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 25 #include <sys/cdefs.h> 26 #ifndef lint 27 __RCSID("$NetBSD: print-llc.c,v 1.9 2017/09/08 14:01:13 christos Exp $"); 28 #endif 29 30 /* \summary: IEEE 802.2 LLC printer */ 31 32 #ifdef HAVE_CONFIG_H 33 #include "config.h" 34 #endif 35 36 #include <netdissect-stdinc.h> 37 38 #include "netdissect.h" 39 #include "addrtoname.h" 40 #include "extract.h" 41 42 #include "llc.h" 43 #include "ethertype.h" 44 #include "oui.h" 45 46 static const struct tok llc_values[] = { 47 { LLCSAP_NULL, "Null" }, 48 { LLCSAP_GLOBAL, "Global" }, 49 { LLCSAP_8021B_I, "802.1B I" }, 50 { LLCSAP_8021B_G, "802.1B G" }, 51 { LLCSAP_IP, "IP" }, 52 { LLCSAP_SNA, "SNA" }, 53 { LLCSAP_PROWAYNM, "ProWay NM" }, 54 { LLCSAP_8021D, "STP" }, 55 { LLCSAP_RS511, "RS511" }, 56 { LLCSAP_ISO8208, "ISO8208" }, 57 { LLCSAP_PROWAY, "ProWay" }, 58 { LLCSAP_SNAP, "SNAP" }, 59 { LLCSAP_IPX, "IPX" }, 60 { LLCSAP_NETBEUI, "NetBeui" }, 61 { LLCSAP_ISONS, "OSI" }, 62 { 0, NULL }, 63 }; 64 65 static const struct tok llc_cmd_values[] = { 66 { LLC_UI, "ui" }, 67 { LLC_TEST, "test" }, 68 { LLC_XID, "xid" }, 69 { LLC_UA, "ua" }, 70 { LLC_DISC, "disc" }, 71 { LLC_DM, "dm" }, 72 { LLC_SABME, "sabme" }, 73 { LLC_FRMR, "frmr" }, 74 { 0, NULL } 75 }; 76 77 static const struct tok llc_flag_values[] = { 78 { 0, "Command" }, 79 { LLC_GSAP, "Response" }, 80 { LLC_U_POLL, "Poll" }, 81 { LLC_GSAP|LLC_U_POLL, "Final" }, 82 { LLC_IS_POLL, "Poll" }, 83 { LLC_GSAP|LLC_IS_POLL, "Final" }, 84 { 0, NULL } 85 }; 86 87 88 static const struct tok llc_ig_flag_values[] = { 89 { 0, "Individual" }, 90 { LLC_IG, "Group" }, 91 { 0, NULL } 92 }; 93 94 95 static const struct tok llc_supervisory_values[] = { 96 { 0, "Receiver Ready" }, 97 { 1, "Receiver not Ready" }, 98 { 2, "Reject" }, 99 { 0, NULL } 100 }; 101 102 103 static const struct tok cisco_values[] = { 104 { PID_CISCO_CDP, "CDP" }, 105 { PID_CISCO_VTP, "VTP" }, 106 { PID_CISCO_DTP, "DTP" }, 107 { PID_CISCO_UDLD, "UDLD" }, 108 { PID_CISCO_PVST, "PVST" }, 109 { PID_CISCO_VLANBRIDGE, "VLAN Bridge" }, 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 uint32_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 * If we printed information about the payload, returns the length of the LLC 148 * header, plus the length of any SNAP header following it. 149 * 150 * Otherwise (for example, if the packet has unknown SAPs or has a SNAP 151 * header with an unknown OUI/PID combination), returns the *negative* 152 * of that value. 153 */ 154 int 155 llc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen, 156 const struct lladdr_info *src, const struct lladdr_info *dst) 157 { 158 uint8_t dsap_field, dsap, ssap_field, ssap; 159 uint16_t control; 160 int hdrlen; 161 int is_u; 162 163 if (caplen < 3) { 164 ND_PRINT((ndo, "[|llc]")); 165 ND_DEFAULTPRINT((const u_char *)p, caplen); 166 return (caplen); 167 } 168 if (length < 3) { 169 ND_PRINT((ndo, "[|llc]")); 170 ND_DEFAULTPRINT((const u_char *)p, caplen); 171 return (length); 172 } 173 174 dsap_field = *p; 175 ssap_field = *(p + 1); 176 177 /* 178 * OK, what type of LLC frame is this? The length 179 * of the control field depends on that - I frames 180 * have a two-byte control field, and U frames have 181 * a one-byte control field. 182 */ 183 control = *(p + 2); 184 if ((control & LLC_U_FMT) == LLC_U_FMT) { 185 /* 186 * U frame. 187 */ 188 is_u = 1; 189 hdrlen = 3; /* DSAP, SSAP, 1-byte control field */ 190 } else { 191 /* 192 * The control field in I and S frames is 193 * 2 bytes... 194 */ 195 if (caplen < 4) { 196 ND_PRINT((ndo, "[|llc]")); 197 ND_DEFAULTPRINT((const u_char *)p, caplen); 198 return (caplen); 199 } 200 if (length < 4) { 201 ND_PRINT((ndo, "[|llc]")); 202 ND_DEFAULTPRINT((const u_char *)p, caplen); 203 return (length); 204 } 205 206 /* 207 * ...and is little-endian. 