xref: /minix/external/bsd/tcpdump/dist/print-sctp.c (revision b636d99d)
1 /*
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 #include <sys/cdefs.h>
37 #ifndef lint
38 __RCSID("$NetBSD: print-sctp.c,v 1.6 2014/11/20 03:05:03 christos Exp $");
39 #endif
40 
41 #define NETDISSECT_REWORKED
42 #ifdef HAVE_CONFIG_H
43 #include "config.h"
44 #endif
45 
46 #include <tcpdump-stdinc.h>
47 
48 #include "interface.h"
49 #include "addrtoname.h"
50 #include "extract.h"			/* must come after interface.h */
51 #include "ip.h"
52 #ifdef INET6
53 #include "ip6.h"
54 #endif
55 
56 /* Definitions from:
57  *
58  * SCTP reference Implementation Copyright (C) 1999 Cisco And Motorola
59  *
60  * Redistribution and use in source and binary forms, with or without
61  * modification, are permitted provided that the following conditions
62  * are met:
63  *
64  * 1. Redistributions of source code must retain the above copyright
65  *    notice, this list of conditions and the following disclaimer.
66  *
67  * 2. Redistributions in binary form must reproduce the above copyright
68  *    notice, this list of conditions and the following disclaimer in the
69  *    documentation and/or other materials provided with the distribution.
70  *
71  * 3. Neither the name of Cisco nor of Motorola may be used
72  *    to endorse or promote products derived from this software without
73  *    specific prior written permission.
74  *
75  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
76  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
77  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
78  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
79  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
80  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
81  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
82  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
83  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
84  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
85  * SUCH DAMAGE.
86  *
87  * This file is part of the SCTP reference Implementation
88  *
89  *
90  * Please send any bug reports or fixes you make to one of the following email
91  * addresses:
92  *
93  * rstewar1@email.mot.com
94  * kmorneau@cisco.com
95  * qxie1@email.mot.com
96  *
97  * Any bugs reported given to us we will try to fix... any fixes shared will
98  * be incorperated into the next SCTP release.
99  */
100 
101 /* The valid defines for all message
102  * types know to SCTP. 0 is reserved
103  */
104 #define SCTP_DATA		0x00
105 #define SCTP_INITIATION		0x01
106 #define SCTP_INITIATION_ACK	0x02
107 #define SCTP_SELECTIVE_ACK	0x03
108 #define SCTP_HEARTBEAT_REQUEST	0x04
109 #define SCTP_HEARTBEAT_ACK	0x05
110 #define SCTP_ABORT_ASSOCIATION	0x06
111 #define SCTP_SHUTDOWN		0x07
112 #define SCTP_SHUTDOWN_ACK	0x08
113 #define SCTP_OPERATION_ERR	0x09
114 #define SCTP_COOKIE_ECHO	0x0a
115 #define SCTP_COOKIE_ACK         0x0b
116 #define SCTP_ECN_ECHO		0x0c
117 #define SCTP_ECN_CWR		0x0d
118 #define SCTP_SHUTDOWN_COMPLETE	0x0e
119 #define SCTP_FORWARD_CUM_TSN    0xc0
120 #define SCTP_RELIABLE_CNTL      0xc1
121 #define SCTP_RELIABLE_CNTL_ACK  0xc2
122 
123 static const struct tok sctp_chunkid_str[] = {
124 	{ SCTP_DATA,              "DATA"              },
125 	{ SCTP_INITIATION,        "INIT"              },
126 	{ SCTP_INITIATION_ACK,    "INIT ACK"          },
127 	{ SCTP_SELECTIVE_ACK,     "SACK"              },
128 	{ SCTP_HEARTBEAT_REQUEST, "HB REQ"            },
129 	{ SCTP_HEARTBEAT_ACK,     "HB ACK"            },
130 	{ SCTP_ABORT_ASSOCIATION, "ABORT"             },
