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wireshark/epan/dissectors/packet-rlc-lte.c

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/* Routines for LTE RLC 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.
*
* 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.
*/
#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"
#include "packet-rlc-lte.h"
#include "packet-pdcp-lte.h"
/* Described in:
* 3GPP TS 36.322 Evolved Universal Terrestial Radio Access (E-UTRA)
* Radio Link Control (RLC) Protocol specification
*/
/* TODO:
- UM & AM re-assembly?
*/
/********************************/
/* Preference settings */
#define SEQUENCE_ANALYSIS_MAC_ONLY 1
#define SEQUENCE_ANALYSIS_RLC_ONLY 2
/* By default don't try to analyse the sequence of messages for AM/UM channels */
static gint global_rlc_lte_am_sequence_analysis = FALSE;
static gint global_rlc_lte_um_sequence_analysis = FALSE;
/* By default don't call PDCP/RRC dissectors for SDU data */
static gboolean global_rlc_lte_call_pdcp_for_srb = FALSE;
enum pdcp_for_drb { PDCP_drb_off, PDCP_drb_SN_7, PDCP_drb_SN_12};
static enum_val_t pdcp_drb_col_vals[] = {
{"pdcp-drb-off", "Off", PDCP_drb_off},
{"pdcp-drb-sn-7", "7-bit SN", PDCP_drb_SN_7},
{"pdcp-drb-sn-12", "12-bit SN", PDCP_drb_SN_12},
{NULL, NULL, -1}
};
static gint global_rlc_lte_call_pdcp_for_drb = (gint)PDCP_drb_off;
static gboolean global_rlc_lte_call_rrc = FALSE;
/* Preference to expect RLC headers without payloads */
static gboolean global_rlc_lte_headers_expected = FALSE;
/* Heuristic dissection */
static gboolean global_rlc_lte_heur = FALSE;
/**************************************************/
/* Initialize the protocol and registered fields. */
int proto_rlc_lte = -1;
extern int proto_mac_lte;
extern int proto_pdcp_lte;
static int rlc_lte_tap = -1;
/* Decoding context */
static int hf_rlc_lte_context = -1;
static int hf_rlc_lte_context_mode = -1;
static int hf_rlc_lte_context_direction = -1;
static int hf_rlc_lte_context_priority = -1;
static int hf_rlc_lte_context_ueid = -1;
static int hf_rlc_lte_context_channel_type = -1;
static int hf_rlc_lte_context_channel_id = -1;
static int hf_rlc_lte_context_pdu_length = -1;
static int hf_rlc_lte_context_um_sn_length = -1;
/* Transparent mode fields */
static int hf_rlc_lte_tm = -1;
static int hf_rlc_lte_tm_data = -1;
/* Unacknowledged mode fields */
static int hf_rlc_lte_um = -1;
static int hf_rlc_lte_um_header = -1;
static int hf_rlc_lte_um_fi = -1;
static int hf_rlc_lte_um_fixed_e = -1;
static int hf_rlc_lte_um_sn = -1;
static int hf_rlc_lte_um_fixed_reserved = -1;
static int hf_rlc_lte_um_data = -1;
static int hf_rlc_lte_extension_part = -1;
/* Extended header (common to UM and AM) */
static int hf_rlc_lte_extension_e = -1;
static int hf_rlc_lte_extension_li = -1;
static int hf_rlc_lte_extension_padding = -1;
/* Acknowledged mode fields */
static int hf_rlc_lte_am = -1;
static int hf_rlc_lte_am_header = -1;
static int hf_rlc_lte_am_data_control = -1;
static int hf_rlc_lte_am_rf = -1;
static int hf_rlc_lte_am_p = -1;
static int hf_rlc_lte_am_fi = -1;
static int hf_rlc_lte_am_fixed_e = -1;
static int hf_rlc_lte_am_fixed_sn = -1;
static int hf_rlc_lte_am_segment_lsf = -1;
static int hf_rlc_lte_am_segment_so = -1;
static int hf_rlc_lte_am_data = -1;
/* Control fields */
static int hf_rlc_lte_am_cpt = -1;
static int hf_rlc_lte_am_ack_sn = -1;
static int hf_rlc_lte_am_e1 = -1;
static int hf_rlc_lte_am_e2 = -1;
static int hf_rlc_lte_am_nack_sn = -1;
static int hf_rlc_lte_am_so_start = -1;
static int hf_rlc_lte_am_so_end = -1;
static int hf_rlc_lte_predefined_pdu = -1;
static int hf_rlc_lte_header_only = -1;
/* Sequence Analysis */
static int hf_rlc_lte_sequence_analysis = -1;
static int hf_rlc_lte_sequence_analysis_ok = -1;
static int hf_rlc_lte_sequence_analysis_previous_frame = -1;
static int hf_rlc_lte_sequence_analysis_expected_sn = -1;
static int hf_rlc_lte_sequence_analysis_framing_info_correct = -1;
static int hf_rlc_lte_sequence_analysis_mac_retx = -1;
static int hf_rlc_lte_sequence_analysis_retx = -1;
static int hf_rlc_lte_sequence_analysis_repeated = -1;
static int hf_rlc_lte_sequence_analysis_skipped = -1;
static int hf_rlc_lte_sequence_analysis_repeated_nack = -1;
static int hf_rlc_lte_sequence_analysis_repeated_nack_original_frame = -1;
/* Subtrees. */
static int ett_rlc_lte = -1;
static int ett_rlc_lte_context = -1;
static int ett_rlc_lte_um_header = -1;
static int ett_rlc_lte_am_header = -1;
static int ett_rlc_lte_extension_part = -1;
static int ett_rlc_lte_sequence_analysis = -1;
/* Value-strings */
static const value_string direction_vals[] =
{
{ DIRECTION_UPLINK, "Uplink"},
{ DIRECTION_DOWNLINK, "Downlink"},
{ 0, NULL }
};
static const value_string rlc_mode_short_vals[] =
{
{ RLC_TM_MODE, "TM"},
{ RLC_UM_MODE, "UM"},
{ RLC_AM_MODE, "AM"},
{ RLC_PREDEF, "PREDEFINED"},
{ 0, NULL }
};
static const value_string rlc_mode_vals[] =
{
{ RLC_TM_MODE, "Transparent Mode"},
{ RLC_UM_MODE, "Unacknowledged Mode"},
{ RLC_AM_MODE, "Acknowledged Mode"},
{ 0, NULL }
};
static const value_string rlc_channel_type_vals[] =
{
{ CHANNEL_TYPE_CCCH, "CCCH"},
{ CHANNEL_TYPE_BCCH, "BCCH"},
{ CHANNEL_TYPE_PCCH, "PCCH"},
{ CHANNEL_TYPE_SRB, "SRB"},
{ CHANNEL_TYPE_DRB, "DRB"},
{ 0, NULL }
};
static const value_string framing_info_vals[] =
{
{ 0, "First byte begins a RLC SDU and last byte ends a RLC SDU"},
{ 1, "First byte begins a RLC SDU and last byte does not end a RLC SDU"},
{ 2, "First byte does not begin a RLC SDU and last byte ends a RLC SDU"},
{ 3, "First byte does not begin a RLC SDU and last byte does not end a RLC SDU"},
{ 0, NULL }
};
static const value_string fixed_extension_vals[] =
{
{ 0, "Data field follows from the octet following the fixed part of the header"},
{ 1, "A set of E field and LI field follows from the octet following the fixed part of the header"},
{ 0, NULL }
};
static const value_string extension_extension_vals[] =
{
{ 0, "Data field follows from the octet following the LI field following this E field"},
{ 1, "A set of E field and LI field follows from the bit following the LI field following this E field"},
{ 0, NULL }
};
static const value_string data_or_control_vals[] =
{
{ 0, "Control PDU"},
{ 1, "Data PDU"},
{ 0, NULL }
};
static const value_string resegmentation_flag_vals[] =
{
{ 0, "AMD PDU"},
{ 1, "AMD PDU segment"},
{ 0, NULL }
};
static const value_string polling_bit_vals[] =
{
{ 0, "Status report not requested"},
{ 1, "Status report is requested"},
{ 0, NULL }
};
static const value_string lsf_vals[] =
{
{ 0, "Last byte of the AMD PDU segment does not correspond to the last byte of an AMD PDU"},
{ 1, "Last byte of the AMD PDU segment corresponds to the last byte of an AMD PDU"},
{ 0, NULL }
};
static const value_string control_pdu_type_vals[] =
{
{ 0, "STATUS PDU"},
{ 0, NULL }
};
static const value_string am_e1_vals[] =
{
{ 0, "A set of NACK_SN, E1 and E2 does not follow"},
{ 1, "A set of NACK_SN, E1 and E2 follows"},
{ 0, NULL }
};
static const value_string am_e2_vals[] =
{
{ 0, "A set of SOstart and SOend does not follow for this NACK_SN"},
{ 1, "A set of SOstart and SOend follows for this NACK_SN"},
{ 0, NULL }
};
static const value_string header_only_vals[] =
{
{ 0, "RLC PDU Headers and body present"},
{ 1, "RLC PDU Headers only"},
{ 0, NULL }
};
/**********************************************************************************/
/* These are for keeping track of UM/AM extension headers, and the lengths found */
/* in them */
static guint8 s_number_of_extensions = 0;
#define MAX_RLC_SDUS 64
static guint16 s_lengths[MAX_RLC_SDUS];
/*********************************************************************/
/* UM/AM sequence analysis */
/* Types for RLC channel hash table */
/* This table is maintained during initial dissection of RLC */
/* frames, mapping from rlc_channel_hash_key -> rlc_channel_status */
/* Channel key */
typedef struct
{
guint16 ueId;
guint16 channelType;
guint16 channelId;
guint8 direction;
} rlc_channel_hash_key;
/* Conversation-type status for sequence analysis on channel */
typedef struct
{
guint8 rlcMode;
/* For UM, we always expect the SN to keep advancing, and these fields
keep track of this.
For AM, these correspond to new data */
guint16 previousSequenceNumber;
guint32 previousFrameNum;
gboolean previousSegmentIncomplete;
} rlc_channel_sequence_analysis_status;
/* The sequence analysis channel hash table */
static GHashTable *rlc_lte_sequence_analysis_channel_hash = NULL;
/* Types for sequence analysis frame report hash table */
/* This is a table from framenum -> state_report_in_frame */
/* This is necessary because the per-packet info is already being used */
/* for context information before the dissector is called */
/* Info to attach to frame when first read, recording what to show about sequence */
typedef struct
{
gboolean sequenceExpectedCorrect;
guint16 sequenceExpected;
guint32 previousFrameNum;
gboolean previousSegmentIncomplete;
guint16 firstSN;
guint16 lastSN;
/* AM/UM */
enum { SN_OK, SN_Repeated, SN_MAC_Retx, SN_Retx, SN_Missing} state;
} state_sequence_analysis_report_in_frame;
/* The sequence analysis frame report hash table instance itself */
static GHashTable *rlc_lte_frame_sequence_analysis_report_hash = NULL;
/******************************************************************/
/* Conversation-type status for repeated NACK checking on channel */
typedef struct
{
guint16 noOfNACKs;
guint16 NACKs[MAX_NACKs];
guint32 frameNum;
} rlc_channel_repeated_nack_status;
static GHashTable *rlc_lte_repeated_nack_channel_hash = NULL;
typedef struct {
guint16 noOfNACKsRepeated;
guint16 repeatedNACKs[MAX_NACKs];
guint32 previousFrameNum;
} rlc_channel_repeated_nack_report_in_frame;
static GHashTable *rlc_lte_frame_repeated_nack_report_hash = NULL;
/********************************************************/
/* Forward declarations & functions */
static void dissect_rlc_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
/* Write the given formatted text to:
- the info column
- the top-level RLC PDU item
- another subtree item (if supplied) */
static void write_pdu_label_and_info(proto_item *pdu_ti, proto_item *sub_ti,
packet_info *pinfo, const char *format, ...)
