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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
    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
    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