131 	{ SCTP_SHUTDOWN,          "SHUTDOWN"          },
132 	{ SCTP_SHUTDOWN_ACK,      "SHUTDOWN ACK"      },
133 	{ SCTP_OPERATION_ERR,     "OP ERR"            },
134 	{ SCTP_COOKIE_ECHO,       "COOKIE ECHO"       },
135 	{ SCTP_COOKIE_ACK,        "COOKIE ACK"        },
136 	{ SCTP_ECN_ECHO,          "ECN ECHO"          },
137 	{ SCTP_ECN_CWR,           "ECN CWR"           },
138 	{ SCTP_SHUTDOWN_COMPLETE, "SHUTDOWN COMPLETE" },
139 	{ SCTP_FORWARD_CUM_TSN,   "FOR CUM TSN"       },
140 	{ SCTP_RELIABLE_CNTL,     "REL CTRL"          },
141 	{ SCTP_RELIABLE_CNTL_ACK, "REL CTRL ACK"      },
142 	{ 0, NULL }
143 };
144 
145 /* Data Chuck Specific Flags */
146 #define SCTP_DATA_FRAG_MASK	0x03
147 #define SCTP_DATA_MIDDLE_FRAG	0x00
148 #define SCTP_DATA_LAST_FRAG	0x01
149 #define SCTP_DATA_FIRST_FRAG	0x02
150 #define SCTP_DATA_NOT_FRAG	0x03
151 #define SCTP_DATA_UNORDERED	0x04
152 
153 #define SCTP_ADDRMAX 60
154 
155 #define CHAN_HP 6704
156 #define CHAN_MP 6705
157 #define CHAN_LP 6706
158 
159 /* the sctp common header */
160 
161 struct sctpHeader{
162   uint16_t source;
163   uint16_t destination;
164   uint32_t verificationTag;
165   uint32_t adler32;
166 };
167 
168 /* various descriptor parsers */
169 
170 struct sctpChunkDesc{
171   uint8_t chunkID;
172   uint8_t chunkFlg;
173   uint16_t chunkLength;
174 };
175 
176 struct sctpParamDesc{
177   uint16_t paramType;
178   uint16_t paramLength;
179 };
180 
181 
182 struct sctpRelChunkDesc{
183   struct sctpChunkDesc chk;
184   uint32_t serialNumber;
185 };
186 
187 struct sctpVendorSpecificParam {
188   struct sctpParamDesc p;  /* type must be 0xfffe */
189   uint32_t vendorId;	   /* vendor ID from RFC 1700 */
190   uint16_t vendorSpecificType;
191   uint16_t vendorSpecificLen;
192 };
193 
194 
195 /* Structures for the control parts */
196 
197 
198 
199 /* Sctp association init request/ack */
200 
201 /* this is used for init ack, too */
202 struct sctpInitiation{
203   uint32_t initTag;		/* tag of mine */
204   uint32_t rcvWindowCredit;	/* rwnd */
205   uint16_t NumPreopenStreams;	/* OS */
206   uint16_t MaxInboundStreams;     /* MIS */
207   uint32_t initialTSN;
208   /* optional param's follow in sctpParamDesc form */
209 };
210 
211 struct sctpV4IpAddress{
212   struct sctpParamDesc p;	/* type is set to SCTP_IPV4_PARAM_TYPE, len=10 */
213   uint32_t  ipAddress;
214 };
215 
216 
217 struct sctpV6IpAddress{
218   struct sctpParamDesc p;	/* type is set to SCTP_IPV6_PARAM_TYPE, len=22 */
219   uint8_t  ipAddress[16];
220 };
221 
222 struct sctpDNSName{
223   struct sctpParamDesc param;
224   uint8_t name[1];
225 };
226 
227 
228 struct sctpCookiePreserve{
229   struct sctpParamDesc p;	/* type is set to SCTP_COOKIE_PRESERVE, len=8 */
230   uint32_t extraTime;
231 };
232 
233 
234 struct sctpTimeStamp{
235   uint32_t ts_sec;
236   uint32_t ts_usec;
237 };
238 
239 /* wire structure of my cookie */
240 struct cookieMessage{
241   uint32_t TieTag_curTag;		/* copied from assoc if present */
242   uint32_t TieTag_hisTag; 		/* copied from assoc if present */
243   int32_t cookieLife;			/* life I will award this cookie */
244   struct sctpTimeStamp timeEnteringState; /* the time I built cookie */
245   struct sctpInitiation initAckISent;	/* the INIT-ACK that I sent to my peer */
246   uint32_t addressWhereISent[4];	/* I make this 4 ints so I get 128bits for future */
247   int32_t addrtype;			/* address type */
248   uint16_t locScope;			/* V6 local scope flag */
249   uint16_t siteScope;			/* V6 site scope flag */
250   /* at the end is tacked on the INIT chunk sent in
251    * its entirety and of course our
252    * signature.
