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Handle very large -f files by rejecting them.
[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(p[0]) || length < 1)
106 return -1;
107 if ((p[0] & FR_EA_BIT))
108 return 0;
109
110 if (!ND_TTEST(p[1]) || length < 2)
111 return -1;
112 *addr_len = 2;
113 *dlci = ((p[0] & 0xFC) << 2) | ((p[1] & 0xF0) >> 4);
114
115 flags[0] = p[0] & 0x02; /* populate the first flag fields */
116 flags[1] = p[1] & 0x0c;
117 flags[2] = 0; /* clear the rest of the flags */
118 flags[3] = 0;
119
120 if (p[1] & FR_EA_BIT)
121 return 1; /* 2-byte Q.922 address */
122
123 p += 2;
124 length -= 2;
125 if (!ND_TTEST(p[0]) || length < 1)
126 return -1;
127 (*addr_len)++; /* 3- or 4-byte Q.922 address */
128 if ((p[0] & FR_EA_BIT) == 0) {
129 *dlci = (*dlci << 7) | (p[0] >> 1);
130 (*addr_len)++; /* 4-byte Q.922 address */
131 p++;
132 length--;
133 }
134
135 if (!ND_TTEST(p[0]) || length < 1)
136 return -1;
137 if ((p[0] & FR_EA_BIT) == 0)
138 return 0; /* more than 4 bytes of Q.922 address? */
139
140 flags[3] = p[0] & 0x02;
141
142 *dlci = (*dlci << 6) | (p[0] >> 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_32BITS(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_32BITS(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_TCHECK2(*p, 4); /* 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(p[addr_len]);
257 if (length < addr_len + 1)
258 goto trunc;
259
260 if (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_TTEST2(p[addr_len], 2) || length < addr_len + 2) {
267 /* no Ethertype */
268 ND_PRINT((ndo, "UI %02x! ", p[addr_len]));
269 } else {
270 extracted_ethertype = EXTRACT_16BITS(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! ", p[addr_len]));
283 else
284 return addr_len + 2;
285 }
286 }
287
288 ND_TCHECK(p[addr_len+1]);
289 if (length < addr_len + 2)
290 goto trunc;
291
292 if (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(p[hdr_len - 1]);
311 if (length < hdr_len)
312 goto trunc;
313 nlpid = 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_TCHECK2(*p, 2); /* 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_TCHECK2(*p, 4); /* minimum frame header length */
460 if (length < 4) {
461 ND_PRINT((ndo, "Message too short (%u bytes)", length));
462 return length;
463 }
464
465 if ((p[0] & MFR_BEC_MASK) == MFR_CTRL_FRAME && p[1] == 0) {
466 ND_PRINT((ndo, "FRF.16 Control, Flags [%s], %s, length %u",
467 bittok2str(frf_flag_values,"none",(p[0] & MFR_BEC_MASK)),
468 tok2str(mfr_ctrl_msg_values,"Unknown Message (0x%02x)",p[2]),
469 length));
470 tptr = p + 3;
471 tlen = length -3;
472 hdr_len = 3;
473
474 if (!ndo->ndo_vflag)
475 return hdr_len;
476
477 while (tlen>sizeof(struct ie_tlv_header_t)) {
478 ND_TCHECK2(*tptr, sizeof(struct ie_tlv_header_t));
479 ie_type=tptr[0];
480 ie_len=tptr[1];
481
482 ND_PRINT((ndo, "\n\tIE %s (%u), length %u: ",
483 tok2str(mfr_ctrl_ie_values,"Unknown",ie_type),
484 ie_type,
