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BSSAP: Split BSSAP-LE, BSAP to pinos 

Move BSSAP-LE and BSAP to pinos so that Decode As on a SCCP SSN
can specify the protocol of choice. The heuristic dissector still
depends on a preference, but change the existing two boolean
preferences to a three way enum. Separate the BSSAP and BSSAP-LE
dissector tables so that the code is cleaner.

Add BSAP, BSSAP-LE, and BSSAP+ to the SCCP UAT for even finer-grained
control. Fix #16828
This commit is contained in:
John Thacker 2021-10-25 21:56:50 -04:00
parent a281afd9fa
commit 511ca9204f
4 changed files with 201 additions and 100 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

227
epan/dissectors/packet-bssap.c
View File

@ -22,6 +22,7 @@
#include <epan/packet.h>
#include <epan/expert.h>
#include <epan/prefs.h>
#include <epan/proto_data.h>
#include <wsutil/str_util.h>
#include "packet-bssap.h"
#include "packet-gsm_a_common.h"
@ -31,9 +32,14 @@ void proto_register_bssap(void);
void proto_reg_handoff_bssap(void);
static dissector_handle_t bssap_handle;
static dissector_handle_t bsap_handle;
static dissector_handle_t bssap_le_handle;
#define BSSAP 0
#define BSAP 1
enum bssap_proto {
BSSAP,
BSAP,
BSSAP_LE,
};
#define GSM_INTERFACE 0
#define LB_INTERFACE 1
@ -230,6 +236,8 @@ static value_string_ext bssap_plus_ie_id_values_ext = VALUE_STRING_EXT_INIT(bssa
/* Initialize the protocol and registered fields */
static int proto_bssap = -1;
static int proto_bsap = -1;
static int proto_bssap_le = -1;
static int proto_bssap_plus = -1;
static int hf_bssap_pdu_type = -1;
static int hf_bsap_pdu_type = -1;
@ -346,51 +354,44 @@ static dissector_handle_t rrlp_handle;
static dissector_table_t bssap_dissector_table;
static dissector_table_t bsap_dissector_table;
static dissector_table_t bssap_le_dissector_table;
static dissector_handle_t gsm_bssmap_le_dissector_handle;
static dissector_handle_t gsm_a_bssmap_dissector_handle;
/*
* Keep track of pdu_type so we can call appropriate sub-dissector
*/
static guint8 pdu_type = 0xFF;
static gint bssap_or_bsap_global = BSSAP_OR_BSAP_DEFAULT;
typedef struct {
guint8 pdu_type;
enum bssap_proto proto;
} bssap_info_t;
static gint gsm_or_lb_interface_global = GSM_OR_LB_INTERFACE_DEFAULT;
static gint default_protocol_global = BSSAP;
static void
dissect_bssap_data_param(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *bssap_tree, proto_tree *tree, struct _sccp_msg_info_t* sccp_info)
{
if ((pdu_type <= 0x01))
{
if (bssap_or_bsap_global == BSSAP)
{
/* BSSAP */
if((gsm_or_lb_interface_global == LB_INTERFACE) && (pdu_type == BSSAP_PDU_TYPE_BSSMAP))
{
call_dissector_with_data(gsm_bssmap_le_dissector_handle, tvb, pinfo, tree, sccp_info);
bssap_info_t* bssap_info;
return;
}
else if((gsm_or_lb_interface_global == GSM_INTERFACE) && (pdu_type == BSSAP_PDU_TYPE_BSSMAP))
{
call_dissector_with_data(gsm_a_bssmap_dissector_handle, tvb, pinfo, tree, sccp_info);
bssap_info = (bssap_info_t *)p_get_proto_data(pinfo->pool, pinfo, proto_bssap, 0);
guint8 pdu_type = bssap_info->pdu_type;
return;
}
else
{
