xref: /freebsd/contrib/tcpdump/print-l2tp.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf)
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 #ifndef lint
25 static const char rcsid[] =
26     "@(#) $Header: /tcpdump/master/tcpdump/print-l2tp.c,v 1.10.2.1 2002/05/25 09:47:07 guy Exp $";
27 #endif
28 
29 #ifdef HAVE_CONFIG_H
30 #include "config.h"
31 #endif
32 
33 #include <stdio.h>
34 #include <sys/types.h>
35 #include <sys/param.h>
36 #include <netinet/in.h>
37 #include <arpa/inet.h>
38 
39 #include "l2tp.h"
40 #include "interface.h"
41 #include "extract.h"
42 
43 static char tstr[] = " [|l2tp]";
44 
45 #ifndef TRUE
46 #define TRUE 1
47 #endif
48 
49 #ifndef FALSE
50 #define FALSE 0
51 #endif
52 
53 #define	L2TP_MSGTYPE_SCCRQ	1  /* Start-Control-Connection-Request */
54 #define	L2TP_MSGTYPE_SCCRP	2  /* Start-Control-Connection-Reply */
55 #define	L2TP_MSGTYPE_SCCCN	3  /* Start-Control-Connection-Connected */
56 #define	L2TP_MSGTYPE_STOPCCN	4  /* Stop-Control-Connection-Notification */
57 #define	L2TP_MSGTYPE_HELLO	6  /* Hello */
58 #define	L2TP_MSGTYPE_OCRQ	7  /* Outgoing-Call-Request */
59 #define	L2TP_MSGTYPE_OCRP	8  /* Outgoing-Call-Reply */
60 #define	L2TP_MSGTYPE_OCCN	9  /* Outgoing-Call-Connected */
61 #define	L2TP_MSGTYPE_ICRQ	10 /* Incoming-Call-Request */
62 #define	L2TP_MSGTYPE_ICRP	11 /* Incoming-Call-Reply */
63 #define	L2TP_MSGTYPE_ICCN	12 /* Incoming-Call-Connected */
64 #define	L2TP_MSGTYPE_CDN	14 /* Call-Disconnect-Notify */
65 #define	L2TP_MSGTYPE_WEN	15 /* WAN-Error-Notify */
66 #define	L2TP_MSGTYPE_SLI	16 /* Set-Link-Info */
67 
68 static struct tok l2tp_msgtype2str[] = {
69 	{ L2TP_MSGTYPE_SCCRQ, 	"SCCRQ" },
70 	{ L2TP_MSGTYPE_SCCRP,	"SCCRP" },
71 	{ L2TP_MSGTYPE_SCCCN,	"SCCCN" },
72 	{ L2TP_MSGTYPE_STOPCCN,	"StopCCN" },
73 	{ L2TP_MSGTYPE_HELLO,	"HELLO" },
74 	{ L2TP_MSGTYPE_OCRQ,	"OCRQ" },
75 	{ L2TP_MSGTYPE_OCRP,	"OCRP" },
76 	{ L2TP_MSGTYPE_OCCN,	"OCCN" },
77 	{ L2TP_MSGTYPE_ICRQ,	"ICRQ" },
78 	{ L2TP_MSGTYPE_ICRP,	"ICRP" },
79 	{ L2TP_MSGTYPE_ICCN,	"ICCN" },
80 	{ L2TP_MSGTYPE_CDN,	"CDN" },
81 	{ L2TP_MSGTYPE_WEN,	"WEN" },
82 	{ L2TP_MSGTYPE_SLI,	"SLI" },
83 	{ 0,			NULL }
84 };
85 
86 #define L2TP_AVP_MSGTYPE		0  /* Message Type */
87 #define L2TP_AVP_RESULT_CODE		1  /* Result Code */
88 #define L2TP_AVP_PROTO_VER		2  /* Protocol Version */
89 #define L2TP_AVP_FRAMING_CAP		3  /* Framing Capabilities */
90 #define L2TP_AVP_BEARER_CAP		4  /* Bearer Capabilities */
91 #define L2TP_AVP_TIE_BREAKER		5  /* Tie Breaker */
92 #define L2TP_AVP_FIRM_VER		6  /* Firmware Revision */
93 #define L2TP_AVP_HOST_NAME		7  /* Host Name */
94 #define L2TP_AVP_VENDOR_NAME		8  /* Vendor Name */
95 #define L2TP_AVP_ASSND_TUN_ID 		9  /* Assigned Tunnel ID */