253    */
254 };
255 
256 
257 /* this guy is for use when
258  * I have a initiate message gloming the
259  * things together.
260 
261  */
262 struct sctpUnifiedInit{
263   struct sctpChunkDesc uh;
264   struct sctpInitiation initm;
265 };
266 
267 struct sctpSendableInit{
268   struct sctpHeader mh;
269   struct sctpUnifiedInit msg;
270 };
271 
272 
273 /* Selective Acknowledgement
274  * has the following structure with
275  * a optional ammount of trailing int's
276  * on the last part (based on the numberOfDesc
277  * field).
278  */
279 
280 struct sctpSelectiveAck{
281   uint32_t highestConseqTSN;
282   uint32_t updatedRwnd;
283   uint16_t numberOfdesc;
284   uint16_t numDupTsns;
285 };
286 
287 struct sctpSelectiveFrag{
288   uint16_t fragmentStart;
289   uint16_t fragmentEnd;
290 };
291 
292 
293 struct sctpUnifiedSack{
294   struct sctpChunkDesc uh;
295   struct sctpSelectiveAck sack;
296 };
297 
298 /* for both RTT request/response the
299  * following is sent
300  */
301 
302 struct sctpHBrequest {
303   uint32_t time_value_1;
304   uint32_t time_value_2;
305 };
306 
307 /* here is what I read and respond with to. */
308 struct sctpHBunified{
309   struct sctpChunkDesc hdr;
310   struct sctpParamDesc hb;
311 };
312 
313 
314 /* here is what I send */
315 struct sctpHBsender{
316   struct sctpChunkDesc hdr;
317   struct sctpParamDesc hb;
318   struct sctpHBrequest rtt;
319   int8_t addrFmt[SCTP_ADDRMAX];
320   uint16_t userreq;
321 };
322 
323 
324 
325 /* for the abort and shutdown ACK
326  * we must carry the init tag in the common header. Just the
327  * common header is all that is needed with a chunk descriptor.
328  */
329 struct sctpUnifiedAbort{
330   struct sctpChunkDesc uh;
331 };
332 
333 struct sctpUnifiedAbortLight{
334   struct sctpHeader mh;
335   struct sctpChunkDesc uh;
336 };
337 
338 struct sctpUnifiedAbortHeavy{
339   struct sctpHeader mh;
340   struct sctpChunkDesc uh;
341   uint16_t causeCode;
342   uint16_t causeLen;
343 };
344 
345 /* For the graceful shutdown we must carry
346  * the tag (in common header)  and the highest consequitive acking value
347  */
348 struct sctpShutdown {
349   uint32_t TSN_Seen;
350 };
351 
352 struct sctpUnifiedShutdown{
353   struct sctpChunkDesc uh;
354   struct sctpShutdown shut;
355 };
356 
357 /* in the unified message we add the trailing
358  * stream id since it is the only message
359  * that is defined as a operation error.
