epan/dissectors/packet-ymsg.c

   1 /* packet-ymsg.c
   2  * Routines for Yahoo Messenger YMSG protocol packet version 13 dissection
   3  * Copyright 2003, Wayne Parrott <wayne_p@pacific.net.au>
   4  * Copied from packet-yhoo.c and updated
   5  *
   6  * $Id$
   7  *
   8  * Wireshark - Network traffic analyzer
   9  * By Gerald Combs <gerald@wireshark.org>
  10  * Copyright 1998 Gerald Combs
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  25  */
  26
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <stdio.h>
  32
  33 #include <string.h>
  34 #include <glib.h>
  35 #include <epan/packet.h>
  36
  37 #include "packet-tcp.h"
  38 #include <epan/prefs.h>
  39
  40 static int proto_ymsg = -1;
  41 static int hf_ymsg_version = -1;
  42 static int hf_ymsg_len = -1;
  43 static int hf_ymsg_service = -1;
  44 static int hf_ymsg_status = -1;
  45 static int hf_ymsg_session_id = -1;
  46
  47 static int hf_ymsg_content = -1;
  48 static int hf_ymsg_content_line = -1;
  49 static int hf_ymsg_content_line_key = -1;
  50 static int hf_ymsg_content_line_value = -1;
  51
  52 static gint ett_ymsg = -1;
  53 static gint ett_ymsg_content = -1;
  54 static gint ett_ymsg_content_line = -1;
  55
  56 #define TCP_PORT_YMSG   23      /* XXX - this is Telnet! */
  57 #define TCP_PORT_YMSG_2 25      /* And this is SMTP! */
  58 #define TCP_PORT_YMSG_3 5050    /* This, however, is regular Yahoo Messenger */
  59
  60 /* desegmentation of YMSG over TCP */
  61 static gboolean ymsg_desegment = TRUE;
  62
  63 /*
  64  * This is from yahoolib2.c from libyahoo2.
  65  *
  66  * See also
  67  *
  68  *      http://libyahoo2.sourceforge.net/ymsg-9.txt
  69  *
  70  * and
  71  *
  72  *      http://www.venkydude.com/articles/yahoo.htm
  73  *
  74  * and
  75  *
  76  *      http://www.cse.iitb.ac.in/~varunk/YahooProtocol.htm
  77  *
  78  * and
  79  *
  80  *      http://www.geocrawler.com/archives/3/4893/2002/1/0/7459037/
  81  *
  82  * and
  83  *
  84  *      http://www.geocities.com/ziggycubbe/ym.html
  85  */
  86
  87 /* Service constants */
  88 enum yahoo_service { /* these are easier to see in hex */
  89         YAHOO_SERVICE_LOGON = 1,
  90         YAHOO_SERVICE_LOGOFF,
  91         YAHOO_SERVICE_ISAWAY,
  92         YAHOO_SERVICE_ISBACK,
  93         YAHOO_SERVICE_IDLE, /* 5 (placemarker) */
  94         YAHOO_SERVICE_MESSAGE,
  95         YAHOO_SERVICE_IDACT,
  96         YAHOO_SERVICE_IDDEACT,
  97         YAHOO_SERVICE_MAILSTAT,
  98         YAHOO_SERVICE_USERSTAT, /* 0xa */
  99         YAHOO_SERVICE_NEWMAIL,
 100         YAHOO_SERVICE_CHATINVITE,
 101         YAHOO_SERVICE_CALENDAR,
 102         YAHOO_SERVICE_NEWPERSONALMAIL,
 103         YAHOO_SERVICE_NEWCONTACT,
 104         YAHOO_SERVICE_ADDIDENT, /* 0x10 */
 105         YAHOO_SERVICE_ADDIGNORE,
 106         YAHOO_SERVICE_PING,
 107         YAHOO_SERVICE_GOTGROUPRENAME, /* < 1, 36(old), 37(new) */
 108         YAHOO_SERVICE_SYSMESSAGE = 0x14,
 109         YAHOO_SERVICE_SKINNAME = 0x15,
