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 #include <sys/cdefs.h>
29 #ifndef lint
30 __RCSID("$NetBSD: print-tcp.c,v 1.10 2020/02/24 18:39:47 kamil 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
58 static 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
63 static void print_tcp_rst_data(netdissect_options *, register const u_char *sp, u_int length);
64 static 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
70 struct tha {
71 struct in_addr src;
72 struct in_addr dst;
73 u_int port;
74 };
75
76 struct tcp_seq_hash {
77 struct tcp_seq_hash *nxt;
78 struct tha addr;
79 tcp_seq seq;
80 tcp_seq ack;
81 };
82
83 struct tha6 {
84 struct in6_addr src;
85 struct in6_addr dst;
86 u_int port;
87 };
88
89 struct 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
101 static struct tcp_seq_hash tcp_seq_hash4[TSEQ_HASHSIZE];
102 static struct tcp_seq_hash6 tcp_seq_hash6[TSEQ_HASHSIZE];
103
104 static 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
116 static 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
139 static int
tcp_cksum(netdissect_options * ndo,register const struct ip * ip,register const struct tcphdr * tp,register u_int len)140 tcp_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
149 static int
tcp6_cksum(netdissect_options * ndo,register const struct ip6_hdr * ip6,register const struct tcphdr * tp,register u_int len)150 tcp6_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
159 UNALIGNED_OK
160 void
tcp_print(netdissect_options * ndo,register const u_char * bp,register u_int length,register const u_char * bp2,int fragmented)161 tcp_print(netdissect_options *ndo,
162 register const u_char *bp, register u_int length,
163 register const u_char *bp2, int fragmented)
164 {
165 register const struct tcphdr *tp;
166 register const struct ip *ip;
167 register u_char flags;
168 register u_int hlen;
169 register char ch;
170 uint16_t sport, dport, win, urp;
171 uint32_t seq, ack, thseq, thack;
172 u_int utoval;
173 uint16_t magic;
174 register int rev;
175 register const struct ip6_hdr *ip6;
176
177 tp = (const struct tcphdr *)bp;
178 ip = (const struct ip *)bp2;
179 if (IP_V(ip) == 6)
180 ip6 = (const struct ip6_hdr *)bp2;
181 else
182 ip6 = NULL;
183 ch = '\0';
184 if (!ND_TTEST(tp->th_dport)) {
185 ND_PRINT((ndo, "%s > %s: [|tcp]",
186 ipaddr_string(ndo, &ip->ip_src),
187 ipaddr_string(ndo, &ip->ip_dst)));
188 return;
189 }
190
191 sport = EXTRACT_16BITS(&tp->th_sport);
192 dport = EXTRACT_16BITS(&tp->th_dport);
193
194 if (ip6) {
195 if (ip6->ip6_nxt == IPPROTO_TCP) {
196 ND_PRINT((ndo, "%s.%s > %s.%s: ",
197 ip6addr_string(ndo, &ip6->ip6_src),
198 tcpport_string(ndo, sport),
199 ip6addr_string(ndo, &ip6->ip6_dst),
200 tcpport_string(ndo, dport)));
201 } else {
202 ND_PRINT((ndo, "%s > %s: ",
203 tcpport_string(ndo, sport), tcpport_string(ndo, dport)));
204 }
205 } else {
206 if (ip->ip_p == IPPROTO_TCP) {
207 ND_PRINT((ndo, "%s.%s > %s.%s: ",
208 ipaddr_string(ndo, &ip->ip_src),
209 tcpport_string(ndo, sport),
210 ipaddr_string(ndo, &ip->ip_dst),
211 tcpport_string(ndo, dport)));
212 } else {
213 ND_PRINT((ndo, "%s > %s: ",
214 tcpport_string(ndo, sport), tcpport_string(ndo, dport)));
215 }
216 }
217
218 ND_TCHECK(*tp);
219
220 hlen = TH_OFF(tp) * 4;
221
222 if (hlen < sizeof(*tp)) {
223 ND_PRINT((ndo, " tcp %d [bad hdr length %u - too short, < %lu]",
224 length - hlen, hlen, (unsigned long)sizeof(*tp)));
225 return;
226 }
227
228 seq = EXTRACT_32BITS(&tp->th_seq);
229 ack = EXTRACT_32BITS(&tp->th_ack);
230 win = EXTRACT_16BITS(&tp->th_win);
231 urp = EXTRACT_16BITS(&tp->th_urp);
232
233 if (ndo->ndo_qflag) {
234 ND_PRINT((ndo, "tcp %d", length - hlen));
235 if (hlen > length) {
236 ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]",
237 hlen, length));
238 }
239 return;
240 }
241
242 flags = tp->th_flags;
243 ND_PRINT((ndo, "Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags)));
244
245 if (!ndo->ndo_Sflag && (flags & TH_ACK)) {
246 /*
247 * Find (or record) the initial sequence numbers for
248 * this conversation. (we pick an arbitrary
249 * collating order so there's only one entry for
250 * both directions).
