tcpsock.c

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/*
 * Copyright (C) 2001-2005 by egnite Software GmbH. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name of the copyright holders nor the names of
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY EGNITE SOFTWARE GMBH 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 EGNITE
 * SOFTWARE GMBH 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.
 *
 * For additional information see http://www.ethernut.de/
 *
 * -
 * Portions Copyright (C) 2000 David J. Hudson <dave@humbug.demon.co.uk>
 *
 * This file is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You can redistribute this file and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software Foundation;
 * either version 2 of the License, or (at your discretion) any later version.
 * See the accompanying file "copying-gpl.txt" for more details.
 *
 * As a special exception to the GPL, permission is granted for additional
 * uses of the text contained in this file.  See the accompanying file
 * "copying-liquorice.txt" for details.
 * -
 * Portions Copyright (c) 1983, 1993 by
 *  The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 * -
 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies, and that
 * the name of Digital Equipment Corporation not be used in advertising or
 * publicity pertaining to distribution of the document or software without
 * specific, written prior permission.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/*
 * $Log$
 * Revision 1.25  2009/02/22 12:31:52  olereinhardt
 * Include "include/errno.h" instead of "include/net/errno.h"
 *
 * Revision 1.24  2009/02/13 14:52:05  haraldkipp
 * Include memdebug.h for heap management debugging support.
 *
 * Revision 1.23  2009/02/06 15:40:29  haraldkipp
 * Using newly available strdup() and calloc().
 * Replaced NutHeap routines by standard malloc/free.
 * Replaced pointer value 0 by NULL.
 *
 * Revision 1.22  2008/08/20 06:57:00  haraldkipp
 * Implemented IP demultiplexer.
 *
 * Revision 1.21  2008/08/11 07:00:32  haraldkipp
 * BSD types replaced by stdint types (feature request #1282721).
 *
 * Revision 1.20  2008/04/18 13:32:00  haraldkipp
 * Changed size parameter from u_short to int, which is easier to handle
 * for 32-bit targets. You need to recompile your ARM code. No impact on
 * AVR expected
 * I changed u_int to int at some places to avoid some warnings during
 * compilation of Nut/Net.
 * libs.
 *
 * Revision 1.19  2006/10/08 16:48:22  haraldkipp
 * Documentation fixed
 *
 * Revision 1.18  2006/03/21 21:22:20  drsung
 * Enhancement made to TCP state machine. Now TCP options
 * are read from peer and at least the maximum segment size is stored.
 *
 * Revision 1.17  2005/10/24 11:00:16  haraldkipp
 * Integer division hack for ARM without CRT removed again.
 *
 * Revision 1.16  2005/08/02 17:47:03  haraldkipp
 * Major API documentation update.
 *
 * Revision 1.15  2005/04/30 16:42:42  chaac
 * Fixed bug in handling of NUTDEBUG. Added include for cfg/os.h. If NUTDEBUG
 * is defined in NutConf, it will make effect where it is used.
 *
 * Revision 1.14  2005/04/08 14:40:36  freckle
 * added <sys/types.h> (__APPLE__) and <netinet/in.h> (__linux__) for htons
 *
 * Revision 1.13  2005/04/05 17:58:02  haraldkipp
 * Avoid integer division on ARM platform as long as we run without crtlib.
 *
 * Revision 1.12  2005/02/04 17:16:45  haraldkipp
 * Stop searching when listening socket found
 *
 * Revision 1.11  2005/01/03 08:44:15  haraldkipp
 * Simplyfied NutTcpSend().
 *
 * Revision 1.10  2004/10/14 16:43:07  drsung
 * Fixed compiler warning "comparison between signed and unsigned"
 *
 * Revision 1.9  2004/07/30 19:54:46  drsung
 * Some code of TCP stack redesigned. Round trip time calculation is now
 * supported. Fixed several bugs in TCP state machine. Now TCP connections
 * should be more reliable under heavy traffic or poor physical connections.
 *
 * Revision 1.8  2004/03/16 16:48:45  haraldkipp
 * Added Jan Dubiec's H8/300 port.
 *
 * Revision 1.7  2004/01/28 12:11:57  drsung
 * Bugfix for ICCAVR ... again
 *
 * Revision 1.6  2004/01/28 07:11:38  drsung
 * Bugfix for ICCAVR
 *
 * Revision 1.5  2004/01/14 19:34:08  drsung
 * New TCP output buffer handling
 *
 * Revision 1.4  2003/11/04 17:58:18  haraldkipp
 * Removed volatile attibute from socket list
 *
 * Revision 1.3  2003/08/14 15:08:36  haraldkipp
 * Bugfix, TCP may reuse socket ports because of wrong byte order during compare.
 *
 * Revision 1.2  2003/07/13 19:23:59  haraldkipp
 * TCP transfer speed increased by changing the character receive buffer
 * in TCPSOCKET to a NETBUF queue.
 *
 * Revision 1.1.1.1  2003/05/09 14:41:44  haraldkipp
 * Initial using 3.2.1
 *
 * Revision 1.18  2003/02/04 18:14:57  harald
 * Version 3 released
 *
 * Revision 1.17  2002/09/15 17:07:05  harald
 * Allow application to read buffered data during close wait
 *
 * Revision 1.16  2002/09/03 17:43:15  harald
 * Configurable receive buffer size
 *
 * Revision 1.15  2002/08/16 17:54:57  harald
 * Count out of sequence drops
 *
 * Revision 1.14  2002/08/11 12:26:21  harald
 * ICC mods
 *
 * Revision 1.13  2002/06/26 17:29:36  harald
 * First pre-release with 2.4 stack
 *
 */

