1 /* $NetBSD: print-tcp.c,v 1.9 2007/07/26 18:15:12 plunky Exp $ */
4 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
5 * The Regents of the University of California. All rights reserved.
7 * Copyright (c) 1999-2004 The tcpdump.org project
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
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.
27 static const char rcsid[] _U_ =
28 "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.130.2.3 2007-12-22 03:08:45 guy Exp $ (LBL)";
30 __RCSID("$NetBSD: print-tcp.c,v 1.8 2007/07/24 11:53:48 drochner Exp $");
37 #include <tcpdump-stdinc.h>
43 #include "interface.h"
44 #include "addrtoname.h"
60 #include <openssl/md5.h>
62 #define SIGNATURE_VALID 0
63 #define SIGNATURE_INVALID 1
64 #define CANT_CHECK_SIGNATURE 2
66 static int tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
67 const u_char *data, int length, const u_char *rcvsig);
70 static void print_tcp_rst_data(register const u_char *sp, u_int length);
72 #define MAX_RST_DATA_LEN 30
87 struct tcp_seq_hash *nxt;
93 #define TSEQ_HASHSIZE 919
95 /* These tcp optinos do not have the size octet */
96 #define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)
98 static struct tcp_seq_hash tcp_seq_hash[TSEQ_HASHSIZE];
100 struct tok tcp_flag_values[] = {
112 struct tok tcp_option_values[] = {
113 { TCPOPT_EOL, "eol" },
114 { TCPOPT_NOP, "nop" },
115 { TCPOPT_MAXSEG, "mss" },
116 { TCPOPT_WSCALE, "wscale" },
117 { TCPOPT_SACKOK, "sackOK" },
118 { TCPOPT_SACK, "sack" },
119 { TCPOPT_ECHO, "echo" },
120 { TCPOPT_ECHOREPLY, "echoreply" },
121 { TCPOPT_TIMESTAMP, "TS" },
123 { TCPOPT_CCNEW, "ccnew" },
124 { TCPOPT_CCECHO, "" },
125 { TCPOPT_SIGNATURE, "md5" },
126 { TCPOPT_AUTH, "enhanced auth" },
130 static int tcp_cksum(register const struct ip *ip,
131 register const struct tcphdr *tp,
146 /* pseudo-header.. */
147 phu.ph.len = htons((u_int16_t)len);
149 phu.ph.proto = IPPROTO_TCP;
150 memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
152 memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
154 phu.ph.dst = ip_finddst(ip);
157 return in_cksum((u_short *)tp, len,
158 sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5]);
162 static int tcp6_cksum(const struct ip6_hdr *ip6, const struct tcphdr *tp,
169 struct in6_addr ph_src;
170 struct in6_addr ph_dst;
179 memset(&phu, 0, sizeof(phu));
180 phu.ph.ph_src = ip6->ip6_src;
181 phu.ph.ph_dst = ip6->ip6_dst;
182 phu.ph.ph_len = htonl(len);
183 phu.ph.ph_nxt = IPPROTO_TCP;
185 for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++)
188 return in_cksum((u_short *)tp, len, sum);
193 tcp_print(register const u_char *bp, register u_int length,
194 register const u_char *bp2, int fragmented)
196 register const struct tcphdr *tp;
197 register const struct ip *ip;
198 register u_char flags;
201 u_int16_t sport, dport, win, urp;
202 u_int32_t seq, ack, thseq, thack;
205 register const struct ip6_hdr *ip6;
208 tp = (struct tcphdr *)bp;
209 ip = (struct ip *)bp2;
212 ip6 = (struct ip6_hdr *)bp2;
217 if (!TTEST(tp->th_dport)) {
218 (void)printf("%s > %s: [|tcp]",
219 ipaddr_string(&ip->ip_src),
220 ipaddr_string(&ip->ip_dst));
224 sport = EXTRACT_16BITS(&tp->th_sport);
225 dport = EXTRACT_16BITS(&tp->th_dport);
227 hlen = TH_OFF(tp) * 4;
230 * If data present, header length valid, and NFS port used,
232 * Pass offset of data plus 4 bytes for RPC TCP msg length
233 * to NFS print routines.
