The Android Open Source Project | 2949f58 | 2009-03-03 19:30:46 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * |
| 5 | * Copyright (c) 1999-2004 The tcpdump.org project |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that: (1) source code distributions |
| 9 | * retain the above copyright notice and this paragraph in its entirety, (2) |
| 10 | * distributions including binary code include the above copyright notice and |
| 11 | * this paragraph in its entirety in the documentation or other materials |
| 12 | * provided with the distribution, and (3) all advertising materials mentioning |
| 13 | * features or use of this software display the following acknowledgement: |
| 14 | * ``This product includes software developed by the University of California, |
| 15 | * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of |
| 16 | * the University nor the names of its contributors may be used to endorse |
| 17 | * or promote products derived from this software without specific prior |
| 18 | * written permission. |
| 19 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED |
| 20 | * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF |
| 21 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| 22 | */ |
| 23 | |
| 24 | #ifndef lint |
| 25 | static const char rcsid[] _U_ = |
| 26 | "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.120.2.3 2005/10/16 06:05:46 guy Exp $ (LBL)"; |
| 27 | #endif |
| 28 | |
| 29 | #ifdef HAVE_CONFIG_H |
| 30 | #include "config.h" |
| 31 | #endif |
| 32 | |
| 33 | #include <tcpdump-stdinc.h> |
| 34 | |
| 35 | #include <stdio.h> |
| 36 | #include <stdlib.h> |
| 37 | #include <string.h> |
| 38 | |
| 39 | #include "interface.h" |
| 40 | #include "addrtoname.h" |
| 41 | #include "extract.h" |
| 42 | |
| 43 | #include "tcp.h" |
| 44 | |
| 45 | #include "ip.h" |
| 46 | #ifdef INET6 |
| 47 | #include "ip6.h" |
| 48 | #endif |
| 49 | #include "ipproto.h" |
| 50 | #include "rpc_auth.h" |
| 51 | #include "rpc_msg.h" |
| 52 | |
| 53 | #include "nameser.h" |
| 54 | |
| 55 | #ifdef HAVE_LIBCRYPTO |
| 56 | #include <openssl/md5.h> |
| 57 | |
| 58 | #define SIGNATURE_VALID 0 |
| 59 | #define SIGNATURE_INVALID 1 |
| 60 | #define CANT_CHECK_SIGNATURE 2 |
| 61 | |
| 62 | static int tcp_verify_signature(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(register const u_char *sp, u_int length); |
| 67 | |
| 68 | #define MAX_RST_DATA_LEN 30 |
| 69 | |
| 70 | |
| 71 | struct tha { |
| 72 | #ifndef INET6 |
| 73 | struct in_addr src; |
| 74 | struct in_addr dst; |
| 75 | #else |
| 76 | struct in6_addr src; |
| 77 | struct in6_addr dst; |
| 78 | #endif /*INET6*/ |
| 79 | u_int port; |
| 80 | }; |
| 81 | |
| 82 | struct tcp_seq_hash { |
| 83 | struct tcp_seq_hash *nxt; |
| 84 | struct tha addr; |
| 85 | tcp_seq seq; |
| 86 | tcp_seq ack; |
| 87 | }; |
| 88 | |
| 89 | #define TSEQ_HASHSIZE 919 |
| 90 | |
| 91 | /* These tcp optinos do not have the size octet */ |
| 92 | #define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP) |
| 93 | |
| 94 | static struct tcp_seq_hash tcp_seq_hash[TSEQ_HASHSIZE]; |
| 95 | |
| 96 | |
| 97 | #ifndef TELNET_PORT |
