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#ifndef lint
27static const char rcsid[] _U_ =
28"@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.135 2008-11-09 23:35:03 mcr Exp $ (LBL)";
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 <tcpdump-stdinc.h>
38
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42
43#include "interface.h"
44#include "addrtoname.h"
45#include "extract.h"
46
47#include "tcp.h"
48
49#include "ip.h"
50#ifdef INET6
51#include "ip6.h"
52#endif
53#include "ipproto.h"
54#include "rpc_auth.h"
55#include "rpc_msg.h"
56
57#include "nameser.h"
58
59#ifdef HAVE_LIBCRYPTO
60#include <openssl/md5.h>
61#include <signature.h>
62
63static int tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
64                                const u_char *data, int length, const u_char *rcvsig);
65#endif
66
67static void print_tcp_rst_data(register const u_char *sp, u_int length);
68
69#define MAX_RST_DATA_LEN	30
70
71
72struct tha {
73        struct in_addr src;
74        struct in_addr dst;
75        u_int port;
76};
77
78struct tcp_seq_hash {
79        struct tcp_seq_hash *nxt;
80        struct tha addr;
81        tcp_seq seq;
82        tcp_seq ack;
83};
84
85#ifdef INET6
86struct tha6 {
87        struct in6_addr src;
88        struct in6_addr dst;
89        u_int port;
90};
91
92struct tcp_seq_hash6 {
93        struct tcp_seq_hash6 *nxt;
94        struct tha6 addr;
95        tcp_seq seq;
96        tcp_seq ack;
97};
98#endif
99
100#define TSEQ_HASHSIZE 919
101
102/* These tcp optinos do not have the size octet */
103#define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)
104
105static struct tcp_seq_hash tcp_seq_hash4[TSEQ_HASHSIZE];
106#ifdef INET6
107static struct tcp_seq_hash6 tcp_seq_hash6[TSEQ_HASHSIZE];
108#endif
109
110static const struct tok tcp_flag_values[] = {
111        { TH_FIN, "F" },
112        { TH_SYN, "S" },
113        { TH_RST, "R" },
114        { TH_PUSH, "P" },
115        { TH_ACK, "." },
116        { TH_URG, "U" },
117        { TH_ECNECHO, "E" },
118        { TH_CWR, "W" },
119        { 0, NULL }
120};
121
122static const struct tok tcp_option_values[] = {
123        { TCPOPT_EOL, "eol" },
124        { TCPOPT_NOP, "nop" },
125        { TCPOPT_MAXSEG, "mss" },
126        { TCPOPT_WSCALE, "wscale" },
127        { TCPOPT_SACKOK, "sackOK" },
128        { TCPOPT_SACK, "sack" },
129        { TCPOPT_ECHO, "echo" },
130        { TCPOPT_ECHOREPLY, "echoreply" },
131        { TCPOPT_TIMESTAMP, "TS" },
132        { TCPOPT_CC, "cc" },
133        { TCPOPT_CCNEW, "ccnew" },
134        { TCPOPT_CCECHO, "" },
135        { TCPOPT_SIGNATURE, "md5" },
136        { TCPOPT_AUTH, "enhanced auth" },
137        { TCPOPT_UTO, "uto" },
138        { TCPOPT_MPTCP, "mptcp" },
139        { TCPOPT_EXPERIMENT2, "exp" },
140        { 0, NULL }
141};
142
143static int tcp_cksum(register const struct ip *ip,
144		     register const struct tcphdr *tp,
145		     register u_int len)
146{
147	return (nextproto4_cksum(ip, (const u_int8_t *)tp, len,
148	    IPPROTO_TCP));
149}
150
151void
152tcp_print(register const u_char *bp, register u_int length,
153	  register const u_char *bp2, int fragmented)
154{
155        register const struct tcphdr *tp;
156        register const struct ip *ip;
157        register u_char flags;
158        register u_int hlen;
159        register char ch;
160        u_int16_t sport, dport, win, urp;
161        u_int32_t seq, ack, thseq, thack;
162        u_int utoval;
163        u_int16_t magic;
164        register int rev;
165#ifdef INET6
166        register const struct ip6_hdr *ip6;
167#endif
168
169        tp = (struct tcphdr *)bp;
170        ip = (struct ip *)bp2;
171#ifdef INET6
172        if (IP_V(ip) == 6)
173                ip6 = (struct ip6_hdr *)bp2;
174        else
175                ip6 = NULL;
176#endif /*INET6*/
177        ch = '\0';
178        if (!TTEST(tp->th_dport)) {
179                (void)printf("%s > %s: [|tcp]",
180                             ipaddr_string(&ip->ip_src),
181                             ipaddr_string(&ip->ip_dst));
182                return;
183        }
184
185        sport = EXTRACT_16BITS(&tp->th_sport);
186        dport = EXTRACT_16BITS(&tp->th_dport);
187
188        hlen = TH_OFF(tp) * 4;
189
190#ifdef INET6
191        if (ip6) {
192                if (ip6->ip6_nxt == IPPROTO_TCP) {
193                        (void)printf("%s.%s > %s.%s: ",
194                                     ip6addr_string(&ip6->ip6_src),
195                                     tcpport_string(sport),
196                                     ip6addr_string(&ip6->ip6_dst),
197                                     tcpport_string(dport));
198                } else {
199                        (void)printf("%s > %s: ",
200                                     tcpport_string(sport), tcpport_string(dport));
201                }
202        } else
203#endif /*INET6*/
204        {
205                if (ip->ip_p == IPPROTO_TCP) {
206                        (void)printf("%s.%s > %s.%s: ",
