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|
/* Routines for LTE MAC disassembly
*
* Martin Mathieson
*
* $Id$
*
* 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.
*
* 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.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <string.h>
#include <epan/packet.h>
#include <epan/expert.h>
#include <epan/prefs.h>
#include <epan/tap.h>
#include "packet-mac-lte.h"
/* Described in:
* 3GPP TS 36.321 Evolved Universal Terrestrial Radio Access (E-UTRA)
* Medium Access Control (MAC) protocol specification (Release 8)
*/
/* TODO:
- more testing of control bodies
- TDD mode
- add a preference so that padding can be verified against an expected pattern?
*/
/* Initialize the protocol and registered fields. */
int proto_mac_lte = -1;
static int mac_lte_tap = -1;
/* Decoding context */
static int hf_mac_lte_context_radio_type = -1;
static int hf_mac_lte_context_direction = -1;
static int hf_mac_lte_context_rnti = -1;
static int hf_mac_lte_context_rnti_type = -1;
static int hf_mac_lte_context_ueid = -1;
static int hf_mac_lte_context_subframe_number = -1;
static int hf_mac_lte_context_predefined_frame = -1;
static int hf_mac_lte_context_length = -1;
static int hf_mac_lte_context_bch_transport_channel = -1;
static int hf_mac_lte_context_retx_count = -1;
static int hf_mac_lte_context_crc_status = -1;
/* MAC SCH header fields */
static int hf_mac_lte_ulsch_header = -1;
static int hf_mac_lte_dlsch_header = -1;
static int hf_mac_lte_sch_subheader = -1;
static int hf_mac_lte_sch_reserved = -1;
static int hf_mac_lte_dlsch_lcid = -1;
static int hf_mac_lte_ulsch_lcid = -1;
static int hf_mac_lte_sch_extended = -1;
static int hf_mac_lte_sch_format = -1;
static int hf_mac_lte_sch_length = -1;
static int hf_mac_lte_sch_header_only = -1;
/* Data */
static int hf_mac_lte_sch_sdu = -1;
static int hf_mac_lte_bch_pdu = -1;
static int hf_mac_lte_pch_pdu = -1;
static int hf_mac_lte_predefined_pdu = -1;
static int hf_mac_lte_padding_data = -1;
static int hf_mac_lte_padding_length = -1;
/* RAR fields */
static int hf_mac_lte_rar = -1;
static int hf_mac_lte_rar_headers = -1;
static int hf_mac_lte_rar_header = -1;
static int hf_mac_lte_rar_extension = -1;
static int hf_mac_lte_rar_t = -1;
static int hf_mac_lte_rar_bi = -1;
static int hf_mac_lte_rar_rapid = -1;
static int hf_mac_lte_rar_reserved = -1;
static int hf_mac_lte_rar_body = -1;
static int hf_mac_lte_rar_reserved2 = -1;
static int hf_mac_lte_rar_ta = -1;
static int hf_mac_lte_rar_ul_grant = -1;
static int hf_mac_lte_rar_ul_grant_hopping = -1;
static int hf_mac_lte_rar_ul_grant_fsrba = -1;
static int hf_mac_lte_rar_ul_grant_tmcs = -1;
static int hf_mac_lte_rar_ul_grant_tcsp = -1;
static int hf_mac_lte_rar_ul_grant_ul_delay = -1;
static int hf_mac_lte_rar_ul_grant_cqi_request = -1;
static int hf_mac_lte_rar_temporary_crnti = -1;
/* Common channel control values */
static int hf_mac_lte_control_lcg_id = -1;
static int hf_mac_lte_control_buffer_size = -1;
static int hf_mac_lte_control_buffer_size_1 = -1;
static int hf_mac_lte_control_buffer_size_2 = -1;
static int hf_mac_lte_control_buffer_size_3 = -1;
static int hf_mac_lte_control_buffer_size_4 = -1;
static int hf_mac_lte_control_crnti = -1;
static int hf_mac_lte_control_timing_advance = -1;
static int hf_mac_lte_control_ue_contention_resolution_identity = -1;
static int hf_mac_lte_control_power_headroom_reserved = -1;
static int hf_mac_lte_control_power_headroom = -1;
static int hf_mac_lte_control_padding = -1;
/* Subtrees. */
static int ett_mac_lte = -1;
static int ett_mac_lte_context = -1;
static int ett_mac_lte_ulsch_header = -1;
static int ett_mac_lte_dlsch_header = -1;
static int ett_mac_lte_sch_subheader = -1;
static int ett_mac_lte_rar_headers = -1;
static int ett_mac_lte_rar_header = -1;
static int ett_mac_lte_rar_body = -1;
static int ett_mac_lte_rar_ul_grant = -1;
static int ett_mac_lte_bch = -1;
static int ett_mac_lte_pch = -1;
/* Constants and value strings */
static const value_string radio_type_vals[] =
{
{ FDD_RADIO, "FDD"},
{ TDD_RADIO, "TDD"},
{ 0, NULL }
};
static const value_string direction_vals[] =
{
{ DIRECTION_UPLINK, "Uplink"},
{ DIRECTION_DOWNLINK, "Downlink"},
{ 0, NULL }
};
static const value_string rnti_type_vals[] =
{
{ NO_RNTI, "NO-RNTI"},
{ P_RNTI, "P-RNTI"},
{ RA_RNTI, "RA-RNTI"},
{ C_RNTI, "C-RNTI"},
{ SI_RNTI, "SI-RNTI"},
{ 0, NULL }
};
static const value_string bch_transport_channel_vals[] =
{
{ SI_RNTI, "DL-SCH"},
{ NO_RNTI, "BCH"},
{ 0, NULL }
};
static const value_string crc_status_vals[] =
{
{ 0, "CRC Status Failed"},
{ 1, "CRC Status OK"},
{ 0, NULL }
};
#define UE_CONTENTION_RESOLUTION_IDENTITY_LCID 0x1c
#define TIMING_ADVANCE_LCID 0x1d
#define DRX_COMMAND_LCID 0x1e
#define PADDING_LCID 0x1f
static const value_string dlsch_lcid_vals[] =
{
{ 0, "CCCH"},
{ 1, "1"},
{ 2, "2"},
{ 3, "3"},
{ 4, "4"},
{ 5, "5"},
{ 6, "6"},
{ 7, "7"},
{ 8, "8"},
{ 9, "9"},
{ 10, "10"},
{ UE_CONTENTION_RESOLUTION_IDENTITY_LCID, "UE Contention Resolution Identity"},
{ TIMING_ADVANCE_LCID , "Timing Advance"},
{ DRX_COMMAND_LCID , "DRX Command"},
{ PADDING_LCID , "Padding" },
{ 0, NULL }
};
#define POWER_HEADROOM_REPORT_LCID 0x1a
#define CRNTI_LCID 0x1b
#define TRUNCATED_BSR_LCID 0x1c
#define SHORT_BSR_LCID 0x1d
#define LONG_BSR_LCID 0x1e
static const value_string ulsch_lcid_vals[] =
{
{ 0, "CCCH"},
{ 1, "1"},
{ 2, "2"},
{ 3, "3"},
{ 4, "4"},
{ 5, "5"},
{ 6, "6"},
{ 7, "7"},
{ 8, "8"},
{ 9, "9"},
{ 10, "10"},
{ POWER_HEADROOM_REPORT_LCID, "Power Headroom Report"},
{ CRNTI_LCID, "C-RNTI"},
{ TRUNCATED_BSR_LCID, "Truncated BSR"},
{ SHORT_BSR_LCID, "Short BSR"},
{ LONG_BSR_LCID, "Long BSR"},
{ PADDING_LCID, "Padding" },
{ 0, NULL }
};
static const value_string format_vals[] =
{
{ 0, "Data length is < 128 bytes"},
{ 1, "Data length is >= 128 bytes"},
{ 0, NULL }
};
static const value_string rar_type_vals[] =
{
{ 0, "Backoff Indicator present"},
{ 1, "RAPID present"},
{ 0, NULL }
};
static const value_string rar_bi_vals[] =
{
{ 0, "0"},
{ 1, "10"},
{ 2, "20"},
{ 3, "30"},
{ 4, "40"},
{ 5, "60"},
