1 /* $NetBSD: socketops.c,v 1.2 2010/12/09 00:10:59 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2010 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Mihai Chelaru <kefren@NetBSD.org> 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/types.h> 33 #include <sys/stat.h> 34 #include <sys/socket.h> 35 #include <sys/ioctl.h> 36 #include <net/if.h> 37 #include <netinet/in.h> 38 #include <arpa/inet.h> 39 40 #include <errno.h> 41 #include <signal.h> 42 #include <stdlib.h> 43 #include <unistd.h> 44 #include <strings.h> 45 #include <stdio.h> 46 #include <ifaddrs.h> 47 #include <poll.h> 48 49 #include "fsm.h" 50 #include "ldp.h" 51 #include "ldp_command.h" 52 #include "tlv.h" 53 #include "ldp_peer.h" 54 #include "notifications.h" 55 #include "tlv_stack.h" 56 #include "mpls_interface.h" 57 #include "label.h" 58 #include "mpls_routes.h" 59 #include "ldp_errors.h" 60 #include "socketops.h" 61 62 int ls; /* TCP listening socket on port 646 */ 63 int route_socket; /* used to see when a route is added/deleted */ 64 int hello_socket; /* hello multicast listener - transmitter */ 65 int command_socket; /* Listening socket for interface command */ 66 int current_msg_id = 0x233; 67 int command_port = LDP_COMMAND_PORT; 68 extern int replay_index; 69 extern struct rt_msg replay_rt[REPLAY_MAX]; 70 extern struct com_sock csockets[MAX_COMMAND_SOCKETS]; 71 72 int ldp_hello_time = LDP_HELLO_TIME; 73 74 void recv_pdu(int); 75 void send_hello_alarm(int); 76 void bail_out(int); 77 static int get_local_addr(struct sockaddr_dl *, struct in_addr *); 78 79 int 80 create_hello_socket() 81 { 82 struct ip_mreq mcast_addr; 83 int s = socket(PF_INET, SOCK_DGRAM, 17); 84 85 if (s < 0) 86 return s; 87 88 /* 89 * RFC3036 specifies we should listen to all subnet routers multicast 90 * group 91 */ 92 mcast_addr.imr_multiaddr.s_addr = inet_addr(ALL_ROUTERS); 93 mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY); 94 95 socket_reuse_port(s); 96 /* Bind it to port 646 on specific address */ 97 if (bind_socket(s, htonl(INADDR_ANY)) == -1) { 98 warnp("Cannot bind hello socket\n"); 99 close(s); 100 return -1; 101 } 102 /* We don't need to receive back our messages */ 103 if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_LOOP, &(uint8_t){0}, 104 sizeof(uint8_t)) == -1) { 105 fatalp("setsockopt: %s", strerror(errno)); 106 close(s); 107 return -1; 108 } 109 /* Finally join the group */ 110 if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *) &mcast_addr, 111 sizeof(mcast_addr)) == -1) { 112 fatalp("setsockopt: %s", strerror(errno)); 113 close(s); 114 return -1; 115 } 116 /* TTL:1, TOS: 0xc0 */ 117 if (set_mcast_ttl(s) == -1) { 118 close(s); 119 return -1; 120 } 121 if (set_tos(s) == -1) { 122 fatalp("set_tos: %s", strerror(errno)); 123 close(s); 124 return -1; 125 } 126 if (setsockopt(s, IPPROTO_IP, IP_RECVIF, &(uint32_t){1}, sizeof(uint32_t)) == -1) { 127 fatalp("Cannot set IP_RECVIF\n"); 128 close(s); 129 return -1; 130 } 131 hello_socket = s; 132 return hello_socket; 133 } 134 135 /* Sets the TTL to 1 as we don't want to transmit outside this subnet */ 136 int 137 set_ttl(int s) 138 { 139 int ret; 140 if ((ret = setsockopt(s, IPPROTO_IP, IP_TTL, &(int){1}, sizeof(int))) 141 == -1) 142 fatalp("set_ttl: %s", strerror(errno)); 143 return ret; 144 } 145 146 /* Sets multicast TTL to 1 */ 147 int 148 set_mcast_ttl(int s) 149 { 150 int ret; 151 if ((ret = setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, &(int){1}, 152 sizeof(int))) == -1) 