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 #include <sys/cdefs.h> 23 #ifndef lint 24 __RCSID("$NetBSD: print-fr.c,v 1.12 2024/09/02 16:15:31 christos Exp $"); 25 #endif 26 27 /* \summary: Frame Relay printer */ 28 29 #include <config.h> 30 31 #include "netdissect-stdinc.h" 32 33 #include <stdio.h> 34 #include <string.h> 35 36 #include "netdissect.h" 37 #include "addrtoname.h" 38 #include "ethertype.h" 39 #include "llc.h" 40 #include "nlpid.h" 41 #include "extract.h" 42 43 static void frf15_print(netdissect_options *ndo, const u_char *, u_int); 44 45 /* 46 * the frame relay header has a variable length 47 * 48 * the EA bit determines if there is another byte 49 * in the header 50 * 51 * minimum header length is 2 bytes 52 * maximum header length is 4 bytes 53 * 54 * 7 6 5 4 3 2 1 0 55 * +----+----+----+----+----+----+----+----+ 56 * | DLCI (6 bits) | CR | EA | 57 * +----+----+----+----+----+----+----+----+ 58 * | DLCI (4 bits) |FECN|BECN| DE | EA | 59 * +----+----+----+----+----+----+----+----+ 60 * | DLCI (7 bits) | EA | 61 * +----+----+----+----+----+----+----+----+ 62 * | DLCI (6 bits) |SDLC| EA | 63 * +----+----+----+----+----+----+----+----+ 64 */ 65 66 #define FR_EA_BIT 0x01 67 68 #define FR_CR_BIT 0x02000000 69 #define FR_DE_BIT 0x00020000 70 #define FR_BECN_BIT 0x00040000 71 #define FR_FECN_BIT 0x00080000 72 #define FR_SDLC_BIT 0x00000002 73 74 75 static const struct tok fr_header_flag_values[] = { 76 { FR_CR_BIT, "C!" }, 77 { FR_DE_BIT, "DE" }, 78 { FR_BECN_BIT, "BECN" }, 79 { FR_FECN_BIT, "FECN" }, 80 { FR_SDLC_BIT, "sdlcore" }, 81 { 0, NULL } 82 }; 83 84 /* FRF.15 / FRF.16 */ 85 #define MFR_B_BIT 0x80 86 #define MFR_E_BIT 0x40 87 #define MFR_C_BIT 0x20 88 #define MFR_BEC_MASK (MFR_B_BIT | MFR_E_BIT | MFR_C_BIT) 89 #define MFR_CTRL_FRAME (MFR_B_BIT | MFR_E_BIT | MFR_C_BIT) 90 #define MFR_FRAG_FRAME (MFR_B_BIT | MFR_E_BIT ) 91 92 static const struct tok frf_flag_values[] = { 93 { MFR_B_BIT, "Begin" }, 94 { MFR_E_BIT, "End" }, 95 { MFR_C_BIT, "Control" }, 96 { 0, NULL } 97 }; 98 99 /* Finds out Q.922 address length, DLCI and flags. Returns 1 on success, 100 * 0 on invalid address, -1 on truncated packet 101 * save the flags dep. on address length 102 */ 103 static int parse_q922_header(netdissect_options *ndo, 104 const u_char *p, u_int *dlci, 105 u_int *addr_len, uint32_t *flags, u_int length) 106 { 107 if (!ND_TTEST_1(p) || length < 1) 108 return -1; 109 if ((GET_U_1(p) & FR_EA_BIT)) 110 return 0; 111 112 if (!ND_TTEST_1(p + 1) || length < 2) 113 return -1; 114 *addr_len = 2; 115 *dlci = ((GET_U_1(p) & 0xFC) << 2) | ((GET_U_1(p + 1) & 0xF0) >> 4); 116 117 *flags = ((GET_U_1(p) & 0x02) << 24) | /* CR flag */ 118 ((GET_U_1(p + 1) & 0x0e) << 16); /* FECN,BECN,DE flags */ 119 120 if (GET_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 ((GET_U_1(p) & FR_EA_BIT) == 0) { 129 *dlci = (*dlci << 7) | (GET_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 ((GET_U_1(p) & FR_EA_BIT) == 0) 138 return 0; /* more than 4 bytes of Q.922 address? */ 139 140 *flags = *flags | (GET_U_1(p) & 0x02); /* SDLC flag */ 141 142 *dlci = (*dlci << 6) | (GET_U_1(p) >> 2); 143 144 return 1; 145 } 146 147 const 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 uint32_t flags; 153 static char buffer[sizeof("parse_q922_header() returned XXXXXXXXXXX")]; 154 int ret; 155 memset(buffer, 0, sizeof(buffer)); 156 157 ret = parse_q922_header(ndo, p, &dlci, &addr_len, &flags, length); 158 if (ret == 1) { 159 snprintf(buffer, sizeof(buffer), "DLCI %u", dlci); 160 return buffer; 161 } else if (ret == 0) { 162 return "<Invalid DLCI>"; 163 } else if (ret == -1) { 164 return "<Truncated>"; 165 } else { 166 snprintf(buffer, sizeof(buffer), "parse_q922_header() returned %d", ret); 167 return buffer; 168 } 169 } 170 171 172 /* Frame Relay packet structure, with flags and CRC removed 173 174 +---------------------------+ 175 | Q.922 Address* | 176 +-- --+ 177 | | 178 +---------------------------+ 179 | Control (UI = 0x03) | 180 +---------------------------+ 181 | Optional Pad (0x00) | 182 +---------------------------+ 183 | NLPID | 184 +---------------------------+ 185 | . | 186 | . | 187 | . | 188 | Data | 189 | . | 190 | . | 191 +---------------------------+ 192 193 * Q.922 addresses, as presently defined, are two octets and 194 contain a 10-bit DLCI. In some networks Q.922 addresses 195 may optionally be increased to three or four octets. 196 */ 197 198 static void 199 fr_hdr_print(netdissect_options *ndo, int length, u_int addr_len, 200 u_int dlci, uint32_t flags, uint16_t nlpid) 201 { 202 if (ndo->ndo_qflag) { 203 ND_PRINT("Q.922, DLCI %u, length %u: ", 204 dlci, 205 length); 206 } else { 207 if (nlpid <= 0xff) /* if its smaller than 256 then its a NLPID */ 208 ND_PRINT("Q.922, hdr-len %u, DLCI %u, Flags [%s], NLPID %s (0x%02x), length %u: ", 209 addr_len, 210 dlci, 211 bittok2str(fr_header_flag_values, "none", flags), 212 tok2str(nlpid_values,"unknown", nlpid), 213 nlpid, 214 length); 215 else /* must be an ethertype */ 216 ND_PRINT("Q.922, hdr-len %u, DLCI %u, Flags [%s], cisco-ethertype %s (0x%04x), length %u: ", 217 addr_len, 218 dlci, 219 bittok2str(fr_header_flag_values, "none", flags), 220 tok2str(ethertype_values, "unknown", nlpid), 221 nlpid, 222 length); 223 } 224 } 225 226 /* Frame Relay */ 227 void 228 fr_if_print(netdissect_options *ndo, 229 const struct pcap_pkthdr *h, const u_char *p) 230 { 231 u_int length = h->len; 232 u_int caplen = h->caplen; 233 234 ndo->ndo_protocol = "fr"; 235 if (caplen < 4) { /* minimum frame header length */ 236 nd_print_trunc(ndo); 237 ndo->ndo_ll_hdr_len += caplen; 238 return; 239 } 240 241 ndo->ndo_ll_hdr_len += fr_print(ndo, p, length); 242 } 243 244 u_int 245 fr_print(netdissect_options *ndo, 246 const u_char *p, u_int length) 247 { 248 int ret; 249 uint16_t extracted_ethertype; 250 u_int dlci; 251 u_int addr_len; 252 uint16_t nlpid; 253 u_int hdr_len; 254 uint32_t flags; 255 256 ndo->ndo_protocol = "fr"; 257 ret = parse_q922_header(ndo, p, &dlci, &addr_len, &flags, length); 258 if (ret == -1) 259 goto trunc; 260 if (ret == 0) { 261 ND_PRINT("Q.922, invalid address"); 262 return 0; 263 } 264 265 ND_TCHECK_1(p + addr_len); 266 if (length < addr_len + 1) 267 goto trunc; 268 269 if (GET_U_1(p + addr_len) != LLC_UI && dlci != 0) { 270 /* 271 * Let's figure out if we have Cisco-style encapsulation, 272 * with an Ethernet type (Cisco HDLC type?) following the 273 * address. 274 */ 275 if (!ND_TTEST_2(p + addr_len) || length < addr_len + 2) { 276 /* no Ethertype */ 277 ND_PRINT("UI %02x! ", GET_U_1(p + addr_len)); 278 } else { 279 extracted_ethertype = GET_BE_U_2(p + addr_len); 280 281 if (ndo->ndo_eflag) 282 fr_hdr_print(ndo, length, addr_len, dlci, 283 flags, extracted_ethertype); 284 285 if (ethertype_print(ndo, extracted_ethertype, 286 p+addr_len+ETHERTYPE_LEN, 287 length-addr_len-ETHERTYPE_LEN, 288 ND_BYTES_AVAILABLE_AFTER(p)-addr_len-ETHERTYPE_LEN, 289 NULL, NULL) == 0) 290 /* ether_type not known, probably it wasn't one */ 291 ND_PRINT("UI %02x! ", GET_U_1(p + addr_len)); 292 else 293 return addr_len + 2; 294 } 295 } 296 297 ND_TCHECK_1(p + addr_len + 1); 298 if (length < addr_len + 2) 299 goto trunc; 300 301 if (GET_U_1(p + addr_len + 1) == 0) { 302 /* 303 * Assume a pad byte after the control (UI) byte. 304 * A pad byte should only be used with 3-byte Q.922. 305 */ 306 if (addr_len != 3) 307 ND_PRINT("Pad! "); 308 hdr_len = addr_len + 1 /* UI */ + 1 /* pad */ + 1 /* NLPID */; 309 } else { 310 /* 311 * Not a pad byte. 312 * A pad byte should be used with 3-byte Q.922. 