print-ip6.c revision 267654 
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: releng/9.3/contrib/tcpdump/print-ip6.c 236192 2012-05-28 19:13:21Z delphij $
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_int8_t *data,
54		 u_int len, u_int next_proto)
55{
56        struct {
57                struct in6_addr ph_src;
58                struct in6_addr ph_dst;
59                u_int32_t       ph_len;
60                u_int8_t        ph_zero[3];
61                u_int8_t        ph_nxt;
62        } ph;
63        struct cksum_vec vec[2];
64
65        /* pseudo-header */
66        memset(&ph, 0, sizeof(ph));
67        ph.ph_src = ip6->ip6_src;
68        ph.ph_dst = ip6->ip6_dst;
69        ph.ph_len = htonl(len);
70        ph.ph_nxt = next_proto;
71
72        vec[0].ptr = (const u_int8_t *)(void *)&ph;
73        vec[0].len = sizeof(ph);
74        vec[1].ptr = data;
75        vec[1].len = len;
76
77        return in_cksum(vec, 2);
78}
79
80/*
81 * print an IP6 datagram.
82 */
83void
84ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
85{
86	register const struct ip6_hdr *ip6;
87	register int advance;
88	u_int len;
89	const u_char *ipend;
90	register const u_char *cp;
91	register u_int payload_len;
92	int nh;
93	int fragmented = 0;
94	u_int flow;
95
96	ip6 = (const struct ip6_hdr *)bp;
97
98	TCHECK(*ip6);
99	if (length < sizeof (struct ip6_hdr)) {
100		(void)ND_PRINT((ndo, "truncated-ip6 %u", length));
101		return;
102	}
103
104        if (!ndo->ndo_eflag)
105            ND_PRINT((ndo, "IP6 "));
106
107	payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
108	len = payload_len + sizeof(struct ip6_hdr);
109	if (length < len)
110		(void)ND_PRINT((ndo, "truncated-ip6 - %u bytes missing!",
111			len - length));
112
113        if (ndo->ndo_vflag) {
114            flow = EXTRACT_32BITS(&ip6->ip6_flow);
115            ND_PRINT((ndo, "("));
116#if 0
117            /* rfc1883 */
118            if (flow & 0x0f000000)
119		(void)ND_PRINT((ndo, "pri 0x%02x, ", (flow & 0x0f000000) >> 24));
120            if (flow & 0x00ffffff)
121		(void)ND_PRINT((ndo, "flowlabel 0x%06x, ", flow & 0x00ffffff));
122#else
123            /* RFC 2460 */
124            if (flow & 0x0ff00000)
125		(void)ND_PRINT((ndo, "class 0x%02x, ", (flow & 0x0ff00000) >> 20));
126            if (flow & 0x000fffff)
127		(void)ND_PRINT((ndo, "flowlabel 0x%05x, ", flow & 0x000fffff));
128#endif
129
130            (void)ND_PRINT((ndo, "hlim %u, next-header %s (%u) payload length: %u) ",
131                         ip6->ip6_hlim,
132                         tok2str(ipproto_values,"unknown",ip6->ip6_nxt),
133                         ip6->ip6_nxt,
134                         payload_len));
135        }
136
137	/*
138	 * Cut off the snapshot length to the end of the IP payload.
139	 */
140	ipend = bp + len;
141	if (ipend < ndo->ndo_snapend)
142		ndo->ndo_snapend = ipend;
143
144	cp = (const u_char *)ip6;
145	advance = sizeof(struct ip6_hdr);
146	nh = ip6->ip6_nxt;
147	while (cp < ndo->ndo_snapend && advance > 0) {
148		cp += advance;
149		len -= advance;
150
151		if (cp == (const u_char *)(ip6 + 1) &&
152		    nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
153		    nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
154			(void)ND_PRINT((ndo, "%s > %s: ", ip6addr_string(&ip6->ip6_src),
155				     ip6addr_string(&ip6->ip6_dst)));
156		}
157
158		switch (nh) {
159		case IPPROTO_HOPOPTS:
160			advance = hbhopt_print(cp);
161			nh = *cp;
162			break;
163		case IPPROTO_DSTOPTS:
164			advance = dstopt_print(cp);
165			nh = *cp;
166			break;
167		case IPPROTO_FRAGMENT:
168			advance = frag6_print(cp, (const u_char *)ip6);
169			if (ndo->ndo_snapend <= cp + advance)
170				return;
171			nh = *cp;
172			fragmented = 1;
173			break;
174
175		case IPPROTO_MOBILITY_OLD:
176		case IPPROTO_MOBILITY:
177			/*
178			 * XXX - we don't use "advance"; the current
179			 * "Mobility Support in IPv6" draft
180			 * (draft-ietf-mobileip-ipv6-24) says that
181			 * the next header field in a mobility header
182			 * should be IPPROTO_NONE, but speaks of
183			 * the possiblity of a future extension in
184			 * which payload can be piggybacked atop a
185			 * mobility header.
186			 */
187			advance = mobility_print(cp, (const u_char *)ip6);
188			nh = *cp;
189			return;
190		case IPPROTO_ROUTING:
191			advance = rt6_print(cp, (const u_char *)ip6);
192			nh = *cp;
193			break;
194		case IPPROTO_SCTP:
195			sctp_print(cp, (const u_char *)ip6, len);
196			return;
197		case IPPROTO_DCCP:
198			dccp_print(cp, (const u_char *)ip6, len);
199			return;
200		case IPPROTO_TCP:
201			tcp_print(cp, len, (const u_char *)ip6, fragmented);
202			return;
203		case IPPROTO_UDP:
204			udp_print(cp, len, (const u_char *)ip6, fragmented);
205			return;
206		case IPPROTO_ICMPV6:
207			icmp6_print(ndo, cp, len, (const u_char *)ip6, fragmented);
208			return;
209		case IPPROTO_AH:
210			advance = ah_print(cp);
211			nh = *cp;
212			break;
213		case IPPROTO_ESP:
214		    {
215			int enh, padlen;
216			advance = esp_print(ndo, cp, len, (const u_char *)ip6, &enh, &padlen);
217			nh = enh & 0xff;
218			len -= padlen;
219			break;
220		    }
221		case IPPROTO_IPCOMP:
222		    {
223			int enh;
224			advance = ipcomp_print(cp, &enh);
225			nh = enh & 0xff;
226			break;
227		    }
228
229		case IPPROTO_PIM:
230			pim_print(cp, len, nextproto6_cksum(ip6, cp, len,
231							    IPPROTO_PIM));
232			return;
233
234		case IPPROTO_OSPF:
235			ospf6_print(cp, len);
236			return;
237
238		case IPPROTO_IPV6:
239			ip6_print(ndo, cp, len);
240			return;
241
242		case IPPROTO_IPV4:
243		        ip_print(ndo, cp, len);
244			return;
245
246                case IPPROTO_PGM:
247                        pgm_print(cp, len, (const u_char *)ip6);
248                        return;
249
250		case IPPROTO_GRE:
251			gre_print(cp, len);
252			return;
253
254		case IPPROTO_RSVP:
255			rsvp_print(cp, len);
256			return;
257
258		case IPPROTO_NONE:
259			(void)ND_PRINT((ndo, "no next header"));
260			return;
261
262		default:
263			(void)ND_PRINT((ndo, "ip-proto-%d %d", nh, len));
264			return;
265		}
266	}
267
268	return;
269trunc:
270	(void)ND_PRINT((ndo, "[|ip6]"));
271}
272
273#endif /* INET6 */
274