251 */
252 rev = 0;
253 if (ip6) {
254 register struct tcp_seq_hash6 *th;
255 struct tcp_seq_hash6 *tcp_seq_hash;
256 const struct in6_addr *src, *dst;
257 struct tha6 tha;
258
259 tcp_seq_hash = tcp_seq_hash6;
260 src = &ip6->ip6_src;
261 dst = &ip6->ip6_dst;
262 if (sport > dport)
263 rev = 1;
264 else if (sport == dport) {
265 if (UNALIGNED_MEMCMP(src, dst, sizeof ip6->ip6_dst) > 0)
266 rev = 1;
267 }
268 if (rev) {
269 UNALIGNED_MEMCPY(&tha.src, dst, sizeof ip6->ip6_dst);
270 UNALIGNED_MEMCPY(&tha.dst, src, sizeof ip6->ip6_src);
271 tha.port = ((u_int)dport) << 16 | sport;
272 } else {
273 UNALIGNED_MEMCPY(&tha.dst, dst, sizeof ip6->ip6_dst);
274 UNALIGNED_MEMCPY(&tha.src, src, sizeof ip6->ip6_src);
275 tha.port = ((u_int)sport) << 16 | dport;
276 }
277
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)
282 break;
283
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));
289 if (th->nxt == NULL)
290 (*ndo->ndo_error)(ndo,
291 "tcp_print: calloc");
292 }
293 th->addr = tha;
294 if (rev)
295 th->ack = seq, th->seq = ack - 1;
296 else
297 th->seq = seq, th->ack = ack - 1;
298 } else {
299 if (rev)
300 seq -= th->ack, ack -= th->seq;
301 else
302 seq -= th->seq, ack -= th->ack;
303 }
304
305 thseq = th->seq;
306 thack = th->ack;
307 } else {
308 register struct tcp_seq_hash *th;
309 struct tcp_seq_hash *tcp_seq_hash;
310 struct tha tha;
311
312 tcp_seq_hash = tcp_seq_hash4;
313 if (sport > dport)
314 rev = 1;
315 else if (sport == dport) {
316 if (UNALIGNED_MEMCMP(&ip->ip_src, &ip->ip_dst, sizeof ip->ip_dst) > 0)
317 rev = 1;
318 }
319 if (rev) {
320 UNALIGNED_MEMCPY(&tha.src, &ip->ip_dst, sizeof ip->ip_dst);
321 UNALIGNED_MEMCPY(&tha.dst, &ip->ip_src, sizeof ip->ip_src);
322 tha.port = ((u_int)dport) << 16 | sport;
323 } else {
324 UNALIGNED_MEMCPY(&tha.dst, &ip->ip_dst, sizeof ip->ip_dst);
325 UNALIGNED_MEMCPY(&tha.src, &ip->ip_src, sizeof ip->ip_src);
326 tha.port = ((u_int)sport) << 16 | dport;
327 }
328
329 for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
330 th->nxt; th = th->nxt)
331 if (memcmp((char *)&tha, (char *)&th->addr,
332 sizeof(th->addr)) == 0)
333 break;
334
335 if (!th->nxt || (flags & TH_SYN)) {
336 /* didn't find it or new conversation */
337 if (th->nxt == NULL) {
338 th->nxt = (struct tcp_seq_hash *)
339 calloc(1, sizeof(*th));
340 if (th->nxt == NULL)
341 (*ndo->ndo_error)(ndo,
342 "tcp_print: calloc");
343 }
344 th->addr = tha;
345 if (rev)
346 th->ack = seq, th->seq = ack - 1;
347 else
348 th->seq = seq, th->ack = ack - 1;
349 } else {
350 if (rev)
351 seq -= th->ack, ack -= th->seq;
352 else
353 seq -= th->seq, ack -= th->ack;
354 }
355
356 thseq = th->seq;
357 thack = th->ack;
358 }
359 } else {
360 /*fool gcc*/
361 thseq = thack = rev = 0;
362 }
363 if (hlen > length) {
364 ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]",
365 hlen, length));
366 return;
367 }
368
369 if (ndo->ndo_vflag && !ndo->ndo_Kflag && !fragmented) {
370 /* Check the checksum, if possible. */
371 uint16_t sum, tcp_sum;
372