485 ie_len));
486
487 /* infinite loop check */
488 if (ie_type == 0 || ie_len <= sizeof(struct ie_tlv_header_t))
489 return hdr_len;
490
491 ND_TCHECK2(*tptr, ie_len);
492 tptr+=sizeof(struct ie_tlv_header_t);
493 /* tlv len includes header */
494 ie_len-=sizeof(struct ie_tlv_header_t);
495 tlen-=sizeof(struct ie_tlv_header_t);
496
497 switch (ie_type) {
498
499 case MFR_CTRL_IE_MAGIC_NUM:
500 /* FRF.16.1 Section 3.4.3 Magic Number Information Element */
501 if (ie_len != 4) {
502 ND_PRINT((ndo, "(invalid length)"));
503 break;
504 }
505 ND_PRINT((ndo, "0x%08x", EXTRACT_32BITS(tptr)));
506 break;
507
508 case MFR_CTRL_IE_BUNDLE_ID: /* same message format */
509 case MFR_CTRL_IE_LINK_ID:
510 for (idx = 0; idx < ie_len && idx < MFR_ID_STRING_MAXLEN; idx++) {
511 if (*(tptr+idx) != 0) /* don't print null termination */
512 safeputchar(ndo, *(tptr + idx));
513 else
514 break;
515 }
516 break;
517
518 case MFR_CTRL_IE_TIMESTAMP:
519 if (ie_len == sizeof(struct timeval)) {
520 ts_print(ndo, (const struct timeval *)tptr);
521 break;
522 }
523 /* fall through and hexdump if no unix timestamp */
524
525 /*
526 * FIXME those are the defined IEs that lack a decoder
527 * you are welcome to contribute code ;-)
528 */
529
530 case MFR_CTRL_IE_VENDOR_EXT:
531 case MFR_CTRL_IE_CAUSE:
532
533 default:
534 if (ndo->ndo_vflag <= 1)
535 print_unknown_data(ndo, tptr, "\n\t ", ie_len);
536 break;
537 }
538
539 /* do we want to see a hexdump of the IE ? */
540 if (ndo->ndo_vflag > 1 )
541 print_unknown_data(ndo, tptr, "\n\t ", ie_len);
542
543 tlen-=ie_len;
544 tptr+=ie_len;
545 }
546 return hdr_len;
547 }
548 /*
549 * FRF.16 Fragmentation Frame
550 *
551 * 7 6 5 4 3 2 1 0
552 * +----+----+----+----+----+----+----+----+
553 * | B | E | C=0|seq. (high 4 bits) | EA |
554 * +----+----+----+----+----+----+----+----+
555 * | sequence (low 8 bits) |
556 * +----+----+----+----+----+----+----+----+
557 * | DLCI (6 bits) | CR | EA |
558 * +----+----+----+----+----+----+----+----+
559 * | DLCI (4 bits) |FECN|BECN| DE | EA |
560 * +----+----+----+----+----+----+----+----+
561 */
562
563 sequence_num = (p[0]&0x1e)<<7 | p[1];
564 /* whole packet or first fragment ? */
565 if ((p[0] & MFR_BEC_MASK) == MFR_FRAG_FRAME ||
566 (p[0] & MFR_BEC_MASK) == MFR_B_BIT) {
567 ND_PRINT((ndo, "FRF.16 Frag, seq %u, Flags [%s], ",
568 sequence_num,
569 bittok2str(frf_flag_values,"none",(p[0] & MFR_BEC_MASK))));
570 hdr_len = 2;
571 fr_print(ndo, p+hdr_len,length-hdr_len);
572 return hdr_len;
573 }
574
575 /* must be a middle or the last fragment */
576 ND_PRINT((ndo, "FRF.16 Frag, seq %u, Flags [%s]",
577 sequence_num,
578 bittok2str(frf_flag_values,"none",(p[0] & MFR_BEC_MASK))));
579 print_unknown_data(ndo, p, "\n\t", length);
580
581 return hdr_len;
582
583 trunc:
584 ND_PRINT((ndo, "[|mfr]"));
585 return length;
586 }
587
588 /* an NLPID of 0xb1 indicates a 2-byte
589 * FRF.15 header
590 *
591 * 7 6 5 4 3 2 1 0
