New upstream version 2.4~beta1upstream/2.4_beta1

1 files changed, 307 insertions, 0 deletions

diff --git a/src/openvpn/comp-lz4.c b/src/openvpn/comp-lz4.c
new file mode 100644
index 0000000..395f3d2
--- /dev/null
+++ b/src/openvpn/comp-lz4.c
@@ -0,0 +1,307 @@
+/*
+ *  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>
+ *  Copyright (C) 2013      Gert Doering <gert@greenie.muc.de>
+ *
+ *  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
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#include "syshead.h"
+
+#if defined(ENABLE_LZ4)
+
+#if defined(NEED_COMPAT_LZ4)
+#include "compat-lz4.h"
+#else
+#include "lz4.h"
+#endif
+
+#include "comp.h"
+#include "error.h"
+
+#include "memdbg.h"
+
+static void
+lz4_compress_init (struct compress_context *compctx)
+{
+  msg (D_INIT_MEDIUM, "LZ4 compression initializing");
+  ASSERT(compctx->flags & COMP_F_SWAP);
+}
+
+static void
+lz4v2_compress_init (struct compress_context *compctx)
+{
+  msg (D_INIT_MEDIUM, "LZ4v2 compression initializing");
+}
+
+static void
+lz4_compress_uninit (struct compress_context *compctx)
+{
+}
+
+static bool
+do_lz4_compress (struct buffer *buf,
+		 struct buffer *work,
+		 struct compress_context *compctx,
+		 const struct frame* frame)
+{
+  /*
+   * In order to attempt compression, length must be at least COMPRESS_THRESHOLD.
+   */
+  if (buf->len >= COMPRESS_THRESHOLD)
+    {
+      const size_t ps = PAYLOAD_SIZE (frame);
+      int zlen_max = ps + COMP_EXTRA_BUFFER (ps);
+      int zlen;
+
+      ASSERT (buf_init (work, FRAME_HEADROOM (frame)));
+      ASSERT (buf_safe (work, zlen_max));
+
+      if (buf->len > ps)
+	{
+	  dmsg (D_COMP_ERRORS, "LZ4 compression buffer overflow");
+	  buf->len = 0;
+	  return false;
+	}
+
+      zlen = LZ4_compress_limitedOutput((const char *)BPTR(buf), (char *)BPTR(work), BLEN(buf), zlen_max );
+
+      if (zlen <= 0)
+	{
+	  dmsg (D_COMP_ERRORS, "LZ4 compression error");
+	  buf->len = 0;
+	  return false;
+	}
+
+      ASSERT (buf_safe (work, zlen));
+      work->len = zlen;
+
+
+      dmsg (D_COMP, "LZ4 compress %d -> %d", buf->len, work->len);
+      compctx->pre_compress += buf->len;
+      compctx->post_compress += work->len;
+      return true;
+    }
+  return false;
+}
+
+
+static void
+lz4_compress (struct buffer *buf, struct buffer work,
+	      struct compress_context *compctx,
+	      const struct frame* frame)
+{
+  bool compressed;
+  if (buf->len <= 0)
+    return;
+
+  compressed = do_lz4_compress(buf, &work, compctx, frame);
+
+  /* On error do_lz4_compress sets buf len to zero, just return */
+  if (buf->len == 0)
+    return;
+
+  /* did compression save us anything? */
+  {
+    uint8_t comp_head_byte = NO_COMPRESS_BYTE_SWAP;
+    if (compressed && work.len < buf->len)
+      {
+	*buf = work;
+	comp_head_byte = LZ4_COMPRESS_BYTE;
+      }
+
+    {
+      uint8_t *head = BPTR (buf);
+      uint8_t *tail  = BEND (buf);
+      ASSERT (buf_safe (buf, 1));
+      ++buf->len;
+
+      /* move head byte of payload to tail */
+      *tail = *head;
+      *head = comp_head_byte;
+    }
+  }
+}
+
+
+static void
+lz4v2_compress (struct buffer *buf, struct buffer work,
+		struct compress_context *compctx,
+		const struct frame* frame)
+{
+  bool compressed;
+  if (buf->len <= 0)
+    return;
+
+  compressed = do_lz4_compress(buf, &work, compctx, frame);
+
+  /* On Error just return */