208 */ 209 control = EXTRACT_LE_16BITS(p + 2); 210 is_u = 0; 211 hdrlen = 4; /* DSAP, SSAP, 2-byte control field */ 212 } 213 214 if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) { 215 /* 216 * This is an Ethernet_802.3 IPX frame; it has an 217 * 802.3 header (i.e., an Ethernet header where the 218 * type/length field is <= ETHERMTU, i.e. it's a length 219 * field, not a type field), but has no 802.2 header - 220 * the IPX packet starts right after the Ethernet header, 221 * with a signature of two bytes of 0xFF (which is 222 * LLCSAP_GLOBAL). 223 * 224 * (It might also have been an Ethernet_802.3 IPX at 225 * one time, but got bridged onto another network, 226 * such as an 802.11 network; this has appeared in at 227 * least one capture file.) 228 */ 229 230 if (ndo->ndo_eflag) 231 ND_PRINT((ndo, "IPX 802.3: ")); 232 233 ipx_print(ndo, p, length); 234 return (0); /* no LLC header */ 235 } 236 237 dsap = dsap_field & ~LLC_IG; 238 ssap = ssap_field & ~LLC_GSAP; 239 240 if (ndo->ndo_eflag) { 241 ND_PRINT((ndo, "LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s", 242 tok2str(llc_values, "Unknown", dsap), 243 dsap, 244 tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG), 245 tok2str(llc_values, "Unknown", ssap), 246 ssap, 247 tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP))); 248 249 if (is_u) { 250 ND_PRINT((ndo, ", ctrl 0x%02x: ", control)); 251 } else { 252 ND_PRINT((ndo, ", ctrl 0x%04x: ", control)); 253 } 254 } 255 256 /* 257 * Skip LLC header. 258 */ 259 p += hdrlen; 260 length -= hdrlen; 261 caplen -= hdrlen; 262 263 if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP 264 && control == LLC_UI) { 265 /* 266 * XXX - what *is* the right bridge pad value here? 267 * Does anybody ever bridge one form of LAN traffic 268 * over a networking type that uses 802.2 LLC? 269 */ 270 if (!snap_print(ndo, p, length, caplen, src, dst, 2)) { 271 /* 272 * Unknown packet type; tell our caller, by 273 * returning a negative value, so they 274 * can print the raw packet. 275 */ 276 return (-(hdrlen + 5)); /* include LLC and SNAP header */ 277 } else 278 return (hdrlen + 5); /* include LLC and SNAP header */ 279 } 280 281 if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D && 282 control == LLC_UI) { 283 stp_print(ndo, p, length); 284 return (hdrlen); 285 } 286 287 if (ssap == LLCSAP_IP && dsap == LLCSAP_IP && 288 control == LLC_UI) { 289 /* 290 * This is an RFC 948-style IP packet, with 291 * an 802.3 header and an 802.2 LLC header 292 * with the source and destination SAPs being 293 * the IP SAP. 294 */ 295 ip_print(ndo, p, length); 296 return (hdrlen); 297 } 298 299 if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX && 300 control == LLC_UI) { 301 /* 302 * This is an Ethernet_802.2 IPX frame, with an 802.3 303 * header and an 802.2 LLC header with the source and 304 * destination SAPs being the IPX SAP. 305 */ 306 if (ndo->ndo_eflag) 307 ND_PRINT((ndo, "IPX 802.2: ")); 308 309 ipx_print(ndo, p, length); 310 return (hdrlen); 311 } 312 313 #ifdef ENABLE_SMB 314 if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI 315 && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) { 316 /* 317 * we don't actually have a full netbeui parser yet, but the 318 * smb parser can handle many smb-in-netbeui packets, which 319 * is very useful, so we call that 320 * 321 * We don't call it for S frames, however, just I frames 322 * (which are frames that don't have the low-order bit, 323 * LLC_S_FMT, set in the first byte of the control field) 324 * and UI frames (whose control field is just 3, LLC_U_FMT). 