xref: /freebsd/contrib/tcpdump/print-ip.c (revision 7453645f2a9411a3f9d982b768bcc323f41cf906)
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  * $FreeBSD$
22  */
23 
24 #define NETDISSECT_REWORKED
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28 
29 #include <tcpdump-stdinc.h>
30 
31 #include <string.h>
32 
33 #include "interface.h"
34 #include "addrtoname.h"
35 #include "extract.h"			/* must come after interface.h */
36 
37 #include "ip.h"
38 #include "ipproto.h"
39 
40 static const char tstr[] = "[|ip]";
41 
42 static const struct tok ip_option_values[] = {
43     { IPOPT_EOL, "EOL" },
44     { IPOPT_NOP, "NOP" },
45     { IPOPT_TS, "timestamp" },
46     { IPOPT_SECURITY, "security" },
47     { IPOPT_RR, "RR" },
48     { IPOPT_SSRR, "SSRR" },
49     { IPOPT_LSRR, "LSRR" },
50     { IPOPT_RA, "RA" },
51     { IPOPT_RFC1393, "traceroute" },
52     { 0, NULL }
53 };
54 
55 /*
56  * print the recorded route in an IP RR, LSRR or SSRR option.
57  */
58 static void
59 ip_printroute(netdissect_options *ndo,
60               register const u_char *cp, u_int length)
61 {
62 	register u_int ptr;
63 	register u_int len;
64 
65 	if (length < 3) {
66 		ND_PRINT((ndo, " [bad length %u]", length));
67 		return;
68 	}
69 	if ((length + 1) & 3)
70 		ND_PRINT((ndo, " [bad length %u]", length));
71 	ptr = cp[2] - 1;
72 	if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
73 		ND_PRINT((ndo, " [bad ptr %u]", cp[2]));
74 
75 	for (len = 3; len < length; len += 4) {
76 		ND_PRINT((ndo, " %s", ipaddr_string(ndo, &cp[len])));
77 		if (ptr > len)
78 			ND_PRINT((ndo, ","));
79 	}
80 }
81 
82 /*
83  * If source-routing is present and valid, return the final destination.
84  * Otherwise, return IP destination.
85  *
86  * This is used for UDP and TCP pseudo-header in the checksum
87  * calculation.
88  */
89 static uint32_t
90 ip_finddst(netdissect_options *ndo,
91            const struct ip *ip)
92 {
93 	int length;
94 	int len;
95 	const u_char *cp;
96 	uint32_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 		ND_TCHECK(*cp);
105 		tt = *cp;
106 		if (tt == IPOPT_EOL)
107 			break;
108 		else if (tt == IPOPT_NOP)
109 			len = 1;
110 		else {
111 			ND_TCHECK(cp[1]);
112 			len = cp[1];
113 			if (len < 2)
114 				break;
115 		}
116 		ND_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(uint32_t));
129 	return retval;
130 }
131 
132 /*
133  * Compute a V4-style checksum by building a pseudoheader.
