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- /****************************************************************************
- * fs/vfs/fs_sendfile.c
- *
- * Copyright (C) 2007, 2009, 2011, 2013, 2017-2018 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>
- #ifdef CONFIG_NET_SENDFILE
- /****************************************************************************
- * 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 Parameters:
- * 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)
- {
- #ifdef CONFIG_NET_SENDFILE
- /* 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;
- int ret;
- /* This appears to be a file-to-socket transfer. Get the file
- * structure.
- */
- ret = fs_getfilep(infd, &filep);
- if (ret < 0)
- {
- set_errno(-ret);
- return ERROR;
- }
- DEBUGASSERT(filep != NULL);
- /* Then let net_sendfile do the work. */
- ret = net_sendfile(outfd, filep, offset, count);
- if (ret >= 0 || get_errno() != ENOSYS)
- {
- return ret;
- }
- /* Fall back to the slow path if errno equals ENOSYS,
- * because net_sendfile fail to optimize this transfer.
- */
- }
- #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_NET_SENDFILE */
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