xref: /freebsd/contrib/tcpdump/print-mobility.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
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 
46 /* Mobility header */
47 struct ip6_mobility {
48 	nd_uint8_t ip6m_pproto;	/* following payload protocol (for PG) */
49 	nd_uint8_t ip6m_len;	/* length in units of 8 octets */
50 	nd_uint8_t ip6m_type;	/* message type */
51 	nd_uint8_t reserved;	/* reserved */
52 	nd_uint16_t ip6m_cksum;	/* sum of IPv6 pseudo-header and MH */
53 	union {
54 		nd_uint16_t	ip6m_un_data16[1]; /* type-specific field */
55 		nd_uint8_t	ip6m_un_data8[2];  /* type-specific field */
56 	} ip6m_dataun;
57 };
58 
59 #define ip6m_data16	ip6m_dataun.ip6m_un_data16
60 #define ip6m_data8	ip6m_dataun.ip6m_un_data8
61 
62 #define IP6M_MINLEN	8
63 
64 /* https://www.iana.org/assignments/mobility-parameters/mobility-parameters.xhtml */
65 
66 /* message type */
67 #define IP6M_BINDING_REQUEST	0	/* Binding Refresh Request */
68 #define IP6M_HOME_TEST_INIT	1	/* Home Test Init */
69 #define IP6M_CAREOF_TEST_INIT	2	/* Care-of Test Init */
70 #define IP6M_HOME_TEST		3	/* Home Test */
71 #define IP6M_CAREOF_TEST	4	/* Care-of Test */
72 #define IP6M_BINDING_UPDATE	5	/* Binding Update */
73 #define IP6M_BINDING_ACK	6	/* Binding Acknowledgement */
74 #define IP6M_BINDING_ERROR	7	/* Binding Error */
75 #define IP6M_MAX		7
76 
77 static const struct tok ip6m_str[] = {
78 	{ IP6M_BINDING_REQUEST,  "BRR"  },
79 	{ IP6M_HOME_TEST_INIT,   "HoTI" },
80 	{ IP6M_CAREOF_TEST_INIT, "CoTI" },
81 	{ IP6M_HOME_TEST,        "HoT"  },
82 	{ IP6M_CAREOF_TEST,      "CoT"  },
83 	{ IP6M_BINDING_UPDATE,   "BU"   },
84 	{ IP6M_BINDING_ACK,      "BA"   },
85 	{ IP6M_BINDING_ERROR,    "BE"   },
86 	{ 0, NULL }
87 };
88 
89 static const unsigned ip6m_hdrlen[IP6M_MAX + 1] = {
90 	IP6M_MINLEN,      /* IP6M_BINDING_REQUEST  */
91 	IP6M_MINLEN + 8,  /* IP6M_HOME_TEST_INIT   */
92 	IP6M_MINLEN + 8,  /* IP6M_CAREOF_TEST_INIT */
93 	IP6M_MINLEN + 16, /* IP6M_HOME_TEST        */
94 	IP6M_MINLEN + 16, /* IP6M_CAREOF_TEST      */
95 	IP6M_MINLEN + 4,  /* IP6M_BINDING_UPDATE   */
96 	IP6M_MINLEN + 4,  /* IP6M_BINDING_ACK      */
97 	IP6M_MINLEN + 16, /* IP6M_BINDING_ERROR    */
98 };
99 
100 /* Mobility Header Options */
101 #define IP6MOPT_MINLEN		2
102 #define IP6MOPT_PAD1          0x0	/* Pad1 */
103 #define IP6MOPT_PADN          0x1	/* PadN */
104 #define IP6MOPT_REFRESH	      0x2	/* Binding Refresh Advice */
105 #define IP6MOPT_REFRESH_MINLEN  4
106 #define IP6MOPT_ALTCOA        0x3	/* Alternate Care-of Address */
107 #define IP6MOPT_ALTCOA_MINLEN  18
108 #define IP6MOPT_NONCEID       0x4	/* Nonce Indices */
109 #define IP6MOPT_NONCEID_MINLEN  6
110 #define IP6MOPT_AUTH          0x5	/* Binding Authorization Data */
111 #define IP6MOPT_AUTH_MINLEN    12
112 
113 static const struct tok ip6m_binding_update_bits [] = {
114 	{ 0x08, "A" },
115 	{ 0x04, "H" },
116 	{ 0x02, "L" },
