/* * Copyright (C) 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. * * $FreeBSD$ */ /* * User level translator from IPv6 to IPv4. * * Usage: faithd [ ...] * e.g. faithd telnet /usr/local/v6/sbin/telnetd telnetd */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef IFT_FAITH # define USE_ROUTE # include # include # include #endif #include #include #include #ifdef FAITH4 #include #include #ifndef FAITH_NS #define FAITH_NS "FAITH_NS" #endif #endif #include "faithd.h" char *serverpath = NULL; char *serverarg[MAXARGV + 1]; static char *faithdname = NULL; char logname[BUFSIZ]; char procname[BUFSIZ]; struct myaddrs { struct myaddrs *next; struct sockaddr *addr; }; struct myaddrs *myaddrs = NULL; static char *service; #ifdef USE_ROUTE static int sockfd = 0; #endif int dflag = 0; static int pflag = 0; int main __P((int, char **)); static void play_service __P((int)); static void play_child __P((int, struct sockaddr *)); static int faith_prefix __P((struct sockaddr *)); static int map6to4 __P((struct sockaddr_in6 *, struct sockaddr_in *)); #ifdef FAITH4 static int map4to6 __P((struct sockaddr_in *, struct sockaddr_in6 *)); #endif static void sig_child __P((int)); static void sig_terminate __P((int)); static void start_daemon __P((void)); static unsigned int if_maxindex __P((void)); static void grab_myaddrs __P((void)); static void free_myaddrs __P((void)); static void update_myaddrs __P((void)); static void usage __P((void)); int main(int argc, char *argv[]) { struct addrinfo hints, *res; int s_wld, error, i, serverargc, on = 1; int family = AF_INET6; int c; #ifdef FAITH_NS char *ns; #endif /* FAITH_NS */ extern int optind; extern char *optarg; /* * Initializing stuff */ faithdname = strrchr(argv[0], '/'); if (faithdname) faithdname++; else faithdname = argv[0]; while ((c = getopt(argc, argv, "dp46")) != -1) { switch (c) { case 'd': dflag++; break; case 'p': pflag++; break; #ifdef FAITH4 case '4': family = AF_INET; break; case '6': family = AF_INET6; break; #endif default: usage(); break; } } argc -= optind; argv += optind; #ifdef FAITH_NS if ((ns = getenv(FAITH_NS)) != NULL) { struct sockaddr_storage ss; struct addrinfo hints, *res; char serv[NI_MAXSERV]; memset(&ss, 0, sizeof(ss)); memset(&hints, 0, sizeof(hints)); snprintf(serv, sizeof(serv), "%u", NAMESERVER_PORT); hints.ai_flags = AI_NUMERICHOST; if (getaddrinfo(ns, serv, &hints, &res) == 0) { res_init(); memcpy(&_res_ext.nsaddr, res->ai_addr, res->ai_addrlen); _res.nscount = 1; } } #endif /* FAITH_NS */ #ifdef USE_ROUTE grab_myaddrs(); #endif switch (argc) { case 0: serverpath = DEFAULT_PATH; serverarg[0] = DEFAULT_NAME; serverarg[1] = NULL; service = DEFAULT_PORT_NAME; break; default: serverargc = argc - NUMARG; if (serverargc > MAXARGV) exit_error("too many arguments"); serverpath = malloc(strlen(argv[NUMPRG])); strcpy(serverpath, argv[NUMPRG]); for (i = 0; i < serverargc; i++) { serverarg[i] = malloc(strlen(argv[i + NUMARG])); strcpy(serverarg[i], argv[i + NUMARG]); } serverarg[i] = NULL; /* FALLTHROUGH */ case 1: /* no local service */ service = argv[NUMPRT]; break; } /* * Opening wild card socket for this service. */ memset(&hints, 0, sizeof(hints)); hints.ai_flags = AI_PASSIVE; hints.ai_family = family; hints.ai_socktype = SOCK_STREAM; hints.ai_protocol = 0; error = getaddrinfo(NULL, service, &hints, &res); if (error) { fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(error)); if (error == EAI_SYSTEM) exit_error("getaddrinfo: %s\n", strerror(errno)); exit(EXIT_FAILURE); } s_wld = socket(res->ai_family, res->ai_socktype, res->ai_protocol); if (s_wld == -1) exit_error("socket: %s", ERRSTR); #ifdef IPV6_FAITH if (res->ai_family == AF_INET6) { error = setsockopt(s_wld, IPPROTO_IPV6, IPV6_FAITH, &on, sizeof(on)); if (error == -1) exit_error("setsockopt(IPV6_FAITH): %s", ERRSTR); } #endif #ifdef FAITH4 #ifdef IP_FAITH if (res->ai_family == AF_INET) { error = setsockopt(s_wld, IPPROTO_IP, IP_FAITH, &on, sizeof(on)); if (error == -1) exit_error("setsockopt(IP_FAITH): %s", ERRSTR); } #endif #endif /* FAITH4 */ error = setsockopt(s_wld, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); if (error == -1) exit_error("setsockopt(SO_REUSEADDR): %s", ERRSTR); error = setsockopt(s_wld, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)); if (error == -1) exit_error("setsockopt(SO_OOBINLINE): %s", ERRSTR); error = bind(s_wld, (struct sockaddr *)res->ai_addr, res->ai_addrlen); if (error == -1) exit_error("bind: %s", ERRSTR); error = listen(s_wld, 5); if (error == -1) exit_error("listen: %s", ERRSTR); #ifdef USE_ROUTE sockfd = socket(PF_ROUTE, SOCK_RAW, PF_UNSPEC); if (sockfd < 0) { exit_error("socket(PF_ROUTE): %s", ERRSTR); /*NOTREACHED*/ } #endif /* * Everything is OK. */ start_daemon(); snprintf(logname, sizeof(logname), "faithd %s", service); snprintf(procname, sizeof(procname), "accepting port %s", service); openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON); syslog(LOG_INFO, "starting faith daemon for %s port", service); play_service(s_wld); /*NOTREACHED*/ exit(1); /*pacify gcc*/ } static void play_service(int s_wld) { struct sockaddr_storage srcaddr; int len; int s_src; pid_t child_pid; fd_set rfds; int error; int maxfd; /* * Wait, accept, fork, faith.... */ again: setproctitle(procname); FD_ZERO(&rfds); FD_SET(s_wld, &rfds); maxfd = s_wld; #ifdef USE_ROUTE if (sockfd) { FD_SET(sockfd, &rfds); maxfd = (maxfd < sockfd) ? sockfd : maxfd; } #endif error = select(maxfd + 1, &rfds, NULL, NULL, NULL); if (error < 0) { if (errno == EINTR) goto again; exit_failure("select: %s", ERRSTR); /*NOTREACHED*/ } #ifdef USE_ROUTE if (FD_ISSET(sockfd, &rfds)) { update_myaddrs(); } #endif if (FD_ISSET(s_wld, &rfds)) { len = sizeof(srcaddr); s_src = accept(s_wld, (struct sockaddr *)&srcaddr, &len); if (s_src == -1) exit_failure("socket: %s", ERRSTR); child_pid = fork(); if (child_pid == 0) { /* child process */ close(s_wld); closelog(); openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON); play_child(s_src, (struct sockaddr *)&srcaddr); exit_failure("should never reach here"); } else { /* parent process */ close(s_src); if (child_pid == -1) syslog(LOG_ERR, "can't fork"); } } goto again; } static void play_child(int s_src, struct sockaddr *srcaddr) { struct sockaddr_storage dstaddr6; struct sockaddr_storage dstaddr4; char src[MAXHOSTNAMELEN]; char dst6[MAXHOSTNAMELEN]; char dst4[MAXHOSTNAMELEN]; int len = sizeof(dstaddr6); int s_dst, error, hport, nresvport, on = 1; struct timeval tv; struct sockaddr *sa4; tv.tv_sec = 1; tv.tv_usec = 