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