313 */ 314 if (addr_len == 3) 315 ND_PRINT("No pad! "); 316 hdr_len = addr_len + 1 /* UI */ + 1 /* NLPID */; 317 } 318 319 ND_TCHECK_1(p + hdr_len - 1); 320 if (length < hdr_len) 321 goto trunc; 322 nlpid = GET_U_1(p + hdr_len - 1); 323 324 if (ndo->ndo_eflag) 325 fr_hdr_print(ndo, length, addr_len, dlci, flags, nlpid); 326 p += hdr_len; 327 length -= hdr_len; 328 329 switch (nlpid) { 330 case NLPID_IP: 331 ip_print(ndo, p, length); 332 break; 333 334 case NLPID_IP6: 335 ip6_print(ndo, p, length); 336 break; 337 338 case NLPID_CLNP: 339 case NLPID_ESIS: 340 case NLPID_ISIS: 341 isoclns_print(ndo, p - 1, length + 1); /* OSI printers need the NLPID field */ 342 break; 343 344 case NLPID_SNAP: 345 if (snap_print(ndo, p, length, ND_BYTES_AVAILABLE_AFTER(p), NULL, NULL, 0) == 0) { 346 /* ether_type not known, print raw packet */ 347 if (!ndo->ndo_eflag) 348 fr_hdr_print(ndo, length + hdr_len, hdr_len, 349 dlci, flags, nlpid); 350 if (!ndo->ndo_suppress_default_print) 351 ND_DEFAULTPRINT(p - hdr_len, length + hdr_len); 352 } 353 break; 354 355 case NLPID_Q933: 356 q933_print(ndo, p, length); 357 break; 358 359 case NLPID_MFR: 360 frf15_print(ndo, p, length); 361 break; 362 363 case NLPID_PPP: 364 ppp_print(ndo, p, length); 365 break; 366 367 default: 368 if (!ndo->ndo_eflag) 369 fr_hdr_print(ndo, length + hdr_len, addr_len, 370 dlci, flags, nlpid); 371 if (!ndo->ndo_xflag) 372 ND_DEFAULTPRINT(p, length); 373 } 374 375 return hdr_len; 376 377 trunc: 378 nd_print_trunc(ndo); 379 return 0; 380 381 } 382 383 /* Multi Link Frame Relay (FRF.16) */ 384 void 385 mfr_if_print(netdissect_options *ndo, 386 const struct pcap_pkthdr *h, const u_char *p) 387 { 388 u_int length = h->len; 389 u_int caplen = h->caplen; 390 391 ndo->ndo_protocol = "mfr"; 392 if (caplen < 2) { /* minimum frame header length */ 393 nd_print_trunc(ndo); 394 ndo->ndo_ll_hdr_len += caplen; 395 return; 396 } 397 398 ndo->ndo_ll_hdr_len += mfr_print(ndo, p, length); 399 } 400 401 402 #define MFR_CTRL_MSG_ADD_LINK 1 403 #define MFR_CTRL_MSG_ADD_LINK_ACK 2 404 #define MFR_CTRL_MSG_ADD_LINK_REJ 3 405 #define MFR_CTRL_MSG_HELLO 4 406 #define MFR_CTRL_MSG_HELLO_ACK 5 407 #define MFR_CTRL_MSG_REMOVE_LINK 6 408 #define MFR_CTRL_MSG_REMOVE_LINK_ACK 7 409 410 static const struct tok mfr_ctrl_msg_values[] = { 411 { MFR_CTRL_MSG_ADD_LINK, "Add Link" }, 412 { MFR_CTRL_MSG_ADD_LINK_ACK, "Add Link ACK" }, 413 { MFR_CTRL_MSG_ADD_LINK_REJ, "Add Link Reject" }, 414 { MFR_CTRL_MSG_HELLO, "Hello" }, 415 { MFR_CTRL_MSG_HELLO_ACK, "Hello ACK" }, 416 { MFR_CTRL_MSG_REMOVE_LINK, "Remove Link" }, 417 { MFR_CTRL_MSG_REMOVE_LINK_ACK, "Remove Link ACK" }, 418 { 0, NULL } 419 }; 420 421 #define MFR_CTRL_IE_BUNDLE_ID 1 422 #define MFR_CTRL_IE_LINK_ID 2 423 #define MFR_CTRL_IE_MAGIC_NUM 3 424 #define MFR_CTRL_IE_TIMESTAMP 5 425 #define MFR_CTRL_IE_VENDOR_EXT 6 426 #define MFR_CTRL_IE_CAUSE 7 427 428 static const struct tok mfr_ctrl_ie_values[] = { 429 { MFR_CTRL_IE_BUNDLE_ID, "Bundle ID"}, 430 { MFR_CTRL_IE_LINK_ID, "Link ID"}, 431 { MFR_CTRL_IE_MAGIC_NUM, "Magic Number"}, 432 { MFR_CTRL_IE_TIMESTAMP, "Timestamp"}, 433 { MFR_CTRL_IE_VENDOR_EXT, "Vendor Extension"}, 434 { MFR_CTRL_IE_CAUSE, "Cause"}, 435 { 0, NULL } 436 }; 437 438 #define MFR_ID_STRING_MAXLEN 50 439 440 struct ie_tlv_header_t { 441 uint8_t ie_type; 442 uint8_t ie_len; 443 }; 444 445 u_int 446 mfr_print(netdissect_options *ndo, 447 const u_char *p, u_int length) 448 { 449 u_int tlen,idx,hdr_len = 0; 450 uint16_t sequence_num; 451 uint8_t ie_type,ie_len; 452 const uint8_t *tptr; 453 454 455 /* 456 * FRF.16 Link Integrity Control Frame 457 * 458 * 7 6 5 4 3 2 1 0 459 * +----+----+----+----+----+----+----+----+ 460 * | B | E | C=1| 0 0 0 0 | EA | 461 * +----+----+----+----+----+----+----+----+ 462 * | 0 0 0 0 0 0 0 0 | 463 * +----+----+----+----+----+----+----+----+ 464 * | message type | 465 * +----+----+----+----+----+----+----+----+ 466 */ 467 468 ndo->ndo_protocol = "mfr"; 469 470 if (length < 4) { /* minimum frame header length */ 471 ND_PRINT("[length %u < 4]", length); 472 nd_print_invalid(ndo); 473 return length; 474 } 475 ND_TCHECK_4(p); 476 477 if ((GET_U_1(p) & MFR_BEC_MASK) == MFR_CTRL_FRAME && GET_U_1(p + 1) == 0) { 478 ND_PRINT("FRF.16 Control, Flags [%s], %s, length %u", 479 bittok2str(frf_flag_values,"none",(GET_U_1(p) & MFR_BEC_MASK)), 480 tok2str(mfr_ctrl_msg_values,"Unknown Message (0x%02x)",GET_U_1(p + 2)), 481 length); 482 tptr = p + 3; 483 tlen = length -3; 484 hdr_len = 3; 485 486 if (!ndo->ndo_vflag) 487 return hdr_len; 488 489 while (tlen>sizeof(struct ie_tlv_header_t)) { 490 ND_TCHECK_LEN(tptr, sizeof(struct ie_tlv_header_t)); 491 ie_type=GET_U_1(tptr); 492 ie_len=GET_U_1(tptr + 1); 493 494 ND_PRINT("\n\tIE %s (%u), length %u: ", 495 tok2str(mfr_ctrl_ie_values,"Unknown",ie_type), 496 ie_type, 497 ie_len); 498 499 /* infinite loop check */ 500 if (ie_type == 0 || ie_len <= sizeof(struct ie_tlv_header_t)) 501 return hdr_len; 502 503 ND_TCHECK_LEN(tptr, ie_len); 504 tptr+=sizeof(struct ie_tlv_header_t); 505 /* tlv len includes header */ 506 ie_len-=sizeof(struct ie_tlv_header_t); 507 tlen-=sizeof(struct ie_tlv_header_t); 508 509 switch (ie_type) { 510 511 case MFR_CTRL_IE_MAGIC_NUM: 512 /* FRF.16.1 Section 3.4.3 Magic Number Information Element */ 513 if (ie_len != 4) { 514 ND_PRINT("[IE data length %d != 4]", ie_len); 515 nd_print_invalid(ndo); 516 break; 517 } 518 ND_PRINT("0x%08x", GET_BE_U_4(tptr)); 519 break; 520 521 case MFR_CTRL_IE_BUNDLE_ID: /* same message format */ 522 case MFR_CTRL_IE_LINK_ID: 523 for (idx = 0; idx < ie_len && idx < MFR_ID_STRING_MAXLEN; idx++) { 524 if (GET_U_1(tptr + idx) != 0) /* don't print null termination */ 525 fn_print_char(ndo, GET_U_1(tptr + idx)); 526 else 527 break; 528 } 529 break; 530 531 case MFR_CTRL_IE_TIMESTAMP: 532 /* 533 * FRF.16.1 Section 3.4.4 Timestamp Information Element 534 * 535 * The maximum length is 14 octets. Format is implementation 536 * specific. 537 */ 538 if (ie_len > 14) { 539 ND_PRINT("[Timestamp IE length %d > 14]", ie_len); 540 nd_print_invalid(ndo); 541 break; 542 } 543 /* fall through and hexdump */ 544 ND_FALL_THROUGH; 545 546 /* 547 * FIXME those are the defined IEs that lack a decoder 548 * you are welcome to contribute code ;-) 549 */ 550 551 case MFR_CTRL_IE_VENDOR_EXT: 552 case MFR_CTRL_IE_CAUSE: 553 554 default: 555 if (ndo->ndo_vflag <= 1) 556 print_unknown_data(ndo, tptr, "\n\t ", ie_len); 557 break; 558 } 559 560 /* do we want to see a hexdump of the IE ? */ 561 if (ndo->ndo_vflag > 1 ) 562 print_unknown_data(ndo, tptr, "\n\t ", ie_len); 563 564 tlen-=ie_len; 565 tptr+=ie_len; 566 } 567 return hdr_len; 568 } 569 /* 570 * FRF.16 Fragmentation Frame 571 * 572 * 7 6 5 4 3 2 1 0 573 * +----+----+----+----+----+----+----+----+ 574 * | B | E | C=0|seq. (high 4 bits) | EA | 575 * +----+----+----+----+----+----+----+----+ 576 * | sequence (low 8 bits) | 577 * +----+----+----+----+----+----+----+----+ 578 * | DLCI (6 bits) | CR | EA | 579 * +----+----+----+----+----+----+----+----+ 580 * | DLCI (4 bits) |FECN|BECN| DE | EA | 581 * +----+----+----+----+----+----+----+----+ 582 */ 583 584 sequence_num = (GET_U_1(p)&0x1e)<<7 | GET_U_1(p + 1); 585 /* whole packet or first fragment ? */ 586 if ((GET_U_1(p) & MFR_BEC_MASK) == MFR_FRAG_FRAME || 587 (GET_U_1(p) & MFR_BEC_MASK) == MFR_B_BIT) { 588 ND_PRINT("FRF.16 Frag, seq %u, Flags [%s], ", 589 sequence_num, 