content: /* ###
   * IP: GHIDRA
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package firmware.cbfs;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.Arrays;
  
  import ghidra.app.util.bin.ByteArrayProvider;
  import ghidra.app.util.bin.ByteProvider;
  import ghidra.formats.gfilesystem.FSUtilities;
  import ghidra.formats.gfilesystem.FileCache;
  import ghidra.formats.gfilesystem.FileSystemService;
  import ghidra.formats.gfilesystem.fileinfo.FileAttributeType;
  import ghidra.formats.gfilesystem.fileinfo.FileAttributes;
  import ghidra.util.exception.CancelledException;
  import ghidra.util.task.TaskMonitor;
  import org.apache.commons.compress.compressors.lz4.FramedLZ4CompressorInputStream;
  import org.apache.commons.compress.compressors.lzma.LZMACompressorInputStream;
  
  import ghidra.app.util.bin.BinaryReader;
  
  /**
   * Parser for CBFS files, which have the following structure:
   *
   *   CBFS File Header
   *   +---------+--------------------------------+
   *   | Type    | Size | Description             |
   *   +---------+--------------------------------+
   *   | char[8] |    8 | Signature ("LARCHIVE")  |
   *   | u32     |    4 | File Size               |
   *   | u32     |    4 | File Type               |
   *   | u32     |    4 | File Attributes Offset  |
   *   | u32     |    4 | Offset of File Contents |
   *   | char[]  |  var | File Name (C string)    |
   *   +---------+--------------------------------+
   *
   * If nonzero, the File Attributes Offset field points to a CBFS file attribute structure. See
   * CBFSFileAttribute for details on this structure.
   *
   * The File Name field is a null-terminated C string.
   */
  public class CBFSFile {
  	// Original header fields
  	private final byte[] signature;
  	private final int size;
  	private final int type;
  	private final long attributesOffset;
  	private final long offset;
  	private final String name;
  
  	private CBFSFileAttribute attribute;
  	private final byte[] data;
  
  	/**
  	 * Constructs a CBFSFile from a specified BinaryReader.
  	 *
  	 * @param reader the specified BinaryReader
  	 */
  	public CBFSFile(BinaryReader reader) throws IOException {
  		long startIndex = reader.getPointerIndex();
  
  		signature = reader.readNextByteArray(CBFSConstants.CBFS_FILE_SIGNATURE.length);
  		if (!Arrays.equals(CBFSConstants.CBFS_FILE_SIGNATURE, signature)) {
  			throw new IOException("Not a valid CBFS file");
  		}
  
  		size = reader.readNextInt();
  		type = reader.readNextInt();
  		attributesOffset = reader.readNextUnsignedInt();
  		offset = reader.readNextUnsignedInt();
  		name = reader.readNextAsciiString();
  
  		// The attributes offset should point past the end of the CBFS file structure.
  		if (attributesOffset != 0 && attributesOffset > CBFSConstants.CBFS_FILE_SIZE) {
  			// TODO: Handle nested file attributes: additional file attributes may be stored in the
  			// first attribute's data section
  			reader.setPointerIndex(startIndex + attributesOffset);
  			attribute = CBFSFileAttributeFactory.parseCBFSFileAttribute(reader);
  		}
  
  		reader.setPointerIndex(startIndex + offset);
  		data = reader.readNextByteArray(size);
  	}
  
  	/**
  	 * Returns a ByteProvider for the contents of the current file. Compressed files will be
  	 * wrapped in a CompressorInputStream for transparent extraction.
  	 *
  	 * @return a ByteProvider for the contents of the current file
  	 */
  	public ByteProvider getByteProvider() throws IOException, CancelledException {
  		// Extract the file if compression is used (specified in a compression attribute).
  		if (attribute != null && attribute instanceof CBFSCompressionAttribute) {
  			InputStream is = new ByteArrayInputStream(data);
  			int compressionType = ((CBFSCompressionAttribute) attribute).getCompressionType();
  			switch (compressionType) {
  				case CBFSConstants.CompressionAlgorithm.NONE: break;
  				case CBFSConstants.CompressionAlgorithm.LZMA: is = new LZMACompressorInputStream(is); break;
  				case CBFSConstants.CompressionAlgorithm.LZ4: is = new FramedLZ4CompressorInputStream(is); break;
  				default: throw new IOException("Unsupported CBFS compression type: " + compressionType);
  			}
  
  			FileCache.FileCacheEntryBuilder tmpFileBuilder = FileSystemService.getInstance().createTempFile(-1);
  			FSUtilities.streamCopy(is, tmpFileBuilder, TaskMonitor.DUMMY);
  			FileCache.FileCacheEntry fce = tmpFileBuilder.finish();
  			return FileSystemService.getInstance().getNamedTempFile(fce, name);
  		} else {
  			return new ByteArrayProvider(data);
  		}
  	}
  
  	/**
  	 * Returns the name of the current file.
  	 *
  	 * @return the name of the current file
  	 */
  	public String getName() {
  		return name;
  	}
  
  	/**
  	 * Returns the offset of the current file's contents.
  	 *
  	 * @return the offset of the current file's contents.
  	 */
  	public long getOffset() {
  		return offset;
  	}
  
  	/**
  	 * Returns the current file's type.
  	 *
  	 * @return the current file's type
  	 */
  	public int getType() {
  		return type;
  	}
  
  	/**
  	 * Returns the size of the current file.
  	 *
  	 * @return the size of the current file
  	 */
  	public int length() {
  		return size;
  	}
  
  	/**
  	 * Returns FileAttributes for the current file.
  	 *
  	 * @return FileAttributes for the current file
  	 */
  	public FileAttributes getFileAttributes() {
  		FileAttributes attributes = new FileAttributes();
  		attributes.add(FileAttributeType.NAME_ATTR, name);
  		attributes.add("File Type", CBFSConstants.FileType.toString(type));
  		if (attribute != null && attribute instanceof CBFSCompressionAttribute) {
  			switch (((CBFSCompressionAttribute) attribute).getCompressionType()) {
  				case CBFSConstants.CompressionAlgorithm.LZMA:
  					attributes.add("Compression Type", "LZMA");
  				case CBFSConstants.CompressionAlgorithm.LZ4:
  					attributes.add("Compression Type", "LZ4");
  					attributes.add(FileAttributeType.COMPRESSED_SIZE_ATTR, Long.valueOf(size));
  					break;
  				default:
  					attributes.add(FileAttributeType.SIZE_ATTR, Long.valueOf(size));
  			}
  		} else {
  			attributes.add(FileAttributeType.SIZE_ATTR, Long.valueOf(size));
  		}
  
  		return attributes;
  	}
  }
  