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

   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 #ifndef lint
  27 static const char rcsid[] _U_ =
  28 "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.135 2008-11-09 23:35:03 mcr Exp $ (LBL)";
  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 <tcpdump-stdinc.h>
  38
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42
  43 #include "interface.h"
  44 #include "addrtoname.h"
  45 #include "extract.h"
  46
  47 #include "tcp.h"
  48
  49 #include "ip.h"
  50 #ifdef INET6
  51 #include "ip6.h"
  52 #endif
  53 #include "ipproto.h"
  54 #include "rpc_auth.h"
  55 #include "rpc_msg.h"
  56
  57 #include "nameser.h"
  58
  59 #ifdef HAVE_LIBCRYPTO
  60 #include <openssl/md5.h>
  61 #include <signature.h>
  62
  63 static int tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
  64                                 const u_char *data, int length, const u_char *rcvsig);
  65 #endif
  66
  67 static void print_tcp_rst_data(register const u_char *sp, u_int length);
  68
  69 #define MAX_RST_DATA_LEN        30
  70
  71
  72 struct tha {
  73         struct in_addr src;
  74         struct in_addr dst;
  75         u_int port;
  76 };
  77
  78 struct tcp_seq_hash {
  79         struct tcp_seq_hash *nxt;
  80         struct tha addr;
  81         tcp_seq seq;
  82         tcp_seq ack;
  83 };
  84
  85 #ifdef INET6
  86 struct tha6 {
  87         struct in6_addr src;
  88         struct in6_addr dst;
  89         u_int port;
  90 };
  91
  92 struct tcp_seq_hash6 {
  93         struct tcp_seq_hash6 *nxt;
  94         struct tha6 addr;
  95         tcp_seq seq;
  96         tcp_seq ack;
  97 };
  98 #endif
  99
 100 #define TSEQ_HASHSIZE 919
 101
 102 /* These tcp optinos do not have the size octet */
 103 #define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)
 104
 105 static struct tcp_seq_hash tcp_seq_hash4[TSEQ_HASHSIZE];
 106 #ifdef INET6
 107 static struct tcp_seq_hash6 tcp_seq_hash6[TSEQ_HASHSIZE];
 108 #endif
 109
 110 static const struct tok tcp_flag_values[] = {
 111         { TH_FIN, "F" },
 112         { TH_SYN, "S" },
 113         { TH_RST, "R" },
 114         { TH_PUSH, "P" },
 115         { TH_ACK, "." },
 116         { TH_URG, "U" },
 117         { TH_ECNECHO, "E" },
 118         { TH_CWR, "W" },
 119         { 0, NULL }
 120 };
 121
 122 static const struct tok tcp_option_values[] = {
 123         { TCPOPT_EOL, "eol" },
 124         { TCPOPT_NOP, "nop" },
 125         { TCPOPT_MAXSEG, "mss" },
 126         { TCPOPT_WSCALE, "wscale" },
 127         { TCPOPT_SACKOK, "sackOK" },
 128         { TCPOPT_SACK, "sack" },
 129         { TCPOPT_ECHO, "echo" },
 130         { TCPOPT_ECHOREPLY, "echoreply" },
 131         { TCPOPT_TIMESTAMP, "TS" },
 132         { TCPOPT_CC, "cc" },
 133         { TCPOPT_CCNEW, "ccnew" },
 134         { TCPOPT_CCECHO, "" },
 135         { TCPOPT_SIGNATURE, "md5" },
 136         { TCPOPT_AUTH, "enhanced auth" },
 137         { TCPOPT_UTO, "uto" },
 138         { TCPOPT_MPTCP, "mptcp" },
 139         { TCPOPT_EXPERIMENT2, "exp" },
 140         { 0, NULL }
 141 };
 142
 143 static int tcp_cksum(register const struct ip *ip,
 144                      register const struct tcphdr *tp,
 145                      register u_int len)
 146 {
 147         return (nextproto4_cksum(ip, (const u_int8_t *)tp, len,
 148             IPPROTO_TCP));
 149 }
 150
 151 void
 152 tcp_print(register const u_char *bp, register u_int length,
 153           register const u_char *bp2, int fragmented)
 154 {
 155         register const struct tcphdr *tp;
 156         register const struct ip *ip;
