/* *  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) 2002-2003 James Yonan <jim@yonan.net> * *  This program is free software; you can redistribute it and/or modify *  it under the terms of the GNU General Public License as published by *  the Free Software Foundation; either version 2 of the License, or *  (at your option) any later version. * *  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 */#ifndef COMMON_H#define COMMON_H/* * Statistics counters. */typedef unsigned long counter_type;/* * Time intervals */typedef int interval_t;/* * Printf formats for special types */#define counter_format          "%10lu"#define ptr_format              "0x%08zx"#define time_format             "%lu"#define fragment_header_format  "0x%08x"/* these are used to cast the arguments * and MUST match the formats above */typedef unsigned long time_type;/* * Functions used for circular buffer index arithmetic. *//* * Return x - y on a circle of circumference mod by shortest path. * * 0 <= x < mod * 0 <= y < mod */static inline intmodulo_subtract(int x, int y, int mod){  const int d1 = x - y;  const int d2 = (x > y ? -mod : mod) + d1;  return abs(d1) > abs(d2) ? d2 : d1;}/* * Return x + y on a circle of circumference mod. * * 0 <= x < mod * -mod <= y <= mod */static inline intmodulo_add(int x, int y, int mod){  int sum = x + y;  if (sum >= mod)    sum -= mod;  if (sum < 0)    sum += mod;  return sum;}static inline intmax_int (int x, int y){  if (x > y)    return x;  else    return y;}static inline intmin_int (int x, int y){  if (x < y)    return x;  else    return y;}static inline intconstrain_int (int x, int min, int max){  if (min > max)    return min;  if (x < min)    return min;  else if (x > max)    return max;  else    return x;}#endif