1 /* $OpenBSD: control.c,v 1.105 2021/04/27 15:34:18 claudio Exp $ */ 2 3 /* 4 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/types.h> 20 #include <sys/stat.h> 21 #include <sys/socket.h> 22 #include <sys/un.h> 23 #include <errno.h> 24 #include <stdlib.h> 25 #include <string.h> 26 #include <unistd.h> 27 28 #include "bgpd.h" 29 #include "session.h" 30 #include "log.h" 31 32 TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns); 33 34 #define CONTROL_BACKLOG 5 35 36 struct ctl_conn *control_connbyfd(int); 37 struct ctl_conn *control_connbypid(pid_t); 38 int control_close(struct ctl_conn *); 39 void control_result(struct ctl_conn *, u_int); 40 ssize_t imsg_read_nofd(struct imsgbuf *); 41 42 int 43 control_check(char *path) 44 { 45 struct sockaddr_un sun; 46 int fd; 47 48 bzero(&sun, sizeof(sun)); 49 sun.sun_family = AF_UNIX; 50 strlcpy(sun.sun_path, path, sizeof(sun.sun_path)); 51 52 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) == -1) { 53 log_warn("%s: socket", __func__); 54 return (-1); 55 } 56 57 if (connect(fd, (struct sockaddr *)&sun, sizeof(sun)) == 0) { 58 log_warnx("control socket %s already in use", path); 59 close(fd); 60 return (-1); 61 } 62 63 close(fd); 64 65 return (0); 66 } 67 68 int 69 control_init(int restricted, char *path) 70 { 71 struct sockaddr_un sun; 72 int fd; 73 mode_t old_umask, mode; 74 75 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 76 0)) == -1) { 77 log_warn("control_init: socket"); 78 return (-1); 79 } 80 81 bzero(&sun, sizeof(sun)); 82 sun.sun_family = AF_UNIX; 83 if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >= 84 sizeof(sun.sun_path)) { 85 log_warn("control_init: socket name too long"); 86 close(fd); 87 return (-1); 88 } 89 90 if (unlink(path) == -1) 91 if (errno != ENOENT) { 92 log_warn("control_init: unlink %s", path); 93 close(fd); 94 return (-1); 95 } 96 97 if (restricted) { 98 old_umask = umask(S_IXUSR|S_IXGRP|S_IXOTH); 99 mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH; 100 } else { 101 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH); 102 mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP; 103 } 104 105 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) { 106 log_warn("control_init: bind: %s", path); 107 close(fd); 108 umask(old_umask); 109 return (-1); 110 } 111 112 umask(old_umask); 113 114 if (chmod(path, mode) == -1) { 115 log_warn("control_init: chmod: %s", path); 116 close(fd); 117 unlink(path); 118 return (-1); 119 } 120 121 return (fd); 122 } 123 124 int 125 control_listen(int fd) 126 { 127 if (fd != -1 && listen(fd, CONTROL_BACKLOG) == -1) { 128 log_warn("control_listen: listen"); 129 return (-1); 130 } 131 132 return (0); 133 } 134 135 void 136 control_shutdown(int fd) 137 { 138 close(fd); 139 } 140 141 size_t 142 