osmith
/
wireshark
forked from osmocom/wireshark
1
0
Fork 0
Code Pull Requests Releases Wiki Activity
wireshark/epan/dissectors/packet-gsm_osmux.c

307 lines
9.7 KiB
C
Raw Blame History

/* packet-gsm_osmux.c
* Routines for packet dissection of Osmux voice/signalling multiplex protocol
* Copyright 2016 sysmocom s.f.m.c Daniel Willmann <dwillmann@sysmocom.de>
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <string.h>
#include <stdio.h>
#include <epan/packet.h>
#include <epan/stats_tree.h>
#include <epan/tap.h>
#include <epan/to_str.h>
#include <epan/strutil.h>
#include "packet-gsm_osmux.h"
void proto_register_osmux(void);
void proto_reg_handoff_osmux(void);
static const value_string osmux_ft_vals[] =
{
{0x00, "Signalling"},
{0x01, "AMR"},
{0x02, "Dummy"},
{0, NULL}
};
/* Initialize the protocol and registered fields */
static dissector_handle_t osmux_handle;
static int proto_osmux = -1;
static int osmux_tap = -1;
static int hf_osmux_ft_ctr = -1;
static int hf_osmux_ft = -1;
static int hf_osmux_ctr = -1;
static int hf_osmux_amr_f = -1;
static int hf_osmux_amr_q = -1;
static int hf_osmux_seq = -1;
static int hf_osmux_circuit_id = -1;
static int hf_osmux_amr_ft_cmr = -1;
static int hf_osmux_amr_ft = -1;
static int hf_osmux_amr_cmr = -1;
static int hf_osmux_amr_data = -1;
/* Initialize the subtree pointers */
static gint ett_osmux = -1;
static gint ett_osmux_ft_ctr = -1;
static gint ett_osmux_amr_ft_cmr = -1;
/* Code to actually dissect the packets */
static gint
dissect_osmux(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
static const gint *ft_ctr_fields[] = {
&hf_osmux_ft,
&hf_osmux_ctr,
&hf_osmux_amr_f,
&hf_osmux_amr_q,
NULL
};
static const gint *amr_ft_cmr_fields[] = {
&hf_osmux_amr_ft,
&hf_osmux_amr_cmr,
NULL
};
int offset = 0;
struct osmux_hdr *osmuxh;
proto_item *ti;
proto_tree *osmux_tree = NULL;
guint8 ft_ctr;
guint32 cid;
guint64 amr_ft_cmr;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "Osmux");
col_clear(pinfo->cinfo, COL_INFO);
osmuxh = wmem_new0(wmem_packet_scope(), struct osmux_hdr);
ft_ctr = tvb_get_guint8(tvb, offset);
osmuxh->ft = ft_ctr >> 5;
osmuxh->ctr = (ft_ctr >> 2) & 0x7;
osmuxh->amr_q = !!(ft_ctr & 0x02);
osmuxh->amr_f = !!(ft_ctr & 0x01);
col_append_fstr(pinfo->cinfo, COL_INFO, "Osmux ");
ti = proto_tree_add_protocol_format(tree, proto_osmux, tvb, offset, -1,
"Osmux type %s frame",
val_to_str(osmuxh->ft, osmux_ft_vals, "unknown 0x%02x"));
osmux_tree = proto_item_add_subtree(ti, ett_osmux);
/* Two-byte dummy packets for firewalls (starts with 0x23) */
if (ft_ctr == 0x23 && tvb_reported_length(tvb) >= 2) {
proto_tree_add_item_ret_uint(osmux_tree, hf_osmux_circuit_id, tvb, offset+1, 1, ENC_BIG_ENDIAN, &cid);
col_append_fstr(pinfo->cinfo, COL_INFO, "Dummy frame (CID %u)", cid);
return 2;
}
col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
val_to_str(osmuxh->ft, osmux_ft_vals,
"unknown 0x%02x"));
proto_tree_add_bitmask(osmux_tree, tvb, offset, hf_osmux_ft_ctr,
ett_osmux_ft_ctr, ft_ctr_fields, ENC_BIG_ENDIAN);
offset++;
proto_tree_add_item_ret_uint(osmux_tree, hf_osmux_seq, tvb, offset, 1, ENC_BIG_ENDIAN, &osmuxh->seq);
offset++;
proto_tree_add_item_ret_uint(osmux_tree, hf_osmux_circuit_id, tvb, offset, 1, ENC_BIG_ENDIAN, &osmuxh->circuit_id);
offset++;
proto_tree_add_bitmask_ret_uint64(osmux_tree, tvb, offset, hf_osmux_amr_ft_cmr,
ett_osmux_amr_ft_cmr, amr_ft_cmr_fields, ENC_BIG_ENDIAN, &amr_ft_cmr);
offset++;
osmuxh->amr_ft = (guint32)(amr_ft_cmr & 0xf0) >> 4;
osmuxh->amr_cmr = (guint32)amr_ft_cmr & 0x0f;
proto_tree_add_item(osmux_tree, hf_osmux_amr_data, tvb, offset, tvb_reported_length_remaining(tvb, offset), ENC_NA);
tap_queue_packet(osmux_tap, pinfo, osmuxh);
return tvb_reported_length(tvb);
}
/* Statistics */
static const gchar *st_str_pkts = "Osmux Packets";
static const gchar *st_str_pkts_by_cid = "Osmux Packets by CID";
static const gchar *st_str_pkts_by_ctr = "Osmux Packets by AMR frame count";
static const gchar *st_str_pkts_by_src = "Osmux Packets by src Addr";
