zeek/src/PacketFilter.h
2020-10-15 12:49:08 -07:00

54 lines
1.5 KiB
C++

// Provides some very limited but fast packet filter mechanisms
#pragma once
#include <memory>
#include "IPAddr.h"
#include "PrefixTable.h"
ZEEK_FORWARD_DECLARE_NAMESPACED(IP_Hdr, zeek);
ZEEK_FORWARD_DECLARE_NAMESPACED(Val, zeek);
namespace zeek::detail {
class PacketFilter {
public:
explicit PacketFilter(bool arg_default);
~PacketFilter() {}
// Drops all packets from a particular source (which may be given
// as an AddrVal or a SubnetVal) which hasn't any of TCP flags set
// (TH_*) with the given probability (from 0..MAX_PROB).
void AddSrc(const IPAddr& src, uint32_t tcp_flags, double probability);
void AddSrc(Val* src, uint32_t tcp_flags, double probability);
void AddDst(const IPAddr& src, uint32_t tcp_flags, double probability);
void AddDst(Val* src, uint32_t tcp_flags, double probability);
// Removes the filter entry for the given src/dst
// Returns false if filter doesn not exist.
bool RemoveSrc(const IPAddr& src);
bool RemoveSrc(Val* dst);
bool RemoveDst(const IPAddr& dst);
bool RemoveDst(Val* dst);
// Returns true if packet matches a drop filter
bool Match(const std::unique_ptr<IP_Hdr>& ip, int len, int caplen);
private:
struct Filter {
uint32_t tcp_flags;
double probability;
};
static void DeleteFilter(void* data);
bool MatchFilter(const Filter& f, const IP_Hdr& ip, int len, int caplen);
bool default_match;
PrefixTable src_filter;
PrefixTable dst_filter;
};
} // namespace zeek::detail
using PacketFilter [[deprecated("Remove in v4.1. Use zeek::detail::PacketFilter.")]] = zeek::detail::PacketFilter;