control_fill_pfds(struct pollfd *pfd, size_t size) 143 { 144 struct ctl_conn *ctl_conn; 145 size_t i = 0; 146 147 TAILQ_FOREACH(ctl_conn, &ctl_conns, entry) { 148 pfd[i].fd = ctl_conn->ibuf.fd; 149 pfd[i].events = POLLIN; 150 if (ctl_conn->ibuf.w.queued > 0) 151 pfd[i].events |= POLLOUT; 152 i++; 153 } 154 return i; 155 } 156 157 unsigned int 158 control_accept(int listenfd, int restricted) 159 { 160 int connfd; 161 socklen_t len; 162 struct sockaddr_un sun; 163 struct ctl_conn *ctl_conn; 164 165 len = sizeof(sun); 166 if ((connfd = accept4(listenfd, 167 (struct sockaddr *)&sun, &len, 168 SOCK_NONBLOCK | SOCK_CLOEXEC)) == -1) { 169 if (errno == ENFILE || errno == EMFILE) { 170 pauseaccept = getmonotime(); 171 return (0); 172 } else if (errno != EWOULDBLOCK && errno != EINTR && 173 errno != ECONNABORTED) 174 log_warn("control_accept: accept"); 175 return (0); 176 } 177 178 if ((ctl_conn = calloc(1, sizeof(struct ctl_conn))) == NULL) { 179 log_warn("control_accept"); 180 close(connfd); 181 return (0); 182 } 183 184 imsg_init(&ctl_conn->ibuf, connfd); 185 ctl_conn->restricted = restricted; 186 187 TAILQ_INSERT_TAIL(&ctl_conns, ctl_conn, entry); 188 189 return (1); 190 } 191 192 struct ctl_conn * 193 control_connbyfd(int fd) 194 { 195 struct ctl_conn *c; 196 197 TAILQ_FOREACH(c, &ctl_conns, entry) { 198 if (c->ibuf.fd == fd) 199 break; 200 } 201 202 return (c); 203 } 204 205 struct ctl_conn * 206 control_connbypid(pid_t pid) 207 { 208 struct ctl_conn *c; 209 210 TAILQ_FOREACH(c, &ctl_conns, entry) { 211 if (c->ibuf.pid == pid) 212 break; 213 } 214 215 return (c); 216 } 217 218 int 219 control_close(struct ctl_conn *c) 220 { 221 if (c->terminate && c->ibuf.pid) 222 imsg_ctl_rde(IMSG_CTL_TERMINATE, c->ibuf.pid, NULL, 0); 223 224 msgbuf_clear(&c->ibuf.w); 225 TAILQ_REMOVE(&ctl_conns, c, entry); 226 227 close(c->ibuf.fd); 228 free(c); 229 pauseaccept = 0; 230 return (1); 231 } 232 233 int 234 control_dispatch_msg(struct pollfd *pfd, struct peer_head *peers) 235 { 236 struct imsg imsg; 237 struct ctl_conn *c; 238 ssize_t n; 239 int verbose, matched; 240 struct peer *p; 241 struct ctl_neighbor *neighbor; 242 struct ctl_show_rib_request *ribreq; 243 244 if ((c = control_connbyfd(pfd->fd)) == NULL) { 245 log_warn("control_dispatch_msg: fd %d: not found", pfd->fd); 246 return (0); 247 } 248 249 if (pfd->revents & POLLOUT) { 250 if (msgbuf_write(&c->ibuf.w) <= 0 && errno != EAGAIN) 251 return control_close(c); 252 if (c->throttled && c->ibuf.w.queued < CTL_MSG_LOW_MARK) { 253 if (imsg_ctl_rde(IMSG_XON, c->ibuf.pid, NULL, 0) != -1) 254 c->throttled = 0; 255 } 256 } 257 258 if (!