/****************************************************************************
* fs/vfs/fs_fcntl.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdarg.h>
#include <fcntl.h>
#include <errno.h>
#include <assert.h>
#include <sys/ioctl.h>
#include <nuttx/sched.h>
#include <nuttx/cancelpt.h>
#include <nuttx/fs/fs.h>
#include "inode/inode.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: file_vfcntl
****************************************************************************/
static int file_vfcntl(FAR struct file *filep, int cmd, va_list ap)
{
int ret = -EINVAL;
/* Was this file opened ? */
if (!filep->f_inode)
{
return -EBADF;
}
switch (cmd)
{
case F_DUPFD:
/* Return a new file descriptor which shall be the lowest numbered
* available (that is, not already open) file descriptor greater than
* or equal to the third argument, arg, taken as an integer of type
* int. The new file descriptor shall refer to the same open file
* description as the original file descriptor, and shall share any
* locks. The FD_CLOEXEC flag associated with the new file
* descriptor shall be cleared to keep the file open across calls to
* one of the exec functions.
*/
{
/* Does not set the errno variable in the event of a failure */
ret = file_dup(filep, va_arg(ap, int));
}
break;
case F_GETFD:
/* Get the file descriptor flags defined in <fcntl.h> that are
* associated with the file descriptor fd. File descriptor flags are
* associated with a single file descriptor and do not affect other
* file descriptors that refer to the same file.
*/
{
ret = filep->f_oflags & O_CLOEXEC ? FD_CLOEXEC : 0;
}
break;
case F_SETFD:
/* Set the file descriptor flags defined in <fcntl.h>, that are
* associated with fd, to the third argument, arg, taken as type int.
* If the FD_CLOEXEC flag in the third argument is 0, the file shall
* remain open across the exec functions; otherwise, the file shall
* be closed upon successful execution of one of the exec functions.
*/
{
int oflags = va_arg(ap, int);
if (oflags & ~FD_CLOEXEC)
{
ret = -ENOSYS;
break;
}
if (oflags & FD_CLOEXEC)
{
ret = file_ioctl(filep, FIOCLEX, NULL);
}
else
{
ret = file_ioctl(filep, FIONCLEX, NULL);
}
}
break;
case F_GETFL:
/* Get the file status flags and file access modes, defined in
* <fcntl.h>, for the file description associated with fd. The file
* access modes can be extracted from the return value using the
* mask O_ACCMODE, which is defined in <fcntl.h>. File status flags
* and file access modes are associated with the file description
* and do not affect other file descriptors that refer to the same
* file with different open file descriptions.
*/
{
ret = filep->f_oflags;
}
break;
case F_SETFL:
/* Set the file status flags, defined in <fcntl.h>, for the file
* description associated with fd from the corresponding bits in
* the third argument, arg, taken as type int. Bits corresponding
* to the file access mode and the file creation flags, as defined
* in <fcntl.h>, that are set in arg shall be ignored. If any bits
* in arg other than those mentioned here are changed by the
* application, the result is unspecified.
*/
{
int oflags = va_arg(ap, int);
int nonblock = !!(oflags & O_NONBLOCK);
ret = file_ioctl(filep, FIONBIO, &nonblock);
if (ret == OK)
{
oflags &= (FFCNTL & ~O_NONBLOCK);
filep->f_oflags &= ~(FFCNTL & ~O_NONBLOCK);
filep->f_oflags |= oflags;
if ((filep->f_oflags & O_APPEND) != 0)
{
file_seek(filep, 0, SEEK_END);
}
}
}
break;
case F_GETOWN:
/* If fd refers to a socket, get the process or process group ID
* specified to receive SIGURG signals when out-of-band data is
* available. Positive values indicate a process ID; negative
* values, other than -1, indicate a process group ID. If fd does
* not refer to a socket, the results are unspecified.
*/
case F_SETOWN:
/* If fd refers to a socket, set the process or process group ID
* specified to receive SIGURG signals when out-of-band data is
* available, using the value of the third argument, arg, taken as
* type int. Positive values indicate a process ID; negative values,
* other than -1, indicate a process group ID. If fd does not refer
* to a socket, the results are unspecified.
*/
ret = -EBADF; /* Only valid on socket descriptors */
break;
case F_GETLK:
/* Get the first lock which blocks the lock description pointed to
* by the third argument, arg, taken as a pointer to type struct
* flock, defined in <fcntl.h>. The information retrieved shall
* overwrite the information passed to fcntl() in the structure
* flock. If no lock is found that would prevent this lock from
* being created, then the structure shall be left unchanged except
* for the lock type which shall be set to F_UNLCK.
