Merge commit '86cc97e55fe346502462284d2e636a2b3708163e' as 'Sources/OpenVPN3'

2026-04-24 00:00:05 +08:00 · 2020-02-24 14:43:11 +03:00
parent 133b3756e6 86cc97e55f
commit 32f1555929
655 changed files with 146468 additions and 0 deletions
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+//    OpenVPN -- An application to securely tunnel IP networks
+//               over a single port, with support for SSL/TLS-based
+//               session authentication and key exchange,
+//               packet encryption, packet authentication, and
+//               packet compression.
+//
+//    Copyright (C) 2012-2017 OpenVPN Inc.
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Affero General Public License Version 3
+//    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 Affero General Public License for more details.
+//
+//    You should have received a copy of the GNU Affero General Public License
+//    along with this program in the COPYING file.
+//    If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef OPENVPN_COMPRESS_SNAPPY_H
+#define OPENVPN_COMPRESS_SNAPPY_H
+
+// Implement Snappy compression.
+// Should only be included by compress.hpp
+
+#include <snappy.h>
+
+namespace openvpn {
+
+  class CompressSnappy : public Compress
+  {
+    // magic number for Snappy compression
+    enum {
+      SNAPPY_COMPRESS = 0x68,
+    };
+
+  public:
+    CompressSnappy(const Frame::Ptr& frame, const SessionStats::Ptr& stats, const bool asym_arg)
+      : Compress(frame, stats),
+	asym(asym_arg)
+    {
+      OPENVPN_LOG_COMPRESS("SNAPPY init asym=" << asym_arg);
+    }
+
+    virtual const char *name() const { return "snappy"; }
+
+    virtual void compress(BufferAllocated& buf, const bool hint)
+    {
+      // skip null packets
+      if (!buf.size())
+	return;
+
+      if (hint && !asym)
+	{
+	  // initialize work buffer
+	  frame->prepare(Frame::COMPRESS_WORK, work);
+
+	  // verify that input data length is not too large
+	  if (snappy::MaxCompressedLength(buf.size()) > work.max_size())
+	    {
+	      error(buf);
+	      return;
+	    }
+
+	  // do compress
+	  size_t comp_size;
+	  snappy::RawCompress((const char *)buf.c_data(), buf.size(), (char *)work.data(), &comp_size);
+
+	  // did compression actually reduce data length?
+	  if (comp_size < buf.size())
+	    {
+	      OPENVPN_LOG_COMPRESS_VERBOSE("SNAPPY compress " << buf.size() << " -> " << comp_size);
+	      work.set_size(comp_size);
+	      do_swap(work, SNAPPY_COMPRESS);
+	      buf.swap(work);
+	      return;
+	    }
+	}
+
+      // indicate that we didn't compress
+      do_swap(buf, NO_COMPRESS_SWAP);
+    }
+
+    virtual void decompress(BufferAllocated& buf)
+    {
+      // skip null packets
+      if (!buf.size())
+	return;
+
+      const unsigned char c = buf.pop_front();
+      switch (c)
+	{
+	case NO_COMPRESS_SWAP:
+	  do_unswap(buf);
+	  break;
+	case SNAPPY_COMPRESS:
+	  {
+	    do_unswap(buf);
+
+	    // initialize work buffer
+	    const size_t payload_size = frame->prepare(Frame::DECOMPRESS_WORK, work);
+
+	    // do uncompress
+	    size_t decomp_size;
+	    if (!snappy::GetUncompressedLength((const char *)buf.c_data(), buf.size(), &decomp_size)
+		|| decomp_size > payload_size)
+	      {
+		error(buf);
+		break;
+	      }
+	    if (!snappy::RawUncompress((const char *)buf.c_data(), buf.size(), (char *)work.data()))
+	      {
+		error(buf);
+		break;
+	      }
+	    OPENVPN_LOG_COMPRESS_VERBOSE("SNAPPY uncompress " << buf.size() << " -> " << decomp_size);
+	    work.set_size(decomp_size);
+	    buf.swap(work);
+	  }
+	  break;
+	default: 
+	  error(buf); // unknown op
+	  break;
+	}
+    }
+
+  private:
+    const bool asym;
+    BufferAllocated work;
+  };
+
+} // namespace openvpn
+
+#endif // OPENVPN_COMPRESS_SNAPPY_H