Move tcpdump-3.9/ to tcpdump/. No need for a versioned dir.
[dragonfly.git] / contrib / tcpdump / print-ip.c
CommitLineData
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1/*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 */
21
22#ifndef lint
23static const char rcsid[] _U_ =
825e8fa1 24 "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.149.2.9 2007/09/14 01:30:02 guy Exp $ (LBL)";
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25#endif
26
27#ifdef HAVE_CONFIG_H
28#include "config.h"
29#endif
30
31#include <tcpdump-stdinc.h>
32
33#include <stdio.h>
34#include <stdlib.h>
35#include <string.h>
36
37#include "addrtoname.h"
38#include "interface.h"
39#include "extract.h" /* must come after interface.h */
40
41#include "ip.h"
42#include "ipproto.h"
43
44struct tok ip_option_values[] = {
45 { IPOPT_EOL, "EOL" },
46 { IPOPT_NOP, "NOP" },
47 { IPOPT_TS, "timestamp" },
48 { IPOPT_SECURITY, "security" },
49 { IPOPT_RR, "RR" },
50 { IPOPT_SSRR, "SSRR" },
51 { IPOPT_LSRR, "LSRR" },
52 { IPOPT_RA, "RA" },
825e8fa1 53 { IPOPT_RFC1393, "traceroute" },
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54 { 0, NULL }
55};
56
57/*
58 * print the recorded route in an IP RR, LSRR or SSRR option.
59 */
60static void
61ip_printroute(register const u_char *cp, u_int length)
62{
63 register u_int ptr;
64 register u_int len;
65
66 if (length < 3) {
67 printf(" [bad length %u]", length);
68 return;
69 }
70 if ((length + 1) & 3)
71 printf(" [bad length %u]", length);
72 ptr = cp[2] - 1;
73 if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
74 printf(" [bad ptr %u]", cp[2]);
75
76 for (len = 3; len < length; len += 4) {
77 printf(" %s", ipaddr_string(&cp[len]));
78 if (ptr > len)
79 printf(",");
80 }
81}
82
83/*
84 * If source-routing is present and valid, return the final destination.
85 * Otherwise, return IP destination.
86 *
87 * This is used for UDP and TCP pseudo-header in the checksum
88 * calculation.
89 */
90u_int32_t
91ip_finddst(const struct ip *ip)
92{
93 int length;
94 int len;
95 const u_char *cp;
96 u_int32_t retval;
97
98 cp = (const u_char *)(ip + 1);
99 length = (IP_HL(ip) << 2) - sizeof(struct ip);
100
101 for (; length > 0; cp += len, length -= len) {
102 int tt;
103
104 TCHECK(*cp);
105 tt = *cp;
106 if (tt == IPOPT_EOL)
107 break;
108 else if (tt == IPOPT_NOP)
109 len = 1;
110 else {
111 TCHECK(cp[1]);
112 len = cp[1];
113 if (len < 2)
114 break;
115 }
116 TCHECK2(*cp, len);
117 switch (tt) {
118
119 case IPOPT_SSRR:
120 case IPOPT_LSRR:
121 if (len < 7)
122 break;
123 memcpy(&retval, cp + len - 4, 4);
124 return retval;
125 }
126 }
127trunc:
128 memcpy(&retval, &ip->ip_dst.s_addr, sizeof(u_int32_t));
129 return retval;
130}
131
132static void
133ip_printts(register const u_char *cp, u_int length)
134{
135 register u_int ptr;
136 register u_int len;
137 int hoplen;
138 const char *type;
139
140 if (length < 4) {
141 printf("[bad length %u]", length);
142 return;
143 }
144 printf(" TS{");
145 hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
146 if ((length - 4) & (hoplen-1))
147 printf("[bad length %u]", length);
148 ptr = cp[2] - 1;
149 len = 0;
150 if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
151 printf("[bad ptr %u]", cp[2]);
152 switch (cp[3]&0xF) {
153 case IPOPT_TS_TSONLY:
154 printf("TSONLY");
155 break;
156 case IPOPT_TS_TSANDADDR:
157 printf("TS+ADDR");
158 break;
159 /*
160 * prespecified should really be 3, but some ones might send 2
161 * instead, and the IPOPT_TS_PRESPEC constant can apparently
162 * have both values, so we have to hard-code it here.
