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.
28 __RCSID("$NetBSD: print-tcp.c,v 1.8 2007/07/24 11:53:48 drochner Exp $");
31 #define NETDISSECT_REWORKED
36 #include <tcpdump-stdinc.h>
41 #include "interface.h"
42 #include "addrtoname.h"
58 #include <openssl/md5.h>
59 #include <signature.h>
61 static int tcp_verify_signature(netdissect_options *ndo,
62 const struct ip *ip, const struct tcphdr *tp,
63 const u_char *data, int length, const u_char *rcvsig);
66 static void print_tcp_rst_data(netdissect_options *, register const u_char *sp, u_int length);
68 #define MAX_RST_DATA_LEN 30
78 struct tcp_seq_hash *nxt;
91 struct tcp_seq_hash6 {
92 struct tcp_seq_hash6 *nxt;
99 #define TSEQ_HASHSIZE 919
101 /* These tcp optinos do not have the size octet */
102 #define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)
104 static struct tcp_seq_hash tcp_seq_hash4[TSEQ_HASHSIZE];
106 static struct tcp_seq_hash6 tcp_seq_hash6[TSEQ_HASHSIZE];
109 static const struct tok tcp_flag_values[] = {
121 static const struct tok tcp_option_values[] = {
122 { TCPOPT_EOL, "eol" },
123 { TCPOPT_NOP, "nop" },
124 { TCPOPT_MAXSEG, "mss" },
125 { TCPOPT_WSCALE, "wscale" },
126 { TCPOPT_SACKOK, "sackOK" },
127 { TCPOPT_SACK, "sack" },
128 { TCPOPT_ECHO, "echo" },
129 { TCPOPT_ECHOREPLY, "echoreply" },
130 { TCPOPT_TIMESTAMP, "TS" },
132 { TCPOPT_CCNEW, "ccnew" },
133 { TCPOPT_CCECHO, "" },
134 { TCPOPT_SIGNATURE, "md5" },
135 { TCPOPT_AUTH, "enhanced auth" },
136 { TCPOPT_UTO, "uto" },
137 { TCPOPT_MPTCP, "mptcp" },
138 { TCPOPT_EXPERIMENT2, "exp" },
143 tcp_cksum(netdissect_options *ndo,
144 register const struct ip *ip,
145 register const struct tcphdr *tp,
148 return nextproto4_cksum(ndo, ip, (const uint8_t *)tp, len, len,
153 tcp_print(netdissect_options *ndo,
154 register const u_char *bp, register u_int length,
155 register const u_char *bp2, int fragmented)
157 register const struct tcphdr *tp;
158 register const struct ip *ip;
159 register u_char flags;
162 uint16_t sport, dport, win, urp;
163 uint32_t seq, ack, thseq, thack;
168 register const struct ip6_hdr *ip6;
171 tp = (struct tcphdr *)bp;
172 ip = (struct ip *)bp2;
175 ip6 = (struct ip6_hdr *)bp2;
180 if (!ND_TTEST(tp->th_dport)) {
181 ND_PRINT((ndo, "%s > %s: [|tcp]",
182 ipaddr_string(ndo, &ip->ip_src),
183 ipaddr_string(ndo, &ip->ip_dst)));
187 sport = EXTRACT_16BITS(&tp->th_sport);
188 dport = EXTRACT_16BITS(&tp->th_dport);
190 hlen = TH_OFF(tp) * 4;
194 if (ip6->ip6_nxt == IPPROTO_TCP) {
195 ND_PRINT((ndo, "%s.%s > %s.%s: ",
196 ip6addr_string(ndo, &ip6->ip6_src),
197 tcpport_string(sport),
198 ip6addr_string(ndo, &ip6->ip6_dst),
199 tcpport_string(dport)));
201 ND_PRINT((ndo, "%s > %s: ",
202 tcpport_string(sport), tcpport_string(dport)));
207 if (ip->ip_p == IPPROTO_TCP) {
208 ND_PRINT((ndo, "%s.%s > %s.%s: ",
209 ipaddr_string(ndo, &ip->ip_src),
210 tcpport_string(sport),
211 ipaddr_string(ndo, &ip->ip_dst),
212 tcpport_string(dport)));
214 ND_PRINT((ndo, "%s > %s: ",
215 tcpport_string(sport), tcpport_string(dport)));
219 if (hlen < sizeof(*tp)) {
220 ND_PRINT((ndo, " tcp %d [bad hdr length %u - too short, < %lu]",
221 length - hlen, hlen, (unsigned long)sizeof(*tp)));
227 seq = EXTRACT_32BITS(&tp->th_seq);
228 ack = EXTRACT_32BITS(&tp->th_ack);
229 win = EXTRACT_16BITS(&tp->th_win);
230 urp = EXTRACT_16BITS(&tp->th_urp);
232 if (ndo->ndo_qflag) {
233 ND_PRINT((ndo, "tcp %d", length - hlen));
235 ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]",
241 flags = tp->th_flags;
242 ND_PRINT((ndo, "Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags)));
