The Tcpdump Group git mirrors - tcpdump/blob - 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 #ifndef lint
  23 static const char rcsid[] _U_ =
  24         "@(#)$Header: /tcpdump/master/tcpdump/print-fr.c,v 1.25 2004-10-09 17:55:26 hannes Exp $ (LBL)";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <tcpdump-stdinc.h>
  32
  33 #include <stdio.h>
  34 #include <string.h>
  35 #include <pcap.h>
  36
  37 #include "addrtoname.h"
  38 #include "interface.h"
  39 #include "ethertype.h"
  40 #include "nlpid.h"
  41 #include "extract.h"
  42
  43 static void lmi_print(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
  67 #define FR_EA_BIT       0x01
  68
  69 #define FR_CR_BIT       0x02000000
  70 #define FR_DE_BIT       0x00020000
  71 #define FR_BECN_BIT     0x00040000
  72 #define FR_FECN_BIT     0x00080000
  73 #define FR_SDLC_BIT     0x00000002
  74
  75
  76 struct tok fr_header_flag_values[] = {
  77     { FR_CR_BIT, "C!" },
  78     { FR_DE_BIT, "DE" },
  79     { FR_BECN_BIT, "BECN" },
  80     { FR_FECN_BIT, "FECN" },
  81     { FR_SDLC_BIT, "sdlcore" },
  82     { 0, NULL }
  83 };
  84
  85
  86 /* Finds out Q.922 address length, DLCI and flags. Returns 0 on success
  87  * save the flags dep. on address length
  88  */
  89 static int parse_q922_addr(const u_char *p, u_int *dlci, u_int *sdlcore,
  90                            u_int *addr_len, u_int8_t *flags)
  91 {
  92         if ((p[0] & FR_EA_BIT))
  93                 return -1;
  94
  95         *addr_len = 2;
  96         *dlci = ((p[0] & 0xFC) << 2) | ((p[1] & 0xF0) >> 4);
  97
  98         flags[0] = p[0] & 0x02; /* populate the frist flag fields */
  99         flags[1] = p[1] & 0x0c;
 100
 101         if (p[1] & FR_EA_BIT)
 102                 return 0;       /* 2-byte Q.922 address */
 103
 104         p += 2;
 105         (*addr_len)++;          /* 3- or 4-byte Q.922 address */
 106         if ((p[0] & FR_EA_BIT) == 0) {
 107                 *dlci = (*dlci << 7) | (p[0] >> 1);
 108                 (*addr_len)++;  /* 4-byte Q.922 address */
 109                 p++;
 110         }
 111
 112         if ((p[0] & FR_EA_BIT) == 0)
 113                 return -1; /* more than 4 bytes of Q.922 address? */
 114
 115         flags[3] = p[0] & 0x02;
 116
 117         if (p[0] & 0x02)
 118                 *sdlcore =  p[0] >> 2;
 119         else
 120                 *dlci = (*dlci << 6) | (p[0] >> 2);
 121
 122         return 0;
 123 }
 124
 125 /* Frame Relay packet structure, with flags and CRC removed
 126
 127                   +---------------------------+
 128                   |       Q.922 Address*      |
 129                   +--                       --+
 130                   |                           |
 131                   +---------------------------+
 132                   | Control (UI = 0x03)       |
 133                   +---------------------------+
 134                   | Optional Pad      (0x00)  |
 135                   +---------------------------+
 136                   | NLPID                     |
 137                   +---------------------------+
 138                   |             .             |
 139                   |             .             |
 140                   |             .             |
 141                   |           Data            |
 142                   |             .             |
 143                   |             .             |
 144                   +---------------------------+
 145
 146            * Q.922 addresses, as presently defined, are two octets and
 147              contain a 10-bit DLCI.  In some networks Q.922 addresses
 148              may optionally be increased to three or four octets.