96 #define L2TP_AVP_RECV_WIN_SIZE		10 /* Receive Window Size */
97 #define L2TP_AVP_CHALLENGE		11 /* Challenge */
98 #define L2TP_AVP_Q931_CC		12 /* Q.931 Cause Code */
99 #define L2TP_AVP_CHALLENGE_RESP		13 /* Challenge Response */
100 #define L2TP_AVP_ASSND_SESS_ID  	14 /* Assigned Session ID */
101 #define L2TP_AVP_CALL_SER_NUM 		15 /* Call Serial Number */
102 #define L2TP_AVP_MINIMUM_BPS		16 /* Minimum BPS */
103 #define L2TP_AVP_MAXIMUM_BPS		17 /* Maximum BPS */
104 #define L2TP_AVP_BEARER_TYPE		18 /* Bearer Type */
105 #define L2TP_AVP_FRAMING_TYPE 		19 /* Framing Type */
106 #define L2TP_AVP_PACKET_PROC_DELAY	20 /* Packet Processing Delay (OBSOLETE) */
107 #define L2TP_AVP_CALLED_NUMBER		21 /* Called Number */
108 #define L2TP_AVP_CALLING_NUMBER		22 /* Calling Number */
109 #define L2TP_AVP_SUB_ADDRESS		23 /* Sub-Address */
110 #define L2TP_AVP_TX_CONN_SPEED		24 /* (Tx) Connect Speed */
111 #define L2TP_AVP_PHY_CHANNEL_ID		25 /* Physical Channel ID */
112 #define L2TP_AVP_INI_RECV_LCP		26 /* Initial Received LCP CONFREQ */
113 #define L2TP_AVP_LAST_SENT_LCP		27 /* Last Sent LCP CONFREQ */
114 #define L2TP_AVP_LAST_RECV_LCP		28 /* Last Received LCP CONFREQ */
115 #define L2TP_AVP_PROXY_AUTH_TYPE	29 /* Proxy Authen Type */
116 #define L2TP_AVP_PROXY_AUTH_NAME	30 /* Proxy Authen Name */
117 #define L2TP_AVP_PROXY_AUTH_CHAL	31 /* Proxy Authen Challenge */
118 #define L2TP_AVP_PROXY_AUTH_ID		32 /* Proxy Authen ID */
119 #define L2TP_AVP_PROXY_AUTH_RESP	33 /* Proxy Authen Response */
120 #define L2TP_AVP_CALL_ERRORS		34 /* Call Errors */
121 #define L2TP_AVP_ACCM			35 /* ACCM */
122 #define L2TP_AVP_RANDOM_VECTOR		36 /* Random Vector */
123 #define L2TP_AVP_PRIVATE_GRP_ID		37 /* Private Group ID */
124 #define L2TP_AVP_RX_CONN_SPEED		38 /* (Rx) Connect Speed */
125 #define L2TP_AVP_SEQ_REQUIRED 		39 /* Sequencing Required */
126 #define L2TP_AVP_PPP_DISCON_CC		46 /* PPP Disconnect Cause Code */
127 
128 static struct tok l2tp_avp2str[] = {
129 	{ L2TP_AVP_MSGTYPE,		"MSGTYPE" },
130 	{ L2TP_AVP_RESULT_CODE,		"RESULT_CODE" },
131 	{ L2TP_AVP_PROTO_VER,		"PROTO_VER" },
132 	{ L2TP_AVP_FRAMING_CAP,		"FRAMING_CAP" },
133 	{ L2TP_AVP_BEARER_CAP,		"BEARER_CAP" },
134 	{ L2TP_AVP_TIE_BREAKER,		"TIE_BREAKER" },
135 	{ L2TP_AVP_FIRM_VER,		"FIRM_VER" },
136 	{ L2TP_AVP_HOST_NAME,		"HOST_NAME" },
137 	{ L2TP_AVP_VENDOR_NAME,		"VENDOR_NAME" },
138 	{ L2TP_AVP_ASSND_TUN_ID,	"ASSND_TUN_ID" },
139 	{ L2TP_AVP_RECV_WIN_SIZE,	"RECV_WIN_SIZE" },
140 	{ L2TP_AVP_CHALLENGE,		"CHALLENGE" },
141 	{ L2TP_AVP_Q931_CC,		"Q931_CC", },
142 	{ L2TP_AVP_CHALLENGE_RESP,	"CHALLENGE_RESP" },
143 	{ L2TP_AVP_ASSND_SESS_ID,	"ASSND_SESS_ID" },