{
#define MAX_INFO_BUFFER 256
static char info_buffer[MAX_INFO_BUFFER];
va_list ap;
va_start(ap, format);
g_vsnprintf(info_buffer, MAX_INFO_BUFFER, format, ap);
va_end(ap);
/* Add to indicated places */
col_append_str(pinfo->cinfo, COL_INFO, info_buffer);
proto_item_append_text(pdu_ti, "%s", info_buffer);
if (sub_ti != NULL) {
proto_item_append_text(sub_ti, "%s", info_buffer);
}
}
/* Dissect extension headers (common to both UM and AM) */
static int dissect_rlc_lte_extension_header(tvbuff_t *tvb, packet_info *pinfo _U_,
proto_tree *tree,
int offset)
{
guint8 isOdd;
guint64 extension = 1;
guint64 length;
/* Reset this count */
s_number_of_extensions = 0;
while (extension && (s_number_of_extensions < MAX_RLC_SDUS)) {
proto_tree *extension_part_tree;
proto_item *extension_part_ti;
isOdd = (s_number_of_extensions % 2);
/* Extension part subtree */
extension_part_ti = proto_tree_add_string_format(tree,
hf_rlc_lte_extension_part,
tvb, offset, 2,
"",
"Extension Part");
extension_part_tree = proto_item_add_subtree(extension_part_ti,
ett_rlc_lte_extension_part);
/* Read next extension */
proto_tree_add_bits_ret_val(extension_part_tree, hf_rlc_lte_extension_e, tvb,
(offset*8) + ((isOdd) ? 4 : 0),
1,
&extension, FALSE);
/* Read length field */
proto_tree_add_bits_ret_val(extension_part_tree, hf_rlc_lte_extension_li, tvb,
(offset*8) + ((isOdd) ? 5 : 1),
11,
&length, FALSE);
proto_item_append_text(extension_part_tree, " (length=%u)", (guint16)length);
/* Move on to byte of next extension */
if (isOdd) {
offset += 2;
} else {
offset++;
}
s_lengths[s_number_of_extensions++] = (guint16)length;
}
/* May need to skip padding after last extension part */
isOdd = (s_number_of_extensions % 2);
if (isOdd) {
guint8 padding;
proto_item *ti;
padding = tvb_get_guint8(tvb, offset) & 0x0f;
ti = proto_tree_add_item(tree, hf_rlc_lte_extension_padding,
tvb, offset, 1, FALSE);
offset++;
}
return offset;
}
/* Show in the info column how many bytes are in the UM/AM PDU, and indicate
whether or not the beginning and end are included in this packet */
static void show_PDU_in_info(packet_info *pinfo,
proto_item *top_ti,
guint16 length,
gboolean first_includes_start,
gboolean last_includes_end)
{
/* Reflect this PDU in the info column */
write_pdu_label_and_info(top_ti, NULL, pinfo,
" %s%u-byte%s%s",
(first_includes_start) ? "[" : "..",
length,
(length > 1) ? "s" : "",
(last_includes_end) ? "]" : "..");
}
/* Show an SDU. If configured, pass to PDCP dissector */
static void show_PDU_in_tree(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, gint offset, gint length,
rlc_lte_info *rlc_info, gboolean whole_pdu)
{
/* Add raw data (according to mode) */
proto_item *data_ti = proto_tree_add_item(tree,
(rlc_info->rlcMode == RLC_AM_MODE) ?
hf_rlc_lte_am_data :
hf_rlc_lte_um_data,
tvb, offset, length, FALSE);
/* Decode signalling PDUs as PDCP */
if (whole_pdu &&
(((global_rlc_lte_call_pdcp_for_srb) && (rlc_info->channelType == CHANNEL_TYPE_SRB)) ||
((global_rlc_lte_call_pdcp_for_drb != PDCP_drb_off) && (rlc_info->channelType == CHANNEL_TYPE_DRB)))) {
/* Attempt to decode payload using LTE PDCP dissector */
tvbuff_t *pdcp_tvb = tvb_new_subset(tvb, offset, length, length);
volatile dissector_handle_t protocol_handle;
struct pdcp_lte_info *p_pdcp_lte_info;
/* Reuse or allocate struct */
p_pdcp_lte_info = p_get_proto_data(pinfo->fd, proto_pdcp_lte);
if (p_pdcp_lte_info == NULL) {
p_pdcp_lte_info = se_alloc0(sizeof(struct pdcp_lte_info));
/* Store info in packet */
p_add_proto_data(pinfo->fd, proto_pdcp_lte, p_pdcp_lte_info);
}
p_pdcp_lte_info->ueid = rlc_info->ueid;
p_pdcp_lte_info->channelType = Channel_DCCH;
p_pdcp_lte_info->channelId = rlc_info->channelId;
p_pdcp_lte_info->direction = rlc_info->direction;
/* Set plane and sequnce number length */
p_pdcp_lte_info->no_header_pdu = FALSE;
if (rlc_info->channelType == CHANNEL_TYPE_SRB) {
p_pdcp_lte_info->plane = SIGNALING_PLANE;
p_pdcp_lte_info->seqnum_length = 5;
}
else {
p_pdcp_lte_info->plane = USER_PLANE;
switch (global_rlc_lte_call_pdcp_for_drb) {
case PDCP_drb_SN_7:
p_pdcp_lte_info->seqnum_length = 7;
break;
case PDCP_drb_SN_12:
p_pdcp_lte_info->seqnum_length = 12;
break;
default:
DISSECTOR_ASSERT(FALSE);
break;
}
}
p_pdcp_lte_info->rohc_compression = FALSE;
/* Get dissector handle */
protocol_handle = find_dissector("pdcp-lte");
TRY {
call_dissector_only(protocol_handle, pdcp_tvb, pinfo, tree);
}
CATCH_ALL {
}
ENDTRY
PROTO_ITEM_SET_HIDDEN(data_ti);
}
}
/* Hash table functions for RLC channels */
/* Equal keys */
static gint rlc_channel_equal(gconstpointer v, gconstpointer v2)
{
const rlc_channel_hash_key* val1 = v;
const rlc_channel_hash_key* val2 = v2;
/* All fields must match */
return ((val1->ueId == val2->ueId) &&
(val1->channelType == val2->channelType) &&
(val1->channelId == val2->channelId) &&
(val1->direction == val2->direction));
}
/* Compute a hash value for a given key. */
static guint rlc_channel_hash_func(gconstpointer v)
{
const rlc_channel_hash_key* val1 = v;
/* TODO: check/reduce multipliers */
return ((val1->ueId * 1024) + (val1->channelType*64) + (val1->channelId*2) + val1->direction);
}
/* Hash table functions for frame reports */
/* Equal keys */
static gint rlc_frame_equal(gconstpointer v, gconstpointer v2)
{
return (v == v2);
}
/* Compute a hash value for a given key. */
static guint rlc_frame_hash_func(gconstpointer v)
{
return GPOINTER_TO_UINT(v);
}
/* Add to the tree values associated with sequence analysis for this frame */
static void addChannelSequenceInfo(state_sequence_analysis_report_in_frame *p,
rlc_lte_info *p_rlc_lte_info,
guint16 sequenceNumber,
gboolean newSegmentStarted,
rlc_lte_tap_info *tap_info,
packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb)
{
proto_tree *seqnum_tree;
proto_item *seqnum_ti;
proto_item *ti;
/* Create subtree */
seqnum_ti = proto_tree_add_string_format(tree,
hf_rlc_lte_sequence_analysis,
tvb, 0, 0,
"", "Sequence Analysis");
seqnum_tree = proto_item_add_subtree(seqnum_ti,
ett_rlc_lte_sequence_analysis);
PROTO_ITEM_SET_GENERATED(seqnum_ti);
switch (p_rlc_lte_info->rlcMode) {
case RLC_AM_MODE:
/********************************************/
/* AM */
/********************************************/
switch (p->state) {
case SN_OK:
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_ok,
tvb, 0, 0, TRUE);
PROTO_ITEM_SET_GENERATED(ti);
proto_item_append_text(seqnum_ti, " - OK");
break;
case SN_MAC_Retx:
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_ok,
tvb, 0, 0, FALSE);
PROTO_ITEM_SET_GENERATED(ti);
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_mac_retx,
tvb, 0, 0, TRUE);
PROTO_ITEM_SET_GENERATED(ti);
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"AM Frame retransmitted for %s on UE %u - due to MAC retx!",
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
break;
case SN_Retx:
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_ok,
tvb, 0, 0, FALSE);
PROTO_ITEM_SET_GENERATED(ti);
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_retx,
tvb, 0, 0, TRUE);
PROTO_ITEM_SET_GENERATED(ti);
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"AM Frame retransmitted for %s on UE %u - most likely in response to NACK",
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
proto_item_append_text(seqnum_ti, " - SN %u retransmitted", p->firstSN);
break;
case SN_Repeated:
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_ok,
tvb, 0, 0, FALSE);
PROTO_ITEM_SET_GENERATED(ti);
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_repeated,
tvb, 0, 0, TRUE);
PROTO_ITEM_SET_GENERATED(ti);
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"AM SN %u Repeated for %s for UE %u - probably because didn't receive Status PDU?",
p->firstSN,
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
proto_item_append_text(seqnum_ti, "- SN %u Repeated",
p->firstSN);
break;
case SN_Missing:
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_ok,
tvb, 0, 0, FALSE);
PROTO_ITEM_SET_GENERATED(ti);
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_skipped,
tvb, 0, 0, TRUE);
PROTO_ITEM_SET_GENERATED(ti);
if (p->lastSN != p->firstSN) {
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"AM SNs (%u to %u) missing for %s on UE %u",
p->firstSN, p->lastSN,
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
proto_item_append_text(seqnum_ti, " - SNs missing (%u to %u)",
p->firstSN, p->lastSN);
tap_info->missingSNs = ((p->lastSN - p->firstSN) % 1024) + 1;
}
else {
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"AM SN (%u) missing for %s on UE %u",
p->firstSN,
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
proto_item_append_text(seqnum_ti, " - SN missing (%u)",
p->firstSN);
tap_info->missingSNs = 1;
}
break;
}
break;
case RLC_UM_MODE:
/********************************************/
/* UM */
/********************************************/
/* Previous channel frame */
if (p->previousFrameNum != 0) {
proto_tree_add_uint(seqnum_tree, hf_rlc_lte_sequence_analysis_previous_frame,
