1 /* 2 * Perform PPPoE discovery 3 * 4 * Copyright (C) 2000-2001 by Roaring Penguin Software Inc. 5 * Copyright (C) 2004 Marco d'Itri <md (at) linux.it> 6 * 7 * This program may be distributed according to the terms of the GNU 8 * General Public License, version 2 or (at your option) any later version. 9 * 10 */ 11 12 #include <stdio.h> 13 #include <stdlib.h> 14 #include <unistd.h> 15 #include <errno.h> 16 #include <string.h> 17 18 #include "pppoe.h" 19 20 #ifdef HAVE_UNISTD_H 21 #include <unistd.h> 22 #endif 23 24 #ifdef HAVE_NETPACKET_PACKET_H 25 #include <netpacket/packet.h> 26 #elif defined(HAVE_LINUX_IF_PACKET_H) 27 #include <linux/if_packet.h> 28 #endif 29 30 #ifdef HAVE_NET_ETHERNET_H 31 #include <net/ethernet.h> 32 #endif 33 34 #ifdef HAVE_ASM_TYPES_H 35 #include <asm/types.h> 36 #endif 37 38 #ifdef HAVE_SYS_IOCTL_H 39 #include <sys/ioctl.h> 40 #endif 41 42 #include <errno.h> 43 #include <stdlib.h> 44 #include <string.h> 45 46 #ifdef HAVE_NET_IF_ARP_H 47 #include <net/if_arp.h> 48 #endif 49 50 char *xstrdup(const char *s); 51 void usage(void); 52 53 void die(int status) 54 { 55 exit(status); 56 } 57 58 /* Initialize frame types to RFC 2516 values. Some broken peers apparently 59 use different frame types... sigh... */ 60 61 UINT16_t Eth_PPPOE_Discovery = ETH_PPPOE_DISCOVERY; 62 UINT16_t Eth_PPPOE_Session = ETH_PPPOE_SESSION; 63 64 /********************************************************************** 65 *%FUNCTION: etherType 66 *%ARGUMENTS: 67 * packet -- a received PPPoE packet 68 *%RETURNS: 69 * ethernet packet type (see /usr/include/net/ethertypes.h) 70 *%DESCRIPTION: 71 * Checks the ethernet packet header to determine its type. 72 * We should only be receveing DISCOVERY and SESSION types if the BPF 73 * is set up correctly. Logs an error if an unexpected type is received. 74 * Note that the ethernet type names come from "pppoe.h" and the packet 75 * packet structure names use the LINUX dialect to maintain consistency 76 * with the rest of this file. See the BSD section of "pppoe.h" for 77 * translations of the data structure names. 78 ***********************************************************************/ 79 UINT16_t 80 etherType(PPPoEPacket *packet) 81 { 82 UINT16_t type = (UINT16_t) ntohs(packet->ethHdr.h_proto); 83 if (type != Eth_PPPOE_Discovery && type != Eth_PPPOE_Session) { 84 fprintf(stderr, "Invalid ether type 0x%x\n", type); 85 } 86 return type; 87 } 88 89 /********************************************************************** 90 *%FUNCTION: openInterface 91 *%ARGUMENTS: 92 * ifname -- name of interface 93 * type -- Ethernet frame type 94 * hwaddr -- if non-NULL, set to the hardware address 95 *%RETURNS: 96 * A raw socket for talking to the Ethernet card. Exits on error. 97 *%DESCRIPTION: 98 * Opens a raw Ethernet socket 99 ***********************************************************************/ 100 int 101 openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr) 102 { 103 int optval=1; 104 int fd; 105 struct ifreq ifr; 106 int domain, stype; 107 108 #ifdef HAVE_STRUCT_SOCKADDR_LL 109 struct sockaddr_ll sa; 110 #else 111 struct sockaddr sa; 112 #endif 113 114 memset(&sa, 0, sizeof(sa)); 115 116 #ifdef HAVE_STRUCT_SOCKADDR_LL 117 domain = PF_PACKET; 118 stype = SOCK_RAW; 119 #else 120 domain = PF_INET; 121 stype = SOCK_PACKET; 122 #endif 123 124 if ((fd = socket(domain, stype, htons(type))) < 0) { 125 /* Give a more helpful message for the common error