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Fix warnings when building for 32-bit and defining _TIME_BITS=64
[tcpdump] / print-fr.c
1 /*
2 * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996
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
22 /* \summary: Frame Relay printer */
23
24 #ifdef HAVE_CONFIG_H
25 #include <config.h>
26 #endif
27
28 #include "netdissect-stdinc.h"
29
30 #include <stdio.h>
31 #include <string.h>
32
33 #include "netdissect.h"
34 #include "addrtoname.h"
35 #include "ethertype.h"
36 #include "llc.h"
37 #include "nlpid.h"
38 #include "extract.h"
39
40 static void frf15_print(netdissect_options *ndo, const u_char *, u_int);
41
42 /*
43 * the frame relay header has a variable length
44 *
45 * the EA bit determines if there is another byte
46 * in the header
47 *
48 * minimum header length is 2 bytes
49 * maximum header length is 4 bytes
50 *
51 * 7 6 5 4 3 2 1 0
52 * +----+----+----+----+----+----+----+----+
53 * | DLCI (6 bits) | CR | EA |
54 * +----+----+----+----+----+----+----+----+
55 * | DLCI (4 bits) |FECN|BECN| DE | EA |
56 * +----+----+----+----+----+----+----+----+
57 * | DLCI (7 bits) | EA |
58 * +----+----+----+----+----+----+----+----+
59 * | DLCI (6 bits) |SDLC| EA |
60 * +----+----+----+----+----+----+----+----+
61 */
62
63 #define FR_EA_BIT 0x01
64
65 #define FR_CR_BIT 0x02000000
66 #define FR_DE_BIT 0x00020000
67 #define FR_BECN_BIT 0x00040000
68 #define FR_FECN_BIT 0x00080000
69 #define FR_SDLC_BIT 0x00000002
70
71
72 static const struct tok fr_header_flag_values[] = {
73 { FR_CR_BIT, "C!" },
74 { FR_DE_BIT, "DE" },
75 { FR_BECN_BIT, "BECN" },
76 { FR_FECN_BIT, "FECN" },
77 { FR_SDLC_BIT, "sdlcore" },
78 { 0, NULL }
79 };
80
81 /* FRF.15 / FRF.16 */
82 #define MFR_B_BIT 0x80
83 #define MFR_E_BIT 0x40
84 #define MFR_C_BIT 0x20
85 #define MFR_BEC_MASK (MFR_B_BIT | MFR_E_BIT | MFR_C_BIT)
86 #define MFR_CTRL_FRAME (MFR_B_BIT | MFR_E_BIT | MFR_C_BIT)
87 #define MFR_FRAG_FRAME (MFR_B_BIT | MFR_E_BIT )
88
89 static const struct tok frf_flag_values[] = {
90 { MFR_B_BIT, "Begin" },
91 { MFR_E_BIT, "End" },
92 { MFR_C_BIT, "Control" },
93 { 0, NULL }
94 };
95
96 /* Finds out Q.922 address length, DLCI and flags. Returns 1 on success,
97 * 0 on invalid address, -1 on truncated packet
98 * save the flags dep. on address length
99 */
100 static int parse_q922_header(netdissect_options *ndo,
101 const u_char *p, u_int *dlci,
102 u_int *addr_len, uint32_t *flags, u_int length)
103 {
104 if (!ND_TTEST_1(p) || length < 1)
105 return -1;
106 if ((GET_U_1(p) & FR_EA_BIT))
107 return 0;
108
109 if (!ND_TTEST_1(p + 1) || length < 2)
110 return -1;
111 *addr_len = 2;
112 *dlci = ((GET_U_1(p) & 0xFC) << 2) | ((GET_U_1(p + 1) & 0xF0) >> 4);
113
114 *flags = ((GET_U_1(p) & 0x02) << 24) | /* CR flag */
115 ((GET_U_1(p + 1) & 0x0e) << 16); /* FECN,BECN,DE flags */
116
117 if (GET_U_1(p + 1) & FR_EA_BIT)
118 return 1; /* 2-byte Q.922 address */
119
120 p += 2;
121 length -= 2;
122 if (!ND_TTEST_1(p) || length < 1)
123 return -1;
124 (*addr_len)++; /* 3- or 4-byte Q.922 address */
125 if ((GET_U_1(p) & FR_EA_BIT) == 0) {
126 *dlci = (*dlci << 7) | (GET_U_1(p) >> 1);
127 (*addr_len)++; /* 4-byte Q.922 address */
128 p++;
129 length--;
130 }
131
132 if (!ND_TTEST_1(p) || length < 1)
133 return -1;
134 if ((GET_U_1(p) & FR_EA_BIT) == 0)
135 return 0; /* more than 4 bytes of Q.922 address? */
136
137 *flags = *flags | (GET_U_1(p) & 0x02); /* SDLC flag */
138
139 *dlci = (*dlci << 6) | (GET_U_1(p) >> 2);
140
141 return 1;
142 }
143
144 const char *
145 q922_string(netdissect_options *ndo, const u_char *p, u_int length)
146 {
147
148 static u_int dlci, addr_len;
149 static uint32_t flags;
150 static char buffer[sizeof("parse_q922_header() returned XXXXXXXXXXX")];
151 int ret;
152 memset(buffer, 0, sizeof(buffer));
153
154 ret = parse_q922_header(ndo, p, &dlci, &addr_len, &flags, length);
155 if (ret == 1) {
156 snprintf(buffer, sizeof(buffer), "DLCI %u", dlci);
157 return buffer;
158 } else if (ret == 0) {
159 return "<Invalid DLCI>";
160 } else if (ret == -1) {
161 return "<Truncated>";
162 } else {
163 snprintf(buffer, sizeof(buffer), "parse_q922_header() returned %d", ret);
164 return buffer;
165 }
166 }
167
168
169 /* Frame Relay packet structure, with flags and CRC removed
170
171 +---------------------------+
172 | Q.922 Address* |
173 +-- --+
174 | |
175 +---------------------------+
176 | Control (UI = 0x03) |
177 +---------------------------+
178 | Optional Pad (0x00) |
179 +---------------------------+
180 | NLPID |
181 +---------------------------+
182 | . |
183 | . |
184 | . |
185 | Data |
186 | . |
187 | . |
188 +---------------------------+
189
190 * Q.922 addresses, as presently defined, are two octets and
191 contain a 10-bit DLCI. In some networks Q.922 addresses
192 may optionally be increased to three or four octets.
