1 /* $OpenBSD: rde.c,v 1.15 2010/12/31 21:49:54 guenther 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/param.h> /* for MIN() */ 23 #include <sys/socket.h> 24 #include <sys/queue.h> 25 #include <netinet/in.h> 26 #include <arpa/inet.h> 27 #include <err.h> 28 #include <errno.h> 29 #include <stdlib.h> 30 #include <signal.h> 31 #include <string.h> 32 #include <pwd.h> 33 #include <unistd.h> 34 #include <event.h> 35 36 #include "ripd.h" 37 #include "rip.h" 38 #include "ripe.h" 39 #include "log.h" 40 #include "rde.h" 41 42 struct ripd_conf *rdeconf = NULL; 43 struct imsgev *iev_ripe; 44 struct imsgev *iev_main; 45 46 void rde_sig_handler(int, short, void *); 47 void rde_shutdown(void); 48 void rde_dispatch_imsg(int, short, void *); 49 void rde_dispatch_parent(int, short, void *); 50 int rde_imsg_compose_ripe(int, u_int32_t, pid_t, void *, u_int16_t); 51 int rde_check_route(struct rip_route *); 52 void triggered_update(struct rt_node *); 53 54 /* ARGSUSED */ 55 void 56 rde_sig_handler(int sig, short event, void *arg) 57 { 58 /* 59 * signal handler rules don't apply, libevent decouples for us 60 */ 61 62 switch (sig) { 63 case SIGINT: 64 case SIGTERM: 65 rde_shutdown(); 66 /* NOTREACHED */ 67 default: 68 fatalx("unexpected signal"); 69 } 70 } 71 72 /* route decision engine */ 73 pid_t 74 rde(struct ripd_conf *xconf, int pipe_parent2rde[2], int pipe_ripe2rde[2], 75 int pipe_parent2ripe[2]) 76 { 77 struct event ev_sigint, ev_sigterm; 78 struct passwd *pw; 79 struct redistribute *r; 80 pid_t pid; 81 82 switch (pid = fork()) { 83 case -1: 84 fatal("cannot fork"); 85 /* NOTREACHED */ 86 case 0: 87 break; 88 default: 89 return (pid); 90 } 91 92 rdeconf = xconf; 93 94 if ((pw = getpwnam(RIPD_USER)) == NULL) 95 fatal("getpwnam"); 96 97 if (chroot(pw->pw_dir) == -1) 98 fatal("chroot"); 99 if (chdir("/") == -1) 100 fatal("chdir(\"/\")"); 101 102 setproctitle("route decision engine"); 103 ripd_process = PROC_RDE_ENGINE; 104 105 if (setgroups(1, &pw->pw_gid) || 106 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) || 107 setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) 108 fatal("can't drop privileges"); 109 110 event_init(); 111 112 /* setup signal handler */ 113 signal_set(&ev_sigint, SIGINT, rde_sig_handler, NULL); 114 signal_set(&ev_sigterm, SIGTERM, rde_sig_handler, NULL); 115 signal_add(&ev_sigint, NULL); 116 signal_add(&ev_sigterm, NULL); 117 signal(SIGPIPE, SIG_IGN); 118 signal(SIGHUP, SIG_IGN); 119 120 /* setup pipes */ 121 close(pipe_ripe2rde[0]); 122 close(pipe_parent2rde[0]); 123 close(pipe_parent2ripe[0]); 124 close(pipe_parent2ripe[1]); 125 126 if ((iev_ripe = malloc(sizeof(struct imsgev))) == NULL || 127 (iev_main = malloc(sizeof(struct imsgev))) == NULL) 128 fatal(NULL); 129 imsg_init(&iev_ripe->ibuf, pipe_ripe2rde[1]); 130 iev_ripe->handler = rde_dispatch_imsg; 131 