244 if (!ndo->ndo_Sflag && (flags & TH_ACK)) {
246 * Find (or record) the initial sequence numbers for
247 * this conversation. (we pick an arbitrary
248 * collating order so there's only one entry for
254 register struct tcp_seq_hash6 *th;
255 struct tcp_seq_hash6 *tcp_seq_hash;
256 const struct in6_addr *src, *dst;
259 tcp_seq_hash = tcp_seq_hash6;
264 else if (sport == dport) {
265 if (UNALIGNED_MEMCMP(src, dst, sizeof ip6->ip6_dst) > 0)
269 UNALIGNED_MEMCPY(&tha.src, dst, sizeof ip6->ip6_dst);
270 UNALIGNED_MEMCPY(&tha.dst, src, sizeof ip6->ip6_src);
271 tha.port = dport << 16 | sport;
273 UNALIGNED_MEMCPY(&tha.dst, dst, sizeof ip6->ip6_dst);
274 UNALIGNED_MEMCPY(&tha.src, src, sizeof ip6->ip6_src);
275 tha.port = sport << 16 | dport;
278 for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
279 th->nxt; th = th->nxt)
280 if (memcmp((char *)&tha, (char *)&th->addr,
281 sizeof(th->addr)) == 0)
284 if (!th->nxt || (flags & TH_SYN)) {
285 /* didn't find it or new conversation */
286 if (th->nxt == NULL) {
287 th->nxt = (struct tcp_seq_hash6 *)
288 calloc(1, sizeof(*th));
290 error("tcp_print: calloc");
294 th->ack = seq, th->seq = ack - 1;
296 th->seq = seq, th->ack = ack - 1;
299 seq -= th->ack, ack -= th->seq;
301 seq -= th->seq, ack -= th->ack;
310 register struct tcp_seq_hash *th;
311 struct tcp_seq_hash *tcp_seq_hash;
312 const struct in_addr *src, *dst;
315 tcp_seq_hash = tcp_seq_hash4;
320 else if (sport == dport) {
321 if (UNALIGNED_MEMCMP(src, dst, sizeof ip->ip_dst) > 0)
325 UNALIGNED_MEMCPY(&tha.src, dst, sizeof ip->ip_dst);
326 UNALIGNED_MEMCPY(&tha.dst, src, sizeof ip->ip_src);
327 tha.port = dport << 16 | sport;
329 UNALIGNED_MEMCPY(&tha.dst, dst, sizeof ip->ip_dst);
330 UNALIGNED_MEMCPY(&tha.src, src, sizeof ip->ip_src);
331 tha.port = sport << 16 | dport;
334 for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
335 th->nxt; th = th->nxt)
336 if (memcmp((char *)&tha, (char *)&th->addr,
337 sizeof(th->addr)) == 0)
340 if (!th->nxt || (flags & TH_SYN)) {
341 /* didn't find it or new conversation */
342 if (th->nxt == NULL) {
343 th->nxt = (struct tcp_seq_hash *)
344 calloc(1, sizeof(*th));
346 error("tcp_print: calloc");
350 th->ack = seq, th->seq = ack - 1;
352 th->seq = seq, th->ack = ack - 1;
355 seq -= th->ack, ack -= th->seq;
357 seq -= th->seq, ack -= th->ack;
365 thseq = thack = rev = 0;
368 ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]",
373 if (ndo->ndo_vflag && !ndo->ndo_Kflag && !fragmented) {
374 /* Check the checksum, if possible. */
375 uint16_t sum, tcp_sum;
378 if (ND_TTEST2(tp->th_sport, length)) {
379 sum = tcp_cksum(ndo, ip, tp, length);
380 tcp_sum = EXTRACT_16BITS(&tp->th_sum);
382 ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum));
384 ND_PRINT((ndo, " (incorrect -> 0x%04x)",
385 in_cksum_shouldbe(tcp_sum, sum)));
387 ND_PRINT((ndo, " (correct)"));
391 else if (IP_V(ip) == 6 && ip6->ip6_plen) {
392 if (ND_TTEST2(tp->th_sport, length)) {
393 sum = nextproto6_cksum(ip6, (const uint8_t *)tp,
394 length, length, IPPROTO_TCP);
395 tcp_sum = EXTRACT_16BITS(&tp->th_sum);
397 ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum));
399 ND_PRINT((ndo, " (incorrect -> 0x%04x)",
400 in_cksum_shouldbe(tcp_sum, sum)));
402 ND_PRINT((ndo, " (correct)"));
410 if (ndo->ndo_vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) {
411 ND_PRINT((ndo, ", seq %u", seq));
414 ND_PRINT((ndo, ":%u", seq + length));
418 if (flags & TH_ACK) {
419 ND_PRINT((ndo, ", ack %u", ack));
422 ND_PRINT((ndo, ", win %d", win));
425 ND_PRINT((ndo, ", urg %d", urp));
427 * Handle any options.