373 if (IP_V(ip) == 4) {
374 if (ND_TTEST2(tp->th_sport, length)) {
375 sum = tcp_cksum(ndo, ip, tp, length);
376 tcp_sum = EXTRACT_16BITS(&tp->th_sum);
377
378 ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum));
379 if (sum != 0)
380 ND_PRINT((ndo, " (incorrect -> 0x%04x)",
381 in_cksum_shouldbe(tcp_sum, sum)));
382 else
383 ND_PRINT((ndo, " (correct)"));
384 }
385 } else if (IP_V(ip) == 6 && ip6->ip6_plen) {
386 if (ND_TTEST2(tp->th_sport, length)) {
387 sum = tcp6_cksum(ndo, ip6, tp, length);
388 tcp_sum = EXTRACT_16BITS(&tp->th_sum);
389
390 ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum));
391 if (sum != 0)
392 ND_PRINT((ndo, " (incorrect -> 0x%04x)",
393 in_cksum_shouldbe(tcp_sum, sum)));
394 else
395 ND_PRINT((ndo, " (correct)"));
396
397 }
398 }
399 }
400
401 length -= hlen;
402 if (ndo->ndo_vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) {
403 ND_PRINT((ndo, ", seq %u", seq));
404
405 if (length > 0) {
406 ND_PRINT((ndo, ":%u", seq + length));
407 }
408 }
409
410 if (flags & TH_ACK) {
411 ND_PRINT((ndo, ", ack %u", ack));
412 }
413
414 ND_PRINT((ndo, ", win %d", win));
415
416 if (flags & TH_URG)
417 ND_PRINT((ndo, ", urg %d", urp));
418 /*
419 * Handle any options.
420 */
421 if (hlen > sizeof(*tp)) {
422 register const u_char *cp;
423 register u_int i, opt, datalen;
424 register u_int len;
425
426 hlen -= sizeof(*tp);
427 cp = (const u_char *)tp + sizeof(*tp);
428 ND_PRINT((ndo, ", options ["));
429 while (hlen > 0) {
430 if (ch != '\0')
431 ND_PRINT((ndo, "%c", ch));
432 ND_TCHECK(*cp);
433 opt = *cp++;
434 if (ZEROLENOPT(opt))
435 len = 1;
436 else {
437 ND_TCHECK(*cp);
438 len = *cp++; /* total including type, len */
439 if (len < 2 || len > hlen)
440 goto bad;
441 --hlen; /* account for length byte */
442 }
443 --hlen; /* account for type byte */
444 datalen = 0;
445
446 /* Bail if "l" bytes of data are not left or were not captured */
447 #define LENCHECK(l) { if ((l) > hlen) goto bad; ND_TCHECK2(*cp, l); }
448
449
450 ND_PRINT((ndo, "%s", tok2str(tcp_option_values, "unknown-%u", opt)));
451
452 switch (opt) {
453
454 case TCPOPT_MAXSEG:
455 datalen = 2;
456 LENCHECK(datalen);
457 ND_PRINT((ndo, " %u", EXTRACT_16BITS(cp)));
458 break;
459
460 case TCPOPT_WSCALE:
461 datalen = 1;
462 LENCHECK(datalen);
463 ND_PRINT((ndo, " %u", *cp));
464 break;
465
466 case TCPOPT_SACK:
467 datalen = len - 2;
468 if (datalen % 8 != 0) {
469 ND_PRINT((ndo, " invalid sack"));
470 } else {
471 uint32_t s, e;
472
473 ND_PRINT((ndo, " %d ", datalen / 8));
474 for (i = 0; i < datalen; i += 8) {
475 LENCHECK(i + 4);
476 s = EXTRACT_32BITS(cp + i);
477 LENCHECK(i + 8);
478 e = EXTRACT_32BITS(cp + i + 4);
479 if (rev) {
480 s -= thseq;
481 e -= thseq;
482 } else {
483 s -= thack;
484 e -= thack;
485 }
486 ND_PRINT((ndo, "{%u:%u}", s, e));
487 }
488 }
489 break;
490
491 case TCPOPT_CC:
492 case TCPOPT_CCNEW:
493 case TCPOPT_CCECHO:
494 case TCPOPT_ECHO:
495 case TCPOPT_ECHOREPLY:
496
497 /*
498 * those options share their semantics.