144 	{ L2TP_AVP_CALL_SER_NUM,	"CALL_SER_NUM" },
145 	{ L2TP_AVP_MINIMUM_BPS,		"MINIMUM_BPS" },
146 	{ L2TP_AVP_MAXIMUM_BPS,		"MAXIMUM_BPS" },
147 	{ L2TP_AVP_BEARER_TYPE,		"BEARER_TYPE" },
148 	{ L2TP_AVP_FRAMING_TYPE,	"FRAMING_TYPE" },
149 	{ L2TP_AVP_PACKET_PROC_DELAY,	"PACKET_PROC_DELAY" },
150 	{ L2TP_AVP_CALLED_NUMBER,	"CALLED_NUMBER" },
151 	{ L2TP_AVP_CALLING_NUMBER,	"CALLING_NUMBER" },
152 	{ L2TP_AVP_SUB_ADDRESS,		"SUB_ADDRESS" },
153 	{ L2TP_AVP_TX_CONN_SPEED,	"TX_CONN_SPEED" },
154 	{ L2TP_AVP_PHY_CHANNEL_ID,	"PHY_CHANNEL_ID" },
155 	{ L2TP_AVP_INI_RECV_LCP,	"INI_RECV_LCP" },
156 	{ L2TP_AVP_LAST_SENT_LCP,	"LAST_SENT_LCP" },
157 	{ L2TP_AVP_LAST_RECV_LCP,	"LAST_RECV_LCP" },
158 	{ L2TP_AVP_PROXY_AUTH_TYPE,	"PROXY_AUTH_TYPE" },
159 	{ L2TP_AVP_PROXY_AUTH_NAME,	"PROXY_AUTH_NAME" },
160 	{ L2TP_AVP_PROXY_AUTH_CHAL,	"PROXY_AUTH_CHAL" },
161 	{ L2TP_AVP_PROXY_AUTH_ID,	"PROXY_AUTH_ID" },
162 	{ L2TP_AVP_PROXY_AUTH_RESP,	"PROXY_AUTH_RESP" },
163 	{ L2TP_AVP_CALL_ERRORS,		"CALL_ERRORS" },
164 	{ L2TP_AVP_ACCM,		"ACCM" },
165 	{ L2TP_AVP_RANDOM_VECTOR,	"RANDOM_VECTOR" },
166 	{ L2TP_AVP_PRIVATE_GRP_ID,	"PRIVATE_GRP_ID" },
167 	{ L2TP_AVP_RX_CONN_SPEED,	"RX_CONN_SPEED" },
168 	{ L2TP_AVP_SEQ_REQUIRED,	"SEQ_REQUIRED" },
169 	{ L2TP_AVP_PPP_DISCON_CC,	"PPP_DISCON_CC" },
170 	{ 0,				NULL }
171 };
172 
173 static struct tok l2tp_authentype2str[] = {
174 	{ L2TP_AUTHEN_TYPE_RESERVED,	"Reserved" },
175 	{ L2TP_AUTHEN_TYPE_TEXTUAL,	"Textual" },
176 	{ L2TP_AUTHEN_TYPE_CHAP,	"CHAP" },
177 	{ L2TP_AUTHEN_TYPE_PAP,		"PAP" },
178 	{ L2TP_AUTHEN_TYPE_NO_AUTH,	"No Auth" },
179 	{ L2TP_AUTHEN_TYPE_MSCHAPv1,	"MS-CHAPv1" },
180 	{ 0,				NULL }
181 };
182 
183 #define L2TP_PPP_DISCON_CC_DIRECTION_GLOBAL	0
184 #define L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER	1
185 #define L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL	2
186 
187 static struct tok l2tp_cc_direction2str[] = {
188 	{ L2TP_PPP_DISCON_CC_DIRECTION_GLOBAL,	"global error" },
189 	{ L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER,	"at peer" },
190 	{ L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL,"at local" },
191 	{ 0,					NULL }
192 };
193 
194 #if 0
195 static char *l2tp_result_code_StopCCN[] = {
196          "Reserved",
197          "General request to clear control connection",
198          "General error--Error Code indicates the problem",
199          "Control channel already exists",
200          "Requester is not authorized to establish a control channel",
201          "The protocol version of the requester is not supported",
202          "Requester is being shut down",
203          "Finite State Machine error"
204 #define L2TP_MAX_RESULT_CODE_STOPCC_INDEX	8