360  */
361 struct sctpOpErrorCause{
362   uint16_t cause;
363   uint16_t causeLen;
364 };
365 
366 struct sctpUnifiedOpError{
367   struct sctpChunkDesc uh;
368   struct sctpOpErrorCause c;
369 };
370 
371 struct sctpUnifiedStreamError{
372   struct sctpHeader mh;
373   struct sctpChunkDesc uh;
374   struct sctpOpErrorCause c;
375   uint16_t strmNum;
376   uint16_t reserved;
377 };
378 
379 struct staleCookieMsg{
380   struct sctpHeader mh;
381   struct sctpChunkDesc uh;
382   struct sctpOpErrorCause c;
383   uint32_t moretime;
384 };
385 
386 /* the following is used in all sends
387  * where nothing is needed except the
388  * chunk/type i.e. shutdownAck Abort */
389 
390 struct sctpUnifiedSingleMsg{
391   struct sctpHeader mh;
392   struct sctpChunkDesc uh;
393 };
394 
395 struct sctpDataPart{
396   uint32_t TSN;
397   uint16_t streamId;
398   uint16_t sequence;
399   uint32_t payloadtype;
400 };
401 
402 struct sctpUnifiedDatagram{
403   struct sctpChunkDesc uh;
404   struct sctpDataPart dp;
405 };
406 
407 struct sctpECN_echo{
408   struct sctpChunkDesc uh;
409   uint32_t Lowest_TSN;
410 };
411 
412 
413 struct sctpCWR{
414   struct sctpChunkDesc uh;
415   uint32_t TSN_reduced_at;
416 };
417 
418 static const struct tok ForCES_channels[] = {
419 	{ CHAN_HP, "ForCES HP" },
420 	{ CHAN_MP, "ForCES MP" },
421 	{ CHAN_LP, "ForCES LP" },
422 	{ 0, NULL }
423 };
424 
425 /* data chunk's payload protocol identifiers */
426 
427 #define SCTP_PPID_IUA 1
428 #define SCTP_PPID_M2UA 2
429 #define SCTP_PPID_M3UA 3
430 #define SCTP_PPID_SUA 4
431 #define SCTP_PPID_M2PA 5
432 #define SCTP_PPID_V5UA 6
433 #define SCTP_PPID_H248 7
434 #define SCTP_PPID_BICC 8
435 #define SCTP_PPID_TALI 9
436 #define SCTP_PPID_DUA 10
437 #define SCTP_PPID_ASAP 11
438 #define SCTP_PPID_ENRP 12
439 #define SCTP_PPID_H323 13
440 #define SCTP_PPID_QIPC 14
441 #define SCTP_PPID_SIMCO 15
442 #define SCTP_PPID_DDPSC 16
443 #define SCTP_PPID_DDPSSC 17
444 #define SCTP_PPID_S1AP 18
445 #define SCTP_PPID_RUA 19
446 #define SCTP_PPID_HNBAP 20
447 #define SCTP_PPID_FORCES_HP 21
448 #define SCTP_PPID_FORCES_MP 22
449 #define SCTP_PPID_FORCES_LP 23
450 #define SCTP_PPID_SBC_AP 24
451 #define SCTP_PPID_NBAP 25
452 /* 26 */
453 #define SCTP_PPID_X2AP 27
454 
455 static const struct tok PayloadProto_idents[] = {
456 	{ SCTP_PPID_IUA,    "ISDN Q.921" },
457 	{ SCTP_PPID_M2UA,   "M2UA"   },
458 	{ SCTP_PPID_M3UA,   "M3UA"   },
459 	{ SCTP_PPID_SUA,    "SUA"    },
460 	{ SCTP_PPID_M2PA,   "M2PA"   },
461 	{ SCTP_PPID_V5UA,   "V5.2"   },
462 	{ SCTP_PPID_H248,   "H.248"  },
463 	{ SCTP_PPID_BICC,   "BICC"   },
464 	{ SCTP_PPID_TALI,   "TALI"   },
