socketops.c revision 1.6.2.1
1 /* $NetBSD: socketops.c,v 1.6.2.1 2011/06/23 14:20:48 cherry 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 (at) 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 <assert.h> 41 #include <errno.h> 42 #include <ifaddrs.h> 43 #include <poll.h> 44 #include <signal.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <strings.h> 48 #include <unistd.h> 49 50 #include "fsm.h" 51 #include "ldp.h" 52 #include "ldp_command.h" 53 #include "tlv.h" 54 #include "ldp_peer.h" 55 #include "notifications.h" 56 #include "tlv_stack.h" 57 #include "mpls_interface.h" 58 #include "label.h" 59 #include "mpls_routes.h" 60 #include "ldp_errors.h" 61 #include "socketops.h" 62 63 int ls; /* TCP listening socket on port 646 */ 64 int route_socket; /* used to see when a route is added/deleted */ 65 int hello_socket; /* hello multicast listener - transmitter */ 66 int command_socket; /* Listening socket for interface command */ 67 int current_msg_id = 0x233; 68 int command_port = LDP_COMMAND_PORT; 69 extern int replay_index; 70 extern struct rt_msg replay_rt[REPLAY_MAX]; 71 extern struct com_sock csockets[MAX_COMMAND_SOCKETS]; 72 73 int ldp_hello_time = LDP_HELLO_TIME; 74 int ldp_keepalive_time = LDP_KEEPALIVE_TIME; 75 int ldp_holddown_time = LDP_HOLDTIME; 76 int no_default_route = 1; 77 78 void recv_pdu(int); 79 void send_hello_alarm(int); 80 void bail_out(int); 81 static int get_local_addr(struct sockaddr_dl *, struct in_addr *); 82 83 int 84 create_hello_socket() 85 { 86 struct ip_mreq mcast_addr; 87 int s = socket(PF_INET, SOCK_DGRAM, 17); 88 89 if (s < 0) 90 return s; 91 92 /* 93 * RFC3036 specifies we should listen to all subnet routers multicast 94 * group 95 */ 96 mcast_addr.imr_multiaddr.s_addr = inet_addr(ALL_ROUTERS); 97 mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY); 98 99 socket_reuse_port(s); 100 /* Bind it to port 646 on specific address */ 101 if (bind_socket(s, htonl(INADDR_ANY)) == -1) { 102 warnp("Cannot bind hello socket\n"); 103 close(s); 104 return -1; 105 } 106 /* We don't need to receive back our messages */ 107 if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_LOOP, &(uint8_t){0}, 108 sizeof(uint8_t)) == -1) { 109 fatalp("setsockopt: %s", strerror(errno)); 110 close(s); 111 return -1; 112 } 113 /* Finally join the group */ 114 if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *) &mcast_addr, 115 sizeof(mcast_addr)) == -1) { 116 fatalp("setsockopt: %s", strerror(errno)); 117 close(s); 118 return -1; 119 } 120 /* TTL:1, TOS: 0xc0 */ 121 if (set_mcast_ttl(s) == -1) { 122 close(s); 123 return -1; 124 } 125 if (set_tos(s) == -1) { 126 fatalp("set_tos: %s", strerror(errno)); 127 close(s); 128 return -1; 129 } 130 if (setsockopt(s, IPPROTO_IP, IP_RECVIF, &(uint32_t){1}, sizeof(uint32_t)) == -1) { 131 fatalp("Cannot set IP_RECVIF\n"); 132 close(s); 133 return -1; 134 } 135 hello_socket = s; 136 return hello_socket; 137 } 138 139 /* Sets the TTL to 1 as we don't want to transmit outside this subnet */ 140 int 141 set_ttl(int s) 142 { 143 int ret; 144 if ((ret = setsockopt(s, IPPROTO_IP, IP_TTL, &(int){1}, sizeof(int))) 145 == -1) 146 fatalp("set_ttl: %s", strerror(errno)); 147 return ret; 148 } 149 150 /* Sets multicast TTL to 1 */ 151 int 152 set_mcast_ttl(int s) 153 { 154 int ret; 155 if ((ret = setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, &(int){1}, 156 sizeof(int))) == -1) 157 fatalp("set_mcast_ttl: %s", strerror(errno)); 158 return ret; 159 } 160 161 /* Sets TOS to 