205 };
206 #endif
207 
208 #if 0
209 static char *l2tp_result_code_CDN[] = {
210 	"Reserved",
211 	"Call disconnected due to loss of carrier",
212 	"Call disconnected for the reason indicated in error code",
213 	"Call disconnected for administrative reasons",
214 	"Call failed due to lack of appropriate facilities being " \
215 	"available (temporary condition)",
216 	"Call failed due to lack of appropriate facilities being " \
217 	"available (permanent condition)",
218 	"Invalid destination",
219 	"Call failed due to no carrier detected",
220 	"Call failed due to detection of a busy signal",
221 	"Call failed due to lack of a dial tone",
222 	"Call was not established within time allotted by LAC",
223 	"Call was connected but no appropriate framing was detected"
224 #define L2TP_MAX_RESULT_CODE_CDN_INDEX	12
225 };
226 #endif
227 
228 #if 0
229 static char *l2tp_error_code_general[] = {
230 	"No general error",
231 	"No control connection exists yet for this LAC-LNS pair",
232 	"Length is wrong",
233 	"One of the field values was out of range or " \
234 	"reserved field was non-zero"
235 	"Insufficient resources to handle this operation now",
236 	"The Session ID is invalid in this context",
237 	"A generic vendor-specific error occurred in the LAC",
238 	"Try another"
239 #define L2TP_MAX_ERROR_CODE_GENERAL_INDEX	8
240 };
241 #endif
242 
243 /******************************/
244 /* generic print out routines */
245 /******************************/
246 static void
247 print_string(const u_char *dat, u_int length)
248 {
249 	int i;
250 	for (i=0; i<length; i++) {
251 		printf("%c", *dat++);
252 	}
253 }
254 
255 static void
256 print_octets(const u_char *dat, u_int length)
257 {
258 	int i;
259 	for (i=0; i<length; i++) {
260 		printf("%02x", *dat++);
261 	}
262 }
263 
264 static void
265 print_16bits_val(const u_int16_t *dat)
266 {
267 	printf("%u", EXTRACT_16BITS(dat));
268 }
269 
270 static void
271 print_32bits_val(const u_int32_t *dat)
272 {
273 	printf("%lu", (u_long)EXTRACT_32BITS(dat));
274 }
275 
276 /***********************************/
277 /* AVP-specific print out routines */
278 /***********************************/
279 static void
280 l2tp_msgtype_print(const u_char *dat)
281 {
282 	u_int16_t *ptr = (u_int16_t*)dat;
283 
284 	printf("%s", tok2str(l2tp_msgtype2str, "MSGTYPE-#%u",
285 	    EXTRACT_16BITS(ptr)));
286 }
287 
288 static void
289 l2tp_result_code_print(const u_char *dat, u_int length)
290 {
291 	u_int16_t *ptr = (u_int16_t *)dat;
292 
293 	printf("%u", EXTRACT_16BITS(ptr)); ptr++;	/* Result Code */
294 	if (length > 2) {				/* Error Code (opt) */
295 	        printf("/%u", EXTRACT_16BITS(ptr)); ptr++;
296 	}
