/* $OpenBSD: engine.c,v 1.21 2022/10/15 13:26:15 florian Exp $ */ /* * Copyright (c) 2018 Florian Obser * Copyright (c) 2004, 2005 Claudio Jeker * Copyright (c) 2004 Esben Norby * Copyright (c) 2003, 2004 Henning Brauer * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "log.h" #include "rad.h" #include "engine.h" struct engine_iface { TAILQ_ENTRY(engine_iface) entry; struct event timer; struct timespec last_ra; uint32_t if_index; int ras_delayed; }; TAILQ_HEAD(, engine_iface) engine_interfaces; __dead void engine_shutdown(void); void engine_sig_handler(int sig, short, void *); void engine_dispatch_frontend(int, short, void *); void engine_dispatch_main(int, short, void *); void parse_ra_rs(struct imsg_ra_rs *); void parse_ra(struct imsg_ra_rs *); void parse_rs(struct imsg_ra_rs *); void update_iface(uint32_t); void remove_iface(uint32_t); struct engine_iface *find_engine_iface_by_id(uint32_t); void iface_timeout(int, short, void *); struct rad_conf *engine_conf; static struct imsgev *iev_frontend; static struct imsgev *iev_main; struct sockaddr_in6 all_nodes; void engine_sig_handler(int sig, short event, void *arg) { /* * Normal signal handler rules don't apply because libevent * decouples for us. */ switch (sig) { case SIGINT: case SIGTERM: engine_shutdown(); default: fatalx("unexpected signal"); } } void engine(int debug, int verbose) { struct event ev_sigint, ev_sigterm; struct passwd *pw; engine_conf = config_new_empty(); log_init(debug, LOG_DAEMON); log_setverbose(verbose); if ((pw = getpwnam(RAD_USER)) == NULL) fatal("getpwnam"); if (chroot(pw->pw_dir) == -1) fatal("chroot"); if (chdir("/") == -1) fatal("chdir(\"/\")"); setproctitle("%s", "engine"); log_procinit("engine"); if (setgroups(1, &pw->pw_gid) || setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) || setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) fatal("can't drop privileges"); if (pledge("stdio recvfd", NULL) == -1) fatal("pledge"); event_init(); /* Setup signal handler(s). */ signal_set(&ev_sigint, SIGINT, engine_sig_handler, NULL); signal_set(&ev_sigterm, SIGTERM, engine_sig_handler, NULL); signal_add(&ev_sigint, NULL); signal_add(&ev_sigterm, NULL); signal(SIGPIPE, SIG_IGN); signal(SIGHUP, SIG_IGN); /* Setup pipe and event handler to the main process. */ if ((iev_main = malloc(sizeof(struct imsgev))) == NULL) fatal(NULL); imsg_init(&iev_main->ibuf, 3); iev_main->handler = engine_dispatch_main; /* Setup event handlers. */ iev_main->events = EV_READ; event_set(&iev_main->ev, iev_main->ibuf.fd, iev_main->events, iev_main->handler, iev_main); event_add(&iev_main->ev, NULL); all_nodes.sin6_len = sizeof(all_nodes); all_nodes.sin6_family = AF_INET6; if (inet_pton(AF_INET6, "ff02::1", &all_nodes.sin6_addr) != 1) fatal("inet_pton"); TAILQ_INIT(&engine_interfaces); event_dispatch(); engine_shutdown(); } __dead void engine_shutdown(void) { /* Close pipes. */ msgbuf_clear(&iev_frontend->ibuf.w); close(iev_frontend->ibuf.fd); msgbuf_clear(&iev_main->ibuf.w); close(iev_main->ibuf.fd); config_clear(engine_conf); free(iev_frontend); free(iev_main); log_info("engine