 149 */
 150
 151 static u_int
 152 fr_hdrlen(const u_char *p, u_int addr_len, u_int caplen)
 153 {
 154         if ((caplen > addr_len + 1 /* UI */ + 1 /* pad */) &&
 155             !p[addr_len + 1] /* pad exist */)
 156                 return addr_len + 1 /* UI */ + 1 /* pad */ + 1 /* NLPID */;
 157         else
 158                 return addr_len + 1 /* UI */ + 1 /* NLPID */;
 159 }
 160
 161 static void
 162 fr_hdr_print(int length, u_int addr_len, u_int dlci, u_int8_t *flags, u_int16_t nlpid)
 163 {
 164     if (qflag) {
 165         (void)printf("Q.922, DLCI %u, length %u: ",
 166                      dlci,
 167                      length);
 168     } else {
 169         if (nlpid <= 0xff) /* if its smaller than 256 then its a NLPID */
 170             (void)printf("Q.922, hdr-len %u, DLCI %u, Flags [%s], NLPID %s (0x%02x), length %u: ",
 171                          addr_len,
 172                          dlci,
 173                          bittok2str(fr_header_flag_values, "none", EXTRACT_32BITS(flags)),
 174                          tok2str(nlpid_values,"unknown", nlpid),
 175                          nlpid,
 176                          length);
 177         else /* must be an ethertype */
 178             (void)printf("Q.922, hdr-len %u, DLCI %u, Flags [%s], cisco-ethertype %s (0x%04x), length %u: ",
 179                          addr_len,
 180                          dlci,
 181                          bittok2str(fr_header_flag_values, "none", EXTRACT_32BITS(flags)),
 182                          tok2str(ethertype_values, "unknown", nlpid),
 183                          nlpid,
 184                          length);
 185     }
 186 }
 187
 188 u_int
 189 fr_if_print(const struct pcap_pkthdr *h, register const u_char *p)
 190 {
 191         register u_int length = h->len;
 192         register u_int caplen = h->caplen;
 193         u_int16_t extracted_ethertype;
 194         u_int32_t orgcode;
 195         register u_short et;
 196         u_int dlci;
 197         u_int sdlcore;
 198         u_int addr_len;
 199         u_int16_t nlpid;
 200         u_int hdr_len;
 201         u_int8_t flags[4];
 202
 203         if (caplen < 4) {       /* minimum frame header length */
 204                 printf("[|fr]");
 205                 return caplen;
 206         }
 207
 208         if (parse_q922_addr(p, &dlci, &sdlcore, &addr_len, flags)) {
 209                 printf("Q.922, invalid address");
 210                 return caplen;
 211         }
 212
 213         hdr_len = fr_hdrlen(p, addr_len, caplen);
 214
 215         if (caplen < hdr_len) {
 216                 printf("[|fr]");
 217                 return caplen;
 218         }
 219
 220         if (p[addr_len] != 0x03) {
 221
 222                 /* lets figure out if we have cisco style encapsulation: */
 223                 extracted_ethertype = EXTRACT_16BITS(p+addr_len);
 224
 225                 if (eflag)
 226                     fr_hdr_print(length, addr_len, dlci, flags, extracted_ethertype);
 227
 228                 if (ether_encap_print(extracted_ethertype,
 229                                       p+addr_len+ETHERTYPE_LEN,
 230                                       length-addr_len-ETHERTYPE_LEN,
 231                                       caplen-addr_len-ETHERTYPE_LEN,
 232                                       &extracted_ethertype) == 0)
 233                     /* ether_type not known, probably it wasn't one */
 234                     printf("UI %02x! ", p[addr_len]);
 235                 else
 236                     return hdr_len;
 237         }
 238
 239         if (!p[addr_len + 1]) { /* pad byte should be used with 3-byte Q.922 */
 240                 if (addr_len != 3)
 241                         printf("Pad! ");
 242         } else if (addr_len == 3)
 243                 printf("No pad! ");
 244