{ 6, "80"},
{ 7, "120"},
{ 8, "160"},
{ 9, "240"},
{ 10, "320"},
{ 11, "480"},
{ 12, "960"},
{ 0, NULL }
};
static const value_string buffer_size_vals[] =
{
{ 0, "BS = 0"},
{ 1, "0 < BS <= 10"},
{ 2, "10 < BS <= 12"},
{ 3, "12 < BS <= 14"},
{ 4, "14 < BS <= 17"},
{ 5, "17 < BS <= 19"},
{ 6, "19 < BS <= 22"},
{ 7, "22 < BS <= 26"},
{ 8, "26 < BS <= 31"},
{ 9, "31 < BS <= 36"},
{ 10, "36 < BS <= 42"},
{ 11, "42 < BS <= 49"},
{ 12, "49 < BS <= 57"},
{ 13, "47 < BS <= 67"},
{ 14, "67 < BS <= 78"},
{ 15, "78 < BS <= 91"},
{ 16, "91 < BS <= 107"},
{ 17, "107 < BS <= 125"},
{ 18, "125 < BS <= 146"},
{ 19, "146 < BS <= 171"},
{ 20, "171 < BS <= 200"},
{ 21, "200 < BS <= 234"},
{ 22, "234 < BS <= 274"},
{ 23, "274 < BS <= 321"},
{ 24, "321 < BS <= 376"},
{ 25, "376 < BS <= 440"},
{ 26, "440 < BS <= 515"},
{ 27, "515 < BS <= 603"},
{ 28, "603 < BS <= 706"},
{ 29, "706 < BS <= 826"},
{ 30, "826 < BS <= 967"},
{ 31, "967 < BS <= 1132"},
{ 32, "1132 < BS <= 1326"},
{ 33, "1326 < BS <= 1552"},
{ 34, "1552 < BS <= 1817"},
{ 35, "1817 < BS <= 2127"},
{ 36, "2127 < BS <= 2490"},
{ 37, "2490 < BS <= 2915"},
{ 38, "2915 < BS <= 3413"},
{ 39, "3413 < BS <= 3995"},
{ 40, "3995 < BS <= 4677"},
{ 41, "4677 < BS <= 5476"},
{ 42, "5476 < BS <= 6411"},
{ 43, "6411 < BS <= 7505"},
{ 44, "7505 < BS <= 8787"},
{ 45, "8787 < BS <= 10276"},
{ 46, "10287 < BS <= 12043"},
{ 47, "12043 < BS <= 14099"},
{ 48, "14099 < BS <= 16507"},
{ 49, "16507 < BS <= 19325"},
{ 50, "19325 < BS <= 22624"},
{ 51, "22624 < BS <= 26487"},
{ 52, "26487 < BS <= 31009"},
{ 53, "31009 < BS <= 36304"},
{ 54, "36304 < BS <= 42502"},
{ 55, "42502 < BS <= 49759"},
{ 56, "49759 < BS <= 58255"},
{ 57, "58255 < BS <= 68201"},
{ 58, "68201 < BS <= 79846"},
{ 59, "79846 < BS <= 93479"},
{ 60, "93479 < BS <= 109439"},
{ 61, "109439 < BS <= 128125"},
{ 62, "128125 < BS <= 150000"},
{ 63, "BS > 150000"},
{ 0, NULL }
};
static const value_string header_only_vals[] =
{
{ 0, "MAC PDU Headers and body present"},
{ 1, "MAC PDU Headers only"},
{ 0, NULL }
};
static const value_string predefined_frame_vals[] =
{
{ 0, "Real MAC PDU present - will dissect"},
{ 1, "Predefined frame present - will not dissect"},
{ 0, NULL }
};
/* By default check and warn about reserved bits not being zero.
December '08 spec says they should be ignored... */
static gboolean global_mac_lte_check_reserved_bits = TRUE;
/* If this PDU has been NACK'd (by HARQ) more than a certain number of times,
we trigger an expert warning. */
static gint global_mac_lte_retx_counter_trigger = 3;
/* By default try to decode transparent data (BCH, PCH and CCCH) data using LTE RRC dissector */
static gboolean global_mac_lte_attempt_rrc_decode = TRUE;
/* Control whether decoding details of RAR UL grant or not */
static gboolean global_mac_lte_decode_rar_ul_grant = TRUE;
/* Dissect a single Random Access Reponse body */
static gint dissect_rar_entry(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
gint offset, guint8 rapid)
{
guint8 reserved;
guint start_body_offset = offset;
proto_item *ti;
proto_item *rar_body_ti;
proto_tree *rar_body_tree;
proto_item *ul_grant_ti;
guint16 timing_advance;
guint32 ul_grant;
guint16 temp_crnti;
/* Create tree for this Body */
rar_body_ti = proto_tree_add_item(tree,
hf_mac_lte_rar_body,
tvb, offset, 0, FALSE);
rar_body_tree = proto_item_add_subtree(rar_body_ti, ett_mac_lte_rar_body);
/* Dissect an RAR entry */
/* Check reserved bit */
reserved = (tvb_get_guint8(tvb, offset) & 0x80) >> 7;
ti = proto_tree_add_item(rar_body_tree, hf_mac_lte_rar_reserved2, tvb, offset, 1, FALSE);
if (global_mac_lte_check_reserved_bits && (reserved != 0)) {
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR,
"MAC RAR header Reserved bit not zero (found 0x%x)", reserved);
}
/* Timing Advance */
timing_advance = (tvb_get_ntohs(tvb, offset) & 0x7ff0) >> 4;
proto_tree_add_item(rar_body_tree, hf_mac_lte_rar_ta, tvb, offset, 2, FALSE);
offset++;
/* UL Grant */
ul_grant = (tvb_get_ntohl(tvb, offset) & 0x0fffff00) >> 8;
ul_grant_ti = proto_tree_add_item(rar_body_tree, hf_mac_lte_rar_ul_grant, tvb, offset, 3, FALSE);
/* Break these 20 bits down as described in 36.213, section 6.2 */
if (global_mac_lte_decode_rar_ul_grant) {
/* Create subtree for UL grant break-down */
proto_tree *ul_grant_tree = proto_item_add_subtree(ul_grant_ti, ett_mac_lte_rar_ul_grant);
/* Hopping flag (1 bit) */
proto_tree_add_item(ul_grant_tree, hf_mac_lte_rar_ul_grant_hopping,
tvb, offset, 1, FALSE);
/* Fixed sized resource block assignment (10 bits) */
proto_tree_add_item(ul_grant_tree, hf_mac_lte_rar_ul_grant_fsrba,
tvb, offset, 2, FALSE);
/* Truncated Modulation and coding scheme (4 bits) */
proto_tree_add_item(ul_grant_tree, hf_mac_lte_rar_ul_grant_tmcs,
tvb, offset+1, 2, FALSE);
/* TPC command for scheduled PUSCH (3 bits) */
proto_tree_add_item(ul_grant_tree, hf_mac_lte_rar_ul_grant_tcsp,
tvb, offset+2, 1, FALSE);
/* UL delay (1 bit) */
proto_tree_add_item(ul_grant_tree, hf_mac_lte_rar_ul_grant_ul_delay,
tvb, offset+2, 1, FALSE);
/* CQI request (1 bit) */
proto_tree_add_item(ul_grant_tree, hf_mac_lte_rar_ul_grant_cqi_request,
tvb, offset+2, 1, FALSE);
}
offset += 3;
/* Temporary C-RNTI */
temp_crnti = tvb_get_ntohs(tvb, offset);
proto_tree_add_item(rar_body_tree, hf_mac_lte_rar_temporary_crnti, tvb, offset, 2, FALSE);
offset += 2;
proto_item_append_text(rar_body_ti, " RAPID=%u (TA=%u, UL-Grant=%u, Temp C-RNTI=%u)",
rapid, timing_advance, ul_grant, temp_crnti);
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, " (RAPID=%u: TA=%u, UL-Grant=%u, Temp C-RNTI=%u)",
rapid, timing_advance, ul_grant, temp_crnti);
}
proto_item_set_len(rar_body_ti, offset-start_body_offset);
return offset;
}
/* Dissect Random Access Reponse (RAR) PDU */
static void dissect_rar(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
gint offset, mac_lte_info *p_mac_lte_info, mac_lte_tap_info *tap_info)
{
gint number_of_rars = 0; /* No of RAR bodies expected following headers */
guint8 rapids[64];
gboolean backoff_indicator_seen = FALSE;
guint8 extension;
gint n;
proto_tree *rar_headers_tree;