exiting"); exit(0); } int engine_imsg_compose_frontend(int type, pid_t pid, void *data, uint16_t datalen) { return (imsg_compose_event(iev_frontend, type, 0, pid, -1, data, datalen)); } void engine_dispatch_frontend(int fd, short event, void *bula) { struct imsgev *iev = bula; struct imsgbuf *ibuf; struct imsg imsg; struct imsg_ra_rs ra_rs; ssize_t n; uint32_t if_index; int shut = 0, verbose; ibuf = &iev->ibuf; if (event & EV_READ) { if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) fatal("imsg_read error"); if (n == 0) /* Connection closed. */ shut = 1; } if (event & EV_WRITE) { if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) fatal("msgbuf_write"); if (n == 0) /* Connection closed. */ shut = 1; } for (;;) { if ((n = imsg_get(ibuf, &imsg)) == -1) fatal("%s: imsg_get error", __func__); if (n == 0) /* No more messages. */ break; switch (imsg.hdr.type) { case IMSG_RA_RS: if (IMSG_DATA_SIZE(imsg) != sizeof(ra_rs)) fatalx("%s: IMSG_RA_RS wrong length: %lu", __func__, IMSG_DATA_SIZE(imsg)); memcpy(&ra_rs, imsg.data, sizeof(ra_rs)); parse_ra_rs(&ra_rs); break; case IMSG_UPDATE_IF: if (IMSG_DATA_SIZE(imsg) != sizeof(if_index)) fatalx("%s: IMSG_UPDATE_IF wrong length: %lu", __func__, IMSG_DATA_SIZE(imsg)); memcpy(&if_index, imsg.data, sizeof(if_index)); update_iface(if_index); break; case IMSG_REMOVE_IF: if (IMSG_DATA_SIZE(imsg) != sizeof(if_index)) fatalx("%s: IMSG_REMOVE_IF wrong length: %lu", __func__, IMSG_DATA_SIZE(imsg)); memcpy(&if_index, imsg.data, sizeof(if_index)); remove_iface(if_index); break; case IMSG_CTL_LOG_VERBOSE: if (IMSG_DATA_SIZE(imsg) != sizeof(verbose)) fatalx("%s: IMSG_CTL_LOG_VERBOSE wrong length: " "%lu", __func__, IMSG_DATA_SIZE(imsg)); memcpy(&verbose, imsg.data, sizeof(verbose)); log_setverbose(verbose); break; default: log_debug("%s: unexpected imsg %d", __func__, imsg.hdr.type); break; } imsg_free(&imsg); } if (!shut) imsg_event_add(iev); else { /* This pipe is dead. Remove its event handler. */ event_del(&iev->ev); event_loopexit(NULL); } } void engine_dispatch_main(int fd, short event, void *bula) { static struct rad_conf *nconf; static struct ra_iface_conf *ra_iface_conf; static struct ra_options_conf *ra_options; struct imsg imsg; struct imsgev *iev = bula; struct imsgbuf *ibuf; struct ra_prefix_conf *ra_prefix_conf; struct ra_rdnss_conf *ra_rdnss_conf; struct ra_dnssl_conf *ra_dnssl_conf; struct ra_pref64_conf *pref64; ssize_t n; int shut = 0; ibuf = &iev->ibuf; if (event & EV_READ) { if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) fatal("imsg_read error"); if (n == 0) /* Connection closed. */ shut = 1; } if (event & EV_WRITE) { if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) fatal("msgbuf_write"); if (n == 0) /* Connection closed. */ shut = 1; } for (;;) { if ((n = imsg_get(ibuf, &imsg)) == -1) fatal("%s: imsg_get error", __func__); if (n == 0) /* No more messages. */ break; switch (imsg.hdr.type) { case IMSG_SOCKET_IPC: /* * Setup pipe and event handler to the frontend * process. */ if (iev_frontend) fatalx("%s: received unexpected imsg fd " "to engine", __func__); if ((fd = imsg.fd) == -1) fatalx("%s: expected to receive imsg fd to " "engine but didn't receive any", __func__); iev_frontend = malloc(sizeof(struct imsgev)); if (iev_frontend == NULL) fatal(NULL); imsg_init(&iev_frontend->ibuf, fd); iev_frontend->handler = engine_dispatch_frontend; iev_frontend->events = EV_READ; event_set(&iev_frontend->ev, iev_frontend->ibuf.fd, iev_frontend->events, iev_frontend->handler, iev_frontend); event_add(&iev_frontend->ev, NULL); break; case IMSG_RECONF_CONF: if (nconf != NULL) fatalx("%s: IMSG_RECONF_CONF already in " "progress", __func__); if (IMSG_DATA_SIZE(imsg) != sizeof(struct rad_conf)) fatalx("%s: IMSG_RECONF_CONF wrong length: %lu", __func__, IMSG_DATA_SIZE(imsg)); if ((nconf = malloc(sizeof(struct rad_conf))) == NULL) fatal(NULL); memcpy(nconf, imsg.data, sizeof(struct rad_conf)); SIMPLEQ_INIT(&nconf->ra_iface_list); SIMPLEQ_INIT(&nconf->ra_options.ra_rdnss_list); SIMPLEQ_INIT(&nconf->ra_options.ra_dnssl_list); SIMPLEQ_INIT(&nconf->ra_options.ra_pref64_list); ra_options = &nconf->ra_options; break; case IMSG_RECONF_RA_IFACE: if (IMSG_DATA_SIZE(imsg) != sizeof(struct ra_iface_conf)) fatalx("%s: IMSG_RECONF_RA_IFACE wrong length: " "%lu", __func__, IMSG_DATA_SIZE(imsg)); if ((ra_iface_conf = malloc(sizeof(struct ra_iface_conf))) == NULL) fatal(NULL); memcpy(ra_iface_conf, imsg.data, sizeof(struct ra_iface_conf)); ra_iface_conf->autoprefix = NULL; SIMPLEQ_INIT(&ra_iface_conf->ra_prefix_list); SIMPLEQ_INIT(&ra_iface_conf->ra_options.ra_rdnss_list); SIMPLEQ_INIT(&ra_iface_conf->ra_options.ra_dnssl_list); SIMPLEQ_INIT(&ra_iface_conf->ra_options.ra_pref64_list); SIMPLEQ_INSERT_TAIL(&nconf->ra_iface_list, ra_iface_conf, entry); ra_options = &ra_iface_conf->ra_options; break; case IMSG_RECONF_RA_AUTOPREFIX: if (IMSG_DATA_SIZE(imsg) != sizeof(struct ra_prefix_conf)) fatalx("%s: IMSG_RECONF_RA_AUTOPREFIX wrong " "length: %lu", __func__, IMSG_DATA_SIZE(imsg)); if ((ra_iface_conf->autoprefix = malloc(sizeof(struct ra_prefix_conf))) == NULL) fatal(NULL); memcpy(ra_iface_conf->autoprefix, imsg.data, sizeof(struct ra_prefix_conf)); break; case IMSG_RECONF_RA_PREFIX: if (IMSG_DATA_SIZE(imsg) != sizeof(struct ra_prefix_conf)) fatalx("%s: IMSG_RECONF_RA_PREFIX wrong " "length: %lu", __func__, IMSG_DATA_SIZE(imsg)); if ((ra_prefix_conf = malloc(sizeof(struct ra_prefix_conf))) == NULL) fatal(NULL); memcpy(ra_prefix_conf, imsg.data, sizeof(struct ra_prefix_conf)); SIMPLEQ_INSERT_TAIL(&ra_iface_conf->ra_prefix_list, ra_prefix_conf, entry); break; case IMSG_RECONF_RA_RDNSS: if(IMSG_DATA_SIZE(imsg) != sizeof(struct ra_rdnss_conf)) fatalx("%s: IMSG_RECONF_RA_RDNSS wrong length: " "%lu", __func__, IMSG_DATA_SIZE(imsg)); if ((ra_rdnss_conf = malloc(sizeof(struct ra_rdnss_conf))) == NULL) fatal(NULL); memcpy(ra_rdnss_conf, imsg.data, sizeof(struct ra_rdnss_conf)); SIMPLEQ_INSERT_TAIL(&ra_options->ra_rdnss_list, ra_rdnss_conf, entry); break; case IMSG_RECONF_RA_DNSSL: if(IMSG_DATA_SIZE(imsg) != sizeof(struct ra_dnssl_conf)) fatalx("%s: IMSG_RECONF_RA_DNSSL wrong length: " "%lu", __func__, IMSG_DATA_SIZE(imsg)); if ((ra_dnssl_conf = malloc(sizeof(struct