163 */
164
165 case 2:
166 printf("PRESPEC2.0");
167 break;
168 case 3: /* IPOPT_TS_PRESPEC */
169 printf("PRESPEC");
170 break;
171 default:
172 printf("[bad ts type %d]", cp[3]&0xF);
173 goto done;
174 }
175
176 type = " ";
177 for (len = 4; len < length; len += hoplen) {
178 if (ptr == len)
179 type = " ^ ";
180 printf("%s%d@%s", type, EXTRACT_32BITS(&cp[len+hoplen-4]),
181 hoplen!=8 ? "" : ipaddr_string(&cp[len]));
182 type = " ";
183 }
184
185done:
186 printf("%s", ptr == len ? " ^ " : "");
187
188 if (cp[3]>>4)
189 printf(" [%d hops not recorded]} ", cp[3]>>4);
190 else
191 printf("}");
192}
193
194/*
195 * print IP options.
196 */
197static void
198ip_optprint(register const u_char *cp, u_int length)
199{
200 register u_int option_len;
201 const char *sep = "";
202
203 for (; length > 0; cp += option_len, length -= option_len) {
204 u_int option_code;
205
206 printf("%s", sep);
207 sep = ",";
208
209 TCHECK(*cp);
210 option_code = *cp;
211
212 printf("%s",
213 tok2str(ip_option_values,"unknown %u",option_code));
214
215 if (option_code == IPOPT_NOP ||
216 option_code == IPOPT_EOL)
217 option_len = 1;
218
219 else {
220 TCHECK(cp[1]);
221 option_len = cp[1];
222 if (option_len < 2) {
223 printf(" [bad length %u]", option_len);
224 return;
225 }
226 }
227
228 if (option_len > length) {
229 printf(" [bad length %u]", option_len);
230 return;
231 }
232
233 TCHECK2(*cp, option_len);
234
235 switch (option_code) {
236 case IPOPT_EOL:
237 return;
238
239 case IPOPT_TS:
240 ip_printts(cp, option_len);
241 break;
242
243 case IPOPT_RR: /* fall through */
244 case IPOPT_SSRR:
245 case IPOPT_LSRR:
246 ip_printroute(cp, option_len);
247 break;
248
249 case IPOPT_RA:
250 if (option_len < 4) {
251 printf(" [bad length %u]", option_len);
252 break;
253 }
254 TCHECK(cp[3]);
255 if (EXTRACT_16BITS(&cp[2]) != 0)
256 printf(" value %u", EXTRACT_16BITS(&cp[2]));
257 break;
258
259 case IPOPT_NOP: /* nothing to print - fall through */
260 case IPOPT_SECURITY:
261 default:
262 break;
263 }
264 }
265 return;
266
267trunc:
268 printf("[|ip]");
269}
270
271/*
272 * compute an IP header checksum.
273 * don't modifiy the packet.
274 */
275u_short
276in_cksum(const u_short *addr, register u_int len, int csum)
277{
278 int nleft = len;
279 const u_short *w = addr;
280 u_short answer;
281 int sum = csum;
282
283 /*
284 * Our algorithm is simple, using a 32 bit accumulator (sum),
285 * we add sequential 16 bit words to it, and at the end, fold
286 * back all the carry bits from the top 16 bits into the lower
287 * 16 bits.
288 */
289 while (nleft > 1) {
290 sum += *w++;
291 nleft -= 2;
292 }
293 if (nleft == 1)
294 sum += htons(*(u_char *)w<<8);
295
296 /*
297 * add back carry outs from top 16 bits to low 16 bits
298 */
299 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
300 sum += (sum >> 16); /* add carry */
301 answer = ~sum; /* truncate to 16 bits */
302 return (answer);
303}
304
305/*
306 * Given the host-byte-order value of the checksum field in a packet
307 * header, and the network-byte-order computed checksum of the data
308 * that the checksum covers (including the checksum itself), compute
309 * what the checksum field *should* have been.
310 */
311u_int16_t
312in_cksum_shouldbe(u_int16_t sum, u_int16_t computed_sum)
313{
314 u_int32_t shouldbe;
315
316 /*
317 * The value that should have gone into the checksum field
318 * is the negative of the value gotten by summing up everything
319 * *but* the checksum field.
320 *
321 * We can compute that by subtracting the value of the checksum
322 * field from the sum of all the data in the packet, and then
323 * computing the negative of that value.
324 *
325 * "sum" is the value of the checksum field, and "computed_sum"
326 * is the negative of the sum of all the data in the packets,
327 * so that's -(-computed_sum - sum), or (sum + computed_sum).
