tcpdump  4.99.1
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print-tcp.c
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1 /* $NetBSD: print-tcp.c,v 1.9 2007/07/26 18:15:12 plunky Exp $ */
2 
3 /*
4  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
5  * The Regents of the University of California. All rights reserved.
6  *
7  * Copyright (c) 1999-2004 The tcpdump.org project
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that: (1) source code distributions
11  * retain the above copyright notice and this paragraph in its entirety, (2)
12  * distributions including binary code include the above copyright notice and
13  * this paragraph in its entirety in the documentation or other materials
14  * provided with the distribution, and (3) all advertising materials mentioning
15  * features or use of this software display the following acknowledgement:
16  * ``This product includes software developed by the University of California,
17  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
18  * the University nor the names of its contributors may be used to endorse
19  * or promote products derived from this software without specific prior
20  * written permission.
21  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
22  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
23  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
24  */
25 
26 /* \summary: TCP printer */
27 
28 #ifndef lint
29 #else
30 __RCSID("$NetBSD: print-tcp.c,v 1.8 2007/07/24 11:53:48 drochner Exp $");
31 #endif
32 
33 #ifdef HAVE_CONFIG_H
34 #include <config.h>
35 #endif
36 
37 #include "netdissect-stdinc.h"
38 
39 #include <stdlib.h>
40 #include <string.h>
41 
42 #include "netdissect.h"
43 #include "addrtoname.h"
44 #include "extract.h"
45 
46 #include "tcp.h"
47 
48 #include "ip.h"
49 #include "ip6.h"
50 #include "ipproto.h"
51 #include "rpc_auth.h"
52 #include "rpc_msg.h"
53 
54 #ifdef HAVE_LIBCRYPTO
55 #include <openssl/md5.h>
56 #include "signature.h"
57 
58 static int tcp_verify_signature(netdissect_options *ndo,
59  const struct ip *ip, const struct tcphdr *tp,
60  const u_char *data, u_int length, const u_char *rcvsig);
61 #endif
62 
63 static void print_tcp_rst_data(netdissect_options *, const u_char *sp, u_int length);
64 static void print_tcp_fastopen_option(netdissect_options *ndo, const u_char *cp,
65  u_int datalen, int exp);
66 
67 #define MAX_RST_DATA_LEN 30
68 
69 
70 struct tha {
73  u_int port;
74 };
75 
76 struct tcp_seq_hash {
77  struct tcp_seq_hash *nxt;
78  struct tha addr;
79  uint32_t seq;
80  uint32_t ack;
81 };
82 
83 struct tha6 {
86  u_int port;
87 };
88 
89 struct tcp_seq_hash6 {
90  struct tcp_seq_hash6 *nxt;
91  struct tha6 addr;
92  uint32_t seq;
93  uint32_t ack;
94 };
95 
96 #define TSEQ_HASHSIZE 919
97 
98 /* These tcp options do not have the size octet */
99 #define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)
100 
103 
104 static const struct tok tcp_flag_values[] = {
105  { TH_FIN, "F" },
106  { TH_SYN, "S" },
107  { TH_RST, "R" },
108  { TH_PUSH, "P" },
109  { TH_ACK, "." },
110  { TH_URG, "U" },
111  { TH_ECNECHO, "E" },
112  { TH_CWR, "W" },
113  { 0, NULL }
114 };
115 
116 static const struct tok tcp_option_values[] = {
117  { TCPOPT_EOL, "eol" },
118  { TCPOPT_NOP, "nop" },
119  { TCPOPT_MAXSEG, "mss" },
120  { TCPOPT_WSCALE, "wscale" },
121  { TCPOPT_SACKOK, "sackOK" },
122  { TCPOPT_SACK, "sack" },
123  { TCPOPT_ECHO, "echo" },
124  { TCPOPT_ECHOREPLY, "echoreply" },
125  { TCPOPT_TIMESTAMP, "TS" },
126  { TCPOPT_CC, "cc" },
127  { TCPOPT_CCNEW, "ccnew" },
128  { TCPOPT_CCECHO, "" },
129  { TCPOPT_SIGNATURE, "md5" },
130  { TCPOPT_SCPS, "scps" },
131  { TCPOPT_UTO, "uto" },
132  { TCPOPT_TCPAO, "tcp-ao" },
133  { TCPOPT_MPTCP, "mptcp" },
134  { TCPOPT_FASTOPEN, "tfo" },
135  { TCPOPT_EXPERIMENT2, "exp" },
136  { 0, NULL }
137 };
138 
139 static uint16_t
141  const struct ip *ip,
142  const struct tcphdr *tp,
143  u_int len)
144 {
145  return nextproto4_cksum(ndo, ip, (const uint8_t *)tp, len, len,
146  IPPROTO_TCP);
147 }
148 
149 static uint16_t
151  const struct ip6_hdr *ip6,
152  const struct tcphdr *tp,
153  u_int len)
154 {
155  return nextproto6_cksum(ndo, ip6, (const uint8_t *)tp, len, len,
156  IPPROTO_TCP);
157 }
158 
159 void
