/*
* Copyright (c) 2010. Stephen Connolly.
* Copyright (C) 2007. Jens Hatlak <hatlak@rbg.informatik.tu-darmstadt.de>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package com.github.stephenc.javaisotools.eltorito.impl;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Arrays;
import com.github.stephenc.javaisotools.iso9660.ISO9660File;
import com.github.stephenc.javaisotools.iso9660.LayoutHelper;
import com.github.stephenc.javaisotools.iso9660.impl.ISO9660Constants;
import com.github.stephenc.javaisotools.iso9660.impl.ISO9660Element;
import com.github.stephenc.javaisotools.iso9660.sabre.impl.LSBFWordDataReference;
import com.github.stephenc.javaisotools.iso9660.volumedescriptors.BootRecord;
import com.github.stephenc.javaisotools.sabre.Element;
import com.github.stephenc.javaisotools.sabre.HandlerException;
import com.github.stephenc.javaisotools.sabre.impl.ChainingStreamHandler;
import com.github.stephenc.javaisotools.sabre.impl.FileDataReference;
import com.github.stephenc.javaisotools.iso9660.impl.LogicalSectorElement;
import com.github.stephenc.javaisotools.sabre.Fixup;
import com.github.stephenc.javaisotools.sabre.StreamHandler;
public class ElToritoHandler extends ChainingStreamHandler {
private ElToritoConfig config;
private Fixup bootCatalogLocation, bootImageLocation;
public ElToritoHandler(StreamHandler streamHandler, ElToritoConfig config) {
super(streamHandler, streamHandler);
this.config = config;
}
public void startElement(Element element) throws HandlerException {
if (element instanceof ISO9660Element) {
String id = (String) element.getId();
process(id);
}
super.startElement(element);
}
private void process(String id) throws HandlerException {
if (id.equals("VDS")) {
doBVD();
} else if (id.equals("BIA")) {
doCatalog();
}
if (id.equals("BDA")) {
doImage();
}
}
private void doBVD() throws HandlerException {
super.startElement(new LogicalSectorElement("BR"));
LayoutHelper helper = new ElToritoLayoutHelper(this);
BootRecord br = new BootRecord(this, helper);
br.setMetadata(config);
br.doBR();
// Remember Boot System Use (absolute pointer to first sector of Boot Catalog)
bootCatalogLocation = fixup(new LSBFWordDataReference(0));
super.endElement();
}
private void doCatalog() throws HandlerException {
super.startElement(new LogicalSectorElement("BCAT"));
// Write and close Boot Catalog Location Fixup
long position = mark();
int location = (int) (position / ISO9660Constants.LOGICAL_BLOCK_SIZE);
bootCatalogLocation.data(new LSBFWordDataReference(location));
bootCatalogLocation.close();
ElToritoFactory etf = new ElToritoFactory(this);
// Validation Entry
int platformID = config.getPlatformID();
String idString = config.getIDString();
etf.doValidationEntry(platformID, idString);
// Initial/Default Entry
boolean bootable = config.getBootable();
int bootMediaType = config.getBootMediaType();
int loadSegment = config.getLoadSegment();
int systemType = config.getSystemType();
int sectorCount = config.getSectorCount();
bootImageLocation = etf.doDefaultEntry(bootable, bootMediaType, loadSegment, systemType, sectorCount);
super.endElement();
}
private void doImage() throws HandlerException {
super.startElement(new LogicalSectorElement("BIMG"));
// Write and close Boot Image Location Fixup
long position = mark();
int location = (int) (position / ISO9660Constants.LOGICAL_BLOCK_SIZE);
bootImageLocation.data(new LSBFWordDataReference(location));
bootImageLocation.close();
if (config.getGenBootInfoTable()) {
this.genBootInfoTable(location);
}
// Write Boot Image
data(config.getBootImage().getDataReference());
super.endElement();
}
private void genBootInfoTable(int lba) throws HandlerException {
// Patch the Boot Image: write 56 byte boot information table
// (cf. man mkisofs, section EL TORITO BOOT INFORMATION TABLE)
try {
String orgName = config.getBootImage().getAbsolutePath();
File orgFile = new File(orgName);
// Compute the checksum over all 32-bit words starting at byte offset 64
FileInputStream fis = new FileInputStream(orgFile);
fis.skip(64);
long checksum = 0;
byte[] buffer = new byte[0x2000];
while (fis.available() > 0) {
int len = fis.read(buffer);
for (int i = 0; i < len;) {
long temp = buffer[i++] & 0xFF;
temp |= (buffer[i++] << 8) & 0xFF00;
temp |= (buffer[i++] << 16) & 0xFF0000;
temp |= (buffer[i++] << 24) & 0xFF000000l;
checksum += temp;
}
}
fis.close();
// Create the patched file
fis = new FileInputStream(orgFile);
File patchedFile = new File(orgName + ".mod");
FileOutputStream fos = new FileOutputStream(patchedFile);
// Copy first 8 bytes
buffer = new byte[8];
fis.read(buffer);
fos.write(buffer);
// Read 56 bytes and init the buffer with as many 0 bytes
buffer = new byte[56];
fis.read(buffer);
Arrays.fill(buffer, (byte) 0);
// Write boot info tables fields
int i = 0;
// PVD LBA (always 16), 7.3.1 format
int pvd = 16;
buffer[i++] = (byte) (pvd & 0xFF);
buffer[i++] = (byte) ((pvd >> 8) & 0xFF);
buffer[i++] = (byte) ((pvd >> 16) & 0xFF);
buffer[i++] = (byte) ((pvd >> 24) & 0xFF);
// Boot file LBA, 7.3.1 format
buffer[i++] = (byte) (lba & 0xFF);
buffer[i++] = (byte) ((lba >> 8) & 0xFF);
buffer[i++] = (byte) ((lba >> 16) & 0xFF);
buffer[i++] = (byte) ((lba >> 24) & 0xFF);
// Boot file length in bytes, 7.3.1 format
int len = (int) config.getBootImage().length();
buffer[i++] = (byte) (len & 0xFF);
buffer[i++] = (byte) ((len >> 8) & 0xFF);
buffer[i++] = (byte) ((len >> 16) & 0xFF);
buffer[i++] = (byte) ((len >> 24) & 0xFF);
// 32-bit checksum, 7.3.1 format
buffer[i++] = (byte) (checksum & 0xFF);
buffer[i++] = (byte) ((checksum >> 8) & 0xFF);
buffer[i++] = (byte) ((checksum >> 16) & 0xFF);
buffer[i++] = (byte) ((checksum >> 24) & 0xFF);
// Write 38 byte buffer
fos.write(buffer);
// Write the rest
buffer = new byte[0x2000];
while (fis.available() > 0) {
len = fis.read(buffer);
fos.write(buffer, 0, len);
}
fis.close();
fos.close();
// Replace original file by patched one
orgFile.delete();
orgFile = new File(orgName);
patchedFile.renameTo(orgFile);
config.setBootImage(new ISO9660File(orgFile));
System.out.println("Patched boot image at " + orgFile.getPath());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}