source: mainline/uspace/srv/net/tl/tcp/tcp.h@ d52b0044

/*
 * Copyright (c) 2008 Lukas Mejdrech
 * 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/** @addtogroup tcp
 * @{
 */

/** @file
 * TCP module.
 */

#ifndef NET_TCP_H_
#define NET_TCP_H_

#include <fibril_synch.h>

#include <net/packet.h>
#include <net/device.h>
#include <socket_core.h>
#include <tl_common.h>

/** Type definition of the TCP global data.
 * @see tcp_globals
 */
typedef struct tcp_globals tcp_globals_t;

/** Type definition of the TCP socket specific data.
 * @see tcp_socket_data
 */
typedef struct tcp_socket_data tcp_socket_data_t;

/** Type definition of the TCP socket specific data pointer.
 * @see tcp_socket_data
 */
typedef tcp_socket_data_t *tcp_socket_data_ref;

/** Type definition of the TCP operation data.
 * @see tcp_operation
 */
typedef struct tcp_operation tcp_operation_t;

/** Type definition of the TCP operation data pointer.
 * @see tcp_operation
 */
typedef tcp_operation_t *tcp_operation_ref;

/** TCP socket state type definition.
 * @see tcp_socket_state
 */
typedef enum tcp_socket_state tcp_socket_state_t;

/** TCP socket state. */
enum tcp_socket_state {
        /** Initial.
         *
         * Not connected or bound.
         */
        TCP_SOCKET_INITIAL,
        
        /** Listening.
         *
         * Awaiting a connection request from another TCP layer.
         * When SYN is received a new bound socket in the
         * TCP_SOCKET_SYN_RECEIVED state should be created.
         */
        TCP_SOCKET_LISTEN,
        
        /** Connecting issued.
         *
         * A SYN has been sent, and TCP is awaiting the response SYN.
         * Should continue to the TCP_SOCKET_ESTABLISHED state.
         */
        TCP_SOCKET_SYN_SENT,
        
        /** Connecting received.
         *
         * A SYN has been received, a SYN has been sent, and TCP is awaiting an
         * ACK. Should continue to the TCP_SOCKET_ESTABLISHED state.
         */
        TCP_SOCKET_SYN_RECEIVED,
        
        /** Connected.
         *
         * The three-way handshake has been completed.
         */
        TCP_SOCKET_ESTABLISHED,
        
        /** Closing started.
         *
         * The local application has issued a CLOSE.
         * TCP has sent a FIN, and is awaiting an ACK or a FIN.
         * Should continue to the TCP_SOCKET_FIN_WAIT_2 state when an ACK is
         * received.
         * Should continue to the TCP_SOCKET_CLOSING state when a FIN is
         * received.
         */
        TCP_SOCKET_FIN_WAIT_1,
        
        /** Closing confirmed.
         *
         * A FIN has been sent, and an ACK received.
         * TCP is awaiting a~FIN from the remote TCP layer.
         * Should continue to the TCP_SOCKET_CLOSING state.
         */
        TCP_SOCKET_FIN_WAIT_2,
        
        /** Closing.
         *
         * A FIN has been sent, a FIN has been received, and an ACK has been
         * sent.
         * TCP is awaiting an ACK for the FIN that was sent.
         * Should continue to the TCP_SOCKET_TIME_WAIT state.
         */
        TCP_SOCKET_CLOSING,
        
        /** Closing received.
         *
         * TCP has received a FIN, and has sent an ACK.
         * It is awaiting a close request from the local application before
         * sending a FIN.
         * Should continue to the TCP_SOCKET_SOCKET_LAST_ACK state.
         */
        TCP_SOCKET_CLOSE_WAIT,
        
        /**
         * A FIN has been received, and an ACK and a FIN have been sent.
         * TCP is awaiting an ACK.
         * Should continue to the TCP_SOCKET_TIME_WAIT state.
         */
        TCP_SOCKET_LAST_ACK,
        
        /** Closing finished.
         *
         * FINs have been received and ACK’d, and TCP is waiting two MSLs to
         * remove the connection from the table.
         */
        TCP_SOCKET_TIME_WAIT,
        