161  const u_char *bp, u_int length,
162  const u_char *bp2, int fragmented)
163 {
164  const struct tcphdr *tp;
165  const struct ip *ip;
166  u_char flags;
167  u_int hlen;
168  char ch;
169  uint16_t sport, dport, win, urp;
170  uint32_t seq, ack, thseq, thack;
171  u_int utoval;
172  uint16_t magic;
173  int rev;
174  const struct ip6_hdr *ip6;
175  u_int header_len; /* Header length in bytes */
176 
177  ndo->ndo_protocol = "tcp";
178  tp = (const struct tcphdr *)bp;
179  ip = (const struct ip *)bp2;
180  if (IP_V(ip) == 6)
181  ip6 = (const struct ip6_hdr *)bp2;
182  else
183  ip6 = NULL;
184  ch = '\0';
185  if (!ND_TTEST_2(tp->th_dport)) {
186  if (ip6) {
187  ND_PRINT("%s > %s:",
190  } else {
191  ND_PRINT("%s > %s:",
194  }
195  nd_print_trunc(ndo);
196  return;
197  }
198 
199  sport = GET_BE_U_2(tp->th_sport);
200  dport = GET_BE_U_2(tp->th_dport);
201 
202  if (ip6) {
203  if (GET_U_1(ip6->ip6_nxt) == IPPROTO_TCP) {
204  ND_PRINT("%s.%s > %s.%s: ",
206  tcpport_string(ndo, sport),
208  tcpport_string(ndo, dport));
209  } else {
210  ND_PRINT("%s > %s: ",
211  tcpport_string(ndo, sport), tcpport_string(ndo, dport));
212  }
213  } else {
214  if (GET_U_1(ip->ip_p) == IPPROTO_TCP) {
215  ND_PRINT("%s.%s > %s.%s: ",
217  tcpport_string(ndo, sport),
219  tcpport_string(ndo, dport));
220  } else {
221  ND_PRINT("%s > %s: ",
222  tcpport_string(ndo, sport), tcpport_string(ndo, dport));
223  }
224  }
225 
226  ND_TCHECK_SIZE(tp);
227 
228  hlen = TH_OFF(tp) * 4;
229 
230  if (hlen < sizeof(*tp)) {
231  ND_PRINT(" tcp %u [bad hdr length %u - too short, < %zu]",
232  length - hlen, hlen, sizeof(*tp));
233  return;
234  }
235 
236  seq = GET_BE_U_4(tp->th_seq);
237  ack = GET_BE_U_4(tp->th_ack);
238  win = GET_BE_U_2(tp->th_win);
239  urp = GET_BE_U_2(tp->th_urp);
240 
241  if (ndo->ndo_qflag) {
242  ND_PRINT("tcp %u", length - hlen);
243  if (hlen > length) {
244  ND_PRINT(" [bad hdr length %u - too long, > %u]",
245  hlen, length);
246  }
247  return;
248  }
249 
250  flags = GET_U_1(tp->th_flags);
251  ND_PRINT("Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags));
252 
253  if (!ndo->ndo_Sflag && (flags & TH_ACK)) {
254  /*
255  * Find (or record) the initial sequence numbers for
256  * this conversation. (we pick an arbitrary
257  * collating order so there's only one entry for
258  * both directions).
259  */
260  rev = 0;
261  if (ip6) {
262  struct tcp_seq_hash6 *th;
263  struct tcp_seq_hash6 *tcp_seq_hash;
264  const void *src, *dst;
265  struct tha6 tha;
266 
268  src = (const void *)ip6->ip6_src;
269  dst = (const void *)ip6->ip6_dst;
270  if (sport > dport)
271  rev = 1;
272  else if (sport == dport) {
273  if (UNALIGNED_MEMCMP(src, dst, sizeof(ip6->ip6_dst)) > 0)
274  rev = 1;
275  }
276  if (rev) {
277  UNALIGNED_MEMCPY(&tha.src, dst, sizeof(ip6->ip6_dst));
278  UNALIGNED_MEMCPY(&tha.dst, src, sizeof(ip6->ip6_src));
279  tha.port = ((u_int)dport) << 16 | sport;
280  } else {
281  UNALIGNED_MEMCPY(&tha.dst, dst, sizeof(ip6->ip6_dst));
282  UNALIGNED_MEMCPY(&tha.src, src, sizeof(ip6->ip6_src));
283  tha.port = ((u_int)sport) << 16 | dport;
284  }
285 
286  for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
287  th->nxt; th = th->nxt)
288  if (memcmp((char *)&tha, (char *)&th->addr,
289  sizeof(th->addr)) == 0)
290  break;
291 
292  if (!th->nxt || (flags & TH_SYN)) {
293  /* didn't find it or new conversation */
294  /* calloc() return used by the 'tcp_seq_hash6'
295  hash table: do not free() */
296  if (th->nxt == NULL) {
297  th->nxt = (struct tcp_seq_hash6 *)
298  calloc(1, sizeof(*th));
299  if (th->nxt == NULL)
300  (*ndo->ndo_error)(ndo,
302  "%s: calloc", __func__);
303  }
304  th->addr = tha;
305  if (rev)
306  th->ack = seq, th->seq = ack - 1;
307  else
308  th->seq = seq, th->ack = ack - 1;
309  } else {
310  if (rev)
311  seq -= th->ack, ack -= th->seq;
312  else
313  seq -= th->seq, ack -= th->ack;
314  }
315 
316  thseq = th->seq;
317  thack = th->ack;
318  } else {
319  struct tcp_seq_hash *th;
320  struct tcp_seq_hash *tcp_seq_hash;
321  struct tha tha;
322 
324  if (sport > dport)
325  rev = 1;
326  else if (sport == dport) {
327  if (UNALIGNED_MEMCMP(ip->ip_src, ip->ip_dst, sizeof(ip->ip_dst)) > 0)
328  rev = 1;
329  }
330  if (rev) {
332  sizeof(ip->ip_dst));