tvb, 0, 0, p->previousFrameNum);
}
/* Expected sequence number */
ti = proto_tree_add_uint(seqnum_tree, hf_rlc_lte_sequence_analysis_expected_sn,
tvb, 0, 0, p->sequenceExpected);
PROTO_ITEM_SET_GENERATED(ti);
if (!p->sequenceExpectedCorrect) {
/* Work out SN wrap (in case needed below) */
guint16 snLimit;
if (p_rlc_lte_info->UMSequenceNumberLength == 5) {
snLimit = 32;
}
else {
snLimit = 1024;
}
switch (p->state) {
case SN_Missing:
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_ok,
tvb, 0, 0, FALSE);
PROTO_ITEM_SET_GENERATED(ti);
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_skipped,
tvb, 0, 0, TRUE);
PROTO_ITEM_SET_GENERATED(ti);
if (p->lastSN != p->firstSN) {
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"UM SNs (%u to %u) missing for %s on UE %u",
p->firstSN, p->lastSN,
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
proto_item_append_text(seqnum_ti, " - SNs missing (%u to %u)",
p->firstSN, p->lastSN);
tap_info->missingSNs = ((p->lastSN - p->firstSN) % snLimit) + 1;
}
else {
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"UM SN (%u) missing for %s on UE %u",
p->firstSN,
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
proto_item_append_text(seqnum_ti, " - SN missing (%u)",
p->firstSN);
tap_info->missingSNs = 1;
}
break;
case SN_Repeated:
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_ok,
tvb, 0, 0, FALSE);
PROTO_ITEM_SET_GENERATED(ti);
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_repeated,
tvb, 0, 0, TRUE);
PROTO_ITEM_SET_GENERATED(ti);
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"UM SN (%u) repeated for %s for UE %u",
p->firstSN,
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
proto_item_append_text(seqnum_ti, "- SN %u Repeated",
p->firstSN);
break;
case SN_MAC_Retx:
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_ok,
tvb, 0, 0, FALSE);
PROTO_ITEM_SET_GENERATED(ti);
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_mac_retx,
tvb, 0, 0, TRUE);
PROTO_ITEM_SET_GENERATED(ti);
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"UM Frame retransmitted for %s on UE %u - due to MAC retx!",
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
break;
default:
/* Incorrect sequence number */
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"Wrong Sequence Number for %s on UE %u - got %u, expected %u",
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid, sequenceNumber, p->sequenceExpected);
break;
}
}
else {
/* Correct sequence number, so check frame indication bits consistent */
if (p->previousSegmentIncomplete) {
/* Previous segment was incomplete, so this PDU should continue it */
if (newSegmentStarted) {
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_framing_info_correct,
tvb, 0, 0, FALSE);
if (!p->sequenceExpectedCorrect) {
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"Last segment of previous PDU was not continued for UE %u",
p_rlc_lte_info->ueid);
}
}
else {
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_framing_info_correct,
tvb, 0, 0, TRUE);
}
}
else {
/* Previous segment was complete, so this PDU should start a new one */
if (!newSegmentStarted) {
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_framing_info_correct,
tvb, 0, 0, FALSE);
if (!p->sequenceExpectedCorrect) {
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
"Last segment of previous PDU was complete, but new segment was not started");
}
}
else {
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_framing_info_correct,
tvb, 0, 0, TRUE);
}
}
PROTO_ITEM_SET_GENERATED(ti);
}
}
}
/* Update the channel status and set report for this frame */
static void checkChannelSequenceInfo(packet_info *pinfo, tvbuff_t *tvb,
rlc_lte_info *p_rlc_lte_info,
guint16 sequenceNumber,
gboolean first_includes_start, gboolean last_includes_end,
gboolean is_resegmented _U_,
rlc_lte_tap_info *tap_info,
proto_tree *tree)
{
rlc_channel_hash_key channel_key;
rlc_channel_hash_key *p_channel_key;
rlc_channel_sequence_analysis_status *p_channel_status;
state_sequence_analysis_report_in_frame *p_report_in_frame = NULL;
gboolean createdChannel = FALSE;
guint16 expectedSequenceNumber = 0;
guint16 snLimit = 0;
/* If find stat_report_in_frame already, use that and get out */
if (pinfo->fd->flags.visited) {
p_report_in_frame = (state_sequence_analysis_report_in_frame*)g_hash_table_lookup(rlc_lte_frame_sequence_analysis_report_hash,
&pinfo->fd->num);
if (p_report_in_frame != NULL) {
addChannelSequenceInfo(p_report_in_frame, p_rlc_lte_info,
sequenceNumber, first_includes_start,
tap_info, pinfo, tree, tvb);
return;
}
else {
/* Give up - we must have tried already... */
return;
}
}
/**************************************************/
/* Create or find an entry for this channel state */
channel_key.ueId = p_rlc_lte_info->ueid;
channel_key.channelType = p_rlc_lte_info->channelType;
channel_key.channelId = p_rlc_lte_info->channelId;
channel_key.direction = p_rlc_lte_info->direction;
/* Do the table lookup */
p_channel_status = (rlc_channel_sequence_analysis_status*)g_hash_table_lookup(rlc_lte_sequence_analysis_channel_hash, &channel_key);
/* Create table entry if necessary */
if (p_channel_status == NULL) {
createdChannel = TRUE;
/* Allocate a new key and value */
p_channel_key = se_alloc(sizeof(rlc_channel_hash_key));
p_channel_status = se_alloc0(sizeof(rlc_channel_sequence_analysis_status));
/* Copy key contents */
memcpy(p_channel_key, &channel_key, sizeof(rlc_channel_hash_key));
/* Set mode */
p_channel_status->rlcMode = p_rlc_lte_info->rlcMode;
/* Add entry */
g_hash_table_insert(rlc_lte_sequence_analysis_channel_hash, p_channel_key, p_channel_status);
}
/* Create space for frame state_report */
p_report_in_frame = se_alloc(sizeof(state_sequence_analysis_report_in_frame));
switch (p_channel_status->rlcMode) {
case RLC_UM_MODE:
if (p_rlc_lte_info->UMSequenceNumberLength == 5) {
snLimit = 32;
}
else {
snLimit = 1024;
}
/* Work out expected sequence number */
if (!createdChannel) {
expectedSequenceNumber = (p_channel_status->previousSequenceNumber + 1) % snLimit;
}
/* Set report for this frame */
/* For UM, sequence number is always expectedSequence number */
p_report_in_frame->sequenceExpectedCorrect = (sequenceNumber == expectedSequenceNumber);
/* For wrong sequence number... */
if (!p_report_in_frame->sequenceExpectedCorrect) {
p_report_in_frame->sequenceExpectedCorrect = FALSE;
/* Don't get confused by MAC (HARQ) retx */
if (is_mac_lte_frame_retx(pinfo, p_rlc_lte_info->direction)) {
p_report_in_frame->state = SN_MAC_Retx;
}
/* Frames are not missing if we get an earlier sequence number again */
else if (((snLimit + expectedSequenceNumber - sequenceNumber) % snLimit) > 40) {
if (!createdChannel) {
p_report_in_frame->state = SN_Missing;
tap_info->missingSNs = (snLimit + sequenceNumber - expectedSequenceNumber) % snLimit;
p_report_in_frame->firstSN = expectedSequenceNumber;
p_report_in_frame->lastSN = (snLimit + sequenceNumber - 1) % snLimit;
p_report_in_frame->sequenceExpected = expectedSequenceNumber;
p_report_in_frame->previousFrameNum = p_channel_status->previousFrameNum;
p_report_in_frame->previousSegmentIncomplete = p_channel_status->previousSegmentIncomplete;
}
else {
/* The log may not contain the very first SNs for this channel, so be forgiving... */
p_report_in_frame->state = SN_OK;
}
/* Update channel status to remember *this* frame */
p_channel_status->previousFrameNum = pinfo->fd->num;
p_channel_status->previousSequenceNumber = sequenceNumber;
p_channel_status->previousSegmentIncomplete = !last_includes_end;
}
else {
/* An SN has been repeated */
p_report_in_frame->state = SN_Repeated;
p_report_in_frame->firstSN = sequenceNumber;
p_report_in_frame->sequenceExpected = expectedSequenceNumber;
p_report_in_frame->previousFrameNum = p_channel_status->previousFrameNum;
}
}
else {
/* SN was OK */
p_report_in_frame->sequenceExpected = expectedSequenceNumber;
p_report_in_frame->previousFrameNum = p_channel_status->previousFrameNum;
p_report_in_frame->previousSegmentIncomplete = p_channel_status->previousSegmentIncomplete;
/* Update channel status to remember *this* frame */
p_channel_status->previousFrameNum = pinfo->fd->num;
p_channel_status->previousSequenceNumber = sequenceNumber;
p_channel_status->previousSegmentIncomplete = !last_includes_end;
}
break;
case RLC_AM_MODE:
/* Work out expected sequence number */
if (!createdChannel) {
expectedSequenceNumber = (p_channel_status->previousSequenceNumber + 1) % 1024;
}
/* For AM, may be:
- expected Sequence number OR
- previous frame repeated
- old SN being sent (in response to NACK)
- new SN, but with frames missed out
Assume window whose front is at expectedSequenceNumber */
/* First of all, check to see whether frame is judged to be MAC Retx */
if (is_mac_lte_frame_retx(pinfo, p_rlc_lte_info->direction)) {
/* Just report that this is a MAC Retx */
p_report_in_frame->state = SN_MAC_Retx;