297 	if (length > 4) {				/* Error Message (opt) */
298 		printf(" ");
299 		print_string((u_char *)ptr, length - 4);
300 	}
301 }
302 
303 static void
304 l2tp_proto_ver_print(const u_int16_t *dat)
305 {
306 	printf("%u.%u", (EXTRACT_16BITS(dat) >> 8),
307 	    (EXTRACT_16BITS(dat) & 0xff));
308 }
309 
310 static void
311 l2tp_framing_cap_print(const u_char *dat)
312 {
313 	u_int32_t *ptr = (u_int32_t *)dat;
314 
315 	if (EXTRACT_32BITS(ptr) &  L2TP_FRAMING_CAP_ASYNC_MASK) {
316 		printf("A");
317 	}
318 	if (EXTRACT_32BITS(ptr) &  L2TP_FRAMING_CAP_SYNC_MASK) {
319 		printf("S");
320 	}
321 }
322 
323 static void
324 l2tp_bearer_cap_print(const u_char *dat)
325 {
326 	u_int32_t *ptr = (u_int32_t *)dat;
327 
328 	if (EXTRACT_32BITS(ptr) &  L2TP_BEARER_CAP_ANALOG_MASK) {
329 		printf("A");
330 	}
331 	if (EXTRACT_32BITS(ptr) &  L2TP_BEARER_CAP_DIGITAL_MASK) {
332 		printf("D");
333 	}
334 }
335 
336 static void
337 l2tp_q931_cc_print(const u_char *dat, u_int length)
338 {
339 	print_16bits_val((u_int16_t *)dat);
340 	printf(", %02x", dat[2]);
341 	if (length > 3) {
342 		printf(" ");
343 		print_string(dat+3, length-3);
344 	}
345 }
346 
347 static void
348 l2tp_bearer_type_print(const u_char *dat)
349 {
350 	u_int32_t *ptr = (u_int32_t *)dat;
351 
352 	if (EXTRACT_32BITS(ptr) &  L2TP_BEARER_TYPE_ANALOG_MASK) {
353 		printf("A");
354 	}
355 	if (EXTRACT_32BITS(ptr) &  L2TP_BEARER_TYPE_DIGITAL_MASK) {
356 		printf("D");
357 	}
358 }
359 
360 static void
361 l2tp_framing_type_print(const u_char *dat)
362 {
363 	u_int32_t *ptr = (u_int32_t *)dat;
364 
365 	if (EXTRACT_32BITS(ptr) &  L2TP_FRAMING_TYPE_ASYNC_MASK) {
366 		printf("A");
367 	}
368 	if (EXTRACT_32BITS(ptr) &  L2TP_FRAMING_TYPE_SYNC_MASK) {
369 		printf("S");
370 	}
371 }
372 
373 static void
374 l2tp_packet_proc_delay_print(void)
375 {
376 	printf("obsolete");
377 }
378 
379 static void
380 l2tp_proxy_auth_type_print(const u_char *dat)
381 {
382 	u_int16_t *ptr = (u_int16_t *)dat;
383 
384 	printf("%s", tok2str(l2tp_authentype2str,
385 			     "AuthType-#%u", EXTRACT_16BITS(ptr)));
386 }
387 
388 static void
389 l2tp_proxy_auth_id_print(const u_char *dat)
390 {
391 	u_int16_t *ptr = (u_int16_t *)dat;
392 
393 	printf("%u", EXTRACT_16BITS(ptr) & L2TP_PROXY_AUTH_ID_MASK);
394 }
395 
396 static void
397 l2tp_call_errors_print(const u_char *dat)
398 {
399 	u_int16_t *ptr = (u_int16_t *)dat;
400 	u_int16_t val_h, val_l;
401 
402 	ptr++;		/* skip "Reserved" */
403 
404 	val_h = EXTRACT_16BITS(ptr); ptr++;
405 	val_l = EXTRACT_16BITS(ptr); ptr++;
406 	printf("CRCErr=%u ", (val_h<<16) + val_l);
407 
408 	val_h = EXTRACT_16BITS(ptr); ptr++;
409 	val_l = EXTRACT_16BITS(ptr); ptr++;
