/* $OpenBSD: rtsold.c,v 1.31 2003/07/07 00:18:30 deraadt Exp $ */ /* $KAME: rtsold.c,v 1.57 2002/09/20 21:59:55 itojun 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 #ifdef HAVE_POLL_H #include #endif #include "rtsold.h" struct ifinfo *iflist; struct timeval tm_max = {0x7fffffff, 0x7fffffff}; int aflag = 0; int dflag = 0; static int log_upto = 999; static int fflag = 0; /* protocol constatns */ #define MAX_RTR_SOLICITATION_DELAY 1 /* second */ #define RTR_SOLICITATION_INTERVAL 4 /* seconds */ #define MAX_RTR_SOLICITATIONS 3 /* times */ /* implementation dependent constants */ #define PROBE_INTERVAL 60 /* secondes XXX: should be configurable */ /* utility macros */ /* a < b */ #define TIMEVAL_LT(a, b) (((a).tv_sec < (b).tv_sec) ||\ (((a).tv_sec == (b).tv_sec) && \ ((a).tv_usec < (b).tv_usec))) /* a <= b */ #define TIMEVAL_LEQ(a, b) (((a).tv_sec < (b).tv_sec) ||\ (((a).tv_sec == (b).tv_sec) &&\ ((a).tv_usec <= (b).tv_usec))) /* a == b */ #define TIMEVAL_EQ(a, b) (((a).tv_sec==(b).tv_sec) && ((a).tv_usec==(b).tv_usec)) /* static variables and functions */ static int mobile_node = 0; volatile sig_atomic_t do_dump; static char *dumpfilename = "/var/run/rtsold.dump"; /* XXX: should be configurable */ #if 0 static int ifreconfig(char *); #endif int ifconfig(char *ifname); void iflist_init(void); static int make_packet(struct ifinfo *); static struct timeval *rtsol_check_timer(void); static void TIMEVAL_ADD(struct timeval *, struct timeval *, struct timeval *); static void TIMEVAL_SUB(struct timeval *, struct timeval *, struct timeval *); static void rtsold_set_dump_file(int); static void usage(char *); int main(int argc, char *argv[]) { int s, ch, once = 0; struct timeval *timeout; char *argv0, *opts; #ifdef HAVE_POLL_H struct pollfd set[2]; #else fd_set *fdsetp, *selectfdp; int fdmasks; int maxfd; #endif #ifdef USE_RTSOCK int rtsock; #endif /* * Initialization */ argv0 = argv[0]; /* get option */ if (argv0 && argv0[strlen(argv0) - 1] != 'd') { fflag = 1; once = 1; opts = "adD"; } else opts = "adDfm1"; while ((ch = getopt(argc, argv, opts)) != -1) { switch (ch) { case 'a': aflag = 1; break; case 'd': dflag = 1; break; case 'D': dflag = 2; break; case 'f': fflag = 1; break; case 'm': mobile_node = 1; break; case '1': once = 1; break; default: usage(argv0); /*NOTREACHED*/ } } argc -= optind; argv += optind; if ((!aflag && argc == 0) || (aflag && argc != 0)) { usage(argv0); /*NOTREACHED*/ } /* set log level */ if (dflag == 0) log_upto = LOG_NOTICE; if (!fflag) { char *ident; ident = strrchr(argv0, '/'); if (!ident) ident = argv0; else ident++; openlog(ident, LOG_NDELAY|LOG_PID, LOG_DAEMON); if (log_upto >= 0) setlogmask(LOG_UPTO(log_upto)); } #ifndef HAVE_ARC4RANDOM /* random value initilization */ srandom((u_long)time(NULL)); #endif /* warn if accept_rtadv is down */ if (!getinet6sysctl(IPV6CTL_ACCEPT_RTADV)) warnx("kernel is configured not to accept RAs"); /* warn if forwarding is up */ if (getinet6sysctl(IPV6CTL_FORWARDING)) warnx("kernel is configured as a router, not a host"); /* initialization to dump internal status to a file */ signal(SIGUSR1, rtsold_set_dump_file); if (!fflag) daemon(0, 0); /* act