1 /* $OpenBSD: dvmrpe.c,v 1.20 2021/01/19 11:46:10 claudio Exp $ */ 2 3 /* 4 * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org> 5 * Copyright (c) 2004, 2005, 2006 Esben Norby <norby@openbsd.org> 6 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org> 7 * 8 * Permission to use, copy, modify, and distribute this software for any 9 * purpose with or without fee is hereby granted, provided that the above 10 * copyright notice and this permission notice appear in all copies. 11 * 12 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 18 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 19 */ 20 21 #include <sys/types.h> 22 #include <sys/socket.h> 23 #include <sys/queue.h> 24 #include <netinet/in.h> 25 #include <arpa/inet.h> 26 #include <net/if_types.h> 27 #include <stdlib.h> 28 #include <signal.h> 29 #include <string.h> 30 #include <fcntl.h> 31 #include <pwd.h> 32 #include <unistd.h> 33 #include <event.h> 34 #include <err.h> 35 #include <errno.h> 36 #include <stdio.h> 37 38 #include "igmp.h" 39 #include "dvmrp.h" 40 #include "dvmrpd.h" 41 #include "dvmrpe.h" 42 #include "control.h" 43 #include "log.h" 44 45 void dvmrpe_sig_handler(int, short, void *); 46 __dead void dvmrpe_shutdown(void); 47 48 volatile sig_atomic_t dvmrpe_quit = 0; 49 struct dvmrpd_conf *deconf = NULL; 50 struct imsgev *iev_main; 51 struct imsgev *iev_rde; 52 struct ctl_conn *ctl_conn; 53 54 void 55 dvmrpe_sig_handler(int sig, short event, void *bula) 56 { 57 switch (sig) { 58 case SIGINT: 59 case SIGTERM: 60 dvmrpe_shutdown(); 61 /* NOTREACHED */ 62 default: 63 fatalx("unexpected signal"); 64 } 65 } 66 67 /* dvmrp engine */ 68 pid_t 69 dvmrpe(struct dvmrpd_conf *xconf, int pipe_parent2dvmrpe[2], 70 int pipe_dvmrpe2rde[2], int pipe_parent2rde[2]) 71 { 72 struct iface *iface = NULL; 73 struct passwd *pw; 74 struct event ev_sigint, ev_sigterm; 75 pid_t pid; 76 77 switch (pid = fork()) { 78 case -1: 79 fatal("cannot fork"); 80 case 0: 81 break; 82 default: 83 84 return (pid); 85 } 86 87 /* create the raw ip socket */ 88 if ((xconf->dvmrp_socket = socket(AF_INET, 89 SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK, 90 IPPROTO_IGMP)) == -1) 91 fatal("error creating raw socket"); 92 93 /* create dvmrpd control socket outside chroot */ 94 if (control_init() == -1) 95 fatalx("control socket setup failed"); 96 97 /* set some defaults */ 98 if (if_set_mcast_ttl(xconf->dvmrp_socket, 99 IP_DEFAULT_MULTICAST_TTL) == -1) 100 fatal("if_set_mcast_ttl"); 101 102 if (if_set_mcast_loop(xconf->dvmrp_socket) == -1) 103 fatal("if_set_mcast_loop"); 104 105 if (if_set_tos(xconf->dvmrp_socket, IPTOS_PREC_INTERNETCONTROL) == -1) 106 fatal("if_set_tos"); 107 108 if_set_recvbuf(xconf->dvmrp_socket); 109 110 deconf = xconf; 111 112 if ((pw = getpwnam(DVMRPD_USER)) == NULL) 113 fatal("getpwnam"); 114 115 if (chroot(pw->pw_dir) == -1) 116 fatal("chroot"); 117 if (chdir("/") == -1) 118 fatal("chdir(\"/\")"); 119 120 setproctitle("dvmrp engine"); 121 dvmrpd_process = PROC_DVMRP_ENGINE; 122 log_procname = log_procnames[dvmrpd_process]; 123 124 if (setgroups(1, &pw->pw_gid) || 125 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) || 126 setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) 127 fatal("can't drop privileges"); 