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 #include <sys/cdefs.h>
23 #ifndef lint
24 __RCSID("$NetBSD: print-ip.c,v 1.8 2015/03/31 21:59:35 christos Exp $");
25 #endif
26
27 #define NETDISSECT_REWORKED
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 #include <tcpdump-stdinc.h>
33
34 #include <string.h>
35
36 #include "interface.h"
37 #include "addrtoname.h"
38 #include "extract.h" /* must come after interface.h */
39
40 #include "ip.h"
41 #include "ipproto.h"
42
43 static const char tstr[] = "[|ip]";
44
45 static const struct tok ip_option_values[] = {
46 { IPOPT_EOL, "EOL" },
47 { IPOPT_NOP, "NOP" },
48 { IPOPT_TS, "timestamp" },
49 { IPOPT_SECURITY, "security" },
50 { IPOPT_RR, "RR" },
51 { IPOPT_SSRR, "SSRR" },
52 { IPOPT_LSRR, "LSRR" },
53 { IPOPT_RA, "RA" },
54 { IPOPT_RFC1393, "traceroute" },
55 { 0, NULL }
56 };
57
58 /*
59 * print the recorded route in an IP RR, LSRR or SSRR option.
60 */
61 static void
ip_printroute(netdissect_options * ndo,register const u_char * cp,u_int length)62 ip_printroute(netdissect_options *ndo,
63 register const u_char *cp, u_int length)
64 {
65 register u_int ptr;
66 register u_int len;
67
68 if (length < 3) {
69 ND_PRINT((ndo, " [bad length %u]", length));
70 return;
71 }
72 if ((length + 1) & 3)
73 ND_PRINT((ndo, " [bad length %u]", length));
74 ptr = cp[2] - 1;
75 if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
76 ND_PRINT((ndo, " [bad ptr %u]", cp[2]));
77
78 for (len = 3; len < length; len += 4) {
79 ND_PRINT((ndo, " %s", ipaddr_string(ndo, &cp[len])));
80 if (ptr > len)
81 ND_PRINT((ndo, ","));
82 }
83 }
84
85 /*
86 * If source-routing is present and valid, return the final destination.
87 * Otherwise, return IP destination.
88 *
89 * This is used for UDP and TCP pseudo-header in the checksum
90 * calculation.
91 */
92 static uint32_t
ip_finddst(netdissect_options * ndo,const struct ip * ip)93 ip_finddst(netdissect_options *ndo,
94 const struct ip *ip)
95 {
96 int length;
97 int len;
98 const u_char *cp;
99 uint32_t retval;
100
101 cp = (const u_char *)(ip + 1);
102 length = (IP_HL(ip) << 2) - sizeof(struct ip);
103
104 for (; length > 0; cp += len, length -= len) {
105 int tt;
106
107 ND_TCHECK(*cp);
108 tt = *cp;
109 if (tt == IPOPT_EOL)
110 break;
111 else if (tt == IPOPT_NOP)
112 len = 1;
113 else {
114 ND_TCHECK(cp[1]);
115 len = cp[1];
116 if (len < 2)
117 break;
118 }
119 ND_TCHECK2(*cp, len);
120 switch (tt) {
121
122 case IPOPT_SSRR:
123 case IPOPT_LSRR:
124 if (len < 7)
125 break;
126 UNALIGNED_MEMCPY(&retval, cp + len - 4, 4);
127 return retval;
128 }
129 }
130 trunc:
131 UNALIGNED_MEMCPY(&retval, &ip->ip_dst.s_addr, sizeof(uint32_t));
132 return retval;
133 }
134
135 /*
136 * Compute a V4-style checksum by building a pseudoheader.
