1//===-- Linux implementation of recv --------------------------------------===//
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/socket/recv.h"
10
11#include <linux/net.h> // For SYS_SOCKET socketcall number.
12#include <sys/syscall.h> // For syscall numbers.
13
14#include "hdr/types/socklen_t.h"
15#include "hdr/types/ssize_t.h"
16#include "hdr/types/struct_sockaddr.h"
17#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
18#include "src/__support/common.h"
19#include "src/__support/libc_errno.h"
20#include "src/__support/macros/sanitizer.h"
21
22namespace LIBC_NAMESPACE_DECL {
23
24LLVM_LIBC_FUNCTION(ssize_t, recv,
25 (int sockfd, void *buf, size_t len, int flags)) {
26#ifdef SYS_recv
27 ssize_t ret =
28 LIBC_NAMESPACE::syscall_impl<ssize_t>(SYS_recv, sockfd, buf, len, flags);
29#elif defined(SYS_recvfrom)
30 ssize_t ret = LIBC_NAMESPACE::syscall_impl<ssize_t>(
31 SYS_recvfrom, sockfd, buf, len, flags, nullptr, nullptr);
32#elif defined(SYS_socketcall)
33 unsigned long sockcall_args[4] = {
34 static_cast<unsigned long>(sockfd), reinterpret_cast<unsigned long>(buf),
35 static_cast<unsigned long>(len), static_cast<unsigned long>(flags)};
36 ssize_t ret = LIBC_NAMESPACE::syscall_impl<ssize_t>(SYS_socketcall, SYS_RECV,
37 sockcall_args);
38#else
39#error "socket and socketcall syscalls unavailable for this platform."
40#endif
41 if (ret < 0) {
42 libc_errno = static_cast<int>(-ret);
43 return -1;
44 }
45
46 MSAN_UNPOISON(buf, ret);
47
48 return ret;
49}
50
51} // namespace LIBC_NAMESPACE_DECL
52

source code of libc/src/sys/socket/linux/recv.cpp