zeek/src/analyzer/Manager.h

413 lines
12 KiB
C++

// See the file "COPYING" in the main distribution directory for copyright.
/**
* The central management unit for registering and instantiating analyzers.
*
* For each protocol that Zeek supports, there's one class derived from
* analyzer::Analyzer. Once we have decided that a connection's payload is to
* be parsed as a given protocol, we instantiate the corresponding
* analyzer-derived class and add the new instance as a child node into the
* connection's analyzer tree.
*
* In addition to the analyzer-derived class itself, for each protocol
* there's also "meta-class" derived from analyzer::Component that describes
* the analyzer, including status information on if that particular protocol
* analysis is currently enabled.
*
* To identify an analyzer (or to be precise: a component), the manager
* maintains mappings of (1) analyzer::Tag to component, and (2)
* human-readable analyzer name to component.
*/
#pragma once
#include <queue>
#include <vector>
#include "zeek/IP.h"
#include "zeek/Tag.h"
#include "zeek/analyzer/Analyzer.h"
#include "zeek/analyzer/Component.h"
#include "zeek/analyzer/analyzer.bif.h"
#include "zeek/net_util.h"
#include "zeek/plugin/ComponentManager.h"
namespace zeek
{
namespace packet_analysis::IP
{
class IPBasedAnalyzer;
class SessionAdapter;
} // namespace packet_analysis::IP
namespace analyzer
{
/**
* Class maintaining and scheduling available protocol analyzers.
*
* The manager maintains a registry of all available protocol analyzers,
* including a mapping between their textual names and Tag. It
* instantiates new analyzers on demand. For new connections, the manager
* sets up their initial analyzer tree, including adding the right \c PIA,
* respecting well-known ports, and tracking any analyzers specifically
* scheduled for individual connections.
*/
class Manager : public plugin::ComponentManager<Component>
{
public:
/**
* Constructor.
*/
Manager();
/**
* Destructor.
*/
~Manager();
/**
* Second-stage initialization of the manager. This is called late
* during Zeek's initialization after any scripts are processed.
*/
void InitPostScript();
/**
* Finished the manager's operations.
*/
void Done();
/**
* Dumps out the state of all registered analyzers to the \c analyzer
* debug stream. Should be called only after any \c zeek_init events
* have executed to ensure that any of their changes are applied.
*/
void DumpDebug(); // Called after zeek_init() events.
/**
* Enables an analyzer type. Only enabled analyzers will be
* instantiated for new connections.
*
* @param tag The analyzer's tag.
*
* @return True if successful.
*/
bool EnableAnalyzer(const zeek::Tag& tag);
/**
* Enables an analyzer type. Only enabled analyzers will be
* instantiated for new connections.
*
* @param tag The analyzer's tag as an enum of script type \c
* Tag.
*
* @return True if successful.
*/
bool EnableAnalyzer(EnumVal* tag);
/**
* Enables an analyzer type. Disabled analyzers will not be
* instantiated for new connections.
*
* @param tag The analyzer's tag.
*
* @return True if successful.
*/
bool DisableAnalyzer(const zeek::Tag& tag);
/**
* Disables an analyzer type. Disabled analyzers will not be
* instantiated for new connections.
*
* @param tag The analyzer's tag as an enum of script type \c
* Tag.
*
* @return True if successful.
*/
bool DisableAnalyzer(EnumVal* tag);
/**
* Disables all currently registered analyzers.
*/
void DisableAllAnalyzers();
/**
* Returns the tag associated with an analyzer name, or the tag
* associated with an error if no such analyzer exists.
*
* @param name The canonical analyzer name to check.
*/
zeek::Tag GetAnalyzerTag(const char* name);
/**
* Returns true if an analyzer is enabled.
*
* @param tag The analyzer's tag.
*/
bool IsEnabled(const zeek::Tag& tag);
/**
* Returns true if an analyzer is enabled.
*
* @param tag The analyzer's tag as an enum of script type \c
* Tag.