590 bittok2str(frf_flag_values,"none",(GET_U_1(p) & MFR_BEC_MASK))); 591 hdr_len = 2; 592 fr_print(ndo, p+hdr_len,length-hdr_len); 593 return hdr_len; 594 } 595 596 /* must be a middle or the last fragment */ 597 ND_PRINT("FRF.16 Frag, seq %u, Flags [%s]", 598 sequence_num, 599 bittok2str(frf_flag_values,"none",(GET_U_1(p) & MFR_BEC_MASK))); 600 print_unknown_data(ndo, p, "\n\t", length); 601 602 return hdr_len; 603 604 trunc: 605 nd_print_trunc(ndo); 606 return length; 607 } 608 609 /* an NLPID of 0xb1 indicates a 2-byte 610 * FRF.15 header 611 * 612 * 7 6 5 4 3 2 1 0 613 * +----+----+----+----+----+----+----+----+ 614 * ~ Q.922 header ~ 615 * +----+----+----+----+----+----+----+----+ 616 * | NLPID (8 bits) | NLPID=0xb1 617 * +----+----+----+----+----+----+----+----+ 618 * | B | E | C |seq. (high 4 bits) | R | 619 * +----+----+----+----+----+----+----+----+ 620 * | sequence (low 8 bits) | 621 * +----+----+----+----+----+----+----+----+ 622 */ 623 624 #define FR_FRF15_FRAGTYPE 0x01 625 626 static void 627 frf15_print(netdissect_options *ndo, 628 const u_char *p, u_int length) 629 { 630 uint16_t sequence_num, flags; 631 632 if (length < 2) 633 goto trunc; 634 635 flags = GET_U_1(p)&MFR_BEC_MASK; 636 sequence_num = (GET_U_1(p)&0x1e)<<7 | GET_U_1(p + 1); 637 638 ND_PRINT("FRF.15, seq 0x%03x, Flags [%s],%s Fragmentation, length %u", 639 sequence_num, 640 bittok2str(frf_flag_values,"none",flags), 641 GET_U_1(p)&FR_FRF15_FRAGTYPE ? "Interface" : "End-to-End", 642 length); 643 644 /* TODO: 645 * depending on all permutations of the B, E and C bit 646 * dig as deep as we can - e.g. on the first (B) fragment 647 * there is enough payload to print the IP header 648 * on non (B) fragments it depends if the fragmentation 649 * model is end-to-end or interface based whether we want to print 650 * another Q.922 header 651 */ 652 return; 653 654 trunc: 655 nd_print_trunc(ndo); 656 } 657 658 /* 659 * Q.933 decoding portion for framerelay specific. 660 */ 661 662 /* Q.933 packet format 663 Format of Other Protocols 664 using Q.933 NLPID 665 +-------------------------------+ 666 | Q.922 Address | 667 +---------------+---------------+ 668 |Control 0x03 | NLPID 0x08 | 669 +---------------+---------------+ 670 | L2 Protocol ID | 671 | octet 1 | octet 2 | 672 +-------------------------------+ 673 | L3 Protocol ID | 674 | octet 2 | octet 2 | 675 +-------------------------------+ 676 | Protocol Data | 677 +-------------------------------+ 678 | FCS | 679 +-------------------------------+ 680 */ 681 682 /* L2 (Octet 1)- Call Reference Usually is 0x0 */ 683 684 /* 685 * L2 (Octet 2)- Message Types definition 1 byte long. 686 */ 687 /* Call Establish */ 688 #define MSG_TYPE_ESC_TO_NATIONAL 0x00 689 #define MSG_TYPE_ALERT 0x01 690 #define MSG_TYPE_CALL_PROCEEDING 0x02 691 #define MSG_TYPE_CONNECT 0x07 692 #define MSG_TYPE_CONNECT_ACK 0x0F 693 #define MSG_TYPE_PROGRESS 0x03 694 #define MSG_TYPE_SETUP 0x05 695 /* Call Clear */ 696 #define MSG_TYPE_DISCONNECT 0x45 697 #define MSG_TYPE_RELEASE 0x4D 698 #define MSG_TYPE_RELEASE_COMPLETE 0x5A 699 #define MSG_TYPE_RESTART 0x46 700 #define MSG_TYPE_RESTART_ACK 0x4E 701 /* Status */ 702 #define MSG_TYPE_STATUS 0x7D 703 #define MSG_TYPE_STATUS_ENQ 0x75 704 705 static const struct tok fr_q933_msg_values[] = { 706 { MSG_TYPE_ESC_TO_NATIONAL, "ESC to National" }, 707 { MSG_TYPE_ALERT, "Alert" }, 708 { MSG_TYPE_CALL_PROCEEDING, "Call proceeding" }, 709 { MSG_TYPE_CONNECT, "Connect" }, 710 { MSG_TYPE_CONNECT_ACK, "Connect ACK" }, 711 { MSG_TYPE_PROGRESS, "Progress" }, 712 { MSG_TYPE_SETUP, "Setup" }, 713 { MSG_TYPE_DISCONNECT, "Disconnect" }, 714 { MSG_TYPE_RELEASE, "Release" }, 715 { MSG_TYPE_RELEASE_COMPLETE, "Release Complete" }, 716 { MSG_TYPE_RESTART, "Restart" }, 717 { MSG_TYPE_RESTART_ACK, "Restart ACK" }, 718 { MSG_TYPE_STATUS, "Status Reply" }, 719 { MSG_TYPE_STATUS_ENQ, "Status Enquiry" }, 720 { 0, NULL } 721 }; 722 723 #define IE_IS_SINGLE_OCTET(iecode) ((iecode) & 0x80) 724 #define IE_IS_SHIFT(iecode) (((iecode) & 0xF0) == 0x90) 725 #define IE_SHIFT_IS_NON_LOCKING(iecode) ((iecode) & 0x08) 726 #define IE_SHIFT_IS_LOCKING(iecode) (!