128 129 event_init(); 130 nbr_init(NBR_HASHSIZE); 131 132 /* setup signal handler */ 133 signal_set(&ev_sigint, SIGINT, dvmrpe_sig_handler, NULL); 134 signal_set(&ev_sigterm, SIGTERM, dvmrpe_sig_handler, NULL); 135 signal_add(&ev_sigint, NULL); 136 signal_add(&ev_sigterm, NULL); 137 signal(SIGPIPE, SIG_IGN); 138 139 /* setup pipes */ 140 close(pipe_parent2dvmrpe[0]); 141 close(pipe_dvmrpe2rde[1]); 142 close(pipe_parent2rde[0]); 143 close(pipe_parent2rde[1]); 144 145 if ((iev_rde = malloc(sizeof(struct imsgev))) == NULL || 146 (iev_main = malloc(sizeof(struct imsgev))) == NULL) 147 fatal(NULL); 148 imsg_init(&iev_rde->ibuf, pipe_dvmrpe2rde[0]); 149 iev_rde->handler = dvmrpe_dispatch_rde; 150 151 imsg_init(&iev_main->ibuf, pipe_parent2dvmrpe[1]); 152 iev_main->handler = dvmrpe_dispatch_main; 153 154 /* setup event handler */ 155 iev_rde->events = EV_READ; 156 event_set(&iev_rde->ev, iev_rde->ibuf.fd, iev_rde->events, 157 iev_rde->handler, iev_rde); 158 event_add(&iev_rde->ev, NULL); 159 160 iev_main->events = EV_READ; 161 event_set(&iev_main->ev, iev_main->ibuf.fd, iev_main->events, 162 iev_main->handler, iev_main); 163 event_add(&iev_main->ev, NULL); 164 165 event_set(&deconf->ev, deconf->dvmrp_socket, EV_READ|EV_PERSIST, 166 recv_packet, deconf); 167 event_add(&deconf->ev, NULL); 168 169 /* listen on dvmrpd control socket */ 170 TAILQ_INIT(&ctl_conns); 171 control_listen(); 172 173 /* start interfaces */ 174 LIST_FOREACH(iface, &deconf->iface_list, entry) { 175 if_init(xconf, iface); 176 if (if_fsm(iface, IF_EVT_UP)) { 177 log_debug("error starting interface %s", iface->name); 178 } 179 } 180 181 evtimer_set(&deconf->report_timer, report_timer, deconf); 182 start_report_timer(); 183 184 event_dispatch(); 185 186 dvmrpe_shutdown(); 187 /* NOTREACHED */ 188 return (0); 189 } 190 191 __dead void 192 dvmrpe_shutdown(void) 193 { 194 struct iface *iface; 195 196 /* close pipes */ 197 msgbuf_write(&iev_rde->ibuf.w); 198 msgbuf_clear(&iev_rde->ibuf.w); 199 close(iev_rde->ibuf.fd); 200 msgbuf_write(&iev_main->ibuf.w); 201 msgbuf_clear(&iev_main->ibuf.w); 202 close(iev_main->ibuf.fd); 203 204 /* stop all interfaces and delete them */ 205 LIST_FOREACH(iface, &deconf->iface_list, entry) { 206 if (if_fsm(iface, IF_EVT_DOWN)) { 207 log_debug("error stopping interface %s", 208 iface->name); 209 } 210 if_del(iface); 211 } 212 213 /* clean up */ 214 free(iev_rde); 215 free(iev_main); 216 217 log_info("dvmrp engine exiting"); 218 _exit(0); 219 } 220 221 int 222 dvmrpe_imsg_compose_parent(int type, pid_t pid, void *data, u_int16_t datalen) 223 { 224 return (imsg_compose_event(iev_main, type, 0, pid, -1, data, datalen)); 225 } 226 227 int 228 dvmrpe_imsg_compose_rde(int type, u_int32_t peerid, pid_t pid, 229 void *data, u_int16_t datalen) 230 { 231 return (imsg_compose_event(iev_rde, type, peerid, pid, 232 -1, data, datalen)); 233 } 234 235 void 236 dvmrpe_dispatch_main(int fd, short event, void *bula) 237 { 238 struct imsg imsg; 239 struct imsgev *iev = bula; 240 struct imsgbuf *ibuf = &iev->ibuf; 241 struct kif *kif; 242 struct iface *iface; 243 ssize_t n; 244 int shut = 0, link_ok; 245 246 if (event & EV_READ) { 247 if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) 248 fatal("imsg_read error"); 249 