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 #else 28 __RCSID("$NetBSD: print-tcp.c,v 1.8 2007/07/24 11:53:48 drochner Exp $"); 29 #endif 30 31 #define NETDISSECT_REWORKED 32 #ifdef HAVE_CONFIG_H 33 #include "config.h" 34 #endif 35 36 #include <tcpdump-stdinc.h> 37 38 #include <stdlib.h> 39 #include <string.h> 40 41 #include "interface.h" 42 #include "addrtoname.h" 43 #include "extract.h" 44 45 #include "tcp.h" 46 47 #include "ip.h" 48 #ifdef INET6 49 #include "ip6.h" 50 #endif 51 #include "ipproto.h" 52 #include "rpc_auth.h" 53 #include "rpc_msg.h" 54 55 #include "nameser.h" 56 57 #ifdef HAVE_LIBCRYPTO 58 #include <openssl/md5.h> 59 #include <signature.h> 60 61 static int tcp_verify_signature(netdissect_options *ndo, 62 const struct ip *ip, const struct tcphdr *tp, 63 const u_char *data, int length, const u_char *rcvsig); 64 #endif 65 66 static void print_tcp_rst_data(netdissect_options *, register const u_char *sp, u_int length); 67 68 #define MAX_RST_DATA_LEN 30 69 70 71 struct tha { 72 struct in_addr src; 73 struct in_addr dst; 74 u_int port; 75 }; 76 77 struct tcp_seq_hash { 78 struct tcp_seq_hash *nxt; 79 struct tha addr; 80 tcp_seq seq; 81 tcp_seq ack; 82 }; 83 84 #ifdef INET6 85 struct tha6 { 86 struct in6_addr src; 87 struct in6_addr dst; 88 u_int port; 89 }; 90 91 struct tcp_seq_hash6 { 92 struct tcp_seq_hash6 *nxt; 93 struct tha6 addr; 94 tcp_seq seq; 95 tcp_seq ack; 96 }; 97 #endif 98 99 #define TSEQ_HASHSIZE 919 100 101 /* These tcp optinos do not have the size octet */ 102 #define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP) 103 104 static struct tcp_seq_hash tcp_seq_hash4[TSEQ_HASHSIZE]; 105 #ifdef INET6 106 static struct tcp_seq_hash6 tcp_seq_hash6[TSEQ_HASHSIZE]; 107 #endif 108 109 static const struct tok tcp_flag_values[] = { 110 { TH_FIN, "F" }, 111 { TH_SYN, "S" }, 112 { TH_RST, "R" }, 113 { TH_PUSH, "P" }, 114 { TH_ACK, "." }, 115 { TH_URG, "U" }, 116 { TH_ECNECHO, "E" }, 117 { TH_CWR, "W" }, 118 { 0, NULL } 119 }; 120 121 static const struct tok tcp_option_values[] = { 122 { TCPOPT_EOL, "eol" }, 123 { TCPOPT_NOP, "nop" }, 124 { TCPOPT_MAXSEG, "mss" }, 125 { TCPOPT_WSCALE, "wscale" }, 126 { TCPOPT_SACKOK, "sackOK" }, 127 { TCPOPT_SACK, "sack" }, 128 { TCPOPT_ECHO, "echo" }, 129 { TCPOPT_ECHOREPLY, "echoreply" }, 130 { TCPOPT_TIMESTAMP, "TS" }, 131 { TCPOPT_CC, "cc" }, 132 { TCPOPT_CCNEW, "ccnew" }, 133 { TCPOPT_CCECHO, "" }, 134 { TCPOPT_SIGNATURE, "md5" }, 135 { TCPOPT_AUTH, "enhanced auth" }, 136 { TCPOPT_UTO, "uto" }, 137 { TCPOPT_MPTCP, "mptcp" }, 138 { TCPOPT_EXPERIMENT2, "exp" }, 139 { 0, NULL } 140 }; 141 142 static int 143 tcp_cksum(netdissect_options *ndo, 144 register const struct ip *ip, 145 register const struct tcphdr *tp, 146 register u_int len) 147 { 148 return nextproto4_cksum(ndo, ip, (const