// See the file "COPYING" in the main distribution directory for copyright.

#pragma once

#include "zeek/Conn.h"
#include "zeek/IPAddr.h"
#include "zeek/analyzer/Analyzer.h"
#include "zeek/analyzer/protocol/tcp/TCP_Endpoint.h"
#include "zeek/analyzer/protocol/tcp/TCP_Flags.h"
#include "zeek/packet_analysis/protocol/tcp/TCPSessionAdapter.h"

namespace zeek::analyzer::pia {
class PIA_TCP;
}

namespace zeek::analyzer::tcp {

class TCP_Endpoint;
class TCP_Reassembler;
class TCP_ApplicationAnalyzer;

/**
 * An abstract base class for analyzers for a protocol running on top
 * of TCP.
 */
class TCP_ApplicationAnalyzer : public analyzer::Analyzer {
public:
    TCP_ApplicationAnalyzer(const char* name, Connection* conn) : Analyzer(name, conn), tcp(nullptr) {}

    explicit TCP_ApplicationAnalyzer(Connection* conn) : Analyzer(conn), tcp(nullptr) {}

    ~TCP_ApplicationAnalyzer() override {}

    // This may be nil if we are not directly associated with a TCP
    // analyzer (e.g., we're part of a tunnel decapsulation pipeline).
    packet_analysis::TCP::TCPSessionAdapter* TCP();

    void SetTCP(packet_analysis::TCP::TCPSessionAdapter* arg_tcp) { tcp = arg_tcp; }

    // The given endpoint's data delivery is complete.
    virtual void EndpointEOF(bool is_orig);

    // Called whenever an end enters TCP_ENDPOINT_CLOSED or
    // TCP_ENDPOINT_RESET.  If gen_event is true and the connection
    // is now fully closed, a connection_finished event will be
    // generated; otherwise not.
    virtual void ConnectionClosed(analyzer::tcp::TCP_Endpoint* endpoint, analyzer::tcp::TCP_Endpoint* peer,
                                  bool gen_event);
    virtual void ConnectionFinished(bool half_finished);
    virtual void ConnectionReset();

    // Called whenever a RST packet is seen - sometimes the invocation
    // of ConnectionReset is delayed.
    virtual void PacketWithRST();

    void DeliverPacket(int len, const u_char* data, bool orig, uint64_t seq, const IP_Hdr* ip, int caplen) override;
    void Init() override;

    // This suppresses violations if the TCP connection wasn't
    // fully established.
    void AnalyzerViolation(const char* reason, const char* data = nullptr, int len = 0,
                           zeek::Tag tag = zeek::Tag()) override;

    // "name" and "val" both now belong to this object, which needs to
    //  delete them when done with them.
    virtual void SetEnv(bool orig, char* name, char* val);

private:
    packet_analysis::TCP::TCPSessionAdapter* tcp;
};

class TCP_SupportAnalyzer : public analyzer::SupportAnalyzer {
public:
    TCP_SupportAnalyzer(const char* name, Connection* conn, bool arg_orig)
        : analyzer::SupportAnalyzer(name, conn, arg_orig) {}

    ~TCP_SupportAnalyzer() override {}

    // These are passed on from TCPSessionAdapter.
    virtual void EndpointEOF(bool is_orig) {}
    virtual void ConnectionClosed(TCP_Endpoint* endpoint, TCP_Endpoint* peer, bool gen_event) {}
    virtual void ConnectionFinished(bool half_finished) {}
    virtual void ConnectionReset() {}
    virtual void PacketWithRST() {}
};

class TCPStats_Endpoint {
public:
    explicit TCPStats_Endpoint(TCP_Endpoint* endp);

    bool DataSent(double t, uint64_t seq, int len, int caplen, const u_char* data, const IP_Hdr* ip,
                  const struct tcphdr* tp);

    RecordVal* BuildStats();

protected:
    TCP_Endpoint* endp;
    int num_pkts;
    int num_rxmit;
    int num_rxmit_bytes;
    int num_in_order;
    int num_OO;
    int num_repl;
    uint64_t max_top_seq;
    int last_id;
    int endian_type;
};

class TCPStats_Analyzer : public tcp::TCP_ApplicationAnalyzer {
public:
    explicit TCPStats_Analyzer(Connection* c);
    ~TCPStats_Analyzer() override;

    void Init() override;
    void Done() override;

    static analyzer::Analyzer* Instantiate(Connection* conn) { return new TCPStats_Analyzer(conn); }

protected:
    void DeliverPacket(int len, const u_char* data, bool is_orig, uint64_t seq, const IP_Hdr* ip, int caplen) override;

    TCPStats_Endpoint* orig_stats;
    TCPStats_Endpoint* resp_stats;
};

} // namespace zeek::analyzer::tcp
