/* $NetBSD: rtadvd.c,v 1.66 2018/04/24 18:31:48 roy Exp $ */ /* $KAME: rtadvd.c,v 1.92 2005/10/17 14:40:02 suz Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef __NetBSD__ #include #endif #include #include #include "rtadvd.h" #include "rrenum.h" #include "advcap.h" #include "timer.h" #include "if.h" #include "config.h" #include "dump.h" #include "logit.h" #include "prog_ops.h" struct msghdr rcvmhdr; static unsigned char *rcvcmsgbuf; static size_t rcvcmsgbuflen; static unsigned char *sndcmsgbuf; static size_t sndcmsgbuflen; volatile sig_atomic_t do_dump; volatile sig_atomic_t do_reconf; volatile sig_atomic_t do_die; struct msghdr sndmhdr; struct iovec rcviov[2]; struct iovec sndiov[2]; struct sockaddr_in6 rcvfrom; static const char *dumpfilename = "/var/run/rtadvd.dump"; /* XXX configurable */ static char *mcastif; int sock; int rtsock = -1; int accept_rr = 0; int dflag = 0, sflag = 0, Dflag; static char **if_argv; static int if_argc; char *conffile = NULL; struct ralist_head_t ralist = TAILQ_HEAD_INITIALIZER(ralist); struct nd_optlist { TAILQ_ENTRY(nd_optlist) next; struct nd_opt_hdr *opt; }; union nd_opts { struct nd_opt_hdr *nd_opt_array[9]; struct { struct nd_opt_hdr *zero; struct nd_opt_hdr *src_lladdr; struct nd_opt_hdr *tgt_lladdr; struct nd_opt_prefix_info *pi; struct nd_opt_rd_hdr *rh; struct nd_opt_mtu *mtu; TAILQ_HEAD(, nd_optlist) list; } nd_opt_each; }; #define nd_opts_src_lladdr nd_opt_each.src_lladdr #define nd_opts_tgt_lladdr nd_opt_each.tgt_lladdr #define nd_opts_pi nd_opt_each.pi #define nd_opts_rh nd_opt_each.rh #define nd_opts_mtu nd_opt_each.mtu #define nd_opts_list nd_opt_each.list #define NDOPT_FLAG_SRCLINKADDR (1 << 0) #define NDOPT_FLAG_TGTLINKADDR (1 << 1) #define NDOPT_FLAG_PREFIXINFO (1 << 2) #define NDOPT_FLAG_RDHDR (1 << 3) #define NDOPT_FLAG_MTU (1 << 4) #define NDOPT_FLAG_RDNSS (1 << 5) #define NDOPT_FLAG_DNSSL (1 << 6) uint32_t ndopt_flags[] = { [ND_OPT_SOURCE_LINKADDR] = NDOPT_FLAG_SRCLINKADDR, [ND_OPT_TARGET_LINKADDR] = NDOPT_FLAG_TGTLINKADDR, [ND_OPT_PREFIX_INFORMATION] = NDOPT_FLAG_PREFIXINFO, [ND_OPT_REDIRECTED_HEADER] = NDOPT_FLAG_RDHDR, [ND_OPT_MTU] = NDOPT_FLAG_MTU, [ND_OPT_RDNSS] = NDOPT_FLAG_RDNSS, [ND_OPT_DNSSL] = NDOPT_FLAG_DNSSL, }; struct sockaddr_in6 sin6_linklocal_allnodes = { .sin6_len = sizeof(sin6_linklocal_allnodes), .sin6_family = AF_INET6, .sin6_addr = IN6ADDR_LINKLOCAL_ALLNODES_INIT, }; #ifdef notdef struct sockaddr_in6 sin6_linklocal_allrouters = { .sin6_len = sizeof(sin6_linklocal_allrouters), .sin6_family = AF_INET6, .sin6_addr = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT, }; #endif struct sockaddr_in6 sin6_sitelocal_allrouters = { .sin6_len = sizeof(sin6_sitelocal_allrouters), .sin6_family = AF_INET6, .sin6_addr = IN6ADDR_SITELOCAL_ALLROUTERS_INIT, }; static void set_die(int); static void die(void); static void set_reconf(int); static void sock_open(void); static void rtsock_open(void); static void rtadvd_input(void); static void rs_input(int, struct nd_router_solicit *, struct in6_pktinfo *, struct sockaddr_in6 *); static void ra_input(int, struct nd_router_advert *, struct in6_pktinfo *, struct sockaddr_in6 *); static struct rainfo *ra_output(struct rainfo *, bool); static int prefix_check(struct nd_opt_prefix_info *, struct rainfo *, struct sockaddr_in6 *); static int nd6_options(struct nd_opt_hdr *, int, union nd_opts *, uint32_t); static void free_ndopts(union nd_opts *); static void rtmsg_input(void); static void rtadvd_set_dump_file(int); int main(int argc, char *argv[]) { struct pollfd set[2]; struct timespec *timeout; int i, ch; int fflag = 0, logopt; struct passwd *pw; const char *pidfilepath = NULL; pid_t pid; /* get command line options and arguments */ #define OPTIONS "c:dDfM:p:Rs" while ((ch = getopt(argc, argv, OPTIONS)) != -1) { #undef OPTIONS switch (ch) { case 'c': conffile = optarg; break; case 'd': dflag++; break; case 'D': Dflag++; break; case 'f': fflag = 1; break; case 'M': mcastif = optarg; break; case 'p': pidfilepath = optarg; break; case 'R': fprintf(stderr, "rtadvd: " "the -R option is currently ignored.\n"); /* accept_rr = 1; */ /* run anyway... */ break; case 's': sflag = 1; break; } } argc -= optind; argv += optind; if (argc == 0) { fprintf(stderr, "Ysage: %s [-DdfRs] [-c conffile]" " [-M ifname] [-p pidfile] interface ...\n", getprogname()); return EXIT_FAILURE; } if ((pid = pidfile_lock(pidfilepath)) != 0) { if (pid == -1) logit(LOG_ERR, "pidfile_lock: %m"); /* Continue */ else { logit(LOG_ERR, "Another instance of `%s' is running " "(pid %d); exiting.", getprogname(), pid); return EXIT_FAILURE; } } if (prog_init && prog_init() == -1) err(EXIT_FAILURE, "init failed"); logopt = LOG_NDELAY | LOG_PID; if (fflag) logopt |= LOG_PERROR; openlog("rtadvd", logopt, LOG_DAEMON); /* set log level */ if (dflag == 0) (void)setlogmask(LOG_UPTO(LOG_ERR)); if (dflag == 1) (void)setlogmask(LOG_UPTO(LOG_INFO)); errno = 0; /* Ensure errno is 0 so we know if getpwnam errors or not */ if ((pw = getpwnam(RTADVD_USER)) == NULL) { if (errno == 0) logit(LOG_ERR, "user %s does not exist, aborting", RTADVD_USER); else logit(LOG_ERR, "getpwnam: %s: %m", RTADVD_USER); return EXIT_FAILURE; } /* timer initialization */ rtadvd_timer_init(); if_argc = argc; if_argv = argv; while (argc--) getconfig(*argv++, 1); if (!fflag) { prog_daemon(1, 0); if (pidfile_lock(pidfilepath) != 0) logit(LOG_ERR, " pidfile_lock: %m"); } sock_open(); set[0].fd = sock; set[0].events = POLLIN; if (sflag == 0) { rtsock_open(); set[1].fd = rtsock; set[1].events = POLLIN; } else set[1].fd = -1; logit(LOG_INFO, "dropping privileges to %s", RTADVD_USER); if (prog_chroot(pw->pw_dir) == -1) { logit(LOG_ERR, "chroot: %s: %m", pw->pw_dir); return EXIT_FAILURE; } if (prog_chdir("/") == -1) { logit(LOG_ERR, "chdir: /: %m"); return EXIT_FAILURE; } if (prog_setgroups(1, &pw->pw_gid) == -1 || prog_setgid(pw->pw_gid) == -1 || prog_setuid(pw->pw_uid) == -1) { logit(LOG_ERR, "failed to drop privileges: %m"); return EXIT_FAILURE; } signal(SIGINT, set_die); signal(SIGTERM, set_die); signal(SIGHUP, set_reconf); signal(SIGUSR1, rtadvd_set_dump_file); for (;;) { if (do_dump) { /* SIGUSR1 */ do_dump = 0; rtadvd_dump_file(dumpfilename); } if (do_reconf) { /* SIGHUP */ do_reconf = 0; logit(LOG_INFO, "%s: reloading config on SIGHUP", __func__); argc = if_argc; argv = if_argv; while (argc--) getconfig(*argv++, 0); } /* timer expiration check and reset the timer */ timeout = rtadvd_check_timer(); if (do_die) { die(); /*NOTREACHED*/ } if (timeout != NULL) { logit(LOG_DEBUG, "%s: set timer to %jd:%jd. waiting for " "inputs or timeout", __func__, (intmax_t)timeout->tv_sec, (intmax_t)timeout->tv_nsec); } else { logit(LOG_DEBUG, "%s: there's no timer. waiting for inputs", __func__); } if ((i = prog_poll(set, 2, timeout ? (timeout->tv_sec * 1000 + (timeout->tv_nsec + 999999) / 1000000) : INFTIM)) == -1) { /* EINTR would occur upon SIGUSR1 for status dump */ if (errno == EINTR) continue; logit(LOG_ERR, "%s: poll: %m", __func__); if (Dflag) exit(1); } if (i == 0) /* timeout */ continue; if (rtsock != -1 && set[1].revents & POLLIN) rtmsg_input(); if (set[0].revents & POLLIN) rtadvd_input(); } return EXIT_SUCCESS; /* NOTREACHED */ } static void rtadvd_set_dump_file(__unused int sig) { do_dump = 1; } static void set_reconf(__unused int sig) { do_reconf = 1; } static void set_die(__unused int sig) { do_die = 1; } static void die(void) { static int waiting; struct rainfo *rai, *ran; struct rdnss *rdnss; struct dnssl *dnssl; if (waiting) { if (TAILQ_FIRST(&ralist)) { logit(LOG_INFO, "%s: waiting for expiration of all RA timers", __func__); return; } logit(LOG_NOTICE, "%s: gracefully terminated", __func__); free(rcvcmsgbuf); free(sndcmsgbuf); exit(EXIT_SUCCESS); /* NOT REACHED */ } if (TAILQ_FIRST(&ralist) == NULL) { logit(LOG_NOTICE, "%s: gracefully terminated", __func__); exit(EXIT_SUCCESS); /* NOT REACHED */ } waiting = 1; logit(LOG_NOTICE, "%s: final RA transmission started", __func__); TAILQ_FOREACH_SAFE(rai, &ralist, next, ran) { if (rai->leaving) { TAILQ_REMOVE(&ralist, rai, next); TAILQ_INSERT_HEAD(&ralist, rai->leaving, next); rai->leaving->leaving = rai->leaving; rai->leaving->leaving_for = rai->leaving; free_rainfo(rai); continue; } rai->lifetime = 0; TAILQ_FOREACH(rdnss, &rai->rdnss, next) rdnss->lifetime = 0; TAILQ_FOREACH(dnssl, &rai->dnssl, next) dnssl->lifetime = 0; make_packet(rai); rai->leaving = rai; rai->leaving_for = rai; rai->initcounter = MAX_INITIAL_RTR_ADVERTISEMENTS; rai->mininterval = MIN_DELAY_BETWEEN_RAS; rai->maxinterval = MIN_DELAY_BETWEEN_RAS; rai->leaving_adv = MAX_FINAL_RTR_ADVERTISEMENTS; ra_output(rai, false); ra_timer_update(rai, &rai->timer->tm); rtadvd_set_timer(&rai->timer->tm, rai->timer); } } static void rtmsg_input(void) { int n, type, ifindex = 0, plen; size_t len; union rt_msghdr_buf { struct rt_msghdr rt_msghdr; char data[2048]; } buffer; char *msg, *next, *lim, **argv; char ifname[IF_NAMESIZE]; struct prefix *prefix; struct rainfo *rai; struct in6_addr *addr; char addrbuf[INET6_ADDRSTRLEN]; int prefixchange = 0, argc; memset(&buffer, 0, sizeof(buffer)); n = prog_read(rtsock, &buffer, sizeof(buffer)); /* We read the buffer first to clear the FD */ if (do_die) return; msg = buffer.data; if (dflag > 1) { logit(LOG_DEBUG, "%s: received a routing message " "(type = %d, len = %d)", __func__, rtmsg_type(msg), rtmsg_len(msg)); } if (n > rtmsg_len(msg)) { /* * This usually won't happen for messages received on * a routing socket. */ if (dflag > 1) logit(LOG_DEBUG, "%s: received data length is larger than " "1st routing message len. multiple messages? " "read %d bytes, but 1st msg len = %d", __func__, n, rtmsg_len(msg)); #if 0 /* adjust length */ n = rtmsg_len(msg); #endif } lim = msg + n; for (next = msg; next < lim; next += len) { int oldifflags; next = get_next_msg(next, lim, 0, &len, RTADV_TYPE2BITMASK(RTM_ADD) | RTADV_TYPE2BITMASK(RTM_DELETE) | RTADV_TYPE2BITMASK(RTM_NEWADDR) | RTADV_TYPE2BITMASK(RTM_DELADDR) | #ifdef RTM_IFANNOUNCE RTADV_TYPE2BITMASK(RTM_IFANNOUNCE) | #endif RTADV_TYPE2BITMASK(RTM_IFINFO)); if (len == 0) break; type = rtmsg_type(next); switch (type) { case RTM_ADD: case RTM_DELETE: ifindex = get_rtm_ifindex(next); break; case RTM_NEWADDR: case RTM_DELADDR: ifindex = get_ifam_ifindex(next); break; #ifdef RTM_IFANNOUNCE case RTM_IFANNOUNCE: ifindex = get_ifan_ifindex(next); if (get_ifan_what(next) == IFAN_ARRIVAL) { logit(LOG_DEBUG, "%s: interface %s