| 98 | #define TELNET_PORT 23 |
| 99 | #endif |
| 100 | #ifndef BGP_PORT |
| 101 | #define BGP_PORT 179 |
| 102 | #endif |
| 103 | #define NETBIOS_SSN_PORT 139 |
| 104 | #ifndef PPTP_PORT |
| 105 | #define PPTP_PORT 1723 |
| 106 | #endif |
| 107 | #define BEEP_PORT 10288 |
| 108 | #ifndef NFS_PORT |
| 109 | #define NFS_PORT 2049 |
| 110 | #endif |
| 111 | #define MSDP_PORT 639 |
| 112 | #define LDP_PORT 646 |
| 113 | |
| 114 | static int tcp_cksum(register const struct ip *ip, |
| 115 | register const struct tcphdr *tp, |
| 116 | register u_int len) |
| 117 | { |
| 118 | union phu { |
| 119 | struct phdr { |
| 120 | u_int32_t src; |
| 121 | u_int32_t dst; |
| 122 | u_char mbz; |
| 123 | u_char proto; |
| 124 | u_int16_t len; |
| 125 | } ph; |
| 126 | u_int16_t pa[6]; |
| 127 | } phu; |
| 128 | const u_int16_t *sp; |
| 129 | |
| 130 | /* pseudo-header.. */ |
| 131 | phu.ph.len = htons((u_int16_t)len); |
| 132 | phu.ph.mbz = 0; |
| 133 | phu.ph.proto = IPPROTO_TCP; |
| 134 | memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t)); |
| 135 | if (IP_HL(ip) == 5) |
| 136 | memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t)); |
| 137 | else |
| 138 | phu.ph.dst = ip_finddst(ip); |
| 139 | |
| 140 | sp = &phu.pa[0]; |
| 141 | return in_cksum((u_short *)tp, len, |
| 142 | sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5]); |
| 143 | } |
| 144 | |
| 145 | #ifdef INET6 |
| 146 | static int tcp6_cksum(const struct ip6_hdr *ip6, const struct tcphdr *tp, |
| 147 | u_int len) |
| 148 | { |
| 149 | size_t i; |
| 150 | register const u_int16_t *sp; |
| 151 | u_int32_t sum; |
| 152 | union { |
| 153 | struct { |
| 154 | struct in6_addr ph_src; |
| 155 | struct in6_addr ph_dst; |
| 156 | u_int32_t ph_len; |
| 157 | u_int8_t ph_zero[3]; |
| 158 | u_int8_t ph_nxt; |
| 159 | } ph; |
| 160 | u_int16_t pa[20]; |
| 161 | } phu; |
| 162 | |
| 163 | /* pseudo-header */ |
| 164 | memset(&phu, 0, sizeof(phu)); |
| 165 | phu.ph.ph_src = ip6->ip6_src; |
| 166 | phu.ph.ph_dst = ip6->ip6_dst; |
| 167 | phu.ph.ph_len = htonl(len); |
| 168 | phu.ph.ph_nxt = IPPROTO_TCP; |
| 169 | |
| 170 | sum = 0; |
| 171 | for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++) |
| 172 | sum += phu.pa[i]; |
| 173 | |
| 174 | sp = (const u_int16_t *)tp; |
| 175 | |
| 176 | for (i = 0; i < (len & ~1); i += 2) |
| 177 | sum += *sp++; |
| 178 | |
| 179 | if (len & 1) |
| 180 | sum += htons((*(const u_int8_t *)sp) << 8); |
| 181 | |
| 182 | while (sum > 0xffff) |
| 183 | sum = (sum & 0xffff) + (sum >> 16); |
| 184 | sum = ~sum & 0xffff; |
| 185 | |
| 186 | return (sum); |
| 187 | } |
| 188 | #endif |
| 189 | |
| 190 | void |
| 191 | tcp_print(register const u_char *bp, register u_int length, |
| 192 | register const u_char *bp2, int fragmented) |
| 193 | { |
| 194 | register const struct tcphdr *tp; |
| 195 | register const struct ip *ip; |
| 196 | register u_char flags; |
| 197 | register u_int hlen; |
| 198 | register char ch; |
| 199 | u_int16_t sport, dport, win, urp; |
| 200 | u_int32_t seq, ack, thseq, thack; |
| 201 | int threv; |
| 202 | #ifdef INET6 |
| 203 | register const struct ip6_hdr *ip6; |
| 204 | #endif |
