_DONE);
  716 }
  717 #endif /* INET6 */
  718 
  719 static void
  720 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
  721 {
  722         struct ifnet *ifp = m->m_pkthdr.rcvif;
  723         struct carp_softc *sc;
  724         u_int64_t tmp_counter;
  725         struct timeval sc_tv, ch_tv;
  726 
  727         /* verify that the VHID is valid on the receiving interface */
  728         CARP_LOCK(ifp->if_carp);
  729         TAILQ_FOREACH(sc, &((struct carp_if *)ifp->if_carp)->vhif_vrs, sc_list)
  730                 if (sc->sc_vhid == ch->carp_vhid)
  731                         break;
  732 
  733         if (!sc || !((SC2IFP(sc)->if_flags & IFF_UP) &&
  734             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING))) {
  735                 CARPSTATS_INC(carps_badvhid);
  736                 CARP_UNLOCK(ifp->if_carp);
  737                 m_freem(m);
  738                 return;
  739         }
  740 
  741         getmicrotime(&SC2IFP(sc)->if_lastchange);
  742         SC2IFP(sc)->if_ipackets++;
  743         SC2IFP(sc)->if_ibytes += m->m_pkthdr.len;
  744 
  745         if (bpf_peers_present(SC2IFP(sc)->if_bpf)) {
  746                 uint32_t af1 = af;
  747 #ifdef INET
  748                 struct ip *ip = mtod(m, struct ip *);
  749 
  750                 /* BPF wants net byte order */
  751                 if (af == AF_INET) {
  752                         ip->ip_len = htons(ip->ip_len + (ip->ip_hl << 2));
  753                         ip->ip_off = htons(ip->ip_off);
  754                 }
  755 #endif
  756                 bpf_mtap2(SC2IFP(sc)->if_bpf, &af1, sizeof(af1), m);
  757         }
  758 
  759         /* verify the CARP version. */
  760         if (ch->carp_version != CARP_VERSION) {
  761                 CARPSTATS_INC(carps_badver);
  762                 SC2IFP(sc)->if_ierrors++;
  763                 CARP_UNLOCK(ifp->if_carp);
  764                 CARP_DEBUG("%s; invalid version %d\n",
  765                     SC2IFP(sc)->if_xname,
  766                     ch->carp_version);
  767                 m_freem(m);
  768                 return;
  769         }
  770 
  771         /* verify the hash */
  772         if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
  773                 CARPSTATS_INC(carps_badauth);
  774                 SC2IFP(sc)->if_ierrors++;
  775                 CARP_UNLOCK(ifp->if_carp);
  776                 CARP_DEBUG("%s: incorrect hash\n", SC2IFP(sc)->if_xname);
  777                 m_freem(m);
  778                 return;
  779         }
  780 
  781         tmp_counter = ntohl(ch->carp_counter[0]);
  782         tmp_counter = tmp_counter<<32;
  783         tmp_counter += ntohl(ch->carp_counter[1]);
  784 
  785         /* XXX Replay protection goes here */
  786 
  787         sc->sc_init_counter = 0;
  788         sc->sc_counter = tmp_counter;
  789 
  790         sc_tv.tv_sec = sc->sc_advbase;
  791         if (carp_suppress_preempt && sc->sc_advskew <  240)
  792                 sc_tv.tv_usec = 240 * 1000000 / 256;
  793         else
  794                 sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
  795         ch_tv.tv_sec = ch->carp_advbase;
  796         ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
  797 
  798         switch (sc->sc_state) {
  799         case INIT:
  800                 break;
  801         case MASTER:
  802                 /*
  803                  * If we receive an advertisement from a master who's going to
  804                  * be more frequent than us, go into BACKUP state.
  805                  */
  806                 if (timevalcmp(&sc_tv, &ch_tv, >) ||
  807                     timevalcmp(&sc_tv, &ch_tv, ==)) {
  808                         callout_stop(&sc->sc_ad_tmo);
  809                         CARP_LOG("%s: MASTER -> BACKUP "
  810                            "(more frequent advertisement received)\n",
  811                            SC2IFP(sc)->if_xname);
  812                         carp_set_state(sc, BACKUP);
  813                         carp_setrun(sc, 0);
  814                         carp_setroute(sc, RTM_DELETE);
  815                 }
  816                 break;
  817         case BACKUP:
  818                 /*
  819                  * If we're pre-empting masters who advertise slower than us,
  820                  * and this one claims to be slower, treat him as down.
  821                  */
  822                 if (carp_opts[CARPCTL_PREEMPT] &&
  823                     timevalcmp(&sc_tv, &ch_tv, <)) {
  824                         CARP_LOG("%s: BACKUP -> MASTER "
  825                             "(preempting a slower master)\n",
  826                             SC2IFP(sc)->if_xname);
  827                         carp_master_down_locked(sc);
  828                         break;
  829                 }
  830 
  831                 /*
  832                  *  If the master is going to advertise at such a low frequency
  833                  *  that he's guaranteed to time out, we'd might as well just
  834                  *  treat him as timed out now.
  835                  */
  836                 sc_tv.tv_sec = sc->sc_advbase * 3;
  837                 if (timevalcmp(&sc_tv, &ch_tv, <)) {
  838                         CARP_LOG("%s: BACKUP -> MASTER "
  839                             "(master timed out)\n",
  840                             SC2IFP(sc)->if_xname);
  841                         carp_master_down_locked(sc);
  842                         break;
  843                 }
  844 
  845                 /*
  846                  * Otherwise, we reset the counter and wait for the next
  847                  * advertisement.
  848                  */
  849                 carp_setrun(sc, af);
  850                 break;
  851         }
  852 
  853         CARP_UNLOCK(ifp->if_carp);
  854 
  855         m_freem(m);
  856         return;
  857 }
  858 
  859 static int
  860 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
  861 {
  862         struct m_tag *mtag;
  863         struct ifnet *ifp = SC2IFP(sc);
  864 
  865         if (sc->sc_init_counter) {
  866                 /* this could also be seconds since unix epoch */
  867                 sc->sc_counter = arc4random();
  868                 sc->sc_counter = sc->sc_counter << 32;
  869                 sc->sc_counter += arc4random();
  870         } else
  871                 sc->sc_counter++;
  872 
  873         ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
  874         ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
  875 
  876         carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
  877 
  878         /* Tag packet for carp_output */
  879         mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct ifnet *), M_NOWAIT);
  880         if (mtag == NULL) {
  881                 m_freem(m);
  882                 SC2IFP(sc)->if_oerrors++;
  883                 return (ENOMEM);
  884         }
  885         bcopy(&ifp, (caddr_t)(mtag + 1), sizeof(struct ifnet *));
  886         m_tag_prepend(m, mtag);
  887 
  888         return (0);
  889 }
  890 
  891 static void
  892 carp_send_ad_all(void)
  893 {
  894         struct carp_softc *sc;
  895 
  896         mtx_lock(&carp_mtx);
  897         LIST_FOREACH(sc, &carpif_list, sc_next) {
  898                 if (sc->sc_carpdev == NULL)
  899                         continue;
  900                 CARP_SCLOCK(sc);
  901                 if ((SC2IFP(sc)->if_flags & IFF_UP) &&
  902                     (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING) &&
  903                      sc->sc_state == MASTER)
  904                         carp_send_ad_locked(sc);
  905                 CARP_SCUNLOCK(sc);
  906         }
  907         mtx_unlock(&carp_mtx);
  908 }
  909 
  910 static void
  911 carp_send_ad(void *v)
  912 {
  913         struct carp_softc *sc = v;
  914 
  915         CARP_SCLOCK(sc);
  916         carp_send_ad_locked(sc);
  917         CARP_SCUNLOCK(sc);
  918 }
  919 
  920 static void
  921 carp_send_ad_locked(struct carp_softc *sc)
  922 {
  923         struct carp_header ch;
  924         struct timeval tv;
  925         struct carp_header *ch_ptr;
  926         struct mbuf *m;
  927         int len, advbase, advskew;
  928 
  929         CARP_SCLOCK_ASSERT(sc);
  930 
  931         /* bow out if we've lost our UPness or RUNNINGuiness */
  932         if (!((SC2IFP(sc)->if_flags & IFF_UP) &&
  933             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING))) {
  934                 advbase = 255;