if (dissector_try_uint_new(bssap_dissector_table, pdu_type, tvb, pinfo, tree, TRUE, sccp_info)) return;
}
}
else
{
/* BSAP */
if (dissector_try_uint_new(bsap_dissector_table, pdu_type, tvb, pinfo, tree, TRUE, sccp_info))
return;
}
switch (bssap_info->proto) {
case BSSAP:
if (dissector_try_uint_new(bssap_dissector_table, pdu_type, tvb, pinfo, tree, TRUE, sccp_info))
return;
break;
case BSSAP_LE:
if (dissector_try_uint_new(bssap_le_dissector_table, pdu_type, tvb, pinfo, tree, TRUE, sccp_info))
return;
break;
case BSAP:
if (dissector_try_uint_new(bsap_dissector_table, pdu_type, tvb, pinfo, tree, TRUE, sccp_info))
return;
break;
}
/* No sub-dissection occurred, treat it as raw data */
@ -398,10 +399,13 @@ dissect_bssap_data_param(tvbuff_t *tvb, packet_info *pinfo,
}
static void
dissect_bssap_dlci_param(tvbuff_t *tvb, proto_tree *tree, guint16 length)
dissect_bssap_dlci_param(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint16 length)
{
proto_tree *dlci_tree;
guint8 oct;
bssap_info_t* bssap_info;
bssap_info = (bssap_info_t *)p_get_proto_data(pinfo->pool, pinfo, proto_bssap, 0);
dlci_tree =
proto_tree_add_subtree(tree, tvb, 0, length,
@ -409,7 +413,7 @@ dissect_bssap_dlci_param(tvbuff_t *tvb, proto_tree *tree, guint16 length)
oct = tvb_get_guint8(tvb, 0);
if (bssap_or_bsap_global == BSSAP)
if (bssap_info->proto != BSAP)
{
proto_tree_add_uint(dlci_tree, hf_bssap_dlci_cc, tvb, 0, length, oct);
proto_tree_add_uint(dlci_tree, hf_bssap_dlci_spare, tvb, 0, length, oct);
@ -447,7 +451,7 @@ dissect_bssap_parameter(tvbuff_t *tvb, packet_info *pinfo, proto_tree *bssap_tre
switch (parameter_type)
{
case PARAMETER_DLCI:
dissect_bssap_dlci_param(parameter_tvb, bssap_tree, parameter_length);
dissect_bssap_dlci_param(parameter_tvb, pinfo, bssap_tree, parameter_length);
break;
case PARAMETER_LENGTH:
@ -492,23 +496,26 @@ dissect_bssap_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *bssap_tree,
{
gint offset;
proto_item* type_item;
bssap_info_t* bssap_info;
bssap_info = (bssap_info_t *)p_get_proto_data(pinfo->pool, pinfo, proto_bssap, 0);
/*
* Extract the PDU type
*/
pdu_type = tvb_get_guint8(tvb, PDU_TYPE_OFFSET);
bssap_info->pdu_type = tvb_get_guint8(tvb, PDU_TYPE_OFFSET);
offset = PDU_TYPE_LENGTH;
/*
* add the message type to the protocol tree
*/
type_item = proto_tree_add_uint(bssap_tree,
(bssap_or_bsap_global == BSSAP) ? hf_bssap_pdu_type : hf_bsap_pdu_type,
tvb, PDU_TYPE_OFFSET, PDU_TYPE_LENGTH, pdu_type);
(bssap_info->proto != BSAP) ? hf_bssap_pdu_type : hf_bsap_pdu_type,
tvb, PDU_TYPE_OFFSET, PDU_TYPE_LENGTH, bssap_info->pdu_type);
/* Starting a new message dissection */
switch (pdu_type)
switch (bssap_info->pdu_type)
{
case BSSAP_PDU_TYPE_BSSMAP:
offset += dissect_bssap_parameter(tvb, pinfo, bssap_tree, tree,
@ -536,8 +543,8 @@ dissect_bssap_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *bssap_tree,
guint32 message_length;
col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
val_to_str_const(pdu_type,
((bssap_or_bsap_global == BSSAP) ?
val_to_str_const(bssap_info->pdu_type,
((bssap_info->proto != BSAP) ?