328 *
329 * All the arithmetic in question is one's complement, so the
330 * addition must include an end-around carry; we do this by
331 * doing the arithmetic in 32 bits (with no sign-extension),
332 * and then adding the upper 16 bits of the sum, which contain
333 * the carry, to the lower 16 bits of the sum, and then do it
334 * again in case *that* sum produced a carry.
335 *
336 * As RFC 1071 notes, the checksum can be computed without
337 * byte-swapping the 16-bit words; summing 16-bit words
338 * on a big-endian machine gives a big-endian checksum, which
339 * can be directly stuffed into the big-endian checksum fields
340 * in protocol headers, and summing words on a little-endian
341 * machine gives a little-endian checksum, which must be
342 * byte-swapped before being stuffed into a big-endian checksum
343 * field.
344 *
345 * "computed_sum" is a network-byte-order value, so we must put
346 * it in host byte order before subtracting it from the
347 * host-byte-order value from the header; the adjusted checksum
348 * will be in host byte order, which is what we'll return.
349 */
350 shouldbe = sum;
351 shouldbe += ntohs(computed_sum);
352 shouldbe = (shouldbe & 0xFFFF) + (shouldbe >> 16);
353 shouldbe = (shouldbe & 0xFFFF) + (shouldbe >> 16);
354 return shouldbe;
355}
356
357#define IP_RES 0x8000
358
359static struct tok ip_frag_values[] = {
360 { IP_MF, "+" },
361 { IP_DF, "DF" },
362 { IP_RES, "rsvd" }, /* The RFC3514 evil ;-) bit */
363 { 0, NULL }
364};
365
366struct ip_print_demux_state {
367 const struct ip *ip;
368 const u_char *cp;
369 u_int len, off;
370 u_char nh;
371 int advance;
372};
373
374static void
375ip_print_demux(netdissect_options *ndo,
376 struct ip_print_demux_state *ipds)
377{
378 struct protoent *proto;
379
380again:
381 switch (ipds->nh) {
382
383 case IPPROTO_AH:
384 ipds->nh = *ipds->cp;
385 ipds->advance = ah_print(ipds->cp);
386 if (ipds->advance <= 0)
387 break;
388 ipds->cp += ipds->advance;
389 ipds->len -= ipds->advance;
390 goto again;
391
392 case IPPROTO_ESP:
393 {
394 int enh, padlen;
395 ipds->advance = esp_print(ndo, ipds->cp, ipds->len,
396 (const u_char *)ipds->ip,
397 &enh, &padlen);
398 if (ipds->advance <= 0)
399 break;
400 ipds->cp += ipds->advance;
401 ipds->len -= ipds->advance + padlen;
402 ipds->nh = enh & 0xff;
403 goto again;
404 }
405
406 case IPPROTO_IPCOMP:
407 {
408 int enh;
409 ipds->advance = ipcomp_print(ipds->cp, &enh);
410 if (ipds->advance <= 0)
411 break;
412 ipds->cp += ipds->advance;
413 ipds->len -= ipds->advance;
414 ipds->nh = enh & 0xff;
415 goto again;
416 }
417
418 case IPPROTO_SCTP:
419 sctp_print(ipds->cp, (const u_char *)ipds->ip, ipds->len);
420 break;
421
422 case IPPROTO_DCCP:
423 dccp_print(ipds->cp, (const u_char *)ipds->ip, ipds->len);
424 break;
425
426 case IPPROTO_TCP:
427 /* pass on the MF bit plus the offset to detect fragments */
428 tcp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
429 ipds->off & (IP_MF|IP_OFFMASK));
430 break;
431
432 case IPPROTO_UDP:
433 /* pass on the MF bit plus the offset to detect fragments */
434 udp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
435 ipds->off & (IP_MF|IP_OFFMASK));
436 break;
437
438 case IPPROTO_ICMP:
439 /* pass on the MF bit plus the offset to detect fragments */
440 icmp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
441 ipds->off & (IP_MF|IP_OFFMASK));
442 break;
443
444 case IPPROTO_PIGP:
445 /*
446 * XXX - the current IANA protocol number assignments
447 * page lists 9 as "any private interior gateway
448 * (used by Cisco for their IGRP)" and 88 as
449 * "EIGRP" from Cisco.
450 *
451 * Recent BSD <netinet/in.h> headers define
452 * IP_PROTO_PIGP as 9 and IP_PROTO_IGRP as 88.
453 * We define IP_PROTO_PIGP as 9 and
454 * IP_PROTO_EIGRP as 88; those names better
455 * match was the current protocol number
456 * assignments say.
