Allow logging filters to inherit default path from stream.

This allows the path for the default filter to be specified explicitly
when creating a stream and reduces the need to rely on the default path
function to magically supply the path.

The default path function is now only used if, when a filter is added to
a stream, it has neither a path nor a path function already.

Adapted the existing Log::create_stream calls to explicitly specify a
path value.

Addresses BIT-1324

scripts/base/frameworks/cluster/main.bro

@@ -159,5 +159,5 @@ event bro_init() &priority=5
 		terminate();
 		}
 	
-	Log::create_stream(Cluster::LOG, [$columns=Info]);
+	Log::create_stream(Cluster::LOG, [$columns=Info, $path="cluster"]);
 	}

scripts/base/frameworks/communication/main.bro

@@ -164,7 +164,7 @@ const src_names = {
 
 event bro_init() &priority=5
 	{
-	Log::create_stream(Communication::LOG, [$columns=Info]);
+	Log::create_stream(Communication::LOG, [$columns=Info, $path="communication"]);
 	}
 
 function do_script_log_common(level: count, src: count, msg: string)

scripts/base/frameworks/dpd/main.bro

@@ -38,7 +38,7 @@ redef record connection += {
 
 event bro_init() &priority=5
 	{
-	Log::create_stream(DPD::LOG, [$columns=Info]);
+	Log::create_stream(DPD::LOG, [$columns=Info, $path="dpd"]);
 	}
 
 event protocol_confirmation(c: connection, atype: Analyzer::Tag, aid: count) &priority=10

scripts/base/frameworks/files/main.bro

@@ -313,7 +313,7 @@ global analyzer_add_callbacks: table[Files::Tag] of function(f: fa_file, args: A
 
 event bro_init() &priority=5
 	{
-	Log::create_stream(Files::LOG, [$columns=Info, $ev=log_files]);
+	Log::create_stream(Files::LOG, [$columns=Info, $ev=log_files, $path="files"]);
 	}
 
 function set_info(f: fa_file)

scripts/base/frameworks/intel/main.bro

@@ -174,7 +174,7 @@ global min_data_store: MinDataStore &redef;
 
 event bro_init() &priority=5
 	{
-	Log::create_stream(LOG, [$columns=Info, $ev=log_intel]);
+	Log::create_stream(LOG, [$columns=Info, $ev=log_intel, $path="intel"]);
 	}
 
 function find(s: Seen): bool

scripts/base/frameworks/logging/main.bro

@@ -50,11 +50,17 @@ export {
 		## The event receives a single same parameter, an instance of
 		## type ``columns``.
 		ev: any &optional;
+
+		## A path that will be inherited by any filters added to the
+		## stream which do not already specify their own path.
+		path: string &optional;
 	};
 
 	## Builds the default path values for log filters if not otherwise
 	## specified by a filter. The default implementation uses *id*
-	## to derive a name.
+	## to derive a name.  Upon adding a filter to a stream, if neither
+	## ``path`` nor ``path_func`` is explicitly set by them, then
+	## this function is used as the ``path_func``.
 	##
 	## id: The ID associated with the log stream.
 	##
@@ -143,7 +149,9 @@ export {
 		## to compute the string dynamically. It is ok to return
 		## different strings for separate calls, but be careful: it's
 		## easy to flood the disk by returning a new string for each
-		## connection.
+		## connection.  Upon adding a filter to a stream, if neither
+		## ``path`` nor ``path_func`` is explicitly set by them, then
+		## :bro:see:`default_path_func` is used.
 		##
 		## id: The ID associated with the log stream.
 		##
@@ -379,6 +387,8 @@ export {
 	global active_streams: table[ID] of Stream = table();
 }
 
+global all_streams: table[ID] of Stream = table();
+
 # We keep a script-level copy of all filters so that we can manipulate them.
 global filters: table[ID, string] of Filter;
 
@@ -463,6 +473,7 @@ function create_stream(id: ID, stream: Stream) : bool
 		return F;
 
 	active_streams[id] = stream;
+	all_streams[id] = stream;
 
 	return add_default_filter(id);
 	}
@@ -470,6 +481,7 @@ function create_stream(id: ID, stream: Stream) : bool
 function remove_stream(id: ID) : bool
 	{
 	delete active_streams[id];
+	delete all_streams[id];
 	return __remove_stream(id);
 	}
 
