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 "diag-control.h" 47 48 #include "tcp.h" 49 50 #include "ip.h" 51 #include "ip6.h" 52 #include "ipproto.h" 53 #include "rpc_auth.h" 54 #include "rpc_msg.h" 55 56 #ifdef HAVE_LIBCRYPTO 57 #include <openssl/md5.h> 58 #include "signature.h" 59 60 static int tcp_verify_signature(netdissect_options *ndo, 61 const struct ip *ip, const struct tcphdr *tp, 62 const u_char *data, u_int length, const u_char *rcvsig); 63 #endif 64 65 static void print_tcp_rst_data(netdissect_options *, const u_char *sp, u_int length); 66 static void print_tcp_fastopen_option(netdissect_options *ndo, const u_char *cp, 67 u_int datalen, int exp); 68 69 #define MAX_RST_DATA_LEN 30 70 71 72 struct tha { 73 nd_ipv4 src; 74 nd_ipv4 dst; 75 u_int port; 76 }; 77 78 struct tcp_seq_hash { 79 struct tcp_seq_hash *nxt; 80 struct tha addr; 81 uint32_t seq; 82 uint32_t ack; 83 }; 84 85 struct tha6 { 86 nd_ipv6 src; 87 nd_ipv6 dst; 88 u_int port; 89 }; 90 91 struct tcp_seq_hash6 { 92 struct tcp_seq_hash6 *nxt; 93 struct tha6 addr; 94 uint32_t seq; 95 uint32_t ack; 96 }; 97 98 #define TSEQ_HASHSIZE 919 99 100 /* These tcp options do not have the size octet */ 101 #define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP) 102 103 static struct tcp_seq_hash tcp_seq_hash4[TSEQ_HASHSIZE]; 104 static struct tcp_seq_hash6 tcp_seq_hash6[TSEQ_HASHSIZE]; 105 106 static const struct tok tcp_flag_values[] = { 107 { TH_FIN, "F" }, 108 { TH_SYN, "S" }, 109 { TH_RST, "R" }, 110 { TH_PUSH, "P" }, 111 { TH_ACK, "." }, 112 { TH_URG, "U" }, 113 { TH_ECNECHO, "E" }, 114 { TH_CWR, "W" }, 115 { 0, NULL } 116 }; 117 118 static const struct tok tcp_option_values[] = { 119 { TCPOPT_EOL, "eol" }, 120 { TCPOPT_NOP, "nop" }, 121 { TCPOPT_MAXSEG, "mss" }, 122 { TCPOPT_WSCALE, "wscale" }, 123 { TCPOPT_SACKOK, "sackOK" }, 124 { TCPOPT_SACK, "sack" }, 125 { TCPOPT_ECHO, "echo" }, 126 { TCPOPT_ECHOREPLY, "echoreply" }, 127 { TCPOPT_TIMESTAMP, "TS" }, 128 { TCPOPT_CC, "cc" }, 129 { TCPOPT_CCNEW, "ccnew" }, 130 { TCPOPT_CCECHO, "" }, 131 { TCPOPT_SIGNATURE, "md5" }, 132 { TCPOPT_SCPS, "scps" }, 133 { TCPOPT_UTO, "uto" }, 134 { TCPOPT_TCPAO, "tcp-ao" }, 135 { TCPOPT_MPTCP, "mptcp" }, 136 { TCPOPT_FASTOPEN, "tfo" }, 137 { TCPOPT_EXPERIMENT2, "exp" }, 138 { 0, NULL } 139 }; 140 141 static uint16_t 142 tcp_cksum(netdissect_options *ndo, 143 const struct ip *ip, 144 const struct tcphdr *tp, 145 u_int len) 146 { 147 return nextproto4_cksum(ndo, ip, (const uint8_t *)tp, len, len, 148 IPPROTO_TCP); 149 } 150 151 static uint16_t 152 tcp6_cksum(netdissect_options *ndo, 153 const struct ip6_hdr *ip6, 154 const struct tcphdr *tp, 155 u_int len) 156 { 157 return nextproto6_cksum(ndo, ip6, (const uint8_t *)tp, len, len, 158 IPPROTO_TCP); 159 } 160 161 void 162 tcp_print(netdissect_options *ndo, 163 const u_char *bp, u_int length, 164 const u_char *bp2, int fragmented) 165 { 166 const struct tcphdr *tp; 167 const struct ip *ip; 168 u_char flags; 