Index: epan/dissectors/packet-gsmtap.c =================================================================== --- /dev/null +++ epan/dissectors/packet-gsmtap.c @@ -0,0 +1,345 @@ +/* packet-gsmtap.c + * Routines for GSMTAP captures + * + * (C) 2008-2010 by Harald Welte + * + * $Id$ + * + * 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., 59 Temple Place - Suite 330, Boston, MA + * 02111-1307, USA. + * + */ + +/* GSMTAP is a generic header format for GSM protocol captures, + * it uses the IANA-assigned UDP port number 4729 and carries + * payload in various formats of GSM interfaces such as Um MAC + * blocks or Um bursts. + * + * Example programs generating GSMTAP data are airprobe + * (http://airprobe.org/) or OsmocomBB (http://bb.osmocom.org/) + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include +#include +#include + +#include "packet-gsmtap.h" + +static int proto_gsmtap = -1; + +static int hf_gsmtap_version = -1; +static int hf_gsmtap_hdrlen = -1; +static int hf_gsmtap_type = -1; +static int hf_gsmtap_timeslot = -1; +static int hf_gsmtap_subslot = -1; +static int hf_gsmtap_arfcn = -1; +static int hf_gsmtap_uplink = -1; +static int hf_gsmtap_noise_dbm = -1; +static int hf_gsmtap_signal_dbm = -1; +static int hf_gsmtap_frame_nr = -1; +static int hf_gsmtap_burst_type = -1; +static int hf_gsmtap_channel_type = -1; +static int hf_gsmtap_antenna = -1; + +static int hf_sacch_l1h_power_lev = -1; +static int hf_sacch_l1h_fpc = -1; +static int hf_sacch_l1h_ta = -1; + +static gint ett_gsmtap = -1; + +enum { + GSMTAP_SUB_DATA = 0, + GSMTAP_SUB_UM, + GSMTAP_SUB_UM_LAPDM, + GSMTAP_SUB_ABIS, + + GSMTAP_SUB_MAX +}; + +static dissector_handle_t sub_handles[GSMTAP_SUB_MAX]; + +static const value_string gsmtap_bursts[] = { + { GSMTAP_BURST_UNKNOWN, "UNKNOWN" }, + { GSMTAP_BURST_FCCH, "FCCH" }, + { GSMTAP_BURST_PARTIAL_SCH, "PARTIAL SCH" }, + { GSMTAP_BURST_SCH, "SCH" }, + { GSMTAP_BURST_CTS_SCH, "CTS SCH" }, + { GSMTAP_BURST_COMPACT_SCH, "COMPACT SCH" }, + { GSMTAP_BURST_NORMAL, "NORMAL" }, + { GSMTAP_BURST_DUMMY, "DUMMY" }, + { GSMTAP_BURST_ACCESS, "RACH" }, + { 0, NULL }, +}; + +static const value_string gsmtap_channels[] = { + { GSMTAP_CHANNEL_UNKNOWN, "UNKNOWN" }, + { GSMTAP_CHANNEL_BCCH, "BCCH" }, + { GSMTAP_CHANNEL_CCCH, "CCCH" }, + { GSMTAP_CHANNEL_RACH, "RACH" }, + { GSMTAP_CHANNEL_AGCH, "AGCH" }, + { GSMTAP_CHANNEL_PCH, "PCH" }, + { GSMTAP_CHANNEL_SDCCH, "SDCCH" }, + { GSMTAP_CHANNEL_SDCCH4, "SDCCH/4" }, + { GSMTAP_CHANNEL_SDCCH8, "SDCCH/8" }, + { GSMTAP_CHANNEL_TCH_F, "FACCH/F" }, + { GSMTAP_CHANNEL_TCH_H, "FACCH/H" }, + { GSMTAP_CHANNEL_ACCH| + GSMTAP_CHANNEL_SDCCH, "LSACCH" }, + { GSMTAP_CHANNEL_ACCH| + GSMTAP_CHANNEL_SDCCH4, "SACCH/4" }, + { GSMTAP_CHANNEL_ACCH| + GSMTAP_CHANNEL_SDCCH8, "SACCH/8" }, + { GSMTAP_CHANNEL_ACCH| + GSMTAP_CHANNEL_TCH_F, "SACCH/F" }, + { GSMTAP_CHANNEL_ACCH| + GSMTAP_CHANNEL_TCH_F, "SACCH/H" }, + { 