cleanup: apply reviewers suggestions

Co-authored-by: Andrea Terzolo <andreaterzolo3@gmail.com>
Signed-off-by: Melissa Kilby <melissa.kilby.oss@gmail.com>

falco.yaml

@@ -333,17 +333,18 @@ rule_matching: first
 # Lowering the number of items can prevent memory from steadily increasing until the OOM
 # killer stops the Falco process. We provide recovery actions to self-limit or self-kill
 # in order to handle this situation earlier, similar to how we expose the kernel buffer size
-# as a parameter.
-# However, it will not address the root cause of the event pipe not keeping up.
+# as a parameter. However, it will not address the root cause of the event pipe not keeping up.
 # 
-# `capacity`: the maximum number of items allowed in the queue, defaulting to 0. This means that
-# the queue remains unbounded aka this setting is disabled.
-# You can experiment with values greater or smaller than the anchor value 1000000.
+# `capacity`: the maximum number of items allowed in the queue is determined by this value. 
+# Setting the value to 0 (which is the default) is equivalent to keeping the queue unbounded. 
+# In other words, when this configuration is set to 0, the number of allowed items is effectively 
+# set to the largest possible long value, disabling this setting.
 # 
-# `recovery`: the strategy to follow when the queue becomes filled up. This also applies when
-# the queue is unbounded, and all available memory on the system is consumed.
-# `exit` is default, `continue` does nothing special and `empty` empties the queue and then
-# continues.
+# `recovery`: strategy to follow when the queue becomes filled up. It applies only when the
+# queue is bounded and there is still available system memory. In the case of an unbounded
+# queue, if the available memory on the system is consumed, the Falco process would be
+# OOM killed. The value `exit` is the default, `continue` does nothing special and `empty` 
+# empties the queue and then continues.
 outputs_queue:
   capacity: 0
   recovery: exit

userspace/engine/falco_common.cpp

@@ -32,7 +32,7 @@ static std::vector<std::string> rule_matching_names = {
 	"all"
 };
 
-static std::vector<std::string> outputs_recovery_names = {
+static std::vector<std::string> outputs_queue_recovery_names = {
 		"continue",
 		"exit",
 		"empty",
@@ -65,13 +65,13 @@ falco_common::priority_type falco_common::parse_priority(std::string v)
 	return out;
 }
 
-bool falco_common::parse_recovery(std::string v, outputs_recovery_type& out)
+bool falco_common::parse_queue_recovery(std::string v, outputs_queue_recovery_type& out)
 {
-	for (size_t i = 0; i < outputs_recovery_names.size(); i++)
+	for (size_t i = 0; i < outputs_queue_recovery_names.size(); i++)
 	{
-		if (!strcasecmp(v.c_str(), outputs_recovery_names[i].c_str()))
+		if (!strcasecmp(v.c_str(), outputs_queue_recovery_names[i].c_str()))
 		{
-			out = (outputs_recovery_type) i;
+			out = (outputs_queue_recovery_type) i;
 			return true;
 		}
 	}

userspace/engine/falco_common.h

@@ -59,7 +59,7 @@ struct falco_exception : std::exception
 namespace falco_common
 {
 
-	enum outputs_recovery_type {
+	enum outputs_queue_recovery_type {
 		RECOVERY_CONTINUE = 0,  /* queue_capacity_outputs recovery strategy of continuing on. */
 		RECOVERY_EXIT = 1,  /* queue_capacity_outputs recovery strategy of exiting, self OOM kill. */
 		RECOVERY_EMPTY = 2,  /* queue_capacity_outputs recovery strategy of emptying queue then continuing. */
@@ -82,7 +82,7 @@ namespace falco_common
 	
 	bool parse_priority(std::string v, priority_type& out);
 	priority_type parse_priority(std::string v);
-	bool parse_recovery(std::string v, outputs_recovery_type& out);
+	bool parse_queue_recovery(std::string v, outputs_queue_recovery_type& out);
 	bool format_priority(priority_type v, std::string& out, bool shortfmt=false);
 	std::string format_priority(priority_type v, bool shortfmt=false);
 

userspace/falco/app/actions/process_events.cpp

@@ -281,7 +281,7 @@ static falco::app::run_result do_inspect(
 			}
 	
 			// for capture mode, the source name can change at every event
-			stats_collector.collect(inspector, inspector->event_sources()[source_engine_idx], s.outputs, num_evts);
+			stats_collector.collect(inspector, inspector->event_sources()[source_engine_idx], num_evts);
 		}
 		else
 		{
@@ -300,7 +300,7 @@ static falco::app::run_result do_inspect(
 			}
 
 			// for live mode, the source name is constant
-			stats_collector.collect(inspector, source, s.outputs, num_evts);
+			stats_collector.collect(inspector, source, num_evts);
 		}
 