153 fatalp("set_mcast_ttl: %s", strerror(errno)); 154 return ret; 155 } 156 157 /* Sets TOS to 0xc0 aka IP Precedence 6 */ 158 int 159 set_tos(int s) 160 { 161 int ret; 162 if ((ret = setsockopt(s, IPPROTO_IP, IP_TOS, &(int){0xc0}, 163 sizeof(int))) == -1) 164 fatalp("set_tos: %s", strerror(errno)); 165 return ret; 166 } 167 168 int 169 socket_reuse_port(int s) 170 { 171 int ret; 172 if ((ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &(int){1}, 173 sizeof(int))) == -1) 174 fatalp("socket_reuse_port: %s", strerror(errno)); 175 return ret; 176 } 177 178 /* binds an UDP socket */ 179 int 180 bind_socket(int s, uint32_t addr) 181 { 182 struct sockaddr_in sa; 183 184 sa.sin_len = sizeof(sa); 185 sa.sin_family = AF_INET; 186 sa.sin_port = htons(LDP_PORT); 187 sa.sin_addr.s_addr = addr; 188 if (bind(s, (struct sockaddr *) (&sa), sizeof(sa))) { 189 fatalp("bind_socket: %s", strerror(errno)); 190 return -1; 191 } 192 return 0; 193 } 194 195 /* Create / bind the TCP socket */ 196 int 197 create_listening_socket(void) 198 { 199 struct sockaddr_in sa; 200 int s; 201 202 sa.sin_len = sizeof(sa); 203 sa.sin_family = AF_INET; 204 sa.sin_port = htons(LDP_PORT); 205 sa.sin_addr.s_addr = htonl(INADDR_ANY); 206 207 s = socket(PF_INET, SOCK_STREAM, 6); 208 if (s < 0) 209 return s; 210 if (bind(s, (struct sockaddr *) & sa, sizeof(sa))) { 211 fatalp("bind: %s", strerror(errno)); 212 close(s); 213 return -1; 214 } 215 if (listen(s, 10) == -1) { 216 fatalp("listen: %s", strerror(errno)); 217 close(s); 218 return -1; 219 } 220 /* if (set_tos(s) == -1) { 221 fatalp("set_tos: %s", strerror(errno)); 222 close(s); 223 return -1; 224 } 225 */ return s; 226 } 227 228 /* 229 * It's ugly. We need a function to pass all tlvs and create pdu but since I 230 * use UDP socket only to send hellos, I didn't bother 231 */ 232 void 233 send_hello(void) 234 { 235 struct hello_tlv *t; 236 struct common_hello_tlv *cht; 237 struct ldp_pdu *spdu; 238 struct transport_address_tlv *trtlv; 239 void *v; 240 struct sockaddr_in sadest; /* Destination ALL_ROUTERS */ 241 int sb = 0; /* sent bytes */ 242 struct ifaddrs *ifa, *ifb; 243 struct sockaddr_in *if_sa; 244 char lastifname[20]; 245 246 #define HELLO_MSG_SIZE (sizeof(struct ldp_pdu) + /* PDU */ \ 247 TLV_TYPE_LENGTH + MSGID_SIZE + /* Hello TLV */ \ 248 /* Common Hello TLV */ \ 249 sizeof(struct common_hello_tlv) + \ 250 /* IPv4 Transport Address */ \ 251 sizeof(struct transport_address_tlv)) 252 253 if ((v = calloc(1, HELLO_MSG_SIZE)) == NULL) { 254 fatalp("malloc problem in send_hello()\n"); 255 return; 256 } 257 258 spdu = (struct ldp_pdu *)((char *)v); 259 t = (struct hello_tlv *)(spdu + 1); 260 cht = &t->ch; /* Hello tlv struct includes CHT */ 261 trtlv = (struct transport_address_tlv *)(t + 1); 262 263 /* Prepare PDU envelope */ 264 spdu->version = htons(LDP_VERSION); 265 spdu->length = htons(HELLO_MSG_SIZE - PDU_VER_LENGTH); 266 inet_aton(LDP_ID, &spdu->ldp_id); 267 268 /* Prepare Hello TLV */ 269 t->type = htons(LDP_HELLO); 270 t->length = htons(MSGID_SIZE + 271 sizeof(struct common_hello_tlv) + 272 sizeof(struct transport_address_tlv)); 273 /* 274 * I used ID 0 instead of htonl(get_message_id()) because I've 275 * seen hellos from a cisco router doing the same thing 276 */ 277 t->messageid = 0; 278 279 /* Prepare Common Hello attributes */ 280 cht->type = htons(TLV_COMMON_HELLO); 281 cht->length = htons(sizeof(cht->holdtime) + sizeof(cht->res)); 282 cht->holdtime = htons(LDP_HOLDTIME); 