  935                 advskew = 255;
  936         } else {
  937                 advbase = sc->sc_advbase;
  938                 if (!carp_suppress_preempt || sc->sc_advskew > 240)
  939                         advskew = sc->sc_advskew;
  940                 else
  941                         advskew = 240;
  942                 tv.tv_sec = advbase;
  943                 tv.tv_usec = advskew * 1000000 / 256;
  944         }
  945 
  946         ch.carp_version = CARP_VERSION;
  947         ch.carp_type = CARP_ADVERTISEMENT;
  948         ch.carp_vhid = sc->sc_vhid;
  949         ch.carp_advbase = advbase;
  950         ch.carp_advskew = advskew;
  951         ch.carp_authlen = 7;    /* XXX DEFINE */
  952         ch.carp_pad1 = 0;       /* must be zero */
  953         ch.carp_cksum = 0;
  954 
  955 #ifdef INET
  956         if (sc->sc_ia) {
  957                 struct ip *ip;
  958 
  959                 MGETHDR(m, M_DONTWAIT, MT_HEADER);
  960                 if (m == NULL) {
  961                         SC2IFP(sc)->if_oerrors++;
  962                         CARPSTATS_INC(carps_onomem);
  963                         /* XXX maybe less ? */
  964                         if (advbase != 255 || advskew != 255)
  965                                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
  966                                     carp_send_ad, sc);
  967                         return;
  968                 }
  969                 len = sizeof(*ip) + sizeof(ch);
  970                 m->m_pkthdr.len = len;
  971                 m->m_pkthdr.rcvif = NULL;
  972                 m->m_len = len;
  973                 MH_ALIGN(m, m->m_len);
  974                 m->m_flags |= M_MCAST;
  975                 ip = mtod(m, struct ip *);
  976                 ip->ip_v = IPVERSION;
  977                 ip->ip_hl = sizeof(*ip) >> 2;
  978                 ip->ip_tos = IPTOS_LOWDELAY;
  979                 ip->ip_len = len;
  980                 ip->ip_id = ip_newid();
  981                 ip->ip_off = IP_DF;
  982                 ip->ip_ttl = CARP_DFLTTL;
  983                 ip->ip_p = IPPROTO_CARP;
  984                 ip->ip_sum = 0;
  985                 ip->ip_src.s_addr = sc->sc_ia->ia_addr.sin_addr.s_addr;
  986                 ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
  987 
  988                 ch_ptr = (struct carp_header *)(&ip[1]);
  989                 bcopy(&ch, ch_ptr, sizeof(ch));
  990                 if (carp_prepare_ad(m, sc, ch_ptr))
  991                         return;
  992 
  993                 m->m_data += sizeof(*ip);
  994                 ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
  995                 m->m_data -= sizeof(*ip);
  996 
  997                 getmicrotime(&SC2IFP(sc)->if_lastchange);
  998                 SC2IFP(sc)->if_opackets++;
  999                 SC2IFP(sc)->if_obytes += len;
 1000                 CARPSTATS_INC(carps_opackets);
 1001 
 1002                 if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL)) {
 1003                         SC2IFP(sc)->if_oerrors++;
 1004                         if (sc->sc_sendad_errors < INT_MAX)
 1005                                 sc->sc_sendad_errors++;
 1006                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
 1007                                 carp_suppress_preempt++;
 1008                                 if (carp_suppress_preempt == 1) {
 1009                                         CARP_SCUNLOCK(sc);
 1010                                         carp_send_ad_all();
 1011                                         CARP_SCLOCK(sc);
 1012                                 }
 1013                         }
 1014                         sc->sc_sendad_success = 0;
 1015                 } else {
 1016                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
 1017                                 if (++sc->sc_sendad_success >=
 1018                                     CARP_SENDAD_MIN_SUCCESS) {
 1019                                         carp_suppress_preempt--;
 1020                                         sc->sc_sendad_errors = 0;
 1021                                 }
 1022                         } else
 1023                                 sc->sc_sendad_errors = 0;
 1024                 }
 1025         }
 1026 #endif /* INET */
 1027 #ifdef INET6
 1028         if (sc->sc_ia6) {
 1029                 struct ip6_hdr *ip6;
 1030 
 1031                 MGETHDR(m, M_DONTWAIT, MT_HEADER);
 1032                 if (m == NULL) {
 1033                         SC2IFP(sc)->if_oerrors++;
 1034                         CARPSTATS_INC(carps_onomem);
 1035                         /* XXX maybe less ? */
 1036                         if (advbase != 255 || advskew != 255)
 1037                                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
 1038                                     carp_send_ad, sc);
 1039                         return;
 1040                 }
 1041                 len = sizeof(*ip6) + sizeof(ch);
 1042                 m->m_pkthdr.len = len;
 1043                 m->m_pkthdr.rcvif = NULL;
 1044                 m->m_len = len;
 1045                 MH_ALIGN(m, m->m_len);
 1046                 m->m_flags |= M_MCAST;
 1047                 ip6 = mtod(m, struct ip6_hdr *);
 1048                 bzero(ip6, sizeof(*ip6));
 1049                 ip6->ip6_vfc |= IPV6_VERSION;
 1050                 ip6->ip6_hlim = CARP_DFLTTL;
 1051                 ip6->ip6_nxt = IPPROTO_CARP;
 1052                 bcopy(&sc->sc_ia6->ia_addr.sin6_addr, &ip6->ip6_src,
 1053                     sizeof(struct in6_addr));
 1054                 /* set the multicast destination */
 1055 
 1056                 ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
 1057                 ip6->ip6_dst.s6_addr8[15] = 0x12;
 1058                 if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
 1059                         SC2IFP(sc)->if_oerrors++;
 1060                         m_freem(m);
 1061                         CARP_DEBUG("%s: in6_setscope failed\n", __func__);
 1062                         return;
 1063                 }
 1064 
 1065                 ch_ptr = (struct carp_header *)(&ip6[1]);
 1066                 bcopy(&ch, ch_ptr, sizeof(ch));
 1067                 if (carp_prepare_ad(m, sc, ch_ptr))
 1068                         return;
 1069 
 1070                 m->m_data += sizeof(*ip6);
 1071                 ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
 1072                 m->m_data -= sizeof(*ip6);
 1073 
 1074                 getmicrotime(&SC2IFP(sc)->if_lastchange);
 1075                 SC2IFP(sc)->if_opackets++;
 1076                 SC2IFP(sc)->if_obytes += len;
 1077                 CARPSTATS_INC(carps_opackets6);
 1078 
 1079                 if (ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL)) {
 1080                         SC2IFP(sc)->if_oerrors++;
 1081                         if (sc->sc_sendad_errors < INT_MAX)
 1082                                 sc->sc_sendad_errors++;
 1083                         if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
 1084                                 carp_suppress_preempt++;
 1085                                 if (carp_suppress_preempt == 1) {
 1086                                         CARP_SCUNLOCK(sc);
 1087                                         carp_send_ad_all();
 1088                                         CARP_SCLOCK(sc);
 1089                                 }
 1090                         }
 1091                         sc->sc_sendad_success = 0;
 1092                 } else {
 1093                         if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
 1094                                 if (++sc->sc_sendad_success >=
 1095                                     CARP_SENDAD_MIN_SUCCESS) {
 1096                                         carp_suppress_preempt--;
 1097                                         sc->sc_sendad_errors = 0;
 1098                                 }
 1099                         } else
 1100                                 sc->sc_sendad_errors = 0;
 1101                 }
 1102         }
 1103 #endif /* INET6 */
 1104 
 1105         if (advbase != 255 || advskew != 255)
 1106                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
 1107                     carp_send_ad, sc);
 1108 
 1109 }
 1110 
 1111 #ifdef INET
 1112 /*
 1113  * Broadcast a gratuitous ARP request containing
 1114  * the virtual router MAC address for each IP address
 1115  * associated with the virtual router.
