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Diffstat (limited to 'lzo.h')
| -rw-r--r-- | lzo.h | 136 |
1 files changed, 136 insertions, 0 deletions
@@ -0,0 +1,136 @@ +/* + * 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) 2002-2010 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 |