bssap_pdu_type_acro_values : bsap_pdu_type_acro_values),
"Unknown"));
@ -557,11 +564,12 @@ dissect_bssap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
proto_item *bssap_item;
proto_tree *bssap_tree;
struct _sccp_msg_info_t* sccp_info = (struct _sccp_msg_info_t*)data;
bssap_info_t *bssap_info;
/*
* Make entry in the Protocol column on summary display
*/
col_set_str(pinfo->cinfo, COL_PROTOCOL, ((bssap_or_bsap_global == BSSAP) ? "BSSAP" : "BSAP"));
col_set_str(pinfo->cinfo, COL_PROTOCOL, "BSSAP");
if (sccp_info && sccp_info->data.co.assoc )
sccp_info->data.co.assoc->payload = SCCP_PLOAD_BSSAP;
@ -569,15 +577,79 @@ dissect_bssap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
/*
* create the bssap protocol tree
*/
bssap_item = proto_tree_add_protocol_format(tree, proto_bssap, tvb, 0, -1,
(bssap_or_bsap_global == BSSAP) ? "BSSAP" : "BSAP");
bssap_item = proto_tree_add_item(tree, proto_bssap, tvb, 0, -1, ENC_NA);
bssap_tree = proto_item_add_subtree(bssap_item, ett_bssap);
bssap_info = wmem_new(pinfo->pool, bssap_info_t);
bssap_info->proto = BSSAP;
p_add_proto_data(pinfo->pool, pinfo, proto_bssap, 0, bssap_info);
/* dissect the message */
return dissect_bssap_message(tvb, pinfo, bssap_tree, tree, sccp_info);
}
static int
dissect_bsap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
proto_item *bssap_item;
proto_tree *bssap_tree;
struct _sccp_msg_info_t* sccp_info = (struct _sccp_msg_info_t*)data;
bssap_info_t *bssap_info;
/*
* Make entry in the Protocol column on summary display
*/
col_set_str(pinfo->cinfo, COL_PROTOCOL, "BSAP");
if (sccp_info && sccp_info->data.co.assoc )
sccp_info->data.co.assoc->payload = SCCP_PLOAD_BSSAP;
/*
* create the bsap protocol tree
*/
bssap_item = proto_tree_add_item(tree, proto_bsap, tvb, 0, -1, ENC_NA);
bssap_tree = proto_item_add_subtree(bssap_item, ett_bssap);
bssap_info = wmem_new(pinfo->pool, bssap_info_t);
bssap_info->proto = BSAP;
p_add_proto_data(pinfo->pool, pinfo, proto_bssap, 0, bssap_info);
/* dissect the message */
return dissect_bssap_message(tvb, pinfo, bssap_tree, tree, sccp_info);
}
static int
dissect_bssap_le(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
proto_item *bssap_item;
proto_tree *bssap_tree;
struct _sccp_msg_info_t* sccp_info = (struct _sccp_msg_info_t*)data;
bssap_info_t *bssap_info;
/*
* Make entry in the Protocol column on summary display
*/
col_set_str(pinfo->cinfo, COL_PROTOCOL, "BSSAP-LE");
if (sccp_info && sccp_info->data.co.assoc )
sccp_info->data.co.assoc->payload = SCCP_PLOAD_BSSAP;
/*
* create the bssap_le protocol tree
*/
bssap_item = proto_tree_add_item(tree, proto_bssap_le, tvb, 0, -1, ENC_NA);
bssap_tree = proto_item_add_subtree(bssap_item, ett_bssap);
bssap_info = wmem_new(pinfo->pool, bssap_info_t);
bssap_info->proto = BSSAP_LE;
p_add_proto_data(pinfo->pool, pinfo, proto_bssap, 0, bssap_info);
/* dissect the message */