169 u_int hlen; 170 char ch; 171 uint16_t sport, dport, win, urp; 172 uint32_t seq, ack, thseq, thack; 173 u_int utoval; 174 uint16_t magic; 175 int rev; 176 const struct ip6_hdr *ip6; 177 u_int header_len; /* Header length in bytes */ 178 179 ndo->ndo_protocol = "tcp"; 180 tp = (const struct tcphdr *)bp; 181 ip = (const struct ip *)bp2; 182 if (IP_V(ip) == 6) 183 ip6 = (const struct ip6_hdr *)bp2; 184 else 185 ip6 = NULL; 186 ch = '\0'; 187 if (!ND_TTEST_2(tp->th_dport)) { 188 if (ip6) { 189 ND_PRINT("%s > %s:", 190 GET_IP6ADDR_STRING(ip6->ip6_src), 191 GET_IP6ADDR_STRING(ip6->ip6_dst)); 192 } else { 193 ND_PRINT("%s > %s:", 194 GET_IPADDR_STRING(ip->ip_src), 195 GET_IPADDR_STRING(ip->ip_dst)); 196 } 197 nd_print_trunc(ndo); 198 return; 199 } 200 201 sport = GET_BE_U_2(tp->th_sport); 202 dport = GET_BE_U_2(tp->th_dport); 203 204 if (ip6) { 205 if (GET_U_1(ip6->ip6_nxt) == IPPROTO_TCP) { 206 ND_PRINT("%s.%s > %s.%s: ", 207 GET_IP6ADDR_STRING(ip6->ip6_src), 208 tcpport_string(ndo, sport), 209 GET_IP6ADDR_STRING(ip6->ip6_dst), 210 tcpport_string(ndo, dport)); 211 } else { 212 ND_PRINT("%s > %s: ", 213 tcpport_string(ndo, sport), tcpport_string(ndo, dport)); 214 } 215 } else { 216 if (GET_U_1(ip->ip_p) == IPPROTO_TCP) { 217 ND_PRINT("%s.%s > %s.%s: ", 218 GET_IPADDR_STRING(ip->ip_src), 219 tcpport_string(ndo, sport), 220 GET_IPADDR_STRING(ip->ip_dst), 221 tcpport_string(ndo, dport)); 222 } else { 223 ND_PRINT("%s > %s: ", 224 tcpport_string(ndo, sport), tcpport_string(ndo, dport)); 225 } 226 } 227 228 ND_TCHECK_SIZE(tp); 229 230 hlen = TH_OFF(tp) * 4; 231 232 if (hlen < sizeof(*tp)) { 233 ND_PRINT(" tcp %u [bad hdr length %u - too short, < %zu]", 234 length - hlen, hlen, sizeof(*tp)); 235 return; 236 } 237 238 seq = GET_BE_U_4(tp->th_seq); 239 ack = GET_BE_U_4(tp->th_ack); 240 win = GET_BE_U_2(tp->th_win); 241 urp = GET_BE_U_2(tp->th_urp); 242 243 if (ndo->ndo_qflag) { 244 ND_PRINT("tcp %u", length - hlen); 245 if (hlen > length) { 246 ND_PRINT(" [bad hdr length %u - too long, > %u]", 247 hlen, length); 248 } 249 return; 250 } 251 252 flags = GET_U_1(tp->th_flags); 253 ND_PRINT("Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags)); 254 255 if (!ndo->ndo_Sflag && (flags & TH_ACK)) { 256 /* 257 * Find (or record) the initial sequence numbers for 258 * this conversation. (we pick an arbitrary 259 * collating order so there's only one entry for 260 * both directions). 261 */ 262 rev = 0; 263 if (ip6) { 264 struct tcp_seq_hash6 *th; 265 struct tcp_seq_hash6 *tcp_seq_hash; 266 const void *src, *dst; 267 struct tha6 tha; 268 269 tcp_seq_hash = tcp_seq_hash6; 270 src = (const void *)ip6->ip6_src; 271 dst = (const void *)ip6->ip6_dst; 272 if (sport > dport) 273 rev = 1; 274 else if (sport == dport) { 275 if (UNALIGNED_MEMCMP(src, dst, sizeof(ip6->ip6_dst)) > 0) 276 rev = 1; 277 } 278 if (rev) { 279 UNALIGNED_MEMCPY(&tha.src, dst, sizeof(ip6->ip6_dst)); 280 UNALIGNED_MEMCPY(&tha.dst, src, sizeof(ip6->ip6_src)); 