 157         register u_char flags;
 158         register u_int hlen;
 159         register char ch;
 160         u_int16_t sport, dport, win, urp;
 161         u_int32_t seq, ack, thseq, thack;
 162         u_int utoval;
 163         u_int16_t magic;
 164         register int rev;
 165 #ifdef INET6
 166         register const struct ip6_hdr *ip6;
 167 #endif
 168
 169         tp = (struct tcphdr *)bp;
 170         ip = (struct ip *)bp2;
 171 #ifdef INET6
 172         if (IP_V(ip) == 6)
 173                 ip6 = (struct ip6_hdr *)bp2;
 174         else
 175                 ip6 = NULL;
 176 #endif /*INET6*/
 177         ch = '\0';
 178         if (!TTEST(tp->th_dport)) {
 179                 (void)printf("%s > %s: [|tcp]",
 180                              ipaddr_string(&ip->ip_src),
 181                              ipaddr_string(&ip->ip_dst));
 182                 return;
 183         }
 184
 185         sport = EXTRACT_16BITS(&tp->th_sport);
 186         dport = EXTRACT_16BITS(&tp->th_dport);
 187
 188         hlen = TH_OFF(tp) * 4;
 189
 190 #ifdef INET6
 191         if (ip6) {
 192                 if (ip6->ip6_nxt == IPPROTO_TCP) {
 193                         (void)printf("%s.%s > %s.%s: ",
 194                                      ip6addr_string(&ip6->ip6_src),
 195                                      tcpport_string(sport),
 196                                      ip6addr_string(&ip6->ip6_dst),
 197                                      tcpport_string(dport));
 198                 } else {
 199                         (void)printf("%s > %s: ",
 200                                      tcpport_string(sport), tcpport_string(dport));
 201                 }
 202         } else
 203 #endif /*INET6*/
 204         {
 205                 if (ip->ip_p == IPPROTO_TCP) {
 206                         (void)printf("%s.%s > %s.%s: ",
 207                                      ipaddr_string(&ip->ip_src),
 208                                      tcpport_string(sport),
 209                                      ipaddr_string(&ip->ip_dst),
 210                                      tcpport_string(dport));
 211                 } else {
 212                         (void)printf("%s > %s: ",
 213                                      tcpport_string(sport), tcpport_string(dport));
 214                 }
 215         }
 216
 217         if (hlen < sizeof(*tp)) {
 218                 (void)printf(" tcp %d [bad hdr length %u - too short, < %lu]",
 219                              length - hlen, hlen, (unsigned long)sizeof(*tp));
 220                 return;
 221         }
 222
 223         TCHECK(*tp);
 224
 225         seq = EXTRACT_32BITS(&tp->th_seq);
 226         ack = EXTRACT_32BITS(&tp->th_ack);
 227         win = EXTRACT_16BITS(&tp->th_win);
 228         urp = EXTRACT_16BITS(&tp->th_urp);
 229
 230         if (qflag) {
 231                 (void)printf("tcp %d", length - hlen);
 232                 if (hlen > length) {
 233                         (void)printf(" [bad hdr length %u - too long, > %u]",
 234                                      hlen, length);
 235                 }
 236                 return;
 237         }
 238
 239         flags = tp->th_flags;
 240         printf("Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags));
 241
 242         if (!Sflag && (flags & TH_ACK)) {
 243                 /*
 244                  * Find (or record) the initial sequence numbers for
 245                  * this conversation.  (we pick an arbitrary
 246                  * collating order so there's only one entry for
 247                  * both directions).