        /** Closed.
         *
         * Imaginary, this indicates that a connection has been removed from
         * the connection table.
         */
        TCP_SOCKET_CLOSED
};

/** TCP operation data. */
struct tcp_operation {
        /** Operation result. */
        int result;
        /** Safety lock. */
        fibril_mutex_t mutex;
        /** Operation result signaling. */
        fibril_condvar_t condvar;
};

/** TCP socket specific data. */
struct tcp_socket_data {
        /** TCP socket state. */
        tcp_socket_state_t state;
        
        /**
         * Data fragment size.
         * Sending optimalization.
         */
        size_t data_fragment_size;
        
        /** Device identifier. */
        device_id_t device_id;
        
        /**
         * Listening backlog.
         * The maximal number of connected but not yet accepted sockets.
         */
        int backlog;
        
//      /** Segment size. */
//      size_t segment_size;

        /**
         * Parent listening socket identifier.
         * Set if this socket is an accepted one.
         */
        int listening_socket_id;
        
        /** Treshold size in bytes. */
        size_t treshold;
        /** Window size in bytes. */
        size_t window;
        /** Acknowledgement timeout. */
        suseconds_t timeout;
        /** Last acknowledged byte. */
        uint32_t acknowledged;
        /** Next incoming sequence number. */
        uint32_t next_incoming;
        /** Incoming FIN. */
        uint32_t fin_incoming;
        /** Next outgoing sequence number. */
        uint32_t next_outgoing;
        /** Last outgoing sequence number. */
        uint32_t last_outgoing;
        /** Outgoing FIN. */
        uint32_t fin_outgoing;
        
        /**
         * Expected sequence number by the remote host.
         * The sequence number the other host expects.
         * The notification is sent only upon a packet reecival.
         */
        uint32_t expected;
        
        /**
         * Expected sequence number counter.
         * Counts the number of received notifications for the same sequence
         * number.
         */
        int expected_count;
        
        /** Incoming packet queue.
         *
         * Packets are buffered until received in the right order.
         * The packets are excluded after successfully read.
         * Packets are sorted by their starting byte.
         * Packets metric is set as their data length.
         */
        packet_t incoming;
        
        /** Outgoing packet queue.
         *
         * Packets are buffered until acknowledged by the remote host in the
         * right order.
         * The packets are excluded after acknowledged.
         * Packets are sorted by their starting byte.
         * Packets metric is set as their data length.
         */
        packet_t outgoing;
        
        /** IP pseudo header. */
        void *pseudo_header;
        /** IP pseudo header length. */
        size_t headerlen;
        /** Remote host address. */
        struct sockaddr *addr;
        /** Remote host address length. */
        socklen_t addrlen;
        /** Remote host port. */
        uint16_t dest_port;
        /** Parent local sockets. */
        socket_cores_ref local_sockets;
        
        /** Local sockets safety lock.
         *
         * May be locked for writing while holding the global lock for reading
         * when changing the local sockets only.
         * The global lock may be locked only before locking the local lock.
         * The global lock may be locked more weakly than the local lock.
         * The global lock may be released before releasing the local lock.
         * @see tcp_globals:lock
         */
        fibril_rwlock_t *local_lock;
        
        /** Pending operation data. */
        tcp_operation_t operation;
        
        /**
         * Timeouts in a row counter.
         * If TCP_MAX_TIMEOUTS is reached, the connection is lost.
         */
        int timeout_count;
};

/** TCP global data. */
struct tcp_globals {
        /** Networking module phone. */
        int net_phone;
        /** IP module phone. */
        int ip_phone;
        /** ICMP module phone. */
        int icmp_phone;
        /** Last used free port. */
        int last_used_port;
        /** Active sockets. */
        socket_ports_t sockets;
        /** Device packet dimensions. */
        packet_dimensions_t dimensions;
        
        /**
         * Safety lock.
         * Write lock is used only for adding or removing socket ports.
         */
        fibril_rwlock_t lock;
};

#endif

/** @}
 */