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[tcpdump] / print-l2tp.c
1 /*
2 * Copyright (c) 1991, 1993, 1994, 1995, 1996, 1997
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 *
21 * L2TP support contributed by Motonori Shindo (mshindo@mshindo.net)
22 */
23
24 #ifdef HAVE_CONFIG_H
25 #include "config.h"
26 #endif
27
28 #include <tcpdump-stdinc.h>
29
30 #include <stdio.h>
31
32 #include "interface.h"
33 #include "extract.h"
34
35 #define L2TP_FLAG_TYPE 0x8000 /* Type (0=Data, 1=Control) */
36 #define L2TP_FLAG_LENGTH 0x4000 /* Length */
37 #define L2TP_FLAG_SEQUENCE 0x0800 /* Sequence */
38 #define L2TP_FLAG_OFFSET 0x0200 /* Offset */
39 #define L2TP_FLAG_PRIORITY 0x0100 /* Priority */
40
41 #define L2TP_VERSION_MASK 0x000f /* Version Mask */
42 #define L2TP_VERSION_L2F 0x0001 /* L2F */
43 #define L2TP_VERSION_L2TP 0x0002 /* L2TP */
44
45 #define L2TP_AVP_HDR_FLAG_MANDATORY 0x8000 /* Mandatory Flag */
46 #define L2TP_AVP_HDR_FLAG_HIDDEN 0x4000 /* Hidden Flag */
47 #define L2TP_AVP_HDR_LEN_MASK 0x03ff /* Length Mask */
48
49 #define L2TP_FRAMING_CAP_SYNC_MASK 0x00000001 /* Synchronous */
50 #define L2TP_FRAMING_CAP_ASYNC_MASK 0x00000002 /* Asynchronous */
51
52 #define L2TP_FRAMING_TYPE_SYNC_MASK 0x00000001 /* Synchronous */
53 #define L2TP_FRAMING_TYPE_ASYNC_MASK 0x00000002 /* Asynchronous */
54
55 #define L2TP_BEARER_CAP_DIGITAL_MASK 0x00000001 /* Digital */
56 #define L2TP_BEARER_CAP_ANALOG_MASK 0x00000002 /* Analog */
57
58 #define L2TP_BEARER_TYPE_DIGITAL_MASK 0x00000001 /* Digital */
59 #define L2TP_BEARER_TYPE_ANALOG_MASK 0x00000002 /* Analog */
60
61 /* Authen Type */
62 #define L2TP_AUTHEN_TYPE_RESERVED 0x0000 /* Reserved */
63 #define L2TP_AUTHEN_TYPE_TEXTUAL 0x0001 /* Textual username/password exchange */
64 #define L2TP_AUTHEN_TYPE_CHAP 0x0002 /* PPP CHAP */
65 #define L2TP_AUTHEN_TYPE_PAP 0x0003 /* PPP PAP */
66 #define L2TP_AUTHEN_TYPE_NO_AUTH 0x0004 /* No Authentication */
67 #define L2TP_AUTHEN_TYPE_MSCHAPv1 0x0005 /* MSCHAPv1 */
68
69 #define L2TP_PROXY_AUTH_ID_MASK 0x00ff
70
71 static const char tstr[] = " [|l2tp]";
72
73 #define L2TP_MSGTYPE_SCCRQ 1 /* Start-Control-Connection-Request */
74 #define L2TP_MSGTYPE_SCCRP 2 /* Start-Control-Connection-Reply */
75 #define L2TP_MSGTYPE_SCCCN 3 /* Start-Control-Connection-Connected */
76 #define L2TP_MSGTYPE_STOPCCN 4 /* Stop-Control-Connection-Notification */
77 #define L2TP_MSGTYPE_HELLO 6 /* Hello */
78 #define L2TP_MSGTYPE_OCRQ 7 /* Outgoing-Call-Request */
79 #define L2TP_MSGTYPE_OCRP 8 /* Outgoing-Call-Reply */
80 #define L2TP_MSGTYPE_OCCN 9 /* Outgoing-Call-Connected */
81 #define L2TP_MSGTYPE_ICRQ 10 /* Incoming-Call-Request */
82 #define L2TP_MSGTYPE_ICRP 11 /* Incoming-Call-Reply */
83 #define L2TP_MSGTYPE_ICCN 12 /* Incoming-Call-Connected */
84 #define L2TP_MSGTYPE_CDN 14 /* Call-Disconnect-Notify */
