print-tcp.c revision 356341 
1/*	$NetBSD: print-tcp.c,v 1.9 2007/07/26 18:15:12 plunky Exp $	*/
2
3/*
4 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Copyright (c) 1999-2004 The tcpdump.org project
8 *
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
20 * written permission.
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.
24 */
25
26/* \summary: TCP printer */
27
28#ifndef lint
29#else
30__RCSID("$NetBSD: print-tcp.c,v 1.8 2007/07/24 11:53:48 drochner Exp $");
31#endif
32
33#ifdef HAVE_CONFIG_H
34#include "config.h"
35#endif
36
37#include <netdissect-stdinc.h>
38
39#include <stdlib.h>
40#include <string.h>
41
42#include "netdissect.h"
43#include "addrtoname.h"
44#include "extract.h"
45
46#include "tcp.h"
47
48#include "ip.h"
49#include "ip6.h"
50#include "ipproto.h"
51#include "rpc_auth.h"
52#include "rpc_msg.h"
53
54#ifdef HAVE_LIBCRYPTO
55#include <openssl/md5.h>
56#include "signature.h"
57
58static int tcp_verify_signature(netdissect_options *ndo,
59                                const struct ip *ip, const struct tcphdr *tp,
60                                const u_char *data, int length, const u_char *rcvsig);
61#endif
62
63static void print_tcp_rst_data(netdissect_options *, register const u_char *sp, u_int length);
64static void print_tcp_fastopen_option(netdissect_options *ndo, register const u_char *cp,
65                                      u_int datalen, int exp);
66
67#define MAX_RST_DATA_LEN	30
68
69
70struct tha {
71        struct in_addr src;
72        struct in_addr dst;
73        u_int port;
74};
75
76struct tcp_seq_hash {
77        struct tcp_seq_hash *nxt;
78        struct tha addr;
79        tcp_seq seq;
80        tcp_seq ack;
81};
82
83struct tha6 {
84        struct in6_addr src;
85        struct in6_addr dst;
86        u_int port;
87};
88
89struct tcp_seq_hash6 {
90        struct tcp_seq_hash6 *nxt;
91        struct tha6 addr;
92        tcp_seq seq;
93        tcp_seq ack;
94};
95
96#define TSEQ_HASHSIZE 919
97
98/* These tcp optinos do not have the size octet */
99#define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)
100
101static struct tcp_seq_hash tcp_seq_hash4[TSEQ_HASHSIZE];
102static struct tcp_seq_hash6 tcp_seq_hash6[TSEQ_HASHSIZE];
103
104static const struct tok tcp_flag_values[] = {
105        { TH_FIN, "F" },
106        { TH_SYN, "S" },
107        { TH_RST, "R" },
108        { TH_PUSH, "P" },
109        { TH_ACK, "." },
110        { TH_URG, "U" },
111        { TH_ECNECHO, "E" },
112        { TH_CWR, "W" },
113        { 0, NULL }
114};
115
116static const struct tok tcp_option_values[] = {
117        { TCPOPT_EOL, "eol" },
118        { TCPOPT_NOP, "nop" },
119        { TCPOPT_MAXSEG, "mss" },
120        { TCPOPT_WSCALE, "wscale" },
121        { TCPOPT_SACKOK, "sackOK" },
122        { TCPOPT_SACK, "sack" },
123        { TCPOPT_ECHO, "echo" },
124        { TCPOPT_ECHOREPLY, "echoreply" },
125        { TCPOPT_TIMESTAMP, "TS" },
126        { TCPOPT_CC, "cc" },
127        { TCPOPT_CCNEW, "ccnew" },
128        { TCPOPT_CCECHO, "" },
129        { TCPOPT_SIGNATURE, "md5" },
130        { TCPOPT_SCPS, "scps" },
131        { TCPOPT_UTO, "uto" },
132        { TCPOPT_TCPAO, "tcp-ao" },
133        { TCPOPT_MPTCP, "mptcp" },
134        { TCPOPT_FASTOPEN, "tfo" },
135        { TCPOPT_EXPERIMENT2, "exp" },
136        { 0, NULL }
137};
138
139static int
140tcp_cksum(netdissect_options *ndo,
141          register const struct ip *ip,
142          register const struct tcphdr *tp,
143          register u_int len)
144{
145	return nextproto4_cksum(ndo, ip, (const uint8_t *)tp, len, len,