465 	{ SCTP_PPID_DUA,    "DUA"    },
466 	{ SCTP_PPID_ASAP,   "ASAP"   },
467 	{ SCTP_PPID_ENRP,   "ENRP"   },
468 	{ SCTP_PPID_H323,   "H.323"  },
469 	{ SCTP_PPID_QIPC,   "Q.IPC"  },
470 	{ SCTP_PPID_SIMCO,  "SIMCO"  },
471 	{ SCTP_PPID_DDPSC,  "DDPSC"  },
472 	{ SCTP_PPID_DDPSSC, "DDPSSC" },
473 	{ SCTP_PPID_S1AP,   "S1AP"   },
474 	{ SCTP_PPID_RUA,    "RUA"    },
475 	{ SCTP_PPID_HNBAP,  "HNBAP"  },
476 	{ SCTP_PPID_FORCES_HP, "ForCES HP" },
477 	{ SCTP_PPID_FORCES_MP, "ForCES MP" },
478 	{ SCTP_PPID_FORCES_LP, "ForCES LP" },
479 	{ SCTP_PPID_SBC_AP, "SBc-AP" },
480 	{ SCTP_PPID_NBAP,   "NBAP"   },
481 	/* 26 */
482 	{ SCTP_PPID_X2AP,   "X2AP"   },
483 	{ 0, NULL }
484 };
485 
486 
isForCES_port(u_short Port)487 static inline int isForCES_port(u_short Port)
488 {
489 	if (Port == CHAN_HP)
490 		return 1;
491 	if (Port == CHAN_MP)
492 		return 1;
493 	if (Port == CHAN_LP)
494 		return 1;
495 
496 	return 0;
497 }
498 
sctp_print(netdissect_options * ndo,const u_char * bp,const u_char * bp2,u_int sctpPacketLength)499 void sctp_print(netdissect_options *ndo,
500                 const u_char *bp,        /* beginning of sctp packet */
501                 const u_char *bp2,       /* beginning of enclosing */
502                 u_int sctpPacketLength)  /* ip packet */
503 {
504   const struct sctpHeader *sctpPktHdr;
505   const struct ip *ip;
506 #ifdef INET6
507   const struct ip6_hdr *ip6;
508 #endif
509   const void *endPacketPtr;
510   u_short sourcePort, destPort;
511   int chunkCount;
512   const struct sctpChunkDesc *chunkDescPtr;
513   const void *nextChunk;
514   const char *sep;
515   int isforces = 0;
516 
517 
518   sctpPktHdr = (const struct sctpHeader*) bp;
519   endPacketPtr = (const u_char*)sctpPktHdr+sctpPacketLength;
520 
521   if( (u_long) endPacketPtr > (u_long) ndo->ndo_snapend)
522     endPacketPtr = (const void *) ndo->ndo_snapend;
523   ip = (struct ip *)bp2;
524 #ifdef INET6
525   if (IP_V(ip) == 6)
526     ip6 = (const struct ip6_hdr *)bp2;
527   else
528     ip6 = NULL;
529 #endif /*INET6*/
530   ND_TCHECK(*sctpPktHdr);
531 
532   if (sctpPacketLength < sizeof(struct sctpHeader))
533     {
534       ND_PRINT((ndo, "truncated-sctp - %ld bytes missing!",
535 		   (long)sctpPacketLength-sizeof(struct sctpHeader)));
536       return;
537     }
538 
539   /*    sctpPacketLength -= sizeof(struct sctpHeader);  packet length  */
540   /*  			      is now only as long as the payload  */
541 
542   sourcePort = EXTRACT_16BITS(&sctpPktHdr->source);
543   destPort = EXTRACT_16BITS(&sctpPktHdr->destination);
544 
545 #ifdef INET6
546   if (ip6) {
547     ND_PRINT((ndo, "%s.%d > %s.%d: sctp",