85 #define L2TP_MSGTYPE_WEN 15 /* WAN-Error-Notify */
86 #define L2TP_MSGTYPE_SLI 16 /* Set-Link-Info */
87
88 static const struct tok l2tp_msgtype2str[] = {
89 { L2TP_MSGTYPE_SCCRQ, "SCCRQ" },
90 { L2TP_MSGTYPE_SCCRP, "SCCRP" },
91 { L2TP_MSGTYPE_SCCCN, "SCCCN" },
92 { L2TP_MSGTYPE_STOPCCN, "StopCCN" },
93 { L2TP_MSGTYPE_HELLO, "HELLO" },
94 { L2TP_MSGTYPE_OCRQ, "OCRQ" },
95 { L2TP_MSGTYPE_OCRP, "OCRP" },
96 { L2TP_MSGTYPE_OCCN, "OCCN" },
97 { L2TP_MSGTYPE_ICRQ, "ICRQ" },
98 { L2TP_MSGTYPE_ICRP, "ICRP" },
99 { L2TP_MSGTYPE_ICCN, "ICCN" },
100 { L2TP_MSGTYPE_CDN, "CDN" },
101 { L2TP_MSGTYPE_WEN, "WEN" },
102 { L2TP_MSGTYPE_SLI, "SLI" },
103 { 0, NULL }
104 };
105
106 #define L2TP_AVP_MSGTYPE 0 /* Message Type */
107 #define L2TP_AVP_RESULT_CODE 1 /* Result Code */
108 #define L2TP_AVP_PROTO_VER 2 /* Protocol Version */
109 #define L2TP_AVP_FRAMING_CAP 3 /* Framing Capabilities */
110 #define L2TP_AVP_BEARER_CAP 4 /* Bearer Capabilities */
111 #define L2TP_AVP_TIE_BREAKER 5 /* Tie Breaker */
112 #define L2TP_AVP_FIRM_VER 6 /* Firmware Revision */
113 #define L2TP_AVP_HOST_NAME 7 /* Host Name */
114 #define L2TP_AVP_VENDOR_NAME 8 /* Vendor Name */
115 #define L2TP_AVP_ASSND_TUN_ID 9 /* Assigned Tunnel ID */
116 #define L2TP_AVP_RECV_WIN_SIZE 10 /* Receive Window Size */
117 #define L2TP_AVP_CHALLENGE 11 /* Challenge */
118 #define L2TP_AVP_Q931_CC 12 /* Q.931 Cause Code */
119 #define L2TP_AVP_CHALLENGE_RESP 13 /* Challenge Response */
120 #define L2TP_AVP_ASSND_SESS_ID 14 /* Assigned Session ID */
121 #define L2TP_AVP_CALL_SER_NUM 15 /* Call Serial Number */
122 #define L2TP_AVP_MINIMUM_BPS 16 /* Minimum BPS */
123 #define L2TP_AVP_MAXIMUM_BPS 17 /* Maximum BPS */
124 #define L2TP_AVP_BEARER_TYPE 18 /* Bearer Type */
125 #define L2TP_AVP_FRAMING_TYPE 19 /* Framing Type */
126 #define L2TP_AVP_PACKET_PROC_DELAY 20 /* Packet Processing Delay (OBSOLETE) */
127 #define L2TP_AVP_CALLED_NUMBER 21 /* Called Number */
128 #define L2TP_AVP_CALLING_NUMBER 22 /* Calling Number */
129 #define L2TP_AVP_SUB_ADDRESS 23 /* Sub-Address */
130 #define L2TP_AVP_TX_CONN_SPEED 24 /* (Tx) Connect Speed */
131 #define L2TP_AVP_PHY_CHANNEL_ID 25 /* Physical Channel ID */
132 #define L2TP_AVP_INI_RECV_LCP 26 /* Initial Received LCP CONFREQ */
133 #define L2TP_AVP_LAST_SENT_LCP 27 /* Last Sent LCP CONFREQ */
134 #define L2TP_AVP_LAST_RECV_LCP 28 /* Last Received LCP CONFREQ */
135 #define L2TP_AVP_PROXY_AUTH_TYPE 29 /* Proxy Authen Type */
136 #define L2TP_AVP_PROXY_AUTH_NAME 30 /* Proxy Authen Name */
137 #define L2TP_AVP_PROXY_AUTH_CHAL 31 /* Proxy Authen Challenge */
138 #define L2TP_AVP_PROXY_AUTH_ID 32 /* Proxy Authen ID */
139 #define L2TP_AVP_PROXY_AUTH_RESP 33 /* Proxy Authen Response */
140 #define L2TP_AVP_CALL_ERRORS 34 /* Call Errors */
141 #define L2TP_AVP_ACCM 35 /* ACCM */
