1 files changed, 131 insertions, 0 deletions
diff --git a/openvpn/src/compat/compat-gettimeofday.c b/openvpn/src/compat/compat-gettimeofday.c
new file mode 100644
index 00000000..0f32d5d1
--- /dev/null
+++ b/openvpn/src/compat/compat-gettimeofday.c
@@ -0,0 +1,131 @@
+/*
+ *  OpenVPN -- An application to securely tunnel IP networks
+ *             over a single UDP port, with support for SSL/TLS-based
+ *             session authentication and key exchange,
+ *             packet encryption, packet authentication, and
+ *             packet compression.
+ *
+ *  Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program (see the file COPYING included with this
+ *  distribution); if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#ifndef HAVE_GETTIMEOFDAY
+
+#include "compat.h"
+
+#ifdef WIN32
+/*
+ * NOTICE: mingw has much faster gettimeofday!
+ * autoconf will set HAVE_GETTIMEOFDAY
+ */
+
+#include <windows.h>
+#include <time.h>
+
+static time_t gtc_base = 0;
+static DWORD gtc_last = 0;
+static time_t last_sec = 0;
+static unsigned int last_msec = 0;
+static int bt_last = 0;
+
+static void
+gettimeofday_calibrate (void)
+{
+  const time_t t = time(NULL);
+  const DWORD gtc = GetTickCount();
+  gtc_base = t - gtc/1000;
+  gtc_last = gtc;
+}
+
+/*
+ * Rewritten by JY for OpenVPN 2.1, after I realized that
+ * QueryPerformanceCounter takes nearly 2 orders of magnitude
+ * more processor cycles than GetTickCount.
+ */
+int
+gettimeofday (struct timeval *tv, void *tz)
+{
+  const DWORD gtc = GetTickCount();
+  int bt = 0;
+  time_t sec;
+  unsigned int msec;
+  const int backtrack_hold_seconds = 10;
+
+  (void)tz;
+
+  /* recalibrate at the dreaded 49.7 day mark */
+  if (!gtc_base || gtc < gtc_last)
+    gettimeofday_calibrate ();
+  gtc_last = gtc;
+
+  sec = gtc_base + gtc / 1000;
+  msec = gtc % 1000;
+
+  if (sec == last_sec)
+    {
+      if (msec < last_msec)
+	{
+	  msec = last_msec;
+	  bt = 1;
+	}
+    }
+  else if (sec < last_sec)
+    {
+      /* We try to dampen out backtracks of less than backtrack_hold_seconds.
+	 Larger backtracks will be passed through and dealt with by the
+	 TIME_BACKTRACK_PROTECTION code (if enabled) */
+      if (sec > last_sec - backtrack_hold_seconds)
+	{
+	  sec = last_sec;
+	  msec = last_msec;
+	}
+      bt = 1;
+    }
+
+  tv->tv_sec = (long)last_sec = (long)sec;
+  tv->tv_usec = (last_msec = msec) * 1000;
+
+  if (bt && !bt_last)
+    gettimeofday_calibrate ();
+  bt_last = bt;
+
+  return 0;
+}
+
+#else
+
+#ifdef HAVE_TIME_H
+#include <time.h>
+#endif
+
+int
+gettimeofday (struct timeval *tv, void *tz)
+{
+	(void)tz;
+	tv->tv_sec = time(NULL);
+	tv->tv_usec = 0;
+	return 0;
+}
+
+#endif /* WIN32 */
+
+#endif /* HAVE_GETTIMEOFDAY */