as a daemon */ /* * Open a socket for sending RS and receiving RA. * This should be done before calling ifinit(), since the function * uses the socket. */ if ((s = sockopen()) < 0) { warnmsg(LOG_ERR, __func__, "failed to open a socket"); exit(1); /*NOTREACHED*/ } #ifdef HAVE_POLL_H set[0].fd = s; set[0].events = POLLIN; #else maxfd = s; #endif #ifdef HAVE_POLL_H set[1].fd = -1; #endif #ifdef USE_RTSOCK if ((rtsock = rtsock_open()) < 0) { warnmsg(LOG_ERR, __func__, "failed to open a socket"); exit(1); /*NOTREACHED*/ } #ifdef HAVE_POLL_H set[1].fd = rtsock; set[1].events = POLLIN; #else if (rtsock > maxfd) maxfd = rtsock; #endif #endif #ifndef HAVE_POLL_H fdmasks = howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask); if ((fdsetp = malloc(fdmasks)) == NULL) { err(1, "malloc"); /*NOTREACHED*/ } if ((selectfdp = malloc(fdmasks)) == NULL) { err(1, "malloc"); /*NOTREACHED*/ } #endif /* configuration per interface */ if (ifinit()) { warnmsg(LOG_ERR, __func__, "failed to initilizatoin interfaces"); exit(1); /*NOTREACHED*/ } if (aflag) argv = autoifprobe(); while (argv && *argv) { if (ifconfig(*argv)) { warnmsg(LOG_ERR, __func__, "failed to initialize %s", *argv); exit(1); /*NOTREACHED*/ } argv++; } /* setup for probing default routers */ if (probe_init()) { warnmsg(LOG_ERR, __func__, "failed to setup for probing routers"); exit(1); /*NOTREACHED*/ } /* dump the current pid */ if (!once) { if (pidfile(NULL) < 0) { warnmsg(LOG_ERR, __func__, "failed to open a pid log file: %s", strerror(errno)); } } #ifndef HAVE_POLL_H memset(fdsetp, 0, fdmasks); FD_SET(s, fdsetp); #ifdef USE_RTSOCK FD_SET(rtsock, fdsetp); #endif #endif while (1) { /* main loop */ int e; #ifndef HAVE_POLL_H memcpy(selectfdp, fdsetp, fdmasks); #endif if (do_dump) { /* SIGUSR1 */ do_dump = 0; rtsold_dump_file(dumpfilename); } timeout = rtsol_check_timer(); if (once) { struct ifinfo *ifi; /* if we have no timeout, we are done (or failed) */ if (timeout == NULL) break; /* if all interfaces have got RA packet, we are done */ for (ifi = iflist; ifi; ifi = ifi->next) { if (ifi->state != IFS_DOWN && ifi->racnt == 0) break; } if (ifi == NULL) break; } #ifdef HAVE_POLL_H e = poll(set, 2, timeout ? (timeout->tv_sec * 1000 + timeout->tv_usec / 1000) : INFTIM); #else e = select(maxfd + 1, selectfdp, NULL, NULL, timeout); #endif if (e < 1) { if (e < 0 && errno != EINTR) { warnmsg(LOG_ERR, __func__, "select: %s", strerror(errno)); } continue; } /* packet reception */ #ifdef USE_RTSOCK #ifdef HAVE_POLL_H if (set[1].revents & POLLIN) #else if (FD_ISSET(rtsock, selectfdp)) #endif rtsock_input(rtsock); #endif #ifdef HAVE_POLL_H if (set[0].revents & POLLIN) #else if (FD_ISSET(s, selectfdp)) #endif rtsol_input(s); } /* NOTREACHED */ return 0; } int ifconfig(char *ifname) { struct ifinfo *ifinfo; struct sockaddr_dl *sdl; int flags; if ((sdl = if_nametosdl(ifname)) == NULL) { warnmsg(LOG_ERR, __func__, "failed to get link layer information for %s", ifname); return(-1); } if (find_ifinfo(sdl->sdl_index)) { warnmsg(LOG_ERR, __func__, "interface %s was already configured", ifname); free(sdl); return(-1); } if ((ifinfo = malloc(sizeof(*ifinfo))) == NULL) { warnmsg(LOG_ERR, __func__, "memory