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
23 static const char rcsid[] _U_ =
24 "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.159 2007-09-14 01:29:28 guy Exp $ (LBL)";
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
44 static const struct 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" },
53 { IPOPT_RFC1393, "traceroute" },
54 { 0, NULL }
55 };
56
57 /*
58 * print the recorded route in an IP RR, LSRR or SSRR option.
59 */
60 static void
ip_printroute(register const u_char * cp,u_int length)61 ip_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 */
90 static u_int32_t
ip_finddst(const struct ip * ip)91 ip_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 UNALIGNED_MEMCPY(&retval, cp + len - 4, 4);
124 return retval;
125 }
126 }
127 trunc:
128 UNALIGNED_MEMCPY(&retval, &ip->ip_dst.s_addr, sizeof(u_int32_t));
129 return retval;
130 }
131
132 /*
133 * Compute a V4-style checksum by building a pseudoheader.
134 */
135 int
nextproto4_cksum(const struct ip * ip,const u_int8_t * data,u_int len,u_int next_proto)136 nextproto4_cksum(const struct ip *ip, const u_int8_t *data,
137 u_int len, u_int next_proto)
138 {
139 struct phdr {
140 u_int32_t src;
141 u_int32_t dst;
142 u_char mbz;
143 u_char proto;
144 u_int16_t len;
145 } ph;
146 struct cksum_vec vec[2];
147
148 /* pseudo-header.. */
149 ph.len = htons((u_int16_t)len);
150 ph.mbz = 0;
151 ph.proto = next_proto;
152 UNALIGNED_MEMCPY(&ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
153 if (IP_HL(ip) == 5)
154 UNALIGNED_MEMCPY(&ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
155 else
156 ph.dst = ip_finddst(ip);
157
158 vec[0].ptr = (const u_int8_t *)(void *)&ph;
159 vec[0].len = sizeof(ph);
160 vec[1].ptr = data;
161 vec[1].len = len;
162 return (in_cksum(vec, 2));
163 }
164
165 static void
ip_printts(register const u_char * cp,u_int length)166 ip_printts(register const u_char *cp, u_int length)
167 {
168 register u_int ptr;
169 register u_int len;
170 int hoplen;
171 const char *type;
172
173 if (length < 4) {
174 printf("[bad length %u]", length);
175 return;
176 }
177 printf(" TS{");
178 hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
179 if ((length - 4) & (hoplen-1))
180 printf("[bad length %u]", length);
181 ptr = cp[2] - 1;
182 len = 0;
183 if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
184 printf("[bad ptr %u]", cp[2]);
185 switch (cp[3]&0xF) {
186 case IPOPT_TS_TSONLY:
187 printf("TSONLY");
188 break;
189 case IPOPT_TS_TSANDADDR:
190 printf("TS+ADDR");
191 break;
192 /*
193 * prespecified should really be 3, but some ones might send 2
194 * instead, and the IPOPT_TS_PRESPEC constant can apparently
195 * have both values, so we have to hard-code it here.
196 */
197
198 case 2:
199 printf("PRESPEC2.0");
200 break;
201 case 3: /* IPOPT_TS_PRESPEC */
202 printf("PRESPEC");
203 break;
204 default:
205 printf("[bad ts type %d]", cp[3]&0xF);
206 goto done;
207 }
208
209 type = " ";
210 for (len = 4; len < length; len += hoplen) {
211 if (ptr == len)
212 type = " ^ ";
213 printf("%s%d@%s", type, EXTRACT_32BITS(&cp[len+hoplen-4]),
214 hoplen!=8 ? "" : ipaddr_string(&cp[len]));
215 type = " ";
216 }
217
218 done:
219 printf("%s", ptr == len ? " ^ " : "");
220
221 if (cp[3]>>4)
222 printf(" [%d hops not recorded]} ", cp[3]>>4);
223 else
224 printf("}");
225 }
226
227 /*
228 * print IP options.
