2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
23 static const char rcsid[] _U_ =
24 "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.107.2.3 2003/11/19 00:17:02 guy Exp $ (LBL)";
31 #include <tcpdump-stdinc.h>
39 #include "interface.h"
40 #include "addrtoname.h"
53 static void print_tcp_rst_data(register const u_char *sp, u_int length);
55 #define MAX_RST_DATA_LEN 30
70 struct tcp_seq_hash *nxt;
76 #define TSEQ_HASHSIZE 919
78 /* These tcp optinos do not have the size octet */
79 #define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)
81 static struct tcp_seq_hash tcp_seq_hash[TSEQ_HASHSIZE];
85 #define TELNET_PORT 23
90 #define NETBIOS_SSN_PORT 139
92 #define PPTP_PORT 1723
94 #define BEEP_PORT 10288
101 static int tcp_cksum(register const struct ip *ip,
102 register const struct tcphdr *tp,
117 /* pseudo-header.. */
118 phu.ph.len = htons((u_int16_t)len);
120 phu.ph.proto = IPPROTO_TCP;
121 memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
123 memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
125 phu.ph.dst = ip_finddst(ip);
128 return in_cksum((u_short *)tp, len,
129 sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5]);
133 static int tcp6_cksum(const struct ip6_hdr *ip6, const struct tcphdr *tp,
137 register const u_int16_t *sp;
141 struct in6_addr ph_src;
142 struct in6_addr ph_dst;
151 memset(&phu, 0, sizeof(phu));
152 phu.ph.ph_src = ip6->ip6_src;
153 phu.ph.ph_dst = ip6->ip6_dst;
154 phu.ph.ph_len = htonl(len);
155 phu.ph.ph_nxt = IPPROTO_TCP;
158 for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++)
161 sp = (const u_int16_t *)tp;
163 for (i = 0; i < (len & ~1); i += 2)
167 sum += htons((*(const u_int8_t *)sp) << 8);
170 sum = (sum & 0xffff) + (sum >> 16);
178 tcp_print(register const u_char *bp, register u_int length,
179 register const u_char *bp2, int fragmented)
181 register const struct tcphdr *tp;
182 register const struct ip *ip;
183 register u_char flags;
186 u_int16_t sport, dport, win, urp;
187 u_int32_t seq, ack, thseq, thack;
190 register const struct ip6_hdr *ip6;
193 tp = (struct tcphdr *)bp;
194 ip = (struct ip *)bp2;
197 ip6 = (struct ip6_hdr *)bp2;
202 if (!TTEST(tp->th_dport)) {
203 (void)printf("%s > %s: [|tcp]",
204 ipaddr_string(&ip->ip_src),
205 ipaddr_string(&ip->ip_dst));
209 sport = EXTRACT_16BITS(&tp->th_sport);
210 dport = EXTRACT_16BITS(&tp->th_dport);
212 hlen = TH_OFF(tp) * 4;
215 * If data present and NFS port used, assume NFS.
216 * Pass offset of data plus 4 bytes for RPC TCP msg length
217 * to NFS print routines.