207                                     ipaddr_string(&ip->ip_src),
208                                     tcpport_string(sport),
209                                     ipaddr_string(&ip->ip_dst),
210                                     tcpport_string(dport));
211                } else {
212                        (void)printf("%s > %s: ",
213                                     tcpport_string(sport), tcpport_string(dport));
214                }
215        }
216
217        if (hlen < sizeof(*tp)) {
218                (void)printf(" tcp %d [bad hdr length %u - too short, < %lu]",
219                             length - hlen, hlen, (unsigned long)sizeof(*tp));
220                return;
221        }
222
223        TCHECK(*tp);
224
225        seq = EXTRACT_32BITS(&tp->th_seq);
226        ack = EXTRACT_32BITS(&tp->th_ack);
227        win = EXTRACT_16BITS(&tp->th_win);
228        urp = EXTRACT_16BITS(&tp->th_urp);
229
230        if (qflag) {
231                (void)printf("tcp %d", length - hlen);
232                if (hlen > length) {
233                        (void)printf(" [bad hdr length %u - too long, > %u]",
234                                     hlen, length);
235                }
236                return;
237        }
238
239        flags = tp->th_flags;
240        printf("Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags));
241
242        if (!Sflag && (flags & TH_ACK)) {
243                /*
244                 * Find (or record) the initial sequence numbers for
245                 * this conversation.  (we pick an arbitrary
246                 * collating order so there's only one entry for
247                 * both directions).
248                 */
249                rev = 0;
250#ifdef INET6
251                if (ip6) {
252                        register struct tcp_seq_hash6 *th;
253                        struct tcp_seq_hash6 *tcp_seq_hash;
254                        const struct in6_addr *src, *dst;
255                        struct tha6 tha;
256
257                        tcp_seq_hash = tcp_seq_hash6;
258                        src = &ip6->ip6_src;
259                        dst = &ip6->ip6_dst;
260                        if (sport > dport)
261                                rev = 1;
262                        else if (sport == dport) {
263                                if (UNALIGNED_MEMCMP(src, dst, sizeof ip6->ip6_dst) > 0)
264                                        rev = 1;
265                        }
266                        if (rev) {
267                                UNALIGNED_MEMCPY(&tha.src, dst, sizeof ip6->ip6_dst);
268                                UNALIGNED_MEMCPY(&tha.dst, src, sizeof ip6->ip6_src);
269                                tha.port = dport << 16 | sport;
270                        } else {
271                                UNALIGNED_MEMCPY(&tha.dst, dst, sizeof ip6->ip6_dst);
272                                UNALIGNED_MEMCPY(&tha.src, src, sizeof ip6->ip6_src);
273                                tha.port = sport << 16 | dport;
274                        }
275
276                        for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
277                             th->nxt; th = th->nxt)
278                                if (memcmp((char *)&tha, (char *)&th->addr,
279                                           sizeof(th->addr)) == 0)
280                                        break;
281
282                        if (!th->nxt || (flags & TH_SYN)) {
283                                /* didn't find it or new conversation */
284                                if (th->nxt == NULL) {
285                                        th->nxt = (struct tcp_seq_hash6 *)
286                                                calloc(1, sizeof(*th));
287                                        if (th->nxt == NULL)
288                                                error("tcp_print: calloc");
289                                }
290                                th->addr = tha;
291                                if (rev)
292                                        th->ack = seq, th->seq = ack - 1;
293                                else
294                                        th->seq = seq, th->ack = ack - 1;
295                        } else {
296                                if (rev)
297                                        seq -= th->ack, ack -= th->seq;
298                                else
299                                        seq -= th->seq, ack -= th->ack;
300                        }
301
302                        thseq = th->seq;
303                        thack = th->ack;
304                } else {
305#else  /*INET6*/
306                {
307#endif /*INET6*/
308                        register struct tcp_seq_hash *th;
309                        struct tcp_seq_hash *tcp_seq_hash;
310                        const struct in_addr *src, *dst;
311                        struct tha tha;
312
313                        tcp_seq_hash = tcp_seq_hash4;
314                        src = &ip->ip_src;
