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Use dissector table to dissect content of ieee1609 

For unsecured and signed data, the dissector uses a dissector table to
determine the next dissector. It uses the psId field to index the table.

In the case no psId is provided inside, the caller can set a default
psid if it is provided beforehand. If none is provided, data are not
dissected.

Change-Id: I6f9d6989cd87dd373a155a5b893c460344a0c857
Reviewed-on: https://code.wireshark.org/review/31237
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>
This commit is contained in:
Christophe GUERBER 2018-12-30 15:40:29 +01:00 committed by Anders Broman
parent c25dbfa8a7
commit e9cf698512
6 changed files with 113 additions and 21 deletions
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26
epan/dissectors/asn1/ieee1609dot2/ieee1609dot2.cnf
View File

@ -45,14 +45,30 @@ UnknownLongitude
#.FN_BODY Ieee1609Dot2Content/unsecuredData
tvbuff_t *parameter_tvb=NULL;
offset = dissect_oer_octet_string(tvb, offset, actx, tree, hf_index,
NO_BOUND, NO_BOUND, FALSE, &parameter_tvb);
NO_BOUND, NO_BOUND, FALSE, (tvbuff_t **)&actx->private_data);
if((parameter_tvb)&& (j2735_handle)){
if (actx->private_data) {
// psid may also be provided in HeaderInfo
guint32 *psid = (guint32*)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_ieee1609dot2, 0);
if (psid) {
/* Call next dissector here */
dissector_try_uint(unsecured_data_subdissector_table, *psid, (tvbuff_t *)(actx->private_data), actx->pinfo, tree);
actx->private_data = NULL;
}
// else: wait for the HeaderInfo for a second chance to dissect the content
}
#.END
#.FN_BODY HeaderInfo/psid
guint64 psid;
offset = dissect_oer_constrained_integer_64b_no_ub(tvb, offset, actx, tree, hf_index,
0U, NO_BOUND, &psid, FALSE);
if (actx->private_data) {
/* Call next dissector here */
call_dissector(j2735_handle, parameter_tvb, actx->pinfo, tree);
dissector_try_uint(unsecured_data_subdissector_table, (guint32) psid, (tvbuff_t *)(actx->private_data), actx->pinfo, tree);
actx->private_data = NULL;
}
#.END

16
epan/dissectors/asn1/ieee1609dot2/packet-ieee1609dot2-template.c
View File

@ -19,6 +19,7 @@
#include <epan/conversation.h>
#include <epan/oids.h>
#include <epan/asn1.h>
#include <epan/proto_data.h>
#include "packet-oer.h"
#include "packet-ieee1609dot2.h"
@ -37,7 +38,15 @@ int proto_ieee1609dot2 = -1;
/* Initialize the subtree pointers */
#include "packet-ieee1609dot2-ett.c"
static dissector_handle_t j2735_handle;
static dissector_table_t unsecured_data_subdissector_table;
void
ieee1609dot2_set_next_default_psid(packet_info *pinfo, guint32 psid)
{
guint32 *ctxt = wmem_new0(wmem_file_scope(), guint32);
*ctxt = psid;
p_add_proto_data(wmem_file_scope(), pinfo, proto_ieee1609dot2, 0, (void*)ctxt);
}
#include "packet-ieee1609dot2-fn.c"
@ -63,11 +72,14 @@ void proto_register_ieee1609dot2(void) {
proto_register_subtree_array(ett, array_length(ett));
register_dissector("ieee1609dot2.data", dissect_Ieee1609Dot2Data_PDU, proto_ieee1609dot2);
// See TS17419_ITS-AID_AssignedNumbers
unsecured_data_subdissector_table = register_dissector_table("ieee1609dot2.psid",
"ATS-AID/PSID based dissector for unsecured/signed data", proto_ieee1609dot2, FT_UINT32, BASE_HEX);
}
void
proto_reg_handoff_IEEE1609dot2(void)
{
j2735_handle = find_dissector_add_dependency("j2735", proto_ieee1609dot2);
}

11
epan/dissectors/asn1/ieee1609dot2/packet-ieee1609dot2-template.h
View File

@ -16,6 +16,17 @@
#include "packet-ieee1609dot2-val.h"
/*
* When dissecting IEEE1609.2 structure containing only unsecured data, no PSID
* is provided inside. Caller has to provide a ITS-AID/PSID before calling the
* dissector to have a chance to dissect the data part.
* For signed data, PSID is provided and the caller do not have to provide the
* PSID. If he does, the provided PSID takes precedence on the PSID inside the
* structure.
*/
WS_DLL_PUBLIC
void ieee1609dot2_set_next_default_psid(packet_info *pinfo, guint32 psid);
#include "packet-ieee1609dot2-exp.h"
#endif /* _IEEE1609DOT2_H_ */