0xc0 aka IP Precedence 6 */ 162 int 163 set_tos(int s) 164 { 165 int ret; 166 if ((ret = setsockopt(s, IPPROTO_IP, IP_TOS, &(int){0xc0}, 167 sizeof(int))) == -1) 168 fatalp("set_tos: %s", strerror(errno)); 169 return ret; 170 } 171 172 int 173 socket_reuse_port(int s) 174 { 175 int ret; 176 if ((ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &(int){1}, 177 sizeof(int))) == -1) 178 fatalp("socket_reuse_port: %s", strerror(errno)); 179 return ret; 180 } 181 182 /* binds an UDP socket */ 183 int 184 bind_socket(int s, uint32_t addr) 185 { 186 struct sockaddr_in sa; 187 188 sa.sin_len = sizeof(sa); 189 sa.sin_family = AF_INET; 190 sa.sin_port = htons(LDP_PORT); 191 sa.sin_addr.s_addr = addr; 192 if (bind(s, (struct sockaddr *) (&sa), sizeof(sa))) { 193 fatalp("bind_socket: %s", strerror(errno)); 194 return -1; 195 } 196 return 0; 197 } 198 199 /* Create / bind the TCP socket */ 200 int 201 create_listening_socket(void) 202 { 203 struct sockaddr_in sa; 204 int s; 205 206 sa.sin_len = sizeof(sa); 207 sa.sin_family = AF_INET; 208 sa.sin_port = htons(LDP_PORT); 209 sa.sin_addr.s_addr = htonl(INADDR_ANY); 210 211 s = socket(PF_INET, SOCK_STREAM, 6); 212 if (s < 0) 213 return s; 214 if (bind(s, (struct sockaddr *) & sa, sizeof(sa))) { 215 fatalp("bind: %s", strerror(errno)); 216 close(s); 217 return -1; 218 } 219 if (listen(s, 10) == -1) { 220 fatalp("listen: %s", strerror(errno)); 221 close(s); 222 return -1; 223 } 224 /* if (set_tos(s) == -1) { 225 fatalp("set_tos: %s", strerror(errno)); 226 close(s); 227 return -1; 228 } 229 */ return s; 230 } 231 232 /* 233 * It's ugly. We need a function to pass all tlvs and create pdu but since I 234 * use UDP socket only to send hellos, I didn't bother 235 */ 236 void 237 send_hello(void) 238 { 239 struct hello_tlv *t; 240 struct common_hello_tlv *cht; 241 struct ldp_pdu *spdu; 242 struct transport_address_tlv *trtlv; 243 void *v; 244 struct sockaddr_in sadest; /* Destination ALL_ROUTERS */ 245 int sb = 0; /* sent bytes */ 246 struct ifaddrs *ifa, *ifb; 247 struct sockaddr_in *if_sa; 248 char lastifname[20]; 249 250 #define HELLO_MSG_SIZE (sizeof(struct ldp_pdu) + /* PDU */ \ 251 TLV_TYPE_LENGTH + MSGID_SIZE + /* Hello TLV */ \ 252 /* Common Hello TLV */ \ 253 sizeof(struct common_hello_tlv) + \ 254 /* IPv4 Transport Address */ \ 255 sizeof(struct transport_address_tlv)) 256 257 if ((v = calloc(1, HELLO_MSG_SIZE)) == NULL) { 258 fatalp("malloc problem in send_hello()\n"); 259 return; 260 } 261 262 spdu = (struct ldp_pdu *)((char *)v); 263 t = (struct hello_tlv *)(spdu + 1); 264 cht = &t->ch; /* Hello tlv struct includes CHT */ 265 trtlv = (struct transport_address_tlv *)(t + 1); 266 267 /* Prepare PDU envelope */ 268 spdu->version = htons(LDP_VERSION); 269 spdu->length = htons(HELLO_MSG_SIZE - PDU_VER_LENGTH); 270 inet_aton(LDP_ID, &spdu->ldp_id); 271 272 /* Prepare Hello TLV */ 273 t->type = htons(LDP_HELLO); 274 t->length = htons(MSGID_SIZE + 275 sizeof(struct common_hello_tlv) + 276 sizeof(struct transport_address_tlv)); 277 /* 278 * I used ID 0 instead of htonl(get_message_id()) because I've 279 * seen hellos from a cisco router doing the same thing 280 */ 281 t->messageid = 0; 282 283 /* Prepare Common Hello attributes */ 284 cht->type = htons(TLV_COMMON_HELLO); 285 cht->length = htons(sizeof(cht->holdtime) + sizeof(cht->res)); 286 cht->holdtime = htons(ldp_holddown_time); 287 cht->res = 0; 288 289 /* 290 * Prepare Transport Address TLV RFC3036 says: "If this optional TLV 291 * is not