283 cht->res = 0; 284 285 /* 286 * Prepare Transport Address TLV RFC3036 says: "If this optional TLV 287 * is not present the IPv4 source address for the UDP packet carrying 288 * the Hello should be used." But we send it because everybody seems 289 * to do so 290 */ 291 trtlv->type = htons(TLV_IPV4_TRANSPORT); 292 trtlv->length = htons(sizeof(struct in_addr)); 293 /* trtlv->address will be set for each socket */ 294 295 /* Destination sockaddr */ 296 memset(&sadest, 0, sizeof(sadest)); 297 sadest.sin_len = sizeof(sadest); 298 sadest.sin_family = AF_INET; 299 sadest.sin_port = htons(LDP_PORT); 300 inet_aton(ALL_ROUTERS, &sadest.sin_addr); 301 302 if (getifaddrs(&ifa) == -1) { 303 free(v); 304 return; 305 } 306 307 lastifname[0] = '\0'; 308 for (ifb = ifa; ifb; ifb = ifb->ifa_next) { 309 if_sa = (struct sockaddr_in *) ifb->ifa_addr; 310 if (if_sa->sin_family != AF_INET) 311 continue; 312 if (ntohl(if_sa->sin_addr.s_addr) >> 24 == IN_LOOPBACKNET) 313 continue; 314 /* Send only once per interface, using master address */ 315 if (strcmp(ifb->ifa_name, lastifname) == 0) 316 continue; 317 debugp("Sending hello on %s\n", ifb->ifa_name); 318 if (setsockopt(hello_socket, IPPROTO_IP, IP_MULTICAST_IF, 319 &if_sa->sin_addr, sizeof(struct in_addr)) == -1) { 320 warnp("setsockopt failed: %s\n", strerror(errno)); 321 continue; 322 } 323 trtlv->address.s_addr = if_sa->sin_addr.s_addr; 324 325 strlcpy(lastifname, ifb->ifa_name, sizeof(lastifname)); 326 327 /* Send to the wire */ 328 sb = sendto(hello_socket, v, HELLO_MSG_SIZE, 329 0, (struct sockaddr *) & sadest, sizeof(sadest)); 330 if (sb < (int)HELLO_MSG_SIZE) 331 fatalp("send: %s", strerror(errno)); 332 else 333 debugp("Send %d bytes (PDU: %d, Hello TLV: %d, CH: %d)\n", 334 sb, (int) (sizeof(struct ldp_pdu) - PDU_VER_LENGTH), 335 (int) (TLV_TYPE_LENGTH + MSGID_SIZE), 336 (int) (sizeof(struct common_hello_tlv))); 337 338 } 339 freeifaddrs(ifa); 340 free(v); 341 } 342 343 int 344 get_message_id(void) 345 { 346 current_msg_id++; 347 return current_msg_id; 348 } 349 350 static int 351 get_local_addr(struct sockaddr_dl *sdl, struct in_addr *sin) 352 { 353 struct ifaddrs *ifa, *ifb; 354 struct sockaddr_in *sinet; 355 356 if (sdl == NULL) 357 return -1; 358 359 if (getifaddrs(&ifa) == -1) 360 return -1; 361 for (ifb = ifa; ifb; ifb = ifb->ifa_next) 362 if (ifb->ifa_addr->sa_family == AF_INET) { 363 if (if_nametoindex(ifb->ifa_name) != sdl->sdl_index) 364 continue; 365 sinet = (struct sockaddr_in*) ifb->ifa_addr; 366 sin->s_addr = sinet->sin_addr.s_addr; 367 freeifaddrs(ifa); 368 return 0; 369 } 370 freeifaddrs(ifa); 371 return -1; 372 } 373 374 /* Receive PDUs on Multicast UDP socket */ 375 void 376 recv_pdu(int sock) 377 { 378 struct ldp_pdu rpdu; 379 int c, i; 380 struct msghdr msg; 381 struct iovec iov[1]; 382 unsigned char recvspace[MAX_PDU_SIZE]; 383 struct hello_tlv *t; 384 struct sockaddr_in fromsa; 385 struct sockaddr_dl *sdl = NULL; 386 struct in_addr my_ldp_addr, local_addr; 387 struct cmsghdr *cmptr; 388 union { 389 struct cmsghdr cm; 390 char control[1024]; 391 } control_un; 392 393 debugp("Entering RECV_PDU\n"); 394 395 memset(&msg, 0, sizeof(msg)); 396 msg.msg_control = control_un.control; 397 msg.msg_controllen = sizeof(control_un.control); 398 msg.msg_flags = 0; 399 msg.msg_name = &fromsa; 400 msg.msg_namelen = sizeof(fromsa); 401 iov[0].iov_base = recvspace; 402 iov[0].iov_len = sizeof(recvspace); 403 msg.msg_iov = iov; 404 msg.msg_iovlen = 1; 405 406 c = recvmsg(sock, &msg, MSG_WAITALL); 407 debugp("Incoming PDU size: %d\n", c); 408 409 debugp("PDU from: %s\n", inet_ntoa(fromsa.sin_addr)); 410 411 /* Check to see if this is larger than MIN_PDU_SIZE */ 412 if (c < MIN_PDU_SIZE) 413 return; 414 415 /* Read the PDU */ 416 i = get_pdu(recvspace, &rpdu); 417 418 /* We currently understand Version 1 */ 419 if (rpdu.version != LDP_VERSION) { 420 fatalp("recv_pdu: Version mismatch\n"); 421 return; 422 } 423 424 /* Maybe it's our hello */ 425 inet_aton(LDP_ID, &my_ldp_addr); 426 if (rpdu.ldp_id.s_addr == my_ldp_addr.s_addr) { 427 fatalp("Received our PDU..\n"); /* it should be not looped */ 428 return; 429 } 430 431 if (msg.msg_controllen < (socklen_t)sizeof(struct cmsghdr) || 432 (msg.msg_flags & MSG_CTRUNC)) 433 local_addr.s_addr = my_ldp_addr.s_addr; 434 else { 435 for (cmptr = CMSG_FIRSTHDR(&msg); cmptr != NULL; 436 cmptr = CMSG_NXTHDR(&msg, cmptr)) 437 if (cmptr->cmsg_level == IPPROTO_IP && 438 cmptr->cmsg_type == IP_RECVIF) { 439 sdl = (struct sockaddr_dl *) CMSG_DATA(cmptr); 440 break; 441 } 442 if (get_local_addr(sdl, &local_addr) != 0) 443 local_addr.s_addr = my_ldp_addr.s_addr; 444 } 445 446 447 debugp("Read %d bytes from address %s Length: %.4d Version: %d\n", 448 c, inet_ntoa(rpdu.ldp_id), rpdu.length, rpdu.version); 449 450 /* Fill the TLV messages */ 451 t = get_hello_tlv(recvspace + i, c - i); 452 run_ldp_hello(&rpdu, t, &fromsa.sin_addr, &local_addr, sock); 453 } 454 455 void 456 send_hello_alarm(int unused) 457 { 458 struct ldp_peer *p; 459 struct hello_info *hi; 460 time_t t = time(NULL); 461 int olderrno = errno; 462 463 /* Send hellos */ 464 if (!(t % ldp_hello_time)) 465 send_hello(); 466 467 /* Timeout -- */ 468 SLIST_FOREACH(p, &ldp_peer_head, peers) 469 p->timeout--; 470 471 /* Check for timeout */ 472 check_peer: 473 SLIST_FOREACH(p, &ldp_peer_head, peers) 474 if (p->timeout < 1) 475 switch (p->state) { 476 case LDP_PEER_HOLDDOWN: 477 debugp("LDP holddown expired for peer %s\n", 478 inet_ntoa(p->ldp_id)); 479 ldp_peer_delete(p); 480 goto check_peer; 481 case LDP_PEER_ESTABLISHED: 482 case LDP_PEER_CONNECTED: 483 send_notification(p, 0, 484 NOTIF_KEEP_ALIVE_TIMER_EXPIRED); 485 warnp("Keepalive expired for %s\n", 486 inet_ntoa(p->ldp_id)); 487 ldp_peer_holddown(p); 488 break; 489 } /* switch */ 490 491 /* send keepalives */ 492 if (!(t % LDP_KEEPALIVE_TIME)) { 493 SLIST_FOREACH(p, &ldp_peer_head, peers) 494 if (p->state == LDP_PEER_ESTABLISHED) { 495 debugp("Sending KeepAlive to %s\n", 496 inet_ntoa(p->ldp_id)); 497 keep_alive(p); 498 } 499 } 500 501 /* Decrement hello info keepalives */ 502 SLIST_FOREACH(hi, &hello_info_head, infos) 503 hi->keepalive--; 504 505 /* Check hello keepalives */ 506 check_hello: 507 SLIST_FOREACH(hi, &hello_info_head, infos) 508 if (hi->keepalive < 1) { 509 SLIST_REMOVE(&hello_info_head, hi, hello_info, infos); 510 goto check_hello; 511 } 512 513 /* Set the alarm again and bail out */ 514 alarm(1); 515 errno = olderrno; 516 } 517 518 void 519 bail_out(int x) 520 { 521 ldp_peer_holddown_all(); 522 flush_mpls_routes(); 523 exit(0); 524 } 525 526 /* 527 * The big poll that catches every single event 528 * on every socket. 