proto_item *ti;
proto_item *rar_headers_ti;
int start_headers_offset = offset;
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, "RAR (RA-RNTI=%u, SF=%u)",
p_mac_lte_info->rnti, p_mac_lte_info->subframeNumber);
}
/* Create hidden 'virtual root' so can filter on mac-lte.rar */
ti = proto_tree_add_item(tree, hf_mac_lte_rar, tvb, offset, -1, FALSE);
PROTO_ITEM_SET_HIDDEN(ti);
/* Create headers tree */
rar_headers_ti = proto_tree_add_item(tree,
hf_mac_lte_rar_headers,
tvb, offset, 0, FALSE);
rar_headers_tree = proto_item_add_subtree(rar_headers_ti, ett_mac_lte_rar_headers);
/***************************/
/* Read the header entries */
do {
int start_header_offset = offset;
proto_tree *rar_header_tree;
proto_item *rar_header_ti;
guint8 type_value;
guint8 first_byte = tvb_get_guint8(tvb, offset);
/* Create tree for this header */
rar_header_ti = proto_tree_add_item(rar_headers_tree,
hf_mac_lte_rar_header,
tvb, offset, 0, FALSE);
rar_header_tree = proto_item_add_subtree(rar_header_ti, ett_mac_lte_rar_header);
/* Extension */
extension = (first_byte & 0x80) >> 7;
proto_tree_add_item(rar_header_tree, hf_mac_lte_rar_extension, tvb, offset, 1, FALSE);
/* Type */
type_value = (first_byte & 0x40) >> 6;
proto_tree_add_item(rar_header_tree, hf_mac_lte_rar_t, tvb, offset, 1, FALSE);
if (type_value == 0) {
guint8 reserved;
guint8 backoff_indicator;
proto_item *ti;
proto_item *bi_ti;
/* 2 Reserved bits */
reserved = (tvb_get_guint8(tvb, offset) & 0x30) >> 4;
ti = proto_tree_add_item(rar_header_tree, hf_mac_lte_rar_reserved, tvb, offset, 1, FALSE);
if (global_mac_lte_check_reserved_bits && (reserved != 0)) {
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR,
"MAC RAR header Reserved bits not zero (found 0x%x)", reserved);
}
/* Backoff Indicator */
backoff_indicator = tvb_get_guint8(tvb, offset) & 0x0f;
bi_ti = proto_tree_add_item(rar_header_tree, hf_mac_lte_rar_bi, tvb, offset, 1, FALSE);
if (backoff_indicator_seen) {
expert_add_info_format(pinfo, bi_ti, PI_MALFORMED, PI_ERROR,
"MAC RAR PDU has > 1 Backoff Indicator subheader present");
}
backoff_indicator_seen = TRUE;
proto_item_append_text(rar_header_ti, " (Backoff Indicator=%sms)",
val_to_str(backoff_indicator, rar_bi_vals, "Illegal value"));
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, " (Backoff Indicator=%sms)",
val_to_str(backoff_indicator, rar_bi_vals, "Illegal value"));
}
}
else {
/* RAPID case */
rapids[number_of_rars] = tvb_get_guint8(tvb, offset) & 0x3f;
proto_tree_add_item(rar_header_tree, hf_mac_lte_rar_rapid, tvb, offset, 1, FALSE);
proto_item_append_text(rar_header_ti, " (RAPID=%u)", rapids[number_of_rars]);
number_of_rars++;
}
offset++;
/* Finalise length of header tree selection */
proto_item_set_len(rar_header_ti, offset - start_header_offset);
} while (extension);
/* Append summary to headers root */
proto_item_append_text(rar_headers_ti, " (%u RARs%s)",
number_of_rars,
backoff_indicator_seen ? ", BI" : "");
/* Set length for headers root */
proto_item_set_len(rar_headers_ti, offset-start_headers_offset);
/***************************/
/* Read any indicated RARs */
for (n=0; n < number_of_rars; n++) {
offset = dissect_rar_entry(tvb, pinfo, tree, offset, rapids[n]);
}
/* Update TAP info */
tap_info->number_of_rars += number_of_rars;
/* Warn if we don't seem to have reached the end of the frame yet */
if (tvb_length_remaining(tvb, offset) != 0) {
expert_add_info_format(pinfo, rar_headers_ti, PI_MALFORMED, PI_ERROR,
"%u bytes remaining after RAR PDU dissected",
tvb_length_remaining(tvb, offset));
}
}
/* Dissect BCH PDU */
static void dissect_bch(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
int offset, mac_lte_info *p_mac_lte_info)
{
proto_item *ti;
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, "BCH PDU (%u bytes, on %s transport) ",
tvb_length_remaining(tvb, offset),
val_to_str(p_mac_lte_info->rntiType,
bch_transport_channel_vals,
"Unknown"));
}
/* Show which transport layer it came in on (inferred from RNTI type) */
ti = proto_tree_add_uint(tree, hf_mac_lte_context_bch_transport_channel,
tvb, offset, 0, p_mac_lte_info->rntiType);
PROTO_ITEM_SET_GENERATED(ti);
/****************************************/
/* Whole frame is BCH data */
/* Raw data */
ti = proto_tree_add_item(tree, hf_mac_lte_bch_pdu,
tvb, offset, -1, FALSE);
if (global_mac_lte_attempt_rrc_decode) {
/* Attempt to decode payload using LTE RRC dissector */
tvbuff_t *rrc_tvb = tvb_new_subset(tvb, offset, -1, tvb_length_remaining(tvb, offset));
/* Get appropriate dissector handle */
dissector_handle_t protocol_handle = 0;
if (p_mac_lte_info->rntiType == SI_RNTI) {
protocol_handle = find_dissector("lte-rrc.bcch.dl.sch");
}
else {
protocol_handle = find_dissector("lte-rrc.bcch.bch");
}
/* Hide raw view of bytes */
PROTO_ITEM_SET_HIDDEN(ti);
/* Call it */
call_dissector_only(protocol_handle, rrc_tvb, pinfo, tree);
}
/* Check that this *is* downlink! */
if (p_mac_lte_info->direction == DIRECTION_UPLINK) {
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR,
"BCH data should not be received in Uplink!");
}
}
/* Dissect PCH PDU */
static void dissect_pch(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
int offset, guint8 direction)
{
proto_item *ti;
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, "PCH PDU (%u bytes) ",
tvb_length_remaining(tvb, offset));
}
/****************************************/
/* Whole frame is PCH data */
/* Always show as raw data */
ti = proto_tree_add_item(tree, hf_mac_lte_pch_pdu,
tvb, offset, -1, FALSE);
if (global_mac_lte_attempt_rrc_decode) {
/* Attempt to decode payload using LTE RRC dissector */
tvbuff_t *rrc_tvb = tvb_new_subset(tvb, offset, -1, tvb_length_remaining(tvb, offset));
/* Get appropriate dissector handle */
dissector_handle_t protocol_handle = find_dissector("lte-rrc.pcch");
/* Hide raw view of bytes */
PROTO_ITEM_SET_HIDDEN(ti);
/* Call it */
call_dissector_only(protocol_handle, rrc_tvb, pinfo, tree);
}
/* Check that this *is* downlink! */
if (direction == DIRECTION_UPLINK) {
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR,