235 if (!qflag && hlen >= sizeof(*tp) && hlen <= length &&
236 (length - hlen) >= 4) {
239 register struct sunrpc_msg *rp;
240 enum sunrpc_msg_type direction;
242 fraglenp = (u_char *)tp + hlen;
243 if (TTEST2(*fraglenp, 4)) {
244 fraglen = EXTRACT_32BITS(fraglenp) & 0x7FFFFFFF;
245 if (fraglen > (length - hlen) - 4)
246 fraglen = (length - hlen) - 4;
247 rp = (struct sunrpc_msg *)(fraglenp + 4);
248 if (TTEST(rp->rm_direction)) {
249 direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction);
250 if (dport == NFS_PORT &&
251 direction == SUNRPC_CALL) {
252 nfsreq_print((u_char *)rp, fraglen,
256 if (sport == NFS_PORT &&
257 direction == SUNRPC_REPLY) {
258 nfsreply_print((u_char *)rp, fraglen,
267 if (ip6->ip6_nxt == IPPROTO_TCP) {
268 (void)printf("%s.%s > %s.%s: ",
269 ip6addr_string(&ip6->ip6_src),
270 tcpport_string(sport),
271 ip6addr_string(&ip6->ip6_dst),
272 tcpport_string(dport));
274 (void)printf("%s > %s: ",
275 tcpport_string(sport), tcpport_string(dport));
280 if (ip->ip_p == IPPROTO_TCP) {
281 (void)printf("%s.%s > %s.%s: ",
282 ipaddr_string(&ip->ip_src),
283 tcpport_string(sport),
284 ipaddr_string(&ip->ip_dst),
285 tcpport_string(dport));
287 (void)printf("%s > %s: ",
288 tcpport_string(sport), tcpport_string(dport));
292 if (hlen < sizeof(*tp)) {
293 (void)printf(" tcp %d [bad hdr length %u - too short, < %lu]",
294 length - hlen, hlen, (unsigned long)sizeof(*tp));
300 seq = EXTRACT_32BITS(&tp->th_seq);
301 ack = EXTRACT_32BITS(&tp->th_ack);
302 win = EXTRACT_16BITS(&tp->th_win);
303 urp = EXTRACT_16BITS(&tp->th_urp);
306 (void)printf("tcp %d", length - hlen);
308 (void)printf(" [bad hdr length %u - too long, > %u]",
314 flags = tp->th_flags;
315 printf("Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags));
317 if (!Sflag && (flags & TH_ACK)) {
318 register struct tcp_seq_hash *th;
319 const void *src, *dst;
323 * Find (or record) the initial sequence numbers for
324 * this conversation. (we pick an arbitrary
325 * collating order so there's only one entry for
329 memset(&tha, 0, sizeof(tha));
336 else if (sport == dport) {
337 if (memcmp(src, dst, sizeof ip6->ip6_dst) > 0)
341 memcpy(&tha.src, dst, sizeof ip6->ip6_dst);
342 memcpy(&tha.dst, src, sizeof ip6->ip6_src);
343 tha.port = dport << 16 | sport;
345 memcpy(&tha.dst, dst, sizeof ip6->ip6_dst);
346 memcpy(&tha.src, src, sizeof ip6->ip6_src);
347 tha.port = sport << 16 | dport;
354 else if (sport == dport) {
355 if (memcmp(src, dst, sizeof ip->ip_dst) > 0)
359 memcpy(&tha.src, dst, sizeof ip->ip_dst);
360 memcpy(&tha.dst, src, sizeof ip->ip_src);
361 tha.port = dport << 16 | sport;
363 memcpy(&tha.dst, dst, sizeof ip->ip_dst);
364 memcpy(&tha.src, src, sizeof ip->ip_src);
365 tha.port = sport << 16 | dport;
374 else if (sport == dport) {
375 if (memcmp(src, dst, sizeof ip->ip_dst) > 0)
379 memcpy(&tha.src, dst, sizeof ip->ip_dst);
380 memcpy(&tha.dst, src, sizeof ip->ip_src);
381 tha.port = dport << 16 | sport;
383 memcpy(&tha.dst, dst, sizeof ip->ip_dst);
384 memcpy(&tha.src, src, sizeof ip->ip_src);
385 tha.port = sport << 16 | dport;
390 for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
391 th->nxt; th = th->nxt)
392 if (memcmp((char *)&tha, (char *)&th->addr,
393 sizeof(th->addr)) == 0)
396 if (!th->nxt || (flags & TH_SYN)) {
397 /* didn't find it or new conversation */
398 if (th->nxt == NULL) {
399 th->nxt = (struct tcp_seq_hash *)