142 #define L2TP_AVP_RANDOM_VECTOR 36 /* Random Vector */
143 #define L2TP_AVP_PRIVATE_GRP_ID 37 /* Private Group ID */
144 #define L2TP_AVP_RX_CONN_SPEED 38 /* (Rx) Connect Speed */
145 #define L2TP_AVP_SEQ_REQUIRED 39 /* Sequencing Required */
146 #define L2TP_AVP_PPP_DISCON_CC 46 /* PPP Disconnect Cause Code */
147
148 static const struct tok l2tp_avp2str[] = {
149 { L2TP_AVP_MSGTYPE, "MSGTYPE" },
150 { L2TP_AVP_RESULT_CODE, "RESULT_CODE" },
151 { L2TP_AVP_PROTO_VER, "PROTO_VER" },
152 { L2TP_AVP_FRAMING_CAP, "FRAMING_CAP" },
153 { L2TP_AVP_BEARER_CAP, "BEARER_CAP" },
154 { L2TP_AVP_TIE_BREAKER, "TIE_BREAKER" },
155 { L2TP_AVP_FIRM_VER, "FIRM_VER" },
156 { L2TP_AVP_HOST_NAME, "HOST_NAME" },
157 { L2TP_AVP_VENDOR_NAME, "VENDOR_NAME" },
158 { L2TP_AVP_ASSND_TUN_ID, "ASSND_TUN_ID" },
159 { L2TP_AVP_RECV_WIN_SIZE, "RECV_WIN_SIZE" },
160 { L2TP_AVP_CHALLENGE, "CHALLENGE" },
161 { L2TP_AVP_Q931_CC, "Q931_CC", },
162 { L2TP_AVP_CHALLENGE_RESP, "CHALLENGE_RESP" },
163 { L2TP_AVP_ASSND_SESS_ID, "ASSND_SESS_ID" },
164 { L2TP_AVP_CALL_SER_NUM, "CALL_SER_NUM" },
165 { L2TP_AVP_MINIMUM_BPS, "MINIMUM_BPS" },
166 { L2TP_AVP_MAXIMUM_BPS, "MAXIMUM_BPS" },
167 { L2TP_AVP_BEARER_TYPE, "BEARER_TYPE" },
168 { L2TP_AVP_FRAMING_TYPE, "FRAMING_TYPE" },
169 { L2TP_AVP_PACKET_PROC_DELAY, "PACKET_PROC_DELAY" },
170 { L2TP_AVP_CALLED_NUMBER, "CALLED_NUMBER" },
171 { L2TP_AVP_CALLING_NUMBER, "CALLING_NUMBER" },
172 { L2TP_AVP_SUB_ADDRESS, "SUB_ADDRESS" },
173 { L2TP_AVP_TX_CONN_SPEED, "TX_CONN_SPEED" },
174 { L2TP_AVP_PHY_CHANNEL_ID, "PHY_CHANNEL_ID" },
175 { L2TP_AVP_INI_RECV_LCP, "INI_RECV_LCP" },
176 { L2TP_AVP_LAST_SENT_LCP, "LAST_SENT_LCP" },
177 { L2TP_AVP_LAST_RECV_LCP, "LAST_RECV_LCP" },
178 { L2TP_AVP_PROXY_AUTH_TYPE, "PROXY_AUTH_TYPE" },
179 { L2TP_AVP_PROXY_AUTH_NAME, "PROXY_AUTH_NAME" },
180 { L2TP_AVP_PROXY_AUTH_CHAL, "PROXY_AUTH_CHAL" },
181 { L2TP_AVP_PROXY_AUTH_ID, "PROXY_AUTH_ID" },
182 { L2TP_AVP_PROXY_AUTH_RESP, "PROXY_AUTH_RESP" },
183 { L2TP_AVP_CALL_ERRORS, "CALL_ERRORS" },
184 { L2TP_AVP_ACCM, "ACCM" },
185 { L2TP_AVP_RANDOM_VECTOR, "RANDOM_VECTOR" },
186 { L2TP_AVP_PRIVATE_GRP_ID, "PRIVATE_GRP_ID" },
187 { L2TP_AVP_RX_CONN_SPEED, "RX_CONN_SPEED" },
188 { L2TP_AVP_SEQ_REQUIRED, "SEQ_REQUIRED" },
189 { L2TP_AVP_PPP_DISCON_CC, "PPP_DISCON_CC" },
190 { 0, NULL }
191 };
192
193 static const struct tok l2tp_authentype2str[] = {
194 { L2TP_AUTHEN_TYPE_RESERVED, "Reserved" },
195 { L2TP_AUTHEN_TYPE_TEXTUAL, "Textual" },
196 { L2TP_AUTHEN_TYPE_CHAP, "CHAP" },
197 { L2TP_AUTHEN_TYPE_PAP, "PAP" },
198 { L2TP_AUTHEN_TYPE_NO_AUTH, "No Auth" },
199 { L2TP_AUTHEN_TYPE_MSCHAPv1, "MS-CHAPv1" },
200 { 0, NULL }
201 };
202
203 #define L2TP_PPP_DISCON_CC_DIRECTION_GLOBAL 0
204 #define L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER 1
205 #define L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL 2
