The Tcpdump Group git mirrors - tcpdump/blob - print-mobility.c

   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 }