ra_dnssl_conf))) == NULL) fatal(NULL); memcpy(ra_dnssl_conf, imsg.data, sizeof(struct ra_dnssl_conf)); SIMPLEQ_INSERT_TAIL(&ra_options->ra_dnssl_list, ra_dnssl_conf, entry); break; case IMSG_RECONF_RA_PREF64: if(IMSG_DATA_SIZE(imsg) != sizeof(struct ra_pref64_conf)) fatalx("%s: IMSG_RECONF_RA_PREF64 wrong length: " "%lu", __func__, IMSG_DATA_SIZE(imsg)); if ((pref64 = malloc(sizeof(struct ra_pref64_conf))) == NULL) fatal(NULL); memcpy(pref64, imsg.data, sizeof(struct ra_pref64_conf)); SIMPLEQ_INSERT_TAIL(&ra_options->ra_pref64_list, pref64, entry); break; case IMSG_RECONF_END: if (nconf == NULL) fatalx("%s: IMSG_RECONF_END without " "IMSG_RECONF_CONF", __func__); merge_config(engine_conf, nconf); nconf = NULL; break; default: log_debug("%s: unexpected imsg %d", __func__, imsg.hdr.type); break; } imsg_free(&imsg); } if (!shut) imsg_event_add(iev); else { /* This pipe is dead. Remove its event handler. */ event_del(&iev->ev); event_loopexit(NULL); } } void parse_ra_rs(struct imsg_ra_rs *ra_rs) { char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; struct icmp6_hdr *hdr; hdr = (struct icmp6_hdr *) ra_rs->packet; switch (hdr->icmp6_type) { case ND_ROUTER_ADVERT: parse_ra(ra_rs); break; case ND_ROUTER_SOLICIT: parse_rs(ra_rs); break; default: log_warnx("unexpected icmp6_type: %d from %s on %s", hdr->icmp6_type, inet_ntop(AF_INET6, &ra_rs->from.sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(ra_rs->if_index, ifnamebuf)); break; } } void parse_ra(struct imsg_ra_rs *ra) { char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; log_debug("got RA from %s on %s", inet_ntop(AF_INET6, &ra->from.sin6_addr, ntopbuf, INET6_ADDRSTRLEN), if_indextoname(ra->if_index, ifnamebuf)); /* XXX not yet */ } void parse_rs(struct imsg_ra_rs *rs) { struct nd_router_solicit *nd_rs; struct engine_iface *engine_iface; ssize_t len; int unicast_ra = 0; const char *hbuf; char ifnamebuf[IFNAMSIZ]; uint8_t *p; hbuf = sin6_to_str(&rs->from); log_debug("got RS from %s on %s", hbuf, if_indextoname(rs->if_index, ifnamebuf)); if ((engine_iface = find_engine_iface_by_id(rs->if_index)) == NULL) return; len = rs->len; if (!(IN6_IS_ADDR_LINKLOCAL(&rs->from.sin6_addr) || IN6_IS_ADDR_UNSPECIFIED(&rs->from.sin6_addr))) { log_warnx("RA from invalid address %s on %s", hbuf, if_indextoname(rs->if_index, ifnamebuf)); return; } if ((size_t)len < sizeof(struct nd_router_solicit)) { log_warnx("received too short message (%ld) from %s", len, hbuf); return; } p = rs->packet; nd_rs = (struct nd_router_solicit *)p; len -= sizeof(struct nd_router_solicit); p += sizeof(struct nd_router_solicit); if (nd_rs->nd_rs_code != 0) { log_warnx("invalid ICMPv6 code (%d) from %s", nd_rs->nd_rs_code, hbuf); return; } while ((size_t)len >= sizeof(struct nd_opt_hdr)) { struct nd_opt_hdr *nd_opt_hdr = (struct nd_opt_hdr *)p; len -= sizeof(struct nd_opt_hdr); p += sizeof(struct nd_opt_hdr); if (nd_opt_hdr->nd_opt_len * 8 - 2 > len) { log_warnx("invalid option len: %u > %ld", nd_opt_hdr->nd_opt_len, len); return; } switch (nd_opt_hdr->nd_opt_type) { case ND_OPT_SOURCE_LINKADDR: log_debug("got RS with source