 110         YAHOO_SERVICE_PASSTHROUGH2 = 0x16,
 111         YAHOO_SERVICE_CONFINVITE = 0x18,
 112         YAHOO_SERVICE_CONFLOGON,
 113         YAHOO_SERVICE_CONFDECLINE,
 114         YAHOO_SERVICE_CONFLOGOFF,
 115         YAHOO_SERVICE_CONFADDINVITE,
 116         YAHOO_SERVICE_CONFMSG,
 117         YAHOO_SERVICE_CHATLOGON,
 118         YAHOO_SERVICE_CHATLOGOFF,
 119         YAHOO_SERVICE_CHATMSG = 0x20,
 120         YAHOO_SERVICE_GAMELOGON = 0x28,
 121         YAHOO_SERVICE_GAMELOGOFF,
 122         YAHOO_SERVICE_GAMEMSG = 0x2a,
 123         YAHOO_SERVICE_FILETRANSFER = 0x46,
 124         YAHOO_SERVICE_VOICECHAT = 0x4A,
 125         YAHOO_SERVICE_NOTIFY,
 126         YAHOO_SERVICE_VERIFY,
 127         YAHOO_SERVICE_P2PFILEXFER,
 128         YAHOO_SERVICE_PEERTOPEER = 0x4F,        /* Checks if P2P possible */
 129         YAHOO_SERVICE_WEBCAM,
 130         YAHOO_SERVICE_AUTHRESP = 0x54,
 131         YAHOO_SERVICE_LIST,
 132         YAHOO_SERVICE_AUTH = 0x57,
 133         YAHOO_SERVICE_AUTHBUDDY = 0x6d,
 134         YAHOO_SERVICE_ADDBUDDY = 0x83,
 135         YAHOO_SERVICE_REMBUDDY,
 136         YAHOO_SERVICE_IGNORECONTACT,    /* > 1, 7, 13 < 1, 66, 13, 0*/
 137         YAHOO_SERVICE_REJECTCONTACT,
 138         YAHOO_SERVICE_GROUPRENAME = 0x89, /* > 1, 65(new), 66(0), 67(old) */
 139         YAHOO_SERVICE_KEEPALIVE = 0x8a,
 140         YAHOO_SERVICE_CHATONLINE = 0x96, /* > 109(id), 1, 6(abcde) < 0,1*/
 141         YAHOO_SERVICE_CHATGOTO,
 142         YAHOO_SERVICE_CHATJOIN, /* > 1 104-room 129-1600326591 62-2 */
 143         YAHOO_SERVICE_CHATLEAVE,
 144         YAHOO_SERVICE_CHATEXIT = 0x9b,
 145         YAHOO_SERVICE_CHATADDINVITE = 0x9d,
 146         YAHOO_SERVICE_CHATLOGOUT = 0xa0,
 147         YAHOO_SERVICE_CHATPING,
 148         YAHOO_SERVICE_COMMENT = 0xa8,
 149         YAHOO_SERVICE_GAME_INVITE = 0xb7,
 150         YAHOO_SERVICE_STEALTH_PERM = 0xb9,
 151         YAHOO_SERVICE_STEALTH_SESSION = 0xba,
 152         YAHOO_SERVICE_AVATAR = 0xbc,
 153         YAHOO_SERVICE_PICTURE_CHECKSUM = 0xbd,
 154         YAHOO_SERVICE_PICTURE = 0xbe,
 155         YAHOO_SERVICE_PICTURE_UPDATE = 0xc1,
 156         YAHOO_SERVICE_PICTURE_UPLOAD = 0xc2,
 157         YAHOO_SERVICE_YAB_UPDATE = 0xc4,
 158         YAHOO_SERVICE_Y6_VISIBLE_TOGGLE = 0xc5, /* YMSG13, key 13: 2 = invisible, 1 = visible */
 159         YAHOO_SERVICE_Y6_STATUS_UPDATE = 0xc6,  /* YMSG13 */
 160         YAHOO_SERVICE_PICTURE_STATUS = 0xc7,    /* YMSG13, key 213: 0 = none, 1 = avatar, 2 = picture */
 161         YAHOO_SERVICE_VERIFY_ID_EXISTS = 0xc8,
 162         YAHOO_SERVICE_AUDIBLE = 0xd0,
 163         YAHOO_SERVICE_Y7_PHOTO_SHARING = 0xd2,
 164         YAHOO_SERVICE_Y7_CONTACT_DETAILS = 0xd3,/* YMSG13 */
 165         YAHOO_SERVICE_Y7_CHAT_SESSION = 0xd4,
 166         YAHOO_SERVICE_Y7_AUTHORIZATION = 0xd6,  /* YMSG13 */
 167         YAHOO_SERVICE_Y7_FILETRANSFER = 0xdc,   /* YMSG13 */
 168         YAHOO_SERVICE_Y7_FILETRANSFERINFO,      /* YMSG13 */
 169         YAHOO_SERVICE_Y7_FILETRANSFERACCEPT,    /* YMSG13 */
