1 /* 2 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.oracle.ipack.macho; 27 28 import java.io.DataInput; 29 import java.io.DataOutput; 30 import java.io.IOException; 31 32 public abstract class MachoCommand { 33 public static final int LC_SEGMENT = 0x1; 34 public static final int LC_CODE_SIGNATURE = 0x1d; 35 36 public abstract int getId(); 37 38 public final int getSize() { 39 return 8 + getPayloadSize(); 40 } 41 42 public static MachoCommand read(final DataInput dataInput) 43 throws IOException { 44 final int commandId = dataInput.readInt(); 45 final int commandSize = dataInput.readInt(); 46 MachoCommand command; 47 switch (commandId) { 48 case LC_SEGMENT: 49 command = new SegmentCommand(); 50 break; 51 case LC_CODE_SIGNATURE: 52 command = new CodeSignatureCommand(); 53 break; 54 default: 55 command = new UnknownCommand(commandId, commandSize - 8); 56 break; 57 } 58 59 command.readPayload(dataInput); 60 if (command.getSize() != commandSize) { 61 throw new IOException("Can't decode command in mach-o header"); 62 } 63 64 return command; 65 } 66 67 public final void write(final DataOutput dataOutput) throws IOException { 68 dataOutput.writeInt(getId()); 69 dataOutput.writeInt(getSize()); 70 writePayload(dataOutput); 71 } 72 73 protected abstract int getPayloadSize(); 74 75 protected abstract void readPayload(final DataInput dataInput) 76 throws IOException; 77 78 protected abstract void writePayload(final DataOutput dataOutput) 79 throws IOException; 80 }