| 205 | |
| 206 | tp = (struct tcphdr *)bp; |
| 207 | ip = (struct ip *)bp2; |
| 208 | #ifdef INET6 |
| 209 | if (IP_V(ip) == 6) |
| 210 | ip6 = (struct ip6_hdr *)bp2; |
| 211 | else |
| 212 | ip6 = NULL; |
| 213 | #endif /*INET6*/ |
| 214 | ch = '\0'; |
| 215 | if (!TTEST(tp->th_dport)) { |
| 216 | (void)printf("%s > %s: [|tcp]", |
| 217 | ipaddr_string(&ip->ip_src), |
| 218 | ipaddr_string(&ip->ip_dst)); |
| 219 | return; |
| 220 | } |
| 221 | |
| 222 | sport = EXTRACT_16BITS(&tp->th_sport); |
| 223 | dport = EXTRACT_16BITS(&tp->th_dport); |
| 224 | |
| 225 | hlen = TH_OFF(tp) * 4; |
| 226 | |
| 227 | /* |
| 228 | * If data present, header length valid, and NFS port used, |
| 229 | * assume NFS. |
| 230 | * Pass offset of data plus 4 bytes for RPC TCP msg length |
| 231 | * to NFS print routines. |
| 232 | */ |
| 233 | if (!qflag && hlen >= sizeof(*tp) && hlen <= length) { |
| 234 | if ((u_char *)tp + 4 + sizeof(struct sunrpc_msg) <= snapend && |
| 235 | dport == NFS_PORT) { |
| 236 | nfsreq_print((u_char *)tp + hlen + 4, length - hlen, |
| 237 | (u_char *)ip); |
| 238 | return; |
| 239 | } else if ((u_char *)tp + 4 + sizeof(struct sunrpc_msg) |
| 240 | <= snapend && |
| 241 | sport == NFS_PORT) { |
| 242 | nfsreply_print((u_char *)tp + hlen + 4, length - hlen, |
| 243 | (u_char *)ip); |
| 244 | return; |
| 245 | } |
| 246 | } |
| 247 | #ifdef INET6 |
| 248 | if (ip6) { |
| 249 | if (ip6->ip6_nxt == IPPROTO_TCP) { |
| 250 | (void)printf("%s.%s > %s.%s: ", |
| 251 | ip6addr_string(&ip6->ip6_src), |
| 252 | tcpport_string(sport), |
| 253 | ip6addr_string(&ip6->ip6_dst), |
| 254 | tcpport_string(dport)); |
| 255 | } else { |
| 256 | (void)printf("%s > %s: ", |
| 257 | tcpport_string(sport), tcpport_string(dport)); |
| 258 | } |
| 259 | } else |
| 260 | #endif /*INET6*/ |
| 261 | { |
| 262 | if (ip->ip_p == IPPROTO_TCP) { |
| 263 | (void)printf("%s.%s > %s.%s: ", |
| 264 | ipaddr_string(&ip->ip_src), |
| 265 | tcpport_string(sport), |
| 266 | ipaddr_string(&ip->ip_dst), |
| 267 | tcpport_string(dport)); |
| 268 | } else { |
| 269 | (void)printf("%s > %s: ", |
| 270 | tcpport_string(sport), tcpport_string(dport)); |
| 271 | } |
| 272 | } |
| 273 | |
| 274 | if (hlen < sizeof(*tp)) { |
| 275 | (void)printf(" tcp %d [bad hdr length %u - too short, < %lu]", |
| 276 | length - hlen, hlen, (unsigned long)sizeof(*tp)); |
| 277 | return; |
| 278 | } |
| 279 | |
| 280 | TCHECK(*tp); |
| 281 | |
| 282 | seq = EXTRACT_32BITS(&tp->th_seq); |
| 283 | ack = EXTRACT_32BITS(&tp->th_ack); |
| 284 | win = EXTRACT_16BITS(&tp->th_win); |
| 285 | urp = EXTRACT_16BITS(&tp->th_urp); |
| 286 | |
| 287 | if (qflag) { |
| 288 | (void)printf("tcp %d", length - hlen); |
| 289 | if (hlen > length) { |
| 290 | (void)printf(" [bad hdr length %u - too long, > %u]", |
| 291 | hlen, length); |
| 292 | } |
| 293 | return; |
| 294 | } |
| 295 | if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH| |
| 296 | TH_ECNECHO|TH_CWR)) { |
| 297 | if (flags & TH_SYN) |
| 298 | putchar('S'); |
| 299 | if (flags & TH_FIN) |
| 300 | putchar('F'); |
| 301 | if (flags & TH_RST) |
| 302 | putchar('R'); |
| 303 | if (flags & TH_PUSH) |
