The Tcpdump Group git mirrors - tcpdump/blob - print-sctp.c

   1 /* Copyright (c) 2001 NETLAB, Temple University
   2  * Copyright (c) 2001 Protocol Engineering Lab, University of Delaware
   3  *
   4  * Jerry Heinz <gheinz@astro.temple.edu>
   5  * John Fiore <jfiore@joda.cis.temple.edu>
   6  * Armando L. Caro Jr. <acaro@cis.udel.edu>
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the University nor of the Laboratory may be used
  20  *    to endorse or promote products derived from this software without
  21  *    specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 /* \summary: Stream Control Transmission Protocol (SCTP) printer */
  37
  38 #ifdef HAVE_CONFIG_H
  39 #include <config.h>
  40 #endif
  41
  42 #include "netdissect-stdinc.h"
  43
  44 #include "netdissect.h"
  45 #include "addrtoname.h"
  46 #include "extract.h"
  47 #include "ip.h"
  48 #include "ip6.h"
  49
  50 /* Definitions from:
  51  *
  52  * SCTP reference Implementation Copyright (C) 1999 Cisco And Motorola
  53  *
  54  * Redistribution and use in source and binary forms, with or without
  55  * modification, are permitted provided that the following conditions
  56  * are met:
  57  *
  58  * 1. Redistributions of source code must retain the above copyright
  59  *    notice, this list of conditions and the following disclaimer.
  60  *
  61  * 2. Redistributions in binary form must reproduce the above copyright
  62  *    notice, this list of conditions and the following disclaimer in the
  63  *    documentation and/or other materials provided with the distribution.
  64  *
  65  * 3. Neither the name of Cisco nor of Motorola may be used
  66  *    to endorse or promote products derived from this software without
  67  *    specific prior written permission.
  68  *
  69  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  70  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  71  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  72  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  73  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  74  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  75  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  76  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  77  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  78  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  79  * SUCH DAMAGE.
  80  *
  81  * This file is part of the SCTP reference Implementation
  82  *
  83  *
  84  * Please send any bug reports or fixes you make to one of the following email
  85  * addresses:
  86  *
  87  * rstewar1@email.mot.com
  88  * kmorneau@cisco.com
  89  * qxie1@email.mot.com
  90  *
  91  * Any bugs reported given to us we will try to fix... any fixes shared will
  92  * be incorperated into the next SCTP release.
  93  */
  94
  95 /* The valid defines for all message
  96  * types know to SCTP. 0 is reserved
  97  */
  98 #define SCTP_DATA               0x00
  99 #define SCTP_INITIATION         0x01
 100 #define SCTP_INITIATION_ACK     0x02
 101 #define SCTP_SELECTIVE_ACK      0x03
 102 #define SCTP_HEARTBEAT_REQUEST  0x04
 103 #define SCTP_HEARTBEAT_ACK      0x05
 104 #define SCTP_ABORT_ASSOCIATION  0x06
 105 #define SCTP_SHUTDOWN           0x07
 106 #define SCTP_SHUTDOWN_ACK       0x08
 107 #define SCTP_OPERATION_ERR      0x09
 108 #define SCTP_COOKIE_ECHO        0x0a
 109 #define SCTP_COOKIE_ACK         0x0b
 110 #define SCTP_ECN_ECHO           0x0c
 111 #define SCTP_ECN_CWR            0x0d
 112 #define SCTP_SHUTDOWN_COMPLETE  0x0e
 113 #define SCTP_FORWARD_CUM_TSN    0xc0
 114 #define SCTP_RELIABLE_CNTL      0xc1
 115 #define SCTP_RELIABLE_CNTL_ACK  0xc2
 116
 117 static const struct tok sctp_chunkid_str[] = {
