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LTE message parsing #12

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LTE message parsing #12

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77 changes: 73 additions & 4 deletions epan/dissectors/packet-gsmtap.c
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,8 @@
#include "packet-lapdm.h"
#include "packet-tetra.h"

#include "packet-mac-lte.h"

void proto_register_gsmtap(void);
void proto_reg_handoff_gsmtap(void);

Expand Down Expand Up @@ -99,6 +101,9 @@ enum {
/* UMTS */
GSMTAP_SUB_UMTS_RLC_MAC,
GSMTAP_SUB_UMTS_RRC,
/* LTE*/
GSMTAP_SUB_LTE_RRC,
GSMTAP_SUB_LTE_MAC,

GSMTAP_SUB_MAX
};
Expand Down Expand Up @@ -170,8 +175,23 @@ enum {
GSMTAP_RRC_SUB_MAX
};

/* LTE RRC message types */
enum {
GSMTAP_LTE_RRC_SUB_DL_CCCH_Message = 0,
GSMTAP_LTE_RRC_SUB_DL_DCCH_Message,
GSMTAP_LTE_RRC_SUB_UL_CCCH_Message,
GSMTAP_LTE_RRC_SUB_UL_DCCH_Message,
GSMTAP_LTE_RRC_SUB_BCCH_BCH_Message,
GSMTAP_LTE_RRC_SUB_BCCH_DL_SCH_Message,
GSMTAP_LTE_RRC_SUB_PCCH_Message,
GSMTAP_LTE_RRC_SUB_MCCH_Message,

GSMTAP_LTE_RRC_SUB_MAX
};

static dissector_handle_t sub_handles[GSMTAP_SUB_MAX];
static dissector_handle_t rrc_sub_handles[GSMTAP_RRC_SUB_MAX];
static dissector_handle_t lte_rrc_sub_handles[GSMTAP_LTE_RRC_SUB_MAX];

static dissector_table_t gsmtap_dissector_table;

Expand Down Expand Up @@ -291,7 +311,8 @@ static const value_string gsmtap_types[] = {
{ GSMTAP_TYPE_GMR1_UM, "GMR-1 air interfeace (MES-MS<->GTS)" },
{ GSMTAP_TYPE_UMTS_RLC_MAC, "UMTS RLC/MAC" },
{ GSMTAP_TYPE_UMTS_RRC, "UMTS RRC" },
{ GSMTAP_TYPE_OSMOCORE_LOG, "libosmocore logging" },
{ GSMTAP_TYPE_UMTS_RRC, "LTE RRC" },
{ GSMTAP_TYPE_UMTS_RRC, "LTE MAC" },
{ 0, NULL },
};

Expand Down Expand Up @@ -345,15 +366,35 @@ handle_tetra(int channel _U_, tvbuff_t *payload_tvb _U_, packet_info *pinfo _U_,
tetra_dissect_pdu(tetra_chan, TETRA_DOWNLINK, payload_tvb, tree, pinfo);
}

static void
attach_mac_lte_info(tvbuff_t *lte_mac_info_tvb, int len, guint8 gsmtap_hdr_len, packet_info *pinfo)
{
struct mac_lte_info *p_mac_lte_info;
guint8 lte_mac_info_len = 15;
int offset = 0;

p_mac_lte_info = get_mac_lte_proto_data(pinfo);
p_mac_lte_info = wmem_new0(wmem_file_scope(), struct mac_lte_info);
p_mac_lte_info->radioType = tvb_get_guint8(lte_mac_info_tvb, offset);
p_mac_lte_info->direction = tvb_get_guint8(lte_mac_info_tvb, offset+1);
p_mac_lte_info->rntiType = tvb_get_guint8(lte_mac_info_tvb, offset+2);
p_mac_lte_info->rnti = tvb_get_ntohs(lte_mac_info_tvb, offset+4);
p_mac_lte_info->ueid = tvb_get_ntohs(lte_mac_info_tvb, offset+7);
p_mac_lte_info->subframeNumber = tvb_get_ntohs(lte_mac_info_tvb, offset+10);
p_mac_lte_info->length = len - (gsmtap_hdr_len + lte_mac_info_len);

set_mac_lte_proto_data(pinfo, p_mac_lte_info);
}

/* dissect a GSMTAP header and hand payload off to respective dissector */
static int
dissect_gsmtap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
int sub_handle, rrc_sub_handle = 0, len, offset = 0;
int sub_handle, rrc_sub_handle = 0, lte_rrc_sub_handle = 0, len, offset = 0;
proto_item *ti;
proto_tree *gsmtap_tree = NULL;
tvbuff_t *payload_tvb, *l1h_tvb = NULL;
guint8 hdr_len, type, sub_type, timeslot, subslot;
tvbuff_t *payload_tvb, *l1h_tvb = NULL, *lte_mac_info_tvb=NULL;;
guint8 hdr_len, type, sub_type, timeslot, subslot, lte_mac_info_len = 15;
guint16 arfcn;