134  */
135 int
136 nextproto4_cksum(netdissect_options *ndo,
137                  const struct ip *ip, const uint8_t *data,
138                  u_int len, u_int covlen, u_int next_proto)
139 {
140 	struct phdr {
141 		uint32_t src;
142 		uint32_t dst;
143 		u_char mbz;
144 		u_char proto;
145 		uint16_t len;
146 	} ph;
147 	struct cksum_vec vec[2];
148 
149 	/* pseudo-header.. */
150 	ph.len = htons((uint16_t)len);
151 	ph.mbz = 0;
152 	ph.proto = next_proto;
153 	UNALIGNED_MEMCPY(&ph.src, &ip->ip_src.s_addr, sizeof(uint32_t));
154 	if (IP_HL(ip) == 5)
155 		UNALIGNED_MEMCPY(&ph.dst, &ip->ip_dst.s_addr, sizeof(uint32_t));
156 	else
157 		ph.dst = ip_finddst(ndo, ip);
158 
159 	vec[0].ptr = (const uint8_t *)(void *)&ph;
160 	vec[0].len = sizeof(ph);
161 	vec[1].ptr = data;
162 	vec[1].len = covlen;
163 	return (in_cksum(vec, 2));
164 }
165 
166 static void
167 ip_printts(netdissect_options *ndo,
168            register const u_char *cp, u_int length)
169 {
170 	register u_int ptr;
171 	register u_int len;
172 	int hoplen;
173 	const char *type;
174 
175 	if (length < 4) {
176 		ND_PRINT((ndo, "[bad length %u]", length));
177 		return;
178 	}
179 	ND_PRINT((ndo, " TS{"));
180 	hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
181 	if ((length - 4) & (hoplen-1))
182 		ND_PRINT((ndo, "[bad length %u]", length));
183 	ptr = cp[2] - 1;
184 	len = 0;
185 	if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
186 		ND_PRINT((ndo, "[bad ptr %u]", cp[2]));
187 	switch (cp[3]&0xF) {
188 	case IPOPT_TS_TSONLY:
189 		ND_PRINT((ndo, "TSONLY"));
190 		break;
191 	case IPOPT_TS_TSANDADDR:
192 		ND_PRINT((ndo, "TS+ADDR"));
193 		break;
194 	/*
195 	 * prespecified should really be 3, but some ones might send 2
196 	 * instead, and the IPOPT_TS_PRESPEC constant can apparently
197 	 * have both values, so we have to hard-code it here.
198 	 */
199 
200 	case 2:
201 		ND_PRINT((ndo, "PRESPEC2.0"));
202 		break;
203 	case 3:			/* IPOPT_TS_PRESPEC */
204 		ND_PRINT((ndo, "PRESPEC"));
205 		break;
206 	default:
207 		ND_PRINT((ndo, "[bad ts type %d]", cp[3]&0xF));
208 		goto done;
209 	}
210 
211 	type = " ";
212 	for (len = 4; len < length; len += hoplen) {
213 		if (ptr == len)
214 			type = " ^ ";
215 		ND_PRINT((ndo, "%s%d@%s", type, EXTRACT_32BITS(&cp[len+hoplen-4]),
216 		       hoplen!=8 ? "" : ipaddr_string(ndo, &cp[len])));
217 		type = " ";
218 	}
219 
220 done:
221 	ND_PRINT((ndo, "%s", ptr == len ? " ^ " : ""));
222 
223 	if (cp[3]>>4)
224 		ND_PRINT((ndo, " [%d hops not recorded]} ", cp[3]>>4));
225 	else
226 		ND_PRINT((ndo, "}"));
227 }
228 
229 /*
230  * print IP options.
231  */
232 static void
233 ip_optprint(netdissect_options *ndo,
234             register const u_char *cp, u_int length)
235 {
236 	register u_int option_len;
237 	const char *sep = "";
238 
239 	for (; length > 0; cp += option_len, length -= option_len) {
240 		u_int option_code;
241 
242 		ND_PRINT((ndo, "%s", sep));
243 		sep = ",";
244 
245 		ND_TCHECK(*cp);
246 		option_code = *cp;
247 
248 		ND_PRINT((ndo, "%s",
249 		          tok2str(ip_option_values,"unknown %u",option_code)));
250 
251 		if (option_code == IPOPT_NOP ||
252                     option_code == IPOPT_EOL)
253 			option_len = 1;
254 
255 		else {
256 			ND_TCHECK(cp[1]);
257 			option_len = cp[1];
258 			if (option_len < 2) {
259 				ND_PRINT((ndo, " [bad length %u]", option_len));
260 				return;
261 			}
262 		}
263 
264 		if (option_len > length) {
265 			ND_PRINT((ndo, " [bad length %u]", option_len));
266 			return;
267 		}