334  sizeof(ip->ip_src));
335  tha.port = ((u_int)dport) << 16 | sport;
336  } else {
338  sizeof(ip->ip_dst));
340  sizeof(ip->ip_src));
341  tha.port = ((u_int)sport) << 16 | dport;
342  }
343 
344  for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
345  th->nxt; th = th->nxt)
346  if (memcmp((char *)&tha, (char *)&th->addr,
347  sizeof(th->addr)) == 0)
348  break;
349 
350  if (!th->nxt || (flags & TH_SYN)) {
351  /* didn't find it or new conversation */
352  /* calloc() return used by the 'tcp_seq_hash4'
353  hash table: do not free() */
354  if (th->nxt == NULL) {
355  th->nxt = (struct tcp_seq_hash *)
356  calloc(1, sizeof(*th));
357  if (th->nxt == NULL)
358  (*ndo->ndo_error)(ndo,
360  "%s: calloc", __func__);
361  }
362  th->addr = tha;
363  if (rev)
364  th->ack = seq, th->seq = ack - 1;
365  else
366  th->seq = seq, th->ack = ack - 1;
367  } else {
368  if (rev)
369  seq -= th->ack, ack -= th->seq;
370  else
371  seq -= th->seq, ack -= th->ack;
372  }
373 
374  thseq = th->seq;
375  thack = th->ack;
376  }
377  } else {
378  /*fool gcc*/
379  thseq = thack = rev = 0;
380  }
381  if (hlen > length) {
382  ND_PRINT(" [bad hdr length %u - too long, > %u]",
383  hlen, length);
384  return;
385  }
386 
387  if (ndo->ndo_vflag && !ndo->ndo_Kflag && !fragmented) {
388  /* Check the checksum, if possible. */
389  uint16_t sum, tcp_sum;
390 
391  if (IP_V(ip) == 4) {
392  if (ND_TTEST_LEN(tp->th_sport, length)) {
393  sum = tcp_cksum(ndo, ip, tp, length);
394  tcp_sum = GET_BE_U_2(tp->th_sum);
395 
396  ND_PRINT(", cksum 0x%04x", tcp_sum);
397  if (sum != 0)
398  ND_PRINT(" (incorrect -> 0x%04x)",
399  in_cksum_shouldbe(tcp_sum, sum));
400  else
401  ND_PRINT(" (correct)");
402  }
403  } else if (IP_V(ip) == 6) {
404  if (ND_TTEST_LEN(tp->th_sport, length)) {
405  sum = tcp6_cksum(ndo, ip6, tp, length);
406  tcp_sum = GET_BE_U_2(tp->th_sum);
407 
408  ND_PRINT(", cksum 0x%04x", tcp_sum);
409  if (sum != 0)
410  ND_PRINT(" (incorrect -> 0x%04x)",
411  in_cksum_shouldbe(tcp_sum, sum));
412  else
413  ND_PRINT(" (correct)");
414 
415  }
416  }
417  }
418 
419  length -= hlen;
420  if (ndo->ndo_vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) {
421  ND_PRINT(", seq %u", seq);
422 
423  if (length > 0) {
424  ND_PRINT(":%u", seq + length);
425  }
426  }
427 
428  if (flags & TH_ACK) {
429  ND_PRINT(", ack %u", ack);
430  }
431 
432  ND_PRINT(", win %u", win);
433 
434  if (flags & TH_URG)
435  ND_PRINT(", urg %u", urp);
436  /*
437  * Handle any options.
438  */
439  if (hlen > sizeof(*tp)) {
440  const u_char *cp;
441  u_int i, opt, datalen;
442  u_int len;
443 
444  hlen -= sizeof(*tp);
445  cp = (const u_char *)tp + sizeof(*tp);
446  ND_PRINT(", options [");
447  while (hlen > 0) {
448  if (ch != '\0')
449  ND_PRINT("%c", ch);
450  opt = GET_U_1(cp);
451  cp++;
452  if (ZEROLENOPT(opt))
453  len = 1;
454  else {
455  len = GET_U_1(cp);
456  cp++; /* total including type, len */
457  if (len < 2 || len > hlen)
458  goto bad;
459  --hlen; /* account for length byte */
460  }
461  --hlen; /* account for type byte */
462  datalen = 0;
463 
464 /* Bail if "l" bytes of data are not left or were not captured */
465 #define LENCHECK(l) { if ((l) > hlen) goto bad; ND_TCHECK_LEN(cp, l); }
466 
467 
468  ND_PRINT("%s", tok2str(tcp_option_values, "unknown-%u", opt));
469 
470  switch (opt) {
471 
472  case TCPOPT_MAXSEG:
473  datalen = 2;
474  LENCHECK(datalen);
475  ND_PRINT(" %u", GET_BE_U_2(cp));
476  break;
477 
478  case TCPOPT_WSCALE:
479  datalen = 1;
480  LENCHECK(datalen);
481  ND_PRINT(" %u", GET_U_1(cp));
482  break;
483 
484  case TCPOPT_SACK:
485  datalen = len - 2;
486  if (datalen % 8 != 0) {
487  ND_PRINT(" invalid sack");
488  } else {
489  uint32_t s, e;
490 
491  ND_PRINT(" %u ", datalen / 8);
492  for (i = 0; i < datalen; i += 8) {
493  LENCHECK(i + 4);
494  s = GET_BE_U_4(cp + i);
495  LENCHECK(i + 8);
496  e = GET_BE_U_4(cp + i + 4);
497  if (rev) {
498  s -= thseq;
499  e -= thseq;
500  } else {
501  s -= thack;
502  e -= thack;
503  }
504  ND_PRINT("{%u:%u}", s, e);
505  }
506  }
507  break;
508 
509  case TCPOPT_CC:
510  case TCPOPT_CCNEW:
511  case TCPOPT_CCECHO:
512  case TCPOPT_ECHO:
513  case TCPOPT_ECHOREPLY:
514 
515  /*
516  * those options share their semantics.
