New upstream version 2.4~beta1upstream/2.4_beta1

1 files changed, 198 insertions, 0 deletions

diff --git a/src/openvpn/comp.h b/src/openvpn/comp.h
new file mode 100644
index 0000000..9ed9532
--- /dev/null
+++ b/src/openvpn/comp.h
@@ -0,0 +1,198 @@
+/*
+ *  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) 2002-2012 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
+ */
+
+/*
+ * Generic compression support.  Currently we support
+ * LZO 2 and LZ4.
+ */
+#ifndef OPENVPN_COMP_H
+#define OPENVPN_COMP_H
+
+#ifdef USE_COMP
+
+#include "buffer.h"
+#include "mtu.h"
+#include "common.h"
+#include "status.h"
+
+/* algorithms */
+#define COMP_ALG_UNDEF  0
+#define COMP_ALG_STUB   1 /* support compression command byte and framing without actual compression */
+#define COMP_ALG_LZO    2 /* LZO algorithm */
+#define COMP_ALG_SNAPPY 3 /* Snappy algorithm (no longer supported) */
+#define COMP_ALG_LZ4    4 /* LZ4 algorithm */
+
+
+/* algorithm v2 */
+#define COMP_ALGV2_UNCOMPRESSED 10
+#define COMP_ALGV2_LZ4	    11
+/*
+#define COMP_ALGV2_LZO	    12
+#define COMP_ALGV2_SNAPPY   13
+*/
+
+/* Compression flags */
+#define COMP_F_ADAPTIVE   (1<<0) /* COMP_ALG_LZO only */
+#define COMP_F_ASYM       (1<<1) /* only downlink is compressed, not uplink */
+#define COMP_F_SWAP       (1<<2) /* initial command byte is swapped with last byte in buffer to preserve payload alignment */
+#define COMP_F_ADVERTISE_STUBS_ONLY (1<<3) /* tell server that we only support compression stubs */
+
+
+/*
+ * Length of prepended prefix on compressed packets
+ */
+#define COMP_PREFIX_LEN 1
+
+/*
+ * Prefix bytes
+ */
+
+/* V1 on wire codes */
+/* Initial command byte to tell our peer if we compressed */
+#define LZO_COMPRESS_BYTE 0x66
+#define LZ4_COMPRESS_BYTE 0x69
+#define NO_COMPRESS_BYTE      0xFA
+#define NO_COMPRESS_BYTE_SWAP 0xFB /* to maintain payload alignment, replace this byte with last byte of packet */
+
+/* V2 on wire code */
+#define COMP_ALGV2_INDICATOR_BYTE	0x50
+#define COMP_ALGV2_UNCOMPRESSED_BYTE	0
+#define COMP_ALGV2_LZ4_BYTE		1
+#define COMP_ALGV2_LZO_BYTE		2
+#define COMP_ALGV2_SNAPPY_BYTE		3
+
+/*
+ * Compress worst case size expansion (for any algorithm)
+ *
+ * LZO:    len + len/8 + 128 + 3
+ * Snappy: len + len/6 + 32
+ * LZ4:    len + len/255 + 16  (LZ4_COMPRESSBOUND(len))
+ */
+#define COMP_EXTRA_BUFFER(len) ((len)/6 + 128 + 3 + COMP_PREFIX_LEN)
+
+/*
+ * Don't try to compress any packet smaller than this.
+ */
+#define COMPRESS_THRESHOLD 100
+
+/* Forward declaration of compression context */
+struct compress_context;
+
+/*
+ * Virtual methods and other static info for each compression algorithm
+ */
+struct compress_alg
+{
+  const char *name;
+  void (*compress_init)(struct compress_context *compctx);
+  void (*compress_uninit)(struct compress_context *compctx);
+  void (*compress)(struct buffer *buf, struct buffer work,
+		   struct compress_context *compctx,
+		   const struct frame* frame);
+
+  void (*decompress)(struct buffer *buf, struct buffer work,
+		     struct compress_context *compctx,
+		     const struct frame* frame);
+};
+
+/*
+ * Headers for each compression implementation
+ */
+#ifdef ENABLE_LZO
+#include "lzo.h"
+#endif
+
+#ifdef ENABLE_LZ4
+#include "comp-lz4.h"
+#endif
+
+/*
+ * Information that basically identifies a compression
+ * algorithm and related flags.
+ */
+struct compress_options
+{
+  int alg;
+  unsigned int flags;
+};
+
+/*
+ * Workspace union of all supported compression algorithms
+ */
+union compress_workspace_union
+{
+#ifdef ENABLE_LZO
+  struct lzo_compress_workspace lzo;
+#endif
+#ifdef ENABLE_LZ4
+  struct lz4_workspace lz4;
+#endif
+};
+
+/*
+ * Context for active compression session
+ */
+struct compress_context
+{
+  unsigned int flags;
+  struct compress_alg alg;
+  union compress_workspace_union wu;
+
+  /* statistics */
+  counter_type pre_decompress;
+  counter_type post_decompress;
+  counter_type pre_compress;
+  counter_type post_compress;
+};
+
+extern const struct compress_alg comp_stub_alg;
+extern const struct compress_alg compv2_stub_alg;
+
+struct compress_context *comp_init(const struct compress_options *opt);
+
+void comp_uninit(struct compress_context *compctx);
+
+void comp_add_to_extra_frame(struct frame *frame);
+void comp_add_to_extra_buffer(struct frame *frame);
+
+void comp_print_stats (const struct compress_context *compctx, struct status_output *so);
+
+void comp_generate_peer_info_string(const struct compress_options *opt, struct buffer *out);
+
+void compv2_escape_data_ifneeded (struct buffer *buf);
+
+static inline bool
+comp_enabled(const struct compress_options *info)
+{
+  return info->alg != COMP_ALG_UNDEF;
+}
+
+static inline bool
+comp_unswapped_prefix(const struct compress_options *info)
+{
+  return !(info->flags & COMP_F_SWAP);
+}
+
+#endif /* USE_COMP */
+#endif