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
23 static 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 */
50 int
nextproto6_cksum(const struct ip6_hdr * ip6,const u_int8_t * data,u_int len,u_int next_proto)51 nextproto6_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 */
81 void
ip6_print(netdissect_options * ndo,const u_char * bp,u_int length)82 ip6_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;
267 trunc:
268 (void)ND_PRINT((ndo, "[|ip6]"));
269 }
270
271 #endif /* INET6 */
272