 170         YAHOO_SERVICE_Y7_MINGLE = 0xe1, /* YMSG13 */
 171         YAHOO_SERVICE_Y7_CHANGE_GROUP = 0xe7, /* YMSG13 */
 172         YAHOO_SERVICE_STATUS_15 = 0xf0,
 173         YAHOO_SERVICE_LIST_15 = 0xf1,
 174         YAHOO_SERVICE_WEBLOGIN = 0x0226,
 175         YAHOO_SERVICE_SMS_MSG = 0x02ea
 176 };
 177
 178 /* Message flags */
 179 enum yahoo_status {
 180         YAHOO_STATUS_AVAILABLE = 0,
 181         YAHOO_STATUS_BRB,
 182         YAHOO_STATUS_BUSY,
 183         YAHOO_STATUS_NOTATHOME,
 184         YAHOO_STATUS_NOTATDESK,
 185         YAHOO_STATUS_NOTINOFFICE,
 186         YAHOO_STATUS_ONPHONE,
 187         YAHOO_STATUS_ONVACATION,
 188         YAHOO_STATUS_OUTTOLUNCH,
 189         YAHOO_STATUS_STEPPEDOUT,
 190         YAHOO_STATUS_INVISIBLE = 12,
 191         YAHOO_STATUS_CUSTOM = 99,
 192         YAHOO_STATUS_IDLE = 999,
 193         YAHOO_STATUS_WEBLOGIN = 0x5a55aa55,
 194         YAHOO_STATUS_OFFLINE = 0x5a55aa56, /* don't ask */
 195         YAHOO_STATUS_TYPING = 0x16,
 196         YAHOO_STATUS_DISCONNECTED = 0xffffffff /* in ymsg 15. doesnt mean the normal sense of 'disconnected' */
 197 };
 198
 199 enum ypacket_status {
 200         YPACKET_STATUS_DISCONNECTED = -1,
 201         YPACKET_STATUS_DEFAULT = 0,
 202         YPACKET_STATUS_SERVERACK = 1,
 203         YPACKET_STATUS_GAME     = 0x2,
 204         YPACKET_STATUS_AWAY     = 0x4,
 205         YPACKET_STATUS_CONTINUED = 0x5,
 206         YPACKET_STATUS_INVISIBLE = 12,
 207         YPACKET_STATUS_NOTIFY = 0x16, /* TYPING */
 208         YPACKET_STATUS_WEBLOGIN = 0x5a55aa55,
 209         YPACKET_STATUS_OFFLINE = 0x5a55aa56
 210 };
 211
 212 struct yahoo_rawpacket
 213 {
 214         char ymsg[4];                   /* Packet identification string (YMSG) */
 215         unsigned char version[4];       /* 4 bytes, little endian? */
 216         unsigned char len[2];           /* length - little endian */
 217         unsigned char service[2];       /* service - little endian */
 218         unsigned char status[4];        /* Status - online, away etc.*/
 219         unsigned char session_id[4];    /* Session ID */
 220         char content[6];                /* 6 is the minimum size of the content */
 221 };
 222
 223 static const value_string ymsg_service_vals[] = {
 224         {YAHOO_SERVICE_LOGON, "Pager Logon"},
 225         {YAHOO_SERVICE_LOGOFF, "Pager Logoff"},
 226         {YAHOO_SERVICE_ISAWAY, "Is Away"},
 227         {YAHOO_SERVICE_ISBACK, "Is Back"},
 228         {YAHOO_SERVICE_IDLE, "Idle"},
 229         {YAHOO_SERVICE_MESSAGE, "Message"},
 230         {YAHOO_SERVICE_IDACT, "Activate Identity"},
 231         {YAHOO_SERVICE_IDDEACT, "Deactivate Identity"},
 232         {YAHOO_SERVICE_MAILSTAT, "Mail Status"},
 233         {YAHOO_SERVICE_USERSTAT, "User Status"},
 234         {YAHOO_SERVICE_NEWMAIL, "New Mail"},
 235         {YAHOO_SERVICE_CHATINVITE, "Chat Invitation"},
 236         {YAHOO_SERVICE_CALENDAR, "Calendar Reminder"},
 237         {YAHOO_SERVICE_NEWPERSONALMAIL, "New Personals Mail"},
