xref: /netbsd-src/external/bsd/tcpdump/dist/print-mobility.c (revision 3117ece4fc4a4ca4489ba793710b60b0d26bab6c)
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 #include <sys/cdefs.h>
31 #ifndef lint
32 __RCSID("$NetBSD: print-mobility.c,v 1.10 2024/09/02 16:15:32 christos Exp $");
33 #endif
34 
35 /* \summary: IPv6 mobility printer */
36 /* RFC 3775 */
37 
38 #include <config.h>
39 
40 #include "netdissect-stdinc.h"
41 
42 #include "netdissect.h"
43 #include "addrtoname.h"
44 #include "extract.h"
45 
46 #include "ip6.h"
47 
48 
49 /* Mobility header */
50 struct ip6_mobility {
51 	nd_uint8_t ip6m_pproto;	/* following payload protocol (for PG) */
52 	nd_uint8_t ip6m_len;	/* length in units of 8 octets */
53 	nd_uint8_t ip6m_type;	/* message type */
54 	nd_uint8_t reserved;	/* reserved */
55 	nd_uint16_t ip6m_cksum;	/* sum of IPv6 pseudo-header and MH */
56 	union {
57 		nd_uint16_t	ip6m_un_data16[1]; /* type-specific field */
58 		nd_uint8_t	ip6m_un_data8[2];  /* type-specific field */
59 	} ip6m_dataun;
60 };
61 
62 #define ip6m_data16	ip6m_dataun.ip6m_un_data16
63 #define ip6m_data8	ip6m_dataun.ip6m_un_data8
64 
65 #define IP6M_MINLEN	8
66 
67 /* https://www.iana.org/assignments/mobility-parameters/mobility-parameters.xhtml */
68 
69 /* message type */
70 #define IP6M_BINDING_REQUEST	0	/* Binding Refresh Request */
71 #define IP6M_HOME_TEST_INIT	1	/* Home Test Init */
72 #define IP6M_CAREOF_TEST_INIT	2	/* Care-of Test Init */
73 #define IP6M_HOME_TEST		3	/* Home Test */
74 #define IP6M_CAREOF_TEST	4	/* Care-of Test */
75 #define IP6M_BINDING_UPDATE	5	/* Binding Update */
76 #define IP6M_BINDING_ACK	6	/* Binding Acknowledgement */
77 #define IP6M_BINDING_ERROR	7	/* Binding Error */
78 #define IP6M_MAX		7
79 
80 static const struct tok ip6m_str[] = {
81 	{ IP6M_BINDING_REQUEST,  "BRR"  },
82 	{ IP6M_HOME_TEST_INIT,   "HoTI" },
83 	{ IP6M_CAREOF_TEST_INIT, "CoTI" },
84 	{ IP6M_HOME_TEST,        "HoT"  },
85 	{ IP6M_CAREOF_TEST,      "CoT"  },
86 	{ IP6M_BINDING_UPDATE,   "BU"   },
87 	{ IP6M_BINDING_ACK,      "BA"   },
88 	{ IP6M_BINDING_ERROR,    "BE"   },
89 	{ 0, NULL }
90 };
91 
92 static const unsigned ip6m_hdrlen[IP6M_MAX + 1] = {
93 	IP6M_MINLEN,      /* IP6M_BINDING_REQUEST  */
94 	IP6M_MINLEN + 8,  /* IP6M_HOME_TEST_INIT   */
95 	IP6M_MINLEN + 8,  /* IP6M_CAREOF_TEST_INIT */
96 	IP6M_MINLEN + 16, /* IP6M_HOME_TEST        */
97 	IP6M_MINLEN + 16, /* IP6M_CAREOF_TEST      */
98 	IP6M_MINLEN + 4,  /* IP6M_BINDING_UPDATE   */
99 	IP6M_MINLEN + 4,  /* IP6M_BINDING_ACK      */
100 	IP6M_MINLEN + 16, /* IP6M_BINDING_ERROR    */
101 };
102 
103 /* Mobility Header Options */
104 #define IP6MOPT_MINLEN		2
105 #define IP6MOPT_PAD1          0x0	/* Pad1 */
106 #define IP6MOPT_PADN          0x1	/* PadN */
107 #define IP6MOPT_REFRESH	      0x2	/* Binding Refresh Advice */
108 #define IP6MOPT_REFRESH_MINLEN  4
109 #define IP6MOPT_ALTCOA        0x3	/* Alternate Care-of Address */
110 #define IP6MOPT_ALTCOA_MINLEN  18
111 #define IP6MOPT_NONCEID       0x4	/* Nonce Indices */
112 #define IP6MOPT_NONCEID_MINLEN  6
113 #define IP6MOPT_AUTH          0x5	/* Binding Authorization Data */