137 */
138 int
nextproto4_cksum(netdissect_options * ndo,const struct ip * ip,const uint8_t * data,u_int len,u_int covlen,u_int next_proto)139 nextproto4_cksum(netdissect_options *ndo,
140 const struct ip *ip, const uint8_t *data,
141 u_int len, u_int covlen, u_int next_proto)
142 {
143 struct phdr {
144 uint32_t src;
145 uint32_t dst;
146 u_char mbz;
147 u_char proto;
148 uint16_t len;
149 } ph;
150 struct cksum_vec vec[2];
151
152 /* pseudo-header.. */
153 ph.len = htons((uint16_t)len);
154 ph.mbz = 0;
155 ph.proto = next_proto;
156 UNALIGNED_MEMCPY(&ph.src, &ip->ip_src.s_addr, sizeof(uint32_t));
157 if (IP_HL(ip) == 5)
158 UNALIGNED_MEMCPY(&ph.dst, &ip->ip_dst.s_addr, sizeof(uint32_t));
159 else
160 ph.dst = ip_finddst(ndo, ip);
161
162 vec[0].ptr = (const uint8_t *)(void *)&ph;
163 vec[0].len = sizeof(ph);
164 vec[1].ptr = data;
165 vec[1].len = covlen;
166 return (in_cksum(vec, 2));
167 }
168
169 static void
ip_printts(netdissect_options * ndo,register const u_char * cp,u_int length)170 ip_printts(netdissect_options *ndo,
171 register const u_char *cp, u_int length)
172 {
173 register u_int ptr;
174 register u_int len;
175 int hoplen;
176 const char *type;
177
178 if (length < 4) {
179 ND_PRINT((ndo, "[bad length %u]", length));
180 return;
181 }
182 ND_PRINT((ndo, " TS{"));
183 hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
184 if ((length - 4) & (hoplen-1))
185 ND_PRINT((ndo, "[bad length %u]", length));
186 ptr = cp[2] - 1;
187 len = 0;
188 if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
189 ND_PRINT((ndo, "[bad ptr %u]", cp[2]));
190 switch (cp[3]&0xF) {
191 case IPOPT_TS_TSONLY:
192 ND_PRINT((ndo, "TSONLY"));
193 break;
194 case IPOPT_TS_TSANDADDR:
195 ND_PRINT((ndo, "TS+ADDR"));
196 break;
197 /*
198 * prespecified should really be 3, but some ones might send 2
199 * instead, and the IPOPT_TS_PRESPEC constant can apparently
200 * have both values, so we have to hard-code it here.
201 */
202
203 case 2:
204 ND_PRINT((ndo, "PRESPEC2.0"));
205 break;
206 case 3: /* IPOPT_TS_PRESPEC */
207 ND_PRINT((ndo, "PRESPEC"));
208 break;
209 default:
210 ND_PRINT((ndo, "[bad ts type %d]", cp[3]&0xF));
211 goto done;
212 }
213
214 type = " ";
215 for (len = 4; len < length; len += hoplen) {
216 if (ptr == len)
217 type = " ^ ";
218 ND_PRINT((ndo, "%s%d@%s", type, EXTRACT_32BITS(&cp[len+hoplen-4]),
219 hoplen!=8 ? "" : ipaddr_string(ndo, &cp[len])));
220 type = " ";
221 }
222
223 done:
224 ND_PRINT((ndo, "%s", ptr == len ? " ^ " : ""));
225
226 if (cp[3]>>4)
227 ND_PRINT((ndo, " [%d hops not recorded]} ", cp[3]>>4));
228 else
229 ND_PRINT((ndo, "}"));
230 }
231
232 /*
233 * print IP options.