"PCH data should not be received in Uplink!");
}
}
/* Does this header entry correspond to a fixed-sized control element? */
static int is_fixed_sized_control_element(guint8 lcid, guint8 direction)
{
if (direction == DIRECTION_UPLINK) {
/* Uplink */
switch (lcid) {
case POWER_HEADROOM_REPORT_LCID:
case CRNTI_LCID:
case TRUNCATED_BSR_LCID:
case SHORT_BSR_LCID:
case LONG_BSR_LCID:
return TRUE;
default:
return FALSE;
}
}
else {
/* Assume Downlink */
switch (lcid) {
case UE_CONTENTION_RESOLUTION_IDENTITY_LCID:
case TIMING_ADVANCE_LCID:
case DRX_COMMAND_LCID:
return TRUE;
default:
return FALSE;
}
}
}
/* Is this a BSR report header? */
static int is_bsr_lcid(guint8 lcid)
{
return ((lcid == TRUNCATED_BSR_LCID) ||
(lcid == SHORT_BSR_LCID) ||
(lcid == LONG_BSR_LCID));
}
#define MAX_HEADERS_IN_PDU 1024
/* UL-SCH and DL-SCH formats have much in common, so handle them in a common
function */
static void dissect_ulsch_or_dlsch(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
int offset, guint8 direction,
mac_lte_info *p_mac_lte_info, mac_lte_tap_info *tap_info)
{
guint8 extension;
guint8 n;
proto_item *truncated_ti;
proto_item *padding_length_ti;
/* Keep track of LCIDs and lengths as we dissect the header */
guint8 number_of_headers = 0;
guint8 lcids[MAX_HEADERS_IN_PDU];
gint16 pdu_lengths[MAX_HEADERS_IN_PDU];
proto_item *pdu_header_ti;
proto_tree *pdu_header_tree;
gboolean have_seen_data_header = FALSE;
gboolean have_seen_bsr = FALSE;
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, "%s: ",
(direction == DIRECTION_UPLINK) ? "UL-SCH" : "DL-SCH");
}
/* Add PDU block header subtree */
pdu_header_ti = proto_tree_add_string_format(tree,
(direction == DIRECTION_UPLINK) ?
hf_mac_lte_ulsch_header :
hf_mac_lte_dlsch_header,
tvb, offset, 0,
"",
"MAC PDU Header");
pdu_header_tree = proto_item_add_subtree(pdu_header_ti,
(direction == DIRECTION_UPLINK) ?
ett_mac_lte_ulsch_header :
ett_mac_lte_dlsch_header);
/************************************************************************/
/* Dissect each sub-header. */
do {
guint8 reserved;
guint64 length = 0;
proto_item *pdu_subheader_ti;
proto_tree *pdu_subheader_tree;
proto_item *lcid_ti;
proto_item *ti;
gint offset_start_subheader = offset;
guint8 first_byte = tvb_get_guint8(tvb, offset);
/* Add PDU block header subtree */
pdu_subheader_ti = proto_tree_add_string_format(pdu_header_tree,
hf_mac_lte_sch_subheader,
tvb, offset, 0,
"",
"Sub-header");
pdu_subheader_tree = proto_item_add_subtree(pdu_subheader_ti,
ett_mac_lte_sch_subheader);
/* Check 1st 2 reserved bits */
reserved = (first_byte & 0xc0) >> 6;
ti = proto_tree_add_item(pdu_subheader_tree, hf_mac_lte_sch_reserved,
tvb, offset, 1, FALSE);
if (global_mac_lte_check_reserved_bits && (reserved != 0)) {
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR,
"MAC U/DL-SCH header Reserved bits not zero");
}
/* Extended bit */
extension = (first_byte & 0x20) >> 5;
proto_tree_add_item(pdu_subheader_tree, hf_mac_lte_sch_extended,
tvb, offset, 1, FALSE);
/* LCID. Has different meaning depending upon direction. */
lcids[number_of_headers] = first_byte & 0x1f;
if (direction == DIRECTION_UPLINK) {
lcid_ti = proto_tree_add_item(pdu_subheader_tree, hf_mac_lte_ulsch_lcid,
tvb, offset, 1, FALSE);
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, "(%s",
val_to_str(lcids[number_of_headers],
ulsch_lcid_vals, "(Unknown LCID)"));
}
}
else {
lcid_ti = proto_tree_add_item(pdu_subheader_tree, hf_mac_lte_dlsch_lcid,
tvb, offset, 1, FALSE);
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, "(%s",
val_to_str(lcids[number_of_headers],
dlsch_lcid_vals, "(Unknown LCID)"));
}
}
offset++;
/* Remember if we've seen a data subheader */
if (lcids[number_of_headers] <= 10) {
have_seen_data_header = TRUE;
}
/* Show an expert item if a contol subheader (except Padding) appears
*after* a data PDU */
if (have_seen_data_header &&
(lcids[number_of_headers] > 10) && (lcids[number_of_headers] != PADDING_LCID)) {
expert_add_info_format(pinfo, lcid_ti, PI_MALFORMED, PI_ERROR,
"Control subheaders should not appear after data subheaders");
}
/* Show an expert item if we're seeing more then one BSR in a frame */
if ((direction == DIRECTION_UPLINK) && is_bsr_lcid(lcids[number_of_headers])) {
if (have_seen_bsr) {
expert_add_info_format(pinfo, lcid_ti, PI_MALFORMED, PI_ERROR,
"There shouldn't be > 1 BSR in a frame");
}
have_seen_bsr = TRUE;
}
/********************************************************************/
/* Length field follows if not the last header or for a fixed-sized
control element */
if (!extension) {
if (is_fixed_sized_control_element(lcids[number_of_headers], direction)) {
pdu_lengths[number_of_headers] = 0;
}
else {
pdu_lengths[number_of_headers] = -1;
}
}
else {
if (!is_fixed_sized_control_element(lcids[number_of_headers], direction) &&
(lcids[number_of_headers] != PADDING_LCID)) {
guint8 format;
/* F(ormat) bit tells us how long the length field is */
format = (tvb_get_guint8(tvb, offset) & 0x80) >> 7;
proto_tree_add_item(pdu_subheader_tree, hf_mac_lte_sch_format,
tvb, offset, 1, FALSE);
/* Now read length field itself */
if (format) {
/* >= 128 - use 15 bits */
proto_tree_add_bits_ret_val(pdu_subheader_tree, hf_mac_lte_sch_length,
tvb, offset*8 + 1, 15, &length, FALSE);
offset += 2;
}
else {
/* Less than 128 - only 7 bits */
proto_tree_add_bits_ret_val(pdu_subheader_tree, hf_mac_lte_sch_length,
tvb, offset*8 + 1, 7, &length, FALSE);
offset++;
}
pdu_lengths[number_of_headers] = (gint16)length;
}
else {
pdu_lengths[number_of_headers] = 0;
}
}
/* Close off description in info column */
if (check_col(pinfo->cinfo, COL_INFO)) {
switch (pdu_lengths[number_of_headers]) {
case 0:
col_append_str(pinfo->cinfo, COL_INFO, ") ");
break;
case -1:
col_append_str(pinfo->cinfo, COL_INFO, ":remainder) ");
break;
default:
col_append_fstr(pinfo->cinfo, COL_INFO, ":%u bytes) ",
pdu_lengths[number_of_headers]);
break;
}
}
/* Append summary to subheader root */
proto_item_append_text(pdu_subheader_ti, " (lcid=%s",
val_to_str(lcids[number_of_headers],
(direction == DIRECTION_UPLINK) ?