114 #define IP6MOPT_AUTH_MINLEN    12
115 
116 static const struct tok ip6m_binding_update_bits [] = {
117 	{ 0x08, "A" },
118 	{ 0x04, "H" },
119 	{ 0x02, "L" },
120 	{ 0x01, "K" },
121 	{ 0, NULL }
122 };
123 
124 static int
125 mobility_opt_print(netdissect_options *ndo,
126                    const u_char *bp, const unsigned len)
127 {
128 	unsigned i, optlen;
129 
130 	for (i = 0; i < len; i += optlen) {
131 		if (GET_U_1(bp + i) == IP6MOPT_PAD1)
132 			optlen = 1;
133 		else {
134 			if (i + 1 < len) {
135 				optlen = GET_U_1(bp + i + 1) + 2;
136 			} else
137 				goto trunc;
138 		}
139 		if (i + optlen > len)
140 			goto trunc;
141 		ND_TCHECK_1(bp + i + optlen);
142 
143 		switch (GET_U_1(bp + i)) {
144 		case IP6MOPT_PAD1:
145 			ND_PRINT("(pad1)");
146 			break;
147 		case IP6MOPT_PADN:
148 			if (len - i < IP6MOPT_MINLEN) {
149 				ND_PRINT("(padn: trunc)");
150 				goto trunc;
151 			}
152 			ND_PRINT("(padn)");
153 			break;
154 		case IP6MOPT_REFRESH:
155 			if (len - i < IP6MOPT_REFRESH_MINLEN) {
156 				ND_PRINT("(refresh: trunc)");
157 				goto trunc;
158 			}
159 			/* units of 4 secs */
160 			ND_PRINT("(refresh: %u)",
161 				GET_BE_U_2(bp + i + 2) << 2);
162 			break;
163 		case IP6MOPT_ALTCOA:
164 			if (len - i < IP6MOPT_ALTCOA_MINLEN) {
165 				ND_PRINT("(altcoa: trunc)");
166 				goto trunc;
167 			}
168 			ND_PRINT("(alt-CoA: %s)", GET_IP6ADDR_STRING(bp + i + 2));
169 			break;
170 		case IP6MOPT_NONCEID:
171 			if (len - i < IP6MOPT_NONCEID_MINLEN) {
172 				ND_PRINT("(ni: trunc)");
173 				goto trunc;
174 			}
175 			ND_PRINT("(ni: ho=0x%04x co=0x%04x)",
176 				GET_BE_U_2(bp + i + 2),
177 				GET_BE_U_2(bp + i + 4));
178 			break;
179 		case IP6MOPT_AUTH:
180 			if (len - i < IP6MOPT_AUTH_MINLEN) {
181 				ND_PRINT("(auth: trunc)");
182 				goto trunc;
183 			}
184 			ND_PRINT("(auth)");
185 			break;
186 		default:
187 			if (len - i < IP6MOPT_MINLEN) {
188 				ND_PRINT("(sopt_type %u: trunc)",
189 					 GET_U_1(bp + i));
190 				goto trunc;
191 			}
192 			ND_PRINT("(type-0x%02x: len=%u)", GET_U_1(bp + i),
193 				 GET_U_1(bp + i + 1));
194 			break;
195 		}
196 	}
197 	return 0;
198 
199 trunc:
200 	return 1;
201 }
202 
203 /*
204  * Mobility Header
205  */
206 int
207 mobility_print(netdissect_options *ndo,
208                const u_char *bp, const u_char *bp2 _U_)
209 {
210 	const struct ip6_mobility *mh;
211 	const u_char *ep;
212 	unsigned mhlen, hlen;
213 	uint8_t type;
214 
215 	ndo->ndo_protocol = "mobility";
216 	mh = (const struct ip6_mobility *)bp;
217 
218 	/* 'ep' points to the end of available data. */
219 	ep = ndo->ndo_snapend;
220 
221 	if (!ND_TTEST_1(mh->ip6m_len)) {
222 		/*
223 		 * There's not enough captured data to include the
224 		 * mobility header length.
225 		 *
226 		 * Our caller expects us to return the length, however,
227 		 * so return a value that will run to the end of the
228 		 * captured data.
229 		 *
230 		 * XXX - "ip6_print()" doesn't do anything with the
231 		 * returned length, however, as it breaks out of the
232 		 * header-processing loop.
