openvpn/lzo.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

137 lines
3.8 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 OPENVPN_LZO_H
#define OPENVPN_LZO_H
#ifdef USE_LZO
#ifdef LZO_HEADER_DIR
#include "lzo/lzoutil.h"
#include "lzo/lzo1x.h"
#else
#include "lzoutil.h"
#include "lzo1x.h"
#endif
#include "buffer.h"
#include "mtu.h"
#include "common.h"
#include "status.h"
/* LZO flags */
#define LZO_SELECTED (1<<0)
#define LZO_ON (1<<1)
#define LZO_ADAPTIVE (1<<2)
/*
* Use LZO compress routine lzo1x_1_15_compress which is described
* as faster but needs a bit more memory than the standard routine.
* Use safe decompress (i.e. check for buffer overflows).
* You may want to use the non-safe version
* of decompress if speed is essential and if you know
* that you will always be using a MAC to verify the
* integrity of incoming packets.
*/
#define LZO_COMPRESS lzo1x_1_15_compress
#define LZO_WORKSPACE LZO1X_1_15_MEM_COMPRESS
#define LZO_DECOMPRESS lzo1x_decompress_safe
#define LZO_EXTRA_BUFFER(len) ((len)/8 + 128 + 3) /* LZO 2.0 worst case size expansion. */
/*
* Don't try to compress any packet smaller than this.
*/
#define COMPRESS_THRESHOLD 100
/*
* Length of prepended prefix on LZO packets
*/
#define LZO_PREFIX_LEN 1
/*
* Adaptive compress parameters
*/
#define AC_SAMP_SEC 2 /* number of seconds in sample period */
#define AC_MIN_BYTES 1000 /* sample period must have at least n bytes
to be valid for testing */
#define AC_SAVE_PCT 5 /* turn off compress if we didn't save at
least this % during sample period */
#define AC_OFF_SEC 60 /* if we turn off compression, don't do sample
retest for n seconds */
struct lzo_adaptive_compress {
bool compress_state;
time_t next;
int n_total;
int n_comp;
};
/*
* Compress and Uncompress routines.
*/
struct lzo_compress_workspace
{
lzo_voidp wmem;
int wmem_size;
struct lzo_adaptive_compress ac;
unsigned int flags;
bool defined;
/* statistics */
counter_type pre_decompress;
counter_type post_decompress;
counter_type pre_compress;
counter_type post_compress;
};
void lzo_adjust_frame_parameters(struct frame *frame);
void lzo_compress_init (struct lzo_compress_workspace *lzowork, unsigned int flags);
void lzo_compress_uninit (struct lzo_compress_workspace *lzowork);
void lzo_modify_flags (struct lzo_compress_workspace *lzowork, unsigned int flags);
void lzo_compress (struct buffer *buf, struct buffer work,
struct lzo_compress_workspace *lzowork,
const struct frame* frame);
void lzo_decompress (struct buffer *buf, struct buffer work,
struct lzo_compress_workspace *lzowork,
const struct frame* frame);
void lzo_print_stats (const struct lzo_compress_workspace *lzo_compwork, struct status_output *so);
static inline bool
lzo_defined (const struct lzo_compress_workspace *lzowork)
{
return lzowork->defined;
}
#endif /* USE_LZO */
#endif