220 if ((u_char *)tp + 4 + sizeof(struct rpc_msg) <= snapend &&
222 nfsreq_print((u_char *)tp + hlen + 4, length - hlen,
225 } else if ((u_char *)tp + 4 + sizeof(struct rpc_msg)
228 nfsreply_print((u_char *)tp + hlen + 4, length - hlen,
235 if (ip6->ip6_nxt == IPPROTO_TCP) {
236 (void)printf("%s.%s > %s.%s: ",
237 ip6addr_string(&ip6->ip6_src),
238 tcpport_string(sport),
239 ip6addr_string(&ip6->ip6_dst),
240 tcpport_string(dport));
242 (void)printf("%s > %s: ",
243 tcpport_string(sport), tcpport_string(dport));
248 if (ip->ip_p == IPPROTO_TCP) {
249 (void)printf("%s.%s > %s.%s: ",
250 ipaddr_string(&ip->ip_src),
251 tcpport_string(sport),
252 ipaddr_string(&ip->ip_dst),
253 tcpport_string(dport));
255 (void)printf("%s > %s: ",
256 tcpport_string(sport), tcpport_string(dport));
262 seq = EXTRACT_32BITS(&tp->th_seq);
263 ack = EXTRACT_32BITS(&tp->th_ack);
264 win = EXTRACT_16BITS(&tp->th_win);
265 urp = EXTRACT_16BITS(&tp->th_urp);
268 (void)printf("tcp %d", length - TH_OFF(tp) * 4);
271 if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH|
272 TH_ECNECHO|TH_CWR)) {
282 putchar('W'); /* congestion _W_indow reduced (ECN) */
283 if (flags & TH_ECNECHO)
284 putchar('E'); /* ecn _E_cho sent (ECN) */
288 if (!Sflag && (flags & TH_ACK)) {
289 register struct tcp_seq_hash *th;
290 const void *src, *dst;
294 * Find (or record) the initial sequence numbers for
295 * this conversation. (we pick an arbitrary
296 * collating order so there's only one entry for
300 memset(&tha, 0, sizeof(tha));
307 else if (sport == dport) {
308 if (memcmp(src, dst, sizeof ip6->ip6_dst) > 0)
312 memcpy(&tha.src, dst, sizeof ip6->ip6_dst);
313 memcpy(&tha.dst, src, sizeof ip6->ip6_src);
314 tha.port = dport << 16 | sport;
316 memcpy(&tha.dst, dst, sizeof ip6->ip6_dst);
317 memcpy(&tha.src, src, sizeof ip6->ip6_src);
318 tha.port = sport << 16 | dport;
325 else if (sport == dport) {
326 if (memcmp(src, dst, sizeof ip->ip_dst) > 0)
330 memcpy(&tha.src, dst, sizeof ip->ip_dst);
331 memcpy(&tha.dst, src, sizeof ip->ip_src);
332 tha.port = dport << 16 | sport;
334 memcpy(&tha.dst, dst, sizeof ip->ip_dst);
335 memcpy(&tha.src, src, sizeof ip->ip_src);
336 tha.port = sport << 16 | dport;
345 else if (sport == dport) {
346 if (memcmp(src, dst, sizeof ip->ip_dst) > 0)
350 memcpy(&tha.src, dst, sizeof ip->ip_dst);
351 memcpy(&tha.dst, src, sizeof ip->ip_src);
352 tha.port = dport << 16 | sport;
354 memcpy(&tha.dst, dst, sizeof ip->ip_dst);
355 memcpy(&tha.src, src, sizeof ip->ip_src);
356 tha.port = sport << 16 | dport;
361 for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
362 th->nxt; th = th->nxt)
363 if (memcmp((char *)&tha, (char *)&th->addr,
364 sizeof(th->addr)) == 0)
367 if (!th->nxt || (flags & TH_SYN)) {
368 /* didn't find it or new conversation */
369 if (th->nxt == NULL) {
370 th->nxt = (struct tcp_seq_hash *)
371 calloc(1, sizeof(*th));
373 error("tcp_print: calloc");
377 th->ack = seq, th->seq = ack - 1;
379 th->seq = seq, th->ack = ack - 1;
382 seq -= th->ack, ack -= th->seq;
384 seq -= th->seq, ack -= th->ack;
391 thseq = thack = threv = 0;
394 (void)printf(" [bad hdr length]");
398 if (IP_V(ip) == 4 && vflag && !fragmented) {
399 u_int16_t sum, tcp_sum;
400 if (TTEST2(tp->th_sport, length)) {
401 sum = tcp_cksum(ip, tp, length);
403 tcp_sum = EXTRACT_16BITS(&tp->th_sum);
404 (void)printf(" [bad tcp cksum %x (->%x)!]",
405 tcp_sum, in_cksum_shouldbe(tcp_sum, sum));
407 (void)printf(" [tcp sum ok]");
411 if (IP_V(ip) == 6 && ip6->ip6_plen && vflag && !fragmented) {
413 if (TTEST2(tp->th_sport, length)) {
414 sum = tcp6_cksum(ip6, tp, length);
416 (void)printf(" [bad tcp cksum %x!]", sum);
418 (void)printf(" [tcp sum ok]");
424 if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST))
425 (void)printf(" %u:%u(%u)", seq, seq + length, length);
427 (void)printf(" ack %u", ack);
429 (void)printf(" win %d", win);
432 (void)printf(" urg %d", urp);
434 * Handle any options.