233 		 */
234 		mhlen = (unsigned)(ep - bp);
235 		goto trunc;
236 	}
237 	mhlen = (GET_U_1(mh->ip6m_len) + 1) << 3;
238 
239 	/* XXX ip6m_cksum */
240 
241 	type = GET_U_1(mh->ip6m_type);
242 	if (type <= IP6M_MAX && mhlen < ip6m_hdrlen[type]) {
243 		ND_PRINT("(header length %u is too small for type %u)", mhlen, type);
244 		goto trunc;
245 	}
246 	ND_PRINT("mobility: %s", tok2str(ip6m_str, "type-#%u", type));
247 	switch (type) {
248 	case IP6M_BINDING_REQUEST:
249 		hlen = IP6M_MINLEN;
250 		break;
251 	case IP6M_HOME_TEST_INIT:
252 	case IP6M_CAREOF_TEST_INIT:
253 		hlen = IP6M_MINLEN;
254 		if (ndo->ndo_vflag) {
255 			ND_PRINT(" %s Init Cookie=%08x:%08x",
256 			       type == IP6M_HOME_TEST_INIT ? "Home" : "Care-of",
257 			       GET_BE_U_4(bp + hlen),
258 			       GET_BE_U_4(bp + hlen + 4));
259 		}
260 		hlen += 8;
261 		break;
262 	case IP6M_HOME_TEST:
263 	case IP6M_CAREOF_TEST:
264 		ND_PRINT(" nonce id=0x%x", GET_BE_U_2(mh->ip6m_data16[0]));
265 		hlen = IP6M_MINLEN;
266 		if (ndo->ndo_vflag) {
267 			ND_PRINT(" %s Init Cookie=%08x:%08x",
268 			       type == IP6M_HOME_TEST ? "Home" : "Care-of",
269 			       GET_BE_U_4(bp + hlen),
270 			       GET_BE_U_4(bp + hlen + 4));
271 		}
272 		hlen += 8;
273 		if (ndo->ndo_vflag) {
274 			ND_PRINT(" %s Keygen Token=%08x:%08x",
275 			       type == IP6M_HOME_TEST ? "Home" : "Care-of",
276 			       GET_BE_U_4(bp + hlen),
277 			       GET_BE_U_4(bp + hlen + 4));
278 		}
279 		hlen += 8;
280 		break;
281 	case IP6M_BINDING_UPDATE:
282 	    {
283 		int bits;
284 		ND_PRINT(" seq#=%u", GET_BE_U_2(mh->ip6m_data16[0]));
285 		hlen = IP6M_MINLEN;
286 		ND_TCHECK_2(bp + hlen);
287 		bits = (GET_U_1(bp + hlen) & 0xf0) >> 4;
288 		if (bits) {
289 			ND_PRINT(" ");
290 			ND_PRINT("%s",
291 				 bittok2str_nosep(ip6m_binding_update_bits,
292 				 "bits-#0x%x", bits));
293 		}
294 		/* Reserved (4bits) */
295 		hlen += 1;
296 		/* Reserved (8bits) */
297 		hlen += 1;
298 		/* units of 4 secs */
299 		ND_PRINT(" lifetime=%u", GET_BE_U_2(bp + hlen) << 2);
300 		hlen += 2;
301 		break;
302 	    }
303 	case IP6M_BINDING_ACK:
304 		ND_PRINT(" status=%u", GET_U_1(mh->ip6m_data8[0]));
305 		if (GET_U_1(mh->ip6m_data8[1]) & 0x80)
306 			ND_PRINT(" K");
307 		/* Reserved (7bits) */
308 		hlen = IP6M_MINLEN;
309 		ND_PRINT(" seq#=%u", GET_BE_U_2(bp + hlen));
310 		hlen += 2;
311 		/* units of 4 secs */
312 		ND_PRINT(" lifetime=%u", GET_BE_U_2(bp + hlen) << 2);
313 		hlen += 2;
314 		break;
315 	case IP6M_BINDING_ERROR:
316 		ND_PRINT(" status=%u", GET_U_1(mh->ip6m_data8[0]));
317 		/* Reserved */
318 		hlen = IP6M_MINLEN;
319 		ND_PRINT(" homeaddr %s", GET_IP6ADDR_STRING(bp + hlen));
320 		hlen += 16;
321 		break;
322 	default:
323 		ND_PRINT(" len=%u", GET_U_1(mh->ip6m_len));
324 		return(mhlen);
325 		break;
326 	}
327 	if (ndo->ndo_vflag)
328 		if (mobility_opt_print(ndo, bp + hlen, mhlen - hlen))
329 			goto trunc;
330 
331 	return(mhlen);
332 
333  trunc:
334 	nd_print_trunc(ndo);
335 	return(-1);
336 }
337