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(for 4.9.3) CVE-2018-14468/FRF.16: Add a missing length check.
[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
461 if ((p[0] & MFR_BEC_MASK) == MFR_CTRL_FRAME && p[1] == 0) {
462 ND_PRINT((ndo, "FRF.16 Control, Flags [%s], %s, length %u",
463 bittok2str(frf_flag_values,"none",(p[0] & MFR_BEC_MASK)),
464 tok2str(mfr_ctrl_msg_values,"Unknown Message (0x%02x)",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 /* FRF.16.1 Section 3.4.3 Magic Number Information Element */
497 if (ie_len != 4) {
498 ND_PRINT((ndo, "(invalid length)"));
499 break;
500 }
501 ND_PRINT((ndo, "0x%08x", EXTRACT_32BITS(tptr)));
502 break;
503
504 case MFR_CTRL_IE_BUNDLE_ID: /* same message format */
505 case MFR_CTRL_IE_LINK_ID:
506 for (idx = 0; idx < ie_len && idx < MFR_ID_STRING_MAXLEN; idx++) {
507 if (*(tptr+idx) != 0) /* don't print null termination */
508 safeputchar(ndo, *(tptr + idx));
509 else
510 break;
511 }
512 break;
513
514 case MFR_CTRL_IE_TIMESTAMP:
515 if (ie_len == sizeof(struct timeval)) {
516 ts_print(ndo, (const struct timeval *)tptr);
517 break;
518 }
519 /* fall through and hexdump if no unix timestamp */
520
521 /*
522 * FIXME those are the defined IEs that lack a decoder
523 * you are welcome to contribute code ;-)
524 */
525
526 case MFR_CTRL_IE_VENDOR_EXT:
527 case MFR_CTRL_IE_CAUSE:
528
529 default:
530 if (ndo->ndo_vflag <= 1)
531 print_unknown_data(ndo, tptr, "\n\t ", ie_len);
532 break;
533 }
534
535 /* do we want to see a hexdump of the IE ? */
536 if (ndo->ndo_vflag > 1 )
537 print_unknown_data(ndo, tptr, "\n\t ", ie_len);
538
539 tlen-=ie_len;
540 tptr+=ie_len;
541 }
542 return hdr_len;
543 }
544 /*
545 * FRF.16 Fragmentation Frame
546 *
547 * 7 6 5 4 3 2 1 0
548 * +----+----+----+----+----+----+----+----+
549 * | B | E | C=0|seq. (high 4 bits) | EA |
550 * +----+----+----+----+----+----+----+----+
551 * | sequence (low 8 bits) |
552 * +----+----+----+----+----+----+----+----+
553 * | DLCI (6 bits) | CR | EA |
554 * +----+----+----+----+----+----+----+----+
555 * | DLCI (4 bits) |FECN|BECN| DE | EA |
556 * +----+----+----+----+----+----+----+----+
557 */
558
559 sequence_num = (p[0]&0x1e)<<7 | p[1];
560 /* whole packet or first fragment ? */
561 if ((p[0] & MFR_BEC_MASK) == MFR_FRAG_FRAME ||
562 (p[0] & MFR_BEC_MASK) == MFR_B_BIT) {
563 ND_PRINT((ndo, "FRF.16 Frag, seq %u, Flags [%s], ",
564 sequence_num,
565 bittok2str(frf_flag_values,"none",(p[0] & MFR_BEC_MASK))));
566 hdr_len = 2;
567 fr_print(ndo, p+hdr_len,length-hdr_len);
568 return hdr_len;
569 }
570
571 /* must be a middle or the last fragment */
572 ND_PRINT((ndo, "FRF.16 Frag, seq %u, Flags [%s]",
573 sequence_num,
574 bittok2str(frf_flag_values,"none",(p[0] & MFR_BEC_MASK))));
575 print_unknown_data(ndo, p, "\n\t", length);
576
577 return hdr_len;
578
579 trunc:
580 ND_PRINT((ndo, "[|mfr]"));
581 return length;
582 }
583
584 /* an NLPID of 0xb1 indicates a 2-byte