429 if (hlen > sizeof(*tp)) {
430 register const u_char *cp;
431 register u_int i, opt, datalen;
435 cp = (const u_char *)tp + sizeof(*tp);
436 ND_PRINT((ndo, ", options ["));
439 ND_PRINT((ndo, "%c", ch));
446 len = *cp++; /* total including type, len */
447 if (len < 2 || len > hlen)
449 --hlen; /* account for length byte */
451 --hlen; /* account for type byte */
454 /* Bail if "l" bytes of data are not left or were not captured */
455 #define LENCHECK(l) { if ((l) > hlen) goto bad; ND_TCHECK2(*cp, l); }
458 ND_PRINT((ndo, "%s", tok2str(tcp_option_values, "unknown-%u", opt)));
465 ND_PRINT((ndo, " %u", EXTRACT_16BITS(cp)));
471 ND_PRINT((ndo, " %u", *cp));
476 if (datalen % 8 != 0) {
477 ND_PRINT((ndo, "malformed sack"));
481 ND_PRINT((ndo, " %d ", datalen / 8));
482 for (i = 0; i < datalen; i += 8) {
484 s = EXTRACT_32BITS(cp + i);
486 e = EXTRACT_32BITS(cp + i + 4);
494 ND_PRINT((ndo, "{%u:%u}", s, e));
503 case TCPOPT_ECHOREPLY:
506 * those options share their semantics.
511 ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
514 case TCPOPT_TIMESTAMP:
517 ND_PRINT((ndo, " val %u ecr %u",
519 EXTRACT_32BITS(cp + 4)));
522 case TCPOPT_SIGNATURE:
523 datalen = TCP_SIGLEN;
525 #ifdef HAVE_LIBCRYPTO
526 switch (tcp_verify_signature(ndo, ip, tp,
527 bp + TH_OFF(tp) * 4, length, cp)) {
529 case SIGNATURE_VALID:
530 ND_PRINT((ndo, "valid"));
533 case SIGNATURE_INVALID:
534 ND_PRINT((ndo, "invalid"));
537 case CANT_CHECK_SIGNATURE:
538 ND_PRINT((ndo, "can't check - "));
539 for (i = 0; i < TCP_SIGLEN; ++i)
540 ND_PRINT((ndo, "%02x", cp[i]));
544 for (i = 0; i < TCP_SIGLEN; ++i)
545 ND_PRINT((ndo, "%02x", cp[i]));
550 ND_PRINT((ndo, "keyid %d", *cp++));
552 for (i = 0; i < datalen; ++i) {
554 ND_PRINT((ndo, "%02x", cp[i]));
563 * Nothing interesting.
571 utoval = EXTRACT_16BITS(cp);
572 ND_PRINT((ndo, "0x%x", utoval));
574 utoval = (utoval >> 1) * 60;
577 ND_PRINT((ndo, " %u", utoval));
583 if (!mptcp_print(ndo, cp-2, len, flags))
587 case TCPOPT_EXPERIMENT2:
593 magic = EXTRACT_16BITS(cp);
594 ND_PRINT((ndo, "-"));
599 /* TCP Fast Open: RFC 7413 */
601 /* Fast Open Cookie Request */
602 ND_PRINT((ndo, "tfo cookiereq"));
604 /* Fast Open Cookie */
605 if (datalen % 2 != 0 || datalen < 6 || datalen > 18) {
606 ND_PRINT((ndo, "tfo malformed"));
608 ND_PRINT((ndo, "tfo cookie "));
609 for (i = 2; i < datalen; ++i)
610 ND_PRINT((ndo, "%02x", cp[i]));
616 /* Unknown magic number */
617 ND_PRINT((ndo, "%04x", magic));
625 ND_PRINT((ndo, " 0x"));
626 for (i = 0; i < datalen; ++i) {
628 ND_PRINT((ndo, "%02x", cp[i]));
633 /* Account for data printed */
637 /* Check specification against observed length */
638 ++datalen; /* option octet */
639 if (!ZEROLENOPT(opt))
640 ++datalen; /* size octet */
642 ND_PRINT((ndo, "[len %d]", len));
644 if (opt == TCPOPT_EOL)
647 ND_PRINT((ndo, "]"));
651 * Print length field before crawling down the stack.
