print-ip6.c revision 214478 
1/*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994
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: head/contrib/tcpdump/print-ip6.c 214478 2010-10-28 19:06:17Z rpaulo $
22 */
23
24#ifndef lint
25static const char rcsid[] _U_ =
26    "@(#) $Header: /tcpdump/master/tcpdump/print-ip6.c,v 1.52 2007-09-21 07:05:33 hannes Exp $";
27#endif
28
29#ifdef HAVE_CONFIG_H
30#include "config.h"
31#endif
32
33#ifdef INET6
34
35#include <tcpdump-stdinc.h>
36
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40
41#include "netdissect.h"
42#include "interface.h"
43#include "addrtoname.h"
44#include "extract.h"
45
46#include "ip6.h"
47#include "ipproto.h"
48
49/*
50 * Compute a V6-style checksum by building a pseudoheader.
51 */
52int
53nextproto6_cksum(const struct ip6_hdr *ip6, const u_short *data,
54		 u_int len, u_int next_proto)
55{
56        size_t i;
57        u_int32_t sum = 0;
58	union ip6_pseudo_hdr phu;
59
60        /* pseudo-header */
61        memset(&phu, 0, sizeof(phu));
62        phu.ph.ph_src = ip6->ip6_src;
63        phu.ph.ph_dst = ip6->ip6_dst;
64        phu.ph.ph_len = htonl(len);
65        phu.ph.ph_nxt = next_proto;
66
67        for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++) {
68                sum += phu.pa[i];
69	}
70
71        return in_cksum(data, len, sum);
72}
73
74/*
75 * print an IP6 datagram.
76 */
77void
78ip6_print(register const u_char *bp, register u_int length)
79{
80	register const struct ip6_hdr *ip6;
81	register int advance;
82	u_int len;
83	const u_char *ipend;
84	register const u_char *cp;
85	register u_int payload_len;
86	int nh;
87	int fragmented = 0;
88	u_int flow;
89
90	ip6 = (const struct ip6_hdr *)bp;
91
92	TCHECK(*ip6);
93	if (length < sizeof (struct ip6_hdr)) {
94		(void)printf("truncated-ip6 %u", length);
95		return;
96	}
97
98        if (!eflag)
99            printf("IP6 ");
100
101	payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
102	len = payload_len + sizeof(struct ip6_hdr);
103	if (length < len)
104		(void)printf("truncated-ip6 - %u bytes missing!",
105			len - length);
106
107        if (vflag) {
108            flow = EXTRACT_32BITS(&ip6->ip6_flow);
109            printf("(");
110#if 0
111            /* rfc1883 */
112            if (flow & 0x0f000000)
113		(void)printf("pri 0x%02x, ", (flow & 0x0f000000) >> 24);
114            if (flow & 0x00ffffff)
115		(void)printf("flowlabel 0x%06x, ", flow & 0x00ffffff);
116#else
117            /* RFC 2460 */
118            if (flow & 0x0ff00000)
119		(void)printf("class 0x%02x, ", (flow & 0x0ff00000) >> 20);
120            if (flow & 0x000fffff)
121		(void)printf("flowlabel 0x%05x, ", flow & 0x000fffff);
122#endif
123
124            (void)printf("hlim %u, next-header %s (%u) payload length: %u) ",
125                         ip6->ip6_hlim,
126                         tok2str(ipproto_values,"unknown",ip6->ip6_nxt),
127                         ip6->ip6_nxt,
128                         payload_len);
129        }
130
131	/*
132	 * Cut off the snapshot length to the end of the IP payload.
133	 */
134	ipend = bp + len;
135	if (ipend < snapend)
136		snapend = ipend;
137
138	cp = (const u_char *)ip6;
139	advance = sizeof(struct ip6_hdr);
140	nh = ip6->ip6_nxt;
141	while (cp < snapend && advance > 0) {
142		cp += advance;
143		len -= advance;
144
145		if (cp == (const u_char *)(ip6 + 1) &&
146		    nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
147		    nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
148			(void)printf("%s > %s: ", ip6addr_string(&ip6->ip6_src),
149				     ip6addr_string(&ip6->ip6_dst));
150		}
151
152		switch (nh) {
153		case IPPROTO_HOPOPTS:
154			advance = hbhopt_print(cp);
155			nh = *cp;
156			break;
157		case IPPROTO_DSTOPTS:
158			advance = dstopt_print(cp);
159			nh = *cp;
160			break;
161		case IPPROTO_FRAGMENT:
162			advance = frag6_print(cp, (const u_char *)ip6);
163			if (snapend <= cp + advance)
164				return;
165			nh = *cp;
166			fragmented = 1;
167			break;
168
169		case IPPROTO_MOBILITY_OLD:
170		case IPPROTO_MOBILITY:
171			/*
172			 * XXX - we don't use "advance"; the current
173			 * "Mobility Support in IPv6" draft
174			 * (draft-ietf-mobileip-ipv6-24) says that
175			 * the next header field in a mobility header
176			 * should be IPPROTO_NONE, but speaks of
177			 * the possiblity of a future extension in
178			 * which payload can be piggybacked atop a
179			 * mobility header.
180			 */
181			advance = mobility_print(cp, (const u_char *)ip6);
182			nh = *cp;
183			return;
184		case IPPROTO_ROUTING:
185			advance = rt6_print(cp, (const u_char *)ip6);
186			nh = *cp;
187			break;
188		case IPPROTO_SCTP:
189			sctp_print(cp, (const u_char *)ip6, len);
190			return;
191		case IPPROTO_DCCP:
192			dccp_print(cp, (const u_char *)ip6, len);
193			return;
194		case IPPROTO_TCP:
195			tcp_print(cp, len, (const u_char *)ip6, fragmented);
196			return;
197		case IPPROTO_UDP:
198			udp_print(cp, len, (const u_char *)ip6, fragmented);
199			return;
200		case IPPROTO_ICMPV6:
201			icmp6_print(gndo, cp, len, (const u_char *)ip6, fragmented);
202			return;
203		case IPPROTO_AH:
204			advance = ah_print(cp);
205			nh = *cp;
206			break;
207		case IPPROTO_ESP:
208		    {
209			int enh, padlen;
210			advance = esp_print(gndo, cp, len, (const u_char *)ip6, &enh, &padlen);
211			nh = enh & 0xff;
212			len -= padlen;
213			break;
214		    }
215		case IPPROTO_IPCOMP:
216		    {
217			int enh;
218			advance = ipcomp_print(cp, &enh);
219			nh = enh & 0xff;
220			break;
221		    }
222
223		case IPPROTO_PIM:
224			pim_print(cp, len, nextproto6_cksum(ip6, (u_short *)cp, len,
225							    IPPROTO_PIM));
226			return;
227
228		case IPPROTO_OSPF:
229			ospf6_print(cp, len);
230			return;
231
232		case IPPROTO_IPV6:
233			ip6_print(cp, len);
234			return;
235
236		case IPPROTO_IPV4:
237		        ip_print(gndo, cp, len);
238			return;
239
240                case IPPROTO_PGM:
241                        pgm_print(cp, len, (const u_char *)ip6);
242                        return;
243
244		case IPPROTO_GRE:
245			gre_print(cp, len);
246			return;
247
248		case IPPROTO_RSVP:
249			rsvp_print(cp, len);
250			return;
251
252		case IPPROTO_NONE:
253			(void)printf("no next header");
254			return;
255
256		default:
257			(void)printf("ip-proto-%d %d", nh, len);
258			return;
259		}
260	}
261
262	return;
263trunc:
264	(void)printf("[|ip6]");
265}
266
267#endif /* INET6 */
268