585 * FRF.15 header
586 *
587 * 7 6 5 4 3 2 1 0
588 * +----+----+----+----+----+----+----+----+
589 * ~ Q.922 header ~
590 * +----+----+----+----+----+----+----+----+
591 * | NLPID (8 bits) | NLPID=0xb1
592 * +----+----+----+----+----+----+----+----+
593 * | B | E | C |seq. (high 4 bits) | R |
594 * +----+----+----+----+----+----+----+----+
595 * | sequence (low 8 bits) |
596 * +----+----+----+----+----+----+----+----+
597 */
598
599 #define FR_FRF15_FRAGTYPE 0x01
600
601 static void
602 frf15_print(netdissect_options *ndo,
603 const u_char *p, u_int length)
604 {
605 uint16_t sequence_num, flags;
606
607 if (length < 2)
608 goto trunc;
609 ND_TCHECK2(*p, 2);
610
611 flags = p[0]&MFR_BEC_MASK;
612 sequence_num = (p[0]&0x1e)<<7 | p[1];
613
614 ND_PRINT((ndo, "FRF.15, seq 0x%03x, Flags [%s],%s Fragmentation, length %u",
615 sequence_num,
616 bittok2str(frf_flag_values,"none",flags),
617 p[0]&FR_FRF15_FRAGTYPE ? "Interface" : "End-to-End",
618 length));
619
620 /* TODO:
621 * depending on all permutations of the B, E and C bit
622 * dig as deep as we can - e.g. on the first (B) fragment
623 * there is enough payload to print the IP header
624 * on non (B) fragments it depends if the fragmentation
625 * model is end-to-end or interface based wether we want to print
626 * another Q.922 header
627 */
628 return;
629
630 trunc:
631 ND_PRINT((ndo, "[|frf.15]"));
632 }
633
634 /*
635 * Q.933 decoding portion for framerelay specific.
636 */
637
638 /* Q.933 packet format
639 Format of Other Protocols
640 using Q.933 NLPID
641 +-------------------------------+
642 | Q.922 Address |
643 +---------------+---------------+
644 |Control 0x03 | NLPID 0x08 |
645 +---------------+---------------+
646 | L2 Protocol ID |
647 | octet 1 | octet 2 |
648 +-------------------------------+
649 | L3 Protocol ID |
650 | octet 2 | octet 2 |
651 +-------------------------------+
652 | Protocol Data |
653 +-------------------------------+
654 | FCS |
655 +-------------------------------+
656 */
657
658 /* L2 (Octet 1)- Call Reference Usually is 0x0 */
659
660 /*
661 * L2 (Octet 2)- Message Types definition 1 byte long.
662 */
663 /* Call Establish */
664 #define MSG_TYPE_ESC_TO_NATIONAL 0x00
665 #define MSG_TYPE_ALERT 0x01
666 #define MSG_TYPE_CALL_PROCEEDING 0x02
667 #define MSG_TYPE_CONNECT 0x07
668 #define MSG_TYPE_CONNECT_ACK 0x0F
669 #define MSG_TYPE_PROGRESS 0x03
670 #define MSG_TYPE_SETUP 0x05
671 /* Call Clear */
672 #define MSG_TYPE_DISCONNECT 0x45
673 #define MSG_TYPE_RELEASE 0x4D
674 #define MSG_TYPE_RELEASE_COMPLETE 0x5A
675 #define MSG_TYPE_RESTART 0x46
676 #define MSG_TYPE_RESTART_ACK 0x4E
677 /* Status */
678 #define MSG_TYPE_STATUS 0x7D
679 #define MSG_TYPE_STATUS_ENQ 0x75
680
681 static const struct tok fr_q933_msg_values[] = {
682 { MSG_TYPE_ESC_TO_NATIONAL, "ESC to National" },
683 { MSG_TYPE_ALERT, "Alert" },
684 { MSG_TYPE_CALL_PROCEEDING, "Call proceeding" },
685 { MSG_TYPE_CONNECT, "Connect" },
686 { MSG_TYPE_CONNECT_ACK, "Connect ACK" },
