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 1.135 2008-11-09 23:35:03 mcr 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>
61 #include <signature.h>
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);
67 static void print_tcp_rst_data(register const u_char *sp, u_int length);
69 #define MAX_RST_DATA_LEN 30
84 struct tcp_seq_hash *nxt;
90 #define TSEQ_HASHSIZE 919
92 /* These tcp optinos do not have the size octet */
93 #define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)
95 static struct tcp_seq_hash tcp_seq_hash[TSEQ_HASHSIZE];
97 struct tok tcp_flag_values[] = {
109 struct tok tcp_option_values[] = {
110 { TCPOPT_EOL, "eol" },
111 { TCPOPT_NOP, "nop" },
112 { TCPOPT_MAXSEG, "mss" },
113 { TCPOPT_WSCALE, "wscale" },
114 { TCPOPT_SACKOK, "sackOK" },
115 { TCPOPT_SACK, "sack" },
116 { TCPOPT_ECHO, "echo" },
117 { TCPOPT_ECHOREPLY, "echoreply" },
118 { TCPOPT_TIMESTAMP, "TS" },
120 { TCPOPT_CCNEW, "ccnew" },
121 { TCPOPT_CCECHO, "" },
122 { TCPOPT_SIGNATURE, "md5" },
123 { TCPOPT_AUTH, "enhanced auth" },
124 { TCPOPT_UTO, "uto" },
128 static int tcp_cksum(register const struct ip *ip,
129 register const struct tcphdr *tp,
132 return (nextproto4_cksum(ip, (const u_int8_t *)tp, len,
137 tcp_print(register const u_char *bp, register u_int length,
138 register const u_char *bp2, int fragmented)
140 register const struct tcphdr *tp;
141 register const struct ip *ip;
142 register u_char flags;
145 u_int16_t sport, dport, win, urp;
146 u_int32_t seq, ack, thseq, thack;
150 register const struct ip6_hdr *ip6;
153 tp = (struct tcphdr *)bp;
154 ip = (struct ip *)bp2;
157 ip6 = (struct ip6_hdr *)bp2;
162 if (!TTEST(tp->th_dport)) {
163 (void)printf("%s > %s: [|tcp]",
164 ipaddr_string(&ip->ip_src),
165 ipaddr_string(&ip->ip_dst));
169 sport = EXTRACT_16BITS(&tp->th_sport);
170 dport = EXTRACT_16BITS(&tp->th_dport);
172 hlen = TH_OFF(tp) * 4;
175 * If data present, header length valid, and NFS port used,
177 * Pass offset of data plus 4 bytes for RPC TCP msg length
178 * to NFS print routines.
180 if (!qflag && hlen >= sizeof(*tp) && hlen <= length &&
181 (length - hlen) >= 4) {
184 register struct sunrpc_msg *rp;
185 enum sunrpc_msg_type direction;
187 fraglenp = (u_char *)tp + hlen;
188 if (TTEST2(*fraglenp, 4)) {
189 fraglen = EXTRACT_32BITS(fraglenp) & 0x7FFFFFFF;
190 if (fraglen > (length - hlen) - 4)
191 fraglen = (length - hlen) - 4;
192 rp = (struct sunrpc_msg *)(fraglenp + 4);
193 if (TTEST(rp->rm_direction)) {
194 direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction);
195 if (dport == NFS_PORT &&
196 direction == SUNRPC_CALL) {
197 nfsreq_print((u_char *)rp, fraglen,
201 if (sport == NFS_PORT &&
202 direction == SUNRPC_REPLY) {
203 nfsreply_print((u_char *)rp, fraglen,
212 if (ip6->ip6_nxt == IPPROTO_TCP) {
213 (void)printf("%s.%s > %s.%s: ",
214 ip6addr_string(&ip6->ip6_src),
215 tcpport_string(sport),
216 ip6addr_string(&ip6->ip6_dst),
217 tcpport_string(dport));
219 (void)printf("%s > %s: ",
220 tcpport_string(sport), tcpport_string(dport));
225 if (ip->ip_p == IPPROTO_TCP) {
226 (void)printf("%s.%s > %s.%s: ",
227 ipaddr_string(&ip->ip_src),
228 tcpport_string(sport),
229 ipaddr_string(&ip->ip_dst),
230 tcpport_string(dport));
232 (void)printf("%s > %s: ",
233 tcpport_string(sport), tcpport_string(dport));
237 if (hlen < sizeof(*tp)) {
238 (void)printf(" tcp %d [bad hdr length %u - too short, < %lu]",
239 length - hlen, hlen, (unsigned long)sizeof(*tp));
245 seq = EXTRACT_32BITS(&tp->th_seq);
246 ack = EXTRACT_32BITS(&tp->th_ack);
247 win = EXTRACT_16BITS(&tp->th_win);
248 urp = EXTRACT_16BITS(&tp->th_urp);
251 (void)printf("tcp %d", length - hlen);
253 (void)printf(" [bad hdr length %u - too long, > %u]",