 238         {YAHOO_SERVICE_NEWCONTACT, "New Friend"},
 239         {YAHOO_SERVICE_ADDIDENT, "Add Identity"},
 240         {YAHOO_SERVICE_ADDIGNORE, "Add Ignore"},
 241         {YAHOO_SERVICE_PING, "Ping"},
 242         {YAHOO_SERVICE_GOTGROUPRENAME, "Got Group Rename"},
 243         {YAHOO_SERVICE_SYSMESSAGE, "System Message"},
 244         {YAHOO_SERVICE_SKINNAME, "Skinname"},
 245         {YAHOO_SERVICE_PASSTHROUGH2, "Passthrough 2"},
 246         {YAHOO_SERVICE_CONFINVITE, "Conference Invitation"},
 247         {YAHOO_SERVICE_CONFLOGON, "Conference Logon"},
 248         {YAHOO_SERVICE_CONFDECLINE, "Conference Decline"},
 249         {YAHOO_SERVICE_CONFLOGOFF, "Conference Logoff"},
 250         {YAHOO_SERVICE_CONFADDINVITE, "Conference Additional Invitation"},
 251         {YAHOO_SERVICE_CONFMSG, "Conference Message"},
 252         {YAHOO_SERVICE_CHATLOGON, "Chat Logon"},
 253         {YAHOO_SERVICE_CHATLOGOFF, "Chat Logoff"},
 254         {YAHOO_SERVICE_CHATMSG, "Chat Message"},
 255         {YAHOO_SERVICE_GAMELOGON, "Game Logon"},
 256         {YAHOO_SERVICE_GAMELOGOFF, "Game Logoff"},
 257         {YAHOO_SERVICE_GAMEMSG, "Game Message"},
 258         {YAHOO_SERVICE_FILETRANSFER, "File Transfer"},
 259         {YAHOO_SERVICE_VOICECHAT, "Voice Chat"},
 260         {YAHOO_SERVICE_NOTIFY, "Notify"},
 261         {YAHOO_SERVICE_VERIFY, "Verify"},
 262         {YAHOO_SERVICE_P2PFILEXFER, "P2P File Transfer"},
 263         {YAHOO_SERVICE_PEERTOPEER, "Peer To Peer"},
 264         {YAHOO_SERVICE_WEBCAM, "WebCam"},
 265         {YAHOO_SERVICE_AUTHRESP, "Authentication Response"},
 266         {YAHOO_SERVICE_LIST, "List"},
 267         {YAHOO_SERVICE_AUTH, "Authentication"},
 268         {YAHOO_SERVICE_AUTHBUDDY, "Authorize Buddy"},
 269         {YAHOO_SERVICE_ADDBUDDY, "Add Buddy"},
 270         {YAHOO_SERVICE_REMBUDDY, "Remove Buddy"},
 271         {YAHOO_SERVICE_IGNORECONTACT, "Ignore Contact"},
 272         {YAHOO_SERVICE_REJECTCONTACT, "Reject Contact"},
 273         {YAHOO_SERVICE_GROUPRENAME, "Group Rename"},
 274         {YAHOO_SERVICE_KEEPALIVE, "Keep Alive"},
 275         {YAHOO_SERVICE_CHATONLINE, "Chat Online"},
 276         {YAHOO_SERVICE_CHATGOTO, "Chat Goto"},
 277         {YAHOO_SERVICE_CHATJOIN, "Chat Join"},
 278         {YAHOO_SERVICE_CHATLEAVE, "Chat Leave"},
 279         {YAHOO_SERVICE_CHATEXIT, "Chat Exit"},
 280         {YAHOO_SERVICE_CHATADDINVITE, "Chat Invite"},
 281         {YAHOO_SERVICE_CHATLOGOUT, "Chat Logout"},
 282         {YAHOO_SERVICE_CHATPING, "Chat Ping"},
 283         {YAHOO_SERVICE_COMMENT, "Comment"},
 284         {YAHOO_SERVICE_GAME_INVITE,"Game Invite"},
 285         {YAHOO_SERVICE_STEALTH_PERM, "Stealth Permanent"},
 286         {YAHOO_SERVICE_STEALTH_SESSION, "Stealth Session"},
 287         {YAHOO_SERVICE_AVATAR,"Avatar"},
 288         {YAHOO_SERVICE_PICTURE_CHECKSUM,"Picture Checksum"},
 289         {YAHOO_SERVICE_PICTURE,"Picture"},
 290         {YAHOO_SERVICE_PICTURE_UPDATE,"Picture Update"},