281 tha.port = ((u_int)dport) << 16 | sport; 282 } else { 283 UNALIGNED_MEMCPY(&tha.dst, dst, sizeof(ip6->ip6_dst)); 284 UNALIGNED_MEMCPY(&tha.src, src, sizeof(ip6->ip6_src)); 285 tha.port = ((u_int)sport) << 16 | dport; 286 } 287 288 for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE]; 289 th->nxt; th = th->nxt) 290 if (memcmp((char *)&tha, (char *)&th->addr, 291 sizeof(th->addr)) == 0) 292 break; 293 294 if (!th->nxt || (flags & TH_SYN)) { 295 /* didn't find it or new conversation */ 296 /* calloc() return used by the 'tcp_seq_hash6' 297 hash table: do not free() */ 298 if (th->nxt == NULL) { 299 th->nxt = (struct tcp_seq_hash6 *) 300 calloc(1, sizeof(*th)); 301 if (th->nxt == NULL) 302 (*ndo->ndo_error)(ndo, 303 S_ERR_ND_MEM_ALLOC, 304 "%s: calloc", __func__); 305 } 306 th->addr = tha; 307 if (rev) 308 th->ack = seq, th->seq = ack - 1; 309 else 310 th->seq = seq, th->ack = ack - 1; 311 } else { 312 if (rev) 313 seq -= th->ack, ack -= th->seq; 314 else 315 seq -= th->seq, ack -= th->ack; 316 } 317 318 thseq = th->seq; 319 thack = th->ack; 320 } else { 321 struct tcp_seq_hash *th; 322 struct tcp_seq_hash *tcp_seq_hash; 323 struct tha tha; 324 325 tcp_seq_hash = tcp_seq_hash4; 326 if (sport > dport) 327 rev = 1; 328 else if (sport == dport) { 329 if (UNALIGNED_MEMCMP(ip->ip_src, ip->ip_dst, sizeof(ip->ip_dst)) > 0) 330 rev = 1; 331 } 332 if (rev) { 333 UNALIGNED_MEMCPY(&tha.src, ip->ip_dst, 334 sizeof(ip->ip_dst)); 335 UNALIGNED_MEMCPY(&tha.dst, ip->ip_src, 336 sizeof(ip->ip_src)); 337 tha.port = ((u_int)dport) << 16 | sport; 338 } else { 339 UNALIGNED_MEMCPY(&tha.dst, ip->ip_dst, 340 sizeof(ip->ip_dst)); 341 UNALIGNED_MEMCPY(&tha.src, ip->ip_src, 342 sizeof(ip->ip_src)); 343 tha.port = ((u_int)sport) << 16 | dport; 344 } 345 346 for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE]; 347 th->nxt; th = th->nxt) 348 if (memcmp((char *)&tha, (char *)&th->addr, 349 sizeof(th->addr)) == 0) 350 break; 351 352 if (!th->nxt || (flags & TH_SYN)) { 353 /* didn't find it or new conversation */ 354 /* calloc() return used by the 'tcp_seq_hash4' 355 hash table: do not free() */ 356 if (th->nxt == NULL) { 357 th->nxt = (struct tcp_seq_hash *) 358 calloc(1, sizeof(*th)); 359 if (th->nxt == NULL) 360 (*ndo->ndo_error)(ndo, 361 S_ERR_ND_MEM_ALLOC, 362 "%s: calloc", __func__); 363 } 364 th->addr = tha; 365 if (rev) 366 th->ack = seq, th->seq = ack - 1; 367 else 368 th->seq = seq, th->ack = ack - 1; 369 } else { 370 if (rev) 371 seq -= th->ack, ack -= th->seq; 372 else 373 seq -= th->seq, ack -= th->ack; 374 } 375 376 thseq = th->seq; 377 thack = th->ack; 378 } 379 } else { 380 /*fool gcc*/ 381 thseq = thack = rev = 0; 382 } 383 if (hlen > length) { 384 ND_PRINT(" [bad hdr length %u - too long, > %u]", 385 hlen, length); 386 return; 387 } 388 389 if (ndo->ndo_vflag && !ndo->ndo_Kflag && !fragmented) { 390 /* Check the checksum, if possible. */ 391 uint16_t sum, tcp_sum; 392 393 if (IP_V(ip) == 4) { 394 if (ND_TTEST_LEN(tp->th_sport, length)) { 395 sum = tcp_cksum(ndo, ip, tp, length); 396 tcp_sum = GET_BE_U_2(tp->th_sum); 397 398 ND_PRINT(", cksum 0x%04x", tcp_sum); 399 if (sum != 0) 400 ND_PRINT(" (incorrect -> 0x%04x)", 401 in_cksum_shouldbe(tcp_sum, sum)); 402 else 403 ND_PRINT(" (correct)"); 404 } 405 } else if (IP_V(ip) == 6) { 406 if (ND_TTEST_LEN(tp->th_sport, length)) { 407 sum = tcp6_cksum(ndo, ip6, tp, length); 408 tcp_sum = GET_BE_U_2(tp->th_sum); 409 410 ND_PRINT(", cksum 0x%04x", tcp_sum); 411 if (sum != 0) 412 ND_PRINT(" (incorrect -> 0x%04x)", 413 in_cksum_shouldbe(tcp_sum, sum)); 414 else 415 ND_PRINT(" (correct)"); 416 417 } 418 } 419 } 420 421 length -= hlen; 422 if (ndo->ndo_vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) { 423 ND_PRINT(", seq %u", seq); 424 425 if (length > 0) { 426 ND_PRINT(":%u", seq + length); 427 } 428 } 429 430 if (flags & TH_ACK) { 431 ND_PRINT(", ack %u", ack); 432 } 433 434 ND_PRINT(", win %u", win); 435 436 if (flags & TH_URG) 437 ND_PRINT(", urg %u", urp); 438 /* 439 * Handle any options. 440 */ 441 if (hlen > sizeof(*tp)) { 442 const u_char *cp; 443 u_int i, opt, datalen; 444 u_int len; 445 446 hlen -= sizeof(*tp); 447 cp = (const u_char *)tp + sizeof(*tp); 448 ND_PRINT(", options ["); 449 while (hlen > 0) { 450 if (ch != '\0') 451 ND_PRINT("%c", ch); 452 opt = GET_U_1(cp); 453 cp++; 454 if (ZEROLENOPT(opt)) 455 len = 1; 456 else { 457 len = GET_U_1(cp); 458 cp++; /* total including type, len */ 459 if (len < 2 || len > hlen) 460 goto bad; 461 --hlen; /* account for length byte */ 462 } 463 --hlen; /* account for type byte */ 464 datalen = 0; 465 466 /* Bail if "l" bytes of data are not left or were not captured */ 467 #define LENCHECK(l) { if ((l) > hlen) goto bad; ND_TCHECK_LEN(cp, l); } 468 469 470 ND_PRINT("%s", tok2str(tcp_option_values, "unknown-%u", opt)); 471 472 switch (opt) { 473 474 case TCPOPT_MAXSEG: 475 datalen = 2; 476 LENCHECK(datalen); 477 ND_PRINT(" %u", GET_BE_U_2(cp)); 478 break; 479 480 case TCPOPT_WSCALE: 481 datalen = 1; 482 LENCHECK(datalen); 483 ND_PRINT(" %u", GET_U_1(cp)); 484 break; 485 486 case TCPOPT_SACK: 487 datalen = len - 2; 488 if (datalen % 8 != 0) { 489 ND_PRINT(" invalid sack"); 490 } else { 491 uint32_t s, e; 492 493 ND_PRINT(" %u ", datalen / 8); 494 for (i = 0; i < datalen; i += 8) { 495 LENCHECK(i + 4); 496 s = GET_BE_U_4(cp + i); 497 LENCHECK(i + 8); 498 e = GET_BE_U_4(cp + i + 4); 499 if (rev) { 500 s -= thseq; 501 e -= thseq; 502 } else { 503 s -= thack; 504 e -= thack; 505 } 506 ND_PRINT("{%u:%u}", s, e); 507 } 508 } 509 break; 510 511 case TCPOPT_CC: 512 case TCPOPT_CCNEW: 513 case TCPOPT_CCECHO: 514 case TCPOPT_ECHO: 515 case TCPOPT_ECHOREPLY: 516 517 /* 518 * those options share their semantics. 