if (n == 0) /* connection closed */ 250 shut = 1; 251 } 252 if (event & EV_WRITE) { 253 if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) 254 fatal("msgbuf_write"); 255 if (n == 0) /* connection closed */ 256 shut = 1; 257 } 258 259 for (;;) { 260 if ((n = imsg_get(ibuf, &imsg)) == -1) 261 fatal("dvmrpe_dispatch_main: imsg_read error"); 262 if (n == 0) 263 break; 264 265 switch (imsg.hdr.type) { 266 case IMSG_IFINFO: 267 if (imsg.hdr.len - IMSG_HEADER_SIZE != 268 sizeof(struct kif)) 269 fatalx("IFINFO imsg with wrong len"); 270 kif = imsg.data; 271 link_ok = (kif->flags & IFF_UP) && 272 LINK_STATE_IS_UP(kif->link_state); 273 274 LIST_FOREACH(iface, &deconf->iface_list, entry) { 275 if (kif->ifindex == iface->ifindex) { 276 iface->flags = kif->flags; 277 iface->linkstate = kif->link_state; 278 279 if (link_ok) { 280 if_fsm(iface, IF_EVT_UP); 281 log_warnx("interface %s up", 282 iface->name); 283 } else { 284 if_fsm(iface, IF_EVT_DOWN); 285 log_warnx("interface %s down", 286 iface->name); 287 } 288 } 289 } 290 break; 291 default: 292 log_debug("dvmrpe_dispatch_main: error handling " 293 "imsg %d", imsg.hdr.type); 294 break; 295 } 296 imsg_free(&imsg); 297 } 298 if (!shut) 299 imsg_event_add(iev); 300 else { 301 /* this pipe is dead, so remove the event handler */ 302 event_del(&iev->ev); 303 event_loopexit(NULL); 304 } 305 } 306 307 void 308 dvmrpe_dispatch_rde(int fd, short event, void *bula) 309 { 310 struct imsgev *iev = bula; 311 struct imsgbuf *ibuf = &iev->ibuf; 312 struct imsg imsg; 313 struct nbr *nbr; 314 struct prune p; 315 struct iface *iface; 316 struct route_report *rr; 317 ssize_t n; 318 int shut = 0; 319 320 if (event & EV_READ) { 321 if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) 322 fatal("imsg_read error"); 323 if (n == 0) /* connection closed */ 324 shut = 1; 325 } 326 if (event & EV_WRITE) { 327 if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) 328 fatal("msgbuf_write"); 329 if (n == 0) /* connection closed */ 330 shut = 1; 331 } 332 333 for (;;) { 334 if ((n = imsg_get(ibuf, &imsg)) == -1) 335 fatal("dvmrpe_dispatch_rde: imsg_read error"); 336 if (n == 0) 337 break; 338 339 switch (imsg.hdr.type) { 340 case IMSG_CTL_SHOW_RIB: 341 case IMSG_CTL_SHOW_SUM: 342 case IMSG_CTL_SHOW_MFC: 343 case IMSG_CTL_END: 344 control_imsg_relay(&imsg); 345 break; 346 case IMSG_FULL_ROUTE_REPORT: 347 /* add route reports to list */ 348 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(*rr)) 349 fatalx("invalid size of RDE request"); 350 351 if ((rr = calloc(1, sizeof(*rr))) == NULL) 352 fatal("dvmrpe_dispatch_rde"); 353 354 memcpy(rr, imsg.data, sizeof(*rr)); 355 356 /* general update, per interface */ 357 if (imsg.hdr.peerid == 0) { 358 /* add to interface list */ 359 LIST_FOREACH(iface, &deconf->iface_list, 360 entry) { 361 if (!if_nbr_list_empty(iface)) 362 rr_list_add(&iface->rr_list, 363 rr); 364 } 365 break; 366 } 367 368 /* add to neighbor list */ 369 nbr = nbr_find_peerid(imsg.hdr.peerid); 370 rr_list_add(&nbr->rr_list, rr); 371 break; 372 case IMSG_FULL_ROUTE_REPORT_END: 373 /* transmit route report */ 374 if (imsg.hdr.peerid == 0) { 375 /* 376 * send general route report on all 377 * interfaces with neighbors. 