#include <cfg/os.h>
#include <sys/types.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>

#include <sys/atom.h>
#include <sys/heap.h>
#include <sys/thread.h>
#include <sys/event.h>
#include <sys/timer.h>

#include <net/route.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/icmp.h>
#include <netinet/ip_icmp.h>
#include <netinet/ipcsum.h>
#include <sys/socket.h>
#include <netinet/tcp.h>
#include <stdio.h>
#include <io.h>
#include <memdebug.h>

#ifdef NUTDEBUG
#include <net/netdebug.h>
#endif

#define TICK_RATE   1


TCPSOCKET *tcpSocketList = 0;   
static volatile uint16_t last_local_port = 4096; /* Unassigned local port. */

static uint_fast8_t registered;

void NutTcpDiscardBuffers(TCPSOCKET * sock)
{
    NETBUF *nb;
    while ((nb = sock->so_rx_buf) != 0) {
        sock->so_rx_buf = nb->nb_next;
        NutNetBufFree(nb);
    }
    while ((nb = sock->so_tx_nbq) != 0) {
        sock->so_tx_nbq = nb->nb_next;
        NutNetBufFree(nb);
    }
    while ((nb = sock->so_rx_nbq) != 0) {
        sock->so_rx_nbq = nb->nb_next;
        NutNetBufFree(nb);
    }
}


void NutTcpDestroySocket(TCPSOCKET * sock)
{
    TCPSOCKET *sp;
    TCPSOCKET *volatile *spp;
    
    //@@@printf ("[%04X] Calling destroy.\n", (u_short) sock);

    /*
     * Remove socket from the list.
     */
    sp = tcpSocketList;
    spp = &tcpSocketList;
    while (sp) {
        if (sp == sock) {
            *spp = sp->so_next;
            break;
        }
        spp = &sp->so_next;
        sp = sp->so_next;
    }

    /*
     * Free all memory occupied by the socket.
     */
    if (sp) {
        NutTcpDiscardBuffers(sock);
        if (sock->so_devocnt)
        {
            free(sock->so_devobuf);
            sock->so_devocnt = 0;
        }
        memset(sock, 0, sizeof(TCPSOCKET));
        free(sock);
    }
}

TCPSOCKET *NutTcpFindSocket(uint16_t lport, uint16_t rport, uint32_t raddr)
{
    TCPSOCKET *sp;
    TCPSOCKET *sock = 0;

    /*
     * Try to find an exact match for the remote
     * address and port first.
     */
    for (sp = tcpSocketList; sp; sp = sp->so_next) {
        if (sp->so_local_port == lport) {
            if (sp->so_remote_addr == raddr && sp->so_remote_port == rport && sp->so_state != TCPS_CLOSED) {
                sock = sp;
                break;
            }
        }
    }

