1 /* $OpenBSD: rde.c,v 1.22 2018/11/04 07:52:55 remi Exp $ */ 2 3 /* 4 * Copyright (c) 2006 Michele Marchetto <mydecay@openbeer.it> 5 * Copyright (c) 2004, 2005 Claudio Jeker <claudio@openbsd.org> 6 * Copyright (c) 2004 Esben Norby <norby@openbsd.org> 7 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org> 8 * 9 * Permission to use, copy, modify, and distribute this software for any 10 * purpose with or without fee is hereby granted, provided that the above 11 * copyright notice and this permission notice appear in all copies. 12 * 13 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 14 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 15 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 16 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 17 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 18 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 19 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 20 */ 21 22 #include <sys/socket.h> 23 #include <sys/queue.h> 24 #include <netinet/in.h> 25 #include <arpa/inet.h> 26 #include <err.h> 27 #include <errno.h> 28 #include <stdlib.h> 29 #include <signal.h> 30 #include <string.h> 31 #include <pwd.h> 32 #include <unistd.h> 33 #include <event.h> 34 35 #include "ripd.h" 36 #include "rip.h" 37 #include "ripe.h" 38 #include "log.h" 39 #include "rde.h" 40 41 #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b)) 42 43 struct ripd_conf *rdeconf = NULL; 44 struct imsgev *iev_ripe; 45 struct imsgev *iev_main; 46 47 void rde_sig_handler(int, short, void *); 48 __dead void rde_shutdown(void); 49 void rde_dispatch_imsg(int, short, void *); 50 void rde_dispatch_parent(int, short, void *); 51 int rde_imsg_compose_ripe(int, u_int32_t, pid_t, void *, u_int16_t); 52 int rde_check_route(struct rip_route *); 53 void triggered_update(struct rt_node *); 54 55 /* ARGSUSED */ 56 void 57 rde_sig_handler(int sig, short event, void *arg) 58 { 59 /* 60 * signal handler rules don't apply, libevent decouples for us 61 */ 62 63 switch (sig) { 64 case SIGINT: 65 case SIGTERM: 66 rde_shutdown(); 67 /* NOTREACHED */ 68 default: 69 fatalx("unexpected signal"); 70 } 71 } 72 73 /* route decision engine */ 74 pid_t 75 rde(struct ripd_conf *xconf, int pipe_parent2rde[2], int pipe_ripe2rde[2], 76 int pipe_parent2ripe[2]) 77 { 78 struct event ev_sigint, ev_sigterm; 79 struct passwd *pw; 80 struct redistribute *r; 81 pid_t pid; 82 83 switch (pid = fork()) { 84 case -1: 85 fatal("cannot fork"); 86 /* NOTREACHED */ 87 case 0: 88 break; 89 default: 90 return (pid); 91 } 92 93 rdeconf = xconf; 94 95 if ((pw = getpwnam(RIPD_USER)) == NULL) 96 fatal("getpwnam"); 97 98 if (chroot(pw->pw_dir) == -1) 99 fatal("chroot"); 100 if (chdir("/") == -1) 101 fatal("chdir(\"/\")"); 102 103 setproctitle("route decision engine"); 104 ripd_process = PROC_RDE_ENGINE; 105 log_procname = log_procnames[ripd_process]; 106 107 if (setgroups(1, &pw->pw_gid) || 108 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) || 109 setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) 110 fatal("can't drop privileges"); 111 112 if (pledge("stdio", NULL) == -1) 113 fatal("pledge"); 114 115 event_init(); 