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Apache Commons Compress software defines an API for working with
compression and archive formats. These include: bzip2, gzip, pack200,
lzma, xz, Snappy, traditional Unix Compress, DEFLATE, DEFLATE64, LZ4,
Brotli, Zstandard and ar, cpio, jar, tar, zip, dump, 7z, arj.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*
*/
/*
* This package is based on the work done by Timothy Gerard Endres
* ([email protected]) to whom the Ant project is very grateful for his great code.
*/
package org.apache.commons.compress.archivers.tar;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.compress.archivers.ArchiveEntry;
import org.apache.commons.compress.archivers.ArchiveInputStream;
import org.apache.commons.compress.archivers.zip.ZipEncoding;
import org.apache.commons.compress.archivers.zip.ZipEncodingHelper;
import org.apache.commons.compress.utils.ArchiveUtils;
import org.apache.commons.compress.utils.CharsetNames;
import org.apache.commons.compress.utils.IOUtils;
/**
* The TarInputStream reads a UNIX tar archive as an InputStream.
* methods are provided to position at each successive entry in
* the archive, and the read each entry as a normal input stream
* using read().
* @NotThreadSafe
*/
public class TarArchiveInputStream extends ArchiveInputStream {
private static final int SMALL_BUFFER_SIZE = 256;
private final byte[] smallBuf = new byte[SMALL_BUFFER_SIZE];
/** The size the TAR header */
private final int recordSize;
/** The size of a block */
private final int blockSize;
/** True if file has hit EOF */
private boolean hasHitEOF;
/** Size of the current entry */
private long entrySize;
/** How far into the entry the stream is at */
private long entryOffset;
/** An input stream to read from */
private final InputStream is;
/** The meta-data about the current entry */
private TarArchiveEntry currEntry;
/** The encoding of the file */
private final ZipEncoding zipEncoding;
// the provided encoding (for unit tests)
final String encoding;
// the global PAX header
private Map globalPaxHeaders = new HashMap<>();
/**
* Constructor for TarInputStream.
* @param is the input stream to use
*/
public TarArchiveInputStream(final InputStream is) {
this(is, TarConstants.DEFAULT_BLKSIZE, TarConstants.DEFAULT_RCDSIZE);
}
/**
* Constructor for TarInputStream.
* @param is the input stream to use
* @param encoding name of the encoding to use for file names
* @since 1.4
*/
public TarArchiveInputStream(final InputStream is, final String encoding) {
this(is, TarConstants.DEFAULT_BLKSIZE, TarConstants.DEFAULT_RCDSIZE,
encoding);
}
/**
* Constructor for TarInputStream.
* @param is the input stream to use
* @param blockSize the block size to use
*/
public TarArchiveInputStream(final InputStream is, final int blockSize) {
this(is, blockSize, TarConstants.DEFAULT_RCDSIZE);
}
/**
* Constructor for TarInputStream.
* @param is the input stream to use
* @param blockSize the block size to use
* @param encoding name of the encoding to use for file names
* @since 1.4
*/
public TarArchiveInputStream(final InputStream is, final int blockSize,
final String encoding) {
this(is, blockSize, TarConstants.DEFAULT_RCDSIZE, encoding);
}
/**
* Constructor for TarInputStream.
* @param is the input stream to use
* @param blockSize the block size to use
* @param recordSize the record size to use
*/
public TarArchiveInputStream(final InputStream is, final int blockSize, final int recordSize) {
this(is, blockSize, recordSize, null);
}
/**
* Constructor for TarInputStream.
* @param is the input stream to use
* @param blockSize the block size to use
* @param recordSize the record size to use
* @param encoding name of the encoding to use for file names
* @since 1.4
*/
public TarArchiveInputStream(final InputStream is, final int blockSize, final int recordSize,
final String encoding) {
this.is = is;
this.hasHitEOF = false;
this.encoding = encoding;
this.zipEncoding = ZipEncodingHelper.getZipEncoding(encoding);
this.recordSize = recordSize;
this.blockSize = blockSize;
}
/**
* Closes this stream. Calls the TarBuffer's close() method.
* @throws IOException on error
*/
@Override
public void close() throws IOException {
is.close();
}
/**
* Get the record size being used by this stream's buffer.
*
* @return The TarBuffer record size.
*/
public int getRecordSize() {
return recordSize;
}
/**
* Get the available data that can be read from the current
* entry in the archive. This does not indicate how much data
* is left in the entire archive, only in the current entry.
