Fixed wrong timestamp under Free- and OpenBSD and macOS over configur…

…e.ac

configure.ac

@@ -6,6 +6,21 @@ AC_PREREQ(2.59)
 AC_INIT([fping],[5.0])
 AC_GNU_SOURCE
 
+AC_CANONICAL_HOST
+only_clock_realtime=no
+
+case "${host_os}" in
+	darwin*)
+		only_clock_realtime=yes
+		;;
+	*freebsd*)
+		only_clock_realtime=yes
+		;;
+	*openbsd*)
+		only_clock_realtime=yes
+		;;
+esac
+
 dnl --disable-ipv4
 AC_ARG_ENABLE([ipv4],
   AS_HELP_STRING([--disable-ipv4], [Disable support for pinging IPv4 hosts]))
@@ -43,6 +58,7 @@ dnl Test if --enable-timestamp is explicitely enabled and make an error if this
 AS_IF([test "x$enable_timestamp" = "xyes" -a "x$have_so_timestamp" = "xno"], [
   AC_MSG_ERROR([--enable-timestamp not supported on this platform])
 ])
+AS_IF([test "x$only_clock_realtime" = "xyes"], [AC_DEFINE(ONLY_CLOCK_REALTIME, [1], [ONLY_CLOCK_REALTIME is defined])])
 
 AC_ARG_ENABLE([safe-limits],
   AS_HELP_STRING([--enable-safe-limits], [Restrict timing parameters (-i, -p) within "safe" limits]))

src/fping.c

@@ -118,7 +118,7 @@ extern int h_errno;
 
 /*** Constants ***/
 
-#if HAVE_SO_TIMESTAMPNS
+#if HAVE_SO_TIMESTAMPNS ^ ONLY_CLOCK_REALTIME
 #define CLOCKID CLOCK_REALTIME
 #endif