687 { MSG_TYPE_PROGRESS, "Progress" },
688 { MSG_TYPE_SETUP, "Setup" },
689 { MSG_TYPE_DISCONNECT, "Disconnect" },
690 { MSG_TYPE_RELEASE, "Release" },
691 { MSG_TYPE_RELEASE_COMPLETE, "Release Complete" },
692 { MSG_TYPE_RESTART, "Restart" },
693 { MSG_TYPE_RESTART_ACK, "Restart ACK" },
694 { MSG_TYPE_STATUS, "Status Reply" },
695 { MSG_TYPE_STATUS_ENQ, "Status Enquiry" },
696 { 0, NULL }
697 };
698
699 #define IE_IS_SINGLE_OCTET(iecode) ((iecode) & 0x80)
700 #define IE_IS_SHIFT(iecode) (((iecode) & 0xF0) == 0x90)
701 #define IE_SHIFT_IS_NON_LOCKING(iecode) ((iecode) & 0x08)
702 #define IE_SHIFT_IS_LOCKING(iecode) (!(IE_SHIFT_IS_NON_LOCKING(iecode)))
703 #define IE_SHIFT_CODESET(iecode) ((iecode) & 0x07)
704
705 #define FR_LMI_ANSI_REPORT_TYPE_IE 0x01
706 #define FR_LMI_ANSI_LINK_VERIFY_IE_91 0x19 /* details? */
707 #define FR_LMI_ANSI_LINK_VERIFY_IE 0x03
708 #define FR_LMI_ANSI_PVC_STATUS_IE 0x07
709
710 #define FR_LMI_CCITT_REPORT_TYPE_IE 0x51
711 #define FR_LMI_CCITT_LINK_VERIFY_IE 0x53
712 #define FR_LMI_CCITT_PVC_STATUS_IE 0x57
713
714 static const struct tok fr_q933_ie_values_codeset_0_5[] = {
715 { FR_LMI_ANSI_REPORT_TYPE_IE, "ANSI Report Type" },
716 { FR_LMI_ANSI_LINK_VERIFY_IE_91, "ANSI Link Verify" },
717 { FR_LMI_ANSI_LINK_VERIFY_IE, "ANSI Link Verify" },
718 { FR_LMI_ANSI_PVC_STATUS_IE, "ANSI PVC Status" },
719 { FR_LMI_CCITT_REPORT_TYPE_IE, "CCITT Report Type" },
720 { FR_LMI_CCITT_LINK_VERIFY_IE, "CCITT Link Verify" },
721 { FR_LMI_CCITT_PVC_STATUS_IE, "CCITT PVC Status" },
722 { 0, NULL }
723 };
724
725 #define FR_LMI_REPORT_TYPE_IE_FULL_STATUS 0
726 #define FR_LMI_REPORT_TYPE_IE_LINK_VERIFY 1
727 #define FR_LMI_REPORT_TYPE_IE_ASYNC_PVC 2
728
729 static const struct tok fr_lmi_report_type_ie_values[] = {
730 { FR_LMI_REPORT_TYPE_IE_FULL_STATUS, "Full Status" },
731 { FR_LMI_REPORT_TYPE_IE_LINK_VERIFY, "Link verify" },
732 { FR_LMI_REPORT_TYPE_IE_ASYNC_PVC, "Async PVC Status" },
733 { 0, NULL }
734 };
735
736 /* array of 16 codesets - currently we only support codepage 0 and 5 */
737 static const struct tok *fr_q933_ie_codesets[] = {
738 fr_q933_ie_values_codeset_0_5,
739 NULL,
740 NULL,
741 NULL,
742 NULL,
743 fr_q933_ie_values_codeset_0_5,
744 NULL,
745 NULL,
746 NULL,
747 NULL,
748 NULL,
749 NULL,
750 NULL,
751 NULL,
752 NULL,
753 NULL
754 };
755
756 static int fr_q933_print_ie_codeset_0_5(netdissect_options *ndo, u_int iecode,
757 u_int ielength, const u_char *p);
758
759 typedef int (*codeset_pr_func_t)(netdissect_options *, u_int iecode,
760 u_int ielength, const u_char *p);
761
762 /* array of 16 codesets - currently we only support codepage 0 and 5 */
763 static const codeset_pr_func_t fr_q933_print_ie_codeset[] = {
764 fr_q933_print_ie_codeset_0_5,
765 NULL,
766 NULL,
767 NULL,
768 NULL,
769 fr_q933_print_ie_codeset_0_5,
770 NULL,
771 NULL,
772 NULL,
773 NULL,
774 NULL,
775 NULL,
776 NULL,
777 NULL,
778 NULL,
779 NULL
780 };
781
782 /*
783 * ITU-T Q.933.