 245         nlpid = p[hdr_len - 1];
 246
 247         if (eflag)
 248                 fr_hdr_print(length, addr_len, dlci, flags, nlpid);
 249
 250         p += hdr_len;
 251         length -= hdr_len;
 252         caplen -= hdr_len;
 253
 254         switch (nlpid) {
 255         case NLPID_IP:
 256                 ip_print(p, length);
 257                 break;
 258
 259 #ifdef INET6
 260         case NLPID_IP6:
 261                 ip6_print(p, length);
 262                 break;
 263 #endif
 264         case NLPID_CLNP:
 265         case NLPID_ESIS:
 266         case NLPID_ISIS:
 267                 isoclns_print(p, length, caplen);
 268                 break;
 269
 270         case NLPID_SNAP:
 271                 orgcode = EXTRACT_24BITS(p);
 272                 et = EXTRACT_16BITS(p + 3);
 273                 if (snap_print((const u_char *)(p + 5), length - 5,
 274                            caplen - 5, &extracted_ethertype, orgcode, et,
 275                            0) == 0) {
 276                         /* ether_type not known, print raw packet */
 277                         if (!eflag)
 278                             fr_hdr_print(length + hdr_len, hdr_len,
 279                                              dlci, flags, nlpid);
 280                         if (extracted_ethertype) {
 281                                 printf("(SNAP %s) ",
 282                                etherproto_string(htons(extracted_ethertype)));
 283                         }
 284                         if (!xflag && !qflag)
 285                                 default_print(p - hdr_len, caplen + hdr_len);
 286                 }
 287                 break;
 288
 289         case NLPID_LMI:
 290                 lmi_print(p, length);
 291                 break;
 292
 293         default:
 294                 if (!eflag)
 295                     fr_hdr_print(length + hdr_len, addr_len,
 296                                      dlci, flags, nlpid);
 297                 if (!xflag)
 298                         default_print(p, caplen);
 299         }
 300
 301         return hdr_len;
 302 }
 303
 304 /*
 305  * Q.933 decoding portion for framerelay specific.
 306  */
 307
 308 /* Q.933 packet format
 309                       Format of Other Protocols
 310                           using Q.933 NLPID
 311                   +-------------------------------+
 312                   |        Q.922 Address          |
 313                   +---------------+---------------+
 314                   |Control  0x03  | NLPID   0x08  |
 315                   +---------------+---------------+
 316                   |          L2 Protocol ID       |
 317                   | octet 1       |  octet 2      |
 318                   +-------------------------------+
 319                   |          L3 Protocol ID       |
 320                   | octet 2       |  octet 2      |
 321                   +-------------------------------+
 322                   |         Protocol Data         |
 323                   +-------------------------------+
 324                   | FCS                           |
 325                   +-------------------------------+
 326  */
 327
 328 /* L2 (Octet 1)- Call Reference Usually is 0x0 */
 329
 330 /*
 331  * L2 (Octet 2)- Message Types definition 1 byte long.
 332  */
 333 /* Call Establish */
 334 #define MSG_TYPE_ESC_TO_NATIONAL  0x00
 335 #define MSG_TYPE_ALERT            0x01
 336 #define MSG_TYPE_CALL_PROCEEDING  0x02
 337 #define MSG_TYPE_CONNECT          0x07
 338 #define MSG_TYPE_CONNECT_ACK      0x0F
 339 #define MSG_TYPE_PROGRESS         0x03
 340 #define MSG_TYPE_SETUP            0x05
 341 /* Call Clear */
 342 #define MSG_TYPE_DISCONNECT       0x45
 343 #define MSG_TYPE_RELEASE          0x4D
 344 #define MSG_TYPE_RELEASE_COMPLETE 0x5A
 345 #define MSG_TYPE_RESTART          0x46
