/* packet-tdmoe.c * Routines for TDM over Ethernet packet disassembly * Copyright 2010, Haakon Nessjoen * * 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. */ #include "config.h" #include #include #include /* Bitmasks for the flags in the fourth byte of the packet */ #define TDMOE_YELLOW_ALARM_BITMASK 0x01 #define TDMOE_SIGBITS_BITMASK 0x02 void proto_reg_handoff_tdmoe(void); void proto_register_tdmoe(void); /* protocols and header fields */ static int proto_tdmoe = -1; static int hf_tdmoe_subaddress = -1; static int hf_tdmoe_samples = -1; static int hf_tdmoe_flags = -1; static int hf_tdmoe_yellow_alarm = -1; static int hf_tdmoe_sig_bits_present = -1; static int hf_tdmoe_packet_counter = -1; static int hf_tdmoe_channels = -1; static int hf_tdmoe_sig_bits = -1; static gint ett_tdmoe = -1; static gint ett_tdmoe_flags = -1; static dissector_handle_t lapd_handle; static gint pref_tdmoe_d_channel = 24; static int dissect_tdmoe(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) { proto_item *ti; proto_tree *tdmoe_tree; tvbuff_t *next_client; guint16 channels; guint16 subaddress; gint32 offset = 0; static const gint *flags[] = { &hf_tdmoe_yellow_alarm, &hf_tdmoe_sig_bits_present, NULL }; int chan; /* Check that there's enough data */ if (tvb_captured_length(tvb) < 8) return 0; subaddress = tvb_get_ntohs(tvb, 0); channels = tvb_get_ntohs(tvb, 6); col_set_str(pinfo->cinfo, COL_PROTOCOL, "TDMoE"); col_add_fstr(pinfo->cinfo, COL_INFO, "Subaddress: %d Channels: %d %s", subaddress, channels, (tvb_get_guint8(tvb, 3) & TDMOE_YELLOW_ALARM_BITMASK ? "[YELLOW ALARM]" : "") ); /* create display subtree for the protocol */ ti = proto_tree_add_item(tree, proto_tdmoe, tvb, 0, -1, ENC_NA); tdmoe_tree = proto_item_add_subtree(ti, ett_tdmoe); /* Subaddress */ proto_tree_add_item(tdmoe_tree, hf_tdmoe_subaddress, tvb, offset, 2, ENC_BIG_ENDIAN); offset+=2; /* Samples (1 byte) */ proto_tree_add_item(tdmoe_tree, hf_tdmoe_samples, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; /* Yellow alarm & "Sig bits present" bits (1 byte) */ proto_tree_add_bitmask(tdmoe_tree, tvb, offset, hf_tdmoe_flags, ett_tdmoe_flags, flags, ENC_BIG_ENDIAN); offset++; /* Packet counter (2 bytes) */ proto_tree_add_item(tdmoe_tree, hf_tdmoe_packet_counter, tvb, offset, 2, ENC_BIG_ENDIAN); offset+=2; /* Number of channels in packet (2 bytes) */ proto_tree_add_item(tdmoe_tree, hf_tdmoe_channels, tvb, offset, 2, ENC_BIG_ENDIAN); offset+=2; if (tvb_get_guint8(tvb, 3) & TDMOE_SIGBITS_BITMASK) { /* 4 sigbits per channel. Might be different on other sub-protocols? */ guint16 length = (channels >> 1) + ((channels & 0x01) ? 1 : 0); proto_tree_add_item(tdmoe_tree, hf_tdmoe_sig_bits, tvb, offset, length, ENC_NA); offset += length; } /* The rest is SAMPLES * CHANNELS bytes of channel data */ for (chan = 1; chan <= channels; chan++) { next_client = tvb_new_subset_length(tvb, offset + ((chan - 1) * 8), 8); if (chan == pref_tdmoe_d_channel) { call_dissector(lapd_handle, next_client, pinfo, tree); } else { call_data_dissector(next_client, pinfo, tree); } } return 1; } void proto_register_tdmoe(void) { static hf_register_info hf[] = { { &hf_tdmoe_subaddress, { "Subaddress", "tdmoe.subaddress", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_tdmoe_samples, { "Samples", "tdmoe.samples", FT_UINT8, BASE_DEC, NULL, 0x0, "Samples per channel", HFILL }}, { &hf_tdmoe_flags, { "Flags", "tdmoe.flags", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }}, { &hf_tdmoe_yellow_alarm, { "Yellow Alarm", "tdmoe.yellowalarm", FT_BOOLEAN, 8, NULL, TDMOE_YELLOW_ALARM_BITMASK, NULL, HFILL }}, { &hf_tdmoe_sig_bits_present, { "Sig bits present", "tdmoe.sig_bits_present", FT_BOOLEAN, 8, NULL, TDMOE_SIGBITS_BITMASK, NULL, HFILL }}, { &hf_tdmoe_packet_counter, { "Counter", "tdmoe.counter", FT_UINT16, BASE_DEC, NULL, 0x0, "Packet number", HFILL }}, { &hf_tdmoe_channels, { "Channels", "tdmoe.channels", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_tdmoe_sig_bits, { "Sig bits", "tdmoe.sig_bits", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }}, }; static gint *ett[] = { &ett_tdmoe, &ett_tdmoe_flags }; module_t *tdmoe_module; proto_tdmoe = proto_register_protocol("Digium TDMoE Protocol", "TDMoE", "tdmoe"); proto_register_field_array(proto_tdmoe, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); tdmoe_module = prefs_register_protocol(proto_tdmoe, proto_reg_handoff_tdmoe); prefs_register_uint_preference(tdmoe_module, "d_channel", "TDMoE D-Channel", "The TDMoE channel that contains the D-Channel.", 10, &pref_tdmoe_d_channel); } void proto_reg_handoff_tdmoe(void) { dissector_handle_t tdmoe_handle; tdmoe_handle = create_dissector_handle(dissect_tdmoe, proto_tdmoe); dissector_add_uint("ethertype", ETHERTYPE_TDMOE, tdmoe_handle); lapd_handle = find_dissector_add_dependency("lapd-bitstream", proto_tdmoe); } /* * 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: */