410 	printf("FrameErr=%u ", (val_h<<16) + val_l);
411 
412 	val_h = EXTRACT_16BITS(ptr); ptr++;
413 	val_l = EXTRACT_16BITS(ptr); ptr++;
414 	printf("HardOver=%u ", (val_h<<16) + val_l);
415 
416 	val_h = EXTRACT_16BITS(ptr); ptr++;
417 	val_l = EXTRACT_16BITS(ptr); ptr++;
418 	printf("BufOver=%u ", (val_h<<16) + val_l);
419 
420 	val_h = EXTRACT_16BITS(ptr); ptr++;
421 	val_l = EXTRACT_16BITS(ptr); ptr++;
422 	printf("Timeout=%u ", (val_h<<16) + val_l);
423 
424 	val_h = EXTRACT_16BITS(ptr); ptr++;
425 	val_l = EXTRACT_16BITS(ptr); ptr++;
426 	printf("AlignErr=%u ", (val_h<<16) + val_l);
427 }
428 
429 static void
430 l2tp_accm_print(const u_char *dat)
431 {
432 	u_int16_t *ptr = (u_int16_t *)dat;
433 	u_int16_t val_h, val_l;
434 
435 	ptr++;		/* skip "Reserved" */
436 
437 	val_h = EXTRACT_16BITS(ptr); ptr++;
438 	val_l = EXTRACT_16BITS(ptr); ptr++;
439 	printf("send=%08x ", (val_h<<16) + val_l);
440 
441 	val_h = EXTRACT_16BITS(ptr); ptr++;
442 	val_l = EXTRACT_16BITS(ptr); ptr++;
443 	printf("recv=%08x ", (val_h<<16) + val_l);
444 }
445 
446 static void
447 l2tp_ppp_discon_cc_print(const u_char *dat, u_int length)
448 {
449 	u_int16_t *ptr = (u_int16_t *)dat;
450 
451 	printf("%04x, ", EXTRACT_16BITS(ptr)); ptr++;	/* Disconnect Code */
452 	printf("%04x ",  EXTRACT_16BITS(ptr)); ptr++;	/* Control Protocol Number */
453 	printf("%s", tok2str(l2tp_cc_direction2str,
454 			     "Direction-#%u", *((u_char *)ptr++)));
455 
456 	if (length > 5) {
457 		printf(" ");
458 		print_string((const u_char *)ptr, length-5);
459 	}
460 }
461 
462 static void
463 l2tp_avp_print(const u_char *dat, int length)
464 {
465 	u_int len;
466 	const u_int16_t *ptr = (u_int16_t *)dat;
467 	u_int16_t attr_type;
468 	int hidden = FALSE;
469 
470 	if (length <= 0) {
471 		return;
472 	}
473 
474 	printf(" ");
475 
476 	TCHECK(*ptr);	/* Flags & Length */
477 	len = EXTRACT_16BITS(ptr) & L2TP_AVP_HDR_LEN_MASK;
478 
479 	/* If it is not long enough to decode the entire AVP, we'll
480 	   abandon. */
481 	TCHECK2(*ptr, len);
482 	/* After this point, no need to worry about truncation */
483 
484 	if (EXTRACT_16BITS(ptr) & L2TP_AVP_HDR_FLAG_MANDATORY) {
485 		printf("*");
486 	}
487 	if (EXTRACT_16BITS(ptr) & L2TP_AVP_HDR_FLAG_HIDDEN) {
488 		hidden = TRUE;
489 		printf("?");
490 	}
491 	ptr++;
492 
493 	if (EXTRACT_16BITS(ptr)) {
494 		/* Vendor Specific Attribute */
495 	        printf("VENDOR%04x:", EXTRACT_16BITS(ptr)); ptr++;
496 		printf("ATTR%04x", EXTRACT_16BITS(ptr)); ptr++;
497 		printf("(");
498 		print_octets((u_char *)ptr, len-6);
499 		printf(")");
500 	} else {
501 		/* IETF-defined Attributes */
502 		ptr++;
503 		attr_type = EXTRACT_16BITS(ptr); ptr++;