 		// Reset the timeouts counter, Falco successfully got an event to process

userspace/falco/configuration.cpp

@@ -290,7 +290,7 @@ void falco_configuration::load_yaml(const std::string& config_name, const yaml_h
 		m_outputs_queue_capacity = DEFAULT_OUTPUTS_QUEUE_CAPACITY;
 	}
 	std::string recovery = config.get_scalar<std::string>("outputs_queue.recovery", "exit");
-	if (!falco_common::parse_recovery(recovery, m_outputs_queue_recovery))
+	if (!falco_common::parse_queue_recovery(recovery, m_outputs_queue_recovery))
 	{
 		throw std::logic_error("Unknown recovery \"" + recovery + "\"--must be one of exit, continue, empty");
 	}

userspace/falco/configuration.h

@@ -73,7 +73,7 @@ public:
 	bool m_watch_config_files;
 	bool m_buffered_outputs;
 	size_t m_outputs_queue_capacity;
-	falco_common::outputs_recovery_type m_outputs_queue_recovery;
+	falco_common::outputs_queue_recovery_type m_outputs_queue_recovery;
 	bool m_time_format_iso_8601;
 	uint32_t m_output_timeout;
 

userspace/falco/falco_outputs.cpp

@@ -47,7 +47,7 @@ falco_outputs::falco_outputs(
 	uint32_t timeout,
 	bool buffered,
 	size_t outputs_queue_capacity,
-	falco_common::outputs_recovery_type outputs_queue_recovery,
+	falco_common::outputs_queue_recovery_type outputs_queue_recovery,
 	bool time_format_iso_8601,
 	const std::string& hostname)
 {

userspace/falco/falco_outputs.h

@@ -49,7 +49,7 @@ public:
 		uint32_t timeout,
 		bool buffered,
 		size_t outputs_queue_capacity,
-		falco_common::outputs_recovery_type outputs_queue_recovery,
+		falco_common::outputs_queue_recovery_type outputs_queue_recovery,
 		bool time_format_iso_8601,
 		const std::string& hostname);
 
@@ -118,7 +118,7 @@ private:
 #ifndef __EMSCRIPTEN__
 	typedef tbb::concurrent_bounded_queue<ctrl_msg> falco_outputs_cbq;
 	falco_outputs_cbq m_queue;
-	uint32_t m_recovery;
+	falco_common::outputs_queue_recovery_type m_recovery;
 	uint64_t m_outputs_queue_num_drops;
 #endif
 

userspace/falco/stats_writer.cpp

@@ -220,7 +220,7 @@ stats_writer::collector::collector(const std::shared_ptr<stats_writer>& writer)
 void stats_writer::collector::get_metrics_output_fields_wrapper(
 		nlohmann::json& output_fields,
 		const std::shared_ptr<sinsp>& inspector, uint64_t now,
-		const std::string& src, uint64_t outputs_queue_num_drops, uint64_t num_evts, double stats_snapshot_time_delta_sec)
+		const std::string& src, uint64_t num_evts, double stats_snapshot_time_delta_sec)
 {
 	static const char* all_driver_engines[] = {
 		BPF_ENGINE, KMOD_ENGINE, MODERN_BPF_ENGINE,
@@ -237,7 +237,7 @@ void stats_writer::collector::get_metrics_output_fields_wrapper(
 	output_fields["falco.host_boot_ts"] = machine_info->boot_ts_epoch;
 	output_fields["falco.hostname"] = machine_info->hostname; /* Explicitly add hostname to log msg in case hostname rule output field is disabled. */
 	output_fields["falco.host_num_cpus"] = machine_info->num_cpus;
-	output_fields["falco.outputs_queue_num_drops"] = outputs_queue_num_drops;
+	output_fields["falco.outputs_queue_num_drops"] = m_writer->m_outputs->get_outputs_queue_num_drops();
 
 	output_fields["evt.source"] = src;
 	for (size_t i = 0; i < sizeof(all_driver_engines) / sizeof(const char*); i++)
@@ -422,7 +422,7 @@ void stats_writer::collector::get_metrics_output_fields_additional(
 #endif
 }
 
-void stats_writer::collector::collect(const std::shared_ptr<sinsp>& inspector, const std::string &src, const std::shared_ptr<falco_outputs>& outputs, uint64_t num_evts)
+void stats_writer::collector::collect(const std::shared_ptr<sinsp>& inspector, const std::string &src, uint64_t num_evts)
 {
 	if (m_writer->has_output())
 	{
@@ -443,8 +443,7 @@ void stats_writer::collector::collect(const std::shared_ptr<sinsp>& inspector, c
 
 			/* Get respective metrics output_fields. */
 			nlohmann::json output_fields;
-			uint64_t outputs_queue_num_drops = outputs->get_outputs_queue_num_drops();
-			get_metrics_output_fields_wrapper(output_fields, inspector, now, src, outputs_queue_num_drops, num_evts, stats_snapshot_time_delta_sec);
+			get_metrics_output_fields_wrapper(output_fields, inspector, now, src, num_evts, stats_snapshot_time_delta_sec);
 			get_metrics_output_fields_additional(output_fields, inspector, stats_snapshot_time_delta_sec, src);
 
 			/* Send message in the queue */

userspace/falco/stats_writer.h

@@ -60,13 +60,13 @@ public:
 			\brief Collects one stats sample from an inspector
 			and for the given event source name
 		*/
-		void collect(const std::shared_ptr<sinsp>& inspector, const std::string& src, const std::shared_ptr<falco_outputs>& outputs, uint64_t num_evts);
+		void collect(const std::shared_ptr<sinsp>& inspector, const std::string& src, uint64_t num_evts);
 
 	private:
 		/*!
 			\brief Collect snapshot metrics wrapper fields as internal rule formatted output fields.
 		*/
-		void get_metrics_output_fields_wrapper(nlohmann::json& output_fields, const std::shared_ptr<sinsp>& inspector, uint64_t now, const std::string& src, uint64_t outputs_queue_num_drops, uint64_t num_evts, double stats_snapshot_time_delta_sec);
+		void get_metrics_output_fields_wrapper(nlohmann::json& output_fields, const std::shared_ptr<sinsp>& inspector, uint64_t now, const std::string& src, uint64_t num_evts, double stats_snapshot_time_delta_sec);
 
 		/*!
 			\brief Collect snapshot metrics syscalls related metrics as internal rule formatted output fields.