 248                  */
 249                 rev = 0;
 250 #ifdef INET6
 251                 if (ip6) {
 252                         register struct tcp_seq_hash6 *th;
 253                         struct tcp_seq_hash6 *tcp_seq_hash;
 254                         const struct in6_addr *src, *dst;
 255                         struct tha6 tha;
 256
 257                         tcp_seq_hash = tcp_seq_hash6;
 258                         src = &ip6->ip6_src;
 259                         dst = &ip6->ip6_dst;
 260                         if (sport > dport)
 261                                 rev = 1;
 262                         else if (sport == dport) {
 263                                 if (memcmp(src, dst, sizeof ip6->ip6_dst) > 0)
 264                                         rev = 1;
 265                         }
 266                         if (rev) {
 267                                 memcpy(&tha.src, dst, sizeof ip6->ip6_dst);
 268                                 memcpy(&tha.dst, src, sizeof ip6->ip6_src);
 269                                 tha.port = dport << 16 | sport;
 270                         } else {
 271                                 memcpy(&tha.dst, dst, sizeof ip6->ip6_dst);
 272                                 memcpy(&tha.src, src, sizeof ip6->ip6_src);
 273                                 tha.port = sport << 16 | dport;
 274                         }
 275
 276                         for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
 277                              th->nxt; th = th->nxt)
 278                                 if (memcmp((char *)&tha, (char *)&th->addr,
 279                                            sizeof(th->addr)) == 0)
 280                                         break;
 281
 282                         if (!th->nxt || (flags & TH_SYN)) {
 283                                 /* didn't find it or new conversation */
 284                                 if (th->nxt == NULL) {
 285                                         th->nxt = (struct tcp_seq_hash6 *)
 286                                                 calloc(1, sizeof(*th));
 287                                         if (th->nxt == NULL)
 288                                                 error("tcp_print: calloc");
 289                                 }
 290                                 th->addr = tha;
 291                                 if (rev)
 292                                         th->ack = seq, th->seq = ack - 1;
 293                                 else
 294                                         th->seq = seq, th->ack = ack - 1;
 295                         } else {
 296                                 if (rev)
 297                                         seq -= th->ack, ack -= th->seq;
 298                                 else
 299                                         seq -= th->seq, ack -= th->ack;
 300                         }
 301
 302                         thseq = th->seq;
 303                         thack = th->ack;
 304                 } else {
 305 #else  /*INET6*/
 306                 {
 307 #endif /*INET6*/
 308                         register struct tcp_seq_hash *th;
 309                         struct tcp_seq_hash *tcp_seq_hash;
 310                         const struct in_addr *src, *dst;
 311                         struct tha tha;
 312
 313                         tcp_seq_hash = tcp_seq_hash4;
 314                         src = &ip->ip_src;
 315                         dst = &ip->ip_dst;
 316                         if (sport > dport)
 317                                 rev = 1;
 318                         else if (sport == dport) {
 319                                 if (memcmp(src, dst, sizeof ip->ip_dst) > 0)
 320                                         rev = 1;
 321                         }
 322                         if (rev) {
 323                                 memcpy(&tha.src, dst, sizeof ip->ip_dst);
 324                                 memcpy(&tha.dst, src, sizeof ip->ip_src);
 325                                 tha.port = dport << 16 | sport;
 326                         } else {
 327                                 memcpy(&tha.dst, dst, sizeof ip->ip_dst);
 328                                 memcpy(&tha.src, src, sizeof ip->ip_src);
 329                                 tha.port = sport << 16 | dport;
 330                         }
 331
 332                         for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
 333                              th->nxt; th = th->nxt)
 334                                 if (memcmp((char *)&tha, (char *)&th->addr,
 335                                            sizeof(th->addr)) == 0)
 336                                         break;
 337
 338                         if (!th->nxt || (flags & TH_SYN)) {
 339                                 /* didn't find it or new conversation */
 340                                 if (th->nxt == NULL) {
 341                                         th->nxt = (struct tcp_seq_hash *)
 342                                                 calloc(1, sizeof(*th));
