1 /* 2 * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997 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 * Code by Matt Thomas, Digital Equipment Corporation 22 * with an awful lot of hacking by Jeffrey Mogul, DECWRL 23 * 24 * $FreeBSD$ 25 */ 26 27 #ifndef lint 28 static const char rcsid[] _U_ = 29 "@(#) $Header: /tcpdump/master/tcpdump/print-llc.c,v 1.61.2.10 2007/02/08 07:07:51 guy Exp $"; 30 #endif 31 32 #ifdef HAVE_CONFIG_H 33 #include "config.h" 34 #endif 35 36 #include <tcpdump-stdinc.h> 37 38 #include <stdio.h> 39 #include <string.h> 40 41 #include "interface.h" 42 #include "addrtoname.h" 43 #include "extract.h" /* must come after interface.h */ 44 45 #include "llc.h" 46 #include "ethertype.h" 47 #include "oui.h" 48 49 static struct tok llc_values[] = { 50 { LLCSAP_NULL, "Null" }, 51 { LLCSAP_GLOBAL, "Global" }, 52 { LLCSAP_8021B_I, "802.1B I" }, 53 { LLCSAP_8021B_G, "802.1B G" }, 54 { LLCSAP_IP, "IP" }, 55 { LLCSAP_SNA, "SNA" }, 56 { LLCSAP_PROWAYNM, "ProWay NM" }, 57 { LLCSAP_8021D, "STP" }, 58 { LLCSAP_RS511, "RS511" }, 59 { LLCSAP_ISO8208, "ISO8208" }, 60 { LLCSAP_PROWAY, "ProWay" }, 61 { LLCSAP_SNAP, "SNAP" }, 62 { LLCSAP_IPX, "IPX" }, 63 { LLCSAP_NETBEUI, "NetBeui" }, 64 { LLCSAP_ISONS, "OSI" }, 65 { 0, NULL }, 66 }; 67 68 static struct tok llc_cmd_values[] = { 69 { LLC_UI, "ui" }, 70 { LLC_TEST, "test" }, 71 { LLC_XID, "xid" }, 72 { LLC_UA, "ua" }, 73 { LLC_DISC, "disc" }, 74 { LLC_DM, "dm" }, 75 { LLC_SABME, "sabme" }, 76 { LLC_FRMR, "frmr" }, 77 { 0, NULL } 78 }; 79 80 static const struct tok llc_flag_values[] = { 81 { 0, "Command" }, 82 { LLC_GSAP, "Response" }, 83 { LLC_U_POLL, "Poll" }, 84 { LLC_GSAP|LLC_U_POLL, "Final" }, 85 { LLC_IS_POLL, "Poll" }, 86 { LLC_GSAP|LLC_IS_POLL, "Final" }, 87 { 0, NULL } 88 }; 89 90 91 static const struct tok llc_ig_flag_values[] = { 92 { 0, "Individual" }, 93 { LLC_IG, "Group" }, 94 { 0, NULL } 95 }; 96 97 98 static const struct tok llc_supervisory_values[] = { 99 { 0, "Receiver Ready" }, 100 { 1, "Receiver not Ready" }, 101 { 2, "Reject" }, 102 { 0, NULL } 103 }; 104 105 106 static const struct tok cisco_values[] = { 107 { PID_CISCO_CDP, "CDP" }, 108 { PID_CISCO_VTP, "VTP" }, 109 { PID_CISCO_DTP, "DTP" }, 110 { 0, NULL } 111 }; 112 113 static const struct tok bridged_values[] = { 114 { PID_RFC2684_ETH_FCS, "Ethernet + FCS" }, 115 { PID_RFC2684_ETH_NOFCS, "Ethernet w/o FCS" }, 116 { PID_RFC2684_802_4_FCS, "802.4 + FCS" }, 117 { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" }, 118 { PID_RFC2684_802_5_FCS, "Token Ring + FCS" }, 119 { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" }, 120 { PID_RFC2684_FDDI_FCS, "FDDI + FCS" }, 121 { PID_RFC2684_FDDI_NOFCS, "FDDI w/o FCS" }, 122 { PID_RFC2684_802_6_FCS, "802.6 + FCS" }, 123 { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" }, 124 { PID_RFC2684_BPDU, "BPDU" }, 125 { 0, NULL }, 126 }; 127 128 static const struct tok null_values[] = { 129 { 0, NULL } 130 }; 131 132 struct oui_tok { 133 u_int32_t oui; 134 const struct tok *tok; 135 }; 136 137 static const struct oui_tok oui_to_tok[] = { 138 { OUI_ENCAP_ETHER, ethertype_values }, 139 { OUI_CISCO_90, ethertype_values }, /* uses some Ethertype values */ 140 { OUI_APPLETALK, ethertype_values }, /* uses