653 ND_PRINT((ndo, ", length %u", length));
659 * Decode payload if necessary.
661 bp += TH_OFF(tp) * 4;
662 if ((flags & TH_RST) && ndo->ndo_vflag) {
663 print_tcp_rst_data(ndo, bp, length);
667 if (ndo->ndo_packettype) {
668 switch (ndo->ndo_packettype) {
670 zmtp1_print(ndo, bp, length);
676 if (sport == TELNET_PORT || dport == TELNET_PORT) {
677 telnet_print(ndo, bp, length);
678 } else if (sport == SMTP_PORT || dport == SMTP_PORT) {
679 ND_PRINT((ndo, ": "));
680 smtp_print(ndo, bp, length);
681 } else if (sport == BGP_PORT || dport == BGP_PORT)
682 bgp_print(ndo, bp, length);
683 else if (sport == PPTP_PORT || dport == PPTP_PORT)
685 #ifdef TCPDUMP_DO_SMB
686 else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
687 nbt_tcp_print(ndo, bp, length);
688 else if (sport == SMB_PORT || dport == SMB_PORT)
689 smb_tcp_print(ndo, bp, length);
691 else if (sport == BEEP_PORT || dport == BEEP_PORT)
692 beep_print(ndo, bp, length);
693 else if (sport == OPENFLOW_PORT_OLD || dport == OPENFLOW_PORT_OLD ||
694 sport == OPENFLOW_PORT_IANA || dport == OPENFLOW_PORT_IANA)
695 openflow_print(ndo, bp, length);
696 else if (sport == FTP_PORT || dport == FTP_PORT) {
697 ND_PRINT((ndo, ": "));
698 ftp_print(ndo, bp, length);
699 } else if (sport == HTTP_PORT || dport == HTTP_PORT ||
700 sport == HTTP_PORT_ALT || dport == HTTP_PORT_ALT) {
701 ND_PRINT((ndo, ": "));
702 http_print(ndo, bp, length);
703 } else if (sport == RTSP_PORT || dport == RTSP_PORT ||
704 sport == RTSP_PORT_ALT || dport == RTSP_PORT_ALT) {
705 ND_PRINT((ndo, ": "));
706 rtsp_print(ndo, bp, length);
707 } else if (length > 2 &&
708 (sport == NAMESERVER_PORT || dport == NAMESERVER_PORT ||
709 sport == MULTICASTDNS_PORT || dport == MULTICASTDNS_PORT)) {
711 * TCP DNS query has 2byte length at the head.
712 * XXX packet could be unaligned, it can go strange
714 ns_print(ndo, bp + 2, length - 2, 0);
715 } else if (sport == MSDP_PORT || dport == MSDP_PORT) {
716 msdp_print(ndo, bp, length);
717 } else if (sport == RPKI_RTR_PORT || dport == RPKI_RTR_PORT) {
718 rpki_rtr_print(ndo, bp, length);
720 else if (length > 0 && (sport == LDP_PORT || dport == LDP_PORT)) {
721 ldp_print(ndo, bp, length);
723 else if ((sport == NFS_PORT || dport == NFS_PORT) &&
724 length >= 4 && ND_TTEST2(*bp, 4)) {
726 * If data present, header length valid, and NFS port used,
728 * Pass offset of data plus 4 bytes for RPC TCP msg length
729 * to NFS print routines.