present the IPv4 source address for the UDP packet carrying 292 * the Hello should be used." But we send it because everybody seems 293 * to do so 294 */ 295 trtlv->type = htons(TLV_IPV4_TRANSPORT); 296 trtlv->length = htons(sizeof(struct in_addr)); 297 /* trtlv->address will be set for each socket */ 298 299 /* Destination sockaddr */ 300 memset(&sadest, 0, sizeof(sadest)); 301 sadest.sin_len = sizeof(sadest); 302 sadest.sin_family = AF_INET; 303 sadest.sin_port = htons(LDP_PORT); 304 inet_aton(ALL_ROUTERS, &sadest.sin_addr); 305 306 if (getifaddrs(&ifa) == -1) { 307 free(v); 308 return; 309 } 310 311 lastifname[0] = '\0'; 312 for (ifb = ifa; ifb; ifb = ifb->ifa_next) { 313 if_sa = (struct sockaddr_in *) ifb->ifa_addr; 314 if (if_sa->sin_family != AF_INET) 315 continue; 316 if (ntohl(if_sa->sin_addr.s_addr) >> 24 == IN_LOOPBACKNET || 317 ntohl(if_sa->sin_addr.s_addr) >> 24 == 0) 318 continue; 319 /* Send only once per interface, using master address */ 320 if (strcmp(ifb->ifa_name, lastifname) == 0) 321 continue; 322 debugp("Sending hello on %s\n", ifb->ifa_name); 323 if (setsockopt(hello_socket, IPPROTO_IP, IP_MULTICAST_IF, 324 &if_sa->sin_addr, sizeof(struct in_addr)) == -1) { 325 warnp("setsockopt failed: %s\n", strerror(errno)); 326 continue; 327 } 328 trtlv->address.s_addr = if_sa->sin_addr.s_addr; 329 330 strlcpy(lastifname, ifb->ifa_name, sizeof(lastifname)); 331 332 /* Send to the wire */ 333 sb = sendto(hello_socket, v, HELLO_MSG_SIZE, 334 0, (struct sockaddr *) & sadest, sizeof(sadest)); 335 if (sb < (int)HELLO_MSG_SIZE) 336 fatalp("send: %s", strerror(errno)); 337 else 338 debugp("Send %d bytes (PDU: %d, Hello TLV: %d, CH: %d)\n", 339 sb, (int) (sizeof(struct ldp_pdu) - PDU_VER_LENGTH), 340 (int) (TLV_TYPE_LENGTH + MSGID_SIZE), 341 (int) (sizeof(struct common_hello_tlv))); 342 343 } 344 freeifaddrs(ifa); 345 free(v); 346 } 347 348 int 349 get_message_id(void) 350 { 351 current_msg_id++; 352 return current_msg_id; 353 } 354 355 static int 356 get_local_addr(struct sockaddr_dl *sdl, struct in_addr *sin) 357 { 358 struct ifaddrs *ifa, *ifb; 359 struct sockaddr_in *sinet; 360 361 if (sdl == NULL) 362 return -1; 363 364 if (getifaddrs(&ifa) == -1) 365 return -1; 366 for (ifb = ifa; ifb; ifb = ifb->ifa_next) 367 if (ifb->ifa_addr->sa_family == AF_INET) { 368 if (if_nametoindex(ifb->ifa_name) != sdl->sdl_index) 369 continue; 370 sinet = (struct sockaddr_in*) ifb->ifa_addr; 371 sin->s_addr = sinet->sin_addr.s_addr; 372 freeifaddrs(ifa); 373 return 0; 374 } 375 freeifaddrs(ifa); 376 return -1; 377 } 378 379 /* Receive PDUs on Multicast UDP socket */ 380 void 381 recv_pdu(int sock) 382 { 383 struct ldp_pdu rpdu; 384 int c, i; 385 struct msghdr msg; 386 struct iovec iov[1]; 387 unsigned char recvspace[MAX_PDU_SIZE]; 388 struct hello_tlv *t; 389 struct sockaddr_in fromsa; 390 struct sockaddr_dl *sdl = NULL; 391 struct in_addr my_ldp_addr, local_addr; 392 struct cmsghdr *cmptr; 393 union { 394 struct cmsghdr cm; 395 char control[1024]; 396 } control_un; 397 398 debugp("Entering RECV_PDU\n"); 399 400 memset(&msg, 0, sizeof(msg)); 401 msg.msg_control = control_un.control; 402 msg.msg_controllen = sizeof(control_un.control); 403 msg.msg_flags = 0; 404 msg.msg_name = &fromsa; 405 msg.msg_namelen = sizeof(fromsa); 406 iov[0].iov_base = recvspace; 407 iov[0].iov_len = sizeof(recvspace); 408 msg.msg_iov = iov; 409 msg.msg_iovlen = 1; 410 411 c = recvmsg(sock, &msg, MSG_WAITALL); 412 debugp("Incoming PDU size: %d\n", c); 413 414 debugp("PDU from: %s\n", inet_ntoa(fromsa.sin_addr)); 415 416 /* Check to see if this is larger than MIN_PDU_SIZE */ 417 if (c < MIN_PDU_SIZE) 418 return; 419 420 /* Read the PDU */ 421 i = get_pdu(recvspace, &rpdu); 422 423 /* We currently understand Version 1 */ 424 if (rpdu.version != LDP_VERSION) { 425 fatalp("recv_pdu: Version mismatch\n"); 426 return; 427 } 428 429 /* Maybe it's our hello */ 430 inet_aton(LDP_ID, &my_ldp_addr); 431 if (rpdu.ldp_id.s_addr == my_ldp_addr.s_addr) { 432 fatalp("Received our PDU..