457 */
458 igrp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
459 break;
460
461 case IPPROTO_EIGRP:
462 eigrp_print(ipds->cp, ipds->len);
463 break;
464
465 case IPPROTO_ND:
466 ND_PRINT((ndo, " nd %d", ipds->len));
467 break;
468
469 case IPPROTO_EGP:
470 egp_print(ipds->cp, ipds->len);
471 break;
472
473 case IPPROTO_OSPF:
474 ospf_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
475 break;
476
477 case IPPROTO_IGMP:
478 igmp_print(ipds->cp, ipds->len);
479 break;
480
481 case IPPROTO_IPV4:
482 /* DVMRP multicast tunnel (ip-in-ip encapsulation) */
483 ip_print(gndo, ipds->cp, ipds->len);
484 if (! vflag) {
485 ND_PRINT((ndo, " (ipip-proto-4)"));
486 return;
487 }
488 break;
489
490#ifdef INET6
491 case IPPROTO_IPV6:
492 /* ip6-in-ip encapsulation */
493 ip6_print(ipds->cp, ipds->len);
494 break;
495#endif /*INET6*/
496
497 case IPPROTO_RSVP:
498 rsvp_print(ipds->cp, ipds->len);
499 break;
500
501 case IPPROTO_GRE:
502 /* do it */
503 gre_print(ipds->cp, ipds->len);
504 break;
505
506 case IPPROTO_MOBILE:
507 mobile_print(ipds->cp, ipds->len);
508 break;
509
510 case IPPROTO_PIM:
511 pim_print(ipds->cp, ipds->len);
512 break;
513
514 case IPPROTO_VRRP:
515 vrrp_print(ipds->cp, ipds->len, ipds->ip->ip_ttl);
516 break;
517
518 case IPPROTO_PGM:
519 pgm_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
520 break;
521
522 default:
523 if ((proto = getprotobynumber(ipds->nh)) != NULL)
524 ND_PRINT((ndo, " %s", proto->p_name));
525 else
526 ND_PRINT((ndo, " ip-proto-%d", ipds->nh));
527 ND_PRINT((ndo, " %d", ipds->len));
528 break;
529 }
530}
531
532void
533ip_print_inner(netdissect_options *ndo,
534 const u_char *bp,
535 u_int length, u_int nh,
536 const u_char *bp2)
537{
538 struct ip_print_demux_state ipd;
539
540 ipd.ip = (const struct ip *)bp2;
541 ipd.cp = bp;
542 ipd.len = length;
543 ipd.off = 0;
544 ipd.nh = nh;
545 ipd.advance = 0;
546
547 ip_print_demux(ndo, &ipd);
548}
549
550
551/*
552 * print an IP datagram.
553 */
554void
555ip_print(netdissect_options *ndo,
556 const u_char *bp,
557 u_int length)
558{
559 struct ip_print_demux_state ipd;
560 struct ip_print_demux_state *ipds=&ipd;
561 const u_char *ipend;
562 u_int hlen;
563 u_int16_t sum, ip_sum;
564 struct protoent *proto;
565
566 ipds->ip = (const struct ip *)bp;
567 if (IP_V(ipds->ip) != 4) { /* print version if != 4 */
568 printf("IP%u ", IP_V(ipds->ip));
569 if (IP_V(ipds->ip) == 6)
570 printf(", wrong link-layer encapsulation");
571 }
572 else if (!eflag)
573 printf("IP ");
574
575 if ((u_char *)(ipds->ip + 1) > snapend) {
576 printf("[|ip]");
577 return;
578 }
579 if (length < sizeof (struct ip)) {
580 (void)printf("truncated-ip %u", length);
581 return;
582 }
583 hlen = IP_HL(ipds->ip) * 4;
584 if (hlen < sizeof (struct ip)) {
585 (void)printf("bad-hlen %u", hlen);
586 return;
587 }
588
589 ipds->len = EXTRACT_16BITS(&ipds->ip->ip_len);
590 if (length < ipds->len)
591 (void)printf("truncated-ip - %u bytes missing! ",
592 ipds->len - length);
593 if (ipds->len < hlen) {
594#ifdef GUESS_TSO
595 if (ipds->len) {
596 (void)printf("bad-len %u", ipds->len);
597 return;
598 }
599 else {
600 /* we guess that it is a TSO send */
601 ipds->len = length;
602 }
603#else
604 (void)printf("bad-len %u", ipds->len);
605 return;
606#endif /* GUESS_TSO */
607 }
608
609 /*
610 * Cut off the snapshot length to the end of the IP payload.