    /*
     * If no exact match exists, try a listening socket.
     * This part had been totally wrong, because it
     * didn't check the local port number and accepted
     * incoming requests on any port. Thanks to
     * Alejandro Lopez, who pointed this out.
     */
    if (sock == 0) {
        for (sp = tcpSocketList; sp; sp = sp->so_next) {
            if (sp->so_state == TCPS_LISTEN && sp->so_local_port == lport) {
                sock = sp;
                break;
            }
        }
    }

    return sock;
}


TCPSOCKET *NutTcpCreateSocket(void)
{
    TCPSOCKET *sock = 0;

    if (!registered) {
        if (NutRegisterIpHandler(IPPROTO_TCP, NutTcpInput) || NutTcpInitStateMachine()) {
            return NULL;
        }
        registered = 1;
    }
    if ((sock = calloc(1, sizeof(TCPSOCKET))) != 0) {
        sock->so_state = TCPS_CLOSED;

        /*
            * Initialize the virtual device interface.
            */
        sock->so_devtype = IFTYP_TCPSOCK;
        sock->so_devread = NutTcpDeviceRead;
        sock->so_devwrite = NutTcpDeviceWrite;
#ifdef __HARVARD_ARCH__
        sock->so_devwrite_P = NutTcpDeviceWrite_P;
#endif
        sock->so_devioctl = NutTcpDeviceIOCtl;

        sock->so_tx_isn = NutGetTickCount();  /* Generate the ISN from the nut_ticks counter */
        sock->so_tx_una = sock->so_tx_isn;
        sock->so_tx_nxt = sock->so_tx_isn;
        sock->so_rx_bsz = sock->so_rx_win = TCP_WINSIZE;

        sock->so_mss = TCP_MSS;
        sock->so_rtto = 1000; /* Initial retransmission time out */

        sock->so_next = tcpSocketList;

        sock->so_devobsz = TCP_MSS; /* Default output buffer size is TCP_MSS bytes */

        tcpSocketList = sock;
    }
    return sock;
}

int NutTcpSetSockOpt(TCPSOCKET * sock, int optname, CONST void *optval, int optlen)
{
    int rc = -1;

    if (sock == 0)
        return -1;
    switch (optname) {

    case TCP_MAXSEG:
        if (optval == 0 || optlen != sizeof(uint16_t))
            sock->so_last_error = EINVAL;
        else if (sock->so_state != TCPS_CLOSED) 
                sock->so_last_error = EISCONN;
        else {
            sock->so_mss = *((uint16_t *) optval);
            rc = 0;
        }
        break;

    case SO_RCVBUF:
        if (optval == 0 || optlen != sizeof(uint16_t))
            sock->so_last_error = EINVAL;
        else {
            sock->so_rx_bsz = *((uint16_t *) optval);
            sock->so_rx_win = sock->so_rx_bsz;
            rc = 0;
        }
        break;

    case SO_SNDTIMEO:
        if (optval == 0 || optlen != sizeof(uint32_t))
            sock->so_last_error = EINVAL;
        else {
            sock->so_write_to = *((uint32_t *) optval);
            rc = 0;
        }
        break;

    case SO_RCVTIMEO:
        if (optval == 0 || optlen != sizeof(uint32_t))
            sock->so_last_error = EINVAL;
        else {
            sock->so_read_to = *((uint32_t *) optval);
            rc = 0;
        }
        break;

    case SO_SNDBUF:
        if (optval == 0 || optlen != sizeof(uint16_t))
            sock->so_last_error = EINVAL;
        else {
            NutTcpDeviceWrite(sock, 0, 0);
            sock->so_devobsz = *((uint16_t *) optval);
            rc = 0;
        }
        break;

    default:
        sock->so_last_error = ENOPROTOOPT;
        break;
    }
    return rc;
}

int NutTcpGetSockOpt(TCPSOCKET * sock, int optname, void *optval, int optlen)
{
    int rc = -1;