592 * +----+----+----+----+----+----+----+----+
593 * ~ Q.922 header ~
594 * +----+----+----+----+----+----+----+----+
595 * | NLPID (8 bits) | NLPID=0xb1
596 * +----+----+----+----+----+----+----+----+
597 * | B | E | C |seq. (high 4 bits) | R |
598 * +----+----+----+----+----+----+----+----+
599 * | sequence (low 8 bits) |
600 * +----+----+----+----+----+----+----+----+
601 */
602
603 #define FR_FRF15_FRAGTYPE 0x01
604
605 static void
606 frf15_print(netdissect_options *ndo,
607 const u_char *p, u_int length)
608 {
609 uint16_t sequence_num, flags;
610
611 if (length < 2)
612 goto trunc;
613 ND_TCHECK2(*p, 2);
614
615 flags = p[0]&MFR_BEC_MASK;
616 sequence_num = (p[0]&0x1e)<<7 | p[1];
617
618 ND_PRINT((ndo, "FRF.15, seq 0x%03x, Flags [%s],%s Fragmentation, length %u",
619 sequence_num,
620 bittok2str(frf_flag_values,"none",flags),
621 p[0]&FR_FRF15_FRAGTYPE ? "Interface" : "End-to-End",
622 length));
623
624 /* TODO:
625 * depending on all permutations of the B, E and C bit
626 * dig as deep as we can - e.g. on the first (B) fragment
627 * there is enough payload to print the IP header
628 * on non (B) fragments it depends if the fragmentation
629 * model is end-to-end or interface based wether we want to print
630 * another Q.922 header
631 */
632 return;
633
634 trunc:
635 ND_PRINT((ndo, "[|frf.15]"));
636 }
637
638 /*
639 * Q.933 decoding portion for framerelay specific.
640 */
641
642 /* Q.933 packet format
643 Format of Other Protocols
644 using Q.933 NLPID
645 +-------------------------------+
646 | Q.922 Address |
647 +---------------+---------------+
648 |Control 0x03 | NLPID 0x08 |
649 +---------------+---------------+
650 | L2 Protocol ID |
651 | octet 1 | octet 2 |
652 +-------------------------------+
653 | L3 Protocol ID |
654 | octet 2 | octet 2 |
655 +-------------------------------+
656 | Protocol Data |
657 +-------------------------------+
658 | FCS |
659 +-------------------------------+
660 */
661
662 /* L2 (Octet 1)- Call Reference Usually is 0x0 */
663
664 /*
665 * L2 (Octet 2)- Message Types definition 1 byte long.
666 */
667 /* Call Establish */
668 #define MSG_TYPE_ESC_TO_NATIONAL 0x00
669 #define MSG_TYPE_ALERT 0x01
670 #define MSG_TYPE_CALL_PROCEEDING 0x02
671 #define MSG_TYPE_CONNECT 0x07
672 #define MSG_TYPE_CONNECT_ACK 0x0F
673 #define MSG_TYPE_PROGRESS 0x03
674 #define MSG_TYPE_SETUP 0x05
675 /* Call Clear */
676 #define MSG_TYPE_DISCONNECT 0x45
677 #define MSG_TYPE_RELEASE 0x4D
678 #define MSG_TYPE_RELEASE_COMPLETE 0x5A
679 #define MSG_TYPE_RESTART 0x46
680 #define MSG_TYPE_RESTART_ACK 0x4E
681 /* Status */
682 #define MSG_TYPE_STATUS 0x7D
683 #define MSG_TYPE_STATUS_ENQ 0x75
684
685 static const struct tok fr_q933_msg_values[] = {
686 { MSG_TYPE_ESC_TO_NATIONAL, "ESC to National" },
687 { MSG_TYPE_ALERT, "Alert" },
688 { MSG_TYPE_CALL_PROCEEDING, "Call proceeding" },
689 { MSG_TYPE_CONNECT, "Connect" },
690 { MSG_TYPE_CONNECT_ACK, "Connect ACK" },