case */ 126 if (errno == EPERM) { 127 rp_fatal("Cannot create raw socket -- pppoe must be run as root."); 128 } 129 fatalSys("socket"); 130 } 131 132 if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &optval, sizeof(optval)) < 0) { 133 fatalSys("setsockopt"); 134 } 135 136 /* Fill in hardware address */ 137 if (hwaddr) { 138 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)); 139 if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) { 140 fatalSys("ioctl(SIOCGIFHWADDR)"); 141 } 142 memcpy(hwaddr, ifr.ifr_hwaddr.sa_data, ETH_ALEN); 143 #ifdef ARPHRD_ETHER 144 if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) { 145 char buffer[256]; 146 sprintf(buffer, "Interface %.16s is not Ethernet", ifname); 147 rp_fatal(buffer); 148 } 149 #endif 150 if (NOT_UNICAST(hwaddr)) { 151 char buffer[256]; 152 sprintf(buffer, 153 "Interface %.16s has broadcast/multicast MAC address??", 154 ifname); 155 rp_fatal(buffer); 156 } 157 } 158 159 /* Sanity check on MTU */ 160 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)); 161 if (ioctl(fd, SIOCGIFMTU, &ifr) < 0) { 162 fatalSys("ioctl(SIOCGIFMTU)"); 163 } 164 if (ifr.ifr_mtu < ETH_DATA_LEN) { 165 fprintf(stderr, "Interface %.16s has MTU of %d -- should be %d.\n", 166 ifname, ifr.ifr_mtu, ETH_DATA_LEN); 167 fprintf(stderr, "You may have serious connection problems.\n"); 168 } 169 170 #ifdef HAVE_STRUCT_SOCKADDR_LL 171 /* Get interface index */ 172 sa.sll_family = AF_PACKET; 173 sa.sll_protocol = htons(type); 174 175 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)); 176 if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) { 177 fatalSys("ioctl(SIOCFIGINDEX): Could not get interface index"); 178 } 179 sa.sll_ifindex = ifr.ifr_ifindex; 180 181 #else 182 strcpy(sa.sa_data, ifname); 183 #endif 184 185 /* We're only interested in packets on specified interface */ 186 if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0) { 187 fatalSys("bind"); 188 } 189 190 return fd; 191 } 192 193 194 /*********************************************************************** 195 *%FUNCTION: sendPacket 196 *%ARGUMENTS: 197 * sock -- socket to send to 198 * pkt -- the packet to transmit 199 * size -- size of packet (in bytes) 200 *%RETURNS: 201 * 0 on success; -1 on failure 202 *%DESCRIPTION: 203 * Transmits a packet 204 ***********************************************************************/ 205 int 206 sendPacket(PPPoEConnection *conn, int sock, PPPoEPacket *pkt, int size) 207 { 208 #if defined(HAVE_STRUCT_SOCKADDR_LL) 209 if (send(sock, pkt, size, 0) < 0) { 210 sysErr("send (sendPacket)"); 211 return -1; 212 } 213 #else 214 struct sockaddr sa; 215 216 if (!conn) { 217 rp_fatal("relay and server not supported on Linux 2.0 kernels"); 218 } 219 strcpy(sa.sa_data, conn->ifName); 220 if (sendto(sock, pkt, size, 0, &sa, sizeof(sa)) < 0) { 221 sysErr("sendto (sendPacket)"); 222 return -1; 223 } 224 #endif 225 return 0; 226 } 227 228 /*********************************************************************** 229 *%FUNCTION: receivePacket 230 *%ARGUMENTS: 231 * sock -- socket to read from 232 * pkt -- place to store the received packet 233 * size -- set to size of packet in bytes 234 *%RETURNS: 235 * >= 0 if all OK; < 0 if error 236 *%DESCRIPTION: 237 * Receives a packet 238 ***********************************************************************/ 239 int 240 receivePacket(int sock, PPPoEPacket *pkt, int *size) 241 { 242 if ((*size = recv(sock, pkt, sizeof(PPPoEPacket), 0)) < 0) { 243 sysErr("recv (receivePacket)"); 244 return -1; 245 } 246 return 0; 247 } 248 249 /********************************************************************** 250 *%FUNCTION: parsePacket 251 *%ARGUMENTS: 252 * packet -- the PPPoE discovery packet to parse 253 * func -- function called for each tag in the packet 254 * extra -- an opaque data pointer supplied to parsing function 255 *%RETURNS: 256 * 0 if everything went well; -1 if there was an error 257 *%DESCRIPTION: 258 * Parses a PPPoE discovery packet, calling "func" for each tag in the packet. 259 * "func" is passed the additional argument "extra". 260 ***********************************************************************/ 261 int 262 parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra) 263 { 264 UINT16_t len = ntohs(packet->length); 265 unsigned char *curTag; 266 UINT16_t tagType, tagLen; 267 268 if (PPPOE_VER(packet->vertype) != 1) { 269 fprintf(stderr, "Invalid PPPoE version (%d)\n", 270 PPPOE_VER(packet->vertype)); 271 return -1; 272 } 273 if (PPPOE_TYPE(packet->vertype) != 1) { 274 fprintf(stderr, "Invalid PPPoE type (%d)\n", 275 PPPOE_TYPE(packet->vertype)); 276 return -1; 277 } 278 279 /* Do some sanity checks on packet */ 280 if (len > ETH_JUMBO_LEN - PPPOE_OVERHEAD) { /* 6-byte overhead for PPPoE header */ 281 fprintf(stderr, "Invalid PPPoE packet length (%u)\n", len); 282 return -1; 283 } 284 285 /* Step through the tags */ 286 curTag = packet->payload; 287 while(curTag - packet->payload < len) { 288 /* Alignment is not guaranteed, so do this by hand... */ 289 tagType = (curTag[0] << 8) + curTag[1]; 290 tagLen = (curTag[2] << 8) + curTag[3]; 291 if (tagType == TAG_END_OF_LIST) { 292 return 0; 293 } 294 if ((curTag - packet->payload) + tagLen + TAG_HDR_SIZE > len) { 295 fprintf(stderr, "Invalid PPPoE tag length (%u)\n", tagLen); 296 return -1; 297 } 298 func(tagType, tagLen, curTag+TAG_HDR_SIZE, extra); 299 curTag = curTag + TAG_HDR_SIZE + tagLen; 300 } 301 return 0; 302 } 303 304 /********************************************************************** 305 *%FUNCTION: parseForHostUniq 306 *%ARGUMENTS: 307 * type -- tag type 308 * len -- tag length 309 * data -- tag data. 310 * extra -- user-supplied pointer. This is assumed to be a pointer to int. 311 *%RETURNS: 312 * Nothing 313 *%DESCRIPTION: 314 * If a HostUnique tag is found which matches our PID, sets *extra to 1. 315 ***********************************************************************/ 316 void 317 parseForHostUniq(UINT16_t type, UINT16_t len, unsigned char *data, 318 void *extra) 319 { 320 int *val = (int *) extra; 321 if (type == TAG_HOST_UNIQ && len == sizeof(pid_t)) { 322 pid_t tmp; 323 memcpy(&tmp, data, len); 324 if (tmp == getpid()) { 325 *val = 1; 326 } 327 } 328 } 329 330 /********************************************************************** 331 *%FUNCTION: packetIsForMe 332 *%ARGUMENTS: 333 * conn -- PPPoE connection info 334 * packet -- a received PPPoE packet 335 *%RETURNS: 336 * 1 if packet is for this PPPoE daemon; 0 otherwise. 337 *%DESCRIPTION: 338 * If we are using the Host-Unique tag, verifies that packet contains 339 * our unique identifier. 