193 */
194
195 static void
196 fr_hdr_print(netdissect_options *ndo, int length, u_int addr_len,
197 u_int dlci, uint32_t flags, uint16_t nlpid)
198 {
199 if (ndo->ndo_qflag) {
200 ND_PRINT("Q.922, DLCI %u, length %u: ",
201 dlci,
202 length);
203 } else {
204 if (nlpid <= 0xff) /* if its smaller than 256 then its a NLPID */
205 ND_PRINT("Q.922, hdr-len %u, DLCI %u, Flags [%s], NLPID %s (0x%02x), length %u: ",
206 addr_len,
207 dlci,
208 bittok2str(fr_header_flag_values, "none", flags),
209 tok2str(nlpid_values,"unknown", nlpid),
210 nlpid,
211 length);
212 else /* must be an ethertype */
213 ND_PRINT("Q.922, hdr-len %u, DLCI %u, Flags [%s], cisco-ethertype %s (0x%04x), length %u: ",
214 addr_len,
215 dlci,
216 bittok2str(fr_header_flag_values, "none", flags),
217 tok2str(ethertype_values, "unknown", nlpid),
218 nlpid,
219 length);
220 }
221 }
222
223 /* Frame Relay */
224 void
225 fr_if_print(netdissect_options *ndo,
226 const struct pcap_pkthdr *h, const u_char *p)
227 {
228 u_int length = h->len;
229 u_int caplen = h->caplen;
230
231 ndo->ndo_protocol = "fr";
232 if (caplen < 4) { /* minimum frame header length */
233 nd_print_trunc(ndo);
234 ndo->ndo_ll_hdr_len += caplen;
235 return;
236 }
237
238 ndo->ndo_ll_hdr_len += fr_print(ndo, p, length);
239 }
240
241 u_int
242 fr_print(netdissect_options *ndo,
243 const u_char *p, u_int length)
244 {
245 int ret;
246 uint16_t extracted_ethertype;
247 u_int dlci;
248 u_int addr_len;
249 uint16_t nlpid;
250 u_int hdr_len;
251 uint32_t flags;
252
253 ndo->ndo_protocol = "fr";
254 ret = parse_q922_header(ndo, p, &dlci, &addr_len, &flags, length);
255 if (ret == -1)
256 goto trunc;
257 if (ret == 0) {
258 ND_PRINT("Q.922, invalid address");
259 return 0;
260 }
261
262 ND_TCHECK_1(p + addr_len);
263 if (length < addr_len + 1)
264 goto trunc;
265
266 if (GET_U_1(p + addr_len) != LLC_UI && dlci != 0) {
267 /*
268 * Let's figure out if we have Cisco-style encapsulation,
269 * with an Ethernet type (Cisco HDLC type?) following the
270 * address.
271 */
272 if (!ND_TTEST_2(p + addr_len) || length < addr_len + 2) {
273 /* no Ethertype */
274 ND_PRINT("UI %02x! ", GET_U_1(p + addr_len));
275 } else {
276 extracted_ethertype = GET_BE_U_2(p + addr_len);
277
278 if (ndo->ndo_eflag)
279 fr_hdr_print(ndo, length, addr_len, dlci,
280 flags, extracted_ethertype);
281
282 if (ethertype_print(ndo, extracted_ethertype,
283 p+addr_len+ETHERTYPE_LEN,
284 length-addr_len-ETHERTYPE_LEN,
285 ND_BYTES_AVAILABLE_AFTER(p)-addr_len-ETHERTYPE_LEN,
286 NULL, NULL) == 0)
287 /* ether_type not known, probably it wasn't one */
288 ND_PRINT("UI %02x! ", GET_U_1(p + addr_len));
289 else
290 return addr_len + 2;
291 }
292 }
293
294 ND_TCHECK_1(p + addr_len + 1);
295 if (length < addr_len + 2)
296 goto trunc;
297
298 if (GET_U_1(p + addr_len + 1) == 0) {
299 /*
300 * Assume a pad byte after the control (UI) byte.
301 * A pad byte should only be used with 3-byte Q.922.
302 */
303 if (addr_len != 3)
304 ND_PRINT("Pad! ");
305 hdr_len = addr_len + 1 /* UI */ + 1 /* pad */ + 1 /* NLPID */;
306 } else {
307 /*
308 * Not a pad byte.
309 * A pad byte should be used with 3-byte Q.922.