 291         {YAHOO_SERVICE_PICTURE_UPLOAD,"Picture Upload"},
 292         {YAHOO_SERVICE_YAB_UPDATE,"Yahoo Address Book Update"},
 293         {YAHOO_SERVICE_Y6_VISIBLE_TOGGLE, "Y6 Visibility Toggle"},
 294         {YAHOO_SERVICE_Y6_STATUS_UPDATE, "Y6 Status Update"},
 295         {YAHOO_SERVICE_PICTURE_STATUS, "Picture Sharing Status"},
 296         {YAHOO_SERVICE_VERIFY_ID_EXISTS, "Verify ID Exists"},
 297         {YAHOO_SERVICE_AUDIBLE, "Audible"},
 298         {YAHOO_SERVICE_Y7_CONTACT_DETAILS,"Y7 Contact Details"},
 299         {YAHOO_SERVICE_Y7_CHAT_SESSION, "Y7 Chat Session"},
 300         {YAHOO_SERVICE_Y7_AUTHORIZATION,"Y7 Buddy Authorization"},
 301         {YAHOO_SERVICE_Y7_FILETRANSFER,"Y7 File Transfer"},
 302         {YAHOO_SERVICE_Y7_FILETRANSFERINFO,"Y7 File Transfer Information"},
 303         {YAHOO_SERVICE_Y7_FILETRANSFERACCEPT,"Y7 File Transfer Accept"},
 304         {YAHOO_SERVICE_Y7_CHANGE_GROUP, "Y7 Change Group"},
 305         {YAHOO_SERVICE_STATUS_15, "Status V15"},
 306         {YAHOO_SERVICE_LIST_15, "List V15"},
 307         {YAHOO_SERVICE_WEBLOGIN,"WebLogin"},
 308         {YAHOO_SERVICE_SMS_MSG,"SMS Message"},
 309         {0, NULL}
 310 };
 311
 312 static const value_string ymsg_status_vals[] = {
 313         {YPACKET_STATUS_DISCONNECTED,"Disconnected"},
 314         {YPACKET_STATUS_DEFAULT,"Default"},
 315         {YPACKET_STATUS_SERVERACK,"Server Ack"},
 316         {YPACKET_STATUS_GAME,"Playing Game"},
 317         {YPACKET_STATUS_AWAY, "Away"},
 318         {YPACKET_STATUS_CONTINUED,"More Packets??"},
 319         {YPACKET_STATUS_NOTIFY, "Notify"},
 320         {YPACKET_STATUS_WEBLOGIN,"Web Login"},
 321         {YPACKET_STATUS_OFFLINE,"Offline"},
 322         {0, NULL}
 323 };
 324
 325 static guint get_ymsg_pdu_len(packet_info *pinfo, tvbuff_t *tvb, int offset);
 326 static void dissect_ymsg_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
 327
 328 /* Find the end of the current content line and return its length */
 329 static int get_content_item_length(tvbuff_t *tvb, int offset)
 330 {
 331         int origoffset = offset;
 332
 333         /* Keep reading until the magic delimiter (or end of tvb) is found */
 334         while (tvb_length_remaining(tvb, offset) >= 2) {
 335                 if (tvb_get_ntohs(tvb, offset) == 0xc080) {
 336                         break;
 337                 }
 338                 offset++;
 339         }
 340         return offset - origoffset;
 341 }
 342
 343
 344 static gboolean
 345 dissect_ymsg(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 346 {
 347
 348   if (tvb_memeql(tvb, 0, "YMSG", 4) == -1) {
 349     /* Not a Yahoo Messenger packet. */
 350     return FALSE;
 351   }
 352
 353   tcp_dissect_pdus(tvb, pinfo, tree, ymsg_desegment, 8, get_ymsg_pdu_len,
 354                    dissect_ymsg_pdu);
 355   return TRUE;
 356 }
 357
 358 static guint
 359 get_ymsg_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
 360 {
 361   guint16 plen;
 362
 363   /*
 364    * Get the length of the YMSG packet.