\n"); /* it should be not looped */ 433 return; 434 } 435 436 if (msg.msg_controllen < (socklen_t)sizeof(struct cmsghdr) || 437 (msg.msg_flags & MSG_CTRUNC)) 438 local_addr.s_addr = my_ldp_addr.s_addr; 439 else { 440 for (cmptr = CMSG_FIRSTHDR(&msg); cmptr != NULL; 441 cmptr = CMSG_NXTHDR(&msg, cmptr)) 442 if (cmptr->cmsg_level == IPPROTO_IP && 443 cmptr->cmsg_type == IP_RECVIF) { 444 sdl = (struct sockaddr_dl *) CMSG_DATA(cmptr); 445 break; 446 } 447 if (get_local_addr(sdl, &local_addr) != 0) 448 local_addr.s_addr = my_ldp_addr.s_addr; 449 } 450 451 452 debugp("Read %d bytes from address %s Length: %.4d Version: %d\n", 453 c, inet_ntoa(rpdu.ldp_id), rpdu.length, rpdu.version); 454 455 /* Fill the TLV messages */ 456 t = get_hello_tlv(recvspace + i, c - i); 457 run_ldp_hello(&rpdu, t, &fromsa.sin_addr, &local_addr, sock); 458 } 459 460 void 461 send_hello_alarm(int unused) 462 { 463 struct ldp_peer *p, *ptmp; 464 struct hello_info *hi, *hinext; 465 time_t t = time(NULL); 466 int olderrno = errno; 467 468 /* Send hellos */ 469 if (!(t % ldp_hello_time)) 470 send_hello(); 471 472 /* Timeout -- */ 473 SLIST_FOREACH(p, &ldp_peer_head, peers) 474 p->timeout--; 475 476 /* Check for timeout */ 477 SLIST_FOREACH_SAFE(p, &ldp_peer_head, peers, ptmp) 478 if (p->timeout < 1) 479 switch (p->state) { 480 case LDP_PEER_HOLDDOWN: 481 debugp("LDP holddown expired for peer %s\n", 482 inet_ntoa(p->ldp_id)); 483 ldp_peer_delete(p); 484 break; 485 case LDP_PEER_ESTABLISHED: 486 case LDP_PEER_CONNECTED: 487 send_notification(p, 0, 488 NOTIF_KEEP_ALIVE_TIMER_EXPIRED); 489 warnp("Keepalive expired for %s\n", 490 inet_ntoa(p->ldp_id)); 491 ldp_peer_holddown(p); 492 break; 493 } /* switch */ 494 495 /* send keepalives */ 496 if (!(t % ldp_keepalive_time)) { 497 SLIST_FOREACH(p, &ldp_peer_head, peers) 498 if (p->state == LDP_PEER_ESTABLISHED) { 499 debugp("Sending KeepAlive to %s\n", 500 inet_ntoa(p->ldp_id)); 501 keep_alive(p); 502 } 503 } 504 505 /* Decrement hello info keepalives */ 506 SLIST_FOREACH(hi, &hello_info_head, infos) 507 if (hi->keepalive != 0xFFFF) 508 hi->keepalive--; 509 510 /* Check hello keepalives */ 511 SLIST_FOREACH_SAFE(hi, &hello_info_head, infos, hinext) 512 if (hi->keepalive < 1) 513 SLIST_REMOVE(&hello_info_head, hi, hello_info, infos); 514 515 /* Set the alarm again and bail out */ 516 alarm(1); 517 errno = olderrno; 518 } 519 520 void 521 bail_out(int x) 522 { 523 ldp_peer_holddown_all(); 524 flush_mpls_routes(); 525 exit(0); 526 } 527 528 /* 529 * The big poll that catches every single event 530 * on every socket. 