(pfd->revents & POLLIN)) 259 return (0); 260 261 if (((n = imsg_read_nofd(&c->ibuf)) == -1 && errno != EAGAIN) || 262 n == 0) 263 return control_close(c); 264 265 for (;;) { 266 if ((n = imsg_get(&c->ibuf, &imsg)) == -1) 267 return control_close(c); 268 269 if (n == 0) 270 break; 271 272 if (c->restricted) { 273 switch (imsg.hdr.type) { 274 case IMSG_CTL_SHOW_NEIGHBOR: 275 case IMSG_CTL_SHOW_NEXTHOP: 276 case IMSG_CTL_SHOW_INTERFACE: 277 case IMSG_CTL_SHOW_RIB_MEM: 278 case IMSG_CTL_SHOW_TERSE: 279 case IMSG_CTL_SHOW_TIMER: 280 case IMSG_CTL_SHOW_NETWORK: 281 case IMSG_CTL_SHOW_RIB: 282 case IMSG_CTL_SHOW_RIB_PREFIX: 283 case IMSG_CTL_SHOW_SET: 284 case IMSG_CTL_SHOW_RTR: 285 break; 286 default: 287 /* clear imsg type to prevent processing */ 288 imsg.hdr.type = IMSG_NONE; 289 control_result(c, CTL_RES_DENIED); 290 break; 291 } 292 } 293 294 switch (imsg.hdr.type) { 295 case IMSG_NONE: 296 /* message was filtered out, nothing to do */ 297 break; 298 case IMSG_CTL_FIB_COUPLE: 299 case IMSG_CTL_FIB_DECOUPLE: 300 imsg_ctl_parent(imsg.hdr.type, imsg.hdr.peerid, 301 0, NULL, 0); 302 break; 303 case IMSG_CTL_SHOW_TERSE: 304 RB_FOREACH(p, peer_head, peers) 305 imsg_compose(&c->ibuf, IMSG_CTL_SHOW_NEIGHBOR, 306 0, 0, -1, p, sizeof(struct peer)); 307 imsg_compose(&c->ibuf, IMSG_CTL_END, 0, 0, -1, NULL, 0); 308 break; 309 case IMSG_CTL_SHOW_NEIGHBOR: 310 c->ibuf.pid = imsg.hdr.pid; 311 312 if (imsg.hdr.len == IMSG_HEADER_SIZE + 313 sizeof(struct ctl_neighbor)) { 314 neighbor = imsg.data; 315 neighbor->descr[PEER_DESCR_LEN - 1] = 0; 316 } else { 317 neighbor = NULL; 318 } 319 matched = 0; 320 RB_FOREACH(p, peer_head, peers) { 321 if (!peer_matched(p, neighbor)) 322 continue; 323 324 matched = 1; 325 if (!neighbor || !neighbor->show_timers) { 326 imsg_ctl_rde(imsg.hdr.type, 327 imsg.hdr.pid, 328 p, sizeof(struct peer)); 329 } else { 330 u_int i; 331 time_t d; 332 struct ctl_timer ct; 333 334 imsg_compose(&c->ibuf, 335 IMSG_CTL_SHOW_NEIGHBOR, 336 0, 0, -1, p, sizeof(*p)); 337 for (i = 1; i < Timer_Max; i++) { 338 if (!timer_running(&p->timers, 339 i, &d)) 340 continue; 341 ct.type = i; 342 ct.val = d; 343 imsg_compose(&c->ibuf, 344 IMSG_CTL_SHOW_TIMER, 345 0, 0, -1, &ct, sizeof(ct)); 346 } 347 } 348 } 349 if (!matched && RB_EMPTY(peers)) { 350 control_result(c, CTL_RES_NOSUCHPEER); 351 } else if (!neighbor || !neighbor->show_timers) { 352 imsg_ctl_rde(IMSG_CTL_END, imsg.hdr.pid, 353 NULL, 0); 354 } else { 355 imsg_compose(&c->ibuf, IMSG_CTL_END, 0, 0, -1, 356 NULL, 0); 357 } 358 break; 359 case IMSG_CTL_NEIGHBOR_UP: 360 case IMSG_CTL_NEIGHBOR_DOWN: 361 case IMSG_CTL_NEIGHBOR_CLEAR: 362 case IMSG_CTL_NEIGHBOR_RREFRESH: 363 case IMSG_CTL_NEIGHBOR_DESTROY: 364 if (imsg.hdr.len != IMSG_HEADER_SIZE + 365 sizeof(struct ctl_neighbor)) { 366 log_warnx("got IMSG_CTL_NEIGHBOR_ with " 367 "wrong length"); 368 break; 369 } 370 371 neighbor = imsg.data; 372 neighbor->descr[PEER_DESCR_LEN - 1] = 0; 373 