 343                                         if (th->nxt == NULL)
 344                                                 error("tcp_print: calloc");
 345                                 }
 346                                 th->addr = tha;
 347                                 if (rev)
 348                                         th->ack = seq, th->seq = ack - 1;
 349                                 else
 350                                         th->seq = seq, th->ack = ack - 1;
 351                         } else {
 352                                 if (rev)
 353                                         seq -= th->ack, ack -= th->seq;
 354                                 else
 355                                         seq -= th->seq, ack -= th->ack;
 356                         }
 357
 358                         thseq = th->seq;
 359                         thack = th->ack;
 360                 }
 361         } else {
 362                 /*fool gcc*/
 363                 thseq = thack = rev = 0;
 364         }
 365         if (hlen > length) {
 366                 (void)printf(" [bad hdr length %u - too long, > %u]",
 367                              hlen, length);
 368                 return;
 369         }
 370
 371         if (vflag && !Kflag && !fragmented) {
 372                 /* Check the checksum, if possible. */
 373                 u_int16_t sum, tcp_sum;
 374
 375                 if (IP_V(ip) == 4) {
 376                         if (TTEST2(tp->th_sport, length)) {
 377                                 sum = tcp_cksum(ip, tp, length);
 378                                 tcp_sum = EXTRACT_16BITS(&tp->th_sum);
 379
 380                                 (void)printf(", cksum 0x%04x", tcp_sum);
 381                                 if (sum != 0)
 382                                         (void)printf(" (incorrect -> 0x%04x)",
 383                                             in_cksum_shouldbe(tcp_sum, sum));
 384                                 else
 385                                         (void)printf(" (correct)");
 386                         }
 387                 }
 388 #ifdef INET6
 389                 else if (IP_V(ip) == 6 && ip6->ip6_plen) {
 390                         if (TTEST2(tp->th_sport, length)) {
 391                                 sum = nextproto6_cksum(ip6, (const u_int8_t *)tp, length, IPPROTO_TCP);
 392                                 tcp_sum = EXTRACT_16BITS(&tp->th_sum);
 393
 394                                 (void)printf(", cksum 0x%04x", tcp_sum);
 395                                 if (sum != 0)
 396                                         (void)printf(" (incorrect -> 0x%04x)",
 397                                             in_cksum_shouldbe(tcp_sum, sum));
 398                                 else
 399                                         (void)printf(" (correct)");
 400
 401                         }
 402                 }
 403 #endif
 404         }
 405
 406         length -= hlen;
 407         if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) {
 408                 (void)printf(", seq %u", seq);
 409
 410                 if (length > 0) {
 411                         (void)printf(":%u", seq + length);
 412                 }
 413         }
 414
 415         if (flags & TH_ACK) {
 416                 (void)printf(", ack %u", ack);
 417         }
 418
 419         (void)printf(", win %d", win);
 420
 421         if (flags & TH_URG)
 422                 (void)printf(", urg %d", urp);
 423         /*
 424          * Handle any options.
 425          */
 426         if (hlen > sizeof(*tp)) {
 427                 register const u_char *cp;
 428                 register u_int i, opt, datalen;
 429                 register u_int len;
 430
 431                 hlen -= sizeof(*tp);
 432                 cp = (const u_char *)tp + sizeof(*tp);
 433                 printf(", options [");
 434                 while (hlen > 0) {
 435                         if (ch != '\0')
 436                                 putchar(ch);
 437                         TCHECK(*cp);
 438                         opt = *cp++;
 439                         if (ZEROLENOPT(opt))
 440                                 len = 1;
 441                         else {
 442                                 TCHECK(*cp);
 443                                 len = *cp++;    /* total including type, len */
 444                                 if (len < 2 || len > hlen)
 445                                         goto bad;
 446                                 --hlen;         /* account for length byte */
 447                         }
 448                         --hlen;                 /* account for type byte */
 449                         datalen = 0;
 450
 451 /* Bail if "l" bytes of data are not left or were not captured  */
 452 #define LENCHECK(l) { if ((l) > hlen) goto bad; TCHECK2(*cp, l); }
 453
 454
 455                         printf("%s", tok2str(tcp_option_values, "unknown-%u", opt));
 456
 457                         switch (opt) {
 458
 459                         case TCPOPT_MAXSEG:
 460                                 datalen = 2;