206
207 static const struct tok l2tp_cc_direction2str[] = {
208 { L2TP_PPP_DISCON_CC_DIRECTION_GLOBAL, "global error" },
209 { L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER, "at peer" },
210 { L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL,"at local" },
211 { 0, NULL }
212 };
213
214 #if 0
215 static char *l2tp_result_code_StopCCN[] = {
216 "Reserved",
217 "General request to clear control connection",
218 "General error--Error Code indicates the problem",
219 "Control channel already exists",
220 "Requester is not authorized to establish a control channel",
221 "The protocol version of the requester is not supported",
222 "Requester is being shut down",
223 "Finite State Machine error"
224 #define L2TP_MAX_RESULT_CODE_STOPCC_INDEX 8
225 };
226 #endif
227
228 #if 0
229 static char *l2tp_result_code_CDN[] = {
230 "Reserved",
231 "Call disconnected due to loss of carrier",
232 "Call disconnected for the reason indicated in error code",
233 "Call disconnected for administrative reasons",
234 "Call failed due to lack of appropriate facilities being " \
235 "available (temporary condition)",
236 "Call failed due to lack of appropriate facilities being " \
237 "available (permanent condition)",
238 "Invalid destination",
239 "Call failed due to no carrier detected",
240 "Call failed due to detection of a busy signal",
241 "Call failed due to lack of a dial tone",
242 "Call was not established within time allotted by LAC",
243 "Call was connected but no appropriate framing was detected"
244 #define L2TP_MAX_RESULT_CODE_CDN_INDEX 12
245 };
246 #endif
247
248 #if 0
249 static char *l2tp_error_code_general[] = {
250 "No general error",
251 "No control connection exists yet for this LAC-LNS pair",
252 "Length is wrong",
253 "One of the field values was out of range or " \
254 "reserved field was non-zero"
255 "Insufficient resources to handle this operation now",
256 "The Session ID is invalid in this context",
257 "A generic vendor-specific error occurred in the LAC",
258 "Try another"
259 #define L2TP_MAX_ERROR_CODE_GENERAL_INDEX 8
260 };
261 #endif
262
263 /******************************/
264 /* generic print out routines */
265 /******************************/
266 static void
267 print_string(const u_char *dat, u_int length)
268 {
269 u_int i;
270 for (i=0; i<length; i++) {
271 printf("%c", *dat++);
272 }
273 }
274
275 static void
276 print_octets(const u_char *dat, u_int length)
277 {
278 u_int i;
279 for (i=0; i<length; i++) {
280 printf("%02x", *dat++);
281 }
282 }
283
284 static void
285 print_16bits_val(const u_int16_t *dat)
286 {
287 printf("%u", EXTRACT_16BITS(dat));
288 }
289
290 static void
291 print_32bits_val(const u_int32_t *dat)
292 {
293 printf("%lu", (u_long)EXTRACT_32BITS(dat));
294 }
295