arrived", __func__, if_indextoname(ifindex, ifname)); if (if_argc == 0) { getconfig(ifname, 0); continue; } argc = if_argc; argv = if_argv; while (argc--) { if (strcmp(ifname, *argv++) == 0) { getconfig(ifname, 0); break; } } continue; } break; #endif case RTM_IFINFO: ifindex = get_ifm_ifindex(next); break; default: /* should not reach here */ if (dflag > 1) { logit(LOG_DEBUG, "%s: unknown rtmsg %d on %s", __func__, type, if_indextoname(ifindex, ifname)); } continue; } if ((rai = if_indextorainfo(ifindex)) == NULL) { if (dflag > 1) { logit(LOG_DEBUG, "%s: route changed on " "non advertising interface %s (%d)", __func__, if_indextoname(ifindex, ifname), ifindex); } continue; } oldifflags = rai->ifflags; switch (type) { case RTM_ADD: /* init ifflags because it may have changed */ rai->ifflags = if_getflags(ifindex, rai->ifflags); if (sflag) break; /* we aren't interested in prefixes */ addr = get_addr(msg); plen = get_prefixlen(msg); /* sanity check for plen */ /* as RFC2373, prefixlen is at least 4 */ if (plen < 4 || plen > 127) { logit(LOG_INFO, "%s: new interface route's" "plen %d is invalid for a prefix", __func__, plen); break; } prefix = find_prefix(rai, addr, plen); if (prefix) { if (prefix->timer) { /* * If the prefix has been invalidated, * make it available again. */ update_prefix(prefix); prefixchange = 1; } else if (dflag > 1) { logit(LOG_DEBUG, "%s: new prefix(%s/%d) " "added on %s, " "but it was already in list", __func__, inet_ntop(AF_INET6, addr, (char *)addrbuf, INET6_ADDRSTRLEN), plen, rai->ifname); } break; } make_prefix(rai, ifindex, addr, plen); prefixchange = 1; break; case RTM_DELETE: /* init ifflags because it may have changed */ rai->ifflags = if_getflags(ifindex, rai->ifflags); if (sflag) break; addr = get_addr(msg); plen = get_prefixlen(msg); /* sanity check for plen */ /* as RFC2373, prefixlen is at least 4 */ if (plen < 4 || plen > 127) { logit(LOG_INFO, "%s: deleted interface route's " "plen %d is invalid for a prefix", __func__, plen); break; } prefix = find_prefix(rai, addr, plen); if (prefix == NULL) { if (dflag > 1) { logit(LOG_DEBUG, "%s: prefix(%s/%d) was " "deleted on %s, " "but it was not in list", __func__, inet_ntop(AF_INET6, addr, (char *)addrbuf, INET6_ADDRSTRLEN), plen, rai->ifname); } break; } invalidate_prefix(prefix); prefixchange = 1; break; case RTM_NEWADDR: case RTM_DELADDR: /* init ifflags because it may have changed */ rai->ifflags = if_getflags(ifindex, rai->ifflags); break; case RTM_IFINFO: rai->ifflags = get_ifm_flags(next); break; #ifdef RTM_IFANNOUNCE case RTM_IFANNOUNCE: if (get_ifan_what(next) == IFAN_DEPARTURE) { logit(LOG_DEBUG, "%s: interface %s departed", __func__, rai->ifname); TAILQ_REMOVE(&ralist, rai, next); if (rai->leaving) free_rainfo(rai->leaving); free_rainfo(rai); continue; } break; #endif default: /* should not reach here */ if (dflag > 1) { logit(LOG_DEBUG, "%s: unknown rtmsg %d on %s", __func__, type, if_indextoname(ifindex, ifname)); } return; } /* check if an interface flag is changed */ if ((oldifflags & IFF_UP) != 0 && /* UP to DOWN */ (rai->ifflags & IFF_UP) == 0) { logit(LOG_INFO, "%s: interface %s becomes down. stop timer.", __func__, rai->ifname); rtadvd_remove_timer(&rai->timer); } else if ((oldifflags & IFF_UP) == 0 && /* DOWN to UP */ (rai->ifflags & IFF_UP) != 0) { logit(LOG_INFO, "%s: interface %s becomes up. restart timer.", __func__, rai->ifname); rai->initcounter = 0; /* reset the counter */ rai->waiting = 0; /* XXX */ rtadvd_remove_timer(&rai->timer); rai->timer = rtadvd_add_timer(ra_timeout, ra_timer_update, rai, rai); ra_timer_update(rai, &rai->timer->tm); rtadvd_set_timer(&rai->timer->tm, rai->timer); rtadvd_remove_timer(&rai->timer_sol); rai->timer_sol = rtadvd_add_timer(ra_timeout_sol, NULL, rai, NULL); } else if (prefixchange && rai->ifflags & IFF_UP) { /* * An advertised prefix has been added or invalidated. * Will notice the change in a short delay. */ rai->initcounter = 0; ra_timer_set_short_delay(rai, rai->timer); } } return; } void rtadvd_input(void) { ssize_t i; int *hlimp = NULL; struct icmp6_hdr *icp; int ifindex = 0; struct cmsghdr *cm; struct in6_pktinfo *pi = NULL; char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; struct in6_addr dst = in6addr_any; struct rainfo *rai; /* * Get message. We reset msg_controllen since the field could * be modified if we had received a message before setting * receive options. */ rcvmhdr.msg_controllen = rcvcmsgbuflen; if ((i = prog_recvmsg(sock, &rcvmhdr, 0)) == -1) return; /* We read the buffer first to clear the FD */ if (do_die) return; /* extract optional information via Advanced API */ for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr); cm; cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) { if (cm->cmsg_level == IPPROTO_IPV6 && cm->cmsg_type == IPV6_PKTINFO && cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) { pi = (struct in6_pktinfo *)(CMSG_DATA(cm)); ifindex = pi->ipi6_ifindex; dst = pi->ipi6_addr; } if (cm->cmsg_level == IPPROTO_IPV6 && cm->cmsg_type == IPV6_HOPLIMIT && cm->cmsg_len == CMSG_LEN(sizeof(int))) hlimp = (int *)CMSG_DATA(cm); } if (ifindex == 0) { logit(LOG_ERR, "%s: failed to get receiving interface", __func__); return; } if (hlimp == NULL) { logit(LOG_ERR, "%s: failed to get receiving hop limit", __func__); return; } if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == NULL) { if (dflag > 1) { logit(LOG_DEBUG, "%s: received data for non advertising " "interface (%s)", __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf)); } return; } /* * If we happen to receive data on an interface which is now down, * just discard the data. */ if ((rai->ifflags & IFF_UP) == 0) { logit(LOG_INFO, "%s: received data on a disabled interface (%s)", __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } if ((size_t)i < sizeof(struct icmp6_hdr)) { logit(LOG_ERR, "%s: packet size(%zd) is too short", __func__, i); return; } icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base; switch (icp->icmp6_type) { case ND_ROUTER_SOLICIT: /* * Message verification - RFC-2461 6.1.1 * XXX: these checks must be done in the kernel as well, * but we can't completely rely on them. */ if (*hlimp != 255) { logit(LOG_NOTICE, "%s: RS with invalid hop limit(%d) " "received from %s on %s", __func__, *hlimp, inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } if (icp->icmp6_code) { logit(LOG_NOTICE, "%s: RS with invalid ICMP6 code(%d) " "received from %s on %s", __func__, icp->icmp6_code, inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } if ((size_t)i < sizeof(struct nd_router_solicit)) { logit(LOG_NOTICE, "%s: RS from %s on %s does not have enough " "length (len = %zd)", __func__, inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(pi->ipi6_ifindex, ifnamebuf), i); return; } rs_input(i, (struct nd_router_solicit *)icp, pi, &rcvfrom); break; case ND_ROUTER_ADVERT: /* * Message verification - RFC-2461 6.1.2 * XXX: there's a same dilemma as above... */ if (*hlimp != 255) { logit(LOG_NOTICE, "%s: RA with invalid hop limit(%d) " "received from %s on %s", __func__, *hlimp, inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } if (icp->icmp6_code) { logit(LOG_NOTICE, "%s: RA with invalid ICMP6 code(%d) " "received from %s on %s", __func__, icp->icmp6_code, inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } if ((size_t)i < sizeof(struct nd_router_advert)) { logit(LOG_NOTICE, "%s: RA from %s on %s does not have enough " "length (len = %zd)", __func__, inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(pi->ipi6_ifindex, ifnamebuf), i); return; } ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom); break; case ICMP6_ROUTER_RENUMBERING: if (accept_rr == 0) { logit(LOG_ERR, "%s: received a router renumbering " "message, but not allowed to be accepted", __func__); break; } rr_input(i, (struct icmp6_router_renum *)icp, pi, &rcvfrom, &dst); break; default: /* * Note that this case is POSSIBLE, especially just * after invocation of the daemon. This is because we * could receive message after opening the socket and * before setting ICMP6 type filter(see sock_open()). */ logit(LOG_ERR, "%s: invalid icmp type(%d)", __func__, icp->icmp6_type); return; } } static void rs_input(int len, struct nd_router_solicit *rs, struct in6_pktinfo *pi, struct sockaddr_in6 *from) { char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; union nd_opts ndopts; struct rainfo *rai; struct soliciter *sol; logit(LOG_DEBUG, "%s: RS received from %s on %s", __func__, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); /* ND option check */ memset(&ndopts, 0, sizeof(ndopts)); TAILQ_INIT(&ndopts.nd_opts_list); if (nd6_options((struct nd_opt_hdr *)(rs + 1), len - sizeof(struct nd_router_solicit), &ndopts, NDOPT_FLAG_SRCLINKADDR)) { logit(LOG_INFO, "%s: ND option check failed for an RS from %s on %s", __func__, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } /* * If the IP source address is the unspecified address, there * must be no source link-layer address option in the message. * (RFC-2461 6.1.1) */ if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) && ndopts.nd_opts_src_lladdr) { logit(LOG_INFO, "%s: RS from unspecified src on %s has a link-layer" " address option", __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf)); goto done; } if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == NULL) { logit(LOG_INFO, "%s: RS received on non advertising interface(%s)", __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf)); goto done; } if (rai->leaving) { logit(LOG_INFO, "%s: RS received on reconfiguring advertising interface(%s)", __func__, rai->ifname); goto done; } rai->rsinput++; /* increment statistics */ /* * Decide whether to send RA according to the rate-limit * consideration. */ /* record sockaddr waiting for RA, if possible */ TAILQ_FOREACH(sol, &rai->soliciter, next) { if (IN6_ARE_ADDR_EQUAL(&sol->addr.sin6_addr, &from->sin6_addr)) break; } if (sol == NULL) { sol = malloc(sizeof(*sol)); if (sol == NULL) { logit(LOG_ERR, "%s: malloc: %m", __func__); } else { sol->addr = *from; /* XXX RFC2553 need clarification on flowinfo */ sol->addr.sin6_flowinfo = 0; TAILQ_INSERT_TAIL(&rai->soliciter, sol, next); } } /* * If there is already a waiting RS packet, don't * update the timer. */ if (rai->waiting++) goto done; ra_timer_set_short_delay(rai, rai->timer_sol); done: free_ndopts(&ndopts); } void ra_timer_set_short_delay(struct rainfo *rai, struct rtadvd_timer *timer) { long delay; /* must not