tcpdump  4.99.1
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print-ip6opts.c
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1 /*
2  * Copyright (C) 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  * notice, this list of conditions and the following disclaimer in the
12  * documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  * may be used to endorse or promote products derived from this software
15  * without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /* \summary: IPv6 header option printer */
31 
32 #ifdef HAVE_CONFIG_H
33 #include <config.h>
34 #endif
35 
36 #include "netdissect-stdinc.h"
37 
38 #include "netdissect.h"
39 #include "addrtoname.h"
40 #include "extract.h"
41 
42 #include "ip6.h"
43 
44 static int
45 ip6_sopt_print(netdissect_options *ndo, const u_char *bp, int len)
46 {
47  int i;
48  int optlen;
49 
50  for (i = 0; i < len; i += optlen) {
51  if (GET_U_1(bp + i) == IP6OPT_PAD1)
52  optlen = 1;
53  else {
54  if (i + 1 < len)
55  optlen = GET_U_1(bp + i + 1) + 2;
56  else
57  goto trunc;
58  }
59  if (i + optlen > len)
60  goto trunc;
61 
62  switch (GET_U_1(bp + i)) {
63  case IP6OPT_PAD1:
64  ND_PRINT(", pad1");
65  break;
66  case IP6OPT_PADN:
67  if (len - i < IP6OPT_MINLEN) {
68  ND_PRINT(", padn: trunc");
69  goto trunc;
70  }
71  ND_PRINT(", padn");
72  break;
73  default:
74  if (len - i < IP6OPT_MINLEN) {
75  ND_PRINT(", sopt_type %u: trunc)", GET_U_1(bp + i));
76  goto trunc;
77  }
78  ND_PRINT(", sopt_type 0x%02x: len=%u", GET_U_1(bp + i),
79  GET_U_1(bp + i + 1));
80  break;
81  }
82  }
83  return 0;
84 
85 trunc:
86  return -1;
87 }
88 
89 static int
90 ip6_opt_process(netdissect_options *ndo, const u_char *bp, int len,
91  int *found_jumbop, uint32_t *payload_len)
92 {
93  int i;
94  int optlen = 0;
95  int found_jumbo = 0;
96  uint32_t jumbolen = 0;
97 
98  if (len == 0)
99  return 0;
100  for (i = 0; i < len; i += optlen) {
101  if (GET_U_1(bp + i) == IP6OPT_PAD1)
102  optlen = 1;
103  else {
104  if (i + 1 < len)
105  optlen = GET_U_1(bp + i + 1) + 2;
106  else
107  goto trunc;
108  }
109  if (i + optlen > len)
110  goto trunc;
111 
112  switch (GET_U_1(bp + i)) {
113  case IP6OPT_PAD1:
114  if (ndo->ndo_vflag)
115  ND_PRINT("(pad1)");
116  break;
117  case IP6OPT_PADN:
118  if (len - i < IP6OPT_MINLEN) {
119  ND_PRINT("(padn: trunc)");
120  goto trunc;
121  }
122  if (ndo->ndo_vflag)
123  ND_PRINT("(padn)");
124  break;
125  case IP6OPT_ROUTER_ALERT:
126  if (len - i < IP6OPT_RTALERT_LEN) {
127  ND_PRINT("(rtalert: trunc)");
128  goto trunc;
129  }
130  if (GET_U_1(bp + i + 1) != IP6OPT_RTALERT_LEN - 2) {
131  ND_PRINT("(rtalert: invalid len %u)", GET_U_1(bp + i + 1));
132  goto trunc;
133  }
134  if (ndo->ndo_vflag)
135  ND_PRINT("(rtalert: 0x%04x) ", GET_BE_U_2(bp + i + 2));
136  break;
137  case IP6OPT_JUMBO:
138  if (len - i < IP6OPT_JUMBO_LEN) {
139  ND_PRINT("(jumbo: trunc)");
140  goto trunc;
141  }
142  if (GET_U_1(bp + i + 1) != IP6OPT_JUMBO_LEN - 2) {
143  ND_PRINT("(jumbo: invalid len %u)", GET_U_1(bp + i + 1));
144  goto trunc;
145  }
146  jumbolen = GET_BE_U_4(bp + i + 2);
147  if (found_jumbo) {
148  /* More than one Jumbo Payload option */
149  if (ndo->ndo_vflag)
150  ND_PRINT("(jumbo: %u - already seen) ", jumbolen);
151  } else {
152  found_jumbo = 1;
153  if (payload_len == NULL) {
154  /* Not a hop-by-hop option - not valid */
155  if (ndo->ndo_vflag)
156  ND_PRINT("(jumbo: %u - not a hop-by-hop option) ", jumbolen);
157  } else if (*payload_len != 0) {
158  /* Payload length was non-zero - not valid */
159  if (ndo->ndo_vflag)
160  ND_PRINT("(jumbo: %u - payload len != 0) ", jumbolen);
161  } else {
162  /*
163  * This is a hop-by-hop option, and Payload length
164  * was zero in the IPv6 header.