504 		printf("%s", tok2str(l2tp_avp2str, "AVP-#%u", attr_type));
505 		printf("(");
506 		if (hidden) {
507 			printf("???");
508 		} else {
509 			switch (attr_type) {
510 			case L2TP_AVP_MSGTYPE:
511 				l2tp_msgtype_print((u_char *)ptr);
512 				break;
513 			case L2TP_AVP_RESULT_CODE:
514 				l2tp_result_code_print((u_char *)ptr, len-6);
515 				break;
516 			case L2TP_AVP_PROTO_VER:
517 				l2tp_proto_ver_print(ptr);
518 				break;
519 			case L2TP_AVP_FRAMING_CAP:
520 				l2tp_framing_cap_print((u_char *)ptr);
521 				break;
522 			case L2TP_AVP_BEARER_CAP:
523 				l2tp_bearer_cap_print((u_char *)ptr);
524 				break;
525 			case L2TP_AVP_TIE_BREAKER:
526 				print_octets((u_char *)ptr, 8);
527 				break;
528 			case L2TP_AVP_FIRM_VER:
529 			case L2TP_AVP_ASSND_TUN_ID:
530 			case L2TP_AVP_RECV_WIN_SIZE:
531 			case L2TP_AVP_ASSND_SESS_ID:
532 				print_16bits_val(ptr);
533 				break;
534 			case L2TP_AVP_HOST_NAME:
535 			case L2TP_AVP_VENDOR_NAME:
536 			case L2TP_AVP_CALLING_NUMBER:
537 			case L2TP_AVP_CALLED_NUMBER:
538 			case L2TP_AVP_SUB_ADDRESS:
539 			case L2TP_AVP_PROXY_AUTH_NAME:
540 			case L2TP_AVP_PRIVATE_GRP_ID:
541 				print_string((u_char *)ptr, len-6);
542 				break;
543 			case L2TP_AVP_CHALLENGE:
544 			case L2TP_AVP_INI_RECV_LCP:
545 			case L2TP_AVP_LAST_SENT_LCP:
546 			case L2TP_AVP_LAST_RECV_LCP:
547 			case L2TP_AVP_PROXY_AUTH_CHAL:
548 			case L2TP_AVP_PROXY_AUTH_RESP:
549 			case L2TP_AVP_RANDOM_VECTOR:
550 				print_octets((u_char *)ptr, len-6);
551 				break;
552 			case L2TP_AVP_Q931_CC:
553 				l2tp_q931_cc_print((u_char *)ptr, len-6);
554 				break;
555 			case L2TP_AVP_CHALLENGE_RESP:
556 				print_octets((u_char *)ptr, 16);
557 				break;
558 			case L2TP_AVP_CALL_SER_NUM:
559 			case L2TP_AVP_MINIMUM_BPS:
560 			case L2TP_AVP_MAXIMUM_BPS:
561 			case L2TP_AVP_TX_CONN_SPEED:
562 			case L2TP_AVP_PHY_CHANNEL_ID:
563 			case L2TP_AVP_RX_CONN_SPEED:
564 				print_32bits_val((u_int32_t *)ptr);
565 				break;
566 			case L2TP_AVP_BEARER_TYPE:
567 				l2tp_bearer_type_print((u_char *)ptr);
568 				break;
569 			case L2TP_AVP_FRAMING_TYPE:
570 				l2tp_framing_type_print((u_char *)ptr);
571 				break;
572 			case L2TP_AVP_PACKET_PROC_DELAY:
573 				l2tp_packet_proc_delay_print();
574 				break;
575 			case L2TP_AVP_PROXY_AUTH_TYPE:
576 				l2tp_proxy_auth_type_print((u_char *)ptr);
577 				break;
578 			case L2TP_AVP_PROXY_AUTH_ID:
579 				l2tp_proxy_auth_id_print((u_char *)ptr);
580 				break;
581 			case L2TP_AVP_CALL_ERRORS:
582 				l2tp_call_errors_print((u_char *)ptr);
583 				break;
584 			case L2TP_AVP_ACCM:
585 				l2tp_accm_print((u_char *)ptr);
586 				break;
587 			case L2TP_AVP_SEQ_REQUIRED:
588 				break;	/* No Attribute Value */