| 304 | putchar('P'); |
| 305 | if (flags & TH_CWR) |
| 306 | putchar('W'); /* congestion _W_indow reduced (ECN) */ |
| 307 | if (flags & TH_ECNECHO) |
| 308 | putchar('E'); /* ecn _E_cho sent (ECN) */ |
| 309 | } else |
| 310 | putchar('.'); |
| 311 | |
| 312 | if (!Sflag && (flags & TH_ACK)) { |
| 313 | register struct tcp_seq_hash *th; |
| 314 | const void *src, *dst; |
| 315 | register int rev; |
| 316 | struct tha tha; |
| 317 | /* |
| 318 | * Find (or record) the initial sequence numbers for |
| 319 | * this conversation. (we pick an arbitrary |
| 320 | * collating order so there's only one entry for |
| 321 | * both directions). |
| 322 | */ |
| 323 | #ifdef INET6 |
| 324 | memset(&tha, 0, sizeof(tha)); |
| 325 | rev = 0; |
| 326 | if (ip6) { |
| 327 | src = &ip6->ip6_src; |
| 328 | dst = &ip6->ip6_dst; |
| 329 | if (sport > dport) |
| 330 | rev = 1; |
| 331 | else if (sport == dport) { |
| 332 | if (memcmp(src, dst, sizeof ip6->ip6_dst) > 0) |
| 333 | rev = 1; |
| 334 | } |
| 335 | if (rev) { |
| 336 | memcpy(&tha.src, dst, sizeof ip6->ip6_dst); |
| 337 | memcpy(&tha.dst, src, sizeof ip6->ip6_src); |
| 338 | tha.port = dport << 16 | sport; |
| 339 | } else { |
| 340 | memcpy(&tha.dst, dst, sizeof ip6->ip6_dst); |
| 341 | memcpy(&tha.src, src, sizeof ip6->ip6_src); |
| 342 | tha.port = sport << 16 | dport; |
| 343 | } |
| 344 | } else { |
| 345 | src = &ip->ip_src; |
| 346 | dst = &ip->ip_dst; |
| 347 | if (sport > dport) |
| 348 | rev = 1; |
| 349 | else if (sport == dport) { |
| 350 | if (memcmp(src, dst, sizeof ip->ip_dst) > 0) |
| 351 | rev = 1; |
| 352 | } |
| 353 | if (rev) { |
| 354 | memcpy(&tha.src, dst, sizeof ip->ip_dst); |
| 355 | memcpy(&tha.dst, src, sizeof ip->ip_src); |
| 356 | tha.port = dport << 16 | sport; |
| 357 | } else { |
| 358 | memcpy(&tha.dst, dst, sizeof ip->ip_dst); |
| 359 | memcpy(&tha.src, src, sizeof ip->ip_src); |
| 360 | tha.port = sport << 16 | dport; |
| 361 | } |
| 362 | } |
| 363 | #else |
| 364 | rev = 0; |
| 365 | src = &ip->ip_src; |
| 366 | dst = &ip->ip_dst; |
| 367 | if (sport > dport) |
| 368 | rev = 1; |
| 369 | else if (sport == dport) { |
| 370 | if (memcmp(src, dst, sizeof ip->ip_dst) > 0) |
| 371 | rev = 1; |
| 372 | } |
| 373 | if (rev) { |
| 374 | memcpy(&tha.src, dst, sizeof ip->ip_dst); |
| 375 | memcpy(&tha.dst, src, sizeof ip->ip_src); |
| 376 | tha.port = dport << 16 | sport; |
| 377 | } else { |
| 378 | memcpy(&tha.dst, dst, sizeof ip->ip_dst); |
| 379 | memcpy(&tha.src, src, sizeof ip->ip_src); |
| 380 | tha.port = sport << 16 | dport; |
| 381 | } |
| 382 | #endif |
| 383 | |
| 384 | threv = rev; |
| 385 | for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE]; |
| 386 | th->nxt; th = th->nxt) |
| 387 | if (memcmp((char *)&tha, (char *)&th->addr, |
| 388 | sizeof(th->addr)) == 0) |
| 389 | break; |
| 390 | |
| 391 | if (!th->nxt || (flags & TH_SYN)) { |
| 392 | /* didn't find it or new conversation */ |
| 393 | if (th->nxt == NULL) { |
| 394 | th->nxt = (struct tcp_seq_hash *) |
| 395 | calloc(1, sizeof(*th)); |
| 396 | if (th->nxt == NULL) |
| 397 | error("tcp_print: calloc"); |
| 398 | } |
| 399 | th->addr = tha; |