784 *
785 * p points to octet 2, the octet containing the length of the
786 * call reference value, so p[n] is octet n+2 ("octet X" is as
787 * used in Q.931/Q.933).
788 *
789 * XXX - actually used both for Q.931 and Q.933.
790 */
791 void
792 q933_print(netdissect_options *ndo,
793 const u_char *p, u_int length)
794 {
795 u_int olen;
796 u_int call_ref_length, i;
797 uint8_t call_ref[15]; /* maximum length - length field is 4 bits */
798 u_int msgtype;
799 u_int iecode;
800 u_int ielength;
801 u_int codeset = 0;
802 u_int is_ansi = 0;
803 u_int ie_is_known;
804 u_int non_locking_shift;
805 u_int unshift_codeset;
806
807 ND_PRINT((ndo, "%s", ndo->ndo_eflag ? "" : "Q.933"));
808
809 if (length == 0 || !ND_TTEST(*p)) {
810 if (!ndo->ndo_eflag)
811 ND_PRINT((ndo, ", "));
812 ND_PRINT((ndo, "length %u", length));
813 goto trunc;
814 }
815
816 /*
817 * Get the length of the call reference value.
818 */
819 olen = length; /* preserve the original length for display */
820 call_ref_length = (*p) & 0x0f;
821 p++;
822 length--;
823
824 /*
825 * Get the call reference value.
826 */
827 for (i = 0; i < call_ref_length; i++) {
828 if (length == 0 || !ND_TTEST(*p)) {
829 if (!ndo->ndo_eflag)
830 ND_PRINT((ndo, ", "));
831 ND_PRINT((ndo, "length %u", olen));
832 goto trunc;
833 }
834 call_ref[i] = *p;
835 p++;
836 length--;
837 }
838
839 /*
840 * Get the message type.
841 */
842 if (length == 0 || !ND_TTEST(*p)) {
843 if (!ndo->ndo_eflag)
844 ND_PRINT((ndo, ", "));
845 ND_PRINT((ndo, "length %u", olen));
846 goto trunc;
847 }
848 msgtype = *p;
849 p++;
850 length--;
851
852 /*
853 * Peek ahead to see if we start with a shift.
854 */
855 non_locking_shift = 0;
856 unshift_codeset = codeset;
857 if (length != 0) {
858 if (!ND_TTEST(*p)) {
859 if (!ndo->ndo_eflag)
860 ND_PRINT((ndo, ", "));
861 ND_PRINT((ndo, "length %u", olen));
862 goto trunc;
863 }
864 iecode = *p;
865 if (IE_IS_SHIFT(iecode)) {
866 /*
867 * It's a shift. Skip over it.
868 */
869 p++;
870 length--;
871
872 /*
873 * Get the codeset.
874 */
875 codeset = IE_SHIFT_CODESET(iecode);
876
877 /*
878 * If it's a locking shift to codeset 5,
879 * mark this as ANSI. (XXX - 5 is actually
880 * for national variants in general, not
881 * the US variant in particular, but maybe
882 * this is more American exceptionalism. :-))
883 */
884 if (IE_SHIFT_IS_LOCKING(iecode)) {
885 /*
886 * It's a locking shift.
887 */
888 if (codeset == 5) {
889 /*
890 * It's a locking shift to
891 * codeset 5, so this is
892 * T1.617 Annex D.
893 */
894 is_ansi = 1;
895 }
896 } else {
897 /*
898 * It's a non-locking shift.
899 * Remember the current codeset, so we
900 * can revert to it after the next IE.
901 */
902 non_locking_shift = 1;
903 unshift_codeset = 0;
904 }
905 }
906 }
907
908 /* printing out header part */
909 if (!ndo->ndo_eflag)
910 ND_PRINT((ndo, ", "));
911 ND_PRINT((ndo, "%s, codeset %u", is_ansi ? "ANSI" : "CCITT", codeset));
912
913 if (call_ref_length != 0) {
914 ND_TCHECK(p[0]);
915 if (call_ref_length > 1 || p[0] != 0) {
916 /*
917 * Not a dummy call reference.