117 	{ 0x01, "K" },
118 	{ 0, NULL }
119 };
120 
121 static int
122 mobility_opt_print(netdissect_options *ndo,
123                    const u_char *bp, const unsigned len)
124 {
125 	unsigned i, optlen;
126 
127 	for (i = 0; i < len; i += optlen) {
128 		if (GET_U_1(bp + i) == IP6MOPT_PAD1)
129 			optlen = 1;
130 		else {
131 			if (i + 1 < len) {
132 				optlen = GET_U_1(bp + i + 1) + 2;
133 			}
134 			else
135 				goto trunc;
136 		}
137 		if (i + optlen > len)
138 			goto trunc;
139 		ND_TCHECK_1(bp + i + optlen);
140 
141 		switch (GET_U_1(bp + i)) {
142 		case IP6MOPT_PAD1:
143 			ND_PRINT("(pad1)");
144 			break;
145 		case IP6MOPT_PADN:
146 			if (len - i < IP6MOPT_MINLEN) {
147 				ND_PRINT("(padn: trunc)");
148 				goto trunc;
149 			}
150 			ND_PRINT("(padn)");
151 			break;
152 		case IP6MOPT_REFRESH:
153 			if (len - i < IP6MOPT_REFRESH_MINLEN) {
154 				ND_PRINT("(refresh: trunc)");
155 				goto trunc;
156 			}
157 			/* units of 4 secs */
158 			ND_PRINT("(refresh: %u)",
159 				GET_BE_U_2(bp + i + 2) << 2);
160 			break;
161 		case IP6MOPT_ALTCOA:
162 			if (len - i < IP6MOPT_ALTCOA_MINLEN) {
163 				ND_PRINT("(altcoa: trunc)");
164 				goto trunc;
165 			}
166 			ND_PRINT("(alt-CoA: %s)", GET_IP6ADDR_STRING(bp + i + 2));
167 			break;
168 		case IP6MOPT_NONCEID:
169 			if (len - i < IP6MOPT_NONCEID_MINLEN) {
170 				ND_PRINT("(ni: trunc)");
171 				goto trunc;
172 			}
173 			ND_PRINT("(ni: ho=0x%04x co=0x%04x)",
174 				GET_BE_U_2(bp + i + 2),
175 				GET_BE_U_2(bp + i + 4));
176 			break;
177 		case IP6MOPT_AUTH:
178 			if (len - i < IP6MOPT_AUTH_MINLEN) {
179 				ND_PRINT("(auth: trunc)");
180 				goto trunc;
181 			}
182 			ND_PRINT("(auth)");
183 			break;
184 		default:
185 			if (len - i < IP6MOPT_MINLEN) {
186 				ND_PRINT("(sopt_type %u: trunc)",
187 					 GET_U_1(bp + i));
188 				goto trunc;
189 			}
190 			ND_PRINT("(type-0x%02x: len=%u)", GET_U_1(bp + i),
191 				 GET_U_1(bp + i + 1));
192 			break;
193 		}
194 	}
195 	return 0;
196 
197 trunc:
198 	return 1;
199 }
200 
201 /*
202  * Mobility Header
203  */
204 int
205 mobility_print(netdissect_options *ndo,
206                const u_char *bp, const u_char *bp2 _U_)
207 {
208 	const struct ip6_mobility *mh;
209 	const u_char *ep;
210 	unsigned mhlen, hlen;
211 	uint8_t type;
212 
213 	ndo->ndo_protocol = "mobility";
214 	mh = (const struct ip6_mobility *)bp;
215 
216 	/* 'ep' points to the end of available data. */
217 	ep = ndo->ndo_snapend;
218 
219 	if (!ND_TTEST_1(mh->ip6m_len)) {
220 		/*
221 		 * There's not enough captured data to include the
222 		 * mobility header length.
223 		 *
224 		 * Our caller expects us to return the length, however,
225 		 * so return a value that will run to the end of the
226 		 * captured data.
227 		 *
228 		 * XXX - "ip6_print()" doesn't do anything with the
229 		 * returned length, however, as it breaks out of the
230 		 * header-processing loop.