548       ip6addr_string(ndo, &ip6->ip6_src),
549       sourcePort,
550       ip6addr_string(ndo, &ip6->ip6_dst),
551       destPort));
552   } else
553 #endif /*INET6*/
554   {
555     ND_PRINT((ndo, "%s.%d > %s.%d: sctp",
556       ipaddr_string(ndo, &ip->ip_src),
557       sourcePort,
558       ipaddr_string(ndo, &ip->ip_dst),
559       destPort));
560   }
561 
562   if (isForCES_port(sourcePort)) {
563          ND_PRINT((ndo, "[%s]", tok2str(ForCES_channels, NULL, sourcePort)));
564          isforces = 1;
565   }
566   if (isForCES_port(destPort)) {
567          ND_PRINT((ndo, "[%s]", tok2str(ForCES_channels, NULL, destPort)));
568          isforces = 1;
569   }
570 
571   if (ndo->ndo_vflag >= 2)
572     sep = "\n\t";
573   else
574     sep = " (";
575   /* cycle through all chunks, printing information on each one */
576   for (chunkCount = 0,
577 	 chunkDescPtr = (const struct sctpChunkDesc *)
578 	    ((const u_char*) sctpPktHdr + sizeof(struct sctpHeader));
579        chunkDescPtr != NULL &&
580 	 ( (const void *)
581 	    ((const u_char *) chunkDescPtr + sizeof(struct sctpChunkDesc))
582 	   <= endPacketPtr);
583 
584        chunkDescPtr = (const struct sctpChunkDesc *) nextChunk, chunkCount++)
585     {
586       uint16_t chunkLength;
587       const u_char *chunkEnd;
588       uint16_t align;
589 
590       ND_TCHECK(*chunkDescPtr);
591       chunkLength = EXTRACT_16BITS(&chunkDescPtr->chunkLength);
592       if (chunkLength < sizeof(*chunkDescPtr)) {
593         ND_PRINT((ndo, "%s%d) [Bad chunk length %u]", sep, chunkCount+1, chunkLength));
594         break;
595       }
596 
597       ND_TCHECK2(*((uint8_t *)chunkDescPtr), chunkLength);
598       chunkEnd = ((const u_char*)chunkDescPtr + chunkLength);
599 
600       align=chunkLength % 4;
601       if (align != 0)
602 	align = 4 - align;
603 
604       nextChunk = (const void *) (chunkEnd + align);
605 
606       ND_PRINT((ndo, "%s%d) ", sep, chunkCount+1));
607       ND_PRINT((ndo, "[%s] ", tok2str(sctp_chunkid_str, "Unknown chunk type: 0x%x",
608                                       chunkDescPtr->chunkID)));
609       switch (chunkDescPtr->chunkID)
610 	{
611 	case SCTP_DATA :
612 	  {
613 	    const struct sctpDataPart *dataHdrPtr;
614 	    uint32_t ppid;
615 	    const u_char *payloadPtr;
616 	    u_int payload_size;
617 
618 	    if ((chunkDescPtr->chunkFlg & SCTP_DATA_UNORDERED)
619 		== SCTP_DATA_UNORDERED)
620 	      ND_PRINT((ndo, "(U)"));
621 
622 	    if ((chunkDescPtr->chunkFlg & SCTP_DATA_FIRST_FRAG)
623 		== SCTP_DATA_FIRST_FRAG)
624 	      ND_PRINT((ndo, "(B)"));
625 
626 	    if ((chunkDescPtr->chunkFlg & SCTP_DATA_LAST_FRAG)