340 ***********************************************************************/ 341 int 342 packetIsForMe(PPPoEConnection *conn, PPPoEPacket *packet) 343 { 344 int forMe = 0; 345 346 /* If packet is not directed to our MAC address, forget it */ 347 if (memcmp(packet->ethHdr.h_dest, conn->myEth, ETH_ALEN)) return 0; 348 349 /* If we're not using the Host-Unique tag, then accept the packet */ 350 if (!conn->useHostUniq) return 1; 351 352 parsePacket(packet, parseForHostUniq, &forMe); 353 return forMe; 354 } 355 356 /********************************************************************** 357 *%FUNCTION: parsePADOTags 358 *%ARGUMENTS: 359 * type -- tag type 360 * len -- tag length 361 * data -- tag data 362 * extra -- extra user data. Should point to a PacketCriteria structure 363 * which gets filled in according to selected AC name and service 364 * name. 365 *%RETURNS: 366 * Nothing 367 *%DESCRIPTION: 368 * Picks interesting tags out of a PADO packet 369 ***********************************************************************/ 370 void 371 parsePADOTags(UINT16_t type, UINT16_t len, unsigned char *data, 372 void *extra) 373 { 374 struct PacketCriteria *pc = (struct PacketCriteria *) extra; 375 PPPoEConnection *conn = pc->conn; 376 int i; 377 378 switch(type) { 379 case TAG_AC_NAME: 380 pc->seenACName = 1; 381 printf("Access-Concentrator: %.*s\n", (int) len, data); 382 if (conn->acName && len == strlen(conn->acName) && 383 !strncmp((char *) data, conn->acName, len)) { 384 pc->acNameOK = 1; 385 } 386 break; 387 case TAG_SERVICE_NAME: 388 pc->seenServiceName = 1; 389 if (len > 0) { 390 printf(" Service-Name: %.*s\n", (int) len, data); 391 } 392 if (conn->serviceName && len == strlen(conn->serviceName) && 393 !strncmp((char *) data, conn->serviceName, len)) { 394 pc->serviceNameOK = 1; 395 } 396 break; 397 case TAG_AC_COOKIE: 398 printf("Got a cookie:"); 399 /* Print first 20 bytes of cookie */ 400 for (i=0; i<len && i < 20; i++) { 401 printf(" %02x", (unsigned) data[i]); 402 } 403 if (i < len) printf("..."); 404 printf("\n"); 405 conn->cookie.type = htons(type); 406 conn->cookie.length = htons(len); 407 memcpy(conn->cookie.payload, data, len); 408 break; 409 case TAG_RELAY_SESSION_ID: 410 printf("Got a Relay-ID:"); 411 /* Print first 20 bytes of relay ID */ 412 for (i=0; i<len && i < 20; i++) { 413 printf(" %02x", (unsigned) data[i]); 414 } 415 if (i < len) printf("..."); 416 printf("\n"); 417 conn->relayId.type = htons(type); 418 conn->relayId.length = htons(len); 419 memcpy(conn->relayId.payload, data, len); 420 break; 421 case TAG_SERVICE_NAME_ERROR: 422 printf("Got a Service-Name-Error tag: %.*s\n", (int) len, data); 423 break; 424 case TAG_AC_SYSTEM_ERROR: 425 printf("Got a System-Error tag: %.*s\n", (int) len, data); 426 break; 427 case TAG_GENERIC_ERROR: 428 printf("Got a Generic-Error tag: %.*s\n", (int) len, data); 429 break; 430 } 431 } 432 433 /*********************************************************************** 434 *%FUNCTION: sendPADI 435 *%ARGUMENTS: 436 * conn -- PPPoEConnection structure 437 *%RETURNS: 438 * Nothing 439 *%DESCRIPTION: 440 * Sends a PADI packet 441 ***********************************************************************/ 442 void 443 sendPADI(PPPoEConnection *conn) 444 { 445 PPPoEPacket packet; 446 unsigned char *cursor = packet.payload; 447 PPPoETag *svc = (PPPoETag *) (&packet.payload); 448 UINT16_t namelen = 0; 449 UINT16_t plen; 450 451 if (conn->serviceName) { 452 namelen = (UINT16_t) strlen(conn->serviceName); 453 } 454 plen = TAG_HDR_SIZE + namelen; 455 CHECK_ROOM(cursor, packet.payload, plen); 456 457 /* Set destination to Ethernet broadcast address */ 458 memset(packet.ethHdr.h_dest, 0xFF, ETH_ALEN); 