0, NULL }, +}; + +static const value_string gsmtap_types[] = { + { GSMTAP_TYPE_UM, "GSM Um (MS<->BTS)" }, + { GSMTAP_TYPE_ABIS, "GSM Abis (BTS<->BSC)" }, + { GSMTAP_TYPE_UM_BURST, "GSM Um burst (MS<->BTS)" }, + { 0, NULL }, +}; + +/* dissect a SACCH L1 header which is included in the first 2 bytes + * of every SACCH frame (according to TS 04.04) */ +static void +dissect_sacch_l1h(tvbuff_t *tvb, proto_tree *tree) +{ + proto_item *ti; + proto_tree *l1h_tree = NULL; + + if (!tree) + return; + + ti = proto_tree_add_protocol_format(tree, proto_gsmtap, tvb, 0, 2, + "SACCH L1 Header, Power Level: %u, Timing Advance: %u", + tvb_get_guint8(tvb, 0) & 0x1f, + tvb_get_guint8(tvb, 1)); + l1h_tree = proto_item_add_subtree(ti, ett_gsmtap); + /* Power Level */ + proto_tree_add_item(l1h_tree, hf_sacch_l1h_power_lev, tvb, 0, 1, FALSE); + /* Fast Power Control */ + proto_tree_add_item(l1h_tree, hf_sacch_l1h_fpc, tvb, 0, 1, FALSE); + /* Acutal Timing Advance */ + proto_tree_add_item(l1h_tree, hf_sacch_l1h_ta, tvb, 1, 1, FALSE); +} + +/* dissect a GSMTAP header and hand payload off to respective dissector */ +static void +dissect_gsmtap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) +{ + int sub_handle, len, offset = 0; + proto_item *ti; + proto_tree *gsmtap_tree = NULL; + tvbuff_t *payload_tvb, *l1h_tvb = NULL; + guint8 hdr_len, type, sub_type; + guint16 arfcn; + + len = tvb_length(tvb); + + hdr_len = tvb_get_guint8(tvb, offset + 1) <<2; + type = tvb_get_guint8(tvb, offset + 2); + sub_type = tvb_get_guint8(tvb, offset + 12); + arfcn = tvb_get_ntohs(tvb, offset + 4); + + /* In case of a SACCH, there is a two-byte L1 header in front + * of the packet (see TS 04.04) */ + if (type == GSMTAP_TYPE_UM && + sub_type & GSMTAP_CHANNEL_ACCH) { + l1h_tvb = tvb_new_subset(tvb, hdr_len, 2, 2); + payload_tvb = tvb_new_subset(tvb, hdr_len+2, len-(hdr_len+2), + len-(hdr_len+2)); + } else { + payload_tvb = tvb_new_subset(tvb, hdr_len, len-hdr_len, + len-hdr_len); + } + + /* We don't want any UDP related info left in the INFO field, as the + * gsm_a_dtap dissector will not clear but only append */ + col_clear(pinfo->cinfo, COL_INFO); + + col_set_str(pinfo->cinfo, COL_PROTOCOL, "GSMTAP"); + + if (arfcn & GSMTAP_ARFCN_F_UPLINK) { + col_append_str(pinfo->cinfo, COL_RES_NET_SRC, "MS"); + col_append_str(pinfo->cinfo, COL_RES_NET_DST, "BTS"); + /* p2p_dir is used by the LAPDm dissector */ + pinfo->p2p_dir = P2P_DIR_SENT; + } else { + col_set_str(pinfo->cinfo, COL_RES_NET_SRC, "BTS"); + switch (sub_type & ~GSMTAP_CHANNEL_ACCH) { + case GSMTAP_CHANNEL_BCCH: + case GSMTAP_CHANNEL_CCCH: + case GSMTAP_CHANNEL_PCH: + case GSMTAP_CHANNEL_AGCH: + col_set_str(pinfo->cinfo, COL_RES_NET_DST, "Broadcast"); + break; + default: + col_set_str(pinfo->cinfo, COL_RES_NET_DST, "MS"); + break; + } + /* p2p_dir is used by the LAPDm dissector */ + pinfo->p2p_dir = P2P_DIR_RECV; + } + + if (tree) { + ti = proto_tree_add_protocol_format(tree, proto_gsmtap, tvb, 0, hdr_len, + "GSM TAP Header, ARFCN: %u (%s), TS: %u, Channel: %s (%u)", + arfcn & GSMTAP_ARFCN_MASK, + arfcn & GSMTAP_ARFCN_F_UPLINK ? "Uplink" : "Downlink", + tvb_get_guint8(tvb, offset+3), + match_strval(tvb_get_guint8(tvb, offset+12), gsmtap_channels), + tvb_get_guint8(tvb, offset+14)); + gsmtap_tree = proto_item_add_subtree(ti, ett_gsmtap); + proto_tree_add_item(gsmtap_tree, hf_gsmtap_version, + tvb, offset, 1, FALSE); + proto_tree_add_uint_format(gsmtap_tree, hf_gsmtap_hdrlen, + tvb, offset+1, 1, hdr_len, + "Header length: %u bytes", hdr_len); + proto_tree_add_item(gsmtap_tree, hf_gsmtap_type, + tvb, offset+2, 1, FALSE); + proto_tree_add_item(gsmtap_tree, hf_gsmtap_timeslot, + tvb, offset+3, 1, FALSE); + proto_tree_add_item(gsmtap_tree, hf_gsmtap_arfcn, + tvb, offset+4, 2, FALSE); + proto_tree_add_item(gsmtap_tree, hf_gsmtap_uplink, + tvb, offset+4, 2, FALSE); + proto_tree_add_item(gsmtap_tree, hf_gsmtap_noise_dbm, + tvb, offset+6, 1, FALSE); + proto_tree_add_item(gsmtap_tree, hf_gsmtap_signal_dbm, + tvb, offset+7, 1, FALSE); + proto_tree_add_item(gsmtap_tree, hf_gsmtap_frame_nr, + tvb, offset+8, 4, FALSE); + if (type == GSMTAP_TYPE_UM_BURST) + proto_tree_add_item(gsmtap_tree, hf_gsmtap_burst_type, + tvb, offset+12, 1, FALSE); + else if (type == GSMTAP_TYPE_UM) + proto_tree_add_item(gsmtap_tree, hf_gsmtap_channel_type, + tvb, offset+12, 1, FALSE); + proto_tree_add_item(gsmtap_tree, hf_gsmtap_antenna, + tvb, offset+13, 1, FALSE); + proto_tree_add_item(gsmtap_tree, hf_gsmtap_subslot, + tvb, offset+14, 1, FALSE); + } + + switch (type) { + case GSMTAP_TYPE_UM: + if (l1h_tvb) + dissect_sacch_l1h(l1h_tvb, tree); + switch (sub_type & ~GSMTAP_CHANNEL_ACCH) { + case GSMTAP_CHANNEL_BCCH: + case GSMTAP_CHANNEL_CCCH: + case GSMTAP_CHANNEL_PCH: + case GSMTAP_CHANNEL_AGCH: + /* FIXME: we might want to skip idle frames */ + sub_handle = GSMTAP_SUB_UM; + break; + case GSMTAP_CHANNEL_SDCCH: + case GSMTAP_CHANNEL_SDCCH4: + case GSMTAP_CHANNEL_SDCCH8: + case GSMTAP_CHANNEL_TCH_F: + case GSMTAP_CHANNEL_TCH_H: + sub_handle = GSMTAP_SUB_UM_LAPDM; + break; + case GSMTAP_CHANNEL_RACH: + default: + sub_handle = GSMTAP_SUB_DATA; + break; + } + break; + case GSMTAP_TYPE_UM_BURST: + default: + sub_handle = GSMTAP_SUB_DATA; + break; + } + call_dissector(sub_handles[sub_handle], payload_tvb, pinfo, tree); +} + +static const true_false_string sacch_l1h_fpc_mode_vals = { + "In use", + "Not in use" +}; + +void +proto_register_gsmtap(void) +{ + static hf_register_info