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iso9660: add VolumeParser

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This commit is contained in:
Zack Buhman 2024-12-31 17:40:27 -06:00
parent b12ac0e017
commit f0c4c64925
5 changed files with 134 additions and 40 deletions
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19
filesystem/iso9660/ByteParser.java
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@ -2,7 +2,7 @@ package filesystem.iso9660;
public class ByteParser {
byte[] array;
int offset;
public int offset;
public ByteParser(byte[] array, int offset) {
this.array = array;
@ -11,7 +11,7 @@ public class ByteParser {
public static int shortLE(int i0, int i1) {
return ((i1 << 8)
| (i0 << 0));
| (i0 << 0)) & 0xffff;
}
public static int intLE(int i0, int i1, int i2, int i3) {
@ -22,21 +22,22 @@ public class ByteParser {
}
public int getByte(int pos) {
return array[offset + pos];
int i0 = array[offset + pos] & 0xff;
return i0;
}
public int getShortLE(int pos) {
int i0 = array[offset + pos + 0];
int i1 = array[offset + pos + 1];
int i0 = array[offset + pos + 0] & 0xff;
int i1 = array[offset + pos + 1] & 0xff;
return shortLE(i0, i1);
}
public int getIntLE(int pos) {
int i0 = array[offset + pos + 0];
int i1 = array[offset + pos + 1];
int i2 = array[offset + pos + 2];
int i3 = array[offset + pos + 3];
int i0 = array[offset + pos + 0] & 0xff;
int i1 = array[offset + pos + 1] & 0xff;
int i2 = array[offset + pos + 2] & 0xff;
int i3 = array[offset + pos + 3] & 0xff;
return intLE(i0, i1, i2, i3);
}

28
filesystem/iso9660/DirectoryRecord.java
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@ -23,28 +23,34 @@ public class DirectoryRecord extends ByteParser {
public static final int LENGTH_OF_FILE_IDENTIFIER_END = 32;
public static final int FILE_IDENTIFIER_START = 33;
public static final int FILE_IDENTIFIER_END = 32;
public static final int lengthOfDirectoryRecord() {
public DirectoryRecord(byte[] array, int offset) {
super(array, offset);
}
public int lengthOfDirectoryRecord() {
return getByte(LENGTH_OF_DIRECTORY_RECORD_START);
}
public static final int extendedAttributeRecordLength() {
public int extendedAttributeRecordLength() {
return getByte(EXTENDED_ATTRIBUTE_RECORD_LENGTH_START);
}
public static final int locationOfExtent() {
return getIntBE(LOCATION_OF_EXTENT_START);
public int locationOfExtent() {
return getIntLE(LOCATION_OF_EXTENT_START);
}
public static final int dataLength() {
return getIntBE(DATA_LENGTH_START);
public int dataLength() {
return getIntLE(DATA_LENGTH_START);
}
public static final int fileUnitSize() {
public int fileFlags() {
return getByte(FILE_FLAGS_START);
}
public int fileUnitSize() {
return getByte(FILE_UNIT_SIZE_START);
}
public static final int interleaveGapSize() {
public int interleaveGapSize() {
return getByte(INTERLEAVE_GAP_SIZE_START);
}
public static final int volumeSequenceNumber() {
return getShortBE(VOLUME_SEQUENCE_NUMBER_START);
public int volumeSequenceNumber() {
return getShortLE(VOLUME_SEQUENCE_NUMBER_START);
}
public static final int lengthOfFileIdentifier() {
public int lengthOfFileIdentifier() {
return getByte(LENGTH_OF_FILE_IDENTIFIER_START);
}
}

2
filesystem/iso9660/PrimaryVolumeDescriptor.java
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@ -57,7 +57,7 @@ public class PrimaryVolumeDescriptor extends ByteParser {
public static final int FILE_STRUCTURE_VERSION_END = 881;
public static final int APPLICATION_USE_START = 883;
public static final int APPLICATION_USE_END = 1394;
PrimaryVolumeDescriptor(byte[] array, int offset) {
public PrimaryVolumeDescriptor(byte[] array, int offset) {
super(array, offset);
}
public int volumeDescriptorType() {

