/* $KAME: rtadvd.c,v 1.82 2003/08/05 12:34:23 itojun Exp $ */ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * Copyright (C) 2011 Hiroki Sato * 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 #include #include #include #include #include #include #include #include #include #include #include "pathnames.h" #include "rtadvd.h" #include "if.h" #include "rrenum.h" #include "advcap.h" #include "timer_subr.h" #include "timer.h" #include "config.h" #include "control.h" #include "control_server.h" #define RTADV_TYPE2BITMASK(type) (0x1 << type) struct msghdr rcvmhdr; static char *rcvcmsgbuf; static size_t rcvcmsgbuflen; static char *sndcmsgbuf = NULL; static size_t sndcmsgbuflen; struct msghdr sndmhdr; struct iovec rcviov[2]; struct iovec sndiov[2]; struct sockaddr_in6 rcvfrom; static const char *pidfilename = _PATH_RTADVDPID; const char *conffile = _PATH_RTADVDCONF; static struct pidfh *pfh; static int dflag, sflag; static int wait_shutdown; #define PFD_RAWSOCK 0 #define PFD_RTSOCK 1 #define PFD_CSOCK 2 #define PFD_MAX 3 struct railist_head_t railist = TAILQ_HEAD_INITIALIZER(railist); struct ifilist_head_t ifilist = TAILQ_HEAD_INITIALIZER(ifilist); struct nd_optlist { TAILQ_ENTRY(nd_optlist) nol_next; struct nd_opt_hdr *nol_opt; }; union nd_opt { struct nd_opt_hdr *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) opt_list; } nd_opt_each; }; #define opt_src_lladdr nd_opt_each.src_lladdr #define opt_tgt_lladdr nd_opt_each.tgt_lladdr #define opt_pi nd_opt_each.pi #define opt_rh nd_opt_each.rh #define opt_mtu nd_opt_each.mtu #define opt_list nd_opt_each.opt_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) static 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, }; static void rtadvd_shutdown(void); static void sock_open(struct sockinfo *); static void rtsock_open(struct sockinfo *); static void rtadvd_input(struct sockinfo *); 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 int prefix_check(struct nd_opt_prefix_info *, struct rainfo *, struct sockaddr_in6 *); static int nd6_options(struct nd_opt_hdr *, int, union nd_opt *, uint32_t); static void free_ndopts(union nd_opt *); static void rtmsg_input(struct sockinfo *); static void set_short_delay(struct ifinfo *); static int check_accept_rtadv(int); static void usage(void) { fprintf(stderr, "usage: rtadvd [-dDfRs] " "[-c configfile] [-C ctlsock] [-M ifname] [-p pidfile]\n"); exit(1); } int main(int argc, char *argv[]) { struct pollfd set[PFD_MAX]; struct timespec *timeout; int i, ch; int fflag = 0, logopt; int error; pid_t pid, otherpid; /* get command line options and arguments */ while ((ch = getopt(argc, argv, "c:C:dDfhM:p:Rs")) != -1) { switch (ch) { case 'c': conffile = optarg; break; case 'C': ctrlsock.si_name = optarg; break; case 'd': dflag++; break; case 'D': dflag += 3; break; case 'f': fflag = 1; break; case 'M': mcastif = 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; case 'p': pidfilename = optarg; break; default: usage(); } } argc -= optind; argv += optind; logopt = LOG_NDELAY | LOG_PID; if (fflag) logopt |= LOG_PERROR; openlog("rtadvd", logopt, LOG_DAEMON); /* set log level */ if (dflag > 2) (void)setlogmask(LOG_UPTO(LOG_DEBUG)); else if (dflag > 1) (void)setlogmask(LOG_UPTO(LOG_INFO)); else if (dflag > 0) (void)setlogmask(LOG_UPTO(LOG_NOTICE)); else (void)setlogmask(LOG_UPTO(LOG_ERR)); /* timer initialization */ rtadvd_timer_init(); pfh = pidfile_open(pidfilename, 0600, &otherpid); if (pfh == NULL) { if (errno == EEXIST) errx(1, "%s already running, pid: %d", getprogname(), otherpid); syslog(LOG_ERR, "failed to open the pid file %s, run anyway.", pidfilename); } if (!fflag) daemon(1, 0); sock_open(&sock); update_ifinfo(&ifilist, UPDATE_IFINFO_ALL); for (i = 0; i < argc; i++) update_persist_ifinfo(&ifilist, argv[i]); csock_open(&ctrlsock, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH); if (ctrlsock.si_fd == -1) { syslog(LOG_ERR, "cannot open control socket: %s", strerror(errno)); exit(1); } /* record the current PID */ pid = getpid(); pidfile_write(pfh); set[PFD_RAWSOCK].fd = sock.si_fd; set[PFD_RAWSOCK].events = POLLIN; if (sflag == 0) { rtsock_open(&rtsock); set[PFD_RTSOCK].fd = rtsock.si_fd; set[PFD_RTSOCK].events = POLLIN; } else set[PFD_RTSOCK].fd = -1; set[PFD_CSOCK].fd = ctrlsock.si_fd; set[PFD_CSOCK].events = POLLIN; signal(SIGTERM, set_do_shutdown); signal(SIGINT, set_do_shutdown); signal(SIGHUP, set_do_reload); error = csock_listen(&ctrlsock); if (error) { syslog(LOG_ERR, "cannot listen control socket: %s", strerror(errno)); exit(1); } /* load configuration file */ set_do_reload(0); while (1) { if (is_do_shutdown()) rtadvd_shutdown(); if (is_do_reload()) { loadconfig_ifname(reload_ifname()); if (reload_ifname() == NULL) syslog(LOG_INFO, "configuration file reloaded."); else syslog(LOG_INFO, "configuration file for %s