1 /***********************************************************************
5 * Perform PPPoE discovery
7 * Copyright (C) 1999 by Roaring Penguin Software Inc.
9 ***********************************************************************/
11 static char const RCSID[] =
12 "$Id: discovery.c,v 1.4 2005/03/22 10:22:32 paulus Exp $";
24 #ifdef HAVE_SYS_TIME_H
36 #ifdef USE_LINUX_PACKET
37 #include <sys/ioctl.h>
43 /**********************************************************************
44 *%FUNCTION: parseForHostUniq
49 * extra -- user-supplied pointer. This is assumed to be a pointer to int.
53 * If a HostUnique tag is found which matches our PID, sets *extra to 1.
54 ***********************************************************************/
56 parseForHostUniq(UINT16_t type, UINT16_t len, unsigned char *data,
59 int *val = (int *) extra;
60 if (type == TAG_HOST_UNIQ && len == sizeof(pid_t)) {
62 memcpy(&tmp, data, len);
63 if (tmp == getpid()) {
69 /**********************************************************************
70 *%FUNCTION: packetIsForMe
72 * conn -- PPPoE connection info
73 * packet -- a received PPPoE packet
75 * 1 if packet is for this PPPoE daemon; 0 otherwise.
77 * If we are using the Host-Unique tag, verifies that packet contains
78 * our unique identifier.
79 ***********************************************************************/
81 packetIsForMe(PPPoEConnection *conn, PPPoEPacket *packet)
85 /* If packet is not directed to our MAC address, forget it */
86 if (memcmp(packet->ethHdr.h_dest, conn->myEth, ETH_ALEN)) return 0;
88 /* If we're not using the Host-Unique tag, then accept the packet */
89 if (!conn->useHostUniq) return 1;
91 parsePacket(packet, parseForHostUniq, &forMe);
95 /**********************************************************************
96 *%FUNCTION: parsePADOTags
101 * extra -- extra user data. Should point to a PacketCriteria structure
102 * which gets filled in according to selected AC name and service
107 * Picks interesting tags out of a PADO packet
108 ***********************************************************************/
110 parsePADOTags(UINT16_t type, UINT16_t len, unsigned char *data,
113 struct PacketCriteria *pc = (struct PacketCriteria *) extra;
114 PPPoEConnection *conn = pc->conn;
120 if (conn->printACNames) {
121 printf("Access-Concentrator: %.*s\n", (int) len, data);
123 if (conn->acName && len == strlen(conn->acName) &&
124 !strncmp((char *) data, conn->acName, len)) {
128 case TAG_SERVICE_NAME:
129 pc->seenServiceName = 1;
130 if (conn->printACNames && len > 0) {
131 printf(" Service-Name: %.*s\n", (int) len, data);
133 if (conn->serviceName && len == strlen(conn->serviceName) &&
134 !strncmp((char *) data, conn->serviceName, len)) {
135 pc->serviceNameOK = 1;
139 if (conn->printACNames) {
140 printf("Got a cookie:");
141 /* Print first 20 bytes of cookie */
142 for (i=0; i<len && i < 20; i++) {
143 printf(" %02x", (unsigned) data[i]);
145 if (i < len) printf("...");
148 conn->cookie.type = htons(type);
149 conn->cookie.length = htons(len);
150 memcpy(conn->cookie.payload, data, len);
152 case TAG_RELAY_SESSION_ID:
153 if (conn->printACNames) {
154 printf("Got a Relay-ID:");
155 /* Print first 20 bytes of relay ID */
156 for (i=0; i<len && i < 20; i++) {
157 printf(" %02x", (unsigned) data[i]);
159 if (i < len) printf("...");
162 conn->relayId.type = htons(type);
163 conn->relayId.length = htons(len);
164 memcpy(conn->relayId.payload, data, len);
166 case TAG_SERVICE_NAME_ERROR:
167 if (conn->printACNames) {
168 printf("Got a Service-Name-Error tag: %.*s\n", (int) len, data);
170 syslog(LOG_ERR, "PADO: Service-Name-Error: %.*s", (int) len, data);
174 case TAG_AC_SYSTEM_ERROR:
175 if (conn->printACNames) {
176 printf("Got a System-Error tag: %.*s\n", (int) len, data);
