zeek/src/packet_analysis/protocol/udp/UDP.h

103 lines
3 KiB
C++

// See the file "COPYING" in the main distribution directory for copyright.
#pragma once
#include "zeek/packet_analysis/Analyzer.h"
#include "zeek/packet_analysis/Component.h"
#include "zeek/packet_analysis/protocol/ip/IPBasedAnalyzer.h"
namespace zeek::packet_analysis::UDP {
class UDPAnalyzer final : public IP::IPBasedAnalyzer {
public:
UDPAnalyzer();
~UDPAnalyzer() override;
static zeek::packet_analysis::AnalyzerPtr Instantiate()
{
return std::make_shared<UDPAnalyzer>();
}
/**
* Initialize the analyzer. This method is called after the configuration
* was read. Derived classes can override this method to implement custom
* initialization.
*/
void Initialize() override;
protected:
/**
* Parse the header from the packet into a ConnTuple object.
*/
bool BuildConnTuple(size_t len, const uint8_t* data, Packet* packet,
ConnTuple& tuple) override;
void DeliverPacket(Connection* c, double t, bool is_orig, int remaining,
Packet* pkt) override;
/**
* Upon seeing the first packet of a connection, checks whether we want
* to analyze it (e.g. we may not want to look at partial connections)
* and, if yes, whether we should flip the roles of originator and
* responder based on known ports and such.
*
* @param src_port The source port of the connection.
* @param dst_port The destination port of the connection.
* @param data The payload data for the packet being processed.
* @param flip_roles Return value if the roles should be flipped.
* @return True if the connection is wanted. False otherwise.
*/
bool WantConnection(uint16_t src_port, uint16_t dst_port,
const u_char* data, bool& flip_roles) const override;
packet_analysis::IP::IPBasedTransportAnalyzer* MakeTransportAnalyzer(Connection* conn) override;
analyzer::pia::PIA* MakePIA(Connection* conn) override;
private:
// Returns true if the checksum is valid, false if not
static bool ValidateChecksum(const IP_Hdr* ip, const struct udphdr* up,
int len);
void ChecksumEvent(bool is_orig, uint32_t threshold);
Connection* conn;
std::vector<uint16_t> vxlan_ports;
};
class UDPTransportAnalyzer final : public IP::IPBasedTransportAnalyzer {
public:
UDPTransportAnalyzer(Connection* conn) :
IP::IPBasedTransportAnalyzer("UDP", conn) { }
static zeek::analyzer::Analyzer* Instantiate(Connection* conn)
{
return new UDPTransportAnalyzer(conn);
}
void AddExtraAnalyzers(Connection* conn) override;
void UpdateConnVal(RecordVal* conn_val) override;
void UpdateLength(bool is_orig, int len);
// For tracking checksum history. These are connection-specific so they
// need to be stored in the transport analyzer created for each
// connection.
uint32_t req_chk_cnt = 0;
uint32_t req_chk_thresh = 1;
uint32_t rep_chk_cnt = 0;
uint32_t rep_chk_thresh = 1;
private:
void UpdateEndpointVal(const ValPtr& endp_arg, bool is_orig);
bro_int_t request_len = -1;
bro_int_t reply_len = -1;
};
}