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
22#ifndef lint
23static const char rcsid[] _U_ =
24    "@(#) $Header: /tcpdump/master/tcpdump/print-ip6.c,v 1.52 2007-09-21 07:05:33 hannes Exp $";
25#endif
26
27#ifdef HAVE_CONFIG_H
28#include "config.h"
29#endif
30
31#ifdef INET6
32
33#include <tcpdump-stdinc.h>
34
35#include <stdio.h>
36#include <stdlib.h>
37#include <string.h>
38
39#include "netdissect.h"
40#include "interface.h"
41#include "addrtoname.h"
42#include "extract.h"
43
44#include "ip6.h"
45#include "ipproto.h"
46
47/*
48 * Compute a V6-style checksum by building a pseudoheader.
49 */
50int
51nextproto6_cksum(const struct ip6_hdr *ip6, const u_int8_t *data,
52		 u_int len, u_int next_proto)
53{
54        struct {
55                struct in6_addr ph_src;
56                struct in6_addr ph_dst;
57                u_int32_t       ph_len;
58                u_int8_t        ph_zero[3];
59                u_int8_t        ph_nxt;
60        } ph;
61        struct cksum_vec vec[2];
62
63        /* pseudo-header */
64        memset(&ph, 0, sizeof(ph));
65        UNALIGNED_MEMCPY(&ph.ph_src, &ip6->ip6_src, sizeof (struct in6_addr));
66        UNALIGNED_MEMCPY(&ph.ph_dst, &ip6->ip6_dst, sizeof (struct in6_addr));
67        ph.ph_len = htonl(len);
68        ph.ph_nxt = next_proto;
69
70        vec[0].ptr = (const u_int8_t *)(void *)&ph;
71        vec[0].len = sizeof(ph);
72        vec[1].ptr = data;
73        vec[1].len = len;
74
75        return in_cksum(vec, 2);
76}
77
78/*
79 * print an IP6 datagram.
80 */
81void
82ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
83{
84	register const struct ip6_hdr *ip6;
85	register int advance;
86	u_int len;
87	const u_char *ipend;
88	register const u_char *cp;
89	register u_int payload_len;
90	int nh;
91	int fragmented = 0;
92	u_int flow;
93
94	ip6 = (const struct ip6_hdr *)bp;
95
96	TCHECK(*ip6);
97	if (length < sizeof (struct ip6_hdr)) {
98		(void)ND_PRINT((ndo, "truncated-ip6 %u", length));
99		return;
100	}
101
102        if (!ndo->ndo_eflag)
103            ND_PRINT((ndo, "IP6 "));
104
105	payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
106	len = payload_len + sizeof(struct ip6_hdr);
107	if (length < len)
108		(void)ND_PRINT((ndo, "truncated-ip6 - %u bytes missing!",
109			len - length));
110
111        if (ndo->ndo_vflag) {
112            flow = EXTRACT_32BITS(&ip6->ip6_flow);
113            ND_PRINT((ndo, "("));
114#if 0
115            /* rfc1883 */
116            if (flow & 0x0f000000)
117		(void)ND_PRINT((ndo, "pri 0x%02x, ", (flow & 0x0f000000) >> 24));
118            if (flow & 0x00ffffff)
119		(void)ND_PRINT((ndo, "flowlabel 0x%06x, ", flow & 0x00ffffff));
120#else
121            /* RFC 2460 */
122            if (flow & 0x0ff00000)
123		(void)ND_PRINT((ndo, "class 0x%02x, ", (flow & 0x0ff00000) >> 20));
124            if (flow & 0x000fffff)
125		(void)ND_PRINT((ndo, "flowlabel 0x%05x, ", flow & 0x000fffff));
126#endif
127
128            (void)ND_PRINT((ndo, "hlim %u, next-header %s (%u) payload length: %u) ",
129                         ip6->ip6_hlim,
130                         tok2str(ipproto_values,"unknown",ip6->ip6_nxt),
131                         ip6->ip6_nxt,
132                         payload_len));
133        }
134
135	/*
136	 * Cut off the snapshot length to the end of the IP payload.