691 { MSG_TYPE_PROGRESS, "Progress" },
692 { MSG_TYPE_SETUP, "Setup" },
693 { MSG_TYPE_DISCONNECT, "Disconnect" },
694 { MSG_TYPE_RELEASE, "Release" },
695 { MSG_TYPE_RELEASE_COMPLETE, "Release Complete" },
696 { MSG_TYPE_RESTART, "Restart" },
697 { MSG_TYPE_RESTART_ACK, "Restart ACK" },
698 { MSG_TYPE_STATUS, "Status Reply" },
699 { MSG_TYPE_STATUS_ENQ, "Status Enquiry" },
700 { 0, NULL }
701 };
702
703 #define IE_IS_SINGLE_OCTET(iecode) ((iecode) & 0x80)
704 #define IE_IS_SHIFT(iecode) (((iecode) & 0xF0) == 0x90)
705 #define IE_SHIFT_IS_NON_LOCKING(iecode) ((iecode) & 0x08)
706 #define IE_SHIFT_IS_LOCKING(iecode) (!(IE_SHIFT_IS_NON_LOCKING(iecode)))
707 #define IE_SHIFT_CODESET(iecode) ((iecode) & 0x07)
708
709 #define FR_LMI_ANSI_REPORT_TYPE_IE 0x01
710 #define FR_LMI_ANSI_LINK_VERIFY_IE_91 0x19 /* details? */
711 #define FR_LMI_ANSI_LINK_VERIFY_IE 0x03
712 #define FR_LMI_ANSI_PVC_STATUS_IE 0x07
713
714 #define FR_LMI_CCITT_REPORT_TYPE_IE 0x51
715 #define FR_LMI_CCITT_LINK_VERIFY_IE 0x53
716 #define FR_LMI_CCITT_PVC_STATUS_IE 0x57
717
718 static const struct tok fr_q933_ie_values_codeset_0_5[] = {
719 { FR_LMI_ANSI_REPORT_TYPE_IE, "ANSI Report Type" },
720 { FR_LMI_ANSI_LINK_VERIFY_IE_91, "ANSI Link Verify" },
721 { FR_LMI_ANSI_LINK_VERIFY_IE, "ANSI Link Verify" },
722 { FR_LMI_ANSI_PVC_STATUS_IE, "ANSI PVC Status" },
723 { FR_LMI_CCITT_REPORT_TYPE_IE, "CCITT Report Type" },
724 { FR_LMI_CCITT_LINK_VERIFY_IE, "CCITT Link Verify" },
725 { FR_LMI_CCITT_PVC_STATUS_IE, "CCITT PVC Status" },
726 { 0, NULL }
727 };
728
729 #define FR_LMI_REPORT_TYPE_IE_FULL_STATUS 0
730 #define FR_LMI_REPORT_TYPE_IE_LINK_VERIFY 1
731 #define FR_LMI_REPORT_TYPE_IE_ASYNC_PVC 2
732
733 static const struct tok fr_lmi_report_type_ie_values[] = {
734 { FR_LMI_REPORT_TYPE_IE_FULL_STATUS, "Full Status" },
735 { FR_LMI_REPORT_TYPE_IE_LINK_VERIFY, "Link verify" },
736 { FR_LMI_REPORT_TYPE_IE_ASYNC_PVC, "Async PVC Status" },
737 { 0, NULL }
738 };
739
740 /* array of 16 codesets - currently we only support codepage 0 and 5 */
741 static const struct tok *fr_q933_ie_codesets[] = {
742 fr_q933_ie_values_codeset_0_5,
743 NULL,
744 NULL,
745 NULL,
746 NULL,
747 fr_q933_ie_values_codeset_0_5,
748 NULL,
749 NULL,
750 NULL,
751 NULL,
752 NULL,
753 NULL,
754 NULL,
755 NULL,
756 NULL,
757 NULL
758 };
759
760 static int fr_q933_print_ie_codeset_0_5(netdissect_options *ndo, u_int iecode,
761 u_int ielength, const u_char *p);
762
763 typedef int (*codeset_pr_func_t)(netdissect_options *, u_int iecode,
764 u_int ielength, const u_char *p);
765
766 /* array of 16 codesets - currently we only support codepage 0 and 5 */
767 static const codeset_pr_func_t fr_q933_print_ie_codeset[] = {
768 fr_q933_print_ie_codeset_0_5,
769 NULL,
770 NULL,
771 NULL,
772 NULL,
773 fr_q933_print_ie_codeset_0_5,
774 NULL,
775 NULL,
776 NULL,
777 NULL,
778 NULL,
779 NULL,
780 NULL,
781 NULL,
782 NULL,
783 NULL
784 };
785
786 /*
787 * ITU-T Q.933.