268 
269 		ND_TCHECK2(*cp, option_len);
270 
271 		switch (option_code) {
272 		case IPOPT_EOL:
273 			return;
274 
275 		case IPOPT_TS:
276 			ip_printts(ndo, cp, option_len);
277 			break;
278 
279 		case IPOPT_RR:       /* fall through */
280 		case IPOPT_SSRR:
281 		case IPOPT_LSRR:
282 			ip_printroute(ndo, cp, option_len);
283 			break;
284 
285 		case IPOPT_RA:
286 			if (option_len < 4) {
287 				ND_PRINT((ndo, " [bad length %u]", option_len));
288 				break;
289 			}
290 			ND_TCHECK(cp[3]);
291 			if (EXTRACT_16BITS(&cp[2]) != 0)
292 				ND_PRINT((ndo, " value %u", EXTRACT_16BITS(&cp[2])));
293 			break;
294 
295 		case IPOPT_NOP:       /* nothing to print - fall through */
296 		case IPOPT_SECURITY:
297 		default:
298 			break;
299 		}
300 	}
301 	return;
302 
303 trunc:
304 	ND_PRINT((ndo, "%s", tstr));
305 }
306 
307 #define IP_RES 0x8000
308 
309 static const struct tok ip_frag_values[] = {
310         { IP_MF,        "+" },
311         { IP_DF,        "DF" },
312 	{ IP_RES,       "rsvd" }, /* The RFC3514 evil ;-) bit */
313         { 0,            NULL }
314 };
315 
316 struct ip_print_demux_state {
317 	const struct ip *ip;
318 	const u_char *cp;
319 	u_int   len, off;
320 	u_char  nh;
321 	int     advance;
322 };
323 
324 static void
325 ip_print_demux(netdissect_options *ndo,
326 	       struct ip_print_demux_state *ipds)
327 {
328 	struct protoent *proto;
329 	struct cksum_vec vec[1];
330 
331 again:
332 	switch (ipds->nh) {
333 
334 	case IPPROTO_AH:
335 		ipds->nh = *ipds->cp;
336 		ipds->advance = ah_print(ndo, ipds->cp);
337 		if (ipds->advance <= 0)
338 			break;
339 		ipds->cp += ipds->advance;
340 		ipds->len -= ipds->advance;
341 		goto again;
342 
343 	case IPPROTO_ESP:
344 	{
345 		int enh, padlen;
346 		ipds->advance = esp_print(ndo, ipds->cp, ipds->len,
347 				    (const u_char *)ipds->ip,
348 				    &enh, &padlen);
349 		if (ipds->advance <= 0)
350 			break;
351 		ipds->cp += ipds->advance;
352 		ipds->len -= ipds->advance + padlen;
353 		ipds->nh = enh & 0xff;
354 		goto again;
355 	}
356 
357 	case IPPROTO_IPCOMP:
358 	{
359 		int enh;
360 		ipds->advance = ipcomp_print(ndo, ipds->cp, &enh);
361 		if (ipds->advance <= 0)
362 			break;
363 		ipds->cp += ipds->advance;
364 		ipds->len -= ipds->advance;
365 		ipds->nh = enh & 0xff;
366 		goto again;
367 	}
368 
369 	case IPPROTO_SCTP:
370 		sctp_print(ndo, ipds->cp, (const u_char *)ipds->ip, ipds->len);
371 		break;
372 
373 	case IPPROTO_DCCP:
374 		dccp_print(ndo, ipds->cp, (const u_char *)ipds->ip, ipds->len);
375 		break;
376 
377 	case IPPROTO_TCP:
378 		/* pass on the MF bit plus the offset to detect fragments */
379 		tcp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
380 			  ipds->off & (IP_MF|IP_OFFMASK));
381 		break;
382 
383 	case IPPROTO_UDP:
384 		/* pass on the MF bit plus the offset to detect fragments */
385 		udp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
386 			  ipds->off & (IP_MF|IP_OFFMASK));
387 		break;
388 
389 	case IPPROTO_ICMP:
390 		/* pass on the MF bit plus the offset to detect fragments */
391 		icmp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
392 			   ipds->off & (IP_MF|IP_OFFMASK));
393 		break;
394 
395 	case IPPROTO_PIGP:
396 		/*
397 		 * XXX - the current IANA protocol number assignments
398 		 * page lists 9 as "any private interior gateway
399 		 * (used by Cisco for their IGRP)" and 88 as
400 		 * "EIGRP" from Cisco.
401 		 *
402 		 * Recent BSD <netinet/in.h> headers define
403 		 * IP_PROTO_PIGP as 9 and IP_PROTO_IGRP as 88.