    if (sock == 0)
        return -1;
    switch (optname) {

    case TCP_MAXSEG:
        if (optval == 0 || optlen != sizeof(uint16_t))
            sock->so_last_error = EINVAL;
        else {
            *((uint16_t *) optval) = sock->so_mss;
            rc = 0;
        }
        break;

    case SO_RCVBUF:
        if (optval == 0 || optlen != sizeof(uint16_t))
            sock->so_last_error = EINVAL;
        else {
            *((uint16_t *) optval) = sock->so_rx_bsz;
            rc = 0;
        }
        break;

    case SO_SNDTIMEO:
        if (optval == 0 || optlen != sizeof(uint32_t))
            sock->so_last_error = EINVAL;
        else {
            *((uint32_t *) optval) = sock->so_write_to;
            rc = 0;
        }
        break;

    case SO_RCVTIMEO:
        if (optval == 0 || optlen != sizeof(uint32_t))
            sock->so_last_error = EINVAL;
        else {
            *((uint32_t *) optval) = sock->so_read_to;
            rc = 0;
        }
        break;

    case SO_SNDBUF:
        if (optval == 0 || optlen != sizeof(uint16_t))
            sock->so_last_error = EINVAL;
        else {
            *((uint16_t *) optval) = sock->so_devobsz;
            rc = 0;
        }
        break;
    default:
        sock->so_last_error = ENOPROTOOPT;
        break;
    }
    return rc;
}

int NutTcpConnect(TCPSOCKET * sock, uint32_t addr, uint16_t port)
{
    TCPSOCKET *sp;
    NUTDEVICE *dev;

    if (sock == 0)
        return -1;
    /*
     * Despite RFC793 we do not allow a passive
     * open to become active.
     */
    if (sock->so_state == TCPS_LISTEN) {
        sock->so_last_error = EOPNOTSUPP;
        return -1;
    } else if (sock->so_state != TCPS_CLOSED) {
        sock->so_last_error = EISCONN;
        return -1;
    }

    /*
     * Find an unused local port.
     */
    do {
        if (++last_local_port == 0)
            last_local_port = 4096;

        sp = tcpSocketList;
        while (sp) {
            /* Thanks to Ralph Mason for fixing the byte order bug. */
            if (sp->so_local_port == htons(last_local_port))
                break;
            sp = sp->so_next;
        }
    } while (sp);

    /*
     * OK - we've got a new port. Now fill
     * remaining parts of the socket structure.
     */
    sock->so_local_port = htons(last_local_port);
    sock->so_remote_port = htons(port);
    sock->so_remote_addr = addr;

    /*
     * Get local address for this destination.
     */
    if ((dev = NutIpRouteQuery(addr, 0)) != 0) {
        IFNET *nif = dev->dev_icb;
        sock->so_local_addr = nif->if_local_ip;
    } else {
        sock->so_last_error = EHOSTUNREACH;
        return -1;
    }

    /*
     * Trigger active open event for the state machine.
     * This will suspend the thread until synchronized.
     */
    return NutTcpStateActiveOpenEvent(sock);
}

int NutTcpAccept(TCPSOCKET * sock, uint16_t port)
{
    sock->so_local_port = htons(port);

    return NutTcpStatePassiveOpenEvent(sock);
}

int NutTcpSend(TCPSOCKET * sock, CONST void *data, int len)
{
    uint16_t unacked;

    /*
     * Check parameters.
     */
    NutThreadYield();
    
    if (sock == 0)
        return -1;
    if (data == 0 || len == 0)
        return 0;

    /*
     * Limit the transmission size to our maximum segment size.
     */
    if (len > sock->so_mss)
        len = sock->so_mss;

    for (;;) {
        /*
         * We can only send on an established connection.
         */
        if (sock->so_state != TCPS_ESTABLISHED) {
            sock->so_last_error = ENOTCONN;
            return -1;
        }