627 		== SCTP_DATA_LAST_FRAG)
628 	      ND_PRINT((ndo, "(E)"));
629 
630 	    if( ((chunkDescPtr->chunkFlg & SCTP_DATA_UNORDERED)
631 		 == SCTP_DATA_UNORDERED)
632 		||
633 		((chunkDescPtr->chunkFlg & SCTP_DATA_FIRST_FRAG)
634 		 == SCTP_DATA_FIRST_FRAG)
635 		||
636 		((chunkDescPtr->chunkFlg & SCTP_DATA_LAST_FRAG)
637 		 == SCTP_DATA_LAST_FRAG) )
638 	      ND_PRINT((ndo, " "));
639 
640 	    dataHdrPtr=(const struct sctpDataPart*)(chunkDescPtr+1);
641 
642 	    ppid = EXTRACT_32BITS(&dataHdrPtr->payloadtype);
643 	    ND_PRINT((ndo, "[TSN: %u] ", EXTRACT_32BITS(&dataHdrPtr->TSN)));
644 	    ND_PRINT((ndo, "[SID: %u] ", EXTRACT_16BITS(&dataHdrPtr->streamId)));
645 	    ND_PRINT((ndo, "[SSEQ %u] ", EXTRACT_16BITS(&dataHdrPtr->sequence)));
646 	    ND_PRINT((ndo, "[PPID %s] ",
647 		    tok2str(PayloadProto_idents, "0x%x", ppid)));
648 
649 	    if (!isforces) {
650 		isforces = (ppid == SCTP_PPID_FORCES_HP) ||
651 		    (ppid == SCTP_PPID_FORCES_MP) ||
652 		    (ppid == SCTP_PPID_FORCES_LP);
653 	    }
654 
655 	    payloadPtr = (const u_char *) (dataHdrPtr + 1);
656 	    if (EXTRACT_16BITS(&chunkDescPtr->chunkLength) <
657 		    sizeof(struct sctpDataPart) + sizeof(struct sctpChunkDesc) + 1) {
658 		ND_PRINT((ndo, "bogus chunk length %u]", EXTRACT_16BITS(&chunkDescPtr->chunkLength)));
659 		return;
660 	    }
661 
662 	    payload_size = EXTRACT_16BITS(&chunkDescPtr->chunkLength) -
663 		(sizeof(struct sctpDataPart) + sizeof(struct sctpChunkDesc));
664 
665 	    if (isforces) {
666 		forces_print(ndo, payloadPtr, payload_size);
667 	    } else if (ndo->ndo_vflag >= 2) {	/* if verbose output is specified */
668 					/* at the command line */
669 		switch (ppid) {
670 		case SCTP_PPID_M3UA :
671 			m3ua_print(ndo, payloadPtr, payload_size);
672 			break;
673 		default:
674 			ND_PRINT((ndo, "[Payload"));
675 			if (!ndo->ndo_suppress_default_print) {
676 				ND_PRINT((ndo, ":"));
677 				ND_DEFAULTPRINT(payloadPtr, payload_size);
678 			}
679 			ND_PRINT((ndo, "]"));
680 			break;
681 		}
682 	    }
683 	    break;
684 	  }
685 	case SCTP_INITIATION :
686 	  {
687 	    const struct sctpInitiation *init;
688 
689 	    init=(const struct sctpInitiation*)(chunkDescPtr+1);
690 	    ND_PRINT((ndo, "[init tag: %u] ", EXTRACT_32BITS(&init->initTag)));
691 	    ND_PRINT((ndo, "[rwnd: %u] ", EXTRACT_32BITS(&init->rcvWindowCredit)));
692 	    ND_PRINT((ndo, "[OS: %u] ", EXTRACT_16BITS(&init->NumPreopenStreams)));
693 	    ND_PRINT((ndo, "[MIS: %u] ", EXTRACT_16BITS(&init->MaxInboundStreams)));
694 	    ND_PRINT((ndo, "[init TSN: %u] ", EXTRACT_32BITS(&init->initialTSN)));
695 
696 #if(0) /* ALC you can add code for optional params here */