296 /***********************************/
297 /* AVP-specific print out routines */
298 /***********************************/
299 static void
300 l2tp_msgtype_print(const u_char *dat)
301 {
302 u_int16_t *ptr = (u_int16_t*)dat;
303
304 printf("%s", tok2str(l2tp_msgtype2str, "MSGTYPE-#%u",
305 EXTRACT_16BITS(ptr)));
306 }
307
308 static void
309 l2tp_result_code_print(const u_char *dat, u_int length)
310 {
311 u_int16_t *ptr = (u_int16_t *)dat;
312
313 printf("%u", EXTRACT_16BITS(ptr)); ptr++; /* Result Code */
314 if (length > 2) { /* Error Code (opt) */
315 printf("/%u", EXTRACT_16BITS(ptr)); ptr++;
316 }
317 if (length > 4) { /* Error Message (opt) */
318 printf(" ");
319 print_string((u_char *)ptr, length - 4);
320 }
321 }
322
323 static void
324 l2tp_proto_ver_print(const u_int16_t *dat)
325 {
326 printf("%u.%u", (EXTRACT_16BITS(dat) >> 8),
327 (EXTRACT_16BITS(dat) & 0xff));
328 }
329
330 static void
331 l2tp_framing_cap_print(const u_char *dat)
332 {
333 u_int32_t *ptr = (u_int32_t *)dat;
334
335 if (EXTRACT_32BITS(ptr) & L2TP_FRAMING_CAP_ASYNC_MASK) {
336 printf("A");
337 }
338 if (EXTRACT_32BITS(ptr) & L2TP_FRAMING_CAP_SYNC_MASK) {
339 printf("S");
340 }
341 }
342
343 static void
344 l2tp_bearer_cap_print(const u_char *dat)
345 {
346 u_int32_t *ptr = (u_int32_t *)dat;
347
348 if (EXTRACT_32BITS(ptr) & L2TP_BEARER_CAP_ANALOG_MASK) {
349 printf("A");
350 }
351 if (EXTRACT_32BITS(ptr) & L2TP_BEARER_CAP_DIGITAL_MASK) {
352 printf("D");
353 }
354 }
355
356 static void
357 l2tp_q931_cc_print(const u_char *dat, u_int length)
358 {
359 print_16bits_val((u_int16_t *)dat);
360 printf(", %02x", dat[2]);
361 if (length > 3) {
362 printf(" ");
363 print_string(dat+3, length-3);
364 }
365 }
366
367 static void
368 l2tp_bearer_type_print(const u_char *dat)
369 {
370 u_int32_t *ptr = (u_int32_t *)dat;
371
372 if (EXTRACT_32BITS(ptr) & L2TP_BEARER_TYPE_ANALOG_MASK) {
373 printf("A");
374 }
375 if (EXTRACT_32BITS(ptr) & L2TP_BEARER_TYPE_DIGITAL_MASK) {
376 printf("D");
377 }
378 }
379
380 static void
381 l2tp_framing_type_print(const u_char *dat)
382 {
383 u_int32_t *ptr = (u_int32_t *)dat;
384
385 if (EXTRACT_32BITS(ptr) & L2TP_FRAMING_TYPE_ASYNC_MASK) {
386 printf("A");
387 }
388 if (EXTRACT_32BITS(ptr) & L2TP_FRAMING_TYPE_SYNC_MASK) {
389 printf("S");
390 }
391 }
392
393 static void
394 l2tp_packet_proc_delay_print(void)
395 {
396 printf("obsolete");
397 }
398
399 static void
400 l2tp_proxy_auth_type_print(const u_char *dat)
401 {
402 u_int16_t *ptr = (u_int16_t *)dat;
403
404 printf("%s", tok2str(l2tp_authentype2str,
405 "AuthType-#%u", EXTRACT_16BITS(ptr)));
406 }
407
408 static void
409 l2tp_proxy_auth_id_print(const u_char *dat)
410 {
411 u_int16_t *ptr = (u_int16_t *)dat;
412
413 printf("%u", EXTRACT_16BITS(ptr) & L2TP_PROXY_AUTH_ID_MASK);
414 }
415
416 static void
417 l2tp_call_errors_print(const u_char *dat)