reloaded.", reload_ifname()); reset_do_reload(); } /* timeout handler update for active interfaces */ rtadvd_update_timeout_handler(); /* timer expiration check and reset the timer */ timeout = rtadvd_check_timer(); if (timeout != NULL) { syslog(LOG_DEBUG, "<%s> set timer to %ld:%ld. waiting for " "inputs or timeout", __func__, (long int)timeout->tv_sec, (long int)timeout->tv_nsec / 1000); } else { syslog(LOG_DEBUG, "<%s> there's no timer. waiting for inputs", __func__); } if ((i = poll(set, sizeof(set)/sizeof(set[0]), timeout ? (timeout->tv_sec * 1000 + timeout->tv_nsec / 1000 / 1000) : INFTIM)) < 0) { /* EINTR would occur if a signal was delivered */ if (errno != EINTR) syslog(LOG_ERR, "poll() failed: %s", strerror(errno)); continue; } if (i == 0) /* timeout */ continue; if (rtsock.si_fd != -1 && set[PFD_RTSOCK].revents & POLLIN) rtmsg_input(&rtsock); if (set[PFD_RAWSOCK].revents & POLLIN) rtadvd_input(&sock); if (set[PFD_CSOCK].revents & POLLIN) { int fd; fd = csock_accept(&ctrlsock); if (fd == -1) syslog(LOG_ERR, "cannot accept() control socket: %s", strerror(errno)); else { cm_handler_server(fd); close(fd); } } } exit(0); /* NOTREACHED */ } static void rtadvd_shutdown(void) { struct ifinfo *ifi; struct rainfo *rai; struct rdnss *rdn; struct dnssl *dns; if (wait_shutdown) { syslog(LOG_INFO, "waiting expiration of the all RA timers."); TAILQ_FOREACH(ifi, &ifilist, ifi_next) { /* * Ignore !IFF_UP interfaces in waiting for shutdown. */ if (!(ifi->ifi_flags & IFF_UP) && ifi->ifi_ra_timer != NULL) { ifi->ifi_state = IFI_STATE_UNCONFIGURED; rtadvd_remove_timer(ifi->ifi_ra_timer); ifi->ifi_ra_timer = NULL; syslog(LOG_DEBUG, "<%s> %s(idx=%d) is down. " "Timer removed and marked as UNCONFIGURED.", __func__, ifi->ifi_ifname, ifi->ifi_ifindex); } } TAILQ_FOREACH(ifi, &ifilist, ifi_next) { if (ifi->ifi_ra_timer != NULL) break; } if (ifi == NULL) { syslog(LOG_NOTICE, "gracefully terminated."); exit(0); } sleep(1); return; } syslog(LOG_DEBUG, "<%s> cease to be an advertising router", __func__); wait_shutdown = 1; TAILQ_FOREACH(rai, &railist, rai_next) { rai->rai_lifetime = 0; TAILQ_FOREACH(rdn, &rai->rai_rdnss, rd_next) rdn->rd_ltime = 0; TAILQ_FOREACH(dns, &rai->rai_dnssl, dn_next) dns->dn_ltime = 0; } TAILQ_FOREACH(ifi, &ifilist, ifi_next) { if (!ifi->ifi_persist) continue; if (ifi->ifi_state == IFI_STATE_UNCONFIGURED) continue; if (ifi->ifi_ra_timer == NULL) continue; if (ifi->ifi_ra_lastsent.tv_sec == 0 && ifi->ifi_ra_lastsent.tv_nsec == 0 && ifi->ifi_ra_timer != NULL) { /* * When RA configured but never sent, * ignore the IF immediately. */ rtadvd_remove_timer(ifi->ifi_ra_timer); ifi->ifi_ra_timer = NULL; ifi->ifi_state = IFI_STATE_UNCONFIGURED; continue; } ifi->ifi_state = IFI_STATE_TRANSITIVE; /* Mark as the shut-down state. */ ifi->ifi_rainfo_trans = ifi->ifi_rainfo; ifi->ifi_rainfo = NULL; ifi->ifi_burstcount = MAX_FINAL_RTR_ADVERTISEMENTS; ifi->ifi_burstinterval = MIN_DELAY_BETWEEN_RAS; ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm); rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm, ifi->ifi_ra_timer); } syslog(LOG_NOTICE, "final RA transmission started."); pidfile_remove(pfh); csock_close(&ctrlsock); } static void rtmsg_input(struct sockinfo *s) { int n, type, ifindex = 0, plen; size_t len; char msg[2048], *next, *lim; char ifname[IFNAMSIZ]; struct if_announcemsghdr *ifan; struct rt_msghdr *rtm; struct prefix *pfx; struct rainfo *rai; struct in6_addr *addr; struct ifinfo *ifi; char addrbuf[INET6_ADDRSTRLEN]; int prefixchange = 0; if (s == NULL) { syslog(LOG_ERR, "<%s> internal error", __func__); exit(1); } n = read(s->si_fd, msg, sizeof(msg)); rtm = (struct rt_msghdr *)msg; syslog(LOG_DEBUG, "<%s> received a routing message " "(type = %d, len = %d)", __func__, rtm->rtm_type, n); if (n > rtm->rtm_msglen) { /* * This usually won't happen for messages received on * a routing socket. */ syslog(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, rtm->rtm_msglen); #if 0 /* adjust length */ n = rtm->rtm_msglen; #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) | RTADV_TYPE2BITMASK(RTM_IFINFO) | RTADV_TYPE2BITMASK(RTM_IFANNOUNCE)); if (len == 0) break; type = ((struct rt_msghdr *)next)->rtm_type; switch (type) { case RTM_ADD: case RTM_DELETE: ifindex = get_rtm_ifindex(next); break; case RTM_NEWADDR: case RTM_DELADDR: ifindex = (int)((struct ifa_msghdr *)next)->ifam_index; break; case RTM_IFINFO: ifindex = (int)((struct if_msghdr *)next)->ifm_index; break; case RTM_IFANNOUNCE: ifan = (struct if_announcemsghdr *)next; switch (ifan->ifan_what) { case IFAN_ARRIVAL: case IFAN_DEPARTURE: break; default: syslog(LOG_DEBUG, "<%s:%d> unknown ifan msg (ifan_what=%d)", __func__, __LINE__, ifan->ifan_what); continue; } syslog(LOG_DEBUG, "<%s>: if_announcemsg (idx=%d:%d)", __func__, ifan->ifan_index, ifan->ifan_what); switch (ifan->ifan_what) { case IFAN_ARRIVAL: syslog(LOG_NOTICE, "interface added (idx=%d)", ifan->ifan_index); update_ifinfo(&ifilist, ifan->ifan_index); loadconfig_index(ifan->ifan_index); break; case IFAN_DEPARTURE: syslog(LOG_NOTICE, "interface removed (idx=%d)", ifan->ifan_index); rm_ifinfo_index(ifan->ifan_index); /* Clear ifi_ifindex */ TAILQ_FOREACH(ifi, &ifilist, ifi_next) { if (ifi->ifi_ifindex == ifan->ifan_index) { ifi->ifi_ifindex = 0; break; } } update_ifinfo(&ifilist, ifan->ifan_index); break; } continue; default: /* should not reach here */ syslog(LOG_DEBUG, "<%s:%d> unknown rtmsg %d on %s", __func__, __LINE__, type, if_indextoname(ifindex, ifname)); continue; } ifi = if_indextoifinfo(ifindex); if (ifi == NULL) { syslog(LOG_DEBUG, "<%s> ifinfo not found for idx=%d. Why?", __func__, ifindex); continue; } rai = ifi->ifi_rainfo; if (rai == NULL) { syslog(LOG_DEBUG, "<%s> route changed on " "non advertising interface(%s)", __func__, ifi->ifi_ifname); continue; } oldifflags = ifi->ifi_flags; /* init ifflags because it may have changed */ update_ifinfo(&ifilist, ifindex); switch (type) { case RTM_ADD: 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) { syslog(LOG_INFO, "<%s> new interface route's" "plen %d is invalid for a prefix", __func__, plen); break; } pfx = find_prefix(rai, addr, plen); if (pfx) { if (pfx->pfx_timer) { /* * If the prefix has been invalidated, * make it available again. */ update_prefix(pfx); prefixchange = 1; } else syslog(LOG_DEBUG, "<%s> new prefix(%s/%d) " "added on %s, " "but it was already in list", __func__, inet_ntop(AF_INET6, addr, (char *)addrbuf, sizeof(addrbuf)), plen, ifi->ifi_ifname); break; } make_prefix(rai, ifindex, addr, plen); prefixchange = 1; break; case RTM_DELETE: 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) { syslog(LOG_INFO, "<%s> deleted interface route's " "plen %d is invalid for a prefix", __func__, plen); break; } pfx = find_prefix(rai, addr, plen); if (pfx == NULL) { syslog(LOG_DEBUG, "<%s> prefix(%s/%d) was deleted on %s, " "but it was not in list", __func__, inet_ntop(AF_INET6, addr, (char *)addrbuf, sizeof(addrbuf)), plen, ifi->ifi_ifname); break; } invalidate_prefix(pfx); prefixchange = 1; break; case RTM_NEWADDR: case RTM_DELADDR: case RTM_IFINFO: break; default: /* should not reach here */ syslog(LOG_DEBUG, "<%s:%d> unknown rtmsg %d on %s", __func__, __LINE__, type, if_indextoname(ifindex, ifname)); return; } /* check if an interface flag is changed */ if ((oldifflags & IFF_UP) && /* UP to DOWN */ !(ifi->ifi_flags & IFF_UP)) { syslog(LOG_NOTICE, "ifi_ifname); rtadvd_remove_timer(ifi->ifi_ra_timer); ifi->ifi_ra_timer = NULL; } else if (!(oldifflags & IFF_UP) && /* DOWN to UP */ (ifi->ifi_flags & IFF_UP)) { syslog(LOG_NOTICE, "interface %s becomes up. restart timer.", ifi->ifi_ifname); ifi->ifi_state = IFI_STATE_TRANSITIVE; ifi->ifi_burstcount = MAX_INITIAL_RTR_ADVERTISEMENTS; ifi->ifi_burstinterval = MAX_INITIAL_RTR_ADVERT_INTERVAL; ifi->ifi_ra_timer = rtadvd_add_timer(ra_timeout, ra_timer_update, ifi, ifi); ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm); rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm, ifi->ifi_ra_timer); } else if (prefixchange && (ifi->ifi_flags & IFF_UP)) { /* * An advertised prefix has been added or invalidated. * Will notice the change in a short delay. */ set_short_delay(ifi); } } return; } void rtadvd_input(struct sockinfo *s) { ssize_t i; int *hlimp = NULL; #ifdef OLDRAWSOCKET struct ip6_hdr *ip; #endif 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 ifinfo *ifi; syslog(LOG_DEBUG, "<%s> enter", __func__); if (s == NULL) { syslog(LOG_ERR, "<%s> internal error", __func__); exit(1); } /* * 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 = recvmsg(s->si_fd, &rcvmhdr, 0)) < 0) 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) { syslog(LOG_ERR, "failed to get receiving interface"); return; } if (hlimp == NULL) { syslog(LOG_ERR, "failed to get receiving hop limit"); return; } /* * If we happen to receive data on an interface which is now gone * or down, just discard the data. */ ifi = if_indextoifinfo(pi->ipi6_ifindex); if (ifi == NULL || !