/* No channel state to update */
}
/* Expected? */
else if (sequenceNumber == expectedSequenceNumber) {
/* Set report for this frame */
p_report_in_frame->sequenceExpectedCorrect = TRUE;
p_report_in_frame->sequenceExpected = expectedSequenceNumber;
p_report_in_frame->previousFrameNum = p_channel_status->previousFrameNum;
p_report_in_frame->previousSegmentIncomplete = p_channel_status->previousSegmentIncomplete;
p_report_in_frame->state = SN_OK;
/* Update channel status */
p_channel_status->previousSequenceNumber = sequenceNumber;
p_channel_status->previousFrameNum = pinfo->fd->num;
p_channel_status->previousSegmentIncomplete = !last_includes_end;
}
/* Previous subframe repeated? */
else if (((sequenceNumber+1) % 1024) == expectedSequenceNumber) {
p_report_in_frame->state = SN_Repeated;
/* Set report for this frame */
p_report_in_frame->sequenceExpectedCorrect = FALSE;
p_report_in_frame->sequenceExpected = expectedSequenceNumber;
p_report_in_frame->firstSN = sequenceNumber;
p_report_in_frame->previousFrameNum = p_channel_status->previousFrameNum;
p_report_in_frame->previousSegmentIncomplete = p_channel_status->previousSegmentIncomplete;
/* Really should be nothing to update... */
p_channel_status->previousSequenceNumber = sequenceNumber;
p_channel_status->previousFrameNum = pinfo->fd->num;
p_channel_status->previousSegmentIncomplete = !last_includes_end;
}
else {
/* Need to work out if new (with skips, or likely a retx (due to NACK)) */
int delta = (1024 + expectedSequenceNumber - sequenceNumber) % 1024;
/* Rx window is 512, so check to see if this is a retx */
if (delta < 512) {
/* Probably a retx due to receiving NACK */
p_report_in_frame->state = SN_Retx;
p_report_in_frame->firstSN = sequenceNumber;
/* Don't update anything in channel state */
}
else {
if (!createdChannel) {
/* Ahead of expected SN. Assume frames have been missed */
p_report_in_frame->state = SN_Missing;
p_report_in_frame->firstSN = expectedSequenceNumber;
p_report_in_frame->lastSN = (1024 + sequenceNumber-1) % 1024;
}
else {
/* The log may not contain the very first SNs for this channel, so be forgiving... */
p_report_in_frame->state = SN_OK;
}
/* Update channel state - forget about missed SNs */
p_report_in_frame->sequenceExpected = expectedSequenceNumber;
p_channel_status->previousSequenceNumber = sequenceNumber;
p_channel_status->previousFrameNum = pinfo->fd->num;
p_channel_status->previousSegmentIncomplete = !last_includes_end;
}
}
break;
default:
/* Shouldn't get here! */
return;
}
/* Associate with this frame number */
g_hash_table_insert(rlc_lte_frame_sequence_analysis_report_hash, &pinfo->fd->num, p_report_in_frame);
/* Add state report for this frame into tree */
addChannelSequenceInfo(p_report_in_frame, p_rlc_lte_info, sequenceNumber,
first_includes_start, tap_info, pinfo, tree, tvb);
}
/* Add to the tree values associated with sequence analysis for this frame */
static void addChannelRepeatedNACKInfo(rlc_channel_repeated_nack_report_in_frame *p,
rlc_lte_info *p_rlc_lte_info,
packet_info *pinfo, proto_tree *tree,
tvbuff_t *tvb)
{
proto_tree *seqnum_tree;
proto_item *seqnum_ti;
proto_item *ti;
gint n;
/* Create subtree */
seqnum_ti = proto_tree_add_string_format(tree,
hf_rlc_lte_sequence_analysis,
tvb, 0, 0,
"", "Sequence Analysis");
seqnum_tree = proto_item_add_subtree(seqnum_ti,
ett_rlc_lte_sequence_analysis);
PROTO_ITEM_SET_GENERATED(seqnum_ti);
/* OK = FALSE */
ti = proto_tree_add_boolean(seqnum_tree, hf_rlc_lte_sequence_analysis_ok,
tvb, 0, 0, FALSE);
PROTO_ITEM_SET_GENERATED(ti);
/* Add each repeated NACK as item & expert info */
for (n=0; n < p->noOfNACKsRepeated; n++) {
ti = proto_tree_add_uint(seqnum_tree, hf_rlc_lte_sequence_analysis_repeated_nack,
tvb, 0, 0, p->repeatedNACKs[n]);
PROTO_ITEM_SET_GENERATED(ti);
expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_ERROR,
"Same SN (%u) NACKd for %s on UE %u in successive Status PDUs",
p->repeatedNACKs[n],
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
}
/* Link back to previous status report */
ti = proto_tree_add_uint(seqnum_tree, hf_rlc_lte_sequence_analysis_repeated_nack_original_frame,
tvb, 0, 0, p->previousFrameNum);
PROTO_ITEM_SET_GENERATED(ti);
/* Append count to sequence analysis root */
proto_item_append_text(seqnum_ti, " - %u SNs repeated from previous Status PDU",
p->noOfNACKsRepeated);
}
/* Update the channel repeated NACK status and set report for this frame */
static void checkChannelRepeatedNACKInfo(packet_info *pinfo,
rlc_lte_info *p_rlc_lte_info,
rlc_lte_tap_info *tap_info,
proto_tree *tree,
tvbuff_t *tvb)
{
rlc_channel_hash_key channel_key;
rlc_channel_hash_key *p_channel_key;
rlc_channel_repeated_nack_status *p_channel_status;
rlc_channel_repeated_nack_report_in_frame *p_report_in_frame = NULL;
guint16 noOfNACKsRepeated = 0;
guint16 repeatedNACKs[MAX_NACKs];
gint n, i, j;
/* If find state_report_in_frame already, use that and get out */
if (pinfo->fd->flags.visited) {
p_report_in_frame = (rlc_channel_repeated_nack_report_in_frame*)g_hash_table_lookup(rlc_lte_frame_repeated_nack_report_hash,
&pinfo->fd->num);
if (p_report_in_frame != NULL) {
addChannelRepeatedNACKInfo(p_report_in_frame, p_rlc_lte_info,
pinfo, tree, tvb);
return;
}
else {
/* Give up - we must have tried already... */
return;
}
}
/**************************************************/
/* Create or find an entry for this channel state */
channel_key.ueId = p_rlc_lte_info->ueid;
channel_key.channelType = p_rlc_lte_info->channelType;
channel_key.channelId = p_rlc_lte_info->channelId;
channel_key.direction = p_rlc_lte_info->direction;
memset(repeatedNACKs, 0, sizeof(repeatedNACKs));
/* Do the table lookup */
p_channel_status = (rlc_channel_repeated_nack_status*)g_hash_table_lookup(rlc_lte_repeated_nack_channel_hash, &channel_key);
/* Create table entry if necessary */
if (p_channel_status == NULL) {
/* Allocate a new key and value */
p_channel_key = se_alloc(sizeof(rlc_channel_hash_key));
p_channel_status = se_alloc0(sizeof(rlc_channel_repeated_nack_status));
/* Copy key contents */
memcpy(p_channel_key, &channel_key, sizeof(rlc_channel_hash_key));
/* Add entry to table */
g_hash_table_insert(rlc_lte_repeated_nack_channel_hash, p_channel_key, p_channel_status);
}
/* Compare NACKs in channel status with NACKs in tap_info.
Note any that are repeated */
for (i=0; i < p_channel_status->noOfNACKs; i++) {
for (j=0; j < MIN(tap_info->noOfNACKs, MAX_NACKs); j++) {
if (tap_info->NACKs[j] == p_channel_status->NACKs[i]) {
/* Don't add the same repeated NACK twice! */
if ((noOfNACKsRepeated == 0) ||
(repeatedNACKs[noOfNACKsRepeated-1] != p_channel_status->NACKs[i])) {
repeatedNACKs[noOfNACKsRepeated++] = p_channel_status->NACKs[i];
}
}
}
}
/* Copy NACKs from tap_info into channel status for next time! */
p_channel_status->noOfNACKs = 0;
for (n=0; n < MIN(tap_info->noOfNACKs, MAX_NACKs); n++) {
p_channel_status->NACKs[p_channel_status->noOfNACKs++] = tap_info->NACKs[n];
}
if (noOfNACKsRepeated >= 1) {
/* Create space for frame state_report */
p_report_in_frame = se_alloc(sizeof(rlc_channel_repeated_nack_report_in_frame));
/* Copy in found duplicates */
for (n=0; n < MIN(tap_info->noOfNACKs, MAX_NACKs); n++) {
p_report_in_frame->repeatedNACKs[n] = repeatedNACKs[n];
}
p_report_in_frame->noOfNACKsRepeated = noOfNACKsRepeated;
p_report_in_frame->previousFrameNum = p_channel_status->frameNum;
/* Associate with this frame number */
g_hash_table_insert(rlc_lte_frame_repeated_nack_report_hash, &pinfo->fd->num, p_report_in_frame);
/* Add state report for this frame into tree */
addChannelRepeatedNACKInfo(p_report_in_frame, p_rlc_lte_info,
pinfo, tree, tvb);
}
/* Save frame number for next comparison */
p_channel_status->frameNum = pinfo->fd->num;
}
/***************************************************/
/* Transparent mode PDU. Call RRC if configured to */
static void dissect_rlc_lte_tm(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree,
int offset,
rlc_lte_info *p_rlc_lte_info,
proto_item *top_ti)
{
proto_item *raw_tm_ti;
proto_item *tm_ti;
/* Create hidden TM root */
tm_ti = proto_tree_add_string_format(tree, hf_rlc_lte_tm,
tvb, offset, 0, "", "UM");
PROTO_ITEM_SET_HIDDEN(tm_ti);
/* Remaining bytes are all data */
raw_tm_ti = proto_tree_add_item(tree, hf_rlc_lte_tm_data, tvb, offset, -1, FALSE);
if (!global_rlc_lte_call_rrc) {
write_pdu_label_and_info(top_ti, NULL, pinfo,
" [%u-bytes]", tvb_length_remaining(tvb, offset));
}
if (global_rlc_lte_call_rrc) {
tvbuff_t *rrc_tvb = tvb_new_subset(tvb, offset, -1, tvb_length_remaining(tvb, offset));
volatile dissector_handle_t protocol_handle = 0;
switch (p_rlc_lte_info->channelType) {
case CHANNEL_TYPE_CCCH:
if (p_rlc_lte_info->direction == DIRECTION_UPLINK) {
protocol_handle = find_dissector("lte_rrc.ul_ccch");
}
else {
protocol_handle = find_dissector("lte_rrc.dl_ccch");
}
break;
case CHANNEL_TYPE_BCCH:
/* TODO: Problem is don't know which transport channel... */
return;
case CHANNEL_TYPE_PCCH:
protocol_handle = find_dissector("lte-rrc.pcch");
break;
case CHANNEL_TYPE_SRB:
case CHANNEL_TYPE_DRB:
default:
/* Shouldn't happen, just return... */
return;
}
/* Hide raw view of bytes */
PROTO_ITEM_SET_HIDDEN(raw_tm_ti);
/* Call it (catch exceptions) */
TRY {
call_dissector_only(protocol_handle, rrc_tvb, pinfo, tree);
}
CATCH_ALL {
}
ENDTRY
}
}
/***************************************************/
/* Unacknowledged mode PDU */
static void dissect_rlc_lte_um(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree,
int offset,
rlc_lte_info *p_rlc_lte_info,
proto_item *top_ti,
rlc_lte_tap_info *tap_info)
{
guint64 framing_info;
gboolean first_includes_start;
gboolean last_includes_end;
guint64 fixed_extension;
guint64 sn;
gint start_offset = offset;
proto_item *um_ti;
proto_tree *um_header_tree;
proto_item *um_header_ti;
gboolean is_truncated;
proto_item *truncated_ti;
/* Hidden UM root */
um_ti = proto_tree_add_string_format(tree, hf_rlc_lte_um,
tvb, offset, 0, "", "UM");
PROTO_ITEM_SET_HIDDEN(um_ti);
/* Add UM header subtree */
um_header_ti = proto_tree_add_string_format(tree, hf_rlc_lte_um_header,
tvb, offset, 0,
"", "UM header");
um_header_tree = proto_item_add_subtree(um_header_ti,
ett_rlc_lte_um_header);
/*******************************/
/* Fixed UM header */
if (p_rlc_lte_info->UMSequenceNumberLength == UM_SN_LENGTH_5_BITS) {
/* Framing info (2 bits) */
proto_tree_add_bits_ret_val(um_header_tree, hf_rlc_lte_um_fi,
tvb, offset*8, 2,
&framing_info, FALSE);
/* Extension (1 bit) */
proto_tree_add_bits_ret_val(um_header_tree, hf_rlc_lte_um_fixed_e, tvb,
(offset*8) + 2, 1,
&fixed_extension, FALSE);
/* Sequence Number (5 bit) */
proto_tree_add_bits_ret_val(um_header_tree, hf_rlc_lte_um_sn, tvb,
(offset*8) + 3, 5,
&sn, FALSE);
offset++;
}
else if (p_rlc_lte_info->UMSequenceNumberLength == UM_SN_LENGTH_10_BITS) {
guint8 reserved;
proto_item *ti;
/* Check 3 Reserved bits */
reserved = (tvb_get_guint8(tvb, offset) & 0xe0) >> 5;
ti = proto_tree_add_item(um_header_tree, hf_rlc_lte_um_fixed_reserved, tvb, offset, 1, FALSE);
if (reserved != 0) {
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR,
"RLC UM Fixed header Reserved bits not zero (found 0x%x)", reserved);
}
/* Framing info (2 bits) */
proto_tree_add_bits_ret_val(um_header_tree, hf_rlc_lte_um_fi,
tvb, (offset*8)+3, 2,
&framing_info, FALSE);
/* Extension (1 bit) */
proto_tree_add_bits_ret_val(um_header_tree, hf_rlc_lte_um_fixed_e, tvb,
(offset*8) + 5, 1,
&fixed_extension, FALSE);
/* Sequence Number (10 bits) */
proto_tree_add_bits_ret_val(um_header_tree, hf_rlc_lte_um_sn, tvb,
(offset*8) + 6, 10,
&sn, FALSE);
offset += 2;
}
else {
/* Invalid length of sequence number */
proto_item *ti;
ti = proto_tree_add_text(um_header_tree, tvb, 0, 0, "Invalid sequence number length (%u bits)",
p_rlc_lte_info->UMSequenceNumberLength);
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR,
"Invalid sequence number length (%u bits)",
p_rlc_lte_info->UMSequenceNumberLength);
return;
}
tap_info->sequenceNumber = (guint16)sn;
/* Show SN in info column */
write_pdu_label_and_info(top_ti, NULL, pinfo, " SN=%-4u", (guint16)sn);
proto_item_set_len(um_header_ti, offset-start_offset);
/*************************************/
/* UM header extension */
if (fixed_extension) {
offset = dissect_rlc_lte_extension_header(tvb, pinfo, tree, offset);
}
if (global_rlc_lte_headers_expected) {
/* There might not be any data, if only headers (plus control data) were logged */
is_truncated = (tvb_length_remaining(tvb, offset) == 0);
truncated_ti = proto_tree_add_uint(tree, hf_rlc_lte_header_only, tvb, 0, 0,
is_truncated);
if (is_truncated) {
PROTO_ITEM_SET_GENERATED(truncated_ti);
expert_add_info_format(pinfo, truncated_ti, PI_SEQUENCE, PI_NOTE,
"RLC PDU SDUs have been omitted");
return;
}
else {
PROTO_ITEM_SET_HIDDEN(truncated_ti);
}
}
/* Extract these 2 flags from framing_info */
first_includes_start = ((guint8)framing_info & 0x02) == 0;
last_includes_end = ((guint8)framing_info & 0x01) == 0;
/* Call sequence analysis function now */
if (((global_rlc_lte_um_sequence_analysis == SEQUENCE_ANALYSIS_MAC_ONLY) &&
(p_get_proto_data(pinfo->fd, proto_mac_lte) != NULL)) ||
((global_rlc_lte_um_sequence_analysis == SEQUENCE_ANALYSIS_RLC_ONLY) &&
(p_get_proto_data(pinfo->fd, proto_mac_lte) == NULL))) {
checkChannelSequenceInfo(pinfo, tvb, p_rlc_lte_info,
(guint16)sn, first_includes_start, last_includes_end,
FALSE, /* UM doesn't re-segment */
tap_info, um_header_tree);
}
/*************************************/
/* Data */
if (s_number_of_extensions > 0) {
/* Show each data segment separately */
int n;
for (n=0; n < s_number_of_extensions; n++) {
show_PDU_in_tree(pinfo, tree, tvb, offset, s_lengths[n], p_rlc_lte_info,
(n==0) ? first_includes_start : TRUE);
show_PDU_in_info(pinfo, top_ti, s_lengths[n],
(n==0) ? first_includes_start : TRUE,
TRUE);
tvb_ensure_bytes_exist(tvb, offset, s_lengths[n]);
offset += s_lengths[n];
}
}
/* Final data element */
show_PDU_in_tree(pinfo, tree, tvb, offset, -1, p_rlc_lte_info,
((s_number_of_extensions == 0) ? first_includes_start : TRUE) && last_includes_end);
show_PDU_in_info(pinfo, top_ti, (guint16)tvb_length_remaining(tvb, offset),
(s_number_of_extensions == 0) ? first_includes_start : TRUE,
last_includes_end);
}
/* Dissect an AM STATUS PDU */
static void dissect_rlc_lte_am_status_pdu(tvbuff_t *tvb,
packet_info *pinfo,
proto_tree *tree,
proto_item *status_ti,
int offset,
proto_item *top_ti,
rlc_lte_info *p_rlc_lte_info,
rlc_lte_tap_info *tap_info)
{
guint8 cpt;
guint64 ack_sn, nack_sn;
guint16 nack_count = 0;
guint64 e1 = 0, e2 = 0;
guint64 so_start, so_end;
int bit_offset = offset * 8;
proto_item *ti;
/****************************************************************/
/* Part of RLC control PDU header */
/* Control PDU Type (CPT) */
cpt = (tvb_get_guint8(tvb, offset) & 0xf0) >> 4;
ti = proto_tree_add_item(tree, hf_rlc_lte_am_cpt, tvb, offset, 1, FALSE);
if (cpt != 0) {
/* Protest and stop - only know about STATUS PDUs */
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR,
"RLC Control frame type %u not handled", cpt);
return;
}
/* The Status PDU itself starts 4 bits into the byte */
bit_offset += 4;
/* ACK SN */
proto_tree_add_bits_ret_val(tree, hf_rlc_lte_am_ack_sn, tvb,
bit_offset, 10, &ack_sn, FALSE);
bit_offset += 10;
write_pdu_label_and_info(top_ti, status_ti, pinfo, " ACK_SN=%-4u", (guint16)ack_sn);
tap_info->ACKNo = (guint16)ack_sn;
/* E1 */
proto_tree_add_bits_ret_val(tree, hf_rlc_lte_am_e1, tvb,
bit_offset, 1, &e1, FALSE);
/* Skip another bit to byte-align the next bit... */
bit_offset++;
/* Optional, extra fields */
do {
if (e1) {
proto_item *nack_ti;
/****************************/
/* Read NACK_SN, E1, E2 */
/* NACK_SN */
nack_ti = proto_tree_add_bits_ret_val(tree, hf_rlc_lte_am_nack_sn, tvb,
bit_offset, 10, &nack_sn, FALSE);
bit_offset += 10;
write_pdu_label_and_info(top_ti, NULL, pinfo, " NACK_SN=%-4u", (guint16)nack_sn);
/* Copy into struct, but don't exceed buffer */
if (nack_count < MAX_NACKs) {
tap_info->NACKs[nack_count++] = (guint16)nack_sn;
}
else {
/* Let it get bigger than the array for accurate stats... */
nack_count++;
}
/* E1 */
proto_tree_add_bits_ret_val(tree, hf_rlc_lte_am_e1, tvb,
bit_offset, 1, &e1, FALSE);
bit_offset++;
/* E2 */
proto_tree_add_bits_ret_val(tree, hf_rlc_lte_am_e2, tvb,
bit_offset, 1, &e2, FALSE);
/* Report as expert info */
if (e2) {
expert_add_info_format(pinfo, nack_ti, PI_SEQUENCE, PI_WARN,
"Status PDU reports NACK (partial) on %s for UE %u",
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
}
else {
expert_add_info_format(pinfo, nack_ti, PI_SEQUENCE, PI_WARN,
"Status PDU reports NACK on %s for UE %u",
val_to_str_const(p_rlc_lte_info->direction, direction_vals, "Unknown"),
p_rlc_lte_info->ueid);
}
bit_offset++;
}
if (e2) {
/* Read SOstart, SOend */
proto_tree_add_bits_ret_val(tree, hf_rlc_lte_am_so_start, tvb,
bit_offset, 15, &so_start, FALSE);
bit_offset += 15;
proto_tree_add_bits_ret_val(tree, hf_rlc_lte_am_so_end, tvb,
bit_offset, 15, &so_end, FALSE);
bit_offset += 15;
if ((guint16)so_end == 0x7fff) {
write_pdu_label_and_info(top_ti, NULL, pinfo,
" (SOstart=%u SOend=<END-OF_PDU>)",
(guint16)so_start);
}
else {
write_pdu_label_and_info(top_ti, NULL, pinfo,
" (SOstart=%u SOend=%u)",
(guint16)so_start, (guint16)so_end);
}
/* Reset this flag here */
e2 = 0;
}
} while (e1 || e2);
if (nack_count > 0) {
proto_item_append_text(status_ti, " (%u NACKs)", nack_count);
tap_info->noOfNACKs = nack_count;
}
/* Check that we've reached the end of the PDU. If not, show malformed */
offset = (bit_offset+7) / 8;
if (tvb_length_remaining(tvb, offset) > 0) {
expert_add_info_format(pinfo, status_ti, PI_MALFORMED, PI_ERROR,
"%cL %u bytes remaining after Status PDU complete",
(p_rlc_lte_info->direction == DIRECTION_UPLINK) ? 'U' : 'D',
tvb_length_remaining(tvb, offset));
}
/* Set selected length of control tree */
proto_item_set_len(status_ti, offset);
