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1 /*
2  * Copyright (C) 2002 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 mobility printer */
31 /* RFC 3775 */
32 
33 #ifdef HAVE_CONFIG_H
34 #include "config.h"
35 #endif
36 
37 #include <netdissect-stdinc.h>
38 
39 #include "netdissect.h"
40 #include "addrtoname.h"
41 #include "extract.h"
42 
43 #include "ip6.h"
44 
45 static const char tstr[] = "[|MOBILITY]";
46 
47 /* Mobility header */
48 struct ip6_mobility {
49 	uint8_t ip6m_pproto;	/* following payload protocol (for PG) */
50 	uint8_t ip6m_len;	/* length in units of 8 octets */
51 	uint8_t ip6m_type;	/* message type */
52 	uint8_t reserved;	/* reserved */
53 	uint16_t ip6m_cksum;	/* sum of IPv6 pseudo-header and MH */
54 	union {
55 		uint16_t	ip6m_un_data16[1]; /* type-specific field */
56 		uint8_t		ip6m_un_data8[2];  /* type-specific field */
57 	} ip6m_dataun;
58 };
59 
60 #define ip6m_data16	ip6m_dataun.ip6m_un_data16
61 #define ip6m_data8	ip6m_dataun.ip6m_un_data8
62 
63 #define IP6M_MINLEN	8
64 
65 /* http://www.iana.org/assignments/mobility-parameters/mobility-parameters.xhtml */
66 
67 /* message type */
68 #define IP6M_BINDING_REQUEST	0	/* Binding Refresh Request */
69 #define IP6M_HOME_TEST_INIT	1	/* Home Test Init */
70 #define IP6M_CAREOF_TEST_INIT	2	/* Care-of Test Init */
71 #define IP6M_HOME_TEST		3	/* Home Test */
72 #define IP6M_CAREOF_TEST	4	/* Care-of Test */
73 #define IP6M_BINDING_UPDATE	5	/* Binding Update */
74 #define IP6M_BINDING_ACK	6	/* Binding Acknowledgement */
75 #define IP6M_BINDING_ERROR	7	/* Binding Error */
76 #define IP6M_MAX		7
77 
78 static const struct tok ip6m_str[] = {
79 	{ IP6M_BINDING_REQUEST,  "BRR"  },
80 	{ IP6M_HOME_TEST_INIT,   "HoTI" },
81 	{ IP6M_CAREOF_TEST_INIT, "CoTI" },
82 	{ IP6M_HOME_TEST,        "HoT"  },
83 	{ IP6M_CAREOF_TEST,      "CoT"  },
84 	{ IP6M_BINDING_UPDATE,   "BU"   },
85 	{ IP6M_BINDING_ACK,      "BA"   },
86 	{ IP6M_BINDING_ERROR,    "BE"   },
87 	{ 0, NULL }
88 };
89 
90 static const unsigned ip6m_hdrlen[IP6M_MAX + 1] = {
91 	IP6M_MINLEN,      /* IP6M_BINDING_REQUEST  */
92 	IP6M_MINLEN + 8,  /* IP6M_HOME_TEST_INIT   */
93 	IP6M_MINLEN + 8,  /* IP6M_CAREOF_TEST_INIT */
94 	IP6M_MINLEN + 16, /* IP6M_HOME_TEST        */
95 	IP6M_MINLEN + 16, /* IP6M_CAREOF_TEST      */
96 	IP6M_MINLEN + 4,  /* IP6M_BINDING_UPDATE   */
97 	IP6M_MINLEN + 4,  /* IP6M_BINDING_ACK      */
98 	IP6M_MINLEN + 16, /* IP6M_BINDING_ERROR    */
99 };
100 
101 /* Mobility Header Options */
102 #define IP6MOPT_MINLEN		2
103 #define IP6MOPT_PAD1          0x0	/* Pad1 */
104 #define IP6MOPT_PADN          0x1	/* PadN */
105 #define IP6MOPT_REFRESH	      0x2	/* Binding Refresh Advice */
106 #define IP6MOPT_REFRESH_MINLEN  4
107 #define IP6MOPT_ALTCOA        0x3	/* Alternate Care-of Address */
108 #define IP6MOPT_ALTCOA_MINLEN  18
109 #define IP6MOPT_NONCEID       0x4	/* Nonce Indices */
110 #define IP6MOPT_NONCEID_MINLEN  6
111 #define IP6MOPT_AUTH          0x5	/* Binding Authorization Data */
112 #define IP6MOPT_AUTH_MINLEN    12
113 
114 static int
mobility_opt_print(netdissect_options * ndo,const u_char * bp,const unsigned len)115 mobility_opt_print(netdissect_options *ndo,
