/* packet-cwids.c * Routines for dissecting wireless ids packets sent from a Cisco * access point to the WLSE (or whatever) * * Copyright 2006 Joerg Mayer (see AUTHORS file) * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ /* With current IOS, you can use Cisco wireless Bridges/APs as * wireless sniffers and configure them to send the data to some * central IDS: * interface dot11Radio 0 * station-role scanner * monitor frames endpoint ip address 172.22.1.1 port 8999 truncate 2312 * These frames are raw, i.e. they don't have a pcap header. * Running wireshark at the receiving end will provide those. */ /* 2do: * - Find out more about the contents of the capture header * - Protect the address fields etc (all columns?) * - Create subelements and put each header and packet into it * - fuzz-test the dissector * - Find some heuristic to detect the packet automagically and * convert dissector into a heuristic dissector * - Is the TRY/CATCH stuff OK? */ #include "config.h" #include #include #include #include #include static int proto_cwids = -1; static int hf_cwids_version = -1; static int hf_cwids_timestamp = -1; static int hf_cwids_unknown1 = -1; static int hf_cwids_channel = -1; static int hf_cwids_unknown2 = -1; static int hf_cwids_reallength = -1; static int hf_cwids_capturelen = -1; static int hf_cwids_unknown3 = -1; static gint ett_cwids = -1; static expert_field ie_ieee80211_subpacket = EI_INIT; static dissector_handle_t cwids_handle; static dissector_handle_t ieee80211_radio_handle; static int dissect_cwids(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { tvbuff_t *wlan_tvb; proto_tree *ti, *cwids_tree; volatile int offset = 0; guint16 capturelen; col_set_str(pinfo->cinfo, COL_PROTOCOL, "CWIDS"); col_set_str(pinfo->cinfo, COL_INFO, "Cwids: "); /* FIXME: col_set_fence(pinfo->cinfo, all-cols, only addr-cols?); */ cwids_tree = NULL; while(tvb_reported_length_remaining(tvb, offset) > 0) { struct ieee_802_11_phdr phdr; ti = proto_tree_add_item(tree, proto_cwids, tvb, offset, 28, ENC_NA); cwids_tree = proto_item_add_subtree(ti, ett_cwids); memset(&phdr, 0, sizeof(phdr)); phdr.fcs_len = 0; /* no FCS */ phdr.decrypted = FALSE; phdr.datapad = FALSE; phdr.phy = PHDR_802_11_PHY_UNKNOWN; proto_tree_add_item(cwids_tree, hf_cwids_version, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; proto_tree_add_item(cwids_tree, hf_cwids_timestamp, tvb, offset, 6, ENC_NA); offset += 6; proto_tree_add_item(cwids_tree, hf_cwids_unknown1, tvb, offset, 1, ENC_NA); offset += 1; phdr.has_channel = TRUE; phdr.channel = tvb_get_guint8(tvb, offset); proto_tree_add_item(cwids_tree, hf_cwids_channel, tvb, offset, 1, ENC_BIG_ENDIAN); offset += 1; proto_tree_add_item(cwids_tree, hf_cwids_unknown2, tvb, offset, 6, ENC_NA); offset += 6; proto_tree_add_item(cwids_tree, hf_cwids_reallength, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; capturelen = tvb_get_ntohs(tvb, offset); proto_tree_add_item(cwids_tree, hf_cwids_capturelen, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; proto_tree_add_item(cwids_tree, hf_cwids_unknown3, tvb, offset, 8, ENC_NA); offset += 8; wlan_tvb = tvb_new_subset_length(tvb, offset, capturelen); /* Continue after ieee80211 dissection errors */ TRY { call_dissector_with_data(ieee80211_radio_handle, wlan_tvb, pinfo, tree, &phdr); } CATCH_BOUNDS_ERRORS { show_exception(wlan_tvb, pinfo, tree, EXCEPT_CODE, GET_MESSAGE); expert_add_info(pinfo, ti, &ie_ieee80211_subpacket); } ENDTRY; offset += capturelen; } return tvb_captured_length(tvb); } void proto_register_cwids(void); void proto_reg_handoff_cwids(void); void proto_register_cwids(void) { static hf_register_info hf[] = { { &hf_cwids_version, { "Capture Version", "cwids.version", FT_UINT16, BASE_DEC, NULL, 0x0, "Version or format of record", HFILL }}, { &hf_cwids_timestamp, { "Timestamp [us]", "cwids.timestamp", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }}, { &hf_cwids_unknown1, { "Unknown1", "cwids.unknown1", FT_BYTES, BASE_NONE, NULL, 0x0, "1st Unknown block", HFILL }}, { &hf_cwids_channel, { "Channel", "cwids.channel", FT_UINT8, BASE_DEC, NULL, 0x0, "Channel for this capture", HFILL }}, { &hf_cwids_unknown2, { "Unknown2", "cwids.unknown2", FT_BYTES, BASE_NONE, NULL, 0x0, "2nd Unknown block", HFILL }}, { &hf_cwids_reallength, { "Original length", "cwids.reallen", FT_UINT16, BASE_DEC, NULL, 0x0, "Original num bytes in frame", HFILL }}, { &hf_cwids_capturelen, { "Capture length", "cwids.caplen", FT_UINT16, BASE_DEC, NULL, 0x0, "Captured bytes in record", HFILL }}, { &hf_cwids_unknown3, { "Unknown3", "cwids.unknown3", FT_BYTES, BASE_NONE, NULL, 0x0, "3rd Unknown block", HFILL }}, }; static gint *ett[] = { &ett_cwids, }; static ei_register_info ei[] = { { &ie_ieee80211_subpacket, { "cwids.ieee80211_malformed", PI_MALFORMED, PI_ERROR, "Malformed or short IEEE80211 subpacket", EXPFILL }}, }; expert_module_t* expert_cwids; proto_cwids = proto_register_protocol("Cisco Wireless IDS Captures", "CWIDS", "cwids"); proto_register_field_array(proto_cwids, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); expert_cwids = expert_register_protocol(proto_cwids); expert_register_field_array(expert_cwids, ei, array_length(ei)); cwids_handle = register_dissector("cwids", dissect_cwids, proto_cwids); } void proto_reg_handoff_cwids(void) { dissector_add_for_decode_as_with_preference("udp.port", cwids_handle); ieee80211_radio_handle = find_dissector_add_dependency("wlan_noqos_radio", proto_cwids); } /* * Editor modelines - https://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: */