allocation failed"); free(sdl); return(-1); } memset(ifinfo, 0, sizeof(*ifinfo)); ifinfo->sdl = sdl; strncpy(ifinfo->ifname, ifname, sizeof(ifinfo->ifname)); /* construct a router solicitation message */ if (make_packet(ifinfo)) goto bad; /* set link ID of this interface. */ #ifdef HAVE_SCOPELIB if (inet_zoneid(AF_INET6, 2, ifname, &ifinfo->linkid)) goto bad; #else /* XXX: assume interface IDs as link IDs */ ifinfo->linkid = ifinfo->sdl->sdl_index; #endif /* * check if the interface is available. * also check if SIOCGIFMEDIA ioctl is OK on the interface. */ ifinfo->mediareqok = 1; ifinfo->active = interface_status(ifinfo); if (!ifinfo->mediareqok) { /* * probe routers periodically even if the link status * does not change. */ ifinfo->probeinterval = PROBE_INTERVAL; } /* activate interface: interface_up returns 0 on success */ flags = interface_up(ifinfo->ifname); if (flags == 0) ifinfo->state = IFS_DELAY; else if (flags == IFS_TENTATIVE) ifinfo->state = IFS_TENTATIVE; else ifinfo->state = IFS_DOWN; rtsol_timer_update(ifinfo); /* link into chain */ if (iflist) ifinfo->next = iflist; iflist = ifinfo; return(0); bad: free(ifinfo->sdl); free(ifinfo); return(-1); } void iflist_init(void) { struct ifinfo *ifi, *next; for (ifi = iflist; ifi; ifi = next) { next = ifi->next; if (ifi->sdl) free(ifi->sdl); if (ifi->rs_data) free(ifi->rs_data); free(ifi); iflist = NULL; } } #if 0 static int ifreconfig(char *ifname) { struct ifinfo *ifi, *prev; int rv; prev = NULL; for (ifi = iflist; ifi; ifi = ifi->next) { if (strncmp(ifi->ifname, ifname, sizeof(ifi->ifname)) == 0) break; prev = ifi; } prev->next = ifi->next; rv = ifconfig(ifname); /* reclaim it after ifconfig() in case ifname is pointer inside ifi */ if (ifi->rs_data) free(ifi->rs_data); free(ifi->sdl); free(ifi); return rv; } #endif struct ifinfo * find_ifinfo(int ifindex) { struct ifinfo *ifi; for (ifi = iflist; ifi; ifi = ifi->next) if (ifi->sdl->sdl_index == ifindex) return(ifi); return(NULL); } static int make_packet(struct ifinfo *ifinfo) { size_t packlen = sizeof(struct nd_router_solicit), lladdroptlen = 0; struct nd_router_solicit *rs; char *buf; if ((lladdroptlen = lladdropt_length(ifinfo->sdl)) == 0) { warnmsg(LOG_INFO, __func__, "link-layer address option has null length" " on %s. Treat as not included.", ifinfo->ifname); } packlen += lladdroptlen; ifinfo->rs_datalen = packlen; /* allocate buffer */ if ((buf = malloc(packlen)) == NULL) { warnmsg(LOG_ERR, __func__, "memory allocation failed for %s", ifinfo->ifname); return(-1); } ifinfo->rs_data = buf; /* fill in the message */ rs = (struct nd_router_solicit *)buf; rs->nd_rs_type = ND_ROUTER_SOLICIT; rs->nd_rs_code = 0; rs->nd_rs_cksum = 0; rs->nd_rs_reserved = 0; buf += sizeof(*rs); /* fill in source link-layer address option */ if (lladdroptlen) lladdropt_fill(ifinfo->sdl, (struct nd_opt_hdr *)buf); return(0); } static struct timeval * rtsol_check_timer(void) { static struct timeval returnval; struct timeval now, rtsol_timer; struct ifinfo *ifinfo; int flags; gettimeofday(&now, NULL); rtsol_timer = tm_max; for (ifinfo = iflist; ifinfo; ifinfo = ifinfo->next) { if (TIMEVAL_LEQ(ifinfo->expire, now)) { if (dflag > 1) warnmsg(LOG_DEBUG, __func__, "timer expiration on %s, " "state = %d", ifinfo->ifname, ifinfo->state); switch (ifinfo->state) { case IFS_DOWN: case IFS_TENTATIVE: /* interface_up returns 0 on success */ flags = interface_up(ifinfo->ifname); if (flags == 0) ifinfo->state = IFS_DELAY; else if (flags == IFS_TENTATIVE) ifinfo->state = IFS_TENTATIVE; else ifinfo->state = IFS_DOWN; break; case IFS_IDLE: { int oldstatus = ifinfo->active; int probe = 0; ifinfo->active = interface_status(ifinfo); if (oldstatus != ifinfo->active) { warnmsg(LOG_DEBUG, __func__, "%s status is changed" " from %d to %d", ifinfo->ifname, oldstatus, ifinfo->active); probe = 1; ifinfo->state = IFS_DELAY; } else if (ifinfo->probeinterval && (ifinfo->probetimer -= ifinfo->timer.tv_sec) <= 0) { /* probe timer expired */ ifinfo->probetimer = ifinfo->probeinterval; probe = 1; ifinfo->state = IFS_PROBE; } if (probe && mobile_node) defrouter_probe(ifinfo); break; } case IFS_DELAY: ifinfo->state = IFS_PROBE; sendpacket(ifinfo); break; case IFS_PROBE: if (ifinfo->probes < MAX_RTR_SOLICITATIONS) sendpacket(ifinfo); else { warnmsg(LOG_INFO, __func__, "No answer after sending %d RSs", ifinfo->probes); ifinfo->probes = 0; ifinfo->state = IFS_IDLE; } break; } rtsol_timer_update(ifinfo); } if (TIMEVAL_LT(ifinfo->expire, rtsol_timer)) rtsol_timer = ifinfo->expire; } if (TIMEVAL_EQ(rtsol_timer, tm_max)) { warnmsg(LOG_DEBUG, __func__, "there is no timer"); return(NULL); } else if (TIMEVAL_LT(rtsol_timer, now)) /* this may occur when the interval is too small */ returnval.tv_sec = returnval.tv_usec = 0; else TIMEVAL_SUB(&rtsol_timer, &now, &returnval); if (dflag > 1) warnmsg(LOG_DEBUG, __func__, "New timer is %ld:%08ld", (long)returnval.tv_sec, (long)returnval.tv_usec); return(&returnval); } void rtsol_timer_update(struct ifinfo *ifinfo) { #define MILLION 1000000 #define DADRETRY 10 /* XXX: adhoc */ long interval; struct timeval now; bzero(&ifinfo->timer, sizeof(ifinfo->timer)); switch (ifinfo->state) { case IFS_DOWN: case IFS_TENTATIVE: if (++ifinfo->dadcount > DADRETRY) { ifinfo->dadcount = 0; ifinfo->timer.tv_sec = PROBE_INTERVAL; } else ifinfo->timer.tv_sec = 1; break; case IFS_IDLE: if (mobile_node) { /* XXX should be configurable */ ifinfo->timer.tv_sec = 3; } else ifinfo->timer = tm_max; /* stop timer(valid?) */ break; case IFS_DELAY: #ifndef HAVE_ARC4RANDOM interval = random() % (MAX_RTR_SOLICITATION_DELAY * MILLION); #else interval = arc4random() % (MAX_RTR_SOLICITATION_DELAY * MILLION); #endif ifinfo->timer.tv_sec = interval / MILLION; ifinfo->timer.tv_usec = interval % MILLION; break; case IFS_PROBE: if (ifinfo->probes < MAX_RTR_SOLICITATIONS) ifinfo->timer.tv_sec = RTR_SOLICITATION_INTERVAL; else { /* * After sending MAX_RTR_SOLICITATIONS solicitations, * we're just waiting for possible replies; there * will be no more solicatation. Thus, we change * the timer value to MAX_RTR_SOLICITATION_DELAY based * on RFC 2461, Section 6.3.7. */ ifinfo->timer.tv_sec = MAX_RTR_SOLICITATION_DELAY; } break; default: warnmsg(LOG_ERR, __func__, "illegal interface state(%d) on %s", ifinfo->state, ifinfo->ifname); return; } /* reset