116 117 /* setup signal handler */ 118 signal_set(&ev_sigint, SIGINT, rde_sig_handler, NULL); 119 signal_set(&ev_sigterm, SIGTERM, rde_sig_handler, NULL); 120 signal_add(&ev_sigint, NULL); 121 signal_add(&ev_sigterm, NULL); 122 signal(SIGPIPE, SIG_IGN); 123 signal(SIGHUP, SIG_IGN); 124 125 /* setup pipes */ 126 close(pipe_ripe2rde[0]); 127 close(pipe_parent2rde[0]); 128 close(pipe_parent2ripe[0]); 129 close(pipe_parent2ripe[1]); 130 131 if ((iev_ripe = malloc(sizeof(struct imsgev))) == NULL || 132 (iev_main = malloc(sizeof(struct imsgev))) == NULL) 133 fatal(NULL); 134 imsg_init(&iev_ripe->ibuf, pipe_ripe2rde[1]); 135 iev_ripe->handler = rde_dispatch_imsg; 136 imsg_init(&iev_main->ibuf, pipe_parent2rde[1]); 137 iev_main->handler = rde_dispatch_parent; 138 139 /* setup event handler */ 140 iev_ripe->events = EV_READ; 141 event_set(&iev_ripe->ev, iev_ripe->ibuf.fd, iev_ripe->events, 142 iev_ripe->handler, iev_ripe); 143 event_add(&iev_ripe->ev, NULL); 144 145 iev_main->events = EV_READ; 146 event_set(&iev_main->ev, iev_main->ibuf.fd, iev_main->events, 147 iev_main->handler, iev_main); 148 event_add(&iev_main->ev, NULL); 149 rt_init(); 150 151 /* remove unneeded config stuff */ 152 while ((r = SIMPLEQ_FIRST(&rdeconf->redist_list)) != NULL) { 153 SIMPLEQ_REMOVE_HEAD(&rdeconf->redist_list, entry); 154 free(r); 155 } 156 157 event_dispatch(); 158 159 rde_shutdown(); 160 /* NOTREACHED */ 161 162 return (0); 163 } 164 165 __dead void 166 rde_shutdown(void) 167 { 168 /* close pipes */ 169 msgbuf_clear(&iev_ripe->ibuf.w); 170 close(iev_ripe->ibuf.fd); 171 msgbuf_clear(&iev_main->ibuf.w); 172 close(iev_main->ibuf.fd); 173 174 rt_clear(); 175 free(iev_ripe); 176 free(iev_main); 177 free(rdeconf); 178 179 log_info("route decision engine exiting"); 180 _exit(0); 181 } 182 183 int 184 rde_imsg_compose_ripe(int type, u_int32_t peerid, pid_t pid, void *data, 185 u_int16_t datalen) 186 { 187 return (imsg_compose_event(iev_ripe, type, peerid, pid, -1, 188 data, datalen)); 189 } 190 191 /* ARGSUSED */ 192 void 193 rde_dispatch_imsg(int fd, short event, void *bula) 194 { 195 struct imsgev *iev = bula; 196 struct imsgbuf *ibuf = &iev->ibuf; 197 struct rip_route rr; 198 struct imsg imsg; 199 ssize_t n; 200 int shut = 0, verbose; 201 202 if (event & EV_READ) { 203 if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) 204 fatal("imsg_read error"); 205 if (n == 0) /* connection closed */ 206 shut = 1; 207 } 208 if (event & EV_WRITE) { 209 if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) 210 fatal("msgbuf_write"); 211 if (n == 0) /* connection closed */ 212 shut = 1; 213 } 214 215 for (;;) { 216 if ((n = imsg_get(ibuf, &imsg)) == -1) 217 fatal("rde_dispatch_imsg: imsg_get error"); 218 if (n == 0) 219 break; 220 221 switch (imsg.hdr.type) { 222 case IMSG_ROUTE_FEED: 223 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(rr)) 224 fatalx("invalid size of RDE request"); 225 226 memcpy(&rr, imsg.data, sizeof(rr)); 227 228 if (rde_check_route(&rr) == -1) 229 log_debug("rde_dispatch_imsg: " 230 "packet malformed\n"); 231 break; 232 case IMSG_FULL_REQUEST: 233 bzero(&rr, sizeof(rr)); 234 /* 235 * AFI == 0 && metric == INFINITY request the 236 * whole routing table 237 */ 238 rr.metric = INFINITY; 239 rde_imsg_compose_ripe(IMSG_REQUEST_ADD, 0, 240 0, &rr, sizeof(rr)); 241 rde_imsg_compose_ripe(IMSG_SEND_REQUEST, 0, 242 0, NULL, 0); 243 break; 244 case IMSG_FULL_RESPONSE: 245 rt_snap(imsg.hdr.peerid); 246 rde_imsg_compose_ripe(IMSG_SEND_RESPONSE, 247 imsg.hdr.peerid, 0, NULL, 0); 248 break; 249 case IMSG_ROUTE_REQUEST: 250 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(rr)) 251 fatalx("invalid size of RDE request"); 252 253 memcpy(&rr, imsg.data, sizeof(rr)); 254 255 rt_complete(&rr); 256 rde_imsg_compose_ripe(IMSG_RESPONSE_ADD, 257 imsg.hdr.peerid, 0, &rr, sizeof(rr)); 258 259 break; 260 case IMSG_ROUTE_REQUEST_END: 261 rde_imsg_compose_ripe(IMSG_SEND_RESPONSE, 262 imsg.hdr.peerid, 0, NULL, 0); 263 break; 264 case IMSG_CTL_SHOW_RIB: 265 rt_dump(imsg.hdr.pid); 266 267 imsg_compose_event(iev_ripe, IMSG_CTL_END, 0, 268 imsg.hdr.pid, -1, NULL, 0); 269 270 break; 271 case IMSG_CTL_LOG_VERBOSE: 272 /* already checked by ripe */ 273 memcpy(&verbose, imsg.data, sizeof(verbose)); 274 log_verbose(verbose); 275 break; 276 default: 277 log_debug("rde_dispatch_msg: unexpected imsg %d", 278 imsg.hdr.type); 279 break; 280 } 281 imsg_free(&imsg); 282 } 283 if (!shut) 284 imsg_event_add(iev); 285 else { 286 /* this pipe is dead, so remove the event handler */ 287 event_del(&iev->ev); 288 event_loopexit(NULL); 289 } 290 } 291 292 /* ARGSUSED */ 293 void 294 rde_dispatch_parent(int fd, short event, void *bula) 295 { 296 struct imsg imsg; 297 struct rt_node *rt; 298 struct kroute kr; 299 struct imsgev *iev = bula; 300 struct imsgbuf *ibuf = &iev->ibuf; 301 ssize_t n; 302 int shut = 0; 303 304 if (event & EV_READ) { 305 if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) 306 fatal("imsg_read error"); 307 if (n == 0) /* connection closed */ 308 shut = 1; 309 } 310 if (event & EV_WRITE) { 311 if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) 312 fatal("msgbuf_write"); 313 if (n == 0) /* connection closed */ 314 shut = 1; 315 } 316 317 for (;;) { 318 if ((n = imsg_get(ibuf, &imsg)) == -1) 319 fatal("rde_dispatch_parent: imsg_get error"); 320 if (n == 0) 321 break; 322 323 switch (imsg.hdr.type) { 324 case IMSG_NETWORK_ADD: 325 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(kr)) { 326 log_warnx("rde_dispatch: wrong imsg len"); 327 break; 328 } 329 330 memcpy(&kr, imsg.data, sizeof(kr)); 331 332 rt = rt_new_kr(&kr); 333 rt_insert(rt); 334 break; 335 case IMSG_NETWORK_DEL: 336 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(kr)) { 337 log_warnx("rde_dispatch: wrong imsg len"); 338 break; 339 } 340 memcpy(&kr, imsg.data, sizeof(kr)); 341 342 if ((rt = rt_find(kr.prefix.s_addr, 343 kr.netmask.s_addr)) != NULL) 344 rt_remove(rt); 345 break; 346 default: 347 log_debug("rde_dispatch_parent: unexpected imsg %d", 348 imsg.hdr.type); 349 break; 350 } 351 imsg_free(&imsg); 352 } 353 if (!shut) 354 imsg_event_add(iev); 355 else { 356 /* this pipe is dead, so remove the event handler */ 357 event_del(&iev->ev); 358 event_loopexit(NULL); 359 } 360 } 361 362 void 363 rde_send_change_kroute(struct rt_node *r) 364 { 365 struct