418 {
419 u_int16_t *ptr = (u_int16_t *)dat;
420 u_int16_t val_h, val_l;
421
422 ptr++; /* skip "Reserved" */
423
424 val_h = EXTRACT_16BITS(ptr); ptr++;
425 val_l = EXTRACT_16BITS(ptr); ptr++;
426 printf("CRCErr=%u ", (val_h<<16) + val_l);
427
428 val_h = EXTRACT_16BITS(ptr); ptr++;
429 val_l = EXTRACT_16BITS(ptr); ptr++;
430 printf("FrameErr=%u ", (val_h<<16) + val_l);
431
432 val_h = EXTRACT_16BITS(ptr); ptr++;
433 val_l = EXTRACT_16BITS(ptr); ptr++;
434 printf("HardOver=%u ", (val_h<<16) + val_l);
435
436 val_h = EXTRACT_16BITS(ptr); ptr++;
437 val_l = EXTRACT_16BITS(ptr); ptr++;
438 printf("BufOver=%u ", (val_h<<16) + val_l);
439
440 val_h = EXTRACT_16BITS(ptr); ptr++;
441 val_l = EXTRACT_16BITS(ptr); ptr++;
442 printf("Timeout=%u ", (val_h<<16) + val_l);
443
444 val_h = EXTRACT_16BITS(ptr); ptr++;
445 val_l = EXTRACT_16BITS(ptr); ptr++;
446 printf("AlignErr=%u ", (val_h<<16) + val_l);
447 }
448
449 static void
450 l2tp_accm_print(const u_char *dat)
451 {
452 u_int16_t *ptr = (u_int16_t *)dat;
453 u_int16_t val_h, val_l;
454
455 ptr++; /* skip "Reserved" */
456
457 val_h = EXTRACT_16BITS(ptr); ptr++;
458 val_l = EXTRACT_16BITS(ptr); ptr++;
459 printf("send=%08x ", (val_h<<16) + val_l);
460
461 val_h = EXTRACT_16BITS(ptr); ptr++;
462 val_l = EXTRACT_16BITS(ptr); ptr++;
463 printf("recv=%08x ", (val_h<<16) + val_l);
464 }
465
466 static void
467 l2tp_ppp_discon_cc_print(const u_char *dat, u_int length)
468 {
469 u_int16_t *ptr = (u_int16_t *)dat;
470
471 printf("%04x, ", EXTRACT_16BITS(ptr)); ptr++; /* Disconnect Code */
472 printf("%04x ", EXTRACT_16BITS(ptr)); ptr++; /* Control Protocol Number */
473 printf("%s", tok2str(l2tp_cc_direction2str,
474 "Direction-#%u", *((u_char *)ptr++)));
475
476 if (length > 5) {
477 printf(" ");
478 print_string((const u_char *)ptr, length-5);
479 }
480 }
481
482 static void
483 l2tp_avp_print(const u_char *dat, int length)
484 {
485 u_int len;
486 const u_int16_t *ptr = (u_int16_t *)dat;
487 u_int16_t attr_type;
488 int hidden = FALSE;
489
490 if (length <= 0) {
491 return;
492 }
493
494 printf(" ");
495
496 TCHECK(*ptr); /* Flags & Length */
497 len = EXTRACT_16BITS(ptr) & L2TP_AVP_HDR_LEN_MASK;
498
499 /* If it is not long enough to contain the header, we'll give up. */
500 if (len < 6)
501 goto trunc;
502
503 /* If it goes past the end of the remaining length of the packet,
504 we'll give up. */
505 if (len > (u_int)length)
506 goto trunc;
507
508 /* If it goes past the end of the remaining length of the captured
509 data, we'll give up. */
510 TCHECK2(*ptr, len);
511 /* After this point, no need to worry about truncation */
512
513 if (EXTRACT_16BITS(ptr) & L2TP_AVP_HDR_FLAG_MANDATORY) {
514 printf("*");
515 }
516 if (EXTRACT_16BITS(ptr) & L2TP_AVP_HDR_FLAG_HIDDEN) {
517 hidden = TRUE;
518 printf("?");