 346 #define MSG_TYPE_RESTART_ACK      0x4E
 347 /* Status */
 348 #define MSG_TYPE_STATUS           0x7D
 349 #define MSG_TYPE_STATUS_ENQ       0x75
 350
 351 struct tok fr_lmi_msg_values[] = {
 352     { MSG_TYPE_ESC_TO_NATIONAL, "ESC to National" },
 353     { MSG_TYPE_ALERT, "Alert" },
 354     { MSG_TYPE_CALL_PROCEEDING, "Call proceeding" },
 355     { MSG_TYPE_CONNECT, "Connect" },
 356     { MSG_TYPE_CONNECT_ACK, "Connect ACK" },
 357     { MSG_TYPE_PROGRESS, "Progress" },
 358     { MSG_TYPE_SETUP, "Setup" },
 359     { MSG_TYPE_DISCONNECT, "Disconnect" },
 360     { MSG_TYPE_RELEASE, "Release" },
 361     { MSG_TYPE_RELEASE_COMPLETE, "Release Complete" },
 362     { MSG_TYPE_RESTART, "Restart" },
 363     { MSG_TYPE_RESTART_ACK, "Restart ACK" },
 364     { MSG_TYPE_STATUS, "Status Reply" },
 365     { MSG_TYPE_STATUS_ENQ, "Status Enquiry" },
 366     { 0, NULL }
 367 };
 368
 369 #define MSG_ANSI_LOCKING_SHIFT  0x95
 370
 371 #define FR_LMI_ANSI_REPORT_TYPE_IE      0x01
 372 #define FR_LMI_ANSI_LINK_VERIFY_IE_91   0x19 /* details? */
 373 #define FR_LMI_ANSI_LINK_VERIFY_IE      0x03
 374 #define FR_LMI_ANSI_PVC_STATUS_IE       0x07
 375
 376 #define FR_LMI_CCITT_REPORT_TYPE_IE     0x51
 377 #define FR_LMI_CCITT_LINK_VERIFY_IE     0x53
 378 #define FR_LMI_CCITT_PVC_STATUS_IE      0x57
 379
 380 struct tok fr_lmi_ie_values[] = {
 381     { FR_LMI_ANSI_REPORT_TYPE_IE, "ANSI Report Type" },
 382     { FR_LMI_ANSI_LINK_VERIFY_IE_91, "ANSI Link Verify" },
 383     { FR_LMI_ANSI_LINK_VERIFY_IE, "ANSI Link Verify" },
 384     { FR_LMI_ANSI_PVC_STATUS_IE, "ANSI PVC Status" },
 385     { FR_LMI_CCITT_REPORT_TYPE_IE, "CCITT Report Type" },
 386     { FR_LMI_CCITT_LINK_VERIFY_IE, "CCITT Link Verify" },
 387     { FR_LMI_CCITT_PVC_STATUS_IE, "CCITT PVC Status" },
 388     { 0, NULL }
 389 };
 390
 391 #define FR_LMI_REPORT_TYPE_IE_FULL_STATUS 0
 392 #define FR_LMI_REPORT_TYPE_IE_LINK_VERIFY 1
 393 #define FR_LMI_REPORT_TYPE_IE_ASYNC_PVC   2
 394
 395 struct tok fr_lmi_report_type_ie_values[] = {
 396     { FR_LMI_REPORT_TYPE_IE_FULL_STATUS, "Full Status" },
 397     { FR_LMI_REPORT_TYPE_IE_LINK_VERIFY, "Link verify" },
 398     { FR_LMI_REPORT_TYPE_IE_ASYNC_PVC, "Async PVC Status" },
 399     { 0, NULL }
 400 };
 401
 402 struct common_ie_header {
 403     u_int8_t ie_id;
 404     u_int8_t ie_len;
 405 };
 406
 407 static void
 408 lmi_print(const u_char *p, u_int length)
 409 {
 410         const u_char *ptemp = p;
 411         struct common_ie_header *ie_p;
 412         int olen;
 413         int is_ansi = 0;
 414         u_int dlci;
 415
 416         if (length < 9) {       /* shortest: Q.933a LINK VERIFY */
 417                 printf("[|lmi]");
 418                 return;
 419         }
 420
 421         if (p[2] == MSG_ANSI_LOCKING_SHIFT)
 422                 is_ansi = 1;
 423
 424         if (!eflag)
 425             printf("Q.933 LMI, ");
 426
 427         /* printing out header part */
 428         printf(is_ansi ? "ANSI" : "CCITT ");
 429
 430         if (p[0])
 431                 printf(", Call Ref: 0x%02x", p[0]);
 432
 433         if (vflag)
 434             printf(", %s (0x%02x), length %u",
 435                    tok2str(fr_lmi_msg_values,"unknown message",p[1]),
 436                    p[1],
 437                    length);
 438         else
 439             printf(", %s",
 440                    tok2str(fr_lmi_msg_values,"unknown message 0x%02x",p[1]));
 441
 442         olen = length; /* preserve the original length for non verbose mode */
 443
 444         if (length < (u_int)(2 - is_ansi)) {
 445                 printf("[|lmi]");
 446                 return;
 447         }
 448         length -= 2 - is_ansi;
 449         ptemp += 2 + is_ansi;
 450
 451         /* Loop through the rest of IE */
 452         while (length > 0) {
 453                 ie_p = (struct common_ie_header *)ptemp;