be greater than 1000000 */ struct timespec interval, now, min_delay, tm_tmp, *rest; /* * Compute a random delay. If the computed value * corresponds to a time later than the time the next * multicast RA is scheduled to be sent, ignore the random * delay and send the advertisement at the * already-scheduled time. RFC2461 6.2.6 */ delay = arc4random() % MAX_RA_DELAY_TIME; interval.tv_sec = 0; interval.tv_nsec = delay; rest = rtadvd_timer_rest(rai->timer); if (timespeccmp(rest, &interval, <)) { logit(LOG_DEBUG, "%s: random delay is larger than " "the rest of current timer", __func__); interval = *rest; } /* * If we sent a multicast Router Advertisement within * the last MIN_DELAY_BETWEEN_RAS seconds, schedule * the advertisement to be sent at a time corresponding to * MIN_DELAY_BETWEEN_RAS plus the random value after the * previous advertisement was sent. */ prog_clock_gettime(CLOCK_MONOTONIC, &now); timespecsub(&now, &rai->lastsent, &tm_tmp); min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS; min_delay.tv_nsec = 0; if (timespeccmp(&tm_tmp, &min_delay, <)) { timespecsub(&min_delay, &tm_tmp, &min_delay); timespecadd(&min_delay, &interval, &interval); } rtadvd_set_timer(&interval, timer); } static void ra_input(int len, struct nd_router_advert *ra, struct in6_pktinfo *pi, struct sockaddr_in6 *from) { struct rainfo *rai; char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; union nd_opts ndopts; const char *on_off[] = {"OFF", "ON"}; uint32_t reachabletime, retranstimer, mtu; struct nd_optlist *optp; int inconsistent = 0; logit(LOG_DEBUG, "%s: RA received from %s on %s", __func__, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); /* ND option check */ memset(&ndopts, 0, sizeof(ndopts)); TAILQ_INIT(&ndopts.nd_opts_list); if (nd6_options((struct nd_opt_hdr *)(ra + 1), len - sizeof(struct nd_router_advert), &ndopts, NDOPT_FLAG_SRCLINKADDR | NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU | NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL)) { logit(LOG_INFO, "%s: ND option check failed for an RA from %s on %s", __func__, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } /* * RA consistency check according to RFC-2461 6.2.7 */ if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == 0) { logit(LOG_INFO, "%s: received RA from %s on non-advertising" " interface(%s)", __func__, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); goto done; } if (rai->leaving) { logit(LOG_DEBUG, "%s: received RA on re-configuring interface (%s)", __func__, rai->ifname); goto done; } rai->rainput++; /* increment statistics */ /* Cur Hop Limit value */ if (ra->nd_ra_curhoplimit && rai->hoplimit && ra->nd_ra_curhoplimit != rai->hoplimit) { logit(LOG_INFO, "%s: CurHopLimit inconsistent on %s:" " %d from %s, %d from us", __func__, rai->ifname, ra->nd_ra_curhoplimit, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), rai->hoplimit); inconsistent++; } /* M flag */ if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) != rai->managedflg) { logit(LOG_INFO, "%s: M flag inconsistent on %s:" " %s from %s, %s from us", __func__, rai->ifname, on_off[!rai->managedflg], inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), on_off[rai->managedflg]); inconsistent++; } /* O flag */ if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) != rai->otherflg) { logit(LOG_INFO, "%s: O flag inconsistent on %s:" " %s from %s, %s from us", __func__, rai->ifname, on_off[!rai->otherflg], inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), on_off[rai->otherflg]); inconsistent++; } /* Reachable Time */ reachabletime = ntohl(ra->nd_ra_reachable); if (reachabletime && rai->reachabletime && reachabletime != rai->reachabletime) { logit(LOG_INFO, "%s: ReachableTime inconsistent on %s:" " %d from %s, %d from us", __func__, rai->ifname, reachabletime, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), rai->reachabletime); inconsistent++; } /* Retrans Timer */ retranstimer = ntohl(ra->nd_ra_retransmit); if (retranstimer && rai->retranstimer && retranstimer != rai->retranstimer) { logit(LOG_INFO, "%s: RetranceTimer inconsistent on %s:" " %d from %s, %d from us", __func__, rai->ifname, retranstimer, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), rai->retranstimer); inconsistent++; } /* Values in the MTU options */ if (ndopts.nd_opts_mtu) { mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu); if (mtu && rai->linkmtu && mtu != rai->linkmtu) { logit(LOG_INFO, "%s: MTU option value inconsistent on %s:" " %d from %s, %d from us", __func__, rai->ifname, mtu, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), rai->linkmtu); inconsistent++; } } /* Preferred and Valid Lifetimes for prefixes */ if (ndopts.nd_opts_pi) if (prefix_check(ndopts.nd_opts_pi, rai, from)) inconsistent++; TAILQ_FOREACH(optp, &ndopts.nd_opts_list, next) if (prefix_check((struct nd_opt_prefix_info *)optp->opt, rai, from)) inconsistent++; if (inconsistent) rai->rainconsistent++; done: free_ndopts(&ndopts); } /* return a non-zero value if the received prefix is inconsitent with ours */ static int prefix_check(struct nd_opt_prefix_info *pinfo, struct rainfo *rai, struct sockaddr_in6 *from) { uint32_t preferred_time, valid_time; struct prefix *pp; int inconsistent = 0; char ntopbuf[INET6_ADDRSTRLEN], prefixbuf[INET6_ADDRSTRLEN]; struct timespec now; struct in6_addr prefix; #if 0 /* impossible */ if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION) return 0; #endif memcpy(&prefix, &pinfo->nd_opt_pi_prefix, sizeof(prefix)); /* * log if the adveritsed prefix has link-local scope(sanity check?) */ if (IN6_IS_ADDR_LINKLOCAL(&prefix)) { logit(LOG_INFO, "%s: link-local prefix %s/%d is advertised " "from %s on %s", __func__, inet_ntop(AF_INET6, &prefix, prefixbuf, INET6_ADDRSTRLEN), pinfo->nd_opt_pi_prefix_len, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), rai->ifname); } if ((pp = find_prefix(rai, &prefix, pinfo->nd_opt_pi_prefix_len)) == NULL) { logit(LOG_INFO, "%s: prefix %s/%d from %s on %s is not in our list", __func__, inet_ntop(AF_INET6, &prefix, prefixbuf, INET6_ADDRSTRLEN), pinfo->nd_opt_pi_prefix_len, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), rai->ifname); return 0; } preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time); if (pp->pltimeexpire) { /* * The lifetime is decremented in real time, so we should * compare the expiration time. * (RFC 2461 Section 6.2.7.) * XXX: can we really expect that all routers on the link * have synchronized clocks? */ prog_clock_gettime(CLOCK_MONOTONIC, &now); preferred_time += now.tv_sec; if (!pp->timer && rai->clockskew && llabs((long long)preferred_time - pp->pltimeexpire) > rai->clockskew) { logit(LOG_INFO, "%s: preferred lifetime for %s/%d" " (decr. in real time) inconsistent on %s:" " %d from %s, %ld from us", __func__, inet_ntop(AF_INET6, &prefix, prefixbuf, INET6_ADDRSTRLEN), pinfo->nd_opt_pi_prefix_len, rai->ifname, preferred_time, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), pp->pltimeexpire); inconsistent++; } } else if (!pp->timer && preferred_time != pp->preflifetime) { logit(LOG_INFO, "%s: preferred lifetime for %s/%d" " inconsistent on %s:" " %d from %s, %d from us", __func__, inet_ntop(AF_INET6, &prefix, prefixbuf, INET6_ADDRSTRLEN), pinfo->nd_opt_pi_prefix_len, rai->ifname, preferred_time, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), pp->preflifetime); } valid_time = ntohl(pinfo->nd_opt_pi_valid_time); if (pp->vltimeexpire) { prog_clock_gettime(CLOCK_MONOTONIC, &now); valid_time += now.tv_sec; if (!pp->timer && rai->clockskew && llabs((long long)valid_time - pp->vltimeexpire) > rai->clockskew) { logit(LOG_INFO, "%s: valid lifetime for %s/%d" " (decr. in real time) inconsistent on %s:" " %d from %s, %ld from us", __func__, inet_ntop(AF_INET6, &prefix, prefixbuf, INET6_ADDRSTRLEN), pinfo->nd_opt_pi_prefix_len, rai->ifname, preferred_time, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), pp->vltimeexpire); inconsistent++; } } else if (!pp->timer && valid_time != pp->validlifetime) { logit(LOG_INFO, "%s: valid lifetime for %s/%d" " inconsistent on %s:" " %d from %s, %d from us", __func__, inet_ntop(AF_INET6, &prefix, prefixbuf, INET6_ADDRSTRLEN), pinfo->nd_opt_pi_prefix_len, rai->ifname, valid_time, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, INET6_ADDRSTRLEN), pp->validlifetime); inconsistent++; } return inconsistent; } struct prefix * find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen) { struct prefix *pp; int bytelen, bitlen; unsigned char bitmask; TAILQ_FOREACH(pp, &rai->prefix, next) { if (plen != pp->prefixlen) continue; bytelen = plen / 8; bitlen = plen % 8; bitmask = 0xff << (8 - bitlen); if (memcmp(prefix, &pp->prefix, bytelen)) continue; if (bitlen == 0 || ((prefix->s6_addr[bytelen] & bitmask) == (pp->prefix.s6_addr[bytelen] & bitmask))) { return pp; } } return NULL; } /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */ int prefix_match(struct in6_addr *p0, int plen0, struct in6_addr *p1, int plen1) { int bytelen, bitlen; unsigned char bitmask; if (plen0 < plen1) return 0; bytelen = plen1 / 8; bitlen = plen1 % 8; bitmask = 0xff << (8 - bitlen); if (memcmp(p0, p1, bytelen)) return 0; if (bitlen == 0 || ((p0->s6_addr[bytelen] & bitmask) == (p1->s6_addr[bytelen] & bitmask))) { return 1; } return 0; } static int nd6_options(struct nd_opt_hdr *hdr, int limit, union nd_opts *ndopts, uint32_t optflags) { int optlen = 0; for (; limit > 0; limit -= optlen) { if ((size_t)limit < sizeof(struct nd_opt_hdr)) { logit(LOG_INFO, "%s: short option header", __func__); goto bad; } hdr = (struct nd_opt_hdr *)((char *)hdr + optlen); if (hdr->nd_opt_len == 0) { logit(LOG_INFO, "%s: bad ND option length(0) (type = %d)", __func__, hdr->nd_opt_type); goto bad; } optlen = hdr->nd_opt_len << 3; if (optlen > limit) { logit(LOG_INFO, "%s: short option", __func__); goto bad; } if (hdr->nd_opt_type > ND_OPT_MTU && hdr->nd_opt_type != ND_OPT_RDNSS && hdr->nd_opt_type != ND_OPT_DNSSL) { logit(LOG_INFO, "%s: unknown ND option(type %d)", __func__, hdr->nd_opt_type); continue; } if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) { logit(LOG_INFO, "%s: unexpected ND option(type %d)", __func__, hdr->nd_opt_type); continue; } /* * Option length check. Do it here for all fixed-length * options. */ if ((hdr->nd_opt_type == ND_OPT_MTU && (optlen != sizeof(struct nd_opt_mtu))) || ((hdr->nd_opt_type == ND_OPT_PREFIX_INFORMATION && optlen != sizeof(struct nd_opt_prefix_info))) || (hdr->nd_opt_type == ND_OPT_RDNSS && ((optlen < (int)sizeof(struct nd_opt_rdnss) || (optlen - sizeof(struct nd_opt_rdnss)) % 16 != 0))) || (hdr->nd_opt_type == ND_OPT_DNSSL && optlen < (int)sizeof(struct nd_opt_dnssl))) { logit(LOG_INFO, "%s: invalid option length", __func__); continue; } switch (hdr->nd_opt_type) { case ND_OPT_TARGET_LINKADDR: case ND_OPT_REDIRECTED_HEADER: case ND_OPT_RDNSS: case ND_OPT_DNSSL: break; /* we don't care about these options */ case ND_OPT_SOURCE_LINKADDR: case ND_OPT_MTU: if (ndopts->nd_opt_array[hdr->nd_opt_type]) { logit(LOG_INFO, "%s: duplicated ND option (type = %d)", __func__, hdr->nd_opt_type); } ndopts->nd_opt_array[hdr->nd_opt_type] = hdr; break; case ND_OPT_PREFIX_INFORMATION: { struct nd_optlist *pfxlist; if (ndopts->nd_opts_pi == 0) { ndopts->nd_opts_pi = (struct nd_opt_prefix_info *)hdr; continue; } if ((pfxlist = malloc(sizeof(*pfxlist))) == NULL) { logit(LOG_ERR, "%s: can't allocate memory", __func__); goto bad; } pfxlist->opt = hdr; TAILQ_INSERT_TAIL(&ndopts->nd_opts_list, pfxlist, next); break; } default: /* impossible */ break; } } return 0; bad: free_ndopts(ndopts); return -1; } static void free_ndopts(union nd_opts *ndopts) { struct nd_optlist *opt; while ((opt = TAILQ_FIRST(&ndopts->nd_opts_list)) != NULL) { TAILQ_REMOVE(&ndopts->nd_opts_list, opt, next); free(opt); } } void sock_open(void) { struct icmp6_filter filt; struct ipv6_mreq mreq; struct rainfo *ra; int on; /* XXX: should be max MTU attached to the node */ static unsigned char answer[1500]; rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) + CMSG_SPACE(sizeof(int)); rcvcmsgbuf = malloc(rcvcmsgbuflen); if (rcvcmsgbuf == NULL) { logit(LOG_ERR, "%s: malloc: %m", __func__); exit(EXIT_FAILURE); } sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)); sndcmsgbuf = malloc(sndcmsgbuflen); if (sndcmsgbuf == NULL) { logit(LOG_ERR, "%s: malloc: %m", __func__); exit(EXIT_FAILURE); } if ((sock = prog_socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) == -1) { logit(LOG_ERR, "%s: socket: %m", __func__); exit(EXIT_FAILURE); } /* RFC 4861 Section 4.2 */ on = 255; if (prog_setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &on, sizeof(on)) == -1) { logit(LOG_ERR, "%s: IPV6_MULTICAST_HOPS: %m", __func__); exit(EXIT_FAILURE); } on = 255; if (prog_setsockopt(sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &on, sizeof(on)) == -1) { logit(LOG_ERR, "%s: IPV6_UNICAST_HOPS: %m", __func__); exit(EXIT_FAILURE); } /* specify to tell receiving interface */ on = 1; if (prog_setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on, sizeof(on)) == -1) { logit(LOG_ERR, "%s: IPV6_RECVPKTINFO: %m", __func__); exit(EXIT_FAILURE); } on = 1; /* specify to tell value of hoplimit field of received IP6 hdr */ if (prog_setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on, sizeof(on)) == -1) { logit(LOG_ERR, "%s: IPV6_RECVHOPLIMIT: %m", __func__); exit(EXIT_FAILURE); } ICMP6_FILTER_SETBLOCKALL(&filt); ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt); ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt); if (accept_rr) ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt); if (prog_setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, sizeof(filt)) == -1) { logit(LOG_ERR, "%s: IICMP6_FILTER: %m", __func__); exit(EXIT_FAILURE); } /* * join all routers multicast address on each advertising interface. */ if (inet_pton(AF_INET6, ALLROUTERS_LINK, mreq.ipv6mr_multiaddr.s6_addr) != 1) { logit(LOG_ERR, "%s: inet_pton failed(library bug?)", __func__); exit(EXIT_FAILURE); } TAILQ_FOREACH(ra, &ralist, next) { mreq.ipv6mr_interface = ra->ifindex; if (prog_setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq, sizeof(mreq)) == -1) { logit(LOG_ERR, "%s: IPV6_JOIN_GROUP(link) on %s: %m", __func__, ra->ifname); continue; } } /* * When attending router renumbering, join all-routers site-local * multicast group. */ if (accept_rr) { if (inet_pton(AF_INET6, ALLROUTERS_SITE, mreq.ipv6mr_multiaddr.s6_addr) != 1) { logit(LOG_ERR, "%s: inet_pton failed(library bug?)", __func__); exit(EXIT_FAILURE); } ra = TAILQ_FIRST(&ralist); if (mcastif) { if ((mreq.ipv6mr_interface = if_nametoindex(mcastif)) == 0) { logit(LOG_ERR, "%s: invalid interface: %s", __func__, mcastif); exit(EXIT_FAILURE); } } else mreq.ipv6mr_interface = ra->ifindex; if (prog_setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq, sizeof(mreq)) == -1) { logit(LOG_ERR, "%s: IPV6_JOIN_GROUP(site) on %s: %m", __func__, mcastif ? mcastif : ra->ifname); exit(EXIT_FAILURE); } } /* initialize msghdr for receiving packets */ rcviov[0].iov_base = answer; rcviov[0].iov_len = sizeof(answer); rcvmhdr.msg_name = &rcvfrom; rcvmhdr.msg_namelen = sizeof(rcvfrom); rcvmhdr.msg_iov = rcviov; rcvmhdr.msg_iovlen = 1; rcvmhdr.msg_control = rcvcmsgbuf; rcvmhdr.msg_controllen = rcvcmsgbuflen; /* initialize msghdr for sending packets */ sndmhdr.msg_namelen = sizeof(struct sockaddr_in6); sndmhdr.msg_iov = sndiov; sndmhdr.msg_iovlen = 1; sndmhdr.msg_control = sndcmsgbuf; sndmhdr.msg_controllen = sndcmsgbuflen; } /* open a routing socket to watch the routing table */ static void rtsock_open(void) { #ifdef RO_MSGFILTER unsigned char msgfilter[] = { RTM_ADD, RTM_DELETE, RTM_NEWADDR, RTM_DELADDR, #ifdef