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