310 */
311 if (addr_len == 3)
312 ND_PRINT("No pad! ");
313 hdr_len = addr_len + 1 /* UI */ + 1 /* NLPID */;
314 }
315
316 ND_TCHECK_1(p + hdr_len - 1);
317 if (length < hdr_len)
318 goto trunc;
319 nlpid = GET_U_1(p + hdr_len - 1);
320
321 if (ndo->ndo_eflag)
322 fr_hdr_print(ndo, length, addr_len, dlci, flags, nlpid);
323 p += hdr_len;
324 length -= hdr_len;
325
326 switch (nlpid) {
327 case NLPID_IP:
328 ip_print(ndo, p, length);
329 break;
330
331 case NLPID_IP6:
332 ip6_print(ndo, p, length);
333 break;
334
335 case NLPID_CLNP:
336 case NLPID_ESIS:
337 case NLPID_ISIS:
338 isoclns_print(ndo, p - 1, length + 1); /* OSI printers need the NLPID field */
339 break;
340
341 case NLPID_SNAP:
342 if (snap_print(ndo, p, length, ND_BYTES_AVAILABLE_AFTER(p), NULL, NULL, 0) == 0) {
343 /* ether_type not known, print raw packet */
344 if (!ndo->ndo_eflag)
345 fr_hdr_print(ndo, length + hdr_len, hdr_len,
346 dlci, flags, nlpid);
347 if (!ndo->ndo_suppress_default_print)
348 ND_DEFAULTPRINT(p - hdr_len, length + hdr_len);
349 }
350 break;
351
352 case NLPID_Q933:
353 q933_print(ndo, p, length);
354 break;
355
356 case NLPID_MFR:
357 frf15_print(ndo, p, length);
358 break;
359
360 case NLPID_PPP:
361 ppp_print(ndo, p, length);
362 break;
363
364 default:
365 if (!ndo->ndo_eflag)
366 fr_hdr_print(ndo, length + hdr_len, addr_len,
367 dlci, flags, nlpid);
368 if (!ndo->ndo_xflag)
369 ND_DEFAULTPRINT(p, length);
370 }
371
372 return hdr_len;
373
374 trunc:
375 nd_print_trunc(ndo);
376 return 0;
377
378 }
379
380 /* Multi Link Frame Relay (FRF.16) */
381 void
382 mfr_if_print(netdissect_options *ndo,
383 const struct pcap_pkthdr *h, const u_char *p)
384 {
385 u_int length = h->len;
386 u_int caplen = h->caplen;
387
388 ndo->ndo_protocol = "mfr";
389 if (caplen < 2) { /* minimum frame header length */
390 nd_print_trunc(ndo);
391 ndo->ndo_ll_hdr_len += caplen;
392 return;
393 }
394
395 ndo->ndo_ll_hdr_len += mfr_print(ndo, p, length);
396 }
397
398
399 #define MFR_CTRL_MSG_ADD_LINK 1
400 #define MFR_CTRL_MSG_ADD_LINK_ACK 2
401 #define MFR_CTRL_MSG_ADD_LINK_REJ 3
402 #define MFR_CTRL_MSG_HELLO 4
403 #define MFR_CTRL_MSG_HELLO_ACK 5
404 #define MFR_CTRL_MSG_REMOVE_LINK 6
405 #define MFR_CTRL_MSG_REMOVE_LINK_ACK 7
406
407 static const struct tok mfr_ctrl_msg_values[] = {
408 { MFR_CTRL_MSG_ADD_LINK, "Add Link" },
409 { MFR_CTRL_MSG_ADD_LINK_ACK, "Add Link ACK" },
410 { MFR_CTRL_MSG_ADD_LINK_REJ, "Add Link Reject" },
411 { MFR_CTRL_MSG_HELLO, "Hello" },
412 { MFR_CTRL_MSG_HELLO_ACK, "Hello ACK" },
413 { MFR_CTRL_MSG_REMOVE_LINK, "Remove Link" },
414 { MFR_CTRL_MSG_REMOVE_LINK_ACK, "Remove Link ACK" },
415 { 0, NULL }
416 };
417
418 #define MFR_CTRL_IE_BUNDLE_ID 1
419 #define MFR_CTRL_IE_LINK_ID 2
420 #define MFR_CTRL_IE_MAGIC_NUM 3
421 #define MFR_CTRL_IE_TIMESTAMP 5
422 #define MFR_CTRL_IE_VENDOR_EXT 6
423 #define MFR_CTRL_IE_CAUSE 7
424
425 static const struct tok mfr_ctrl_ie_values[] = {
426 { MFR_CTRL_IE_BUNDLE_ID, "Bundle ID"},
427 { MFR_CTRL_IE_LINK_ID, "Link ID"},
428 { MFR_CTRL_IE_MAGIC_NUM, "Magic Number"},
429 { MFR_CTRL_IE_TIMESTAMP, "Timestamp"},
430 { MFR_CTRL_IE_VENDOR_EXT, "Vendor Extension"},
431 { MFR_CTRL_IE_CAUSE, "Cause"},
432 { 0, NULL }
433 };
434
435 #define MFR_ID_STRING_MAXLEN 50
436
437 struct ie_tlv_header_t {
438 uint8_t ie_type;
439 uint8_t ie_len;
440 };
441
442 u_int
443 mfr_print(netdissect_options *ndo,
444 const u_char *p, u_int length)
445 {
446 u_int tlen,idx,hdr_len = 0;
447 uint16_t sequence_num;
448 uint8_t ie_type,ie_len;
449 const uint8_t *tptr;
450
451
452 /*
453 * FRF.16 Link Integrity Control Frame
454 *
455 * 7 6 5 4 3 2 1 0
456 * +----+----+----+----+----+----+----+----+