106
filesystem/iso9660/VolumeParser.java Normal file
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@ -0,0 +1,106 @@
package p;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.io.IOException;
import filesystem.iso9660.PrimaryVolumeDescriptor;
import filesystem.iso9660.DirectoryRecord;
class ISOParser {
byte[] buf;
DirectoryRecord dr;
static final int FILE_FLAGS__DIRECTORY = 2;
public static void printIdentifier(byte[] buf, int offset, int start, int length) {
for (int i = 0; i < length; i++) {
System.out.print((char)buf[offset + start + i]);
}
}
public boolean drIsSelfOrParent() {
if (dr.lengthOfFileIdentifier() != 1) {
return false;
}
byte start = buf[DirectoryRecord.FILE_IDENTIFIER_START];
return (start == 0 || start == 1);
}
public void walkDirectory(int extent, int num_extents, int indent) {
int[] child_extents = new int[64];
int[] child_lengths = new int[64];
int child_ix = 0;
while (num_extents > 0) {
int offset = extent * 2048;
while (true) {
dr.offset = offset;
if (dr.lengthOfDirectoryRecord() == 0) {
System.out.print("break\n");
break;
}
if (!drIsSelfOrParent()) {
for (int i = 0; i < indent; i++)
System.out.print(" ");
System.out.print("offset: ");
System.out.print(dr.offset);
System.out.print("; file_flags: ");
System.out.print((int)dr.fileFlags());
if ((dr.fileFlags() & FILE_FLAGS__DIRECTORY) == 0) {
System.out.print(" [regular file] ");
//dr.locationOfExtent();
//dr.dataLength();
} else {
System.out.print(" [directory] ");
child_extents[child_ix] = dr.locationOfExtent();
child_lengths[child_ix] = dr.dataLength();
child_ix += 1;
}
System.out.print("; file_identifier: ");
printIdentifier(buf, offset, DirectoryRecord.FILE_IDENTIFIER_START, dr.lengthOfFileIdentifier());
System.out.println();
}
offset += dr.lengthOfDirectoryRecord();
}
num_extents -= 1;
extent += 1;
}
for (int i = 0; i < child_ix; i++) {
int child_extent = child_extents[i];
int child_num_extents = child_lengths[i] >> 11; // division by 2048
walkDirectory(child_extent, child_num_extents, indent + 1);
}
}
public static void main(String[] args) throws IOException {
ISOParser parser = new ISOParser();
parser.buf = Files.readAllBytes(Paths.get("classes.iso"));
int pvd_offset = 2048 * 16;
System.out.print("standard identifier: ");
for (int i = PrimaryVolumeDescriptor.STANDARD_IDENTIFIER_START; i <= PrimaryVolumeDescriptor.STANDARD_IDENTIFIER_END; i++) {
System.out.print((char)parser.buf[pvd_offset + i]);
}
System.out.println();
int directory_record_for_root_directory = pvd_offset + PrimaryVolumeDescriptor.DIRECTORY_RECORD_FOR_ROOT_DIRECTORY_START;
System.out.println("root directory record: ");
parser.dr = new DirectoryRecord(parser.buf, directory_record_for_root_directory);
System.out.println(parser.dr.locationOfExtent());
System.out.println(parser.dr.dataLength());
int extent = parser.dr.locationOfExtent();
int num_extents = parser.dr.dataLength() >> 11; // division by 2048
parser.walkDirectory(extent, num_extents, 0);
}
}

19
p/ISOParser.java
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@ -1,19 +0,0 @@
package p;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.io.IOException;
import filesystem.iso9660.PrimaryVolumeDescriptor;
class ISOParser {
public static void main(String[] args) throws IOException {
byte[] buf = Files.readAllBytes(Paths.get("test.iso"));
for (int i = PrimaryVolumeDescriptor.STANDARD_IDENTIFIER_START; i <= PrimaryVolumeDescriptor.STANDARD_IDENTIFIER_END; i++) {
System.out.print(buf[i]);
}
System.out.println();
}
}