519 }
520 ptr++;
521
522 if (EXTRACT_16BITS(ptr)) {
523 /* Vendor Specific Attribute */
524 printf("VENDOR%04x:", EXTRACT_16BITS(ptr)); ptr++;
525 printf("ATTR%04x", EXTRACT_16BITS(ptr)); ptr++;
526 printf("(");
527 print_octets((u_char *)ptr, len-6);
528 printf(")");
529 } else {
530 /* IETF-defined Attributes */
531 ptr++;
532 attr_type = EXTRACT_16BITS(ptr); ptr++;
533 printf("%s", tok2str(l2tp_avp2str, "AVP-#%u", attr_type));
534 printf("(");
535 if (hidden) {
536 printf("???");
537 } else {
538 switch (attr_type) {
539 case L2TP_AVP_MSGTYPE:
540 l2tp_msgtype_print((u_char *)ptr);
541 break;
542 case L2TP_AVP_RESULT_CODE:
543 l2tp_result_code_print((u_char *)ptr, len-6);
544 break;
545 case L2TP_AVP_PROTO_VER:
546 l2tp_proto_ver_print(ptr);
547 break;
548 case L2TP_AVP_FRAMING_CAP:
549 l2tp_framing_cap_print((u_char *)ptr);
550 break;
551 case L2TP_AVP_BEARER_CAP:
552 l2tp_bearer_cap_print((u_char *)ptr);
553 break;
554 case L2TP_AVP_TIE_BREAKER:
555 print_octets((u_char *)ptr, 8);
556 break;
557 case L2TP_AVP_FIRM_VER:
558 case L2TP_AVP_ASSND_TUN_ID:
559 case L2TP_AVP_RECV_WIN_SIZE:
560 case L2TP_AVP_ASSND_SESS_ID:
561 print_16bits_val(ptr);
562 break;
563 case L2TP_AVP_HOST_NAME:
564 case L2TP_AVP_VENDOR_NAME:
565 case L2TP_AVP_CALLING_NUMBER:
566 case L2TP_AVP_CALLED_NUMBER:
567 case L2TP_AVP_SUB_ADDRESS:
568 case L2TP_AVP_PROXY_AUTH_NAME:
569 case L2TP_AVP_PRIVATE_GRP_ID:
570 print_string((u_char *)ptr, len-6);
571 break;
572 case L2TP_AVP_CHALLENGE:
573 case L2TP_AVP_INI_RECV_LCP:
574 case L2TP_AVP_LAST_SENT_LCP:
575 case L2TP_AVP_LAST_RECV_LCP:
576 case L2TP_AVP_PROXY_AUTH_CHAL:
577 case L2TP_AVP_PROXY_AUTH_RESP:
578 case L2TP_AVP_RANDOM_VECTOR:
579 print_octets((u_char *)ptr, len-6);
580 break;
581 case L2TP_AVP_Q931_CC:
582 l2tp_q931_cc_print((u_char *)ptr, len-6);
583 break;
584 case L2TP_AVP_CHALLENGE_RESP:
585 print_octets((u_char *)ptr, 16);
586 break;
587 case L2TP_AVP_CALL_SER_NUM:
588 case L2TP_AVP_MINIMUM_BPS:
589 case L2TP_AVP_MAXIMUM_BPS:
590 case L2TP_AVP_TX_CONN_SPEED:
591 case L2TP_AVP_PHY_CHANNEL_ID:
592 case L2TP_AVP_RX_CONN_SPEED:
593 print_32bits_val((u_int32_t *)ptr);
594 break;
595 case L2TP_AVP_BEARER_TYPE:
596 l2tp_bearer_type_print((u_char *)ptr);
597 break;
598 case L2TP_AVP_FRAMING_TYPE:
599 l2tp_framing_type_print((u_char *)ptr);
600 break;
601 case L2TP_AVP_PACKET_PROC_DELAY:
602 l2tp_packet_proc_delay_print();
603 break;
604 case L2TP_AVP_PROXY_AUTH_TYPE:
605 l2tp_proxy_auth_type_print((u_char *)ptr);
606 break;
607 case L2TP_AVP_PROXY_AUTH_ID:
608 l2tp_proxy_auth_id_print((u_char *)ptr);
609 break;
610 case L2TP_AVP_CALL_ERRORS:
611 l2tp_call_errors_print((u_char *)ptr);
612 break;
613 case L2TP_AVP_ACCM:
614 l2tp_accm_print((u_char *)ptr);
615 break;
616 case L2TP_AVP_SEQ_REQUIRED:
617 break; /* No Attribute Value */