457 * | B | E | C=1| 0 0 0 0 | EA |
458 * +----+----+----+----+----+----+----+----+
459 * | 0 0 0 0 0 0 0 0 |
460 * +----+----+----+----+----+----+----+----+
461 * | message type |
462 * +----+----+----+----+----+----+----+----+
463 */
464
465 ndo->ndo_protocol = "mfr";
466
467 if (length < 4) { /* minimum frame header length */
468 ND_PRINT("[length %u < 4]", length);
469 nd_print_invalid(ndo);
470 return length;
471 }
472 ND_TCHECK_4(p);
473
474 if ((GET_U_1(p) & MFR_BEC_MASK) == MFR_CTRL_FRAME && GET_U_1(p + 1) == 0) {
475 ND_PRINT("FRF.16 Control, Flags [%s], %s, length %u",
476 bittok2str(frf_flag_values,"none",(GET_U_1(p) & MFR_BEC_MASK)),
477 tok2str(mfr_ctrl_msg_values,"Unknown Message (0x%02x)",GET_U_1(p + 2)),
478 length);
479 tptr = p + 3;
480 tlen = length -3;
481 hdr_len = 3;
482
483 if (!ndo->ndo_vflag)
484 return hdr_len;
485
486 while (tlen>sizeof(struct ie_tlv_header_t)) {
487 ND_TCHECK_LEN(tptr, sizeof(struct ie_tlv_header_t));
488 ie_type=GET_U_1(tptr);
489 ie_len=GET_U_1(tptr + 1);
490
491 ND_PRINT("\n\tIE %s (%u), length %u: ",
492 tok2str(mfr_ctrl_ie_values,"Unknown",ie_type),
493 ie_type,
494 ie_len);
495
496 /* infinite loop check */
497 if (ie_type == 0 || ie_len <= sizeof(struct ie_tlv_header_t))
498 return hdr_len;
499
500 ND_TCHECK_LEN(tptr, ie_len);
501 tptr+=sizeof(struct ie_tlv_header_t);
502 /* tlv len includes header */
503 ie_len-=sizeof(struct ie_tlv_header_t);
504 tlen-=sizeof(struct ie_tlv_header_t);
505
506 switch (ie_type) {
507
508 case MFR_CTRL_IE_MAGIC_NUM:
509 /* FRF.16.1 Section 3.4.3 Magic Number Information Element */
510 if (ie_len != 4) {
511 ND_PRINT("[IE data length %d != 4]", ie_len);
512 nd_print_invalid(ndo);
513 break;
514 }
515 ND_PRINT("0x%08x", GET_BE_U_4(tptr));
516 break;
517
518 case MFR_CTRL_IE_BUNDLE_ID: /* same message format */
519 case MFR_CTRL_IE_LINK_ID:
520 for (idx = 0; idx < ie_len && idx < MFR_ID_STRING_MAXLEN; idx++) {
521 if (GET_U_1(tptr + idx) != 0) /* don't print null termination */
522 fn_print_char(ndo, GET_U_1(tptr + idx));
523 else
524 break;
525 }
526 break;
527
528 case MFR_CTRL_IE_TIMESTAMP:
529 /*
530 * FRF.16.1 Section 3.4.4 Timestamp Information Element
531 *
532 * The maximum length is 14 octets. Format is implementation
533 * specific.
534 */
535 if (ie_len > 14) {
536 ND_PRINT("[Timestamp IE length %d > 14]", ie_len);
537 nd_print_invalid(ndo);
538 break;
539 }
540 /* fall through and hexdump */
541 ND_FALL_THROUGH;
542
543 /*
544 * FIXME those are the defined IEs that lack a decoder
545 * you are welcome to contribute code ;-)
546 */
547
548 case MFR_CTRL_IE_VENDOR_EXT:
549 case MFR_CTRL_IE_CAUSE:
550
551 default:
552 if (ndo->ndo_vflag <= 1)
553 print_unknown_data(ndo, tptr, "\n\t ", ie_len);
554 break;
555 }
556
557 /* do we want to see a hexdump of the IE ? */
558 if (ndo->ndo_vflag > 1 )
559 print_unknown_data(ndo, tptr, "\n\t ", ie_len);
560
561 tlen-=ie_len;
562 tptr+=ie_len;
563 }
564 return hdr_len;
565 }
566 /*
567 * FRF.16 Fragmentation Frame
568 *
569 * 7 6 5 4 3 2 1 0
570 * +----+----+----+----+----+----+----+----+
571 * | B | E | C=0|seq. (high 4 bits) | EA |
572 * +----+----+----+----+----+----+----+----+
573 * | sequence (low 8 bits) |
574 * +----+----+----+----+----+----+----+----+
575 * | DLCI (6 bits) | CR | EA |
576 * +----+----+----+----+----+----+----+----+
577 * | DLCI (4 bits) |FECN|BECN| DE | EA |
578 * +----+----+----+----+----+----+----+----+
579 */
580
581 sequence_num = (GET_U_1(p)&0x1e)<<7 | GET_U_1(p + 1);
582 /* whole packet or first fragment ? */
583 if ((GET_U_1(p) & MFR_BEC_MASK) == MFR_FRAG_FRAME ||
584 (GET_U_1(p) & MFR_BEC_MASK) == MFR_B_BIT) {
585 ND_PRINT("FRF.16 Frag, seq %u, Flags [%s], ",
586 sequence_num,