0; getnameinfo(srcaddr, srcaddr->sa_len, src, sizeof(src), NULL, 0, NI_NUMERICHOST); syslog(LOG_INFO, "accepted a client from %s", src); error = getsockname(s_src, (struct sockaddr *)&dstaddr6, &len); if (error == -1) exit_failure("getsockname: %s", ERRSTR); getnameinfo((struct sockaddr *)&dstaddr6, len, dst6, sizeof(dst6), NULL, 0, NI_NUMERICHOST); syslog(LOG_INFO, "the client is connecting to %s", dst6); if (!faith_prefix((struct sockaddr *)&dstaddr6)) { if (serverpath) { /* * Local service */ syslog(LOG_INFO, "executing local %s", serverpath); dup2(s_src, 0); close(s_src); dup2(0, 1); dup2(0, 2); execv(serverpath, serverarg); syslog(LOG_ERR, "execv %s: %s", serverpath, ERRSTR); _exit(EXIT_FAILURE); } else { close(s_src); exit_success("no local service for %s", service); } } /* * Act as a translator */ switch (((struct sockaddr *)&dstaddr6)->sa_family) { case AF_INET6: if (!map6to4((struct sockaddr_in6 *)&dstaddr6, (struct sockaddr_in *)&dstaddr4)) { close(s_src); exit_error("map6to4 failed"); } syslog(LOG_INFO, "translating from v6 to v4"); break; #ifdef FAITH4 case AF_INET: if (!map4to6((struct sockaddr_in *)&dstaddr6, (struct sockaddr_in6 *)&dstaddr4)) { close(s_src); exit_error("map4to6 failed"); } syslog(LOG_INFO, "translating from v4 to v6"); break; #endif default: close(s_src); exit_error("family not supported"); /*NOTREACHED*/ } sa4 = (struct sockaddr *)&dstaddr4; getnameinfo(sa4, sa4->sa_len, dst4, sizeof(dst4), NULL, 0, NI_NUMERICHOST); syslog(LOG_INFO, "the translator is connecting to %s", dst4); setproctitle("port %s, %s -> %s", service, src, dst4); if (sa4->sa_family == AF_INET6) hport = ntohs(((struct sockaddr_in6 *)&dstaddr4)->sin6_port); else /* AF_INET */ hport = ntohs(((struct sockaddr_in *)&dstaddr4)->sin_port); switch (hport) { case RLOGIN_PORT: case RSH_PORT: s_dst = rresvport_af(&nresvport, sa4->sa_family); break; default: if (pflag) s_dst = rresvport_af(&nresvport, sa4->sa_family); else s_dst = socket(sa4->sa_family, SOCK_STREAM, 0); break; } if (s_dst == -1) exit_failure("socket: %s", ERRSTR); error = setsockopt(s_dst, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)); if (error == -1) exit_error("setsockopt(SO_OOBINLINE): %s", ERRSTR); error = setsockopt(s_src, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)); if (error == -1) exit_error("setsockopt(SO_SNDTIMEO): %s", ERRSTR); error = setsockopt(s_dst, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)); if (error == -1) exit_error("setsockopt(SO_SNDTIMEO): %s", ERRSTR); error = connect(s_dst, sa4, sa4->sa_len); if (error == -1) exit_failure("connect: %s", ERRSTR); switch (hport) { case FTP_PORT: ftp_relay(s_src, s_dst); break; case RSH_PORT: rsh_relay(s_src, s_dst); break; default: tcp_relay(s_src, s_dst, service); break; } /* NOTREACHED */ } /* 0: non faith, 1: faith */ static int faith_prefix(struct sockaddr *dst) { #ifndef USE_ROUTE int mib[4], size; struct in6_addr faith_prefix; struct sockaddr_in6 *dst6 = (struct sockaddr_in *)dst; if (dst->sa_family != AF_INET6) return 0; mib[0] = CTL_NET; mib[1] = PF_INET6; mib[2] = IPPROTO_IPV6; mib[3] = IPV6CTL_FAITH_PREFIX; size = sizeof(struct in6_addr); if (sysctl(mib, 4, &faith_prefix, &size, NULL, 0) < 0) exit_error("sysctl: %s", ERRSTR); if (memcmp(dst, &faith_prefix, sizeof(struct in6_addr) - sizeof(struct in_addr) == 0) { return 1; } return 0; #else struct myaddrs *p; struct sockaddr_in6 *sin6; struct sockaddr_in *sin4; struct sockaddr_in6 *dst6; struct sockaddr_in *dst4; struct sockaddr_in dstmap; dst6 = (struct sockaddr_in6 *)dst; if (dst->sa_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&dst6->sin6_addr)) { /* ugly... */ memset(&dstmap, 0, sizeof(dstmap)); dstmap.sin_family = AF_INET; dstmap.sin_len = sizeof(dstmap); memcpy(&dstmap.sin_addr, &dst6->sin6_addr.s6_addr[12], sizeof(dstmap.sin_addr)); dst = (struct sockaddr *)&dstmap; } dst6 = (struct sockaddr_in6 *)dst; dst4 = (struct sockaddr_in *)dst; for (p = myaddrs; p; p = p->next) { sin6 = (struct sockaddr_in6 *)p->addr; sin4 = (struct sockaddr_in *)p->addr; if (p->addr->sa_len != dst->sa_len || p->addr->sa_family != dst->sa_family) continue; switch (dst->sa_family) { case AF_INET6: if (sin6->sin6_scope_id == dst6->sin6_scope_id && IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &dst6->sin6_addr)) return 0; break; case AF_INET: if (sin4->sin_addr.s_addr == dst4->sin_addr.s_addr) return 0; break; } } return 1; #endif } /* 0: non faith, 1: faith */ static int map6to4(struct sockaddr_in6 *dst6, struct sockaddr_in *dst4) { memset(dst4, 0, sizeof(*dst4)); dst4->sin_len = sizeof(*dst4); dst4->sin_family = AF_INET; dst4->sin_port = dst6->sin6_port; memcpy(&dst4->sin_addr, &dst6->sin6_addr.s6_addr[12], sizeof(dst4->sin_addr)); if (dst4->sin_addr.s_addr == INADDR_ANY || dst4->sin_addr.s_addr == INADDR_BROADCAST || IN_MULTICAST(dst4->sin_addr.s_addr)) return 0; return 1; } #ifdef FAITH4 /* 0: non faith, 1: faith */ static int map4to6(struct sockaddr_in *dst4, struct sockaddr_in6 *dst6) { char host[NI_MAXHOST]; char serv[NI_MAXSERV]; struct addrinfo hints, *res; int ai_errno; if (getnameinfo((struct sockaddr *)dst4, dst4->sin_len, host, sizeof(host), serv, sizeof(serv), NI_NAMEREQD|NI_NUMERICSERV) != 0) return 0; memset(&hints, 0, sizeof(hints)); hints.ai_flags = 0; hints.ai_family = AF_INET6; hints.ai_socktype = SOCK_STREAM; hints.ai_protocol = 0; if ((ai_errno = getaddrinfo(host, serv, &hints, &res)) != 0) { syslog(LOG_INFO, "%s %s: %s", host, serv, gai_strerror(ai_errno)); if (ai_errno == EAI_SYSTEM) syslog(LOG_INFO, "%s %s: %s", host, serv, strerror(errno)); return 0; } memcpy(dst6, res->ai_addr, res->ai_addrlen); freeaddrinfo(res); return 1; } #endif /* FAITH4 */ static void sig_child(int sig) { int status; pid_t pid; pid = wait3(&status, WNOHANG, (struct rusage *)0); if (pid && status) syslog(LOG_WARNING, "child %d exit status 0x%x", pid, status); } void sig_terminate(int sig) { syslog(LOG_INFO, "terminating faith daemon"); exit(EXIT_SUCCESS); } static void start_daemon(void) { if (daemon(0, 0) == -1) exit_error("daemon: %s", ERRSTR); if (signal(SIGCHLD, sig_child) == SIG_ERR) exit_failure("signal CHLD: %s", ERRSTR); if (signal(SIGTERM, sig_terminate) == SIG_ERR) exit_failure("signal TERM: %s", ERRSTR); } void exit_error(const char *fmt, ...) { va_list ap; char buf[BUFSIZ]; va_start(ap, fmt); vsnprintf(buf, sizeof(buf), fmt, ap); va_end(ap); fprintf(stderr, "%s\n", buf); exit(EXIT_FAILURE); } void exit_failure(const char *fmt, ...) { va_list ap; char