315                        dst = &ip->ip_dst;
316                        if (sport > dport)
317                                rev = 1;
318                        else if (sport == dport) {
319                                if (UNALIGNED_MEMCMP(src, dst, sizeof ip->ip_dst) > 0)
320                                        rev = 1;
321                        }
322                        if (rev) {
323                                UNALIGNED_MEMCPY(&tha.src, dst, sizeof ip->ip_dst);
324                                UNALIGNED_MEMCPY(&tha.dst, src, sizeof ip->ip_src);
325                                tha.port = dport << 16 | sport;
326                        } else {
327                                UNALIGNED_MEMCPY(&tha.dst, dst, sizeof ip->ip_dst);
328                                UNALIGNED_MEMCPY(&tha.src, src, sizeof ip->ip_src);
329                                tha.port = sport << 16 | dport;
330                        }
331
332                        for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
333                             th->nxt; th = th->nxt)
334                                if (memcmp((char *)&tha, (char *)&th->addr,
335                                           sizeof(th->addr)) == 0)
336                                        break;
337
338                        if (!th->nxt || (flags & TH_SYN)) {
339                                /* didn't find it or new conversation */
340                                if (th->nxt == NULL) {
341                                        th->nxt = (struct tcp_seq_hash *)
342                                                calloc(1, sizeof(*th));
343                                        if (th->nxt == NULL)
344                                                error("tcp_print: calloc");
345                                }
346                                th->addr = tha;
347                                if (rev)
348                                        th->ack = seq, th->seq = ack - 1;
349                                else
350                                        th->seq = seq, th->ack = ack - 1;
351                        } else {
352                                if (rev)
353                                        seq -= th->ack, ack -= th->seq;
354                                else
355                                        seq -= th->seq, ack -= th->ack;
356                        }
357
358                        thseq = th->seq;
359                        thack = th->ack;
360                }
361        } else {
362                /*fool gcc*/
363                thseq = thack = rev = 0;
364        }
365        if (hlen > length) {
366                (void)printf(" [bad hdr length %u - too long, > %u]",
367                             hlen, length);
368                return;
369        }
370
371        if (vflag && !Kflag && !fragmented) {
372                /* Check the checksum, if possible. */
373                u_int16_t sum, tcp_sum;
374
375                if (IP_V(ip) == 4) {
376                        if (TTEST2(tp->th_sport, length)) {
377                                sum = tcp_cksum(ip, tp, length);
378                                tcp_sum = EXTRACT_16BITS(&tp->th_sum);
379
380                                (void)printf(", cksum 0x%04x", tcp_sum);
381                                if (sum != 0)
382                                        (void)printf(" (incorrect -> 0x%04x)",
383                                            in_cksum_shouldbe(tcp_sum, sum));
384                                else
385                                        (void)printf(" (correct)");
386                        }
387                }
388#ifdef INET6
389                else if (IP_V(ip) == 6 && ip6->ip6_plen) {
390                        if (TTEST2(tp->th_sport, length)) {
391                                sum = nextproto6_cksum(ip6, (const u_int8_t *)tp, length, IPPROTO_TCP);
392                                tcp_sum = EXTRACT_16BITS(&tp->th_sum);
393
394                                (void)printf(", cksum 0x%04x", tcp_sum);
395                                if (sum != 0)
396                                        (void)printf(" (incorrect -> 0x%04x)",
397                                            in_cksum_shouldbe(tcp_sum, sum));
398                                else
399                                        (void)printf(" (correct)");
400
401                        }
402                }
403#endif
404        }
405
406        length -= hlen;
407        if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) {
408                (void)printf(", seq %u", seq);
409
410                if (length > 0) {
411                        (void)printf(":%u", seq + length);
412                }
413        }
414
415        if (flags & TH_ACK) {
416                (void)printf(", ack %u", ack);
417        }
418
419        (void)printf(", win %d", win);
420
421        if (flags & TH_URG)
422                (void)printf(", urg %d", urp);
423        /*
424         * Handle any options.
