--- /dev/null
+/* packet-gsmtap.c
+ * Routines for GSMTAP captures
+ *
+ * (C) 2008-2010 by Harald Welte <laforge@gnumonks.org>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * 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 <glib.h>
+#include <epan/packet.h>
+#include <epan/prefs.h>
+
+#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)
+}
+ */
+
+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);
+}
git.samba.org / obnox / wireshark / wip.git / commitdiff