531 */ 532 int 533 the_big_loop(void) 534 { 535 int sock_error; 536 uint32_t i; 537 socklen_t sock_error_size = sizeof(int); 538 struct ldp_peer *p; 539 struct com_sock *cs; 540 struct pollfd pfd[MAX_POLL_FDS]; 541 542 assert(MAX_POLL_FDS > 3); 543 544 SLIST_INIT(&hello_info_head); 545 546 signal(SIGALRM, send_hello_alarm); 547 signal(SIGPIPE, SIG_IGN); 548 signal(SIGINT, bail_out); 549 signal(SIGTERM, bail_out); 550 send_hello_alarm(1); 551 552 route_socket = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC); 553 554 sock_error = bind_current_routes(); 555 if (sock_error != LDP_E_OK) { 556 fatalp("Cannot get current routes\n"); 557 return sock_error; 558 } 559 560 for (;;) { 561 nfds_t pollsum = 4; 562 563 pfd[0].fd = ls; 564 pfd[0].events = POLLRDNORM; 565 pfd[0].revents = 0; 566 567 pfd[1].fd = route_socket; 568 pfd[1].events = POLLRDNORM; 569 pfd[1].revents = 0; 570 571 pfd[2].fd = command_socket; 572 pfd[2].events = POLLRDNORM; 573 pfd[2].revents = 0; 574 575 /* Hello socket */ 576 pfd[3].fd = hello_socket; 577 pfd[3].events = POLLIN; 578 pfd[3].revents = 0; 579 580 /* Command sockets */ 581 for (i=0; i < MAX_COMMAND_SOCKETS; i++) 582 if (csockets[i].socket != -1) { 583 if (pollsum >= MAX_POLL_FDS) 584 break; 585 pfd[pollsum].fd = csockets[i].socket; 586 pfd[pollsum].events = POLLIN; 587 pfd[pollsum].revents = 0; 588 pollsum++; 589 } 590 591 /* LDP Peer sockets */ 592 SLIST_FOREACH(p, &ldp_peer_head, peers) { 593 if (p->socket < 1) 594 continue; 595 switch (p->state) { 596 case LDP_PEER_CONNECTED: 597 case LDP_PEER_ESTABLISHED: 598 if (pollsum >= MAX_POLL_FDS) 599 break; 600 pfd[pollsum].fd = p->socket; 601 pfd[pollsum].events = POLLRDNORM; 602 pfd[pollsum].revents = 0; 603 pollsum++; 604 break; 605 case LDP_PEER_CONNECTING: 606 if (pollsum >= MAX_POLL_FDS) 607 break; 608 pfd[pollsum].fd = p->socket; 609 pfd[pollsum].events = POLLWRNORM; 610 pfd[pollsum].revents = 0; 611 pollsum++; 612 break; 613 } 614 } 615 616 if (pollsum >= MAX_POLL_FDS) { 617 fatalp("Too many sockets. Increase MAX_POLL_FDS\n"); 618 return LDP_E_TOO_MANY_FDS; 619 } 620 if (poll(pfd, pollsum, INFTIM) < 0) { 621 if (errno != EINTR) 622 fatalp("poll: %s", strerror(errno)); 623 continue; 624 } 625 626 for (i = 0; i < pollsum; i++) { 627 if ((pfd[i].revents & POLLRDNORM) || 628 (pfd[i].revents & POLLIN)) { 629 if(pfd[i].fd == ls) 630 new_peer_connection(); 631 else if (pfd[i].fd == route_socket) { 632 struct rt_msg xbuf; 633 int l; 634 do { 635 l = read(route_socket, &xbuf, 636 sizeof(xbuf)); 637 } while ((l == -1) && (errno == EINTR)); 638 639 if (l == -1) 640 break; 641 642 check_route(&xbuf, l); 643 644 } else if (pfd[i].fd == hello_socket) { 645 /* Receiving hello socket */ 646 recv_pdu(pfd[i].fd); 647 } else if (pfd[i].fd == command_socket) { 648 command_accept(command_socket); 649 } else if ((cs = is_command_socket(pfd[i].fd)) 650 != NULL) { 651 command_dispatch(cs); 652 } else { 653 /* ldp peer socket */ 654 p = get_ldp_peer_by_socket(pfd[i].fd); 655 if (p) 656 recv_session_pdu(p); 657 } 658 } else if(pfd[i].revents & POLLWRNORM) { 659 p = get_ldp_peer_by_socket(pfd[i].fd); 660 if (!p) 661 continue; 662 if (getsockopt(pfd[i].fd, SOL_SOCKET, SO_ERROR, 663 &sock_error, &sock_error_size) != 0 || 664 sock_error != 0) { 665 ldp_peer_holddown(p); 666 sock_error = 0; 667 } else { 668 p->state = LDP_PEER_CONNECTED; 669 send_initialize(p); 670 } 671 } 672 } 673 674 for (int ri = 0; ri < replay_index; ri++) { 675 debugp("Replaying: PID %d, SEQ %d\n", 676 replay_rt[ri].m_rtm.rtm_pid, 677 replay_rt[ri].m_rtm.rtm_seq); 678 check_route(&replay_rt[ri], sizeof(struct rt_msg)); 679 } 680 replay_index = 0; 681 } /* for (;;) */ 682 } 683 684 void 685 new_peer_connection() 686 { 687 struct sockaddr_in sa, sin_me; 688 int s; 689 690 s = accept(ls, (struct sockaddr *) & sa, 691 & (socklen_t) { sizeof(struct sockaddr_in) } ); 692 if (s < 0) { 693 fatalp("accept: %s", strerror(errno)); 