400 calloc(1, sizeof(*th));
402 error("tcp_print: calloc");
406 th->ack = seq, th->seq = ack - 1;
408 th->seq = seq, th->ack = ack - 1;
411 seq -= th->ack, ack -= th->seq;
413 seq -= th->seq, ack -= th->ack;
420 thseq = thack = threv = 0;
423 (void)printf(" [bad hdr length %u - too long, > %u]",
428 if (IP_V(ip) == 4 && vflag && !Kflag && !fragmented) {
429 u_int16_t sum, tcp_sum;
430 if (TTEST2(tp->th_sport, length)) {
431 sum = tcp_cksum(ip, tp, length);
433 (void)printf(", cksum 0x%04x",EXTRACT_16BITS(&tp->th_sum));
435 tcp_sum = EXTRACT_16BITS(&tp->th_sum);
436 (void)printf(" (incorrect -> 0x%04x)",in_cksum_shouldbe(tcp_sum, sum));
438 (void)printf(" (correct)");
442 if (IP_V(ip) == 6 && ip6->ip6_plen && vflag && !Kflag && !fragmented) {
443 u_int16_t sum,tcp_sum;
444 if (TTEST2(tp->th_sport, length)) {
445 sum = tcp6_cksum(ip6, tp, length);
446 (void)printf(", cksum 0x%04x",EXTRACT_16BITS(&tp->th_sum));
448 tcp_sum = EXTRACT_16BITS(&tp->th_sum);
449 (void)printf(" (incorrect -> 0x%04x)",in_cksum_shouldbe(tcp_sum, sum));
451 (void)printf(" (correct)");
458 if (vflag > 1 || flags & (TH_SYN | TH_FIN | TH_RST)) {
459 (void)printf(", seq %u", seq);
462 (void)printf(":%u", seq + length);
466 if (flags & TH_ACK) {
467 (void)printf(", ack %u", ack);
470 (void)printf(", win %d", win);
473 (void)printf(", urg %d", urp);
475 * Handle any options.
477 if (hlen > sizeof(*tp)) {
478 register const u_char *cp;
479 register u_int i, opt, datalen;
483 cp = (const u_char *)tp + sizeof(*tp);
484 printf(", options [");
494 len = *cp++; /* total including type, len */
495 if (len < 2 || len > hlen)
497 --hlen; /* account for length byte */
499 --hlen; /* account for type byte */
502 /* Bail if "l" bytes of data are not left or were not captured */
503 #define LENCHECK(l) { if ((l) > hlen) goto bad; TCHECK2(*cp, l); }
506 printf("%s", tok2str(tcp_option_values, "Unknown Option %u", opt));
513 (void)printf(" %u", EXTRACT_16BITS(cp));
519 (void)printf(" %u", *cp);
524 if (datalen % 8 != 0) {
525 (void)printf("malformed sack");
529 (void)printf(" %d ", datalen / 8);
530 for (i = 0; i < datalen; i += 8) {
532 s = EXTRACT_32BITS(cp + i);
534 e = EXTRACT_32BITS(cp + i + 4);
542 (void)printf("{%u:%u}", s, e);
551 case TCPOPT_ECHOREPLY:
554 * those options share their semantics.
559 (void)printf(" %u", EXTRACT_32BITS(cp));
562 case TCPOPT_TIMESTAMP:
565 (void)printf(" val %u ecr %u",
567 EXTRACT_32BITS(cp + 4));
570 case TCPOPT_SIGNATURE:
571 datalen = TCP_SIGLEN;
573 #ifdef HAVE_LIBCRYPTO
574 switch (tcp_verify_signature(ip, tp,
575 bp + TH_OFF(tp) * 4, length, cp)) {
577 case SIGNATURE_VALID:
578 (void)printf("valid");
581 case SIGNATURE_INVALID:
582 (void)printf("invalid");
585 case CANT_CHECK_SIGNATURE:
586 (void)printf("can't check - ");
587 for (i = 0; i < TCP_SIGLEN; ++i)
588 (void)printf("%02x", cp[i]);
592 for (i = 0; i < TCP_SIGLEN; ++i)
593 (void)printf("%02x", cp[i]);
598 (void)printf("keyid %d", *cp++);
600 for (i = 0; i < datalen; ++i) {
602 (void)printf("%02x", cp[i]);
611 * Nothing interesting.
618 for (i = 0; i < datalen; ++i) {
620 (void)printf("%02x", cp[i]);
625 /* Account for data printed */
629 /* Check specification against observed length */
630 ++datalen; /* option octet */
631 if (!ZEROLENOPT(opt))
632 ++datalen; /* size octet */
634 (void)printf("[len %d]", len);
636 if (opt == TCPOPT_EOL)
643 * Print length field before crawling down the stack.
