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Use more ND_TCHECK_n()/ND_TTEST_n() macros
[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 #include "oui.h"
40
41 static void frf15_print(netdissect_options *ndo, const u_char *, u_int);
42
43 /*
44 * the frame relay header has a variable length
45 *
46 * the EA bit determines if there is another byte
47 * in the header
48 *
49 * minimum header length is 2 bytes
50 * maximum header length is 4 bytes
51 *
52 * 7 6 5 4 3 2 1 0
53 * +----+----+----+----+----+----+----+----+
54 * | DLCI (6 bits) | CR | EA |
55 * +----+----+----+----+----+----+----+----+
56 * | DLCI (4 bits) |FECN|BECN| DE | EA |
57 * +----+----+----+----+----+----+----+----+
58 * | DLCI (7 bits) | EA |
59 * +----+----+----+----+----+----+----+----+
60 * | DLCI (6 bits) |SDLC| EA |
61 * +----+----+----+----+----+----+----+----+
62 */
63
64 #define FR_EA_BIT 0x01
65
66 #define FR_CR_BIT 0x02000000
67 #define FR_DE_BIT 0x00020000
68 #define FR_BECN_BIT 0x00040000
69 #define FR_FECN_BIT 0x00080000
70 #define FR_SDLC_BIT 0x00000002
71
72
73 static const struct tok fr_header_flag_values[] = {
74 { FR_CR_BIT, "C!" },
75 { FR_DE_BIT, "DE" },
76 { FR_BECN_BIT, "BECN" },
77 { FR_FECN_BIT, "FECN" },
78 { FR_SDLC_BIT, "sdlcore" },
79 { 0, NULL }
80 };
81
82 /* FRF.15 / FRF.16 */
83 #define MFR_B_BIT 0x80
84 #define MFR_E_BIT 0x40
85 #define MFR_C_BIT 0x20
86 #define MFR_BEC_MASK (MFR_B_BIT | MFR_E_BIT | MFR_C_BIT)
87 #define MFR_CTRL_FRAME (MFR_B_BIT | MFR_E_BIT | MFR_C_BIT)
88 #define MFR_FRAG_FRAME (MFR_B_BIT | MFR_E_BIT )
89
90 static const struct tok frf_flag_values[] = {
91 { MFR_B_BIT, "Begin" },
92 { MFR_E_BIT, "End" },
93 { MFR_C_BIT, "Control" },
94 { 0, NULL }
95 };
96
97 /* Finds out Q.922 address length, DLCI and flags. Returns 1 on success,
98 * 0 on invalid address, -1 on truncated packet
99 * save the flags dep. on address length
100 */
101 static int parse_q922_addr(netdissect_options *ndo,
102 const u_char *p, u_int *dlci,
103 u_int *addr_len, uint8_t *flags, u_int length)
104 {
105 if (!ND_TTEST_1(p) || length < 1)
106 return -1;
107 if ((EXTRACT_U_1(p) & FR_EA_BIT))
108 return 0;
109
110 if (!ND_TTEST_1(p + 1) || length < 2)
111 return -1;
112 *addr_len = 2;
113 *dlci = ((EXTRACT_U_1(p) & 0xFC) << 2) | ((EXTRACT_U_1(p + 1) & 0xF0) >> 4);
114
115 flags[0] = EXTRACT_U_1(p) & 0x02; /* populate the first flag fields */
116 flags[1] = EXTRACT_U_1(p + 1) & 0x0c;
117 flags[2] = 0; /* clear the rest of the flags */
118 flags[3] = 0;
119
120 if (EXTRACT_U_1(p + 1) & FR_EA_BIT)
121 return 1; /* 2-byte Q.922 address */
122
123 p += 2;
124 length -= 2;
125 if (!ND_TTEST_1(p) || length < 1)
126 return -1;
127 (*addr_len)++; /* 3- or 4-byte Q.922 address */
128 if ((EXTRACT_U_1(p) & FR_EA_BIT) == 0) {
129 *dlci = (*dlci << 7) | (EXTRACT_U_1(p) >> 1);
130 (*addr_len)++; /* 4-byte Q.922 address */
131 p++;
132 length--;
133 }
134
135 if (!ND_TTEST_1(p) || length < 1)
136 return -1;
137 if ((EXTRACT_U_1(p) & FR_EA_BIT) == 0)
138 return 0; /* more than 4 bytes of Q.922 address? */
139
140 flags[3] = EXTRACT_U_1(p) & 0x02;
141
142 *dlci = (*dlci << 6) | (EXTRACT_U_1(p) >> 2);
143
144 return 1;
145 }
146
147 char *
148 q922_string(netdissect_options *ndo, const u_char *p, u_int length)
149 {
150
151 static u_int dlci, addr_len;
152 static uint8_t flags[4];
153 static char buffer[sizeof("DLCI xxxxxxxxxx")];
154 memset(buffer, 0, sizeof(buffer));
155
156 if (parse_q922_addr(ndo, p, &dlci, &addr_len, flags, length) == 1){
157 snprintf(buffer, sizeof(buffer), "DLCI %u", dlci);
158 }
159
160 return buffer;
161 }
162
163
164 /* Frame Relay packet structure, with flags and CRC removed
165
166 +---------------------------+
167 | Q.922 Address* |
168 +-- --+
169 | |
170 +---------------------------+
171 | Control (UI = 0x03) |
172 +---------------------------+
173 | Optional Pad (0x00) |
174 +---------------------------+
175 | NLPID |
176 +---------------------------+
177 | . |
178 | . |
179 | . |
180 | Data |
181 | . |
182 | . |
183 +---------------------------+
184
185 * Q.922 addresses, as presently defined, are two octets and
186 contain a 10-bit DLCI. In some networks Q.922 addresses
187 may optionally be increased to three or four octets.