529 */ 530 void 531 the_big_loop(void) 532 { 533 int sock_error; 534 uint32_t i; 535 socklen_t sock_error_size = sizeof(int); 536 struct ldp_peer *p; 537 struct com_sock *cs; 538 struct pollfd pfd[MAX_POLL_FDS]; 539 540 SLIST_INIT(&hello_info_head); 541 542 signal(SIGALRM, send_hello_alarm); 543 signal(SIGPIPE, SIG_IGN); 544 signal(SIGTERM, bail_out); 545 send_hello_alarm(1); 546 547 route_socket = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC); 548 549 if (bind_current_routes() != LDP_E_OK) 550 fatalp("Cannot get current routes\n"); 551 552 for (;;) { 553 nfds_t pollsum = 4; 554 555 pfd[0].fd = ls; 556 pfd[0].events = POLLRDNORM; 557 pfd[0].revents = 0; 558 559 pfd[1].fd = route_socket; 560 pfd[1].events = POLLRDNORM; 561 pfd[1].revents = 0; 562 563 pfd[2].fd = command_socket; 564 pfd[2].events = POLLRDNORM; 565 pfd[2].revents = 0; 566 567 /* Hello socket */ 568 pfd[3].fd = hello_socket; 569 pfd[3].events = POLLIN; 570 pfd[3].revents = 0; 571 572 /* Command sockets */ 573 for (i=0; i < MAX_COMMAND_SOCKETS; i++) 574 if (csockets[i].socket != -1) { 575 pfd[pollsum].fd = csockets[i].socket; 576 pfd[pollsum].events = POLLIN; 577 pfd[pollsum].revents = 0; 578 pollsum++; 579 } 580 581 /* LDP Peer sockets */ 582 SLIST_FOREACH(p, &ldp_peer_head, peers) { 583 if (p->socket < 1) 584 continue; 585 switch (p->state) { 586 case LDP_PEER_CONNECTED: 587 case LDP_PEER_ESTABLISHED: 588 pfd[pollsum].fd = p->socket; 589 pfd[pollsum].events = POLLRDNORM; 590 pfd[pollsum].revents = 0; 591 pollsum++; 592 break; 593 case LDP_PEER_CONNECTING: 594 pfd[pollsum].fd = p->socket; 595 pfd[pollsum].events = POLLWRNORM; 596 pfd[pollsum].revents = 0; 597 pollsum++; 598 break; 599 } 600 } 601 602 if (pollsum >= MAX_POLL_FDS) { 603 fatalp("Too many sockets. Increase MAX_POLL_FDS\n"); 604 return; 605 } 606 if (poll(pfd, pollsum, INFTIM) < 0) { 607 if (errno != EINTR) 608 fatalp("poll: %s", strerror(errno)); 609 continue; 610 } 611 612 for (i = 0; i < pollsum; i++) { 613 if ((pfd[i].revents & POLLRDNORM) || 614 (pfd[i].revents & POLLIN)) { 615 if(pfd[i].fd == ls) { 616 new_peer_connection(); 617 } else if (pfd[i].fd == route_socket) { 618 struct rt_msg xbuf; 619 int l, to_read; 620 do { 621 l = recv(route_socket, &xbuf, 622 sizeof(struct rt_msg), MSG_PEEK); 623 } while ((l == -1) && (errno == EINTR)); 624 625 if (l == -1) 626 break; 627 628 to_read = l; 629 l = 0; 630 do { 631 l += recv(route_socket, &xbuf, 632 to_read - l, MSG_WAITALL); 633 } while (l != to_read); 634 635 check_route(&xbuf, to_read); 636 637 } else if (pfd[i].fd == hello_socket) { 638 /* Receiving hello socket */ 639 recv_pdu(pfd[i].fd); 640 } else if (pfd[i].fd == command_socket) { 641 command_accept(command_socket); 642 } else if ((cs = is_command_socket(pfd[i].fd)) 643 != NULL) { 644 command_dispatch(cs); 645 } else { 646 /* ldp peer socket */ 647 p = get_ldp_peer_by_socket(pfd[i].fd); 648 if (p) 649 recv_session_pdu(p); 650 } 651 } else if(pfd[i].revents & POLLWRNORM) { 652 p = get_ldp_peer_by_socket(pfd[i].fd); 653 if (!p) 654 continue; 655 if ((getsockopt(pfd[i].fd, SOL_SOCKET, SO_ERROR, 656 &sock_error, &sock_error_size) != 0) || 657 (sock_error)) { 658 ldp_peer_holddown(p); 659 } else { 660 p->state = LDP_PEER_CONNECTED; 661 send_initialize(p); 662 } 663 } 664 } 665 666 for (int ri = 0; ri < replay_index; ri++) { 667 debugp("Replaying: PID %d, SEQ %d\n", 668 replay_rt[ri].m_rtm.rtm_pid, 669 replay_rt[ri].m_rtm.rtm_seq); 670 check_route(&replay_rt[ri], sizeof(struct rt_msg)); 671 } 672 replay_index = 0; 673 } /* for (;;) */ 674 } 675 676 void 677 new_peer_connection() 678 { 679 struct sockaddr_in sa, sin_me; 680 int s; 681 682 s = accept(ls, (struct sockaddr *) & sa, 683 & (socklen_t) { sizeof(struct sockaddr_in) } ); 684 if (s < 0) { 685 fatalp("accept: %s", strerror(errno)); 