 118         { SCTP_DATA,              "DATA"              },
 119         { SCTP_INITIATION,        "INIT"              },
 120         { SCTP_INITIATION_ACK,    "INIT ACK"          },
 121         { SCTP_SELECTIVE_ACK,     "SACK"              },
 122         { SCTP_HEARTBEAT_REQUEST, "HB REQ"            },
 123         { SCTP_HEARTBEAT_ACK,     "HB ACK"            },
 124         { SCTP_ABORT_ASSOCIATION, "ABORT"             },
 125         { SCTP_SHUTDOWN,          "SHUTDOWN"          },
 126         { SCTP_SHUTDOWN_ACK,      "SHUTDOWN ACK"      },
 127         { SCTP_OPERATION_ERR,     "OP ERR"            },
 128         { SCTP_COOKIE_ECHO,       "COOKIE ECHO"       },
 129         { SCTP_COOKIE_ACK,        "COOKIE ACK"        },
 130         { SCTP_ECN_ECHO,          "ECN ECHO"          },
 131         { SCTP_ECN_CWR,           "ECN CWR"           },
 132         { SCTP_SHUTDOWN_COMPLETE, "SHUTDOWN COMPLETE" },
 133         { SCTP_FORWARD_CUM_TSN,   "FOR CUM TSN"       },
 134         { SCTP_RELIABLE_CNTL,     "REL CTRL"          },
 135         { SCTP_RELIABLE_CNTL_ACK, "REL CTRL ACK"      },
 136         { 0, NULL }
 137 };
 138
 139 /* Data Chuck Specific Flags */
 140 #define SCTP_DATA_FRAG_MASK     0x03
 141 #define SCTP_DATA_MIDDLE_FRAG   0x00
 142 #define SCTP_DATA_LAST_FRAG     0x01
 143 #define SCTP_DATA_FIRST_FRAG    0x02
 144 #define SCTP_DATA_NOT_FRAG      0x03
 145 #define SCTP_DATA_UNORDERED     0x04
 146
 147 #define SCTP_ADDRMAX 60
 148
 149 #define CHAN_HP 6704
 150 #define CHAN_MP 6705
 151 #define CHAN_LP 6706
 152
 153 /* the sctp common header */
 154
 155 struct sctpHeader{
 156   nd_uint16_t source;
 157   nd_uint16_t destination;
 158   nd_uint32_t verificationTag;
 159   nd_uint32_t adler32;
 160 };
 161
 162 /* various descriptor parsers */
 163
 164 struct sctpChunkDesc{
 165   nd_uint8_t  chunkID;
 166   nd_uint8_t  chunkFlg;
 167   nd_uint16_t chunkLength;
 168 };
 169
 170 struct sctpParamDesc{
 171   nd_uint16_t paramType;
 172   nd_uint16_t paramLength;
 173 };
 174
 175
 176 struct sctpRelChunkDesc{
 177   struct sctpChunkDesc chk;
 178   nd_uint32_t serialNumber;
 179 };
 180
 181 struct sctpVendorSpecificParam {
 182   struct sctpParamDesc p;  /* type must be 0xfffe */
 183   nd_uint32_t vendorId;    /* vendor ID from RFC 1700 */
 184   nd_uint16_t vendorSpecificType;
 185   nd_uint16_t vendorSpecificLen;
 186 };
 187
 188
 189 /* Structures for the control parts */
 190
 191
 192
 193 /* Sctp association init request/ack */
 194
 195 /* this is used for init ack, too */
 196 struct sctpInitiation{
 197   nd_uint32_t initTag;                  /* tag of mine */
 198   nd_uint32_t rcvWindowCredit;          /* rwnd */
 199   nd_uint16_t NumPreopenStreams;        /* OS */
 200   nd_uint16_t MaxInboundStreams;        /* MIS */
 201   nd_uint32_t initialTSN;
 202   /* optional param's follow in sctpParamDesc form */
 203 };
 204
 205 struct sctpV4IpAddress{
 206   struct sctpParamDesc p;       /* type is set to SCTP_IPV4_PARAM_TYPE, len=10 */
 207   nd_ipv4  ipAddress;
 208 };
 209
 210
 211 struct sctpV6IpAddress{
 212   struct sctpParamDesc p;       /* type is set to SCTP_IPV6_PARAM_TYPE, len=22 */
 213   nd_ipv6  ipAddress;
 214 };
 215
 216 struct sctpDNSName{
 217   struct sctpParamDesc param;
 218   nd_byte name[1];
 219 };
 220
 221
 222 struct sctpCookiePreserve{
 223   struct sctpParamDesc p;       /* type is set to SCTP_COOKIE_PRESERVE, len=8 */
 224   nd_uint32_t extraTime;
 225 };
 226
 227
 228 struct sctpTimeStamp{
 229   nd_uint32_t ts_sec;
 230   nd_uint32_t ts_usec;
 231 };
 232
 233
 234 /* this guy is for use when
 235  * I have a initiate message gloming the
 236  * things together.
