accept.c

一款类linux的操作系统源码

/*
 *  Roadrunner/pk
 *    Copyright (C) 1989-2002  Cornfed Systems, Inc.
 *
 *  The Roadrunner/pk operating system is free software; you can
 *  redistribute and/or modify it under the terms of the GNU General
 *  Public License, version 2, as published by the Free Software
 *  Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public
 *  License along with this program; if not, write to the Free
 *  Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *  MA 02111-1307 USA
 *
 *  More information about the Roadrunner/pk operating system of
 *  which this file is a part is available on the World-Wide Web
 *  at: http://www.cornfed.com.
 *
 */

#include <errno.h>
#include <fs.h>
#include <net/tcp.h>
#if _DEBUG
#include <stdio.h>
#endif
#include <stdlib.h>
#include <sys/intr.h>
#include <sys/socket.h>

int
accept(int s, struct sockaddr *addr, int *addrlen)
{
    socket_t socket;
    tcb_t tcb;

    if (s < 0 || s >= FILES)
	return EINVAL;

    if (filetab[s].type != FT_SOCKET)
	return ENOTSOCK;

    socket = (socket_t) filetab[s].data;
    if (socket->state != SS_LISTEN) {
#if _DEBUG
	kprintf("accept: socket not listening\n");
#endif
	return EBADF;
    }
    disable;

    /* Allocate and link a TCP control block to the socket */
    tcb = tcb_alloc(TCPS_LISTEN);
    if (tcb == NULL) {
	enable;
	return EAGAIN;
    }
    socket->pcb = tcb;
    tcb->socket = socket;
    tcb->rcv_wnd = RCV_WND;

    /* Place the thread in socket connection queue */
    current->state = PS_SOCKET;
    insq(current, &(socket->conn));
    proc_transfer();		       /* enables interrupts */

    return 0;
}