146				IPPROTO_TCP);
147}
148
149static int
150tcp6_cksum(netdissect_options *ndo,
151           register const struct ip6_hdr *ip6,
152           register const struct tcphdr *tp,
153           register u_int len)
154{
155	return nextproto6_cksum(ndo, ip6, (const uint8_t *)tp, len, len,
156				IPPROTO_TCP);
157}
158
159void
160tcp_print(netdissect_options *ndo,
161          register const u_char *bp, register u_int length,
162          register const u_char *bp2, int fragmented)
163{
164        register const struct tcphdr *tp;
165        register const struct ip *ip;
166        register u_char flags;
167        register u_int hlen;
168        register char ch;
169        uint16_t sport, dport, win, urp;
170        uint32_t seq, ack, thseq, thack;
171        u_int utoval;
172        uint16_t magic;
173        register int rev;
174        register const struct ip6_hdr *ip6;
175
176        tp = (const struct tcphdr *)bp;
177        ip = (const struct ip *)bp2;
178        if (IP_V(ip) == 6)
179                ip6 = (const struct ip6_hdr *)bp2;
180        else
181                ip6 = NULL;
182        ch = '\0';
183        if (!ND_TTEST(tp->th_dport)) {
184                ND_PRINT((ndo, "%s > %s: [|tcp]",
185                             ipaddr_string(ndo, &ip->ip_src),
186                             ipaddr_string(ndo, &ip->ip_dst)));
187                return;
188        }
189
190        sport = EXTRACT_16BITS(&tp->th_sport);
191        dport = EXTRACT_16BITS(&tp->th_dport);
192
193        if (ip6) {
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(ndo, sport),
198                                     ip6addr_string(ndo, &ip6->ip6_dst),
199                                     tcpport_string(ndo, dport)));
200                } else {
201                        ND_PRINT((ndo, "%s > %s: ",
202                                     tcpport_string(ndo, sport), tcpport_string(ndo, dport)));
203                }
204        } else {
205                if (ip->ip_p == IPPROTO_TCP) {
206                        ND_PRINT((ndo, "%s.%s > %s.%s: ",
207                                     ipaddr_string(ndo, &ip->ip_src),
208                                     tcpport_string(ndo, sport),
209                                     ipaddr_string(ndo, &ip->ip_dst),
210                                     tcpport_string(ndo, dport)));
211                } else {
212                        ND_PRINT((ndo, "%s > %s: ",
213                                     tcpport_string(ndo, sport), tcpport_string(ndo, dport)));
214                }
215        }
216
217        ND_TCHECK(*tp);
218
219        hlen = TH_OFF(tp) * 4;
220
221        if (hlen < sizeof(*tp)) {
222                ND_PRINT((ndo, " tcp %d [bad hdr length %u - too short, < %lu]",
223                             length - hlen, hlen, (unsigned long)sizeof(*tp)));
224                return;
225        }
226
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);
231
232        if (ndo->ndo_qflag) {
233                ND_PRINT((ndo, "tcp %d", length - hlen));
234                if (hlen > length) {
235                        ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]",
236                                     hlen, length));
237                }
238                return;
239        }
240
241        flags = tp->th_flags;
242        ND_PRINT((ndo, "Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags)));
243
244        if (!ndo->ndo_Sflag && (flags & TH_ACK)) {
245                /*
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
249                 * both directions).