uint8_t *)tp, len, len, 149 IPPROTO_TCP); 150 } 151 152 void 153 tcp_print(netdissect_options *ndo, 154 register const u_char *bp, register u_int length, 155 register const u_char *bp2, int fragmented) 156 { 157 register const struct tcphdr *tp; 158 register const struct ip *ip; 159 register u_char flags; 160 register u_int hlen; 161 register char ch; 162 uint16_t sport, dport, win, urp; 163 uint32_t seq, ack, thseq, thack; 164 u_int utoval; 165 uint16_t magic; 166 register int rev; 167 #ifdef INET6 168 register const struct ip6_hdr *ip6; 169 #endif 170 171 tp = (struct tcphdr *)bp; 172 ip = (struct ip *)bp2; 173 #ifdef INET6 174 if (IP_V(ip) == 6) 175 ip6 = (struct ip6_hdr *)bp2; 176 else 177 ip6 = NULL; 178 #endif /*INET6*/ 179 ch = '\0'; 180 if (!ND_TTEST(tp->th_dport)) { 181 ND_PRINT((ndo, "%s > %s: [|tcp]", 182 ipaddr_string(ndo, &ip->ip_src), 183 ipaddr_string(ndo, &ip->ip_dst))); 184 return; 185 } 186 187 sport = EXTRACT_16BITS(&tp->th_sport); 188 dport = EXTRACT_16BITS(&tp->th_dport); 189 190 hlen = TH_OFF(tp) * 4; 191 192 #ifdef INET6 193 if (ip6) { 194 if (ip6->ip6_nxt == IPPROTO_TCP) { 195 ND_PRINT((ndo, "%s.%s > %s.%s: ", 196 ip6addr_string(ndo, &ip6->ip6_src), 197 tcpport_string(sport), 198 ip6addr_string(ndo, &ip6->ip6_dst), 199 tcpport_string(dport))); 200 } else { 201 ND_PRINT((ndo, "%s > %s: ", 202 tcpport_string(sport), tcpport_string(dport))); 203 } 204 } else 205 #endif /*INET6*/ 206 { 207 if (ip->ip_p == IPPROTO_TCP) { 208 ND_PRINT((ndo, "%s.%s > %s.%s: ", 209 ipaddr_string(ndo, &ip->ip_src), 210 tcpport_string(sport), 211 ipaddr_string(ndo, &ip->ip_dst), 212 tcpport_string(dport))); 213 } else { 214 ND_PRINT((ndo, "%s > %s: ", 215 tcpport_string(sport), tcpport_string(dport))); 216 } 217 } 218 219 if (hlen < sizeof(*tp)) { 220 ND_PRINT((ndo, " tcp %d [bad hdr length %u - too short, < %lu]", 221 length - hlen, hlen, (unsigned long)sizeof(*tp))); 222 return; 223 } 224 225 ND_TCHECK(*tp); 226 227 seq = EXTRACT_32BITS(&tp->th_seq); 228 ack = EXTRACT_32BITS(&tp->th_ack); 229 win = EXTRACT_16BITS(&tp->th_win); 230 urp = EXTRACT_16BITS(&tp->th_urp); 231 232 if (ndo->ndo_qflag) { 233 ND_PRINT((ndo, "tcp %d", length - hlen)); 234 if (hlen > length) { 235 ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]", 236 hlen, length)); 237 } 238 return; 239 } 240 241 flags = tp->th_flags; 242 ND_PRINT((ndo, "Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags))); 243 244 if (!ndo->ndo_Sflag && (flags & TH_ACK)) { 245 /* 246 * Find (or record) the initial sequence numbers for 247 * this conversation. (we pick an arbitrary 248 * collating order so there's only one entry for 249 * both directions). 