Imported Upstream version 2.2.1upstream/2.2.1

1 files changed, 275 insertions, 0 deletions

diff --git a/lzo.c b/lzo.c
new file mode 100644
index 0000000..6ea0d03
--- /dev/null
+++ b/lzo.c
@@ -0,0 +1,275 @@
+/*
+ *  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
+ */
+
+#include "syshead.h"
+
+#ifdef USE_LZO
+
+#include "lzo.h"
+#include "error.h"
+#include "otime.h"
+
+#include "memdbg.h"
+
+static bool
+lzo_adaptive_compress_test (struct lzo_adaptive_compress *ac)
+{
+  const bool save = ac->compress_state;
+  const time_t local_now = now;
+
+  if (!ac->compress_state)
+    {
+      if (local_now >= ac->next)
+	{
+	  if (ac->n_total > AC_MIN_BYTES
+	      && (ac->n_total - ac->n_comp) < (ac->n_total / (100 / AC_SAVE_PCT)))
+	    {
+	      ac->compress_state = true;
+	      ac->next = local_now + AC_OFF_SEC;
+	    }
+	  else
+	    {
+	      ac->next = local_now + AC_SAMP_SEC;
+	    }
+	  dmsg (D_COMP, "lzo_adaptive_compress_test: comp=%d total=%d", ac->n_comp, ac->n_total);
+	  ac->n_total = ac->n_comp = 0;
+	}
+    }
+  else 
+    {
+      if (local_now >= ac->next)
+	{
+	  ac->next = local_now + AC_SAMP_SEC;
+	  ac->n_total = ac->n_comp = 0;
+	  ac->compress_state = false;
+	}
+    }
+
+  if (ac->compress_state != save)
+    dmsg (D_COMP_LOW, "Adaptive compression state %s", (ac->compress_state ? "OFF" : "ON"));
+
+  return !ac->compress_state;
+}
+
+static inline void
+lzo_adaptive_compress_data (struct lzo_adaptive_compress *ac, int n_total, int n_comp)
+{
+  ac->n_total += n_total;
+  ac->n_comp += n_comp;
+}
+
+void lzo_adjust_frame_parameters (struct frame *frame)
+{
+  /* Leave room for our one-byte compressed/didn't-compress prefix byte. */
+  frame_add_to_extra_frame (frame, LZO_PREFIX_LEN);
+
+  /* Leave room for compression buffer to expand in worst case scenario
+     where data is totally uncompressible */
+  frame_add_to_extra_buffer (frame, LZO_EXTRA_BUFFER (EXPANDED_SIZE(frame)));
+}
+
+void
+lzo_compress_init (struct lzo_compress_workspace *lzowork, unsigned int flags)
+{
+  CLEAR (*lzowork);
+
+  lzowork->wmem_size = LZO_WORKSPACE;
+  lzowork->flags = flags;
+
+  if (lzo_init () != LZO_E_OK)
+    msg (M_FATAL, "Cannot initialize LZO compression library");
+  lzowork->wmem = (lzo_voidp) lzo_malloc (lzowork->wmem_size);
+  check_malloc_return (lzowork->wmem);
+  msg (M_INFO, "LZO compression initialized");
+  lzowork->defined = true;
+}
+
+void
+lzo_compress_uninit (struct lzo_compress_workspace *lzowork)
+{
+  if (lzowork)
+    {
+      ASSERT (lzowork->defined);
+      lzo_free (lzowork->wmem);
+      lzowork->wmem = NULL;
+      lzowork->defined = false;
+    }
+}
+
+static inline bool
+lzo_compression_enabled (struct lzo_compress_workspace *lzowork)
+{
+  if ((lzowork->flags & (LZO_SELECTED|LZO_ON)) == (LZO_SELECTED|LZO_ON))
+    {
+      if (lzowork->flags & LZO_ADAPTIVE)
+	return lzo_adaptive_compress_test (&lzowork->ac);
+      else
+	return true;
+    }
+  return false;
+}
+
+/* Magic numbers to tell our peer if we compressed or not */
+#define YES_COMPRESS 0x66
+#define NO_COMPRESS  0xFA
+
+void
+lzo_compress (struct buffer *buf, struct buffer work,
+	      struct lzo_compress_workspace *lzowork,
+	      const struct frame* frame)
+{
+  lzo_uint zlen = 0;
+  int err;
+  bool compressed = false;
+
+  ASSERT (lzowork->defined);
+
+  if (buf->len <= 0)
+    return;
+
+  /*
+   * In order to attempt compression, length must be at least COMPRESS_THRESHOLD,
+   * and our adaptive level must give the OK.