ulsch_lcid_vals :
dlsch_lcid_vals,
"Unknown"));
switch (pdu_lengths[number_of_headers]) {
case -1:
proto_item_append_text(pdu_subheader_ti, ", length is remainder)");
break;
case 0:
proto_item_append_text(pdu_subheader_ti, ")");
break;
default:
proto_item_append_text(pdu_subheader_ti, ", length=%u)",
pdu_lengths[number_of_headers]);
break;
}
/* Flag unknown lcid values in expert info */
if (strncmp(val_to_str(lcids[number_of_headers],
(direction == DIRECTION_UPLINK) ? ulsch_lcid_vals : dlsch_lcid_vals,
"Unknown"),
"Unknown",
sizeof("Unknown")) == 0) {
expert_add_info_format(pinfo, pdu_subheader_ti, PI_MALFORMED, PI_ERROR,
"Unexpected LCID received (%u)", lcids[number_of_headers]);
}
/* Set length of this subheader */
proto_item_set_len(pdu_subheader_ti, offset- offset_start_subheader);
number_of_headers++;
} while (extension);
/* Append summary to overall PDU header root */
proto_item_append_text(pdu_header_ti, " (%u subheaders)",
number_of_headers);
/* And set its length to offset */
proto_item_set_len(pdu_header_ti, offset);
/* There might not be any data, if only headers were logged */
truncated_ti = proto_tree_add_uint(tree, hf_mac_lte_sch_header_only, tvb, 0, 0,
tvb_length_remaining(tvb, offset) == 0);
PROTO_ITEM_SET_GENERATED(truncated_ti);
if (tvb_length_remaining(tvb, offset) == 0) {
expert_add_info_format(pinfo, truncated_ti, PI_SEQUENCE, PI_NOTE,
"MAC PDU SDUs have been ommitted");
return;
}
/************************************************************************/
/* Dissect SDUs / control elements / padding. */
/************************************************************************/
for (n=0; n < number_of_headers; n++) {
/* Data SDUs treated identically for Uplink or downlink channels */
if (lcids[n] <= 10) {
proto_item *sdu_ti;
guint16 data_length = (pdu_lengths[n] == -1) ?
tvb_length_remaining(tvb, offset) :
pdu_lengths[n];
/* Dissect SDU */
sdu_ti = proto_tree_add_bytes_format(tree, hf_mac_lte_sch_sdu, tvb, offset, pdu_lengths[n],
tvb_get_ptr(tvb, offset, pdu_lengths[n]),
"SDU (%s, length = %u bytes)",
val_to_str(lcids[n],
(direction == DIRECTION_UPLINK) ?
ulsch_lcid_vals :
dlsch_lcid_vals,
"Unknown"),
data_length);
/* CCCH frames can be dissected directly by LTE RRC... */
if ((lcids[n] == 0) && global_mac_lte_attempt_rrc_decode) {
tvbuff_t *rrc_tvb = tvb_new_subset(tvb, offset, data_length, data_length);
/* Get appropriate dissector handle */
dissector_handle_t protocol_handle = 0;
if (p_mac_lte_info->direction == DIRECTION_UPLINK) {
protocol_handle = find_dissector("lte-rrc.ul.ccch");
}
else {
protocol_handle = find_dissector("lte-rrc.dl.ccch");
}
/* Hide raw view of bytes */
PROTO_ITEM_SET_HIDDEN(sdu_ti);
/* Call it */
call_dissector_only(protocol_handle, rrc_tvb, pinfo, tree);
}
offset += data_length;
/* Update tap byte count for this channel */
tap_info->bytes_for_lcid[lcids[n]] += data_length;
tap_info->sdus_for_lcid[lcids[n]]++;
}
else {
/* See if its a control PDU type */
if (direction == DIRECTION_DOWNLINK) {
/****************************/
/* DL-SCH Control PDUs */
switch (lcids[n]) {
case UE_CONTENTION_RESOLUTION_IDENTITY_LCID:
proto_tree_add_item(tree, hf_mac_lte_control_ue_contention_resolution_identity,
tvb, offset, 6, FALSE);
offset += 6;
break;
case TIMING_ADVANCE_LCID:
proto_tree_add_item(tree, hf_mac_lte_control_timing_advance,
tvb, offset, 1, FALSE);
offset++;
break;
case DRX_COMMAND_LCID:
/* No payload */
break;
case PADDING_LCID:
/* No payload, unless its the last subheader, in which case
it extends to the end of the PDU */
if (n == (number_of_headers-1)) {
if (tvb_length_remaining(tvb, offset) > 0) {
proto_tree_add_item(tree, hf_mac_lte_padding_data,
tvb, offset, -1, FALSE);
}
padding_length_ti = proto_tree_add_uint(tree, hf_mac_lte_padding_length,
tvb, offset, 0,
p_mac_lte_info->length - offset);
PROTO_ITEM_SET_GENERATED(padding_length_ti);
}
break;
default:
break;
}
}
else {
/**********************************/
/* UL-SCH Control PDUs */
switch (lcids[n]) {
case POWER_HEADROOM_REPORT_LCID:
{
proto_item *ti;
guint8 reserved;
/* Check 2 Reserved bits */
reserved = (tvb_get_guint8(tvb, offset) & 0xc0) >> 6;
ti = proto_tree_add_item(tree, hf_mac_lte_control_power_headroom_reserved,
tvb, offset, 1, FALSE);
if (global_mac_lte_check_reserved_bits && (reserved != 0)) {
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR,
"Power Headroom Reserved bits not zero (found 0x%x)", reserved);
}
}
proto_tree_add_item(tree, hf_mac_lte_control_power_headroom,
tvb, offset, 1, FALSE);
offset++;
break;
case CRNTI_LCID:
proto_tree_add_item(tree, hf_mac_lte_control_crnti,
tvb, offset, 2, FALSE);
offset += 2;
break;
case TRUNCATED_BSR_LCID:
case SHORT_BSR_LCID:
/* LCG ID */
proto_tree_add_item(tree, hf_mac_lte_control_lcg_id,
tvb, offset, 1, FALSE);
/* Buffer Size */
proto_tree_add_item(tree, hf_mac_lte_control_buffer_size,
tvb, offset, 1, FALSE);
offset++;
break;
case LONG_BSR_LCID:
proto_tree_add_item(tree, hf_mac_lte_control_buffer_size_1,
tvb, offset, 1, FALSE);
proto_tree_add_item(tree, hf_mac_lte_control_buffer_size_2,
tvb, offset, 1, FALSE);
offset++;
proto_tree_add_item(tree, hf_mac_lte_control_buffer_size_3,
tvb, offset, 1, FALSE);
offset++;
proto_tree_add_item(tree, hf_mac_lte_control_buffer_size_4,
tvb, offset, 1, FALSE);
offset++;
break;
case PADDING_LCID:
/* No payload, unless its the last subheader, in which case
it extends to the end of the PDU */
if (n == (number_of_headers-1)) {