788 *
789 * p points to octet 2, the octet containing the length of the
790 * call reference value, so p[n] is octet n+2 ("octet X" is as
791 * used in Q.931/Q.933).
792 *
793 * XXX - actually used both for Q.931 and Q.933.
794 */
795 void
796 q933_print(netdissect_options *ndo,
797 const u_char *p, u_int length)
798 {
799 u_int olen;
800 u_int call_ref_length, i;
801 uint8_t call_ref[15]; /* maximum length - length field is 4 bits */
802 u_int msgtype;
803 u_int iecode;
804 u_int ielength;
805 u_int codeset = 0;
806 u_int is_ansi = 0;
807 u_int ie_is_known;
808 u_int non_locking_shift;
809 u_int unshift_codeset;
810
811 ND_PRINT((ndo, "%s", ndo->ndo_eflag ? "" : "Q.933"));
812
813 if (length == 0 || !ND_TTEST(*p)) {
814 if (!ndo->ndo_eflag)
815 ND_PRINT((ndo, ", "));
816 ND_PRINT((ndo, "length %u", length));
817 goto trunc;
818 }
819
820 /*
821 * Get the length of the call reference value.
822 */
823 olen = length; /* preserve the original length for display */
824 call_ref_length = (*p) & 0x0f;
825 p++;
826 length--;
827
828 /*
829 * Get the call reference value.
830 */
831 for (i = 0; i < call_ref_length; i++) {
832 if (length == 0 || !ND_TTEST(*p)) {
833 if (!ndo->ndo_eflag)
834 ND_PRINT((ndo, ", "));
835 ND_PRINT((ndo, "length %u", olen));
836 goto trunc;
837 }
838 call_ref[i] = *p;
839 p++;
840 length--;
841 }
842
843 /*
844 * Get the message type.
845 */
846 if (length == 0 || !ND_TTEST(*p)) {
847 if (!ndo->ndo_eflag)
848 ND_PRINT((ndo, ", "));
849 ND_PRINT((ndo, "length %u", olen));
850 goto trunc;
851 }
852 msgtype = *p;
853 p++;
854 length--;
855
856 /*
857 * Peek ahead to see if we start with a shift.
858 */
859 non_locking_shift = 0;
860 unshift_codeset = codeset;
861 if (length != 0) {
862 if (!ND_TTEST(*p)) {
863 if (!ndo->ndo_eflag)
864 ND_PRINT((ndo, ", "));
865 ND_PRINT((ndo, "length %u", olen));
866 goto trunc;
867 }
868 iecode = *p;
869 if (IE_IS_SHIFT(iecode)) {
870 /*
871 * It's a shift. Skip over it.
872 */
873 p++;
874 length--;
875
876 /*
877 * Get the codeset.
878 */
879 codeset = IE_SHIFT_CODESET(iecode);
880
881 /*
882 * If it's a locking shift to codeset 5,
883 * mark this as ANSI. (XXX - 5 is actually
884 * for national variants in general, not
885 * the US variant in particular, but maybe
886 * this is more American exceptionalism. :-))
887 */
888 if (IE_SHIFT_IS_LOCKING(iecode)) {
889 /*
890 * It's a locking shift.
891 */
892 if (codeset == 5) {
893 /*
894 * It's a locking shift to
895 * codeset 5, so this is
896 * T1.617 Annex D.
897 */
898 is_ansi = 1;
899 }
900 } else {
901 /*
902 * It's a non-locking shift.
903 * Remember the current codeset, so we
904 * can revert to it after the next IE.
905 */
906 non_locking_shift = 1;
907 unshift_codeset = 0;
908 }
909 }
910 }
911
912 /* printing out header part */
913 if (!ndo->ndo_eflag)
914 ND_PRINT((ndo, ", "));
915 ND_PRINT((ndo, "%s, codeset %u", is_ansi ? "ANSI" : "CCITT", codeset));
916
917 if (call_ref_length != 0) {
918 ND_TCHECK(p[0]);
919 if (call_ref_length > 1 || p[0] != 0) {
920 /*
921 * Not a dummy call reference.