 365    */
 366   plen = tvb_get_ntohs(tvb, offset + 8);
 367
 368   /*
 369    * That length doesn't include the length of the header itself; add that in.
 370    */
 371   return plen + 20;
 372 }
 373
 374 static void
 375 dissect_ymsg_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 376 {
 377         proto_tree      *ymsg_tree, *ti;
 378         proto_item      *content_item;
 379         proto_tree      *content_tree;
 380         char *keybuf;
 381         char *valbuf;
 382         int headersize = sizeof(struct yahoo_rawpacket)-6;
 383         int keylen = 0;
 384         int vallen = 0;
 385         int offset = 0;
 386         int content_len = 0;
 387
 388         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 389                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "YMSG");
 390
 391         offset = 0;
 392         if (check_col(pinfo->cinfo, COL_INFO)) {
 393                 col_add_fstr(pinfo->cinfo, COL_INFO,
 394                         "%s (status=%s)   ",
 395                         val_to_str(tvb_get_ntohs(tvb, offset + 10),
 396                                  ymsg_service_vals, "Unknown Service: %u"),
 397                         val_to_str(tvb_get_ntohl(tvb, offset + 12),
 398                                  ymsg_status_vals, "Unknown Status: %u")
 399                 );
 400         }
 401
 402         if (tree) {
 403                 ti = proto_tree_add_item(tree, proto_ymsg, tvb, offset, -1, FALSE);
 404                 ymsg_tree = proto_item_add_subtree(ti, ett_ymsg);
 405
 406                 offset += 4; /* skip the YMSG string */
 407
 408                 /* Version */
 409                 proto_tree_add_item(ymsg_tree, hf_ymsg_version, tvb, offset, 2, FALSE);
 410                 offset += 2;
 411
 412                 offset += 2;    /* XXX - padding? */
 413
 414                 /* Length */
 415                 content_len = tvb_get_ntohs(tvb, offset);
 416                 proto_tree_add_item(ymsg_tree, hf_ymsg_len, tvb, offset, 2, FALSE);
 417                 offset += 2;
 418
 419                 /* Service */
 420                 proto_item_append_text(ti, " (%s)",
 421                                        val_to_str(tvb_get_ntohs(tvb, offset),
 422                                                   ymsg_service_vals,
 423                                                   "Unknown"));
 424
 425                 proto_tree_add_item(ymsg_tree, hf_ymsg_service, tvb, offset, 2, FALSE);
 426                 offset += 2;
 427
 428                 /* Status */
 429                 proto_tree_add_item(ymsg_tree, hf_ymsg_status, tvb, offset, 4, FALSE);
 430                 offset += 4;
 431
 432                 /* Session id */
 433                 proto_tree_add_item(ymsg_tree, hf_ymsg_session_id, tvb, offset, 4, TRUE);
 434                 offset += 4;
 435
 436                 /* Contents */
 437                 if (content_len) {
 438                         /* Create content subtree */
 439                         content_item = proto_tree_add_item(ymsg_tree, hf_ymsg_content, tvb,
 440                                                            offset, -1, TRUE);
 441                         content_tree = proto_item_add_subtree(content_item, ett_ymsg_content);
 442
 443                         /* Each entry consists of:
 444                            <key string> <delimiter> <value string> <delimiter>
 445                         */
 446
 447                         /* Parse and show each line of the contents */
 448                         for (;;)
 449                         {
 450                                 proto_item  *ti = NULL;
 451                                 proto_tree  *content_line_tree = NULL;
 452
 453                                 /* Don't continue unless there is room for another whole item.