static const gchar *st_str_pkts_by_dst = "Osmux Packets by dst Addr";
static const gchar *st_str_pkts_by_conn = "Osmux Packets by stream";
static int st_osmux_stats = -1;
static int st_osmux_stats_cid = -1;
static int st_osmux_stats_ctr = -1;
static int st_osmux_stats_src = -1;
static int st_osmux_stats_dst = -1;
static int st_osmux_stats_conn = -1;
static void osmux_stats_tree_init(stats_tree *st)
{
st_osmux_stats = stats_tree_create_node(st, st_str_pkts, 0, TRUE);
st_osmux_stats_cid = stats_tree_create_node(st, st_str_pkts_by_cid, st_osmux_stats, TRUE);
st_osmux_stats_ctr = stats_tree_create_node(st, st_str_pkts_by_ctr, st_osmux_stats, TRUE);
st_osmux_stats_src = stats_tree_create_node(st, st_str_pkts_by_src, st_osmux_stats, TRUE);
st_osmux_stats_dst = stats_tree_create_node(st, st_str_pkts_by_dst, st_osmux_stats, TRUE);
st_osmux_stats_conn = stats_tree_create_node(st, st_str_pkts_by_conn, st_osmux_stats, TRUE);
}
static int osmux_stats_tree_packet(stats_tree *st, packet_info *pinfo,
epan_dissect_t *edt _U_, const void *p _U_)
{
gchar *ip_str, *ip2_str;
gchar temp[40];
struct osmux_hdr *osmuxh = (struct osmux_hdr*) p;
tick_stat_node(st, st_str_pkts, 0, FALSE);
tick_stat_node(st, st_str_pkts_by_cid, st_osmux_stats, FALSE);
g_snprintf(temp, 30, "%i", osmuxh->circuit_id);
tick_stat_node(st, temp, st_osmux_stats_cid, TRUE);
tick_stat_node(st, st_str_pkts_by_ctr, st_osmux_stats, FALSE);
g_snprintf(temp, 30, "%i", osmuxh->ctr);
tick_stat_node(st, temp, st_osmux_stats_ctr, TRUE);
tick_stat_node(st, st_str_pkts_by_src, 0, FALSE);
ip_str = address_to_str(NULL, &pinfo->src);
tick_stat_node(st, ip_str, st_osmux_stats_src, TRUE);
tick_stat_node(st, st_str_pkts_by_dst, 0, FALSE);
ip2_str = address_to_str(NULL, &pinfo->dst);
tick_stat_node(st, ip2_str, st_osmux_stats_dst, TRUE);
tick_stat_node(st, st_str_pkts_by_conn, 0, FALSE);
g_snprintf(temp, 40, "%s->%s:%i", ip_str, ip2_str, osmuxh->circuit_id);
tick_stat_node(st, temp, st_osmux_stats_conn, TRUE);
wmem_free(NULL, ip_str);
wmem_free(NULL, ip2_str);
return 1;
}
void proto_register_osmux(void)
{
static hf_register_info hf[] = {
{&hf_osmux_ft_ctr,
{"FTCTRByte", "osmux.ft_ctr",
FT_UINT8, BASE_DEC, NULL, 0x00,
"Byte with Fieldtype, Counter", HFILL}
},
{&hf_osmux_ft,
{"FieldType", "osmux.ft",
FT_UINT8, BASE_DEC, VALS(osmux_ft_vals), 0xe0,
"Type of data in packet", HFILL}
},
{&hf_osmux_ctr,
{"CTR", "osmux.ctr",
FT_UINT8, BASE_HEX, NULL, 0x1c,
"Number of AMR packets inside", HFILL}
},
{&hf_osmux_amr_q,
{"AMR f", "osmux.amr_f",
FT_BOOLEAN, 8, NULL, 0x02,
"AMR f parameter", HFILL}
},
{&hf_osmux_amr_f,
{"AMR q", "osmux.amr_q",
FT_BOOLEAN, 8, NULL, 0x01,
"AMR q parameter", HFILL}
},
{&hf_osmux_seq,
{"Seq", "osmux.seq",
FT_UINT8, BASE_HEX, NULL, 0x0,
"Sequence number", HFILL}
},
{&hf_osmux_circuit_id,
{"Circuit ID", "osmux.circuit_id",
FT_UINT8, BASE_HEX, NULL, 0x0,
NULL, HFILL}
},
{&hf_osmux_amr_ft_cmr,
{"AMR info", "osmux.amr_ft_cmr",
FT_UINT8, BASE_DEC, NULL, 0x00,
"Byte with AMR params ft and cmr", HFILL}
},
{&hf_osmux_amr_ft,
{"AMR ft", "osmux.amr_ft",
FT_UINT8, BASE_HEX, NULL, 0xf0,
"AMR parameter ft", HFILL}
},
{&hf_osmux_amr_cmr,
{"AMR cmr", "osmux.amr_cmr",
FT_UINT8, BASE_HEX, NULL, 0x0f,
"AMR parameter cmr", HFILL}
},
{&hf_osmux_amr_data,
{"AMR data", "osmux.amr_data",
FT_BYTES, BASE_NONE, NULL, 0x00,
"AMR voice data", HFILL}
},
};
static gint *ett[] = {
&ett_osmux,
&ett_osmux_ft_ctr,
&ett_osmux_amr_ft_cmr,
};
proto_osmux = proto_register_protocol("GSM multiplexing for AMR", "GSM Osmux", "osmux");
proto_register_field_array(proto_osmux, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void proto_reg_handoff_osmux(void)
{
osmux_handle = create_dissector_handle(dissect_osmux, proto_osmux);
dissector_add_for_decode_as_with_preference("udp.port", osmux_handle);
osmux_tap = register_tap("osmux");
stats_tree_register("osmux", "osmux", "Osmux/Packets", 0,
osmux_stats_tree_packet, osmux_stats_tree_init,
NULL);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
View Git Blame Copy Permalink