618 case L2TP_AVP_PPP_DISCON_CC:
619 l2tp_ppp_discon_cc_print((u_char *)ptr, len-6);
620 break;
621 default:
622 break;
623 }
624 }
625 printf(")");
626 }
627
628 l2tp_avp_print(dat+len, length-len);
629 return;
630
631 trunc:
632 printf("|...");
633 }
634
635
636 void
637 l2tp_print(const u_char *dat, u_int length)
638 {
639 const u_char *ptr = dat;
640 u_int cnt = 0; /* total octets consumed */
641 u_int16_t pad;
642 int flag_t, flag_l, flag_s, flag_o;
643 u_int16_t l2tp_len;
644
645 flag_t = flag_l = flag_s = flag_o = FALSE;
646
647 TCHECK2(*ptr, 2); /* Flags & Version */
648 if ((EXTRACT_16BITS(ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2TP) {
649 printf(" l2tp:");
650 } else if ((EXTRACT_16BITS(ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2F) {
651 printf(" l2f:");
652 return; /* nothing to do */
653 } else {
654 printf(" Unknown Version, neither L2F(1) nor L2TP(2)");
655 return; /* nothing we can do */
656 }
657
658 printf("[");
659 if (EXTRACT_16BITS(ptr) & L2TP_FLAG_TYPE) {
660 flag_t = TRUE;
661 printf("T");
662 }
663 if (EXTRACT_16BITS(ptr) & L2TP_FLAG_LENGTH) {
664 flag_l = TRUE;
665 printf("L");
666 }
667 if (EXTRACT_16BITS(ptr) & L2TP_FLAG_SEQUENCE) {
668 flag_s = TRUE;
669 printf("S");
670 }
671 if (EXTRACT_16BITS(ptr) & L2TP_FLAG_OFFSET) {
672 flag_o = TRUE;
673 printf("O");
674 }
675 if (EXTRACT_16BITS(ptr) & L2TP_FLAG_PRIORITY)
676 printf("P");
677 printf("]");
678
679 ptr += 2;
680 cnt += 2;
681
682 if (flag_l) {
683 TCHECK2(*ptr, 2); /* Length */
684 l2tp_len = EXTRACT_16BITS(ptr);
685 ptr += 2;
686 cnt += 2;
687 } else {
688 l2tp_len = 0;
689 }
690
691 TCHECK2(*ptr, 2); /* Tunnel ID */
692 printf("(%u/", EXTRACT_16BITS(ptr));
693 ptr += 2;
694 cnt += 2;
695 TCHECK2(*ptr, 2); /* Session ID */
696 printf("%u)", EXTRACT_16BITS(ptr));
697 ptr += 2;
698 cnt += 2;
699
700 if (flag_s) {
701 TCHECK2(*ptr, 2); /* Ns */
702 printf("Ns=%u,", EXTRACT_16BITS(ptr));
703 ptr += 2;
704 cnt += 2;
705 TCHECK2(*ptr, 2); /* Nr */
706 printf("Nr=%u", EXTRACT_16BITS(ptr));
707 ptr += 2;
708 cnt += 2;
709 }
710
711 if (flag_o) {
712 TCHECK2(*ptr, 2); /* Offset Size */
713 pad = EXTRACT_16BITS(ptr);
714 ptr += (2 + pad);
715 cnt += (2 + pad);
716 }
717
718 if (flag_l) {
719 if (length < l2tp_len) {
720 printf(" Length %u larger than packet", l2tp_len);
721 return;
722 }
723 length = l2tp_len;
724 }
725 if (length < cnt) {
726 printf(" Length %u smaller than header length", length);
727 return;
728 }
729 if (flag_t) {
730 if (!flag_l) {
731 printf(" No length");
732 return;
733 }
734 if (length - cnt == 0) {
735 printf(" ZLB");
736 } else {
737 l2tp_avp_print(ptr, length - cnt);
738 }
739 } else {
740 printf(" {");
741 ppp_print(ptr, length - cnt);
742 printf("}");
743 }
744
745 return;
746
747 trunc:
748 printf("%s", tstr);
749 }
[mirror] the TCPdump network dissector