732 register struct sunrpc_msg *rp;
733 enum sunrpc_msg_type direction;
735 fraglen = EXTRACT_32BITS(bp) & 0x7FFFFFFF;
736 if (fraglen > (length) - 4)
737 fraglen = (length) - 4;
738 rp = (struct sunrpc_msg *)(bp + 4);
739 if (ND_TTEST(rp->rm_direction)) {
740 direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction);
741 if (dport == NFS_PORT && direction == SUNRPC_CALL) {
742 ND_PRINT((ndo, ": NFS request xid %u ", EXTRACT_32BITS(&rp->rm_xid)));
743 nfsreq_print_noaddr(ndo, (u_char *)rp, fraglen, (u_char *)ip);
746 if (sport == NFS_PORT && direction == SUNRPC_REPLY) {
747 ND_PRINT((ndo, ": NFS reply xid %u ", EXTRACT_32BITS(&rp->rm_xid)));
748 nfsreply_print_noaddr(ndo, (u_char *)rp, fraglen, (u_char *)ip);
756 ND_PRINT((ndo, "[bad opt]"));
758 ND_PRINT((ndo, ">"));
761 ND_PRINT((ndo, "[|tcp]"));
763 ND_PRINT((ndo, ">"));
767 * RFC1122 says the following on data in RST segments:
769 * 4.2.2.12 RST Segment: RFC-793 Section 3.4
771 * A TCP SHOULD allow a received RST segment to include data.
774 * It has been suggested that a RST segment could contain
775 * ASCII text that encoded and explained the cause of the
776 * RST. No standard has yet been established for such
782 print_tcp_rst_data(netdissect_options *ndo,
783 register const u_char *sp, u_int length)
787 ND_PRINT((ndo, ND_TTEST2(*sp, length) ? " [RST" : " [!RST"));
788 if (length > MAX_RST_DATA_LEN) {
789 length = MAX_RST_DATA_LEN; /* can use -X for longer */
790 ND_PRINT((ndo, "+")); /* indicate we truncate */
792 ND_PRINT((ndo, " "));
793 while (length-- && sp <= ndo->ndo_snapend) {
797 ND_PRINT((ndo, "]"));
800 #ifdef HAVE_LIBCRYPTO
801 USES_APPLE_DEPRECATED_API
803 tcp_verify_signature(netdissect_options *ndo,
804 const struct ip *ip, const struct tcphdr *tp,
805 const u_char *data, int length, const u_char *rcvsig)
808 u_char sig[TCP_SIGLEN];
811 uint16_t savecsum, tlen;
818 if (data + length > ndo->ndo_snapend) {
819 ND_PRINT((ndo, "snaplen too short, "));
820 return (CANT_CHECK_SIGNATURE);
825 if (ndo->ndo_sigsecret == NULL) {
826 ND_PRINT((ndo, "shared secret not supplied with -M, "));
827 return (CANT_CHECK_SIGNATURE);
832 * Step 1: Update MD5 hash with IP pseudo-header.
835 MD5_Update(&ctx, (char *)&ip->ip_src, sizeof(ip->ip_src));
836 MD5_Update(&ctx, (char *)&ip->ip_dst, sizeof(ip->ip_dst));
837 MD5_Update(&ctx, (char *)&zero_proto, sizeof(zero_proto));
838 MD5_Update(&ctx, (char *)&ip->ip_p, sizeof(ip->ip_p));
839 tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4;
841 MD5_Update(&ctx, (char *)&tlen, sizeof(tlen));
843 } else if (IP_V(ip) == 6) {
844 ip6 = (struct ip6_hdr *)ip;
845 MD5_Update(&ctx, (char *)&ip6->ip6_src, sizeof(ip6->ip6_src));
846 MD5_Update(&ctx, (char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));
847 len32 = htonl(EXTRACT_16BITS(&ip6->ip6_plen));
848 MD5_Update(&ctx, (char *)&len32, sizeof(len32));
850 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
851 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
852 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
854 MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
858 ND_PRINT((ndo, "IP version not 4 or 6, "));
860 ND_PRINT((ndo, "IP version not 4, "));
862 return (CANT_CHECK_SIGNATURE);
866 * Step 2: Update MD5 hash with TCP header, excluding options.
867 * The TCP checksum must be set to zero.
869 savecsum = tp1.th_sum;
871 MD5_Update(&ctx, (char *)&tp1, sizeof(struct tcphdr));
872 tp1.th_sum = savecsum;
874 * Step 3: Update MD5 hash with TCP segment data, if present.
877 MD5_Update(&ctx, data, length);
879 * Step 4: Update MD5 hash with shared secret.
881 MD5_Update(&ctx, ndo->ndo_sigsecret, strlen(ndo->ndo_sigsecret));
882 MD5_Final(sig, &ctx);
884 if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0)
885 return (SIGNATURE_VALID);
887 return (SIGNATURE_INVALID);
890 #endif /* HAVE_LIBCRYPTO */
894 * c-style: whitesmith