imsg_init(&iev_main->ibuf, pipe_parent2rde[1]); 132 iev_main->handler = rde_dispatch_parent; 133 134 /* setup event handler */ 135 iev_ripe->events = EV_READ; 136 event_set(&iev_ripe->ev, iev_ripe->ibuf.fd, iev_ripe->events, 137 iev_ripe->handler, iev_ripe); 138 event_add(&iev_ripe->ev, NULL); 139 140 iev_main->events = EV_READ; 141 event_set(&iev_main->ev, iev_main->ibuf.fd, iev_main->events, 142 iev_main->handler, iev_main); 143 event_add(&iev_main->ev, NULL); 144 rt_init(); 145 146 /* remove unneeded config stuff */ 147 while ((r = SIMPLEQ_FIRST(&rdeconf->redist_list)) != NULL) { 148 SIMPLEQ_REMOVE_HEAD(&rdeconf->redist_list, entry); 149 free(r); 150 } 151 152 event_dispatch(); 153 154 rde_shutdown(); 155 /* NOTREACHED */ 156 157 return (0); 158 } 159 160 void 161 rde_shutdown(void) 162 { 163 rt_clear(); 164 165 msgbuf_clear(&iev_ripe->ibuf.w); 166 free(iev_ripe); 167 msgbuf_clear(&iev_main->ibuf.w); 168 free(iev_main); 169 free(rdeconf); 170 171 log_info("route decision engine exiting"); 172 _exit(0); 173 } 174 175 int 176 rde_imsg_compose_ripe(int type, u_int32_t peerid, pid_t pid, void *data, 177 u_int16_t datalen) 178 { 179 return (imsg_compose_event(iev_ripe, type, peerid, pid, -1, 180 data, datalen)); 181 } 182 183 /* ARGSUSED */ 184 void 185 rde_dispatch_imsg(int fd, short event, void *bula) 186 { 187 struct imsgev *iev = bula; 188 struct imsgbuf *ibuf = &iev->ibuf; 189 struct rip_route rr; 190 struct imsg imsg; 191 ssize_t n; 192 int shut = 0, verbose; 193 194 if (event & EV_READ) { 195 if ((n = imsg_read(ibuf)) == -1) 196 fatal("imsg_read error"); 197 if (n == 0) /* connection closed */ 198 shut = 1; 199 } 200 if (event & EV_WRITE) { 201 if (msgbuf_write(&ibuf->w) == -1) 202 fatal("msgbuf_write"); 203 } 204 205 for (;;) { 206 if ((n = imsg_get(ibuf, &imsg)) == -1) 207 fatal("rde_dispatch_imsg: imsg_read error"); 208 if (n == 0) 209 break; 210 211 switch (imsg.hdr.type) { 212 case IMSG_ROUTE_FEED: 213 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(rr)) 214 fatalx("invalid size of RDE request"); 215 216 memcpy(&rr, imsg.data, sizeof(rr)); 217 218 if (rde_check_route(&rr) == -1) 219 log_debug("rde_dispatch_imsg: " 220 "packet malformed\n"); 221 break; 222 case IMSG_FULL_REQUEST: 223 bzero(&rr, sizeof(rr)); 224 /* 225 * AFI == 0 && metric == INFINITY request the 226 * whole routing table 227 */ 228 rr.metric = INFINITY; 229 rde_imsg_compose_ripe(IMSG_REQUEST_ADD, 0, 230 0, &rr, sizeof(rr)); 231 rde_imsg_compose_ripe(IMSG_SEND_REQUEST, 0, 232 0, NULL, 0); 233 break; 234 case IMSG_FULL_RESPONSE: 235 rt_snap(imsg.hdr.peerid); 236 rde_imsg_compose_ripe(IMSG_SEND_RESPONSE, 237 imsg.hdr.peerid, 0, NULL, 0); 238 break; 239 case IMSG_ROUTE_REQUEST: 240 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(rr)) 241 fatalx("invalid size of RDE request"); 242 243 memcpy(&rr, imsg.data, sizeof(rr)); 