1 /***********************************************************************
2 *
3 * if.c
4 *
5 * Implementation of user-space PPPoE redirector for Linux.
6 *
7 * Functions for opening a raw socket and reading/writing raw Ethernet frames.
8 *
9 * Copyright (C) 2000 by Roaring Penguin Software Inc.
10 *
11 * This program may be distributed according to the terms of the GNU
12 * General Public License, version 2 or (at your option) any later version.
13 *
14 ***********************************************************************/
15
16 static char const RCSID[] =
17 "$Id: if.c,v 1.1 2001/12/14 02:55:20 mostrows Exp $";
18
19 #include "pppoe.h"
20
21 #ifdef HAVE_UNISTD_H
22 #include <unistd.h>
23 #endif
24
25 #ifdef HAVE_NETPACKET_PACKET_H
26 #include <netpacket/packet.h>
27 #elif defined(HAVE_LINUX_IF_PACKET_H)
28 #include <linux/if_packet.h>
29 #endif
30
31 #ifdef HAVE_NET_ETHERNET_H
32 #include <net/ethernet.h>
33 #endif
34
35 #ifdef HAVE_ASM_TYPES_H
36 #include <asm/types.h>
37 #endif
38
39 #ifdef HAVE_SYS_IOCTL_H
40 #include <sys/ioctl.h>
41 #endif
42
43 #ifdef HAVE_SYSLOG_H
44 #include <syslog.h>
45 #endif
46
47 #include <errno.h>
48 #include <stdlib.h>
49 #include <string.h>
50
51 #ifdef HAVE_NET_IF_ARP_H
52 #include <net/if_arp.h>
53 #endif
54
55 #ifdef USE_DLPI
56
57 #include <limits.h>
58 #include <fcntl.h>
59 #include <stdlib.h>
60 #include <sys/types.h>
61 #include <sys/time.h>
62 #include <sys/stream.h>
63 #include <sys/stropts.h>
64 #include <sys/dlpi.h>
65 #include <sys/bufmod.h>
66 #include <stdio.h>
67 #include <signal.h>
68 #include <stropts.h>
69
70 /* function declarations */
71
72 void dlpromisconreq( int fd, u_long level);
73 void dlinforeq(int fd);
74 void dlunitdatareq(int fd, u_char *addrp, int addrlen, u_long minpri, u_long maxpri, u_char *datap, int datalen);
75 void dlinfoack(int fd, char *bufp);
76 void dlbindreq(int fd, u_long sap, u_long max_conind, u_long service_mode, u_long conn_mgmt, u_long xidtest);
77 void dlattachreq(int fd, u_long ppa);
78 void dlokack(int fd, char *bufp);
79 void dlbindack(int fd, char *bufp);
80 int strioctl(int fd, int cmd, int timout, int len, char *dp);
81 void strgetmsg(int fd, struct strbuf *ctlp, struct strbuf *datap, int *flagsp, char *caller);
82 void sigalrm(int sig);
83 void expecting(int prim, union DL_primitives *dlp);
84 char *dlprim(u_long prim);
85
86 /* #define DL_DEBUG */
87
88 static int dl_abssaplen;
89 static int dl_saplen;
90 static int dl_addrlen;
91
92 #endif
93
94 #ifdef USE_BPF
95 #include <net/bpf.h>
96 #include <fcntl.h>
97
98 unsigned char *bpfBuffer; /* Packet filter buffer */
99 int bpfLength = 0; /* Packet filter buffer length */
100 int bpfSize = 0; /* Number of unread bytes in buffer */
101 int bpfOffset = 0; /* Current offset in bpfBuffer */
102 #endif
103
104 /* Initialize frame types to RFC 2516 values. Some broken peers apparently
105 use different frame types... sigh... */
106
107 UINT16_t Eth_PPPOE_Discovery = ETH_PPPOE_DISCOVERY;
108 UINT16_t Eth_PPPOE_Session = ETH_PPPOE_SESSION;
109
110 /**********************************************************************
111 *%FUNCTION: etherType
112 *%ARGUMENTS:
113 * packet -- a received PPPoE packet
114 *%RETURNS:
115 * ethernet packet type (see /usr/include/net/ethertypes.h)
116 *%DESCRIPTION:
117 * Checks the ethernet packet header to determine its type.
118 * We should only be receveing DISCOVERY and SESSION types if the BPF
119 * is set up correctly. Logs an error if an unexpected type is received.
120 * Note that the ethernet type names come from "pppoe.h" and the packet
121 * packet structure names use the LINUX dialect to maintain consistency
122 * with the rest of this file. See the BSD section of "pppoe.h" for
123 * translations of the data structure names.
124 ***********************************************************************/
125 UINT16_t
etherType(PPPoEPacket * packet)126 etherType(PPPoEPacket *packet)
127 {
128 UINT16_t type = (UINT16_t) ntohs(packet->ethHdr.h_proto);
129 if (type != Eth_PPPOE_Discovery && type != Eth_PPPOE_Session) {
130 syslog(LOG_ERR, "Invalid ether type 0x%x", type);
131 }
132 return type;
133 }
134
135 #ifdef USE_BPF
136 /**********************************************************************
137 *%FUNCTION: getHWaddr
138 *%ARGUMENTS:
139 * ifname -- name of interface
140 * hwaddr -- buffer for ehthernet address
141 *%RETURNS:
142 * Nothing
143 *%DESCRIPTION:
144 * Locates the Ethernet hardware address for an interface.
