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 #include <sys/cdefs.h>
23 #ifndef lint
24 __RCSID("$NetBSD: print-ip6.c,v 1.5 2015/03/31 21:59:35 christos Exp $");
25 #endif
26
27 #define NETDISSECT_REWORKED
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 #include <tcpdump-stdinc.h>
33
34 #include <string.h>
35
36 #include "interface.h"
37 #include "addrtoname.h"
38 #include "extract.h"
39
40 #ifdef INET6
41
42 #include "ip6.h"
43 #include "ipproto.h"
44
45 /*
46 * Compute a V6-style checksum by building a pseudoheader.
47 */
48 int
nextproto6_cksum(const struct ip6_hdr * ip6,const uint8_t * data,u_int len,u_int covlen,u_int next_proto)49 nextproto6_cksum(const struct ip6_hdr *ip6, const uint8_t *data,
50 u_int len, u_int covlen, u_int next_proto)
51 {
52 struct {
53 struct in6_addr ph_src;
54 struct in6_addr ph_dst;
55 uint32_t ph_len;
56 uint8_t ph_zero[3];
57 uint8_t ph_nxt;
58 } ph;
59 struct cksum_vec vec[2];
60
61 /* pseudo-header */
62 memset(&ph, 0, sizeof(ph));
63 UNALIGNED_MEMCPY(&ph.ph_src, &ip6->ip6_src, sizeof (struct in6_addr));
64 UNALIGNED_MEMCPY(&ph.ph_dst, &ip6->ip6_dst, sizeof (struct in6_addr));
65 ph.ph_len = htonl(len);
66 ph.ph_nxt = next_proto;
67
68 vec[0].ptr = (const uint8_t *)(void *)&ph;
69 vec[0].len = sizeof(ph);
70 vec[1].ptr = data;
71 vec[1].len = covlen;
72
73 return in_cksum(vec, 2);
74 }
75
76 /*
77 * print an IP6 datagram.
78 */
79 void
ip6_print(netdissect_options * ndo,const u_char * bp,u_int length)80 ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
81 {
82 register const struct ip6_hdr *ip6;
83 register int advance;
84 u_int len;
85 const u_char *ipend;
86 register const u_char *cp;
87 register u_int payload_len;
88 int nh;
89 int fragmented = 0;
90 u_int flow;
91
92 ip6 = (const struct ip6_hdr *)bp;
93
94 ND_TCHECK(*ip6);
95 if (length < sizeof (struct ip6_hdr)) {
96 ND_PRINT((ndo, "truncated-ip6 %u", length));
97 return;
98 }
99
100 if (!ndo->ndo_eflag)
101 ND_PRINT((ndo, "IP6 "));
102
103 if (IP6_VERSION(ip6) != 6) {
104 ND_PRINT((ndo,"version error: %u != 6", IP6_VERSION(ip6)));
105 return;
106 }
107
108 payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
109 len = payload_len + sizeof(struct ip6_hdr);
110 if (length < len)
111 ND_PRINT((ndo, "truncated-ip6 - %u bytes missing!",
112 len - length));
113
114 if (ndo->ndo_vflag) {
115 flow = EXTRACT_32BITS(&ip6->ip6_flow);
116 ND_PRINT((ndo, "("));
117 #if 0
118 /* rfc1883 */
119 if (flow & 0x0f000000)
120 ND_PRINT((ndo, "pri 0x%02x, ", (flow & 0x0f000000) >> 24));
121 if (flow & 0x00ffffff)
122 ND_PRINT((ndo, "flowlabel 0x%06x, ", flow & 0x00ffffff));
123 #else
124 /* RFC 2460 */
125 if (flow & 0x0ff00000)
126 ND_PRINT((ndo, "class 0x%02x, ", (flow & 0x0ff00000) >> 20));
127 if (flow & 0x000fffff)
128 ND_PRINT((ndo, "flowlabel 0x%05x, ", flow & 0x000fffff));
129 #endif
130
131 ND_PRINT((ndo, "hlim %u, next-header %s (%u) payload length: %u) ",
132 ip6->ip6_hlim,
133 tok2str(ipproto_values,"unknown",ip6->ip6_nxt),
134 ip6->ip6_nxt,
135 payload_len));
136 }
137
138 /*
139 * Cut off the snapshot length to the end of the IP payload.