116                    const u_char *bp, const unsigned len)
117 {
118 	unsigned i, optlen;
119 
120 	for (i = 0; i < len; i += optlen) {
121 		ND_TCHECK(bp[i]);
122 		if (bp[i] == IP6MOPT_PAD1)
123 			optlen = 1;
124 		else {
125 			if (i + 1 < len) {
126 				ND_TCHECK(bp[i + 1]);
127 				optlen = bp[i + 1] + 2;
128 			}
129 			else
130 				goto trunc;
131 		}
132 		if (i + optlen > len)
133 			goto trunc;
134 		ND_TCHECK(bp[i + optlen]);
135 
136 		switch (bp[i]) {
137 		case IP6MOPT_PAD1:
138 			ND_PRINT((ndo, "(pad1)"));
139 			break;
140 		case IP6MOPT_PADN:
141 			if (len - i < IP6MOPT_MINLEN) {
142 				ND_PRINT((ndo, "(padn: trunc)"));
143 				goto trunc;
144 			}
145 			ND_PRINT((ndo, "(padn)"));
146 			break;
147 		case IP6MOPT_REFRESH:
148 			if (len - i < IP6MOPT_REFRESH_MINLEN) {
149 				ND_PRINT((ndo, "(refresh: trunc)"));
150 				goto trunc;
151 			}
152 			/* units of 4 secs */
153 			ND_TCHECK_16BITS(&bp[i+2]);
154 			ND_PRINT((ndo, "(refresh: %u)",
155 				EXTRACT_16BITS(&bp[i+2]) << 2));
156 			break;
157 		case IP6MOPT_ALTCOA:
158 			if (len - i < IP6MOPT_ALTCOA_MINLEN) {
159 				ND_PRINT((ndo, "(altcoa: trunc)"));
160 				goto trunc;
161 			}
162 			ND_TCHECK_128BITS(&bp[i+2]);
163 			ND_PRINT((ndo, "(alt-CoA: %s)", ip6addr_string(ndo, &bp[i+2])));
164 			break;
165 		case IP6MOPT_NONCEID:
166 			if (len - i < IP6MOPT_NONCEID_MINLEN) {
167 				ND_PRINT((ndo, "(ni: trunc)"));
168 				goto trunc;
169 			}
170 			ND_TCHECK_16BITS(&bp[i+2]);
171 			ND_TCHECK_16BITS(&bp[i+4]);
172 			ND_PRINT((ndo, "(ni: ho=0x%04x co=0x%04x)",
173 				EXTRACT_16BITS(&bp[i+2]),
174 				EXTRACT_16BITS(&bp[i+4])));
175 			break;
176 		case IP6MOPT_AUTH:
177 			if (len - i < IP6MOPT_AUTH_MINLEN) {
178 				ND_PRINT((ndo, "(auth: trunc)"));
179 				goto trunc;
180 			}
181 			ND_PRINT((ndo, "(auth)"));
182 			break;
183 		default:
184 			if (len - i < IP6MOPT_MINLEN) {
185 				ND_PRINT((ndo, "(sopt_type %u: trunc)", bp[i]));
186 				goto trunc;
187 			}
188 			ND_PRINT((ndo, "(type-0x%02x: len=%u)", bp[i], bp[i + 1]));
189 			break;
190 		}
191 	}
192 	return 0;
193 
194 trunc:
195 	return 1;
196 }
197 
198 /*
199  * Mobility Header
200  */
201 int
mobility_print(netdissect_options * ndo,const u_char * bp,const u_char * bp2 _U_)202 mobility_print(netdissect_options *ndo,
203                const u_char *bp, const u_char *bp2 _U_)
204 {
205 	const struct ip6_mobility *mh;
206 	const u_char *ep;
207 	unsigned mhlen, hlen;
208 	uint8_t type;
209 
210 	mh = (const struct ip6_mobility *)bp;
211 
212 	/* 'ep' points to the end of available data. */
213 	ep = ndo->ndo_snapend;
214 
215 	if (!ND_TTEST(mh->ip6m_len)) {
216 		/*
217 		 * There's not enough captured data to include the
218 		 * mobility header length.
219 		 *
220 		 * Our caller expects us to return the length, however,
221 		 * so return a value that will run to the end of the
222 		 * captured data.
223 		 *
224 		 * XXX - "ip6_print()" doesn't do anything with the
225 		 * returned length, however, as it breaks out of the
226 		 * header-processing loop.
