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AUTOSAR-NM: Adding support for PDU ranges and clean up 

This patch:
- adds support for PDU ranges instead of one single PDUs
- simplifies the dissection code for CAN messages
- cleans up some some comments
This commit is contained in:
Dr. Lars Völker 2021-01-14 00:01:41 +01:00 committed by AndersBroman
parent 5f36e597a0
commit 4d515f70af
1 changed files with 84 additions and 53 deletions
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137
epan/dissectors/packet-autosar-nm.c
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@ -1,7 +1,7 @@
/* packet-autosar-nm.c
* AUTOSAR-NM Dissector
* By Dr. Lars Voelker <lars.voelker@bmw.de>
* Copyright 2014-2017 Dr. Lars Voelker, BMW
* By Dr. Lars Voelker <lars.voelker@technica-engineering.de> / <lars.voelker@bmw.de>
* Copyright 2014-2021 Dr. Lars Voelker
* Copyright 2019 Maksim Salau <maksim.salau@gmail.com>
*
* Wireshark - Network traffic analyzer
@ -45,6 +45,9 @@ static int proto_canfd = -1;
static int proto_caneth = -1;
static int proto_udp = -1;
static dissector_handle_t nm_handle;
static dissector_handle_t nm_handle_can;
/*** header fields ***/
static int hf_autosar_nm_source_node_identifier = -1;
static int hf_autosar_nm_control_bit_vector = -1;
@ -88,12 +91,13 @@ static gboolean g_autosar_nm_interpret_coord_id = FALSE;
static guint32 g_autosar_nm_can_id = 0;
static guint32 g_autosar_nm_can_id_mask = 0;
/* Relevant PDUs */
static range_t *g_autosar_nm_pdus = NULL;
/*******************************
****** User data fields ******
*******************************/
/*** stolen from the HTTP disector ;-) ***/
static user_data_field_t* user_data_fields;
static guint num_user_data_fields;
static GHashTable* user_data_fields_hash_hf;
@ -139,9 +143,7 @@ user_data_fields_update_cb(void *r, char **err)
return (*err == NULL);
}
/* Check for invalid characters (to avoid asserting out when
* registering the field).
*/
/* Check for invalid characters (to avoid asserting out when registering the field). */
c = proto_check_field_name(rec->udf_name);
if (c) {
*err = g_strdup_printf("Name of user data field can't contain '%c'", c);
@ -152,7 +154,7 @@ user_data_fields_update_cb(void *r, char **err)
}
static void *
user_data_fields_copy_cb(void* n, const void* o, size_t siz _U_)
user_data_fields_copy_cb(void* n, const void* o, size_t size _U_)
{
user_data_field_t* new_rec = (user_data_field_t*)n;
const user_data_field_t* old_rec = (const user_data_field_t*)o;
@ -204,7 +206,7 @@ calc_hf_key(user_data_field_t udf)
}
/*
*
* Lookup the hf for the user data based on the key
*/
static gint*
get_hf_for_user_data(gchar* key)
@ -222,7 +224,7 @@ get_hf_for_user_data(gchar* key)
}
/*
*
* Lookup the ett for the user data based on the key
*/
static gint*
get_ett_for_user_data(guint32 offset, guint32 length)
@ -242,7 +244,7 @@ get_ett_for_user_data(guint32 offset, guint32 length)
}
/*
*
* clean up user data
*/
static void
deregister_user_data(void)
@ -280,7 +282,7 @@ user_data_post_update_cb(void)
deregister_user_data();
// we cannot unregister ETTs, so we should try to limit the damage of an update
/* we cannot unregister ETTs, so we should try to limit the damage of an update */
if (num_user_data_fields) {
user_data_fields_hash_hf = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);
dynamic_hf = g_new0(hf_register_info, num_user_data_fields);
@ -313,14 +315,14 @@ user_data_post_update_cb(void)
dynamic_hf[i].hfinfo.abbrev = g_strdup_printf("nm.user_data.%s.%s", user_data_fields[i].udf_name, user_data_fields[i].udf_value_desc);
dynamic_hf[i].hfinfo.type = FT_BOOLEAN;
dynamic_hf[i].hfinfo.display = 8 * (user_data_fields[i].udf_length);
// dynamic_hf[i].hfinfo.bitmask = 0;
/* dynamic_hf[i].hfinfo.bitmask = 0; */
dynamic_hf[i].hfinfo.blurb = g_strdup(user_data_fields[i].udf_value_desc);
}
tmp = calc_hf_key(user_data_fields[i]);
g_hash_table_insert(user_data_fields_hash_hf, tmp, hf_id);
// generate etts for new fields only
/* generate etts for new fields only */
if (get_ett_for_user_data(user_data_fields[i].udf_offset, user_data_fields[i].udf_length) == NULL) {
ett_dummy = -1;
proto_register_subtree_array(ett, array_length(ett));
@ -350,10 +352,28 @@ user_data_reset_cb(void)
****** The dissector itself ******
**********************************/
static int
dissect_autosar_nm(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree, void *data)
static gboolean
is_relevant_can_message(void *data)
{
const struct can_info *can_info = (struct can_info *)data;
DISSECTOR_ASSERT(can_info);
if (can_info->id & (CAN_ERR_FLAG | CAN_RTR_FLAG)) {
/* Error and RTR frames are not for us. */
return FALSE;
}