 1116  */
 1117 static void
 1118 carp_send_arp(struct carp_softc *sc)
 1119 {
 1120         struct ifaddr *ifa;
 1121 
 1122         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 1123 
 1124                 if (ifa->ifa_addr->sa_family != AF_INET)
 1125                         continue;
 1126 
 1127 /*              arprequest(sc->sc_carpdev, &in, &in, IF_LLADDR(sc->sc_ifp)); */
 1128                 arp_ifinit2(sc->sc_carpdev, ifa, IF_LLADDR(sc->sc_ifp));
 1129 
 1130                 DELAY(1000);    /* XXX */
 1131         }
 1132 }
 1133 #endif
 1134 
 1135 #ifdef INET6
 1136 static void
 1137 carp_send_na(struct carp_softc *sc)
 1138 {
 1139         struct ifaddr *ifa;
 1140         struct in6_addr *in6;
 1141         static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 1142 
 1143         TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 1144 
 1145                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1146                         continue;
 1147 
 1148                 in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
 1149                 nd6_na_output(sc->sc_carpdev, &mcast, in6,
 1150                     ND_NA_FLAG_OVERRIDE, 1, NULL);
 1151                 DELAY(1000);    /* XXX */
 1152         }
 1153 }
 1154 #endif /* INET6 */
 1155 
 1156 #ifdef INET
 1157 static int
 1158 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
 1159 {
 1160         struct carp_softc *vh;
 1161         struct ifaddr *ifa;
 1162         int count = 0;
 1163 
 1164         CARP_LOCK_ASSERT(cif);
 1165 
 1166         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
 1167                 if ((type == CARP_COUNT_RUNNING &&
 1168                     (SC2IFP(vh)->if_flags & IFF_UP) &&
 1169                     (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING)) ||
 1170                     (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
 1171                         IF_ADDR_RLOCK(SC2IFP(vh));
 1172                         TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist,
 1173                             ifa_list) {
 1174                                 if (ifa->ifa_addr->sa_family == AF_INET &&
 1175                                     ia->ia_addr.sin_addr.s_addr ==
 1176                                     ifatoia(ifa)->ia_addr.sin_addr.s_addr)
 1177                                         count++;
 1178                         }
 1179                         IF_ADDR_RUNLOCK(SC2IFP(vh));
 1180                 }
 1181         }
 1182         return (count);
 1183 }
 1184 
 1185 int
 1186 carp_iamatch(struct ifnet *ifp, struct in_ifaddr *ia,
 1187     struct in_addr *isaddr, u_int8_t **enaddr)
 1188 {
 1189         struct carp_if *cif;
 1190         struct carp_softc *vh;
 1191         int index, count = 0;
 1192         struct ifaddr *ifa;
 1193 
 1194         cif = ifp->if_carp;
 1195         CARP_LOCK(cif);
 1196 
 1197         if (carp_opts[CARPCTL_ARPBALANCE]) {
 1198                 /*
 1199                  * XXX proof of concept implementation.
 1200                  * We use the source ip to decide which virtual host should
 1201                  * handle the request. If we're master of that virtual host,
 1202                  * then we respond, otherwise, just drop the arp packet on
 1203                  * the floor.
 1204                  */
 1205                 count = carp_addrcount(cif, ia, CARP_COUNT_RUNNING);
 1206                 if (count == 0) {
 1207                         /* should never reach this */
 1208                         CARP_UNLOCK(cif);
 1209                         return (0);
 1210                 }
 1211 
 1212                 /* this should be a hash, like pf_hash() */
 1213                 index = ntohl(isaddr->s_addr) % count;
 1214                 count = 0;
 1215 
 1216                 TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
 1217                         if ((SC2IFP(vh)->if_flags & IFF_UP) &&
 1218                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING)) {
 1219                                 IF_ADDR_RLOCK(SC2IFP(vh));
 1220                                 TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist,
 1221                                     ifa_list) {
 1222                                         if (ifa->ifa_addr->sa_family ==
 1223                                             AF_INET &&
 1224                                             ia->ia_addr.sin_addr.s_addr ==
 1225                                             ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
 1226                                                 if (count == index) {
 1227                                                         if (vh->sc_state ==
 1228                                                             MASTER) {
 1229                                                                 *enaddr = IF_LLADDR(vh->sc_ifp);
 1230                                                                 IF_ADDR_RUNLOCK(SC2IFP(vh));
 1231                                                                 CARP_UNLOCK(cif);
 1232                                                                 return (1);
 1233                                                         } else {
 1234                                                                 IF_ADDR_RUNLOCK(SC2IFP(vh));
 1235                                                                 CARP_UNLOCK(cif);
 1236                                                                 return (0);
 1237                                                         }
 1238                                                 }
 1239                                                 count++;
 1240                                         }
 1241                                 }
 1242                                 IF_ADDR_RUNLOCK(SC2IFP(vh));
 1243                         }
 1244                 }
 1245         } else {
 1246                 TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
 1247                         if ((SC2IFP(vh)->if_flags & IFF_UP) &&
 1248                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
 1249                             ia->ia_ifp == SC2IFP(vh) &&
 1250                             vh->sc_state == MASTER) {
 1251                                 *enaddr = IF_LLADDR(vh->sc_ifp);
 1252                                 CARP_UNLOCK(cif);
 1253                                 return (1);
 1254                         }
 1255                 }
 1256         }
 1257         CARP_UNLOCK(cif);
 1258         return (0);
 1259 }
 1260 #endif
 1261 
 1262 #ifdef INET6
 1263 struct ifaddr *
 1264 carp_iamatch6(struct ifnet *ifp, struct in6_addr *taddr)
 1265 {
 1266         struct carp_if *cif;
 1267         struct carp_softc *vh;
 1268         struct ifaddr *ifa;
 1269 
 1270         cif = ifp->if_carp;
 1271         CARP_LOCK(cif);
 1272         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
 1273                 IF_ADDR_RLOCK(SC2IFP(vh));
 1274                 TAILQ_FOREACH(ifa, &SC2IFP(vh)->if_addrlist, ifa_list) {
 1275                         if (IN6_ARE_ADDR_EQUAL(taddr,
 1276                             &ifatoia6(ifa)->ia_addr.sin6_addr) &&
 1277                             (SC2IFP(vh)->if_flags & IFF_UP) &&
 1278                             (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
 1279                             vh->sc_state == MASTER) {
 1280                                 ifa_ref(ifa);
 1281                                 IF_ADDR_RUNLOCK(SC2IFP(vh));
 1282                                 CARP_UNLOCK(cif);
 1283                                 return (ifa);
 1284                         }
 1285                 }
 1286                 IF_ADDR_RUNLOCK(SC2IFP(vh));
 1287         }
 1288         CARP_UNLOCK(cif);
 1289         
 1290         return (NULL);
 1291 }
 1292 
 1293 caddr_t
 1294 carp_macmatch6(struct ifnet *ifp, struct mbuf *m, const struct in6_addr *taddr)
 1295 {
 1296         struct m_tag *mtag;
 1297         struct carp_if *cif;
 1298         struct carp_softc *sc;
 1299         struct ifaddr *ifa;
 1300 
 1301         cif = ifp->if_carp;
 1302         CARP_LOCK(cif);
 1303         TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
 1304                 IF_ADDR_RLOCK(SC2IFP(sc));
 1305                 TAILQ_FOREACH(ifa, &SC2IFP(sc)->if_addrlist, ifa_list) {
 1306                         if (IN6_ARE_ADDR_EQUAL(taddr,
 1307                             &ifatoia6(ifa)->ia_addr.sin6_addr) &&
 1308                             (SC2IFP(sc)->if_flags & IFF_UP) &&
 1309                             (SC2IFP(sc)->if_drv_flags & IFF_DRV_RUNNING)) {
 1310                                 struct ifnet *ifp = SC2IFP(sc);
 1311                                 mtag = m_tag_get(PACKET_TAG_CARP,
 1312                                     sizeof(struct ifnet *), M_NOWAIT);
