1 //===-- Linux implementation of recvmsg -----------------------------------===// 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/recvmsg.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/ssize_t.h" 15 #include "hdr/types/struct_msghdr.h" 16 #include "src/__support/OSUtil/syscall.h" // For internal syscall function. 17 #include "src/__support/common.h" 18 #include "src/__support/macros/sanitizer.h" 19 #include "src/errno/libc_errno.h" 20 21 namespace LIBC_NAMESPACE_DECL { 22 23 LLVM_LIBC_FUNCTION(ssize_t, recvmsg, (int sockfd, msghdr *msg, int flags)) { 24 #ifdef SYS_recvmsg 25 ssize_t ret = 26 LIBC_NAMESPACE::syscall_impl<ssize_t>(SYS_recvmsg, sockfd, msg, flags); 27 #elif defined(SYS_socketcall) 28 unsigned long sockcall_args[3] = {static_cast<unsigned long>(sockfd), 29 reinterpret_cast<unsigned long>(msg), 30 static_cast<unsigned long>(flags)}; 31 ssize_t ret = LIBC_NAMESPACE::syscall_impl<ssize_t>( 32 SYS_socketcall, SYS_RECVMSG, sockcall_args); 33 #else 34 #error "socket and socketcall syscalls unavailable for this platform." 35 #endif 36 if (ret < 0) { 37 libc_errno = static_cast<int>(-ret); 38 return -1; 39 } 40 41 // Unpoison the msghdr, as well as all its components. 42 MSAN_UNPOISON(msg, sizeof(msghdr)); 43 MSAN_UNPOISON(msg->msg_name, msg->msg_namelen); 44 45 for (size_t i = 0; i < msg->msg_iovlen; ++i) { 46 MSAN_UNPOISON(msg->msg_iov[i].iov_base, msg->msg_iov[i].iov_len); 47 } 48 MSAN_UNPOISON(msg->msg_control, msg->msg_controllen); 49 50 return ret; 51 } 52 53 } // namespace LIBC_NAMESPACE_DECL 54