519 * fall through 520 */ 521 datalen = 4; 522 LENCHECK(datalen); 523 ND_PRINT(" %u", GET_BE_U_4(cp)); 524 break; 525 526 case TCPOPT_TIMESTAMP: 527 datalen = 8; 528 LENCHECK(datalen); 529 ND_PRINT(" val %u ecr %u", 530 GET_BE_U_4(cp), 531 GET_BE_U_4(cp + 4)); 532 break; 533 534 case TCPOPT_SIGNATURE: 535 datalen = TCP_SIGLEN; 536 LENCHECK(datalen); 537 ND_PRINT(" "); 538 #ifdef HAVE_LIBCRYPTO 539 switch (tcp_verify_signature(ndo, ip, tp, 540 bp + TH_OFF(tp) * 4, length, cp)) { 541 542 case SIGNATURE_VALID: 543 ND_PRINT("valid"); 544 break; 545 546 case SIGNATURE_INVALID: 547 nd_print_invalid(ndo); 548 break; 549 550 case CANT_CHECK_SIGNATURE: 551 ND_PRINT("can't check - "); 552 for (i = 0; i < TCP_SIGLEN; ++i) 553 ND_PRINT("%02x", 554 GET_U_1(cp + i)); 555 break; 556 } 557 #else 558 for (i = 0; i < TCP_SIGLEN; ++i) 559 ND_PRINT("%02x", GET_U_1(cp + i)); 560 #endif 561 break; 562 563 case TCPOPT_SCPS: 564 datalen = 2; 565 LENCHECK(datalen); 566 ND_PRINT(" cap %02x id %u", GET_U_1(cp), 567 GET_U_1(cp + 1)); 568 break; 569 570 case TCPOPT_TCPAO: 571 datalen = len - 2; 572 /* RFC 5925 Section 2.2: 573 * "The Length value MUST be greater than or equal to 4." 574 * (This includes the Kind and Length fields already processed 575 * at this point.) 576 */ 577 if (datalen < 2) { 578 nd_print_invalid(ndo); 579 } else { 580 LENCHECK(1); 581 ND_PRINT(" keyid %u", GET_U_1(cp)); 582 LENCHECK(2); 583 ND_PRINT(" rnextkeyid %u", 584 GET_U_1(cp + 1)); 585 if (datalen > 2) { 586 ND_PRINT(" mac 0x"); 587 for (i = 2; i < datalen; i++) { 588 LENCHECK(i + 1); 589 ND_PRINT("%02x", 590 GET_U_1(cp + i)); 591 } 592 } 593 } 594 break; 595 596 case TCPOPT_EOL: 597 case TCPOPT_NOP: 598 case TCPOPT_SACKOK: 599 /* 600 * Nothing interesting. 601 * fall through 602 */ 603 break; 604 605 case TCPOPT_UTO: 606 datalen = 2; 607 LENCHECK(datalen); 608 utoval = GET_BE_U_2(cp); 609 ND_PRINT(" 0x%x", utoval); 610 if (utoval & 0x0001) 611 utoval = (utoval >> 1) * 60; 612 else 613 utoval >>= 1; 614 ND_PRINT(" %u", utoval); 615 break; 616 617 case TCPOPT_MPTCP: 618 { 619 const u_char *snapend_save; 620 int ret; 621 622 datalen = len - 2; 623 LENCHECK(datalen); 624 /* Update the snapend to the end of the option 625 * before calling mptcp_print(). Some options 626 * (MPTCP or others) may be present after a 627 * MPTCP option. This prevents that, in 628 * mptcp_print(), the remaining length < the 629 * remaining caplen. 630 */ 631 snapend_save = ndo->ndo_snapend; 632 ndo->ndo_snapend = ND_MIN(cp - 2 + len, 633 ndo->ndo_snapend); 634 ret = mptcp_print(ndo, cp - 2, len, flags); 635 ndo->ndo_snapend = snapend_save; 636 if (!ret) 637 goto bad; 638 break; 639 } 640 641 case TCPOPT_FASTOPEN: 642 datalen = len - 2; 643 LENCHECK(datalen); 644 ND_PRINT(" "); 645 print_tcp_fastopen_option(ndo, cp, datalen, FALSE); 646 break; 647 648 case TCPOPT_EXPERIMENT2: 649 datalen = len - 2; 650 LENCHECK(datalen); 651 if (datalen < 2) 652 goto bad; 653 /* RFC6994 */ 654 magic = GET_BE_U_2(cp); 655 ND_PRINT("-"); 656 657 switch(magic) { 658 659 case 0xf989: /* TCP Fast Open RFC 7413 */ 660 print_tcp_fastopen_option(ndo, cp + 2, datalen - 2, TRUE); 661 break; 662 663 default: 664 /* Unknown magic