178 syslog(LOG_ERR, "PADO: System-Error: %.*s", (int) len, data);
182 case TAG_GENERIC_ERROR:
183 if (conn->printACNames) {
184 printf("Got a Generic-Error tag: %.*s\n", (int) len, data);
186 syslog(LOG_ERR, "PADO: Generic-Error: %.*s", (int) len, data);
193 /**********************************************************************
194 *%FUNCTION: parsePADSTags
199 * extra -- extra user data (pointer to PPPoEConnection structure)
203 * Picks interesting tags out of a PADS packet
204 ***********************************************************************/
206 parsePADSTags(UINT16_t type, UINT16_t len, unsigned char *data,
209 PPPoEConnection *conn = (PPPoEConnection *) extra;
211 case TAG_SERVICE_NAME:
212 syslog(LOG_DEBUG, "PADS: Service-Name: '%.*s'", (int) len, data);
214 case TAG_SERVICE_NAME_ERROR:
215 syslog(LOG_ERR, "PADS: Service-Name-Error: %.*s", (int) len, data);
216 fprintf(stderr, "PADS: Service-Name-Error: %.*s\n", (int) len, data);
218 case TAG_AC_SYSTEM_ERROR:
219 syslog(LOG_ERR, "PADS: System-Error: %.*s", (int) len, data);
220 fprintf(stderr, "PADS: System-Error: %.*s\n", (int) len, data);
222 case TAG_GENERIC_ERROR:
223 syslog(LOG_ERR, "PADS: Generic-Error: %.*s", (int) len, data);
224 fprintf(stderr, "PADS: Generic-Error: %.*s\n", (int) len, data);
226 case TAG_RELAY_SESSION_ID:
227 conn->relayId.type = htons(type);
228 conn->relayId.length = htons(len);
229 memcpy(conn->relayId.payload, data, len);
234 /***********************************************************************
237 * conn -- PPPoEConnection structure
241 * Sends a PADI packet
242 ***********************************************************************/
244 sendPADI(PPPoEConnection *conn)
247 unsigned char *cursor = packet.payload;
248 PPPoETag *svc = (PPPoETag *) (&packet.payload);
249 UINT16_t namelen = 0;
252 if (conn->serviceName) {
253 namelen = (UINT16_t) strlen(conn->serviceName);
255 plen = TAG_HDR_SIZE + namelen;
256 CHECK_ROOM(cursor, packet.payload, plen);
258 /* Set destination to Ethernet broadcast address */
259 memset(packet.ethHdr.h_dest, 0xFF, ETH_ALEN);
260 memcpy(packet.ethHdr.h_source, conn->myEth, ETH_ALEN);
262 packet.ethHdr.h_proto = htons(Eth_PPPOE_Discovery);
265 packet.code = CODE_PADI;
268 svc->type = TAG_SERVICE_NAME;
269 svc->length = htons(namelen);
270 CHECK_ROOM(cursor, packet.payload, namelen+TAG_HDR_SIZE);
272 if (conn->serviceName) {
273 memcpy(svc->payload, conn->serviceName, strlen(conn->serviceName));
275 cursor += namelen + TAG_HDR_SIZE;
277 /* If we're using Host-Uniq, copy it over */
278 if (conn->useHostUniq) {
280 pid_t pid = getpid();
281 hostUniq.type = htons(TAG_HOST_UNIQ);
282 hostUniq.length = htons(sizeof(pid));
283 memcpy(hostUniq.payload, &pid, sizeof(pid));
284 CHECK_ROOM(cursor, packet.payload, sizeof(pid) + TAG_HDR_SIZE);
285 memcpy(cursor, &hostUniq, sizeof(pid) + TAG_HDR_SIZE);
286 cursor += sizeof(pid) + TAG_HDR_SIZE;
287 plen += sizeof(pid) + TAG_HDR_SIZE;
290 packet.length = htons(plen);
292 sendPacket(conn, conn->discoverySocket, &packet, (int) (plen + HDR_SIZE));
293 if (conn->debugFile) {
294 dumpPacket(conn->debugFile, &packet, "SENT");
295 fprintf(conn->debugFile, "\n");
296 fflush(conn->debugFile);
300 /**********************************************************************
301 *%FUNCTION: waitForPADO
303 * conn -- PPPoEConnection structure
304 * timeout -- how long to wait (in seconds)
308 * Waits for a PADO packet and copies useful information
309 ***********************************************************************/
311 waitForPADO(PPPoEConnection *conn, int timeout)
319 struct PacketCriteria pc;
321 pc.acNameOK = (conn->acName) ? 0 : 1;
322 pc.serviceNameOK = (conn->serviceName) ? 0 : 1;
324 pc.seenServiceName = 0;
327 if (BPF_BUFFER_IS_EMPTY) {
332 FD_SET(conn->discoverySocket, &readable);