250                 */
251                rev = 0;
252                if (ip6) {
253                        register struct tcp_seq_hash6 *th;
254                        struct tcp_seq_hash6 *tcp_seq_hash;
255                        const struct in6_addr *src, *dst;
256                        struct tha6 tha;
257
258                        tcp_seq_hash = tcp_seq_hash6;
259                        src = &ip6->ip6_src;
260                        dst = &ip6->ip6_dst;
261                        if (sport > dport)
262                                rev = 1;
263                        else if (sport == dport) {
264                                if (UNALIGNED_MEMCMP(src, dst, sizeof ip6->ip6_dst) > 0)
265                                        rev = 1;
266                        }
267                        if (rev) {
268                                UNALIGNED_MEMCPY(&tha.src, dst, sizeof ip6->ip6_dst);
269                                UNALIGNED_MEMCPY(&tha.dst, src, sizeof ip6->ip6_src);
270                                tha.port = ((u_int)dport) << 16 | sport;
271                        } else {
272                                UNALIGNED_MEMCPY(&tha.dst, dst, sizeof ip6->ip6_dst);
273                                UNALIGNED_MEMCPY(&tha.src, src, sizeof ip6->ip6_src);
274                                tha.port = ((u_int)sport) << 16 | dport;
275                        }
276
277                        for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
278                             th->nxt; th = th->nxt)
279                                if (memcmp((char *)&tha, (char *)&th->addr,
280                                           sizeof(th->addr)) == 0)
281                                        break;
282
283                        if (!th->nxt || (flags & TH_SYN)) {
284                                /* didn't find it or new conversation */
285                                if (th->nxt == NULL) {
286                                        th->nxt = (struct tcp_seq_hash6 *)
287                                                calloc(1, sizeof(*th));
288                                        if (th->nxt == NULL)
289                                                (*ndo->ndo_error)(ndo,
290								  "tcp_print: calloc");
291                                }
292                                th->addr = tha;
293                                if (rev)
294                                        th->ack = seq, th->seq = ack - 1;
295                                else
296                                        th->seq = seq, th->ack = ack - 1;
297                        } else {
298                                if (rev)
299                                        seq -= th->ack, ack -= th->seq;
300                                else
301                                        seq -= th->seq, ack -= th->ack;
302                        }
303
304                        thseq = th->seq;
305                        thack = th->ack;
306                } else {
307                        register struct tcp_seq_hash *th;
308                        struct tcp_seq_hash *tcp_seq_hash;
309                        struct tha tha;
310
311                        tcp_seq_hash = tcp_seq_hash4;
312                        if (sport > dport)
313                                rev = 1;
314                        else if (sport == dport) {
315                                if (UNALIGNED_MEMCMP(&ip->ip_src, &ip->ip_dst, sizeof ip->ip_dst) > 0)
316                                        rev = 1;
317                        }
318                        if (rev) {
319                                UNALIGNED_MEMCPY(&tha.src, &ip->ip_dst, sizeof ip->ip_dst);
320                                UNALIGNED_MEMCPY(&tha.dst, &ip->ip_src, sizeof ip->ip_src);
321                                tha.port = ((u_int)dport) << 16 | sport;
322                        } else {
323                                UNALIGNED_MEMCPY(&tha.dst, &ip->ip_dst, sizeof ip->ip_dst);
324                                UNALIGNED_MEMCPY(&tha.src, &ip->ip_src, sizeof ip->ip_src);
325                                tha.port = ((u_int)sport) << 16 | dport;
326                        }
327
328                        for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
329                             th->nxt; th = th->nxt)
330                                if (memcmp((char *)&tha, (char *)&th->addr,
331                                           sizeof(th->addr)) == 0)
332                                        break;
333
334                        if (!th->nxt || (flags & TH_SYN)) {
335                                /* didn't find it or new conversation */
336                                if (th->nxt == NULL) {
337                                        th->nxt = (struct tcp_seq_hash *)
338                                                calloc(1, sizeof(*th));
339                                        if (th->nxt == NULL)
340                                                (*ndo->ndo_error)(ndo,
341								  "tcp_print: calloc");
342                                }
343                                th->addr = tha;
344                                if (rev)
345                                        th->ack = seq, th->seq = ack - 1;
346                                else
347                                        th->seq = seq, th->ack = ack - 1;
348                        } else {
349                                if (rev)
350                                        seq -= th->ack, ack -= th->seq;
351                                else
352                                        seq -= th->seq, ack -= th->ack;
353                        }
354
355                        thseq = th->seq;
356                        thack = th->ack;
357                }
358        } else {
359                /*fool gcc*/
360                thseq = thack = rev = 0;
361        }
362        if (hlen > length) {
363                ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]",
364                             hlen, length));