 1313                                 if (mtag == NULL) {
 1314                                         /* better a bit than nothing */
 1315                                         IF_ADDR_RUNLOCK(SC2IFP(sc));
 1316                                         CARP_UNLOCK(cif);
 1317                                         return (IF_LLADDR(sc->sc_ifp));
 1318                                 }
 1319                                 bcopy(&ifp, (caddr_t)(mtag + 1),
 1320                                     sizeof(struct ifnet *));
 1321                                 m_tag_prepend(m, mtag);
 1322 
 1323                                 IF_ADDR_RUNLOCK(SC2IFP(sc));
 1324                                 CARP_UNLOCK(cif);
 1325                                 return (IF_LLADDR(sc->sc_ifp));
 1326                         }
 1327                 }
 1328                 IF_ADDR_RUNLOCK(SC2IFP(sc));
 1329         }
 1330         CARP_UNLOCK(cif);
 1331 
 1332         return (NULL);
 1333 }
 1334 #endif
 1335 
 1336 struct ifnet *
 1337 carp_forus(struct ifnet *ifp, u_char *dhost)
 1338 {
 1339         struct carp_if *cif;
 1340         struct carp_softc *vh;
 1341         u_int8_t *ena = dhost;
 1342 
 1343         if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
 1344                 return (NULL);
 1345 
 1346         cif = ifp->if_carp;
 1347         CARP_LOCK(cif);
 1348         TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
 1349                 if ((SC2IFP(vh)->if_flags & IFF_UP) &&
 1350                     (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
 1351                     vh->sc_state == MASTER &&
 1352                     !bcmp(dhost, IF_LLADDR(vh->sc_ifp), ETHER_ADDR_LEN)) {
 1353                         CARP_UNLOCK(cif);
 1354                         return (SC2IFP(vh));
 1355                 }
 1356 
 1357         CARP_UNLOCK(cif);
 1358         return (NULL);
 1359 }
 1360 
 1361 static void
 1362 carp_master_down(void *v)
 1363 {
 1364         struct carp_softc *sc = v;
 1365 
 1366         CARP_SCLOCK(sc);
 1367         carp_master_down_locked(sc);
 1368         CARP_SCUNLOCK(sc);
 1369 }
 1370 
 1371 static void
 1372 carp_master_down_locked(struct carp_softc *sc)
 1373 {
 1374         if (sc->sc_carpdev)
 1375                 CARP_SCLOCK_ASSERT(sc);
 1376 
 1377         switch (sc->sc_state) {
 1378         case INIT:
 1379                 printf("%s: master_down event in INIT state\n",
 1380                     SC2IFP(sc)->if_xname);
 1381                 break;
 1382         case MASTER:
 1383                 break;
 1384         case BACKUP:
 1385                 carp_set_state(sc, MASTER);
 1386                 carp_send_ad_locked(sc);
 1387 #ifdef INET
 1388                 carp_send_arp(sc);
 1389 #endif
 1390 #ifdef INET6
 1391                 carp_send_na(sc);
 1392 #endif /* INET6 */
 1393                 carp_setrun(sc, 0);
 1394                 carp_setroute(sc, RTM_ADD);
 1395                 break;
 1396         }
 1397 }
 1398 
 1399 /*
 1400  * When in backup state, af indicates whether to reset the master down timer
 1401  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
 1402  */
 1403 static void
 1404 carp_setrun(struct carp_softc *sc, sa_family_t af)
 1405 {
 1406         struct timeval tv;
 1407 
 1408         if (sc->sc_carpdev == NULL) {
 1409                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
 1410                 carp_set_state(sc, INIT);
 1411                 return;
 1412         } else
 1413                 CARP_SCLOCK_ASSERT(sc);
 1414 
 1415         if (SC2IFP(sc)->if_flags & IFF_UP &&
 1416             sc->sc_vhid > 0 && (sc->sc_naddrs || sc->sc_naddrs6) &&
 1417             sc->sc_carpdev->if_link_state == LINK_STATE_UP)
 1418                 SC2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
 1419         else {
 1420                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
 1421                 carp_setroute(sc, RTM_DELETE);
 1422                 return;
 1423         }
 1424 
 1425         switch (sc->sc_state) {
 1426         case INIT:
 1427                 CARP_LOG("%s: INIT -> BACKUP\n", SC2IFP(sc)->if_xname);
 1428                 carp_set_state(sc, BACKUP);
 1429                 carp_setroute(sc, RTM_DELETE);
 1430                 carp_setrun(sc, 0);
 1431                 break;
 1432         case BACKUP:
 1433                 callout_stop(&sc->sc_ad_tmo);
 1434                 tv.tv_sec = 3 * sc->sc_advbase;
 1435                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
 1436                 switch (af) {
 1437 #ifdef INET
 1438                 case AF_INET:
 1439                         callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
 1440                             carp_master_down, sc);
 1441                         break;
 1442 #endif /* INET */
 1443 #ifdef INET6
 1444                 case AF_INET6:
 1445                         callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
 1446                             carp_master_down, sc);
 1447                         break;
 1448 #endif /* INET6 */
 1449                 default:
 1450                         if (sc->sc_naddrs)
 1451                                 callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
 1452                                     carp_master_down, sc);
 1453                         if (sc->sc_naddrs6)
 1454                                 callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
 1455                                     carp_master_down, sc);
 1456                         break;
 1457                 }
 1458                 break;
 1459         case MASTER:
 1460                 tv.tv_sec = sc->sc_advbase;
 1461                 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
 1462                 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
 1463                     carp_send_ad, sc);
 1464                 break;
 1465         }
 1466 }
 1467 
 1468 #ifdef INET
 1469 static void
 1470 carp_multicast_cleanup(struct carp_softc *sc, int dofree)
 1471 {
 1472         struct ip_moptions *imo = &sc->sc_imo;
 1473         u_int16_t n = imo->imo_num_memberships;
 1474 
 1475         /* Clean up our own multicast memberships */
 1476         while (n-- > 0) {
 1477                 if (imo->imo_membership[n] != NULL) {
 1478                         if (dofree)
 1479                                 in_delmulti(imo->imo_membership[n]);
 1480                         imo->imo_membership[n] = NULL;
 1481                 }
 1482         }
 1483         KASSERT(imo->imo_mfilters == NULL,
 1484            ("%s: imo_mfilters != NULL", __func__));
 1485         imo->imo_num_memberships = 0;
 1486         imo->imo_multicast_ifp = NULL;
 1487 }
 1488 #endif
 1489 
 1490 #ifdef INET6
 1491 static void
 1492 carp_multicast6_cleanup(struct carp_softc *sc, int dofree)
 1493 {
 1494         struct ip6_moptions *im6o = &sc->sc_im6o;
 1495         u_int16_t n = im6o->im6o_num_memberships;
 1496 
 1497         while (n-- > 0) {
 1498                 if (im6o->im6o_membership[n] != NULL) {
 1499                         if (dofree)
 1500                                 in6_mc_leave(im6o->im6o_membership[n], NULL);
 1501                         im6o->im6o_membership[n] = NULL;
 1502                 }
 1503         }
 1504         KASSERT(im6o->im6o_mfilters == NULL,
 1505            ("%s: im6o_mfilters != NULL", __func__));
 1506         im6o->im6o_num_memberships = 0;
 1507         im6o->im6o_multicast_ifp = NULL;
 1508 }
 1509 #endif
 1510 
 1511 #ifdef INET
 1512 static int
 1513 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
 1514 {
 1515         struct ifnet *ifp;
 1516         struct carp_if *cif;
 1517         struct in_ifaddr *ia, *ia_if;
 1518         struct ip_moptions *imo = &sc->sc_imo;
 1519         struct in_addr addr;
 1520         u_long iaddr = htonl(sin->sin_addr.s_addr);
 1521         int own, error;
 1522 
 1523         if (sin->sin_addr.s_addr == 0) {
 1524                 if (!(SC2IFP(sc)->if_flags & IFF_UP))
 1525                         carp_set_state(sc, INIT);
 1526                 if (sc->sc_naddrs)
 1527                         SC2IFP(sc)->if_flags |= IFF_UP;
 1528                 if (sc->sc_carpdev)
 1529                         CARP_SCLOCK(sc);
 1530                 carp_setrun(sc, 0);
 1531                 if (sc->sc_carpdev)
 1532                         CARP_SCUNLOCK(sc);
 1533                 return (0);
 1534         }
 1535 
 1536         /* we have to do it by hands to check we won't match on us */
 1537         ia_if = NULL; own = 0;
 1538         IN_IFADDR_RLOCK();
 1539         TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
 1540                 /* and, yeah, we need a multicast-capable iface too */
 1541                 if (ia->ia_ifp != SC2IFP(sc) &&
