/************************************************************************
* fs/vfs/fs_sendfile.c
*
* Copyright (C) 2007, 2009, 2011, 2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 NuttX 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 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.
*
************************************************************************/
/************************************************************************
* Included Files
************************************************************************/
#include <nuttx/config.h>
#include <sys/sendfile.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <assert.h>
#include <nuttx/sched.h>
#include <nuttx/net/net.h>
#if CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_NET_SENDFILE
/************************************************************************
* Private types
************************************************************************/
/************************************************************************
* Private Variables
************************************************************************/
/************************************************************************
* Public Variables
************************************************************************/
/************************************************************************
* Private Functions
************************************************************************/
/************************************************************************
* Public Functions
************************************************************************/
/************************************************************************
* Name: sendfile
*
* Description:
* sendfile() copies data between one file descriptor and another.
* Used with file descriptors it basically just wraps a sequence of
* reads() and writes() to perform a copy.
*
* If the destination descriptor is a socket, it gives a better
* performance than simple reds() and writes(). The data is read directly
* into the net buffer and the whole tcp window is filled if possible.
*
* NOTE: This interface is *not* specified in POSIX.1-2001, or other
* standards. The implementation here is very similar to the Linux
* sendfile interface. Other UNIX systems implement sendfile() with
* different semantics and prototypes. sendfile() should not be used
* in portable programs.
*
* Input Parmeters:
* infd - A file (or socket) descriptor opened for reading
* outfd - A descriptor opened for writing.
* offset - If 'offset' is not NULL, then it points to a variable
* holding the file offset from which sendfile() will start
* reading data from 'infd'. When sendfile() returns, this
* variable will be set to the offset of the byte following
* the last byte that was read. If 'offset' is not NULL,
* then sendfile() does not modify the current file offset of
* 'infd'; otherwise the current file offset is adjusted to
* reflect the number of bytes read from 'infd.'
*
* If 'offset' is NULL, then data will be read from 'infd'
* starting at the current file offset, and the file offset
* will be updated by the call.
* count - The number of bytes to copy between the file descriptors.
*
* Returned Value:
* If the transfer was successful, the number of bytes written to outfd is
* returned. On error, -1 is returned, and errno is set appropriately.
* There error values are those returned by read() or write() plus:
*
* EINVAL - Bad input parameters.
* ENOMEM - Could not allocated an I/O buffer
*
************************************************************************/
ssize_t sendfile(int outfd, int infd, off_t *offset, size_t count)
{
#if defined(CONFIG_NET_TCP) && CONFIG_NSOCKET_DESCRIPTORS > 0
/* Check the destination file descriptor: Is it a (probable) file
* descriptor? Check the source file: Is it a normal file?
*/
if ((unsigned int)outfd >= CONFIG_NFILE_DESCRIPTORS &&
(unsigned int)infd < CONFIG_NFILE_DESCRIPTORS)
{
FAR struct file *filep;
/* This appears to be a file-to-socket transfer. Get the file
* structure.
*/
filep = fs_getfilep(fd);
if (!filep)
{
/* The errno value has already been set */
return ERROR;
}
/* Then let net_sendfile do the work. */
return net_sendfile(outfd, filep, offset, count);
}
else
#endif
{
/* No... then this is probably a file-to-file transfer. The generic
* lib_sendfile() can handle that case.
*/
return lib_sendfile(outfd, infd, offset, count);
}
}
#endif /* CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_NET_SENDFILE */