365                return;
366        }
367
368        if (ndo->ndo_vflag && !ndo->ndo_Kflag && !fragmented) {
369                /* Check the checksum, if possible. */
370                uint16_t sum, tcp_sum;
371
372                if (IP_V(ip) == 4) {
373                        if (ND_TTEST2(tp->th_sport, length)) {
374                                sum = tcp_cksum(ndo, ip, tp, length);
375                                tcp_sum = EXTRACT_16BITS(&tp->th_sum);
376
377                                ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum));
378                                if (sum != 0)
379                                        ND_PRINT((ndo, " (incorrect -> 0x%04x)",
380                                            in_cksum_shouldbe(tcp_sum, sum)));
381                                else
382                                        ND_PRINT((ndo, " (correct)"));
383                        }
384                } else if (IP_V(ip) == 6 && ip6->ip6_plen) {
385                        if (ND_TTEST2(tp->th_sport, length)) {
386                                sum = tcp6_cksum(ndo, ip6, tp, length);
387                                tcp_sum = EXTRACT_16BITS(&tp->th_sum);
388
389                                ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum));
390                                if (sum != 0)
391                                        ND_PRINT((ndo, " (incorrect -> 0x%04x)",
392                                            in_cksum_shouldbe(tcp_sum, sum)));
393                                else
394                                        ND_PRINT((ndo, " (correct)"));
395
396                        }
397                }
398        }
399
400        length -= hlen;
401        if (ndo->ndo_vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) {
402                ND_PRINT((ndo, ", seq %u", seq));
403
404                if (length > 0) {
405                        ND_PRINT((ndo, ":%u", seq + length));
406                }
407        }
408
409        if (flags & TH_ACK) {
410                ND_PRINT((ndo, ", ack %u", ack));
411        }
412
413        ND_PRINT((ndo, ", win %d", win));
414
415        if (flags & TH_URG)
416                ND_PRINT((ndo, ", urg %d", urp));
417        /*
418         * Handle any options.
419         */
420        if (hlen > sizeof(*tp)) {
421                register const u_char *cp;
422                register u_int i, opt, datalen;
423                register u_int len;
424
425                hlen -= sizeof(*tp);
426                cp = (const u_char *)tp + sizeof(*tp);
427                ND_PRINT((ndo, ", options ["));
428                while (hlen > 0) {
429                        if (ch != '\0')
430                                ND_PRINT((ndo, "%c", ch));
431                        ND_TCHECK(*cp);
432                        opt = *cp++;
433                        if (ZEROLENOPT(opt))
434                                len = 1;
435                        else {
436                                ND_TCHECK(*cp);
437                                len = *cp++;	/* total including type, len */
438                                if (len < 2 || len > hlen)
439                                        goto bad;
440                                --hlen;		/* account for length byte */
441                        }
442                        --hlen;			/* account for type byte */
443                        datalen = 0;
444
445/* Bail if "l" bytes of data are not left or were not captured  */
446#define LENCHECK(l) { if ((l) > hlen) goto bad; ND_TCHECK2(*cp, l); }
447
448
449                        ND_PRINT((ndo, "%s", tok2str(tcp_option_values, "unknown-%u", opt)));
450
451                        switch (opt) {
452
453                        case TCPOPT_MAXSEG:
454                                datalen = 2;
455                                LENCHECK(datalen);
456                                ND_PRINT((ndo, " %u", EXTRACT_16BITS(cp)));
457                                break;
458
459                        case TCPOPT_WSCALE:
460                                datalen = 1;
461                                LENCHECK(datalen);
462                                ND_PRINT((ndo, " %u", *cp));
463                                break;
464
465                        case TCPOPT_SACK:
466                                datalen = len - 2;
467                                if (datalen % 8 != 0) {
468                                        ND_PRINT((ndo, " invalid sack"));
469                                } else {
470                                        uint32_t s, e;
471
472                                        ND_PRINT((ndo, " %d ", datalen / 8));
473                                        for (i = 0; i < datalen; i += 8) {
474                                                LENCHECK(i + 4);
475                                                s = EXTRACT_32BITS(cp + i);
476                                                LENCHECK(i + 8);
477                                                e = EXTRACT_32BITS(cp + i + 4);
478                                                if (rev) {
479                                                        s -= thseq;
480                                                        e -= thseq;
481                                                } else {
482                                                        s -= thack;
483                                                        e -= thack;
484                                                }
485                                                ND_PRINT((ndo, "{%u:%u}", s, e));
486                                        }
487                                }
488                                break;
489
490                        case TCPOPT_CC:
491                        case TCPOPT_CCNEW:
492                        case TCPOPT_CCECHO:
493                        case TCPOPT_ECHO:
494                        case TCPOPT_ECHOREPLY:
495
496                                /*
497                                 * those options share their semantics.