linkaddr option"); unicast_ra = 1; break; default: log_debug("\t\tUNKNOWN: %d", nd_opt_hdr->nd_opt_type); break; } len -= nd_opt_hdr->nd_opt_len * 8 - 2; p += nd_opt_hdr->nd_opt_len * 8 - 2; } if (unicast_ra) { struct imsg_send_ra send_ra; send_ra.if_index = rs->if_index; memcpy(&send_ra.to, &rs->from, sizeof(send_ra.to)); engine_imsg_compose_frontend(IMSG_SEND_RA, 0, &send_ra, sizeof(send_ra)); } else { struct timespec now, diff, ra_delay = {MIN_DELAY_BETWEEN_RAS, 0}; struct timeval tv = {0, 0}; /* a multicast RA is already scheduled within the next 3 seconds */ if (engine_iface->ras_delayed) return; engine_iface->ras_delayed = 1; clock_gettime(CLOCK_MONOTONIC, &now); timespecsub(&now, &engine_iface->last_ra, &diff); if (timespeccmp(&diff, &ra_delay, <)) { timespecsub(&ra_delay, &diff, &ra_delay); TIMESPEC_TO_TIMEVAL(&tv, &ra_delay); } tv.tv_usec = arc4random_uniform(MAX_RA_DELAY_TIME * 1000); evtimer_add(&engine_iface->timer, &tv); } } struct engine_iface* find_engine_iface_by_id(uint32_t if_index) { struct engine_iface *engine_iface; TAILQ_FOREACH(engine_iface, &engine_interfaces, entry) { if (engine_iface->if_index == if_index) return engine_iface; } return (NULL); } void update_iface(uint32_t if_index) { struct engine_iface *engine_iface; struct timeval tv; if ((engine_iface = find_engine_iface_by_id(if_index)) == NULL) { engine_iface = calloc(1, sizeof(*engine_iface)); engine_iface->if_index = if_index; evtimer_set(&engine_iface->timer, iface_timeout, engine_iface); TAILQ_INSERT_TAIL(&engine_interfaces, engine_iface, entry); } tv.tv_sec = 0; tv.tv_usec = arc4random_uniform(1000000); evtimer_add(&engine_iface->timer, &tv); } void remove_iface(uint32_t if_index) { struct engine_iface *engine_iface; struct imsg_send_ra send_ra; char if_name[IF_NAMESIZE]; if ((engine_iface = find_engine_iface_by_id(if_index)) == NULL) { /* we don't know this interface, frontend can delete it */ engine_imsg_compose_frontend(IMSG_REMOVE_IF, 0, &if_index, sizeof(if_index)); return; } send_ra.if_index = engine_iface->if_index; memcpy(&send_ra.to, &all_nodes, sizeof(send_ra.to)); TAILQ_REMOVE(&engine_interfaces, engine_iface, entry); evtimer_del(&engine_iface->timer); if (if_indextoname(if_index, if_name) != NULL) engine_imsg_compose_frontend(IMSG_SEND_RA, 0, &send_ra, sizeof(send_ra)); engine_imsg_compose_frontend(IMSG_REMOVE_IF, 0, &engine_iface->if_index, sizeof(engine_iface->if_index)); free(engine_iface); } void iface_timeout(int fd, short events, void *arg) { struct engine_iface *engine_iface = (struct engine_iface *)arg; struct imsg_send_ra send_ra; struct timeval tv; tv.tv_sec = MIN_RTR_ADV_INTERVAL + arc4random_uniform(MAX_RTR_ADV_INTERVAL - MIN_RTR_ADV_INTERVAL); tv.tv_usec = arc4random_uniform(1000000); log_debug("%s new timeout in %lld", __func__, tv.tv_sec); evtimer_add(&engine_iface->timer, &tv); send_ra.if_index = engine_iface->if_index; memcpy(&send_ra.to, &all_nodes, sizeof(send_ra.to)); engine_imsg_compose_frontend(IMSG_SEND_RA, 0, &send_ra, sizeof(send_ra)); clock_gettime(CLOCK_MONOTONIC, &engine_iface->last_ra); engine_iface->ras_delayed = 0; }