140 */
141 ipend = bp + len;
142 if (ipend < ndo->ndo_snapend)
143 ndo->ndo_snapend = ipend;
144
145 cp = (const u_char *)ip6;
146 advance = sizeof(struct ip6_hdr);
147 nh = ip6->ip6_nxt;
148 while (cp < ndo->ndo_snapend && advance > 0) {
149 cp += advance;
150 len -= advance;
151
152 if (cp == (const u_char *)(ip6 + 1) &&
153 nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
154 nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
155 ND_PRINT((ndo, "%s > %s: ", ip6addr_string(ndo, &ip6->ip6_src),
156 ip6addr_string(ndo, &ip6->ip6_dst)));
157 }
158
159 switch (nh) {
160 case IPPROTO_HOPOPTS:
161 advance = hbhopt_print(ndo, cp);
162 nh = *cp;
163 break;
164 case IPPROTO_DSTOPTS:
165 advance = dstopt_print(ndo, cp);
166 nh = *cp;
167 break;
168 case IPPROTO_FRAGMENT:
169 advance = frag6_print(ndo, cp, (const u_char *)ip6);
170 if (ndo->ndo_snapend <= cp + advance)
171 return;
172 nh = *cp;
173 fragmented = 1;
174 break;
175
176 case IPPROTO_MOBILITY_OLD:
177 case IPPROTO_MOBILITY:
178 /*
179 * XXX - we don't use "advance"; the current
180 * "Mobility Support in IPv6" draft
181 * (draft-ietf-mobileip-ipv6-24) says that
182 * the next header field in a mobility header
183 * should be IPPROTO_NONE, but speaks of
184 * the possiblity of a future extension in
185 * which payload can be piggybacked atop a
186 * mobility header.
187 */
188 advance = mobility_print(ndo, cp, (const u_char *)ip6);
189 nh = *cp;
190 return;
191 case IPPROTO_ROUTING:
192 advance = rt6_print(ndo, cp, (const u_char *)ip6);
193 nh = *cp;
194 break;
195 case IPPROTO_SCTP:
196 sctp_print(ndo, cp, (const u_char *)ip6, len);
197 return;
198 case IPPROTO_DCCP:
199 dccp_print(ndo, cp, (const u_char *)ip6, len);
200 return;
201 case IPPROTO_TCP:
202 tcp_print(ndo, cp, len, (const u_char *)ip6, fragmented);
203 return;
204 case IPPROTO_UDP:
205 udp_print(ndo, cp, len, (const u_char *)ip6, fragmented);
206 return;
207 case IPPROTO_ICMPV6:
208 icmp6_print(ndo, cp, len, (const u_char *)ip6, fragmented);
209 return;
210 case IPPROTO_AH:
211 advance = ah_print(ndo, cp);
212 nh = *cp;
213 break;
214 case IPPROTO_ESP:
215 {
216 int enh, padlen;
217 advance = esp_print(ndo, cp, len, (const u_char *)ip6, &enh, &padlen);
218 nh = enh & 0xff;
219 len -= padlen;
220 break;
221 }
222 case IPPROTO_IPCOMP:
223 {
224 int enh;
225 advance = ipcomp_print(ndo, cp, &enh);
226 nh = enh & 0xff;
227 break;
228 }
229
230 case IPPROTO_PIM:
231 pim_print(ndo, cp, len, nextproto6_cksum(ip6, cp, len, len,
232 IPPROTO_PIM));
233 return;
234
235 case IPPROTO_OSPF:
236 ospf6_print(ndo, cp, len);
237 return;
238
239 case IPPROTO_IPV6:
240 ip6_print(ndo, cp, len);
241 return;
242
243 case IPPROTO_IPV4:
244 ip_print(ndo, cp, len);
245 return;
246
247 case IPPROTO_PGM:
248 pgm_print(ndo, cp, len, (const u_char *)ip6);
249 return;
250
251 case IPPROTO_GRE:
252 gre_print(ndo, cp, len);
253 return;
254
255 case IPPROTO_RSVP:
256 rsvp_print(ndo, cp, len);
257 return;
258
259 case IPPROTO_NONE:
260 ND_PRINT((ndo, "no next header"));
261 return;
262
263 default:
264 ND_PRINT((ndo, "ip-proto-%d %d", nh, len));
265 return;
266 }
267 }
268
269 return;
270 trunc:
271 ND_PRINT((ndo, "[|ip6]"));
272 }
273
274 #else /* INET6 */
275
276 void
ip6_print(netdissect_options * ndo,const u_char * bp _U_,u_int length)277 ip6_print(netdissect_options *ndo, const u_char *bp _U_, u_int length)
278 {
279 ND_PRINT((ndo, "IP6, length: %u (printing not supported)", length));
280 }
281
282 #endif /* INET6 */
283