250 */ 251 rev = 0; 252 #ifdef INET6 253 if (ip6) { 254 register struct tcp_seq_hash6 *th; 255 struct tcp_seq_hash6 *tcp_seq_hash; 256 const struct in6_addr *src, *dst; 257 struct tha6 tha; 258 259 tcp_seq_hash = tcp_seq_hash6; 260 src = &ip6->ip6_src; 261 dst = &ip6->ip6_dst; 262 if (sport > dport) 263 rev = 1; 264 else if (sport == dport) { 265 if (UNALIGNED_MEMCMP(src, dst, sizeof ip6->ip6_dst) > 0) 266 rev = 1; 267 } 268 if (rev) { 269 UNALIGNED_MEMCPY(&tha.src, dst, sizeof ip6->ip6_dst); 270 UNALIGNED_MEMCPY(&tha.dst, src, sizeof ip6->ip6_src); 271 tha.port = dport << 16 | sport; 272 } else { 273 UNALIGNED_MEMCPY(&tha.dst, dst, sizeof ip6->ip6_dst); 274 UNALIGNED_MEMCPY(&tha.src, src, sizeof ip6->ip6_src); 275 tha.port = sport << 16 | dport; 276 } 277 278 for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE]; 279 th->nxt; th = th->nxt) 280 if (memcmp((char *)&tha, (char *)&th->addr, 281 sizeof(th->addr)) == 0) 282 break; 283 284 if (!th->nxt || (flags & TH_SYN)) { 285 /* didn't find it or new conversation */ 286 if (th->nxt == NULL) { 287 th->nxt = (struct tcp_seq_hash6 *) 288 calloc(1, sizeof(*th)); 289 if (th->nxt == NULL) 290 error("tcp_print: calloc"); 291 } 292 th->addr = tha; 293 if (rev) 294 th->ack = seq, th->seq = ack - 1; 295 else 296 th->seq = seq, th->ack = ack - 1; 297 } else { 298 if (rev) 299 seq -= th->ack, ack -= th->seq; 300 else 301 seq -= th->seq, ack -= th->ack; 302 } 303 304 thseq = th->seq; 305 thack = th->ack; 306 } else { 307 #else /*INET6*/ 308 { 309 #endif /*INET6*/ 310 register struct tcp_seq_hash *th; 311 struct tcp_seq_hash *tcp_seq_hash; 312 const struct in_addr *src, *dst; 313 struct tha tha; 314 315 tcp_seq_hash = tcp_seq_hash4; 316 src = &ip->ip_src; 317 dst = &ip->ip_dst; 318 if (sport > dport) 319 rev = 1; 320 else if (sport == dport) { 321 if (UNALIGNED_MEMCMP(src, dst, sizeof ip->ip_dst) > 0) 322 rev = 1; 323 } 324 if (rev) { 325 UNALIGNED_MEMCPY(&tha.src, dst, sizeof ip->ip_dst); 326 UNALIGNED_MEMCPY(&tha.dst, src, sizeof ip->ip_src); 327 tha.port = dport << 16 | sport; 328 } else { 329 UNALIGNED_MEMCPY(&tha.dst, dst, sizeof ip->ip_dst); 330 UNALIGNED_MEMCPY(&tha.src, src, sizeof ip->ip_src); 331 tha.port = sport << 16 | dport; 332 } 333 334 for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE]; 335 th->nxt; th = th->nxt) 336 if (memcmp((char *)&tha, (char *)&th->addr, 337 sizeof(th->addr)) == 0) 338 break; 339 340 if (!th->nxt || (flags & TH_SYN)) { 341 /* didn't find it or new conversation */ 342 if (th->nxt == NULL) { 343 th->nxt = (struct tcp_seq_hash *) 344 calloc(1, sizeof(*th)); 345 if (th->nxt == NULL) 346 error("tcp_print: calloc"); 347 } 348 th->addr = tha; 349 if (rev) 350 th->ack = seq, th->seq = ack - 1; 351 else 352 th->seq = seq, th->ack = ack - 1; 353 } else { 354 if (rev) 355 seq -= th->ack, ack -= th->seq; 356 else 357 seq -= th->seq, ack -= th->ack; 358 } 359 360 thseq = th->seq; 361 thack = th->ack; 362 } 363 } else { 