* This value is determined from the entry's size header field
* and the amount of data already read from the current entry.
* Integer.MAX_VALUE is returned in case more than Integer.MAX_VALUE
* bytes are left in the current entry in the archive.
*
* @return The number of available bytes for the current entry.
* @throws IOException for signature
*/
@Override
public int available() throws IOException {
if (isDirectory()) {
return 0;
}
if (entrySize - entryOffset > Integer.MAX_VALUE) {
return Integer.MAX_VALUE;
}
return (int) (entrySize - entryOffset);
}
/**
* Skips over and discards n bytes of data from this input
* stream. The skip method may, for a variety of reasons, end
* up skipping over some smaller number of bytes, possibly 0.
* This may result from any of a number of conditions; reaching end of file
* or end of entry before n bytes have been skipped; are only
* two possibilities. The actual number of bytes skipped is returned. If
* n is negative, no bytes are skipped.
*
*
* @param n
* the number of bytes to be skipped.
* @return the actual number of bytes skipped.
* @throws IOException
* if some other I/O error occurs.
*/
@Override
public long skip(final long n) throws IOException {
if (n <= 0 || isDirectory()) {
return 0;
}
final long available = entrySize - entryOffset;
final long skipped = is.skip(Math.min(n, available));
count(skipped);
entryOffset += skipped;
return skipped;
}
/**
* Since we do not support marking just yet, we return false.
*
* @return False.
*/
@Override
public boolean markSupported() {
return false;
}
/**
* Since we do not support marking just yet, we do nothing.
*
* @param markLimit The limit to mark.
*/
@Override
public void mark(final int markLimit) {
}
/**
* Since we do not support marking just yet, we do nothing.
*/
@Override
public synchronized void reset() {
}
/**
* Get the next entry in this tar archive. This will skip
* over any remaining data in the current entry, if there
* is one, and place the input stream at the header of the
* next entry, and read the header and instantiate a new
* TarEntry from the header bytes and return that entry.
* If there are no more entries in the archive, null will
* be returned to indicate that the end of the archive has
* been reached.
*
* @return The next TarEntry in the archive, or null.
* @throws IOException on error
*/
public TarArchiveEntry getNextTarEntry() throws IOException {
if (isAtEOF()) {
return null;
}
if (currEntry != null) {
/* Skip will only go to the end of the current entry */
IOUtils.skip(this, Long.MAX_VALUE);
/* skip to the end of the last record */
skipRecordPadding();
}
final byte[] headerBuf = getRecord();
if (headerBuf == null) {
/* hit EOF */
currEntry = null;
return null;
}
try {
currEntry = new TarArchiveEntry(headerBuf, zipEncoding);
} catch (final IllegalArgumentException e) {
throw new IOException("Error detected parsing the header", e);
}
entryOffset = 0;
entrySize = currEntry.getSize();
if (currEntry.isGNULongLinkEntry()) {
final byte[] longLinkData = getLongNameData();
if (longLinkData == null) {
// Bugzilla: 40334
// Malformed tar file - long link entry name not followed by
// entry
return null;
}
currEntry.setLinkName(zipEncoding.decode(longLinkData));
}
if (currEntry.isGNULongNameEntry()) {
final byte[] longNameData = getLongNameData();
if (longNameData == null) {
// Bugzilla: 40334
// Malformed tar file - long entry name not followed by
// entry
return null;
}
currEntry.setName(zipEncoding.decode(longNameData));
}
if (currEntry.isGlobalPaxHeader()){ // Process Global Pax headers
readGlobalPaxHeaders();
}
if (currEntry.isPaxHeader()){ // Process Pax headers
paxHeaders();
} else if (!globalPaxHeaders.isEmpty()) {
applyPaxHeadersToCurrentEntry(globalPaxHeaders);
}
if (currEntry.isOldGNUSparse()){ // Process sparse files
readOldGNUSparse();
}
// If the size of the next element in the archive has changed
// due to a new size being reported in the posix header
// information, we update entrySize here so that it contains
// the correct value.
entrySize = currEntry.getSize();
return currEntry;
}
/**
* The last record block should be written at the full size, so skip any
* additional space used to fill a record after an entry
*/
private void skipRecordPadding() throws IOException {
if (!isDirectory() && this.entrySize > 0 && this.entrySize % this.recordSize != 0) {
final long numRecords = (this.entrySize / this.recordSize) + 1;
final long padding = (numRecords * this.recordSize) - this.entrySize;
final long skipped = IOUtils.skip(is, padding);
count(skipped);
}
}
/**
* Get the next entry in this tar archive as longname data.