 237
 238  */
 239 struct sctpUnifiedInit{
 240   struct sctpChunkDesc uh;
 241   struct sctpInitiation initm;
 242 };
 243
 244 struct sctpSendableInit{
 245   struct sctpHeader mh;
 246   struct sctpUnifiedInit msg;
 247 };
 248
 249
 250 /* Selective Acknowledgement
 251  * has the following structure with
 252  * a optional ammount of trailing int's
 253  * on the last part (based on the numberOfDesc
 254  * field).
 255  */
 256
 257 struct sctpSelectiveAck{
 258   nd_uint32_t highestConseqTSN;
 259   nd_uint32_t updatedRwnd;
 260   nd_uint16_t numberOfdesc;
 261   nd_uint16_t numDupTsns;
 262 };
 263
 264 struct sctpSelectiveFrag{
 265   nd_uint16_t fragmentStart;
 266   nd_uint16_t fragmentEnd;
 267 };
 268
 269
 270 struct sctpUnifiedSack{
 271   struct sctpChunkDesc uh;
 272   struct sctpSelectiveAck sack;
 273 };
 274
 275 /* for the abort and shutdown ACK
 276  * we must carry the init tag in the common header. Just the
 277  * common header is all that is needed with a chunk descriptor.
 278  */
 279 struct sctpUnifiedAbort{
 280   struct sctpChunkDesc uh;
 281 };
 282
 283 struct sctpUnifiedAbortLight{
 284   struct sctpHeader mh;
 285   struct sctpChunkDesc uh;
 286 };
 287
 288 struct sctpUnifiedAbortHeavy{
 289   struct sctpHeader mh;
 290   struct sctpChunkDesc uh;
 291   nd_uint16_t causeCode;
 292   nd_uint16_t causeLen;
 293 };
 294
 295 /* For the graceful shutdown we must carry
 296  * the tag (in common header)  and the highest consequitive acking value
 297  */
 298 struct sctpShutdown {
 299   nd_uint32_t TSN_Seen;
 300 };
 301
 302 struct sctpUnifiedShutdown{
 303   struct sctpChunkDesc uh;
 304   struct sctpShutdown shut;
 305 };
 306
 307 /* in the unified message we add the trailing
 308  * stream id since it is the only message
 309  * that is defined as a operation error.