(ifi->ifi_flags & IFF_UP)) { syslog(LOG_INFO, "<%s> received data on a disabled interface (%s)", __func__, (ifi == NULL) ? "[gone]" : ifi->ifi_ifname); return; } #ifdef OLDRAWSOCKET if ((size_t)i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) { syslog(LOG_ERR, "packet size(%d) is too short", i); return; } ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base; icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */ #else if ((size_t)i < sizeof(struct icmp6_hdr)) { syslog(LOG_ERR, "packet size(%zd) is too short", i); return; } icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base; #endif switch (icp->icmp6_type) { case ND_ROUTER_SOLICIT: /* * Message verification - RFC 4861 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) { syslog(LOG_NOTICE, "RS with invalid hop limit(%d) " "received from %s on %s", *hlimp, inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } if (icp->icmp6_code) { syslog(LOG_NOTICE, "RS with invalid ICMP6 code(%d) " "received from %s on %s", icp->icmp6_code, inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } if ((size_t)i < sizeof(struct nd_router_solicit)) { syslog(LOG_NOTICE, "RS from %s on %s does not have enough " "length (len = %zd)", inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, sizeof(ntopbuf)), 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 4861 6.1.2 * XXX: there's the same dilemma as above... */ if (!IN6_IS_ADDR_LINKLOCAL(&rcvfrom.sin6_addr)) { syslog(LOG_NOTICE, "RA with non-linklocal source address " "received from %s on %s", inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } if (*hlimp != 255) { syslog(LOG_NOTICE, "RA with invalid hop limit(%d) " "received from %s on %s", *hlimp, inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } if (icp->icmp6_code) { syslog(LOG_NOTICE, "RA with invalid ICMP6 code(%d) " "received from %s on %s", icp->icmp6_code, inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } if ((size_t)i < sizeof(struct nd_router_advert)) { syslog(LOG_NOTICE, "RA from %s on %s does not have enough " "length (len = %zd)", inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, ifnamebuf), i); return; } ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom); break; case ICMP6_ROUTER_RENUMBERING: if (mcastif == NULL) { syslog(LOG_ERR, "received a router renumbering " "message, but not allowed to be accepted"); 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()). */ syslog(LOG_ERR, "invalid icmp type(%d)", icp->icmp6_type); return; } return; } static void rs_input(int len, struct nd_router_solicit *rs, struct in6_pktinfo *pi, struct sockaddr_in6 *from) { char ntopbuf[INET6_ADDRSTRLEN]; char ifnamebuf[IFNAMSIZ]; union nd_opt ndopts; struct rainfo *rai; struct ifinfo *ifi; struct soliciter *sol; syslog(LOG_DEBUG, "<%s> RS received from %s on %s", __func__, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); /* ND option check */ memset(&ndopts, 0, sizeof(ndopts)); TAILQ_INIT(&ndopts.opt_list); if (nd6_options((struct nd_opt_hdr *)(rs + 1), len - sizeof(struct nd_router_solicit), &ndopts, NDOPT_FLAG_SRCLINKADDR)) { syslog(LOG_INFO, "<%s> ND option check failed for an RS from %s on %s", __func__, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), 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 4861 6.1.1) */ if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) && ndopts.opt_src_lladdr) { syslog(LOG_INFO, "<%s> RS from unspecified src on %s has a link-layer" " address option", __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf)); goto done; } ifi = if_indextoifinfo(pi->ipi6_ifindex); if (ifi == NULL) { syslog(LOG_INFO, "<%s> if (idx=%d) not found. Why?", __func__, pi->ipi6_ifindex); goto done; } rai = ifi->ifi_rainfo; if (rai == NULL) { syslog(LOG_INFO, "<%s> RS received on non advertising interface(%s)", __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf)); goto done; } rai->rai_ifinfo->ifi_rsinput++; /* * Decide whether to send RA according to the rate-limit * consideration. */ /* record sockaddr waiting for RA, if possible */ sol = (struct soliciter *)malloc(sizeof(*sol)); if (sol) { sol->sol_addr = *from; /* XXX RFC 2553 need clarification on flowinfo */ sol->sol_addr.sin6_flowinfo = 0; TAILQ_INSERT_TAIL(&rai->rai_soliciter, sol, sol_next); } /* * If there is already a waiting RS packet, don't * update the timer. */ if (ifi->ifi_rs_waitcount++) goto done; set_short_delay(ifi); done: free_ndopts(&ndopts); return; } static void set_short_delay(struct ifinfo *ifi) { long delay; /* must not be greater than 1000000 */ struct timespec interval, now, min_delay, tm_tmp, *rest; if (ifi->ifi_ra_timer == NULL) return; /* * 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. RFC 4861 6.2.6 */ delay = arc4random_uniform(MAX_RA_DELAY_TIME); interval.tv_sec = 0; interval.tv_nsec = delay * 1000; rest = rtadvd_timer_rest(ifi->ifi_ra_timer); if (TS_CMP(rest, &interval, <)) { syslog(LOG_DEBUG, "<%s> random delay is larger than " "the rest of the 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. */ clock_gettime(CLOCK_MONOTONIC_FAST, &now); TS_SUB(&now, &ifi->ifi_ra_lastsent, &tm_tmp); min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS; min_delay.tv_nsec = 0; if (TS_CMP(&tm_tmp, &min_delay, <)) { TS_SUB(&min_delay, &tm_tmp, &min_delay); TS_ADD(&min_delay, &interval, &interval); } rtadvd_set_timer(&interval, ifi->ifi_ra_timer); } static int check_accept_rtadv(int idx) { struct ifinfo *ifi; TAILQ_FOREACH(ifi, &ifilist, ifi_next) { if (ifi->ifi_ifindex == idx) break; } if (ifi == NULL) { syslog(LOG_DEBUG, "<%s> if (idx=%d) not found. Why?", __func__, idx); return (0); } /* * RA_RECV: ND6_IFF_ACCEPT_RTADV * RA_SEND: ip6.forwarding */ if (update_ifinfo_nd_flags(ifi) != 0) { syslog(LOG_ERR, "cannot get nd6 flags (idx=%d)", idx); return (0); } return (ifi->ifi_nd_flags & ND6_IFF_ACCEPT_RTADV); } static void ra_input(int len, struct nd_router_advert *nra, struct in6_pktinfo *pi, struct sockaddr_in6 *from) { struct rainfo *rai; struct ifinfo *ifi; char ntopbuf[INET6_ADDRSTRLEN]; char ifnamebuf[IFNAMSIZ]; union nd_opt ndopts; const char *on_off[] = {"OFF", "ON"}; uint32_t reachabletime, retranstimer, mtu; int inconsistent = 0; int error; syslog(LOG_DEBUG, "<%s> RA received from %s on %s", __func__, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); /* ND option check */ memset(&ndopts, 0, sizeof(ndopts)); TAILQ_INIT(&ndopts.opt_list); error = nd6_options((struct nd_opt_hdr *)(nra + 1), len - sizeof(struct nd_router_advert), &ndopts, NDOPT_FLAG_SRCLINKADDR | NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU | NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL); if (error) { syslog(LOG_INFO, "<%s> ND option check failed for an RA from %s on %s", __func__, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); return; } /* * RA consistency check according to RFC 4861 6.2.7 */ ifi = if_indextoifinfo(pi->ipi6_ifindex); if (ifi->ifi_rainfo == NULL) { syslog(LOG_INFO, "<%s> received RA from %s on non-advertising" " interface(%s)", __func__, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, ifnamebuf)); goto done; } rai = ifi->ifi_rainfo; ifi->ifi_rainput++; syslog(LOG_DEBUG, "<%s> ifi->ifi_rainput = %" PRIu64, __func__, ifi->ifi_rainput); /* Cur Hop Limit value */ if (nra->nd_ra_curhoplimit && rai->rai_hoplimit && nra->nd_ra_curhoplimit != rai->rai_hoplimit) { syslog(LOG_NOTICE, "CurHopLimit inconsistent on %s:" " %d from %s, %d from us", ifi->ifi_ifname, nra->nd_ra_curhoplimit, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), rai->rai_hoplimit); inconsistent++; } /* M flag */ if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) != rai->rai_managedflg) { syslog(LOG_NOTICE, "M flag inconsistent on %s:" " %s from %s, %s from us", ifi->ifi_ifname, on_off[!rai->rai_managedflg], inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), on_off[rai->rai_managedflg]); inconsistent++; } /* O flag */ if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) != rai->rai_otherflg) { syslog(LOG_NOTICE, "O flag inconsistent on %s:" " %s from %s, %s from us", ifi->ifi_ifname, on_off[!rai->rai_otherflg], inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), on_off[rai->rai_otherflg]); inconsistent++; } #ifdef DRAFT_IETF_6MAN_IPV6ONLY_FLAG /* S "IPv6-Only" (Six, Silence-IPv4) flag */ if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_IPV6_ONLY) != rai->rai_ipv6onlyflg) { syslog(LOG_NOTICE, "S flag inconsistent on %s:" " %s from %s, %s from us", ifi->ifi_ifname, on_off[!rai->rai_ipv6onlyflg], inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), on_off[rai->rai_ipv6onlyflg]); inconsistent++; } #endif /* Reachable Time */ reachabletime = ntohl(nra->nd_ra_reachable); if (reachabletime && rai->rai_reachabletime && reachabletime != rai->rai_reachabletime) { syslog(LOG_NOTICE, "ReachableTime inconsistent on %s:" " %d from %s, %d from us", ifi->ifi_ifname, reachabletime, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), rai->rai_reachabletime); inconsistent++; } /* Retrans Timer */ retranstimer = ntohl(nra->nd_ra_retransmit); if (retranstimer && rai->rai_retranstimer && retranstimer != rai->rai_retranstimer) { syslog(LOG_NOTICE, "RetranceTimer inconsistent on %s:" " %d from %s, %d from us", ifi->ifi_ifname, retranstimer, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), rai->rai_retranstimer); inconsistent++; } /* Values in the MTU options */ if (ndopts.opt_mtu) { mtu = ntohl(ndopts.opt_mtu->nd_opt_mtu_mtu); if (mtu && rai->rai_linkmtu && mtu != rai->rai_linkmtu) { syslog(LOG_NOTICE, "MTU option value inconsistent on %s:" " %d from %s, %d from us", ifi->ifi_ifname, mtu, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), rai->rai_linkmtu); inconsistent++; } } /* Preferred and Valid Lifetimes for prefixes */ { struct nd_optlist *nol; if (ndopts.opt_pi) if (prefix_check(ndopts.opt_pi, rai, from)) inconsistent++; TAILQ_FOREACH(nol, &ndopts.opt_list, nol_next) if (prefix_check((struct nd_opt_prefix_info *)nol->nol_opt, rai, from)) inconsistent++; } if (inconsistent) ifi->ifi_rainconsistent++; done: free_ndopts(&ndopts); return; } static uint32_t udiff(uint32_t u, uint32_t v) { return (u >= v ? u - v : v - u); } /* return a non-zero value if the received prefix is inconsistent with ours */ static int prefix_check(struct nd_opt_prefix_info *pinfo, struct