 461                                 LENCHECK(datalen);
 462                                 (void)printf(" %u", EXTRACT_16BITS(cp));
 463                                 break;
 464
 465                         case TCPOPT_WSCALE:
 466                                 datalen = 1;
 467                                 LENCHECK(datalen);
 468                                 (void)printf(" %u", *cp);
 469                                 break;
 470
 471                         case TCPOPT_SACK:
 472                                 datalen = len - 2;
 473                                 if (datalen % 8 != 0) {
 474                                         (void)printf("malformed sack");
 475                                 } else {
 476                                         u_int32_t s, e;
 477
 478                                         (void)printf(" %d ", datalen / 8);
 479                                         for (i = 0; i < datalen; i += 8) {
 480                                                 LENCHECK(i + 4);
 481                                                 s = EXTRACT_32BITS(cp + i);
 482                                                 LENCHECK(i + 8);
 483                                                 e = EXTRACT_32BITS(cp + i + 4);
 484                                                 if (rev) {
 485                                                         s -= thseq;
 486                                                         e -= thseq;
 487                                                 } else {
 488                                                         s -= thack;
 489                                                         e -= thack;
 490                                                 }
 491                                                 (void)printf("{%u:%u}", s, e);
 492                                         }
 493                                 }
 494                                 break;
 495
 496                         case TCPOPT_CC:
 497                         case TCPOPT_CCNEW:
 498                         case TCPOPT_CCECHO:
 499                         case TCPOPT_ECHO:
 500                         case TCPOPT_ECHOREPLY:
 501
 502                                 /*
 503                                  * those options share their semantics.
 504                                  * fall through
 505                                  */
 506                                 datalen = 4;
 507                                 LENCHECK(datalen);
 508                                 (void)printf(" %u", EXTRACT_32BITS(cp));
 509                                 break;
 510
 511                         case TCPOPT_TIMESTAMP:
 512                                 datalen = 8;
 513                                 LENCHECK(datalen);
 514                                 (void)printf(" val %u ecr %u",
 515                                              EXTRACT_32BITS(cp),
 516                                              EXTRACT_32BITS(cp + 4));
 517                                 break;
 518
 519                         case TCPOPT_SIGNATURE:
 520                                 datalen = TCP_SIGLEN;
 521                                 LENCHECK(datalen);
 522 #ifdef HAVE_LIBCRYPTO
 523                                 switch (tcp_verify_signature(ip, tp,
 524                                                              bp + TH_OFF(tp) * 4, length, cp)) {
 525
 526                                 case SIGNATURE_VALID:
 527                                         (void)printf("valid");
 528                                         break;
 529
 530                                 case SIGNATURE_INVALID:
 531                                         (void)printf("invalid");
 532                                         break;
 533
 534                                 case CANT_CHECK_SIGNATURE:
 535                                         (void)printf("can't check - ");
 536                                         for (i = 0; i < TCP_SIGLEN; ++i)
 537                                                 (void)printf("%02x", cp[i]);
 538                                         break;
 539                                 }
 540 #else
 541                                 for (i = 0; i < TCP_SIGLEN; ++i)
 542                                         (void)printf("%02x", cp[i]);
 543 #endif
 544                                 break;
 545
 546                         case TCPOPT_AUTH:
 547                                 (void)printf("keyid %d", *cp++);
 548                                 datalen = len - 3;
 549                                 for (i = 0; i < datalen; ++i) {
 550                                         LENCHECK(i);
 551                                         (void)printf("%02x", cp[i]);
 552                                 }
 553                                 break;
 554
 555
 556                         case TCPOPT_EOL:
 557                         case TCPOPT_NOP:
 558                         case TCPOPT_SACKOK:
 559                                 /*
 560                                  * Nothing interesting.