if (tvb_length_remaining(tvb, offset) > 0) {
proto_tree_add_item(tree, hf_mac_lte_padding_data,
tvb, offset, -1, FALSE);
}
padding_length_ti = proto_tree_add_uint(tree, hf_mac_lte_padding_length,
tvb, offset, 0,
p_mac_lte_info->length - offset);
PROTO_ITEM_SET_GENERATED(padding_length_ti);
}
break;
default:
break;
}
}
}
}
}
/*****************************/
/* Main dissection function. */
void dissect_mac_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *mac_lte_tree;
proto_item *ti;
gint offset = 0;
struct mac_lte_info *p_mac_lte_info = NULL;
static mac_lte_tap_info tap_info;
memset(&tap_info, 0, sizeof(mac_lte_tap_info));
/* Set protocol name */
if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
col_set_str(pinfo->cinfo, COL_PROTOCOL, "MAC-LTE");
}
/* Create protocol tree. */
ti = proto_tree_add_item(tree, proto_mac_lte, tvb, offset, -1, FALSE);
mac_lte_tree = proto_item_add_subtree(ti, ett_mac_lte);
/* Look for packet info! */
p_mac_lte_info = p_get_proto_data(pinfo->fd, proto_mac_lte);
/* Can't dissect anything without it... */
if (p_mac_lte_info == NULL) {
proto_item *ti =
proto_tree_add_text(mac_lte_tree, tvb, offset, -1,
"Can't dissect LTE MAC frame because no per-frame info was attached!");
PROTO_ITEM_SET_GENERATED(ti);
return;
}
/*****************************************/
/* Show context information */
ti = proto_tree_add_uint(mac_lte_tree, hf_mac_lte_context_radio_type,
tvb, 0, 0, p_mac_lte_info->radioType);
PROTO_ITEM_SET_GENERATED(ti);
ti = proto_tree_add_uint(mac_lte_tree, hf_mac_lte_context_direction,
tvb, 0, 0, p_mac_lte_info->direction);
PROTO_ITEM_SET_GENERATED(ti);
if (p_mac_lte_info->ueid != 0) {
ti = proto_tree_add_uint(mac_lte_tree, hf_mac_lte_context_ueid,
tvb, 0, 0, p_mac_lte_info->ueid);
PROTO_ITEM_SET_GENERATED(ti);
}
ti = proto_tree_add_uint(mac_lte_tree, hf_mac_lte_context_subframe_number,
tvb, 0, 0, p_mac_lte_info->subframeNumber);
PROTO_ITEM_SET_GENERATED(ti);
if (p_mac_lte_info->rntiType != NO_RNTI) {
ti = proto_tree_add_uint(mac_lte_tree, hf_mac_lte_context_rnti,
tvb, 0, 0, p_mac_lte_info->rnti);
PROTO_ITEM_SET_GENERATED(ti);
}
ti = proto_tree_add_uint(mac_lte_tree, hf_mac_lte_context_rnti_type,
tvb, 0, 0, p_mac_lte_info->rntiType);
PROTO_ITEM_SET_GENERATED(ti);
ti = proto_tree_add_uint(mac_lte_tree, hf_mac_lte_context_predefined_frame,
tvb, 0, 0, p_mac_lte_info->isPredefinedData);
PROTO_ITEM_SET_GENERATED(ti);
ti = proto_tree_add_uint(mac_lte_tree, hf_mac_lte_context_length,
tvb, 0, 0, p_mac_lte_info->length);
PROTO_ITEM_SET_GENERATED(ti);
if (p_mac_lte_info->reTxCount) {
ti = proto_tree_add_uint(mac_lte_tree, hf_mac_lte_context_retx_count,
tvb, 0, 0, p_mac_lte_info->reTxCount);
PROTO_ITEM_SET_GENERATED(ti);
if (p_mac_lte_info->reTxCount >= global_mac_lte_retx_counter_trigger) {
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_ERROR,
"Frame has now been NACK'd %u times",
p_mac_lte_info->reTxCount);
}
}
if (p_mac_lte_info->crcStatusValid) {
ti = proto_tree_add_uint(mac_lte_tree, hf_mac_lte_context_crc_status,
tvb, 0, 0, p_mac_lte_info->crcStatus);
PROTO_ITEM_SET_GENERATED(ti);
if (p_mac_lte_info->crcStatus != TRUE) {
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR,
"Frame has CRC error");
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, "<CRC FAILURE>");
}
}
}
/* Set context-info parts of tap struct */
tap_info.rnti = p_mac_lte_info->rnti;
tap_info.rntiType = p_mac_lte_info->rntiType;
tap_info.isPredefinedData = p_mac_lte_info->isPredefinedData;
tap_info.reTxCount = p_mac_lte_info->reTxCount;
tap_info.crcStatusValid = p_mac_lte_info->crcStatusValid;
tap_info.crcStatus = p_mac_lte_info->crcStatus;
tap_info.direction = p_mac_lte_info->direction;
/* Also set total number of bytes (won't be used for UL/DL-SCH) */
tap_info.single_number_of_bytes = tvb_length_remaining(tvb, offset);
/* If we know its predefined data, don't try to decode any further */
if (p_mac_lte_info->isPredefinedData) {
proto_tree_add_item(mac_lte_tree, hf_mac_lte_predefined_pdu, tvb, offset, -1, FALSE);
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, "Predefined data (%u bytes)", tvb_length_remaining(tvb, offset));
}
/* Queue tap info */
if (!pinfo->in_error_pkt) {
tap_queue_packet(mac_lte_tap, pinfo, &tap_info);
}
return;
}
/* Dissect the MAC PDU itself. Format depends upon RNTI type. */
switch (p_mac_lte_info->rntiType) {
case P_RNTI:
/* PCH PDU */
dissect_pch(tvb, pinfo, mac_lte_tree, offset, p_mac_lte_info->direction);
break;
case RA_RNTI:
/* RAR PDU */
dissect_rar(tvb, pinfo, mac_lte_tree, offset, p_mac_lte_info, &tap_info);
break;
case C_RNTI:
/* Can be UL-SCH or DL-SCH */
dissect_ulsch_or_dlsch(tvb, pinfo, mac_lte_tree, offset, p_mac_lte_info->direction,
p_mac_lte_info, &tap_info);
break;
case SI_RNTI:
/* BCH over DL-SCH */
dissect_bch(tvb, pinfo, mac_lte_tree, offset, p_mac_lte_info);
break;
case NO_RNTI:
/* Must be BCH over BCH... */
dissect_bch(tvb, pinfo, mac_lte_tree, offset, p_mac_lte_info);
break;
default:
break;
}
/* Queue tap info */
/* TODO: if any of above (esp RRC dissection) throws exception, this isn't reached,
but if call too early, won't have details... */
tap_queue_packet(mac_lte_tap, pinfo, &tap_info);
}
void proto_register_mac_lte(void)
{
static hf_register_info hf[] =
{
/**********************************/
/* Items for decoding context */
{ &hf_mac_lte_context_radio_type,
{ "Radio Type",
"mac-lte.radio-type", FT_UINT8, BASE_DEC, VALS(radio_type_vals), 0x0,