499 * fall through
500 */
501 datalen = 4;
502 LENCHECK(datalen);
503 ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
504 break;
505
506 case TCPOPT_TIMESTAMP:
507 datalen = 8;
508 LENCHECK(datalen);
509 ND_PRINT((ndo, " val %u ecr %u",
510 EXTRACT_32BITS(cp),
511 EXTRACT_32BITS(cp + 4)));
512 break;
513
514 case TCPOPT_SIGNATURE:
515 datalen = TCP_SIGLEN;
516 LENCHECK(datalen);
517 ND_PRINT((ndo, " "));
518 #ifdef HAVE_LIBCRYPTO
519 switch (tcp_verify_signature(ndo, ip, tp,
520 bp + TH_OFF(tp) * 4, length, cp)) {
521
522 case SIGNATURE_VALID:
523 ND_PRINT((ndo, "valid"));
524 break;
525
526 case SIGNATURE_INVALID:
527 ND_PRINT((ndo, "invalid"));
528 break;
529
530 case CANT_CHECK_SIGNATURE:
531 ND_PRINT((ndo, "can't check - "));
532 for (i = 0; i < TCP_SIGLEN; ++i)
533 ND_PRINT((ndo, "%02x", cp[i]));
534 break;
535 }
536 #else
537 for (i = 0; i < TCP_SIGLEN; ++i)
538 ND_PRINT((ndo, "%02x", cp[i]));
539 #endif
540 break;
541
542 case TCPOPT_SCPS:
543 datalen = 2;
544 LENCHECK(datalen);
545 ND_PRINT((ndo, " cap %02x id %u", cp[0], cp[1]));
546 break;
547
548 case TCPOPT_TCPAO:
549 datalen = len - 2;
550 /* RFC 5925 Section 2.2:
551 * "The Length value MUST be greater than or equal to 4."
552 * (This includes the Kind and Length fields already processed
553 * at this point.)
554 */
555 if (datalen < 2) {
556 ND_PRINT((ndo, " invalid"));
557 } else {
558 LENCHECK(1);
559 ND_PRINT((ndo, " keyid %u", cp[0]));
560 LENCHECK(2);
561 ND_PRINT((ndo, " rnextkeyid %u", cp[1]));
562 if (datalen > 2) {
563 ND_PRINT((ndo, " mac 0x"));
564 for (i = 2; i < datalen; i++) {
565 LENCHECK(i + 1);
566 ND_PRINT((ndo, "%02x", cp[i]));
567 }
568 }
569 }
570 break;
571
572 case TCPOPT_EOL:
573 case TCPOPT_NOP:
574 case TCPOPT_SACKOK:
575 /*
576 * Nothing interesting.