188 */
189
190 static void
191 fr_hdr_print(netdissect_options *ndo,
192 int length, u_int addr_len, u_int dlci, uint8_t *flags, uint16_t nlpid)
193 {
194 if (ndo->ndo_qflag) {
195 ND_PRINT((ndo, "Q.922, DLCI %u, length %u: ",
196 dlci,
197 length));
198 } else {
199 if (nlpid <= 0xff) /* if its smaller than 256 then its a NLPID */
200 ND_PRINT((ndo, "Q.922, hdr-len %u, DLCI %u, Flags [%s], NLPID %s (0x%02x), length %u: ",
201 addr_len,
202 dlci,
203 bittok2str(fr_header_flag_values, "none", EXTRACT_BE_U_4(flags)),
204 tok2str(nlpid_values,"unknown", nlpid),
205 nlpid,
206 length));
207 else /* must be an ethertype */
208 ND_PRINT((ndo, "Q.922, hdr-len %u, DLCI %u, Flags [%s], cisco-ethertype %s (0x%04x), length %u: ",
209 addr_len,
210 dlci,
211 bittok2str(fr_header_flag_values, "none", EXTRACT_BE_U_4(flags)),
212 tok2str(ethertype_values, "unknown", nlpid),
213 nlpid,
214 length));
215 }
216 }
217
218 u_int
219 fr_if_print(netdissect_options *ndo,
220 const struct pcap_pkthdr *h, register const u_char *p)
221 {
222 register u_int length = h->len;
223 register u_int caplen = h->caplen;
224
225 ND_TCHECK_4(p); /* minimum frame header length */
226
227 if ((length = fr_print(ndo, p, length)) == 0)
228 return (0);
229 else
230 return length;
231 trunc:
232 ND_PRINT((ndo, "[|fr]"));
233 return caplen;
234 }
235
236 u_int
237 fr_print(netdissect_options *ndo,
238 register const u_char *p, u_int length)
239 {
240 int ret;
241 uint16_t extracted_ethertype;
242 u_int dlci;
243 u_int addr_len;
244 uint16_t nlpid;
245 u_int hdr_len;
246 uint8_t flags[4];
247
248 ret = parse_q922_addr(ndo, p, &dlci, &addr_len, flags, length);
249 if (ret == -1)
250 goto trunc;
251 if (ret == 0) {
252 ND_PRINT((ndo, "Q.922, invalid address"));
253 return 0;
254 }
255
256 ND_TCHECK_1(p + addr_len);
257 if (length < addr_len + 1)
258 goto trunc;
259
260 if (EXTRACT_U_1(p + addr_len) != LLC_UI && dlci != 0) {
261 /*
262 * Let's figure out if we have Cisco-style encapsulation,
263 * with an Ethernet type (Cisco HDLC type?) following the
264 * address.
265 */
266 if (!ND_TTEST_2(p + addr_len) || length < addr_len + 2) {
267 /* no Ethertype */
268 ND_PRINT((ndo, "UI %02x! ", EXTRACT_U_1(p + addr_len)));
269 } else {
270 extracted_ethertype = EXTRACT_BE_U_2(p + addr_len);
271
272 if (ndo->ndo_eflag)
273 fr_hdr_print(ndo, length, addr_len, dlci,
274 flags, extracted_ethertype);
275
276 if (ethertype_print(ndo, extracted_ethertype,
277 p+addr_len+ETHERTYPE_LEN,
278 length-addr_len-ETHERTYPE_LEN,
279 ndo->ndo_snapend-p-addr_len-ETHERTYPE_LEN,
280 NULL, NULL) == 0)
281 /* ether_type not known, probably it wasn't one */
282 ND_PRINT((ndo, "UI %02x! ", EXTRACT_U_1(p + addr_len)));
283 else
284 return addr_len + 2;
285 }
286 }
287
288 ND_TCHECK_1(p + addr_len + 1);
289 if (length < addr_len + 2)
290 goto trunc;
291
292 if (EXTRACT_U_1(p + addr_len + 1) == 0) {
293 /*
294 * Assume a pad byte after the control (UI) byte.
295 * A pad byte should only be used with 3-byte Q.922.
296 */
297 if (addr_len != 3)
298 ND_PRINT((ndo, "Pad! "));
299 hdr_len = addr_len + 1 /* UI */ + 1 /* pad */ + 1 /* NLPID */;
300 } else {
301 /*
302 * Not a pad byte.
303 * A pad byte should be used with 3-byte Q.922.
