| /* |
| * 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) 2002-2018 OpenVPN 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; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 _WIN32 */ |
| |
| #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 */ |