len = tvb_reported_length(tvb);
Expand All @@ -371,6 +412,9 @@ dissect_gsmtap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _
sub_type & GSMTAP_CHANNEL_ACCH) {
l1h_tvb = tvb_new_subset_length(tvb, hdr_len, 2);
payload_tvb = tvb_new_subset_length(tvb, hdr_len+2, len-(hdr_len+2));
} else if (type == GSMTAP_TYPE_LTE_MAC) {
lte_mac_info_tvb = tvb_new_subset_length(tvb, hdr_len, lte_mac_info_len);
payload_tvb = tvb_new_subset_length(tvb, hdr_len+lte_mac_info_len, len - (hdr_len + lte_mac_info_len));
} else {
payload_tvb = tvb_new_subset_length(tvb, hdr_len, len-hdr_len);
}
Expand Down Expand Up @@ -485,6 +529,18 @@ dissect_gsmtap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _
* sub-dissector */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "RRC");
break;
case GSMTAP_TYPE_LTE_RRC:
sub_handle = GSMTAP_SUB_LTE_RRC;
lte_rrc_sub_handle = sub_type;
if (lte_rrc_sub_handle >= GSMTAP_LTE_RRC_SUB_MAX) {
sub_handle = GSMTAP_SUB_DATA;
}
/*Directly call the respective lte rrc message dissector */
break;
case GSMTAP_TYPE_LTE_MAC:
attach_mac_lte_info(lte_mac_info_tvb, len, hdr_len, pinfo);
sub_handle=GSMTAP_SUB_LTE_MAC;
break;
case GSMTAP_TYPE_UM:
if (l1h_tvb)
dissect_sacch_l1h(l1h_tvb, tree);
Expand Down Expand Up @@ -593,6 +649,9 @@ dissect_gsmtap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _
if (sub_handle == GSMTAP_SUB_UMTS_RRC)
call_dissector(rrc_sub_handles[rrc_sub_handle], payload_tvb,
pinfo, tree);
else if (sub_handle == GSMTAP_SUB_LTE_RRC)
call_dissector(lte_rrc_sub_handles[lte_rrc_sub_handle], payload_tvb,
pinfo, tree);
else if (sub_handles[sub_handle] != NULL)
call_dissector(sub_handles[sub_handle], payload_tvb, pinfo, tree);
/* TODO: warn user that the WiMAX plugin must be enabled for some types */
Expand Down Expand Up @@ -685,6 +744,7 @@ proto_reg_handoff_gsmtap(void)
sub_handles[GSMTAP_SUB_GMR1_LAPSAT] = find_dissector_add_dependency("lapsat", proto_gsmtap);
sub_handles[GSMTAP_SUB_GMR1_RACH] = find_dissector_add_dependency("gmr1_rach", proto_gsmtap);
sub_handles[GSMTAP_SUB_UMTS_RRC] = find_dissector_add_dependency("rrc", proto_gsmtap);
sub_handles[GSMTAP_SUB_LTE_MAC] = find_dissector_add_dependency("mac-lte", proto_gsmtap);

rrc_sub_handles[GSMTAP_RRC_SUB_DL_DCCH_Message] = find_dissector_add_dependency("rrc.dl.dcch", proto_gsmtap);
rrc_sub_handles[GSMTAP_RRC_SUB_UL_DCCH_Message] = find_dissector_add_dependency("rrc.ul.dcch", proto_gsmtap);
Expand Down Expand Up @@ -749,6 +809,15 @@ proto_reg_handoff_gsmtap(void)
rrc_sub_handles[GSMTAP_RRC_SUB_ToTargetRNC_Container] = find_dissector_add_dependency("rrc.s_to_trnc_cont", proto_gsmtap);
rrc_sub_handles[GSMTAP_RRC_SUB_TargetRNC_ToSourceRNC_Container] = find_dissector_add_dependency("rrc.t_to_srnc_cont", proto_gsmtap);

lte_rrc_sub_handles[GSMTAP_LTE_RRC_SUB_DL_CCCH_Message] = find_dissector_add_dependency("lte_rrc.dl_ccch", proto_gsmtap);
lte_rrc_sub_handles[GSMTAP_LTE_RRC_SUB_DL_DCCH_Message] = find_dissector_add_dependency("lte_rrc.dl_dcch", proto_gsmtap);
lte_rrc_sub_handles[GSMTAP_LTE_RRC_SUB_UL_CCCH_Message] = find_dissector_add_dependency("lte_rrc.ul_ccch", proto_gsmtap);
lte_rrc_sub_handles[GSMTAP_LTE_RRC_SUB_UL_DCCH_Message] = find_dissector_add_dependency("lte_rrc.ul_dcch", proto_gsmtap);
lte_rrc_sub_handles[GSMTAP_LTE_RRC_SUB_BCCH_BCH_Message] = find_dissector_add_dependency("lte_rrc.bcch_bch", proto_gsmtap);
lte_rrc_sub_handles[GSMTAP_LTE_RRC_SUB_BCCH_DL_SCH_Message] = find_dissector_add_dependency("lte_rrc.bcch_dl_sch", proto_gsmtap);
lte_rrc_sub_handles[GSMTAP_LTE_RRC_SUB_PCCH_Message] = find_dissector_add_dependency("lte_rrc.pcch", proto_gsmtap);
lte_rrc_sub_handles[GSMTAP_LTE_RRC_SUB_MCCH_Message] = find_dissector_add_dependency("lte_rrc.mcch", proto_gsmtap);

gsmtap_handle = create_dissector_handle(dissect_gsmtap, proto_gsmtap);
dissector_add_uint_with_preference("udp.port", GSMTAP_UDP_PORT, gsmtap_handle);
}
Expand Down
2 changes: 2 additions & 0 deletions epan/dissectors/packet-gsmtap.h
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,8 @@
#define GSMTAP_TYPE_GMR1_UM 0x0a /* GMR-1 L2 packets */
#define GSMTAP_TYPE_UMTS_RLC_MAC 0x0b
#define GSMTAP_TYPE_UMTS_RRC 0x0c
#define GSMTAP_TYPE_LTE_RRC 0x0d /* LTE interface */
#define GSMTAP_TYPE_LTE_MAC 0x0e /* LTE interface */
#define GSMTAP_TYPE_OSMOCORE_LOG 0x10 /* libosmocore logging */

/* ====== DO NOT MAKE UNAPPROVED MODIFICATIONS HERE ===== */
Expand Down