 1542                     (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
 1543                     (iaddr & ia->ia_subnetmask) == ia->ia_subnet) {
 1544                         if (!ia_if)
 1545                                 ia_if = ia;
 1546                         if (sin->sin_addr.s_addr ==
 1547                             ia->ia_addr.sin_addr.s_addr)
 1548                                 own++;
 1549                 }
 1550         }
 1551 
 1552         if (!ia_if) {
 1553                 IN_IFADDR_RUNLOCK();
 1554                 return (EADDRNOTAVAIL);
 1555         }
 1556 
 1557         ia = ia_if;
 1558         ifa_ref(&ia->ia_ifa);
 1559         IN_IFADDR_RUNLOCK();
 1560 
 1561         ifp = ia->ia_ifp;
 1562 
 1563         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
 1564             (imo->imo_multicast_ifp && imo->imo_multicast_ifp != ifp)) {
 1565                 ifa_free(&ia->ia_ifa);
 1566                 return (EADDRNOTAVAIL);
 1567         }
 1568 
 1569         if (imo->imo_num_memberships == 0) {
 1570                 addr.s_addr = htonl(INADDR_CARP_GROUP);
 1571                 if ((imo->imo_membership[0] = in_addmulti(&addr, ifp)) ==
 1572                     NULL) {
 1573                         ifa_free(&ia->ia_ifa);
 1574                         return (ENOBUFS);
 1575                 }
 1576                 imo->imo_num_memberships++;
 1577                 imo->imo_multicast_ifp = ifp;
 1578                 imo->imo_multicast_ttl = CARP_DFLTTL;
 1579                 imo->imo_multicast_loop = 0;
 1580         }
 1581 
 1582         if (!ifp->if_carp) {
 1583 
 1584                 cif = malloc(sizeof(*cif), M_CARP,
 1585                     M_WAITOK|M_ZERO);
 1586                 if (!cif) {
 1587                         error = ENOBUFS;
 1588                         goto cleanup;
 1589                 }
 1590                 if ((error = ifpromisc(ifp, 1))) {
 1591                         free(cif, M_CARP);
 1592                         goto cleanup;
 1593                 }
 1594                 
 1595                 CARP_LOCK_INIT(cif);
 1596                 CARP_LOCK(cif);
 1597                 cif->vhif_ifp = ifp;
 1598                 TAILQ_INIT(&cif->vhif_vrs);
 1599                 ifp->if_carp = cif;
 1600 
 1601         } else {
 1602                 struct carp_softc *vr;
 1603 
 1604                 cif = (struct carp_if *)ifp->if_carp;
 1605                 CARP_LOCK(cif);
 1606                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
 1607                         if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
 1608                                 CARP_UNLOCK(cif);
 1609                                 error = EEXIST;
 1610                                 goto cleanup;
 1611                         }
 1612         }
 1613         sc->sc_ia = ia;
 1614         sc->sc_carpdev = ifp;
 1615 
 1616         { /* XXX prevent endless loop if already in queue */
 1617         struct carp_softc *vr, *after = NULL;
 1618         int myself = 0;
 1619         cif = (struct carp_if *)ifp->if_carp;
 1620 
 1621         /* XXX: cif should not change, right? So we still hold the lock */
 1622         CARP_LOCK_ASSERT(cif);
 1623 
 1624         TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
 1625                 if (vr == sc)
 1626                         myself = 1;
 1627                 if (vr->sc_vhid < sc->sc_vhid)
 1628                         after = vr;
 1629         }
 1630 
 1631         if (!myself) {
 1632                 /* We're trying to keep things in order */
 1633                 if (after == NULL) {
 1634                         TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
 1635                 } else {
 1636                         TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
 1637                 }
 1638                 cif->vhif_nvrs++;
 1639         }
 1640         }
 1641 
 1642         sc->sc_naddrs++;
 1643         SC2IFP(sc)->if_flags |= IFF_UP;
 1644         if (own)
 1645                 sc->sc_advskew = 0;
 1646         carp_sc_state_locked(sc);
 1647         carp_setrun(sc, 0);
 1648 
 1649         CARP_UNLOCK(cif);
 1650         ifa_free(&ia->ia_ifa);  /* XXXRW: should hold reference for softc. */
 1651 
 1652         return (0);
 1653 
 1654 cleanup:
 1655         in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
 1656         ifa_free(&ia->ia_ifa);
 1657         return (error);
 1658 }
 1659 
 1660 static int
 1661 carp_del_addr(struct carp_softc *sc, struct sockaddr_in *sin)
 1662 {
 1663         int error = 0;
 1664 
 1665         if (!--sc->sc_naddrs) {
 1666                 struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
 1667                 struct ip_moptions *imo = &sc->sc_imo;
 1668 
 1669                 CARP_LOCK(cif);
 1670                 callout_stop(&sc->sc_ad_tmo);
 1671                 SC2IFP(sc)->if_flags &= ~IFF_UP;
 1672                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
 1673                 sc->sc_vhid = -1;
 1674                 in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
 1675                 imo->imo_multicast_ifp = NULL;
 1676                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
 1677                 if (!--cif->vhif_nvrs) {
 1678                         sc->sc_carpdev->if_carp = NULL;
 1679                         CARP_LOCK_DESTROY(cif);
 1680                         free(cif, M_CARP);
 1681                 } else {
 1682                         CARP_UNLOCK(cif);
 1683                 }
 1684         }
 1685 
 1686         return (error);
 1687 }
 1688 #endif
 1689 
 1690 #ifdef INET6
 1691 static int
 1692 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
 1693 {
 1694         struct ifnet *ifp;
 1695         struct carp_if *cif;
 1696         struct in6_ifaddr *ia, *ia_if;
 1697         struct ip6_moptions *im6o = &sc->sc_im6o;
 1698         struct in6_addr in6;
 1699         int own, error;
 1700 
 1701         error = 0;
 1702 
 1703         if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
 1704                 if (!(SC2IFP(sc)->if_flags & IFF_UP))
 1705                         carp_set_state(sc, INIT);
 1706                 if (sc->sc_naddrs6)
 1707                         SC2IFP(sc)->if_flags |= IFF_UP;
 1708                 if (sc->sc_carpdev)
 1709                         CARP_SCLOCK(sc);
 1710                 carp_setrun(sc, 0);
 1711                 if (sc->sc_carpdev)
 1712                         CARP_SCUNLOCK(sc);
 1713                 return (0);
 1714         }
 1715 
 1716         /* we have to do it by hands to check we won't match on us */
 1717         ia_if = NULL; own = 0;
 1718         IN6_IFADDR_RLOCK();
 1719         TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
 1720                 int i;
 1721 
 1722                 for (i = 0; i < 4; i++) {
 1723                         if ((sin6->sin6_addr.s6_addr32[i] &
 1724                             ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
 1725                             (ia->ia_addr.sin6_addr.s6_addr32[i] &
 1726                             ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
 1727                                 break;
 1728                 }
 1729                 /* and, yeah, we need a multicast-capable iface too */
 1730                 if (ia->ia_ifp != SC2IFP(sc) &&
 1731                     (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
 1732                     (i == 4)) {
 1733                         if (!ia_if)
 1734                                 ia_if = ia;
 1735                         if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr,
 1736                             &ia->ia_addr.sin6_addr))
 1737                                 own++;
 1738                 }
 1739         }
 1740 
 1741         if (!ia_if) {
 1742                 IN6_IFADDR_RUNLOCK();
 1743                 return (EADDRNOTAVAIL);
 1744         }
 1745         ia = ia_if;
 1746         ifa_ref(&ia->ia_ifa);
 1747         IN6_IFADDR_RUNLOCK();
 1748         ifp = ia->ia_ifp;
 1749 
 1750         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0 ||
 1751             (im6o->im6o_multicast_ifp && im6o->im6o_multicast_ifp != ifp)) {
 1752                 ifa_free(&ia->ia_ifa);
 1753                 return (EADDRNOTAVAIL);
 1754         }
 1755 
 1756         if (!sc->sc_naddrs6) {
 1757                 struct in6_multi *in6m;
 1758 
 1759                 im6o->im6o_multicast_ifp = ifp;
 1760 
 1761                 /* join CARP multicast address */
 1762                 bzero(&in6, sizeof(in6));
 1763                 in6.s6_addr16[0] = htons(0xff02);
 1764                 in6.s6_addr8[15] = 0x12;
 1765                 if (in6_setscope(&in6, ifp, NULL) != 0)
 1766                         goto cleanup;