404 		 * We define IP_PROTO_PIGP as 9 and
405 		 * IP_PROTO_EIGRP as 88; those names better
406 		 * match was the current protocol number
407 		 * assignments say.
408 		 */
409 		igrp_print(ndo, ipds->cp, ipds->len);
410 		break;
411 
412 	case IPPROTO_EIGRP:
413 		eigrp_print(ndo, ipds->cp, ipds->len);
414 		break;
415 
416 	case IPPROTO_ND:
417 		ND_PRINT((ndo, " nd %d", ipds->len));
418 		break;
419 
420 	case IPPROTO_EGP:
421 		egp_print(ndo, ipds->cp, ipds->len);
422 		break;
423 
424 	case IPPROTO_OSPF:
425 		ospf_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
426 		break;
427 
428 	case IPPROTO_IGMP:
429 		igmp_print(ndo, ipds->cp, ipds->len);
430 		break;
431 
432 	case IPPROTO_IPV4:
433 		/* DVMRP multicast tunnel (ip-in-ip encapsulation) */
434 		ip_print(ndo, ipds->cp, ipds->len);
435 		if (! ndo->ndo_vflag) {
436 			ND_PRINT((ndo, " (ipip-proto-4)"));
437 			return;
438 		}
439 		break;
440 
441 	case IPPROTO_IPV6:
442 		/* ip6-in-ip encapsulation */
443 		ip6_print(ndo, ipds->cp, ipds->len);
444 		break;
445 
446 	case IPPROTO_RSVP:
447 		rsvp_print(ndo, ipds->cp, ipds->len);
448 		break;
449 
450 	case IPPROTO_GRE:
451 		/* do it */
452 		gre_print(ndo, ipds->cp, ipds->len);
453 		break;
454 
455 	case IPPROTO_MOBILE:
456 		mobile_print(ndo, ipds->cp, ipds->len);
457 		break;
458 
459 	case IPPROTO_PIM:
460 		vec[0].ptr = ipds->cp;
461 		vec[0].len = ipds->len;
462 		pim_print(ndo, ipds->cp, ipds->len, in_cksum(vec, 1));
463 		break;
464 
465 	case IPPROTO_VRRP:
466 		if (ndo->ndo_packettype == PT_CARP) {
467 			if (ndo->ndo_vflag)
468 				ND_PRINT((ndo, "carp %s > %s: ",
469 					     ipaddr_string(ndo, &ipds->ip->ip_src),
470 					     ipaddr_string(ndo, &ipds->ip->ip_dst)));
471 			carp_print(ndo, ipds->cp, ipds->len, ipds->ip->ip_ttl);
472 		} else {
473 			if (ndo->ndo_vflag)
474 				ND_PRINT((ndo, "vrrp %s > %s: ",
475 					     ipaddr_string(ndo, &ipds->ip->ip_src),
476 					     ipaddr_string(ndo, &ipds->ip->ip_dst)));
477 			vrrp_print(ndo, ipds->cp, ipds->len,
478 				(const u_char *)ipds->ip, ipds->ip->ip_ttl);
479 		}
480 		break;
481 
482 	case IPPROTO_PGM:
483 		pgm_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
484 		break;
485 
486 #if defined(HAVE_NET_PFVAR_H)
487 	case IPPROTO_PFSYNC:
488 		pfsync_ip_print(ndo, ipds->cp, ipds->len);
489 		break;
490 #endif
491 
492 	default:
493 		if (ndo->ndo_nflag==0 && (proto = getprotobynumber(ipds->nh)) != NULL)
494 			ND_PRINT((ndo, " %s", proto->p_name));
495 		else
496 			ND_PRINT((ndo, " ip-proto-%d", ipds->nh));
497 		ND_PRINT((ndo, " %d", ipds->len));
498 		break;
499 	}
500 }
501 
502 void
503 ip_print_inner(netdissect_options *ndo,
504 	       const u_char *bp,
505 	       u_int length, u_int nh,
506 	       const u_char *bp2)
507 {
508 	struct ip_print_demux_state  ipd;
509 
510 	ipd.ip = (const struct ip *)bp2;
511 	ipd.cp = bp;
512 	ipd.len  = length;
513 	ipd.off  = 0;
514 	ipd.nh   = nh;
515 	ipd.advance = 0;
516 
517 	ip_print_demux(ndo, &ipd);
518 }
519 
520 
521 /*
522  * print an IP datagram.