918 */
919 ND_PRINT((ndo, ", Call Ref: 0x"));
920 for (i = 0; i < call_ref_length; i++)
921 ND_PRINT((ndo, "%02x", call_ref[i]));
922 }
923 }
924 if (ndo->ndo_vflag) {
925 ND_PRINT((ndo, ", %s (0x%02x), length %u",
926 tok2str(fr_q933_msg_values,
927 "unknown message", msgtype),
928 msgtype,
929 olen));
930 } else {
931 ND_PRINT((ndo, ", %s",
932 tok2str(fr_q933_msg_values,
933 "unknown message 0x%02x", msgtype)));
934 }
935
936 /* Loop through the rest of the IEs */
937 while (length != 0) {
938 /*
939 * What's the state of any non-locking shifts?
940 */
941 if (non_locking_shift == 1) {
942 /*
943 * There's a non-locking shift in effect for
944 * this IE. Count it, so we reset the codeset
945 * before the next IE.
946 */
947 non_locking_shift = 2;
948 } else if (non_locking_shift == 2) {
949 /*
950 * Unshift.
951 */
952 codeset = unshift_codeset;
953 non_locking_shift = 0;
954 }
955
956 /*
957 * Get the first octet of the IE.
958 */
959 if (!ND_TTEST(*p)) {
960 if (!ndo->ndo_vflag) {
961 ND_PRINT((ndo, ", length %u", olen));
962 }
963 goto trunc;
964 }
965 iecode = *p;
966 p++;
967 length--;
968
969 /* Single-octet IE? */
970 if (IE_IS_SINGLE_OCTET(iecode)) {
971 /*
972 * Yes. Is it a shift?
973 */
974 if (IE_IS_SHIFT(iecode)) {
975 /*
976 * Yes. Is it locking?
977 */
978 if (IE_SHIFT_IS_LOCKING(iecode)) {
979 /*
980 * Yes.
981 */
982 non_locking_shift = 0;
983 } else {
984 /*
985 * No. Remember the current
986 * codeset, so we can revert
987 * to it after the next IE.
988 */
989 non_locking_shift = 1;
990 unshift_codeset = codeset;
991 }
992
993 /*
994 * Get the codeset.
995 */
996 codeset = IE_SHIFT_CODESET(iecode);
997 }
998 } else {
999 /*
1000 * No. Get the IE length.
1001 */
1002 if (length == 0 || !ND_TTEST(*p)) {
1003 if (!ndo->ndo_vflag) {
1004 ND_PRINT((ndo, ", length %u", olen));
1005 }
1006 goto trunc;
1007 }
1008 ielength = *p;
1009 p++;
1010 length--;
1011
1012 /* lets do the full IE parsing only in verbose mode
1013 * however some IEs (DLCI Status, Link Verify)
1014 * are also interesting in non-verbose mode */
1015 if (ndo->ndo_vflag) {
1016 ND_PRINT((ndo, "\n\t%s IE (0x%02x), length %u: ",
1017 tok2str(fr_q933_ie_codesets[codeset],
1018 "unknown", iecode),
1019 iecode,
1020 ielength));
1021 }
1022
1023 /* sanity checks */
1024 if (iecode == 0 || ielength == 0) {
1025 return;
1026 }
1027 if (length < ielength || !ND_TTEST2(*p, ielength)) {
1028 if (!ndo->ndo_vflag) {
1029 ND_PRINT((ndo, ", length %u", olen));
1030 }
1031 goto trunc;
1032 }
1033
1034 ie_is_known = 0;
1035 if (fr_q933_print_ie_codeset[codeset] != NULL) {
1036 ie_is_known = fr_q933_print_ie_codeset[codeset](ndo, iecode, ielength, p);
1037 }
1038
1039 if (ie_is_known) {
1040 /*
1041 * Known IE; do we want to see a hexdump
1042 * of it?