RTM_IFANNOUNCE RTM_IFANNOUNCE, #endif RTM_IFINFO, }; #endif if ((rtsock = prog_socket(PF_ROUTE, SOCK_RAW, 0)) == -1) { logit(LOG_ERR, "%s: socket: %m", __func__); exit(EXIT_FAILURE); } #ifdef RO_MSGFILTER if (setsockopt(rtsock, PF_ROUTE, RO_MSGFILTER, &msgfilter, sizeof(msgfilter) == -1)) logit(LOG_ERR, "%s: RO_MSGFILTER: %m", __func__); #endif } struct rainfo * if_indextorainfo(unsigned int idx) { struct rainfo *rai; TAILQ_FOREACH(rai, &ralist, next) { if (rai->ifindex == idx) return rai; } return NULL; /* search failed */ } struct rainfo * ra_output(struct rainfo *rai, bool solicited) { int i; struct cmsghdr *cm; struct in6_pktinfo *pi; struct soliciter *sol; if ((rai->ifflags & IFF_UP) == 0) { logit(LOG_DEBUG, "%s: %s is not up, skip sending RA", __func__, rai->ifname); return NULL; } make_packet(rai); /* XXX: inefficient */ sndmhdr.msg_name = (void *)&sin6_linklocal_allnodes; sndmhdr.msg_iov[0].iov_base = (void *)rai->ra_data; sndmhdr.msg_iov[0].iov_len = rai->ra_datalen; /* specify the outgoing interface */ cm = CMSG_FIRSTHDR(&sndmhdr); cm->cmsg_level = IPPROTO_IPV6; cm->cmsg_type = IPV6_PKTINFO; cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); pi = (struct in6_pktinfo *)CMSG_DATA(cm); memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/ pi->ipi6_ifindex = rai->ifindex; logit(LOG_DEBUG, "%s: send RA on %s, # of waitings = %d", __func__, rai->ifname, rai->waiting); if (solicited) { /* unicast solicited RA's as per RFC 7772 */ while ((sol = TAILQ_FIRST(&rai->soliciter)) != NULL) { sndmhdr.msg_name = (void *)&sol->addr; i = prog_sendmsg(sock, &sndmhdr, 0); if (i < 0 || (size_t)i != rai->ra_datalen) { if (i < 0) { logit(LOG_ERR, "%s: unicast sendmsg on %s: %m", __func__, rai->ifname); } } TAILQ_REMOVE(&rai->soliciter, sol, next); free(sol); } /* reset waiting conter */ rai->waiting = 0; /* disable timer */ rai->timer_sol->enabled = false; return rai; } i = prog_sendmsg(sock, &sndmhdr, 0); if (i < 0 || (size_t)i != rai->ra_datalen) { if (i < 0) { logit(LOG_ERR, "%s: sendmsg on %s: %m", __func__, rai->ifname); } } if (rai->leaving_adv > 0) { if (--(rai->leaving_adv) == 0) { /* leaving for ourself means we're shutting down */ if (rai->leaving_for == rai) { TAILQ_REMOVE(&ralist, rai, next); free_rainfo(rai); return NULL; } logit(LOG_DEBUG, "%s: expired RA," " new config active for interface (%s)", __func__, rai->ifname); rai->leaving_for->timer = rtadvd_add_timer(ra_timeout, ra_timer_update, rai->leaving_for, rai->leaving_for); ra_timer_set_short_delay(rai->leaving_for, rai->timer); rai->leaving_for->leaving = NULL; free_rainfo(rai); return NULL; } } /* update counter */ if (rai->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS) rai->initcounter++; rai->raoutput++; /* update timestamp */ prog_clock_gettime(CLOCK_MONOTONIC, &rai->lastsent); return rai; } /* process unsolicited RA timer */ struct rtadvd_timer * ra_timeout(void *data) { struct rainfo *rai = (struct rainfo *)data; logit(LOG_DEBUG, "%s: unsolicited RA timer on %s is expired", __func__, rai->ifname); if (ra_output(rai, false)) return rai->timer; return NULL; } /* process solicited RA timer */ struct rtadvd_timer * ra_timeout_sol(void *data) { struct rainfo *rai = (struct rainfo *)data; logit(LOG_DEBUG, "%s: solicited RA timer on %s is expired", __func__, rai->ifname); if (ra_output(rai, true)) return rai->timer_sol; return NULL; } /* update RA timer */ void ra_timer_update(void *data, struct timespec *tm) { struct rainfo *rai = (struct rainfo *)data; long interval; /* * Whenever a multicast advertisement is sent from an interface, * the timer is reset to a uniformly-distributed random value * between the interface's configured MinRtrAdvInterval and * MaxRtrAdvInterval (RFC2461 6.2.4). */ interval = rai->mininterval; if (rai->mininterval != rai->maxinterval) interval += arc4random() % (rai->maxinterval-rai->mininterval); /* * For the first few advertisements (up to * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen interval * is greater than MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer * SHOULD be set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead. * (RFC-2461 6.2.4) */ if (rai->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS && interval > MAX_INITIAL_RTR_ADVERT_INTERVAL) interval = MAX_INITIAL_RTR_ADVERT_INTERVAL; tm->tv_sec = interval; tm->tv_nsec = 0; logit(LOG_DEBUG, "%s: RA timer on %s is set to %jd:%jd", __func__, rai->ifname, (intmax_t)tm->tv_sec, (intmax_t)tm->tv_nsec); } __format_arg(3) static const char * expandm(char *buf, size_t len, const char *fmt) { char *ptr; const char *e = strerror(errno); size_t cur = 0, elen = strlen(e); *buf = '\0'; while ((ptr = strstr(fmt, "%m")) != NULL) { size_t l = (size_t)(ptr - fmt); if (cur + elen + l + 1 >= len) return buf; memcpy(buf + cur, fmt, l); cur += l; memcpy(buf + cur, e, elen); cur += elen; fmt += l + 2; buf[cur] = '\0'; } strlcat(buf, fmt, len); strlcat(buf, "\n", len); /* syslog does not need \n, printf does */ return buf; } void logit(int level, const char *fmt, ...) { va_list ap; char buf[1024]; va_start(ap, fmt); if (!Dflag) { vsyslog(level, fmt, ap); va_end(ap); return; } vfprintf(stderr, expandm(buf, sizeof(buf), fmt), ap); va_end(ap); }