some Ethertype values */ 141 { OUI_CISCO, cisco_values }, 142 { OUI_RFC2684, bridged_values }, /* bridged, RFC 2427 FR or RFC 2864 ATM */ 143 { 0, NULL } 144 }; 145 146 /* 147 * Returns non-zero IFF it succeeds in printing the header 148 */ 149 int 150 llc_print(const u_char *p, u_int length, u_int caplen, 151 const u_char *esrc, const u_char *edst, u_short *extracted_ethertype) 152 { 153 u_int8_t dsap_field, dsap, ssap_field, ssap; 154 u_int16_t control; 155 int is_u; 156 register int ret; 157 158 *extracted_ethertype = 0; 159 160 if (caplen < 3) { 161 (void)printf("[|llc]"); 162 default_print((u_char *)p, caplen); 163 return(0); 164 } 165 166 dsap_field = *p; 167 ssap_field = *(p + 1); 168 169 /* 170 * OK, what type of LLC frame is this? The length 171 * of the control field depends on that - I frames 172 * have a two-byte control field, and U frames have 173 * a one-byte control field. 174 */ 175 control = *(p + 2); 176 if ((control & LLC_U_FMT) == LLC_U_FMT) { 177 /* 178 * U frame. 179 */ 180 is_u = 1; 181 } else { 182 /* 183 * The control field in I and S frames is 184 * 2 bytes... 185 */ 186 if (caplen < 4) { 187 (void)printf("[|llc]"); 188 default_print((u_char *)p, caplen); 189 return(0); 190 } 191 192 /* 193 * ...and is little-endian. 194 */ 195 control = EXTRACT_LE_16BITS(p + 2); 196 is_u = 0; 197 } 198 199 if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) { 200 /* 201 * This is an Ethernet_802.3 IPX frame; it has an 202 * 802.3 header (i.e., an Ethernet header where the 203 * type/length field is <= ETHERMTU, i.e. it's a length 204 * field, not a type field), but has no 802.2 header - 205 * the IPX packet starts right after the Ethernet header, 206 * with a signature of two bytes of 0xFF (which is 207 * LLCSAP_GLOBAL). 208 * 209 * (It might also have been an Ethernet_802.3 IPX at 210 * one time, but got bridged onto another network, 211 * such as an 802.11 network; this has appeared in at 212 * least one capture file.) 213 */ 214 215 if (eflag) 216 printf("IPX 802.3: "); 217 218 ipx_print(p, length); 219 return (1); 220 } 221 222 dsap = dsap_field & ~LLC_IG; 223 ssap = ssap_field & ~LLC_GSAP; 224 225 if (eflag) { 226 printf("LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s", 227 tok2str(llc_values, "Unknown", dsap), 228 dsap, 229 tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG), 230 tok2str(llc_values, "Unknown", ssap), 231 ssap, 232 tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP)); 233 234 if (is_u) { 235 printf(", ctrl 0x%02x: ", control); 236 } else { 237 printf(", ctrl 0x%04x: ", control); 238 } 239 } 240 241 if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D && 242 control == LLC_UI) { 243 stp_print(p+3, length-3); 244 return (1); 245 } 246 247 if (ssap == LLCSAP_IP && dsap == LLCSAP_IP && 248 control == LLC_UI) { 249 ip_print(gndo, p+4, length-4); 250 return (1); 251 } 252 253 if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX && 254 control == LLC_UI) { 255 /* 256 * This is an Ethernet_802.2 IPX frame, with an 802.3 257 * header and an 802.2 LLC header with the source and 258 * destination SAPs being the IPX SAP. 259 * 260 * Skip DSAP, LSAP, and control field. 