| 400 | if (rev) |
| 401 | th->ack = seq, th->seq = ack - 1; |
| 402 | else |
| 403 | th->seq = seq, th->ack = ack - 1; |
| 404 | } else { |
| 405 | if (rev) |
| 406 | seq -= th->ack, ack -= th->seq; |
| 407 | else |
| 408 | seq -= th->seq, ack -= th->ack; |
| 409 | } |
| 410 | |
| 411 | thseq = th->seq; |
| 412 | thack = th->ack; |
| 413 | } else { |
| 414 | /*fool gcc*/ |
| 415 | thseq = thack = threv = 0; |
| 416 | } |
| 417 | if (hlen > length) { |
| 418 | (void)printf(" [bad hdr length %u - too long, > %u]", |
| 419 | hlen, length); |
| 420 | return; |
| 421 | } |
| 422 | |
| 423 | if (IP_V(ip) == 4 && vflag && !fragmented) { |
| 424 | u_int16_t sum, tcp_sum; |
| 425 | if (TTEST2(tp->th_sport, length)) { |
| 426 | sum = tcp_cksum(ip, tp, length); |
| 427 | |
| 428 | (void)printf(", cksum 0x%04x",EXTRACT_16BITS(&tp->th_sum)); |
| 429 | if (sum != 0) { |
| 430 | tcp_sum = EXTRACT_16BITS(&tp->th_sum); |
| 431 | (void)printf(" (incorrect (-> 0x%04x),",in_cksum_shouldbe(tcp_sum, sum)); |
| 432 | } else |
| 433 | (void)printf(" (correct),"); |
| 434 | } |
| 435 | } |
| 436 | #ifdef INET6 |
| 437 | if (IP_V(ip) == 6 && ip6->ip6_plen && vflag && !fragmented) { |
| 438 | u_int16_t sum,tcp_sum; |
| 439 | if (TTEST2(tp->th_sport, length)) { |
| 440 | sum = tcp6_cksum(ip6, tp, length); |
| 441 | (void)printf(", cksum 0x%04x",EXTRACT_16BITS(&tp->th_sum)); |
| 442 | if (sum != 0) { |
| 443 | tcp_sum = EXTRACT_16BITS(&tp->th_sum); |
| 444 | (void)printf(" (incorrect (-> 0x%04x),",in_cksum_shouldbe(tcp_sum, sum)); |
| 445 | } else |
| 446 | (void)printf(" (correct),"); |
| 447 | |
| 448 | } |
| 449 | } |
| 450 | #endif |
| 451 | |
| 452 | length -= hlen; |
| 453 | if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) |
| 454 | (void)printf(" %u:%u(%u)", seq, seq + length, length); |
| 455 | if (flags & TH_ACK) |
| 456 | (void)printf(" ack %u", ack); |
| 457 | |
| 458 | (void)printf(" win %d", win); |
| 459 | |
| 460 | if (flags & TH_URG) |
| 461 | (void)printf(" urg %d", urp); |
| 462 | /* |
| 463 | * Handle any options. |
| 464 | */ |
| 465 | if (hlen > sizeof(*tp)) { |
| 466 | register const u_char *cp; |
| 467 | register u_int i, opt, datalen; |
| 468 | register u_int len; |
| 469 | |
| 470 | hlen -= sizeof(*tp); |
| 471 | cp = (const u_char *)tp + sizeof(*tp); |
| 472 | putchar(' '); |
| 473 | ch = '<'; |
| 474 | while (hlen > 0) { |
| 475 | putchar(ch); |
| 476 | TCHECK(*cp); |
| 477 | opt = *cp++; |
| 478 | if (ZEROLENOPT(opt)) |
| 479 | len = 1; |
| 480 | else { |
| 481 | TCHECK(*cp); |
| 482 | len = *cp++; /* total including type, len */ |
| 483 | if (len < 2 || len > hlen) |
| 484 | goto bad; |
| 485 | --hlen; /* account for length byte */ |
| 486 | } |
| 487 | --hlen; /* account for type byte */ |
| 488 | datalen = 0; |
| 489 | |
| 490 | /* Bail if "l" bytes of data are not left or were not captured */ |
| 491 | #define LENCHECK(l) { if ((l) > hlen) goto bad; TCHECK2(*cp, l); } |
| 492 | |
| 493 | switch (opt) { |
| 494 | |
| 495 | case TCPOPT_MAXSEG: |
| 496 | (void)printf("mss"); |
| 497 | datalen = 2; |
| 498 | LENCHECK(datalen); |
| 499 | (void)printf(" %u", EXTRACT_16BITS(cp)); |