/* Repeated NACK analysis */
if (((global_rlc_lte_am_sequence_analysis == SEQUENCE_ANALYSIS_MAC_ONLY) &&
(p_get_proto_data(pinfo->fd, proto_mac_lte) != NULL)) ||
((global_rlc_lte_am_sequence_analysis == SEQUENCE_ANALYSIS_RLC_ONLY) &&
(p_get_proto_data(pinfo->fd, proto_mac_lte) == NULL))) {
if (!is_mac_lte_frame_retx(pinfo, p_rlc_lte_info->direction)) {
checkChannelRepeatedNACKInfo(pinfo, p_rlc_lte_info, tap_info, tree, tvb);
}
}
}
/***************************************************/
/* Acknowledged mode PDU */
static void dissect_rlc_lte_am(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree,
int offset,
rlc_lte_info *p_rlc_lte_info,
proto_item *top_ti,
rlc_lte_tap_info *tap_info)
{
guint8 is_data;
guint8 is_resegmented;
guint8 polling;
guint8 fixed_extension;
guint8 framing_info;
gboolean first_includes_start;
gboolean last_includes_end;
proto_item *am_ti;
proto_tree *am_header_tree;
proto_item *am_header_ti;
gint start_offset = offset;
guint16 sn;
gboolean is_truncated;
proto_item *truncated_ti;
/* Hidden AM root */
am_ti = proto_tree_add_string_format(tree, hf_rlc_lte_am,
tvb, offset, 0, "", "AM");
PROTO_ITEM_SET_HIDDEN(am_ti);
/* Add AM header subtree */
am_header_ti = proto_tree_add_string_format(tree, hf_rlc_lte_am_header,
tvb, offset, 0,
"", "AM Header ");
am_header_tree = proto_item_add_subtree(am_header_ti,
ett_rlc_lte_am_header);
/* First bit is Data/Control flag */
is_data = (tvb_get_guint8(tvb, offset) & 0x80) >> 7;
proto_tree_add_item(am_header_tree, hf_rlc_lte_am_data_control, tvb, offset, 1, FALSE);
tap_info->isControlPDU = !is_data;
if (!is_data) {
/**********************/
/* Status PDU */
write_pdu_label_and_info(top_ti, NULL, pinfo, " [CONTROL]");
/* Control PDUs are a completely separate format */
dissect_rlc_lte_am_status_pdu(tvb, pinfo, am_header_tree, am_header_ti,
offset, top_ti,
p_rlc_lte_info, tap_info);
return;
}
/******************************/
/* Data PDU fixed header */
/* Re-segmentation Flag (RF) field */
is_resegmented = (tvb_get_guint8(tvb, offset) & 0x40) >> 6;
proto_tree_add_item(am_header_tree, hf_rlc_lte_am_rf, tvb, offset, 1, FALSE);
tap_info->isResegmented = is_resegmented;
write_pdu_label_and_info(top_ti, NULL, pinfo,
(is_resegmented) ? " [DATA-SEGMENT]" : " [DATA]");
/* Polling bit */
polling = (tvb_get_guint8(tvb, offset) & 0x20) >> 5;
proto_tree_add_item(am_header_tree, hf_rlc_lte_am_p, tvb, offset, 1, FALSE);
write_pdu_label_and_info(top_ti, NULL, pinfo, (polling) ? " (P) " : " ");
if (polling) {
proto_item_append_text(am_header_ti, " (P) ");
}
/* Framing Info */
framing_info = (tvb_get_guint8(tvb, offset) & 0x18) >> 3;
proto_tree_add_item(am_header_tree, hf_rlc_lte_am_fi, tvb, offset, 1, FALSE);
/* Extension bit */
fixed_extension = (tvb_get_guint8(tvb, offset) & 0x04) >> 2;
proto_tree_add_item(am_header_tree, hf_rlc_lte_am_fixed_e, tvb, offset, 1, FALSE);
/* Sequence Number */
sn = tvb_get_ntohs(tvb, offset) & 0x03ff;
proto_tree_add_item(am_header_tree, hf_rlc_lte_am_fixed_sn, tvb, offset, 2, FALSE);
offset += 2;
tap_info->sequenceNumber = sn;
write_pdu_label_and_info(top_ti, am_header_ti, pinfo, "sn=%-4u", sn);
/***************************************/
/* Dissect extra segment header fields */
if (is_resegmented) {
guint16 segmentOffset;
/* Last Segment Field (LSF) */
proto_tree_add_item(am_header_tree, hf_rlc_lte_am_segment_lsf, tvb, offset, 1, FALSE);
/* SO */
segmentOffset = tvb_get_ntohs(tvb, offset) & 0x7fff;
proto_tree_add_item(am_header_tree, hf_rlc_lte_am_segment_so, tvb, offset, 2, FALSE);
write_pdu_label_and_info(top_ti, NULL, pinfo, " SO=%u ", segmentOffset);
offset += 2;
}
/*************************************/
/* AM header extension */
if (fixed_extension) {
offset = dissect_rlc_lte_extension_header(tvb, pinfo, tree, offset);
}
/* There might not be any data, if only headers (plus control data) were logged */
if (global_rlc_lte_headers_expected) {
is_truncated = (tvb_length_remaining(tvb, offset) == 0);
truncated_ti = proto_tree_add_uint(tree, hf_rlc_lte_header_only, tvb, 0, 0,
is_truncated);
if (is_truncated) {
PROTO_ITEM_SET_GENERATED(truncated_ti);
expert_add_info_format(pinfo, truncated_ti, PI_SEQUENCE, PI_NOTE,
"RLC PDU SDUs have been omitted");
return;
}
else {
PROTO_ITEM_SET_HIDDEN(truncated_ti);
}
}
/* Head is now complete */
proto_item_set_len(am_header_ti, offset-start_offset);
/* Extract these 2 flags from framing_info */
first_includes_start = (framing_info & 0x02) == 0;
last_includes_end = (framing_info & 0x01) == 0;
/* Call sequence analysis function now */
if (((global_rlc_lte_am_sequence_analysis == SEQUENCE_ANALYSIS_MAC_ONLY) &&
(p_get_proto_data(pinfo->fd, proto_mac_lte) != NULL)) ||
((global_rlc_lte_am_sequence_analysis == SEQUENCE_ANALYSIS_RLC_ONLY) &&
(p_get_proto_data(pinfo->fd, proto_mac_lte) == NULL))) {
checkChannelSequenceInfo(pinfo, tvb, p_rlc_lte_info, (guint16)sn,
first_includes_start, last_includes_end,
is_resegmented, tap_info, tree);
}
/*************************************/
/* Data */
if (s_number_of_extensions > 0) {
/* Show each data segment separately */
int n;
for (n=0; n < s_number_of_extensions; n++) {
show_PDU_in_tree(pinfo, tree, tvb, offset, s_lengths[n], p_rlc_lte_info,
(n==0) ? first_includes_start : TRUE);
show_PDU_in_info(pinfo, top_ti, s_lengths[n],
(n==0) ? first_includes_start : TRUE,
TRUE);
tvb_ensure_bytes_exist(tvb, offset, s_lengths[n]);
offset += s_lengths[n];
}
}
/* Final data element */
if (tvb_length_remaining(tvb, offset) > 0) {
show_PDU_in_tree(pinfo, tree, tvb, offset, -1, p_rlc_lte_info,
((s_number_of_extensions == 0) ? first_includes_start : TRUE) && last_includes_end);
show_PDU_in_info(pinfo, top_ti, (guint16)tvb_length_remaining(tvb, offset),
(s_number_of_extensions == 0) ? first_includes_start : TRUE,
last_includes_end);
}
else {
/* Report that expected data was missing (unless we know it might happen) */
if (!global_rlc_lte_headers_expected) {
if (s_number_of_extensions > 0) {
expert_add_info_format(pinfo, am_header_ti, PI_MALFORMED, PI_ERROR,
"AM data PDU doesn't contain any data beyond extensions");
}
else {
expert_add_info_format(pinfo, am_header_ti, PI_MALFORMED, PI_ERROR,
"AM data PDU doesn't contain any data");
}
}
}
}
/* Heuristic dissector looks for supported framing protocol (see wiki page) */
static gboolean dissect_rlc_lte_heur(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree)
{
gint offset = 0;
struct rlc_lte_info *p_rlc_lte_info;
tvbuff_t *rlc_tvb;
guint8 tag = 0;
gboolean infoAlreadySet = FALSE;
gboolean umSeqNumLengthTagPresent = FALSE;
/* This is a heuristic dissector, which means we get all the UDP
* traffic not sent to a known dissector and not claimed by
* a heuristic dissector called before us!
*/
if (!global_rlc_lte_heur) {
return FALSE;
}
/* Do this again on re-dissection to re-discover offset of actual PDU */
/* Needs to be at least as long as:
- the signature string
- fixed header bytes
- tag for data
- at least one byte of RLC PDU payload */
if ((size_t)tvb_length_remaining(tvb, offset) < (strlen(RLC_LTE_START_STRING)+1+2)) {
return FALSE;
}
/* OK, compare with signature string */
if (tvb_strneql(tvb, offset, RLC_LTE_START_STRING, (gint)strlen(RLC_LTE_START_STRING)) != 0) {
return FALSE;
}
offset += (gint)strlen(RLC_LTE_START_STRING);
/* If redissecting, use previous info struct (if available) */
p_rlc_lte_info = p_get_proto_data(pinfo->fd, proto_rlc_lte);
if (p_rlc_lte_info == NULL) {
/* Allocate new info struct for this frame */
p_rlc_lte_info = se_alloc0(sizeof(struct rlc_lte_info));
infoAlreadySet = FALSE;
}
else {
infoAlreadySet = TRUE;
}
/* Read fixed fields */
p_rlc_lte_info->rlcMode = tvb_get_guint8(tvb, offset++);
/* Read optional fields */
while (tag != RLC_LTE_PAYLOAD_TAG) {
/* Process next tag */
tag = tvb_get_guint8(tvb, offset++);
switch (tag) {
case RLC_LTE_UM_SN_LENGTH_TAG:
p_rlc_lte_info->UMSequenceNumberLength = tvb_get_guint8(tvb, offset);
offset++;
umSeqNumLengthTagPresent = TRUE;
break;
case RLC_LTE_DIRECTION_TAG:
p_rlc_lte_info->direction = tvb_get_guint8(tvb, offset);
offset++;
break;
case RLC_LTE_PRIORITY_TAG:
p_rlc_lte_info->priority = tvb_get_guint8(tvb, offset);
offset++;
break;
case RLC_LTE_UEID_TAG:
p_rlc_lte_info->ueid = tvb_get_ntohs(tvb, offset);
offset += 2;
break;
case RLC_LTE_CHANNEL_TYPE_TAG:
p_rlc_lte_info->channelType = tvb_get_ntohs(tvb, offset);
offset += 2;
break;
case RLC_LTE_CHANNEL_ID_TAG:
p_rlc_lte_info->channelId = tvb_get_ntohs(tvb, offset);
offset += 2;
break;
case RLC_LTE_PAYLOAD_TAG:
/* Have reached data, so set payload length and get out of loop */
p_rlc_lte_info->pduLength= tvb_length_remaining(tvb, offset);
continue;
default:
/* It must be a recognised tag */
return FALSE;
}
}
if ((p_rlc_lte_info->rlcMode == RLC_UM_MODE) && (umSeqNumLengthTagPresent == FALSE)) {
/* Conditional field is not present */
return FALSE;
}
if (!infoAlreadySet) {
/* Store info in packet */
p_add_proto_data(pinfo->fd, proto_rlc_lte, p_rlc_lte_info);