517  * fall through
518  */
519  datalen = 4;
520  LENCHECK(datalen);
521  ND_PRINT(" %u", GET_BE_U_4(cp));
522  break;
523 
524  case TCPOPT_TIMESTAMP:
525  datalen = 8;
526  LENCHECK(datalen);
527  ND_PRINT(" val %u ecr %u",
528  GET_BE_U_4(cp),
529  GET_BE_U_4(cp + 4));
530  break;
531 
532  case TCPOPT_SIGNATURE:
533  datalen = TCP_SIGLEN;
534  LENCHECK(datalen);
535  ND_PRINT(" ");
536 #ifdef HAVE_LIBCRYPTO
537  switch (tcp_verify_signature(ndo, ip, tp,
538  bp + TH_OFF(tp) * 4, length, cp)) {
539 
540  case SIGNATURE_VALID:
541  ND_PRINT("valid");
542  break;
543 
544  case SIGNATURE_INVALID:
545  nd_print_invalid(ndo);
546  break;
547 
549  ND_PRINT("can't check - ");
550  for (i = 0; i < TCP_SIGLEN; ++i)
551  ND_PRINT("%02x",
552  GET_U_1(cp + i));
553  break;
554  }
555 #else
556  for (i = 0; i < TCP_SIGLEN; ++i)
557  ND_PRINT("%02x", GET_U_1(cp + i));
558 #endif
559  break;
560 
561  case TCPOPT_SCPS:
562  datalen = 2;
563  LENCHECK(datalen);
564  ND_PRINT(" cap %02x id %u", GET_U_1(cp),
565  GET_U_1(cp + 1));
566  break;
567 
568  case TCPOPT_TCPAO:
569  datalen = len - 2;
570  /* RFC 5925 Section 2.2:
571  * "The Length value MUST be greater than or equal to 4."
572  * (This includes the Kind and Length fields already processed
573  * at this point.)
574  */
575  if (datalen < 2) {
576  nd_print_invalid(ndo);
577  } else {
578  LENCHECK(1);
579  ND_PRINT(" keyid %u", GET_U_1(cp));
580  LENCHECK(2);
581  ND_PRINT(" rnextkeyid %u",
582  GET_U_1(cp + 1));
583  if (datalen > 2) {
584  ND_PRINT(" mac 0x");
585  for (i = 2; i < datalen; i++) {
586  LENCHECK(i + 1);
587  ND_PRINT("%02x",
588  GET_U_1(cp + i));
589  }
590  }
591  }
592  break;
593 
594  case TCPOPT_EOL:
595  case TCPOPT_NOP:
596  case TCPOPT_SACKOK:
597  /*
598  * Nothing interesting.
599  * fall through
600  */
601  break;
602 
603  case TCPOPT_UTO:
604  datalen = 2;
605  LENCHECK(datalen);
606  utoval = GET_BE_U_2(cp);
607  ND_PRINT(" 0x%x", utoval);
608  if (utoval & 0x0001)
609  utoval = (utoval >> 1) * 60;
610  else
611  utoval >>= 1;
612  ND_PRINT(" %u", utoval);
613  break;
614 
615  case TCPOPT_MPTCP:
616  {
617  const u_char *snapend_save;
618  int ret;
619 
620  datalen = len - 2;
621  LENCHECK(datalen);
622  /* Update the snapend to the end of the option
623  * before calling mptcp_print(). Some options
624  * (MPTCP or others) may be present after a
625  * MPTCP option. This prevents that, in
626  * mptcp_print(), the remaining length < the
627  * remaining caplen.
628  */
629  snapend_save = ndo->ndo_snapend;
630  ndo->ndo_snapend = ND_MIN(cp - 2 + len,
631  ndo->ndo_snapend);
632  ret = mptcp_print(ndo, cp - 2, len, flags);
633  ndo->ndo_snapend = snapend_save;
634  if (!ret)
635  goto bad;
636  break;
637  }
638 
639  case TCPOPT_FASTOPEN:
640  datalen = len - 2;
641  LENCHECK(datalen);
642  ND_PRINT(" ");
643  print_tcp_fastopen_option(ndo, cp, datalen, FALSE);
644  break;
645 
646  case TCPOPT_EXPERIMENT2:
647  datalen = len - 2;
648  LENCHECK(datalen);
649  if (datalen < 2)
650  goto bad;
651  /* RFC6994 */
652  magic = GET_BE_U_2(cp);
653  ND_PRINT("-");
654 
655  switch(magic) {
656 
657  case 0xf989: /* TCP Fast Open RFC 7413 */
658  print_tcp_fastopen_option(ndo, cp + 2, datalen - 2, TRUE);
659  break;
660 
661  default:
662  /* Unknown magic number */
663  ND_PRINT("%04x", magic);
664  break;
665  }
666  break;
667 
668  default:
669  datalen = len - 2;
670  if (datalen)
671  ND_PRINT(" 0x");
672  for (i = 0; i < datalen; ++i) {
673  LENCHECK(i + 1);
674  ND_PRINT("%02x", GET_U_1(cp + i));
675  }
676  break;
677  }
678 
679  /* Account for data printed */
680  cp += datalen;
681  hlen -= datalen;
682 
683  /* Check specification against observed length */
684  ++datalen; /* option octet */
685  if (!ZEROLENOPT(opt))
686  ++datalen; /* size octet */
687  if (datalen != len)
688  ND_PRINT("[len %u]", len);
689  ch = ',';
690  if (opt == TCPOPT_EOL)
691  break;
692  }
693  ND_PRINT("]");
694  }
695 
696  /*
697  * Print length field before crawling down the stack.