| 500 | |
| 501 | break; |
| 502 | |
| 503 | case TCPOPT_EOL: |
| 504 | (void)printf("eol"); |
| 505 | break; |
| 506 | |
| 507 | case TCPOPT_NOP: |
| 508 | (void)printf("nop"); |
| 509 | break; |
| 510 | |
| 511 | case TCPOPT_WSCALE: |
| 512 | (void)printf("wscale"); |
| 513 | datalen = 1; |
| 514 | LENCHECK(datalen); |
| 515 | (void)printf(" %u", *cp); |
| 516 | break; |
| 517 | |
| 518 | case TCPOPT_SACKOK: |
| 519 | (void)printf("sackOK"); |
| 520 | break; |
| 521 | |
| 522 | case TCPOPT_SACK: |
| 523 | datalen = len - 2; |
| 524 | if (datalen % 8 != 0) { |
| 525 | (void)printf("malformed sack"); |
| 526 | } else { |
| 527 | u_int32_t s, e; |
| 528 | |
| 529 | (void)printf("sack %d ", datalen / 8); |
| 530 | for (i = 0; i < datalen; i += 8) { |
| 531 | LENCHECK(i + 4); |
| 532 | s = EXTRACT_32BITS(cp + i); |
| 533 | LENCHECK(i + 8); |
| 534 | e = EXTRACT_32BITS(cp + i + 4); |
| 535 | if (threv) { |
| 536 | s -= thseq; |
| 537 | e -= thseq; |
| 538 | } else { |
| 539 | s -= thack; |
| 540 | e -= thack; |
| 541 | } |
| 542 | (void)printf("{%u:%u}", s, e); |
| 543 | } |
| 544 | } |
| 545 | break; |
| 546 | |
| 547 | case TCPOPT_ECHO: |
| 548 | (void)printf("echo"); |
| 549 | datalen = 4; |
| 550 | LENCHECK(datalen); |
| 551 | (void)printf(" %u", EXTRACT_32BITS(cp)); |
| 552 | break; |
| 553 | |
| 554 | case TCPOPT_ECHOREPLY: |
| 555 | (void)printf("echoreply"); |
| 556 | datalen = 4; |
| 557 | LENCHECK(datalen); |
| 558 | (void)printf(" %u", EXTRACT_32BITS(cp)); |
| 559 | break; |
| 560 | |
| 561 | case TCPOPT_TIMESTAMP: |
| 562 | (void)printf("timestamp"); |
| 563 | datalen = 8; |
| 564 | LENCHECK(4); |
| 565 | (void)printf(" %u", EXTRACT_32BITS(cp)); |
| 566 | LENCHECK(datalen); |
| 567 | (void)printf(" %u", EXTRACT_32BITS(cp + 4)); |
| 568 | break; |
| 569 | |
| 570 | case TCPOPT_CC: |
| 571 | (void)printf("cc"); |
| 572 | datalen = 4; |
| 573 | LENCHECK(datalen); |
| 574 | (void)printf(" %u", EXTRACT_32BITS(cp)); |
| 575 | break; |
| 576 | |
| 577 | case TCPOPT_CCNEW: |
| 578 | (void)printf("ccnew"); |
| 579 | datalen = 4; |
| 580 | LENCHECK(datalen); |
| 581 | (void)printf(" %u", EXTRACT_32BITS(cp)); |
| 582 | break; |
| 583 | |
| 584 | case TCPOPT_CCECHO: |
| 585 | (void)printf("ccecho"); |
| 586 | datalen = 4; |
| 587 | LENCHECK(datalen); |
| 588 | (void)printf(" %u", EXTRACT_32BITS(cp)); |
| 589 | break; |
| 590 | |
| 591 | case TCPOPT_SIGNATURE: |
| 592 | (void)printf("md5:"); |
| 593 | datalen = TCP_SIGLEN; |
| 594 | LENCHECK(datalen); |
| 595 | #ifdef HAVE_LIBCRYPTO |
| 596 | switch (tcp_verify_signature(ip, tp, |
| 597 | bp + TH_OFF(tp) * 4, length, cp)) { |
| 598 | |
| 599 | case SIGNATURE_VALID: |
| 600 | (void)printf("valid"); |
| 601 | break; |
| 602 | |
| 603 | case SIGNATURE_INVALID: |
| 604 | (void)printf("invalid"); |
| 605 | break; |
| 606 | |
| 607 | case CANT_CHECK_SIGNATURE: |
| 608 | (void)printf("can't check - "); |
| 609 | for (i = 0; i < TCP_SIGLEN; ++i) |
| 610 | (void)printf("%02x", cp[i]); |
| 611 | break; |
| 612 | } |
| 613 | #else |
| 614 | for (i = 0; i < TCP_SIGLEN; ++i) |
| 615 | (void)printf("%02x", cp[i]); |
| 616 | #endif |