686 return; 687 } 688 689 if (get_ldp_peer(&sa.sin_addr) != NULL) { 690 close(s); 691 return; 692 } 693 694 warnp("Accepted a connection from %s\n", inet_ntoa(sa.sin_addr)); 695 696 if (getsockname(s, (struct sockaddr *)&sin_me, 697 & (socklen_t) { sizeof(struct sockaddr_in) } )) { 698 fatalp("new_peer_connection(): cannot getsockname\n"); 699 close(s); 700 return; 701 } 702 703 if (ntohl(sa.sin_addr.s_addr) < ntohl(sin_me.sin_addr.s_addr)) { 704 fatalp("Peer %s: connect from lower ID\n", 705 inet_ntoa(sa.sin_addr)); 706 close(s); 707 return; 708 } 709 /* XXX: sa.sin_addr ain't peer LDP ID ... */ 710 ldp_peer_new(&sa.sin_addr, &sa.sin_addr, NULL, LDP_HOLDTIME, s); 711 712 } 713 714 void 715 send_initialize(struct ldp_peer * p) 716 { 717 struct init_tlv ti; 718 719 ti.type = htons(LDP_INITIALIZE); 720 ti.length = htons(sizeof(struct init_tlv) - TLV_TYPE_LENGTH); 721 ti.messageid = htonl(get_message_id()); 722 ti.cs_type = htons(TLV_COMMON_SESSION); 723 ti.cs_len = htons(CS_LEN); 724 ti.cs_version = htons(LDP_VERSION); 725 ti.cs_keepalive = htons(2 * LDP_KEEPALIVE_TIME); 726 ti.cs_adpvlim = 0; 727 ti.cs_maxpdulen = htons(MAX_PDU_SIZE); 728 ti.cs_peeraddress.s_addr = p->ldp_id.s_addr; 729 ti.cs_peeraddrspace = 0; 730 731 send_tlv(p, (struct tlv *) (void *) &ti); 732 } 733 734 void 735 keep_alive(struct ldp_peer * p) 736 { 737 struct ka_tlv kt; 738 739 kt.type = htons(LDP_KEEPALIVE); 740 kt.length = htons(sizeof(kt.messageid)); 741 kt.messageid = htonl(get_message_id()); 742 743 send_tlv(p, (struct tlv *) (void *) &kt); 744 745 } 746 747 void 748 recv_session_pdu(struct ldp_peer * p) 749 { 750 struct ldp_pdu *rpdu; 751 struct address_tlv *atlv; 752 struct al_tlv *altlv; 753 struct init_tlv *itlv; 754 struct label_map_tlv *lmtlv; 755 struct fec_tlv *fectlv; 756 struct label_tlv *__packed labeltlv; 757 struct notification_tlv *nottlv; 758 struct hello_info *hi; 759 760 int c; 761 int32_t wo = 0; 762 struct tlv *ttmp; 763 unsigned char recvspace[MAX_PDU_SIZE]; 764 765 memset(recvspace, 0, MAX_PDU_SIZE); 766 767 c = recv(p->socket, (void *) recvspace, MAX_PDU_SIZE, MSG_PEEK); 768 769 debugp("Ready to read %d bytes\n", c); 770 771 if (c < 1) { /* Session closed */ 772 warnp("Error in connection with %s\n", inet_ntoa(p->ldp_id)); 773 ldp_peer_holddown(p); 774 return; 775 } 776 if (c > MAX_PDU_SIZE) { 777 debugp("Incoming PDU size exceeds MAX_PDU_SIZE !\n"); 778 return; 779 } 780 if (c < MIN_PDU_SIZE) { 781 debugp("PDU too small received from peer %s\n", inet_ntoa(p->ldp_id)); 782 return; 783 } 784 rpdu = (struct ldp_pdu *) recvspace; 785 /* XXX: buggy messages may crash the whole thing */ 786 c = recv(p->socket, (void *) recvspace, 787 ntohs(rpdu->length) + PDU_VER_LENGTH, MSG_WAITALL); 788 rpdu = (struct ldp_pdu *) recvspace; 789 790 /* Check if it's somehow OK... */ 791 if (check_recv_pdu(p, rpdu, c) != 0) 792 return; 793 794 debugp("Read %d bytes, PDU size: %d bytes\n", c, ntohs(rpdu->length)); 795 wo = sizeof(struct ldp_pdu); 796 797 while (wo + TLV_TYPE_LENGTH < (uint)c) { 798 799 ttmp = (struct tlv *) (&recvspace[wo]); 800 801 if ((ntohs(ttmp->type) != LDP_KEEPALIVE) && 802 (ntohs(ttmp->type) != LDP_LABEL_MAPPING)) { 803 debugp("Got Type: 0x%.4X (Length: %d) from %s\n", 804 ntohs(ttmp->type), ntohs(ttmp->length), 805 inet_ntoa(p->ldp_id)); 806 } else 807 debugp("Got Type: 0x%.4X (Length: %d) from %s\n", 808 ntohs(ttmp->type), ntohs(ttmp->length), 809 inet_ntoa(p->ldp_id)); 810 811 /* Should we get the message ? */ 812 