227 		 */
228 		mhlen = ep - bp;
229 		goto trunc;
230 	}
231 	mhlen = (mh->ip6m_len + 1) << 3;
232 
233 	/* XXX ip6m_cksum */
234 
235 	ND_TCHECK(mh->ip6m_type);
236 	type = mh->ip6m_type;
237 	if (type <= IP6M_MAX && mhlen < ip6m_hdrlen[type]) {
238 		ND_PRINT((ndo, "(header length %u is too small for type %u)", mhlen, type));
239 		goto trunc;
240 	}
241 	ND_PRINT((ndo, "mobility: %s", tok2str(ip6m_str, "type-#%u", type)));
242 	switch (type) {
243 	case IP6M_BINDING_REQUEST:
244 		hlen = IP6M_MINLEN;
245 		break;
246 	case IP6M_HOME_TEST_INIT:
247 	case IP6M_CAREOF_TEST_INIT:
248 		hlen = IP6M_MINLEN;
249 		if (ndo->ndo_vflag) {
250 			ND_TCHECK_32BITS(&bp[hlen + 4]);
251 			ND_PRINT((ndo, " %s Init Cookie=%08x:%08x",
252 			       type == IP6M_HOME_TEST_INIT ? "Home" : "Care-of",
253 			       EXTRACT_32BITS(&bp[hlen]),
254 			       EXTRACT_32BITS(&bp[hlen + 4])));
255 		}
256 		hlen += 8;
257 		break;
258 	case IP6M_HOME_TEST:
259 	case IP6M_CAREOF_TEST:
260 		ND_TCHECK(mh->ip6m_data16[0]);
261 		ND_PRINT((ndo, " nonce id=0x%x", EXTRACT_16BITS(&mh->ip6m_data16[0])));
262 		hlen = IP6M_MINLEN;
263 		if (ndo->ndo_vflag) {
264 			ND_TCHECK_32BITS(&bp[hlen + 4]);
265 			ND_PRINT((ndo, " %s Init Cookie=%08x:%08x",
266 			       type == IP6M_HOME_TEST ? "Home" : "Care-of",
267 			       EXTRACT_32BITS(&bp[hlen]),
268 			       EXTRACT_32BITS(&bp[hlen + 4])));
269 		}
270 		hlen += 8;
271 		if (ndo->ndo_vflag) {
272 			ND_TCHECK_32BITS(&bp[hlen + 4]);
273 			ND_PRINT((ndo, " %s Keygen Token=%08x:%08x",
274 			       type == IP6M_HOME_TEST ? "Home" : "Care-of",
275 			       EXTRACT_32BITS(&bp[hlen]),
276 			       EXTRACT_32BITS(&bp[hlen + 4])));
277 		}
278 		hlen += 8;
279 		break;
280 	case IP6M_BINDING_UPDATE:
281 		ND_TCHECK(mh->ip6m_data16[0]);
282 		ND_PRINT((ndo, " seq#=%u", EXTRACT_16BITS(&mh->ip6m_data16[0])));
283 		hlen = IP6M_MINLEN;
284 		ND_TCHECK_16BITS(&bp[hlen]);
285 		if (bp[hlen] & 0xf0) {
286 			ND_PRINT((ndo, " "));
287 			if (bp[hlen] & 0x80)
288 				ND_PRINT((ndo, "A"));
289 			if (bp[hlen] & 0x40)
290 				ND_PRINT((ndo, "H"));
291 			if (bp[hlen] & 0x20)
292 				ND_PRINT((ndo, "L"));
293 			if (bp[hlen] & 0x10)
294 				ND_PRINT((ndo, "K"));
295 		}
296 		/* Reserved (4bits) */
297 		hlen += 1;
298 		/* Reserved (8bits) */
299 		hlen += 1;
300 		ND_TCHECK_16BITS(&bp[hlen]);
301 		/* units of 4 secs */
302 		ND_PRINT((ndo, " lifetime=%u", EXTRACT_16BITS(&bp[hlen]) << 2));
303 		hlen += 2;
304 		break;
305 	case IP6M_BINDING_ACK:
306 		ND_TCHECK(mh->ip6m_data8[0]);
307 		ND_PRINT((ndo, " status=%u", mh->ip6m_data8[0]));
308 		ND_TCHECK(mh->ip6m_data8[1]);
309 		if (mh->ip6m_data8[1] & 0x80)
310 			ND_PRINT((ndo, " K"));
311 		/* Reserved (7bits) */
312 		hlen = IP6M_MINLEN;
313 		ND_TCHECK_16BITS(&bp[hlen]);
314 		ND_PRINT((ndo, " seq#=%u", EXTRACT_16BITS(&bp[hlen])));
315 		hlen += 2;
316 		ND_TCHECK_16BITS(&bp[hlen]);
317 		/* units of 4 secs */
318 		ND_PRINT((ndo, " lifetime=%u", EXTRACT_16BITS(&bp[hlen]) << 2));
319 		hlen += 2;
320 		break;
321 	case IP6M_BINDING_ERROR:
322 		ND_TCHECK(mh->ip6m_data8[0]);
323 		ND_PRINT((ndo, " status=%u", mh->ip6m_data8[0]));
324 		/* Reserved */
325 		hlen = IP6M_MINLEN;
326 		ND_TCHECK2(bp[hlen], 16);
327 		ND_PRINT((ndo, " homeaddr %s", ip6addr_string(ndo, &bp[hlen])));
328 		hlen += 16;
329 		break;
330 	default:
331 		ND_PRINT((ndo, " len=%u", mh->ip6m_len));
332 		return(mhlen);
333 		break;
334 	}
335 	if (ndo->ndo_vflag)
336 		if (mobility_opt_print(ndo, &bp[hlen], mhlen - hlen))
337 			goto trunc;;
338 
339 	return(mhlen);
340 
341  trunc:
342 	ND_PRINT((ndo, "%s", tstr));
343 	return(-1);
344 }
345