+   */
+  if (buf->len >= COMPRESS_THRESHOLD && lzo_compression_enabled (lzowork))
+    {
+      ASSERT (buf_init (&work, FRAME_HEADROOM (frame)));
+      ASSERT (buf_safe (&work, LZO_EXTRA_BUFFER (PAYLOAD_SIZE (frame))));
+
+      if (!(buf->len <= PAYLOAD_SIZE (frame)))
+	{
+	  dmsg (D_COMP_ERRORS, "LZO compression buffer overflow");
+	  buf->len = 0;
+	  return;
+	}
+
+      err = LZO_COMPRESS (BPTR (buf), BLEN (buf), BPTR (&work), &zlen, lzowork->wmem);
+      if (err != LZO_E_OK)
+	{
+	  dmsg (D_COMP_ERRORS, "LZO compression error: %d", err);
+	  buf->len = 0;
+	  return;
+	}
+
+      ASSERT (buf_safe (&work, zlen));
+      work.len = zlen;
+      compressed = true;
+
+      dmsg (D_COMP, "compress %d -> %d", buf->len, work.len);
+      lzowork->pre_compress += buf->len;
+      lzowork->post_compress += work.len;
+
+      /* tell adaptive level about our success or lack thereof in getting any size reduction */
+      if (lzowork->flags & LZO_ADAPTIVE)
+	lzo_adaptive_compress_data (&lzowork->ac, buf->len, work.len);
+    }
+
+  /* did compression save us anything ? */
+  if (compressed && work.len < buf->len)
+    {
+      uint8_t *header = buf_prepend (&work, 1);
+      *header = YES_COMPRESS;
+      *buf = work;
+    }
+  else
+    {
+      uint8_t *header = buf_prepend (buf, 1);
+      *header = NO_COMPRESS;
+    }
+}
+
+void
+lzo_decompress (struct buffer *buf, struct buffer work,
+		struct lzo_compress_workspace *lzowork,
+		const struct frame* frame)
+{
+  lzo_uint zlen = EXPANDED_SIZE (frame);
+  uint8_t c;		/* flag indicating whether or not our peer compressed */
+  int err;
+
+  ASSERT (lzowork->defined);
+
+  if (buf->len <= 0)
+    return;
+
+  ASSERT (buf_init (&work, FRAME_HEADROOM (frame)));
+
+  c = *BPTR (buf);
+  ASSERT (buf_advance (buf, 1));
+
+  if (c == YES_COMPRESS)	/* packet was compressed */
+    {
+      ASSERT (buf_safe (&work, zlen));
+      err = LZO_DECOMPRESS (BPTR (buf), BLEN (buf), BPTR (&work), &zlen,
+			    lzowork->wmem);
+      if (err != LZO_E_OK)
+	{
+	  dmsg (D_COMP_ERRORS, "LZO decompression error: %d", err);
+	  buf->len = 0;
+	  return;
+	}
+
+      ASSERT (buf_safe (&work, zlen));
+      work.len = zlen;
+
+      dmsg (D_COMP, "decompress %d -> %d", buf->len, work.len);
+      lzowork->pre_decompress += buf->len;
+      lzowork->post_decompress += work.len;
+
+      *buf = work;
+    }
+  else if (c == NO_COMPRESS)	/* packet was not compressed */
+    {
+      ;
+    }
+  else
+    {
+      dmsg (D_COMP_ERRORS, "Bad LZO decompression header byte: %d", c);
+      buf->len = 0;
+    }
+}
+
+void
+lzo_modify_flags (struct lzo_compress_workspace *lzowork, unsigned int flags)
+{
+  ASSERT (lzowork->defined);
+  lzowork->flags = flags;
+}
+
+/*
+ * Print statistics
+ */
+void lzo_print_stats (const struct lzo_compress_workspace *lzo_compwork, struct status_output *so)
+{
+  ASSERT (lzo_compwork->defined);
+
+  status_printf (so, "pre-compress bytes," counter_format, lzo_compwork->pre_compress);
+  status_printf (so, "post-compress bytes," counter_format, lzo_compwork->post_compress);
+  status_printf (so, "pre-decompress bytes," counter_format, lzo_compwork->pre_decompress);
+  status_printf (so, "post-decompress bytes," counter_format, lzo_compwork->post_decompress);
+}
+
+#else
+static void dummy(void) {}
+#endif /* USE_LZO */