 561                                  * fall through
 562                                  */
 563                                 break;
 564
 565                         case TCPOPT_UTO:
 566                                 datalen = 2;
 567                                 LENCHECK(datalen);
 568                                 utoval = EXTRACT_16BITS(cp);
 569                                 (void)printf("0x%x", utoval);
 570                                 if (utoval & 0x0001)
 571                                         utoval = (utoval >> 1) * 60;
 572                                 else
 573                                         utoval >>= 1;
 574                                 (void)printf(" %u", utoval);
 575                                 break;
 576
 577                         case TCPOPT_MPTCP:
 578                                 datalen = len - 2;
 579                                 LENCHECK(datalen);
 580                                 if (!mptcp_print(cp-2, len, flags))
 581                                         goto bad;
 582                                 break;
 583
 584                         case TCPOPT_EXPERIMENT2:
 585                                 datalen = len - 2;
 586                                 LENCHECK(datalen);
 587                                 if (datalen < 2)
 588                                         goto bad;
 589                                 /* RFC6994 */
 590                                 magic = EXTRACT_16BITS(cp);
 591                                 (void)printf("-");
 592
 593                                 switch(magic) {
 594
 595                                 case 0xf989:
 596                                         /* TCP Fast Open: draft-ietf-tcpm-fastopen-04 */
 597                                         if (datalen == 2) {
 598                                                 /* Fast Open Cookie Request */
 599                                                 (void)printf("tfo cookiereq");
 600                                         } else {
 601                                                 /* Fast Open Cookie */
 602                                                 if (datalen % 2 != 0 || datalen < 6 || datalen > 18) {
 603                                                         (void)printf("tfo malformed");
 604                                                 } else {
 605                                                         (void)printf("tfo cookie ");
 606                                                         for (i = 2; i < datalen; ++i)
 607                                                                 (void)printf("%02x", cp[i]);
 608                                                 }
 609                                         }
 610                                         break;
 611
 612                                 default:
 613                                         /* Unknown magic number */
 614                                         (void)printf("%04x", magic);
 615                                         break;
 616                                 }
 617                                 break;
 618
 619                         default:
 620                                 datalen = len - 2;
 621                                 if (datalen)
 622                                         printf(" 0x");
 623                                 for (i = 0; i < datalen; ++i) {
 624                                         LENCHECK(i);
 625                                         (void)printf("%02x", cp[i]);
 626                                 }
 627                                 break;
 628                         }
 629
 630                         /* Account for data printed */
 631                         cp += datalen;
 632                         hlen -= datalen;
 633
 634                         /* Check specification against observed length */
 635                         ++datalen;                      /* option octet */
 636                         if (!ZEROLENOPT(opt))
 637                                 ++datalen;              /* size octet */
 638                         if (datalen != len)
 639                                 (void)printf("[len %d]", len);
 640                         ch = ',';
 641                         if (opt == TCPOPT_EOL)
 642                                 break;
 643                 }
 644                 putchar(']');
 645         }
 646
 647         /*
 648          * Print length field before crawling down the stack.
 649          */
 650         printf(", length %u", length);
 651
 652         if (length <= 0)
 653                 return;
 654
 655         /*
 656          * Decode payload if necessary.
 657          */
 658         bp += TH_OFF(tp) * 4;
 659         if ((flags & TH_RST) && vflag) {
 660                 print_tcp_rst_data(bp, length);
 661                 return;
 662         }
 663
 664         if (packettype) {
 665                 switch (packettype) {
 666                 case PT_ZMTP1:
 667                         zmtp1_print(bp, length);
 668                         break;
 669                 }
 670                 return;
 671         }
 672
 673         if (sport == TELNET_PORT || dport == TELNET_PORT) {
 674                 if (!qflag && vflag)
 675                         telnet_print(bp, length);
 676         } else if (sport == BGP_PORT || dport == BGP_PORT)
 677                 bgp_print(bp, length);
 678         else if (sport == PPTP_PORT || dport == PPTP_PORT)
 679                 pptp_print(bp);
 680 #ifdef TCPDUMP_DO_SMB
 681         else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
 682                 nbt_tcp_print(bp, length);
 683         else if (sport == SMB_PORT || dport == SMB_PORT)
 684                 smb_tcp_print(bp, length);
 685 #endif
 686         else if (sport == BEEP_PORT || dport == BEEP_PORT)
 687                 beep_print(bp, length);
 688         else if (sport == OPENFLOW_PORT || dport == OPENFLOW_PORT)
 689                 openflow_print(bp, length);
 690         else if (length > 2 &&
 691                  (sport == NAMESERVER_PORT || dport == NAMESERVER_PORT ||
 692                   sport == MULTICASTDNS_PORT || dport == MULTICASTDNS_PORT)) {
 693                 /*
 694                  * TCP DNS query has 2byte length at the head.