(IE_SHIFT_IS_NON_LOCKING(iecode))) 727 #define IE_SHIFT_CODESET(iecode) ((iecode) & 0x07) 728 729 #define FR_LMI_ANSI_REPORT_TYPE_IE 0x01 730 #define FR_LMI_ANSI_LINK_VERIFY_IE_91 0x19 /* details? */ 731 #define FR_LMI_ANSI_LINK_VERIFY_IE 0x03 732 #define FR_LMI_ANSI_PVC_STATUS_IE 0x07 733 734 #define FR_LMI_CCITT_REPORT_TYPE_IE 0x51 735 #define FR_LMI_CCITT_LINK_VERIFY_IE 0x53 736 #define FR_LMI_CCITT_PVC_STATUS_IE 0x57 737 738 static const struct tok fr_q933_ie_values_codeset_0_5[] = { 739 { FR_LMI_ANSI_REPORT_TYPE_IE, "ANSI Report Type" }, 740 { FR_LMI_ANSI_LINK_VERIFY_IE_91, "ANSI Link Verify" }, 741 { FR_LMI_ANSI_LINK_VERIFY_IE, "ANSI Link Verify" }, 742 { FR_LMI_ANSI_PVC_STATUS_IE, "ANSI PVC Status" }, 743 { FR_LMI_CCITT_REPORT_TYPE_IE, "CCITT Report Type" }, 744 { FR_LMI_CCITT_LINK_VERIFY_IE, "CCITT Link Verify" }, 745 { FR_LMI_CCITT_PVC_STATUS_IE, "CCITT PVC Status" }, 746 { 0, NULL } 747 }; 748 749 #define FR_LMI_REPORT_TYPE_IE_FULL_STATUS 0 750 #define FR_LMI_REPORT_TYPE_IE_LINK_VERIFY 1 751 #define FR_LMI_REPORT_TYPE_IE_ASYNC_PVC 2 752 753 static const struct tok fr_lmi_report_type_ie_values[] = { 754 { FR_LMI_REPORT_TYPE_IE_FULL_STATUS, "Full Status" }, 755 { FR_LMI_REPORT_TYPE_IE_LINK_VERIFY, "Link verify" }, 756 { FR_LMI_REPORT_TYPE_IE_ASYNC_PVC, "Async PVC Status" }, 757 { 0, NULL } 758 }; 759 760 /* array of 16 codesets - currently we only support codepage 0 and 5 */ 761 static const struct tok *fr_q933_ie_codesets[] = { 762 fr_q933_ie_values_codeset_0_5, 763 NULL, 764 NULL, 765 NULL, 766 NULL, 767 fr_q933_ie_values_codeset_0_5, 768 NULL, 769 NULL, 770 NULL, 771 NULL, 772 NULL, 773 NULL, 774 NULL, 775 NULL, 776 NULL, 777 NULL 778 }; 779 780 static int fr_q933_print_ie_codeset_0_5(netdissect_options *ndo, u_int iecode, 781 u_int ielength, const u_char *p); 782 783 typedef int (*codeset_pr_func_t)(netdissect_options *, u_int iecode, 784 u_int ielength, const u_char *p); 785 786 /* array of 16 codesets - currently we only support codepage 0 and 5 */ 787 static const codeset_pr_func_t fr_q933_print_ie_codeset[] = { 788 fr_q933_print_ie_codeset_0_5, 789 NULL, 790 NULL, 791 NULL, 792 NULL, 793 fr_q933_print_ie_codeset_0_5, 794 NULL, 795 NULL, 796 NULL, 797 NULL, 798 NULL, 799 NULL, 800 NULL, 801 NULL, 802 NULL, 803 NULL 804 }; 805 806 /* 807 * ITU-T Q.933. 808 * 809 * p points to octet 2, the octet containing the length of the 810 * call reference value, so p[n] is octet n+2 ("octet X" is as 811 * used in Q.931/Q.933). 812 * 813 * XXX - actually used both for Q.931 and Q.933. 814 */ 815 void 816 q933_print(netdissect_options *ndo, 817 const u_char *p, u_int length) 818 { 819 u_int olen; 820 u_int call_ref_length, i; 821 uint8_t call_ref[15]; /* maximum length - length field is 4 bits */ 822 u_int msgtype; 823 u_int iecode; 824 u_int ielength; 825 u_int codeset = 0; 826 u_int is_ansi = 0; 827 u_int ie_is_known; 828 u_int non_locking_shift; 829 u_int unshift_codeset; 830 831 ndo->ndo_protocol = "q.933"; 832 ND_PRINT("%s", ndo->ndo_eflag ? "" : "Q.933"); 833 834 if (length == 0 || !ND_TTEST_1(p)) { 835 if (!ndo->ndo_eflag) 836 ND_PRINT(", "); 837 ND_PRINT("length %u", length); 838 goto trunc; 839 } 840 841 /* 842 * Get the length of the call reference value. 843 */ 844 olen = length; /* preserve the original length for display */ 845 call_ref_length = GET_U_1(p) & 0x0f; 846 p++; 847 length--; 848 849 /* 850 * Get the call reference value. 