304 */
305 if (addr_len == 3)
306 ND_PRINT((ndo, "No pad! "));
307 hdr_len = addr_len + 1 /* UI */ + 1 /* NLPID */;
308 }
309
310 ND_TCHECK_1(p + hdr_len - 1);
311 if (length < hdr_len)
312 goto trunc;
313 nlpid = EXTRACT_U_1(p + hdr_len - 1);
314
315 if (ndo->ndo_eflag)
316 fr_hdr_print(ndo, length, addr_len, dlci, flags, nlpid);
317 p += hdr_len;
318 length -= hdr_len;
319
320 switch (nlpid) {
321 case NLPID_IP:
322 ip_print(ndo, p, length);
323 break;
324
325 case NLPID_IP6:
326 ip6_print(ndo, p, length);
327 break;
328
329 case NLPID_CLNP:
330 case NLPID_ESIS:
331 case NLPID_ISIS:
332 isoclns_print(ndo, p - 1, length + 1); /* OSI printers need the NLPID field */
333 break;
334
335 case NLPID_SNAP:
336 if (snap_print(ndo, p, length, ndo->ndo_snapend - p, NULL, NULL, 0) == 0) {
337 /* ether_type not known, print raw packet */
338 if (!ndo->ndo_eflag)
339 fr_hdr_print(ndo, length + hdr_len, hdr_len,
340 dlci, flags, nlpid);
341 if (!ndo->ndo_suppress_default_print)
342 ND_DEFAULTPRINT(p - hdr_len, length + hdr_len);
343 }
344 break;
345
346 case NLPID_Q933:
347 q933_print(ndo, p, length);
348 break;
349
350 case NLPID_MFR:
351 frf15_print(ndo, p, length);
352 break;
353
354 case NLPID_PPP:
355 ppp_print(ndo, p, length);
356 break;
357
358 default:
359 if (!ndo->ndo_eflag)
360 fr_hdr_print(ndo, length + hdr_len, addr_len,
361 dlci, flags, nlpid);
362 if (!ndo->ndo_xflag)
363 ND_DEFAULTPRINT(p, length);
364 }
365
366 return hdr_len;
367
368 trunc:
369 ND_PRINT((ndo, "[|fr]"));
370 return 0;
371
372 }
373
374 u_int
375 mfr_if_print(netdissect_options *ndo,
376 const struct pcap_pkthdr *h, register const u_char *p)
377 {
378 register u_int length = h->len;
379 register u_int caplen = h->caplen;
380
381 ND_TCHECK_2(p); /* minimum frame header length */
382
383 if ((length = mfr_print(ndo, p, length)) == 0)
384 return (0);
385 else
386 return length;
387 trunc:
388 ND_PRINT((ndo, "[|mfr]"));
389 return caplen;
390 }
391
392
393 #define MFR_CTRL_MSG_ADD_LINK 1
394 #define MFR_CTRL_MSG_ADD_LINK_ACK 2
395 #define MFR_CTRL_MSG_ADD_LINK_REJ 3
396 #define MFR_CTRL_MSG_HELLO 4
397 #define MFR_CTRL_MSG_HELLO_ACK 5
398 #define MFR_CTRL_MSG_REMOVE_LINK 6
399 #define MFR_CTRL_MSG_REMOVE_LINK_ACK 7
400
401 static const struct tok mfr_ctrl_msg_values[] = {
402 { MFR_CTRL_MSG_ADD_LINK, "Add Link" },
403 { MFR_CTRL_MSG_ADD_LINK_ACK, "Add Link ACK" },
404 { MFR_CTRL_MSG_ADD_LINK_REJ, "Add Link Reject" },
405 { MFR_CTRL_MSG_HELLO, "Hello" },
406 { MFR_CTRL_MSG_HELLO_ACK, "Hello ACK" },
407 { MFR_CTRL_MSG_REMOVE_LINK, "Remove Link" },
408 { MFR_CTRL_MSG_REMOVE_LINK_ACK, "Remove Link ACK" },
409 { 0, NULL }
410 };
411
412 #define MFR_CTRL_IE_BUNDLE_ID 1
413 #define MFR_CTRL_IE_LINK_ID 2
414 #define MFR_CTRL_IE_MAGIC_NUM 3
415 #define MFR_CTRL_IE_TIMESTAMP 5
416 #define MFR_CTRL_IE_VENDOR_EXT 6
417 #define MFR_CTRL_IE_CAUSE 7
418
419 static const struct tok mfr_ctrl_ie_values[] = {
420 { MFR_CTRL_IE_BUNDLE_ID, "Bundle ID"},
421 { MFR_CTRL_IE_LINK_ID, "Link ID"},
422 { MFR_CTRL_IE_MAGIC_NUM, "Magic Number"},
423 { MFR_CTRL_IE_TIMESTAMP, "Timestamp"},
424 { MFR_CTRL_IE_VENDOR_EXT, "Vendor Extension"},
425 { MFR_CTRL_IE_CAUSE, "Cause"},
426 { 0, NULL }
427 };
428
429 #define MFR_ID_STRING_MAXLEN 50
430
431 struct ie_tlv_header_t {
432 uint8_t ie_type;
433 uint8_t ie_len;
434 };
435
436 u_int
437 mfr_print(netdissect_options *ndo,
438 register const u_char *p, u_int length)
439 {
440 u_int tlen,idx,hdr_len = 0;
441 uint16_t sequence_num;
442 uint8_t ie_type,ie_len;
443 const uint8_t *tptr;
444
445
446 /*
447 * FRF.16 Link Integrity Control Frame
448 *
449 * 7 6 5 4 3 2 1 0
450 * +----+----+----+----+----+----+----+----+
451 * | B | E | C=1| 0 0 0 0 | EA |