244 245 rt_complete(&rr); 246 rde_imsg_compose_ripe(IMSG_RESPONSE_ADD, 247 imsg.hdr.peerid, 0, &rr, sizeof(rr)); 248 249 break; 250 case IMSG_ROUTE_REQUEST_END: 251 rde_imsg_compose_ripe(IMSG_SEND_RESPONSE, 252 imsg.hdr.peerid, 0, NULL, 0); 253 break; 254 case IMSG_CTL_SHOW_RIB: 255 rt_dump(imsg.hdr.pid); 256 257 imsg_compose_event(iev_ripe, IMSG_CTL_END, 0, 258 imsg.hdr.pid, -1, NULL, 0); 259 260 break; 261 case IMSG_CTL_LOG_VERBOSE: 262 /* already checked by ripe */ 263 memcpy(&verbose, imsg.data, sizeof(verbose)); 264 log_verbose(verbose); 265 break; 266 default: 267 log_debug("rde_dispatch_msg: unexpected imsg %d", 268 imsg.hdr.type); 269 break; 270 } 271 imsg_free(&imsg); 272 } 273 if (!shut) 274 imsg_event_add(iev); 275 else { 276 /* this pipe is dead, so remove the event handler */ 277 event_del(&iev->ev); 278 event_loopexit(NULL); 279 } 280 } 281 282 /* ARGSUSED */ 283 void 284 rde_dispatch_parent(int fd, short event, void *bula) 285 { 286 struct imsg imsg; 287 struct rt_node *rt; 288 struct kroute kr; 289 struct imsgev *iev = bula; 290 struct imsgbuf *ibuf = &iev->ibuf; 291 ssize_t n; 292 int shut = 0; 293 294 if (event & EV_READ) { 295 if ((n = imsg_read(ibuf)) == -1) 296 fatal("imsg_read error"); 297 if (n == 0) /* connection closed */ 298 shut = 1; 299 } 300 if (event & EV_WRITE) { 301 if (msgbuf_write(&ibuf->w) == -1) 302 fatal("msgbuf_write"); 303 } 304 305 for (;;) { 306 if ((n = imsg_get(ibuf, &imsg)) == -1) 307 fatal("rde_dispatch_parent: imsg_read error"); 308 if (n == 0) 309 break; 310 311 switch (imsg.hdr.type) { 312 case IMSG_NETWORK_ADD: 313 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(kr)) { 314 log_warnx("rde_dispatch: wrong imsg len"); 315 break; 316 } 317 318 memcpy(&kr, imsg.data, sizeof(kr)); 319 320 rt = rt_new_kr(&kr); 321 rt_insert(rt); 322 break; 323 case IMSG_NETWORK_DEL: 324 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(kr)) { 325 log_warnx("rde_dispatch: wrong imsg len"); 326 break; 327 } 328 memcpy(&kr, imsg.data, sizeof(kr)); 329 330 if ((rt = rt_find(kr.prefix.s_addr, 331 kr.netmask.s_addr)) != NULL) 332 rt_remove(rt); 333 break; 334 default: 335 log_debug("rde_dispatch_parent: unexpected imsg %d", 336 imsg.hdr.type); 337 break; 338 } 339 imsg_free(&imsg); 340 } 341 if (!shut) 342 imsg_event_add(iev); 343 else { 344 /* this pipe is dead, so remove the event handler */ 345 event_del(&iev->ev); 346 event_loopexit(NULL); 347 } 348 } 349 350 void 351 rde_send_change_kroute(struct rt_node *r) 352 { 353 struct kroute kr; 354 355 bzero(&kr, sizeof(kr)); 356 kr.prefix.s_addr = r->prefix.s_addr; 357 kr.nexthop.s_addr = r->nexthop.s_addr; 358 kr.netmask.s_addr = r->netmask.s_addr; 359 kr.metric = r->metric; 360 kr.flags = r->flags; 361 kr.ifindex = r->ifindex; 362 363 imsg_compose_event(iev_main, IMSG_KROUTE_CHANGE, 0, 0, -1, 