Merge remote-tracking branch 'origin/topic/jsiwek/empty-lines'

* origin/topic/jsiwek/empty-lines:
  Add 'smtp_excessive_pending_cmds' weird
  Fix SMTP command string comparisons
  Improve handling of empty lines in several text protocol analyzers
  Add rate-limiting sampling mechanism for weird events
  Teach timestamp canonifier about timestamps before ~2001

scripts/base/init-bare.bro

@@ -82,6 +82,13 @@ type addr_vec: vector of addr;
 ##    directly and then remove this alias.
 type table_string_of_string: table[string] of string;
 
+## A table of counts indexed by strings.
+##
+## .. todo:: We need this type definition only for declaring builtin functions
+##    via ``bifcl``. We should extend ``bifcl`` to understand composite types
+##    directly and then remove this alias.
+type table_string_of_count: table[string] of count;
+
 ## A set of file analyzer tags.
 ##
 ## .. todo:: We need this type definition only for declaring builtin functions
@@ -626,6 +633,17 @@ type BrokerStats: record {
 	num_ids_outgoing: count;
 };
 
+## Statistics about reporter messages and weirds.
+##
+## .. bro:see:: get_reporter_stats
+type ReporterStats: record {
+	## Number of total weirds encountered, before any rate-limiting.
+	weirds: count;
+	## Number of times each individual weird is encountered, before any
+	## rate-limiting is applied.
+	weirds_by_type:	table[string] of count;
+};
+
 ## Deprecated.
 ##
 ## .. todo:: Remove. It's still declared internally but doesn't seem  used anywhere
@@ -4826,6 +4844,35 @@ export {
 	type Cluster::Pool: record {};
 }
 
+module Weird;
+export {
+	## Prevents rate-limiting sampling of any weirds named in the table.
+	const sampling_whitelist: set[string] &redef;
+
+	## How many weirds of a given type to tolerate before sampling begins.
+	## i.e. this many consecutive weirds of a given type will be allowed to
+	## raise events for script-layer handling before being rate-limited.
+	const sampling_threshold = 25 &redef;
+
+	## The rate-limiting sampling rate.  One out of every of this number of
+	## rate-limited weirds of a given type will be allowed to raise events
+	## for further script-layer handling.
+	const sampling_rate = 1000 &redef;
+
+	## How long a weird of a given type is allowed to keep state/counters in
+	## memory.  For "net" weirds an expiration timer starts per weird name when
+	## first initializing its counter.  For "flow" weirds an expiration timer
+	## starts once per src/dst IP pair for the first weird of any name.  For
+	## "conn" weirds, counters and expiration timers are kept for the duration
+	## of the connection for each named weird and reset when necessary.  e.g.
+	## if a "conn" weird by the name of "foo" is seen more than
+	## :bro:see:`Weird::sampling_threshold` times, then an expiration timer
+	## begins for "foo" and upon triggering will reset the counter for "foo"
+	## and unthrottle its rate-limiting until it once again exceeds the
+	## threshold.
+	const sampling_duration = 10min &redef;
+}
+
 module GLOBAL;
 
 ## Seed for hashes computed internally for probabilistic data structures. Using

scripts/base/protocols/http/main.bro

@@ -199,7 +199,7 @@ event http_request(c: connection, method: string, original_URI: string,
 	c$http$uri = unescaped_URI;
 
 	if ( method !in http_methods )
-		event conn_weird("unknown_HTTP_method", c, method);
+		Reporter::conn_weird("unknown_HTTP_method", c, method);
 	}
 
 event http_reply(c: connection, version: string, code: count, reason: string) &priority=5

scripts/base/protocols/sip/main.bro

@@ -168,7 +168,7 @@ event sip_request(c: connection, method: string, original_URI: string, version:
 	c$sip$uri = original_URI;
 
 	if ( method !in sip_methods )
-		event conn_weird("unknown_SIP_method", c, method);
+		Reporter::conn_weird("unknown_SIP_method", c, method);
 	}
 
 event sip_reply(c: connection, version: string, code: count, reason: string) &priority=5

scripts/base/protocols/smb/smb1-main.bro

@@ -309,7 +309,7 @@ event smb_pipe_request(c: connection, hdr: SMB1::Header, op_num: count)
 	if ( ! f?$uuid )
 		{
 		# TODO: figure out why this is happening.
-		event conn_weird("smb_pipe_request_missing_uuid", c, "");
+		Reporter::conn_weird("smb_pipe_request_missing_uuid", c, "");
 		return;
 		}
 	local arg = fmt("%s: %s",

scripts/base/protocols/ssl/main.bro

@@ -263,7 +263,7 @@ event ssl_extension_server_name(c: connection, is_orig: bool, names: string_vec)
 		{
 		c$ssl$server_name = names[0];
 		if ( |names| > 1 )
-			event conn_weird("SSL_many_server_names", c, cat(names));
+			Reporter::conn_weird("SSL_many_server_names", c, cat(names));
 		}
 	}