return dissect_bssap_message(tvb, pinfo, bssap_tree, tree, sccp_info);
}
/*
* BSSAP+ Routines
@ -2077,7 +2149,21 @@ dissect_bssap_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *da
return(FALSE);
}
dissect_bssap(tvb, pinfo, tree, data);
switch (default_protocol_global) {
case BSSAP:
dissect_bssap(tvb, pinfo, tree, data);
break;
case BSAP:
dissect_bsap(tvb, pinfo, tree, data);
break;
case BSSAP_LE:
dissect_bssap_le(tvb, pinfo, tree, data);
break;
}
return(TRUE);
}
@ -2466,15 +2552,10 @@ proto_register_bssap(void)
&ett_bssap_plmn,
};
static const enum_val_t gsm_or_lb_interface_options[] = {
{ "gsm a", "GSM A", GSM_INTERFACE },
{ "lb", "Lb", LB_INTERFACE },
{ NULL, NULL, 0 }
};
static const enum_val_t bssap_or_bsap_options[] = {
{ "bssap", "BSSAP", BSSAP },
{ "bsap", "BSAP", BSAP },
static const enum_val_t default_protocol_options[] = {
{ "bssap", "BSSAP (GSM A-I/F)", BSSAP },
{ "bsap", "BSAP (CDMA2000 A-I/F)", BSAP },
{ "bssap_le", "BSSAP-LE (GSM Lb-I/F)", BSSAP_LE },
{ NULL, NULL, 0 }
};
@ -2485,10 +2566,14 @@ proto_register_bssap(void)
};
/* Register the protocol name and description */
proto_bssap = proto_register_protocol("BSSAP/BSAP", "BSSAP", "bssap");
proto_bssap = proto_register_protocol("BSSAP", "BSSAP", "bssap");
proto_bssap_plus = proto_register_protocol("BSSAP2", "BSSAP2", "bssap_plus");
proto_bsap = proto_register_protocol_in_name_only("BSAP", "BSAP", "bsap", proto_bssap, FT_PROTOCOL);
proto_bssap_le = proto_register_protocol_in_name_only("BSSAP-LE", "BSSAP-LE", "bssap_le", proto_bssap, FT_PROTOCOL);
bssap_handle = register_dissector("bssap", dissect_bssap, proto_bssap);
bsap_handle = register_dissector("bsap", dissect_bsap, proto_bsap);
bssap_le_handle = register_dissector("bssap_le", dissect_bssap_le, proto_bssap_le);
register_dissector("bssap.imei", dissect_bssap_imei_dissector, proto_bssap);
register_dissector("bssap_plus", dissect_bssap_plus, proto_bssap_plus);
@ -2500,22 +2585,19 @@ proto_register_bssap(void)
bssap_module = prefs_register_protocol(proto_bssap, proto_reg_handoff_bssap);
prefs_register_enum_preference(bssap_module,
"bsap_or_bssap",
"Identify to sub-dissector as",
"For the sake of sub-dissectors registering to accept data "
"from the BSSAP/BSAP dissector, this defines whether it is "
"identified as BSSAP or BSAP.",
&bssap_or_bsap_global,
bssap_or_bsap_options,
FALSE);
prefs_register_obsolete_preference(bssap_module, "bsap_or_bssap");
prefs_register_obsolete_preference(bssap_module, "gsm_or_lb_interface");
prefs_register_enum_preference(bssap_module,
"gsm_or_lb_interface",
"Identify the BSSAP interface",
"GSM-A is the interface between the BSC and the MSC. Lb is the interface between the BSC and the SMLC.",
&gsm_or_lb_interface_global,
gsm_or_lb_interface_options,
"default_protocol",
"Default protocol",
"The default protocol assumed by the heuristic dissector,"
"which does not easily distinguish between BSSAP "