694 return; 695 } 696 697 if (get_ldp_peer(&sa.sin_addr) != NULL) { 698 close(s); 699 return; 700 } 701 702 warnp("Accepted a connection from %s\n", inet_ntoa(sa.sin_addr)); 703 704 if (getsockname(s, (struct sockaddr *)&sin_me, 705 & (socklen_t) { sizeof(struct sockaddr_in) } )) { 706 fatalp("new_peer_connection(): cannot getsockname\n"); 707 close(s); 708 return; 709 } 710 711 if (ntohl(sa.sin_addr.s_addr) < ntohl(sin_me.sin_addr.s_addr)) { 712 fatalp("Peer %s: connect from lower ID\n", 713 inet_ntoa(sa.sin_addr)); 714 close(s); 715 return; 716 } 717 /* XXX: sa.sin_addr ain't peer LDP ID ... */ 718 ldp_peer_new(&sa.sin_addr, &sa.sin_addr, NULL, ldp_holddown_time, s); 719 720 } 721 722 void 723 send_initialize(struct ldp_peer * p) 724 { 725 struct init_tlv ti; 726 727 ti.type = htons(LDP_INITIALIZE); 728 ti.length = htons(sizeof(struct init_tlv) - TLV_TYPE_LENGTH); 729 ti.messageid = htonl(get_message_id()); 730 ti.cs_type = htons(TLV_COMMON_SESSION); 731 ti.cs_len = htons(CS_LEN); 732 ti.cs_version = htons(LDP_VERSION); 733 ti.cs_keepalive = htons(2 * ldp_keepalive_time); 734 ti.cs_adpvlim = 0; 735 ti.cs_maxpdulen = htons(MAX_PDU_SIZE); 736 ti.cs_peeraddress.s_addr = p->ldp_id.s_addr; 737 ti.cs_peeraddrspace = 0; 738 739 send_tlv(p, (struct tlv *) (void *) &ti); 740 } 741 742 void 743 keep_alive(struct ldp_peer * p) 744 { 745 struct ka_tlv kt; 746 747 kt.type = htons(LDP_KEEPALIVE); 748 kt.length = htons(sizeof(kt.messageid)); 749 kt.messageid = htonl(get_message_id()); 750 751 send_tlv(p, (struct tlv *) (void *) &kt); 752 753 } 754 755 void 756 recv_session_pdu(struct ldp_peer * p) 757 { 758 struct ldp_pdu *rpdu; 759 struct address_tlv *atlv; 760 struct al_tlv *altlv; 761 struct init_tlv *itlv; 762 struct label_map_tlv *lmtlv; 763 struct fec_tlv *fectlv; 764 struct label_tlv *labeltlv; 765 struct notification_tlv *nottlv; 766 struct hello_info *hi; 767 768 int c; 769 int32_t wo = 0; 770 struct tlv *ttmp; 771 unsigned char recvspace[MAX_PDU_SIZE]; 772 773 memset(recvspace, 0, MAX_PDU_SIZE); 774 775 c = recv(p->socket, (void *) recvspace, MAX_PDU_SIZE, MSG_PEEK); 776 777 debugp("Ready to read %d bytes\n", c); 778 779 if (c < 1) { /* Session closed */ 780 warnp("Error in connection with %s\n", inet_ntoa(p->ldp_id)); 781 ldp_peer_holddown(p); 782 return; 783 } 784 if (c > MAX_PDU_SIZE) { 785 debugp("Incoming PDU size exceeds MAX_PDU_SIZE !\n"); 786 return; 787 } 788 if (c < MIN_PDU_SIZE) { 789 debugp("PDU too small received from peer %s\n", inet_ntoa(p->ldp_id)); 790 return; 791 } 792 rpdu = (struct ldp_pdu *) recvspace; 793 /* XXX: buggy messages may crash the whole thing */ 794 c = recv(p->socket, (void *) recvspace, 795 ntohs(rpdu->length) + PDU_VER_LENGTH, MSG_WAITALL); 796 rpdu = (struct ldp_pdu *) recvspace; 797 798 /* Check if it's somehow OK... */ 799 if (check_recv_pdu(p, rpdu, c) != 0) 800 return; 801 802 debugp("Read %d bytes, PDU size: %d bytes\n", c, ntohs(rpdu->length)); 803 wo = sizeof(struct ldp_pdu); 804 805 while (wo + TLV_TYPE_LENGTH < (uint)c) { 806 807 ttmp = (struct tlv *) (&recvspace[wo]); 808 809 if ((ntohs(ttmp->type) != LDP_KEEPALIVE) && 810 (ntohs(ttmp->type) != LDP_LABEL_MAPPING)) { 811 debugp("Got Type: 0x%.4X (Length: %d) from %s\n", 812 ntohs(ttmp->type), ntohs(ttmp->length), 813 inet_ntoa(p->ldp_id)); 814 } else 815 debugp("Got Type: 0x%.4X (Length: %d) from %s\n", 816 ntohs(ttmp->type), ntohs(ttmp->length), 817 inet_ntoa(p->ldp_id)); 818 819 /* Should we get the message ? */ 820 if (p->state != LDP_PEER_ESTABLISHED && 821 ntohs(ttmp->type) != LDP_INITIALIZE && 822 ntohs(ttmp->type) != LDP_KEEPALIVE) 823 break; 824 /* The big switch */ 825 switch (ntohs(ttmp->type)) { 826 case LDP_INITIALIZE: 827 itlv = (struct init_tlv *)ttmp; 828 /* Check size */ 829 if (ntohs(itlv->length) < 830 sizeof(struct init_tlv) - TLV_TYPE_LENGTH) { 831 send_notification(p, 0, 832 NOTIF_BAD_PDU_LEN | NOTIF_FATAL); 833 ldp_peer_holddown(p); 834 break; 835 } 836 /* Check version */ 837 if (ntohs(itlv->cs_version) != LDP_VERSION) { 838 send_notification(p, ntohl(itlv->messageid), 839 NOTIF_BAD_LDP_VER | NOTIF_FATAL); 840 ldp_peer_holddown(p); 841 break; 842 } 843 /* Check if we got any hello from this one */ 844 SLIST_FOREACH(hi, &hello_info_head, infos) 845 if (hi->ldp_id.s_addr == rpdu->ldp_id.s_addr) 846 break; 847 if (hi == NULL) { 848 send_notification(p, ntohl(itlv->messageid), 849 NOTIF_SESSION_REJECTED_NO_HELLO | NOTIF_FATAL); 850 ldp_peer_holddown(p); 851 break; 852 } 853 854 if (!p->master) { 855 keep_alive(p); 856 send_initialize(p); 857 } else { 858 p->state = LDP_PEER_ESTABLISHED; 859 p->established_t = time(NULL); 860 keep_alive(p); 861 862 /* 863 * Recheck here ldp id because we accepted 864 * connection without knowing who is it for sure 865 */ 866 p->ldp_id.s_addr = rpdu->ldp_id.s_addr; 867 868 fatalp("LDP neighbour %s is UP\n", 869 inet_ntoa(p->ldp_id)); 870 mpls_add_ldp_peer(p); 871 send_addresses(p); 872 send_all_bindings(p); 873 } 874 break; 875 case LDP_KEEPALIVE: 876 if ((p->state == LDP_PEER_CONNECTED) && (!p->master)) { 877 p->state = LDP_PEER_ESTABLISHED; 878 p->established_t = time(NULL); 879 fatalp("LDP neighbour %s is UP\n", 880 inet_ntoa(p->ldp_id)); 881 mpls_add_ldp_peer(p); 882 send_addresses(p); 883 send_all_bindings(p); 884 } 885 p->timeout = p->holdtime; 886 break; 887 case LDP_ADDRESS: 888 /* Add peer addresses */ 889 atlv = (struct address_tlv *) ttmp; 890 altlv = (struct al_tlv *) (&atlv[1]); 891 add_ifaddresses(p, altlv); 892 print_bounded_addresses(p); 893 break; 894 case LDP_ADDRESS_WITHDRAW: 895 atlv = (struct address_tlv *) ttmp; 896 altlv = (struct al_tlv *) (&atlv[1]); 897 del_ifaddresses(p, altlv); 898 break; 899 case LDP_LABEL_MAPPING: 900 lmtlv = (struct label_map_tlv *) ttmp; 901 fectlv = (struct fec_tlv *) (&lmtlv[1]); 902 labeltlv = (struct label_tlv *)((unsigned char *)fectlv 903 + ntohs(fectlv->length) + TLV_TYPE_LENGTH); 904 map_label(p, fectlv, labeltlv); 905 break; 906 case LDP_LABEL_REQUEST: 907 lmtlv = (struct label_map_tlv *) ttmp; 908 fectlv = (struct fec_tlv *) (&lmtlv[1]); 909 switch (request_respond(p, lmtlv, fectlv)) { 910 case LDP_E_BAD_FEC: 911 send_notification(p, ntohl(lmtlv->messageid), 912 NOTIF_UNKNOWN_TLV); 913 break; 914 case LDP_E_BAD_AF: 915 send_notification(p, ntohl(lmtlv->messageid), 916 NOTIF_UNSUPPORTED_AF); 917 break; 918 case LDP_E_NO_SUCH_ROUTE: 919 send_notification(p, ntohl(lmtlv->messageid), 920 NOTIF_NO_ROUTE); 921 break; 922 } 923 break; 924 case LDP_LABEL_WITHDRAW: 925 lmtlv = (struct label_map_tlv *) ttmp; 926 fectlv = (struct fec_tlv *) (&lmtlv[1]); 927 if (withdraw_label(p, fectlv) == LDP_E_OK) { 928 /* Send RELEASE */ 929 prepare_release(ttmp); 930 send_tlv(p, ttmp); 931 } 932 break; 933 case LDP_LABEL_RELEASE: 934 /* 935 * XXX: we need to make a timed queue... 