523  */
524 void
525 ip_print(netdissect_options *ndo,
526 	 const u_char *bp,
527 	 u_int length)
528 {
529 	struct ip_print_demux_state  ipd;
530 	struct ip_print_demux_state *ipds=&ipd;
531 	const u_char *ipend;
532 	u_int hlen;
533 	struct cksum_vec vec[1];
534 	uint16_t sum, ip_sum;
535 	struct protoent *proto;
536 
537 	ipds->ip = (const struct ip *)bp;
538 	ND_TCHECK(ipds->ip->ip_vhl);
539 	if (IP_V(ipds->ip) != 4) { /* print version if != 4 */
540 	    if (IP_V(ipds->ip) == 6)
541 	      ND_PRINT((ndo, "IP6, wrong link-layer encapsulation "));
542 	    else
543 	      ND_PRINT((ndo, "IP%u ", IP_V(ipds->ip)));
544 	}
545 	else if (!ndo->ndo_eflag)
546 		ND_PRINT((ndo, "IP "));
547 
548 	ND_TCHECK(*ipds->ip);
549 	if (length < sizeof (struct ip)) {
550 		ND_PRINT((ndo, "truncated-ip %u", length));
551 		return;
552 	}
553 	hlen = IP_HL(ipds->ip) * 4;
554 	if (hlen < sizeof (struct ip)) {
555 		ND_PRINT((ndo, "bad-hlen %u", hlen));
556 		return;
557 	}
558 
559 	ipds->len = EXTRACT_16BITS(&ipds->ip->ip_len);
560 	if (length < ipds->len)
561 		ND_PRINT((ndo, "truncated-ip - %u bytes missing! ",
562 			ipds->len - length));
563 	if (ipds->len < hlen) {
564 #ifdef GUESS_TSO
565             if (ipds->len) {
566                 ND_PRINT((ndo, "bad-len %u", ipds->len));
567                 return;
568             }
569             else {
570                 /* we guess that it is a TSO send */
571                 ipds->len = length;
572             }
573 #else
574             ND_PRINT((ndo, "bad-len %u", ipds->len));
575             return;
576 #endif /* GUESS_TSO */
577 	}
578 
579 	/*
580 	 * Cut off the snapshot length to the end of the IP payload.
581 	 */
582 	ipend = bp + ipds->len;
583 	if (ipend < ndo->ndo_snapend)
584 		ndo->ndo_snapend = ipend;
585 
586 	ipds->len -= hlen;
587 
588 	ipds->off = EXTRACT_16BITS(&ipds->ip->ip_off);
589 
590         if (ndo->ndo_vflag) {
591             ND_PRINT((ndo, "(tos 0x%x", (int)ipds->ip->ip_tos));
592             /* ECN bits */
593             if (ipds->ip->ip_tos & 0x03) {
594                 switch (ipds->ip->ip_tos & 0x03) {
595                 case 1:
596                     ND_PRINT((ndo, ",ECT(1)"));
597                     break;
598                 case 2:
599                     ND_PRINT((ndo, ",ECT(0)"));
600                     break;
601                 case 3:
602                     ND_PRINT((ndo, ",CE"));
603                 }
604             }
605 
606             if (ipds->ip->ip_ttl >= 1)
607                 ND_PRINT((ndo, ", ttl %u", ipds->ip->ip_ttl));
608 
609 	    /*
610 	     * for the firewall guys, print id, offset.
611              * On all but the last stick a "+" in the flags portion.
612 	     * For unfragmented datagrams, note the don't fragment flag.