325 */ 326 netbeui_print(ndo, control, p, length); 327 return (hdrlen); 328 } 329 #endif 330 if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS 331 && control == LLC_UI) { 332 isoclns_print(ndo, p, length); 333 return (hdrlen); 334 } 335 336 if (!ndo->ndo_eflag) { 337 if (ssap == dsap) { 338 if (src == NULL || dst == NULL) 339 ND_PRINT((ndo, "%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap))); 340 else 341 ND_PRINT((ndo, "%s > %s %s ", 342 (src->addr_string)(ndo, src->addr), 343 (dst->addr_string)(ndo, dst->addr), 344 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap))); 345 } else { 346 if (src == NULL || dst == NULL) 347 ND_PRINT((ndo, "%s > %s ", 348 tok2str(llc_values, "Unknown SSAP 0x%02x", ssap), 349 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap))); 350 else 351 ND_PRINT((ndo, "%s %s > %s %s ", 352 (src->addr_string)(ndo, src->addr), 353 tok2str(llc_values, "Unknown SSAP 0x%02x", ssap), 354 (dst->addr_string)(ndo, dst->addr), 355 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap))); 356 } 357 } 358 359 if (is_u) { 360 ND_PRINT((ndo, "Unnumbered, %s, Flags [%s], length %u", 361 tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)), 362 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)), 363 length + hdrlen)); 364 365 if ((control & ~LLC_U_POLL) == LLC_XID) { 366 if (length == 0) { 367 /* 368 * XID with no payload. 369 * This could, for example, be an SNA 370 * "short form" XID. 371 */ 372 return (hdrlen); 373 } 374 if (caplen < 1) { 375 ND_PRINT((ndo, "[|llc]")); 376 if (caplen > 0) 377 ND_DEFAULTPRINT((const u_char *)p, caplen); 378 return (hdrlen); 379 } 380 if (*p == LLC_XID_FI) { 381 if (caplen < 3 || length < 3) { 382 ND_PRINT((ndo, "[|llc]")); 383 if (caplen > 0) 384 ND_DEFAULTPRINT((const u_char *)p, caplen); 385 } else 386 ND_PRINT((ndo, ": %02x %02x", p[1], p[2])); 387 return (hdrlen); 388 } 389 } 390 } else { 391 if ((control & LLC_S_FMT) == LLC_S_FMT) { 392 ND_PRINT((ndo, "Supervisory, %s, rcv seq %u, Flags [%s], length %u", 393 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)), 394 LLC_IS_NR(control), 395 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)), 396 length + hdrlen)); 397 return (hdrlen); /* no payload to print */ 398 } else { 399 ND_PRINT((ndo, "Information, send seq %u, rcv seq %u, Flags [%s], length %u", 400 LLC_I_NS(control), 401 LLC_IS_NR(control), 402 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)), 403 length + hdrlen)); 404 } 405 } 406 return (-hdrlen); 407 } 408 409 static const struct tok * 410 oui_to_struct_tok(uint32_t orgcode) 411 { 412 const struct tok *tok = null_values; 413 const struct oui_tok *otp; 414 415 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) { 416 if (otp->oui == orgcode) { 417 tok = otp->tok; 418 break; 419 } 420 } 421 return (tok); 422 } 423 424 int 425 snap_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen, 426 const struct lladdr_info *src, const struct lladdr_info *dst, 427 u_int bridge_pad) 428 { 429 uint32_t orgcode; 430 register u_short et; 431 register int ret; 432 433 ND_TCHECK2(*p, 5); 434 if (caplen < 5 || length < 5) 435 goto trunc; 436 orgcode = EXTRACT_24BITS(p); 437 et = EXTRACT_16BITS(p + 3); 438 439 if (ndo->ndo_eflag) { 440 /* 441 * Somebody's already printed the MAC addresses, if there 442 * are any, so just print the SNAP header, not the MAC 443 * addresses. 