 454                                    (including 2 2-byte delimiters */
 455                                 if (offset >= (headersize+content_len-4))
 456                                 {
 457                                         break;
 458                                 }
 459
 460                                 /* Get the length of the key */
 461                                 keylen = get_content_item_length(tvb, offset);
 462                                 /* Extract the key */
 463                                 keybuf = tvb_format_text(tvb, offset, keylen);
 464
 465                                 /* Get the length of the value */
 466                                 vallen = get_content_item_length(tvb, offset+keylen+2);
 467                                 /* Extract the value */
 468                                 valbuf = tvb_format_text(tvb, offset+keylen+2, vallen);
 469
 470                                 /* Add a text item with the key... */
 471                                 ti =  proto_tree_add_string_format(content_tree, hf_ymsg_content_line, tvb,
 472                                                                    offset, keylen+2+vallen+2,
 473                                                                    "", "%s:%s", keybuf, valbuf);
 474                                 content_line_tree = proto_item_add_subtree(ti, ett_ymsg_content_line);
 475
 476                                 /* And add the key and value separately inside */
 477                                 proto_tree_add_item(content_line_tree, hf_ymsg_content_line_key, tvb,
 478                                                     offset, keylen, FALSE);
 479                                 proto_tree_add_item(content_line_tree, hf_ymsg_content_line_value, tvb,
 480                                                     offset+keylen+2, vallen, FALSE);
 481
 482                                 /* Move beyone key and value lines */
 483                                 offset += keylen+2+vallen+2;
 484                         }
 485                 }
 486         }
 487
 488         col_set_fence(pinfo->cinfo, COL_INFO);
 489
 490         return;
 491 }
 492
 493 void
 494 proto_register_ymsg(void)
 495 {
 496         static hf_register_info hf[] = {
 497                         { &hf_ymsg_version, {
 498                                 "Version", "ymsg.version", FT_UINT16, BASE_DEC,
 499                                 NULL, 0, "Packet version identifier", HFILL }},
 500                         { &hf_ymsg_len, {
 501                                 "Packet Length", "ymsg.len", FT_UINT16, BASE_DEC,
 502                                 NULL, 0, "Packet Length", HFILL }},
 503                         { &hf_ymsg_service, {
 504                                 "Service", "ymsg.service", FT_UINT16, BASE_DEC,
 505                                 VALS(ymsg_service_vals), 0, "Service Type", HFILL }},
 506                         { &hf_ymsg_status, {
 507                                 "Status", "ymsg.status", FT_UINT32, BASE_DEC,
 508                                 VALS(ymsg_status_vals), 0, "Message Type Flags", HFILL }},
 509                         { &hf_ymsg_session_id, {
 510                                 "Session ID", "ymsg.session_id", FT_UINT32, BASE_HEX,
 511                                 NULL, 0, "Connection ID", HFILL }},
 512
 513                         { &hf_ymsg_content, {
 514                                 "Content", "ymsg.content", FT_STRING, BASE_NONE,
 515                                 NULL, 0, "Data portion of the packet", HFILL }},
 516                         { &hf_ymsg_content_line, {
 517                                 "Content-line", "ymsg.content-line", FT_STRING, BASE_NONE,
 518                                 NULL, 0, "Data portion of the packet", HFILL }},
 519                         { &hf_ymsg_content_line_key, {
 520                                 "Key", "ymsg.content-line.key", FT_STRING, BASE_NONE,
 521                                 NULL, 0, "Content line key", HFILL }},
 522                         { &hf_ymsg_content_line_value, {
 523                                 "Value", "ymsg.content-line.value", FT_STRING, BASE_NONE,
 524                                 NULL, 0, "Content line value", HFILL }}
 525         };
 526         static gint *ett[] = {
 527                 &ett_ymsg,
 528                 &ett_ymsg_content,
 529                 &ett_ymsg_content_line
 530         };
 531         module_t *ymsg_module;
 532
 533         proto_ymsg = proto_register_protocol("Yahoo YMSG Messenger Protocol",
 534             "YMSG", "ymsg");
 535
 536         proto_register_field_array(proto_ymsg, hf, array_length(hf));
 537
 538         proto_register_subtree_array(ett, array_length(ett));
 539
 540         ymsg_module = prefs_register_protocol(proto_ymsg, NULL);
 541         prefs_register_bool_preference(ymsg_module, "desegment",
 542                                        "Reassemble YMSG messages spanning multiple TCP segments",
 543                                        "Whether the YMSG dissector should reassemble messages spanning multiple TCP segments. "
 544                                        "To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
 545                                        &ymsg_desegment);
 546 }
 547
 548 void
 549 proto_reg_handoff_ymsg(void)
 550 {
 551         /*
 552          * DO NOT register for port 23, as that's Telnet, or for port
 553          * 25, as that's SMTP.
 554          *
 555          * Also, DO NOT register for port 5050, as that's used by the
 556          * old and new Yahoo messenger protocols.
 557          *
 558          * Just register as a heuristic TCP dissector, and reject stuff
 559          * that doesn't begin with a YMSG signature.
 560          */
 561         heur_dissector_add("tcp", dissect_ymsg, proto_ymsg);
 562 }