229 */
230 static void
ip_optprint(register const u_char * cp,u_int length)231 ip_optprint(register const u_char *cp, u_int length)
232 {
233 register u_int option_len;
234 const char *sep = "";
235
236 for (; length > 0; cp += option_len, length -= option_len) {
237 u_int option_code;
238
239 printf("%s", sep);
240 sep = ",";
241
242 TCHECK(*cp);
243 option_code = *cp;
244
245 printf("%s",
246 tok2str(ip_option_values,"unknown %u",option_code));
247
248 if (option_code == IPOPT_NOP ||
249 option_code == IPOPT_EOL)
250 option_len = 1;
251
252 else {
253 TCHECK(cp[1]);
254 option_len = cp[1];
255 if (option_len < 2) {
256 printf(" [bad length %u]", option_len);
257 return;
258 }
259 }
260
261 if (option_len > length) {
262 printf(" [bad length %u]", option_len);
263 return;
264 }
265
266 TCHECK2(*cp, option_len);
267
268 switch (option_code) {
269 case IPOPT_EOL:
270 return;
271
272 case IPOPT_TS:
273 ip_printts(cp, option_len);
274 break;
275
276 case IPOPT_RR: /* fall through */
277 case IPOPT_SSRR:
278 case IPOPT_LSRR:
279 ip_printroute(cp, option_len);
280 break;
281
282 case IPOPT_RA:
283 if (option_len < 4) {
284 printf(" [bad length %u]", option_len);
285 break;
286 }
287 TCHECK(cp[3]);
288 if (EXTRACT_16BITS(&cp[2]) != 0)
289 printf(" value %u", EXTRACT_16BITS(&cp[2]));
290 break;
291
292 case IPOPT_NOP: /* nothing to print - fall through */
293 case IPOPT_SECURITY:
294 default:
295 break;
296 }
297 }
298 return;
299
300 trunc:
301 printf("[|ip]");
302 }
303
304 #define IP_RES 0x8000
305
306 static const struct tok ip_frag_values[] = {
307 { IP_MF, "+" },
308 { IP_DF, "DF" },
309 { IP_RES, "rsvd" }, /* The RFC3514 evil ;-) bit */
310 { 0, NULL }
311 };
312
313 struct ip_print_demux_state {
314 const struct ip *ip;
315 const u_char *cp;
316 u_int len, off;
317 u_char nh;
318 int advance;
319 };
320
321 static void
ip_print_demux(netdissect_options * ndo,struct ip_print_demux_state * ipds)322 ip_print_demux(netdissect_options *ndo,
323 struct ip_print_demux_state *ipds)
324 {
325 struct protoent *proto;
326 struct cksum_vec vec[1];
327
328 again:
329 switch (ipds->nh) {
330
331 case IPPROTO_AH:
332 ipds->nh = *ipds->cp;
333 ipds->advance = ah_print(ipds->cp);
334 if (ipds->advance <= 0)
335 break;
336 ipds->cp += ipds->advance;
337 ipds->len -= ipds->advance;
338 goto again;
339
340 case IPPROTO_ESP:
341 {
342 int enh, padlen;
343 ipds->advance = esp_print(ndo, ipds->cp, ipds->len,
344 (const u_char *)ipds->ip,
345 &enh, &padlen);
346 if (ipds->advance <= 0)
347 break;
348 ipds->cp += ipds->advance;
349 ipds->len -= ipds->advance + padlen;
350 ipds->nh = enh & 0xff;
351 goto again;
352 }
353
354 case IPPROTO_IPCOMP:
355 {
356 int enh;
357 ipds->advance = ipcomp_print(ipds->cp, &enh);
358 if (ipds->advance <= 0)
359 break;
360 ipds->cp += ipds->advance;
361 ipds->len -= ipds->advance;
362 ipds->nh = enh & 0xff;
363 goto again;
364 }
365
366 case IPPROTO_SCTP:
367 sctp_print(ipds->cp, (const u_char *)ipds->ip, ipds->len);
368 break;
369
370 case IPPROTO_DCCP:
371 dccp_print(ipds->cp, (const u_char *)ipds->ip, ipds->len);
372 break;
373
374 case IPPROTO_TCP:
375 /* pass on the MF bit plus the offset to detect fragments */
376 tcp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
377 ipds->off & (IP_MF|IP_OFFMASK));
378 break;
379
380 case IPPROTO_UDP:
381 /* pass on the MF bit plus the offset to detect fragments */
382 udp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
383 ipds->off & (IP_MF|IP_OFFMASK));
384 break;
385
386 case IPPROTO_ICMP:
387 /* pass on the MF bit plus the offset to detect fragments */
388 icmp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
389 ipds->off & (IP_MF|IP_OFFMASK));
390 break;
391
392 case IPPROTO_PIGP:
393 /*
394 * XXX - the current IANA protocol number assignments
395 * page lists 9 as "any private interior gateway
396 * (used by Cisco for their IGRP)" and 88 as
397 * "EIGRP" from Cisco.