"Radio Type", HFILL
}
},
{ &hf_mac_lte_context_direction,
{ "Direction",
"mac-lte.direction", FT_UINT8, BASE_DEC, VALS(direction_vals), 0x0,
"Direction of message", HFILL
}
},
{ &hf_mac_lte_context_rnti,
{ "RNTI",
"mac-lte.rnti", FT_UINT16, BASE_DEC, 0, 0x0,
"RNTI associated with message", HFILL
}
},
{ &hf_mac_lte_context_rnti_type,
{ "RNTI Type",
"mac-lte.rnti-type", FT_UINT8, BASE_DEC, VALS(rnti_type_vals), 0x0,
"Type of RNTI associated with message", HFILL
}
},
{ &hf_mac_lte_context_ueid,
{ "UEId",
"mac-lte.ueid", FT_UINT16, BASE_DEC, 0, 0x0,
"User Equipment Identifier associated with message", HFILL
}
},
{ &hf_mac_lte_context_subframe_number,
{ "Subframe",
"mac-lte.subframe", FT_UINT16, BASE_DEC, 0, 0x0,
"Subframe number associate with message", HFILL
}
},
{ &hf_mac_lte_context_predefined_frame,
{ "Predefined frame",
"mac-lte.is-predefined-frame", FT_UINT8, BASE_DEC, VALS(predefined_frame_vals), 0x0,
"Predefined test frame (or real MAC PDU)", HFILL
}
},
{ &hf_mac_lte_context_length,
{ "Length of frame",
"mac-lte.length", FT_UINT8, BASE_DEC, 0, 0x0,
"Original length of frame (including SDUs and padding)", HFILL
}
},
{ &hf_mac_lte_context_bch_transport_channel,
{ "Transport channel",
"mac-lte.bch-transport-channel", FT_UINT8, BASE_DEC, VALS(bch_transport_channel_vals), 0x0,
"Transport channel BCH data was carried on", HFILL
}
},
{ &hf_mac_lte_context_retx_count,
{ "ReTX count",
"mac-lte.retx-count", FT_UINT8, BASE_DEC, 0, 0x0,
"Number of times this PDU has been retransmitted", HFILL
}
},
{ &hf_mac_lte_context_crc_status,
{ "CRC Status",
"mac-lte.crc-status", FT_UINT8, BASE_DEC, VALS(crc_status_vals), 0x0,
"CRC Status as reported by PHY", HFILL
}
},
/*******************************************/
/* MAC shared channel header fields */
{ &hf_mac_lte_ulsch_header,
{ "UL-SCH Header",
"mac-lte.ulsch.header", FT_STRING, BASE_NONE, NULL, 0x0,
"UL-SCH Header", HFILL
}
},
{ &hf_mac_lte_dlsch_header,
{ "DL-SCH Header",
"mac-lte.dlsch.header", FT_STRING, BASE_NONE, NULL, 0x0,
"DL-SCH Header", HFILL
}
},
{ &hf_mac_lte_sch_subheader,
{ "SCH sub-header",
"mac-lte.sch.subheader", FT_STRING, BASE_NONE, NULL, 0x0,
"SCH sub-header", HFILL
}
},
{ &hf_mac_lte_sch_reserved,
{ "SCH reserved bits",
"mac-lte.sch.reserved", FT_UINT8, BASE_HEX, NULL, 0xc0,
"SCH reserved bits", HFILL
}
},
{ &hf_mac_lte_sch_extended,
{ "Extension",
"mac-lte.sch.extended", FT_UINT8, BASE_HEX, 0, 0x20,
"Extension - i.e. further headers after this one", HFILL
}
},
{ &hf_mac_lte_dlsch_lcid,
{ "LCID",
"mac-lte.dlsch.lcid", FT_UINT8, BASE_HEX, VALS(dlsch_lcid_vals), 0x1f,
"DL-SCH Logical Channel Identifier", HFILL
}
},
{ &hf_mac_lte_ulsch_lcid,
{ "LCID",
"mac-lte.ulsch.lcid", FT_UINT8, BASE_HEX, VALS(ulsch_lcid_vals), 0x1f,
"UL-SCH Logical Channel Identifier", HFILL
}
},
{ &hf_mac_lte_sch_format,
{ "Format",
"mac-lte.sch.format", FT_UINT8, BASE_HEX, VALS(format_vals), 0x80,
"Format", HFILL
}
},
{ &hf_mac_lte_sch_length,
{ "Length",
"mac-lte.sch.length", FT_UINT16, BASE_DEC, 0, 0x0,
"Length of MAC SDU or MAC control element", HFILL
}
},
{ &hf_mac_lte_sch_header_only,
{ "MAC PDU Header only",
"mac-lte.sch.header-only", FT_UINT8, BASE_DEC, VALS(header_only_vals), 0x0,
"MAC PDU Header only", HFILL
}
},
/********************************/
/* Data */
{ &hf_mac_lte_sch_sdu,
{ "SDU",
"mac-lte.sch.sdu", FT_BYTES, BASE_HEX, 0, 0x0,
"Shared channel SDU", HFILL
}
},
{ &hf_mac_lte_bch_pdu,
{ "BCH PDU",
"mac-lte.bch.pdu", FT_BYTES, BASE_HEX, 0, 0x0,
"BCH PDU", HFILL
}
},
{ &hf_mac_lte_pch_pdu,
{ "PCH PDU",
"mac-lte.pch.pdu", FT_BYTES, BASE_HEX, 0, 0x0,
"PCH PDU", HFILL
}
},
{ &hf_mac_lte_predefined_pdu,
{ "Predefined data",
"mac-lte.predefined-data", FT_BYTES, BASE_HEX, 0, 0x0,
"Predefined test data", HFILL
}
},
{ &hf_mac_lte_padding_data,
{ "Padding data",
"mac-lte.padding-data", FT_BYTES, BASE_HEX, 0, 0x0,
"Padding data", HFILL
}
},
{ &hf_mac_lte_padding_length,
{ "Padding length",
"mac-lte.padding-length", FT_UINT32, BASE_DEC, 0, 0x0,
"Length of padding data at end of frame", HFILL
}
},
/*********************************/
/* RAR fields */
{ &hf_mac_lte_rar,
{ "RAR",
"mac-lte.rar", FT_NONE, BASE_NONE, NULL, 0x0,
"RAR", HFILL
}
},
{ &hf_mac_lte_rar_headers,
{ "RAR Headers",
"mac-lte.rar.headers", FT_STRING, BASE_NONE, NULL, 0x0,
"RAR Headers", HFILL
}
},
{ &hf_mac_lte_rar_header,
{ "RAR Header",
"mac-lte.rar.header", FT_STRING, BASE_NONE, NULL, 0x0,
"RAR Header", HFILL
}
},
{ &hf_mac_lte_rar_extension,
{ "Extension",
"mac-lte.rar.e", FT_UINT8, BASE_HEX, 0, 0x80,
"Extension - i.e. further RAR headers after this one", HFILL
}
},
{ &hf_mac_lte_rar_t,
{ "Type",
"mac-lte.rar.t", FT_UINT8, BASE_HEX, VALS(rar_type_vals), 0x40,
"Type field indicating whether the payload is RAPID or BI", HFILL
}
},
{ &hf_mac_lte_rar_bi,
{ "BI",
"mac-lte.rar.bi", FT_UINT8, BASE_HEX, VALS(rar_bi_vals), 0x0f,
"Backoff Indicator (ms)", HFILL
}
},
{ &hf_mac_lte_rar_rapid,
{ "RAPID",
"mac-lte.rar.rapid", FT_UINT8, BASE_HEX_DEC, 0, 0x3f,
"Random Access Preamble IDentifier", HFILL
}
},
{ &hf_mac_lte_rar_reserved,
{ "Reserved",
"mac-lte.rar.reserved", FT_UINT8, BASE_HEX, 0, 0x30,
"Reserved bits in RAR header - should be 0", HFILL
}
},
{ &hf_mac_lte_rar_body,
{ "RAR Body",
"mac-lte.rar.body", FT_STRING, BASE_NONE, NULL, 0x0,
"RAR Body", HFILL
}
},
{ &hf_mac_lte_rar_reserved2,
{ "Reserved",
"mac-lte.rar.reserved2", FT_UINT8, BASE_HEX, 0, 0x80,
"Reserved bit in RAR body - should be 0", HFILL
}
},
{ &hf_mac_lte_rar_ta,