452 * +----+----+----+----+----+----+----+----+
453 * | 0 0 0 0 0 0 0 0 |
454 * +----+----+----+----+----+----+----+----+
455 * | message type |
456 * +----+----+----+----+----+----+----+----+
457 */
458
459 ND_TCHECK_4(p); /* minimum frame header length */
460
461 if ((EXTRACT_U_1(p) & MFR_BEC_MASK) == MFR_CTRL_FRAME && EXTRACT_U_1(p + 1) == 0) {
462 ND_PRINT((ndo, "FRF.16 Control, Flags [%s], %s, length %u",
463 bittok2str(frf_flag_values,"none",(EXTRACT_U_1(p) & MFR_BEC_MASK)),
464 tok2str(mfr_ctrl_msg_values,"Unknown Message (0x%02x)",EXTRACT_U_1(p + 2)),
465 length));
466 tptr = p + 3;
467 tlen = length -3;
468 hdr_len = 3;
469
470 if (!ndo->ndo_vflag)
471 return hdr_len;
472
473 while (tlen>sizeof(struct ie_tlv_header_t)) {
474 ND_TCHECK2(*tptr, sizeof(struct ie_tlv_header_t));
475 ie_type=tptr[0];
476 ie_len=tptr[1];
477
478 ND_PRINT((ndo, "\n\tIE %s (%u), length %u: ",
479 tok2str(mfr_ctrl_ie_values,"Unknown",ie_type),
480 ie_type,
481 ie_len));
482
483 /* infinite loop check */
484 if (ie_type == 0 || ie_len <= sizeof(struct ie_tlv_header_t))
485 return hdr_len;
486
487 ND_TCHECK2(*tptr, ie_len);
488 tptr+=sizeof(struct ie_tlv_header_t);
489 /* tlv len includes header */
490 ie_len-=sizeof(struct ie_tlv_header_t);
491 tlen-=sizeof(struct ie_tlv_header_t);
492
493 switch (ie_type) {
494
495 case MFR_CTRL_IE_MAGIC_NUM:
496 ND_PRINT((ndo, "0x%08x", EXTRACT_BE_U_4(tptr)));
497 break;
498
499 case MFR_CTRL_IE_BUNDLE_ID: /* same message format */
500 case MFR_CTRL_IE_LINK_ID:
501 for (idx = 0; idx < ie_len && idx < MFR_ID_STRING_MAXLEN; idx++) {
502 if (*(tptr+idx) != 0) /* don't print null termination */
503 safeputchar(ndo, *(tptr + idx));
504 else
505 break;
506 }
507 break;
508
509 case MFR_CTRL_IE_TIMESTAMP:
510 if (ie_len == sizeof(struct timeval)) {
511 ts_print(ndo, (const struct timeval *)tptr);
512 break;
513 }
514 /* fall through and hexdump if no unix timestamp */
515 ND_FALL_THROUGH;
516
517 /*
518 * FIXME those are the defined IEs that lack a decoder
519 * you are welcome to contribute code ;-)
520 */
521
522 case MFR_CTRL_IE_VENDOR_EXT:
523 case MFR_CTRL_IE_CAUSE:
524
525 default:
526 if (ndo->ndo_vflag <= 1)
527 print_unknown_data(ndo, tptr, "\n\t ", ie_len);
528 break;
529 }
530
531 /* do we want to see a hexdump of the IE ? */
532 if (ndo->ndo_vflag > 1 )
533 print_unknown_data(ndo, tptr, "\n\t ", ie_len);
534
535 tlen-=ie_len;
536 tptr+=ie_len;
537 }
538 return hdr_len;
539 }
540 /*
541 * FRF.16 Fragmentation Frame
542 *
543 * 7 6 5 4 3 2 1 0
544 * +----+----+----+----+----+----+----+----+
545 * | B | E | C=0|seq. (high 4 bits) | EA |
546 * +----+----+----+----+----+----+----+----+
547 * | sequence (low 8 bits) |
548 * +----+----+----+----+----+----+----+----+
549 * | DLCI (6 bits) | CR | EA |
550 * +----+----+----+----+----+----+----+----+
551 * | DLCI (4 bits) |FECN|BECN| DE | EA |
552 * +----+----+----+----+----+----+----+----+
553 */
554
555 sequence_num = (EXTRACT_U_1(p)&0x1e)<<7 | EXTRACT_U_1(p + 1);
556 /* whole packet or first fragment ? */
557 if ((EXTRACT_U_1(p) & MFR_BEC_MASK) == MFR_FRAG_FRAME ||
558 (EXTRACT_U_1(p) & MFR_BEC_MASK) == MFR_B_BIT) {
559 ND_PRINT((ndo, "FRF.16 Frag, seq %u, Flags [%s], ",
560 sequence_num,
561 bittok2str(frf_flag_values,"none",(EXTRACT_U_1(p) & MFR_BEC_MASK))));
562 hdr_len = 2;
563 fr_print(ndo, p+hdr_len,length-hdr_len);
564 return hdr_len;
565 }
566
567 /* must be a middle or the last fragment */
568 ND_PRINT((ndo, "FRF.16 Frag, seq %u, Flags [%s]",
569 sequence_num,
570 bittok2str(frf_flag_values,"none",(EXTRACT_U_1(p) & MFR_BEC_MASK))));
571 print_unknown_data(ndo, p, "\n\t", length);
572
573 return hdr_len;
574
575 trunc:
576 ND_PRINT((ndo, "[|mfr]"));
577 return length;