if ((can_info->id & g_autosar_nm_can_id_mask) != (g_autosar_nm_can_id & g_autosar_nm_can_id_mask)) {
/* Id doesn't match. The frame is not for us. */
return FALSE;
}
return TRUE;
}
static int
dissect_autosar_nm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
wmem_list_frame_t *prev_layer;
proto_item *ti;
proto_tree *autosar_nm_tree;
proto_tree *autosar_nm_subtree = NULL;
@ -367,7 +387,7 @@ dissect_autosar_nm(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree, void
int* hf_id;
int ett_id;
// AUTOSAR says default is Source Node ID first and Ctrl Bit Vector second but this can be also swapped
/* AUTOSAR says default is Source Node ID first and Ctrl Bit Vector second but this can be also swapped */
guint32 offset_ctrl_bit_vector = 1;
guint32 offset_src_node_id = 0;
@ -394,32 +414,6 @@ dissect_autosar_nm(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree, void
NULL
};
prev_layer = wmem_list_frame_prev(wmem_list_tail(pinfo->layers));
if (prev_layer) {
const int prev_proto = GPOINTER_TO_INT(wmem_list_frame_data(prev_layer));
if (prev_proto != proto_udp) {
const gboolean is_can_frame = (prev_proto == proto_can) || (prev_proto == proto_canfd) ||
(wmem_list_find(pinfo->layers, GINT_TO_POINTER(proto_caneth)) != NULL);
if (is_can_frame) {
const struct can_info *can_info = (struct can_info *)data;
DISSECTOR_ASSERT(can_info);
if (can_info->id & (CAN_ERR_FLAG | CAN_RTR_FLAG)) {
/* Error and RTR frames are not for us. */
return 0;
}
if ((can_info->id & g_autosar_nm_can_id_mask) != (g_autosar_nm_can_id & g_autosar_nm_can_id_mask)) {
/* Id doesn't match. The frame is not for us. */
return 0;
}
}
}
}
if (g_autosar_nm_swap_first_fields == TRUE) {
offset_ctrl_bit_vector = 0;
offset_src_node_id = 1;
@ -484,6 +478,25 @@ dissect_autosar_nm(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree, void
return offset;
}
static int
dissect_autosar_nm_can(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
if (!is_relevant_can_message(data)) {
return 0;
}
return dissect_autosar_nm(tvb, pinfo, tree, data);
}
static gboolean
dissect_autosar_nm_can_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
if (!is_relevant_can_message(data)) {
return FALSE;
}
dissect_autosar_nm(tvb, pinfo, tree, data);
return TRUE;
}
void proto_register_autosar_nm(void)
{
module_t *autosar_nm_module;
@ -542,7 +555,7 @@ void proto_register_autosar_nm(void)
proto_register_subtree_array(ett, array_length(ett));
/* Register configuration options */
autosar_nm_module = prefs_register_protocol(proto_autosar_nm, NULL);
autosar_nm_module = prefs_register_protocol(proto_autosar_nm, proto_reg_handoff_autosar_nm);
prefs_register_bool_preference(autosar_nm_module, "swap_ctrl_and_src",
"Swap Source Node Identifier and Control Bit Vector",
@ -591,20 +604,38 @@ void proto_register_autosar_nm(void)
"Mask applied to CAN identifiers when decoding whether a packet should dissected. "
"Use 0xFFFFFFFF mask to require exact match.",
16, &g_autosar_nm_can_id_mask);
range_convert_str(wmem_epan_scope(), &g_autosar_nm_pdus, "", 0xffffffff);
prefs_register_range_preference(autosar_nm_module, "pdu_transport.ids", "AUTOSAR NM PDU IDs",
"PDU Transport IDs.",
&g_autosar_nm_pdus, 0xffffffff);
}
void proto_reg_handoff_autosar_nm(void)
{
dissector_handle_t nm_handle = create_dissector_handle(dissect_autosar_nm, proto_autosar_nm);
static gboolean initialized = FALSE;
dissector_add_for_decode_as_with_preference("udp.port", nm_handle);
dissector_add_for_decode_as("can.subdissector", nm_handle);
dissector_add_for_decode_as_with_preference("pdu_transport.id", nm_handle);
if (!initialized) {
nm_handle = create_dissector_handle(dissect_autosar_nm, proto_autosar_nm);
dissector_add_for_decode_as_with_preference("udp.port", nm_handle);
proto_can = proto_get_id_by_filter_name("can");
proto_canfd = proto_get_id_by_filter_name("canfd");
proto_caneth = proto_get_id_by_filter_name("caneth");
proto_udp = proto_get_id_by_filter_name("udp");
nm_handle_can = create_dissector_handle(dissect_autosar_nm_can, proto_autosar_nm);
dissector_add_for_decode_as("can.subdissector", nm_handle_can);
proto_can = proto_get_id_by_filter_name("can");
proto_canfd = proto_get_id_by_filter_name("canfd");
proto_caneth = proto_get_id_by_filter_name("caneth");
proto_udp = proto_get_id_by_filter_name("udp");
/* heuristics default on since they do nothing without IDs being configured */
heur_dissector_add("can", dissect_autosar_nm_can_heur, "AUTOSAR_NM_Heuristic", "autosar_nm_can_heur", proto_autosar_nm, HEURISTIC_ENABLE);
initialized = TRUE;
} else {
dissector_delete_all("pdu_transport.id", nm_handle);
}
dissector_add_uint_range("pdu_transport.id", g_autosar_nm_pdus, nm_handle);
}
/*