851 */ 852 for (i = 0; i < call_ref_length; i++) { 853 if (length == 0 || !ND_TTEST_1(p)) { 854 if (!ndo->ndo_eflag) 855 ND_PRINT(", "); 856 ND_PRINT("length %u", olen); 857 goto trunc; 858 } 859 call_ref[i] = GET_U_1(p); 860 p++; 861 length--; 862 } 863 864 /* 865 * Get the message type. 866 */ 867 if (length == 0 || !ND_TTEST_1(p)) { 868 if (!ndo->ndo_eflag) 869 ND_PRINT(", "); 870 ND_PRINT("length %u", olen); 871 goto trunc; 872 } 873 msgtype = GET_U_1(p); 874 p++; 875 length--; 876 877 /* 878 * Peek ahead to see if we start with a shift. 879 */ 880 non_locking_shift = 0; 881 unshift_codeset = codeset; 882 if (length != 0) { 883 if (!ND_TTEST_1(p)) { 884 if (!ndo->ndo_eflag) 885 ND_PRINT(", "); 886 ND_PRINT("length %u", olen); 887 goto trunc; 888 } 889 iecode = GET_U_1(p); 890 if (IE_IS_SHIFT(iecode)) { 891 /* 892 * It's a shift. Skip over it. 893 */ 894 p++; 895 length--; 896 897 /* 898 * Get the codeset. 899 */ 900 codeset = IE_SHIFT_CODESET(iecode); 901 902 /* 903 * If it's a locking shift to codeset 5, 904 * mark this as ANSI. (XXX - 5 is actually 905 * for national variants in general, not 906 * the US variant in particular, but maybe 907 * this is more American exceptionalism. :-)) 908 */ 909 if (IE_SHIFT_IS_LOCKING(iecode)) { 910 /* 911 * It's a locking shift. 912 */ 913 if (codeset == 5) { 914 /* 915 * It's a locking shift to 916 * codeset 5, so this is 917 * T1.617 Annex D. 918 */ 919 is_ansi = 1; 920 } 921 } else { 922 /* 923 * It's a non-locking shift. 924 * Remember the current codeset, so we 925 * can revert to it after the next IE. 926 */ 927 non_locking_shift = 1; 928 unshift_codeset = 0; 929 } 930 } 931 } 932 933 /* printing out header part */ 934 if (!ndo->ndo_eflag) 935 ND_PRINT(", "); 936 ND_PRINT("%s, codeset %u", is_ansi ? "ANSI" : "CCITT", codeset); 937 938 if (call_ref_length != 0) { 939 if (call_ref_length > 1 || GET_U_1(p) != 0) { 940 /* 941 * Not a dummy call reference. 942 */ 943 ND_PRINT(", Call Ref: 0x"); 944 for (i = 0; i < call_ref_length; i++) 945 ND_PRINT("%02x", call_ref[i]); 946 } 947 } 948 if (ndo->ndo_vflag) { 949 ND_PRINT(", %s (0x%02x), length %u", 950 tok2str(fr_q933_msg_values, 951 "unknown message", msgtype), 952 msgtype, 953 olen); 954 } else { 955 ND_PRINT(", %s", 956 tok2str(fr_q933_msg_values, 957 "unknown message 0x%02x", msgtype)); 958 } 959 960 /* Loop through the rest of the IEs */ 961 while (length != 0) { 962 /* 963 * What's the state of any non-locking shifts? 964 */ 965 if (non_locking_shift == 1) { 966 /* 967 * There's a non-locking shift in effect for 968 * this IE. Count it, so we reset the codeset 969 * before the next IE. 970 */ 971 non_locking_shift = 2; 972 } else if (non_locking_shift == 2) { 973 /* 974 * Unshift. 975 */ 976 codeset = unshift_codeset; 977 non_locking_shift = 0; 978 } 979 980 /* 981 * Get the first octet of the IE. 982 */ 983 if (!ND_TTEST_1(p)) { 984 if (!ndo->ndo_vflag) { 985 ND_PRINT(", length %u", olen); 986 } 987 goto trunc; 988 } 989 iecode = GET_U_1(p); 990 p++; 991 length--; 992 993 /* Single-octet IE? */ 994 if (IE_IS_SINGLE_OCTET(iecode)) { 995 /* 996 * Yes. Is it a shift? 997 */ 998 if (IE_IS_SHIFT(iecode)) { 999 /* 1000 * Yes. Is it locking? 1001 */ 1002 if (IE_SHIFT_IS_LOCKING(iecode)) { 1003 /* 1004 * Yes. 1005 */ 1006 non_locking_shift = 0; 1007 } else { 1008 /* 1009 * No. Remember the current 1010 * codeset, so we can revert 1011 * to it after the next IE. 1012 */ 1013 non_locking_shift = 1; 1014 unshift_codeset = codeset; 1015 } 1016 1017 /* 1018 * Get the codeset. 1019 */ 1020 codeset = IE_SHIFT_CODESET(iecode); 1021 } 1022 } else { 1023 /* 1024 * No. Get the IE length. 