587 bittok2str(frf_flag_values,"none",(GET_U_1(p) & MFR_BEC_MASK)));
588 hdr_len = 2;
589 fr_print(ndo, p+hdr_len,length-hdr_len);
590 return hdr_len;
591 }
592
593 /* must be a middle or the last fragment */
594 ND_PRINT("FRF.16 Frag, seq %u, Flags [%s]",
595 sequence_num,
596 bittok2str(frf_flag_values,"none",(GET_U_1(p) & MFR_BEC_MASK)));
597 print_unknown_data(ndo, p, "\n\t", length);
598
599 return hdr_len;
600
601 trunc:
602 nd_print_trunc(ndo);
603 return length;
604 }
605
606 /* an NLPID of 0xb1 indicates a 2-byte
607 * FRF.15 header
608 *
609 * 7 6 5 4 3 2 1 0
610 * +----+----+----+----+----+----+----+----+
611 * ~ Q.922 header ~
612 * +----+----+----+----+----+----+----+----+
613 * | NLPID (8 bits) | NLPID=0xb1
614 * +----+----+----+----+----+----+----+----+
615 * | B | E | C |seq. (high 4 bits) | R |
616 * +----+----+----+----+----+----+----+----+
617 * | sequence (low 8 bits) |
618 * +----+----+----+----+----+----+----+----+
619 */
620
621 #define FR_FRF15_FRAGTYPE 0x01
622
623 static void
624 frf15_print(netdissect_options *ndo,
625 const u_char *p, u_int length)
626 {
627 uint16_t sequence_num, flags;
628
629 if (length < 2)
630 goto trunc;
631
632 flags = GET_U_1(p)&MFR_BEC_MASK;
633 sequence_num = (GET_U_1(p)&0x1e)<<7 | GET_U_1(p + 1);
634
635 ND_PRINT("FRF.15, seq 0x%03x, Flags [%s],%s Fragmentation, length %u",
636 sequence_num,
637 bittok2str(frf_flag_values,"none",flags),
638 GET_U_1(p)&FR_FRF15_FRAGTYPE ? "Interface" : "End-to-End",
639 length);
640
641 /* TODO:
642 * depending on all permutations of the B, E and C bit
643 * dig as deep as we can - e.g. on the first (B) fragment
644 * there is enough payload to print the IP header
645 * on non (B) fragments it depends if the fragmentation
646 * model is end-to-end or interface based whether we want to print
647 * another Q.922 header
648 */
649 return;
650
651 trunc:
652 nd_print_trunc(ndo);
653 }
654
655 /*
656 * Q.933 decoding portion for framerelay specific.
657 */
658
659 /* Q.933 packet format
660 Format of Other Protocols
661 using Q.933 NLPID
662 +-------------------------------+
663 | Q.922 Address |
664 +---------------+---------------+
665 |Control 0x03 | NLPID 0x08 |
666 +---------------+---------------+
667 | L2 Protocol ID |
668 | octet 1 | octet 2 |
669 +-------------------------------+
670 | L3 Protocol ID |
671 | octet 2 | octet 2 |
672 +-------------------------------+
673 | Protocol Data |
674 +-------------------------------+
675 | FCS |
676 +-------------------------------+
677 */
678
679 /* L2 (Octet 1)- Call Reference Usually is 0x0 */
680
681 /*
682 * L2 (Octet 2)- Message Types definition 1 byte long.
683 */
684 /* Call Establish */
685 #define MSG_TYPE_ESC_TO_NATIONAL 0x00
686 #define MSG_TYPE_ALERT 0x01
687 #define MSG_TYPE_CALL_PROCEEDING 0x02
688 #define MSG_TYPE_CONNECT 0x07
689 #define MSG_TYPE_CONNECT_ACK 0x0F
690 #define MSG_TYPE_PROGRESS 0x03
691 #define MSG_TYPE_SETUP 0x05
692 /* Call Clear */
693 #define MSG_TYPE_DISCONNECT 0x45
694 #define MSG_TYPE_RELEASE 0x4D
695 #define MSG_TYPE_RELEASE_COMPLETE 0x5A
696 #define MSG_TYPE_RESTART 0x46
697 #define MSG_TYPE_RESTART_ACK 0x4E
698 /* Status */
699 #define MSG_TYPE_STATUS 0x7D
700 #define MSG_TYPE_STATUS_ENQ 0x75
701
702 static const struct tok fr_q933_msg_values[] = {
703 { MSG_TYPE_ESC_TO_NATIONAL, "ESC to National" },
704 { MSG_TYPE_ALERT, "Alert" },
705 { MSG_TYPE_CALL_PROCEEDING, "Call proceeding" },
706 { MSG_TYPE_CONNECT, "Connect" },
707 { MSG_TYPE_CONNECT_ACK, "Connect ACK" },
708 { MSG_TYPE_PROGRESS, "Progress" },
709 { MSG_TYPE_SETUP, "Setup" },
710 { MSG_TYPE_DISCONNECT, "Disconnect" },
711 { MSG_TYPE_RELEASE, "Release" },