rainfo *rai, struct sockaddr_in6 *from) { struct ifinfo *ifi; uint32_t preferred_time, valid_time; struct prefix *pfx; int inconsistent = 0; char ntopbuf[INET6_ADDRSTRLEN]; char prefixbuf[INET6_ADDRSTRLEN]; struct timespec now; #if 0 /* impossible */ if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION) return (0); #endif ifi = rai->rai_ifinfo; /* * log if the adveritsed prefix has link-local scope(sanity check?) */ if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix)) syslog(LOG_INFO, "<%s> link-local prefix %s/%d is advertised " "from %s on %s", __func__, inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, sizeof(prefixbuf)), pinfo->nd_opt_pi_prefix_len, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), ifi->ifi_ifname); if ((pfx = find_prefix(rai, &pinfo->nd_opt_pi_prefix, pinfo->nd_opt_pi_prefix_len)) == NULL) { syslog(LOG_INFO, "<%s> prefix %s/%d from %s on %s is not in our list", __func__, inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, sizeof(prefixbuf)), pinfo->nd_opt_pi_prefix_len, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), ifi->ifi_ifname); return (0); } preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time); if (pfx->pfx_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? */ clock_gettime(CLOCK_MONOTONIC_FAST, &now); preferred_time += now.tv_sec; if (!pfx->pfx_timer && rai->rai_clockskew && udiff(preferred_time, pfx->pfx_pltimeexpire) > rai->rai_clockskew) { syslog(LOG_INFO, "<%s> preferred lifetime for %s/%d" " (decr. in real time) inconsistent on %s:" " %" PRIu32 " from %s, %" PRIu32 " from us", __func__, inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, sizeof(prefixbuf)), pinfo->nd_opt_pi_prefix_len, ifi->ifi_ifname, preferred_time, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), pfx->pfx_pltimeexpire); inconsistent++; } } else if (!pfx->pfx_timer && preferred_time != pfx->pfx_preflifetime) syslog(LOG_INFO, "<%s> preferred lifetime for %s/%d" " inconsistent on %s:" " %d from %s, %d from us", __func__, inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, sizeof(prefixbuf)), pinfo->nd_opt_pi_prefix_len, ifi->ifi_ifname, preferred_time, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), pfx->pfx_preflifetime); valid_time = ntohl(pinfo->nd_opt_pi_valid_time); if (pfx->pfx_vltimeexpire) { clock_gettime(CLOCK_MONOTONIC_FAST, &now); valid_time += now.tv_sec; if (!pfx->pfx_timer && rai->rai_clockskew && udiff(valid_time, pfx->pfx_vltimeexpire) > rai->rai_clockskew) { syslog(LOG_INFO, "<%s> valid lifetime for %s/%d" " (decr. in real time) inconsistent on %s:" " %d from %s, %" PRIu32 " from us", __func__, inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, sizeof(prefixbuf)), pinfo->nd_opt_pi_prefix_len, ifi->ifi_ifname, preferred_time, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), pfx->pfx_vltimeexpire); inconsistent++; } } else if (!pfx->pfx_timer && valid_time != pfx->pfx_validlifetime) { syslog(LOG_INFO, "<%s> valid lifetime for %s/%d" " inconsistent on %s:" " %d from %s, %d from us", __func__, inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, sizeof(prefixbuf)), pinfo->nd_opt_pi_prefix_len, ifi->ifi_ifname, valid_time, inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), pfx->pfx_validlifetime); inconsistent++; } return (inconsistent); } struct prefix * find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen) { struct prefix *pfx; int bytelen, bitlen; char bitmask; TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) { if (plen != pfx->pfx_prefixlen) continue; bytelen = plen / 8; bitlen = plen % 8; bitmask = 0xff << (8 - bitlen); if (memcmp((void *)prefix, (void *)&pfx->pfx_prefix, bytelen)) continue; if (bitlen == 0 || ((prefix->s6_addr[bytelen] & bitmask) == (pfx->pfx_prefix.s6_addr[bytelen] & bitmask))) { return (pfx); } } 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; char bitmask; if (plen0 < plen1) return (0); bytelen = plen1 / 8; bitlen = plen1 % 8; bitmask = 0xff << (8 - bitlen); if (memcmp((void *)p0, (void *)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_opt *ndopts, uint32_t optflags) { int optlen = 0; for (; limit > 0; limit -= optlen) { if ((size_t)limit < sizeof(struct nd_opt_hdr)) { syslog(LOG_INFO, "<%s> short option header", __func__); goto bad; } hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen); if (hdr->nd_opt_len == 0) { syslog(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) { syslog(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) { syslog(LOG_INFO, "<%s> unknown ND option(type %d)", __func__, hdr->nd_opt_type); continue; } if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) { syslog(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. */ switch (hdr->nd_opt_type) { case ND_OPT_MTU: if (optlen == sizeof(struct nd_opt_mtu)) break; goto skip; case