*
* @return The next entry in the archive as longname data, or null.
* @throws IOException on error
*/
protected byte[] getLongNameData() throws IOException {
// read in the name
final ByteArrayOutputStream longName = new ByteArrayOutputStream();
int length = 0;
while ((length = read(smallBuf)) >= 0) {
longName.write(smallBuf, 0, length);
}
getNextEntry();
if (currEntry == null) {
// Bugzilla: 40334
// Malformed tar file - long entry name not followed by entry
return null;
}
byte[] longNameData = longName.toByteArray();
// remove trailing null terminator(s)
length = longNameData.length;
while (length > 0 && longNameData[length - 1] == 0) {
--length;
}
if (length != longNameData.length) {
final byte[] l = new byte[length];
System.arraycopy(longNameData, 0, l, 0, length);
longNameData = l;
}
return longNameData;
}
/**
* Get the next record in this tar archive. This will skip
* over any remaining data in the current entry, if there
* is one, and place the input stream at the header of the
* next entry.
*
* If there are no more entries in the archive, null will be
* returned to indicate that the end of the archive has been
* reached. At the same time the {@code hasHitEOF} marker will be
* set to true.
*
* @return The next header in the archive, or null.
* @throws IOException on error
*/
private byte[] getRecord() throws IOException {
byte[] headerBuf = readRecord();
setAtEOF(isEOFRecord(headerBuf));
if (isAtEOF() && headerBuf != null) {
tryToConsumeSecondEOFRecord();
consumeRemainderOfLastBlock();
headerBuf = null;
}
return headerBuf;
}
/**
* Determine if an archive record indicate End of Archive. End of
* archive is indicated by a record that consists entirely of null bytes.
*
* @param record The record data to check.
* @return true if the record data is an End of Archive
*/
protected boolean isEOFRecord(final byte[] record) {
return record == null || ArchiveUtils.isArrayZero(record, recordSize);
}
/**
* Read a record from the input stream and return the data.
*
* @return The record data or null if EOF has been hit.
* @throws IOException on error
*/
protected byte[] readRecord() throws IOException {
final byte[] record = new byte[recordSize];
final int readNow = IOUtils.readFully(is, record);
count(readNow);
if (readNow != recordSize) {
return null;
}
return record;
}
private void readGlobalPaxHeaders() throws IOException {
globalPaxHeaders = parsePaxHeaders(this);
getNextEntry(); // Get the actual file entry
}
private void paxHeaders() throws IOException{
final Map headers = parsePaxHeaders(this);
getNextEntry(); // Get the actual file entry
applyPaxHeadersToCurrentEntry(headers);
}
// NOTE, using a Map here makes it impossible to ever support GNU
// sparse files using the PAX Format 0.0, see
// https://www.gnu.org/software/tar/manual/html_section/tar_92.html#SEC188
Map parsePaxHeaders(final InputStream i)
throws IOException {
final Map headers = new HashMap<>(globalPaxHeaders);
// Format is "length keyword=value\n";
while(true){ // get length
int ch;
int len = 0;
int read = 0;
while((ch = i.read()) != -1) {
read++;
if (ch == '\n') { // blank line in header
break;
} else if (ch == ' '){ // End of length string
// Get keyword
final ByteArrayOutputStream coll = new ByteArrayOutputStream();
while((ch = i.read()) != -1) {
read++;
if (ch == '='){ // end of keyword
final String keyword = coll.toString(CharsetNames.UTF_8);
// Get rest of entry
final int restLen = len - read;
if (restLen == 1) { // only NL
headers.remove(keyword);
} else {
final byte[] rest = new byte[restLen];
final int got = IOUtils.readFully(i, rest);
if (got != restLen) {
throw new IOException("Failed to read "
+ "Paxheader. Expected "
+ restLen
+ " bytes, read "
+ got);
}
// Drop trailing NL
final String value = new String(rest, 0,
restLen - 1, CharsetNames.UTF_8);
headers.put(keyword, value);
}
break;
}
coll.write((byte) ch);
}
break; // Processed single header
}
len *= 10;
len += ch - '0';
}
if (ch == -1){ // EOF
break;
}
}
return headers;
}
private void applyPaxHeadersToCurrentEntry(final Map headers) {
currEntry.updateEntryFromPaxHeaders(headers);
}
/**
* Adds the sparse chunks from the current entry to the sparse chunks,
* including any additional sparse entries following the current entry.