 1767                 in6m = NULL;
 1768                 error = in6_mc_join(ifp, &in6, NULL, &in6m, 0);
 1769                 if (error)
 1770                         goto cleanup;
 1771                 im6o->im6o_membership[0] = in6m;
 1772                 im6o->im6o_num_memberships++;
 1773 
 1774                 /* join solicited multicast address */
 1775                 bzero(&in6, sizeof(in6));
 1776                 in6.s6_addr16[0] = htons(0xff02);
 1777                 in6.s6_addr32[1] = 0;
 1778                 in6.s6_addr32[2] = htonl(1);
 1779                 in6.s6_addr32[3] = sin6->sin6_addr.s6_addr32[3];
 1780                 in6.s6_addr8[12] = 0xff;
 1781                 if (in6_setscope(&in6, ifp, NULL) != 0)
 1782                         goto cleanup;
 1783                 in6m = NULL;
 1784                 error = in6_mc_join(ifp, &in6, NULL, &in6m, 0);
 1785                 if (error)
 1786                         goto cleanup;
 1787                 im6o->im6o_membership[1] = in6m;
 1788                 im6o->im6o_num_memberships++;
 1789         }
 1790 
 1791         if (!ifp->if_carp) {
 1792                 cif = malloc(sizeof(*cif), M_CARP,
 1793                     M_WAITOK|M_ZERO);
 1794                 if (!cif) {
 1795                         error = ENOBUFS;
 1796                         goto cleanup;
 1797                 }
 1798                 if ((error = ifpromisc(ifp, 1))) {
 1799                         free(cif, M_CARP);
 1800                         goto cleanup;
 1801                 }
 1802 
 1803                 CARP_LOCK_INIT(cif);
 1804                 CARP_LOCK(cif);
 1805                 cif->vhif_ifp = ifp;
 1806                 TAILQ_INIT(&cif->vhif_vrs);
 1807                 ifp->if_carp = cif;
 1808 
 1809         } else {
 1810                 struct carp_softc *vr;
 1811 
 1812                 cif = (struct carp_if *)ifp->if_carp;
 1813                 CARP_LOCK(cif);
 1814                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
 1815                         if (vr != sc && vr->sc_vhid == sc->sc_vhid) {
 1816                                 CARP_UNLOCK(cif);
 1817                                 error = EINVAL;
 1818                                 goto cleanup;
 1819                         }
 1820         }
 1821         sc->sc_ia6 = ia;
 1822         sc->sc_carpdev = ifp;
 1823 
 1824         { /* XXX prevent endless loop if already in queue */
 1825         struct carp_softc *vr, *after = NULL;
 1826         int myself = 0;
 1827         cif = (struct carp_if *)ifp->if_carp;
 1828         CARP_LOCK_ASSERT(cif);
 1829 
 1830         TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
 1831                 if (vr == sc)
 1832                         myself = 1;
 1833                 if (vr->sc_vhid < sc->sc_vhid)
 1834                         after = vr;
 1835         }
 1836 
 1837         if (!myself) {
 1838                 /* We're trying to keep things in order */
 1839                 if (after == NULL) {
 1840                         TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
 1841                 } else {
 1842                         TAILQ_INSERT_AFTER(&cif->vhif_vrs, after, sc, sc_list);
 1843                 }
 1844                 cif->vhif_nvrs++;
 1845         }
 1846         }
 1847 
 1848         sc->sc_naddrs6++;
 1849         SC2IFP(sc)->if_flags |= IFF_UP;
 1850         if (own)
 1851                 sc->sc_advskew = 0;
 1852         carp_sc_state_locked(sc);
 1853         carp_setrun(sc, 0);
 1854 
 1855         CARP_UNLOCK(cif);
 1856         ifa_free(&ia->ia_ifa);  /* XXXRW: should hold reference for softc. */
 1857 
 1858         return (0);
 1859 
 1860 cleanup:
 1861         if (!sc->sc_naddrs6)
 1862                 carp_multicast6_cleanup(sc, 1);
 1863         ifa_free(&ia->ia_ifa);
 1864         return (error);
 1865 }
 1866 
 1867 static int
 1868 carp_del_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
 1869 {
 1870         int error = 0;
 1871 
 1872         if (!--sc->sc_naddrs6) {
 1873                 struct carp_if *cif = (struct carp_if *)sc->sc_carpdev->if_carp;
 1874 
 1875                 CARP_LOCK(cif);
 1876                 callout_stop(&sc->sc_ad_tmo);
 1877                 SC2IFP(sc)->if_flags &= ~IFF_UP;
 1878                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
 1879                 sc->sc_vhid = -1;
 1880                 carp_multicast6_cleanup(sc, 1);
 1881                 TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
 1882                 if (!--cif->vhif_nvrs) {
 1883                         CARP_LOCK_DESTROY(cif);
 1884                         sc->sc_carpdev->if_carp = NULL;
 1885                         free(cif, M_CARP);
 1886                 } else
 1887                         CARP_UNLOCK(cif);
 1888         }
 1889 
 1890         return (error);
 1891 }
 1892 #endif /* INET6 */
 1893 
 1894 static int
 1895 carp_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
 1896 {
 1897         struct carp_softc *sc = ifp->if_softc, *vr;
 1898         struct carpreq carpr;
 1899         struct ifaddr *ifa;
 1900         struct ifreq *ifr;
 1901         struct ifaliasreq *ifra;
 1902         int locked = 0, error = 0;
 1903 
 1904         ifa = (struct ifaddr *)addr;
 1905         ifra = (struct ifaliasreq *)addr;
 1906         ifr = (struct ifreq *)addr;
 1907 
 1908         switch (cmd) {
 1909         case SIOCSIFADDR:
 1910                 switch (ifa->ifa_addr->sa_family) {
 1911 #ifdef INET
 1912                 case AF_INET:
 1913                         SC2IFP(sc)->if_flags |= IFF_UP;
 1914                         bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
 1915                             sizeof(struct sockaddr));
 1916                         error = carp_set_addr(sc, satosin(ifa->ifa_addr));
 1917                         break;
 1918 #endif /* INET */
 1919 #ifdef INET6
 1920                 case AF_INET6:
 1921                         SC2IFP(sc)->if_flags |= IFF_UP;
 1922                         error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
 1923                         break;
 1924 #endif /* INET6 */
 1925                 default:
 1926                         error = EAFNOSUPPORT;
 1927                         break;
 1928                 }
 1929                 break;
 1930 
 1931         case SIOCAIFADDR:
 1932                 switch (ifa->ifa_addr->sa_family) {
 1933 #ifdef INET
 1934                 case AF_INET:
 1935                         SC2IFP(sc)->if_flags |= IFF_UP;
 1936                         bcopy(ifa->ifa_addr, ifa->ifa_dstaddr,
 1937                             sizeof(struct sockaddr));
 1938                         error = carp_set_addr(sc, satosin(&ifra->ifra_addr));
 1939                         break;
 1940 #endif /* INET */
 1941 #ifdef INET6
 1942                 case AF_INET6:
 1943                         SC2IFP(sc)->if_flags |= IFF_UP;
 1944                         error = carp_set_addr6(sc, satosin6(&ifra->ifra_addr));
 1945                         break;
 1946 #endif /* INET6 */
 1947                 default:
 1948                         error = EAFNOSUPPORT;
 1949                         break;
 1950                 }
 1951                 break;
 1952 
 1953         case SIOCDIFADDR:
 1954                 switch (ifa->ifa_addr->sa_family) {
 1955 #ifdef INET
 1956                 case AF_INET:
 1957                         error = carp_del_addr(sc, satosin(&ifra->ifra_addr));
 1958                         break;
 1959 #endif /* INET */
 1960 #ifdef INET6
 1961                 case AF_INET6:
 1962                         error = carp_del_addr6(sc, satosin6(&ifra->ifra_addr));
 1963                         break;
 1964 #endif /* INET6 */
 1965                 default:
 1966                         error = EAFNOSUPPORT;
 1967                         break;
 1968                 }
 1969                 break;
 1970 
 1971         case SIOCSIFFLAGS:
 1972                 if (sc->sc_carpdev) {
 1973                         locked = 1;
 1974                         CARP_SCLOCK(sc);
 1975                 }
 1976                 if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
 1977                         callout_stop(&sc->sc_ad_tmo);
 1978                         callout_stop(&sc->sc_md_tmo);
 1979                         callout_stop(&sc->sc_md6_tmo);
 1980                         if (sc->sc_state == MASTER)
 1981                                 carp_send_ad_locked(sc);
 1982                         carp_set_state(sc, INIT);
 1983                         carp_setrun(sc, 0);
 1984                 } else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
 1985                         SC2IFP(sc)->if_flags |= IFF_UP;
 1986                         carp_setrun(sc, 0);
 1987                 }
 1988                 break;
 1989 