698  */
699  ND_PRINT(", length %u", length);
700 
701  if (length <= 0)
702  return;
703 
704  /*
705  * Decode payload if necessary.
706  */
707  header_len = TH_OFF(tp) * 4;
708  /*
709  * Do a bounds check before decoding the payload.
710  * At least the header data is required.
711  */
712  if (!ND_TTEST_LEN(bp, header_len)) {
713  ND_PRINT(" [remaining caplen(%u) < header length(%u)]",
714  ND_BYTES_AVAILABLE_AFTER(bp), header_len);
715  nd_trunc_longjmp(ndo);
716  }
717  bp += header_len;
718  if ((flags & TH_RST) && ndo->ndo_vflag) {
719  print_tcp_rst_data(ndo, bp, length);
720  return;
721  }
722 
723  if (ndo->ndo_packettype) {
724  switch (ndo->ndo_packettype) {
725  case PT_ZMTP1:
726  zmtp1_print(ndo, bp, length);
727  break;
728  case PT_RESP:
729  resp_print(ndo, bp, length);
730  break;
731  case PT_DOMAIN:
732  /* over_tcp: TRUE, is_mdns: FALSE */
733  domain_print(ndo, bp, length, TRUE, FALSE);
734  break;
735  }
736  return;
737  }
738 
740  telnet_print(ndo, bp, length);
741  } else if (IS_SRC_OR_DST_PORT(SMTP_PORT)) {
742  ND_PRINT(": ");
743  smtp_print(ndo, bp, length);
744  } else if (IS_SRC_OR_DST_PORT(WHOIS_PORT)) {
745  ND_PRINT(": ");
746  ndo->ndo_protocol = "whois"; /* needed by txtproto_print() */
747  txtproto_print(ndo, bp, length, NULL, 0); /* RFC 3912 */
748  } else if (IS_SRC_OR_DST_PORT(BGP_PORT))
749  bgp_print(ndo, bp, length);
750  else if (IS_SRC_OR_DST_PORT(PPTP_PORT))
751  pptp_print(ndo, bp);
752  else if (IS_SRC_OR_DST_PORT(REDIS_PORT))
753  resp_print(ndo, bp, length);
754  else if (IS_SRC_OR_DST_PORT(SSH_PORT))
755  ssh_print(ndo, bp, length);
756 #ifdef ENABLE_SMB
758  nbt_tcp_print(ndo, bp, length);
759  else if (IS_SRC_OR_DST_PORT(SMB_PORT))
760  smb_tcp_print(ndo, bp, length);
761 #endif
762  else if (IS_SRC_OR_DST_PORT(BEEP_PORT))
763  beep_print(ndo, bp, length);
765  openflow_print(ndo, bp, length);
766  else if (IS_SRC_OR_DST_PORT(FTP_PORT)) {
767  ND_PRINT(": ");
768  ftp_print(ndo, bp, length);
770  ND_PRINT(": ");
771  http_print(ndo, bp, length);
773  ND_PRINT(": ");
774  rtsp_print(ndo, bp, length);
775  } else if (IS_SRC_OR_DST_PORT(NAMESERVER_PORT)) {
776  /* over_tcp: TRUE, is_mdns: FALSE */
777  domain_print(ndo, bp, length, TRUE, FALSE);
778  } else if (IS_SRC_OR_DST_PORT(MSDP_PORT)) {
779  msdp_print(ndo, bp, length);
780  } else if (IS_SRC_OR_DST_PORT(RPKI_RTR_PORT)) {
781  rpki_rtr_print(ndo, bp, length);
782  } else if (IS_SRC_OR_DST_PORT(LDP_PORT)) {
783  ldp_print(ndo, bp, length);
784  } else if ((IS_SRC_OR_DST_PORT(NFS_PORT)) &&
785  length >= 4 && ND_TTEST_4(bp)) {
786  /*
787  * If data present, header length valid, and NFS port used,
788  * assume NFS.
789  * Pass offset of data plus 4 bytes for RPC TCP msg length
790  * to NFS print routines.
791  */
792  uint32_t fraglen;
793  const struct sunrpc_msg *rp;
795 
796  fraglen = GET_BE_U_4(bp) & 0x7FFFFFFF;
797  if (fraglen > (length) - 4)
798  fraglen = (length) - 4;
799  rp = (const struct sunrpc_msg *)(bp + 4);
800  if (ND_TTEST_4(rp->rm_direction)) {
802  if (dport == NFS_PORT && direction == SUNRPC_CALL) {
803  ND_PRINT(": NFS request xid %u ",
804  GET_BE_U_4(rp->rm_xid));
805  nfsreq_noaddr_print(ndo, (const u_char *)rp, fraglen, (const u_char *)ip);
806  return;
807  }
808  if (sport == NFS_PORT && direction == SUNRPC_REPLY) {
809  ND_PRINT(": NFS reply xid %u ",
810  GET_BE_U_4(rp->rm_xid));
811  nfsreply_noaddr_print(ndo, (const u_char *)rp, fraglen, (const u_char *)ip);
812  return;
813  }
814  }
815  }
816 
817  return;
818 bad:
819  ND_PRINT("[bad opt]");
820  if (ch != '\0')
821  ND_PRINT("]");
822  return;
823 trunc:
824  nd_print_trunc(ndo);
825  if (ch != '\0')
826  ND_PRINT(">");
827 }
828 
829 /*
830  * RFC1122 says the following on data in RST segments:
831  *
832  * 4.2.2.12 RST Segment: RFC-793 Section 3.4
833  *
834  * A TCP SHOULD allow a received RST segment to include data.