712 { MSG_TYPE_RELEASE_COMPLETE, "Release Complete" },
713 { MSG_TYPE_RESTART, "Restart" },
714 { MSG_TYPE_RESTART_ACK, "Restart ACK" },
715 { MSG_TYPE_STATUS, "Status Reply" },
716 { MSG_TYPE_STATUS_ENQ, "Status Enquiry" },
717 { 0, NULL }
718 };
719
720 #define IE_IS_SINGLE_OCTET(iecode) ((iecode) & 0x80)
721 #define IE_IS_SHIFT(iecode) (((iecode) & 0xF0) == 0x90)
722 #define IE_SHIFT_IS_NON_LOCKING(iecode) ((iecode) & 0x08)
723 #define IE_SHIFT_IS_LOCKING(iecode) (!(IE_SHIFT_IS_NON_LOCKING(iecode)))
724 #define IE_SHIFT_CODESET(iecode) ((iecode) & 0x07)
725
726 #define FR_LMI_ANSI_REPORT_TYPE_IE 0x01
727 #define FR_LMI_ANSI_LINK_VERIFY_IE_91 0x19 /* details? */
728 #define FR_LMI_ANSI_LINK_VERIFY_IE 0x03
729 #define FR_LMI_ANSI_PVC_STATUS_IE 0x07
730
731 #define FR_LMI_CCITT_REPORT_TYPE_IE 0x51
732 #define FR_LMI_CCITT_LINK_VERIFY_IE 0x53
733 #define FR_LMI_CCITT_PVC_STATUS_IE 0x57
734
735 static const struct tok fr_q933_ie_values_codeset_0_5[] = {
736 { FR_LMI_ANSI_REPORT_TYPE_IE, "ANSI Report Type" },
737 { FR_LMI_ANSI_LINK_VERIFY_IE_91, "ANSI Link Verify" },
738 { FR_LMI_ANSI_LINK_VERIFY_IE, "ANSI Link Verify" },
739 { FR_LMI_ANSI_PVC_STATUS_IE, "ANSI PVC Status" },
740 { FR_LMI_CCITT_REPORT_TYPE_IE, "CCITT Report Type" },
741 { FR_LMI_CCITT_LINK_VERIFY_IE, "CCITT Link Verify" },
742 { FR_LMI_CCITT_PVC_STATUS_IE, "CCITT PVC Status" },
743 { 0, NULL }
744 };
745
746 #define FR_LMI_REPORT_TYPE_IE_FULL_STATUS 0
747 #define FR_LMI_REPORT_TYPE_IE_LINK_VERIFY 1
748 #define FR_LMI_REPORT_TYPE_IE_ASYNC_PVC 2
749
750 static const struct tok fr_lmi_report_type_ie_values[] = {
751 { FR_LMI_REPORT_TYPE_IE_FULL_STATUS, "Full Status" },
752 { FR_LMI_REPORT_TYPE_IE_LINK_VERIFY, "Link verify" },
753 { FR_LMI_REPORT_TYPE_IE_ASYNC_PVC, "Async PVC Status" },
754 { 0, NULL }
755 };
756
757 /* array of 16 codesets - currently we only support codepage 0 and 5 */
758 static const struct tok *fr_q933_ie_codesets[] = {
759 fr_q933_ie_values_codeset_0_5,
760 NULL,
761 NULL,
762 NULL,
763 NULL,
764 fr_q933_ie_values_codeset_0_5,
765 NULL,
766 NULL,
767 NULL,
768 NULL,
769 NULL,
770 NULL,
771 NULL,
772 NULL,
773 NULL,
774 NULL
775 };
776
777 static int fr_q933_print_ie_codeset_0_5(netdissect_options *ndo, u_int iecode,
778 u_int ielength, const u_char *p);
779
780 typedef int (*codeset_pr_func_t)(netdissect_options *, u_int iecode,
781 u_int ielength, const u_char *p);
782
783 /* array of 16 codesets - currently we only support codepage 0 and 5 */
784 static const codeset_pr_func_t fr_q933_print_ie_codeset[] = {
785 fr_q933_print_ie_codeset_0_5,
786 NULL,
787 NULL,
788 NULL,
789 NULL,
790 fr_q933_print_ie_codeset_0_5,
791 NULL,
792 NULL,
793 NULL,
794 NULL,
795 NULL,
796 NULL,
797 NULL,
798 NULL,
799 NULL,
800 NULL
801 };
802
803 /*
804 * ITU-T Q.933.
805 *
806 * p points to octet 2, the octet containing the length of the
807 * call reference value, so p[n] is octet n+2 ("octet X" is as
808 * used in Q.931/Q.933).
809 *
810 * XXX - actually used both for Q.931 and Q.933.
811 */
812 void
813 q933_print(netdissect_options *ndo,
814 const u_char *p, u_int length)
815 {
816 u_int olen;
817 u_int call_ref_length, i;
818 uint8_t call_ref[15]; /* maximum length - length field is 4 bits */
819 u_int msgtype;
820 u_int iecode;
821 u_int ielength;
822 u_int codeset = 0;
823 u_int is_ansi = 0;
824 u_int ie_is_known;
825 u_int non_locking_shift;
826 u_int unshift_codeset;
827
828 ndo->ndo_protocol = "q.933";
829 ND_PRINT("%s", ndo->ndo_eflag ? "" : "Q.933");
830
831 if (length == 0 || !ND_TTEST_1(p)) {
832 if (!ndo->ndo_eflag)
833 ND_PRINT(", ");
834 ND_PRINT("length %u", length);
835 goto trunc;
836 }
837
838 /*
839 * Get the length of the call reference value.