+  if (buf->len == 0)
+    return;
+
+  /* did compression save us anything?  Include 2 byte compression header
+     in calculation */
+  if (compressed && work.len + 2 < buf->len)
+    {
+      ASSERT(buf_prepend(&work, 2));
+      uint8_t *head = BPTR (&work);
+      head[0] = COMP_ALGV2_INDICATOR_BYTE;
+      head[1] = COMP_ALGV2_LZ4_BYTE;
+      *buf = work;
+    }
+  else
+    {
+      compv2_escape_data_ifneeded(buf);
+    }
+}
+
+void
+do_lz4_decompress(size_t zlen_max,
+		  struct buffer *work,
+		  struct buffer *buf,
+		  struct compress_context *compctx)
+{
+  int uncomp_len;
+  ASSERT (buf_safe (work, zlen_max));
+  uncomp_len = LZ4_decompress_safe((const char *)BPTR(buf), (char *)BPTR(work), (size_t)BLEN(buf), zlen_max);
+  if (uncomp_len <= 0)
+    {
+      dmsg (D_COMP_ERRORS, "LZ4 decompression error: %d", uncomp_len);
+      buf->len = 0;
+      return;
+    }
+
+  ASSERT (buf_safe (work, uncomp_len));
+  work->len = uncomp_len;
+
+  dmsg (D_COMP, "LZ4 decompress %d -> %d", buf->len, work->len);
+  compctx->pre_decompress += buf->len;
+  compctx->post_decompress += work->len;
+
+  *buf = *work;
+}
+
+static void
+lz4_decompress (struct buffer *buf, struct buffer work,
+		struct compress_context *compctx,
+		const struct frame* frame)
+{
+  size_t zlen_max = EXPANDED_SIZE (frame);
+  uint8_t c;		/* flag indicating whether or not our peer compressed */
+
+  if (buf->len <= 0)
+    return;
+
+  ASSERT (buf_init (&work, FRAME_HEADROOM (frame)));
+
+  /* do unframing/swap (assumes buf->len > 0) */
+  {
+    uint8_t *head = BPTR (buf);
+    c = *head;
+    --buf->len;
+    *head = *BEND (buf);
+  }
+
+  if (c == LZ4_COMPRESS_BYTE)	/* packet was compressed */
+    {
+      do_lz4_decompress(zlen_max, &work, buf, compctx);
+    }
+  else if (c == NO_COMPRESS_BYTE_SWAP)	/* packet was not compressed */
+    {
+      ;
+    }
+  else
+    {
+      dmsg (D_COMP_ERRORS, "Bad LZ4 decompression header byte: %d", c);
+      buf->len = 0;
+    }
+}
+
+static void
+lz4v2_decompress (struct buffer *buf, struct buffer work,
+		  struct compress_context *compctx,
+		  const struct frame* frame)
+{
+  size_t zlen_max = EXPANDED_SIZE (frame);
+  uint8_t c;		/* flag indicating whether or not our peer compressed */
+
+  if (buf->len <= 0)
+    return;
+
+  ASSERT (buf_init (&work, FRAME_HEADROOM (frame)));
+
+  /* do unframing/swap (assumes buf->len > 0) */
+  uint8_t *head = BPTR (buf);
+  c = *head;
+
+  /* Not compressed */
+  if (c != COMP_ALGV2_INDICATOR_BYTE) {
+    return;
+  }
+
+  /* Packet to short to make sense */
+  if (buf->len <= 1)
+    {
+      buf->len=0;
+      return;
+    }
+
+  c = head[1];
+  if (c == COMP_ALGV2_LZ4_BYTE) /* packet was compressed */
+    {
+      buf_advance(buf,2);
+      do_lz4_decompress(zlen_max, &work, buf, compctx);
+    }
+  else if (c == COMP_ALGV2_UNCOMPRESSED_BYTE)
+    {
+      buf_advance(buf,2);
+    }
+  else
+    {
+      dmsg (D_COMP_ERRORS, "Bad LZ4v2 decompression header byte: %d", c);
+      buf->len = 0;
+    }
+}
+
+const struct compress_alg lz4_alg = {
+  "lz4",
+  lz4_compress_init,
+  lz4_compress_uninit,
+  lz4_compress,
+  lz4_decompress
+};
+
+const struct compress_alg lz4v2_alg = {
+  "lz4v2",
+  lz4v2_compress_init,
+  lz4_compress_uninit,
+  lz4v2_compress,
+  lz4v2_decompress
+};
+
+#else
+static void dummy(void) {}
+#endif /* ENABLE_LZ4 */