refactor(userspace/engine): improve ruleset interface definitions

The filter_ruleset interface its implementation evt_type_index_ruleset
have been modified as follows:
- Only keep track of ruleset ids and not names. The falco engine will take
care of mapping easy-to-remember ruleset names to ruleset ids.
To emphasize this, use ruleset_id everywhere and not ruleset.
Also, make it non-optional.
- Have explicit separate functions to enable/disable rules, instead of a single enable() method combined with a boolean flag.
This does *not* change the falco_engine interface, which has
similar methods, to avoid breaking API changes.

Signed-off-by: Jason Dellaluce <jasondellaluce@gmail.com>
Co-authored-by: Mark Stemm <mark.stemm@gmail.com>

userspace/engine/evttype_index_ruleset.cpp

@@ -179,17 +179,6 @@ void evttype_index_ruleset::add(
 	}
 }
 
-uint16_t evttype_index_ruleset::ruleset_id(const std::string &name)
-{
-	auto it = find(m_ruleset_names.begin(), m_ruleset_names.end(), name);
-	if (it != m_ruleset_names.end())
-	{
-		return it - m_ruleset_names.begin();
-	}
-	m_ruleset_names.push_back(name);
-	return m_ruleset_names.size() - 1;
-}
-
 void evttype_index_ruleset::on_loading_complete()
 {
 	// nothing to do for now
@@ -205,9 +194,19 @@ void evttype_index_ruleset::clear()
 	m_filters.clear();
 }
 
-void evttype_index_ruleset::enable(const string &substring, bool match_exact, bool enabled, uint16_t ruleset)
+void evttype_index_ruleset::enable(const string &substring, bool match_exact, uint16_t ruleset_id)
 {
-	while(m_rulesets.size() < (size_t)ruleset + 1)
+	enable_disable(substring, match_exact, true, ruleset_id);
+}
+
+void evttype_index_ruleset::disable(const string &substring, bool match_exact, uint16_t ruleset_id)
+{
+	enable_disable(substring, match_exact, false, ruleset_id);
+}
+
+void evttype_index_ruleset::enable_disable(const string &substring, bool match_exact, bool enabled, uint16_t ruleset_id)
+{
+	while(m_rulesets.size() < (size_t)ruleset_id + 1)
 	{
 		m_rulesets.emplace_back(new ruleset_filters());
 	}
@@ -232,19 +231,29 @@ void evttype_index_ruleset::enable(const string &substring, bool match_exact, bo
 		{
 			if(enabled)
 			{
-				m_rulesets[ruleset]->add_filter(wrap);
+				m_rulesets[ruleset_id]->add_filter(wrap);
 			}
 			else
 			{
-				m_rulesets[ruleset]->remove_filter(wrap);
+				m_rulesets[ruleset_id]->remove_filter(wrap);
 			}
 		}
 	}
 }
 
-void evttype_index_ruleset::enable_tags(const set<string> &tags, bool enabled, uint16_t ruleset)
+void evttype_index_ruleset::enable_tags(const set<string> &tags, uint16_t ruleset_id)
 {
-	while(m_rulesets.size() < (size_t)ruleset + 1)
+	enable_disable_tags(tags, true, ruleset_id);
+}
+
+void evttype_index_ruleset::disable_tags(const set<string> &tags, uint16_t ruleset_id)
+{
+	enable_disable_tags(tags, false, ruleset_id);
+}
+
+void evttype_index_ruleset::enable_disable_tags(const set<string> &tags, bool enabled, uint16_t ruleset_id)
+{
+	while(m_rulesets.size() < (size_t)ruleset_id + 1)
 	{
 		m_rulesets.emplace_back(new ruleset_filters());
 	}
@@ -261,42 +270,42 @@ void evttype_index_ruleset::enable_tags(const set<string> &tags, bool enabled, u
 		{
 			if(enabled)
 			{
-				m_rulesets[ruleset]->add_filter(wrap);
+				m_rulesets[ruleset_id]->add_filter(wrap);
 			}
 			else
 			{
-				m_rulesets[ruleset]->remove_filter(wrap);
+				m_rulesets[ruleset_id]->remove_filter(wrap);
 			}
 		}
 	}
 }
 