 695                  * XXX packet could be unaligned, it can go strange
 696                  */
 697                 ns_print(bp + 2, length - 2, 0);
 698         } else if (sport == MSDP_PORT || dport == MSDP_PORT) {
 699                 msdp_print(bp, length);
 700         } else if (sport == RPKI_RTR_PORT || dport == RPKI_RTR_PORT) {
 701                 rpki_rtr_print(bp, length);
 702         }
 703         else if (length > 0 && (sport == LDP_PORT || dport == LDP_PORT)) {
 704                 ldp_print(bp, length);
 705         }
 706         else if ((sport == NFS_PORT || dport == NFS_PORT) &&
 707                  length >= 4 && TTEST2(*bp, 4)) {
 708                 /*
 709                  * If data present, header length valid, and NFS port used,
 710                  * assume NFS.
 711                  * Pass offset of data plus 4 bytes for RPC TCP msg length
 712                  * to NFS print routines.
 713                  */
 714                 u_int32_t fraglen;
 715                 register struct sunrpc_msg *rp;
 716                 enum sunrpc_msg_type direction;
 717
 718                 fraglen = EXTRACT_32BITS(bp) & 0x7FFFFFFF;
 719                 if (fraglen > (length) - 4)
 720                         fraglen = (length) - 4;
 721                 rp = (struct sunrpc_msg *)(bp + 4);
 722                 if (TTEST(rp->rm_direction)) {
 723                         direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction);
 724                         if (dport == NFS_PORT && direction == SUNRPC_CALL) {
 725                                 (void)printf(": NFS request xid %u ", EXTRACT_32BITS(&rp->rm_xid));
 726                                 nfsreq_print_noaddr((u_char *)rp, fraglen, (u_char *)ip);
 727                                 return;
 728                         }
 729                         if (sport == NFS_PORT && direction == SUNRPC_REPLY) {
 730                                 (void)printf(": NFS reply xid %u ", EXTRACT_32BITS(&rp->rm_xid));
 731                                 nfsreply_print_noaddr((u_char *)rp, fraglen, (u_char *)ip);
 732                                 return;
 733                         }
 734                 }
 735         }
 736
 737         return;
 738  bad:
 739         fputs("[bad opt]", stdout);
 740         if (ch != '\0')
 741                 putchar('>');
 742         return;
 743  trunc:
 744         fputs("[|tcp]", stdout);
 745         if (ch != '\0')
 746                 putchar('>');
 747 }
 748
 749 /*
 750  * RFC1122 says the following on data in RST segments:
 751  *
 752  *         4.2.2.12  RST Segment: RFC-793 Section 3.4
 753  *
 754  *            A TCP SHOULD allow a received RST segment to include data.
 755  *
 756  *            DISCUSSION
 757  *                 It has been suggested that a RST segment could contain
 758  *                 ASCII text that encoded and explained the cause of the
 759  *                 RST.  No standard has yet been established for such
 760  *                 data.