261 */ 262 if (eflag) 263 printf("IPX 802.2: "); 264 265 ipx_print(p+3, length-3); 266 return (1); 267 } 268 269 #ifdef TCPDUMP_DO_SMB 270 if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI 271 && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) { 272 /* 273 * we don't actually have a full netbeui parser yet, but the 274 * smb parser can handle many smb-in-netbeui packets, which 275 * is very useful, so we call that 276 * 277 * We don't call it for S frames, however, just I frames 278 * (which are frames that don't have the low-order bit, 279 * LLC_S_FMT, set in the first byte of the control field) 280 * and UI frames (whose control field is just 3, LLC_U_FMT). 281 */ 282 283 /* 284 * Skip the LLC header. 285 */ 286 if (is_u) { 287 p += 3; 288 length -= 3; 289 caplen -= 3; 290 } else { 291 p += 4; 292 length -= 4; 293 caplen -= 4; 294 } 295 netbeui_print(control, p, length); 296 return (1); 297 } 298 #endif 299 if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS 300 && control == LLC_UI) { 301 isoclns_print(p + 3, length - 3, caplen - 3); 302 return (1); 303 } 304 305 if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP 306 && control == LLC_UI) { 307 /* 308 * XXX - what *is* the right bridge pad value here? 309 * Does anybody ever bridge one form of LAN traffic 310 * over a networking type that uses 802.2 LLC? 311 */ 312 ret = snap_print(p+3, length-3, caplen-3, extracted_ethertype, 313 2); 314 if (ret) 315 return (ret); 316 } 317 318 if (!eflag) { 319 if (ssap == dsap) { 320 if (esrc == NULL || edst == NULL) 321 (void)printf("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)); 322 else 323 (void)printf("%s > %s %s ", 324 etheraddr_string(esrc), 325 etheraddr_string(edst), 326 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)); 327 } else { 328 if (esrc == NULL || edst == NULL) 329 (void)printf("%s > %s ", 330 tok2str(llc_values, "Unknown SSAP 0x%02x", ssap), 331 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)); 332 else 333 (void)printf("%s %s > %s %s ", 334 etheraddr_string(esrc), 335 tok2str(llc_values, "Unknown SSAP 0x%02x", ssap), 336 etheraddr_string(edst), 337 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)); 338 } 339 } 340 341 if (is_u) { 342 printf("Unnumbered, %s, Flags [%s], length %u", 343 tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)), 344 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)), 345 length); 346 347 p += 3; 348 length -= 3; 349 caplen -= 3; 350 351 if ((control & ~LLC_U_POLL) == LLC_XID) { 352 if (*p == LLC_XID_FI) { 353 printf(": %02x %02x", p[1], p[2]); 354 p += 3; 355 length -= 3; 356 caplen -= 3; 357 } 358 } 359 } else { 360 if ((control & LLC_S_FMT) == LLC_S_FMT) { 361 (void)printf("Supervisory, %s, rcv seq %u, Flags [%s], length %u", 362 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)), 363 LLC_IS_NR(control), 364 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)), 365 length); 366 } else { 367 (void)printf("Information, send seq %u, rcv seq %u, Flags [%s], length %u", 368 LLC_I_NS(control), 369 LLC_IS_NR(control), 370 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)), 371 length); 372 } 373 p += 4; 374 length -= 4; 375 caplen -= 4; 376 } 377 return(1); 378 } 379 380 int 381 snap_print(const u_char *p, u_int length, u_int