openSAFETY: Set filter list for nodes

To enhance the possibility for dissections, add a list
of nodes, you explicitly want to see and print an info
text in the node list for all nodes filtered

Change-Id: I08e8a7ddcfd7b78fee24431ffdae75124a8ecddd
Reviewed-on: https://code.wireshark.org/review/21383
Reviewed-by: Roland Knall <rknall@gmail.com>

1 files changed, 47 insertions, 1 deletions

diff --git a/epan/dissectors/packet-opensafety.c b/epan/dissectors/packet-opensafety.c
index 0fb098da71..ffa20bf289 100644
--- a/epan/dissectors/packet-opensafety.c
+++ b/epan/dissectors/packet-opensafety.c
@@ -274,6 +274,10 @@ static gboolean global_enable_mbtcp  = TRUE;
 
 static gboolean global_opensafety_debug_verbose = FALSE;
 
+static const char * global_filter_nodes = "";
+static gboolean global_show_only_node_in_filter = TRUE;
+static wmem_list_t * global_filter_list = NULL;
+
 static gboolean heuristic_siii_dissection_enabled = TRUE;
 
 static heur_dissector_list_t heur_opensafety_spdo_subdissector_list;
@@ -297,6 +301,17 @@ setup_dissector(void)
 {
     heur_dtbl_entry_t * heur_entry = NULL;
 
+    /* create list if it does not exist, but clean existing elements anyway,
+     * as options might have changed */
+    global_filter_list = wmem_list_new(wmem_file_scope());
+
+    gchar ** vector = wmem_strsplit(wmem_file_scope(), global_filter_nodes, ",", -1);
+    for (; NULL != *vector; vector++ )
+    {
+        if ( *vector && g_ascii_strtoll(*vector, NULL, 10) > 0 )
+            wmem_list_append(global_filter_list, GINT_TO_POINTER(g_ascii_strtoll(*vector, NULL, 10)));
+    }
+
     heur_entry = find_heur_dissector_by_unique_short_name("opensafety_sercosiii");
     if ( heur_entry != NULL )
         heuristic_siii_dissection_enabled = heur_entry->enabled;
@@ -306,6 +321,12 @@ static void
 cleanup_dissector(void)
 {
     local_scm_udid = NULL;
+
+    if ( global_filter_list )
+    {
+        wmem_destroy_list(global_filter_list);
+        global_filter_list = NULL;
+    }
 }
 
 void proto_register_opensafety(void);
@@ -2161,6 +2182,23 @@ opensafety_package_dissector(const gchar *protocolName, const gchar *sub_diss_ha
                 }
             }
 
+            /* Filter node list */
+            gint addr = OSS_FRAME_ADDR_T(message_tvb, byte_offset + frameStart1);
+            if ( global_filter_list && wmem_list_count ( global_filter_list ) > 0 )
+            {
+                gboolean found_in_list = wmem_list_find(global_filter_list, GINT_TO_POINTER( addr )) ? TRUE : FALSE;
+
+                if ( ( ! global_show_only_node_in_filter && found_in_list ) ||
+                        ( global_show_only_node_in_filter && ! found_in_list ) )
+                {
+                    opensafety_item = proto_tree_add_item(tree, proto_opensafety, message_tvb, frameOffset, frameLength, ENC_NA);
+                    proto_item_append_text(opensafety_item, ", Filtered Node: 0x%03X (%d)", addr, addr);
+                    frameOffset += 2;
+                    found--;
+                    continue;
+                }
+            }
+
             /* From here on, the package should be correct. Even if it is not correct, it will be dissected
              * anyway and marked as malformed. Therefore it can be assumed, that a gap will end here.
              */
@@ -2431,7 +2469,6 @@ apply_prefs ( void )
     /* Preference names to specific to use "auto" preference */
     dissector_add_uint("udp.port", opensafety_udp_port_number, opensafety_udpdata_handle);
     dissector_add_uint("udp.port", opensafety_udp_siii_port_number, opensafety_udpdata_handle);
-
 }
 
 void
@@ -2811,6 +2848,15 @@ proto_register_opensafety(void)
                  "Automatically assign a detected SCM UDID (by reading SNMT->SNTM_assign_UDID_SCM) and set it for the file",
                  &global_scm_udid_autoset);
 
+    prefs_register_string_preference(opensafety_module, "filter_nodes",
+                 "Filter openSAFETY Nodes",
+                 "A comma-separated list of nodes to be filtered during dissection",
+                 &global_filter_nodes);
+    prefs_register_bool_preference(opensafety_module, "filter_show_nodes_in_filterlist",
+                 "Show nodes in filter, hide otherwise",
+                 "If set to true, only nodes in the list will be shown, otherwise they will be hidden",
+                 &global_show_only_node_in_filter);
+
     prefs_register_uint_preference(opensafety_module, "network_udp_port",
                 "Port used for Generic UDP",
                 "Port used by any UDP demo implementation to transport data", 10,