hf[] = { + { &hf_gsmtap_version, { "Version", "gsmtap.version", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } }, + { &hf_gsmtap_hdrlen, { "Header Length", "gsmtap.hdr_len", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } }, + { &hf_gsmtap_type, { "Payload Type", "gsmtap.type", + FT_UINT8, BASE_DEC, VALS(gsmtap_types), 0, NULL, HFILL } }, + { &hf_gsmtap_timeslot, { "Time Slot", "gsmtap.ts", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } }, + { &hf_gsmtap_arfcn, { "ARFCN", "gsmtap.arfcn", + FT_UINT16, BASE_DEC, NULL, GSMTAP_ARFCN_MASK, NULL, HFILL } }, + { &hf_gsmtap_uplink, { "Uplink", "gsmtap.uplink", + FT_UINT16, BASE_DEC, NULL, GSMTAP_ARFCN_F_UPLINK, NULL, HFILL } }, + { &hf_gsmtap_noise_dbm, { "Signal/Noise Ratio (dB)", "gsmtap.snr_db", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } }, + { &hf_gsmtap_signal_dbm, { "Signal Level (dBm)", "gsmtap.signal_dbm", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } }, + { &hf_gsmtap_frame_nr, { "GSM Frame Number", "gsmtap.frame_nr", + FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL } }, + { &hf_gsmtap_burst_type, { "Burst Type", "gsmtap.burst_type", + FT_UINT8, BASE_DEC, VALS(gsmtap_bursts), 0, NULL, HFILL }}, + { &hf_gsmtap_channel_type, { "Channel Type", "gsmtap.chan_type", + FT_UINT8, BASE_DEC, VALS(gsmtap_channels), 0, NULL, HFILL }}, + { &hf_gsmtap_antenna, { "Antenna Number", "gsmtap.antenna", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } }, + { &hf_gsmtap_subslot, { "Sub-Slot", "gsmtap.sub_slot", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } }, + + { &hf_sacch_l1h_power_lev, { "MS power level", "gsmtap.sacch_l1.power_lev", + FT_UINT8, BASE_DEC, NULL, 0x1f, NULL, HFILL } }, + { &hf_sacch_l1h_fpc, { "FPC", "gsmtap.sacch_l1.fpc", + FT_BOOLEAN, 8, TFS(&sacch_l1h_fpc_mode_vals), 0x04, + NULL, HFILL } }, + { &hf_sacch_l1h_ta, { "Actual Timing Advance", "gsmtap.sacch_l1.ta", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } }, + }; + static gint *ett[] = { + &ett_gsmtap + }; + + proto_gsmtap = proto_register_protocol("GSM Radiotap", "GSMTAP", "gsmtap"); + proto_register_field_array(proto_gsmtap, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); +} + +void +proto_reg_handoff_gsmtap(void) +{ + dissector_handle_t gsmtap_handle; + + sub_handles[GSMTAP_SUB_DATA] = find_dissector("data"); + sub_handles[GSMTAP_SUB_UM] = find_dissector("gsm_a_ccch"); + sub_handles[GSMTAP_SUB_UM_LAPDM] = find_dissector("lapdm"); + sub_handles[GSMTAP_SUB_ABIS] = find_dissector("gsm_a_dtap"); + gsmtap_handle = create_dissector_handle(dissect_gsmtap, proto_gsmtap); + dissector_add("udp.port", GSMTAP_UDP_PORT, gsmtap_handle); +} Index: epan/dissectors/packet-gsmtap.h =================================================================== --- /dev/null +++ epan/dissectors/packet-gsmtap.h @@ -0,0 +1,70 @@ +#ifndef _GSMTAP_H +#define _GSMTAP_H + +/* gsmtap header, pseudo-header in front of the actua/ GSM payload */ + +/* GSMTAP is a generic header format for GSM protocol captures, + * it uses the IANA-assigned UDP port number 4729 and carries + * payload in various formats of GSM interfaces such as Um MAC + * blocks or Um bursts. + * + * Example programs generating GSMTAP data are airprobe + * (http://airprobe.org/) or OsmocomBB (http://bb.osmocom.org/) + */ + +#define GSMTAP_TYPE_UM 0x01 +#define GSMTAP_TYPE_ABIS 0x02 +#define GSMTAP_TYPE_UM_BURST 0x03 /* raw burst bits */ + +#define GSMTAP_BURST_UNKNOWN 0x00 +#define GSMTAP_BURST_FCCH 0x01 +#define GSMTAP_BURST_PARTIAL_SCH 0x02 +#define GSMTAP_BURST_SCH 0x03 +#define GSMTAP_BURST_CTS_SCH 0x04 +#define GSMTAP_BURST_COMPACT_SCH 0x05 +#define GSMTAP_BURST_NORMAL 0x06 +#define GSMTAP_BURST_DUMMY 0x07 +#define GSMTAP_BURST_ACCESS 0x08 +#define GSMTAP_BURST_NONE 0x09 + +#define GSMTAP_CHANNEL_UNKNOWN 0x00 +#define GSMTAP_CHANNEL_BCCH 0x01 +#define GSMTAP_CHANNEL_CCCH 0x02 +#define GSMTAP_CHANNEL_RACH 0x03 +#define GSMTAP_CHANNEL_AGCH 0x04 +#define GSMTAP_CHANNEL_PCH 0x05 +#define GSMTAP_CHANNEL_SDCCH 0x06 +#define GSMTAP_CHANNEL_SDCCH4 0x07 +#define GSMTAP_CHANNEL_SDCCH8 0x08 +#define GSMTAP_CHANNEL_TCH_F 0x09 +#define GSMTAP_CHANNEL_TCH_H 0x0a +#define GSMTAP_CHANNEL_ACCH 0x80 + +#define GSMTAP_ARFCN_F_PCS 0x8000 +#define GSMTAP_ARFCN_F_UPLINK 0x4000 +#define GSMTAP_ARFCN_MASK 0x3fff + +#define GSMTAP_UDP_PORT 4729 + +/* This is the header as it is used by gsmtap-generating software. + * It is not used by the wireshark dissector and provided for reference only. +struct gsmtap_hdr { + guint8 version; // version, set to 0x01 currently + guint8 hdr_len; // length in number of 32bit words + guint8 type; // see GSMTAP_TYPE_* + guint8 timeslot; // timeslot (0..7 on Um) + + guint16 arfcn; // ARFCN (frequency) + gint8 signal_dbm; // signal level in dBm + gint8 snr_db; // signal/noise ratio in dB + + guint32 frame_number; // GSM Frame Number (FN) + + guint8 sub_type; // Type of burst/channel, see above + guint8 antenna_nr; // Antenna Number + guint8 sub_slot; // sub-slot within timeslot + guint8 res; // reserved for future use (RFU) +} + */ + +#endif /* _GSMTAP_H */ Index: epan/dissectors/Makefile.common =================================================================== --- epan/dissectors/Makefile.common.orig +++ epan/dissectors/Makefile.common @@ -484,6 +484,7 @@ packet-gsm_sms.c \ packet-gsm_sms_ud.c \ packet-gsm_um.c \ + packet-gsmtap.c \ packet-gssapi.c \ packet-gtp.c \ packet-gtpv2.c \ @@ -1072,6 +1073,7 @@ packet-gsm_a_common.h \ packet-gsm_map.h \ packet-gsm_sms.h \ + packet-gsmtap.h \ packet-gssapi.h \ packet-gtp.h \ packet-h223.h \