if (p->state != LDP_PEER_ESTABLISHED && 813 ntohs(ttmp->type) != LDP_INITIALIZE && 814 ntohs(ttmp->type) != LDP_KEEPALIVE) 815 break; 816 /* The big switch */ 817 switch (ntohs(ttmp->type)) { 818 case LDP_INITIALIZE: 819 itlv = (struct init_tlv *)ttmp; 820 /* Check size */ 821 if (ntohs(itlv->length) < 822 sizeof(struct init_tlv) - TLV_TYPE_LENGTH) { 823 send_notification(p, 0, 824 NOTIF_BAD_PDU_LEN | NOTIF_FATAL); 825 ldp_peer_holddown(p); 826 break; 827 } 828 /* Check version */ 829 if (ntohs(itlv->cs_version) != LDP_VERSION) { 830 send_notification(p, ntohl(itlv->messageid), 831 NOTIF_BAD_LDP_VER | NOTIF_FATAL); 832 ldp_peer_holddown(p); 833 break; 834 } 835 /* Check if we got any hello from this one */ 836 SLIST_FOREACH(hi, &hello_info_head, infos) 837 if (hi->ldp_id.s_addr == rpdu->ldp_id.s_addr) 838 break; 839 if (hi == NULL) { 840 send_notification(p, ntohl(itlv->messageid), 841 NOTIF_SESSION_REJECTED_NO_HELLO | NOTIF_FATAL); 842 ldp_peer_holddown(p); 843 break; 844 } 845 846 if (!p->master) { 847 keep_alive(p); 848 send_initialize(p); 849 } else { 850 p->state = LDP_PEER_ESTABLISHED; 851 p->established_t = time(NULL); 852 keep_alive(p); 853 854 /* 855 * Recheck here ldp id because we accepted 856 * connection without knowing who is it for sure 857 */ 858 p->ldp_id.s_addr = rpdu->ldp_id.s_addr; 859 860 fatalp("LDP neighbour %s is UP\n", 861 inet_ntoa(p->ldp_id)); 862 mpls_add_ldp_peer(p); 863 send_addresses(p); 864 send_all_bindings(p); 865 } 866 break; 867 case LDP_KEEPALIVE: 868 if ((p->state == LDP_PEER_CONNECTED) && (!p->master)) { 869 p->state = LDP_PEER_ESTABLISHED; 870 p->established_t = time(NULL); 871 fatalp("LDP neighbour %s is UP\n", 872 inet_ntoa(p->ldp_id)); 873 mpls_add_ldp_peer(p); 874 send_addresses(p); 875 send_all_bindings(p); 876 } 877 p->timeout = p->holdtime; 878 break; 879 case LDP_ADDRESS: 880 /* Add peer addresses */ 881 atlv = (struct address_tlv *) ttmp; 882 altlv = (struct al_tlv *) (&atlv[1]); 883 add_ifaddresses(p, altlv); 884 print_bounded_addresses(p); 885 break; 886 case LDP_ADDRESS_WITHDRAW: 887 atlv = (struct address_tlv *) ttmp; 888 altlv = (struct al_tlv *) (&atlv[1]); 889 del_ifaddresses(p, altlv); 890 break; 891 case LDP_LABEL_MAPPING: 892 lmtlv = (struct label_map_tlv *) ttmp; 893 fectlv = (struct fec_tlv *) (&lmtlv[1]); 894 labeltlv = (struct label_tlv *)((unsigned char *)fectlv 895 + ntohs(fectlv->length) + TLV_TYPE_LENGTH); 896 map_label(p, fectlv, labeltlv); 897 break; 898 case LDP_LABEL_REQUEST: 899 lmtlv = (struct label_map_tlv *) ttmp; 900 fectlv = (struct fec_tlv *) (&lmtlv[1]); 901 switch (request_respond(p, lmtlv, fectlv)) { 902 case LDP_E_BAD_FEC: 903 send_notification(p, ntohl(lmtlv->messageid), 904 NOTIF_UNKNOWN_TLV); 905 break; 906 case LDP_E_BAD_AF: 907 send_notification(p, ntohl(lmtlv->messageid), 908 NOTIF_UNSUPPORTED_AF); 909 break; 910 case LDP_E_NO_SUCH_ROUTE: 911 send_notification(p, ntohl(lmtlv->messageid), 912 NOTIF_NO_ROUTE); 913 break; 914 } 915 break; 916 case LDP_LABEL_WITHDRAW: 917 lmtlv = (struct label_map_tlv *) ttmp; 918 fectlv = (struct fec_tlv *) (&lmtlv[1]); 919 if (withdraw_label(p, fectlv) == LDP_E_OK) { 920 /* Send RELEASE */ 921 prepare_release(ttmp); 922 send_tlv(p, ttmp); 923 } 924 break; 925 case LDP_LABEL_RELEASE: 926 /* 927 * XXX: we need to make a timed queue... 