936 * For now I just assume peers are processing messages 937 * correctly so I just ignore confirmations 938 */ 939 wo = -1; /* Ignore rest of message */ 940 break; 941 case LDP_LABEL_ABORT: 942 /* XXX: For now I pretend I can process everything 943 * RFC 3036, Section 3.5.9.1 944 * If an LSR receives a Label Abort Request Message after it 945 * has responded to the Label Request in question with a Label 946 * Mapping message or a Notification message, it ignores the 947 * abort request. 948 */ 949 wo = -1; 950 break; 951 case LDP_NOTIFICATION: 952 nottlv = (struct notification_tlv *) ttmp; 953 nottlv->st_code = ntohl(nottlv->st_code); 954 fatalp("Got notification 0x%X from peer %s\n", 955 nottlv->st_code, inet_ntoa(p->ldp_id)); 956 if (nottlv->st_code >> 31) { 957 fatalp("LDP peer %s signalized %s\n", 958 inet_ntoa(p->ldp_id), 959 NOTIF_STR[(nottlv->st_code << 1) >> 1]); 960 ldp_peer_holddown(p); 961 wo = -1; 962 } 963 break; 964 case LDP_HELLO: 965 /* No hellos should came on tcp session */ 966 wo = -1; 967 break; 968 default: 969 warnp("Unknown TLV received from %s\n", 970 inet_ntoa(p->ldp_id)); 971 debug_tlv(ttmp); 972 wo = -1;/* discard the rest of the message */ 973 break; 974 } 975 if (wo < 0) { 976 debugp("Discarding the rest of the message\n"); 977 break; 978 } else { 979 wo += ntohs(ttmp->length) + TLV_TYPE_LENGTH; 980 debugp("WORKED ON %u bytes (Left %d)\n", wo, c - wo); 981 } 982 } /* while */ 983 984 } 985 986 /* Sends a pdu, tlv pair to a connected peer */ 987 int 988 send_message(struct ldp_peer * p, struct ldp_pdu * pdu, struct tlv * t) 989 { 990 unsigned char sendspace[MAX_PDU_SIZE]; 991 992 /* Check if peer is connected */ 993 switch (p->state) { 994 case LDP_PEER_CONNECTED: 995 case LDP_PEER_ESTABLISHED: 996 break; 997 default: 998 return -1; 999 } 1000 1001 /* Check length validity first */ 1002 if (ntohs(pdu->length) != 1003 ntohs(t->length) + TLV_TYPE_LENGTH + PDU_PAYLOAD_LENGTH) { 1004 fatalp("LDP: TLV - PDU incompability. Message discarded\n"); 1005 fatalp("LDP: TLV len %d - PDU len %d\n", ntohs(t->length), 1006 ntohs(pdu->length)); 1007 return -1; 1008 } 1009 if (ntohs(t->length) + PDU_VER_LENGTH > MAX_PDU_SIZE) { 1010 fatalp("Message to large discarded\n"); 1011 return -1; 1012 } 1013 /* Arrange them in a buffer and send */ 1014 memcpy(sendspace, pdu, sizeof(struct ldp_pdu)); 1015 memcpy(sendspace + sizeof(struct ldp_pdu), t, 1016 ntohs(t->length) + TLV_TYPE_LENGTH); 1017 1018 /* Report keepalives only for DEBUG */ 1019 if ((ntohs(t->type) != 0x201) && (ntohs(t->type) != 0x400)) { 1020 debugp("Sending message type 0x%.4X to %s (size: %d)\n", 1021 ntohs(t->type), inet_ntoa(p->ldp_id), ntohs(t->length)); 1022 } else 1023 /* downgraded from warnp to debugp for now */ 1024 debugp("Sending message type 0x%.4X to %s (size: %d)\n", 1025 ntohs(t->type), inet_ntoa(p->ldp_id), ntohs(t->length)); 1026 1027 /* Send it finally */ 1028 return send(p->socket, sendspace, 1029 ntohs(pdu->length) + PDU_VER_LENGTH, 0); 1030 } 1031 1032 /* 1033 * Encapsulates TLV into a PDU and sends it to a peer 1034 */ 1035 int 1036 send_tlv(struct ldp_peer * p, struct tlv * t) 1037 { 1038 struct ldp_pdu pdu; 1039 1040 pdu.version = htons(LDP_VERSION); 1041 inet_aton(LDP_ID, &pdu.ldp_id); 1042 pdu.label_space = 0; 1043 pdu.length = htons(ntohs(t->length) + TLV_TYPE_LENGTH + 1044 PDU_PAYLOAD_LENGTH); 1045 1046 return send_message(p, &pdu, t); 1047 } 1048 1049 1050 int 1051 send_addresses(struct ldp_peer * p) 1052 { 1053 struct address_list_tlv *t; 1054 int ret; 1055 1056 t = build_address_list_tlv(); 1057 1058 ret = send_tlv(p, (struct tlv *) t); 1059 free(t); 1060 return ret; 1061 1062 } 1063
Indexes created Thu Oct 23 18:09:57 GMT 2025