364 /*fool gcc*/ 365 thseq = thack = rev = 0; 366 } 367 if (hlen > length) { 368 ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]", 369 hlen, length)); 370 return; 371 } 372 373 if (ndo->ndo_vflag && !ndo->ndo_Kflag && !fragmented) { 374 /* Check the checksum, if possible. */ 375 uint16_t sum, tcp_sum; 376 377 if (IP_V(ip) == 4) { 378 if (ND_TTEST2(tp->th_sport, length)) { 379 sum = tcp_cksum(ndo, ip, tp, length); 380 tcp_sum = EXTRACT_16BITS(&tp->th_sum); 381 382 ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum)); 383 if (sum != 0) 384 ND_PRINT((ndo, " (incorrect -> 0x%04x)", 385 in_cksum_shouldbe(tcp_sum, sum))); 386 else 387 ND_PRINT((ndo, " (correct)")); 388 } 389 } 390 #ifdef INET6 391 else if (IP_V(ip) == 6 && ip6->ip6_plen) { 392 if (ND_TTEST2(tp->th_sport, length)) { 393 sum = nextproto6_cksum(ip6, (const uint8_t *)tp, 394 length, length, IPPROTO_TCP); 395 tcp_sum = EXTRACT_16BITS(&tp->th_sum); 396 397 ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum)); 398 if (sum != 0) 399 ND_PRINT((ndo, " (incorrect -> 0x%04x)", 400 in_cksum_shouldbe(tcp_sum, sum))); 401 else 402 ND_PRINT((ndo, " (correct)")); 403 404 } 405 } 406 #endif 407 } 408 409 length -= hlen; 410 if (ndo->ndo_vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) { 411 ND_PRINT((ndo, ", seq %u", seq)); 412 413 if (length > 0) { 414 ND_PRINT((ndo, ":%u", seq + length)); 415 } 416 } 417 418 if (flags & TH_ACK) { 419 ND_PRINT((ndo, ", ack %u", ack)); 420 } 421 422 ND_PRINT((ndo, ", win %d", win)); 423 424 if (flags & TH_URG) 425 ND_PRINT((ndo, ", urg %d", urp)); 426 /* 427 * Handle any options. 428 */ 429 if (hlen > sizeof(*tp)) { 430 register const u_char *cp; 431 register u_int i, opt, datalen; 432 register u_int len; 433 434 hlen -= sizeof(*tp); 435 cp = (const u_char *)tp + sizeof(*tp); 436 ND_PRINT((ndo, ", options [")); 437 while (hlen > 0) { 438 if (ch != '\0') 439 ND_PRINT((ndo, "%c", ch)); 440 ND_TCHECK(*cp); 441 opt = *cp++; 442 if (ZEROLENOPT(opt)) 443 len = 1; 444 else { 445 ND_TCHECK(*cp); 446 len = *cp++; /* total including type, len */ 447 if (len < 2 || len > hlen) 448 goto bad; 449 --hlen; /* account for length byte */ 450 } 451 --hlen; /* account for type byte */ 452 datalen = 0; 453 454 /* Bail if "l" bytes of data are not left or were not captured */ 455 #define LENCHECK(l) { if ((l) > hlen) goto bad; ND_TCHECK2(*cp, l); } 456 457 458 ND_PRINT((ndo, "%s", tok2str(tcp_option_values, "unknown-%u", opt))); 459 460 switch (opt) { 461 462 case TCPOPT_MAXSEG: 463 datalen = 2; 464 LENCHECK(datalen); 465 ND_PRINT((ndo, " %u", EXTRACT_16BITS(cp))); 466 break; 467 468 case TCPOPT_WSCALE: 469 datalen = 1; 470 LENCHECK(datalen); 471 ND_PRINT((ndo, " %u", *cp)); 472 break; 473 474 case TCPOPT_SACK: 475 datalen = len - 2; 476 if (datalen % 8 != 0) { 477 