1  /* Return whether socket supports 64-bit timestamps.
       2     Copyright (C) 2022-2023 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
      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  }