flow.h

/*
 * Copyright (c) 2017, Matias Fontanini
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following disclaimer
 *   in the documentation and/or other materials provided with the
 *   distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#ifndef TINS_TCP_IP_FLOW_H
#define TINS_TCP_IP_FLOW_H

#include <tins/config.h>

#ifdef TINS_HAVE_TCPIP

#include <array>
#include <functional>
#include <stdint.h>
#include <tins/macros.h>
#include <tins/tcp_ip/ack_tracker.h>
#include <tins/tcp_ip/data_tracker.h>

namespace Tins {

class PDU;
class TCP;
class IPv4Address;
class IPv6Address;

namespace TCPIP {

class TINS_API Flow {
public:
    enum State {
        UNKNOWN,
        SYN_SENT,
        ESTABLISHED,
        FIN_SENT,
        RST_SENT
    };

    typedef DataTracker::payload_type payload_type;

    typedef DataTracker::buffered_payload_type buffered_payload_type;

    typedef std::function<void(Flow&)> data_available_callback_type;

    typedef std::function<void(Flow&,
                               uint32_t,
                               const payload_type&)> flow_packet_callback_type;

    Flow(const IPv4Address& dst_address, uint16_t dst_port,
         uint32_t sequence_number);
    
    Flow(const IPv6Address& dst_address, uint16_t dst_port,
         uint32_t sequence_number);

    void data_callback(const data_available_callback_type& callback);

    void out_of_order_callback(const flow_packet_callback_type& callback);

    void process_packet(PDU& pdu);

    void advance_sequence(uint32_t seq);

    bool is_v6() const;

    bool is_finished() const;

    bool packet_belongs(const PDU& packet) const;

    IPv4Address dst_addr_v4() const;

    IPv6Address dst_addr_v6() const;

    uint16_t dport() const;

    const payload_type& payload() const;

    payload_type& payload();

    State state() const;

    uint32_t sequence_number() const;

    const buffered_payload_type& buffered_payload() const;

    buffered_payload_type& buffered_payload();

    uint32_t total_buffered_bytes() const;

    void state(State new_state);

    void ignore_data_packets();

    int mss() const;

    bool sack_permitted() const;

    void enable_ack_tracking();

    bool ack_tracking_enabled() const;

    #ifdef TINS_HAVE_ACK_TRACKER

    const AckTracker& ack_tracker() const;

    AckTracker& ack_tracker();
    #endif // TINS_HAVE_ACK_TRACKER
private:
    // Compress all flags into just one struct using bitfields 
    struct flags {
        flags() : is_v6(0), ignore_data_packets(0), sack_permitted(0), ack_tracking(0) {

        }

        uint32_t is_v6:1,
                 ignore_data_packets:1,
                 sack_permitted:1,
                 ack_tracking:1;
    };

    void update_state(const TCP& tcp);
    void initialize();

    DataTracker data_tracker_;
    std::array<uint8_t, 16> dest_address_;
    uint16_t dest_port_;
    data_available_callback_type on_data_callback_;
    flow_packet_callback_type on_out_of_order_callback_;
    State state_;
    int mss_;
    flags flags_;
    #ifdef TINS_HAVE_ACK_TRACKER
    AckTracker ack_tracker_;
    #endif // TINS_HAVE_ACK_TRACKER
};

} // TCPIP
} // TINS

#endif // TINS_HAVE_TCPIP
#endif // TINS_TCP_IP_FLOW_H