/* packet-turnchannel.c * Routines for TURN channel dissection (TURN negociation is handled * in the STUN2 dissector * Copyright 2008, 8x8 Inc. * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * Please refer to the following specs for protocol detail: * - draft-ietf-behave-rfc3489bis-15 * - draft-ietf-mmusic-ice-19 * - draft-ietf-behave-nat-behavior-discovery-03 * - draft-ietf-behave-turn-07 * - draft-ietf-behave-turn-ipv6-03 */ #include "config.h" #include #include "packet-tcp.h" void proto_register_turnchannel(void); void proto_reg_handoff_turnchannel(void); /* heuristic subdissectors */ static heur_dissector_list_t heur_subdissector_list; /* data dissector handle */ static dissector_handle_t data_handle; /* Initialize the protocol and registered fields */ static int proto_turnchannel = -1; static int hf_turnchannel_id = -1; static int hf_turnchannel_len = -1; #define TURNCHANNEL_HDR_LEN ((guint)4) /* Initialize the subtree pointers */ static gint ett_turnchannel = -1; static int dissect_turnchannel_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) { guint len; guint16 channel_id; guint16 data_len; proto_item *ti; proto_tree *turnchannel_tree; heur_dtbl_entry_t *hdtbl_entry; len = tvb_captured_length(tvb); /* First, make sure we have enough data to do the check. */ if (len < TURNCHANNEL_HDR_LEN) { return 0; } channel_id = tvb_get_ntohs(tvb, 0); data_len = tvb_get_ntohs(tvb, 2); if ((channel_id < 0x4000) || (channel_id > 0xFFFE)) { return 0; } if (len != TURNCHANNEL_HDR_LEN + data_len) { return 0; } /* Seems to be a decent TURN channel message */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "TURN CHANNEL"); col_add_fstr(pinfo->cinfo, COL_INFO, "Channel Id 0x%x", channel_id); ti = proto_tree_add_item(tree, proto_turnchannel, tvb, 0, -1, ENC_NA); turnchannel_tree = proto_item_add_subtree(ti, ett_turnchannel); proto_tree_add_uint(turnchannel_tree, hf_turnchannel_id, tvb, 0, 2, channel_id); proto_tree_add_uint(turnchannel_tree, hf_turnchannel_len, tvb, 2, 2, data_len); if (len > TURNCHANNEL_HDR_LEN) { tvbuff_t *next_tvb; guint reported_len, new_len; new_len = tvb_captured_length_remaining(tvb, TURNCHANNEL_HDR_LEN); reported_len = tvb_reported_length_remaining(tvb, TURNCHANNEL_HDR_LEN); if (data_len < reported_len) { reported_len = data_len; } next_tvb = tvb_new_subset(tvb, TURNCHANNEL_HDR_LEN, new_len, reported_len); if (!dissector_try_heuristic(heur_subdissector_list, next_tvb, pinfo, tree, &hdtbl_entry, NULL)) { call_dissector(data_handle,next_tvb, pinfo, tree); } } return tvb_captured_length(tvb); } static guint get_turnchannel_message_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_) { return (guint)tvb_get_ntohs(tvb, offset+2) + TURNCHANNEL_HDR_LEN; } static int dissect_turnchannel_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data) { tcp_dissect_pdus(tvb, pinfo, tree, TRUE, TURNCHANNEL_HDR_LEN, get_turnchannel_message_len, dissect_turnchannel_message, data); return tvb_captured_length(tvb); } static gboolean dissect_turnchannel_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) { guint len; guint16 channel_id; guint16 data_len; len = tvb_captured_length(tvb); /* First, make sure we have enough data to do the check. */ if (len < TURNCHANNEL_HDR_LEN) { return FALSE; } channel_id = tvb_get_ntohs(tvb, 0); data_len = tvb_get_ntohs(tvb, 2); if ((channel_id < 0x4000) || (channel_id > 0xFFFE)) { return FALSE; } if (len != TURNCHANNEL_HDR_LEN + data_len) { return FALSE; } return dissect_turnchannel_message(tvb, pinfo, tree, NULL); } void proto_register_turnchannel(void) { static hf_register_info hf[] = { { &hf_turnchannel_id, { "TURN Channel ID", "turnchannel.id", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_turnchannel_len, { "Data Length", "turnchannel.length", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } }, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_turnchannel, }; /* Register the protocol name and description */ proto_turnchannel = proto_register_protocol("TURN Channel", "TURNCHANNEL", "turnchannel"); register_dissector("turnchannel", dissect_turnchannel_message, proto_turnchannel); /* subdissectors */ heur_subdissector_list = register_heur_dissector_list("turnchannel"); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_turnchannel, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); } void proto_reg_handoff_turnchannel(void) { dissector_handle_t turnchannel_tcp_handle; dissector_handle_t turnchannel_udp_handle; turnchannel_tcp_handle = create_dissector_handle(dissect_turnchannel_tcp, proto_turnchannel); turnchannel_udp_handle = find_dissector("turnchannel"); /* Register for "Decode As" in case STUN negotiation isn't captured */ dissector_add_for_decode_as("tcp.port", turnchannel_tcp_handle); dissector_add_for_decode_as("udp.port", turnchannel_udp_handle); /* TURN negotiation is handled through STUN2 dissector (packet-stun.c), so only it should be able to determine if a packet is a TURN packet */ heur_dissector_add("stun", dissect_turnchannel_heur, "TURN Channel over STUN", "turnchannel_stun", proto_turnchannel, HEURISTIC_ENABLE); data_handle = find_dissector("data"); } /* * Editor modelines - http://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 8 * tab-width: 8 * indent-tabs-mode: t * End: * * vi: set shiftwidth=8 tabstop=8 noexpandtab: * :indentSize=8:tabSize=8:noTabs=false: */