259 flags = tp->th_flags;
260 printf("Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags));
262 if (!Sflag && (flags & TH_ACK)) {
263 register struct tcp_seq_hash *th;
264 const void *src, *dst;
268 * Find (or record) the initial sequence numbers for
269 * this conversation. (we pick an arbitrary
270 * collating order so there's only one entry for
280 else if (sport == dport) {
281 if (memcmp(src, dst, sizeof ip6->ip6_dst) > 0)
285 memcpy(&tha.src, dst, sizeof ip6->ip6_dst);
286 memcpy(&tha.dst, src, sizeof ip6->ip6_src);
287 tha.port = dport << 16 | sport;
289 memcpy(&tha.dst, dst, sizeof ip6->ip6_dst);
290 memcpy(&tha.src, src, sizeof ip6->ip6_src);
291 tha.port = sport << 16 | dport;
295 * Zero out the tha structure; the src and dst
296 * fields are big enough to hold an IPv6
297 * address, but we only have IPv4 addresses
298 * and thus must clear out the remaining 124
301 * XXX - should we just clear those bytes after
302 * copying the IPv4 addresses, rather than
303 * zeroing out the entire structure and then
304 * overwriting some of the zeroes?
306 * XXX - this could fail if we see TCP packets
307 * with an IPv6 address with the lower 124 bits
308 * all zero and also see TCP packes with an
309 * IPv4 address with the same 32 bits as the
310 * upper 32 bits of the IPv6 address in question.
311 * Can that happen? Is it likely enough to be
314 memset(&tha, 0, sizeof(tha));
319 else if (sport == dport) {
320 if (memcmp(src, dst, sizeof ip->ip_dst) > 0)
324 memcpy(&tha.src, dst, sizeof ip->ip_dst);
325 memcpy(&tha.dst, src, sizeof ip->ip_src);
326 tha.port = dport << 16 | sport;
328 memcpy(&tha.dst, dst, sizeof ip->ip_dst);
329 memcpy(&tha.src, src, sizeof ip->ip_src);
330 tha.port = sport << 16 | dport;
339 else if (sport == dport) {
340 if (memcmp(src, dst, sizeof ip->ip_dst) > 0)
344 memcpy(&tha.src, dst, sizeof ip->ip_dst);
345 memcpy(&tha.dst, src, sizeof ip->ip_src);
346 tha.port = dport << 16 | sport;
348 memcpy(&tha.dst, dst, sizeof ip->ip_dst);
349 memcpy(&tha.src, src, sizeof ip->ip_src);
350 tha.port = sport << 16 | dport;
355 for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
356 th->nxt; th = th->nxt)
357 if (memcmp((char *)&tha, (char *)&th->addr,
358 sizeof(th->addr)) == 0)
361 if (!th->nxt || (flags & TH_SYN)) {
362 /* didn't find it or new conversation */
363 if (th->nxt == NULL) {
364 th->nxt = (struct tcp_seq_hash *)
365 calloc(1, sizeof(*th));
367 error("tcp_print: calloc");
371 th->ack = seq, th->seq = ack - 1;
373 th->seq = seq, th->ack = ack - 1;
376 seq -= th->ack, ack -= th->seq;
378 seq -= th->seq, ack -= th->ack;
385 thseq = thack = threv = 0;
388 (void)printf(" [bad hdr length %u - too long, > %u]",
393 if (vflag && !Kflag && !fragmented) {
394 /* Check the checksum, if possible. */
395 u_int16_t sum, tcp_sum;
398 if (TTEST2(tp->th_sport, length)) {
399 sum = tcp_cksum(ip, tp, length);
400 tcp_sum = EXTRACT_16BITS(&tp->th_sum);
402 (void)printf(", cksum 0x%04x", tcp_sum);
404 (void)printf(" (incorrect -> 0x%04x)",
405 in_cksum_shouldbe(tcp_sum, sum));
407 (void)printf(" (correct)");
411 else if (IP_V(ip) == 6 && ip6->ip6_plen) {
412 if (TTEST2(tp->th_sport, length)) {
413 sum = nextproto6_cksum(ip6, (const u_int8_t *)tp, length, IPPROTO_TCP);
414 tcp_sum = EXTRACT_16BITS(&tp->th_sum);
416 (void)printf(", cksum 0x%04x", tcp_sum);
418 (void)printf(" (incorrect -> 0x%04x)",
419 in_cksum_shouldbe(tcp_sum, sum));
421 (void)printf(" (correct)");
429 if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) {
430 (void)printf(", seq %u", seq);
433 (void)printf(":%u", seq + length);
437 if (flags & TH_ACK) {
438 (void)printf(", ack %u", ack);
441 (void)printf(", win %d", win);
444 (void)printf(", urg %d", urp);
446 * Handle any options.