425         */
426        if (hlen > sizeof(*tp)) {
427                register const u_char *cp;
428                register u_int i, opt, datalen;
429                register u_int len;
430
431                hlen -= sizeof(*tp);
432                cp = (const u_char *)tp + sizeof(*tp);
433                printf(", options [");
434                while (hlen > 0) {
435                        if (ch != '\0')
436                                putchar(ch);
437                        TCHECK(*cp);
438                        opt = *cp++;
439                        if (ZEROLENOPT(opt))
440                                len = 1;
441                        else {
442                                TCHECK(*cp);
443                                len = *cp++;	/* total including type, len */
444                                if (len < 2 || len > hlen)
445                                        goto bad;
446                                --hlen;		/* account for length byte */
447                        }
448                        --hlen;			/* account for type byte */
449                        datalen = 0;
450
451/* Bail if "l" bytes of data are not left or were not captured  */
452#define LENCHECK(l) { if ((l) > hlen) goto bad; TCHECK2(*cp, l); }
453
454
455                        printf("%s", tok2str(tcp_option_values, "unknown-%u", opt));
456
457                        switch (opt) {
458
459                        case TCPOPT_MAXSEG:
460                                datalen = 2;
461                                LENCHECK(datalen);
462                                (void)printf(" %u", EXTRACT_16BITS(cp));
463                                break;
464
465                        case TCPOPT_WSCALE:
466                                datalen = 1;
467                                LENCHECK(datalen);
468                                (void)printf(" %u", *cp);
469                                break;
470
471                        case TCPOPT_SACK:
472                                datalen = len - 2;
473                                if (datalen % 8 != 0) {
474                                        (void)printf("malformed sack");
475                                } else {
476                                        u_int32_t s, e;
477
478                                        (void)printf(" %d ", datalen / 8);
479                                        for (i = 0; i < datalen; i += 8) {
480                                                LENCHECK(i + 4);
481                                                s = EXTRACT_32BITS(cp + i);
482                                                LENCHECK(i + 8);
483                                                e = EXTRACT_32BITS(cp + i + 4);
484                                                if (rev) {
485                                                        s -= thseq;
486                                                        e -= thseq;
487                                                } else {
488                                                        s -= thack;
489                                                        e -= thack;
490                                                }
491                                                (void)printf("{%u:%u}", s, e);
492                                        }
493                                }
494                                break;
495
496                        case TCPOPT_CC:
497                        case TCPOPT_CCNEW:
498                        case TCPOPT_CCECHO:
499                        case TCPOPT_ECHO:
500                        case TCPOPT_ECHOREPLY:
501
502                                /*
503                                 * those options share their semantics.