-uint64_t evttype_index_ruleset::enabled_count(uint16_t ruleset)
+uint64_t evttype_index_ruleset::enabled_count(uint16_t ruleset_id)
 {
-	while(m_rulesets.size() < (size_t)ruleset + 1)
+	while(m_rulesets.size() < (size_t)ruleset_id + 1)
 	{
 		m_rulesets.emplace_back(new ruleset_filters());
 	}
 
-	return m_rulesets[ruleset]->num_filters();
+	return m_rulesets[ruleset_id]->num_filters();
 }
 
-bool evttype_index_ruleset::run(gen_event *evt, falco_rule& match, uint16_t ruleset)
+bool evttype_index_ruleset::run(gen_event *evt, falco_rule& match, uint16_t ruleset_id)
 {
-	if(m_rulesets.size() < (size_t)ruleset + 1)
+	if(m_rulesets.size() < (size_t)ruleset_id + 1)
 	{
 		return false;
 	}
 
-	return m_rulesets[ruleset]->run(evt, match);
+	return m_rulesets[ruleset_id]->run(evt, match);
 }
 
-void evttype_index_ruleset::enabled_evttypes(set<uint16_t> &evttypes, uint16_t ruleset)
+void evttype_index_ruleset::enabled_evttypes(set<uint16_t> &evttypes, uint16_t ruleset_id)
 {
-	if(m_rulesets.size() < (size_t)ruleset + 1)
+	if(m_rulesets.size() < (size_t)ruleset_id + 1)
 	{
 		return;
 	}
 
-	return m_rulesets[ruleset]->evttypes_for_ruleset(evttypes);
+	return m_rulesets[ruleset_id]->evttypes_for_ruleset(evttypes);
 }

userspace/engine/evttype_index_ruleset.h

@@ -45,24 +45,29 @@ public:
 
 	void clear() override;
 
-	uint16_t ruleset_id(const std::string &name) override;
+	bool run(gen_event *evt, falco_rule& match, uint16_t rulset_id);
 
-	bool run(gen_event *evt, falco_rule& match, uint16_t ruleset = 0);
-	
-	uint64_t enabled_count(uint16_t ruleset = 0) override;
+	uint64_t enabled_count(uint16_t ruleset_id) override;
 
 	void on_loading_complete() override;
 
 	void enable(
 		const std::string &substring,
 		bool match_exact,
-		bool enabled,
-		uint16_t ruleset = 0) override;
+		uint16_t rulset_id) override;
+
+	void disable(
+		const std::string &substring,
+		bool match_exact,
+		uint16_t rulset_id) override;
 
 	void enable_tags(
 		const std::set<std::string> &tags,
-		bool enabled,
-		uint16_t ruleset = 0) override;
+		uint16_t rulset_id) override;
+
+	void disable_tags(
+		const std::set<std::string> &tags,
+		uint16_t rulset_id) override;
 
 	// evttypes for a ruleset
 	void enabled_evttypes(
@@ -71,6 +76,19 @@ public:
 
 private:
 
+	// Helper used by enable()/disable()
+	void enable_disable(
+		const std::string &substring,
+		bool match_exact,
+		bool enabled,
+		uint16_t rulset_id);
+
+	// Helper used by enable_tags()/disable_tags()
+	void enable_disable_tags(
+		const std::set<std::string> &tags,
+		bool enabled,
+		uint16_t rulset_id);
+
 	struct filter_wrapper
 	{
 		falco_rule rule;

userspace/engine/ruleset.h

@@ -51,14 +51,6 @@ public:
 	*/
 	virtual void clear() = 0;
 