498                                 * fall through
499                                 */
500                                datalen = 4;
501                                LENCHECK(datalen);
502                                ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
503                                break;
504
505                        case TCPOPT_TIMESTAMP:
506                                datalen = 8;
507                                LENCHECK(datalen);
508                                ND_PRINT((ndo, " val %u ecr %u",
509                                             EXTRACT_32BITS(cp),
510                                             EXTRACT_32BITS(cp + 4)));
511                                break;
512
513                        case TCPOPT_SIGNATURE:
514                                datalen = TCP_SIGLEN;
515                                LENCHECK(datalen);
516                                ND_PRINT((ndo, " "));
517#ifdef HAVE_LIBCRYPTO
518                                switch (tcp_verify_signature(ndo, ip, tp,
519                                                             bp + TH_OFF(tp) * 4, length, cp)) {
520
521                                case SIGNATURE_VALID:
522                                        ND_PRINT((ndo, "valid"));
523                                        break;
524
525                                case SIGNATURE_INVALID:
526                                        ND_PRINT((ndo, "invalid"));
527                                        break;
528
529                                case CANT_CHECK_SIGNATURE:
530                                        ND_PRINT((ndo, "can't check - "));
531                                        for (i = 0; i < TCP_SIGLEN; ++i)
532                                                ND_PRINT((ndo, "%02x", cp[i]));
533                                        break;
534                                }
535#else
536                                for (i = 0; i < TCP_SIGLEN; ++i)
537                                        ND_PRINT((ndo, "%02x", cp[i]));
538#endif
539                                break;
540
541                        case TCPOPT_SCPS:
542                                datalen = 2;
543                                LENCHECK(datalen);
544                                ND_PRINT((ndo, " cap %02x id %u", cp[0], cp[1]));
545                                break;
546
547                        case TCPOPT_TCPAO:
548                                datalen = len - 2;
549                                /* RFC 5925 Section 2.2:
550                                 * "The Length value MUST be greater than or equal to 4."
551                                 * (This includes the Kind and Length fields already processed
552                                 * at this point.)
553                                 */
554                                if (datalen < 2) {
555                                        ND_PRINT((ndo, " invalid"));
556                                } else {
557                                        LENCHECK(1);
558                                        ND_PRINT((ndo, " keyid %u", cp[0]));
559                                        LENCHECK(2);
560                                        ND_PRINT((ndo, " rnextkeyid %u", cp[1]));
561                                        if (datalen > 2) {
562                                                ND_PRINT((ndo, " mac 0x"));
563                                                for (i = 2; i < datalen; i++) {
564                                                        LENCHECK(i + 1);
565                                                        ND_PRINT((ndo, "%02x", cp[i]));
566                                                }
567                                        }
568                                }
569                                break;
570
571                        case TCPOPT_EOL:
572                        case TCPOPT_NOP:
573                        case TCPOPT_SACKOK:
574                                /*
575                                 * Nothing interesting.