 310  */
 311 struct sctpOpErrorCause{
 312   nd_uint16_t cause;
 313   nd_uint16_t causeLen;
 314 };
 315
 316 struct sctpUnifiedOpError{
 317   struct sctpChunkDesc uh;
 318   struct sctpOpErrorCause c;
 319 };
 320
 321 struct sctpUnifiedStreamError{
 322   struct sctpHeader mh;
 323   struct sctpChunkDesc uh;
 324   struct sctpOpErrorCause c;
 325   nd_uint16_t strmNum;
 326   nd_uint16_t reserved;
 327 };
 328
 329 struct staleCookieMsg{
 330   struct sctpHeader mh;
 331   struct sctpChunkDesc uh;
 332   struct sctpOpErrorCause c;
 333   nd_uint32_t moretime;
 334 };
 335
 336 /* the following is used in all sends
 337  * where nothing is needed except the
 338  * chunk/type i.e. shutdownAck Abort */
 339
 340 struct sctpUnifiedSingleMsg{
 341   struct sctpHeader mh;
 342   struct sctpChunkDesc uh;
 343 };
 344
 345 struct sctpDataPart{
 346   nd_uint32_t TSN;
 347   nd_uint16_t streamId;
 348   nd_uint16_t sequence;
 349   nd_uint32_t payloadtype;
 350 };
 351
 352 struct sctpUnifiedDatagram{
 353   struct sctpChunkDesc uh;
 354   struct sctpDataPart dp;
 355 };
 356
 357 struct sctpECN_echo{
 358   struct sctpChunkDesc uh;
 359   nd_uint32_t Lowest_TSN;
 360 };
 361
 362
 363 struct sctpCWR{
 364   struct sctpChunkDesc uh;
 365   nd_uint32_t TSN_reduced_at;
 366 };
 367
 368 static const struct tok ForCES_channels[] = {
 369         { CHAN_HP, "ForCES HP" },
 370         { CHAN_MP, "ForCES MP" },
 371         { CHAN_LP, "ForCES LP" },
 372         { 0, NULL }
 373 };
 374
 375 /* data chunk's payload protocol identifiers */
 376
 377 #define SCTP_PPID_IUA 1
 378 #define SCTP_PPID_M2UA 2
 379 #define SCTP_PPID_M3UA 3
 380 #define SCTP_PPID_SUA 4
 381 #define SCTP_PPID_M2PA 5
 382 #define SCTP_PPID_V5UA 6
 383 #define SCTP_PPID_H248 7
 384 #define SCTP_PPID_BICC 8
 385 #define SCTP_PPID_TALI 9
 386 #define SCTP_PPID_DUA 10
 387 #define SCTP_PPID_ASAP 11
 388 #define SCTP_PPID_ENRP 12
 389 #define SCTP_PPID_H323 13
 390 #define SCTP_PPID_QIPC 14
 391 #define SCTP_PPID_SIMCO 15
 392 #define SCTP_PPID_DDPSC 16
 393 #define SCTP_PPID_DDPSSC 17
 394 #define SCTP_PPID_S1AP 18
 395 #define SCTP_PPID_RUA 19
 396 #define SCTP_PPID_HNBAP 20
 397 #define SCTP_PPID_FORCES_HP 21
 398 #define SCTP_PPID_FORCES_MP 22
 399 #define SCTP_PPID_FORCES_LP 23
 400 #define SCTP_PPID_SBC_AP 24
 401 #define SCTP_PPID_NBAP 25
 402 /* 26 */
 403 #define SCTP_PPID_X2AP 27
 404
 405 static const struct tok PayloadProto_idents[] = {
 406         { SCTP_PPID_IUA,    "ISDN Q.921" },
 407         { SCTP_PPID_M2UA,   "M2UA"   },
 408         { SCTP_PPID_M3UA,   "M3UA"   },
 409         { SCTP_PPID_SUA,    "SUA"    },
 410         { SCTP_PPID_M2PA,   "M2PA"   },
 411         { SCTP_PPID_V5UA,   "V5.2"   },
 412         { SCTP_PPID_H248,   "H.248"  },
 413         { SCTP_PPID_BICC,   "BICC"   },
 414         { SCTP_PPID_TALI,   "TALI"   },
 415         { SCTP_PPID_DUA,    "DUA"    },
 416         { SCTP_PPID_ASAP,   "ASAP"   },
 417         { SCTP_PPID_ENRP,   "ENRP"   },
 418         { SCTP_PPID_H323,   "H.323"  },
 419         { SCTP_PPID_QIPC,   "Q.IPC"  },
 420         { SCTP_PPID_SIMCO,  "SIMCO"  },
 421         { SCTP_PPID_DDPSC,  "DDPSC"  },
 422         { SCTP_PPID_DDPSSC, "DDPSSC" },
 423         { SCTP_PPID_S1AP,   "S1AP"   },
 424         { SCTP_PPID_RUA,    "RUA"    },
 425         { SCTP_PPID_HNBAP,  "HNBAP"  },
 426         { SCTP_PPID_FORCES_HP, "ForCES HP" },
 427         { SCTP_PPID_FORCES_MP, "ForCES MP" },