444 */ 445 ND_PRINT((ndo, "oui %s (0x%06x), %s %s (0x%04x), length %u: ", 446 tok2str(oui_values, "Unknown", orgcode), 447 orgcode, 448 (orgcode == 0x000000 ? "ethertype" : "pid"), 449 tok2str(oui_to_struct_tok(orgcode), "Unknown", et), 450 et, length - 5)); 451 } 452 p += 5; 453 length -= 5; 454 caplen -= 5; 455 456 switch (orgcode) { 457 case OUI_ENCAP_ETHER: 458 case OUI_CISCO_90: 459 /* 460 * This is an encapsulated Ethernet packet, 461 * or a packet bridged by some piece of 462 * Cisco hardware; the protocol ID is 463 * an Ethernet protocol type. 464 */ 465 ret = ethertype_print(ndo, et, p, length, caplen, src, dst); 466 if (ret) 467 return (ret); 468 break; 469 470 case OUI_APPLETALK: 471 if (et == ETHERTYPE_ATALK) { 472 /* 473 * No, I have no idea why Apple used one 474 * of their own OUIs, rather than 475 * 0x000000, and an Ethernet packet 476 * type, for Appletalk data packets, 477 * but used 0x000000 and an Ethernet 478 * packet type for AARP packets. 479 */ 480 ret = ethertype_print(ndo, et, p, length, caplen, src, dst); 481 if (ret) 482 return (ret); 483 } 484 break; 485 486 case OUI_CISCO: 487 switch (et) { 488 case PID_CISCO_CDP: 489 cdp_print(ndo, p, length, caplen); 490 return (1); 491 case PID_CISCO_DTP: 492 dtp_print(ndo, p, length); 493 return (1); 494 case PID_CISCO_UDLD: 495 udld_print(ndo, p, length); 496 return (1); 497 case PID_CISCO_VTP: 498 vtp_print(ndo, p, length); 499 return (1); 500 case PID_CISCO_PVST: 501 case PID_CISCO_VLANBRIDGE: 502 stp_print(ndo, p, length); 503 return (1); 504 default: 505 break; 506 } 507 break; 508 509 case OUI_RFC2684: 510 switch (et) { 511 512 case PID_RFC2684_ETH_FCS: 513 case PID_RFC2684_ETH_NOFCS: 514 /* 515 * XXX - remove the last two bytes for 516 * PID_RFC2684_ETH_FCS? 517 */ 518 /* 519 * Skip the padding. 520 */ 521 ND_TCHECK2(*p, bridge_pad); 522 caplen -= bridge_pad; 523 length -= bridge_pad; 524 p += bridge_pad; 525 526 /* 527 * What remains is an Ethernet packet. 528 */ 529 ether_print(ndo, p, length, caplen, NULL, NULL); 530 return (1); 531 532 case PID_RFC2684_802_5_FCS: 533 case PID_RFC2684_802_5_NOFCS: 534 /* 535 * XXX - remove the last two bytes for 536 * PID_RFC2684_ETH_FCS? 537 */ 538 /* 539 * Skip the padding, but not the Access 540 * Control field. 541 */ 542 ND_TCHECK2(*p, bridge_pad); 543 caplen -= bridge_pad; 544 length -= bridge_pad; 545 p += bridge_pad; 546 547 /* 548 * What remains is an 802.5 Token Ring 549 * packet. 550 */ 551 token_print(ndo, p, length, caplen); 552 return (1); 553 554 case PID_RFC2684_FDDI_FCS: 555 case PID_RFC2684_FDDI_NOFCS: 556 /* 557 * XXX - remove the last two bytes for 558 * PID_RFC2684_ETH_FCS? 559 */ 560 /* 561 * Skip the padding. 562 */ 563 ND_TCHECK2(*p, bridge_pad + 1); 564 caplen -= bridge_pad + 1; 565 length -= bridge_pad + 1; 566 p += bridge_pad + 1; 567 568 /* 569 * What remains is an FDDI packet. 570 */ 571 fddi_print(ndo, p, length, caplen); 572 return (1); 573 574 case PID_RFC2684_BPDU: 575 stp_print(ndo, p, length); 576 return (1); 577 } 578 } 579 if (!ndo->ndo_eflag) { 580 /* 581 * Nobody printed the link-layer addresses, so print them, if 582 * we have any. 583 */ 584 if (src != NULL && dst != NULL) { 585 ND_PRINT((ndo, "%s > %s ", 586 (src->addr_string)(ndo, src->addr), 587 (dst->addr_string)(ndo, dst->addr))); 588 } 589 /* 590 * Print the SNAP header, but if the OUI is 000000, don't 591 * bother printing it, and report the PID as being an 592 * ethertype. 593 */ 594 if (orgcode == 0x000000) { 595 ND_PRINT((ndo, "SNAP, ethertype %s (0x%04x), length %u: ", 596 tok2str(ethertype_values, "Unknown", et), 597 et, length)); 598 } else { 599 ND_PRINT((ndo, "SNAP, oui %s (0x%06x), pid %s (0x%04x), length %u: ", 600 tok2str(oui_values, "Unknown", orgcode), 601 orgcode, 602 tok2str(oui_to_struct_tok(orgcode), "Unknown", et), 603 et, length)); 604 } 605 } 606 return (0); 607 608 trunc: 609 ND_PRINT((ndo, "[|snap]")); 610 return (1); 611 } 612 613 614 /* 615 * Local Variables: 616 * c-style: whitesmith 617 * c-basic-offset: 8 618 * End: 619 */ 620