576                                 * fall through
577                                 */
578                                break;
579
580                        case TCPOPT_UTO:
581                                datalen = 2;
582                                LENCHECK(datalen);
583                                utoval = EXTRACT_16BITS(cp);
584                                ND_PRINT((ndo, " 0x%x", utoval));
585                                if (utoval & 0x0001)
586                                        utoval = (utoval >> 1) * 60;
587                                else
588                                        utoval >>= 1;
589                                ND_PRINT((ndo, " %u", utoval));
590                                break;
591
592                        case TCPOPT_MPTCP:
593                                datalen = len - 2;
594                                LENCHECK(datalen);
595                                if (!mptcp_print(ndo, cp-2, len, flags))
596                                        goto bad;
597                                break;
598
599                        case TCPOPT_FASTOPEN:
600                                datalen = len - 2;
601                                LENCHECK(datalen);
602                                ND_PRINT((ndo, " "));
603                                print_tcp_fastopen_option(ndo, cp, datalen, FALSE);
604                                break;
605
606                        case TCPOPT_EXPERIMENT2:
607                                datalen = len - 2;
608                                LENCHECK(datalen);
609                                if (datalen < 2)
610                                        goto bad;
611                                /* RFC6994 */
612                                magic = EXTRACT_16BITS(cp);
613                                ND_PRINT((ndo, "-"));
614
615                                switch(magic) {
616
617                                case 0xf989: /* TCP Fast Open RFC 7413 */
618                                        print_tcp_fastopen_option(ndo, cp + 2, datalen - 2, TRUE);
619                                        break;
620
621                                default:
622                                        /* Unknown magic number */
623                                        ND_PRINT((ndo, "%04x", magic));
624                                        break;
625                                }
626                                break;
627
628                        default:
629                                datalen = len - 2;
630                                if (datalen)
631                                        ND_PRINT((ndo, " 0x"));
632                                for (i = 0; i < datalen; ++i) {
633                                        LENCHECK(i + 1);
634                                        ND_PRINT((ndo, "%02x", cp[i]));
635                                }
636                                break;
637                        }
638
639                        /* Account for data printed */
640                        cp += datalen;
641                        hlen -= datalen;
642
643                        /* Check specification against observed length */
644                        ++datalen;			/* option octet */
645                        if (!ZEROLENOPT(opt))
646                                ++datalen;		/* size octet */
647                        if (datalen != len)
648                                ND_PRINT((ndo, "[len %d]", len));
649                        ch = ',';
650                        if (opt == TCPOPT_EOL)
651                                break;
652                }
653                ND_PRINT((ndo, "]"));
654        }
655
656        /*
657         * Print length field before crawling down the stack.
658         */
659        ND_PRINT((ndo, ", length %u", length));
660
661        if (length <= 0)
662                return;
663
664        /*
665         * Decode payload if necessary.
666         */
667        bp += TH_OFF(tp) * 4;
668        if ((flags & TH_RST) && ndo->ndo_vflag) {
669                print_tcp_rst_data(ndo, bp, length);
670                return;
671        }
672
673        if (ndo->ndo_packettype) {
674                switch (ndo->ndo_packettype) {
675                case PT_ZMTP1:
676                        zmtp1_print(ndo, bp, length);
677                        break;
678                case PT_RESP:
679                        resp_print(ndo, bp, length);
680                        break;
681                }
682                return;
683        }
684
685        if (IS_SRC_OR_DST_PORT(TELNET_PORT)) {
686                telnet_print(ndo, bp, length);
687        } else if (IS_SRC_OR_DST_PORT(SMTP_PORT)) {
688                ND_PRINT((ndo, ": "));
689                smtp_print(ndo, bp, length);
690        } else if (IS_SRC_OR_DST_PORT(BGP_PORT))
691                bgp_print(ndo, bp, length);
692        else if (IS_SRC_OR_DST_PORT(PPTP_PORT))
693                pptp_print(ndo, bp);
694        else if (IS_SRC_OR_DST_PORT(REDIS_PORT))
695                resp_print(ndo, bp, length);
696#ifdef ENABLE_SMB
697        else if (IS_SRC_OR_DST_PORT(NETBIOS_SSN_PORT))
698                nbt_tcp_print(ndo, bp, length);
699	else if (IS_SRC_OR_DST_PORT(SMB_PORT))
700		smb_tcp_print(ndo, bp, length);
701#endif
702        else if (IS_SRC_OR_DST_PORT(BEEP_PORT))
703                beep_print(ndo, bp, length);
704        else if (IS_SRC_OR_DST_PORT(OPENFLOW_PORT_OLD) || IS_SRC_OR_DST_PORT(OPENFLOW_PORT_IANA))
705                openflow_print(ndo, bp, length);
706        else if (IS_SRC_OR_DST_PORT(FTP_PORT)) {
707                ND_PRINT((ndo, ": "));
708                ftp_print(ndo, bp, length);
709        } else if (IS_SRC_OR_DST_PORT(HTTP_PORT) || IS_SRC_OR_DST_PORT(HTTP_PORT_ALT)) {
710                ND_PRINT((ndo, ": "));
711                http_print(ndo, bp, length);
712        } else if (IS_SRC_OR_DST_PORT(RTSP_PORT) || IS_SRC_OR_DST_PORT(RTSP_PORT_ALT)) {
713                ND_PRINT((ndo, ": "));
714                rtsp_print(ndo, bp, length);
715        } else if (length > 2 &&
716                 (IS_SRC_OR_DST_PORT(NAMESERVER_PORT))) {
717                /* domain_print() assumes it does not have to prepend a space before its
718                 * own output to separate it from the output of the calling function. This
719                 * works well with udp_print(), but requires a small prop here.