611 */
612 ipend = bp + ipds->len;
613 if (ipend < snapend)
614 snapend = ipend;
615
616 ipds->len -= hlen;
617
618 ipds->off = EXTRACT_16BITS(&ipds->ip->ip_off);
619
620 if (vflag) {
621 (void)printf("(tos 0x%x", (int)ipds->ip->ip_tos);
622 /* ECN bits */
623 if (ipds->ip->ip_tos & 0x03) {
624 switch (ipds->ip->ip_tos & 0x03) {
625 case 1:
626 (void)printf(",ECT(1)");
627 break;
628 case 2:
629 (void)printf(",ECT(0)");
630 break;
631 case 3:
632 (void)printf(",CE");
633 }
634 }
635
636 if (ipds->ip->ip_ttl >= 1)
66170f0a 637 (void)printf(", ttl %u", ipds->ip->ip_ttl);
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638
639 /*
640 * for the firewall guys, print id, offset.
641 * On all but the last stick a "+" in the flags portion.
642 * For unfragmented datagrams, note the don't fragment flag.
643 */
644
66170f0a 645 (void)printf(", id %u, offset %u, flags [%s], proto %s (%u)",
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646 EXTRACT_16BITS(&ipds->ip->ip_id),
647 (ipds->off & 0x1fff) * 8,
66170f0a 648 bittok2str(ip_frag_values, "none", ipds->off&0xe000),
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649 tok2str(ipproto_values,"unknown",ipds->ip->ip_p),
650 ipds->ip->ip_p);
651
66170f0a 652 (void)printf(", length %u", EXTRACT_16BITS(&ipds->ip->ip_len));
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653
654 if ((hlen - sizeof(struct ip)) > 0) {
655 printf(", options (");
656 ip_optprint((u_char *)(ipds->ip + 1), hlen - sizeof(struct ip));
657 printf(")");
658 }
659
660 if ((u_char *)ipds->ip + hlen <= snapend) {
661 sum = in_cksum((const u_short *)ipds->ip, hlen, 0);
662 if (sum != 0) {
663 ip_sum = EXTRACT_16BITS(&ipds->ip->ip_sum);
664 (void)printf(", bad cksum %x (->%x)!", ip_sum,
665 in_cksum_shouldbe(ip_sum, sum));
666 }
667 }
668
669 printf(") ");
670 }
671
672 /*
673 * If this is fragment zero, hand it to the next higher
674 * level protocol.
675 */
676 if ((ipds->off & 0x1fff) == 0) {
677 ipds->cp = (const u_char *)ipds->ip + hlen;
678 ipds->nh = ipds->ip->ip_p;
679
680 if (ipds->nh != IPPROTO_TCP && ipds->nh != IPPROTO_UDP &&
681 ipds->nh != IPPROTO_SCTP && ipds->nh != IPPROTO_DCCP) {
682 (void)printf("%s > %s: ",
683 ipaddr_string(&ipds->ip->ip_src),
684 ipaddr_string(&ipds->ip->ip_dst));
685 }
686 ip_print_demux(ndo, ipds);
687 } else {
688 /* Ultra quiet now means that all this stuff should be suppressed */
689 if (qflag > 1) return;
690
691 /*
692 * if this isn't the first frag, we're missing the
693 * next level protocol header. print the ip addr
694 * and the protocol.
695 */
696 if (ipds->off & 0x1fff) {
697 (void)printf("%s > %s:", ipaddr_string(&ipds->ip->ip_src),
698 ipaddr_string(&ipds->ip->ip_dst));
699 if ((proto = getprotobynumber(ipds->ip->ip_p)) != NULL)
700 (void)printf(" %s", proto->p_name);
701 else
702 (void)printf(" ip-proto-%d", ipds->ip->ip_p);
703 }
704 }
705}
706
707void
708ipN_print(register const u_char *bp, register u_int length)
709{
710 struct ip *ip, hdr;
711
712 ip = (struct ip *)bp;
713 if (length < 4) {
714 (void)printf("truncated-ip %d", length);
715 return;
716 }
717 memcpy (&hdr, (char *)ip, 4);
718 switch (IP_V(&hdr)) {
719 case 4:
720 ip_print (gndo, bp, length);
721 return;
722#ifdef INET6
723 case 6:
724 ip6_print (bp, length);
725 return;
726#endif
727 default:
728 (void)printf("unknown ip %d", IP_V(&hdr));
729 return;
730 }
731}
732
733/*
734 * Local Variables:
735 * c-style: whitesmith
736 * c-basic-offset: 8
737 * End:
738 */
739
740