697 	    if( (init+1) < chunkEnd )
698 	      ND_PRINT((ndo, " @@@@@ UNFINISHED @@@@@@%s\n",
699 		     "Optional params present, but not printed."));
700 #endif
701 	    break;
702 	  }
703 	case SCTP_INITIATION_ACK :
704 	  {
705 	    const struct sctpInitiation *init;
706 
707 	    init=(const struct sctpInitiation*)(chunkDescPtr+1);
708 	    ND_PRINT((ndo, "[init tag: %u] ", EXTRACT_32BITS(&init->initTag)));
709 	    ND_PRINT((ndo, "[rwnd: %u] ", EXTRACT_32BITS(&init->rcvWindowCredit)));
710 	    ND_PRINT((ndo, "[OS: %u] ", EXTRACT_16BITS(&init->NumPreopenStreams)));
711 	    ND_PRINT((ndo, "[MIS: %u] ", EXTRACT_16BITS(&init->MaxInboundStreams)));
712 	    ND_PRINT((ndo, "[init TSN: %u] ", EXTRACT_32BITS(&init->initialTSN)));
713 
714 #if(0) /* ALC you can add code for optional params here */
715 	    if( (init+1) < chunkEnd )
716 	      ND_PRINT((ndo, " @@@@@ UNFINISHED @@@@@@%s\n",
717 		     "Optional params present, but not printed."));
718 #endif
719 	    break;
720 	  }
721 	case SCTP_SELECTIVE_ACK:
722 	  {
723 	    const struct sctpSelectiveAck *sack;
724 	    const struct sctpSelectiveFrag *frag;
725 	    int fragNo, tsnNo;
726 	    const u_char *dupTSN;
727 
728 	    sack=(const struct sctpSelectiveAck*)(chunkDescPtr+1);
729 	    ND_PRINT((ndo, "[cum ack %u] ", EXTRACT_32BITS(&sack->highestConseqTSN)));
730 	    ND_PRINT((ndo, "[a_rwnd %u] ", EXTRACT_32BITS(&sack->updatedRwnd)));
731 	    ND_PRINT((ndo, "[#gap acks %u] ", EXTRACT_16BITS(&sack->numberOfdesc)));
732 	    ND_PRINT((ndo, "[#dup tsns %u] ", EXTRACT_16BITS(&sack->numDupTsns)));
733 
734 
735 	    /* print gaps */
736 	    for (frag = ( (const struct sctpSelectiveFrag *)
737 			  ((const struct sctpSelectiveAck *) sack+1)),
738 		   fragNo=0;
739 		 (const void *)frag < nextChunk && fragNo < EXTRACT_16BITS(&sack->numberOfdesc);
740 		 frag++, fragNo++)
741 	      ND_PRINT((ndo, "\n\t\t[gap ack block #%d: start = %u, end = %u] ",
742 		     fragNo+1,
743 		     EXTRACT_32BITS(&sack->highestConseqTSN) + EXTRACT_16BITS(&frag->fragmentStart),
744 		     EXTRACT_32BITS(&sack->highestConseqTSN) + EXTRACT_16BITS(&frag->fragmentEnd)));
745 
746 
747 	    /* print duplicate TSNs */
748 	    for (dupTSN = (const u_char *)frag, tsnNo=0;
749 		 (const void *) dupTSN < nextChunk && tsnNo<EXTRACT_16BITS(&sack->numDupTsns);
750 		 dupTSN += 4, tsnNo++)
751 	      ND_PRINT((ndo, "\n\t\t[dup TSN #%u: %u] ", tsnNo+1,
752 	          EXTRACT_32BITS(dupTSN)));
753 
754 	    break;
755 	  }
756 	}
757 
758 	if (ndo->ndo_vflag < 2)
759 	  sep = ", (";
760     }
761     return;
762 
763 trunc:
764     ND_PRINT((ndo, "[|sctp]"));
765 }
766