 428         { SCTP_PPID_FORCES_LP, "ForCES LP" },
 429         { SCTP_PPID_SBC_AP, "SBc-AP" },
 430         { SCTP_PPID_NBAP,   "NBAP"   },
 431         /* 26 */
 432         { SCTP_PPID_X2AP,   "X2AP"   },
 433         { 0, NULL }
 434 };
 435
 436
 437 static int
 438 isForCES_port(u_short Port)
 439 {
 440         if (Port == CHAN_HP)
 441                 return 1;
 442         if (Port == CHAN_MP)
 443                 return 1;
 444         if (Port == CHAN_LP)
 445                 return 1;
 446
 447         return 0;
 448 }
 449
 450 void
 451 sctp_print(netdissect_options *ndo,
 452            const u_char *bp,        /* beginning of sctp packet */
 453            const u_char *bp2,       /* beginning of enclosing */
 454            u_int sctpPacketLength)  /* ip packet */
 455 {
 456   u_int sctpPacketLengthRemaining;
 457   const struct sctpHeader *sctpPktHdr;
 458   const struct ip *ip;
 459   const struct ip6_hdr *ip6;
 460   uint8_t chunkID;
 461   u_short sourcePort, destPort;
 462   u_int chunkCount;
 463   const struct sctpChunkDesc *chunkDescPtr;
 464   const char *sep;
 465   int isforces = 0;
 466
 467   if (sctpPacketLength < sizeof(struct sctpHeader))
 468     {
 469       ND_PRINT("truncated-sctp - %ld bytes missing!",
 470                    (long)(sizeof(struct sctpHeader) - sctpPacketLength));
 471       return;
 472     }
 473   sctpPktHdr = (const struct sctpHeader*) bp;
 474   ND_TCHECK_SIZE(sctpPktHdr);
 475   sctpPacketLengthRemaining = sctpPacketLength;
 476
 477   sourcePort = EXTRACT_BE_U_2(sctpPktHdr->source);
 478   destPort = EXTRACT_BE_U_2(sctpPktHdr->destination);
 479
 480   ip = (const struct ip *)bp2;
 481   if (IP_V(ip) == 6)
 482     ip6 = (const struct ip6_hdr *)bp2;
 483   else
 484     ip6 = NULL;
 485
 486   if (ip6) {
 487     ND_PRINT("%s.%u > %s.%u: sctp",
 488       ip6addr_string(ndo, ip6->ip6_src),
 489       sourcePort,
 490       ip6addr_string(ndo, ip6->ip6_dst),
 491       destPort);
 492   } else
 493   {
 494     ND_PRINT("%s.%u > %s.%u: sctp",
 495       ipaddr_string(ndo, ip->ip_src),
 496       sourcePort,
 497       ipaddr_string(ndo, ip->ip_dst),
 498       destPort);
 499   }
 500
 501   if (isForCES_port(sourcePort)) {
 502          ND_PRINT("[%s]", tok2str(ForCES_channels, NULL, sourcePort));
 503          isforces = 1;
 504   }
 505   if (isForCES_port(destPort)) {
 506          ND_PRINT("[%s]", tok2str(ForCES_channels, NULL, destPort));
 507          isforces = 1;
 508   }
 509
 510   bp += sizeof(struct sctpHeader);
 511   sctpPacketLengthRemaining -= sizeof(struct sctpHeader);
 512
 513   if (ndo->ndo_vflag >= 2)
 514     sep = "\n\t";
 515   else
 516     sep = " (";
 517   /* cycle through all chunks, printing information on each one */
 518   for (chunkCount = 0, chunkDescPtr = (const struct sctpChunkDesc *)bp;
 519       sctpPacketLengthRemaining != 0;
 520       chunkCount++)
 521     {
 522       uint16_t chunkLength, chunkLengthRemaining;
 523       uint16_t align;
 524
 525       chunkDescPtr = (const struct sctpChunkDesc *)bp;
 526       if (sctpPacketLengthRemaining < sizeof(*chunkDescPtr)) {
 527         ND_PRINT("%s%u) [chunk descriptor cut off at end of packet]", sep, chunkCount+1);
 528         break;
 529       }
 530       ND_TCHECK_SIZE(chunkDescPtr);
 531       chunkLength = EXTRACT_BE_U_2(chunkDescPtr->chunkLength);
 532       if (chunkLength < sizeof(*chunkDescPtr)) {