        /*
         * Limit the size of unacknowledged data to four full segments.
         * Also wait for peer's window open wide enough to take all our 
         * data. This also avoids silly window syndrome on our side.
         */
        unacked = sock->so_tx_nxt - sock->so_tx_una;
        if ((unacked >> 2) < sock->so_mss && len <= sock->so_tx_win - unacked) {
            break;
        }
        if (NutEventWait(&sock->so_tx_tq, sock->so_write_to)) {
            return 0;
        }
    }
    /*
     * The segment will be automatically retransmitted if not 
     * acknowledged in time. If this returns an error, it's a 
     * fatal one.
     */
    sock->so_tx_flags |= SO_ACK;
    if (NutTcpOutput(sock, data, len))
        return -1;
    return len;
}

int NutTcpReceive(TCPSOCKET * sock, void *data, int size)
{
    int i;

    NutThreadYield();
    /*
     * Check parameters.
     */
    if (sock == 0)
        return -1;
    if (sock->so_state != TCPS_ESTABLISHED && sock->so_state != TCPS_CLOSE_WAIT) {
        sock->so_last_error = ENOTCONN;
        return -1;
    }
    if (data == 0 || size == 0)
        return 0;

    /*
     * Wait until any data arrived, a timeout occurs
     * or the connection terminates.
     */
    while (sock->so_rx_cnt - sock->so_rd_cnt == 0) {
        if (sock->so_state != TCPS_ESTABLISHED) {
            sock->so_last_error = ENOTCONN;
            return -1;
        }
        if (NutEventWait(&sock->so_rx_tq, sock->so_read_to))
            return 0;
    }

    if (size > sock->so_rx_cnt - sock->so_rd_cnt)
        size = sock->so_rx_cnt - sock->so_rd_cnt;
    if (size) {
        NETBUF *nb;
        uint16_t rd_cnt;         /* Bytes read from NETBUF. */
        uint16_t nb_cnt;         /* Bytes left in NETBUF. */
        uint16_t ab_cnt;         /* Total bytes in app buffer. */
        uint16_t mv_cnt;         /* Bytes to move to app buffer. */

        rd_cnt = sock->so_rd_cnt;

        ab_cnt = 0;
        while (ab_cnt < size) {
            nb = sock->so_rx_buf;
            nb_cnt = nb->nb_ap.sz - rd_cnt;
            mv_cnt = size - ab_cnt;
            if (mv_cnt > nb_cnt)
                mv_cnt = nb_cnt;
            memcpy((char *) data + ab_cnt, (char *) (nb->nb_ap.vp) + rd_cnt, mv_cnt);
            ab_cnt += mv_cnt;
            rd_cnt += mv_cnt;
            if (mv_cnt >= nb_cnt) {
                sock->so_rx_buf = nb->nb_next;
                sock->so_rx_cnt -= rd_cnt;
                NutNetBufFree(nb);
                sock->so_rx_apc--;
                nb = sock->so_rx_buf;
                rd_cnt = 0;
            }
        }
        sock->so_rd_cnt = rd_cnt;

        /*
         * Update our receive window.
         */
        if (sock->so_state == TCPS_ESTABLISHED) {
            i = sock->so_rx_win;
            if ((i += size) > sock->so_rx_bsz)
                i = sock->so_rx_bsz;

            if (sock->so_rx_win <= sock->so_mss && i > sock->so_mss) {
                sock->so_rx_win = i;
                NutTcpStateWindowEvent(sock);
            } else {
                sock->so_rx_win = i;
            }
        }
    }
    return size;
}

int NutTcpCloseSocket(TCPSOCKET * sock)
{
    /* Flush buffer first */
    //@@@printf ("[%04X] Calling close\n", (u_short) sock);
    NutTcpDeviceWrite(sock, 0, 0);
    return NutTcpStateCloseEvent(sock);
}

int NutTcpError(TCPSOCKET * sock)
{
    if (sock == 0)
        return ENOTSOCK;
    return sock->so_last_error;
}

int NutTcpDeviceRead(TCPSOCKET * sock, void *buffer, int size)
{
    return NutTcpReceive(sock, buffer, size);
}

static int SendBuffer(TCPSOCKET * sock, CONST void *buffer, int size)
{
    int rc;
    int bite;

    for (rc = 0; rc < size; rc += bite) {
        if ((bite = NutTcpSend(sock, (uint8_t *) buffer + rc, size - rc)) <= 0) {
            return -1;
        }
    }
    return rc;
}

int NutTcpDeviceWrite(TCPSOCKET * sock, CONST void *buf, int size)
{
    int rc;
    uint16_t sz;
    /* hack alert for ICCAVR */
    uint8_t *buffer = (uint8_t*) buf;