}
/**************************************/
/* OK, now dissect as RLC LTE */
/* Create tvb that starts at actual RLC PDU */
rlc_tvb = tvb_new_subset(tvb, offset, -1, tvb_reported_length(tvb)-offset);
dissect_rlc_lte(rlc_tvb, pinfo, tree);
return TRUE;
}
/*****************************/
/* Main dissection function. */
/*****************************/
static void dissect_rlc_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *rlc_lte_tree;
proto_tree *context_tree;
proto_item *top_ti;
proto_item *context_ti;
proto_item *ti;
proto_item *mode_ti;
gint offset = 0;
struct rlc_lte_info *p_rlc_lte_info = NULL;
/* Allocate and Zero tap struct */
rlc_lte_tap_info *tap_info = ep_alloc0(sizeof(rlc_lte_tap_info));
/* Set protocol name */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLC-LTE");
/* Create protocol tree. */
top_ti = proto_tree_add_item(tree, proto_rlc_lte, tvb, offset, -1, FALSE);
rlc_lte_tree = proto_item_add_subtree(top_ti, ett_rlc_lte);
/* Look for packet info! */
p_rlc_lte_info = p_get_proto_data(pinfo->fd, proto_rlc_lte);
/* Can't dissect anything without it... */
if (p_rlc_lte_info == NULL) {
ti = proto_tree_add_text(rlc_lte_tree, tvb, offset, -1,
"Can't dissect LTE RLC frame because no per-frame info was attached!");
PROTO_ITEM_SET_GENERATED(ti);
return;
}
/*****************************************/
/* Show context information */
/* Create context root */
context_ti = proto_tree_add_string_format(rlc_lte_tree, hf_rlc_lte_context,
tvb, offset, 0, "", "Context");
context_tree = proto_item_add_subtree(context_ti, ett_rlc_lte_context);
PROTO_ITEM_SET_GENERATED(context_ti);
ti = proto_tree_add_uint(context_tree, hf_rlc_lte_context_direction,
tvb, 0, 0, p_rlc_lte_info->direction);
PROTO_ITEM_SET_GENERATED(ti);
mode_ti = proto_tree_add_uint(context_tree, hf_rlc_lte_context_mode,
tvb, 0, 0, p_rlc_lte_info->rlcMode);
PROTO_ITEM_SET_GENERATED(mode_ti);
if (p_rlc_lte_info->ueid != 0) {
ti = proto_tree_add_uint(context_tree, hf_rlc_lte_context_ueid,
tvb, 0, 0, p_rlc_lte_info->ueid);
PROTO_ITEM_SET_GENERATED(ti);
}
ti = proto_tree_add_uint(context_tree, hf_rlc_lte_context_priority,
tvb, 0, 0, p_rlc_lte_info->priority);
PROTO_ITEM_SET_GENERATED(ti);
ti = proto_tree_add_uint(context_tree, hf_rlc_lte_context_channel_type,
tvb, 0, 0, p_rlc_lte_info->channelType);
PROTO_ITEM_SET_GENERATED(ti);
if ((p_rlc_lte_info->channelType == CHANNEL_TYPE_SRB) ||
(p_rlc_lte_info->channelType == CHANNEL_TYPE_DRB)) {
ti = proto_tree_add_uint(context_tree, hf_rlc_lte_context_channel_id,
tvb, 0, 0, p_rlc_lte_info->channelId);
PROTO_ITEM_SET_GENERATED(ti);
}
ti = proto_tree_add_uint(context_tree, hf_rlc_lte_context_pdu_length,
tvb, 0, 0, p_rlc_lte_info->pduLength);
PROTO_ITEM_SET_GENERATED(ti);
if (p_rlc_lte_info->rlcMode == RLC_UM_MODE) {
ti = proto_tree_add_uint(context_tree, hf_rlc_lte_context_um_sn_length,
tvb, 0, 0, p_rlc_lte_info->UMSequenceNumberLength);
PROTO_ITEM_SET_GENERATED(ti);
}
/* Append highlights to top-level item */
if (p_rlc_lte_info->ueid != 0) {
proto_item_append_text(top_ti, " UEId=%u", p_rlc_lte_info->ueid);
}
if (p_rlc_lte_info->channelId == 0) {
proto_item_append_text(top_ti, " (%s) ",
val_to_str_const(p_rlc_lte_info->channelType, rlc_channel_type_vals, "Unknown"));
}
else {
proto_item_append_text(top_ti, " (%s:%u) ",
val_to_str_const(p_rlc_lte_info->channelType, rlc_channel_type_vals, "Unknown"),
p_rlc_lte_info->channelId);
}
proto_item_append_text(top_ti, "[%s] ",
val_to_str_const(p_rlc_lte_info->rlcMode, rlc_mode_short_vals, "Unknown"));
/* Append context highlights to info column */
write_pdu_label_and_info(top_ti, NULL, pinfo,
"[%s] [%s] ",
(p_rlc_lte_info->direction == 0) ? "UL" : "DL",
val_to_str_const(p_rlc_lte_info->rlcMode, rlc_mode_short_vals, "Unknown"));
if (p_rlc_lte_info->ueid != 0) {
col_append_fstr(pinfo->cinfo, COL_INFO, "UEId=%u ", p_rlc_lte_info->ueid);
}
if (p_rlc_lte_info->channelId == 0) {
write_pdu_label_and_info(top_ti, NULL, pinfo, "%s",
val_to_str_const(p_rlc_lte_info->channelType, rlc_channel_type_vals, "Unknown"));
}
else {
write_pdu_label_and_info(top_ti, NULL, pinfo, "%s:%-2u",
val_to_str_const(p_rlc_lte_info->channelType, rlc_channel_type_vals, "Unknown"),
p_rlc_lte_info->channelId);
}
/* Set context-info parts of tap struct */
tap_info->rlcMode = p_rlc_lte_info->rlcMode;
tap_info->direction = p_rlc_lte_info->direction;
tap_info->priority = p_rlc_lte_info->priority;
tap_info->ueid = p_rlc_lte_info->ueid;
tap_info->channelType = p_rlc_lte_info->channelType;
tap_info->channelId = p_rlc_lte_info->channelId;
tap_info->pduLength = p_rlc_lte_info->pduLength;
tap_info->UMSequenceNumberLength = p_rlc_lte_info->UMSequenceNumberLength;
tap_info->loggedInMACFrame = (p_get_proto_data(pinfo->fd, proto_mac_lte) != NULL);
tap_info->time = pinfo->fd->abs_ts;
/* Reset this count */
s_number_of_extensions = 0;
/* Dissect the RLC PDU itself. Format depends upon mode... */
switch (p_rlc_lte_info->rlcMode) {
case RLC_TM_MODE:
dissect_rlc_lte_tm(tvb, pinfo, rlc_lte_tree, offset, p_rlc_lte_info, top_ti);
break;
case RLC_UM_MODE:
dissect_rlc_lte_um(tvb, pinfo, rlc_lte_tree, offset, p_rlc_lte_info, top_ti,
tap_info);
break;
case RLC_AM_MODE:
dissect_rlc_lte_am(tvb, pinfo, rlc_lte_tree, offset, p_rlc_lte_info, top_ti,
tap_info);
break;
case RLC_PREDEF:
/* Predefined data (i.e. not containing a valid RLC header */
proto_tree_add_item(rlc_lte_tree, hf_rlc_lte_predefined_pdu, tvb, offset, -1, FALSE);
write_pdu_label_and_info(top_ti, NULL, pinfo, " [%u-bytes]",
tvb_length_remaining(tvb, offset));
break;
default:
/* Error - unrecognised mode */
expert_add_info_format(pinfo, mode_ti, PI_MALFORMED, PI_ERROR,
"Unrecognised RLC Mode set (%u)", p_rlc_lte_info->rlcMode);
break;
}
/* Queue tap info */
tap_queue_packet(rlc_lte_tap, pinfo, tap_info);
}
/* Initializes the hash table and the mem_chunk area each time a new
* file is loaded or re-loaded in wireshark */
static void
rlc_lte_init_protocol(void)
{
/* Destroy any existing hashes. */
if (rlc_lte_sequence_analysis_channel_hash) {
g_hash_table_destroy(rlc_lte_sequence_analysis_channel_hash);
}
if (rlc_lte_frame_sequence_analysis_report_hash) {
g_hash_table_destroy(rlc_lte_frame_sequence_analysis_report_hash);
}
if (rlc_lte_repeated_nack_channel_hash) {
g_hash_table_destroy(rlc_lte_repeated_nack_channel_hash);
}
if (rlc_lte_frame_repeated_nack_report_hash) {
g_hash_table_destroy(rlc_lte_frame_repeated_nack_report_hash);
}
/* Now create them over */
rlc_lte_sequence_analysis_channel_hash = g_hash_table_new(rlc_channel_hash_func, rlc_channel_equal);
rlc_lte_frame_sequence_analysis_report_hash = g_hash_table_new(rlc_frame_hash_func, rlc_frame_equal);
rlc_lte_repeated_nack_channel_hash = g_hash_table_new(rlc_channel_hash_func, rlc_channel_equal);
rlc_lte_frame_repeated_nack_report_hash = g_hash_table_new(rlc_frame_hash_func, rlc_frame_equal);
}
void proto_register_rlc_lte(void)
{
static hf_register_info hf[] =
{
/**********************************/
/* Items for decoding context */
{ &hf_rlc_lte_context,
{ "Context",
"rlc-lte.context", FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_context_mode,
{ "RLC Mode",
"rlc-lte.mode", FT_UINT8, BASE_DEC, VALS(rlc_mode_vals), 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_context_direction,
{ "Direction",
"rlc-lte.direction", FT_UINT8, BASE_DEC, VALS(direction_vals), 0x0,
"Direction of message", HFILL
}
},
{ &hf_rlc_lte_context_priority,
{ "Priority",
"rlc-lte.priority", FT_UINT8, BASE_DEC, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_context_ueid,
{ "UEId",
"rlc-lte.ueid", FT_UINT16, BASE_DEC, 0, 0x0,
"User Equipment Identifier associated with message", HFILL
}
},
{ &hf_rlc_lte_context_channel_type,
{ "Channel Type",
"rlc-lte.channel-type", FT_UINT16, BASE_DEC, VALS(rlc_channel_type_vals), 0x0,
"Channel Type associated with message", HFILL
}
},
{ &hf_rlc_lte_context_channel_id,
{ "Channel ID",
"rlc-lte.channel-id", FT_UINT16, BASE_DEC, 0, 0x0,
"Channel ID associated with message", HFILL
}
},
{ &hf_rlc_lte_context_pdu_length,
{ "PDU Length",
"rlc-lte.pdu_length", FT_UINT16, BASE_DEC, 0, 0x0,
"Length of PDU (in bytes)", HFILL
}
},
{ &hf_rlc_lte_context_um_sn_length,
{ "UM Sequence number length",
"rlc-lte.um-seqnum-length", FT_UINT8, BASE_DEC, 0, 0x0,
"Length of UM sequence number in bits", HFILL
}
},
/* Transparent mode fields */
{ &hf_rlc_lte_tm,
{ "TM",
"rlc-lte.tm", FT_STRING, BASE_NONE, NULL, 0x0,
"Transparent Mode", HFILL
}
},
{ &hf_rlc_lte_tm_data,
{ "TM Data",
"rlc-lte.tm.data", FT_BYTES, BASE_NONE, 0, 0x0,
"Transparent Mode Data", HFILL
}
},
/* Unacknowledged mode fields */
{ &hf_rlc_lte_um,
{ "UM",
"rlc-lte.um", FT_STRING, BASE_NONE, NULL, 0x0,
"Unackowledged Mode", HFILL
}
},
{ &hf_rlc_lte_um_header,
{ "UM Header",
"rlc-lte.um.header", FT_STRING, BASE_NONE, NULL, 0x0,
"Unackowledged Mode Header", HFILL
}
},
{ &hf_rlc_lte_um_fi,
{ "Framing Info",
