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1 /*
2  * Perform PPPoE discovery
3  *
4  * Copyright (C) 2000-2001 by Roaring Penguin Software Inc.
5  * Copyright (C) 2004 Marco d'Itri <md@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 
die(int status)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
etherType(PPPoEPacket * packet)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
openInterface(char const * ifname,UINT16_t type,unsigned char * hwaddr)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
sendPacket(PPPoEConnection * conn,int sock,PPPoEPacket * pkt,int size)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
receivePacket(int sock,PPPoEPacket * pkt,int * size)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
parsePacket(PPPoEPacket * packet,ParseFunc * func,void * extra)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
parseForHostUniq(UINT16_t type,UINT16_t len,unsigned char * data,void * extra)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
packetIsForMe(PPPoEConnection * conn,PPPoEPacket * packet)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
parsePADOTags(UINT16_t type,UINT16_t len,unsigned char * data,void * extra)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
sendPADI(PPPoEConnection * conn)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
waitForPADO(PPPoEConnection * conn,int timeout)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
discovery(PPPoEConnection * conn)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 
main(int argc,char * argv[])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 
rp_fatal(char const * str)695 void rp_fatal(char const *str)
696 {
697     fprintf(stderr, "%s\n", str);
698     exit(1);
699 }
700 
fatalSys(char const * str)701 void fatalSys(char const *str)
702 {
703     perror(str);
704     exit(1);
705 }
706 
sysErr(char const * str)707 void sysErr(char const *str)
708 {
709     rp_fatal(str);
710 }
711 
xstrdup(const char * s)712 char *xstrdup(const char *s)
713 {
714     register char *ret = strdup(s);
715     if (!ret)
716 	sysErr("strdup");
717     return ret;
718 }
719 
usage(void)720 void usage(void)
721 {
722     fprintf(stderr, "Usage: pppoe-discovery [options]\n");
723     fprintf(stderr, "\nVersion " RP_VERSION "\n");
724 }
725