234 */
235 static void
ip_optprint(netdissect_options * ndo,register const u_char * cp,u_int length)236 ip_optprint(netdissect_options *ndo,
237 register const u_char *cp, u_int length)
238 {
239 register u_int option_len;
240 const char *sep = "";
241
242 for (; length > 0; cp += option_len, length -= option_len) {
243 u_int option_code;
244
245 ND_PRINT((ndo, "%s", sep));
246 sep = ",";
247
248 ND_TCHECK(*cp);
249 option_code = *cp;
250
251 ND_PRINT((ndo, "%s",
252 tok2str(ip_option_values,"unknown %u",option_code)));
253
254 if (option_code == IPOPT_NOP ||
255 option_code == IPOPT_EOL)
256 option_len = 1;
257
258 else {
259 ND_TCHECK(cp[1]);
260 option_len = cp[1];
261 if (option_len < 2) {
262 ND_PRINT((ndo, " [bad length %u]", option_len));
263 return;
264 }
265 }
266
267 if (option_len > length) {
268 ND_PRINT((ndo, " [bad length %u]", option_len));
269 return;
270 }
271
272 ND_TCHECK2(*cp, option_len);
273
274 switch (option_code) {
275 case IPOPT_EOL:
276 return;
277
278 case IPOPT_TS:
279 ip_printts(ndo, cp, option_len);
280 break;
281
282 case IPOPT_RR: /* fall through */
283 case IPOPT_SSRR:
284 case IPOPT_LSRR:
285 ip_printroute(ndo, cp, option_len);
286 break;
287
288 case IPOPT_RA:
289 if (option_len < 4) {
290 ND_PRINT((ndo, " [bad length %u]", option_len));
291 break;
292 }
293 ND_TCHECK(cp[3]);
294 if (EXTRACT_16BITS(&cp[2]) != 0)
295 ND_PRINT((ndo, " value %u", EXTRACT_16BITS(&cp[2])));
296 break;
297
298 case IPOPT_NOP: /* nothing to print - fall through */
299 case IPOPT_SECURITY:
300 default:
301 break;
302 }
303 }
304 return;
305
306 trunc:
307 ND_PRINT((ndo, "%s", tstr));
308 }
309
310 #define IP_RES 0x8000
311
312 static const struct tok ip_frag_values[] = {
313 { IP_MF, "+" },
314 { IP_DF, "DF" },
315 { IP_RES, "rsvd" }, /* The RFC3514 evil ;-) bit */
316 { 0, NULL }
317 };
318
319 struct ip_print_demux_state {
320 const struct ip *ip;
321 const u_char *cp;
322 u_int len, off;
323 u_char nh;
324 int advance;
325 };
326
327 static void
ip_print_demux(netdissect_options * ndo,struct ip_print_demux_state * ipds)328 ip_print_demux(netdissect_options *ndo,
329 struct ip_print_demux_state *ipds)
330 {
331 struct protoent *proto;
332 struct cksum_vec vec[1];
333
334 again:
335 switch (ipds->nh) {
336
337 case IPPROTO_AH:
338 ipds->nh = *ipds->cp;
339 ipds->advance = ah_print(ndo, ipds->cp);
340 if (ipds->advance <= 0)
341 break;
342 ipds->cp += ipds->advance;
343 ipds->len -= ipds->advance;
344 goto again;
345
346 case IPPROTO_ESP:
347 {
348 int enh, padlen;
349 ipds->advance = esp_print(ndo, ipds->cp, ipds->len,
350 (const u_char *)ipds->ip,
351 &enh, &padlen);
352 if (ipds->advance <= 0)
353 break;
354 ipds->cp += ipds->advance;
355 ipds->len -= ipds->advance + padlen;
356 ipds->nh = enh & 0xff;
357 goto again;
358 }
359
360 case IPPROTO_IPCOMP:
361 {
362 int enh;
363 ipds->advance = ipcomp_print(ndo, ipds->cp, &enh);
364 if (ipds->advance <= 0)
365 break;
366 ipds->cp += ipds->advance;
367 ipds->len -= ipds->advance;
368 ipds->nh = enh & 0xff;
369 goto again;
370 }
371
372 case IPPROTO_SCTP:
373 sctp_print(ndo, ipds->cp, (const u_char *)ipds->ip, ipds->len);
374 break;
375
376 case IPPROTO_DCCP:
377 dccp_print(ndo, ipds->cp, (const u_char *)ipds->ip, ipds->len);
378 break;
379
380 case IPPROTO_TCP:
381 /* pass on the MF bit plus the offset to detect fragments */
382 tcp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
383 ipds->off & (IP_MF|IP_OFFMASK));
384 break;
385
386 case IPPROTO_UDP:
387 /* pass on the MF bit plus the offset to detect fragments */
388 udp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
389 ipds->off & (IP_MF|IP_OFFMASK));
390 break;
391
392 case IPPROTO_ICMP:
393 /* pass on the MF bit plus the offset to detect fragments */
394 icmp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
395 ipds->off & (IP_MF|IP_OFFMASK));
396 break;
397
398 case IPPROTO_PIGP:
399 /*
400 * XXX - the current IANA protocol number assignments
401 * page lists 9 as "any private interior gateway
402 * (used by Cisco for their IGRP)" and 88 as
403 * "EIGRP" from Cisco.