66
epan/dissectors/packet-ieee1609dot2.c
View File

@ -27,6 +27,7 @@
#include <epan/conversation.h>
#include <epan/oids.h>
#include <epan/asn1.h>
#include <epan/proto_data.h>
#include "packet-oer.h"
#include "packet-ieee1609dot2.h"
@ -130,6 +131,7 @@ static int hf_ieee1609dot2_self = -1; /* NULL */
static int hf_ieee1609dot2_payload = -1; /* SignedDataPayload */
static int hf_ieee1609dot2_headerInfo = -1; /* HeaderInfo */
static int hf_ieee1609dot2_sha256HashedData = -1; /* OCTET_STRING_SIZE_32 */
static int hf_ieee1609dot2_psid_01 = -1; /* T_psid */
static int hf_ieee1609dot2_generationTime = -1; /* Time64 */
static int hf_ieee1609dot2_expiryTime = -1; /* Time64 */
static int hf_ieee1609dot2_generationLocation = -1; /* ThreeDLocation */
@ -191,7 +193,7 @@ static int hf_ieee1609dot2_EndEntityType_app = -1;
static int hf_ieee1609dot2_EndEntityType_enrol = -1;
/*--- End of included file: packet-ieee1609dot2-hf.c ---*/
#line 36 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.c"
#line 37 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.c"
/* Initialize the subtree pointers */
@ -262,9 +264,17 @@ static gint ett_ieee1609dot2_SubjectPermissions = -1;
static gint ett_ieee1609dot2_VerificationKeyIndicator = -1;
/*--- End of included file: packet-ieee1609dot2-ett.c ---*/
#line 39 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.c"
#line 40 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.c"
static dissector_handle_t j2735_handle;
static dissector_table_t unsecured_data_subdissector_table;
void
ieee1609dot2_set_next_default_psid(packet_info *pinfo, guint32 psid)
{
guint32 *ctxt = wmem_new0(wmem_file_scope(), guint32);
*ctxt = psid;
p_add_proto_data(wmem_file_scope(), pinfo, proto_ieee1609dot2, 0, (void*)ctxt);
}
/*--- Included file: packet-ieee1609dot2-fn.c ---*/
@ -1271,14 +1281,37 @@ static int
dissect_ieee1609dot2_T_unsecuredData(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
#line 47 "./asn1/ieee1609dot2/ieee1609dot2.cnf"
tvbuff_t *parameter_tvb=NULL;
offset = dissect_oer_octet_string(tvb, offset, actx, tree, hf_index,
NO_BOUND, NO_BOUND, FALSE, &parameter_tvb);
NO_BOUND, NO_BOUND, FALSE, (tvbuff_t **)&actx->private_data);
if((parameter_tvb)&& (j2735_handle)){
if (actx->private_data) {
// psid may also be provided in HeaderInfo
guint32 *psid = (guint32*)p_get_proto_data(wmem_file_scope(), actx->pinfo, proto_ieee1609dot2, 0);
if (psid) {
/* Call next dissector here */
dissector_try_uint(unsecured_data_subdissector_table, *psid, (tvbuff_t *)(actx->private_data), actx->pinfo, tree);
actx->private_data = NULL;
}
// else: wait for the HeaderInfo for a second chance to dissect the content
}
return offset;
}
static int
dissect_ieee1609dot2_T_psid(tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
#line 65 "./asn1/ieee1609dot2/ieee1609dot2.cnf"
guint64 psid;
offset = dissect_oer_constrained_integer_64b_no_ub(tvb, offset, actx, tree, hf_index,
0U, NO_BOUND, &psid, FALSE);
if (actx->private_data) {
/* Call next dissector here */
call_dissector(j2735_handle, parameter_tvb, actx->pinfo, tree);
dissector_try_uint(unsecured_data_subdissector_table, (guint32) psid, (tvbuff_t *)(actx->private_data), actx->pinfo, tree);
actx->private_data = NULL;
}
@ -1303,7 +1336,7 @@ dissect_ieee1609dot2_MissingCrlIdentifier(tvbuff_t *tvb _U_, int offset _U_, asn
static const oer_sequence_t HeaderInfo_sequence[] = {
{ &hf_ieee1609dot2_psid , ASN1_EXTENSION_ROOT , ASN1_NOT_OPTIONAL, dissect_ieee1609dot2_Psid },
{ &hf_ieee1609dot2_psid_01, ASN1_EXTENSION_ROOT , ASN1_NOT_OPTIONAL, dissect_ieee1609dot2_T_psid },
{ &hf_ieee1609dot2_generationTime, ASN1_EXTENSION_ROOT , ASN1_OPTIONAL , dissect_ieee1609dot2_Time64 },
{ &hf_ieee1609dot2_expiryTime, ASN1_EXTENSION_ROOT , ASN1_OPTIONAL , dissect_ieee1609dot2_Time64 },
{ &hf_ieee1609dot2_generationLocation, ASN1_EXTENSION_ROOT , ASN1_OPTIONAL , dissect_ieee1609dot2_ThreeDLocation },
@ -1875,7 +1908,7 @@ static int dissect_Ieee1609Dot2Data_PDU(tvbuff_t *tvb _U_, packet_info *pinfo _U
/*--- End of included file: packet-ieee1609dot2-fn.c ---*/
#line 43 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.c"
#line 52 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.c"
/*--- proto_register_ieee1609dot2 ----------------------------------------------*/
@ -2234,6 +2267,10 @@ void proto_register_ieee1609dot2(void) {
{ "sha256HashedData", "ieee1609dot2.sha256HashedData",
FT_BYTES, BASE_NONE, NULL, 0,
"OCTET_STRING_SIZE_32", HFILL }},
{ &hf_ieee1609dot2_psid_01,
{ "psid", "ieee1609dot2.psid",
FT_UINT64, BASE_DEC|BASE_VAL64_STRING, VALS64(ieee1609dot2_Psid_vals), 0,
NULL, HFILL }},
{ &hf_ieee1609dot2_generationTime,
{ "generationTime", "ieee1609dot2.generationTime",
FT_UINT64, BASE_DEC, NULL, 0,
@ -2468,7 +2505,7 @@ void proto_register_ieee1609dot2(void) {
NULL, HFILL }},
/*--- End of included file: packet-ieee1609dot2-hfarr.c ---*/
#line 51 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.c"
#line 60 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.c"
};
/* List of subtrees */
@ -2541,7 +2578,7 @@ void proto_register_ieee1609dot2(void) {
&ett_ieee1609dot2_VerificationKeyIndicator,
/*--- End of included file: packet-ieee1609dot2-ettarr.c ---*/
#line 56 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.c"
#line 65 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.c"
};
/* Register protocol */
@ -2552,11 +2589,14 @@ void proto_register_ieee1609dot2(void) {
proto_register_subtree_array(ett, array_length(ett));
register_dissector("ieee1609dot2.data", dissect_Ieee1609Dot2Data_PDU, proto_ieee1609dot2);
// See TS17419_ITS-AID_AssignedNumbers
unsecured_data_subdissector_table = register_dissector_table("ieee1609dot2.psid",
"ATS-AID/PSID based dissector for unsecured/signed data", proto_ieee1609dot2, FT_UINT32, BASE_HEX);
}
void
proto_reg_handoff_IEEE1609dot2(void)
{
j2735_handle = find_dissector_add_dependency("j2735", proto_ieee1609dot2);
}