374 matched = 0; 375 RB_FOREACH(p, peer_head, peers) { 376 if (!peer_matched(p, neighbor)) 377 continue; 378 379 matched = 1; 380 381 switch (imsg.hdr.type) { 382 case IMSG_CTL_NEIGHBOR_UP: 383 bgp_fsm(p, EVNT_START); 384 p->conf.down = 0; 385 p->conf.reason[0] = '\0'; 386 p->IdleHoldTime = 387 INTERVAL_IDLE_HOLD_INITIAL; 388 p->errcnt = 0; 389 control_result(c, CTL_RES_OK); 390 break; 391 case IMSG_CTL_NEIGHBOR_DOWN: 392 p->conf.down = 1; 393 strlcpy(p->conf.reason, 394 neighbor->reason, 395 sizeof(neighbor->reason)); 396 session_stop(p, ERR_CEASE_ADMIN_DOWN); 397 control_result(c, CTL_RES_OK); 398 break; 399 case IMSG_CTL_NEIGHBOR_CLEAR: 400 strlcpy(p->conf.reason, 401 neighbor->reason, 402 sizeof(neighbor->reason)); 403 p->IdleHoldTime = 404 INTERVAL_IDLE_HOLD_INITIAL; 405 p->errcnt = 0; 406 if (!p->conf.down) { 407 session_stop(p, 408 ERR_CEASE_ADMIN_RESET); 409 timer_set(&p->timers, 410 Timer_IdleHold, 411 SESSION_CLEAR_DELAY); 412 } else { 413 session_stop(p, 414 ERR_CEASE_ADMIN_DOWN); 415 } 416 control_result(c, CTL_RES_OK); 417 break; 418 case IMSG_CTL_NEIGHBOR_RREFRESH: 419 if (session_neighbor_rrefresh(p)) 420 control_result(c, 421 CTL_RES_NOCAP); 422 else 423 control_result(c, CTL_RES_OK); 424 break; 425 case IMSG_CTL_NEIGHBOR_DESTROY: 426 if (!p->template) 427 control_result(c, 428 CTL_RES_BADPEER); 429 else if (p->state != STATE_IDLE) 430 control_result(c, 431 CTL_RES_BADSTATE); 432 else { 433 /* 434 * Mark as deleted, will be 435 * collected on next poll loop. 436 */ 437 p->reconf_action = 438 RECONF_DELETE; 439 control_result(c, CTL_RES_OK); 440 } 441 break; 442 default: 443 fatal("king bula wants more humppa"); 444 } 445 } 446 if (!matched) 447 control_result(c, CTL_RES_NOSUCHPEER); 448 break; 449 case IMSG_CTL_RELOAD: 450 case IMSG_CTL_SHOW_INTERFACE: 451 case IMSG_CTL_SHOW_FIB_TABLES: 452 case IMSG_CTL_SHOW_RTR: 453 c->ibuf.pid = imsg.hdr.pid; 454 imsg_ctl_parent(imsg.hdr.type, 0, imsg.hdr.pid, 455 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 456 break; 457 case IMSG_CTL_KROUTE: 458 case IMSG_CTL_KROUTE_ADDR: 459 case IMSG_CTL_SHOW_NEXTHOP: 460 c->ibuf.pid = imsg.hdr.pid; 461 imsg_ctl_parent(imsg.hdr.type, imsg.hdr.peerid, 462 imsg.hdr.pid, imsg.data, imsg.hdr.len - 463 IMSG_HEADER_SIZE); 464 break; 465 case IMSG_CTL_SHOW_RIB: 466 case IMSG_CTL_SHOW_RIB_PREFIX: 467 if (imsg.hdr.len != IMSG_HEADER_SIZE + 468 sizeof(struct ctl_show_rib_request)) { 469 log_warnx("got IMSG_CTL_SHOW_RIB with " 470 "wrong length"); 471 break; 472 } 473 474 ribreq = imsg.data; 475 neighbor = &ribreq->neighbor; 476 neighbor->descr[PEER_DESCR_LEN - 1] = 0; 477 478 /* check if at least one neighbor exists */ 479 RB_FOREACH(p, peer_head, peers) 480 if (peer_matched(p, neighbor)) 481 break; 482 if (p == NULL && RB_EMPTY(peers)) { 