 1990         case SIOCSVH:
 1991                 error = priv_check(curthread, PRIV_NETINET_CARP);
 1992                 if (error)
 1993                         break;
 1994                 if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
 1995                         break;
 1996                 error = 1;
 1997                 if (sc->sc_carpdev) {
 1998                         locked = 1;
 1999                         CARP_SCLOCK(sc);
 2000                 }
 2001                 if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
 2002                         switch (carpr.carpr_state) {
 2003                         case BACKUP:
 2004                                 callout_stop(&sc->sc_ad_tmo);
 2005                                 carp_set_state(sc, BACKUP);
 2006                                 carp_setrun(sc, 0);
 2007                                 carp_setroute(sc, RTM_DELETE);
 2008                                 break;
 2009                         case MASTER:
 2010                                 carp_master_down_locked(sc);
 2011                                 break;
 2012                         default:
 2013                                 break;
 2014                         }
 2015                 }
 2016                 if (carpr.carpr_vhid > 0) {
 2017                         if (carpr.carpr_vhid > 255) {
 2018                                 error = EINVAL;
 2019                                 break;
 2020                         }
 2021                         if (sc->sc_carpdev) {
 2022                                 struct carp_if *cif;
 2023                                 cif = (struct carp_if *)sc->sc_carpdev->if_carp;
 2024                                 TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
 2025                                         if (vr != sc &&
 2026                                             vr->sc_vhid == carpr.carpr_vhid) {
 2027                                                 error = EEXIST;
 2028                                                 break;
 2029                                         }
 2030                                 if (error == EEXIST)
 2031                                         break;
 2032                         }
 2033                         sc->sc_vhid = carpr.carpr_vhid;
 2034                         IF_LLADDR(sc->sc_ifp)[0] = 0;
 2035                         IF_LLADDR(sc->sc_ifp)[1] = 0;
 2036                         IF_LLADDR(sc->sc_ifp)[2] = 0x5e;
 2037                         IF_LLADDR(sc->sc_ifp)[3] = 0;
 2038                         IF_LLADDR(sc->sc_ifp)[4] = 1;
 2039                         IF_LLADDR(sc->sc_ifp)[5] = sc->sc_vhid;
 2040                         error--;
 2041                 }
 2042                 if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
 2043                         if (carpr.carpr_advskew >= 255) {
 2044                                 error = EINVAL;
 2045                                 break;
 2046                         }
 2047                         if (carpr.carpr_advbase > 255) {
 2048                                 error = EINVAL;
 2049                                 break;
 2050                         }
 2051                         sc->sc_advbase = carpr.carpr_advbase;
 2052                         sc->sc_advskew = carpr.carpr_advskew;
 2053                         error--;
 2054                 }
 2055                 bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
 2056                 if (error > 0)
 2057                         error = EINVAL;
 2058                 else {
 2059                         error = 0;
 2060                         carp_setrun(sc, 0);
 2061                 }
 2062                 break;
 2063 
 2064         case SIOCGVH:
 2065                 /* XXX: lockless read */
 2066                 bzero(&carpr, sizeof(carpr));
 2067                 carpr.carpr_state = sc->sc_state;
 2068                 carpr.carpr_vhid = sc->sc_vhid;
 2069                 carpr.carpr_advbase = sc->sc_advbase;
 2070                 carpr.carpr_advskew = sc->sc_advskew;
 2071                 error = priv_check(curthread, PRIV_NETINET_CARP);
 2072                 if (error == 0)
 2073                         bcopy(sc->sc_key, carpr.carpr_key,
 2074                             sizeof(carpr.carpr_key));
 2075                 error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
 2076                 break;
 2077 
 2078         default:
 2079                 error = EINVAL;
 2080         }
 2081 
 2082         if (locked)
 2083                 CARP_SCUNLOCK(sc);
 2084 
 2085         carp_hmac_prepare(sc);
 2086 
 2087         return (error);
 2088 }
 2089 
 2090 /*
 2091  * XXX: this is looutput. We should eventually use it from there.
 2092  */
 2093 static int
 2094 carp_looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
 2095     struct route *ro)
 2096 {
 2097         u_int32_t af;
 2098         struct rtentry *rt = NULL;
 2099 
 2100         M_ASSERTPKTHDR(m); /* check if we have the packet header */
 2101 
 2102         if (ro != NULL)
 2103                 rt = ro->ro_rt;
 2104         if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
 2105                 m_freem(m);
 2106                 return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
 2107                         rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
 2108         }
 2109 
 2110         ifp->if_opackets++;
 2111         ifp->if_obytes += m->m_pkthdr.len;
 2112 
 2113         /* BPF writes need to be handled specially. */
 2114         if (dst->sa_family == AF_UNSPEC) {
 2115                 bcopy(dst->sa_data, &af, sizeof(af));
 2116                 dst->sa_family = af;
 2117         }
 2118 
 2119 #if 1   /* XXX */
 2120         switch (dst->sa_family) {
 2121         case AF_INET:
 2122         case AF_INET6:
 2123         case AF_IPX:
 2124         case AF_APPLETALK:
 2125                 break;
 2126         default:
 2127                 printf("carp_looutput: af=%d unexpected\n", dst->sa_family);
 2128                 m_freem(m);
 2129                 return (EAFNOSUPPORT);
 2130         }
 2131 #endif
 2132         return(if_simloop(ifp, m, dst->sa_family, 0));
 2133 }
 2134 
 2135 /*
 2136  * Start output on carp interface. This function should never be called.
 2137  */
 2138 static void
 2139 carp_start(struct ifnet *ifp)
 2140 {
 2141 #ifdef DEBUG
 2142         printf("%s: start called\n", ifp->if_xname);
 2143 #endif
 2144 }
 2145 
 2146 int
 2147 carp_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
 2148     struct rtentry *rt)
 2149 {
 2150         struct m_tag *mtag;
 2151         struct carp_softc *sc;
 2152         struct ifnet *carp_ifp;
 2153 
 2154         if (!sa)
 2155                 return (0);
 2156 
 2157         switch (sa->sa_family) {
 2158 #ifdef INET
 2159         case AF_INET:
 2160                 break;
 2161 #endif /* INET */
 2162 #ifdef INET6
 2163         case AF_INET6:
 2164                 break;
 2165 #endif /* INET6 */
 2166         default:
 2167                 return (0);
 2168         }
 2169 
 2170         mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
 2171         if (mtag == NULL)
 2172                 return (0);
 2173 
 2174         bcopy(mtag + 1, &carp_ifp, sizeof(struct ifnet *));
 2175         sc = carp_ifp->if_softc;
 2176 
 2177         /* Set the source MAC address to Virtual Router MAC Address */
 2178         switch (ifp->if_type) {
 2179         case IFT_ETHER:
 2180         case IFT_L2VLAN: {
 2181                         struct ether_header *eh;
 2182 
 2183                         eh = mtod(m, struct ether_header *);
 2184                         eh->ether_shost[0] = 0;
 2185                         eh->ether_shost[1] = 0;
 2186                         eh->ether_shost[2] = 0x5e;
 2187                         eh->ether_shost[3] = 0;
 2188                         eh->ether_shost[4] = 1;
 2189                         eh->ether_shost[5] = sc->sc_vhid;
 2190                 }
 2191                 break;
 2192         case IFT_FDDI: {
 2193                         struct fddi_header *fh;
 2194 
 2195                         fh = mtod(m, struct fddi_header *);
 2196                         fh->fddi_shost[0] = 0;
 2197                         fh->fddi_shost[1] = 0;
 2198                         fh->fddi_shost[2] = 0x5e;
 2199                         fh->fddi_shost[3] = 0;
 2200                         fh->fddi_shost[4] = 1;
 2201                         fh->fddi_shost[5] = sc->sc_vhid;
 2202                 }
 2203                 break;
 2204         case IFT_ISO88025: {
 2205                         struct iso88025_header *th;
 2206                         th = mtod(m, struct iso88025_header *);
 2207                         th->iso88025_shost[0] = 3;
 2208                         th->iso88025_shost[1] = 0;