835  *
836  * DISCUSSION
837  * It has been suggested that a RST segment could contain
838  * ASCII text that encoded and explained the cause of the
839  * RST. No standard has yet been established for such
840  * data.
841  *
842  */
843 
844 static void
846  const u_char *sp, u_int length)
847 {
848  u_char c;
849 
850  ND_PRINT(ND_TTEST_LEN(sp, length) ? " [RST" : " [!RST");
851  if (length > MAX_RST_DATA_LEN) {
852  length = MAX_RST_DATA_LEN; /* can use -X for longer */
853  ND_PRINT("+"); /* indicate we truncate */
854  }
855  ND_PRINT(" ");
856  while (length && sp < ndo->ndo_snapend) {
857  c = GET_U_1(sp);
858  sp++;
859  fn_print_char(ndo, c);
860  length--;
861  }
862  ND_PRINT("]");
863 }
864 
865 static void
867  u_int datalen, int exp)
868 {
869  u_int i;
870 
871  if (exp)
872  ND_PRINT("tfo");
873 
874  if (datalen == 0) {
875  /* Fast Open Cookie Request */
876  ND_PRINT(" cookiereq");
877  } else {
878  /* Fast Open Cookie */
879  if (datalen % 2 != 0 || datalen < 4 || datalen > 16) {
880  nd_print_invalid(ndo);
881  } else {
882  ND_PRINT(" cookie ");
883  for (i = 0; i < datalen; ++i)
884  ND_PRINT("%02x", GET_U_1(cp + i));
885  }
886  }
887 }
888 
889 #ifdef HAVE_LIBCRYPTO
891 static int
892 tcp_verify_signature(netdissect_options *ndo,
893  const struct ip *ip, const struct tcphdr *tp,
894  const u_char *data, u_int length, const u_char *rcvsig)
895 {
896  struct tcphdr tp1;
897  u_char sig[TCP_SIGLEN];
898  char zero_proto = 0;
899  MD5_CTX ctx;
900  uint16_t savecsum, tlen;
901  const struct ip6_hdr *ip6;
902  uint32_t len32;
903  uint8_t nxt;
904 
905  if (data + length > ndo->ndo_snapend) {
906  ND_PRINT("snaplen too short, ");
907  return (CANT_CHECK_SIGNATURE);
908  }
909 
910  tp1 = *tp;
911 
912  if (ndo->ndo_sigsecret == NULL) {
913  ND_PRINT("shared secret not supplied with -M, ");
914  return (CANT_CHECK_SIGNATURE);
915  }
916 
917  MD5_Init(&ctx);
918  /*
919  * Step 1: Update MD5 hash with IP pseudo-header.
920  */
921  if (IP_V(ip) == 4) {
922  MD5_Update(&ctx, (const char *)&ip->ip_src, sizeof(ip->ip_src));
923  MD5_Update(&ctx, (const char *)&ip->ip_dst, sizeof(ip->ip_dst));
924  MD5_Update(&ctx, (const char *)&zero_proto, sizeof(zero_proto));
925  MD5_Update(&ctx, (const char *)&ip->ip_p, sizeof(ip->ip_p));
926  tlen = GET_BE_U_2(ip->ip_len) - IP_HL(ip) * 4;
927  tlen = htons(tlen);
928  MD5_Update(&ctx, (const char *)&tlen, sizeof(tlen));
929  } else if (IP_V(ip) == 6) {
930  ip6 = (const struct ip6_hdr *)ip;
931  MD5_Update(&ctx, (const char *)&ip6->ip6_src, sizeof(ip6->ip6_src));
932  MD5_Update(&ctx, (const char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));
933  len32 = htonl(GET_BE_U_2(ip6->ip6_plen));
934  MD5_Update(&ctx, (const char *)&len32, sizeof(len32));
935  nxt = 0;
936  MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
937  MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
938  MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
939  nxt = IPPROTO_TCP;
940  MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
941  } else {
942  ND_PRINT("IP version not 4 or 6, ");
943  return (CANT_CHECK_SIGNATURE);
944  }
945 
946  /*
947  * Step 2: Update MD5 hash with TCP header, excluding options.
948  * The TCP checksum must be set to zero.
949  */
950  memcpy(&savecsum, tp1.th_sum, sizeof(savecsum));
951  memset(tp1.th_sum, 0, sizeof(tp1.th_sum));
952  MD5_Update(&ctx, (const char *)&tp1, sizeof(struct tcphdr));
953  memcpy(tp1.th_sum, &savecsum, sizeof(tp1.th_sum));
954  /*
955  * Step 3: Update MD5 hash with TCP segment data, if present.
956  */
957  if (length > 0)
958  MD5_Update(&ctx, data, length);
959  /*
960  * Step 4: Update MD5 hash with shared secret.