928 * For now I just assume peers are processing messages 929 * correctly so I just ignore confirmations 930 */ 931 wo = -1; /* Ignore rest of message */ 932 break; 933 case LDP_LABEL_ABORT: 934 /* XXX: For now I pretend I can process everything 935 * RFC 3036, Section 3.5.9.1 936 * If an LSR receives a Label Abort Request Message after it 937 * has responded to the Label Request in question with a Label 938 * Mapping message or a Notification message, it ignores the 939 * abort request. 940 */ 941 wo = -1; 942 break; 943 case LDP_NOTIFICATION: 944 nottlv = (struct notification_tlv *) ttmp; 945 nottlv->st_code = ntohl(nottlv->st_code); 946 fatalp("Got notification 0x%X from peer %s\n", 947 nottlv->st_code, inet_ntoa(p->ldp_id)); 948 if (nottlv->st_code >> 31) { 949 fatalp("LDP peer %s signalized %s\n", 950 inet_ntoa(p->ldp_id), 951 NOTIF_STR[(nottlv->st_code << 1) >> 1]); 952 ldp_peer_holddown(p); 953 wo = -1; 954 } 955 break; 956 case LDP_HELLO: 957 /* No hellos should came on tcp session */ 958 wo = -1; 959 break; 960 default: 961 warnp("Unknown TLV received from %s\n", 962 inet_ntoa(p->ldp_id)); 963 debug_tlv(ttmp); 964 wo = -1;/* discard the rest of the message */ 965 break; 966 } 967 if (wo < 0) { 968 debugp("Discarding the rest of the message\n"); 969 break; 970 } else { 971 wo += ntohs(ttmp->length) + TLV_TYPE_LENGTH; 972 debugp("WORKED ON %u bytes (Left %d)\n", wo, c - wo); 973 } 974 } /* while */ 975 976 } 977 978 /* Sends a pdu, tlv pair to a connected peer */ 979 int 980 send_message(struct ldp_peer * p, struct ldp_pdu * pdu, struct tlv * t) 981 { 982 unsigned char sendspace[MAX_PDU_SIZE]; 983 984 /* Check if peer is connected */ 985 switch (p->state) { 986 case LDP_PEER_CONNECTED: 987 case LDP_PEER_ESTABLISHED: 988 break; 989 default: 990 return -1; 991 } 992 993 /* Check length validity first */ 994 if (ntohs(pdu->length) != 995 ntohs(t->length) + TLV_TYPE_LENGTH + PDU_PAYLOAD_LENGTH) { 996 fatalp("LDP: TLV - PDU incompability. Message discarded\n"); 997 fatalp("LDP: TLV len %d - PDU len %d\n", ntohs(t->length), 998 ntohs(pdu->length)); 999 return -1; 1000 } 1001 if (ntohs(t->length) + PDU_VER_LENGTH > MAX_PDU_SIZE) { 1002 fatalp("Message to large discarded\n"); 1003 return -1; 1004 } 1005 /* Arrange them in a buffer and send */ 1006 memcpy(sendspace, pdu, sizeof(struct ldp_pdu)); 1007 memcpy(sendspace + sizeof(struct ldp_pdu), t, 1008 ntohs(t->length) + TLV_TYPE_LENGTH); 1009 1010 /* Report keepalives only for DEBUG */ 1011 if ((ntohs(t->type) != 0x201) && (ntohs(t->type) != 0x400)) { 1012 debugp("Sending message type 0x%.4X to %s (size: %d)\n", 1013 ntohs(t->type), inet_ntoa(p->ldp_id), ntohs(t->length)); 1014 } else 1015 /* downgraded from warnp to debugp for now */ 1016 debugp("Sending message type 0x%.4X to %s (size: %d)\n", 1017 ntohs(t->type), inet_ntoa(p->ldp_id), ntohs(t->length)); 1018 1019 /* Send it finally */ 1020 return send(p->socket, sendspace, 1021 ntohs(pdu->length) + PDU_VER_LENGTH, 0); 1022 } 1023 1024 /* 1025 * Encapsulates TLV into a PDU and sends it to a peer 1026 */ 1027 int 1028 send_tlv(struct ldp_peer * p, struct tlv * t) 1029 { 1030 struct ldp_pdu pdu; 1031 1032 pdu.version = htons(LDP_VERSION); 1033 inet_aton(LDP_ID, &pdu.ldp_id); 1034 pdu.label_space = 0; 1035 pdu.length = htons(ntohs(t->length) + TLV_TYPE_LENGTH + 1036 PDU_PAYLOAD_LENGTH); 1037 1038 return send_message(p, &pdu, t); 1039 } 1040 1041 1042 int 1043 send_addresses(struct ldp_peer * p) 1044 { 1045 struct address_list_tlv *t; 1046 int ret; 1047 1048 t = build_address_list_tlv(); 1049 1050 ret = send_tlv(p, (struct tlv *) t); 1051 free(t); 1052 return ret; 1053 1054 } 1055