number */ 665 ND_PRINT("%04x", magic); 666 break; 667 } 668 break; 669 670 default: 671 datalen = len - 2; 672 if (datalen) 673 ND_PRINT(" 0x"); 674 for (i = 0; i < datalen; ++i) { 675 LENCHECK(i + 1); 676 ND_PRINT("%02x", GET_U_1(cp + i)); 677 } 678 break; 679 } 680 681 /* Account for data printed */ 682 cp += datalen; 683 hlen -= datalen; 684 685 /* Check specification against observed length */ 686 ++datalen; /* option octet */ 687 if (!ZEROLENOPT(opt)) 688 ++datalen; /* size octet */ 689 if (datalen != len) 690 ND_PRINT("[len %u]", len); 691 ch = ','; 692 if (opt == TCPOPT_EOL) 693 break; 694 } 695 ND_PRINT("]"); 696 } 697 698 /* 699 * Print length field before crawling down the stack. 700 */ 701 ND_PRINT(", length %u", length); 702 703 if (length == 0) 704 return; 705 706 /* 707 * Decode payload if necessary. 708 */ 709 header_len = TH_OFF(tp) * 4; 710 /* 711 * Do a bounds check before decoding the payload. 712 * At least the header data is required. 713 */ 714 if (!ND_TTEST_LEN(bp, header_len)) { 715 ND_PRINT(" [remaining caplen(%u) < header length(%u)]", 716 ND_BYTES_AVAILABLE_AFTER(bp), header_len); 717 nd_trunc_longjmp(ndo); 718 } 719 bp += header_len; 720 if ((flags & TH_RST) && ndo->ndo_vflag) { 721 print_tcp_rst_data(ndo, bp, length); 722 return; 723 } 724 725 if (ndo->ndo_packettype) { 726 switch (ndo->ndo_packettype) { 727 case PT_ZMTP1: 728 zmtp1_print(ndo, bp, length); 729 break; 730 case PT_RESP: 731 resp_print(ndo, bp, length); 732 break; 733 case PT_DOMAIN: 734 /* over_tcp: TRUE, is_mdns: FALSE */ 735 domain_print(ndo, bp, length, TRUE, FALSE); 736 break; 737 } 738 return; 739 } 740 741 if (IS_SRC_OR_DST_PORT(TELNET_PORT)) { 742 telnet_print(ndo, bp, length); 743 } else if (IS_SRC_OR_DST_PORT(SMTP_PORT)) { 744 ND_PRINT(": "); 745 smtp_print(ndo, bp, length); 746 } else if (IS_SRC_OR_DST_PORT(WHOIS_PORT)) { 747 ND_PRINT(": "); 748 whois_print(ndo, bp, length); 749 } else if (IS_SRC_OR_DST_PORT(BGP_PORT)) 750 bgp_print(ndo, bp, length); 751 else if (IS_SRC_OR_DST_PORT(PPTP_PORT)) 752 pptp_print(ndo, bp); 753 else if (IS_SRC_OR_DST_PORT(REDIS_PORT)) 754 resp_print(ndo, bp, length); 755 else if (IS_SRC_OR_DST_PORT(SSH_PORT)) 756 ssh_print(ndo, bp, length); 757 #ifdef ENABLE_SMB 758 else if (IS_SRC_OR_DST_PORT(NETBIOS_SSN_PORT)) 759 nbt_tcp_print(ndo, bp, length); 760 else if (IS_SRC_OR_DST_PORT(SMB_PORT)) 761 smb_tcp_print(ndo, bp, length); 762 #endif 763 else if (IS_SRC_OR_DST_PORT(BEEP_PORT)) 764 beep_print(ndo, bp, length); 765 else if (IS_SRC_OR_DST_PORT(OPENFLOW_PORT_OLD) || IS_SRC_OR_DST_PORT(OPENFLOW_PORT_IANA)) 766 openflow_print(ndo, bp, length); 767 else if (IS_SRC_OR_DST_PORT(FTP_PORT)) { 768 ND_PRINT(": "); 769 ftp_print(ndo, bp, length); 770 } else if (IS_SRC_OR_DST_PORT(HTTP_PORT) || IS_SRC_OR_DST_PORT(HTTP_PORT_ALT)) { 771 ND_PRINT(": "); 772 http_print(ndo, bp, length); 773 } else if (IS_SRC_OR_DST_PORT(RTSP_PORT) || IS_SRC_OR_DST_PORT(RTSP_PORT_ALT)) { 774 ND_PRINT(": "); 775 