578 }
579
580 /* an NLPID of 0xb1 indicates a 2-byte
581 * FRF.15 header
582 *
583 * 7 6 5 4 3 2 1 0
584 * +----+----+----+----+----+----+----+----+
585 * ~ Q.922 header ~
586 * +----+----+----+----+----+----+----+----+
587 * | NLPID (8 bits) | NLPID=0xb1
588 * +----+----+----+----+----+----+----+----+
589 * | B | E | C |seq. (high 4 bits) | R |
590 * +----+----+----+----+----+----+----+----+
591 * | sequence (low 8 bits) |
592 * +----+----+----+----+----+----+----+----+
593 */
594
595 #define FR_FRF15_FRAGTYPE 0x01
596
597 static void
598 frf15_print(netdissect_options *ndo,
599 const u_char *p, u_int length)
600 {
601 uint16_t sequence_num, flags;
602
603 if (length < 2)
604 goto trunc;
605 ND_TCHECK_2(p);
606
607 flags = EXTRACT_U_1(p)&MFR_BEC_MASK;
608 sequence_num = (EXTRACT_U_1(p)&0x1e)<<7 | EXTRACT_U_1(p + 1);
609
610 ND_PRINT((ndo, "FRF.15, seq 0x%03x, Flags [%s],%s Fragmentation, length %u",
611 sequence_num,
612 bittok2str(frf_flag_values,"none",flags),
613 EXTRACT_U_1(p)&FR_FRF15_FRAGTYPE ? "Interface" : "End-to-End",
614 length));
615
616 /* TODO:
617 * depending on all permutations of the B, E and C bit
618 * dig as deep as we can - e.g. on the first (B) fragment
619 * there is enough payload to print the IP header
620 * on non (B) fragments it depends if the fragmentation
621 * model is end-to-end or interface based wether we want to print
622 * another Q.922 header
623 */
624 return;
625
626 trunc:
627 ND_PRINT((ndo, "[|frf.15]"));
628 }
629
630 /*
631 * Q.933 decoding portion for framerelay specific.
632 */
633
634 /* Q.933 packet format
635 Format of Other Protocols
636 using Q.933 NLPID
637 +-------------------------------+
638 | Q.922 Address |
639 +---------------+---------------+
640 |Control 0x03 | NLPID 0x08 |
641 +---------------+---------------+
642 | L2 Protocol ID |
643 | octet 1 | octet 2 |
644 +-------------------------------+
645 | L3 Protocol ID |
646 | octet 2 | octet 2 |
647 +-------------------------------+
648 | Protocol Data |
649 +-------------------------------+
650 | FCS |
651 +-------------------------------+
652 */
653
654 /* L2 (Octet 1)- Call Reference Usually is 0x0 */
655
656 /*
657 * L2 (Octet 2)- Message Types definition 1 byte long.
658 */
659 /* Call Establish */
660 #define MSG_TYPE_ESC_TO_NATIONAL 0x00
661 #define MSG_TYPE_ALERT 0x01
662 #define MSG_TYPE_CALL_PROCEEDING 0x02
663 #define MSG_TYPE_CONNECT 0x07
664 #define MSG_TYPE_CONNECT_ACK 0x0F
665 #define MSG_TYPE_PROGRESS 0x03
666 #define MSG_TYPE_SETUP 0x05
667 /* Call Clear */
668 #define MSG_TYPE_DISCONNECT 0x45
669 #define MSG_TYPE_RELEASE 0x4D
670 #define MSG_TYPE_RELEASE_COMPLETE 0x5A
671 #define MSG_TYPE_RESTART 0x46
672 #define MSG_TYPE_RESTART_ACK 0x4E
673 /* Status */
674 #define MSG_TYPE_STATUS 0x7D
675 #define MSG_TYPE_STATUS_ENQ 0x75
676
677 static const struct tok fr_q933_msg_values[] = {
678 { MSG_TYPE_ESC_TO_NATIONAL, "ESC to National" },
679 { MSG_TYPE_ALERT, "Alert" },
680 { MSG_TYPE_CALL_PROCEEDING, "Call proceeding" },
681 { MSG_TYPE_CONNECT, "Connect" },
682 { MSG_TYPE_CONNECT_ACK, "Connect ACK" },
683 { MSG_TYPE_PROGRESS, "Progress" },
684 { MSG_TYPE_SETUP, "Setup" },
685 { MSG_TYPE_DISCONNECT, "Disconnect" },
686 { MSG_TYPE_RELEASE, "Release" },
687 { MSG_TYPE_RELEASE_COMPLETE, "Release Complete" },
688 { MSG_TYPE_RESTART, "Restart" },
689 { MSG_TYPE_RESTART_ACK, "Restart ACK" },
690 { MSG_TYPE_STATUS, "Status Reply" },
691 { MSG_TYPE_STATUS_ENQ, "Status Enquiry" },
692 { 0, NULL }
693 };
694
695 #define IE_IS_SINGLE_OCTET(iecode) ((iecode) & 0x80)
696 #define IE_IS_SHIFT(iecode) (((iecode) & 0xF0) == 0x90)
697 #define IE_SHIFT_IS_NON_LOCKING(iecode) ((iecode) & 0x08)
698 #define IE_SHIFT_IS_LOCKING(iecode) (!(IE_SHIFT_IS_NON_LOCKING(iecode)))
