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: stable/10/contrib/tcpdump/print-ip6.c 235530 2012-05-17 05:11:57Z delphij $
22 */
23
24 #ifndef lint
25 static 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 */
52 int
nextproto6_cksum(const struct ip6_hdr * ip6,const u_int8_t * data,u_int len,u_int next_proto)53 nextproto6_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 */
83 void
ip6_print(netdissect_options * ndo,const u_char * bp,u_int length)84 ip6_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;
269 trunc:
270 (void)ND_PRINT((ndo, "[|ip6]"));
271 }
272
273 #endif /* INET6 */
274