zeek/src/analyzer/protocol/tcp/TCP_Reassembler.h

125 lines
3.8 KiB
C++

#pragma once
#include "zeek/Reassem.h"
#include "zeek/analyzer/protocol/tcp/TCP_Endpoint.h"
#include "zeek/analyzer/protocol/tcp/TCP_Flags.h"
#include "zeek/File.h"
namespace zeek {
namespace packet_analysis::TCP { class TCPSessionAdapter; }
class Connection;
namespace analyzer {
class Analyzer;
namespace tcp {
using TCP_Analyzer [[deprecated("Remove in v5.1. Use zeek::packet_analysis::TCP::TCPSessionAdapter.")]] =
zeek::packet_analysis::TCP::TCPSessionAdapter;
class TCP_Reassembler final : public Reassembler {
public:
enum Type {
Direct, // deliver to destination analyzer itself
Forward, // forward to destination analyzer's children
};
TCP_Reassembler(analyzer::Analyzer* arg_dst_analyzer,
packet_analysis::TCP::TCPSessionAdapter* arg_tcp_analyzer,
Type arg_type, TCP_Endpoint* arg_endp);
void Done();
void SetDstAnalyzer(analyzer::Analyzer* analyzer) { dst_analyzer = analyzer; }
void SetType(Type arg_type) { type = arg_type; }
packet_analysis::TCP::TCPSessionAdapter* GetTCPAnalyzer() { return tcp_analyzer; }
// Returns the volume of data buffered in the reassembler.
// First parameter returns data that is above a hole, and thus is
// waiting on the hole being filled. Second parameter returns
// data that has been processed but is awaiting an ACK to free
// it up.
//
// If we're not processing contents, then naturally each of
// these is empty.
//
// WARNING: this is an O(n) operation and potentially very slow.
void SizeBufferedData(uint64_t& waiting_on_hole, uint64_t& waiting_on_ack) const;
// How much data is pending delivery since it's not yet reassembled.
// Includes the data due to holes (so this value is a bit different
// from waiting_on_hole above; and is computed in a different fashion).
uint64_t NumUndeliveredBytes() const;
void SetContentsFile(FilePtr f);
const FilePtr& GetContentsFile() const { return record_contents_file; }
void MatchUndelivered(uint64_t up_to_seq, bool use_last_upper);
// Skip up to seq, as if there's a content gap.
// Can be used to skip HTTP data for performance considerations.
void SkipToSeq(uint64_t seq);
bool DataSent(double t, uint64_t seq, int len, const u_char* data,
analyzer::tcp::TCP_Flags flags, bool replaying=true);
void AckReceived(uint64_t seq);
// Checks if we have delivered all contents that we can possibly
// deliver for this endpoint. Calls TCPSessionAdapter::EndpointEOF()
// when so.
void CheckEOF();
bool HasUndeliveredData() const { return HasBlocks(); }
bool HadGap() const { return had_gap; }
bool DataPending() const;
uint64_t DataSeq() const { return LastReassemSeq(); }
void DeliverBlock(uint64_t seq, int len, const u_char* data);
virtual void Deliver(uint64_t seq, int len, const u_char* data);
TCP_Endpoint* Endpoint() { return endp; }
const TCP_Endpoint* Endpoint() const { return endp; }
bool IsOrig() const { return endp->IsOrig(); }
bool IsSkippedContents(uint64_t seq, int length) const
{ return seq + length <= seq_to_skip; }
private:
void Undelivered(uint64_t up_to_seq) override;
void Gap(uint64_t seq, uint64_t len);
void RecordToSeq(uint64_t start_seq, uint64_t stop_seq, const FilePtr& f);
void RecordBlock(const DataBlock& b, const FilePtr& f);
void RecordGap(uint64_t start_seq, uint64_t upper_seq, const FilePtr& f);
void BlockInserted(DataBlockMap::const_iterator it) override;
void Overlap(const u_char* b1, const u_char* b2, uint64_t n) override;
TCP_Endpoint* endp;
bool deliver_tcp_contents;
bool had_gap;
bool did_EOF;
bool skip_deliveries;
uint64_t seq_to_skip;
bool in_delivery;
analyzer::tcp::TCP_Flags flags;
FilePtr record_contents_file; // file on which to reassemble contents
analyzer::Analyzer* dst_analyzer;
packet_analysis::TCP::TCPSessionAdapter* tcp_analyzer;
Type type;
};
} // namespace tcp
} // namespace analyzer
} // namespace zeek