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/macros/sanitizer.h" 20 #include "src/errno/libc_errno.h" 21 22 namespace LIBC_NAMESPACE_DECL { 23 24 LLVM_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