*/
case F_SETLK:
/* Set or clear a file segment lock according to the lock
* description pointed to by the third argument, arg, taken as a
* pointer to type struct flock, defined in <fcntl.h>. F_SETLK can
* establish shared (or read) locks (F_RDLCK) or exclusive (or
* write) locks (F_WRLCK), as well as to remove either type of lock
* (F_UNLCK). F_RDLCK, F_WRLCK, and F_UNLCK are defined in
* <fcntl.h>. If a shared or exclusive lock cannot be set, fcntl()
* shall return immediately with a return value of -1.
*/
case F_SETLKW:
/* This command shall be equivalent to F_SETLK except that if a
* shared or exclusive lock is blocked by other locks, the thread
* shall wait until the request can be satisfied. If a signal that
* is to be caught is received while fcntl() is waiting for a
* region, fcntl() shall be interrupted. Upon return from the signal
* handler, fcntl() shall return -1 with errno set to [EINTR], and
* the lock operation shall not be done.
*/
ret = -ENOSYS; /* Not implemented */
break;
case F_GETPATH:
/* Get the path of the file descriptor. The argument must be a buffer
* of size PATH_MAX or greater.
*/
{
ret = file_ioctl(filep, FIOC_FILEPATH, va_arg(ap, FAR char *));
}
default:
break;
}
return ret;
}
/****************************************************************************
* Name: nx_vfcntl
****************************************************************************/
static int nx_vfcntl(int fd, int cmd, va_list ap)
{
FAR struct file *filep;
int ret;
/* Get the file structure corresponding to the file descriptor. */
ret = fs_getfilep(fd, &filep);
if (ret >= 0)
{
DEBUGASSERT(filep != NULL);
/* Let file_vfcntl() do the real work. The errno is not set on
* failures.
*/
ret = file_vfcntl(filep, cmd, ap);
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: file_fcntl
*
* Description:
* Similar to the standard fcntl function except that is accepts a struct
* struct file instance instead of a file descriptor.
*
* Input Parameters:
* filep - Instance for struct file for the opened file.
* cmd - Identifies the operation to be performed. Command specific
* arguments may follow.
*
* Returned Value:
* The nature of the return value depends on the command. Non-negative
* values indicate success. Failures are reported as negated errno
* values.
*
****************************************************************************/
int file_fcntl(FAR struct file *filep, int cmd, ...)
{
va_list ap;
int ret;
/* Setup to access the variable argument list */
va_start(ap, cmd);
/* Let file_vfcntl() do the real work. The errno is not set on
* failures.
*/
ret = file_vfcntl(filep, cmd, ap);
va_end(ap);
return ret;
}
/****************************************************************************
* Name: nx_fcntl
*
* Description:
* nx_fcntl() is similar to the standard 'fcntl' interface except that is
* not a cancellation point and it does not modify the errno variable.
*
* nx_fcntl() is an internal NuttX interface and should not be called
* from applications.
*
* Returned Value:
* Returns a non-negative number on success; A negated errno value is
* returned on any failure (see comments fcntl() for a list of appropriate
* errno values).
*
****************************************************************************/
int nx_fcntl(int fd, int cmd, ...)
{
va_list ap;
int ret;
/* Setup to access the variable argument list */
va_start(ap, cmd);
/* Let nx_vfcntl() do the real work. The errno is not set on
* failures.
*/
ret = nx_vfcntl(fd, cmd, ap);
va_end(ap);
return ret;
}
/****************************************************************************
* Name: fcntl
*
* Description:
* fcntl() will perform the operation specified by 'cmd' on an open file.
*
* Input Parameters:
* fd - File descriptor of the open file
* cmd - Identifies the operation to be performed. Command specific
* arguments may follow.
*
* Returned Value:
* The returned value depends on the nature of the command but for all
* commands the return value of -1 (ERROR) indicates that an error has
* occurred and, in this case, the errno variable will be set
* appropriately
*
****************************************************************************/
int fcntl(int fd, int cmd, ...)
{
va_list ap;
int ret;
/* fcntl() is a cancellation point */
enter_cancellation_point();
/* Setup to access the variable argument list */
va_start(ap, cmd);
/* Let nx_vfcntl() do the real work. The errno is not set on
* failures.
*/
ret = nx_vfcntl(fd, cmd, ap);
va_end(ap);
if (ret < 0)
{
set_errno(-ret);
ret = ERROR;
}
leave_cancellation_point();
return ret;
}