/*
  *  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.

  */
 

 #ifndef OPENVPN_LZO_H
 #define OPENVPN_LZO_H
 

 
 /**
  * @file
  * Data Channel Compression module header file.
  */
 
 

 #if defined(ENABLE_LZO)

 /**
  * @addtogroup compression
  * @{
  */
 

 #if defined(HAVE_LZO_LZOUTIL_H)

 #include "lzo/lzoutil.h"

 #elif defined(HAVE_LZOUTIL_H)

 #include "lzoutil.h"

 #endif
 #if defined(HAVE_LZO_LZO1X_H)
 #include "lzo/lzo1x.h"
 #elif defined(HAVE_LZO1X_H)

 #include "lzo1x.h"
 #endif
 
 #include "buffer.h"
 #include "mtu.h"
 #include "common.h"
 #include "status.h"
 

 extern const struct compress_alg lzo_alg;

 /**************************************************************************/
 /** @name LZO library interface defines *//** @{ *//***********************/

 #define LZO_COMPRESS    lzo1x_1_15_compress

 /**< LZO library compression function.
  *
  *   Use \c lzo1x_1_15_compress because it
  *   is described as faster than the
  *   standard routine, although it does
  *   need a bit more memory. */
 #define LZO_WORKSPACE   LZO1X_1_15_MEM_COMPRESS
 /**< The size in bytes of the memory
  *   %buffer required by the LZO library
  *   compression algorithm. */

 #define LZO_DECOMPRESS  lzo1x_decompress_safe

 /**< LZO library decompression function.
  *
  *   Use safe decompress because it
  *   includes checks for possible %buffer
  *   overflows. If speed is essential and
  *   you will always be using a MAC to
  *   verify the integrity of incoming
  *   packets, you might want to consider
  *   using the non-safe version. */

 /** @} name LZO library interface *//**************************************/

 /**************************************************************************/
 /** @name Adaptive compression defines *//** @{ *//************************/
 #define AC_SAMP_SEC    2        /**< Number of seconds in a sample period. */
 #define AC_MIN_BYTES   1000     /**< Minimum number of bytes a sample
                                  *   period must contain for it to be
                                  *   evaluated. */
 #define AC_SAVE_PCT    5        /**< Minimum size reduction percentage
                                  *   below which compression will be
                                  *   turned off. */
 #define AC_OFF_SEC     60       /**< Seconds to wait after compression has
                                  *   been turned off before retesting. */
 /** @} name Adaptive compression defines *//*******************************/
 
 /**
  * Adaptive compression state.
  */

 struct lzo_adaptive_compress {

     bool compress_state;
     time_t next;
     int n_total;
     int n_comp;

 };
 
 

 /**
  * State for the compression and decompression routines.
  *
  * This structure contains compression module state, such as whether
  * compression is enabled and the status of the adaptive compression
  * routines.  It also contains an allocated working buffer.
  *
  * One of these compression workspace structures is maintained for each
  * VPN tunnel.
  */

 struct lzo_compress_workspace
 {

     lzo_voidp wmem;
     int wmem_size;
     struct lzo_adaptive_compress ac;

 };
 

 /** @} addtogroup compression */
 

 #endif /* ENABLE_LZO && USE_COMP */

 #endif /* ifndef OPENVPN_LZO_H */