@@ -482,10 +494,12 @@ function disable_stream(id: ID) : bool
 
 function add_filter(id: ID, filter: Filter) : bool
 	{
-	# This is a work-around for the fact that we can't forward-declare
-	# the default_path_func and then use it as &default in the record
-	# definition.
-	if ( ! filter?$path_func )
+	local stream = all_streams[id];
+
+	if ( stream?$path && ! filter?$path )
+		filter$path = stream$path;
+
+	if ( ! filter?$path && ! filter?$path_func )
 		filter$path_func = default_path_func;
 
 	filters[id, filter$name] = filter;

scripts/base/frameworks/notice/main.bro

@@ -349,9 +349,9 @@ function log_mailing_postprocessor(info: Log::RotationInfo): bool
 
 event bro_init() &priority=5
 	{
-	Log::create_stream(Notice::LOG, [$columns=Info, $ev=log_notice]);
+	Log::create_stream(Notice::LOG, [$columns=Info, $ev=log_notice, $path="notice"]);
 
-	Log::create_stream(Notice::ALARM_LOG, [$columns=Notice::Info]);
+	Log::create_stream(Notice::ALARM_LOG, [$columns=Notice::Info, $path="notice_alarm"]);
 	# If Bro is configured for mailing notices, set up mailing for alarms.
 	# Make sure that this alarm log is also output as text so that it can
 	# be packaged up and emailed later.

scripts/base/frameworks/notice/weird.bro

@@ -294,7 +294,7 @@ global current_conn: connection;
 
 event bro_init() &priority=5
 	{
-	Log::create_stream(Weird::LOG, [$columns=Info, $ev=log_weird]);
+	Log::create_stream(Weird::LOG, [$columns=Info, $ev=log_weird, $path="weird"]);
 	}
 
 function flow_id_string(src: addr, dst: addr): string

scripts/base/frameworks/packet-filter/main.bro

@@ -159,7 +159,7 @@ event filter_change_tracking()
 
 event bro_init() &priority=5
 	{
-	Log::create_stream(PacketFilter::LOG, [$columns=Info]);
+	Log::create_stream(PacketFilter::LOG, [$columns=Info, $path="packet_filter"]);
 
 	# Preverify the capture and restrict filters to give more granular failure messages.
 	for ( id in capture_filters )

scripts/base/frameworks/reporter/main.bro

@@ -45,7 +45,7 @@ export {
 
 event bro_init() &priority=5
 	{
-	Log::create_stream(Reporter::LOG, [$columns=Info]);
+	Log::create_stream(Reporter::LOG, [$columns=Info, $path="reporter"]);
 	}
 
 event reporter_info(t: time, msg: string, location: string) &priority=-5

scripts/base/frameworks/signatures/main.bro

@@ -142,7 +142,7 @@ global did_sig_log: set[string] &read_expire = 1 hr;
 
 event bro_init()
 	{
-	Log::create_stream(Signatures::LOG, [$columns=Info, $ev=log_signature]);
+	Log::create_stream(Signatures::LOG, [$columns=Info, $ev=log_signature, $path="signatures"]);
 	}
 		
 # Returns true if the given signature has already been triggered for the given

scripts/base/frameworks/software/main.bro

@@ -105,7 +105,7 @@ export {
 
 event bro_init() &priority=5
 	{
-	Log::create_stream(Software::LOG, [$columns=Info, $ev=log_software]);
+	Log::create_stream(Software::LOG, [$columns=Info, $ev=log_software, $path="software"]);
 	}
 	
 type Description: record {

scripts/base/frameworks/tunnels/main.bro

@@ -89,7 +89,7 @@ redef likely_server_ports += { ayiya_ports, teredo_ports, gtpv1_ports };
 
 event bro_init() &priority=5
 	{
-	Log::create_stream(Tunnel::LOG, [$columns=Info]);
+	Log::create_stream(Tunnel::LOG, [$columns=Info, $path="tunnel"]);
 
 	Analyzer::register_for_ports(Analyzer::ANALYZER_AYIYA, ayiya_ports);
 	Analyzer::register_for_ports(Analyzer::ANALYZER_TEREDO, teredo_ports);