epan/dissectors/packet-igap.c

   1 /* packet-igap.c
   2  * Routines for IGMP/IGAP packet disassembly
   3  * 2003, Endoh Akria (see AUTHORS for email)
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 /*
  27         IGAP "Internet Group membership Authentication Protocol"
  28         is defined in draft-hayashi-igap-03.txt.
  29
  30         (Author's memo)
  31          Type  Subtype  Message                     Msize
  32         -----------------------------------------------------
  33          ----   0x02    User password               variable
  34          ----   0x03    ----                        00
  35          ----   0x04    Result of MD5 calculation   16
  36          0x41   0x23    Challenge value             ??
  37          0x41   0x24    Authentication result code   1
  38          0x41   0x25    Accounting status code       1
  39          ----   0x42    User password               variable
  40          ----   0x43    ----                        00
  41          ----   0x44    Result of MD5 calculation   16
  42
  43 */
  44
  45 #include "config.h"
  46
  47 #include <glib.h>
  48 #include <epan/packet.h>
  49 #include <epan/to_str.h>
  50 #include "packet-igmp.h"
  51 #include "packet-igap.h"
  52
  53
  54 static int proto_igap      = -1;
  55 static int hf_type         = -1;
  56 static int hf_max_resp     = -1;
  57 static int hf_checksum     = -1;
  58 static int hf_checksum_bad = -1;
  59 static int hf_maddr        = -1;
  60 static int hf_version      = -1;
  61 static int hf_subtype      = -1;
  62 static int hf_challengeid  = -1;
  63 static int hf_asize        = -1;
  64 static int hf_msize        = -1;
  65 static int hf_account      = -1;
  66
  67 static int ett_igap = -1;
  68
  69
  70 static const value_string igap_types[] = {
  71     {IGMP_IGAP_JOIN,  "Membership Report (Join)"},
  72     {IGMP_IGAP_QUERY, "Membership Query"},
  73     {IGMP_IGAP_LEAVE, "Leave Group"},
  74     {0, NULL}
  75 };
  76
  77 #define IGAP_VERSION_1 0x10
  78 static const value_string igap_version[] = {
  79     {IGAP_VERSION_1, "1"},
  80     {0, NULL}
  81 };
  82
  83 #define IGAP_SUBTYPE_PASSWORD_JOIN            0x02
  84 #define IGAP_SUBTYPE_CHALLENGE_REQUEST_JOIN   0x03
  85 #define IGAP_SUBTYPE_CHALLENGE_RESPONSE_JOIN  0x04
  86 #define IGAP_SUBTYPE_BASIC_QUERY              0x21
  87 #define IGAP_SUBTYPE_CHALLENGE                0x23
  88 #define IGAP_SUBTYPE_AUTH_MESSAGE             0x24
  89 #define IGAP_SUBTYPE_ACCOUNTING_MESSAGE       0x25
  90 #define IGAP_SUBTYPE_BASIC_LEAVE              0x41
  91 #define IGAP_SUBTYPE_PASSWORD_LEAVE           0x42
  92 #define IGAP_SUBTYPE_CHALLENGE_REQUEST_LEAVE  0x43
  93 #define IGAP_SUBTYPE_CHALLENGE_RESPONSE_LEAVE 0x44
  94 static const value_string igap_subtypes[] = {
  95     {IGAP_SUBTYPE_PASSWORD_JOIN,            "Password Mechanism Join (Password-Join)"},
  96     {IGAP_SUBTYPE_CHALLENGE_REQUEST_JOIN,   "Challenge-Response Mechanism Join Request (Challenge-Request-Join)"},
  97     {IGAP_SUBTYPE_CHALLENGE_RESPONSE_JOIN,  "Challenge-Response Mechanism Join Response (Challenge-Response-Join)"},
  98     {IGAP_SUBTYPE_BASIC_QUERY,              "Basic Query"},
  99     {IGAP_SUBTYPE_CHALLENGE,                "Challenge-Response Mechanism Challenge (Challenge)"},
 100     {IGAP_SUBTYPE_AUTH_MESSAGE,             "Authentication Message"},
 101     {IGAP_SUBTYPE_ACCOUNTING_MESSAGE,       "Accounting Message"},
 102     {IGAP_SUBTYPE_BASIC_LEAVE,              "Basic Leave"},
 103     {IGAP_SUBTYPE_PASSWORD_LEAVE,           "Password Mechanism Leave (Password-Leave)"},
