1 /* Return whether socket supports 64-bit timestamps.
2    Copyright (C) 2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #include <errno.h>
20 #include <unistd.h>
21 #include <sys/syscall.h>
22 #include <sys/socket.h>
23 #include <support/support.h>
24 #ifdef __linux__
25 # include <socket-constants-time64.h>
26 #endif
27 
28 bool
support_socket_so_timestamp_time64(int fd)29 support_socket_so_timestamp_time64 (int fd)
30 {
31 #ifdef __linux__
32 # if __LINUX_KERNEL_VERSION >= 0x050100                          \
33    || __WORDSIZE == 64                                           \
34    || (defined __SYSCALL_WORDSIZE && __SYSCALL_WORDSIZE == 64)
35   return true;
36 # else
37   int level = SOL_SOCKET;
38   int optname = COMPAT_SO_TIMESTAMP_NEW;
39   int optval;
40   socklen_t len = sizeof (optval);
41 
42   int r = syscall (__NR_getsockopt, fd, level, optname, &optval, &len);
43   return r != -1;
44 # endif
45 #else
46   return false;
47 #endif
48 }
49