"(on the GSM A interface between the BSC and the MSC), "
"BSSAP-LE (on the GSM Lb interface between the BSC and the SMLC), "
"and BSAP (on the CDMA2000 A interface between the BS and MSC).",
&default_protocol_global,
default_protocol_options,
FALSE);
bssap_plus_module = prefs_register_protocol(proto_bssap_plus, proto_reg_handoff_bssap);
@ -2526,6 +2608,7 @@ proto_register_bssap(void)
bssap_dissector_table = register_dissector_table("bssap.pdu_type", "BSSAP Message Type", proto_bssap, FT_UINT8, BASE_DEC);
bsap_dissector_table = register_dissector_table("bsap.pdu_type", "BSAP Message Type", proto_bssap, FT_UINT8, BASE_DEC);
bssap_le_dissector_table = register_dissector_table("bssap_le.pdu_type", "BSSAP Message Type", proto_bssap, FT_UINT8, BASE_DEC);
}
void
@ -2551,6 +2634,8 @@ proto_reg_handoff_bssap(void)
}
dissector_add_for_decode_as("sccp.ssn", bssap_handle);
dissector_add_for_decode_as("sccp.ssn", bsap_handle);
dissector_add_for_decode_as("sccp.ssn", bssap_le_handle);
dissector_add_uint("sccp.ssn", global_bssap_ssn, bssap_plus_handle);
old_bssap_ssn = global_bssap_ssn;

1
epan/dissectors/packet-gsm_a_dtap.c
View File

@ -8499,6 +8499,7 @@ void
proto_reg_handoff_gsm_a_dtap(void)
{
dissector_add_uint("bssap.pdu_type", BSSAP_PDU_TYPE_DTAP, dtap_handle);
dissector_add_uint("bssap_le.pdu_type", BSSAP_PDU_TYPE_DTAP, dtap_handle);
dissector_add_uint("ranap.nas_pdu", BSSAP_PDU_TYPE_DTAP, dtap_handle);
dissector_add_uint("llcgprs.sapi", 1 , dtap_handle); /* GPRS Mobility Management */
dissector_add_uint("llcgprs.sapi", 7 , dtap_handle); /* SMS */

2
epan/dissectors/packet-gsm_bssmap_le.c
View File

@ -1313,7 +1313,7 @@ proto_register_gsm_bssmap_le(void)
void
proto_reg_handoff_gsm_bssmap_le(void)
{
dissector_add_uint("bssap.pdu_type", BSSAP_PDU_TYPE_BSSMAP, bssmap_le_handle);
dissector_add_uint("bssap_le.pdu_type", BSSAP_PDU_TYPE_BSSMAP, bssmap_le_handle);
gsm_bsslap_handle = find_dissector_add_dependency("gsm_bsslap", proto_bssmap_le);
}

71
epan/dissectors/packet-sccp.c
View File

@ -744,13 +744,16 @@ static const fragment_items sccp_xudt_msg_frag_items = {
static reassembly_table sccp_xudt_msg_reassembly_table;
#define SCCP_USER_DATA 0
#define SCCP_USER_TCAP 1
#define SCCP_USER_RANAP 2
#define SCCP_USER_BSSAP 3
#define SCCP_USER_GSMMAP 4
#define SCCP_USER_CAMEL 5
#define SCCP_USER_INAP 6
#define SCCP_USER_DATA 0
#define SCCP_USER_TCAP 1
#define SCCP_USER_RANAP 2
#define SCCP_USER_BSSAP 3
#define SCCP_USER_GSMMAP 4
#define SCCP_USER_CAMEL 5
#define SCCP_USER_INAP 6
#define SCCP_USER_BSAP 7
#define SCCP_USER_BSSAP_LE 8
#define SCCP_USER_BSSAP_PLUS 9
typedef struct _sccp_user_t {
guint ni;
@ -772,18 +775,24 @@ static dissector_handle_t bssap_handle;
static dissector_handle_t gsmmap_handle;
static dissector_handle_t camel_handle;
static dissector_handle_t inap_handle;
static dissector_handle_t bsap_handle;