459 memcpy(packet.ethHdr.h_source, conn->myEth, ETH_ALEN); 460 461 packet.ethHdr.h_proto = htons(Eth_PPPOE_Discovery); 462 packet.vertype = PPPOE_VER_TYPE(1, 1); 463 packet.code = CODE_PADI; 464 packet.session = 0; 465 466 svc->type = TAG_SERVICE_NAME; 467 svc->length = htons(namelen); 468 CHECK_ROOM(cursor, packet.payload, namelen+TAG_HDR_SIZE); 469 470 if (conn->serviceName) { 471 memcpy(svc->payload, conn->serviceName, strlen(conn->serviceName)); 472 } 473 cursor += namelen + TAG_HDR_SIZE; 474 475 /* If we're using Host-Uniq, copy it over */ 476 if (conn->useHostUniq) { 477 PPPoETag hostUniq; 478 pid_t pid = getpid(); 479 hostUniq.type = htons(TAG_HOST_UNIQ); 480 hostUniq.length = htons(sizeof(pid)); 481 memcpy(hostUniq.payload, &pid, sizeof(pid)); 482 CHECK_ROOM(cursor, packet.payload, sizeof(pid) + TAG_HDR_SIZE); 483 memcpy(cursor, &hostUniq, sizeof(pid) + TAG_HDR_SIZE); 484 cursor += sizeof(pid) + TAG_HDR_SIZE; 485 plen += sizeof(pid) + TAG_HDR_SIZE; 486 } 487 488 packet.length = htons(plen); 489 490 sendPacket(conn, conn->discoverySocket, &packet, (int) (plen + HDR_SIZE)); 491 if (conn->debugFile) { 492 dumpPacket(conn->debugFile, &packet, "SENT"); 493 fprintf(conn->debugFile, "\n"); 494 fflush(conn->debugFile); 495 } 496 } 497 498 /********************************************************************** 499 *%FUNCTION: waitForPADO 500 *%ARGUMENTS: 501 * conn -- PPPoEConnection structure 502 * timeout -- how long to wait (in seconds) 503 *%RETURNS: 504 * Nothing 505 *%DESCRIPTION: 506 * Waits for a PADO packet and copies useful information 507 ***********************************************************************/ 508 void 509 waitForPADO(PPPoEConnection *conn, int timeout) 510 { 511 fd_set readable; 512 int r; 513 struct timeval tv; 514 PPPoEPacket packet; 515 int len; 516 517 struct PacketCriteria pc; 518 pc.conn = conn; 519 pc.acNameOK = (conn->acName) ? 0 : 1; 520 pc.serviceNameOK = (conn->serviceName) ? 0 : 1; 521 pc.seenACName = 0; 522 pc.seenServiceName = 0; 523 conn->error = 0; 524 525 do { 526 if (BPF_BUFFER_IS_EMPTY) { 527 tv.tv_sec = timeout; 528 tv.tv_usec = 0; 529 530 FD_ZERO(&readable); 531 FD_SET(conn->discoverySocket, &readable); 532 533 while(1) { 534 r = select(conn->discoverySocket+1, &readable, NULL, NULL, &tv); 535 if (r >= 0 || errno != EINTR) break; 536 } 537 if (r < 0) { 538 perror("select (waitForPADO)"); 539 return; 540 } 541 if (r == 0) return; /* Timed out */ 542 } 543 544 /* Get the packet */ 545 receivePacket(conn->discoverySocket, &packet, &len); 546 547 /* Check length */ 548 if (ntohs(packet.length) + HDR_SIZE > len) { 549 fprintf(stderr, "Bogus PPPoE length field (%u)\n", 550 (unsigned int) ntohs(packet.length)); 551 continue; 552 } 553 554 #ifdef USE_BPF 555 /* If it's not a Discovery packet, loop again */ 556 if (etherType(&packet) != Eth_PPPOE_Discovery) continue; 557 #endif 558 559 if (conn->debugFile) { 560 dumpPacket(conn->debugFile, &packet, "RCVD"); 561 fprintf(conn->debugFile, "\n"); 562 fflush(conn->debugFile); 563 } 564 /* If it's not for us, loop again */ 565 if (!packetIsForMe(conn, &packet)) continue; 566 567 if (packet.code == CODE_PADO) { 568 if (BROADCAST(packet.ethHdr.h_source)) { 569 fprintf(stderr, "Ignoring PADO packet from broadcast MAC address\n"); 570 continue; 571 } 572 parsePacket(&packet, parsePADOTags, &pc); 573 if (conn->error) 574 return; 575 if (!pc.seenACName) { 576 fprintf(stderr, "Ignoring PADO packet