 533         ND_PRINT("%s%u) [Bad chunk length %u, < size of chunk descriptor]", sep, chunkCount+1, chunkLength);
 534         break;
 535       }
 536       chunkLengthRemaining = chunkLength;
 537
 538       align = chunkLength % 4;
 539       if (align != 0)
 540         align = 4 - align;
 541
 542       if (sctpPacketLengthRemaining < align) {
 543         ND_PRINT("%s%u) [Bad chunk length %u, > remaining data in packet]", sep, chunkCount+1, chunkLength);
 544         break;
 545       }
 546
 547       ND_TCHECK_LEN(bp, chunkLength);
 548
 549       bp += sizeof(*chunkDescPtr);
 550       sctpPacketLengthRemaining -= sizeof(*chunkDescPtr);
 551       chunkLengthRemaining -= sizeof(*chunkDescPtr);
 552
 553       ND_PRINT("%s%u) ", sep, chunkCount+1);
 554       chunkID = EXTRACT_U_1(chunkDescPtr->chunkID);
 555       ND_PRINT("[%s] ", tok2str(sctp_chunkid_str, "Unknown chunk type: 0x%x",
 556                                       chunkID));
 557       switch (chunkID)
 558         {
 559         case SCTP_DATA :
 560           {
 561             const struct sctpDataPart *dataHdrPtr;
 562             uint8_t chunkFlg;
 563             uint32_t ppid;
 564             u_int payload_size;
 565
 566             chunkFlg = EXTRACT_U_1(chunkDescPtr->chunkFlg);
 567             if ((chunkFlg & SCTP_DATA_UNORDERED) == SCTP_DATA_UNORDERED)
 568               ND_PRINT("(U)");
 569
 570             if ((chunkFlg & SCTP_DATA_FIRST_FRAG) == SCTP_DATA_FIRST_FRAG)
 571               ND_PRINT("(B)");
 572
 573             if ((chunkFlg & SCTP_DATA_LAST_FRAG) == SCTP_DATA_LAST_FRAG)
 574               ND_PRINT("(E)");
 575
 576             if( ((chunkFlg & SCTP_DATA_UNORDERED) == SCTP_DATA_UNORDERED) ||
 577                 ((chunkFlg & SCTP_DATA_FIRST_FRAG) == SCTP_DATA_FIRST_FRAG) ||
 578                 ((chunkFlg & SCTP_DATA_LAST_FRAG) == SCTP_DATA_LAST_FRAG) )
 579               ND_PRINT(" ");
 580
 581             if (chunkLengthRemaining < sizeof(*dataHdrPtr)) {
 582                 ND_PRINT("bogus chunk length %u]", chunkLength);
 583                 return;
 584             }
 585             dataHdrPtr=(const struct sctpDataPart*)bp;
 586
 587             ppid = EXTRACT_BE_U_4(dataHdrPtr->payloadtype);
 588             ND_PRINT("[TSN: %u] ", EXTRACT_BE_U_4(dataHdrPtr->TSN));
 589             ND_PRINT("[SID: %u] ", EXTRACT_BE_U_2(dataHdrPtr->streamId));
 590             ND_PRINT("[SSEQ %u] ", EXTRACT_BE_U_2(dataHdrPtr->sequence));
 591             ND_PRINT("[PPID %s] ",
 592                     tok2str(PayloadProto_idents, "0x%x", ppid));
 593
 594             if (!isforces) {
 595                 isforces = (ppid == SCTP_PPID_FORCES_HP) ||
 596                     (ppid == SCTP_PPID_FORCES_MP) ||
 597                     (ppid == SCTP_PPID_FORCES_LP);
 598             }
 599
 600             bp += sizeof(*dataHdrPtr);
 601             sctpPacketLengthRemaining -= sizeof(*dataHdrPtr);
 602             chunkLengthRemaining -= sizeof(*dataHdrPtr);
 603             payload_size = chunkLengthRemaining;
 604             if (payload_size == 0) {
 605                 ND_PRINT("bogus chunk length %u]", chunkLength);
 606                 return;
 607             }
 608
 609             if (isforces) {
 610                 forces_print(ndo, bp, payload_size);
 611             } else if (ndo->ndo_vflag >= 2) {   /* if verbose output is specified */
 612                                         /* at the command line */
 613                 switch (ppid) {