398 *
399 * Recent BSD <netinet/in.h> headers define
400 * IP_PROTO_PIGP as 9 and IP_PROTO_IGRP as 88.
401 * We define IP_PROTO_PIGP as 9 and
402 * IP_PROTO_EIGRP as 88; those names better
403 * match was the current protocol number
404 * assignments say.
405 */
406 igrp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
407 break;
408
409 case IPPROTO_EIGRP:
410 eigrp_print(ipds->cp, ipds->len);
411 break;
412
413 case IPPROTO_ND:
414 ND_PRINT((ndo, " nd %d", ipds->len));
415 break;
416
417 case IPPROTO_EGP:
418 egp_print(ipds->cp, ipds->len);
419 break;
420
421 case IPPROTO_OSPF:
422 ospf_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
423 break;
424
425 case IPPROTO_IGMP:
426 igmp_print(ipds->cp, ipds->len);
427 break;
428
429 case IPPROTO_IPV4:
430 /* DVMRP multicast tunnel (ip-in-ip encapsulation) */
431 ip_print(ndo, ipds->cp, ipds->len);
432 if (! vflag) {
433 ND_PRINT((ndo, " (ipip-proto-4)"));
434 return;
435 }
436 break;
437
438 #ifdef INET6
439 case IPPROTO_IPV6:
440 /* ip6-in-ip encapsulation */
441 ip6_print(ndo, ipds->cp, ipds->len);
442 break;
443 #endif /*INET6*/
444
445 case IPPROTO_RSVP:
446 rsvp_print(ipds->cp, ipds->len);
447 break;
448
449 case IPPROTO_GRE:
450 /* do it */
451 gre_print(ipds->cp, ipds->len);
452 break;
453
454 case IPPROTO_MOBILE:
455 mobile_print(ipds->cp, ipds->len);
456 break;
457
458 case IPPROTO_PIM:
459 vec[0].ptr = ipds->cp;
460 vec[0].len = ipds->len;
461 pim_print(ipds->cp, ipds->len, in_cksum(vec, 1));
462 break;
463
464 case IPPROTO_VRRP:
465 if (packettype == PT_CARP) {
466 if (vflag)
467 (void)printf("carp %s > %s: ",
468 ipaddr_string(&ipds->ip->ip_src),
469 ipaddr_string(&ipds->ip->ip_dst));
470 carp_print(ipds->cp, ipds->len, ipds->ip->ip_ttl);
471 } else {
472 if (vflag)
473 (void)printf("vrrp %s > %s: ",
474 ipaddr_string(&ipds->ip->ip_src),
475 ipaddr_string(&ipds->ip->ip_dst));
476 vrrp_print(ipds->cp, ipds->len, ipds->ip->ip_ttl);
477 }
478 break;
479
480 case IPPROTO_PGM:
481 pgm_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
482 break;
483
484 default:
485 if (ndo->ndo_nflag==0 && (proto = getprotobynumber(ipds->nh)) != NULL)
486 ND_PRINT((ndo, " %s", proto->p_name));
487 else
488 ND_PRINT((ndo, " ip-proto-%d", ipds->nh));
489 ND_PRINT((ndo, " %d", ipds->len));
490 break;
491 }
492 }
493
494 void
ip_print_inner(netdissect_options * ndo,const u_char * bp,u_int length,u_int nh,const u_char * bp2)495 ip_print_inner(netdissect_options *ndo,
496 const u_char *bp,
497 u_int length, u_int nh,
498 const u_char *bp2)
499 {
500 struct ip_print_demux_state ipd;
501
502 ipd.ip = (const struct ip *)bp2;
503 ipd.cp = bp;
504 ipd.len = length;
505 ipd.off = 0;
506 ipd.nh = nh;
507 ipd.advance = 0;
508
509 ip_print_demux(ndo, &ipd);
510 }
511
512
513 /*
514 * print an IP datagram.