961  */
962  MD5_Update(&ctx, ndo->ndo_sigsecret, strlen(ndo->ndo_sigsecret));
963  MD5_Final(sig, &ctx);
964 
965  if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0)
966  return (SIGNATURE_VALID);
967  else
968  return (SIGNATURE_INVALID);
969 }
971 #endif /* HAVE_LIBCRYPTO */
const char * tcpport_string(netdissect_options *ndo, u_short port)
Definition: addrtoname.c:739
#define GET_IPADDR_STRING(p)
Definition: addrtoname.h:120
#define GET_IP6ADDR_STRING(p)
Definition: addrtoname.h:121
#define GET_BE_U_4(p)
Definition: extract.h:877
#define GET_BE_U_2(p)
Definition: extract.h:875
#define ND_TTEST_2(p)
Definition: extract.h:554
#define GET_U_1(p)
Definition: extract.h:872
static void nd_trunc_longjmp(netdissect_options *ndo)
Definition: extract.h:579
#define ND_TTEST_4(p)
Definition: extract.h:560
uint16_t in_cksum_shouldbe(uint16_t sum, uint16_t computed_sum)
Definition: in_cksum.c:157
#define IP_HL(ip)
Definition: ip.h:55
#define IP_V(ip)
Definition: ip.h:54
#define IPPROTO_TCP
Definition: ipproto.h:57
#define USES_APPLE_DEPRECATED_API
#define TRUE
#define FALSE
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Definition: netdissect.h:294
void bgp_print(netdissect_options *, const u_char *, u_int)
Definition: print-bgp.c:3098
#define UNALIGNED_MEMCMP(p, q, l)
Definition: netdissect.h:444
void ssh_print(netdissect_options *, const u_char *, u_int)
Definition: print-ssh.c:94
void http_print(netdissect_options *, const u_char *, u_int)
Definition: print-http.c:70
void resp_print(netdissect_options *, const u_char *, u_int)
Definition: print-resp.c:201
uint16_t nextproto6_cksum(netdissect_options *, const struct ip6_hdr *, const uint8_t *, u_int, u_int, uint8_t)
Definition: print-ip6.c:173
void beep_print(netdissect_options *, const u_char *, u_int)
Definition: print-beep.c:49
void nfsreq_noaddr_print(netdissect_options *, const u_char *, u_int, const u_char *)
Definition: print-nfs.c:552
void fn_print_char(netdissect_options *, u_char)
Definition: util-print.c:70
void telnet_print(netdissect_options *, const u_char *, u_int)
Definition: print-telnet.c:496
void rtsp_print(netdissect_options *, const u_char *, u_int)
Definition: print-rtsp.c:40
uint16_t nextproto4_cksum(netdissect_options *, const struct ip *, const uint8_t *, u_int, u_int, uint8_t)
Definition: print-ip.c:137
int mptcp_print(netdissect_options *, const u_char *, u_int, u_char)
Definition: print-mptcp.c:467
void ldp_print(netdissect_options *, const u_char *, u_int)
Definition: print-ldp.c:548
void smtp_print(netdissect_options *, const u_char *, u_int)
Definition: print-smtp.c:25
const char * tok2str(const struct tok *, const char *, u_int)
Definition: util-print.c:485
#define PT_DOMAIN
Definition: netdissect.h:292
void nfsreply_noaddr_print(netdissect_options *, const u_char *, u_int, const u_char *)
Definition: print-nfs.c:358
#define ND_TTEST_LEN(p, l)
Definition: netdissect.h:356
#define ND_TCHECK_SIZE(p)
Definition: netdissect.h:372
void pptp_print(netdissect_options *, const u_char *)
Definition: print-pptp.c:773
void nd_print_invalid(netdissect_options *)
Definition: util-print.c:429
void smb_tcp_print(netdissect_options *, const u_char *, u_int)
Definition: print-smb.c:1217
void domain_print(netdissect_options *, const u_char *, u_int, int, int)
Definition: print-domain.c:880
void msdp_print(netdissect_options *, const u_char *, u_int)
Definition: print-msdp.c:34
void openflow_print(netdissect_options *, const u_char *, u_int)
void nd_print_trunc(netdissect_options *)
Definition: util-print.c:409
#define PT_RESP
Definition: netdissect.h:289
char * bittok2str_nosep(const struct tok *, const char *, u_int)
Definition: util-print.c:547
#define IS_SRC_OR_DST_PORT(p)
Definition: netdissect.h:298
void zmtp1_print(netdissect_options *, const u_char *, u_int)
Definition: print-zeromq.c:140
unsigned char nd_ipv4[4]
Definition: netdissect.h:92
void ftp_print(netdissect_options *, const u_char *, u_int)
Definition: print-ftp.c:25
#define ND_PRINT(...)
Definition: netdissect.h:385
#define PT_ZMTP1
Definition: netdissect.h:284
void rpki_rtr_print(netdissect_options *, const u_char *, u_int)
void txtproto_print(netdissect_options *, const u_char *, u_int, const char **, u_int)
Definition: util-print.c:811
unsigned char nd_ipv6[16]
Definition: netdissect.h:97
#define ND_BYTES_AVAILABLE_AFTER(p)
Definition: netdissect.h:383
void nbt_tcp_print(netdissect_options *, const u_char *, u_int)
Definition: print-smb.c:905
#define UNALIGNED_MEMCPY(p, q, l)
Definition: netdissect.h:443
#define NFS_PORT
Definition: nfs.h:52
static const struct tok tcp_option_values[]
Definition: print-tcp.c:116
#define TSEQ_HASHSIZE
Definition: print-tcp.c:96
#define MAX_RST_DATA_LEN
Definition: print-tcp.c:67
#define ZEROLENOPT(o)
Definition: print-tcp.c:99
#define LENCHECK(l)
static struct tcp_seq_hash6 tcp_seq_hash6[919]
Definition: print-tcp.c:102
static uint16_t tcp_cksum(netdissect_options *ndo, const struct ip *ip, const struct tcphdr *tp, u_int len)
Definition: print-tcp.c:140