699 #define IE_SHIFT_CODESET(iecode) ((iecode) & 0x07)
700
701 #define FR_LMI_ANSI_REPORT_TYPE_IE 0x01
702 #define FR_LMI_ANSI_LINK_VERIFY_IE_91 0x19 /* details? */
703 #define FR_LMI_ANSI_LINK_VERIFY_IE 0x03
704 #define FR_LMI_ANSI_PVC_STATUS_IE 0x07
705
706 #define FR_LMI_CCITT_REPORT_TYPE_IE 0x51
707 #define FR_LMI_CCITT_LINK_VERIFY_IE 0x53
708 #define FR_LMI_CCITT_PVC_STATUS_IE 0x57
709
710 static const struct tok fr_q933_ie_values_codeset_0_5[] = {
711 { FR_LMI_ANSI_REPORT_TYPE_IE, "ANSI Report Type" },
712 { FR_LMI_ANSI_LINK_VERIFY_IE_91, "ANSI Link Verify" },
713 { FR_LMI_ANSI_LINK_VERIFY_IE, "ANSI Link Verify" },
714 { FR_LMI_ANSI_PVC_STATUS_IE, "ANSI PVC Status" },
715 { FR_LMI_CCITT_REPORT_TYPE_IE, "CCITT Report Type" },
716 { FR_LMI_CCITT_LINK_VERIFY_IE, "CCITT Link Verify" },
717 { FR_LMI_CCITT_PVC_STATUS_IE, "CCITT PVC Status" },
718 { 0, NULL }
719 };
720
721 #define FR_LMI_REPORT_TYPE_IE_FULL_STATUS 0
722 #define FR_LMI_REPORT_TYPE_IE_LINK_VERIFY 1
723 #define FR_LMI_REPORT_TYPE_IE_ASYNC_PVC 2
724
725 static const struct tok fr_lmi_report_type_ie_values[] = {
726 { FR_LMI_REPORT_TYPE_IE_FULL_STATUS, "Full Status" },
727 { FR_LMI_REPORT_TYPE_IE_LINK_VERIFY, "Link verify" },
728 { FR_LMI_REPORT_TYPE_IE_ASYNC_PVC, "Async PVC Status" },
729 { 0, NULL }
730 };
731
732 /* array of 16 codesets - currently we only support codepage 0 and 5 */
733 static const struct tok *fr_q933_ie_codesets[] = {
734 fr_q933_ie_values_codeset_0_5,
735 NULL,
736 NULL,
737 NULL,
738 NULL,
739 fr_q933_ie_values_codeset_0_5,
740 NULL,
741 NULL,
742 NULL,
743 NULL,
744 NULL,
745 NULL,
746 NULL,
747 NULL,
748 NULL,
749 NULL
750 };
751
752 static int fr_q933_print_ie_codeset_0_5(netdissect_options *ndo, u_int iecode,
753 u_int ielength, const u_char *p);
754
755 typedef int (*codeset_pr_func_t)(netdissect_options *, u_int iecode,
756 u_int ielength, const u_char *p);
757
758 /* array of 16 codesets - currently we only support codepage 0 and 5 */
759 static const codeset_pr_func_t fr_q933_print_ie_codeset[] = {
760 fr_q933_print_ie_codeset_0_5,
761 NULL,
762 NULL,
763 NULL,
764 NULL,
765 fr_q933_print_ie_codeset_0_5,
766 NULL,
767 NULL,
768 NULL,
769 NULL,
770 NULL,
771 NULL,
772 NULL,
773 NULL,
774 NULL,
775 NULL
776 };
777
778 /*
779 * ITU-T Q.933.
780 *
781 * p points to octet 2, the octet containing the length of the
782 * call reference value, so p[n] is octet n+2 ("octet X" is as
783 * used in Q.931/Q.933).
784 *
785 * XXX - actually used both for Q.931 and Q.933.
786 */
787 void
788 q933_print(netdissect_options *ndo,
789 const u_char *p, u_int length)
790 {
791 u_int olen;
792 u_int call_ref_length, i;
793 uint8_t call_ref[15]; /* maximum length - length field is 4 bits */
794 u_int msgtype;
795 u_int iecode;
796 u_int ielength;
797 u_int codeset = 0;
798 u_int is_ansi = 0;
799 u_int ie_is_known;
800 u_int non_locking_shift;
801 u_int unshift_codeset;
802
803 ND_PRINT((ndo, "%s", ndo->ndo_eflag ? "" : "Q.933"));
804
805 if (length == 0 || !ND_TTEST(*p)) {
806 if (!ndo->ndo_eflag)
807 ND_PRINT((ndo, ", "));
808 ND_PRINT((ndo, "length %u", length));
809 goto trunc;
810 }
811
812 /*
813 * Get the length of the call reference value.
814 */
815 olen = length; /* preserve the original length for display */
816 call_ref_length = EXTRACT_U_1(p) & 0x0f;
817 p++;
818 length--;
819
820 /*
821 * Get the call reference value.
822 */
823 for (i = 0; i < call_ref_length; i++) {
824 if (length == 0 || !ND_TTEST(*p)) {
825 if (!ndo->ndo_eflag)
826 ND_PRINT((ndo, ", "));
827 ND_PRINT((ndo, "length %u", olen));
828 goto trunc;
829 }
830 call_ref[i] = EXTRACT_U_1(p);
831 p++;
832 length--;
833 }
834
835 /*
836 * Get the message type.