404 *
405 * Recent BSD <netinet/in.h> headers define
406 * IP_PROTO_PIGP as 9 and IP_PROTO_IGRP as 88.
407 * We define IP_PROTO_PIGP as 9 and
408 * IP_PROTO_EIGRP as 88; those names better
409 * match was the current protocol number
410 * assignments say.
411 */
412 igrp_print(ndo, ipds->cp, ipds->len);
413 break;
414
415 case IPPROTO_EIGRP:
416 eigrp_print(ndo, ipds->cp, ipds->len);
417 break;
418
419 case IPPROTO_ND:
420 ND_PRINT((ndo, " nd %d", ipds->len));
421 break;
422
423 case IPPROTO_EGP:
424 egp_print(ndo, ipds->cp, ipds->len);
425 break;
426
427 case IPPROTO_OSPF:
428 ospf_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
429 break;
430
431 case IPPROTO_IGMP:
432 igmp_print(ndo, ipds->cp, ipds->len);
433 break;
434
435 case IPPROTO_IPV4:
436 /* DVMRP multicast tunnel (ip-in-ip encapsulation) */
437 ip_print(ndo, ipds->cp, ipds->len);
438 if (! ndo->ndo_vflag) {
439 ND_PRINT((ndo, " (ipip-proto-4)"));
440 return;
441 }
442 break;
443
444 case IPPROTO_IPV6:
445 /* ip6-in-ip encapsulation */
446 ip6_print(ndo, ipds->cp, ipds->len);
447 break;
448
449 case IPPROTO_RSVP:
450 rsvp_print(ndo, ipds->cp, ipds->len);
451 break;
452
453 case IPPROTO_GRE:
454 /* do it */
455 gre_print(ndo, ipds->cp, ipds->len);
456 break;
457
458 case IPPROTO_MOBILE:
459 mobile_print(ndo, ipds->cp, ipds->len);
460 break;
461
462 case IPPROTO_PIM:
463 vec[0].ptr = ipds->cp;
464 vec[0].len = ipds->len;
465 pim_print(ndo, ipds->cp, ipds->len, in_cksum(vec, 1));
466 break;
467
468 case IPPROTO_VRRP:
469 if (ndo->ndo_packettype == PT_CARP) {
470 if (ndo->ndo_vflag)
471 ND_PRINT((ndo, "carp %s > %s: ",
472 ipaddr_string(ndo, &ipds->ip->ip_src),
473 ipaddr_string(ndo, &ipds->ip->ip_dst)));
474 carp_print(ndo, ipds->cp, ipds->len, ipds->ip->ip_ttl);
475 } else {
476 if (ndo->ndo_vflag)
477 ND_PRINT((ndo, "vrrp %s > %s: ",
478 ipaddr_string(ndo, &ipds->ip->ip_src),
479 ipaddr_string(ndo, &ipds->ip->ip_dst)));
480 vrrp_print(ndo, ipds->cp, ipds->len,
481 (const u_char *)ipds->ip, ipds->ip->ip_ttl);
482 }
483 break;
484
485 case IPPROTO_PGM:
486 pgm_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
487 break;
488
489 case IPPROTO_PFSYNC:
490 pfsync_ip_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
491 break;
492
493 default:
494 if (ndo->ndo_nflag==0 && (proto = getprotobynumber(ipds->nh)) != NULL)
495 ND_PRINT((ndo, " %s", proto->p_name));
496 else
497 ND_PRINT((ndo, " ip-proto-%d", ipds->nh));
498 ND_PRINT((ndo, " %d", ipds->len));
499 break;
500 }
501 }
502
503 void
ip_print_inner(netdissect_options * ndo,const u_char * bp,u_int length,u_int nh,const u_char * bp2)504 ip_print_inner(netdissect_options *ndo,
505 const u_char *bp,
506 u_int length, u_int nh,
507 const u_char *bp2)
508 {
509 struct ip_print_demux_state ipd;
510
511 ipd.ip = (const struct ip *)bp2;
512 ipd.cp = bp;
513 ipd.len = length;
514 ipd.off = 0;
515 ipd.nh = nh;
516 ipd.advance = 0;
517
518 ip_print_demux(ndo, &ipd);
519 }
520
521
522 /*
523 * print an IP datagram.