| 617 | break; |
| 618 | |
| 619 | default: |
| 620 | (void)printf("opt-%u:", opt); |
| 621 | datalen = len - 2; |
| 622 | for (i = 0; i < datalen; ++i) { |
| 623 | LENCHECK(i); |
| 624 | (void)printf("%02x", cp[i]); |
| 625 | } |
| 626 | break; |
| 627 | } |
| 628 | |
| 629 | /* Account for data printed */ |
| 630 | cp += datalen; |
| 631 | hlen -= datalen; |
| 632 | |
| 633 | /* Check specification against observed length */ |
| 634 | ++datalen; /* option octet */ |
| 635 | if (!ZEROLENOPT(opt)) |
| 636 | ++datalen; /* size octet */ |
| 637 | if (datalen != len) |
| 638 | (void)printf("[len %d]", len); |
| 639 | ch = ','; |
| 640 | if (opt == TCPOPT_EOL) |
| 641 | break; |
| 642 | } |
| 643 | putchar('>'); |
| 644 | } |
| 645 | |
| 646 | if (length <= 0) |
| 647 | return; |
| 648 | |
| 649 | /* |
| 650 | * Decode payload if necessary. |
| 651 | */ |
| 652 | bp += TH_OFF(tp) * 4; |
| 653 | if (flags & TH_RST) { |
| 654 | if (vflag) |
| 655 | print_tcp_rst_data(bp, length); |
| 656 | } else { |
| 657 | if (sport == TELNET_PORT || dport == TELNET_PORT) { |
| 658 | if (!qflag && vflag) |
| 659 | telnet_print(bp, length); |
| 660 | } else if (sport == BGP_PORT || dport == BGP_PORT) |
| 661 | bgp_print(bp, length); |
| 662 | else if (sport == PPTP_PORT || dport == PPTP_PORT) |
| 663 | pptp_print(bp); |
| 664 | #ifdef TCPDUMP_DO_SMB |
| 665 | else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT) |
| 666 | nbt_tcp_print(bp, length); |
| 667 | #endif |
| 668 | else if (sport == BEEP_PORT || dport == BEEP_PORT) |
| 669 | beep_print(bp, length); |
| 670 | else if (length > 2 && |
| 671 | (sport == NAMESERVER_PORT || dport == NAMESERVER_PORT || |
| 672 | sport == MULTICASTDNS_PORT || dport == MULTICASTDNS_PORT)) { |
| 673 | /* |
| 674 | * TCP DNS query has 2byte length at the head. |
| 675 | * XXX packet could be unaligned, it can go strange |
| 676 | */ |
| 677 | ns_print(bp + 2, length - 2, 0); |
| 678 | } else if (sport == MSDP_PORT || dport == MSDP_PORT) { |
| 679 | msdp_print(bp, length); |
| 680 | } |
| 681 | else if (length > 0 && (sport == LDP_PORT || dport == LDP_PORT)) { |
| 682 | ldp_print(bp, length); |
| 683 | } |
| 684 | } |
| 685 | return; |
| 686 | bad: |
| 687 | fputs("[bad opt]", stdout); |
| 688 | if (ch != '\0') |
| 689 | putchar('>'); |
| 690 | return; |
| 691 | trunc: |
| 692 | fputs("[|tcp]", stdout); |
| 693 | if (ch != '\0') |
| 694 | putchar('>'); |
| 695 | } |
| 696 | |
| 697 | /* |
| 698 | * RFC1122 says the following on data in RST segments: |
| 699 | * |
| 700 | * 4.2.2.12 RST Segment: RFC-793 Section 3.4 |
| 701 | * |
| 702 | * A TCP SHOULD allow a received RST segment to include data. |
| 703 | * |
| 704 | * DISCUSSION |
| 705 | * It has been suggested that a RST segment could contain |
| 706 | * ASCII text that encoded and explained the cause of the |
| 707 | * RST. No standard has yet been established for such |
| 708 | * data. |
| 709 | * |
| 710 | */ |
| 711 | |
| 712 | static void |
| 713 | print_tcp_rst_data(register const u_char *sp, u_int length) |
| 714 | { |
| 715 | int c; |
| 716 | |
| 717 | if (TTEST2(*sp, length)) |
| 718 | printf(" [RST"); |
