diff options
Diffstat (limited to 'plugins/epan/wimax/wimax_pdu_decoder.c')
-rw-r--r-- | plugins/epan/wimax/wimax_pdu_decoder.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/plugins/epan/wimax/wimax_pdu_decoder.c b/plugins/epan/wimax/wimax_pdu_decoder.c new file mode 100644 index 0000000000..d17b46288f --- /dev/null +++ b/plugins/epan/wimax/wimax_pdu_decoder.c @@ -0,0 +1,267 @@ +/* wimax_pdu_decoder.c + * WiMax PDU Burst decoder + * + * Copyright (c) 2007 by Intel Corporation. + * + * Author: Lu Pan <lu.pan@intel.com> + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1999 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 files */ + +#include "config.h" + +#include <epan/packet.h> +#include "crc.h" +#include "wimax-int.h" +#include "wimax_utils.h" + +extern gint proto_wimax; + +void proto_reg_handoff_wimax_pdu(void); + +static dissector_handle_t mac_generic_decoder_handle = NULL; +static dissector_handle_t mac_header_type1_handle = NULL; +static dissector_handle_t mac_header_type2_handle = NULL; +static dissector_handle_t wimax_harq_map_handle = NULL; + +#define WIMAX_PDU_PADDING_MASK 0xFF +#define WIMAX_INVALID_PDU_MASK 0xF0 +#define WIMAX_MAP_TYPE_MASK 0xE0 /* 0b111 */ +#define WIMAX_HARQ_MAP_MSG_IND 0xE0 /* 0b111 */ +#define WIMAX_COMPRESSED_DL_MAP_IND 0xC0 /* 0b110 */ +#define REDUCED_PRIVATE_MAP_MASK 0x0C /* 0b11 */ + +#define WIMAX_MAC_HEADER_SIZE 6 +#define WIMAX_MAC_HEADER_INFO_FIELDS 5 +#define WIMAX_MAC_HEADER_HT_FIELD 0x80 +#define WIMAX_MAC_HEADER_EC_FIELD 0x40 +#define WIMAX_MAC_HEADER_LENGTH_MSB_MASK 0x07 + +#define WIMAX_HARQ_MAP_MSG_LENGTH_MASK1 0x07FC +/* Global Variables. */ +gboolean first_gmh; + +static gint proto_wimax_pdu_decoder = -1; +static gint ett_wimax_pdu_decoder = -1; + +static int hf_wimax_value_bytes = -1; + +static int dissect_wimax_pdu_decoder(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) +{ + guint offset; + guint mac_ht, mac_ec; + guint first_byte, length; + guint mac_hcs, mac_hcs_calculated; + proto_item *pdu_item = NULL; + proto_tree *pdu_tree = NULL; + +#ifndef STATIC_DATA + /* generate the table of CRC32 remainders for all possible bytes */ + wimax_mac_gen_crc32_table(); + /* generate the table of CRC8 remainders for all possible bytes */ + wimax_mac_gen_crc8_table(); +#endif + + /* parsing the PDU burst */ + for(offset = 0; offset < tvb_reported_length(tvb); ) + { + if (offset == 0) + { + first_gmh = TRUE; + } + else + { + first_gmh = FALSE; + } + /* get the length of the remainder */ + length = tvb_reported_length_remaining(tvb, offset); + /* get the first byte at offset */ + first_byte = tvb_get_guint8(tvb, offset); + /* check for padding */ + if(first_byte == WIMAX_PDU_PADDING_MASK) + { /* Padding */ + /* display message */ + pdu_item = proto_tree_add_protocol_format(tree, proto_wimax_pdu_decoder, tvb, offset, length, "Padding (%u bytes)", length); + /* add subtree */ + pdu_tree = proto_item_add_subtree(pdu_item, ett_wimax_pdu_decoder); + /* display the padding in Hex */ + proto_tree_add_item(pdu_tree, hf_wimax_value_bytes, tvb, offset, length, ENC_NA); + break; + } + else if((first_byte & WIMAX_MAP_TYPE_MASK) == WIMAX_HARQ_MAP_MSG_IND) + { /* HARQ MAP message (no mac header) */ + /* get the HARQ MAp Message Length */ + length = ((tvb_get_ntohs(tvb, offset) & WIMAX_HARQ_MAP_MSG_LENGTH_MASK1) >> 2); + if (length == 0) + { + length = 3; /* At least 3 bytes. This prevents endless loop */ + } + call_dissector(wimax_harq_map_handle, tvb_new_subset_length(tvb,offset,length), pinfo, tree); + offset += length; + continue; + } + else if((first_byte & WIMAX_MAP_TYPE_MASK) == WIMAX_COMPRESSED_DL_MAP_IND) + { + if(is_down_link(pinfo)) + { /* decode compressed dl-map without mac header */ + if ((first_byte & REDUCED_PRIVATE_MAP_MASK) == REDUCED_PRIVATE_MAP_MASK) + { + length = wimax_decode_dlmap_reduced_aas(tvb, pinfo, tree); + } + else + { + length = wimax_decode_dlmapc(tvb, pinfo, tree); + } + offset += length; + continue; + } + } + else if((first_byte & WIMAX_INVALID_PDU_MASK) == WIMAX_INVALID_PDU_MASK) + { /* Invalid PDU */ + /* update the info column */ + col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "Invalid PDU"); + /* display message */ + pdu_item = proto_tree_add_protocol_format(tree, proto_wimax_pdu_decoder, tvb, offset, length, "Invalid PDU (%u bytes)", length); + /* add subtree */ + pdu_tree = proto_item_add_subtree(pdu_item, ett_wimax_pdu_decoder); + /* display the invalid MAC Header in Hex */ + proto_tree_add_item(pdu_tree, hf_wimax_value_bytes, tvb, offset, length, ENC_NA); + break; + } + /* calculate the MAC header HCS */ + mac_hcs_calculated = wimax_mac_calc_crc8(tvb_get_ptr(tvb, offset, WIMAX_MAC_HEADER_INFO_FIELDS), WIMAX_MAC_HEADER_INFO_FIELDS); + /* get the Header Check Sequence (HCS) in the header */ + mac_hcs = tvb_get_guint8(tvb, offset + WIMAX_MAC_HEADER_SIZE - 1); + /* verify the HCS */ + if(mac_hcs != mac_hcs_calculated) + { + /* update the info column */ + col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "MAC Header CRC error"); + /* display message */ + pdu_item = proto_tree_add_protocol_format(tree, proto_wimax_pdu_decoder, tvb, offset, WIMAX_MAC_HEADER_SIZE, "MAC Header CRC error %X (in header) and %X (calculated)", mac_hcs, mac_hcs_calculated); + /* add subtree */ + pdu_tree = proto_item_add_subtree(pdu_item, ett_wimax_pdu_decoder); + /* display the bad MAC Header in Hex */ + proto_tree_add_item(pdu_tree, hf_wimax_value_bytes, tvb, offset, length, ENC_NA); + break; + } + /* get the Header Type (HT) */ + mac_ht = ((first_byte & WIMAX_MAC_HEADER_HT_FIELD)?1:0); + /* get the Encryption Control (EC) */ + mac_ec = ((first_byte & WIMAX_MAC_HEADER_EC_FIELD)?1:0); + /* update the MAC length for Generic MAC frame */ + if(!mac_ht) + { /* Generic MAC Header with payload */ + /* get the MAC length */ + length = (tvb_get_guint8(tvb, offset+1) & WIMAX_MAC_HEADER_LENGTH_MSB_MASK); + length = ((length<<8) | tvb_get_guint8(tvb, offset+2)); + } + else /* MAC signaling Headers or Bandwidth Request Headers */ + { /* set the mac length */ + length = WIMAX_MAC_HEADER_SIZE; + } + /* display PDU frame info */ + /* + pdu_item = proto_tree_add_protocol_format(tree, proto_wimax_pdu_decoder, tvb, offset, length, "PDU Frame (%u bytes)", length); + */ + pdu_item = proto_tree_add_protocol_format(tree, proto_wimax_pdu_decoder, tvb, offset, length, "PDU (%u bytes)", length); + /* add PDU subtree */ + pdu_tree = proto_item_add_subtree(pdu_item, ett_wimax_pdu_decoder); + if (length == 0) { + offset += 6; /* Add header size. */ + /* Must skip the code below or tvb_new_subset_length() + * keeps allocating memory until it runs out. */ + continue; + } + /* process the valid MAC header */ + if(mac_ht) + { /* MAC signaling Headers or Bandwidth Request Headers */ + /* check the header type */ + if(mac_ec) + { /* MAC Signaling Header Type II Header */ + proto_item_append_text(pdu_item, " - Mac Type II Header: "); + call_dissector(mac_header_type2_handle, tvb_new_subset_length(tvb,offset,length), pinfo, pdu_tree); + } + else + { /* MAC Signaling Header Type I Header */ + proto_item_append_text(pdu_item, " - Mac Type I Header: "); + call_dissector(mac_header_type1_handle, tvb_new_subset_length(tvb,offset,length), pinfo, pdu_tree); + } + } + else /* Generic MAC Header with payload */ + { + call_dissector(mac_generic_decoder_handle, tvb_new_subset_length(tvb,offset,length), pinfo, pdu_tree); + } + offset += length; + } + return tvb_captured_length(tvb); +} + +/* Register Wimax PDU Burst Protocol */ +void wimax_proto_register_wimax_pdu(void) +{ + /* PDU display */ + static hf_register_info hf[] = + { + { + &hf_wimax_value_bytes, + { + "Values", "wmx.pdu.value", + FT_BYTES, BASE_NONE, NULL, 0x0, + NULL, HFILL + } + }, + }; + + /* Setup protocol subtree array */ + static gint *ett[] = + { + &ett_wimax_pdu_decoder, + }; + + proto_wimax_pdu_decoder = proto_wimax; + + register_dissector("wimax_pdu_burst_handler", dissect_wimax_pdu_decoder, -1); + proto_register_field_array(proto_wimax_pdu_decoder, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); +} + +void +wimax_proto_reg_handoff_wimax_pdu(void) +{ + mac_generic_decoder_handle = find_dissector("mac_header_generic_handler"); + mac_header_type1_handle = find_dissector("mac_header_type_1_handler"); + mac_header_type2_handle = find_dissector("mac_header_type_2_handler"); + wimax_harq_map_handle = find_dissector("wimax_harq_map_handler"); +} + +/* + * 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: + */ |