145 ***********************************************************************/
146 void
getHWaddr(int sock,char const * ifname,unsigned char * hwaddr)147 getHWaddr(int sock, char const *ifname, unsigned char *hwaddr)
148 {
149 char inbuf[8192];
150 const struct sockaddr_dl *sdl;
151 struct ifconf ifc;
152 struct ifreq ifreq, *ifr;
153 int i;
154 int found = 0;
155
156 ifc.ifc_len = sizeof(inbuf);
157 ifc.ifc_buf = inbuf;
158 if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
159 fatalSys("SIOCGIFCONF");
160 }
161 ifr = ifc.ifc_req;
162 ifreq.ifr_name[0] = '\0';
163 for (i = 0; i < ifc.ifc_len; ) {
164 ifr = (struct ifreq *)((caddr_t)ifc.ifc_req + i);
165 i += sizeof(ifr->ifr_name) +
166 (ifr->ifr_addr.sa_len > sizeof(struct sockaddr)
167 ? ifr->ifr_addr.sa_len
168 : sizeof(struct sockaddr));
169 if (ifr->ifr_addr.sa_family == AF_LINK) {
170 sdl = (const struct sockaddr_dl *) &ifr->ifr_addr;
171 if ((sdl->sdl_type == IFT_ETHER) &&
172 (sdl->sdl_alen == ETH_ALEN) &&
173 !strncmp(ifname, ifr->ifr_name, sizeof(ifr->ifr_name))) {
174 if (found) {
175 char buffer[256];
176 sprintf(buffer, "interface %.16s has more than one ethernet address", ifname);
177 rp_fatal(buffer);
178 } else {
179 found = 1;
180 memcpy(hwaddr, LLADDR(sdl), ETH_ALEN);
181 }
182 }
183 }
184 }
185 if (!found) {
186 char buffer[256];
187 sprintf(buffer, "interface %.16s has no ethernet address", ifname);
188 rp_fatal(buffer);
189 }
190 }
191
192 /**********************************************************************
193 *%FUNCTION: initFilter
194 *%ARGUMENTS:
195 * fd -- file descriptor of BSD device
196 * type -- Ethernet frame type (0 for watch mode)
197 * hwaddr -- buffer with ehthernet address
198 *%RETURNS:
199 * Nothing
200 *%DESCRIPTION:
201 * Initializes the packet filter rules.
202 ***********************************************************************/
203 void
initFilter(int fd,UINT16_t type,unsigned char * hwaddr)204 initFilter(int fd, UINT16_t type, unsigned char *hwaddr)
205 {
206 /* Packet Filter Instructions:
207 * Note that the ethernet type names come from "pppoe.h" and are
208 * used here to maintain consistency with the rest of this file. */
209 static struct bpf_insn bpfRun[] = { /* run PPPoE */
210 BPF_STMT(BPF_LD+BPF_H+BPF_ABS, 12), /* ethernet type */
211 BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, ETH_PPPOE_SESSION, 5, 0),
212 BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, ETH_PPPOE_DISCOVERY, 0, 9),
213 BPF_STMT(BPF_LD+BPF_W+BPF_ABS, 0), /* first word of dest. addr */
214 #define PPPOE_BCAST_CMPW 4 /* offset of word compare */
215 BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, 0, 0, 2),
216 BPF_STMT(BPF_LD+BPF_H+BPF_ABS, 4), /* next 1/2 word of dest. */
217 #define PPPOE_BCAST_CMPH 6 /* offset of 1/2 word compare */
218 BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, 0, 4, 0),
219 BPF_STMT(BPF_LD+BPF_W+BPF_ABS, 0), /* first word of dest. addr */
220 #define PPPOE_FILTER_CMPW 8 /* offset of word compare */
221 BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, 0, 0, 3),
222 BPF_STMT(BPF_LD+BPF_H+BPF_ABS, 4), /* next 1/2 word of dest. */
223 #define PPPOE_FILTER_CMPH 10 /* offset of 1/rd compare */
224 BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, 0, 0, 1),
225 BPF_STMT(BPF_RET+BPF_K, (u_int) -1), /* keep packet */
226 BPF_STMT(BPF_RET+BPF_K, 0), /* drop packet */
227 };
228
229 /* Fix the potentially varying parts */
230 bpfRun[1].code = (u_short) BPF_JMP+BPF_JEQ+BPF_K;
231 bpfRun[1].jt = 5;
232 bpfRun[1].jf = 0;
233 bpfRun[1].k = Eth_PPPOE_Session;
234
235 bpfRun[2].code = (u_short) BPF_JMP+BPF_JEQ+BPF_K;
236 bpfRun[2].jt = 0;
237 bpfRun[2].jf = 9;
238 bpfRun[2].k = Eth_PPPOE_Discovery;
239
240 {
241 struct bpf_insn bpfInsn[sizeof(bpfRun) / sizeof(bpfRun[0])];
242 struct bpf_program bpfProgram;
243 memcpy(bpfInsn, bpfRun, sizeof(bpfRun));
244 bpfInsn[PPPOE_BCAST_CMPW].k = ((0xff << 24) | (0xff << 16) |
245 (0xff << 8) | 0xff);
246 bpfInsn[PPPOE_BCAST_CMPH].k = ((0xff << 8) | 0xff);
247 bpfInsn[PPPOE_FILTER_CMPW].k = ((hwaddr[0] << 24) | (hwaddr[1] << 16) |
248 (hwaddr[2] << 8) | hwaddr[3]);
249 bpfInsn[PPPOE_FILTER_CMPH].k = ((hwaddr[4] << 8) | hwaddr[5]);
250 bpfProgram.bf_len = (sizeof(bpfInsn) / sizeof(bpfInsn[0]));
251 bpfProgram.bf_insns = &bpfInsn[0];
252
253 /* Apply the filter */
254 if (ioctl(fd, BIOCSETF, &bpfProgram) < 0) {
255 fatalSys("ioctl(BIOCSETF)");
256 }
257 }
258 }
259
260 /**********************************************************************
261 *%FUNCTION: openInterface
262 *%ARGUMENTS:
263 * ifname -- name of interface
264 * type -- Ethernet frame type (0 for any frame type)
265 * hwaddr -- if non-NULL, set to the hardware address
266 *%RETURNS:
267 * A file descriptor for talking with the Ethernet card. Exits on error.