577 * fall through
578 */
579 break;
580
581 case TCPOPT_UTO:
582 datalen = 2;
583 LENCHECK(datalen);
584 utoval = EXTRACT_16BITS(cp);
585 ND_PRINT((ndo, " 0x%x", utoval));
586 if (utoval & 0x0001)
587 utoval = (utoval >> 1) * 60;
588 else
589 utoval >>= 1;
590 ND_PRINT((ndo, " %u", utoval));
591 break;
592
593 case TCPOPT_MPTCP:
594 datalen = len - 2;
595 LENCHECK(datalen);
596 if (!mptcp_print(ndo, cp-2, len, flags))
597 goto bad;
598 break;
599
600 case TCPOPT_FASTOPEN:
601 datalen = len - 2;
602 LENCHECK(datalen);
603 ND_PRINT((ndo, " "));
604 print_tcp_fastopen_option(ndo, cp, datalen, FALSE);
605 break;
606
607 case TCPOPT_EXPERIMENT2:
608 datalen = len - 2;
609 LENCHECK(datalen);
610 if (datalen < 2)
611 goto bad;
612 /* RFC6994 */
613 magic = EXTRACT_16BITS(cp);
614 ND_PRINT((ndo, "-"));
615
616 switch(magic) {
617
618 case 0xf989: /* TCP Fast Open RFC 7413 */
619 print_tcp_fastopen_option(ndo, cp + 2, datalen - 2, TRUE);
620 break;
621
622 default:
623 /* Unknown magic number */
624 ND_PRINT((ndo, "%04x", magic));
625 break;
626 }
627 break;
628
629 default:
630 datalen = len - 2;
631 if (datalen)
632 ND_PRINT((ndo, " 0x"));
633 for (i = 0; i < datalen; ++i) {
634 LENCHECK(i + 1);
635 ND_PRINT((ndo, "%02x", cp[i]));
636 }
637 break;
638 }
639
640 /* Account for data printed */
641 cp += datalen;
642 hlen -= datalen;
643
644 /* Check specification against observed length */
645 ++datalen; /* option octet */
646 if (!ZEROLENOPT(opt))
647 ++datalen; /* size octet */
648 if (datalen != len)
649 ND_PRINT((ndo, "[len %d]", len));
650 ch = ',';
651 if (opt == TCPOPT_EOL)
652 break;
653 }
654 ND_PRINT((ndo, "]"));
655 }
656
657 /*
658 * Print length field before crawling down the stack.
659 */
660 ND_PRINT((ndo, ", length %u", length));
661
662 if (length <= 0)
663 return;
664
665 /*
666 * Decode payload if necessary.
667 */
668 bp += TH_OFF(tp) * 4;
669 if ((flags & TH_RST) && ndo->ndo_vflag) {
670 print_tcp_rst_data(ndo, bp, length);
671 return;
672 }
673
674 if (ndo->ndo_packettype) {
675 switch (ndo->ndo_packettype) {
676 case PT_ZMTP1:
677 zmtp1_print(ndo, bp, length);
678 break;
679 case PT_RESP:
680 resp_print(ndo, bp, length);
681 break;
682 }
683 return;
684 }
685
686 if (IS_SRC_OR_DST_PORT(TELNET_PORT)) {
687 telnet_print(ndo, bp, length);
688 } else if (IS_SRC_OR_DST_PORT(SMTP_PORT)) {
689 ND_PRINT((ndo, ": "));
690 smtp_print(ndo, bp, length);
691 } else if (IS_SRC_OR_DST_PORT(BGP_PORT))
692 bgp_print(ndo, bp, length);
693 else if (IS_SRC_OR_DST_PORT(PPTP_PORT))
694 pptp_print(ndo, bp);
695 else if (IS_SRC_OR_DST_PORT(REDIS_PORT))
696 resp_print(ndo, bp, length);
697 #ifdef ENABLE_SMB
698 else if (IS_SRC_OR_DST_PORT(NETBIOS_SSN_PORT))
699 nbt_tcp_print(ndo, bp, length);
700 else if (IS_SRC_OR_DST_PORT(SMB_PORT))
701 smb_tcp_print(ndo, bp, length);
702 #endif
703 else if (IS_SRC_OR_DST_PORT(BEEP_PORT))
704 beep_print(ndo, bp, length);
705 else if (IS_SRC_OR_DST_PORT(OPENFLOW_PORT_OLD) || IS_SRC_OR_DST_PORT(OPENFLOW_PORT_IANA))
706 openflow_print(ndo, bp, length);
707 else if (IS_SRC_OR_DST_PORT(FTP_PORT)) {
708 ND_PRINT((ndo, ": "));
709 ftp_print(ndo, bp, length);
710 } else if (IS_SRC_OR_DST_PORT(HTTP_PORT) || IS_SRC_OR_DST_PORT(HTTP_PORT_ALT)) {
711 ND_PRINT((ndo, ": "));
712 http_print(ndo, bp, length);
713 } else if (IS_SRC_OR_DST_PORT(RTSP_PORT) || IS_SRC_OR_DST_PORT(RTSP_PORT_ALT)) {
714 ND_PRINT((ndo, ": "));
715 rtsp_print(ndo, bp, length);
716 } else if (length > 2 &&
717 (IS_SRC_OR_DST_PORT(NAMESERVER_PORT))) {
718 /* domain_print() assumes it does not have to prepend a space before its
719 * own output to separate it from the output of the calling function. This
720 * works well with udp_print(), but requires a small prop here.