840 */
841 olen = length; /* preserve the original length for display */
842 call_ref_length = GET_U_1(p) & 0x0f;
843 p++;
844 length--;
845
846 /*
847 * Get the call reference value.
848 */
849 for (i = 0; i < call_ref_length; i++) {
850 if (length == 0 || !ND_TTEST_1(p)) {
851 if (!ndo->ndo_eflag)
852 ND_PRINT(", ");
853 ND_PRINT("length %u", olen);
854 goto trunc;
855 }
856 call_ref[i] = GET_U_1(p);
857 p++;
858 length--;
859 }
860
861 /*
862 * Get the message type.
863 */
864 if (length == 0 || !ND_TTEST_1(p)) {
865 if (!ndo->ndo_eflag)
866 ND_PRINT(", ");
867 ND_PRINT("length %u", olen);
868 goto trunc;
869 }
870 msgtype = GET_U_1(p);
871 p++;
872 length--;
873
874 /*
875 * Peek ahead to see if we start with a shift.
876 */
877 non_locking_shift = 0;
878 unshift_codeset = codeset;
879 if (length != 0) {
880 if (!ND_TTEST_1(p)) {
881 if (!ndo->ndo_eflag)
882 ND_PRINT(", ");
883 ND_PRINT("length %u", olen);
884 goto trunc;
885 }
886 iecode = GET_U_1(p);
887 if (IE_IS_SHIFT(iecode)) {
888 /*
889 * It's a shift. Skip over it.
890 */
891 p++;
892 length--;
893
894 /*
895 * Get the codeset.
896 */
897 codeset = IE_SHIFT_CODESET(iecode);
898
899 /*
900 * If it's a locking shift to codeset 5,
901 * mark this as ANSI. (XXX - 5 is actually
902 * for national variants in general, not
903 * the US variant in particular, but maybe
904 * this is more American exceptionalism. :-))
905 */
906 if (IE_SHIFT_IS_LOCKING(iecode)) {
907 /*
908 * It's a locking shift.
909 */
910 if (codeset == 5) {
911 /*
912 * It's a locking shift to
913 * codeset 5, so this is
914 * T1.617 Annex D.
915 */
916 is_ansi = 1;
917 }
918 } else {
919 /*
920 * It's a non-locking shift.
921 * Remember the current codeset, so we
922 * can revert to it after the next IE.
923 */
924 non_locking_shift = 1;
925 unshift_codeset = 0;
926 }
927 }
928 }
929
930 /* printing out header part */
931 if (!ndo->ndo_eflag)
932 ND_PRINT(", ");
933 ND_PRINT("%s, codeset %u", is_ansi ? "ANSI" : "CCITT", codeset);
934
935 if (call_ref_length != 0) {
936 if (call_ref_length > 1 || GET_U_1(p) != 0) {
937 /*
938 * Not a dummy call reference.
939 */
940 ND_PRINT(", Call Ref: 0x");
941 for (i = 0; i < call_ref_length; i++)
942 ND_PRINT("%02x", call_ref[i]);
943 }
944 }
945 if (ndo->ndo_vflag) {
946 ND_PRINT(", %s (0x%02x), length %u",
947 tok2str(fr_q933_msg_values,
948 "unknown message", msgtype),
949 msgtype,
950 olen);
951 } else {
952 ND_PRINT(", %s",
953 tok2str(fr_q933_msg_values,
954 "unknown message 0x%02x", msgtype));
955 }
956
957 /* Loop through the rest of the IEs */
958 while (length != 0) {
959 /*
960 * What's the state of any non-locking shifts?
961 */
962 if (non_locking_shift == 1) {
963 /*
964 * There's a non-locking shift in effect for
965 * this IE. Count it, so we reset the codeset
966 * before the next IE.
967 */
968 non_locking_shift = 2;
969 } else if (non_locking_shift == 2) {
970 /*
971 * Unshift.
972 */
973 codeset = unshift_codeset;
974 non_locking_shift = 0;
975 }
976
977 /*
978 * Get the first octet of the IE.
979 */
980 if (!ND_TTEST_1(p)) {
981 if (!ndo->ndo_vflag) {
982 ND_PRINT(", length %u", olen);
983 }
984 goto trunc;
985 }
986 iecode = GET_U_1(p);
987 p++;
988 length--;
989
990 /* Single-octet IE? */
991 if (IE_IS_SINGLE_OCTET(iecode)) {
992 /*
993 * Yes. Is it a shift?
994 */
995 if (IE_IS_SHIFT(iecode)) {
996 /*
997 * Yes. Is it locking?
998 */
999 if (IE_SHIFT_IS_LOCKING(iecode)) {
1000 /*
1001 * Yes.
1002 */
1003 non_locking_shift = 0;
1004 } else {
1005 /*
1006 * No. Remember the current
1007 * codeset, so we can revert
1008 * to it after the next IE.
1009 */
1010 non_locking_shift = 1;
1011 unshift_codeset = codeset;
1012 }
1013
1014 /*
1015 * Get the codeset.
1016 */
1017 codeset = IE_SHIFT_CODESET(iecode);
1018 }
1019 } else {
1020 /*
1021 * No. Get the IE length.
