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/* Copyright (C) 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library 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. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#include "utmpd-private.h"
/* Prototypes for the local functions. */
static client_connection *alloc_connection (void);
static void free_connection (client_connection *connection);
static int set_nonblock_flag (int desc, int value);
/* The head of the connection list. */
static client_connection *connection_list = NULL;
/* Accept connection on SOCK, with access permissions given by ACCESS.
Returns a pointer to a newly allocated client_connection if
successful, NULL if not. */
client_connection *
accept_connection (int sock, int access)
{
client_connection *connection;
connection = alloc_connection ();
if (connection == NULL)
return NULL;
connection->sock = accept (sock, NULL, NULL);
connection->access = access;
if (connection->sock < 0)
{
free_connection (connection);
return NULL;
}
if (set_nonblock_flag (connection->sock, 1) < 0)
{
close_connection (connection);
return NULL;
}
return connection;
}
/* Close CONNECTION. */
void
close_connection (client_connection *connection)
{
close (connection->sock);
free_connection (connection);
}
/* Return the connection for SOCK. */
client_connection *
find_connection (int sock)
{
client_connection *connection;
for (connection = connection_list; connection;
connection = connection->next)
{
if (connection->sock == sock)
return connection;
}
return NULL;
}
static client_connection *
alloc_connection (void)
{
client_connection *connection;
size_t read_bufsize = 1024;
size_t write_bufsize = 1024;
connection = (client_connection *)malloc (sizeof (client_connection));
if (connection == NULL)
return NULL;
memset (connection, 0, sizeof (client_connection));
/* Allocate read buffer. */
connection->read_base = malloc (read_bufsize);
connection->read_ptr = connection->read_base;
connection->read_end = connection->read_base + read_bufsize;
if (connection->read_base == NULL)
{
free (connection);
return NULL;
}
/* Allocate write buffer. */
connection->write_base = malloc (write_bufsize);
connection->write_ptr = connection->write_base;
connection->write_end = connection->write_base + write_bufsize;
if (connection->write_base == NULL)
{
free (connection->read_base);
free (connection);
return NULL;
}
/* Link connection. */
connection->next = connection_list;
connection_list = connection;
if (connection->next)
connection->next->prev = connection;
return connection;
}
static void
free_connection (client_connection *connection)
{
/* Unlink connection. */
if (connection->next)
connection->next->prev = connection->prev;
if (connection->prev)
connection->prev->next = connection->next;
/* Take care of the head of the list. */
if (connection == connection_list)
connection_list = connection->next;
/* Free buffers. */
if (connection->read_base)
free (connection->read_base);
if (connection->write_base)
free (connection->write_base);
free (connection);
}
/* Set the `O_NONBLOCK' flag of DESC if VALUE is nonzero,
or clear the flag if VALUE is 0.
Return 0 on success, or -1 on error with `errno' set. */
static int
set_nonblock_flag (int desc, int value)
{
int oldflags = fcntl (desc, F_GETFL, 0);
/* If reading the flags failed, return error indication now. */
if (oldflags == -1)
return -1;
/* Set just the flag we want to set. */
if (value != 0)
oldflags |= O_NONBLOCK;
else
oldflags &= ~O_NONBLOCK;
/* Store modified flag word in the descriptor. */
return fcntl (desc, F_SETFL, oldflags);
}
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