720                 */
721                ND_PRINT((ndo, " "));
722
723                /*
724                 * TCP DNS query has 2byte length at the head.
725                 * XXX packet could be unaligned, it can go strange
726                 */
727                ns_print(ndo, bp + 2, length - 2, 0);
728        } else if (IS_SRC_OR_DST_PORT(MSDP_PORT)) {
729                msdp_print(ndo, bp, length);
730        } else if (IS_SRC_OR_DST_PORT(RPKI_RTR_PORT)) {
731                rpki_rtr_print(ndo, bp, length);
732        }
733        else if (length > 0 && (IS_SRC_OR_DST_PORT(LDP_PORT))) {
734                ldp_print(ndo, bp, length);
735        }
736        else if ((IS_SRC_OR_DST_PORT(NFS_PORT)) &&
737                 length >= 4 && ND_TTEST2(*bp, 4)) {
738                /*
739                 * If data present, header length valid, and NFS port used,
740                 * assume NFS.
741                 * Pass offset of data plus 4 bytes for RPC TCP msg length
742                 * to NFS print routines.
743                 */
744                uint32_t fraglen;
745                register const struct sunrpc_msg *rp;
746                enum sunrpc_msg_type direction;
747
748                fraglen = EXTRACT_32BITS(bp) & 0x7FFFFFFF;
749                if (fraglen > (length) - 4)
750                        fraglen = (length) - 4;
751                rp = (const struct sunrpc_msg *)(bp + 4);
752                if (ND_TTEST(rp->rm_direction)) {
753                        direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction);
754                        if (dport == NFS_PORT && direction == SUNRPC_CALL) {
755                                ND_PRINT((ndo, ": NFS request xid %u ", EXTRACT_32BITS(&rp->rm_xid)));
756                                nfsreq_print_noaddr(ndo, (const u_char *)rp, fraglen, (const u_char *)ip);
757                                return;
758                        }
759                        if (sport == NFS_PORT && direction == SUNRPC_REPLY) {
760                                ND_PRINT((ndo, ": NFS reply xid %u ", EXTRACT_32BITS(&rp->rm_xid)));
761                                nfsreply_print_noaddr(ndo, (const u_char *)rp, fraglen, (const u_char *)ip);
762                                return;
763                        }
764                }
765        }
766
767        return;
768 bad:
769        ND_PRINT((ndo, "[bad opt]"));
770        if (ch != '\0')
771                ND_PRINT((ndo, ">"));
772        return;
773 trunc:
774        ND_PRINT((ndo, "[|tcp]"));
775        if (ch != '\0')
776                ND_PRINT((ndo, ">"));
777}
778
779/*
780 * RFC1122 says the following on data in RST segments:
781 *
782 *         4.2.2.12  RST Segment: RFC-793 Section 3.4
783 *
784 *            A TCP SHOULD allow a received RST segment to include data.
785 *
786 *            DISCUSSION
787 *                 It has been suggested that a RST segment could contain
788 *                 ASCII text that encoded and explained the cause of the
789 *                 RST.  No standard has yet been established for such
790 *                 data.