1025 */ 1026 if (length == 0 || !ND_TTEST_1(p)) { 1027 if (!ndo->ndo_vflag) { 1028 ND_PRINT(", length %u", olen); 1029 } 1030 goto trunc; 1031 } 1032 ielength = GET_U_1(p); 1033 p++; 1034 length--; 1035 1036 /* lets do the full IE parsing only in verbose mode 1037 * however some IEs (DLCI Status, Link Verify) 1038 * are also interesting in non-verbose mode */ 1039 if (ndo->ndo_vflag) { 1040 ND_PRINT("\n\t%s IE (0x%02x), length %u: ", 1041 tok2str(fr_q933_ie_codesets[codeset], 1042 "unknown", iecode), 1043 iecode, 1044 ielength); 1045 } 1046 1047 /* sanity checks */ 1048 if (iecode == 0 || ielength == 0) { 1049 return; 1050 } 1051 if (length < ielength || !ND_TTEST_LEN(p, ielength)) { 1052 if (!ndo->ndo_vflag) { 1053 ND_PRINT(", length %u", olen); 1054 } 1055 goto trunc; 1056 } 1057 1058 ie_is_known = 0; 1059 if (fr_q933_print_ie_codeset[codeset] != NULL) { 1060 ie_is_known = fr_q933_print_ie_codeset[codeset](ndo, iecode, ielength, p); 1061 } 1062 1063 if (ie_is_known) { 1064 /* 1065 * Known IE; do we want to see a hexdump 1066 * of it? 1067 */ 1068 if (ndo->ndo_vflag > 1) { 1069 /* Yes. */ 1070 print_unknown_data(ndo, p, "\n\t ", ielength); 1071 } 1072 } else { 1073 /* 1074 * Unknown IE; if we're printing verbosely, 1075 * print its content in hex. 1076 */ 1077 if (ndo->ndo_vflag >= 1) { 1078 print_unknown_data(ndo, p, "\n\t", ielength); 1079 } 1080 } 1081 1082 length -= ielength; 1083 p += ielength; 1084 } 1085 } 1086 if (!ndo->ndo_vflag) { 1087 ND_PRINT(", length %u", olen); 1088 } 1089 return; 1090 1091 trunc: 1092 nd_print_trunc(ndo); 1093 } 1094 1095 static int 1096 fr_q933_print_ie_codeset_0_5(netdissect_options *ndo, u_int iecode, 1097 u_int ielength, const u_char *p) 1098 { 1099 u_int dlci; 1100 1101 switch (iecode) { 1102 1103 case FR_LMI_ANSI_REPORT_TYPE_IE: /* fall through */ 1104 case FR_LMI_CCITT_REPORT_TYPE_IE: 1105 if (ielength < 1) { 1106 if (!ndo->ndo_vflag) { 1107 ND_PRINT(", "); 1108 } 1109 ND_PRINT("Invalid REPORT TYPE IE"); 1110 return 1; 1111 } 1112 if (ndo->ndo_vflag) { 1113 ND_PRINT("%s (%u)", 1114 tok2str(fr_lmi_report_type_ie_values,"unknown",GET_U_1(p)), 1115 GET_U_1(p)); 1116 } 1117 return 1; 1118 1119 case FR_LMI_ANSI_LINK_VERIFY_IE: /* fall through */ 1120 case FR_LMI_CCITT_LINK_VERIFY_IE: 1121 case FR_LMI_ANSI_LINK_VERIFY_IE_91: 1122 if (!ndo->ndo_vflag) { 1123 ND_PRINT(", "); 1124 } 1125 if (ielength < 2) { 1126 ND_PRINT("Invalid LINK VERIFY IE"); 1127 return 1; 1128 } 1129 ND_PRINT("TX Seq: %3d, RX Seq: %3d", GET_U_1(p), GET_U_1(p + 1)); 1130 return 1; 1131 1132 case FR_LMI_ANSI_PVC_STATUS_IE: /* fall through */ 1133 case FR_LMI_CCITT_PVC_STATUS_IE: 1134 if (!ndo->ndo_vflag) { 1135 ND_PRINT(", "); 1136 } 1137 /* now parse the DLCI information element. */ 1138 if ((ielength < 3) || 1139 (GET_U_1(p) & 0x80) || 1140 ((ielength == 3) && !(GET_U_1(p + 1) & 0x80)) || 1141 ((ielength == 4) && 1142 ((GET_U_1(p + 1) & 0x80) || !(GET_U_1(p + 2) & 0x80))) || 1143 ((ielength == 5) && 1144 ((GET_U_1(p + 1) & 0x80) || (GET_U_1(p + 2) & 0x80) || 1145 !(GET_U_1(p + 3) & 0x80))) || 1146 (ielength > 5) || 1147 !(GET_U_1(p + ielength - 1) & 0x80)) { 1148 ND_PRINT("Invalid DLCI in PVC STATUS IE"); 1149 return 1; 1150 } 1151 1152 dlci = ((GET_U_1(p) & 0x3F) << 4) | ((GET_U_1(p + 1) & 0x78) >> 3); 1153 if (ielength == 4) { 1154 dlci = (dlci << 6) | ((GET_U_1(p + 2) & 0x7E) >> 1); 1155 } else if (ielength == 5) { 1156 dlci = (dlci << 13) | (GET_U_1(p + 2) & 0x7F) | ((GET_U_1(p + 3) & 0x7E) >> 1); 1157 } 1158 1159 ND_PRINT("DLCI %u: status %s%s", dlci, 1160 GET_U_1(p + ielength - 1) & 0x8 ? "New, " : "", 1161 GET_U_1(p + ielength - 1) & 0x2 ? "Active" : "Inactive"); 1162 return 1; 1163 } 1164 1165 return 0; 1166 } 1167
Indexes created Tue Feb 24 08:35:24 UTC 2026