268 * Note that the Linux version of this routine returns a socket instead.
269 *%DESCRIPTION:
270 * Opens a BPF on an interface for all PPPoE traffic (discovery and
271 * session). If 'type' is 0, uses promiscuous mode to watch any PPPoE
272 * traffic on this network.
273 ***********************************************************************/
274 int
openInterface(char const * ifname,UINT16_t type,unsigned char * hwaddr)275 openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr)
276 {
277 static int fd = -1;
278 char bpfName[32];
279 u_int optval;
280 struct bpf_version bpf_ver;
281 struct ifreq ifr;
282 int sock;
283 int i;
284
285 /* BSD only opens one socket for both Discovery and Session packets */
286 if (fd >= 0) {
287 return fd;
288 }
289
290 /* Find a free BPF device */
291 for (i = 0; i < 256; i++) {
292 sprintf(bpfName, "/dev/bpf%d", i);
293 if (((fd = open(bpfName, O_RDWR, 0)) >= 0) ||
294 (errno != EBUSY)) {
295 break;
296 }
297 }
298 if (fd < 0) {
299 switch (errno) {
300 case EACCES: /* permission denied */
301 {
302 char buffer[256];
303 sprintf(buffer, "Cannot open %.32s -- pppoe must be run as root.", bpfName);
304 rp_fatal(buffer);
305 }
306 break;
307 case EBUSY:
308 case ENOENT: /* no such file */
309 if (i == 0) {
310 rp_fatal("No /dev/bpf* devices (check your kernel configuration for BPF support)");
311 } else {
312 rp_fatal("All /dev/bpf* devices are in use");
313 }
314 break;
315 }
316 fatalSys(bpfName);
317 }
318
319 if ((sock = socket(AF_LOCAL, SOCK_DGRAM, 0)) < 0) {
320 fatalSys("socket");
321 }
322
323 /* Check that the interface is up */
324 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
325 if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
326 fatalSys("ioctl(SIOCGIFFLAGS)");
327 }
328 if ((ifr.ifr_flags & IFF_UP) == 0) {
329 char buffer[256];
330 sprintf(buffer, "Interface %.16s is not up\n", ifname);
331 rp_fatal(buffer);
332 }
333
334 /* Fill in hardware address and initialize the packet filter rules */
335 if (hwaddr == NULL) {
336 rp_fatal("openInterface: no hwaddr arg.");
337 }
338 getHWaddr(sock, ifname, hwaddr);
339 initFilter(fd, type, hwaddr);
340
341 /* Sanity check on MTU -- apparently does not work on OpenBSD */
342 #if !defined(__OpenBSD__)
343 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
344 if (ioctl(sock, SIOCGIFMTU, &ifr) < 0) {
345 fatalSys("ioctl(SIOCGIFMTU)");
346 }
347 if (ifr.ifr_mtu < ETH_DATA_LEN) {
348 char buffer[256];
349 sprintf(buffer, "Interface %.16s has MTU of %d -- should be %d. You may have serious connection problems.",
350 ifname, ifr.ifr_mtu, ETH_DATA_LEN);
351 printErr(buffer);
352 }
353 #endif
354
355 /* done with the socket */
356 if (close(sock) < 0) {
357 fatalSys("close");
358 }
359
360 /* Check the BPF version number */
361 if (ioctl(fd, BIOCVERSION, &bpf_ver) < 0) {
362 fatalSys("ioctl(BIOCVERSION)");
363 }
364 if ((bpf_ver.bv_major != BPF_MAJOR_VERSION) ||
365 (bpf_ver.bv_minor < BPF_MINOR_VERSION)) {
366 char buffer[256];
367 sprintf(buffer, "Unsupported BPF version: %d.%d (kernel: %d.%d)",
368 BPF_MAJOR_VERSION, BPF_MINOR_VERSION,
369 bpf_ver.bv_major, bpf_ver.bv_minor);
370 rp_fatal(buffer);
371 }
372
373 /* allocate a receive packet buffer */
374 if (ioctl(fd, BIOCGBLEN, &bpfLength) < 0) {
375 fatalSys("ioctl(BIOCGBLEN)");
376 }
377 if (!(bpfBuffer = (unsigned char *) malloc(bpfLength))) {
378 rp_fatal("malloc");
379 }
380
381 /* reads should return as soon as there is a packet available */
382 optval = 1;
383 if (ioctl(fd, BIOCIMMEDIATE, &optval) < 0) {
384 fatalSys("ioctl(BIOCIMMEDIATE)");
385 }
386
387 /* Bind the interface to the filter */
388 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
389 if (ioctl(fd, BIOCSETIF, &ifr) < 0) {
390 char buffer[256];
391 sprintf(buffer, "ioctl(BIOCSETIF) can't select interface %.16s",
392 ifname);
393 rp_fatal(buffer);
394 }
395
396 syslog(LOG_INFO, "Interface=%.16s HWaddr=%02X:%02X:%02X:%02X:%02X:%02X Device=%.32s Buffer size=%d",
397 ifname,
398 hwaddr[0], hwaddr[1], hwaddr[2],
399 hwaddr[3], hwaddr[4], hwaddr[5],
400 bpfName, bpfLength);
401 return fd;
402 }
403
404 #endif /* USE_BPF */
405
406 #ifdef USE_LINUX_PACKET
407 /**********************************************************************
408 *%FUNCTION: openInterface
409 *%ARGUMENTS:
410 * ifname -- name of interface
411 * type -- Ethernet frame type
412 * hwaddr -- if non-NULL, set to the hardware address
413 *%RETURNS:
414 * A raw socket for talking to the Ethernet card. Exits on error.