791 *
792 */
793
794static void
795print_tcp_rst_data(netdissect_options *ndo,
796                   register const u_char *sp, u_int length)
797{
798        int c;
799
800        ND_PRINT((ndo, ND_TTEST2(*sp, length) ? " [RST" : " [!RST"));
801        if (length > MAX_RST_DATA_LEN) {
802                length = MAX_RST_DATA_LEN;	/* can use -X for longer */
803                ND_PRINT((ndo, "+"));			/* indicate we truncate */
804        }
805        ND_PRINT((ndo, " "));
806        while (length-- && sp < ndo->ndo_snapend) {
807                c = *sp++;
808                safeputchar(ndo, c);
809        }
810        ND_PRINT((ndo, "]"));
811}
812
813static void
814print_tcp_fastopen_option(netdissect_options *ndo, register const u_char *cp,
815                          u_int datalen, int exp)
816{
817        u_int i;
818
819        if (exp)
820                ND_PRINT((ndo, "tfo"));
821
822        if (datalen == 0) {
823                /* Fast Open Cookie Request */
824                ND_PRINT((ndo, " cookiereq"));
825        } else {
826                /* Fast Open Cookie */
827                if (datalen % 2 != 0 || datalen < 4 || datalen > 16) {
828                        ND_PRINT((ndo, " invalid"));
829                } else {
830                        ND_PRINT((ndo, " cookie "));
831                        for (i = 0; i < datalen; ++i)
832                                ND_PRINT((ndo, "%02x", cp[i]));
833                }
834        }
835}
836
837#ifdef HAVE_LIBCRYPTO
838USES_APPLE_DEPRECATED_API
839static int
840tcp_verify_signature(netdissect_options *ndo,
841                     const struct ip *ip, const struct tcphdr *tp,
842                     const u_char *data, int length, const u_char *rcvsig)
843{
844        struct tcphdr tp1;
845        u_char sig[TCP_SIGLEN];
846        char zero_proto = 0;
847        MD5_CTX ctx;
848        uint16_t savecsum, tlen;
849        const struct ip6_hdr *ip6;
850        uint32_t len32;
851        uint8_t nxt;
852
853	if (data + length > ndo->ndo_snapend) {
854		ND_PRINT((ndo, "snaplen too short, "));
855		return (CANT_CHECK_SIGNATURE);
856	}
857
858        tp1 = *tp;
859
860        if (ndo->ndo_sigsecret == NULL) {
861		ND_PRINT((ndo, "shared secret not supplied with -M, "));
862                return (CANT_CHECK_SIGNATURE);
863        }
864
865        MD5_Init(&ctx);
866        /*
867         * Step 1: Update MD5 hash with IP pseudo-header.
868         */
869        if (IP_V(ip) == 4) {
870                MD5_Update(&ctx, (const char *)&ip->ip_src, sizeof(ip->ip_src));
871                MD5_Update(&ctx, (const char *)&ip->ip_dst, sizeof(ip->ip_dst));
872                MD5_Update(&ctx, (const char *)&zero_proto, sizeof(zero_proto));
873                MD5_Update(&ctx, (const char *)&ip->ip_p, sizeof(ip->ip_p));
874                tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4;
875                tlen = htons(tlen);
876                MD5_Update(&ctx, (const char *)&tlen, sizeof(tlen));
877        } else if (IP_V(ip) == 6) {
878                ip6 = (const struct ip6_hdr *)ip;
879                MD5_Update(&ctx, (const char *)&ip6->ip6_src, sizeof(ip6->ip6_src));
880                MD5_Update(&ctx, (const char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));
881                len32 = htonl(EXTRACT_16BITS(&ip6->ip6_plen));
882                MD5_Update(&ctx, (const char *)&len32, sizeof(len32));
883                nxt = 0;
884                MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
885                MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
886                MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
887                nxt = IPPROTO_TCP;
888                MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
889        } else {
890		ND_PRINT((ndo, "IP version not 4 or 6, "));
891                return (CANT_CHECK_SIGNATURE);
892        }
893
894        /*
895         * Step 2: Update MD5 hash with TCP header, excluding options.
896         * The TCP checksum must be set to zero.
897         */
898        savecsum = tp1.th_sum;
899        tp1.th_sum = 0;
900        MD5_Update(&ctx, (const char *)&tp1, sizeof(struct tcphdr));
901        tp1.th_sum = savecsum;
902        /*
903         * Step 3: Update MD5 hash with TCP segment data, if present.
904         */
905        if (length > 0)
906                MD5_Update(&ctx, data, length);
907        /*
908         * Step 4: Update MD5 hash with shared secret.
909         */
910        MD5_Update(&ctx, ndo->ndo_sigsecret, strlen(ndo->ndo_sigsecret));
911        MD5_Final(sig, &ctx);
912
913        if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0)
914                return (SIGNATURE_VALID);
915        else
916                return (SIGNATURE_INVALID);
917}
918USES_APPLE_RST
919#endif /* HAVE_LIBCRYPTO */
920
921/*
922 * Local Variables:
923 * c-style: whitesmith
924 * c-basic-offset: 8
925 * End:
926 */
927