837 */
838 if (length == 0 || !ND_TTEST(*p)) {
839 if (!ndo->ndo_eflag)
840 ND_PRINT((ndo, ", "));
841 ND_PRINT((ndo, "length %u", olen));
842 goto trunc;
843 }
844 msgtype = EXTRACT_U_1(p);
845 p++;
846 length--;
847
848 /*
849 * Peek ahead to see if we start with a shift.
850 */
851 non_locking_shift = 0;
852 unshift_codeset = codeset;
853 if (length != 0) {
854 if (!ND_TTEST(*p)) {
855 if (!ndo->ndo_eflag)
856 ND_PRINT((ndo, ", "));
857 ND_PRINT((ndo, "length %u", olen));
858 goto trunc;
859 }
860 iecode = EXTRACT_U_1(p);
861 if (IE_IS_SHIFT(iecode)) {
862 /*
863 * It's a shift. Skip over it.
864 */
865 p++;
866 length--;
867
868 /*
869 * Get the codeset.
870 */
871 codeset = IE_SHIFT_CODESET(iecode);
872
873 /*
874 * If it's a locking shift to codeset 5,
875 * mark this as ANSI. (XXX - 5 is actually
876 * for national variants in general, not
877 * the US variant in particular, but maybe
878 * this is more American exceptionalism. :-))
879 */
880 if (IE_SHIFT_IS_LOCKING(iecode)) {
881 /*
882 * It's a locking shift.
883 */
884 if (codeset == 5) {
885 /*
886 * It's a locking shift to
887 * codeset 5, so this is
888 * T1.617 Annex D.
889 */
890 is_ansi = 1;
891 }
892 } else {
893 /*
894 * It's a non-locking shift.
895 * Remember the current codeset, so we
896 * can revert to it after the next IE.
897 */
898 non_locking_shift = 1;
899 unshift_codeset = 0;
900 }
901 }
902 }
903
904 /* printing out header part */
905 if (!ndo->ndo_eflag)
906 ND_PRINT((ndo, ", "));
907 ND_PRINT((ndo, "%s, codeset %u", is_ansi ? "ANSI" : "CCITT", codeset));
908
909 if (call_ref_length != 0) {
910 ND_TCHECK_1(p);
911 if (call_ref_length > 1 || EXTRACT_U_1(p) != 0) {
912 /*
913 * Not a dummy call reference.
914 */
915 ND_PRINT((ndo, ", Call Ref: 0x"));
916 for (i = 0; i < call_ref_length; i++)
917 ND_PRINT((ndo, "%02x", call_ref[i]));
918 }
919 }
920 if (ndo->ndo_vflag) {
921 ND_PRINT((ndo, ", %s (0x%02x), length %u",
922 tok2str(fr_q933_msg_values,
923 "unknown message", msgtype),
924 msgtype,
925 olen));
926 } else {
927 ND_PRINT((ndo, ", %s",
928 tok2str(fr_q933_msg_values,
929 "unknown message 0x%02x", msgtype)));
930 }
931
932 /* Loop through the rest of the IEs */
933 while (length != 0) {
934 /*
935 * What's the state of any non-locking shifts?
936 */
937 if (non_locking_shift == 1) {
938 /*
939 * There's a non-locking shift in effect for
940 * this IE. Count it, so we reset the codeset
941 * before the next IE.
942 */
943 non_locking_shift = 2;
944 } else if (non_locking_shift == 2) {
945 /*
946 * Unshift.
947 */
948 codeset = unshift_codeset;
949 non_locking_shift = 0;
950 }
951
952 /*
953 * Get the first octet of the IE.
954 */
955 if (!ND_TTEST(*p)) {
956 if (!ndo->ndo_vflag) {
957 ND_PRINT((ndo, ", length %u", olen));
958 }
959 goto trunc;
960 }
961 iecode = EXTRACT_U_1(p);
962 p++;
963 length--;
964
965 /* Single-octet IE? */
966 if (IE_IS_SINGLE_OCTET(iecode)) {
967 /*
968 * Yes. Is it a shift?
969 */
970 if (IE_IS_SHIFT(iecode)) {
971 /*
972 * Yes. Is it locking?
973 */
974 if (IE_SHIFT_IS_LOCKING(iecode)) {
975 /*
976 * Yes.
977 */
978 non_locking_shift = 0;
979 } else {
980 /*
981 * No. Remember the current
982 * codeset, so we can revert
983 * to it after the next IE.
984 */
985 non_locking_shift = 1;
986 unshift_codeset = codeset;
987 }
988
989 /*
990 * Get the codeset.
991 */
992 codeset = IE_SHIFT_CODESET(iecode);
993 }
994 } else {
995 /*
996 * No. Get the IE length.
997 */
998 if (length == 0 || !ND_TTEST(*p)) {
999 if (!ndo->ndo_vflag) {
1000 ND_PRINT((ndo, ", length %u", olen));
1001 }
1002 goto trunc;
1003 }
1004 ielength = EXTRACT_U_1(p);
1005 p++;
1006 length--;
1007
1008 /* lets do the full IE parsing only in verbose mode
1009 * however some IEs (DLCI Status, Link Verify)
1010 * are also interesting in non-verbose mode */
1011 if (ndo->ndo_vflag) {
1012 ND_PRINT((ndo, "\n\t%s IE (0x%02x), length %u: ",
1013 tok2str(fr_q933_ie_codesets[codeset],
1014 "unknown", iecode),
1015 iecode,
1016 ielength));
1017 }
1018
1019 /* sanity checks */
1020 if (iecode == 0 || ielength == 0) {
1021 return;
1022 }
1023 if (length < ielength || !ND_TTEST2(*p, ielength)) {
1024 if (!ndo->ndo_vflag) {
1025 ND_PRINT((ndo, ", length %u", olen));
1026 }
1027 goto trunc;
1028 }
1029
1030 ie_is_known = 0;
1031 if (fr_q933_print_ie_codeset[codeset] != NULL) {
1032 ie_is_known = fr_q933_print_ie_codeset[codeset](ndo, iecode, ielength, p);
1033 }
1034
1035 if (ie_is_known) {
1036 /*
1037 * Known IE; do we want to see a hexdump
1038 * of it?