415 *%DESCRIPTION:
416 * Opens a raw Ethernet socket
417 ***********************************************************************/
418 int
openInterface(char const * ifname,UINT16_t type,unsigned char * hwaddr)419 openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr)
420 {
421 int optval=1;
422 int fd;
423 struct ifreq ifr;
424 int domain, stype;
425
426 #ifdef HAVE_STRUCT_SOCKADDR_LL
427 struct sockaddr_ll sa;
428 #else
429 struct sockaddr sa;
430 #endif
431
432 memset(&sa, 0, sizeof(sa));
433
434 #ifdef HAVE_STRUCT_SOCKADDR_LL
435 domain = PF_PACKET;
436 stype = SOCK_RAW;
437 #else
438 domain = PF_INET;
439 stype = SOCK_PACKET;
440 #endif
441
442 if ((fd = socket(domain, stype, htons(type))) < 0) {
443 /* Give a more helpful message for the common error case */
444 if (errno == EPERM) {
445 rp_fatal("Cannot create raw socket -- pppoe must be run as root.");
446 }
447 fatalSys("socket");
448 }
449
450 if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &optval, sizeof(optval)) < 0) {
451 fatalSys("setsockopt");
452 }
453
454 /* Fill in hardware address */
455 if (hwaddr) {
456 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
457 if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
458 fatalSys("ioctl(SIOCGIFHWADDR)");
459 }
460 memcpy(hwaddr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
461 #ifdef ARPHRD_ETHER
462 if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
463 char buffer[256];
464 sprintf(buffer, "Interface %.16s is not Ethernet", ifname);
465 rp_fatal(buffer);
466 }
467 #endif
468 if (NOT_UNICAST(hwaddr)) {
469 char buffer[256];
470 sprintf(buffer,
471 "Interface %.16s has broadcast/multicast MAC address??",
472 ifname);
473 rp_fatal(buffer);
474 }
475 }
476
477 /* Sanity check on MTU */
478 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
479 if (ioctl(fd, SIOCGIFMTU, &ifr) < 0) {
480 fatalSys("ioctl(SIOCGIFMTU)");
481 }
482 if (ifr.ifr_mtu < ETH_DATA_LEN) {
483 char buffer[256];
484 sprintf(buffer, "Interface %.16s has MTU of %d -- should be %d. You may have serious connection problems.",
485 ifname, ifr.ifr_mtu, ETH_DATA_LEN);
486 printErr(buffer);
487 }
488
489 #ifdef HAVE_STRUCT_SOCKADDR_LL
490 /* Get interface index */
491 sa.sll_family = AF_PACKET;
492 sa.sll_protocol = htons(type);
493
494 strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
495 if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
496 fatalSys("ioctl(SIOCFIGINDEX): Could not get interface index");
497 }
498 sa.sll_ifindex = ifr.ifr_ifindex;
499
500 #else
501 strcpy(sa.sa_data, ifname);
502 #endif
503
504 /* We're only interested in packets on specified interface */
505 if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0) {
506 fatalSys("bind");
507 }
508
509 return fd;
510 }
511
512 #endif /* USE_LINUX */
513
514 /***********************************************************************
515 *%FUNCTION: sendPacket
516 *%ARGUMENTS:
517 * sock -- socket to send to
518 * pkt -- the packet to transmit
519 * size -- size of packet (in bytes)
520 *%RETURNS:
521 * 0 on success; -1 on failure
522 *%DESCRIPTION:
523 * Transmits a packet
524 ***********************************************************************/
525 int
sendPacket(PPPoEConnection * conn,int sock,PPPoEPacket * pkt,int size)526 sendPacket(PPPoEConnection *conn, int sock, PPPoEPacket *pkt, int size)
527 {
528 #if defined(USE_BPF)
529 if (write(sock, pkt, size) < 0) {
530 sysErr("write (sendPacket)");
531 return -1;
532 }
533 #elif defined(HAVE_STRUCT_SOCKADDR_LL)
534 if (send(sock, pkt, size, 0) < 0) {
535 sysErr("send (sendPacket)");
536 return -1;
537 }
538 #else
539 #ifdef USE_DLPI
540
541 #define ABS(x) ((x) < 0 ? -(x) : (x))
542
543 u_char addr[MAXDLADDR];
544 u_char phys[MAXDLADDR];
