1 files changed, 218 insertions, 0 deletions

diff --git a/OpenSim/Framework/Archive/TarArchiveReader.cs b/OpenSim/Framework/Archive/TarArchiveReader.cs
new file mode 100644
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+++ b/OpenSim/Framework/Archive/TarArchiveReader.cs
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+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSim Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.IO;
+using System.Reflection;
+using System.Text;
+using log4net;
+
+namespace OpenSim.Framework.Archive
+{
+    /// <summary>
+    /// Temporary code to do the bare minimum required to read a tar archive for our purposes
+    /// </summary>
+    public class TarArchiveReader
+    {
+        //private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
+        public enum TarEntryType
+        {
+            TYPE_UNKNOWN = 0,
+            TYPE_NORMAL_FILE = 1,
+            TYPE_HARD_LINK = 2,
+            TYPE_SYMBOLIC_LINK = 3,
+            TYPE_CHAR_SPECIAL = 4,
+            TYPE_BLOCK_SPECIAL = 5,
+            TYPE_DIRECTORY = 6,
+            TYPE_FIFO = 7,
+            TYPE_CONTIGUOUS_FILE = 8,
+        }
+
+        protected static ASCIIEncoding m_asciiEncoding = new ASCIIEncoding();
+
+        /// <summary>
+        /// Binary reader for the underlying stream
+        /// </summary>
+        protected BinaryReader m_br;
+
+        /// <summary>
+        /// Used to trim off null chars
+        /// </summary>
+        protected char[] m_nullCharArray = new char[] { '\0' };
+
+        /// <summary>
+        /// Generate a tar reader which reads from the given stream.
+        /// </summary>
+        /// <param name="s"></param>
+        public TarArchiveReader(Stream s)
+        {
+            m_br = new BinaryReader(s);
+        }
+
+        /// <summary>
+        /// Read the next entry in the tar file.
+        /// </summary>
+        /// <param name="filePath"></param>
+        /// <returns>the data for the entry.  Returns null if there are no more entries</returns>
+        public byte[] ReadEntry(out string filePath, out TarEntryType entryType)
+        {
+            filePath = String.Empty;
+            entryType = TarEntryType.TYPE_UNKNOWN;
+            TarHeader header = ReadHeader();
+
+            if (null == header)
+                return null;
+
+            entryType = header.EntryType;
+            filePath = header.FilePath;
+            return ReadData(header.FileSize);
+        }
+
+        /// <summary>
+        /// Read the next 512 byte chunk of data as a tar header.
+        /// </summary>
+        /// <returns>A tar header struct.  null if we have reached the end of the archive.</returns>
+        protected TarHeader ReadHeader()
+        {
+            byte[] header = m_br.ReadBytes(512);
+
+            // If we've reached the end of the archive we'll be in null block territory, which means
+            // the next byte will be 0
+            if (header[0] == 0)
+                return null;
+
+            TarHeader tarHeader = new TarHeader();
+
+            // If we're looking at a GNU tar long link then extract the long name and pull up the next header
+            if (header[156] == (byte)'L')
+            {
+                int longNameLength = ConvertOctalBytesToDecimal(header, 124, 11);
+                tarHeader.FilePath = m_asciiEncoding.GetString(ReadData(longNameLength));
+                //m_log.DebugFormat("[TAR ARCHIVE READER]: Got long file name {0}", tarHeader.FilePath);
+                header = m_br.ReadBytes(512);
+            }
+            else
+            {
+                tarHeader.FilePath = m_asciiEncoding.GetString(header, 0, 100);
+                tarHeader.FilePath = tarHeader.FilePath.Trim(m_nullCharArray);
+                //m_log.DebugFormat("[TAR ARCHIVE READER]: Got short file name {0}", tarHeader.FilePath);
+            }
+
+            tarHeader.FileSize = ConvertOctalBytesToDecimal(header, 124, 11);
+
+            switch (header[156])
+            {
+                case 0:
+                    tarHeader.EntryType = TarEntryType.TYPE_NORMAL_FILE;
+                    break;
+                case (byte)'0':
+                    tarHeader.EntryType = TarEntryType.TYPE_NORMAL_FILE;
+                break;
+                case (byte)'1':
+                    tarHeader.EntryType = TarEntryType.TYPE_HARD_LINK;
+                break;
+                case (byte)'2':
+                    tarHeader.EntryType = TarEntryType.TYPE_SYMBOLIC_LINK;
+                break;
+                case (byte)'3':
+                    tarHeader.EntryType = TarEntryType.TYPE_CHAR_SPECIAL;
+                break;
+                case (byte)'4':
+                    tarHeader.EntryType = TarEntryType.TYPE_BLOCK_SPECIAL;
+                break;
+                case (byte)'5':
+                    tarHeader.EntryType = TarEntryType.TYPE_DIRECTORY;
+                break;
+                case (byte)'6':
+                    tarHeader.EntryType = TarEntryType.TYPE_FIFO;
+                break;
+                case (byte)'7':
+                    tarHeader.EntryType = TarEntryType.TYPE_CONTIGUOUS_FILE;
+                break;
+            }
+
+            return tarHeader;
+        }
+
+        /// <summary>
+        /// Read data following a header
+        /// </summary>
+        /// <param name="fileSize"></param>
+        /// <returns></returns>
+        protected byte[] ReadData(int fileSize)
+        {
+            byte[] data = m_br.ReadBytes(fileSize);
+
+            //m_log.DebugFormat("[TAR ARCHIVE READER]: fileSize {0}", fileSize);
+
+            // Read the rest of the empty padding in the 512 byte block
+            if (fileSize % 512 != 0)
+            {
+                int paddingLeft = 512 - (fileSize % 512);
+
+                //m_log.DebugFormat("[TAR ARCHIVE READER]: Reading {0} padding bytes", paddingLeft);
+
+                m_br.ReadBytes(paddingLeft);
+            }
+
+            return data;
+        }
+
+        public void Close()
+        {
+            m_br.Close();
+        }
+
+        /// <summary>
+        /// Convert octal bytes to a decimal representation
+        /// </summary>
+        /// <param name="bytes"></param>
+        /// <returns></returns>
+        public static int ConvertOctalBytesToDecimal(byte[] bytes, int startIndex, int count)
+        {
+            string oString = m_asciiEncoding.GetString(bytes, startIndex, count);
+
+            int d = 0;
+
+            foreach (char c in oString)
+            {
+                d <<= 3;
+                d |= c - '0';
+            }
+
+            return d;
+        }
+    }
+
+    public class TarHeader
+    {
+        public string FilePath;
+        public int FileSize;
+        public TarArchiveReader.TarEntryType EntryType;
+    }
+}