"rlc-lte.um.fi", FT_UINT8, BASE_HEX, VALS(framing_info_vals), 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_um_fixed_e,
{ "Extension",
"rlc-lte.um.fixed.e", FT_UINT8, BASE_HEX, VALS(fixed_extension_vals), 0x0,
"Extension in fixed part of UM header", HFILL
}
},
{ &hf_rlc_lte_um_sn,
{ "Sequence number",
"rlc-lte.um.sn", FT_UINT8, BASE_DEC, 0, 0x0,
"Unacknowledged Mode Sequence Number", HFILL
}
},
{ &hf_rlc_lte_um_fixed_reserved,
{ "Reserved",
"rlc-lte.um.reserved", FT_UINT8, BASE_DEC, 0, 0xe0,
"Unacknowledged Mode Fixed header reserved bits", HFILL
}
},
{ &hf_rlc_lte_um_data,
{ "UM Data",
"rlc-lte.um.data", FT_BYTES, BASE_NONE, 0, 0x0,
"Unacknowledged Mode Data", HFILL
}
},
{ &hf_rlc_lte_extension_part,
{ "Extension Part",
"rlc-lte.extension-part", FT_STRING, BASE_NONE, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_extension_e,
{ "Extension",
"rlc-lte.extension.e", FT_UINT8, BASE_HEX, VALS(extension_extension_vals), 0x0,
"Extension in extended part of the header", HFILL
}
},
{ &hf_rlc_lte_extension_li,
{ "Length Indicator",
"rlc-lte.extension.li", FT_UINT16, BASE_DEC, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_extension_padding,
{ "Padding",
"rlc-lte.extension.padding", FT_UINT8, BASE_HEX, 0, 0x0f,
"Extension header padding", HFILL
}
},
{ &hf_rlc_lte_am,
{ "AM",
"rlc-lte.am", FT_STRING, BASE_NONE, NULL, 0x0,
"Ackowledged Mode", HFILL
}
},
{ &hf_rlc_lte_am_header,
{ "AM Header",
"rlc-lte.am.header", FT_STRING, BASE_NONE, NULL, 0x0,
"Ackowledged Mode Header", HFILL
}
},
{ &hf_rlc_lte_am_data_control,
{ "Frame type",
"rlc-lte.am.frame_type", FT_UINT8, BASE_HEX, VALS(data_or_control_vals), 0x80,
"AM Frame Type (Control or Data)", HFILL
}
},
{ &hf_rlc_lte_am_rf,
{ "Re-segmentation Flag",
"rlc-lte.am.rf", FT_UINT8, BASE_HEX, VALS(resegmentation_flag_vals), 0x40,
"AM Re-segmentation Flag", HFILL
}
},
{ &hf_rlc_lte_am_p,
{ "Polling Bit",
"rlc-lte.am.p", FT_UINT8, BASE_HEX, VALS(polling_bit_vals), 0x20,
NULL, HFILL
}
},
{ &hf_rlc_lte_am_fi,
{ "Framing Info",
"rlc-lte.am.fi", FT_UINT8, BASE_HEX, VALS(framing_info_vals), 0x18,
"AM Framing Info", HFILL
}
},
{ &hf_rlc_lte_am_fixed_e,
{ "Extension",
"rlc-lte.am.fixed.e", FT_UINT8, BASE_HEX, VALS(fixed_extension_vals), 0x04,
"Fixed Extension Bit", HFILL
}
},
{ &hf_rlc_lte_am_fixed_sn,
{ "Sequence Number",
"rlc-lte.am.fixed.sn", FT_UINT16, BASE_DEC, 0, 0x03ff,
"AM Fixed Sequence Number", HFILL
}
},
{ &hf_rlc_lte_am_segment_lsf,
{ "Last Segment Flag",
"rlc-lte.am.segment.lsf", FT_UINT8, BASE_HEX, VALS(lsf_vals), 0x80,
NULL, HFILL
}
},
{ &hf_rlc_lte_am_segment_so,
{ "Segment Offset",
"rlc-lte.am.segment.offset", FT_UINT16, BASE_DEC, 0, 0x7fff,
NULL, HFILL
}
},
{ &hf_rlc_lte_am_data,
{ "AM Data",
"rlc-lte.am.data", FT_BYTES, BASE_NONE, 0, 0x0,
"Acknowledged Mode Data", HFILL
}
},
{ &hf_rlc_lte_am_cpt,
{ "Control PDU Type",
"rlc-lte.am.cpt", FT_UINT8, BASE_HEX, VALS(control_pdu_type_vals), 0x70,
"AM Control PDU Type", HFILL
}
},
{ &hf_rlc_lte_am_ack_sn,
{ "ACK Sequence Number",
"rlc-lte.am.ack-sn", FT_UINT16, BASE_DEC, 0, 0x0,
"Sequence Number we expect to receive next", HFILL
}
},
{ &hf_rlc_lte_am_e1,
{ "Extension bit 1",
"rlc-lte.am.e1", FT_UINT8, BASE_HEX, VALS(am_e1_vals), 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_am_e2,
{ "Extension bit 2",
"rlc-lte.am.e2", FT_UINT8, BASE_HEX, VALS(am_e2_vals), 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_am_nack_sn,
{ "NACK Sequence Number",
"rlc-lte.am.nack-sn", FT_UINT16, BASE_DEC, 0, 0x0,
"Negative Acknowledgement Sequence Number", HFILL
}
},
{ &hf_rlc_lte_am_so_start,
{ "SO Start",
"rlc-lte.am.so-start", FT_UINT16, BASE_DEC, 0, 0x0,
"Segment Offset Start byte index", HFILL
}
},
{ &hf_rlc_lte_am_so_end,
{ "SO End",
"rlc-lte.am.so-end", FT_UINT16, BASE_DEC, 0, 0x0,
"Segment Offset End byte index", HFILL
}
},
{ &hf_rlc_lte_predefined_pdu,
{ "Predefined data",
"rlc-lte.predefined-data", FT_BYTES, BASE_NONE, 0, 0x0,
"Predefined test data", HFILL
}
},
{ &hf_rlc_lte_sequence_analysis,
{ "Sequence Analysis",
"rlc-lte.sequence-analysis", FT_STRING, BASE_NONE, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_sequence_analysis_ok,
{ "OK",
"rlc-lte.sequence-analysis.ok", FT_BOOLEAN, BASE_NONE, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_sequence_analysis_previous_frame,
{ "Previous frame for channel",
"rlc-lte.sequence-analysis.previous-frame", FT_FRAMENUM, BASE_NONE, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_sequence_analysis_expected_sn,
{ "Expected SN",
"rlc-lte.sequence-analysis.expected-sn", FT_UINT16, BASE_DEC, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_sequence_analysis_framing_info_correct,
{ "Frame info continued correctly",
"rlc-lte.sequence-analysis.framing-info-correct", FT_BOOLEAN, BASE_NONE, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_sequence_analysis_mac_retx,
{ "Frame retransmitted by MAC",
"rlc-lte.sequence-analysis.mac-retx", FT_BOOLEAN, BASE_NONE, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_sequence_analysis_retx,
{ "Retransmitted frame",
"rlc-lte.sequence-analysis.retx", FT_BOOLEAN, BASE_NONE, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_sequence_analysis_skipped,
{ "Skipped frames",
"rlc-lte.sequence-analysis.skipped-frames", FT_BOOLEAN, BASE_NONE, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_sequence_analysis_repeated,
{ "Repeated frame",
"rlc-lte.sequence-analysis.repeated-frame", FT_BOOLEAN, BASE_NONE, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_sequence_analysis_repeated_nack,
{ "Repeated NACK",
"rlc-lte.sequence-analysis.repeated-nack", FT_UINT16, BASE_DEC, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_sequence_analysis_repeated_nack_original_frame,
{ "Frame with previous status PDU",
"rlc-lte.sequence-analysis.repeated-nack.original-frame", FT_FRAMENUM, BASE_NONE, 0, 0x0,
NULL, HFILL
}
},
{ &hf_rlc_lte_header_only,
{ "RLC PDU Header only",
"rlc-lte.header-only", FT_UINT8, BASE_DEC, VALS(header_only_vals), 0x0,
NULL, HFILL
}
},
};
static gint *ett[] =
{
&ett_rlc_lte,
&ett_rlc_lte_context,
&ett_rlc_lte_um_header,
&ett_rlc_lte_am_header,
&ett_rlc_lte_extension_part,
&ett_rlc_lte_sequence_analysis
};
static enum_val_t sequence_analysis_vals[] = {
{"no-analysis", "No-Analysis", FALSE},
{"mac-only", "Only-MAC-frames", SEQUENCE_ANALYSIS_MAC_ONLY},
{"rlc-only", "Only-RLC-frames", SEQUENCE_ANALYSIS_RLC_ONLY},
{NULL, NULL, -1}
};
module_t *rlc_lte_module;
/* Register protocol. */
proto_rlc_lte = proto_register_protocol("RLC-LTE", "RLC-LTE", "rlc-lte");
proto_register_field_array(proto_rlc_lte, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
/* Allow other dissectors to find this one by name. */
register_dissector("rlc-lte", dissect_rlc_lte, proto_rlc_lte);
/* Register the tap name */
rlc_lte_tap = register_tap("rlc-lte");
/* Preferences */
rlc_lte_module = prefs_register_protocol(proto_rlc_lte, NULL);
prefs_register_enum_preference(rlc_lte_module, "do_sequence_analysis_am",
"Do sequence analysis for AM channels",
"Attempt to keep track of PDUs for AM channels, and point out problems",
&global_rlc_lte_am_sequence_analysis, sequence_analysis_vals, FALSE);
prefs_register_enum_preference(rlc_lte_module, "do_sequence_analysis",
"Do sequence analysis for UM channels",
"Attempt to keep track of PDUs for UM channels, and point out problems",
&global_rlc_lte_um_sequence_analysis, sequence_analysis_vals, FALSE);
prefs_register_bool_preference(rlc_lte_module, "call_pdcp_for_srb",
"Call PDCP dissector for SRB PDUs",
"Call PDCP dissector for signalling PDUs. Note that without reassembly, it can"
"only be called for complete PDus (i.e. not segmented over RLC)",
&global_rlc_lte_call_pdcp_for_srb);
prefs_register_enum_preference(rlc_lte_module, "call_pdcp_for_drb",
"Call PDCP dissector for DRB PDUs",
"Call PDCP dissector for user-plane PDUs. Note that without reassembly, it can"
"only be called for complete PDus (i.e. not segmented over RLC)",
&global_rlc_lte_call_pdcp_for_drb, pdcp_drb_col_vals, FALSE);
prefs_register_bool_preference(rlc_lte_module, "call_rrc_for_ccch",
"Call RRC dissector for CCCH PDUs",
"Call RRC dissector for CCCH PDUs",
&global_rlc_lte_call_rrc);
prefs_register_bool_preference(rlc_lte_module, "heuristic_rlc_lte_over_udp",
"Try Heuristic LTE-RLC over UDP framing",
"When enabled, use heuristic dissector to find RLC-LTE frames sent with "
"UDP framing",
&global_rlc_lte_heur);
prefs_register_bool_preference(rlc_lte_module, "header_only_mode",
"May see RLC headers only",
"When enabled, if data is not present, don't report as an error, but instead "
"add expert info to indicate that headers were omitted",
&global_rlc_lte_headers_expected);
register_init_routine(&rlc_lte_init_protocol);
}
void
proto_reg_handoff_rlc_lte(void)
{
dissector_handle_t rlc_lte_handle;
rlc_lte_handle = find_dissector("rlc-lte");
/* Add as a heuristic UDP dissector */
heur_dissector_add("udp", dissect_rlc_lte_heur, proto_rlc_lte);
}
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