545 u_char sap[MAXDLADDR];
546 u_char xmitbuf[MAXDLBUF];
547 int data_size;
548
549 short tmp_sap;
550
551 tmp_sap = htons(pkt->ethHdr.h_proto);
552 data_size = size - sizeof(struct ethhdr);
553
554 memcpy((char *)phys, (char *)pkt->ethHdr.h_dest, ETHERADDRL);
555 memcpy((char *)sap, (char *)&tmp_sap, sizeof(ushort_t));
556 memcpy((char *)xmitbuf, (char *)pkt + sizeof(struct ethhdr), data_size);
557
558 if (dl_saplen > 0) { /* order is sap+phys */
559 (void) memcpy((char*)addr, (char*)&sap, dl_abssaplen);
560 (void) memcpy((char*)addr+dl_abssaplen, (char*)phys, ETHERADDRL);
561 } else { /* order is phys+sap */
562 (void) memcpy((char*)addr, (char*)phys, ETHERADDRL);
563 (void) memcpy((char*)addr+ETHERADDRL, (char*)&sap, dl_abssaplen);
564 }
565
566 #ifdef DL_DEBUG
567 printf("%02x:%02x:%02x:%02x:%02x:%02x %02x:%02x\n",
568 addr[0],addr[1],addr[2],addr[3],addr[4],addr[5],
569 addr[6],addr[7]);
570 #endif
571
572 dlunitdatareq(sock, addr, dl_addrlen, 0, 0, xmitbuf, data_size);
573
574
575
576 #else
577 struct sockaddr sa;
578
579 if (!conn) {
580 rp_fatal("relay and server not supported on Linux 2.0 kernels");
581 }
582 strcpy(sa.sa_data, conn->ifName);
583 if (sendto(sock, pkt, size, 0, &sa, sizeof(sa)) < 0) {
584 sysErr("sendto (sendPacket)");
585 return -1;
586 }
587 #endif
588 #endif
589 return 0;
590 }
591
592 #ifdef USE_BPF
593 /***********************************************************************
594 *%FUNCTION: clearPacketHeader
595 *%ARGUMENTS:
596 * pkt -- packet that needs its head clearing
597 *%RETURNS:
598 * nothing
599 *%DESCRIPTION:
600 * Clears a PPPoE packet header after a truncated packet has been
601 * received. Insures that the packet will fail any integrity tests
602 * and will be discarded by upper level routines. Also resets the
603 * bpfSize and bpfOffset variables to force a new read on the next
604 * call to receivePacket().
605 ***********************************************************************/
606 void
clearPacketHeader(PPPoEPacket * pkt)607 clearPacketHeader(PPPoEPacket *pkt)
608 {
609 bpfSize = bpfOffset = 0;
610 memset(pkt, 0, HDR_SIZE);
611 }
612 #endif
613
614 /***********************************************************************
615 *%FUNCTION: receivePacket
616 *%ARGUMENTS:
617 * sock -- socket to read from
618 * pkt -- place to store the received packet
619 * size -- set to size of packet in bytes
620 *%RETURNS:
621 * >= 0 if all OK; < 0 if error
622 *%DESCRIPTION:
623 * Receives a packet
624 ***********************************************************************/
625 int
receivePacket(int sock,PPPoEPacket * pkt,int * size)626 receivePacket(int sock, PPPoEPacket *pkt, int *size)
627 {
628 #ifdef USE_BPF
629 struct bpf_hdr hdr;
630 int seglen, copylen;
631
632 if (bpfSize <= 0) {
633 bpfOffset = 0;
634 if ((bpfSize = read(sock, bpfBuffer, bpfLength)) < 0) {
635 sysErr("read (receivePacket)");
636 return -1;
637 }
638 }
639 if (bpfSize < sizeof(hdr)) {
640 syslog(LOG_ERR, "Truncated bpf packet header: len=%d", bpfSize);
641 clearPacketHeader(pkt); /* resets bpfSize and bpfOffset */
642 return 0;
643 }
644 memcpy(&hdr, bpfBuffer + bpfOffset, sizeof(hdr));
645 if (hdr.bh_caplen != hdr.bh_datalen) {
646 syslog(LOG_ERR, "Truncated bpf packet: caplen=%d, datalen=%d",
647 hdr.bh_caplen, hdr.bh_datalen);
648 clearPacketHeader(pkt); /* resets bpfSize and bpfOffset */
649 return 0;
650 }
651 seglen = hdr.bh_hdrlen + hdr.bh_caplen;
652 if (seglen > bpfSize) {
653 syslog(LOG_ERR, "Truncated bpf packet: seglen=%d, bpfSize=%d",
654 seglen, bpfSize);
655 clearPacketHeader(pkt); /* resets bpfSize and bpfOffset */
656 return 0;
657 }
658 seglen = BPF_WORDALIGN(seglen);
659 *size = copylen = ((hdr.bh_caplen < sizeof(PPPoEPacket)) ?