 614                 case SCTP_PPID_M3UA :
 615                         m3ua_print(ndo, bp, payload_size);
 616                         break;
 617                 default:
 618                         ND_PRINT("[Payload");
 619                         if (!ndo->ndo_suppress_default_print) {
 620                                 ND_PRINT(":");
 621                                 ND_DEFAULTPRINT(bp, payload_size);
 622                         }
 623                         ND_PRINT("]");
 624                         break;
 625                 }
 626             }
 627             bp += payload_size;
 628             sctpPacketLengthRemaining -= payload_size;
 629             chunkLengthRemaining -= payload_size;
 630             break;
 631           }
 632         case SCTP_INITIATION :
 633           {
 634             const struct sctpInitiation *init;
 635
 636             if (chunkLengthRemaining < sizeof(*init)) {
 637                 ND_PRINT("bogus chunk length %u]", chunkLength);
 638                 return;
 639             }
 640             init=(const struct sctpInitiation*)bp;
 641             ND_PRINT("[init tag: %u] ", EXTRACT_BE_U_4(init->initTag));
 642             ND_PRINT("[rwnd: %u] ", EXTRACT_BE_U_4(init->rcvWindowCredit));
 643             ND_PRINT("[OS: %u] ", EXTRACT_BE_U_2(init->NumPreopenStreams));
 644             ND_PRINT("[MIS: %u] ", EXTRACT_BE_U_2(init->MaxInboundStreams));
 645             ND_PRINT("[init TSN: %u] ", EXTRACT_BE_U_4(init->initialTSN));
 646             bp += sizeof(*init);
 647             sctpPacketLengthRemaining -= sizeof(*init);
 648             chunkLengthRemaining -= sizeof(*init);
 649
 650 #if 0 /* ALC you can add code for optional params here */
 651             if( chunkLengthRemaining != 0 )
 652               ND_PRINT(" @@@@@ UNFINISHED @@@@@@%s\n",
 653                      "Optional params present, but not printed.");
 654 #endif
 655             bp += chunkLengthRemaining;
 656             sctpPacketLengthRemaining -= chunkLengthRemaining;
 657             chunkLengthRemaining = 0;
 658             break;
 659           }
 660         case SCTP_INITIATION_ACK :
 661           {
 662             const struct sctpInitiation *init;
 663
 664             if (chunkLengthRemaining < sizeof(*init)) {
 665                 ND_PRINT("bogus chunk length %u]", chunkLength);
 666                 return;
 667             }
 668             init=(const struct sctpInitiation*)bp;
 669             ND_PRINT("[init tag: %u] ", EXTRACT_BE_U_4(init->initTag));
 670             ND_PRINT("[rwnd: %u] ", EXTRACT_BE_U_4(init->rcvWindowCredit));
 671             ND_PRINT("[OS: %u] ", EXTRACT_BE_U_2(init->NumPreopenStreams));
 672             ND_PRINT("[MIS: %u] ", EXTRACT_BE_U_2(init->MaxInboundStreams));
 673             ND_PRINT("[init TSN: %u] ", EXTRACT_BE_U_4(init->initialTSN));
 674             bp += sizeof(*init);
 675             sctpPacketLengthRemaining -= sizeof(*init);
 676             chunkLengthRemaining -= sizeof(*init);
 677
 678 #if 0 /* ALC you can add code for optional params here */
 679             if( chunkLengthRemaining != 0 )
 680               ND_PRINT(" @@@@@ UNFINISHED @@@@@@%s\n",
 681                      "Optional params present, but not printed.");
 682 #endif
 683             bp += chunkLengthRemaining;
 684             sctpPacketLengthRemaining -= chunkLengthRemaining;
 685             chunkLengthRemaining = 0;
 686             break;