static void print_tcp_fastopen_option(netdissect_options *ndo, const u_char *cp, u_int datalen, int exp)
Definition: print-tcp.c:866
static uint16_t tcp6_cksum(netdissect_options *ndo, const struct ip6_hdr *ip6, const struct tcphdr *tp, u_int len)
Definition: print-tcp.c:150
static struct tcp_seq_hash tcp_seq_hash4[919]
Definition: print-tcp.c:101
static const struct tok tcp_flag_values[]
Definition: print-tcp.c:104
void tcp_print(netdissect_options *ndo, const u_char *bp, u_int length, const u_char *bp2, int fragmented)
Definition: print-tcp.c:160
static void print_tcp_rst_data(netdissect_options *, const u_char *sp, u_int length)
Definition: print-tcp.c:845
static const char * direction[]
Definition: print-token.c:130
sunrpc_msg_type
Definition: rpc_msg.h:49
@ SUNRPC_REPLY
Definition: rpc_msg.h:51
@ SUNRPC_CALL
Definition: rpc_msg.h:50
#define CANT_CHECK_SIGNATURE
Definition: signature.h:25
#define SIGNATURE_INVALID
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#define SIGNATURE_VALID
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@ S_ERR_ND_MEM_ALLOC
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nd_ipv6 ip6_dst
Definition: ip6.h:87
nd_ipv6 ip6_src
Definition: ip6.h:86
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nd_uint16_t ip_len
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nd_ipv4 ip_dst
Definition: ip.h:66
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nd_ipv4 ip_src
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const u_char * ndo_snapend
Definition: netdissect.h:239
int(*) void NORETURN_FUNCPTR(* ndo_error)(netdissect_options *, status_exit_codes_t status, const char *fmt,...) PRINTFLIKE_FUNCPTR(3
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const char * ndo_protocol
Definition: netdissect.h:218
nd_uint32_t rm_xid
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nd_uint32_t rm_direction
Definition: rpc_msg.h:118
uint32_t ack
Definition: print-tcp.c:93
struct tha6 addr
Definition: print-tcp.c:91
struct tcp_seq_hash6 * nxt
Definition: print-tcp.c:90
uint32_t seq
Definition: print-tcp.c:92
uint32_t ack
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struct tha addr
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struct tcp_seq_hash * nxt
Definition: print-tcp.c:77
uint32_t seq
Definition: print-tcp.c:79
Definition: tcp.h:40
nd_uint16_t th_dport
Definition: tcp.h:42
nd_uint16_t th_win
Definition: tcp.h:47
nd_uint32_t th_seq
Definition: tcp.h:43
nd_uint16_t th_sport
Definition: tcp.h:41
nd_uint8_t th_flags
Definition: tcp.h:46
nd_uint32_t th_ack
Definition: tcp.h:44
nd_uint16_t th_sum
Definition: tcp.h:48
nd_uint16_t th_urp
Definition: tcp.h:49
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u_int port
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nd_ipv6 src
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Definition: print-tcp.c:70
nd_ipv4 src
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u_int port
Definition: print-tcp.c:73
nd_ipv4 dst
Definition: print-tcp.c:72
#define TH_OFF(th)
Definition: tcp.h:52
#define TCPOPT_EXPERIMENT2
Definition: tcp.h:89
#define TCPOPT_SACK
Definition: tcp.h:71
#define HTTP_PORT
Definition: tcp.h:113
#define LDP_PORT
Definition: tcp.h:134
#define NETBIOS_SSN_PORT
Definition: tcp.h:116
#define TH_FIN
Definition: tcp.h:55
#define FTP_PORT
Definition: tcp.h:95
#define TCPOPT_CCECHO
Definition: tcp.h:79
#define MSDP_PORT
Definition: tcp.h:131
#define TCPOPT_MPTCP
Definition: tcp.h:87
#define TCPOPT_UTO
Definition: tcp.h:84
#define TH_ACK
Definition: tcp.h:59
#define TCPOPT_TIMESTAMP
Definition: tcp.h:74
#define BEEP_PORT
Definition: tcp.h:155
#define TH_CWR
Definition: tcp.h:62
#define OPENFLOW_PORT_OLD
Definition: tcp.h:143
#define TH_PUSH
Definition: tcp.h:58
#define PPTP_PORT
Definition: tcp.h:137
#define TCPOPT_EOL
Definition: tcp.h:65
#define TCPOPT_MAXSEG
Definition: tcp.h:67
#define TCPOPT_TCPAO
Definition: tcp.h:86
#define TCPOPT_WSCALE
Definition: tcp.h:69
#define TCPOPT_ECHOREPLY
Definition: tcp.h:73
#define RTSP_PORT_ALT
Definition: tcp.h:152
#define OPENFLOW_PORT_IANA
Definition: tcp.h:146
#define HTTP_PORT_ALT
Definition: tcp.h:149
#define TCPOPT_ECHO
Definition: tcp.h:72
#define TH_URG
Definition: tcp.h:60
#define TH_RST
Definition: tcp.h:57
#define RTSP_PORT
Definition: tcp.h:128
#define REDIS_PORT
Definition: tcp.h:158
#define TCPOPT_FASTOPEN
Definition: tcp.h:88
#define TH_SYN
Definition: tcp.h:56
#define SSH_PORT
Definition: tcp.h:98
#define TCP_SIGLEN
Definition: tcp.h:82
#define TCPOPT_SCPS
Definition: tcp.h:83
#define TCPOPT_CCNEW
Definition: tcp.h:78
#define BGP_PORT
Definition: tcp.h:119
#define SMB_PORT
Definition: tcp.h:125
#define NAMESERVER_PORT
Definition: tcp.h:110
#define TCPOPT_CC
Definition: tcp.h:77
#define TCPOPT_SIGNATURE
Definition: tcp.h:80
#define TCPOPT_NOP
Definition: tcp.h:66
#define TELNET_PORT
Definition: tcp.h:101
#define WHOIS_PORT
Definition: tcp.h:107
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Definition: tcp.h:61
#define SMTP_PORT
Definition: tcp.h:104
#define TCPOPT_SACKOK
Definition: tcp.h:70
#define RPKI_RTR_PORT
Definition: tcp.h:122