613 	     */
614 
615 	    ND_PRINT((ndo, ", id %u, offset %u, flags [%s], proto %s (%u)",
616                          EXTRACT_16BITS(&ipds->ip->ip_id),
617                          (ipds->off & 0x1fff) * 8,
618                          bittok2str(ip_frag_values, "none", ipds->off&0xe000),
619                          tok2str(ipproto_values,"unknown",ipds->ip->ip_p),
620                          ipds->ip->ip_p));
621 
622             ND_PRINT((ndo, ", length %u", EXTRACT_16BITS(&ipds->ip->ip_len)));
623 
624             if ((hlen - sizeof(struct ip)) > 0) {
625                 ND_PRINT((ndo, ", options ("));
626                 ip_optprint(ndo, (u_char *)(ipds->ip + 1), hlen - sizeof(struct ip));
627                 ND_PRINT((ndo, ")"));
628             }
629 
630 	    if (!ndo->ndo_Kflag && (u_char *)ipds->ip + hlen <= ndo->ndo_snapend) {
631 	        vec[0].ptr = (const uint8_t *)(void *)ipds->ip;
632 	        vec[0].len = hlen;
633 	        sum = in_cksum(vec, 1);
634 		if (sum != 0) {
635 		    ip_sum = EXTRACT_16BITS(&ipds->ip->ip_sum);
636 		    ND_PRINT((ndo, ", bad cksum %x (->%x)!", ip_sum,
637 			     in_cksum_shouldbe(ip_sum, sum)));
638 		}
639 	    }
640 
641 		ND_PRINT((ndo, ")\n    "));
642 	}
643 
644 	/*
645 	 * If this is fragment zero, hand it to the next higher
646 	 * level protocol.
647 	 */
648 	if ((ipds->off & 0x1fff) == 0) {
649 		ipds->cp = (const u_char *)ipds->ip + hlen;
650 		ipds->nh = ipds->ip->ip_p;
651 
652 		if (ipds->nh != IPPROTO_TCP && ipds->nh != IPPROTO_UDP &&
653 		    ipds->nh != IPPROTO_SCTP && ipds->nh != IPPROTO_DCCP) {
654 			ND_PRINT((ndo, "%s > %s: ",
655 				     ipaddr_string(ndo, &ipds->ip->ip_src),
656 				     ipaddr_string(ndo, &ipds->ip->ip_dst)));
657 		}
658 		ip_print_demux(ndo, ipds);
659 	} else {
660 	    /* Ultra quiet now means that all this stuff should be suppressed */
661 	    if (ndo->ndo_qflag > 1) return;
662 
663 	    /*
664 	     * if this isn't the first frag, we're missing the
665 	     * next level protocol header.  print the ip addr
666 	     * and the protocol.
667 	     */
668 		if (ipds->off & 0x1fff) {
669 			ND_PRINT((ndo, "%s > %s:", ipaddr_string(ndo, &ipds->ip->ip_src),
670 			          ipaddr_string(ndo, &ipds->ip->ip_dst)));
671 			if (!ndo->ndo_nflag && (proto = getprotobynumber(ipds->ip->ip_p)) != NULL)
672 				ND_PRINT((ndo, " %s", proto->p_name));
673 			else
674 				ND_PRINT((ndo, " ip-proto-%d", ipds->ip->ip_p));
675 		}
676 	}
677 	return;
678 
679 trunc:
680 	ND_PRINT((ndo, "%s", tstr));
681 	return;
682 }
683 
684 void
685 ipN_print(netdissect_options *ndo, register const u_char *bp, register u_int length)
686 {
687 	struct ip hdr;
688 
689 	if (length < 4) {
690 		ND_PRINT((ndo, "truncated-ip %d", length));
691 		return;
692 	}
693 	memcpy (&hdr, bp, 4);
694 	switch (IP_V(&hdr)) {
695 	case 4:
696 		ip_print (ndo, bp, length);
697 		return;
698 	case 6:
699 		ip6_print (ndo, bp, length);
700 		return;
701 	default:
702 		ND_PRINT((ndo, "unknown ip %d", IP_V(&hdr)));
703 		return;
704 	}
705 }
706 
707 /*
708  * Local Variables:
709  * c-style: whitesmith
710  * c-basic-offset: 8
711  * End:
712  */
713 
714 
715