335 r = select(conn->discoverySocket+1, &readable, NULL, NULL, &tv);
336 if (r >= 0 || errno != EINTR) break;
339 fatalSys("select (waitForPADO)");
341 if (r == 0) return; /* Timed out */
345 receivePacket(conn->discoverySocket, &packet, &len);
348 if (ntohs(packet.length) + HDR_SIZE > len) {
349 syslog(LOG_ERR, "Bogus PPPoE length field (%u)",
350 (unsigned int) ntohs(packet.length));
355 /* If it's not a Discovery packet, loop again */
356 if (etherType(&packet) != Eth_PPPOE_Discovery) continue;
359 if (conn->debugFile) {
360 dumpPacket(conn->debugFile, &packet, "RCVD");
361 fprintf(conn->debugFile, "\n");
362 fflush(conn->debugFile);
364 /* If it's not for us, loop again */
365 if (!packetIsForMe(conn, &packet)) continue;
367 if (packet.code == CODE_PADO) {
368 if (BROADCAST(packet.ethHdr.h_source)) {
369 printErr("Ignoring PADO packet from broadcast MAC address");
372 parsePacket(&packet, parsePADOTags, &pc);
373 if (!pc.seenACName) {
374 printErr("Ignoring PADO packet with no AC-Name tag");
377 if (!pc.seenServiceName) {
378 printErr("Ignoring PADO packet with no Service-Name tag");
382 if (conn->printACNames) {
383 printf("--------------------------------------------------\n");
385 if (pc.acNameOK && pc.serviceNameOK) {
386 memcpy(conn->peerEth, packet.ethHdr.h_source, ETH_ALEN);
387 if (conn->printACNames) {
388 printf("AC-Ethernet-Address: %02x:%02x:%02x:%02x:%02x:%02x\n",
389 (unsigned) conn->peerEth[0],
390 (unsigned) conn->peerEth[1],
391 (unsigned) conn->peerEth[2],
392 (unsigned) conn->peerEth[3],
393 (unsigned) conn->peerEth[4],
394 (unsigned) conn->peerEth[5]);
397 conn->discoveryState = STATE_RECEIVED_PADO;
401 } while (conn->discoveryState != STATE_RECEIVED_PADO);
404 /***********************************************************************
407 * conn -- PPPoE connection structur
411 * Sends a PADR packet
412 ***********************************************************************/
414 sendPADR(PPPoEConnection *conn)
417 PPPoETag *svc = (PPPoETag *) packet.payload;
418 unsigned char *cursor = packet.payload;
420 UINT16_t namelen = 0;
423 if (conn->serviceName) {
424 namelen = (UINT16_t) strlen(conn->serviceName);
426 plen = TAG_HDR_SIZE + namelen;
427 CHECK_ROOM(cursor, packet.payload, plen);
429 memcpy(packet.ethHdr.h_dest, conn->peerEth, ETH_ALEN);
430 memcpy(packet.ethHdr.h_source, conn->myEth, ETH_ALEN);
432 packet.ethHdr.h_proto = htons(Eth_PPPOE_Discovery);
435 packet.code = CODE_PADR;
438 svc->type = TAG_SERVICE_NAME;
439 svc->length = htons(namelen);
440 if (conn->serviceName) {
441 memcpy(svc->payload, conn->serviceName, namelen);
443 cursor += namelen + TAG_HDR_SIZE;
445 /* If we're using Host-Uniq, copy it over */
446 if (conn->useHostUniq) {
448 pid_t pid = getpid();
449 hostUniq.type = htons(TAG_HOST_UNIQ);
450 hostUniq.length = htons(sizeof(pid));
451 memcpy(hostUniq.payload, &pid, sizeof(pid));
452 CHECK_ROOM(cursor, packet.payload, sizeof(pid)+TAG_HDR_SIZE);
453 memcpy(cursor, &hostUniq, sizeof(pid) + TAG_HDR_SIZE);
454 cursor += sizeof(pid) + TAG_HDR_SIZE;
455 plen += sizeof(pid) + TAG_HDR_SIZE;
458 /* Copy cookie and relay-ID if needed */
459 if (conn->cookie.type) {
460 CHECK_ROOM(cursor, packet.payload,
461 ntohs(conn->cookie.length) + TAG_HDR_SIZE);
462 memcpy(cursor, &conn->cookie, ntohs(conn->cookie.length) + TAG_HDR_SIZE);
463 cursor += ntohs(conn->cookie.length) + TAG_HDR_SIZE;
464 plen += ntohs(conn->cookie.length) + TAG_HDR_SIZE;
467 if (conn->relayId.type) {
468 CHECK_ROOM(cursor, packet.payload,
469 ntohs(conn->relayId.length) + TAG_HDR_SIZE);
470 memcpy(cursor, &conn->relayId, ntohs(conn->relayId.length) + TAG_HDR_SIZE);
471 cursor += ntohs(conn->relayId.length) + TAG_HDR_SIZE;
472 plen += ntohs(conn->relayId.length) + TAG_HDR_SIZE;
475 packet.length = htons(plen);
476 sendPacket(conn, conn->discoverySocket, &packet, (int) (plen + HDR_SIZE));