364 &kr, sizeof(kr)); 365 } 366 367 void 368 rde_send_delete_kroute(struct rt_node *r) 369 { 370 struct kroute kr; 371 372 bzero(&kr, sizeof(kr)); 373 kr.prefix.s_addr = r->prefix.s_addr; 374 kr.nexthop.s_addr = r->nexthop.s_addr; 375 kr.netmask.s_addr = r->netmask.s_addr; 376 kr.metric = r->metric; 377 kr.flags = r->flags; 378 kr.ifindex = r->ifindex; 379 380 imsg_compose_event(iev_main, IMSG_KROUTE_DELETE, 0, 0, -1, 381 &kr, sizeof(kr)); 382 } 383 384 int 385 rde_check_route(struct rip_route *e) 386 { 387 struct timeval tv, now; 388 struct rt_node *rn; 389 struct iface *iface; 390 u_int8_t metric; 391 392 if ((e->nexthop.s_addr & htonl(IN_CLASSA_NET)) == 393 htonl(INADDR_LOOPBACK & IN_CLASSA_NET) || 394 e->nexthop.s_addr == INADDR_ANY) 395 return (-1); 396 397 if ((iface = if_find_index(e->ifindex)) == NULL) 398 return (-1); 399 400 metric = MIN(INFINITY, e->metric + iface->cost); 401 402 if ((rn = rt_find(e->address.s_addr, e->mask.s_addr)) == NULL) { 403 if (metric >= INFINITY) 404 return (0); 405 rn = rt_new_rr(e, metric); 406 rt_insert(rn); 407 rde_send_change_kroute(rn); 408 route_start_timeout(rn); 409 triggered_update(rn); 410 } else { 411 /* 412 * XXX don't we have to track all incoming routes? 413 * what happens if the kernel route is removed later. 414 */ 415 if (rn->flags & F_KERNEL) 416 return (0); 417 418 if (metric < rn->metric) { 419 rn->metric = metric; 420 rn->nexthop.s_addr = e->nexthop.s_addr; 421 rn->ifindex = e->ifindex; 422 rde_send_change_kroute(rn); 423 triggered_update(rn); 424 } else if (e->nexthop.s_addr == rn->nexthop.s_addr && 425 metric > rn->metric) { 426 rn->metric = metric; 427 rde_send_change_kroute(rn); 428 triggered_update(rn); 429 if (rn->metric == INFINITY) 430 route_start_garbage(rn); 431 } else if (e->nexthop.s_addr != rn->nexthop.s_addr && 432 metric == rn->metric) { 433 /* If the new metric is the same as the old one, 434 * examine the timeout for the existing route. If it 435 * is at least halfway to the expiration point, switch 436 * to the new route. 437 */ 438 timerclear(&tv); 439 gettimeofday(&now, NULL); 440 evtimer_pending(&rn->timeout_timer, &tv); 441 if (tv.tv_sec - now.tv_sec < ROUTE_TIMEOUT / 2) { 442 rn->nexthop.s_addr = e->nexthop.s_addr; 443 rn->ifindex = e->ifindex; 444 rde_send_change_kroute(rn); 445 } 446 } 447 448 if (e->nexthop.s_addr == rn->nexthop.s_addr && 449 rn->metric < INFINITY) 450 route_reset_timers(rn); 451 } 452 453 return (0); 454 } 455 456 void 457 triggered_update(struct rt_node *rn) 458 { 459 struct rip_route rr; 460 461 rr.address.s_addr = rn->prefix.s_addr; 462 rr.mask.s_addr = rn->netmask.s_addr; 463 rr.nexthop.s_addr = rn->nexthop.s_addr; 464 rr.metric = rn->metric; 465 rr.ifindex = rn->ifindex; 466 467 rde_imsg_compose_ripe(IMSG_SEND_TRIGGERED_UPDATE, 0, 0, &rr, 468 sizeof(struct rip_route)); 469 } 470