ND_OPT_RDNSS: if (optlen >= 24 && (optlen - sizeof(struct nd_opt_rdnss)) % 16 == 0) break; goto skip; case ND_OPT_DNSSL: if (optlen >= 16 && (optlen - sizeof(struct nd_opt_dnssl)) % 8 == 0) break; goto skip; case ND_OPT_PREFIX_INFORMATION: if (optlen == sizeof(struct nd_opt_prefix_info)) break; skip: syslog(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->opt_array[hdr->nd_opt_type]) { syslog(LOG_INFO, "<%s> duplicated ND option (type = %d)", __func__, hdr->nd_opt_type); } ndopts->opt_array[hdr->nd_opt_type] = hdr; break; case ND_OPT_PREFIX_INFORMATION: { struct nd_optlist *nol; if (ndopts->opt_pi == 0) { ndopts->opt_pi = (struct nd_opt_prefix_info *)hdr; continue; } nol = malloc(sizeof(*nol)); if (nol == NULL) { syslog(LOG_ERR, "<%s> can't allocate memory", __func__); goto bad; } nol->nol_opt = hdr; TAILQ_INSERT_TAIL(&(ndopts->opt_list), nol, nol_next); break; } default: /* impossible */ break; } } return (0); bad: free_ndopts(ndopts); return (-1); } static void free_ndopts(union nd_opt *ndopts) { struct nd_optlist *nol; while ((nol = TAILQ_FIRST(&ndopts->opt_list)) != NULL) { TAILQ_REMOVE(&ndopts->opt_list, nol, nol_next); free(nol); } } void sock_open(struct sockinfo *s) { struct icmp6_filter filt; int on; /* XXX: should be max MTU attached to the node */ static char answer[1500]; syslog(LOG_DEBUG, "<%s> enter", __func__); if (s == NULL) { syslog(LOG_ERR, "<%s> internal error", __func__); exit(1); } rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) + CMSG_SPACE(sizeof(int)); rcvcmsgbuf = (char *)malloc(rcvcmsgbuflen); if (rcvcmsgbuf == NULL) { syslog(LOG_ERR, "<%s> not enough core", __func__); exit(1); } sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) + CMSG_SPACE(sizeof(int)); sndcmsgbuf = (char *)malloc(sndcmsgbuflen); if (sndcmsgbuf == NULL) { syslog(LOG_ERR, "<%s> not enough core", __func__); exit(1); } if ((s->si_fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) { syslog(LOG_ERR, "<%s> socket: %s", __func__, strerror(errno)); exit(1); } /* specify to tell receiving interface */ on = 1; if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on, sizeof(on)) < 0) { syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s", __func__, strerror(errno)); exit(1); } on = 1; /* specify to tell value of hoplimit field of received IP6 hdr */ if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on, sizeof(on)) < 0) { syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s", __func__, strerror(errno)); exit(1); } ICMP6_FILTER_SETBLOCKALL(&filt); ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt); ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt); if (mcastif != NULL) ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt); if (setsockopt(s->si_fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, sizeof(filt)) < 0) { syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s", __func__, strerror(errno)); exit(1); } /* initialize msghdr for receiving packets */ rcviov[0].iov_base = (caddr_t)answer; rcviov[0].iov_len = sizeof(answer); rcvmhdr.msg_name = (caddr_t)&rcvfrom; rcvmhdr.msg_namelen = sizeof(rcvfrom); rcvmhdr.msg_iov = rcviov; rcvmhdr.msg_iovlen = 1; rcvmhdr.msg_control = (caddr_t) 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 = (caddr_t)sndcmsgbuf; sndmhdr.msg_controllen = sndcmsgbuflen; return; } /* open a routing socket to watch the routing table */ static void rtsock_open(struct sockinfo *s) { if (s == NULL) { syslog(LOG_ERR, "<%s> internal error", __func__); exit(1); } if ((s->si_fd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) { syslog(LOG_ERR, "<%s> socket: %s", __func__, strerror(errno)); exit(1); } } struct ifinfo * if_indextoifinfo(int idx) { struct ifinfo *ifi; char *name, name0[IFNAMSIZ]; /* Check if the interface has a valid name or not. */ if (if_indextoname(idx, name0) == NULL) return (NULL); TAILQ_FOREACH(ifi, &ifilist, ifi_next) { if (ifi->ifi_ifindex == idx) return (ifi); } if (ifi != NULL) syslog(LOG_DEBUG, "<%s> ifi found (idx=%d)", __func__, idx); else syslog(LOG_DEBUG, "<%s> ifi not found (idx=%d)", __func__, idx); return (NULL); /* search failed */ } void ra_output(struct ifinfo *ifi) { int i; struct cmsghdr *cm; struct in6_pktinfo *pi; struct soliciter *sol; struct rainfo *rai; switch (ifi->ifi_state) { case IFI_STATE_CONFIGURED: rai = ifi->ifi_rainfo; break; case IFI_STATE_TRANSITIVE: rai = ifi->ifi_rainfo_trans; break; case IFI_STATE_UNCONFIGURED: syslog(LOG_DEBUG, "<%s> %s is unconfigured. " "Skip sending RAs.", __func__, ifi->ifi_ifname); return; default: rai = NULL; } if (rai == NULL) { syslog(LOG_DEBUG, "<%s> rainfo is NULL on %s." "Skip sending RAs.", __func__, ifi->ifi_ifname); return; } if (!