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0d46fcf819
container.info handling used to be handled by the the falco_outputs object. However, this caused problems for applications that only used the falco engine, doing their own output formatting for matching events. Fix this by moving output formatting into the falco engine itself. The part that replaces %container.info/adds extra formatting to the end of a rule's output now happens while loading the rule.
150 lines
4.2 KiB
C++
150 lines
4.2 KiB
C++
/*
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Copyright (C) 2016 Draios inc.
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This file is part of falco.
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falco is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License version 2 as
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published by the Free Software Foundation.
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falco is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with falco. If not, see <http://www.gnu.org/licenses/>.
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*/
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#pragma once
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#include <string>
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#include "sinsp.h"
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#include "filter.h"
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#include "rules.h"
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#include "falco_common.h"
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//
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// This class acts as the primary interface between a program and the
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// falco rules engine. Falco outputs (writing to files/syslog/etc) are
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// handled in a separate class falco_outputs.
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//
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class falco_engine : public falco_common
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{
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public:
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falco_engine(bool seed_rng=true);
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virtual ~falco_engine();
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//
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// Load rules either directly or from a filename.
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//
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void load_rules_file(const std::string &rules_filename, bool verbose, bool all_events);
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void load_rules(const std::string &rules_content, bool verbose, bool all_events);
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//
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// Enable/Disable any rules matching the provided pattern (regex).
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//
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void enable_rule(std::string &pattern, bool enabled);
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struct rule_result {
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sinsp_evt *evt;
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std::string rule;
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std::string priority;
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std::string format;
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};
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//
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// Given an event, check it against the set of rules in the
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// engine and if a matching rule is found, return details on
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// the rule that matched. If no rule matched, returns NULL.
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//
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// the reutrned rule_result is allocated and must be delete()d.
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rule_result *process_event(sinsp_evt *ev);
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//
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// Print details on the given rule. If rule is NULL, print
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// details on all rules.
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//
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void describe_rule(std::string *rule);
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//
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// Print statistics on how many events matched each rule.
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//
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void print_stats();
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//
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// Add a filter, which is related to the specified list of
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// event types, to the engine.
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//
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void add_evttype_filter(std::string &rule,
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list<uint32_t> &evttypes,
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sinsp_filter* filter);
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//
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// Set the sampling ratio, which can affect which events are
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// matched against the set of rules.
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//
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void set_sampling_ratio(uint32_t sampling_ratio);
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//
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// Set the sampling ratio multiplier, which can affect which
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// events are matched against the set of rules.
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//
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void set_sampling_multiplier(double sampling_multiplier);
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//
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// You can optionally add "extra" formatting fields to the end
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// of all output expressions. You can also choose to replace
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// %container.info with the extra information or add it to the
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// end of the expression. This is used in open source falco to
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// add k8s/mesos/container information to outputs when
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// available.
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//
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void set_extra(string &extra, bool replace_container_info);
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private:
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//
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// Determine whether the given event should be matched at all
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// against the set of rules, given the current sampling
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// ratio/multiplier.
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//
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inline bool should_drop_evt();
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falco_rules *m_rules;
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sinsp_evttype_filter m_evttype_filter;
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//
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// Here's how the sampling ratio and multiplier influence
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// whether or not an event is dropped in
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// should_drop_evt(). The intent is that m_sampling_ratio is
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// generally changing external to the engine e.g. in the main
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// inspector class based on how busy the inspector is. A
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// sampling ratio implies no dropping. Values > 1 imply
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// increasing levels of dropping. External to the engine, the
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// sampling ratio results in events being dropped at the
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// kernel/inspector interface.
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//
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// The sampling multiplier is an amplification to the sampling
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// factor in m_sampling_ratio. If 0, no additional events are
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// dropped other than those that might be dropped by the
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// kernel/inspector interface. If 1, events that make it past
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// the kernel module are subject to an additional level of
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// dropping at the falco engine, scaling with the sampling
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// ratio in m_sampling_ratio.
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//
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uint32_t m_sampling_ratio;
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double m_sampling_multiplier;
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std::string m_lua_main_filename = "rule_loader.lua";
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std::string m_extra;
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bool m_replace_container_info;
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};
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