448 if (hlen > sizeof(*tp)) {
449 register const u_char *cp;
450 register u_int i, opt, datalen;
454 cp = (const u_char *)tp + sizeof(*tp);
455 printf(", options [");
465 len = *cp++; /* total including type, len */
466 if (len < 2 || len > hlen)
468 --hlen; /* account for length byte */
470 --hlen; /* account for type byte */
473 /* Bail if "l" bytes of data are not left or were not captured */
474 #define LENCHECK(l) { if ((l) > hlen) goto bad; TCHECK2(*cp, l); }
477 printf("%s", tok2str(tcp_option_values, "Unknown Option %u", opt));
484 (void)printf(" %u", EXTRACT_16BITS(cp));
490 (void)printf(" %u", *cp);
495 if (datalen % 8 != 0) {
496 (void)printf("malformed sack");
500 (void)printf(" %d ", datalen / 8);
501 for (i = 0; i < datalen; i += 8) {
503 s = EXTRACT_32BITS(cp + i);
505 e = EXTRACT_32BITS(cp + i + 4);
513 (void)printf("{%u:%u}", s, e);
522 case TCPOPT_ECHOREPLY:
525 * those options share their semantics.
530 (void)printf(" %u", EXTRACT_32BITS(cp));
533 case TCPOPT_TIMESTAMP:
536 (void)printf(" val %u ecr %u",
538 EXTRACT_32BITS(cp + 4));
541 case TCPOPT_SIGNATURE:
542 datalen = TCP_SIGLEN;
544 #ifdef HAVE_LIBCRYPTO
545 switch (tcp_verify_signature(ip, tp,
546 bp + TH_OFF(tp) * 4, length, cp)) {
548 case SIGNATURE_VALID:
549 (void)printf("valid");
552 case SIGNATURE_INVALID:
553 (void)printf("invalid");
556 case CANT_CHECK_SIGNATURE:
557 (void)printf("can't check - ");
558 for (i = 0; i < TCP_SIGLEN; ++i)
559 (void)printf("%02x", cp[i]);
563 for (i = 0; i < TCP_SIGLEN; ++i)
564 (void)printf("%02x", cp[i]);
569 (void)printf("keyid %d", *cp++);
571 for (i = 0; i < datalen; ++i) {
573 (void)printf("%02x", cp[i]);
582 * Nothing interesting.
590 utoval = EXTRACT_16BITS(cp);
591 (void)printf("0x%x", utoval);
593 utoval = (utoval >> 1) * 60;
596 (void)printf(" %u", utoval);
601 for (i = 0; i < datalen; ++i) {
603 (void)printf("%02x", cp[i]);
608 /* Account for data printed */
612 /* Check specification against observed length */
613 ++datalen; /* option octet */
614 if (!ZEROLENOPT(opt))
615 ++datalen; /* size octet */
617 (void)printf("[len %d]", len);
619 if (opt == TCPOPT_EOL)
626 * Print length field before crawling down the stack.
628 printf(", length %u", length);
634 * Decode payload if necessary.
