support/support_socket_so_timestamp_time64.c

   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 }