| 719 | else |
| 720 | printf(" [!RST"); |
| 721 | if (length > MAX_RST_DATA_LEN) { |
| 722 | length = MAX_RST_DATA_LEN; /* can use -X for longer */ |
| 723 | putchar('+'); /* indicate we truncate */ |
| 724 | } |
| 725 | putchar(' '); |
| 726 | while (length-- && sp <= snapend) { |
| 727 | c = *sp++; |
| 728 | safeputchar(c); |
| 729 | } |
| 730 | putchar(']'); |
| 731 | } |
| 732 | |
| 733 | #ifdef HAVE_LIBCRYPTO |
| 734 | static int |
| 735 | tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp, |
| 736 | const u_char *data, int length, const u_char *rcvsig) |
| 737 | { |
| 738 | struct tcphdr tp1; |
| 739 | u_char sig[TCP_SIGLEN]; |
| 740 | char zero_proto = 0; |
| 741 | MD5_CTX ctx; |
| 742 | u_int16_t savecsum, tlen; |
| 743 | #ifdef INET6 |
| 744 | struct ip6_hdr *ip6; |
| 745 | #endif |
| 746 | u_int32_t len32; |
| 747 | u_int8_t nxt; |
| 748 | |
| 749 | tp1 = *tp; |
| 750 | |
| 751 | if (tcpmd5secret == NULL) |
| 752 | return (CANT_CHECK_SIGNATURE); |
| 753 | |
| 754 | MD5_Init(&ctx); |
| 755 | /* |
| 756 | * Step 1: Update MD5 hash with IP pseudo-header. |
| 757 | */ |
| 758 | if (IP_V(ip) == 4) { |
| 759 | MD5_Update(&ctx, (char *)&ip->ip_src, sizeof(ip->ip_src)); |
| 760 | MD5_Update(&ctx, (char *)&ip->ip_dst, sizeof(ip->ip_dst)); |
| 761 | MD5_Update(&ctx, (char *)&zero_proto, sizeof(zero_proto)); |
| 762 | MD5_Update(&ctx, (char *)&ip->ip_p, sizeof(ip->ip_p)); |
| 763 | tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4; |
| 764 | tlen = htons(tlen); |
| 765 | MD5_Update(&ctx, (char *)&tlen, sizeof(tlen)); |
| 766 | #ifdef INET6 |
| 767 | } else if (IP_V(ip) == 6) { |
| 768 | ip6 = (struct ip6_hdr *)ip; |
| 769 | MD5_Update(&ctx, (char *)&ip6->ip6_src, sizeof(ip6->ip6_src)); |
| 770 | MD5_Update(&ctx, (char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst)); |
| 771 | len32 = htonl(ntohs(ip6->ip6_plen)); |
| 772 | MD5_Update(&ctx, (char *)&len32, sizeof(len32)); |
| 773 | nxt = 0; |
| 774 | MD5_Update(&ctx, (char *)&nxt, sizeof(nxt)); |
| 775 | MD5_Update(&ctx, (char *)&nxt, sizeof(nxt)); |
| 776 | MD5_Update(&ctx, (char *)&nxt, sizeof(nxt)); |
| 777 | nxt = IPPROTO_TCP; |
| 778 | MD5_Update(&ctx, (char *)&nxt, sizeof(nxt)); |
| 779 | #endif |
| 780 | } else |
| 781 | return (CANT_CHECK_SIGNATURE); |
| 782 | |
| 783 | /* |
| 784 | * Step 2: Update MD5 hash with TCP header, excluding options. |
| 785 | * The TCP checksum must be set to zero. |
| 786 | */ |
| 787 | savecsum = tp1.th_sum; |
| 788 | tp1.th_sum = 0; |
| 789 | MD5_Update(&ctx, (char *)&tp1, sizeof(struct tcphdr)); |
| 790 | tp1.th_sum = savecsum; |
| 791 | /* |
| 792 | * Step 3: Update MD5 hash with TCP segment data, if present. |
| 793 | */ |
| 794 | if (length > 0) |
| 795 | MD5_Update(&ctx, data, length); |
| 796 | /* |
| 797 | * Step 4: Update MD5 hash with shared secret. |
| 798 | */ |
| 799 | MD5_Update(&ctx, tcpmd5secret, strlen(tcpmd5secret)); |
| 800 | MD5_Final(sig, &ctx); |
| 801 | |
| 802 | if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0) |
| 803 | return (SIGNATURE_VALID); |
| 804 | else |
| 805 | return (SIGNATURE_INVALID); |
| 806 | } |
| 807 | #endif /* HAVE_LIBCRYPTO */ |