477 if (conn->debugFile) {
478 dumpPacket(conn->debugFile, &packet, "SENT");
479 fprintf(conn->debugFile, "\n");
480 fflush(conn->debugFile);
484 /**********************************************************************
485 *%FUNCTION: waitForPADS
487 * conn -- PPPoE connection info
488 * timeout -- how long to wait (in seconds)
492 * Waits for a PADS packet and copies useful information
493 ***********************************************************************/
495 waitForPADS(PPPoEConnection *conn, int timeout)
504 if (BPF_BUFFER_IS_EMPTY) {
509 FD_SET(conn->discoverySocket, &readable);
512 r = select(conn->discoverySocket+1, &readable, NULL, NULL, &tv);
513 if (r >= 0 || errno != EINTR) break;
516 fatalSys("select (waitForPADS)");
522 receivePacket(conn->discoverySocket, &packet, &len);
525 if (ntohs(packet.length) + HDR_SIZE > len) {
526 syslog(LOG_ERR, "Bogus PPPoE length field (%u)",
527 (unsigned int) ntohs(packet.length));
532 /* If it's not a Discovery packet, loop again */
533 if (etherType(&packet) != Eth_PPPOE_Discovery) continue;
535 if (conn->debugFile) {
536 dumpPacket(conn->debugFile, &packet, "RCVD");
537 fprintf(conn->debugFile, "\n");
538 fflush(conn->debugFile);
541 /* If it's not from the AC, it's not for me */
542 if (memcmp(packet.ethHdr.h_source, conn->peerEth, ETH_ALEN)) continue;
544 /* If it's not for us, loop again */
545 if (!packetIsForMe(conn, &packet)) continue;
548 if (packet.code == CODE_PADS) {
549 /* Parse for goodies */
550 parsePacket(&packet, parsePADSTags, conn);
551 conn->discoveryState = STATE_SESSION;
554 } while (conn->discoveryState != STATE_SESSION);
556 /* Don't bother with ntohs; we'll just end up converting it back... */
557 conn->session = packet.session;
559 syslog(LOG_INFO, "PPP session is %d", (int) ntohs(conn->session));
561 /* RFC 2516 says session id MUST NOT be zero or 0xFFFF */
562 if (ntohs(conn->session) == 0 || ntohs(conn->session) == 0xFFFF) {
563 syslog(LOG_ERR, "Access concentrator used a session value of %x -- the AC is violating RFC 2516", (unsigned int) ntohs(conn->session));
567 /**********************************************************************
568 *%FUNCTION: discovery
570 * conn -- PPPoE connection info structure
574 * Performs the PPPoE discovery phase
575 ***********************************************************************/
577 discovery(PPPoEConnection *conn)
579 int padiAttempts = 0;
580 int padrAttempts = 0;
581 int timeout = PADI_TIMEOUT;
583 /* Skip discovery and don't open discovery socket? */
584 if (conn->skipDiscovery && conn->noDiscoverySocket) {
585 conn->discoveryState = STATE_SESSION;
589 conn->discoverySocket =
590 openInterface(conn->ifName, Eth_PPPOE_Discovery, conn->myEth);
592 /* Skip discovery? */
593 if (conn->skipDiscovery) {
594 conn->discoveryState = STATE_SESSION;
600 if (padiAttempts > MAX_PADI_ATTEMPTS) {
601 warn("Timeout waiting for PADO packets");
602 close(conn->discoverySocket);
603 conn->discoverySocket = -1;
607 conn->discoveryState = STATE_SENT_PADI;
608 waitForPADO(conn, timeout);
610 /* If we're just probing for access concentrators, don't do
611 exponential backoff. This reduces the time for an unsuccessful
612 probe to 15 seconds. */
613 if (!conn->printACNames) {
616 if (conn->printACNames && conn->numPADOs) {
619 } while (conn->discoveryState == STATE_SENT_PADI);
621 /* If we're only printing access concentrator names, we're done */
622 if (conn->printACNames) {
626 timeout = PADI_TIMEOUT;
629 if (padrAttempts > MAX_PADI_ATTEMPTS) {
630 warn("Timeout waiting for PADS packets");
631 close(conn->discoverySocket);
632 conn->discoverySocket = -1;
636 conn->discoveryState = STATE_SENT_PADR;
637 waitForPADS(conn, timeout);
639 } while (conn->discoveryState == STATE_SENT_PADR);
642 conn->discoveryState = STATE_SESSION;