515 */
516 void
ip_print(netdissect_options * ndo,const u_char * bp,u_int length)517 ip_print(netdissect_options *ndo,
518 const u_char *bp,
519 u_int length)
520 {
521 struct ip_print_demux_state ipd;
522 struct ip_print_demux_state *ipds=&ipd;
523 const u_char *ipend;
524 u_int hlen;
525 struct cksum_vec vec[1];
526 u_int16_t sum, ip_sum;
527 struct protoent *proto;
528
529 ipds->ip = (const struct ip *)bp;
530 if (IP_V(ipds->ip) != 4) { /* print version if != 4 */
531 printf("IP%u ", IP_V(ipds->ip));
532 if (IP_V(ipds->ip) == 6)
533 printf(", wrong link-layer encapsulation");
534 }
535 else if (!eflag)
536 printf("IP ");
537
538 if ((u_char *)(ipds->ip + 1) > ndo->ndo_snapend) {
539 printf("[|ip]");
540 return;
541 }
542 if (length < sizeof (struct ip)) {
543 (void)printf("truncated-ip %u", length);
544 return;
545 }
546 hlen = IP_HL(ipds->ip) * 4;
547 if (hlen < sizeof (struct ip)) {
548 (void)printf("bad-hlen %u", hlen);
549 return;
550 }
551
552 ipds->len = EXTRACT_16BITS(&ipds->ip->ip_len);
553 if (length < ipds->len)
554 (void)printf("truncated-ip - %u bytes missing! ",
555 ipds->len - length);
556 if (ipds->len < hlen) {
557 #ifdef GUESS_TSO
558 if (ipds->len) {
559 (void)printf("bad-len %u", ipds->len);
560 return;
561 }
562 else {
563 /* we guess that it is a TSO send */
564 ipds->len = length;
565 }
566 #else
567 (void)printf("bad-len %u", ipds->len);
568 return;
569 #endif /* GUESS_TSO */
570 }
571
572 /*
573 * Cut off the snapshot length to the end of the IP payload.
574 */
575 ipend = bp + ipds->len;
576 if (ipend < ndo->ndo_snapend)
577 ndo->ndo_snapend = ipend;
578
579 ipds->len -= hlen;
580
581 ipds->off = EXTRACT_16BITS(&ipds->ip->ip_off);
582
583 if (vflag) {
584 (void)printf("(tos 0x%x", (int)ipds->ip->ip_tos);
585 /* ECN bits */
586 if (ipds->ip->ip_tos & 0x03) {
587 switch (ipds->ip->ip_tos & 0x03) {
588 case 1:
589 (void)printf(",ECT(1)");
590 break;
591 case 2:
592 (void)printf(",ECT(0)");
593 break;
594 case 3:
595 (void)printf(",CE");
596 }
597 }
598
599 if (ipds->ip->ip_ttl >= 1)
600 (void)printf(", ttl %u", ipds->ip->ip_ttl);
601
602 /*
603 * for the firewall guys, print id, offset.