1043 */
1044 if (ndo->ndo_vflag > 1) {
1045 /* Yes. */
1046 print_unknown_data(ndo, p, "\n\t ", ielength);
1047 }
1048 } else {
1049 /*
1050 * Unknown IE; if we're printing verbosely,
1051 * print its content in hex.
1052 */
1053 if (ndo->ndo_vflag >= 1) {
1054 print_unknown_data(ndo, p, "\n\t", ielength);
1055 }
1056 }
1057
1058 length -= ielength;
1059 p += ielength;
1060 }
1061 }
1062 if (!ndo->ndo_vflag) {
1063 ND_PRINT((ndo, ", length %u", olen));
1064 }
1065 return;
1066
1067 trunc:
1068 ND_PRINT((ndo, "[|q.933]"));
1069 }
1070
1071 static int
1072 fr_q933_print_ie_codeset_0_5(netdissect_options *ndo, u_int iecode,
1073 u_int ielength, const u_char *p)
1074 {
1075 u_int dlci;
1076
1077 switch (iecode) {
1078
1079 case FR_LMI_ANSI_REPORT_TYPE_IE: /* fall through */
1080 case FR_LMI_CCITT_REPORT_TYPE_IE:
1081 if (ielength < 1) {
1082 if (!ndo->ndo_vflag) {
1083 ND_PRINT((ndo, ", "));
1084 }
1085 ND_PRINT((ndo, "Invalid REPORT TYPE IE"));
1086 return 1;
1087 }
1088 if (ndo->ndo_vflag) {
1089 ND_PRINT((ndo, "%s (%u)",
1090 tok2str(fr_lmi_report_type_ie_values,"unknown",p[0]),
1091 p[0]));
1092 }
1093 return 1;
1094
1095 case FR_LMI_ANSI_LINK_VERIFY_IE: /* fall through */
1096 case FR_LMI_CCITT_LINK_VERIFY_IE:
1097 case FR_LMI_ANSI_LINK_VERIFY_IE_91:
1098 if (!ndo->ndo_vflag) {
1099 ND_PRINT((ndo, ", "));
1100 }
1101 if (ielength < 2) {
1102 ND_PRINT((ndo, "Invalid LINK VERIFY IE"));
1103 return 1;
1104 }
1105 ND_PRINT((ndo, "TX Seq: %3d, RX Seq: %3d", p[0], p[1]));
1106 return 1;
1107
1108 case FR_LMI_ANSI_PVC_STATUS_IE: /* fall through */
1109 case FR_LMI_CCITT_PVC_STATUS_IE:
1110 if (!ndo->ndo_vflag) {
1111 ND_PRINT((ndo, ", "));
1112 }
1113 /* now parse the DLCI information element. */
1114 if ((ielength < 3) ||
1115 (p[0] & 0x80) ||
1116 ((ielength == 3) && !(p[1] & 0x80)) ||
1117 ((ielength == 4) && ((p[1] & 0x80) || !(p[2] & 0x80))) ||
1118 ((ielength == 5) && ((p[1] & 0x80) || (p[2] & 0x80) ||
1119 !(p[3] & 0x80))) ||
1120 (ielength > 5) ||
1121 !(p[ielength - 1] & 0x80)) {
1122 ND_PRINT((ndo, "Invalid DLCI in PVC STATUS IE"));
1123 return 1;
1124 }
1125
1126 dlci = ((p[0] & 0x3F) << 4) | ((p[1] & 0x78) >> 3);
1127 if (ielength == 4) {
1128 dlci = (dlci << 6) | ((p[2] & 0x7E) >> 1);
1129 }
1130 else if (ielength == 5) {
1131 dlci = (dlci << 13) | (p[2] & 0x7F) | ((p[3] & 0x7E) >> 1);
1132 }
1133
1134 ND_PRINT((ndo, "DLCI %u: status %s%s", dlci,
1135 p[ielength - 1] & 0x8 ? "New, " : "",
1136 p[ielength - 1] & 0x2 ? "Active" : "Inactive"));
1137 return 1;
1138 }
1139
1140 return 0;
1141 }
1142 /*
1143 * Local Variables:
1144 * c-style: whitesmith
1145 * c-basic-offset: 8
1146 * End:
1147 */
[mirror] the TCPdump network dissector