 2209                         th->iso88025_shost[2] = 0x40 >> (sc->sc_vhid - 1);
 2210                         th->iso88025_shost[3] = 0x40000 >> (sc->sc_vhid - 1);
 2211                         th->iso88025_shost[4] = 0;
 2212                         th->iso88025_shost[5] = 0;
 2213                 }
 2214                 break;
 2215         default:
 2216                 printf("%s: carp is not supported for this interface type\n",
 2217                     ifp->if_xname);
 2218                 return (EOPNOTSUPP);
 2219         }
 2220 
 2221         return (0);
 2222 }
 2223 
 2224 static void
 2225 carp_set_state(struct carp_softc *sc, int state)
 2226 {
 2227         int link_state;
 2228 
 2229         if (sc->sc_carpdev)
 2230                 CARP_SCLOCK_ASSERT(sc);
 2231 
 2232         if (sc->sc_state == state)
 2233                 return;
 2234 
 2235         sc->sc_state = state;
 2236         switch (state) {
 2237         case BACKUP:
 2238                 link_state = LINK_STATE_DOWN;
 2239                 break;
 2240         case MASTER:
 2241                 link_state = LINK_STATE_UP;
 2242                 break;
 2243         default:
 2244                 link_state = LINK_STATE_UNKNOWN;
 2245                 break;
 2246         }
 2247         if_link_state_change(SC2IFP(sc), link_state);
 2248 }
 2249 
 2250 void
 2251 carp_carpdev_state(struct ifnet *ifp)
 2252 {
 2253         struct carp_if *cif;
 2254 
 2255         cif = ifp->if_carp;
 2256         CARP_LOCK(cif);
 2257         carp_carpdev_state_locked(cif);
 2258         CARP_UNLOCK(cif);
 2259 }
 2260 
 2261 static void
 2262 carp_carpdev_state_locked(struct carp_if *cif)
 2263 {
 2264         struct carp_softc *sc;
 2265 
 2266         TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list)
 2267                 carp_sc_state_locked(sc);
 2268 }
 2269 
 2270 static void
 2271 carp_sc_state_locked(struct carp_softc *sc)
 2272 {
 2273         CARP_SCLOCK_ASSERT(sc);
 2274 
 2275         if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
 2276             !(sc->sc_carpdev->if_flags & IFF_UP)) {
 2277                 sc->sc_flags_backup = SC2IFP(sc)->if_flags;
 2278                 SC2IFP(sc)->if_flags &= ~IFF_UP;
 2279                 SC2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
 2280                 callout_stop(&sc->sc_ad_tmo);
 2281                 callout_stop(&sc->sc_md_tmo);
 2282                 callout_stop(&sc->sc_md6_tmo);
 2283                 carp_set_state(sc, INIT);
 2284                 carp_setrun(sc, 0);
 2285                 if (!sc->sc_suppress) {
 2286                         carp_suppress_preempt++;
 2287                         if (carp_suppress_preempt == 1) {
 2288                                 CARP_SCUNLOCK(sc);
 2289                                 carp_send_ad_all();
 2290                                 CARP_SCLOCK(sc);
 2291                         }
 2292                 }
 2293                 sc->sc_suppress = 1;
 2294         } else {
 2295                 SC2IFP(sc)->if_flags |= sc->sc_flags_backup;
 2296                 carp_set_state(sc, INIT);
 2297                 carp_setrun(sc, 0);
 2298                 if (sc->sc_suppress)
 2299                         carp_suppress_preempt--;
 2300                 sc->sc_suppress = 0;
 2301         }
 2302 
 2303         return;
 2304 }
 2305 
 2306 #ifdef INET
 2307 extern  struct domain inetdomain;
 2308 static struct protosw in_carp_protosw = {
 2309         .pr_type =              SOCK_RAW,
 2310         .pr_domain =            &inetdomain,
 2311         .pr_protocol =          IPPROTO_CARP,
 2312         .pr_flags =             PR_ATOMIC|PR_ADDR,
 2313         .pr_input =             carp_input,
 2314         .pr_output =            (pr_output_t *)rip_output,
 2315         .pr_ctloutput =         rip_ctloutput,
 2316         .pr_usrreqs =           &rip_usrreqs
 2317 };
 2318 #endif
 2319 
 2320 #ifdef INET6
 2321 extern  struct domain inet6domain;
 2322 static struct ip6protosw in6_carp_protosw = {
 2323         .pr_type =              SOCK_RAW,
 2324         .pr_domain =            &inet6domain,
 2325         .pr_protocol =          IPPROTO_CARP,
 2326         .pr_flags =             PR_ATOMIC|PR_ADDR,
 2327         .pr_input =             carp6_input,
 2328         .pr_output =            rip6_output,
 2329         .pr_ctloutput =         rip6_ctloutput,
 2330         .pr_usrreqs =           &rip6_usrreqs
 2331 };
 2332 #endif
 2333 
 2334 static void
 2335 carp_mod_cleanup(void)
 2336 {
 2337 
 2338         if (if_detach_event_tag == NULL)
 2339                 return;
 2340         EVENTHANDLER_DEREGISTER(ifnet_departure_event, if_detach_event_tag);
 2341         if_clone_detach(&carp_cloner);
 2342 #ifdef INET
 2343         if (proto_reg[CARP_INET] == 0) {
 2344                 (void)ipproto_unregister(IPPROTO_CARP);
 2345                 pf_proto_unregister(PF_INET, IPPROTO_CARP, SOCK_RAW);
 2346                 proto_reg[CARP_INET] = -1;
 2347         }
 2348         carp_iamatch_p = NULL;
 2349 #endif
 2350 #ifdef INET6
 2351         if (proto_reg[CARP_INET6] == 0) {
 2352                 (void)ip6proto_unregister(IPPROTO_CARP);
 2353                 pf_proto_unregister(PF_INET6, IPPROTO_CARP, SOCK_RAW);
 2354                 proto_reg[CARP_INET6] = -1;
 2355         }
 2356         carp_iamatch6_p = NULL;
 2357         carp_macmatch6_p = NULL;
 2358 #endif
 2359         carp_linkstate_p = NULL;
 2360         carp_forus_p = NULL;
 2361         carp_output_p = NULL;
 2362         mtx_destroy(&carp_mtx);
 2363 }
 2364 
 2365 static int
 2366 carp_mod_load(void)
 2367 {
 2368         int err;
 2369 
 2370         if_detach_event_tag = EVENTHANDLER_REGISTER(ifnet_departure_event,
 2371                 carp_ifdetach, NULL, EVENTHANDLER_PRI_ANY);
 2372         if (if_detach_event_tag == NULL)
 2373                 return (ENOMEM);
 2374         mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
 2375         LIST_INIT(&carpif_list);
 2376         if_clone_attach(&carp_cloner);
 2377         carp_linkstate_p = carp_carpdev_state;
 2378         carp_forus_p = carp_forus;
 2379         carp_output_p = carp_output;
 2380 #ifdef INET6
 2381         carp_iamatch6_p = carp_iamatch6;
 2382         carp_macmatch6_p = carp_macmatch6;
 2383         proto_reg[CARP_INET6] = pf_proto_register(PF_INET6,
 2384             (struct protosw *)&in6_carp_protosw);
 2385         if (proto_reg[CARP_INET6] != 0) {
 2386                 printf("carp: error %d attaching to PF_INET6\n",
 2387                     proto_reg[CARP_INET6]);
 2388                 carp_mod_cleanup();
 2389                 return (proto_reg[CARP_INET6]);
 2390         }
 2391         err = ip6proto_register(IPPROTO_CARP);
 2392         if (err) {
 2393                 printf("carp: error %d registering with INET6\n", err);
 2394                 carp_mod_cleanup();
 2395                 return (err);
 2396         }
 2397 #endif
 2398 #ifdef INET
 2399         carp_iamatch_p = carp_iamatch;
 2400         proto_reg[CARP_INET] = pf_proto_register(PF_INET, &in_carp_protosw);
 2401         if (proto_reg[CARP_INET] != 0) {
 2402                 printf("carp: error %d attaching to PF_INET\n",
 2403                     proto_reg[CARP_INET]);
 2404                 carp_mod_cleanup();
 2405                 return (proto_reg[CARP_INET]);
 2406         }
 2407         err = ipproto_register(IPPROTO_CARP);
 2408         if (err) {
 2409                 printf("carp: error %d registering with INET\n", err);
 2410                 carp_mod_cleanup();
 2411                 return (err);
 2412         }
 2413 #endif
 2414         return 0;
 2415 }
 2416 
 2417 static int
 2418 carp_modevent(module_t mod, int type, void *data)
 2419 {
 2420         switch (type) {
 2421         case MOD_LOAD:
 2422                 return carp_mod_load();
 2423                 /* NOTREACHED */
 2424         case MOD_UNLOAD:
 2425                 /*
 2426                  * XXX: For now, disallow module unloading by default due to
 2427                  * a race condition where a thread may dereference one of the
 2428                  * function pointer hooks after the module has been
 2429                  * unloaded, during processing of a packet, causing a panic.
 2430                  */
 2431 #ifdef CARPMOD_CAN_UNLOAD
 2432                 carp_mod_cleanup();
 2433 #else
 2434                 return (EBUSY);
 2435 #endif
 2436                 break;
 2437 
 2438         default:
 2439                 return (EINVAL);
 2440         }
 2441 
 2442         return (0);
 2443 }
 2444 
 2445 static moduledata_t carp_mod = {
 2446         "carp",
 2447         carp_modevent,
 2448         0
 2449 };
 2450 
 2451 DECLARE_MODULE(carp, carp_mod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);

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