1022 */
1023 if (length == 0 || !ND_TTEST_1(p)) {
1024 if (!ndo->ndo_vflag) {
1025 ND_PRINT(", length %u", olen);
1026 }
1027 goto trunc;
1028 }
1029 ielength = GET_U_1(p);
1030 p++;
1031 length--;
1032
1033 /* lets do the full IE parsing only in verbose mode
1034 * however some IEs (DLCI Status, Link Verify)
1035 * are also interesting in non-verbose mode */
1036 if (ndo->ndo_vflag) {
1037 ND_PRINT("\n\t%s IE (0x%02x), length %u: ",
1038 tok2str(fr_q933_ie_codesets[codeset],
1039 "unknown", iecode),
1040 iecode,
1041 ielength);
1042 }
1043
1044 /* sanity checks */
1045 if (iecode == 0 || ielength == 0) {
1046 return;
1047 }
1048 if (length < ielength || !ND_TTEST_LEN(p, ielength)) {
1049 if (!ndo->ndo_vflag) {
1050 ND_PRINT(", length %u", olen);
1051 }
1052 goto trunc;
1053 }
1054
1055 ie_is_known = 0;
1056 if (fr_q933_print_ie_codeset[codeset] != NULL) {
1057 ie_is_known = fr_q933_print_ie_codeset[codeset](ndo, iecode, ielength, p);
1058 }
1059
1060 if (ie_is_known) {
1061 /*
1062 * Known IE; do we want to see a hexdump
1063 * of it?
1064 */
1065 if (ndo->ndo_vflag > 1) {
1066 /* Yes. */
1067 print_unknown_data(ndo, p, "\n\t ", ielength);
1068 }
1069 } else {
1070 /*
1071 * Unknown IE; if we're printing verbosely,
1072 * print its content in hex.
1073 */
1074 if (ndo->ndo_vflag >= 1) {
1075 print_unknown_data(ndo, p, "\n\t", ielength);
1076 }
1077 }
1078
1079 length -= ielength;
1080 p += ielength;
1081 }
1082 }
1083 if (!ndo->ndo_vflag) {
1084 ND_PRINT(", length %u", olen);
1085 }
1086 return;
1087
1088 trunc:
1089 nd_print_trunc(ndo);
1090 }
1091
1092 static int
1093 fr_q933_print_ie_codeset_0_5(netdissect_options *ndo, u_int iecode,
1094 u_int ielength, const u_char *p)
1095 {
1096 u_int dlci;
1097
1098 switch (iecode) {
1099
1100 case FR_LMI_ANSI_REPORT_TYPE_IE: /* fall through */
1101 case FR_LMI_CCITT_REPORT_TYPE_IE:
1102 if (ielength < 1) {
1103 if (!ndo->ndo_vflag) {
1104 ND_PRINT(", ");
1105 }
1106 ND_PRINT("Invalid REPORT TYPE IE");
1107 return 1;
1108 }
1109 if (ndo->ndo_vflag) {
1110 ND_PRINT("%s (%u)",
1111 tok2str(fr_lmi_report_type_ie_values,"unknown",GET_U_1(p)),
1112 GET_U_1(p));
1113 }
1114 return 1;
1115
1116 case FR_LMI_ANSI_LINK_VERIFY_IE: /* fall through */
1117 case FR_LMI_CCITT_LINK_VERIFY_IE:
1118 case FR_LMI_ANSI_LINK_VERIFY_IE_91:
1119 if (!ndo->ndo_vflag) {
1120 ND_PRINT(", ");
1121 }
1122 if (ielength < 2) {
1123 ND_PRINT("Invalid LINK VERIFY IE");
1124 return 1;
1125 }
1126 ND_PRINT("TX Seq: %3d, RX Seq: %3d", GET_U_1(p), GET_U_1(p + 1));
1127 return 1;
1128
1129 case FR_LMI_ANSI_PVC_STATUS_IE: /* fall through */
1130 case FR_LMI_CCITT_PVC_STATUS_IE:
1131 if (!ndo->ndo_vflag) {
1132 ND_PRINT(", ");
1133 }
1134 /* now parse the DLCI information element. */
1135 if ((ielength < 3) ||
1136 (GET_U_1(p) & 0x80) ||
1137 ((ielength == 3) && !(GET_U_1(p + 1) & 0x80)) ||
1138 ((ielength == 4) &&
1139 ((GET_U_1(p + 1) & 0x80) || !(GET_U_1(p + 2) & 0x80))) ||
1140 ((ielength == 5) &&
1141 ((GET_U_1(p + 1) & 0x80) || (GET_U_1(p + 2) & 0x80) ||
1142 !(GET_U_1(p + 3) & 0x80))) ||
1143 (ielength > 5) ||
1144 !(GET_U_1(p + ielength - 1) & 0x80)) {
1145 ND_PRINT("Invalid DLCI in PVC STATUS IE");
1146 return 1;
1147 }
1148
1149 dlci = ((GET_U_1(p) & 0x3F) << 4) | ((GET_U_1(p + 1) & 0x78) >> 3);
1150 if (ielength == 4) {
1151 dlci = (dlci << 6) | ((GET_U_1(p + 2) & 0x7E) >> 1);
1152 } else if (ielength == 5) {
1153 dlci = (dlci << 13) | (GET_U_1(p + 2) & 0x7F) | ((GET_U_1(p + 3) & 0x7E) >> 1);
1154 }
1155
1156 ND_PRINT("DLCI %u: status %s%s", dlci,
1157 GET_U_1(p + ielength - 1) & 0x8 ? "New, " : "",
1158 GET_U_1(p + ielength - 1) & 0x2 ? "Active" : "Inactive");
1159 return 1;
1160 }
1161
1162 return 0;
1163 }
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