436 if (hlen > sizeof(*tp)) {
437 register const u_char *cp;
438 register u_int i, opt, datalen;
442 cp = (const u_char *)tp + sizeof(*tp);
453 len = *cp++; /* total including type, len */
454 if (len < 2 || len > hlen)
456 --hlen; /* account for length byte */
458 --hlen; /* account for type byte */
461 /* Bail if "l" bytes of data are not left or were not captured */
462 #define LENCHECK(l) { if ((l) > hlen) goto bad; TCHECK2(*cp, l); }
470 (void)printf(" %u", EXTRACT_16BITS(cp));
483 (void)printf("wscale");
486 (void)printf(" %u", *cp);
490 (void)printf("sackOK");
494 (void)printf("sack");
496 if (datalen % 8 != 0) {
497 (void)printf(" malformed sack ");
501 (void)printf(" sack %d ", datalen / 8);
502 for (i = 0; i < datalen; i += 8) {
504 s = EXTRACT_32BITS(cp + i);
506 e = EXTRACT_32BITS(cp + i + 4);
514 (void)printf("{%u:%u}", s, e);
521 (void)printf("echo");
524 (void)printf(" %u", EXTRACT_32BITS(cp));
527 case TCPOPT_ECHOREPLY:
528 (void)printf("echoreply");
531 (void)printf(" %u", EXTRACT_32BITS(cp));
534 case TCPOPT_TIMESTAMP:
535 (void)printf("timestamp");
538 (void)printf(" %u", EXTRACT_32BITS(cp));
540 (void)printf(" %u", EXTRACT_32BITS(cp + 4));
547 (void)printf(" %u", EXTRACT_32BITS(cp));
551 (void)printf("ccnew");
554 (void)printf(" %u", EXTRACT_32BITS(cp));
558 (void)printf("ccecho");
561 (void)printf(" %u", EXTRACT_32BITS(cp));
565 (void)printf("opt-%u:", opt);
567 for (i = 0; i < datalen; ++i) {
569 (void)printf("%02x", cp[i]);
574 /* Account for data printed */
578 /* Check specification against observed length */
579 ++datalen; /* option octet */
580 if (!ZEROLENOPT(opt))
581 ++datalen; /* size octet */
583 (void)printf("[len %d]", len);
585 if (opt == TCPOPT_EOL)
595 * Decode payload if necessary.
597 bp += TH_OFF(tp) * 4;
598 if (flags & TH_RST) {
600 print_tcp_rst_data(bp, length);
602 if (sport == TELNET_PORT || dport == TELNET_PORT) {
604 telnet_print(bp, length);
605 } else if (sport == BGP_PORT || dport == BGP_PORT)
606 bgp_print(bp, length);
607 else if (sport == PPTP_PORT || dport == PPTP_PORT)
609 #ifdef TCPDUMP_DO_SMB
610 else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
611 nbt_tcp_print(bp, length);
613 else if (sport == BEEP_PORT || dport == BEEP_PORT)
614 beep_print(bp, length);
615 else if (length > 2 &&
616 (sport == NAMESERVER_PORT || dport == NAMESERVER_PORT ||
617 sport == MULTICASTDNS_PORT || dport == MULTICASTDNS_PORT)) {
619 * TCP DNS query has 2byte length at the head.
620 * XXX packet could be unaligned, it can go strange
622 ns_print(bp + 2, length - 2, 0);
623 } else if (sport == MSDP_PORT || dport == MSDP_PORT) {
624 msdp_print(bp, length);
626 else if (sport == LDP_PORT || dport == LDP_PORT)
627 printf(": LDP, length: %u", length);
631 fputs("[bad opt]", stdout);
636 fputs("[|tcp]", stdout);
642 * RFC1122 says the following on data in RST segments:
644 * 4.2.2.12 RST Segment: RFC-793 Section 3.4
646 * A TCP SHOULD allow a received RST segment to include data.
649 * It has been suggested that a RST segment could contain
650 * ASCII text that encoded and explained the cause of the
651 * RST. No standard has yet been established for such
657 print_tcp_rst_data(register const u_char *sp, u_int length)
661 if (TTEST2(*sp, length))
665 if (length > MAX_RST_DATA_LEN) {
666 length = MAX_RST_DATA_LEN; /* can use -X for longer */
667 putchar('+'); /* indicate we truncate */
670 while (length-- && sp <= snapend) {