openvpn/integer.h
james 367ed084db Copyright notice changed to reflect change in name of
Telethra to OpenVPN Technologies.


git-svn-id: http://svn.openvpn.net/projects/openvpn/branches/BETA21/openvpn@3409 e7ae566f-a301-0410-adde-c780ea21d3b5
2008-10-06 07:33:45 +00:00

115 lines
2.5 KiB
C

/*
* 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) 2002-2008 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
*/
#ifndef INTEGER_H
#define INTEGER_H
#include "error.h"
/*
* min/max functions
*/
static inline int
max_int (int x, int y)
{
if (x > y)
return x;
else
return y;
}
static inline int
min_int (int x, int y)
{
if (x < y)
return x;
else
return y;
}
static inline int
constrain_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;
}
/*
* 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 int
modulo_subtract(int x, int y, int mod)
{
const int d1 = x - y;
const int d2 = (x > y ? -mod : mod) + d1;
ASSERT (0 <= x && x < mod && 0 <= y && y < mod);
return abs(d1) > abs(d2) ? d2 : d1;
}
/*
* Return x + y on a circle of circumference mod.
*
* 0 <= x < mod
* -mod <= y <= mod
*/
static inline int
modulo_add(int x, int y, int mod)
{
int sum = x + y;
ASSERT (0 <= x && x < mod && -mod <= y && y <= mod);
if (sum >= mod)
sum -= mod;
if (sum < 0)
sum += mod;
return sum;
}
static inline int
index_verify (int index, int size, const char *file, int line)
{
if (index < 0 || index >= size)
msg (M_FATAL, "Assertion Failed: Array index=%d out of bounds for array size=%d in %s:%d",
index,
size,
file,
line);
return index;
}
#endif