with no AC-Name tag\n"); 577 continue; 578 } 579 if (!pc.seenServiceName) { 580 fprintf(stderr, "Ignoring PADO packet with no Service-Name tag\n"); 581 continue; 582 } 583 conn->numPADOs++; 584 printf("--------------------------------------------------\n"); 585 if (pc.acNameOK && pc.serviceNameOK) { 586 memcpy(conn->peerEth, packet.ethHdr.h_source, ETH_ALEN); 587 if (conn->printACNames) { 588 printf("AC-Ethernet-Address: %02x:%02x:%02x:%02x:%02x:%02x\n", 589 (unsigned) conn->peerEth[0], 590 (unsigned) conn->peerEth[1], 591 (unsigned) conn->peerEth[2], 592 (unsigned) conn->peerEth[3], 593 (unsigned) conn->peerEth[4], 594 (unsigned) conn->peerEth[5]); 595 continue; 596 } 597 conn->discoveryState = STATE_RECEIVED_PADO; 598 break; 599 } 600 } 601 } while (conn->discoveryState != STATE_RECEIVED_PADO); 602 } 603 604 /********************************************************************** 605 *%FUNCTION: discovery 606 *%ARGUMENTS: 607 * conn -- PPPoE connection info structure 608 *%RETURNS: 609 * Nothing 610 *%DESCRIPTION: 611 * Performs the PPPoE discovery phase 612 ***********************************************************************/ 613 void 614 discovery(PPPoEConnection *conn) 615 { 616 int padiAttempts = 0; 617 int timeout = PADI_TIMEOUT; 618 619 conn->discoverySocket = 620 openInterface(conn->ifName, Eth_PPPOE_Discovery, conn->myEth); 621 622 do { 623 padiAttempts++; 624 if (padiAttempts > MAX_PADI_ATTEMPTS) { 625 fprintf(stderr, "Timeout waiting for PADO packets\n"); 626 close(conn->discoverySocket); 627 conn->discoverySocket = -1; 628 return; 629 } 630 sendPADI(conn); 631 conn->discoveryState = STATE_SENT_PADI; 632 waitForPADO(conn, timeout); 633 } while (!conn->numPADOs); 634 } 635 636 int main(int argc, char *argv[]) 637 { 638 int opt; 639 PPPoEConnection *conn; 640 641 conn = malloc(sizeof(PPPoEConnection)); 642 if (!conn) 643 fatalSys("malloc"); 644 645 memset(conn, 0, sizeof(PPPoEConnection)); 646 647 while ((opt = getopt(argc, argv, "I:D:VUAS:C:h")) > 0) { 648 switch(opt) { 649 case 'S': 650 conn->serviceName = xstrdup(optarg); 651 break; 652 case 'C': 653 conn->acName = xstrdup(optarg); 654 break; 655 case 'U': 656 conn->useHostUniq = 1; 657 break; 658 case 'D': 659 conn->debugFile = fopen(optarg, "w"); 660 if (!conn->debugFile) { 661 fprintf(stderr, "Could not open %s: %s\n", 662 optarg, strerror(errno)); 663 exit(1); 664 } 665 fprintf(conn->debugFile, "pppoe-discovery %s\n", RP_VERSION); 666 break; 667 case 'I': 668 conn->ifName = xstrdup(optarg); 669 break; 670 case 'A': 671 /* this is the default */ 672 break; 673 case 'V': 674 case 'h': 675 usage(); 676 exit(0); 677 default: 678 usage(); 679 exit(1); 680 } 681 } 682 683 /* default interface name */ 684 if (!conn->ifName) 685 conn->ifName = strdup("eth0"); 686 687 conn->discoverySocket = -1; 688 conn->sessionSocket = -1; 689 conn->printACNames = 1; 690 691 discovery(conn); 692 exit(0); 693 } 694 695 void rp_fatal(char const *str) 696 { 697 fprintf(stderr, "%s\n", str); 698 exit(1); 699 } 700 701 void fatalSys(char const *str) 702 { 703 perror(str); 704 exit(1); 705 } 706 707 void sysErr(char const *str) 708 { 709 rp_fatal(str); 710 } 711 712 char *xstrdup(const char *s) 713 { 714 register char *ret = strdup(s); 715 if (!ret) 716 sysErr("strdup"); 717 return ret; 718 } 719 720 void usage(void) 721 { 722 fprintf(stderr, "Usage: pppoe-discovery [options]\n"); 723 fprintf(stderr, "\nVersion " RP_VERSION "\n"); 724 } 725