660 hdr.bh_caplen : sizeof(PPPoEPacket));
661 memcpy(pkt, bpfBuffer + bpfOffset + hdr.bh_hdrlen, copylen);
662 if (seglen >= bpfSize) {
663 bpfSize = bpfOffset = 0;
664 } else {
665 bpfSize -= seglen;
666 bpfOffset += seglen;
667 }
668 #else
669 #ifdef USE_DLPI
670 struct strbuf data;
671 int flags = 0;
672 int retval;
673
674 data.buf = (char *) pkt;
675 data.maxlen = MAXDLBUF;
676 data.len = 0;
677
678 if ((retval = getmsg(sock, NULL, &data, &flags)) < 0) {
679 sysErr("read (receivePacket)");
680 return -1;
681 }
682
683 *size = data.len;
684
685 #else
686 if ((*size = recv(sock, pkt, sizeof(PPPoEPacket), 0)) < 0) {
687 sysErr("recv (receivePacket)");
688 return -1;
689 }
690 #endif
691 #endif
692 return 0;
693 }
694
695 #ifdef USE_DLPI
696 /**********************************************************************
697 *%FUNCTION: openInterface
698 *%ARGUMENTS:
699 * ifname -- name of interface
700 * type -- Ethernet frame type
701 * hwaddr -- if non-NULL, set to the hardware address
702 *%RETURNS:
703 * A raw socket for talking to the Ethernet card. Exits on error.
704 *%DESCRIPTION:
705 * Opens a raw Ethernet socket
706 ***********************************************************************/
707 int
openInterface(char const * ifname,UINT16_t type,unsigned char * hwaddr)708 openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr)
709 {
710 int fd;
711 long buf[MAXDLBUF];
712
713 union DL_primitives *dlp;
714
715 char base_dev[PATH_MAX];
716 int ppa;
717
718 if(strlen(ifname) > PATH_MAX) {
719 rp_fatal("socket: string to long");
720 }
721
722 ppa = atoi(&ifname[strlen(ifname)-1]);
723 strncpy(base_dev, ifname, PATH_MAX);
724 base_dev[strlen(base_dev)-1] = '\0';
725
726 /* rearranged order of DLPI code - delphys 20010803 */
727 dlp = (union DL_primitives*) buf;
728
729 if (( fd = open(base_dev, O_RDWR)) < 0) {
730 /* Give a more helpful message for the common error case */
731 if (errno == EPERM) {
732 rp_fatal("Cannot create raw socket -- pppoe must be run as root.");
733 }
734 fatalSys("socket");
735 }
736
737 /* rearranged order of DLPI code - delphys 20010803 */
738 dlattachreq(fd, ppa);
739 dlokack(fd, (char *)buf);
740
741 dlbindreq(fd, type, 0, DL_CLDLS, 0, 0);
742 dlbindack(fd, (char *)buf);
743
744 dlinforeq(fd);
745 dlinfoack(fd, (char *)buf);
746
747 dl_abssaplen = ABS(dlp->info_ack.dl_sap_length);
748 dl_saplen = dlp->info_ack.dl_sap_length;
749 if (ETHERADDRL != (dlp->info_ack.dl_addr_length - dl_abssaplen))
750 fatalSys("invalid destination physical address length");
751 dl_addrlen = dl_abssaplen + ETHERADDRL;
752
753 /* ethernet address retrieved as part of DL_INFO_ACK - delphys 20010803 */
754 memcpy(hwaddr, (u_char*)((char*)(dlp) + (int)(dlp->info_ack.dl_addr_offset)), ETHERADDRL);
755
756 if ( strioctl(fd, DLIOCRAW, -1, 0, NULL) < 0 ) {
757 fatalSys("DLIOCRAW");
758 }
759
760 if (ioctl(fd, I_FLUSH, FLUSHR) < 0) fatalSys("I_FLUSH");
761
762 return fd;
763 }
764
765 /* cloned from dlcommon.c */
766
dlpromisconreq(int fd,u_long level)767 void dlpromisconreq(int fd, u_long level)
768 {
769 dl_promiscon_req_t promiscon_req;
770 struct strbuf ctl;
771 int flags;
772
773 promiscon_req.dl_primitive = DL_PROMISCON_REQ;
774 promiscon_req.dl_level = level;
775
776 ctl.maxlen = 0;
777 ctl.len = sizeof (promiscon_req);
778 ctl.buf = (char *) &promiscon_req;
779
780 flags = 0;
781
782 if (putmsg(fd, &ctl, (struct strbuf*) NULL, flags) < 0)
783 fatalSys("dlpromiscon: putmsg");
784
785 }
786
dlinforeq(int fd)787 void dlinforeq(int fd)
788 {
789 dl_info_req_t info_req;
790 struct strbuf ctl;
791 int flags;
792
793 info_req.dl_primitive = DL_INFO_REQ;
794
795 ctl.maxlen = 0;
796 ctl.len = sizeof (info_req);
797 ctl.buf = (char *) &info_req;
798
799 flags = RS_HIPRI;
800
801 if (putmsg(fd, &ctl, (struct strbuf*) NULL, flags) < 0)
802 fatalSys("dlinforeq: putmsg");
803 }
804
dlunitdatareq(int fd,u_char * addrp,int addrlen,u_long minpri,u_long maxpri,u_char * datap,int datalen)805 void dlunitdatareq(int fd, u_char *addrp, int addrlen, u_long minpri, u_long maxpri, u_char *datap, int datalen)
806 {
807 long buf[MAXDLBUF];
808 union DL_primitives *dlp;
809 struct strbuf data, ctl;
810
811 dlp = (union DL_primitives*) buf;
812
813 dlp->unitdata_req.dl_primitive = DL_UNITDATA_REQ;
814 dlp->unitdata_req.dl_dest_addr_length = addrlen;
815 dlp->unitdata_req.dl_dest_addr_offset = sizeof (dl_unitdata_req_t);
816 dlp->unitdata_req.dl_priority.dl_min = minpri;