378 */ 379 LIST_FOREACH(iface, &deconf->iface_list, 380 entry) { 381 rr_list_send(&iface->rr_list, 382 iface, NULL); 383 } 384 break; 385 } 386 387 nbr = nbr_find_peerid(imsg.hdr.peerid); 388 rr_list_send(&nbr->rr_list, NULL, nbr); 389 break; 390 case IMSG_SEND_PRUNE: 391 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(p)) 392 fatalx("invalid size of RDE request"); 393 394 memcpy(&p, imsg.data, sizeof(p)); 395 396 LIST_FOREACH(iface, &deconf->iface_list, entry) 397 if (p.ifindex == iface->ifindex) 398 break; 399 400 if (iface == NULL) 401 fatalx("invalid interface in mfc"); 402 403 nbr = nbr_find_ip(iface, p.nexthop.s_addr); 404 if (nbr == NULL) 405 fatalx("unknown neighbor to send prune"); 406 407 send_prune(nbr, &p); 408 409 break; 410 case IMSG_FLASH_UPDATE: 411 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(*rr)) 412 fatalx("invalid size of RDE request"); 413 414 if ((rr = calloc(1, sizeof(*rr))) == NULL) 415 fatal("dvmrpe_dispatch_rde"); 416 417 memcpy(rr, imsg.data, sizeof(*rr)); 418 419 LIST_FOREACH(iface, &deconf->iface_list, entry) { 420 if (!if_nbr_list_empty(iface)) { 421 rr_list_add(&iface->rr_list, rr); 422 rr_list_send(&iface->rr_list, iface, 423 NULL); 424 } 425 } 426 break; 427 case IMSG_FLASH_UPDATE_DS: 428 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(*rr)) 429 fatalx("invalid size of RDE request"); 430 431 if ((rr = calloc(1, sizeof(*rr))) == NULL) 432 fatal("dvmrpe_dispatch_rde"); 433 434 memcpy(rr, imsg.data, sizeof(*rr)); 435 436 LIST_FOREACH(iface, &deconf->iface_list, entry) { 437 if (iface->ifindex == rr->ifindex) 438 continue; 439 if (!if_nbr_list_empty(iface)) { 440 rr_list_add(&iface->rr_list, rr); 441 rr_list_send(&iface->rr_list, iface, 442 NULL); 443 } 444 } 445 break; 446 default: 447 log_debug("dvmrpe_dispatch_rde: error handling imsg %d", 448 imsg.hdr.type); 449 break; 450 } 451 imsg_free(&imsg); 452 } 453 if (!shut) 454 imsg_event_add(iev); 455 else { 456 /* this pipe is dead, so remove the event handler */ 457 event_del(&iev->ev); 458 event_loopexit(NULL); 459 } 460 } 461 462 void 463 dvmrpe_iface_ctl(struct ctl_conn *c, unsigned int idx) 464 { 465 struct iface *iface; 466 struct ctl_iface *ictl; 467 468 LIST_FOREACH(iface, &deconf->iface_list, entry) 469 if (idx == 0 || idx == iface->ifindex) { 470 ictl = if_to_ctl(iface); 471 imsg_compose_event(&c->iev, IMSG_CTL_SHOW_IFACE, 472 0, 0, -1, ictl, sizeof(struct ctl_iface)); 473 } 474 } 475 476 void 477 dvmrpe_iface_igmp_ctl(struct ctl_conn *c, unsigned int idx) 478 { 479 struct iface *iface; 480 struct ctl_iface *ictl; 481 482 LIST_FOREACH(iface, &deconf->iface_list, entry) 483 if (idx == 0 || idx == iface->ifindex) { 484 ictl = if_to_ctl(iface); 485 imsg_compose_event(&c->iev, IMSG_CTL_SHOW_IFACE, 486 0, 0, -1, ictl, sizeof(struct ctl_iface)); 487 group_list_dump(iface, c); 488 489 } 490 } 491 492 void 493 dvmrpe_nbr_ctl(struct ctl_conn *c) 494 { 495 struct iface *iface; 496 struct nbr *nbr; 497 struct ctl_nbr *nctl; 498 499 LIST_FOREACH(iface, &deconf->iface_list, entry) 500 LIST_FOREACH(nbr, &iface->nbr_list, entry) { 501 nctl = nbr_to_ctl(nbr); 502 imsg_compose_event(&c->iev, IMSG_CTL_SHOW_NBR, 503 0, 0, -1, nctl, sizeof(struct ctl_nbr)); 504 } 505 506 imsg_compose_event(&c->iev, IMSG_CTL_END, 0, 0, -1, NULL, 0); 507 } 508