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TECMP: Adding heuristics support for CAN and FlexRay messages 

This patch adds support for TECMP to hand over CAN and FlexRay
messages to heuristics dissectors registers.
This commit is contained in:
Dr. Lars Völker 2021-01-14 00:08:11 +01:00 committed by AndersBroman
parent 4d515f70af
commit fab3070e79
1 changed files with 45 additions and 11 deletions
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56
epan/dissectors/packet-tecmp.c
View File

@ -1,7 +1,7 @@
/* packet-tecmp.c
* Technically Enhanced Capture Module Protocol (TECMP) dissector.
* By <lars.voelker@technica-engineering.de>
* Copyright 2019-2020 Dr. Lars Voelker
* Copyright 2019-2021 Dr. Lars Voelker
* Copyright 2020 Ayoub Kaanich
*
* Wireshark - Network traffic analyzer
@ -35,11 +35,20 @@ void proto_reg_handoff_tecmp_payload(void);
static int proto_tecmp = -1;
static int proto_tecmp_payload = -1;
static dissector_handle_t eth_handle;
static int proto_vlan;
static gboolean heuristic_first = FALSE;
static dissector_table_t can_subdissector_table;
static heur_dissector_list_t can_heur_subdissector_list;
static heur_dtbl_entry_t *can_heur_dtbl_entry;
static dissector_table_t fr_subdissector_table;
static heur_dissector_list_t fr_heur_subdissector_list;
static heur_dtbl_entry_t *fr_heur_dtbl_entry;
/* Header fields */
/* TECMP */
@ -1060,8 +1069,7 @@ dissect_tecmp_log_or_replay_stream(tvbuff_t *tvb, packet_info *pinfo, proto_tree
}
if (length2 > 0) {
proto_tree_add_item(tecmp_tree, hf_tecmp_payload_data_payload, sub_tvb, offset2, (gint)length2,
ENC_NA);
proto_tree_add_item(tecmp_tree, hf_tecmp_payload_data_payload, sub_tvb, offset2, (gint)length2, ENC_NA);
offset2 += (gint)length2;
proto_tree_add_item(tecmp_tree, hf_tecmp_payload_data_checksum_8bit, sub_tvb, offset2, 1, ENC_NA);
}
@ -1104,9 +1112,18 @@ dissect_tecmp_log_or_replay_stream(tvbuff_t *tvb, packet_info *pinfo, proto_tree
can_info.id |= CAN_ERR_FLAG;
}
if (!dissector_try_payload_new(can_subdissector_table, payload_tvb, pinfo, tree, TRUE, &can_info))
{
proto_tree_add_item(tecmp_tree, hf_tecmp_payload_data_payload, payload_tvb, 0, (gint)length2, ENC_NA);
if (!heuristic_first) {
if (!dissector_try_payload_new(can_subdissector_table, payload_tvb, pinfo, tree, TRUE, &can_info)) {
if (!dissector_try_heuristic(can_heur_subdissector_list, payload_tvb, pinfo, tree, &can_heur_dtbl_entry, &can_info)) {
proto_tree_add_item(tecmp_tree, hf_tecmp_payload_data_payload, payload_tvb, 0, (gint)length2, ENC_NA);
}
}
} else {
if (!dissector_try_heuristic(can_heur_subdissector_list, payload_tvb, pinfo, tree, &can_heur_dtbl_entry, &can_info)) {
if (!dissector_try_payload_new(can_subdissector_table, payload_tvb, pinfo, tree, FALSE, &can_info)) {
proto_tree_add_item(tecmp_tree, hf_tecmp_payload_data_payload, payload_tvb, 0, (gint)length2, ENC_NA);
}
}
}
}
break;
@ -1121,8 +1138,7 @@ dissect_tecmp_log_or_replay_stream(tvbuff_t *tvb, packet_info *pinfo, proto_tree
proto_tree_add_item_ret_uint(tecmp_tree, hf_tecmp_payload_data_frame_id, sub_tvb, offset2 + 1, 2, ENC_NA, &tmp);
fr_info.id = (guint16)tmp;
ti = proto_tree_add_item_ret_uint(tecmp_tree, hf_tecmp_payload_data_length, sub_tvb, offset2 + 3, 1, ENC_NA,
&length2);
ti = proto_tree_add_item_ret_uint(tecmp_tree, hf_tecmp_payload_data_length, sub_tvb, offset2 + 3, 1, ENC_NA, &length2);
offset2 += 4;
if (tvb_captured_length_remaining(sub_tvb, offset2) < (gint)length2) {
@ -1133,9 +1149,18 @@ dissect_tecmp_log_or_replay_stream(tvbuff_t *tvb, packet_info *pinfo, proto_tree
if (length2 > 0) {
payload_tvb = tvb_new_subset_length(sub_tvb, offset2, tvb_captured_length_remaining(sub_tvb, offset2));
if (!dissector_try_payload_new(fr_subdissector_table, payload_tvb, pinfo, tree, TRUE, &fr_info))
{
proto_tree_add_item(tecmp_tree, hf_tecmp_payload_data_payload, payload_tvb, 0, (gint)length2, ENC_NA);
if (!heuristic_first) {
if (!dissector_try_payload_new(fr_subdissector_table, payload_tvb, pinfo, tree, TRUE, &fr_info)) {
if (!dissector_try_heuristic(fr_heur_subdissector_list, payload_tvb, pinfo, tree, &fr_heur_dtbl_entry, &fr_info)) {
proto_tree_add_item(tecmp_tree, hf_tecmp_payload_data_payload, payload_tvb, 0, (gint)length2, ENC_NA);
}
}
} else {
if (!dissector_try_heuristic(fr_heur_subdissector_list, payload_tvb, pinfo, tree, &fr_heur_dtbl_entry, &fr_info)) {
if (!dissector_try_payload_new(fr_subdissector_table, payload_tvb, pinfo, tree, FALSE, &fr_info)) {
proto_tree_add_item(tecmp_tree, hf_tecmp_payload_data_payload, payload_tvb, 0, (gint)length2, ENC_NA);
}
}
}
}
break;
@ -1631,6 +1656,12 @@ proto_register_tecmp(void) {
prefs_register_uat_preference(tecmp_module, "_udf_tecmp_cms", "Capture Modules",
"A table to define names of Capture Modules, which override default names.", tecmp_cmid_uat);
prefs_register_bool_preference(tecmp_module, "try_heuristic_first",
"Try heuristic sub-dissectors first",
"Try to decode a packet using an heuristic sub-dissector"
" before using a sub-dissector registered to \"decode as\"",
&heuristic_first);
}
void
@ -1641,7 +1672,10 @@ proto_reg_handoff_tecmp(void) {
dissector_add_uint("ethertype", ETHERTYPE_TECMP, tecmp_handle);
can_subdissector_table = find_dissector_table("can.subdissector");
can_heur_subdissector_list = find_heur_dissector_list("can");
fr_subdissector_table = find_dissector_table("flexray.subdissector");
fr_heur_subdissector_list = find_heur_dissector_list("flexray");
}
/*