1039 */
1040 if (ndo->ndo_vflag > 1) {
1041 /* Yes. */
1042 print_unknown_data(ndo, p, "\n\t ", ielength);
1043 }
1044 } else {
1045 /*
1046 * Unknown IE; if we're printing verbosely,
1047 * print its content in hex.
1048 */
1049 if (ndo->ndo_vflag >= 1) {
1050 print_unknown_data(ndo, p, "\n\t", ielength);
1051 }
1052 }
1053
1054 length -= ielength;
1055 p += ielength;
1056 }
1057 }
1058 if (!ndo->ndo_vflag) {
1059 ND_PRINT((ndo, ", length %u", olen));
1060 }
1061 return;
1062
1063 trunc:
1064 ND_PRINT((ndo, "[|q.933]"));
1065 }
1066
1067 static int
1068 fr_q933_print_ie_codeset_0_5(netdissect_options *ndo, u_int iecode,
1069 u_int ielength, const u_char *p)
1070 {
1071 u_int dlci;
1072
1073 switch (iecode) {
1074
1075 case FR_LMI_ANSI_REPORT_TYPE_IE: /* fall through */
1076 case FR_LMI_CCITT_REPORT_TYPE_IE:
1077 if (ielength < 1) {
1078 if (!ndo->ndo_vflag) {
1079 ND_PRINT((ndo, ", "));
1080 }
1081 ND_PRINT((ndo, "Invalid REPORT TYPE IE"));
1082 return 1;
1083 }
1084 if (ndo->ndo_vflag) {
1085 ND_PRINT((ndo, "%s (%u)",
1086 tok2str(fr_lmi_report_type_ie_values,"unknown",EXTRACT_U_1(p)),
1087 EXTRACT_U_1(p)));
1088 }
1089 return 1;
1090
1091 case FR_LMI_ANSI_LINK_VERIFY_IE: /* fall through */
1092 case FR_LMI_CCITT_LINK_VERIFY_IE:
1093 case FR_LMI_ANSI_LINK_VERIFY_IE_91:
1094 if (!ndo->ndo_vflag) {
1095 ND_PRINT((ndo, ", "));
1096 }
1097 if (ielength < 2) {
1098 ND_PRINT((ndo, "Invalid LINK VERIFY IE"));
1099 return 1;
1100 }
1101 ND_PRINT((ndo, "TX Seq: %3d, RX Seq: %3d", EXTRACT_U_1(p), EXTRACT_U_1(p + 1)));
1102 return 1;
1103
1104 case FR_LMI_ANSI_PVC_STATUS_IE: /* fall through */
1105 case FR_LMI_CCITT_PVC_STATUS_IE:
1106 if (!ndo->ndo_vflag) {
1107 ND_PRINT((ndo, ", "));
1108 }
1109 /* now parse the DLCI information element. */
1110 if ((ielength < 3) ||
1111 (EXTRACT_U_1(p) & 0x80) ||
1112 ((ielength == 3) && !(EXTRACT_U_1(p + 1) & 0x80)) ||
1113 ((ielength == 4) &&
1114 ((EXTRACT_U_1(p + 1) & 0x80) || !(EXTRACT_U_1(p + 2) & 0x80))) ||
1115 ((ielength == 5) &&
1116 ((EXTRACT_U_1(p + 1) & 0x80) || (EXTRACT_U_1(p + 2) & 0x80) ||
1117 !(EXTRACT_U_1(p + 3) & 0x80))) ||
1118 (ielength > 5) ||
1119 !(EXTRACT_U_1(p + ielength - 1) & 0x80)) {
1120 ND_PRINT((ndo, "Invalid DLCI in PVC STATUS IE"));
1121 return 1;
1122 }
1123
1124 dlci = ((EXTRACT_U_1(p) & 0x3F) << 4) | ((EXTRACT_U_1(p + 1) & 0x78) >> 3);
1125 if (ielength == 4) {
1126 dlci = (dlci << 6) | ((EXTRACT_U_1(p + 2) & 0x7E) >> 1);
1127 }
1128 else if (ielength == 5) {
1129 dlci = (dlci << 13) | (EXTRACT_U_1(p + 2) & 0x7F) | ((EXTRACT_U_1(p + 3) & 0x7E) >> 1);
1130 }
1131
1132 ND_PRINT((ndo, "DLCI %u: status %s%s", dlci,
1133 EXTRACT_U_1(p + ielength - 1) & 0x8 ? "New, " : "",
1134 EXTRACT_U_1(p + ielength - 1) & 0x2 ? "Active" : "Inactive"));
1135 return 1;
1136 }
1137
1138 return 0;
1139 }
1140 /*
1141 * Local Variables:
1142 * c-style: whitesmith
1143 * c-basic-offset: 8
1144 * End:
1145 */
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