kroute kr; 366 367 bzero(&kr, sizeof(kr)); 368 kr.prefix.s_addr = r->prefix.s_addr; 369 kr.nexthop.s_addr = r->nexthop.s_addr; 370 kr.netmask.s_addr = r->netmask.s_addr; 371 kr.metric = r->metric; 372 kr.flags = r->flags; 373 kr.ifindex = r->ifindex; 374 375 imsg_compose_event(iev_main, IMSG_KROUTE_CHANGE, 0, 0, -1, 376 &kr, sizeof(kr)); 377 } 378 379 void 380 rde_send_delete_kroute(struct rt_node *r) 381 { 382 struct kroute kr; 383 384 bzero(&kr, sizeof(kr)); 385 kr.prefix.s_addr = r->prefix.s_addr; 386 kr.nexthop.s_addr = r->nexthop.s_addr; 387 kr.netmask.s_addr = r->netmask.s_addr; 388 kr.metric = r->metric; 389 kr.flags = r->flags; 390 kr.ifindex = r->ifindex; 391 392 imsg_compose_event(iev_main, IMSG_KROUTE_DELETE, 0, 0, -1, 393 &kr, sizeof(kr)); 394 } 395 396 int 397 rde_check_route(struct rip_route *e) 398 { 399 struct timeval tv, now; 400 struct rt_node *rn; 401 struct iface *iface; 402 u_int8_t metric; 403 404 if ((e->nexthop.s_addr & htonl(IN_CLASSA_NET)) == 405 htonl(INADDR_LOOPBACK & IN_CLASSA_NET) || 406 e->nexthop.s_addr == INADDR_ANY) 407 return (-1); 408 409 if ((iface = if_find_index(e->ifindex)) == NULL) 410 return (-1); 411 412 metric = MINIMUM(INFINITY, e->metric + iface->cost); 413 414 if ((rn = rt_find(e->address.s_addr, e->mask.s_addr)) == NULL) { 415 if (metric >= INFINITY) 416 return (0); 417 rn = rt_new_rr(e, metric); 418 rt_insert(rn); 419 rde_send_change_kroute(rn); 420 route_start_timeout(rn); 421 triggered_update(rn); 422 } else { 423 /* 424 * XXX don't we have to track all incoming routes? 425 * what happens if the kernel route is removed later. 426 */ 427 if (rn->flags & F_KERNEL) 428 return (0); 429 430 if (metric < rn->metric) { 431 rn->metric = metric; 432 rn->nexthop.s_addr = e->nexthop.s_addr; 433 rn->ifindex = e->ifindex; 434 rde_send_change_kroute(rn); 435 triggered_update(rn); 436 } else if (e->nexthop.s_addr == rn->nexthop.s_addr && 437 metric > rn->metric) { 438 rn->metric = metric; 439 rde_send_change_kroute(rn); 440 triggered_update(rn); 441 if (rn->metric == INFINITY) 442 route_start_garbage(rn); 443 } else if (e->nexthop.s_addr != rn->nexthop.s_addr && 444 metric == rn->metric) { 445 /* If the new metric is the same as the old one, 446 * examine the timeout for the existing route. If it 447 * is at least halfway to the expiration point, switch 448 * to the new route. 449 */ 450 timerclear(&tv); 451 gettimeofday(&now, NULL); 452 evtimer_pending(&rn->timeout_timer, &tv); 453 if (tv.tv_sec - now.tv_sec < ROUTE_TIMEOUT / 2) { 454 rn->nexthop.s_addr = e->nexthop.s_addr; 455 rn->ifindex = e->ifindex; 456 rde_send_change_kroute(rn); 457 } 458 } 459 460 if (e->nexthop.s_addr == rn->nexthop.s_addr && 461 rn->metric < INFINITY) 462 route_reset_timers(rn); 463 } 464 465 return (0); 466 } 467 468 void 469 triggered_update(struct rt_node *rn) 470 { 471 struct rip_route rr; 472 473 rr.address.s_addr = rn->prefix.s_addr; 474 rr.mask.s_addr = rn->netmask.s_addr; 475 rr.nexthop.s_addr = rn->nexthop.s_addr; 476 rr.metric = rn->metric; 477 rr.ifindex = rn->ifindex; 478 479 rde_imsg_compose_ripe(IMSG_SEND_TRIGGERED_UPDATE, 0, 0, &rr, 480 sizeof(struct rip_route)); 481 } 482