(ifi->ifi_flags & IFF_UP)) { syslog(LOG_DEBUG, "<%s> %s is not up. " "Skip sending RAs.", __func__, ifi->ifi_ifname); return; } /* * Check lifetime, ACCEPT_RTADV flag, and ip6.forwarding. * * (lifetime == 0) = output * (lifetime != 0 && (check_accept_rtadv()) = no output * * Basically, hosts MUST NOT send Router Advertisement * messages at any time (RFC 4861, Section 6.2.3). However, it * would sometimes be useful to allow hosts to advertise some * parameters such as prefix information and link MTU. Thus, * we allow hosts to invoke rtadvd only when router lifetime * (on every advertising interface) is explicitly set * zero. (see also the above section) */ syslog(LOG_DEBUG, "<%s> check lifetime=%d, ACCEPT_RTADV=%d, ip6.forwarding=%d " "on %s", __func__, rai->rai_lifetime, check_accept_rtadv(ifi->ifi_ifindex), getinet6sysctl(IPV6CTL_FORWARDING), ifi->ifi_ifname); if (rai->rai_lifetime != 0) { if (getinet6sysctl(IPV6CTL_FORWARDING) == 0) { syslog(LOG_ERR, "non-zero lifetime RA " "but net.inet6.ip6.forwarding=0. " "Ignored."); return; } if (check_accept_rtadv(ifi->ifi_ifindex)) { syslog(LOG_ERR, "non-zero lifetime RA " "on RA receiving interface %s." " Ignored.", ifi->ifi_ifname); return; } } make_packet(rai); /* XXX: inefficient */ sndmhdr.msg_name = (caddr_t)&sin6_linklocal_allnodes; sndmhdr.msg_iov[0].iov_base = (caddr_t)rai->rai_ra_data; sndmhdr.msg_iov[0].iov_len = rai->rai_ra_datalen; cm = CMSG_FIRSTHDR(&sndmhdr); /* specify the outgoing interface */ 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 = ifi->ifi_ifindex; /* specify the hop limit of the packet */ { int hoplimit = 255; cm = CMSG_NXTHDR(&sndmhdr, cm); cm->cmsg_level = IPPROTO_IPV6; cm->cmsg_type = IPV6_HOPLIMIT; cm->cmsg_len = CMSG_LEN(sizeof(int)); memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int)); } syslog(LOG_DEBUG, "<%s> send RA on %s, # of RS waitings = %d", __func__, ifi->ifi_ifname, ifi->ifi_rs_waitcount); i = sendmsg(sock.si_fd, &sndmhdr, 0); if (i < 0 || (size_t)i != rai->rai_ra_datalen) { if (i < 0) { syslog(LOG_ERR, "<%s> sendmsg on %s: %s", __func__, ifi->ifi_ifname, strerror(errno)); } } /* * unicast advertisements * XXX commented out. reason: though spec does not forbit it, unicast * advert does not really help */ while ((sol = TAILQ_FIRST(&rai->rai_soliciter)) != NULL) { TAILQ_REMOVE(&rai->rai_soliciter, sol, sol_next); free(sol); } /* update timestamp */ clock_gettime(CLOCK_MONOTONIC_FAST, &ifi->ifi_ra_lastsent); /* update counter */ ifi->ifi_rs_waitcount = 0; ifi->ifi_raoutput++; switch (ifi->ifi_state) { case IFI_STATE_CONFIGURED: if (ifi->ifi_burstcount > 0) ifi->ifi_burstcount--; break; case IFI_STATE_TRANSITIVE: ifi->ifi_burstcount--; if (ifi->ifi_burstcount == 0) { if (ifi->ifi_rainfo == ifi->ifi_rainfo_trans) { /* Initial burst finished. */ if (ifi->ifi_rainfo_trans != NULL) ifi->ifi_rainfo_trans = NULL; } /* Remove burst RA information */ if (ifi->ifi_rainfo_trans != NULL) { rm_rainfo(ifi->ifi_rainfo_trans); ifi->ifi_rainfo_trans = NULL; } if (ifi->ifi_rainfo != NULL) { /* * TRANSITIVE -> CONFIGURED * * After initial burst or transition from * one configuration to another, * ifi_rainfo always points to the next RA * information. */ ifi->ifi_state = IFI_STATE_CONFIGURED; syslog(LOG_DEBUG, "<%s> ifname=%s marked as " "CONFIGURED.", __func__, ifi->ifi_ifname); } else { /* * TRANSITIVE -> UNCONFIGURED * * If ifi_rainfo points to NULL, this * interface is shutting down. * */ int error; ifi->ifi_state = IFI_STATE_UNCONFIGURED; syslog(LOG_DEBUG, "<%s> ifname=%s marked as " "UNCONFIGURED.", __func__, ifi->ifi_ifname); error = sock_mc_leave(&sock, ifi->ifi_ifindex); if (error) exit(1); } } break; } } /* process RA timer */ struct rtadvd_timer * ra_timeout(void *arg) { struct ifinfo *ifi; ifi = (struct ifinfo *)arg; syslog(LOG_DEBUG, "<%s> RA timer on %s is expired", __func__, ifi->ifi_ifname); ra_output(ifi); return (ifi->ifi_ra_timer); } /* update RA timer */ void ra_timer_update(void *arg, struct timespec *tm) { uint16_t interval; struct rainfo *rai; struct ifinfo *ifi; ifi = (struct ifinfo *)arg; rai = ifi->ifi_rainfo; interval = 0; switch (ifi->ifi_state) { case IFI_STATE_UNCONFIGURED: return; break; case IFI_STATE_CONFIGURED: /* * 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 (RFC4861 6.2.4). */ interval = rai->rai_mininterval; interval += arc4random_uniform(rai->rai_maxinterval - rai->rai_mininterval); break; case IFI_STATE_TRANSITIVE: /* * 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 * 4861 6.2.4) * * In such cases, the router SHOULD transmit one or more * (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final * multicast Router Advertisements on the interface with a * Router Lifetime field of zero. (RFC 4861 6.2.5) */ interval = ifi->ifi_burstinterval; break; } tm->tv_sec = interval; tm->tv_nsec = 0; syslog(LOG_DEBUG, "<%s> RA timer on %s is set to %ld:%ld", __func__, ifi->ifi_ifname, (long int)tm->tv_sec, (long int)tm->tv_nsec / 1000); return; }