231 		 */
232 		mhlen = (unsigned)(ep - bp);
233 		goto trunc;
234 	}
235 	mhlen = (GET_U_1(mh->ip6m_len) + 1) << 3;
236 
237 	/* XXX ip6m_cksum */
238 
239 	type = GET_U_1(mh->ip6m_type);
240 	if (type <= IP6M_MAX && mhlen < ip6m_hdrlen[type]) {
241 		ND_PRINT("(header length %u is too small for type %u)", mhlen, type);
242 		goto trunc;
243 	}
244 	ND_PRINT("mobility: %s", tok2str(ip6m_str, "type-#%u", type));
245 	switch (type) {
246 	case IP6M_BINDING_REQUEST:
247 		hlen = IP6M_MINLEN;
248 		break;
249 	case IP6M_HOME_TEST_INIT:
250 	case IP6M_CAREOF_TEST_INIT:
251 		hlen = IP6M_MINLEN;
252 		if (ndo->ndo_vflag) {
253 			ND_PRINT(" %s Init Cookie=%08x:%08x",
254 			       type == IP6M_HOME_TEST_INIT ? "Home" : "Care-of",
255 			       GET_BE_U_4(bp + hlen),
256 			       GET_BE_U_4(bp + hlen + 4));
257 		}
258 		hlen += 8;
259 		break;
260 	case IP6M_HOME_TEST:
261 	case IP6M_CAREOF_TEST:
262 		ND_PRINT(" nonce id=0x%x", GET_BE_U_2(mh->ip6m_data16[0]));
263 		hlen = IP6M_MINLEN;
264 		if (ndo->ndo_vflag) {
265 			ND_PRINT(" %s Init Cookie=%08x:%08x",
266 			       type == IP6M_HOME_TEST ? "Home" : "Care-of",
267 			       GET_BE_U_4(bp + hlen),
268 			       GET_BE_U_4(bp + hlen + 4));
269 		}
270 		hlen += 8;
271 		if (ndo->ndo_vflag) {
272 			ND_PRINT(" %s Keygen Token=%08x:%08x",
273 			       type == IP6M_HOME_TEST ? "Home" : "Care-of",
274 			       GET_BE_U_4(bp + hlen),
275 			       GET_BE_U_4(bp + hlen + 4));
276 		}
277 		hlen += 8;
278 		break;
279 	case IP6M_BINDING_UPDATE:
280 	    {
281 		int bits;
282 		ND_PRINT(" seq#=%u", GET_BE_U_2(mh->ip6m_data16[0]));
283 		hlen = IP6M_MINLEN;
284 		ND_TCHECK_2(bp + hlen);
285 		bits = (GET_U_1(bp + hlen) & 0xf0) >> 4;
286 		if (bits) {
287 			ND_PRINT(" ");
288 			ND_PRINT("%s",
289 				 bittok2str_nosep(ip6m_binding_update_bits,
290 				 "bits-#0x%x", bits));
291 		}
292 		/* Reserved (4bits) */
293 		hlen += 1;
294 		/* Reserved (8bits) */
295 		hlen += 1;
296 		/* units of 4 secs */
297 		ND_PRINT(" lifetime=%u", GET_BE_U_2(bp + hlen) << 2);
298 		hlen += 2;
299 		break;
300 	    }
301 	case IP6M_BINDING_ACK:
302 		ND_PRINT(" status=%u", GET_U_1(mh->ip6m_data8[0]));
303 		if (GET_U_1(mh->ip6m_data8[1]) & 0x80)
304 			ND_PRINT(" K");
305 		/* Reserved (7bits) */
306 		hlen = IP6M_MINLEN;
307 		ND_PRINT(" seq#=%u", GET_BE_U_2(bp + hlen));
308 		hlen += 2;
309 		/* units of 4 secs */
310 		ND_PRINT(" lifetime=%u", GET_BE_U_2(bp + hlen) << 2);
311 		hlen += 2;
312 		break;
313 	case IP6M_BINDING_ERROR:
314 		ND_PRINT(" status=%u", GET_U_1(mh->ip6m_data8[0]));
315 		/* Reserved */
316 		hlen = IP6M_MINLEN;
317 		ND_PRINT(" homeaddr %s", GET_IP6ADDR_STRING(bp + hlen));
318 		hlen += 16;
319 		break;
320 	default:
321 		ND_PRINT(" len=%u", GET_U_1(mh->ip6m_len));
322 		return(mhlen);
323 		break;
324 	}
325 	if (ndo->ndo_vflag)
326 		if (mobility_opt_print(ndo, bp + hlen, mhlen - hlen))
327 			goto trunc;
328 
329 	return(mhlen);
330 
331  trunc:
332 	nd_print_trunc(ndo);
333 	return(-1);
334 }
335