    /*
     * Check parameters.
     */
    if (sock == 0)
        return -1;
    if (sock->so_state != TCPS_ESTABLISHED) {
        sock->so_last_error = ENOTCONN;
        return -1;
    }

    /* Flush buffer? */
    if (size == 0) {
        if (sock->so_devocnt) {
            if (SendBuffer(sock, sock->so_devobuf, sock->so_devocnt) < 0) {
                free(sock->so_devobuf);
                sock->so_devocnt = 0;
                return -1;
            }
            free(sock->so_devobuf);
            sock->so_devocnt = 0;
        }
        return 0;
    }

    /* If we don't have a buffer so far... */
    if (sock->so_devocnt == 0) {
        /* If new data block is bigger or equal than buffer size
         * send first part of data to nic and store remaining
         * bytes in buffer
         */
        if ((uint16_t) size >= sock->so_devobsz) {
            rc = size % sock->so_devobsz;
            if (SendBuffer(sock, buffer, size - rc) < 0)
                return -1;
            buffer += size - rc;
        } else
            rc = size;

        /* If there are some remainings bytes, allocate buffer
         * and store them
         */
        if (rc) {
            if (!(sock->so_devobuf = malloc(sock->so_devobsz)))
                return -1;
            memcpy(sock->so_devobuf, buffer, rc);
            sock->so_devocnt = rc;
        }
        return size;
    }

    /* Check if new data fully fits in output buffer */
    if (sock->so_devocnt + size < sock->so_devobsz) {
        memcpy(sock->so_devobuf + sock->so_devocnt, buffer, size);
        sock->so_devocnt += size;
        return size;
    }

    /* Otherwise store first bytes of new data in buffer and flush
     * the buffer
     */
    sz = sock->so_devobsz - sock->so_devocnt;
    memcpy(sock->so_devobuf + sock->so_devocnt, buffer, sz);
    buffer += sz;
    if (SendBuffer(sock, sock->so_devobuf, sock->so_devobsz) < 0) {
        free(sock->so_devobuf);
        sock->so_devocnt = 0;
        return -1;
    }

    /* If remaining data is bigger or equal than buffer size
     * send first part of data to nic and later store remaining
     * bytes in buffer
     */
    sz = size - sz;
    if (sz >= sock->so_devobsz) {
        rc = size % sock->so_devobsz;
        if (SendBuffer(sock, buffer, sz - rc) < 0) {
            free(sock->so_devobuf);
            sock->so_devocnt = 0;
            return -1;
        }
        buffer += sz - rc;
    } else
        rc = sz;

    /* If there are some remainings bytes, store them in buffer
     */
    if (rc)
        memcpy(sock->so_devobuf, buffer, rc);
    else                        /* Otherwise free buffer */
        free(sock->so_devobuf);
    sock->so_devocnt = rc;

    return size;
}

#ifdef __HARVARD_ARCH__
int NutTcpDeviceWrite_P(TCPSOCKET * sock, PGM_P buffer, int size)
{
    int rc;
    char *rp = 0;

    /*
     * Hack alert. Neither do we handle out of memory correctly
     * nor do we pass the PGM pointer to lower levels.
     */
    if (size && (rp = NutHeapAlloc(size)) != 0)
        memcpy_P(rp, buffer, size);
    rc = NutTcpDeviceWrite(sock, rp, size);
    if (rp)
        NutHeapFree(rp);

    return rc;
}
#endif

int NutTcpDeviceIOCtl(TCPSOCKET * sock, int cmd, void *param)
{
    uint32_t *lvp = (uint32_t *) param;
    int rc = 0;
    
    switch (cmd) {
    case IOCTL_GETFILESIZE:
    case IOCTL_GETINBUFCOUNT:
        *lvp = (sock->so_rx_cnt - sock->so_rd_cnt);
        break;
    case IOCTL_GETOUTBUFCOUNT:
        *lvp = (sock->so_devocnt);
        break;
    default:
        rc = -1;
    }
    
    return rc;    
}