137	 */
138	ipend = bp + len;
139	if (ipend < ndo->ndo_snapend)
140		ndo->ndo_snapend = ipend;
141
142	cp = (const u_char *)ip6;
143	advance = sizeof(struct ip6_hdr);
144	nh = ip6->ip6_nxt;
145	while (cp < ndo->ndo_snapend && advance > 0) {
146		cp += advance;
147		len -= advance;
148
149		if (cp == (const u_char *)(ip6 + 1) &&
150		    nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
151		    nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
152			(void)ND_PRINT((ndo, "%s > %s: ", ip6addr_string(&ip6->ip6_src),
153				     ip6addr_string(&ip6->ip6_dst)));
154		}
155
156		switch (nh) {
157		case IPPROTO_HOPOPTS:
158			advance = hbhopt_print(cp);
159			nh = *cp;
160			break;
161		case IPPROTO_DSTOPTS:
162			advance = dstopt_print(cp);
163			nh = *cp;
164			break;
165		case IPPROTO_FRAGMENT:
166			advance = frag6_print(cp, (const u_char *)ip6);
167			if (ndo->ndo_snapend <= cp + advance)
168				return;
169			nh = *cp;
170			fragmented = 1;
171			break;
172
173		case IPPROTO_MOBILITY_OLD:
174		case IPPROTO_MOBILITY:
175			/*
176			 * XXX - we don't use "advance"; the current
177			 * "Mobility Support in IPv6" draft
178			 * (draft-ietf-mobileip-ipv6-24) says that
179			 * the next header field in a mobility header
180			 * should be IPPROTO_NONE, but speaks of
181			 * the possiblity of a future extension in
182			 * which payload can be piggybacked atop a
183			 * mobility header.
184			 */
185			advance = mobility_print(cp, (const u_char *)ip6);
186			nh = *cp;
187			return;
188		case IPPROTO_ROUTING:
189			advance = rt6_print(cp, (const u_char *)ip6);
190			nh = *cp;
191			break;
192		case IPPROTO_SCTP:
193			sctp_print(cp, (const u_char *)ip6, len);
194			return;
195		case IPPROTO_DCCP:
196			dccp_print(cp, (const u_char *)ip6, len);
197			return;
198		case IPPROTO_TCP:
199			tcp_print(cp, len, (const u_char *)ip6, fragmented);
200			return;
201		case IPPROTO_UDP:
202			udp_print(cp, len, (const u_char *)ip6, fragmented);
203			return;
204		case IPPROTO_ICMPV6:
205			icmp6_print(ndo, cp, len, (const u_char *)ip6, fragmented);
206			return;
207		case IPPROTO_AH:
208			advance = ah_print(cp);
209			nh = *cp;
210			break;
211		case IPPROTO_ESP:
212		    {
213			int enh, padlen;
214			advance = esp_print(ndo, cp, len, (const u_char *)ip6, &enh, &padlen);
215			nh = enh & 0xff;
216			len -= padlen;
217			break;
218		    }
219		case IPPROTO_IPCOMP:
220		    {
221			int enh;
222			advance = ipcomp_print(cp, &enh);
223			nh = enh & 0xff;
224			break;
225		    }
226
227		case IPPROTO_PIM:
228			pim_print(cp, len, nextproto6_cksum(ip6, cp, len,
229							    IPPROTO_PIM));
230			return;
231
232		case IPPROTO_OSPF:
233			ospf6_print(cp, len);
234			return;
235
236		case IPPROTO_IPV6:
237			ip6_print(ndo, cp, len);
238			return;
239
240		case IPPROTO_IPV4:
241		        ip_print(ndo, cp, len);
242			return;
243
244                case IPPROTO_PGM:
245                        pgm_print(cp, len, (const u_char *)ip6);
246                        return;
247
248		case IPPROTO_GRE:
249			gre_print(cp, len);
250			return;
251
252		case IPPROTO_RSVP:
253			rsvp_print(cp, len);
254			return;
255
256		case IPPROTO_NONE:
257			(void)ND_PRINT((ndo, "no next header"));
258			return;
259
260		default:
261			(void)ND_PRINT((ndo, "ip-proto-%d %d", nh, len));
262			return;
263		}
264	}
265
266	return;
267trunc:
268	(void)ND_PRINT((ndo, "[|ip6]"));
269}
270
271#endif /* INET6 */
272