buf[BUFSIZ]; va_start(ap, fmt); vsnprintf(buf, sizeof(buf), fmt, ap); va_end(ap); syslog(LOG_ERR, buf); exit(EXIT_FAILURE); } void exit_success(const char *fmt, ...) { va_list ap; char buf[BUFSIZ]; va_start(ap, fmt); vsnprintf(buf, sizeof(buf), fmt, ap); va_end(ap); syslog(LOG_INFO, buf); exit(EXIT_SUCCESS); } #ifdef USE_ROUTE static unsigned int if_maxindex() { struct if_nameindex *p, *p0; unsigned int max = 0; p0 = if_nameindex(); for (p = p0; p && p->if_index && p->if_name; p++) { if (max < p->if_index) max = p->if_index; } if_freenameindex(p0); return max; } static void grab_myaddrs() { int s; unsigned int maxif; struct ifreq *iflist; struct ifconf ifconf; struct ifreq *ifr, *ifr_end; struct myaddrs *p; struct sockaddr_in6 *sin6; maxif = if_maxindex() + 1; iflist = (struct ifreq *)malloc(maxif * BUFSIZ); /* XXX */ if (!iflist) { exit_failure("not enough core"); /*NOTREACHED*/ } if ((s = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { exit_failure("socket(SOCK_DGRAM)"); /*NOTREACHED*/ } memset(&ifconf, 0, sizeof(ifconf)); ifconf.ifc_req = iflist; ifconf.ifc_len = maxif * BUFSIZ; /* XXX */ if (ioctl(s, SIOCGIFCONF, &ifconf) < 0) { exit_failure("ioctl(SIOCGIFCONF)"); /*NOTREACHED*/ } close(s); /* Look for this interface in the list */ ifr_end = (struct ifreq *) (ifconf.ifc_buf + ifconf.ifc_len); for (ifr = ifconf.ifc_req; ifr < ifr_end; ifr = (struct ifreq *) ((char *) &ifr->ifr_addr + ifr->ifr_addr.sa_len)) { switch (ifr->ifr_addr.sa_family) { case AF_INET: case AF_INET6: p = (struct myaddrs *)malloc(sizeof(struct myaddrs) + ifr->ifr_addr.sa_len); if (!p) { exit_failure("not enough core"); /*NOTREACHED*/ } memcpy(p + 1, &ifr->ifr_addr, ifr->ifr_addr.sa_len); p->next = myaddrs; p->addr = (struct sockaddr *)(p + 1); #ifdef __KAME__ if (ifr->ifr_addr.sa_family == AF_INET6) { sin6 = (struct sockaddr_in6 *)p->addr; if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) || IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr)) { sin6->sin6_scope_id = ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]); sin6->sin6_addr.s6_addr[2] = 0; sin6->sin6_addr.s6_addr[3] = 0; } } #endif myaddrs = p; if (dflag) { char hbuf[NI_MAXHOST]; getnameinfo(p->addr, p->addr->sa_len, hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST); syslog(LOG_INFO, "my interface: %s %s", hbuf, ifr->ifr_name); } break; default: break; } } free(iflist); } static void free_myaddrs() { struct myaddrs *p, *q; p = myaddrs; while (p) { q = p->next; free(p); p = q; } myaddrs = NULL; } static void update_myaddrs() { char msg[BUFSIZ]; int len; struct rt_msghdr *rtm; len = read(sockfd, msg, sizeof(msg)); if (len < 0) { syslog(LOG_ERR, "read(PF_ROUTE) failed"); return; } rtm = (struct rt_msghdr *)msg; if (len < 4 || len < rtm->rtm_msglen) { syslog(LOG_ERR, "read(PF_ROUTE) short read"); return; } if (rtm->rtm_version != RTM_VERSION) { syslog(LOG_ERR, "routing socket version mismatch"); close(sockfd); sockfd = 0; return; } switch (rtm->rtm_type) { case RTM_NEWADDR: case RTM_DELADDR: case RTM_IFINFO: break; default: return; } /* XXX more filters here? */ syslog(LOG_INFO, "update interface address list"); free_myaddrs(); grab_myaddrs(); } #endif /*USE_ROUTE*/ static void usage() { fprintf(stderr, "usage: %s [-dp] [service [serverpath [serverargs]]]\n", faithdname); exit(0); }