817 dlp->unitdata_req.dl_priority.dl_max = maxpri;
818
819 (void) memcpy(OFFADDR(dlp, sizeof (dl_unitdata_req_t)), addrp, addrlen);
820
821 ctl.maxlen = 0;
822 ctl.len = sizeof (dl_unitdata_req_t) + addrlen;
823 ctl.buf = (char *) buf;
824
825 data.maxlen = 0;
826 data.len = datalen;
827 data.buf = (char *) datap;
828
829 if (putmsg(fd, &ctl, &data, 0) < 0)
830 fatalSys("dlunitdatareq: putmsg");
831 }
832
dlinfoack(int fd,char * bufp)833 void dlinfoack(int fd, char *bufp)
834 {
835 union DL_primitives *dlp;
836 struct strbuf ctl;
837 int flags;
838
839 ctl.maxlen = MAXDLBUF;
840 ctl.len = 0;
841 ctl.buf = bufp;
842
843 strgetmsg(fd, &ctl, (struct strbuf*)NULL, &flags, "dlinfoack");
844
845 dlp = (union DL_primitives *) ctl.buf;
846
847 expecting(DL_INFO_ACK, dlp);
848
849 if (ctl.len < sizeof (dl_info_ack_t)) {
850 char buffer[256];
851 sprintf(buffer, "dlinfoack: response ctl.len too short: %d", ctl.len);
852 rp_fatal(buffer);
853 }
854
855 if (flags != RS_HIPRI)
856 rp_fatal("dlinfoack: DL_INFO_ACK was not M_PCPROTO");
857
858 if (ctl.len < sizeof (dl_info_ack_t)) {
859 char buffer[256];
860 sprintf(buffer, "dlinfoack: short response ctl.len: %d", ctl.len);
861 rp_fatal(buffer);
862 }
863 }
864
dlbindreq(int fd,u_long sap,u_long max_conind,u_long service_mode,u_long conn_mgmt,u_long xidtest)865 void dlbindreq(int fd, u_long sap, u_long max_conind, u_long service_mode, u_long conn_mgmt, u_long xidtest)
866 {
867 dl_bind_req_t bind_req;
868 struct strbuf ctl;
869 int flags;
870
871 bind_req.dl_primitive = DL_BIND_REQ;
872 bind_req.dl_sap = sap;
873 bind_req.dl_max_conind = max_conind;
874 bind_req.dl_service_mode = service_mode;
875 bind_req.dl_conn_mgmt = conn_mgmt;
876 bind_req.dl_xidtest_flg = xidtest;
877
878 ctl.maxlen = 0;
879 ctl.len = sizeof (bind_req);
880 ctl.buf = (char *) &bind_req;
881
882 flags = 0;
883
884 if (putmsg(fd, &ctl, (struct strbuf*) NULL, flags) < 0)
885 fatalSys("dlbindreq: putmsg");
886 }
887
dlattachreq(int fd,u_long ppa)888 void dlattachreq(int fd, u_long ppa)
889 {
890 dl_attach_req_t attach_req;
891 struct strbuf ctl;
892 int flags;
893
894 attach_req.dl_primitive = DL_ATTACH_REQ;
895 attach_req.dl_ppa = ppa;
896
897 ctl.maxlen = 0;
898 ctl.len = sizeof (attach_req);
899 ctl.buf = (char *) &attach_req;
900
901 flags = 0;
902
903 if (putmsg(fd, &ctl, (struct strbuf*) NULL, flags) < 0)
904 fatalSys("dlattachreq: putmsg");
905 }
906
dlokack(int fd,char * bufp)907 void dlokack(int fd, char *bufp)
908 {
909 union DL_primitives *dlp;
910 struct strbuf ctl;
911 int flags;
912
913 ctl.maxlen = MAXDLBUF;
914 ctl.len = 0;
915 ctl.buf = bufp;
916
917 strgetmsg(fd, &ctl, (struct strbuf*)NULL, &flags, "dlokack");
918
919 dlp = (union DL_primitives *) ctl.buf;
920
921 expecting(DL_OK_ACK, dlp);
922
923 if (ctl.len < sizeof (dl_ok_ack_t)) {
924 char buffer[256];
925 sprintf(buffer, "dlokack: response ctl.len too short: %d", ctl.len);
926 rp_fatal(buffer);
927 }
928
929 if (flags != RS_HIPRI)
930 rp_fatal("dlokack: DL_OK_ACK was not M_PCPROTO");
931
932 if (ctl.len < sizeof (dl_ok_ack_t)) {
933 char buffer[256];
934 sprintf(buffer, "dlokack: short response ctl.len: %d", ctl.len);
935 rp_fatal(buffer);
936 }
937 }
938
dlbindack(int fd,char * bufp)939 void dlbindack(int fd, char *bufp)
940 {
941 union DL_primitives *dlp;
942 struct strbuf ctl;
943 int flags;
944
945 ctl.maxlen = MAXDLBUF;
946 ctl.len = 0;
947 ctl.buf = bufp;
948
949 strgetmsg(fd, &ctl, (struct strbuf*)NULL, &flags, "dlbindack");
950
951 dlp = (union DL_primitives *) ctl.buf;
952
953 expecting(DL_BIND_ACK, dlp);
954
955 if (flags != RS_HIPRI)
956 rp_fatal("dlbindack: DL_OK_ACK was not M_PCPROTO");
957
958 if (ctl.len < sizeof (dl_bind_ack_t)) {
959 char buffer[256];
960 sprintf(buffer, "dlbindack: short response ctl.len: %d", ctl.len);
961 rp_fatal(buffer);
962 }
963 }
964
strioctl(int fd,int cmd,int timout,int len,char * dp)965 int strioctl(int fd, int cmd, int timout, int len, char *dp)
966 {
967 struct strioctl sioc;
968 int rc;
969
970 sioc.ic_cmd = cmd;
971 sioc.ic_timout = timout;
972 sioc.ic_len = len;
973 sioc.ic_dp = dp;
974 rc = ioctl(fd, I_STR, &sioc);
975
976 if (rc < 0)
977 return (rc);
978 else
979 return (sioc.ic_len);
980 }
981
strgetmsg(int fd,struct strbuf * ctlp,struct strbuf * datap,int * flagsp,char * caller)982 void strgetmsg(int fd, struct strbuf *ctlp, struct strbuf *datap, int *flagsp, char *caller)
983 {
984 int rc;
985 static char errmsg[80];
986
987 /*
988 * Start timer.
