1//===-- Linux implementation of sendfile ----------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "src/sys/sendfile/sendfile.h"
10
11#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
12#include "src/__support/common.h"
13
14#include "src/__support/libc_errno.h"
15#include "src/__support/macros/config.h"
16#include <sys/sendfile.h>
17#include <sys/syscall.h> // For syscall numbers.
18
19namespace LIBC_NAMESPACE_DECL {
20
21LLVM_LIBC_FUNCTION(ssize_t, sendfile,
22 (int out_fd, int in_fd, off_t *offset, size_t count)) {
23#ifdef SYS_sendfile
24 ssize_t ret = LIBC_NAMESPACE::syscall_impl<ssize_t>(SYS_sendfile, in_fd,
25 out_fd, offset, count);
26#elif defined(SYS_sendfile64)
27 // Same as sendfile but can handle large offsets
28 static_assert(sizeof(off_t) == 8);
29 ssize_t ret = LIBC_NAMESPACE::syscall_impl<ssize_t>(SYS_sendfile64, in_fd,
30 out_fd, offset, count);
31#else
32#error "sendfile and sendfile64 syscalls not available."
33#endif
34 if (ret < 0) {
35 libc_errno = static_cast<int>(-ret);
36 return -1;
37 }
38 return ret;
39}
40
41} // namespace LIBC_NAMESPACE_DECL
42

source code of libc/src/sys/sendfile/linux/sendfile.cpp