721 */
722 ND_PRINT((ndo, " "));
723
724 /*
725 * TCP DNS query has 2byte length at the head.
726 * XXX packet could be unaligned, it can go strange
727 */
728 ns_print(ndo, bp + 2, length - 2, 0);
729 } else if (IS_SRC_OR_DST_PORT(MSDP_PORT)) {
730 msdp_print(ndo, bp, length);
731 } else if (IS_SRC_OR_DST_PORT(RPKI_RTR_PORT)) {
732 rpki_rtr_print(ndo, bp, length);
733 }
734 else if (length > 0 && (IS_SRC_OR_DST_PORT(LDP_PORT))) {
735 ldp_print(ndo, bp, length);
736 }
737 else if ((IS_SRC_OR_DST_PORT(NFS_PORT)) &&
738 length >= 4 && ND_TTEST2(*bp, 4)) {
739 /*
740 * If data present, header length valid, and NFS port used,
741 * assume NFS.
742 * Pass offset of data plus 4 bytes for RPC TCP msg length
743 * to NFS print routines.
744 */
745 uint32_t fraglen;
746 register const struct sunrpc_msg *rp;
747 enum sunrpc_msg_type direction;
748
749 fraglen = EXTRACT_32BITS(bp) & 0x7FFFFFFF;
750 if (fraglen > (length) - 4)
751 fraglen = (length) - 4;
752 rp = (const struct sunrpc_msg *)(bp + 4);
753 if (ND_TTEST(rp->rm_direction)) {
754 direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction);
755 if (dport == NFS_PORT && direction == SUNRPC_CALL) {
756 ND_PRINT((ndo, ": NFS request xid %u ", EXTRACT_32BITS(&rp->rm_xid)));
757 nfsreq_print_noaddr(ndo, (const u_char *)rp, fraglen, (const u_char *)ip);
758 return;
759 }
760 if (sport == NFS_PORT && direction == SUNRPC_REPLY) {
761 ND_PRINT((ndo, ": NFS reply xid %u ", EXTRACT_32BITS(&rp->rm_xid)));
762 nfsreply_print_noaddr(ndo, (const u_char *)rp, fraglen, (const u_char *)ip);
763 return;
764 }
765 }
766 }
767
768 return;
769 bad:
770 ND_PRINT((ndo, "[bad opt]"));
771 if (ch != '\0')
772 ND_PRINT((ndo, ">"));
773 return;
774 trunc:
775 ND_PRINT((ndo, "[|tcp]"));
776 if (ch != '\0')
777 ND_PRINT((ndo, ">"));
778 }
779
780 /*
781 * RFC1122 says the following on data in RST segments:
782 *
783 * 4.2.2.12 RST Segment: RFC-793 Section 3.4
784 *
785 * A TCP SHOULD allow a received RST segment to include data.
786 *
787 * DISCUSSION
788 * It has been suggested that a RST segment could contain
789 * ASCII text that encoded and explained the cause of the
790 * RST. No standard has yet been established for such
791 * data.