989 */
990 (void) signal(SIGALRM, sigalrm);
991 if (alarm(MAXWAIT) < 0) {
992 (void) sprintf(errmsg, "%s: alarm", caller);
993 fatalSys(errmsg);
994 }
995
996 /*
997 * Set flags argument and issue getmsg().
998 */
999 *flagsp = 0;
1000 if ((rc = getmsg(fd, ctlp, datap, flagsp)) < 0) {
1001 (void) sprintf(errmsg, "%s: getmsg", caller);
1002 fatalSys(errmsg);
1003 }
1004
1005 /*
1006 * Stop timer.
1007 */
1008 if (alarm(0) < 0) {
1009 (void) sprintf(errmsg, "%s: alarm", caller);
1010 fatalSys(errmsg);
1011 }
1012
1013 /*
1014 * Check for MOREDATA and/or MORECTL.
1015 */
1016 if ((rc & (MORECTL | MOREDATA)) == (MORECTL | MOREDATA)) {
1017 char buffer[256];
1018 sprintf(buffer, "%s: MORECTL|MOREDATA", caller);
1019 rp_fatal(buffer);
1020 }
1021
1022 if (rc & MORECTL) {
1023 char buffer[256];
1024 sprintf(buffer, "%s: MORECTL", caller);
1025 rp_fatal(buffer);
1026 }
1027
1028 if (rc & MOREDATA) {
1029 char buffer[256];
1030 sprintf(buffer, "%s: MOREDATA", caller);
1031 rp_fatal(buffer);
1032 }
1033
1034 /*
1035 * Check for at least sizeof (long) control data portion.
1036 */
1037 if (ctlp->len < sizeof (long)) {
1038 char buffer[256];
1039 sprintf(buffer, "getmsg: control portion length < sizeof (long): %d", ctlp->len);
1040 rp_fatal(buffer);
1041 }
1042 }
1043
sigalrm(int sig)1044 void sigalrm(int sig)
1045 {
1046 (void) rp_fatal("sigalrm: TIMEOUT");
1047 }
1048
expecting(int prim,union DL_primitives * dlp)1049 void expecting(int prim, union DL_primitives *dlp)
1050 {
1051 if (dlp->dl_primitive != (u_long)prim) {
1052 char buffer[256];
1053 sprintf(buffer, "expected %s got %s", dlprim(prim), dlprim(dlp->dl_primitive));
1054 rp_fatal(buffer);
1055 exit(1);
1056 }
1057 }
1058
dlprim(u_long prim)1059 char *dlprim(u_long prim)
1060 {
1061 static char primbuf[80];
1062
1063 switch ((int)prim) {
1064 CASERET(DL_INFO_REQ);
1065 CASERET(DL_INFO_ACK);
1066 CASERET(DL_ATTACH_REQ);
1067 CASERET(DL_DETACH_REQ);
1068 CASERET(DL_BIND_REQ);
1069 CASERET(DL_BIND_ACK);
1070 CASERET(DL_UNBIND_REQ);
1071 CASERET(DL_OK_ACK);
1072 CASERET(DL_ERROR_ACK);
1073 CASERET(DL_SUBS_BIND_REQ);
1074 CASERET(DL_SUBS_BIND_ACK);
1075 CASERET(DL_UNITDATA_REQ);
1076 CASERET(DL_UNITDATA_IND);
1077 CASERET(DL_UDERROR_IND);
1078 CASERET(DL_UDQOS_REQ);
1079 CASERET(DL_CONNECT_REQ);
1080 CASERET(DL_CONNECT_IND);
1081 CASERET(DL_CONNECT_RES);
1082 CASERET(DL_CONNECT_CON);
1083 CASERET(DL_TOKEN_REQ);
1084 CASERET(DL_TOKEN_ACK);
1085 CASERET(DL_DISCONNECT_REQ);
1086 CASERET(DL_DISCONNECT_IND);
1087 CASERET(DL_RESET_REQ);
1088 CASERET(DL_RESET_IND);
1089 CASERET(DL_RESET_RES);
1090 CASERET(DL_RESET_CON);
1091 default:
1092 (void) sprintf(primbuf, "unknown primitive 0x%lx", prim);
1093 return (primbuf);
1094 }
1095 }
1096
1097 #endif /* USE_DLPI */
1098