589 			case L2TP_AVP_PPP_DISCON_CC:
590 				l2tp_ppp_discon_cc_print((u_char *)ptr, len-6);
591 				break;
592 			default:
593 				break;
594 			}
595 		}
596 		printf(")");
597 	}
598 
599 	l2tp_avp_print(dat+len, length-len);
600 	return;
601 
602  trunc:
603 	printf("|...");
604 }
605 
606 
607 void
608 l2tp_print(const u_char *dat, u_int length)
609 {
610 	const u_int16_t *ptr = (u_int16_t *)dat;
611 	u_int cnt = 0;			/* total octets consumed */
612 	u_int16_t pad;
613 	int flag_t, flag_l, flag_s, flag_o, flag_p;
614 	u_int16_t l2tp_len;
615 
616 	flag_t = flag_l = flag_s = flag_o = flag_p = FALSE;
617 
618 	TCHECK(*ptr);	/* Flags & Version */
619 	if ((EXTRACT_16BITS(ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2TP) {
620 		printf(" l2tp:");
621 	} else if ((EXTRACT_16BITS(ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2F) {
622 		printf(" l2f:");
623 		return;		/* nothing to do */
624 	} else {
625 		printf(" Unknown Version, neither L2F(1) nor L2TP(2)");
626 		return;		/* nothing we can do */
627 	}
628 
629 	printf("[");
630 	if (EXTRACT_16BITS(ptr) & L2TP_FLAG_TYPE) {
631 		flag_t = TRUE;
632 		printf("T");
633 	}
634 	if (EXTRACT_16BITS(ptr) & L2TP_FLAG_LENGTH) {
635 		flag_l = TRUE;
636 		printf("L");
637 	}
638 	if (EXTRACT_16BITS(ptr) & L2TP_FLAG_SEQUENCE) {
639 		flag_s = TRUE;
640 		printf("S");
641 	}
642 	if (EXTRACT_16BITS(ptr) & L2TP_FLAG_OFFSET) {
643 		flag_o = TRUE;
644 		printf("O");
645 	}
646 	if (EXTRACT_16BITS(ptr) & L2TP_FLAG_PRIORITY) {
647 		flag_p = TRUE;
648 		printf("P");
649 	}
650 	printf("]");
651 
652 	ptr++;
653 	cnt += 2;
654 
655 	if (flag_l) {
656 		TCHECK(*ptr);	/* Length */
657 		l2tp_len = EXTRACT_16BITS(ptr); ptr++;
658 		cnt += 2;
659 	} else {
660 		l2tp_len = 0;
661 	}
662 
663 	TCHECK(*ptr);		/* Tunnel ID */
664 	printf("(%u/", EXTRACT_16BITS(ptr)); ptr++;
665 	cnt += 2;
666 	TCHECK(*ptr);		/* Session ID */
667 	printf("%u)",  EXTRACT_16BITS(ptr)); ptr++;
668 	cnt += 2;
669 
670 	if (flag_s) {
671 		TCHECK(*ptr);	/* Ns */
672 		printf("Ns=%u,", EXTRACT_16BITS(ptr)); ptr++;
673 		cnt += 2;
674 		TCHECK(*ptr);	/* Nr */
675 		printf("Nr=%u",  EXTRACT_16BITS(ptr)); ptr++;
676 		cnt += 2;
677 	}
678 
679 	if (flag_o) {
680 		TCHECK(*ptr);	/* Offset Size */
681 		pad =  EXTRACT_16BITS(ptr); ptr++;
682 		ptr += pad / sizeof(*ptr);
683 		cnt += (2 + pad);
684 	}
685 
686 	if (flag_t) {
687 		if (length - cnt == 0) {
688 			printf(" ZLB");
689 		} else {
690 			l2tp_avp_print((u_char *)ptr, length - cnt);
691 		}
692 	} else {
693 		printf(" {");
694 		ppp_print((u_char *)ptr, length - cnt);
695 		printf("}");
696 	}
697 
698 	return;
699 
700  trunc:
701 	printf("%s", tstr);
702 }
703