604 * On all but the last stick a "+" in the flags portion.
605 * For unfragmented datagrams, note the don't fragment flag.
606 */
607
608 (void)printf(", id %u, offset %u, flags [%s], proto %s (%u)",
609 EXTRACT_16BITS(&ipds->ip->ip_id),
610 (ipds->off & 0x1fff) * 8,
611 bittok2str(ip_frag_values, "none", ipds->off&0xe000),
612 tok2str(ipproto_values,"unknown",ipds->ip->ip_p),
613 ipds->ip->ip_p);
614
615 (void)printf(", length %u", EXTRACT_16BITS(&ipds->ip->ip_len));
616
617 if ((hlen - sizeof(struct ip)) > 0) {
618 printf(", options (");
619 ip_optprint((u_char *)(ipds->ip + 1), hlen - sizeof(struct ip));
620 printf(")");
621 }
622
623 if (!Kflag && (u_char *)ipds->ip + hlen <= ndo->ndo_snapend) {
624 vec[0].ptr = (const u_int8_t *)(void *)ipds->ip;
625 vec[0].len = hlen;
626 sum = in_cksum(vec, 1);
627 if (sum != 0) {
628 ip_sum = EXTRACT_16BITS(&ipds->ip->ip_sum);
629 (void)printf(", bad cksum %x (->%x)!", ip_sum,
630 in_cksum_shouldbe(ip_sum, sum));
631 }
632 }
633
634 printf(")\n ");
635 }
636
637 /*
638 * If this is fragment zero, hand it to the next higher
639 * level protocol.
640 */
641 if ((ipds->off & 0x1fff) == 0) {
642 ipds->cp = (const u_char *)ipds->ip + hlen;
643 ipds->nh = ipds->ip->ip_p;
644
645 if (ipds->nh != IPPROTO_TCP && ipds->nh != IPPROTO_UDP &&
646 ipds->nh != IPPROTO_SCTP && ipds->nh != IPPROTO_DCCP) {
647 (void)printf("%s > %s: ",
648 ipaddr_string(&ipds->ip->ip_src),
649 ipaddr_string(&ipds->ip->ip_dst));
650 }
651 ip_print_demux(ndo, ipds);
652 } else {
653 /* Ultra quiet now means that all this stuff should be suppressed */
654 if (qflag > 1) return;
655
656 /*
657 * if this isn't the first frag, we're missing the
658 * next level protocol header. print the ip addr
659 * and the protocol.
660 */
661 if (ipds->off & 0x1fff) {
662 (void)printf("%s > %s:", ipaddr_string(&ipds->ip->ip_src),
663 ipaddr_string(&ipds->ip->ip_dst));
664 if (!ndo->ndo_nflag && (proto = getprotobynumber(ipds->ip->ip_p)) != NULL)
665 (void)printf(" %s", proto->p_name);
666 else
667 (void)printf(" ip-proto-%d", ipds->ip->ip_p);
668 }
669 }
670 }
671
672 void
ipN_print(register const u_char * bp,register u_int length)673 ipN_print(register const u_char *bp, register u_int length)
674 {
675 struct ip hdr;
676
677 if (length < 4) {
678 (void)printf("truncated-ip %d", length);
679 return;
680 }
681 memcpy (&hdr, bp, 4);
682 switch (IP_V(&hdr)) {
683 case 4:
684 ip_print (gndo, bp, length);
685 return;
686 #ifdef INET6
687 case 6:
688 ip6_print (gndo, bp, length);
689 return;
690 #endif
691 default:
692 (void)printf("unknown ip %d", IP_V(&hdr));
693 return;
694 }
695 }
696
697 /*
698 * Local Variables:
699 * c-style: whitesmith
700 * c-basic-offset: 8
701 * End:
702 */
703
704
705