uclibc-ng/libc/sysdeps/linux/common/sendfile.c

/*
 * sendfile() for uClibc
 *
 * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
 *
 * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
 */

#include <sys/syscall.h>

# include <sys/sendfile.h>
# include <bits/wordsize.h>

#if defined __NR_sendfile
_syscall4(ssize_t, sendfile, int, out_fd, int, in_fd, __off_t *, offset,
	  size_t, count)
# if !defined __NR_sendfile64 || __WORDSIZE == 64
libc_hidden_def(sendfile64)
strong_alias_untyped(sendfile,sendfile64)
# endif

#elif defined __NR_sendfile64 && !defined __NR_sendfile
# include <unistd.h>
# include <stddef.h>

ssize_t sendfile(int out_fd, int in_fd, __off_t *offset, size_t count)
{
	__off64_t off64, *off;
	ssize_t res;

	/*
	 * Check if valid fds and valid pointers were passed
	 * This does not prevent the user from passing
	 * an arbitrary pointer causing a segfault or
	 * other security issues
	 */

	if (in_fd < 0 || out_fd < 0) {
		__set_errno(EBADF);
		return -1;
	}

	if ((int)offset < 0) {
		__set_errno(EFAULT);
		return -1;
	}

	if (offset) {
		off = &off64;
		off64 = *offset;
	} else {
		off = NULL;
	}

	res = INLINE_SYSCALL(sendfile64, 4, out_fd, in_fd, off, count);

	if (res >= 0 && offset != NULL)
		*offset = off64;

	return res;
}

#endif