504                                 * fall through
505                                 */
506                                datalen = 4;
507                                LENCHECK(datalen);
508                                (void)printf(" %u", EXTRACT_32BITS(cp));
509                                break;
510
511                        case TCPOPT_TIMESTAMP:
512                                datalen = 8;
513                                LENCHECK(datalen);
514                                (void)printf(" val %u ecr %u",
515                                             EXTRACT_32BITS(cp),
516                                             EXTRACT_32BITS(cp + 4));
517                                break;
518
519                        case TCPOPT_SIGNATURE:
520                                datalen = TCP_SIGLEN;
521                                LENCHECK(datalen);
522#ifdef HAVE_LIBCRYPTO
523                                switch (tcp_verify_signature(ip, tp,
524                                                             bp + TH_OFF(tp) * 4, length, cp)) {
525
526                                case SIGNATURE_VALID:
527                                        (void)printf("valid");
528                                        break;
529
530                                case SIGNATURE_INVALID:
531                                        (void)printf("invalid");
532                                        break;
533
534                                case CANT_CHECK_SIGNATURE:
535                                        (void)printf("can't check - ");
536                                        for (i = 0; i < TCP_SIGLEN; ++i)
537                                                (void)printf("%02x", cp[i]);
538                                        break;
539                                }
540#else
541                                for (i = 0; i < TCP_SIGLEN; ++i)
542                                        (void)printf("%02x", cp[i]);
543#endif
544                                break;
545
546                        case TCPOPT_AUTH:
547                                (void)printf("keyid %d", *cp++);
548                                datalen = len - 3;
549                                for (i = 0; i < datalen; ++i) {
550                                        LENCHECK(i);
551                                        (void)printf("%02x", cp[i]);
552                                }
553                                break;
554
555
556                        case TCPOPT_EOL:
557                        case TCPOPT_NOP:
558                        case TCPOPT_SACKOK:
559                                /*
560                                 * Nothing interesting.
561                                 * fall through
562                                 */
563                                break;
564
565                        case TCPOPT_UTO:
566                                datalen = 2;
567                                LENCHECK(datalen);
568                                utoval = EXTRACT_16BITS(cp);
569                                (void)printf("0x%x", utoval);
570                                if (utoval & 0x0001)
571                                        utoval = (utoval >> 1) * 60;
572                                else
573                                        utoval >>= 1;
574                                (void)printf(" %u", utoval);
575                                break;
576
577                        case TCPOPT_MPTCP:
578                                datalen = len - 2;
579                                LENCHECK(datalen);
580                                if (!mptcp_print(cp-2, len, flags))
581                                        goto bad;
582                                break;
583
584                        case TCPOPT_EXPERIMENT2:
585                                datalen = len - 2;
586                                LENCHECK(datalen);
587                                if (datalen < 2)
588                                        goto bad;
589                                /* RFC6994 */
590                                magic = EXTRACT_16BITS(cp);
591                                (void)printf("-");
592
593                                switch(magic) {
594
595                                case 0xf989:
596                                        /* TCP Fast Open: draft-ietf-tcpm-fastopen-04 */
597                                        if (datalen == 2) {
598                                                /* Fast Open Cookie Request */
599                                                (void)printf("tfo cookiereq");
600                                        } else {
601                                                /* Fast Open Cookie */
602                                                if (datalen % 2 != 0 || datalen < 6 || datalen > 18) {
603                                                        (void)printf("tfo malformed");
604                                                } else {
605                                                        (void)printf("tfo cookie ");
606                                                        for (i = 2; i < datalen; ++i)
607                                                                (void)printf("%02x", cp[i]);
608                                                }
609                                        }
610                                        break;
611
612                                default:
613                                        /* Unknown magic number */
614                                        (void)printf("%04x", magic);
615                                        break;
616                                }
617                                break;
618
619                        default:
620                                datalen = len - 2;
621                                if (datalen)
622                                        printf(" 0x");
623                                for (i = 0; i < datalen; ++i) {
624                                        LENCHECK(i);
625                                        (void)printf("%02x", cp[i]);
626                                }
627                                break;
628                        }
629
630                        /* Account for data printed */
631                        cp += datalen;
632                        hlen -= datalen;
633
634                        /* Check specification against observed length */
635                        ++datalen;			/* option octet */
636                        if (!ZEROLENOPT(opt))
637                                ++datalen;		/* size octet */
638                        if (datalen != len)
639                                (void)printf("[len %d]", len);
640                        ch = ',';
641                        if (opt == TCPOPT_EOL)
642                                break;
643                }
644                putchar(']');
645        }
646
647        /*
648         * Print length field before crawling down the stack.