*/
bool IsEnabled(EnumVal* tag);
/**
* Registers a well-known port for an analyzer. Once registered,
* connection on that port will start with a corresponding analyzer
* assigned.
*
* @param tag The analyzer's tag as an enum of script type \c
* Tag.
*
* @param port The well-known port.
*
* @return True if successful.
*/
bool RegisterAnalyzerForPort(EnumVal* tag, PortVal* port);
/**
* Registers a well-known port for an analyzer. Once registered,
* connection on that port will start with a corresponding analyzer
* assigned.
*
* @param tag The analyzer's tag.
*
* @param proto The port's protocol.
*
* @param port The port's number.
*
* @return True if successful.
*/
bool RegisterAnalyzerForPort(const zeek::Tag& tag, TransportProto proto, uint32_t port);
/**
* Unregisters a well-known port for an analyzers.
*
* @param tag The analyzer's tag as an enum of script type \c
* Tag.
*
* @param port The well-known port.
*
* @return True if successful (incl. when the port wasn't actually
* registered for the analyzer).
*
*/
bool UnregisterAnalyzerForPort(EnumVal* tag, PortVal* port);
/**
* Unregisters a well-known port for an analyzers.
*
* @param tag The analyzer's tag.
*
* @param proto The port's protocol.
*
* @param port The port's number.
*
* @param tag The analyzer's tag as an enum of script type \c
* Tag.
*/
bool UnregisterAnalyzerForPort(const zeek::Tag& tag, TransportProto proto, uint32_t port);
/**
* Instantiates a new analyzer instance for a connection.
*
* @param tag The analyzer's tag.
*
* @param conn The connection the analyzer is to be associated with.
*
* @return The new analyzer instance. Note that the analyzer will not
* have been added to the connection's analyzer tree yet. Returns
* null if tag is invalid, the requested analyzer is disabled, or the
* analyzer can't be instantiated.
*/
Analyzer* InstantiateAnalyzer(const zeek::Tag& tag, Connection* c);
/**
* Instantiates a new analyzer instance for a connection.
*
* @param name The name of the analyzer.
*
* @param conn The connection the analyzer is to be associated with.
*
* @return The new analyzer instance. Note that the analyzer will not
* have been added to the connection's analyzer tree yet. Returns
* null if the name is not known or if the requested analyzer that is
* disabled.
*/
Analyzer* InstantiateAnalyzer(const char* name, Connection* c);
/**
* Schedules a particular analyzer for an upcoming connection. Once
* the connection is seen, BuildInitAnalyzerTree() will add the
* specified analyzer to its tree.
*
* @param orig The connection's anticipated originator address.
* 0.0.0.0 can be used as a wildcard matching any originator.
*
* @param resp The connection's anticipated responder address (no
* wildcard).
*
* @param resp_p The connection's anticipated responder port.
*
* @param proto The connection's anticipated transport protocol.
*
* @param analyzer The analyzer to use once the connection is seen.
*
* @param timeout An interval after which to timeout the request to
* schedule this analyzer. Must be non-zero.
*/
void ScheduleAnalyzer(const IPAddr& orig, const IPAddr& resp, uint16_t resp_p,
TransportProto proto, const zeek::Tag& analyzer, double timeout);
/**
* Schedules a particular analyzer for an upcoming connection. Once
* the connection is seen, BuildInitAnalyzerTree() will add the
* specified analyzer to its tree.
*
* @param orig The connection's anticipated originator address. 0 can
* be used as a wildcard matching any originator.
*
* @param resp The connection's anticipated responder address (no
* wildcard).
*
* @param resp_p The connection's anticipated responder port.
*
* @param proto The connection's anticipated transport protocol.
*
* @param analyzer The name of the analyzer to use once the
* connection is seen.
*
* @param timeout An interval after which to timeout the request to
* schedule this analyzer. Must be non-zero.
*/
void ScheduleAnalyzer(const IPAddr& orig, const IPAddr& resp, uint16_t resp_p,
TransportProto proto, const char* analyzer, double timeout);
/**
* Searched for analyzers scheduled to be attached to a given connection
* and then attaches them.