524 */
525 void
ip_print(netdissect_options * ndo,const u_char * bp,u_int length)526 ip_print(netdissect_options *ndo,
527 const u_char *bp,
528 u_int length)
529 {
530 struct ip_print_demux_state ipd;
531 struct ip_print_demux_state *ipds=&ipd;
532 const u_char *ipend;
533 u_int hlen;
534 struct cksum_vec vec[1];
535 uint16_t sum, ip_sum;
536 struct protoent *proto;
537
538 ipds->ip = (const struct ip *)bp;
539 ND_TCHECK(ipds->ip->ip_vhl);
540 if (IP_V(ipds->ip) != 4) { /* print version if != 4 */
541 if (IP_V(ipds->ip) == 6)
542 ND_PRINT((ndo, "IP6, wrong link-layer encapsulation "));
543 else
544 ND_PRINT((ndo, "IP%u ", IP_V(ipds->ip)));
545 }
546 else if (!ndo->ndo_eflag)
547 ND_PRINT((ndo, "IP "));
548
549 ND_TCHECK(*ipds->ip);
550 if (length < sizeof (struct ip)) {
551 ND_PRINT((ndo, "truncated-ip %u", length));
552 return;
553 }
554 hlen = IP_HL(ipds->ip) * 4;
555 if (hlen < sizeof (struct ip)) {
556 ND_PRINT((ndo, "bad-hlen %u", hlen));
557 return;
558 }
559
560 ipds->len = EXTRACT_16BITS(&ipds->ip->ip_len);
561 if (length < ipds->len)
562 ND_PRINT((ndo, "truncated-ip - %u bytes missing! ",
563 ipds->len - length));
564 if (ipds->len < hlen) {
565 #ifdef GUESS_TSO
566 if (ipds->len) {
567 ND_PRINT((ndo, "bad-len %u", ipds->len));
568 return;
569 }
570 else {
571 /* we guess that it is a TSO send */
572 ipds->len = length;
573 }
574 #else
575 ND_PRINT((ndo, "bad-len %u", ipds->len));
576 return;
577 #endif /* GUESS_TSO */
578 }
579
580 /*
581 * Cut off the snapshot length to the end of the IP payload.
582 */
583 ipend = bp + ipds->len;
584 if (ipend < ndo->ndo_snapend)
585 ndo->ndo_snapend = ipend;
586
587 ipds->len -= hlen;
588
589 ipds->off = EXTRACT_16BITS(&ipds->ip->ip_off);
590
591 if (ndo->ndo_vflag) {
592 ND_PRINT((ndo, "(tos 0x%x", (int)ipds->ip->ip_tos));
593 /* ECN bits */
594 if (ipds->ip->ip_tos & 0x03) {
595 switch (ipds->ip->ip_tos & 0x03) {
596 case 1:
597 ND_PRINT((ndo, ",ECT(1)"));
598 break;
599 case 2:
600 ND_PRINT((ndo, ",ECT(0)"));
601 break;
602 case 3:
603 ND_PRINT((ndo, ",CE"));
604 }
605 }
606
607 if (ipds->ip->ip_ttl >= 1)
608 ND_PRINT((ndo, ", ttl %u", ipds->ip->ip_ttl));
609
610 /*
611 * for the firewall guys, print id, offset.
612 * On all but the last stick a "+" in the flags portion.
613 * For unfragmented datagrams, note the don't fragment flag.