rtsp_print(ndo, bp, length); 776 } else if (IS_SRC_OR_DST_PORT(NAMESERVER_PORT)) { 777 /* over_tcp: TRUE, is_mdns: FALSE */ 778 domain_print(ndo, bp, length, TRUE, FALSE); 779 } else if (IS_SRC_OR_DST_PORT(MSDP_PORT)) { 780 msdp_print(ndo, bp, length); 781 } else if (IS_SRC_OR_DST_PORT(RPKI_RTR_PORT)) { 782 rpki_rtr_print(ndo, bp, length); 783 } else if (IS_SRC_OR_DST_PORT(LDP_PORT)) { 784 ldp_print(ndo, bp, length); 785 } else if ((IS_SRC_OR_DST_PORT(NFS_PORT)) && 786 length >= 4 && ND_TTEST_4(bp)) { 787 /* 788 * If data present, header length valid, and NFS port used, 789 * assume NFS. 790 * Pass offset of data plus 4 bytes for RPC TCP msg length 791 * to NFS print routines. 792 */ 793 uint32_t fraglen; 794 const struct sunrpc_msg *rp; 795 enum sunrpc_msg_type direction; 796 797 fraglen = GET_BE_U_4(bp) & 0x7FFFFFFF; 798 if (fraglen > (length) - 4) 799 fraglen = (length) - 4; 800 rp = (const struct sunrpc_msg *)(bp + 4); 801 if (ND_TTEST_4(rp->rm_direction)) { 802 direction = (enum sunrpc_msg_type) GET_BE_U_4(rp->rm_direction); 803 if (dport == NFS_PORT && direction == SUNRPC_CALL) { 804 ND_PRINT(": NFS request xid %u ", 805 GET_BE_U_4(rp->rm_xid)); 806 nfsreq_noaddr_print(ndo, (const u_char *)rp, fraglen, (const u_char *)ip); 807 return; 808 } 809 if (sport == NFS_PORT && direction == SUNRPC_REPLY) { 810 ND_PRINT(": NFS reply xid %u ", 811 GET_BE_U_4(rp->rm_xid)); 812 nfsreply_noaddr_print(ndo, (const u_char *)rp, fraglen, (const u_char *)ip); 813 return; 814 } 815 } 816 } 817 818 return; 819 bad: 820 ND_PRINT("[bad opt]"); 821 if (ch != '\0') 822 ND_PRINT("]"); 823 return; 824 trunc: 825 nd_print_trunc(ndo); 826 if (ch != '\0') 827 ND_PRINT(">"); 828 } 829 830 /* 831 * RFC1122 says the following on data in RST segments: 832 * 833 * 4.2.2.12 RST Segment: RFC-793 Section 3.4 834 * 835 * A TCP SHOULD allow a received RST segment to include data. 836 * 837 * DISCUSSION 838 * It has been suggested that a RST segment could contain 839 * ASCII text that encoded and explained the cause of the 840 * RST. No standard has yet been established for such 841 * data. 842 * 843 */ 844 845 static void 846 print_tcp_rst_data(netdissect_options *ndo, 847 const u_char *sp, u_int length) 848 { 849 u_char c; 850 851 ND_PRINT(ND_TTEST_LEN(sp, length) ? " [RST" : " [!RST"); 852 if (length > MAX_RST_DATA_LEN) { 853 length = MAX_RST_DATA_LEN; /* can use -X for longer */ 854 ND_PRINT("+"); /* indicate we truncate */ 855 } 856 ND_PRINT(" "); 857 while (length && sp < ndo->ndo_snapend) { 858 c = GET_U_1(sp); 859 sp++; 860 fn_print_char(ndo, c); 861 length--; 862 } 863 ND_PRINT("]"); 864 } 865 866 static void 867 print_tcp_fastopen_option(netdissect_options *ndo, const u_char *cp, 868 u_int datalen, int exp) 869 { 870 u_int i; 871 872 if (exp) 873 ND_PRINT("tfo"); 874 875 if (datalen == 0) { 876 /* Fast Open Cookie Request */ 877 ND_PRINT(" cookiereq"); 878 } else { 879 /* Fast Open Cookie */ 880 if (datalen % 2 != 0 || datalen < 4 || datalen > 16) { 881 nd_print_invalid(ndo); 882 } else { 883 ND_PRINT(" cookie "); 884 for (i = 0; i < datalen; ++i) 885 ND_PRINT("%02x", GET_U_1(cp + i)); 886 } 887 } 888 } 889 890 #ifdef HAVE_LIBCRYPTO 891 DIAG_OFF_DEPRECATION 892 static int 893 tcp_verify_signature(netdissect_options *ndo, 894 const struct ip *ip, const struct tcphdr *tp, 895 const u_char *data, u_int length, const u_char *rcvsig) 896 { 897 struct tcphdr tp1; 898 u_char sig[TCP_SIGLEN]; 899 char zero_proto = 0; 900 MD5_CTX ctx; 901 uint16_t savecsum, tlen; 902 const struct ip6_hdr *ip6; 903 uint32_t len32; 904 uint8_t nxt; 905 906 if (data + length > ndo->ndo_snapend) { 907 ND_PRINT("snaplen too short, "); 908 return (CANT_CHECK_SIGNATURE); 909 } 910 911 tp1 = *tp; 912 913 if (ndo->ndo_sigsecret == NULL) { 914 ND_PRINT("shared secret not supplied with -M, "); 915 return (CANT_CHECK_SIGNATURE); 916 } 917 918 MD5_Init(&ctx); 919 /* 920 * Step 1: Update MD5 hash with IP pseudo-header. 921 */ 922 if (IP_V(ip) == 4) { 923 MD5_Update(&ctx, (const char *)&ip->ip_src, sizeof(ip->ip_src)); 924 MD5_Update(&ctx, (const char *)&ip->ip_dst, sizeof(ip->ip_dst)); 925 MD5_Update(&ctx, (const char *)&zero_proto, sizeof(zero_proto)); 926 MD5_Update(&ctx, (const char *)&ip->ip_p, sizeof(ip->ip_p)); 927 tlen = GET_BE_U_2(ip->ip_len) - IP_HL(ip) * 4; 928 tlen = htons(tlen); 929 MD5_Update(&ctx, (const char *)&tlen, sizeof(tlen)); 930 } else if (IP_V(ip) == 6) { 931 ip6 = (const struct ip6_hdr *)ip; 932 MD5_Update(&ctx, (const char *)&ip6->ip6_src, sizeof(ip6->ip6_src)); 933 MD5_Update(&ctx, (const char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst)); 934 len32 = htonl(GET_BE_U_2(ip6->ip6_plen)); 935 MD5_Update(&ctx, (const char *)&len32, sizeof(len32)); 936 nxt = 0; 937 MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); 938 MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); 939 MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); 940 nxt = IPPROTO_TCP; 941 MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); 942 } else { 943 ND_PRINT("IP version not 4 or 6, "); 944 return (CANT_CHECK_SIGNATURE); 945 } 946 947 /* 948 * Step 2: Update MD5 hash with TCP header, excluding options. 949 * The TCP checksum must be set to zero. 950 */ 951 memcpy(&savecsum, tp1.th_sum, sizeof(savecsum)); 952 memset(tp1.th_sum, 0, sizeof(tp1.th_sum)); 953 MD5_Update(&ctx, (const char *)&tp1, sizeof(struct tcphdr)); 954 memcpy(tp1.th_sum, &savecsum, sizeof(tp1.th_sum)); 955 /* 956 * Step 3: Update MD5 hash with TCP segment data, if present. 957 */ 958 if (length > 0) 959 MD5_Update(&ctx, data, length); 960 /* 961 * Step 4: Update MD5 hash with shared secret. 962 */ 963 MD5_Update(&ctx, ndo->ndo_sigsecret, strlen(ndo->ndo_sigsecret)); 964 MD5_Final(sig, &ctx); 965 966 if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0) 967 return (SIGNATURE_VALID); 968 else 969 return (SIGNATURE_INVALID); 970 } 971 DIAG_ON_DEPRECATION 972 #endif /* HAVE_LIBCRYPTO */ 973