ND_PRINT((ndo, "malformed sack")); 478 } else { 479 uint32_t s, e; 480 481 ND_PRINT((ndo, " %d ", datalen / 8)); 482 for (i = 0; i < datalen; i += 8) { 483 LENCHECK(i + 4); 484 s = EXTRACT_32BITS(cp + i); 485 LENCHECK(i + 8); 486 e = EXTRACT_32BITS(cp + i + 4); 487 if (rev) { 488 s -= thseq; 489 e -= thseq; 490 } else { 491 s -= thack; 492 e -= thack; 493 } 494 ND_PRINT((ndo, "{%u:%u}", s, e)); 495 } 496 } 497 break; 498 499 case TCPOPT_CC: 500 case TCPOPT_CCNEW: 501 case TCPOPT_CCECHO: 502 case TCPOPT_ECHO: 503 case TCPOPT_ECHOREPLY: 504 505 /* 506 * those options share their semantics. 507 * fall through 508 */ 509 datalen = 4; 510 LENCHECK(datalen); 511 ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp))); 512 break; 513 514 case TCPOPT_TIMESTAMP: 515 datalen = 8; 516 LENCHECK(datalen); 517 ND_PRINT((ndo, " val %u ecr %u", 518 EXTRACT_32BITS(cp), 519 EXTRACT_32BITS(cp + 4))); 520 break; 521 522 case TCPOPT_SIGNATURE: 523 datalen = TCP_SIGLEN; 524 LENCHECK(datalen); 525 #ifdef HAVE_LIBCRYPTO 526 switch (tcp_verify_signature(ndo, ip, tp, 527 bp + TH_OFF(tp) * 4, length, cp)) { 528 529 case SIGNATURE_VALID: 530 ND_PRINT((ndo, "valid")); 531 break; 532 533 case SIGNATURE_INVALID: 534 ND_PRINT((ndo, "invalid")); 535 break; 536 537 case CANT_CHECK_SIGNATURE: 538 ND_PRINT((ndo, "can't check - ")); 539 for (i = 0; i < TCP_SIGLEN; ++i) 540 ND_PRINT((ndo, "%02x", cp[i])); 541 break; 542 } 543 #else 544 for (i = 0; i < TCP_SIGLEN; ++i) 545 ND_PRINT((ndo, "%02x", cp[i])); 546 #endif 547 break; 548 549 case TCPOPT_AUTH: 550 ND_PRINT((ndo, "keyid %d", *cp++)); 551 datalen = len - 3; 552 for (i = 0; i < datalen; ++i) { 553 LENCHECK(i); 554 ND_PRINT((ndo, "%02x", cp[i])); 555 } 556 break; 557 558 559 case TCPOPT_EOL: 560 case TCPOPT_NOP: 561 case TCPOPT_SACKOK: 562 /* 563 * Nothing interesting. 564 * fall through 565 */ 566 break; 567 568 case TCPOPT_UTO: 569 datalen = 2; 570 LENCHECK(datalen); 571 utoval = EXTRACT_16BITS(cp); 572 ND_PRINT((ndo, "0x%x", utoval)); 573 if (utoval & 0x0001) 574 utoval = (utoval >> 1) * 60; 575 else 576 utoval >>= 1; 577 ND_PRINT((ndo, " %u", utoval)); 578 break; 579 580 case TCPOPT_MPTCP: 581 datalen = len - 2; 582 LENCHECK(datalen); 583 if (!mptcp_print(ndo, cp-2, len, flags)) 584 goto bad; 585 break; 586 587 case TCPOPT_EXPERIMENT2: 588 datalen = len - 2; 589 LENCHECK(datalen); 590 if (datalen < 2) 591 goto bad; 592 /* RFC6994 */ 593 magic = EXTRACT_16BITS(cp); 594 ND_PRINT((ndo, "-")); 595 596 switch(magic) { 597 598 case 0xf989: 599 /* TCP Fast Open: RFC 7413 */ 600 if (datalen == 2) { 601 /* Fast Open Cookie Request */ 602 ND_PRINT((ndo, "tfo cookiereq")); 603 } else { 604 /* Fast Open Cookie */ 605 if (datalen % 2 != 0 || datalen < 6 || datalen > 18) { 606 ND_PRINT((ndo, "tfo malformed")); 607 } else { 608 ND_PRINT((ndo, "tfo