*
* @param conn The connection to which scheduled analyzers are attached.
*
* @param init True if the newly added analyzers should be
* immediately initialized.
*
* @param root If given, the scheduled analyzers will become children
* of this; if not given the connection's root analyzer is used
* instead.
*
* @return True if at least one scheduled analyzer was found.
*/
bool ApplyScheduledAnalyzers(Connection* conn, bool init_and_event = true,
packet_analysis::IP::SessionAdapter* parent = nullptr);
/**
* Schedules a particular analyzer for an upcoming connection. Once
* the connection is seen, BuildInitAnalyzerTree() will add the
* specified analyzer to its tree.
*
* @param orig The connection's anticipated originator address. 0 can
* be used as a wildcard matching any originator.
*
* @param resp The connection's anticipated responder address (no
* wildcard).
*
* @param resp_p The connection's anticipated responder port.
*
* @param analyzer The analyzer to use once the connection is seen as
* an enum value of script-type \c Tag.
*
* @param timeout An interval after which to timeout the request to
* schedule this analyzer. Must be non-zero.
*/
void ScheduleAnalyzer(const IPAddr& orig, const IPAddr& resp, PortVal* resp_p, Val* analyzer,
double timeout);
/**
* @return the UDP port numbers to be associated with VXLAN traffic.
*/
const std::vector<uint16_t>& GetVxlanPorts() const { return vxlan_ports; }
private:
// Internal version that must be used only once InitPostScript has completed.
bool RegisterAnalyzerForPort(const std::tuple<zeek::Tag, TransportProto, uint32_t>& p);
friend class packet_analysis::IP::IPBasedAnalyzer;
using tag_set = std::set<zeek::Tag>;
tag_set GetScheduled(const Connection* conn);
void ExpireScheduledAnalyzers();
//// Data structures to track analyzed scheduled for future connections.
// The index for a scheduled connection.
struct ConnIndex
{
IPAddr orig;
IPAddr resp;
uint16_t resp_p;
uint16_t proto;
ConnIndex(const IPAddr& _orig, const IPAddr& _resp, uint16_t _resp_p, uint16_t _proto);
ConnIndex();
bool operator<(const ConnIndex& other) const;
};
// Information associated with a scheduled connection.
struct ScheduledAnalyzer
{
ConnIndex conn;
zeek::Tag analyzer;
double timeout;
struct Comparator
{
bool operator()(ScheduledAnalyzer* a, ScheduledAnalyzer* b)
{
return a->timeout > b->timeout;
}
};
};
using protocol_analyzers = std::set<std::tuple<zeek::Tag, TransportProto, uint32_t>>;
using conns_map = std::multimap<ConnIndex, ScheduledAnalyzer*>;
using conns_queue = std::priority_queue<ScheduledAnalyzer*, std::vector<ScheduledAnalyzer*>,
ScheduledAnalyzer::Comparator>;
bool initialized = false;
protocol_analyzers pending_analyzers_for_ports;
conns_map conns;
conns_queue conns_by_timeout;
std::vector<uint16_t> vxlan_ports;
};
} // namespace analyzer
extern analyzer::Manager* analyzer_mgr;
} // namespace zeek
// Macros for analyzer debug logging which include the connection id into the
// message.
#ifdef DEBUG
#define DBG_ANALYZER(conn, txt) \
DBG_LOG(zeek::DBG_ANALYZER, "%s " txt, \
fmt_conn_id(conn->OrigAddr(), ntohs(conn->OrigPort()), conn->RespAddr(), \
ntohs(conn->RespPort())));
#define DBG_ANALYZER_ARGS(conn, fmt, ...) \
DBG_LOG(zeek::DBG_ANALYZER, "%s " fmt, \
fmt_conn_id(conn->OrigAddr(), ntohs(conn->OrigPort()), conn->RespAddr(), \
ntohs(conn->RespPort())), \
##__VA_ARGS__);
#else
#define DBG_ANALYZER(conn, txt)
#define DBG_ANALYZER_ARGS(conn, fmt, ...)
#endif