-	/*!
-		\brief Returns the numeric id of a ruleset given its name.
-		If a ruleset has been used before, its previously assigned id is
-		returned. Otherwise, a new ruleset is created with the given name
-		and a new id is assigned to it.
-	*/
-	virtual uint16_t ruleset_id(const std::string &name) = 0;
-
 	/*!
 		\brief This is meant to be called after all rules have been added
 		with add() and enabled on the given ruleset with enable()/enable_tags().
@@ -71,61 +63,87 @@ public:
 		\param evt The event to be processed
 		\param match If true is returned, this is filled-out with the rule
 		that matched the event
-		\param ruleset The id of the ruleset to be used
+		\param ruleset_id The id of the ruleset to be used
 	*/
 	virtual bool run(
 		gen_event *evt,
 		falco_rule& match,
-		uint16_t ruleset = 0) = 0;
+		uint16_t ruleset_id) = 0;
 
 	/*!
 		\brief Returns the number of rules enabled in a given ruleset
-		\param ruleset The id of the ruleset to be used
+		\param ruleset_id The id of the ruleset to be used
 	*/
-	virtual uint64_t enabled_count(uint16_t ruleset = 0) = 0;
+	virtual uint64_t enabled_count(uint16_t ruleset_id) = 0;
 
 	/*!
 		\brief Returns the union of the evttypes of all the rules enabled
 		in a given ruleset
-		\param ruleset The id of the ruleset to be used
+		\param ruleset_id The id of the ruleset to be used
 	*/
 	virtual void enabled_evttypes(
 		std::set<uint16_t> &evttypes,
 		uint16_t ruleset) = 0;
 
 	/*!
-		\brief Find those rules matching the provided substring and set
-		their enabled status to enabled in a given ruleset.
+		\brief Find those rules matching the provided substring and enable
+		them in the provided ruleset.
 		\param substring Substring used to match rule names.
 		If empty, all rules are matched.
 		\param match_exact If true, substring must be an exact match for a
 		given rule name. Otherwise, any rules having substring as a substring
 		in the rule name are enabled/disabled.
-		\param enabled The enabled status to set on all matching rules
-		\param ruleset The id of the ruleset to be used
+		\param ruleset_id The id of the ruleset to be used
 	*/
 	virtual void enable(
 		const std::string &substring,
 		bool match_exact,
-		bool enabled,
-		uint16_t ruleset = 0) = 0;
+		uint16_t ruleset_id) = 0;
+
+	/*!
+		\brief Find those rules matching the provided substring and disable
+		them in the provided ruleset.
+		\param substring Substring used to match rule names.
+		If empty, all rules are matched.
+		\param match_exact If true, substring must be an exact match for a
+		given rule name. Otherwise, any rules having substring as a substring
+		in the rule name are enabled/disabled.
+		\param ruleset_id The id of the ruleset to be used
+	*/
+	virtual void disable(
+		const std::string &substring,
+		bool match_exact,
+		uint16_t ruleset_id) = 0;
 
 	/*!
 		\brief Find those rules that have a tag in the set of tags and
-		set their enabled status to enabled. Note that the enabled
+		enable them for the provided ruleset. Note that the enabled
 		status is on the rules, and not the tags--if a rule R has
-		tags (a, b), and you call enable_tags([a], true) and then
-		enable_tags([b], false), R will be disabled despite the
+		tags (a, b), and you call enable_tags([a]) and then
+		disable_tags([b]), R will be disabled despite the
 		fact it has tag a and was enabled by the first call to
 		enable_tags.
 		\param substring Tags used to match ruless
-		\param enabled The enabled status to set on all matching rules
-		\param ruleset The id of the ruleset to be used
+		\param ruleset_id The id of the ruleset to be used
 	*/
 	virtual void enable_tags(
 		const std::set<std::string> &tags,
-		bool enabled,
-		uint16_t ruleset = 0) = 0;
+		uint16_t ruleset_id) = 0;
+
+	/*!
+		\brief Find those rules that have a tag in the set of tags and
+		disable them for the provided ruleset. Note that the disabled
+		status is on the rules, and not the tags--if a rule R has
+		tags (a, b), and you call enable_tags([a]) and then
+		disable_tags([b]), R will be disabled despite the
+		fact it has tag a and was enabled by the first call to
+		enable_tags.
+		\param substring Tags used to match ruless
+		\param ruleset_id The id of the ruleset to be used
+	*/
+	virtual void disable_tags(
+		const std::set<std::string> &tags,
+		uint16_t ruleset_id) = 0;
 };
 
 /*!