the timer */ if (TIMEVAL_EQ(ifinfo->timer, tm_max)) { ifinfo->expire = tm_max; warnmsg(LOG_DEBUG, __func__, "stop timer for %s", ifinfo->ifname); } else { gettimeofday(&now, NULL); TIMEVAL_ADD(&now, &ifinfo->timer, &ifinfo->expire); if (dflag > 1) warnmsg(LOG_DEBUG, __func__, "set timer for %s to %d:%d", ifinfo->ifname, (int)ifinfo->timer.tv_sec, (int)ifinfo->timer.tv_usec); } #undef MILLION } /* timer related utility functions */ #define MILLION 1000000 /* result = a + b */ static void TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result) { long l; if ((l = a->tv_usec + b->tv_usec) < MILLION) { result->tv_usec = l; result->tv_sec = a->tv_sec + b->tv_sec; } else { result->tv_usec = l - MILLION; result->tv_sec = a->tv_sec + b->tv_sec + 1; } } /* * result = a - b * XXX: this function assumes that a >= b. */ void TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result) { long l; if ((l = a->tv_usec - b->tv_usec) >= 0) { result->tv_usec = l; result->tv_sec = a->tv_sec - b->tv_sec; } else { result->tv_usec = MILLION + l; result->tv_sec = a->tv_sec - b->tv_sec - 1; } } static void rtsold_set_dump_file(int sig) { do_dump = 1; } static void usage(char *progname) { if (progname && progname[strlen(progname) - 1] != 'd') { fprintf(stderr, "usage: rtsol [-dD] interfaces...\n"); fprintf(stderr, "usage: rtsol [-dD] -a\n"); } else { fprintf(stderr, "usage: rtsold [-adDfm1] interfaces...\n"); fprintf(stderr, "usage: rtsold [-dDfm1] -a\n"); } exit(1); } void warnmsg(int priority, const char *func, const char *msg, ...) { va_list ap; char buf[BUFSIZ]; va_start(ap, msg); if (fflag) { if (priority <= log_upto) { (void)vfprintf(stderr, msg, ap); (void)fprintf(stderr, "\n"); } } else { snprintf(buf, sizeof(buf), "<%s> %s", func, msg); msg = buf; vsyslog(priority, msg, ap); } va_end(ap); } /* * return a list of interfaces which is suitable to sending an RS. */ char ** autoifprobe(void) { static char **argv = NULL; static int n = 0; char **a; int i, found; struct ifaddrs *ifap, *ifa, *target; /* initialize */ while (n--) free(argv[n]); if (argv) { free(argv); argv = NULL; } n = 0; if (getifaddrs(&ifap) != 0) return NULL; target = NULL; /* find an ethernet */ for (ifa = ifap; ifa; ifa = ifa->ifa_next) { if ((ifa->ifa_flags & IFF_UP) == 0) continue; if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0) continue; if ((ifa->ifa_flags & IFF_LOOPBACK) != 0) continue; if ((ifa->ifa_flags & IFF_MULTICAST) == 0) continue; if (ifa->ifa_addr->sa_family != AF_INET6) continue; found = 0; for (i = 0; i < n; i++) { if (strcmp(argv[i], ifa->ifa_name) == 0) { found++; break; } } if (found) continue; /* if we find multiple candidates, just warn. */ if (n != 0 && dflag > 1) warnx("multiple interfaces found"); a = (char **)realloc(argv, (n + 1) * sizeof(char **)); if (a == NULL) err(1, "realloc"); argv = a; if ((argv[n] = strdup(ifa->ifa_name)) == NULL) err(1, "strdup"); n++; } if (n) { a = (char **)realloc(argv, (n + 1) * sizeof(char **)); if (a == NULL) err(1, "realloc"); argv = a; argv[n] = NULL; if (dflag > 0) { for (i = 0; i < n; i++) warnx("probing %s", argv[i]); } } freeifaddrs(ifap); return argv; }