483 control_result(c, CTL_RES_NOSUCHPEER); 484 break; 485 } 486 487 if ((imsg.hdr.type == IMSG_CTL_SHOW_RIB_PREFIX) 488 && (ribreq->prefix.aid == AID_UNSPEC)) { 489 /* malformed request, must specify af */ 490 control_result(c, CTL_RES_PARSE_ERROR); 491 break; 492 } 493 494 c->ibuf.pid = imsg.hdr.pid; 495 c->terminate = 1; 496 497 imsg_ctl_rde(imsg.hdr.type, imsg.hdr.pid, 498 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 499 break; 500 case IMSG_CTL_SHOW_NETWORK: 501 c->terminate = 1; 502 /* FALLTHROUGH */ 503 case IMSG_CTL_SHOW_RIB_MEM: 504 case IMSG_CTL_SHOW_SET: 505 c->ibuf.pid = imsg.hdr.pid; 506 imsg_ctl_rde(imsg.hdr.type, imsg.hdr.pid, 507 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 508 break; 509 case IMSG_NETWORK_ADD: 510 case IMSG_NETWORK_ASPATH: 511 case IMSG_NETWORK_ATTR: 512 case IMSG_NETWORK_REMOVE: 513 case IMSG_NETWORK_FLUSH: 514 case IMSG_NETWORK_DONE: 515 case IMSG_FILTER_SET: 516 imsg_ctl_rde(imsg.hdr.type, 0, 517 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 518 break; 519 case IMSG_CTL_LOG_VERBOSE: 520 if (imsg.hdr.len != IMSG_HEADER_SIZE + 521 sizeof(verbose)) 522 break; 523 524 /* forward to other processes */ 525 imsg_ctl_parent(imsg.hdr.type, 0, imsg.hdr.pid, 526 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 527 imsg_ctl_rde(imsg.hdr.type, 0, 528 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 529 530 memcpy(&verbose, imsg.data, sizeof(verbose)); 531 log_setverbose(verbose); 532 break; 533 default: 534 break; 535 } 536 imsg_free(&imsg); 537 } 538 539 return (0); 540 } 541 542 int 543 control_imsg_relay(struct imsg *imsg) 544 { 545 struct ctl_conn *c; 546 547 if ((c = control_connbypid(imsg->hdr.pid)) == NULL) 548 return (0); 549 550 /* if command finished no need to send exit message */ 551 if (imsg->hdr.type == IMSG_CTL_END || imsg->hdr.type == IMSG_CTL_RESULT) 552 c->terminate = 0; 553 554 if (!c->throttled && c->ibuf.w.queued > CTL_MSG_HIGH_MARK) { 555 if (imsg_ctl_rde(IMSG_XOFF, imsg->hdr.pid, NULL, 0) != -1) 556 c->throttled = 1; 557 } 558 559 return (imsg_compose(&c->ibuf, imsg->hdr.type, 0, imsg->hdr.pid, -1, 560 imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE)); 561 } 562 563 void 564 control_result(struct ctl_conn *c, u_int code) 565 { 566 imsg_compose(&c->ibuf, IMSG_CTL_RESULT, 0, c->ibuf.pid, -1, 567 &code, sizeof(code)); 568 } 569 570 /* This should go into libutil, from smtpd/mproc.c */ 571 ssize_t 572 imsg_read_nofd(struct imsgbuf *ibuf) 573 { 574 ssize_t n; 575 char *buf; 576 size_t len; 577 578 buf = ibuf->r.buf + ibuf->r.wpos; 579 len = sizeof(ibuf->r.buf) - ibuf->r.wpos; 580 581 while ((n = recv(ibuf->fd, buf, len, 0)) == -1) { 582 if (errno != EINTR) 583 return (n); 584 } 585 586 ibuf->r.wpos += n; 587 return (n); 588 } 589