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8192ad581d
This could lead to a noticeable (single-percent) performance improvement. Most of the functionality for this is in the packet analyzers that now cache ignore_chesksums_nets. Based on a patch by Arne Welzel (Corelight).
91 lines
3 KiB
C++
91 lines
3 KiB
C++
// See the file "COPYING" in the main distribution directory for copyright.
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#pragma once
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#include "zeek/packet_analysis/Analyzer.h"
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#include "zeek/packet_analysis/Component.h"
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#include "zeek/packet_analysis/protocol/ip/IPBasedAnalyzer.h"
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#include "zeek/packet_analysis/protocol/tcp/Stats.h"
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#include "zeek/analyzer/protocol/tcp/TCP_Flags.h"
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namespace zeek::analyzer::tcp { class TCP_Endpoint; }
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namespace zeek::packet_analysis::TCP {
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class TCPSessionAdapter;
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class TCPAnalyzer final : public IP::IPBasedAnalyzer {
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public:
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TCPAnalyzer();
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~TCPAnalyzer() override = default;
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static zeek::packet_analysis::AnalyzerPtr Instantiate()
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{
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return std::make_shared<TCPAnalyzer>();
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}
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/*
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* Initialize the analyzer. This method is called after the configuration
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* was read. Derived classes can override this method to implement custom
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* initialization.
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*/
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void Initialize() override;
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static TCPStateStats& GetStats()
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{
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static TCPStateStats stats;
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return stats;
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}
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protected:
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/**
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* Parse the header from the packet into a ConnTuple object.
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*/
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bool BuildConnTuple(size_t len, const uint8_t* data, Packet* packet,
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ConnTuple& tuple) override;
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void DeliverPacket(Connection* c, double t, bool is_orig, int remaining,
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Packet* pkt) override;
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/**
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* Upon seeing the first packet of a connection, checks whether we want
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* to analyze it (e.g. we may not want to look at partial connections)
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* and, if yes, whether we should flip the roles of originator and
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* responder based on known ports and such.
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*
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* @param src_port The source port of the connection.
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* @param dst_port The destination port of the connection.
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* @param data The payload data for the packet being processed.
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* @param flip_roles Return value if the roles should be flipped.
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* @return True if the connection is wanted. False otherwise.
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*/
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bool WantConnection(uint16_t src_port, uint16_t dst_port,
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const u_char* data, bool& flip_roles) const override;
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/**
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* Returns an analyzer adapter appropriate for this IP-based analyzer. This adapter
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* is used to hook into the session analyzer framework. This function can also be used
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* to do any extra initialization of connection timers, etc.
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*/
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packet_analysis::IP::SessionAdapter* MakeSessionAdapter(Connection* conn) override;
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/**
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* Returns a PIA appropriate for this IP-based analyzer. This method is optional to
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* override in child classes, as not all analyzers need a PIA.
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*/
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analyzer::pia::PIA* MakePIA(Connection* conn) override;
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private:
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const struct tcphdr* ExtractTCP_Header(const u_char*& data, int& len, int& remaining,
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TCPSessionAdapter* adapter);
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// Returns true if the checksum is valid, false if not (and in which
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// case also updates the status history of the endpoint).
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bool ValidateChecksum(const IP_Hdr* ip, const struct tcphdr* tp,
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analyzer::tcp::TCP_Endpoint* endpoint,
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int len, int caplen, TCPSessionAdapter* adapter);
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};
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}
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