epan/dissectors/packet-paltalk.c

   1 /* packet-paltalk.c
   2  * Routines for Paltalk dissection
   3  * Copyright 2005, Tim Hentenaar < tim at hentenaar dot com >
   4  * Copyright 2008, Mohammad Ebrahim Mohammadi Panah < mebrahim at gmail dot com >
   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 <string.h>
  32
  33 #include <gmodule.h>
  34 #include <epan/packet.h>
  35
  36 #include "packet-tcp.h"
  37
  38 #define INET_IPV4_ADDRESS_FROM_BYTES(a,b,c,d) g_htonl(((a)<<24) | ((b)<<16) | ((c)<<8) | (d)) /* *network* order */
  39
  40 #define PALTALK_SERVERS_ADDRESS INET_IPV4_ADDRESS_FROM_BYTES(199,106,0,0)      /* 199.106.0.0 in *network* order */
  41 #define PALTALK_SERVERS_NETMASK INET_IPV4_ADDRESS_FROM_BYTES(0xFF, 0xFE, 0x00, 0x00)  /* /15  in *network* order */
  42
  43 #define PALTALK_HEADER_LENGTH 6
  44
  45 /* forward reference */
  46 static guint dissect_paltalk_get_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset);
  47 static void dissect_paltalk_desegmented(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
  48
  49 static int proto_paltalk = -1;
  50
  51 static int hf_paltalk_pdu_type = -1;
  52 static int hf_paltalk_version = -1;
  53 static int hf_paltalk_length = -1;
  54 static int hf_paltalk_content = -1;
  55
  56 static gint ett_paltalk = -1;
  57
  58 static gboolean
  59 dissect_paltalk(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  60 {
  61         guint32 src32, dst32;
  62
  63         /* Detect if this TCP session is a Paltalk one */
  64         /* TODO: Optimize detection logic if possible */
  65
  66         if ((pinfo->net_src.type != AT_IPv4)
  67             || (pinfo->net_dst.type != AT_IPv4)
  68             || (pinfo->net_src.len != 4)
  69             || (pinfo->net_dst.len != 4)
  70             || !pinfo->net_src.data
  71             || !pinfo->net_dst.data)
  72                 return FALSE;
  73
  74         memcpy((guint8 *)&src32, pinfo->net_src.data, 4); /* *Network* order */
  75         memcpy((guint8 *)&dst32, pinfo->net_dst.data, 4); /* *Network* order */
  76
  77         if ( ((src32 & PALTALK_SERVERS_NETMASK) != PALTALK_SERVERS_ADDRESS)
  78              &&
  79              ((dst32 & PALTALK_SERVERS_NETMASK) != PALTALK_SERVERS_ADDRESS))
  80                 return FALSE;
  81
  82         /* Dissect result of desegmented TCP data */
  83         tcp_dissect_pdus(tvb, pinfo, tree, TRUE, PALTALK_HEADER_LENGTH
  84                         , dissect_paltalk_get_len, dissect_paltalk_desegmented);
  85         return TRUE;
  86 }
  87
  88 static guint
  89 dissect_paltalk_get_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
  90 {
  91         return tvb_get_ntohs(tvb, offset + 4) + PALTALK_HEADER_LENGTH;
  92 }
  93
  94 static void
  95 dissect_paltalk_desegmented(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  96 {
  97         proto_item *ti = NULL;
  98         proto_tree *pt_tree = NULL;
  99
 100         col_set_str(pinfo->cinfo, COL_PROTOCOL, "Paltalk");
 101         col_clear(pinfo->cinfo, COL_INFO);
 102
 103         if (tree)               /* we are being asked for details */
 104         {
 105                 ti = proto_tree_add_item(tree, proto_paltalk, tvb, 0, -1, FALSE);
 106                 pt_tree = proto_item_add_subtree(ti, ett_paltalk);
 107                 proto_tree_add_item(pt_tree, hf_paltalk_pdu_type, tvb, 0, 2, FALSE);
 108                 proto_tree_add_item(pt_tree, hf_paltalk_version, tvb, 2, 2, FALSE);
 109                 proto_tree_add_item(pt_tree, hf_paltalk_length, tvb, 4, 2, FALSE);
 110                 proto_tree_add_item(pt_tree, hf_paltalk_content, tvb, 6, tvb_get_ntohs(tvb, 4), FALSE);
 111         }
 112 }
 113
 114 void
 115 proto_register_paltalk(void)
 116 {
 117         static hf_register_info hf[] = {
 118                 { &hf_paltalk_pdu_type, { "Packet Type", "paltalk.type",
 119                                           FT_UINT16, BASE_HEX, NULL, 0x00, NULL, HFILL }},
 120                 { &hf_paltalk_version,  { "Protocol Version", "paltalk.version",
 121                                           FT_INT16, BASE_DEC, NULL, 0x00, NULL, HFILL }},
 122                 { &hf_paltalk_length,   { "Payload Length", "paltalk.length",
 123                                           FT_INT16, BASE_DEC, NULL, 0x00, NULL, HFILL }},
 124                 { &hf_paltalk_content,  { "Payload Content", "paltalk.content",
 125                                           FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }}
 126         };
 127
 128         static gint *ett[] = { &ett_paltalk };
 129
 130         proto_paltalk = proto_register_protocol("Paltalk Messenger Protocol", "Paltalk", "paltalk");
 131         proto_register_field_array(proto_paltalk, hf, array_length(hf));
 132         proto_register_subtree_array(ett, array_length(ett));
 133 }
 134
 135 void
 136 proto_reg_handoff_paltalk(void)
 137 {
 138         heur_dissector_add("tcp", dissect_paltalk, proto_paltalk);
 139 }
 140