 761  *
 762  */
 763
 764 static void
 765 print_tcp_rst_data(register const u_char *sp, u_int length)
 766 {
 767         int c;
 768
 769         if (TTEST2(*sp, length))
 770                 printf(" [RST");
 771         else
 772                 printf(" [!RST");
 773         if (length > MAX_RST_DATA_LEN) {
 774                 length = MAX_RST_DATA_LEN;      /* can use -X for longer */
 775                 putchar('+');                   /* indicate we truncate */
 776         }
 777         putchar(' ');
 778         while (length-- && sp <= snapend) {
 779                 c = *sp++;
 780                 safeputchar(c);
 781         }
 782         putchar(']');
 783 }
 784
 785 #ifdef HAVE_LIBCRYPTO
 786 USES_APPLE_DEPRECATED_API
 787 static int
 788 tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
 789                      const u_char *data, int length, const u_char *rcvsig)
 790 {
 791         struct tcphdr tp1;
 792         u_char sig[TCP_SIGLEN];
 793         char zero_proto = 0;
 794         MD5_CTX ctx;
 795         u_int16_t savecsum, tlen;
 796 #ifdef INET6
 797         struct ip6_hdr *ip6;
 798         u_int32_t len32;
 799         u_int8_t nxt;
 800 #endif
 801
 802         if (data + length > snapend) {
 803                 printf("snaplen too short, ");
 804                 return (CANT_CHECK_SIGNATURE);
 805         }
 806
 807         tp1 = *tp;
 808
 809         if (sigsecret == NULL) {
 810                 printf("shared secret not supplied with -M, ");
 811                 return (CANT_CHECK_SIGNATURE);
 812         }
 813
 814         MD5_Init(&ctx);
 815         /*
 816          * Step 1: Update MD5 hash with IP pseudo-header.
 817          */
 818         if (IP_V(ip) == 4) {
 819                 MD5_Update(&ctx, (char *)&ip->ip_src, sizeof(ip->ip_src));
 820                 MD5_Update(&ctx, (char *)&ip->ip_dst, sizeof(ip->ip_dst));
 821                 MD5_Update(&ctx, (char *)&zero_proto, sizeof(zero_proto));
 822                 MD5_Update(&ctx, (char *)&ip->ip_p, sizeof(ip->ip_p));
 823                 tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4;
 824                 tlen = htons(tlen);
 825                 MD5_Update(&ctx, (char *)&tlen, sizeof(tlen));
 826 #ifdef INET6
 827         } else if (IP_V(ip) == 6) {
 828                 ip6 = (struct ip6_hdr *)ip;
 829                 MD5_Update(&ctx, (char *)&ip6->ip6_src, sizeof(ip6->ip6_src));
 830                 MD5_Update(&ctx, (char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));
 831                 len32 = htonl(EXTRACT_16BITS(&ip6->ip6_plen));
 832                 MD5_Update(&ctx, (char *)&len32, sizeof(len32));
 833                 nxt = 0;
 834                 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
 835                 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
 836                 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
 837                 nxt = IPPROTO_TCP;
 838                 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
 839 #endif
 840         } else {
 841 #ifdef INET6
 842                 printf("IP version not 4 or 6, ");
 843 #else
 844                 printf("IP version not 4, ");
 845 #endif
 846                 return (CANT_CHECK_SIGNATURE);
 847         }
 848
 849         /*
 850          * Step 2: Update MD5 hash with TCP header, excluding options.
 851          * The TCP checksum must be set to zero.
 852          */
 853         savecsum = tp1.th_sum;
 854         tp1.th_sum = 0;
 855         MD5_Update(&ctx, (char *)&tp1, sizeof(struct tcphdr));
 856         tp1.th_sum = savecsum;
 857         /*
 858          * Step 3: Update MD5 hash with TCP segment data, if present.
 859          */
 860         if (length > 0)
 861                 MD5_Update(&ctx, data, length);
 862         /*
 863          * Step 4: Update MD5 hash with shared secret.
 864          */
 865         MD5_Update(&ctx, sigsecret, strlen(sigsecret));
 866         MD5_Final(sig, &ctx);
 867
 868         if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0)
 869                 return (SIGNATURE_VALID);
 870         else
 871                 return (SIGNATURE_INVALID);
 872 }
 873 USES_APPLE_RST
 874 #endif /* HAVE_LIBCRYPTO */
 875
 876 /*
 877  * Local Variables:
 878  * c-style: whitesmith
 879  * c-basic-offset: 8
 880  * End:
 881  */