165  */
166  if (jumbolen < 65536) {
167  /* Too short */
168  if (ndo->ndo_vflag)
169  ND_PRINT("(jumbo: %u - < 65536) ", jumbolen);
170  } else {
171  /* OK, this is valid */
172  *found_jumbop = 1;
173  *payload_len = jumbolen;
174  if (ndo->ndo_vflag)
175  ND_PRINT("(jumbo: %u) ", jumbolen);
176  }
177  }
178  }
179  break;
180  case IP6OPT_HOME_ADDRESS:
181  if (len - i < IP6OPT_HOMEADDR_MINLEN) {
182  ND_PRINT("(homeaddr: trunc)");
183  goto trunc;
184  }
185  if (GET_U_1(bp + i + 1) < IP6OPT_HOMEADDR_MINLEN - 2) {
186  ND_PRINT("(homeaddr: invalid len %u)", GET_U_1(bp + i + 1));
187  goto trunc;
188  }
189  if (ndo->ndo_vflag) {
190  ND_PRINT("(homeaddr: %s", GET_IP6ADDR_STRING(bp + i + 2));
191  if (GET_U_1(bp + i + 1) > IP6OPT_HOMEADDR_MINLEN - 2) {
192  if (ip6_sopt_print(ndo, bp + i + IP6OPT_HOMEADDR_MINLEN,
193  (optlen - IP6OPT_HOMEADDR_MINLEN)) == -1)
194  goto trunc;
195  }
196  ND_PRINT(")");
197  }
198  break;
199  default:
200  if (len - i < IP6OPT_MINLEN) {
201  ND_PRINT("(type %u: trunc)", GET_U_1(bp + i));
202  goto trunc;
203  }
204  if (ndo->ndo_vflag)
205  ND_PRINT("(opt_type 0x%02x: len=%u)", GET_U_1(bp + i),
206  GET_U_1(bp + i + 1));
207  break;
208  }
209  }
210  if (ndo->ndo_vflag)
211  ND_PRINT(" ");
212  return 0;
213 
214 trunc:
215  return -1;
216 }
217 
218 int
219 hbhopt_process(netdissect_options *ndo, const u_char *bp, int *found_jumbo,
220  uint32_t *jumbolen)
221 {
222  const struct ip6_hbh *dp = (const struct ip6_hbh *)bp;
223  u_int hbhlen = 0;
224 
225  ndo->ndo_protocol = "hbhopt";
226  hbhlen = (GET_U_1(dp->ip6h_len) + 1) << 3;
227  ND_TCHECK_LEN(dp, hbhlen);
228  ND_PRINT("HBH ");
229  if (ip6_opt_process(ndo, (const u_char *)dp + sizeof(*dp),
230  hbhlen - sizeof(*dp), found_jumbo, jumbolen) == -1)
231  goto trunc;
232  return hbhlen;
233 
234 trunc:
235  nd_print_trunc(ndo);
236  return -1;
237 }
238 
239 int
240 dstopt_process(netdissect_options *ndo, const u_char *bp)
241 {
242  const struct ip6_dest *dp = (const struct ip6_dest *)bp;
243  u_int dstoptlen = 0;
244 
245  ndo->ndo_protocol = "dstopt";
246  dstoptlen = (GET_U_1(dp->ip6d_len) + 1) << 3;
247  ND_TCHECK_LEN(dp, dstoptlen);
248  ND_PRINT("DSTOPT ");
249  if (ndo->ndo_vflag) {
250  /*
251  * The Jumbo Payload option is a hop-by-hop option; we don't
252  * honor Jumbo Payload destination options, reporting them
253  * as invalid.
254  */
255  if (ip6_opt_process(ndo, (const u_char *)dp + sizeof(*dp),
256  dstoptlen - sizeof(*dp), NULL, NULL) == -1)
257  goto trunc;
258  }
259 
260  return dstoptlen;
261 
262 trunc:
263  nd_print_trunc(ndo);
264  return -1;
265 }
#define GET_IP6ADDR_STRING(p)
Definition: addrtoname.h:121
#define GET_BE_U_4(p)
Definition: extract.h:877
#define GET_BE_U_2(p)
Definition: extract.h:875
#define GET_U_1(p)
Definition: extract.h:872
#define IP6OPT_RTALERT_LEN
Definition: ip6.h:136
#define IP6OPT_ROUTER_ALERT
Definition: ip6.h:134
#define IP6OPT_HOMEADDR_MINLEN
Definition: ip6.h:146
#define IP6OPT_JUMBO
Definition: ip6.h:130
#define IP6OPT_HOME_ADDRESS
Definition: ip6.h:145
#define IP6OPT_PAD1
Definition: ip6.h:128
#define IP6OPT_MINLEN
Definition: ip6.h:140
#define IP6OPT_JUMBO_LEN
Definition: ip6.h:131
#define IP6OPT_PADN
Definition: ip6.h:129
#define ND_TCHECK_LEN(p, l)
Definition: netdissect.h:368
void nd_print_trunc(netdissect_options *)
Definition: util-print.c:409
#define ND_PRINT(...)
Definition: netdissect.h:385
int hbhopt_process(netdissect_options *ndo, const u_char *bp, int *found_jumbo, uint32_t *jumbolen)
int dstopt_process(netdissect_options *ndo, const u_char *bp)
static int ip6_sopt_print(netdissect_options *ndo, const u_char *bp, int len)
Definition: print-ip6opts.c:45
static int ip6_opt_process(netdissect_options *ndo, const u_char *bp, int len, int *found_jumbop, uint32_t *payload_len)
Definition: print-ip6opts.c:90
Definition: ip6.h:119
nd_uint8_t ip6d_len
Definition: ip6.h:121
Definition: ip6.h:112
nd_uint8_t ip6h_len
Definition: ip6.h:114
const char * ndo_protocol
Definition: netdissect.h:218