 104     {IGAP_SUBTYPE_CHALLENGE_REQUEST_LEAVE,  "Challenge-Response Mechanism Leave Challenge Request (Challenge-Request-Leave)"},
 105     {IGAP_SUBTYPE_CHALLENGE_RESPONSE_LEAVE, "Challenge-Response Mechanism Response (Challenge-Response-Leave)"},
 106     {0, NULL}
 107 };
 108
 109 #define IGAP_AUTH_SUCCESS 0x11
 110 #define IGAP_AUTH_FAIL    0x21
 111 static const value_string igap_auth_result[] = {
 112     {IGAP_AUTH_SUCCESS, "Authentication success"},
 113     {IGAP_AUTH_FAIL,    "Authentication failure"},
 114     {0, NULL}
 115 };
 116
 117 #define IGAP_ACCOUNT_START 0x11
 118 #define IGAP_ACCOUNT_STOP  0x21
 119 static const value_string igap_account_status[] = {
 120     {IGAP_ACCOUNT_START, "Accounting start"},
 121     {IGAP_ACCOUNT_STOP,  "Accounting stop"},
 122     {0, NULL}
 123 };
 124
 125 #define ACCOUNT_SIZE    16
 126 #define MESSAGE_SIZE    64
 127
 128 /* This function is only called from the IGMP dissector */
 129 int
 130 dissect_igap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 131 {
 132     proto_tree *tree;
 133     proto_item *item;
 134     guint8 type, tsecs, subtype, asize, msize;
 135     guchar account[ACCOUNT_SIZE+1], message[MESSAGE_SIZE+1];
 136
 137     if (!proto_is_protocol_enabled(find_protocol_by_id(proto_igap))) {
 138         /* we are not enabled, skip entire packet to be nice
 139            to the igmp layer. (so clicking on IGMP will display the data)
 140            */
 141         return offset + tvb_length_remaining(tvb, offset);
 142     }
 143
 144     item = proto_tree_add_item(parent_tree, proto_igap, tvb, offset, -1, ENC_NA);
 145     tree = proto_item_add_subtree(item, ett_igap);
 146
 147     col_set_str(pinfo->cinfo, COL_PROTOCOL, "IGAP");
 148     col_clear(pinfo->cinfo, COL_INFO);
 149
 150     type = tvb_get_guint8(tvb, offset);
 151         col_add_str(pinfo->cinfo, COL_INFO,
 152                      val_to_str(type, igap_types, "Unknown Type: 0x%02x"));
 153     proto_tree_add_uint(tree, hf_type, tvb, offset, 1, type);
 154     offset += 1;
 155
 156     tsecs = tvb_get_guint8(tvb, offset);
 157     proto_tree_add_uint_format_value(tree, hf_max_resp, tvb, offset, 1, tsecs,
 158         "%.1f sec (0x%02x)", tsecs * 0.1, tsecs);
 159     offset += 1;
 160
 161     igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 162     offset += 2;
 163
 164     proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, ENC_BIG_ENDIAN);
 165     offset += 4;
 166
 167     proto_tree_add_uint(tree, hf_version, tvb, offset, 1,
 168         tvb_get_guint8(tvb, offset));
 169     offset += 1;
 170
 171     subtype = tvb_get_guint8(tvb, offset);
 172     proto_tree_add_uint(tree, hf_subtype, tvb, offset, 1, subtype);
 173     offset += 2;
 174
 175     proto_tree_add_uint(tree, hf_challengeid, tvb, offset, 1,
 176         tvb_get_guint8(tvb, offset));
 177     offset += 1;
 178
 179     asize = tvb_get_guint8(tvb, offset);
 180     proto_tree_add_uint(tree, hf_asize, tvb, offset, 1, asize);
 181     offset += 1;
 182
 183     msize = tvb_get_guint8(tvb, offset);
 184     proto_tree_add_uint(tree, hf_msize, tvb, offset, 1, msize);
 185     offset += 3;
 186
 187     if (asize > 0) {
 188         if (asize > ACCOUNT_SIZE) {
 189             /* Bogus account size.
 190                XXX - flag this? */
 191             asize = ACCOUNT_SIZE;
 192         }
 193         tvb_memcpy(tvb, account, offset, asize);
 194         account[asize] = '\0';
 195         proto_tree_add_string(tree, hf_account, tvb, offset, asize, account);
 196     }
 197     offset += ACCOUNT_SIZE;
 198
 199     if (msize > 0) {
 200         if (msize > MESSAGE_SIZE) {
 201             /* Bogus message size.