cookie ")); 609 for (i = 2; i < datalen; ++i) 610 ND_PRINT((ndo, "%02x", cp[i])); 611 } 612 } 613 break; 614 615 default: 616 /* Unknown magic number */ 617 ND_PRINT((ndo, "%04x", magic)); 618 break; 619 } 620 break; 621 622 default: 623 datalen = len - 2; 624 if (datalen) 625 ND_PRINT((ndo, " 0x")); 626 for (i = 0; i < datalen; ++i) { 627 LENCHECK(i); 628 ND_PRINT((ndo, "%02x", cp[i])); 629 } 630 break; 631 } 632 633 /* Account for data printed */ 634 cp += datalen; 635 hlen -= datalen; 636 637 /* Check specification against observed length */ 638 ++datalen; /* option octet */ 639 if (!ZEROLENOPT(opt)) 640 ++datalen; /* size octet */ 641 if (datalen != len) 642 ND_PRINT((ndo, "[len %d]", len)); 643 ch = ','; 644 if (opt == TCPOPT_EOL) 645 break; 646 } 647 ND_PRINT((ndo, "]")); 648 } 649 650 /* 651 * Print length field before crawling down the stack. 652 */ 653 ND_PRINT((ndo, ", length %u", length)); 654 655 if (length <= 0) 656 return; 657 658 /* 659 * Decode payload if necessary. 660 */ 661 bp += TH_OFF(tp) * 4; 662 if ((flags & TH_RST) && ndo->ndo_vflag) { 663 print_tcp_rst_data(ndo, bp, length); 664 return; 665 } 666 667 if (ndo->ndo_packettype) { 668 switch (ndo->ndo_packettype) { 669 case PT_ZMTP1: 670 zmtp1_print(ndo, bp, length); 671 break; 672 } 673 return; 674 } 675 676 if (sport == TELNET_PORT || dport == TELNET_PORT) { 677 telnet_print(ndo, bp, length); 678 } else if (sport == SMTP_PORT || dport == SMTP_PORT) { 679 ND_PRINT((ndo, ": ")); 680 smtp_print(ndo, bp, length); 681 } else if (sport == BGP_PORT || dport == BGP_PORT) 682 bgp_print(ndo, bp, length); 683 else if (sport == PPTP_PORT || dport == PPTP_PORT) 684 pptp_print(ndo, bp); 685 #ifdef TCPDUMP_DO_SMB 686 else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT) 687 nbt_tcp_print(ndo, bp, length); 688 else if (sport == SMB_PORT || dport == SMB_PORT) 689 smb_tcp_print(ndo, bp, length); 690 #endif 691 else if (sport == BEEP_PORT || dport == BEEP_PORT) 692 beep_print(ndo, bp, length); 693 else if (sport == OPENFLOW_PORT_OLD || dport == OPENFLOW_PORT_OLD || 694 sport == OPENFLOW_PORT_IANA || dport == OPENFLOW_PORT_IANA) 695 openflow_print(ndo, bp, length); 696 else if (sport == FTP_PORT || dport == FTP_PORT) { 697 ND_PRINT((ndo, ": ")); 698 ftp_print(ndo, bp, length); 699 } else if (sport == HTTP_PORT || dport == HTTP_PORT || 700 sport == HTTP_PORT_ALT || dport == HTTP_PORT_ALT) { 701 ND_PRINT((ndo, ": ")); 702 http_print(ndo, bp, length); 703 } else if (sport == RTSP_PORT || dport == RTSP_PORT || 704 sport == RTSP_PORT_ALT || dport == RTSP_PORT_ALT) { 705 ND_PRINT((ndo, ": ")); 706 rtsp_print(ndo, bp, length); 707 } else if (length > 2 && 708 (sport == NAMESERVER_PORT || dport == NAMESERVER_PORT || 709 sport == MULTICASTDNS_PORT || dport == MULTICASTDNS_PORT)) { 710 /* 711 * TCP