636 bp += TH_OFF(tp) * 4;
637 if ((flags & TH_RST) && vflag) {
638 print_tcp_rst_data(bp, length);
642 if (sport == TELNET_PORT || dport == TELNET_PORT) {
644 telnet_print(bp, length);
645 } else if (sport == BGP_PORT || dport == BGP_PORT)
646 bgp_print(bp, length);
647 else if (sport == PPTP_PORT || dport == PPTP_PORT)
649 #ifdef TCPDUMP_DO_SMB
650 else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
651 nbt_tcp_print(bp, length);
652 else if (sport == SMB_PORT || dport == SMB_PORT)
653 smb_tcp_print(bp, length);
655 else if (sport == BEEP_PORT || dport == BEEP_PORT)
656 beep_print(bp, length);
657 else if (length > 2 &&
658 (sport == NAMESERVER_PORT || dport == NAMESERVER_PORT ||
659 sport == MULTICASTDNS_PORT || dport == MULTICASTDNS_PORT)) {
661 * TCP DNS query has 2byte length at the head.
662 * XXX packet could be unaligned, it can go strange
664 ns_print(bp + 2, length - 2, 0);
665 } else if (sport == MSDP_PORT || dport == MSDP_PORT) {
666 msdp_print(bp, length);
667 } else if (sport == RPKI_RTR_PORT || dport == RPKI_RTR_PORT) {
668 rpki_rtr_print(bp, length);
670 else if (length > 0 && (sport == LDP_PORT || dport == LDP_PORT)) {
671 ldp_print(bp, length);
676 fputs("[bad opt]", stdout);
681 fputs("[|tcp]", stdout);
687 * RFC1122 says the following on data in RST segments:
689 * 4.2.2.12 RST Segment: RFC-793 Section 3.4
691 * A TCP SHOULD allow a received RST segment to include data.
694 * It has been suggested that a RST segment could contain
695 * ASCII text that encoded and explained the cause of the
696 * RST. No standard has yet been established for such
702 print_tcp_rst_data(register const u_char *sp, u_int length)
706 if (TTEST2(*sp, length))
710 if (length > MAX_RST_DATA_LEN) {
711 length = MAX_RST_DATA_LEN; /* can use -X for longer */
712 putchar('+'); /* indicate we truncate */
715 while (length-- && sp <= snapend) {
722 #ifdef HAVE_LIBCRYPTO
724 tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
725 const u_char *data, int length, const u_char *rcvsig)
728 u_char sig[TCP_SIGLEN];
731 u_int16_t savecsum, tlen;
738 if (data + length > snapend) {
739 printf("snaplen too short, ");
740 return (CANT_CHECK_SIGNATURE);
745 if (sigsecret == NULL) {
746 printf("shared secret not supplied with -M, ");
747 return (CANT_CHECK_SIGNATURE);
752 * Step 1: Update MD5 hash with IP pseudo-header.
755 MD5_Update(&ctx, (char *)&ip->ip_src, sizeof(ip->ip_src));
756 MD5_Update(&ctx, (char *)&ip->ip_dst, sizeof(ip->ip_dst));
757 MD5_Update(&ctx, (char *)&zero_proto, sizeof(zero_proto));
758 MD5_Update(&ctx, (char *)&ip->ip_p, sizeof(ip->ip_p));
759 tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4;
761 MD5_Update(&ctx, (char *)&tlen, sizeof(tlen));
763 } else if (IP_V(ip) == 6) {
764 ip6 = (struct ip6_hdr *)ip;
765 MD5_Update(&ctx, (char *)&ip6->ip6_src, sizeof(ip6->ip6_src));
766 MD5_Update(&ctx, (char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));
767 len32 = htonl(EXTRACT_16BITS(&ip6->ip6_plen));
768 MD5_Update(&ctx, (char *)&len32, sizeof(len32));
770 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
771 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
772 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
774 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
778 printf("IP version not 4 or 6, ");
780 printf("IP version not 4, ");
782 return (CANT_CHECK_SIGNATURE);
786 * Step 2: Update MD5 hash with TCP header, excluding options.
787 * The TCP checksum must be set to zero.
789 savecsum = tp1.th_sum;
791 MD5_Update(&ctx, (char *)&tp1, sizeof(struct tcphdr));
792 tp1.th_sum = savecsum;
794 * Step 3: Update MD5 hash with TCP segment data, if present.
797 MD5_Update(&ctx, data, length);
799 * Step 4: Update MD5 hash with shared secret.
801 MD5_Update(&ctx, sigsecret, strlen(sigsecret));
802 MD5_Final(sig, &ctx);
804 if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0)
805 return (SIGNATURE_VALID);
807 return (SIGNATURE_INVALID);
809 #endif /* HAVE_LIBCRYPTO */
813 * c-style: whitesmith