 454                 if (length < sizeof(struct common_ie_header) ||
 455                     length < sizeof(struct common_ie_header) + ie_p->ie_len) {
 456                     if (vflag) /* not bark if there is just a trailer */
 457                         printf("\n[|lmi]");
 458                     else
 459                         printf(", length %u",olen);
 460                     return;
 461                 }
 462
 463                 /* lets do the full IE parsing only in verbose mode
 464                  * however some IEs (DLCI Status, Link Verify)
 465                  * are also intereststing in non-verbose mode */
 466                 if (vflag)
 467                     printf("\n\t%s IE (%u), length %u: ",
 468                            tok2str(fr_lmi_ie_values,"unknown",ie_p->ie_id),
 469                            ie_p->ie_id,
 470                            ie_p->ie_len);
 471
 472                 switch (ie_p->ie_id) {
 473
 474                 case FR_LMI_ANSI_REPORT_TYPE_IE: /* fall through */
 475                 case FR_LMI_CCITT_REPORT_TYPE_IE:
 476                     if (vflag)
 477                         printf("%s (%u)",
 478                                tok2str(fr_lmi_report_type_ie_values,"unknown",ptemp[2]),
 479                                ptemp[2]);
 480                     break;
 481
 482                 case FR_LMI_ANSI_LINK_VERIFY_IE: /* fall through */
 483                 case FR_LMI_CCITT_LINK_VERIFY_IE:
 484                 case FR_LMI_ANSI_LINK_VERIFY_IE_91:
 485                     if (!vflag)
 486                         printf(", ");
 487                     printf("TX Seq: %3d, RX Seq: %3d", ptemp[2], ptemp[3]);
 488                     break;
 489                 case FR_LMI_ANSI_PVC_STATUS_IE: /* fall through */
 490                 case FR_LMI_CCITT_PVC_STATUS_IE:
 491                     if (!vflag)
 492                         printf(", ");
 493                     /* now parse the DLCI information element. */
 494                     if ((ie_p->ie_len < 3) ||
 495                         (ptemp[2] & 0x80) ||
 496                         ((ie_p->ie_len == 3) && !(ptemp[3] & 0x80)) ||
 497                         ((ie_p->ie_len == 4) && ((ptemp[3] & 0x80) || !(ptemp[4] & 0x80))) ||
 498                         ((ie_p->ie_len == 5) && ((ptemp[3] & 0x80) || (ptemp[4] & 0x80) ||
 499                                            !(ptemp[5] & 0x80))) ||
 500                         (ie_p->ie_len > 5) ||
 501                         !(ptemp[ie_p->ie_len + 1] & 0x80))
 502                         printf("Invalid DLCI IE");
 503
 504                     dlci = ((ptemp[2] & 0x3F) << 4) | ((ptemp[3] & 0x78) >> 3);
 505                     if (ie_p->ie_len == 4)
 506                         dlci = (dlci << 6) | ((ptemp[4] & 0x7E) >> 1);
 507                     else if (ie_p->ie_len == 5)
 508                         dlci = (dlci << 13) | (ptemp[4] & 0x7F) | ((ptemp[5] & 0x7E) >> 1);
 509
 510                     printf("DLCI %u: status %s%s", dlci,
 511                              ptemp[ie_p->ie_len + 1] & 0x8 ? "New, " : "",
 512                              ptemp[ie_p->ie_len + 1] & 0x2 ? "Active" : "Inactive");
 513                     break;
 514
 515                 default:
 516                     if (vflag <= 1)
 517                         print_unknown_data(ptemp+2,"\n\t",ie_p->ie_len);
 518                     break;
 519                 }
 520
 521                 /* do we want to see a hexdump of the IE ? */
 522                 if (vflag> 1)
 523                     print_unknown_data(ptemp+2,"\n\t  ",ie_p->ie_len);
 524
 525                 length = length - ie_p->ie_len - 2;
 526                 ptemp = ptemp + ie_p->ie_len + 2;
 527         }
 528         if (!vflag)
 529             printf(", length %u",olen);
 530 }