649         */
650        printf(", length %u", length);
651
652        if (length <= 0)
653                return;
654
655        /*
656         * Decode payload if necessary.
657         */
658        bp += TH_OFF(tp) * 4;
659        if ((flags & TH_RST) && vflag) {
660                print_tcp_rst_data(bp, length);
661                return;
662        }
663
664        if (packettype) {
665                switch (packettype) {
666                case PT_ZMTP1:
667                        zmtp1_print(bp, length);
668                        break;
669                }
670                return;
671        }
672
673        if (sport == TELNET_PORT || dport == TELNET_PORT) {
674                if (!qflag && vflag)
675                        telnet_print(bp, length);
676        } else if (sport == BGP_PORT || dport == BGP_PORT)
677                bgp_print(bp, length);
678        else if (sport == PPTP_PORT || dport == PPTP_PORT)
679                pptp_print(bp);
680#ifdef TCPDUMP_DO_SMB
681        else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
682                nbt_tcp_print(bp, length);
683	else if (sport == SMB_PORT || dport == SMB_PORT)
684		smb_tcp_print(bp, length);
685#endif
686        else if (sport == BEEP_PORT || dport == BEEP_PORT)
687                beep_print(bp, length);
688        else if (sport == OPENFLOW_PORT || dport == OPENFLOW_PORT)
689                openflow_print(bp, length);
690        else if (length > 2 &&
691                 (sport == NAMESERVER_PORT || dport == NAMESERVER_PORT ||
692                  sport == MULTICASTDNS_PORT || dport == MULTICASTDNS_PORT)) {
693                /*
694                 * TCP DNS query has 2byte length at the head.
695                 * XXX packet could be unaligned, it can go strange
696                 */
697                ns_print(bp + 2, length - 2, 0);
698        } else if (sport == MSDP_PORT || dport == MSDP_PORT) {
699                msdp_print(bp, length);
700        } else if (sport == RPKI_RTR_PORT || dport == RPKI_RTR_PORT) {
701                rpki_rtr_print(bp, length);
702        }
703        else if (length > 0 && (sport == LDP_PORT || dport == LDP_PORT)) {
704                ldp_print(bp, length);
705        }
706        else if ((sport == NFS_PORT || dport == NFS_PORT) &&
707                 length >= 4 && TTEST2(*bp, 4)) {
708                /*
709                 * If data present, header length valid, and NFS port used,
710                 * assume NFS.
711                 * Pass offset of data plus 4 bytes for RPC TCP msg length
712                 * to NFS print routines.
713                 */
714                u_int32_t fraglen;
715                register struct sunrpc_msg *rp;
716                enum sunrpc_msg_type direction;
717
718                fraglen = EXTRACT_32BITS(bp) & 0x7FFFFFFF;
719                if (fraglen > (length) - 4)
720                        fraglen = (length) - 4;
721                rp = (struct sunrpc_msg *)(bp + 4);
722                if (TTEST(rp->rm_direction)) {
723                        direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction);
724                        if (dport == NFS_PORT && direction == SUNRPC_CALL) {
725                                (void)printf(": NFS request xid %u ", EXTRACT_32BITS(&rp->rm_xid));
726                                nfsreq_print_noaddr((u_char *)rp, fraglen, (u_char *)ip);
727                                return;
728                        }
729                        if (sport == NFS_PORT && direction == SUNRPC_REPLY) {
730                                (void)printf(": NFS reply xid %u ", EXTRACT_32BITS(&rp->rm_xid));
731                                nfsreply_print_noaddr((u_char *)rp, fraglen, (u_char *)ip);
732                                return;
733                        }
734                }
735        }
736
737        return;
738 bad:
739        fputs("[bad opt]", stdout);
740        if (ch != '\0')
741                putchar('>');
742        return;
743 trunc:
744        fputs("[|tcp]", stdout);
745        if (ch != '\0')
746                putchar('>');
747}
748
749/*
750 * RFC1122 says the following on data in RST segments:
751 *
752 *         4.2.2.12  RST Segment: RFC-793 Section 3.4
753 *
754 *            A TCP SHOULD allow a received RST segment to include data.