922 */
923 ND_PRINT((ndo, ", Call Ref: 0x"));
924 for (i = 0; i < call_ref_length; i++)
925 ND_PRINT((ndo, "%02x", call_ref[i]));
926 }
927 }
928 if (ndo->ndo_vflag) {
929 ND_PRINT((ndo, ", %s (0x%02x), length %u",
930 tok2str(fr_q933_msg_values,
931 "unknown message", msgtype),
932 msgtype,
933 olen));
934 } else {
935 ND_PRINT((ndo, ", %s",
936 tok2str(fr_q933_msg_values,
937 "unknown message 0x%02x", msgtype)));
938 }
939
940 /* Loop through the rest of the IEs */
941 while (length != 0) {
942 /*
943 * What's the state of any non-locking shifts?
944 */
945 if (non_locking_shift == 1) {
946 /*
947 * There's a non-locking shift in effect for
948 * this IE. Count it, so we reset the codeset
949 * before the next IE.
950 */
951 non_locking_shift = 2;
952 } else if (non_locking_shift == 2) {
953 /*
954 * Unshift.
955 */
956 codeset = unshift_codeset;
957 non_locking_shift = 0;
958 }
959
960 /*
961 * Get the first octet of the IE.
962 */
963 if (!ND_TTEST(*p)) {
964 if (!ndo->ndo_vflag) {
965 ND_PRINT((ndo, ", length %u", olen));
966 }
967 goto trunc;
968 }
969 iecode = *p;
970 p++;
971 length--;
972
973 /* Single-octet IE? */
974 if (IE_IS_SINGLE_OCTET(iecode)) {
975 /*
976 * Yes. Is it a shift?
977 */
978 if (IE_IS_SHIFT(iecode)) {
979 /*
980 * Yes. Is it locking?
981 */
982 if (IE_SHIFT_IS_LOCKING(iecode)) {
983 /*
984 * Yes.
985 */
986 non_locking_shift = 0;
987 } else {
988 /*
989 * No. Remember the current
990 * codeset, so we can revert
991 * to it after the next IE.
992 */
993 non_locking_shift = 1;
994 unshift_codeset = codeset;
995 }
996
997 /*
998 * Get the codeset.
999 */
1000 codeset = IE_SHIFT_CODESET(iecode);
1001 }
1002 } else {
1003 /*
1004 * No. Get the IE length.
1005 */
1006 if (length == 0 || !ND_TTEST(*p)) {
1007 if (!ndo->ndo_vflag) {
1008 ND_PRINT((ndo, ", length %u", olen));
1009 }
1010 goto trunc;
1011 }
1012 ielength = *p;
1013 p++;
1014 length--;
1015
1016 /* lets do the full IE parsing only in verbose mode
1017 * however some IEs (DLCI Status, Link Verify)
1018 * are also interesting in non-verbose mode */
1019 if (ndo->ndo_vflag) {
1020 ND_PRINT((ndo, "\n\t%s IE (0x%02x), length %u: ",
1021 tok2str(fr_q933_ie_codesets[codeset],
1022 "unknown", iecode),
1023 iecode,
1024 ielength));
1025 }
1026
1027 /* sanity checks */
1028 if (iecode == 0 || ielength == 0) {
1029 return;
1030 }
1031 if (length < ielength || !ND_TTEST2(*p, ielength)) {
1032 if (!ndo->ndo_vflag) {
1033 ND_PRINT((ndo, ", length %u", olen));
1034 }
1035 goto trunc;
1036 }
1037
1038 ie_is_known = 0;
1039 if (fr_q933_print_ie_codeset[codeset] != NULL) {
1040 ie_is_known = fr_q933_print_ie_codeset[codeset](ndo, iecode, ielength, p);
1041 }
1042
1043 if (ie_is_known) {
1044 /*
1045 * Known IE; do we want to see a hexdump
1046 * of it?
1047 */
1048 if (ndo->ndo_vflag > 1) {
1049 /* Yes. */
1050 print_unknown_data(ndo, p, "\n\t ", ielength);
1051 }
1052 } else {
1053 /*
1054 * Unknown IE; if we're printing verbosely,
1055 * print its content in hex.