DNS query has 2byte length at the head. 712 * XXX packet could be unaligned, it can go strange 713 */ 714 ns_print(ndo, bp + 2, length - 2, 0); 715 } else if (sport == MSDP_PORT || dport == MSDP_PORT) { 716 msdp_print(ndo, bp, length); 717 } else if (sport == RPKI_RTR_PORT || dport == RPKI_RTR_PORT) { 718 rpki_rtr_print(ndo, bp, length); 719 } 720 else if (length > 0 && (sport == LDP_PORT || dport == LDP_PORT)) { 721 ldp_print(ndo, bp, length); 722 } 723 else if ((sport == NFS_PORT || dport == NFS_PORT) && 724 length >= 4 && ND_TTEST2(*bp, 4)) { 725 /* 726 * If data present, header length valid, and NFS port used, 727 * assume NFS. 728 * Pass offset of data plus 4 bytes for RPC TCP msg length 729 * to NFS print routines. 730 */ 731 uint32_t fraglen; 732 register struct sunrpc_msg *rp; 733 enum sunrpc_msg_type direction; 734 735 fraglen = EXTRACT_32BITS(bp) & 0x7FFFFFFF; 736 if (fraglen > (length) - 4) 737 fraglen = (length) - 4; 738 rp = (struct sunrpc_msg *)(bp + 4); 739 if (ND_TTEST(rp->rm_direction)) { 740 direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction); 741 if (dport == NFS_PORT && direction == SUNRPC_CALL) { 742 ND_PRINT((ndo, ": NFS request xid %u ", EXTRACT_32BITS(&rp->rm_xid))); 743 nfsreq_print_noaddr(ndo, (u_char *)rp, fraglen, (u_char *)ip); 744 return; 745 } 746 if (sport == NFS_PORT && direction == SUNRPC_REPLY) { 747 ND_PRINT((ndo, ": NFS reply xid %u ", EXTRACT_32BITS(&rp->rm_xid))); 748 nfsreply_print_noaddr(ndo, (u_char *)rp, fraglen, (u_char *)ip); 749 return; 750 } 751 } 752 } 753 754 return; 755 bad: 756 ND_PRINT((ndo, "[bad opt]")); 757 if (ch != '\0') 758 ND_PRINT((ndo, ">")); 759 return; 760 trunc: 761 ND_PRINT((ndo, "[|tcp]")); 762 if (ch != '\0') 763 ND_PRINT((ndo, ">")); 764 } 765 766 /* 767 * RFC1122 says the following on data in RST segments: 768 * 769 * 4.2.2.12 RST Segment: RFC-793 Section 3.4 770 * 771 * A TCP SHOULD allow a received RST segment to include data. 772 * 773 * DISCUSSION 774 * It has been suggested that a RST segment could contain 775 * ASCII text that encoded and explained the cause of the 776 * RST. No standard has yet been established for such 777 * data. 778 * 779 */ 780 781 static void 782 print_tcp_rst_data(netdissect_options *ndo, 783 register const u_char *sp, u_int length) 784 { 785 int c; 786 787 ND_PRINT((ndo, ND_TTEST2(*sp, length) ? " [RST" : " [!RST")); 788 if (length > MAX_RST_DATA_LEN) { 789 length = MAX_RST_DATA_LEN; /* can use -X for longer */ 790 ND_PRINT((ndo, "+")); /* indicate we truncate */ 791 } 792 ND_PRINT((ndo, " ")); 793 while (length-- && sp <= ndo->ndo_snapend) { 794 c = *sp++; 795 safeputchar(ndo, c); 796 } 797 ND_PRINT((ndo, "]")); 798 } 799 800 #ifdef HAVE_LIBCRYPTO 801 USES_APPLE_DEPRECATED_API 802 static int 803 tcp_verify_signature(netdissect_options *ndo, 804 const struct ip *ip, const struct tcphdr *tp, 805 const u_char *data, int length, const u_char *rcvsig) 806 { 807 struct tcphdr tp1; 808 u_char sig[TCP_SIGLEN]; 809 char zero_proto = 0; 810 MD5_CTX ctx; 811 uint16_t savecsum, tlen; 812 #ifdef INET6 813 struct ip6_hdr *ip6; 814 uint32_t len32; 815 uint8_t nxt; 816 #endif 817 818 if (data + length > ndo->ndo_snapend) { 819 ND_PRINT((ndo, "snaplen too short, ")); 820 return (CANT_CHECK_SIGNATURE); 821 } 822 823 tp1 = *tp; 824 825 if (ndo->ndo_sigsecret == NULL) { 826 ND_PRINT((ndo, "shared secret not supplied with -M, ")); 827 return (CANT_CHECK_SIGNATURE); 828 } 829 830 MD5_Init(&ctx); 831 /* 832 * Step 1: Update MD5 hash with IP pseudo-header. 833 */ 834 if (IP_V(ip) == 4) { 835 MD5_Update(&ctx, (char *)&ip->ip_src, sizeof(ip->ip_src)); 836 MD5_Update(&ctx, (char *)&ip->ip_dst, sizeof(ip->ip_dst)); 837 MD5_Update(&ctx, (char *)&zero_proto, sizeof(zero_proto)); 838 MD5_Update(&ctx, (char *)&ip->ip_p, sizeof(ip->ip_p)); 839 tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4; 840 tlen = htons(tlen); 841 MD5_Update(&ctx, (char *)&tlen, sizeof(tlen)); 842 #ifdef INET6 843 } else if (IP_V(ip) == 6) { 844 ip6 = (struct ip6_hdr *)ip; 845 MD5_Update(&ctx, (char *)&ip6->ip6_src, sizeof(ip6->ip6_src)); 846 MD5_Update(&ctx, (char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst)); 847 len32 = htonl(EXTRACT_16BITS(&ip6->ip6_plen)); 848 MD5_Update(&ctx, (char *)&len32, sizeof(len32)); 849 nxt = 0; 850 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt)); 851 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt)); 852 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt)); 853 nxt = IPPROTO_TCP; 854 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt)); 855 #endif 856 } else { 857 #ifdef INET6 858 ND_PRINT((ndo, "IP version not 4 or 6, ")); 859 #else 860 ND_PRINT((ndo, "IP version not 4, ")); 861 #endif 862 return (CANT_CHECK_SIGNATURE); 863 } 864 865 /* 866 * Step 2: Update MD5 hash with TCP header, excluding options. 867 * The TCP checksum must be set to zero. 868 */ 869 savecsum = tp1.th_sum; 870 tp1.th_sum = 0; 871 MD5_Update(&ctx, (char *)&tp1, sizeof(struct tcphdr)); 872 tp1.th_sum = savecsum; 873 /* 874 * Step 3: Update MD5 hash with TCP segment data, if present. 875 */ 876 if (length > 0) 877 MD5_Update(&ctx, data, length); 878 /* 879 * Step 4: Update MD5 hash with shared secret. 880 */ 881 MD5_Update(&ctx, ndo->ndo_sigsecret, strlen(ndo->ndo_sigsecret)); 882 MD5_Final(sig, &ctx); 883 884 if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0) 885 return (SIGNATURE_VALID); 886 else 887 return (SIGNATURE_INVALID); 888 } 889 USES_APPLE_RST 890 #endif /* HAVE_LIBCRYPTO */ 891 892 /* 893 * Local Variables: 894 * c-style: whitesmith 895 * c-basic-offset: 8 896 * End: 897 */ 898