755 *
756 *            DISCUSSION
757 *                 It has been suggested that a RST segment could contain
758 *                 ASCII text that encoded and explained the cause of the
759 *                 RST.  No standard has yet been established for such
760 *                 data.
761 *
762 */
763
764static void
765print_tcp_rst_data(register const u_char *sp, u_int length)
766{
767        int c;
768
769        if (TTEST2(*sp, length))
770                printf(" [RST");
771        else
772                printf(" [!RST");
773        if (length > MAX_RST_DATA_LEN) {
774                length = MAX_RST_DATA_LEN;	/* can use -X for longer */
775                putchar('+');			/* indicate we truncate */
776        }
777        putchar(' ');
778        while (length-- && sp <= snapend) {
779                c = *sp++;
780                safeputchar(c);
781        }
782        putchar(']');
783}
784
785#ifdef HAVE_LIBCRYPTO
786USES_APPLE_DEPRECATED_API
787static int
788tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
789                     const u_char *data, int length, const u_char *rcvsig)
790{
791        struct tcphdr tp1;
792        u_char sig[TCP_SIGLEN];
793        char zero_proto = 0;
794        MD5_CTX ctx;
795        u_int16_t savecsum, tlen;
796#ifdef INET6
797        struct ip6_hdr *ip6;
798        u_int32_t len32;
799        u_int8_t nxt;
800#endif
801
802	if (data + length > snapend) {
803		printf("snaplen too short, ");
804		return (CANT_CHECK_SIGNATURE);
805	}
806
807        tp1 = *tp;
808
809        if (sigsecret == NULL) {
810		printf("shared secret not supplied with -M, ");
811                return (CANT_CHECK_SIGNATURE);
812        }
813
814        MD5_Init(&ctx);
815        /*
816         * Step 1: Update MD5 hash with IP pseudo-header.
817         */
818        if (IP_V(ip) == 4) {
819                MD5_Update(&ctx, (char *)&ip->ip_src, sizeof(ip->ip_src));
820                MD5_Update(&ctx, (char *)&ip->ip_dst, sizeof(ip->ip_dst));
821                MD5_Update(&ctx, (char *)&zero_proto, sizeof(zero_proto));
822                MD5_Update(&ctx, (char *)&ip->ip_p, sizeof(ip->ip_p));
823                tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4;
824                tlen = htons(tlen);
825                MD5_Update(&ctx, (char *)&tlen, sizeof(tlen));
826#ifdef INET6
827        } else if (IP_V(ip) == 6) {
828                ip6 = (struct ip6_hdr *)ip;
829                MD5_Update(&ctx, (char *)&ip6->ip6_src, sizeof(ip6->ip6_src));
830                MD5_Update(&ctx, (char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));
831                len32 = htonl(EXTRACT_16BITS(&ip6->ip6_plen));
832                MD5_Update(&ctx, (char *)&len32, sizeof(len32));
833                nxt = 0;
834                MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
835                MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
836                MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
837                nxt = IPPROTO_TCP;
838                MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
839#endif
840        } else {
841#ifdef INET6
842		printf("IP version not 4 or 6, ");
843#else
844		printf("IP version not 4, ");
845#endif
846                return (CANT_CHECK_SIGNATURE);
847        }
848
849        /*
850         * Step 2: Update MD5 hash with TCP header, excluding options.
851         * The TCP checksum must be set to zero.
852         */
853        savecsum = tp1.th_sum;
854        tp1.th_sum = 0;
855        MD5_Update(&ctx, (char *)&tp1, sizeof(struct tcphdr));
856        tp1.th_sum = savecsum;
857        /*
858         * Step 3: Update MD5 hash with TCP segment data, if present.
859         */
860        if (length > 0)
861                MD5_Update(&ctx, data, length);
862        /*
863         * Step 4: Update MD5 hash with shared secret.
864         */
865        MD5_Update(&ctx, sigsecret, strlen(sigsecret));
866        MD5_Final(sig, &ctx);
867
868        if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0)
869                return (SIGNATURE_VALID);
870        else
871                return (SIGNATURE_INVALID);
872}
873USES_APPLE_RST
874#endif /* HAVE_LIBCRYPTO */
875
876/*
877 * Local Variables:
878 * c-style: whitesmith
879 * c-basic-offset: 8
880 * End:
881 */
882