1056 */
1057 if (ndo->ndo_vflag >= 1) {
1058 print_unknown_data(ndo, p, "\n\t", ielength);
1059 }
1060 }
1061
1062 length -= ielength;
1063 p += ielength;
1064 }
1065 }
1066 if (!ndo->ndo_vflag) {
1067 ND_PRINT((ndo, ", length %u", olen));
1068 }
1069 return;
1070
1071 trunc:
1072 ND_PRINT((ndo, "[|q.933]"));
1073 }
1074
1075 static int
1076 fr_q933_print_ie_codeset_0_5(netdissect_options *ndo, u_int iecode,
1077 u_int ielength, const u_char *p)
1078 {
1079 u_int dlci;
1080
1081 switch (iecode) {
1082
1083 case FR_LMI_ANSI_REPORT_TYPE_IE: /* fall through */
1084 case FR_LMI_CCITT_REPORT_TYPE_IE:
1085 if (ielength < 1) {
1086 if (!ndo->ndo_vflag) {
1087 ND_PRINT((ndo, ", "));
1088 }
1089 ND_PRINT((ndo, "Invalid REPORT TYPE IE"));
1090 return 1;
1091 }
1092 if (ndo->ndo_vflag) {
1093 ND_PRINT((ndo, "%s (%u)",
1094 tok2str(fr_lmi_report_type_ie_values,"unknown",p[0]),
1095 p[0]));
1096 }
1097 return 1;
1098
1099 case FR_LMI_ANSI_LINK_VERIFY_IE: /* fall through */
1100 case FR_LMI_CCITT_LINK_VERIFY_IE:
1101 case FR_LMI_ANSI_LINK_VERIFY_IE_91:
1102 if (!ndo->ndo_vflag) {
1103 ND_PRINT((ndo, ", "));
1104 }
1105 if (ielength < 2) {
1106 ND_PRINT((ndo, "Invalid LINK VERIFY IE"));
1107 return 1;
1108 }
1109 ND_PRINT((ndo, "TX Seq: %3d, RX Seq: %3d", p[0], p[1]));
1110 return 1;
1111
1112 case FR_LMI_ANSI_PVC_STATUS_IE: /* fall through */
1113 case FR_LMI_CCITT_PVC_STATUS_IE:
1114 if (!ndo->ndo_vflag) {
1115 ND_PRINT((ndo, ", "));
1116 }
1117 /* now parse the DLCI information element. */
1118 if ((ielength < 3) ||
1119 (p[0] & 0x80) ||
1120 ((ielength == 3) && !(p[1] & 0x80)) ||
1121 ((ielength == 4) && ((p[1] & 0x80) || !(p[2] & 0x80))) ||
1122 ((ielength == 5) && ((p[1] & 0x80) || (p[2] & 0x80) ||
1123 !(p[3] & 0x80))) ||
1124 (ielength > 5) ||
1125 !(p[ielength - 1] & 0x80)) {
1126 ND_PRINT((ndo, "Invalid DLCI in PVC STATUS IE"));
1127 return 1;
1128 }
1129
1130 dlci = ((p[0] & 0x3F) << 4) | ((p[1] & 0x78) >> 3);
1131 if (ielength == 4) {
1132 dlci = (dlci << 6) | ((p[2] & 0x7E) >> 1);
1133 }
1134 else if (ielength == 5) {
1135 dlci = (dlci << 13) | (p[2] & 0x7F) | ((p[3] & 0x7E) >> 1);
1136 }
1137
1138 ND_PRINT((ndo, "DLCI %u: status %s%s", dlci,
1139 p[ielength - 1] & 0x8 ? "New, " : "",
1140 p[ielength - 1] & 0x2 ? "Active" : "Inactive"));
1141 return 1;
1142 }
1143
1144 return 0;
1145 }
1146 /*
1147 * Local Variables:
1148 * c-style: whitesmith
1149 * c-basic-offset: 8
1150 * End:
1151 */
[mirror] the TCPdump network dissector