645 printf(", length %u", length);
651 * Decode payload if necessary.
653 bp += TH_OFF(tp) * 4;
654 if ((flags & TH_RST) && vflag) {
655 print_tcp_rst_data(bp, length);
659 if (sport == TELNET_PORT || dport == TELNET_PORT) {
661 telnet_print(bp, length);
662 } else if (sport == BGP_PORT || dport == BGP_PORT)
663 bgp_print(bp, length);
664 else if (sport == PPTP_PORT || dport == PPTP_PORT)
666 #ifdef TCPDUMP_DO_SMB
667 else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
668 nbt_tcp_print(bp, length);
669 else if (sport == SMB_PORT || dport == SMB_PORT)
670 smb_tcp_print(bp, length);
672 else if (sport == BEEP_PORT || dport == BEEP_PORT)
673 beep_print(bp, length);
674 else if (length > 2 &&
675 (sport == NAMESERVER_PORT || dport == NAMESERVER_PORT ||
676 sport == MULTICASTDNS_PORT || dport == MULTICASTDNS_PORT)) {
678 * TCP DNS query has 2byte length at the head.
679 * XXX packet could be unaligned, it can go strange
681 ns_print(bp + 2, length - 2, 0);
682 } else if (sport == MSDP_PORT || dport == MSDP_PORT) {
683 msdp_print(bp, length);
685 else if (length > 0 && (sport == LDP_PORT || dport == LDP_PORT)) {
686 ldp_print(bp, length);
691 fputs("[bad opt]", stdout);
696 fputs("[|tcp]", stdout);
702 * RFC1122 says the following on data in RST segments:
704 * 4.2.2.12 RST Segment: RFC-793 Section 3.4
706 * A TCP SHOULD allow a received RST segment to include data.
709 * It has been suggested that a RST segment could contain
710 * ASCII text that encoded and explained the cause of the
711 * RST. No standard has yet been established for such
717 print_tcp_rst_data(register const u_char *sp, u_int length)
721 if (TTEST2(*sp, length))
725 if (length > MAX_RST_DATA_LEN) {
726 length = MAX_RST_DATA_LEN; /* can use -X for longer */
727 putchar('+'); /* indicate we truncate */
730 while (length-- && sp <= snapend) {
737 #ifdef HAVE_LIBCRYPTO
739 tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
740 const u_char *data, int length, const u_char *rcvsig)
743 u_char sig[TCP_SIGLEN];
746 u_int16_t savecsum, tlen;
755 if (tcpmd5secret == NULL)
756 return (CANT_CHECK_SIGNATURE);
760 * Step 1: Update MD5 hash with IP pseudo-header.
763 MD5_Update(&ctx, (char *)&ip->ip_src, sizeof(ip->ip_src));
764 MD5_Update(&ctx, (char *)&ip->ip_dst, sizeof(ip->ip_dst));
765 MD5_Update(&ctx, (char *)&zero_proto, sizeof(zero_proto));
766 MD5_Update(&ctx, (char *)&ip->ip_p, sizeof(ip->ip_p));
767 tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4;
769 MD5_Update(&ctx, (char *)&tlen, sizeof(tlen));
771 } else if (IP_V(ip) == 6) {
772 ip6 = (struct ip6_hdr *)ip;
773 MD5_Update(&ctx, (char *)&ip6->ip6_src, sizeof(ip6->ip6_src));
774 MD5_Update(&ctx, (char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));
775 len32 = htonl(ntohs(ip6->ip6_plen));
776 MD5_Update(&ctx, (char *)&len32, sizeof(len32));
778 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
779 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
780 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
782 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
785 return (CANT_CHECK_SIGNATURE);
788 * Step 2: Update MD5 hash with TCP header, excluding options.
789 * The TCP checksum must be set to zero.
791 savecsum = tp1.th_sum;
793 MD5_Update(&ctx, (char *)&tp1, sizeof(struct tcphdr));
794 tp1.th_sum = savecsum;
796 * Step 3: Update MD5 hash with TCP segment data, if present.
799 MD5_Update(&ctx, data, length);
801 * Step 4: Update MD5 hash with shared secret.
803 MD5_Update(&ctx, tcpmd5secret, strlen(tcpmd5secret));
804 MD5_Final(sig, &ctx);
806 if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0)
807 return (SIGNATURE_VALID);
809 return (SIGNATURE_INVALID);
811 #endif /* HAVE_LIBCRYPTO */
815 * c-style: whitesmith