13
epan/dissectors/packet-ieee1609dot2.h
View File

@ -98,13 +98,24 @@ typedef enum _Psid_enum {
/*--- End of included file: packet-ieee1609dot2-val.h ---*/
#line 18 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.h"
/*
* When dissecting IEEE1609.2 structure containing only unsecured data, no PSID
* is provided inside. Caller has to provide a ITS-AID/PSID before calling the
* dissector to have a chance to dissect the data part.
* For signed data, PSID is provided and the caller do not have to provide the
* PSID. If he does, the provided PSID takes precedence on the PSID inside the
* structure.
*/
WS_DLL_PUBLIC
void ieee1609dot2_set_next_default_psid(packet_info *pinfo, guint32 psid);
/*--- Included file: packet-ieee1609dot2-exp.h ---*/
#line 1 "./asn1/ieee1609dot2/packet-ieee1609dot2-exp.h"
WS_DLL_PUBLIC const val64_string ieee1609dot2_Psid_vals[];
/*--- End of included file: packet-ieee1609dot2-exp.h ---*/
#line 20 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.h"
#line 31 "./asn1/ieee1609dot2/packet-ieee1609dot2-template.h"
#endif /* _IEEE1609DOT2_H_ */

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

@ -291,9 +291,11 @@ dissect_wsmp_v3(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint8 oct)
data_tree = proto_tree_add_subtree(tree, tvb, offset, wsm_len, ett_wsmdata, NULL, "Wave Short Message");
if((psid == (guint32)psid_vehicle_to_vehicle_safety_and_awarenesss) && (IEEE1609dot2_handle)){
ieee1609dot2_set_next_default_psid(pinfo, psid);
tvbuff_t * tvb_new = tvb_new_subset_remaining(tvb, offset);
call_dissector(IEEE1609dot2_handle, tvb_new, pinfo, data_tree);
} else if ((psid == (guint32)psid_intersection_safety_and_awareness) && (IEEE1609dot2_handle)) {
ieee1609dot2_set_next_default_psid(pinfo, psid);
tvbuff_t * tvb_new = tvb_new_subset_remaining(tvb, offset);
call_dissector(IEEE1609dot2_handle, tvb_new, pinfo, data_tree);
}