{ "Timing Advance",
"mac-lte.rar.ta", FT_UINT16, BASE_DEC, 0, 0x7ff0,
"Required adjustment to uplink transmission timing", HFILL
}
},
{ &hf_mac_lte_rar_ul_grant,
{ "UL Grant",
"mac-lte.rar.ul-grant", FT_UINT24, BASE_DEC, 0, 0x0fffff,
"Size of UL Grant", HFILL
}
},
{ &hf_mac_lte_rar_ul_grant_hopping,
{ "Hopping Flag",
"mac-lte.rar.ul-grant.hopping", FT_UINT8, BASE_DEC, 0, 0x08,
"Size of UL Grant", HFILL
}
},
{ &hf_mac_lte_rar_ul_grant_fsrba,
{ "Fixed sized resource block assignment",
"mac-lte.rar.ul.fsrba", FT_UINT16, BASE_DEC, 0, 0x07fe,
"Fixed sized resource block assignment", HFILL
}
},
{ &hf_mac_lte_rar_ul_grant_tmcs,
{ "Truncated Modulation and coding scheme",
"mac-lte.rar.ul.tmcs", FT_UINT16, BASE_DEC, 0, 0x01e0,
"Truncated Modulation and coding scheme", HFILL
}
},
{ &hf_mac_lte_rar_ul_grant_tcsp,
{ "TPC command for scheduled PUSCH",
"mac-lte.rar.ul.tcsp", FT_UINT8, BASE_DEC, 0, 0x01c,
"TPC command for scheduled PUSCH", HFILL
}
},
{ &hf_mac_lte_rar_ul_grant_ul_delay,
{ "UL Delay",
"mac-lte.rar.ul.ul-delay", FT_UINT8, BASE_DEC, 0, 0x02,
"UL Delay", HFILL
}
},
{ &hf_mac_lte_rar_ul_grant_cqi_request,
{ "CQI Request",
"mac-lte.rar.ul.cqi-request", FT_UINT8, BASE_DEC, 0, 0x01,
"CQI Request", HFILL
}
},
{ &hf_mac_lte_rar_temporary_crnti,
{ "Temporary C-RNTI",
"mac-lte.rar.temporary-crnti", FT_UINT16, BASE_DEC, 0, 0x0,
"Temporary C-RNTI", HFILL
}
},
/**********************/
/* Control PDU fields */
{ &hf_mac_lte_control_lcg_id,
{ "Logical Channel Group ID",
"mac-lte.control.lcg-id", FT_UINT8, BASE_DEC, 0, 0xc0,
"Logical Channel Group ID", HFILL
}
},
{ &hf_mac_lte_control_buffer_size,
{ "Buffer Size",
"mac-lte.control.buffer-size", FT_UINT8, BASE_DEC, VALS(buffer_size_vals), 0x3f,
"Buffer Size available in all channels in group", HFILL
}
},
{ &hf_mac_lte_control_buffer_size_1,
{ "Buffer Size 1",
"mac-lte.control.buffer-size-1", FT_UINT8, BASE_DEC, VALS(buffer_size_vals), 0xfc,
"Buffer Size available in for 1st channel in group", HFILL
}
},
{ &hf_mac_lte_control_buffer_size_2,
{ "Buffer Size 2",
"mac-lte.control.buffer-size-2", FT_UINT16, BASE_DEC, VALS(buffer_size_vals), 0x03c0,
"Buffer Size available in for 2nd channel in group", HFILL
}
},
{ &hf_mac_lte_control_buffer_size_3,
{ "Buffer Size 3",
"mac-lte.control.buffer-size-3", FT_UINT16, BASE_DEC, VALS(buffer_size_vals), 0x0fc0,
"Buffer Size available in for 3rd channel in group", HFILL
}
},
{ &hf_mac_lte_control_buffer_size_4,
{ "Buffer Size 4",
"mac-lte.control.buffer-size-4", FT_UINT8, BASE_DEC, VALS(buffer_size_vals), 0x3f,
"Buffer Size available in for 4th channel in group", HFILL
}
},
{ &hf_mac_lte_control_crnti,
{ "C-RNTI",
"mac-lte.control.crnti", FT_UINT16, BASE_DEC, 0, 0x0,
"C-RNTI for the UE", HFILL
}
},
{ &hf_mac_lte_control_timing_advance,
{ "Timing Advance",
"mac-lte.control.timing-advance", FT_UINT8, BASE_DEC, 0, 0x0,
"Timing Advance (TODO: units)", HFILL
}
},
{ &hf_mac_lte_control_ue_contention_resolution_identity,
{ "UE Contention Resoluation Identity",
"mac-lte.control.ue-contention-resoluation-identity", FT_BYTES, BASE_HEX, 0, 0x0,
"UE Contention Resoluation Identity", HFILL
}
},
{ &hf_mac_lte_control_power_headroom_reserved,
{ "Reserved",
"mac-lte.control.power-headroom.reserved", FT_UINT8, BASE_DEC, 0, 0xc0,
"Reserved bits, should be 0", HFILL
}
},
{ &hf_mac_lte_control_power_headroom,
{ "Power Headroom",
"mac-lte.control.power-headroom", FT_UINT8, BASE_DEC, 0, 0x3f,
"Power Headroom", HFILL
}
},
{ &hf_mac_lte_control_padding,
{ "Padding",
"mac-lte.control.padding", FT_NONE, BASE_NONE, 0, 0x0,
"Padding", HFILL
}
},
};
static gint *ett[] =
{
&ett_mac_lte,
&ett_mac_lte_context,
&ett_mac_lte_rar_headers,
&ett_mac_lte_rar_header,
&ett_mac_lte_rar_body,
&ett_mac_lte_rar_ul_grant,
&ett_mac_lte_ulsch_header,
&ett_mac_lte_dlsch_header,
&ett_mac_lte_sch_subheader,
&ett_mac_lte_bch,
&ett_mac_lte_pch
};
module_t *mac_lte_module;
/* Register protocol. */
proto_mac_lte = proto_register_protocol("MAC-LTE", "MAC-LTE", "mac-lte");
proto_register_field_array(proto_mac_lte, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
/* Allow other dissectors to find this one by name. */
register_dissector("mac-lte", dissect_mac_lte, proto_mac_lte);
/* Register the tap name */
mac_lte_tap = register_tap("mac-lte");
/* Preferences */
mac_lte_module = prefs_register_protocol(proto_mac_lte, NULL);
/* Obsolete this preference? (TODO: just delete since never in proper release?) */
prefs_register_obsolete_preference(mac_lte_module, "single_rar");
prefs_register_bool_preference(mac_lte_module, "check_reserved_bits",
"Warn if reserved bits are not 0",
"When set, an expert warning will indicate if reserved bits are not zero",
&global_mac_lte_check_reserved_bits);
prefs_register_uint_preference(mac_lte_module, "retx_count_warn",
"Number of Re-Transmits before expert warning triggered",
"Number of Re-Transmits before expert warning triggered",
10, &global_mac_lte_retx_counter_trigger);
prefs_register_bool_preference(mac_lte_module, "attempt_rrc_decode",
"Attempt to decode BCH, PCH and CCCH data using LTE RRC dissector",
"Attempt to decode BCH, PCH and CCCH data using LTE RRC dissector",
&global_mac_lte_attempt_rrc_decode);
prefs_register_bool_preference(mac_lte_module, "decode_rar_ul_grant",
"Attempt to decode details of RAR UL grant field",
"Attempt to decode details of RAR UL grant field",
&global_mac_lte_decode_rar_ul_grant);
}
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