792 *
793 */
794
795 static void
print_tcp_rst_data(netdissect_options * ndo,register const u_char * sp,u_int length)796 print_tcp_rst_data(netdissect_options *ndo,
797 register const u_char *sp, u_int length)
798 {
799 int c;
800
801 ND_PRINT((ndo, ND_TTEST2(*sp, length) ? " [RST" : " [!RST"));
802 if (length > MAX_RST_DATA_LEN) {
803 length = MAX_RST_DATA_LEN; /* can use -X for longer */
804 ND_PRINT((ndo, "+")); /* indicate we truncate */
805 }
806 ND_PRINT((ndo, " "));
807 while (length-- && sp < ndo->ndo_snapend) {
808 c = *sp++;
809 safeputchar(ndo, c);
810 }
811 ND_PRINT((ndo, "]"));
812 }
813
814 static void
print_tcp_fastopen_option(netdissect_options * ndo,register const u_char * cp,u_int datalen,int exp)815 print_tcp_fastopen_option(netdissect_options *ndo, register const u_char *cp,
816 u_int datalen, int exp)
817 {
818 u_int i;
819
820 if (exp)
821 ND_PRINT((ndo, "tfo"));
822
823 if (datalen == 0) {
824 /* Fast Open Cookie Request */
825 ND_PRINT((ndo, " cookiereq"));
826 } else {
827 /* Fast Open Cookie */
828 if (datalen % 2 != 0 || datalen < 4 || datalen > 16) {
829 ND_PRINT((ndo, " invalid"));
830 } else {
831 ND_PRINT((ndo, " cookie "));
832 for (i = 0; i < datalen; ++i)
833 ND_PRINT((ndo, "%02x", cp[i]));
834 }
835 }
836 }
837
838 #ifdef HAVE_LIBCRYPTO
839 USES_APPLE_DEPRECATED_API
840 static int
tcp_verify_signature(netdissect_options * ndo,const struct ip * ip,const struct tcphdr * tp,const u_char * data,int length,const u_char * rcvsig)841 tcp_verify_signature(netdissect_options *ndo,
842 const struct ip *ip, const struct tcphdr *tp,
843 const u_char *data, int length, const u_char *rcvsig)
844 {
845 struct tcphdr tp1;
846 u_char sig[TCP_SIGLEN];
847 char zero_proto = 0;
848 MD5_CTX ctx;
849 uint16_t savecsum, tlen;
850 const struct ip6_hdr *ip6;
851 uint32_t len32;
852 uint8_t nxt;
853
854 if (data + length > ndo->ndo_snapend) {
855 ND_PRINT((ndo, "snaplen too short, "));
856 return (CANT_CHECK_SIGNATURE);
857 }
858
859 tp1 = *tp;
860
861 if (ndo->ndo_sigsecret == NULL) {
862 ND_PRINT((ndo, "shared secret not supplied with -M, "));
863 return (CANT_CHECK_SIGNATURE);
864 }
865
866 MD5_Init(&ctx);
867 /*
868 * Step 1: Update MD5 hash with IP pseudo-header.
869 */
870 if (IP_V(ip) == 4) {
871 MD5_Update(&ctx, (const char *)&ip->ip_src, sizeof(ip->ip_src));
872 MD5_Update(&ctx, (const char *)&ip->ip_dst, sizeof(ip->ip_dst));
873 MD5_Update(&ctx, (const char *)&zero_proto, sizeof(zero_proto));
874 MD5_Update(&ctx, (const char *)&ip->ip_p, sizeof(ip->ip_p));
875 tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4;
876 tlen = htons(tlen);
877 MD5_Update(&ctx, (const char *)&tlen, sizeof(tlen));
878 } else if (IP_V(ip) == 6) {
879 ip6 = (const struct ip6_hdr *)ip;
880 MD5_Update(&ctx, (const char *)&ip6->ip6_src, sizeof(ip6->ip6_src));
881 MD5_Update(&ctx, (const char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));
882 len32 = htonl(EXTRACT_16BITS(&ip6->ip6_plen));
883 MD5_Update(&ctx, (const char *)&len32, sizeof(len32));
884 nxt = 0;
885 MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
886 MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
887 MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
888 nxt = IPPROTO_TCP;
889 MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));
890 } else {
891 ND_PRINT((ndo, "IP version not 4 or 6, "));
892 return (CANT_CHECK_SIGNATURE);
893 }
894
895 /*
896 * Step 2: Update MD5 hash with TCP header, excluding options.
897 * The TCP checksum must be set to zero.
898 */
899 savecsum = tp1.th_sum;
900 tp1.th_sum = 0;
901 MD5_Update(&ctx, (const char *)&tp1, sizeof(struct tcphdr));
902 tp1.th_sum = savecsum;
903 /*
904 * Step 3: Update MD5 hash with TCP segment data, if present.
905 */
906 if (length > 0)
907 MD5_Update(&ctx, data, length);
908 /*
909 * Step 4: Update MD5 hash with shared secret.
910 */
911 MD5_Update(&ctx, ndo->ndo_sigsecret, strlen(ndo->ndo_sigsecret));
912 MD5_Final(sig, &ctx);
913
914 if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0)
915 return (SIGNATURE_VALID);
916 else
917 return (SIGNATURE_INVALID);
918 }
919 USES_APPLE_RST
920 #endif /* HAVE_LIBCRYPTO */
921
922 /*
923 * Local Variables:
924 * c-style: whitesmith
925 * c-basic-offset: 8
926 * End:
927 */
928