static dissector_handle_t bssap_le_handle;
static dissector_handle_t bssap_plus_handle;
static dissector_handle_t default_handle;
static const char *default_payload = NULL;
static const value_string sccp_users_vals[] = {
{ SCCP_USER_DATA, "Data"},
{ SCCP_USER_TCAP, "TCAP"},
{ SCCP_USER_RANAP, "RANAP"},
{ SCCP_USER_BSSAP, "BSSAP"},
{ SCCP_USER_GSMMAP, "GSM MAP"},
{ SCCP_USER_CAMEL, "CAMEL"},
{ SCCP_USER_INAP, "INAP"},
{ SCCP_USER_DATA, "Data"},
{ SCCP_USER_TCAP, "TCAP"},
{ SCCP_USER_RANAP, "RANAP"},
{ SCCP_USER_BSSAP, "BSSAP"},
{ SCCP_USER_GSMMAP, "GSM MAP"},
{ SCCP_USER_CAMEL, "CAMEL"},
{ SCCP_USER_INAP, "INAP"},
{ SCCP_USER_BSAP, "BSAP"},
{ SCCP_USER_BSSAP_LE, "BSSAP-LE"},
{ SCCP_USER_BSSAP_PLUS, "BSSAP+"},
{ 0, NULL }
};
@ -3486,13 +3495,16 @@ static struct _sccp_ul {
dissector_handle_t *handlep;
} user_list[] = {
{SCCP_USER_DATA, FALSE, &data_handle},
{SCCP_USER_TCAP, FALSE, &tcap_handle},
{SCCP_USER_RANAP, FALSE, &ranap_handle},
{SCCP_USER_BSSAP, FALSE, &bssap_handle},
{SCCP_USER_GSMMAP, TRUE, &gsmmap_handle},
{SCCP_USER_CAMEL, TRUE, &camel_handle},
{SCCP_USER_INAP, TRUE, &inap_handle},
{SCCP_USER_DATA, FALSE, &data_handle},
{SCCP_USER_TCAP, FALSE, &tcap_handle},
{SCCP_USER_RANAP, FALSE, &ranap_handle},
{SCCP_USER_BSSAP, FALSE, &bssap_handle},
{SCCP_USER_GSMMAP, TRUE, &gsmmap_handle},
{SCCP_USER_CAMEL, TRUE, &camel_handle},
{SCCP_USER_INAP, TRUE, &inap_handle},
{SCCP_USER_BSAP, FALSE, &bsap_handle},
{SCCP_USER_BSSAP_LE, FALSE, &bssap_le_handle},
{SCCP_USER_BSSAP_PLUS, FALSE, &bssap_plus_handle},
{0, FALSE, NULL}
};
@ -4235,13 +4247,16 @@ proto_reg_handoff_sccp(void)
dissector_add_uint("mtp3.service_indicator", MTP_SI_SCCP, sccp_handle);
dissector_add_string("tali.opcode", "sccp", sccp_handle);
data_handle = find_dissector("data");
tcap_handle = find_dissector_add_dependency("tcap", proto_sccp);
ranap_handle = find_dissector_add_dependency("ranap", proto_sccp);
bssap_handle = find_dissector_add_dependency("bssap", proto_sccp);
gsmmap_handle = find_dissector_add_dependency("gsm_map_sccp", proto_sccp);
camel_handle = find_dissector_add_dependency("camel", proto_sccp);
inap_handle = find_dissector_add_dependency("inap", proto_sccp);
data_handle = find_dissector("data");
tcap_handle = find_dissector_add_dependency("tcap", proto_sccp);
ranap_handle = find_dissector_add_dependency("ranap", proto_sccp);
bssap_handle = find_dissector_add_dependency("bssap", proto_sccp);
gsmmap_handle = find_dissector_add_dependency("gsm_map_sccp", proto_sccp);
camel_handle = find_dissector_add_dependency("camel", proto_sccp);
inap_handle = find_dissector_add_dependency("inap", proto_sccp);
bsap_handle = find_dissector_add_dependency("bsap", proto_sccp);
bssap_le_handle = find_dissector_add_dependency("bssap_le", proto_sccp);
bssap_plus_handle = find_dissector_add_dependency("bssap_plus", proto_sccp);
ss7pc_address_type = address_type_get_by_name("AT_SS7PC");