 687           }
 688         case SCTP_SELECTIVE_ACK:
 689           {
 690             const struct sctpSelectiveAck *sack;
 691             const struct sctpSelectiveFrag *frag;
 692             u_int fragNo, tsnNo;
 693             const u_char *dupTSN;
 694
 695             if (chunkLengthRemaining < sizeof(*sack)) {
 696               ND_PRINT("bogus chunk length %u]", chunkLength);
 697               return;
 698             }
 699             sack=(const struct sctpSelectiveAck*)bp;
 700             ND_PRINT("[cum ack %u] ", EXTRACT_BE_U_4(sack->highestConseqTSN));
 701             ND_PRINT("[a_rwnd %u] ", EXTRACT_BE_U_4(sack->updatedRwnd));
 702             ND_PRINT("[#gap acks %u] ", EXTRACT_BE_U_2(sack->numberOfdesc));
 703             ND_PRINT("[#dup tsns %u] ", EXTRACT_BE_U_2(sack->numDupTsns));
 704             bp += sizeof(*sack);
 705             sctpPacketLengthRemaining -= sizeof(*sack);
 706             chunkLengthRemaining -= sizeof(*sack);
 707
 708
 709             /* print gaps */
 710             for (fragNo=0;
 711                  chunkLengthRemaining != 0 && fragNo < EXTRACT_BE_U_2(sack->numberOfdesc);
 712                  bp += sizeof(*frag), sctpPacketLengthRemaining -= sizeof(*frag), chunkLengthRemaining -= sizeof(*frag), fragNo++) {
 713               if (chunkLengthRemaining < sizeof(*frag)) {
 714                 ND_PRINT("bogus chunk length %u]", chunkLength);
 715                 return;
 716               }
 717               frag = (const struct sctpSelectiveFrag *)bp;
 718               ND_PRINT("\n\t\t[gap ack block #%u: start = %u, end = %u] ",
 719                      fragNo+1,
 720                      EXTRACT_BE_U_4(sack->highestConseqTSN) + EXTRACT_BE_U_2(frag->fragmentStart),
 721                      EXTRACT_BE_U_4(sack->highestConseqTSN) + EXTRACT_BE_U_2(frag->fragmentEnd));
 722             }
 723
 724             /* print duplicate TSNs */
 725             for (tsnNo=0;
 726                  chunkLengthRemaining != 0 && tsnNo<EXTRACT_BE_U_2(sack->numDupTsns);
 727                  bp += 4, sctpPacketLengthRemaining -= 4, chunkLengthRemaining -= 4, tsnNo++) {
 728               if (chunkLengthRemaining < 4) {
 729                 ND_PRINT("bogus chunk length %u]", chunkLength);
 730                 return;
 731               }
 732               dupTSN = (const u_char *)bp;
 733               ND_PRINT("\n\t\t[dup TSN #%u: %u] ", tsnNo+1,
 734                 EXTRACT_BE_U_4(dupTSN));
 735             }
 736             break;
 737           }
 738         default :
 739           {
 740             bp += chunkLengthRemaining;
 741             sctpPacketLengthRemaining -= chunkLengthRemaining;
 742             chunkLengthRemaining = 0;
 743             break;
 744           }
 745         }
 746
 747       /*
 748        * Any extra stuff at the end of the chunk?
 749        * XXX - report this?
 750        */
 751       bp += chunkLengthRemaining;
 752       sctpPacketLengthRemaining -= chunkLengthRemaining;
 753
 754       if (ndo->ndo_vflag < 2)
 755         sep = ", (";
 756
 757       if (align != 0) {
 758         /*
 759          * Fail if the alignment padding isn't in the captured data.
 760          * Otherwise, skip it.
 761          */
 762         ND_TCHECK_LEN(bp, align);
 763         bp += align;
 764         sctpPacketLengthRemaining -= align;
 765       }
 766     }
 767     return;
 768
 769 trunc:
 770     ND_PRINT("[|sctp]");
 771 }