 202                XXX - flag this? */
 203             msize = MESSAGE_SIZE;
 204         }
 205         tvb_memcpy(tvb, message, offset, msize);
 206         switch (subtype) {
 207         case IGAP_SUBTYPE_PASSWORD_JOIN:
 208         case IGAP_SUBTYPE_PASSWORD_LEAVE:
 209             /* Challenge field is user's password */
 210             message[msize] = '\0';
 211             proto_tree_add_text(tree, tvb, offset, msize,
 212                                 "User password: %s", message);
 213             break;
 214         case IGAP_SUBTYPE_CHALLENGE_RESPONSE_JOIN:
 215         case IGAP_SUBTYPE_CHALLENGE_RESPONSE_LEAVE:
 216             /* Challenge field is the results of MD5 calculation */
 217             proto_tree_add_text(tree, tvb, offset, msize,
 218                                 "Result of MD5 calculation: 0x%s",
 219                                 bytes_to_str(message, msize));
 220             break;
 221         case IGAP_SUBTYPE_CHALLENGE:
 222             /* Challenge field is the challenge value */
 223             proto_tree_add_text(tree, tvb, offset, msize,
 224                                 "Challenge: 0x%s",
 225                                 bytes_to_str(message, msize));
 226             break;
 227         case IGAP_SUBTYPE_AUTH_MESSAGE:
 228             /* Challenge field indicates the result of the authenticaion */
 229             proto_tree_add_text(tree, tvb, offset, msize,
 230                                 "Authentication result: %s (0x%x)",
 231                                 val_to_str_const(message[0], igap_auth_result, "Unknown"),
 232                                 message[0]);
 233             break;
 234         case IGAP_SUBTYPE_ACCOUNTING_MESSAGE:
 235             /* Challenge field indicates the accounting status */
 236             proto_tree_add_text(tree, tvb, offset, msize,
 237                                 "Accounting status: %s (0x%x)",
 238                                 val_to_str_const(message[0], igap_account_status, "Unknown"),
 239                                 message[0]);
 240             break;
 241         default:
 242             proto_tree_add_text(tree, tvb, offset, msize,
 243                                 "Message: (Unknown)");
 244         }
 245     }
 246     offset += MESSAGE_SIZE;
 247
 248     if (item) proto_item_set_len(item, offset);
 249     return offset;
 250 }
 251
 252
 253 void
 254 proto_register_igap(void)
 255 {
 256     static hf_register_info hf[] = {
 257         { &hf_type,
 258           { "Type", "igap.type", FT_UINT8, BASE_HEX,
 259             VALS(igap_types), 0, "IGAP Packet Type", HFILL }
 260         },
 261
 262         { &hf_max_resp,
 263           { "Max Response Time", "igap.max_resp", FT_UINT8, BASE_DEC,
 264             NULL, 0, NULL, HFILL }
 265         },
 266
 267         { &hf_checksum,
 268           { "Checksum", "igap.checksum", FT_UINT16, BASE_HEX,
 269             NULL, 0, NULL, HFILL }
 270         },
 271
 272         { &hf_checksum_bad,
 273           { "Bad Checksum", "igap.checksum_bad", FT_BOOLEAN, BASE_NONE,
 274             NULL, 0x0, NULL, HFILL }
 275         },
 276
 277         { &hf_maddr,
 278           { "Multicast group address", "igap.maddr", FT_IPv4, BASE_NONE,
 279             NULL, 0, NULL, HFILL }
 280         },
 281
 282         { &hf_version,
 283           { "Version", "igap.version", FT_UINT8, BASE_HEX,
 284             VALS(igap_version), 0, "IGAP protocol version", HFILL }
 285         },
 286
 287         { &hf_subtype,
 288           { "Subtype", "igap.subtype", FT_UINT8, BASE_HEX,
 289             VALS(igap_subtypes), 0, NULL, HFILL }
 290         },
 291
 292         { &hf_challengeid,
 293           { "Challenge ID", "igap.challengeid", FT_UINT8, BASE_HEX,
 294             NULL, 0, NULL, HFILL }
 295         },
 296
 297         { &hf_asize,
 298           { "Account Size", "igap.asize", FT_UINT8, BASE_DEC,
 299             NULL, 0, "Length of the User Account field", HFILL }
 300         },
 301
 302         { &hf_msize,
 303           { "Message Size", "igap.msize", FT_UINT8, BASE_DEC,
 304             NULL, 0, "Length of the Message field", HFILL }
 305         },
 306
 307         { &hf_account,
 308           { "User Account", "igap.account", FT_STRING, BASE_NONE,
 309             NULL, 0, NULL, HFILL }
 310         }
 311     };
 312
 313     static gint *ett[] = {
 314         &ett_igap
 315     };
 316
 317     proto_igap = proto_register_protocol
 318         ("Internet Group membership Authentication Protocol",
 319          "IGAP", "igap");
 320     proto_register_field_array(proto_igap, hf, array_length(hf));
 321     proto_register_subtree_array(ett, array_length(ett));
 322 }