caplen, 382 u_short *extracted_ethertype, u_int bridge_pad) 383 { 384 u_int32_t orgcode; 385 register u_short et; 386 register int ret; 387 388 TCHECK2(*p, 5); 389 orgcode = EXTRACT_24BITS(p); 390 et = EXTRACT_16BITS(p + 3); 391 392 if (eflag) { 393 const struct tok *tok = null_values; 394 const struct oui_tok *otp; 395 396 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) { 397 if (otp->oui == orgcode) { 398 tok = otp->tok; 399 break; 400 } 401 } 402 (void)printf("oui %s (0x%06x), %s %s (0x%04x): ", 403 tok2str(oui_values, "Unknown", orgcode), 404 orgcode, 405 (orgcode == 0x000000 ? "ethertype" : "pid"), 406 tok2str(tok, "Unknown", et), 407 et); 408 } 409 p += 5; 410 length -= 5; 411 caplen -= 5; 412 413 switch (orgcode) { 414 case OUI_ENCAP_ETHER: 415 case OUI_CISCO_90: 416 /* 417 * This is an encapsulated Ethernet packet, 418 * or a packet bridged by some piece of 419 * Cisco hardware; the protocol ID is 420 * an Ethernet protocol type. 421 */ 422 ret = ether_encap_print(et, p, length, caplen, 423 extracted_ethertype); 424 if (ret) 425 return (ret); 426 break; 427 428 case OUI_APPLETALK: 429 if (et == ETHERTYPE_ATALK) { 430 /* 431 * No, I have no idea why Apple used one 432 * of their own OUIs, rather than 433 * 0x000000, and an Ethernet packet 434 * type, for Appletalk data packets, 435 * but used 0x000000 and an Ethernet 436 * packet type for AARP packets. 437 */ 438 ret = ether_encap_print(et, p, length, caplen, 439 extracted_ethertype); 440 if (ret) 441 return (ret); 442 } 443 break; 444 445 case OUI_CISCO: 446 if (et == PID_CISCO_CDP) { 447 cdp_print(p, length, caplen); 448 return (1); 449 } 450 break; 451 452 case OUI_RFC2684: 453 switch (et) { 454 455 case PID_RFC2684_ETH_FCS: 456 case PID_RFC2684_ETH_NOFCS: 457 /* 458 * XXX - remove the last two bytes for 459 * PID_RFC2684_ETH_FCS? 460 */ 461 /* 462 * Skip the padding. 463 */ 464 TCHECK2(*p, bridge_pad); 465 caplen -= bridge_pad; 466 length -= bridge_pad; 467 p += bridge_pad; 468 469 /* 470 * What remains is an Ethernet packet. 471 */ 472 ether_print(p, length, caplen); 473 return (1); 474 475 case PID_RFC2684_802_5_FCS: 476 case PID_RFC2684_802_5_NOFCS: 477 /* 478 * XXX - remove the last two bytes for 479 * PID_RFC2684_ETH_FCS? 480 */ 481 /* 482 * Skip the padding, but not the Access 483 * Control field. 484 */ 485 TCHECK2(*p, bridge_pad); 486 caplen -= bridge_pad; 487 length -= bridge_pad; 488 p += bridge_pad; 489 490 /* 491 * What remains is an 802.5 Token Ring 492 * packet. 493 */ 494 token_print(p, length, caplen); 495 return (1); 496 497 case PID_RFC2684_FDDI_FCS: 498 case PID_RFC2684_FDDI_NOFCS: 499 /* 500 * XXX - remove the last two bytes for 501 * PID_RFC2684_ETH_FCS? 502 */ 503 /* 504 * Skip the padding. 505 */ 506 TCHECK2(*p, bridge_pad + 1); 507 caplen -= bridge_pad + 1; 508 length -= bridge_pad + 1; 509 p += bridge_pad + 1; 510 511 /* 512 * What remains is an FDDI packet. 513 */ 514 fddi_print(p, length, caplen); 515 return (1); 516 517 case PID_RFC2684_BPDU: 518 stp_print(p, length); 519 return (1); 520 } 521 } 522 return (0); 523 524 trunc: 525 (void)printf("[|snap]"); 526 return (1); 527 } 528 529 530 /* 531 * Local Variables: 532 * c-style: whitesmith 533 * c-basic-offset: 8 534 * End: 535 */ 536