614 */
615
616 ND_PRINT((ndo, ", id %u, offset %u, flags [%s], proto %s (%u)",
617 EXTRACT_16BITS(&ipds->ip->ip_id),
618 (ipds->off & 0x1fff) * 8,
619 bittok2str(ip_frag_values, "none", ipds->off&0xe000),
620 tok2str(ipproto_values,"unknown",ipds->ip->ip_p),
621 ipds->ip->ip_p));
622
623 ND_PRINT((ndo, ", length %u", EXTRACT_16BITS(&ipds->ip->ip_len)));
624
625 if ((hlen - sizeof(struct ip)) > 0) {
626 ND_PRINT((ndo, ", options ("));
627 ip_optprint(ndo, (u_char *)(ipds->ip + 1), hlen - sizeof(struct ip));
628 ND_PRINT((ndo, ")"));
629 }
630
631 if (!ndo->ndo_Kflag && (u_char *)ipds->ip + hlen <= ndo->ndo_snapend) {
632 vec[0].ptr = (const uint8_t *)(void *)ipds->ip;
633 vec[0].len = hlen;
634 sum = in_cksum(vec, 1);
635 if (sum != 0) {
636 ip_sum = EXTRACT_16BITS(&ipds->ip->ip_sum);
637 ND_PRINT((ndo, ", bad cksum %x (->%x)!", ip_sum,
638 in_cksum_shouldbe(ip_sum, sum)));
639 }
640 }
641
642 ND_PRINT((ndo, ")\n "));
643 }
644
645 /*
646 * If this is fragment zero, hand it to the next higher
647 * level protocol.
648 */
649 if ((ipds->off & 0x1fff) == 0) {
650 ipds->cp = (const u_char *)ipds->ip + hlen;
651 ipds->nh = ipds->ip->ip_p;
652
653 if (ipds->nh != IPPROTO_TCP && ipds->nh != IPPROTO_UDP &&
654 ipds->nh != IPPROTO_SCTP && ipds->nh != IPPROTO_DCCP) {
655 ND_PRINT((ndo, "%s > %s: ",
656 ipaddr_string(ndo, &ipds->ip->ip_src),
657 ipaddr_string(ndo, &ipds->ip->ip_dst)));
658 }
659 ip_print_demux(ndo, ipds);
660 } else {
661 /* Ultra quiet now means that all this stuff should be suppressed */
662 if (ndo->ndo_qflag > 1) return;
663
664 /*
665 * if this isn't the first frag, we're missing the
666 * next level protocol header. print the ip addr
667 * and the protocol.
668 */
669 if (ipds->off & 0x1fff) {
670 ND_PRINT((ndo, "%s > %s:", ipaddr_string(ndo, &ipds->ip->ip_src),
671 ipaddr_string(ndo, &ipds->ip->ip_dst)));
672 if (!ndo->ndo_nflag && (proto = getprotobynumber(ipds->ip->ip_p)) != NULL)
673 ND_PRINT((ndo, " %s", proto->p_name));
674 else
675 ND_PRINT((ndo, " ip-proto-%d", ipds->ip->ip_p));
676 }
677 }
678 return;
679
680 trunc:
681 ND_PRINT((ndo, "%s", tstr));
682 return;
683 }
684
685 void
ipN_print(netdissect_options * ndo,register const u_char * bp,register u_int length)686 ipN_print(netdissect_options *ndo, register const u_char *bp, register u_int length)
687 {
688 struct ip hdr;
689
690 if (length < 4) {
691 ND_PRINT((ndo, "truncated-ip %d", length));
692 return;
693 }
694 memcpy (&hdr, bp, 4);
695 switch (IP_V(&hdr)) {
696 case 4:
697 ip_print (ndo, bp, length);
698 return;
699 case 6:
700 ip6_print (ndo, bp, length);
701 return;
702 default:
703 ND_PRINT((ndo, "unknown ip %d", IP_V(&hdr)));
704 return;
705 }
706 }
707
708 /*
709 * Local Variables:
710 * c-style: whitesmith
711 * c-basic-offset: 8
712 * End:
713 */
714
715
716