amiga-clib2/library/fcntl_fcntl.c

/*
 * $Id: fcntl_fcntl.c,v 1.2 2004-08-07 09:15:32 obarthel Exp $
 *
 * :ts=4
 *
 * Portable ISO 'C' (1994) runtime library for the Amiga computer
 * Copyright (c) 2002-2004 by Olaf Barthel <olsen@sourcery.han.de>
 * 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.
 *
 *   - Neither the name of Olaf Barthel 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 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 _FCNTL_HEADERS_H
#include "fcntl_headers.h"
#endif /* _FCNTL_HEADERS_H */

/****************************************************************************/

/* The following is not part of the ISO 'C' (1994) standard. */

/****************************************************************************/

int
fcntl(int file_descriptor, int cmd, ... /* int arg */ )
{
	DECLARE_UTILITYBASE();
	struct file_hook_message message;
	struct flock * l;
	int result = -1;
	struct fd * fd;
	va_list arg;
	int flags;
	int fdbase;
	int i;

	ENTER();

	SHOWVALUE(file_descriptor);
	SHOWVALUE(cmd);

	assert( UtilityBase != NULL );

	assert( file_descriptor >= 0 && file_descriptor < __num_fd );
	assert( __fd[file_descriptor] != NULL );
	assert( FLAG_IS_SET(__fd[file_descriptor]->fd_Flags,FDF_IN_USE) );

	if(__check_abort_enabled)
		__check_abort();

	fd = __get_file_descriptor(file_descriptor);
	if(fd == NULL)
	{
		errno = EBADF;
		goto out;
	}

	switch(cmd)
	{
		case F_GETLK:
		case F_SETLK:
		case F_SETLKW:

			SHOWMSG("cmd=F_GETLK/F_SETLK/F_SETLKW");

			va_start(arg,cmd);

			l = va_arg(arg,struct flock *);

			assert( l != NULL );

			if(l->l_type < F_RDLCK || l->l_type > F_WRLCK)
			{
				SHOWMSG("invalid flock type");
				va_end(arg);

				errno = EINVAL;
				break;
			}

			if(l->l_whence < SEEK_SET || l->l_whence > SEEK_END)
			{
				SHOWMSG("invalid flock offset");
				va_end(arg);

				errno = EINVAL;
				break;
			}

			message.action	= file_hook_action_lock_record;
			message.lock	= l;
			message.command	= cmd;

			assert( fd->fd_Hook != NULL );

			CallHookPkt(fd->fd_Hook,fd,&message);

			result = message.result;
			errno = message.error;

			va_end(arg);

			break;

		case F_GETFL:

			SHOWMSG("cmd=F_GETFL");

			if(FLAG_IS_SET(fd->fd_Flags,FDF_NON_BLOCKING))
				result = O_NONBLOCK;
			else
				result = 0;

			break;

		case F_SETFL:

			SHOWMSG("cmd=F_SETFL");

			result = 0;

			va_start(arg,cmd);

			flags = va_arg(arg,int);

			if((FLAG_IS_SET(flags,O_NONBLOCK) && FLAG_IS_CLEAR(fd->fd_Flags,FDF_NON_BLOCKING)) ||
			   (FLAG_IS_CLEAR(flags,O_NONBLOCK) && FLAG_IS_SET(fd->fd_Flags,FDF_NON_BLOCKING)))
			{
				message.action	= file_hook_action_set_blocking;
				message.block	= FLAG_IS_CLEAR(flags,O_NONBLOCK);

				assert( fd->fd_Hook != NULL );

				CallHookPkt(fd->fd_Hook,fd,&message);

				result = message.result;
				if(result < 0)
				{
					errno = message.error;

					va_end(arg);
					goto out;
				}

				if(FLAG_IS_SET(flags,O_NONBLOCK))
					SET_FLAG(fd->fd_Flags,FDF_NON_BLOCKING);
				else
					CLEAR_FLAG(fd->fd_Flags,FDF_NON_BLOCKING);
			}

			va_end(arg);

			break;

		case F_DUPFD:

			SHOWMSG("cmd=F_DUPFD");
			
			va_start(arg, cmd);
			fdbase = va_arg(arg, int);
			va_end(arg);
			
			if(fdbase < 0)
			{
				errno = EINVAL;
				goto out;
			}
			
			/* Check if we have that many fd's already */
			while(fdbase >= __num_fd)
			{
				if(__check_abort_enabled)
					__check_abort();

				/* No; enlarge it */
				if(__grow_fd_table() < 0)
					goto out;
			}

			/* Guaranteed to have enough here */
			while(TRUE)
			{
				if(__check_abort_enabled)
					__check_abort();

				for(i = fdbase ; i < __num_fd ; i++)
				{
					if(FLAG_IS_CLEAR(__fd[i]->fd_Flags,FDF_IN_USE))
					{
						/* Got a file descriptor, duplicate it */
						message.action = file_hook_action_duplicate_fd;
						message.duplicate_fd = __fd[i];

						assert( fd->fd_Hook != NULL );

						CallHookPkt(fd->fd_Hook,fd,&message);

						/* If it worked, leave */
						if (message.result == 0)
						{
							result = i;
							goto out;
						}
					}
				}

				/* Didn't really find any, grow the table further */
				if (__grow_fd_table() < 0)
					goto out;
			}

			errno = EMFILE;
			break;		
			
		default:

			SHOWMSG("something else");

			errno = ENOSYS;
			break;
	}

 out:

	RETURN(result);
	return(result);
}