*
* @throws IOException on error
*
* @todo Sparse files get not yet really processed.
*/
private void readOldGNUSparse() throws IOException {
/* we do not really process sparse files yet
sparses = new ArrayList();
sparses.addAll(currEntry.getSparses());
*/
if (currEntry.isExtended()) {
TarArchiveSparseEntry entry;
do {
final byte[] headerBuf = getRecord();
if (headerBuf == null) {
currEntry = null;
break;
}
entry = new TarArchiveSparseEntry(headerBuf);
/* we do not really process sparse files yet
sparses.addAll(entry.getSparses());
*/
} while (entry.isExtended());
}
}
private boolean isDirectory() {
return currEntry != null && currEntry.isDirectory();
}
/**
* Returns the next Archive Entry in this Stream.
*
* @return the next entry,
* or {@code null} if there are no more entries
* @throws IOException if the next entry could not be read
*/
@Override
public ArchiveEntry getNextEntry() throws IOException {
return getNextTarEntry();
}
/**
* Tries to read the next record rewinding the stream if it is not a EOF record.
*
* This is meant to protect against cases where a tar
* implementation has written only one EOF record when two are
* expected. Actually this won't help since a non-conforming
* implementation likely won't fill full blocks consisting of - by
* default - ten records either so we probably have already read
* beyond the archive anyway.
*/
private void tryToConsumeSecondEOFRecord() throws IOException {
boolean shouldReset = true;
final boolean marked = is.markSupported();
if (marked) {
is.mark(recordSize);
}
try {
shouldReset = !isEOFRecord(readRecord());
} finally {
if (shouldReset && marked) {
pushedBackBytes(recordSize);
is.reset();
}
}
}
/**
* Reads bytes from the current tar archive entry.
*
* This method is aware of the boundaries of the current
* entry in the archive and will deal with them as if they
* were this stream's start and EOF.
*
* @param buf The buffer into which to place bytes read.
* @param offset The offset at which to place bytes read.
* @param numToRead The number of bytes to read.
* @return The number of bytes read, or -1 at EOF.
* @throws IOException on error
*/
@Override
public int read(final byte[] buf, final int offset, int numToRead) throws IOException {
int totalRead = 0;
if (isAtEOF() || isDirectory() || entryOffset >= entrySize) {
return -1;
}
if (currEntry == null) {
throw new IllegalStateException("No current tar entry");
}
numToRead = Math.min(numToRead, available());
totalRead = is.read(buf, offset, numToRead);
if (totalRead == -1) {
if (numToRead > 0) {
throw new IOException("Truncated TAR archive");
}
setAtEOF(true);
} else {
count(totalRead);
entryOffset += totalRead;
}
return totalRead;
}
/**
* Whether this class is able to read the given entry.
*
* May return false if the current entry is a sparse file.
*/
@Override
public boolean canReadEntryData(final ArchiveEntry ae) {
if (ae instanceof TarArchiveEntry) {
final TarArchiveEntry te = (TarArchiveEntry) ae;
return !te.isSparse();
}
return false;
}
/**
* Get the current TAR Archive Entry that this input stream is processing
*
* @return The current Archive Entry
*/
public TarArchiveEntry getCurrentEntry() {
return currEntry;
}
protected final void setCurrentEntry(final TarArchiveEntry e) {
currEntry = e;
}
protected final boolean isAtEOF() {
return hasHitEOF;
}
protected final void setAtEOF(final boolean b) {
hasHitEOF = b;
}
/**
* This method is invoked once the end of the archive is hit, it
* tries to consume the remaining bytes under the assumption that
* the tool creating this archive has padded the last block.
*/
private void consumeRemainderOfLastBlock() throws IOException {
final long bytesReadOfLastBlock = getBytesRead() % blockSize;
if (bytesReadOfLastBlock > 0) {
final long skipped = IOUtils.skip(is, blockSize - bytesReadOfLastBlock);
count(skipped);
}
}
/**
* Checks if the signature matches what is expected for a tar file.
*
* @param signature
* the bytes to check
* @param length
* the number of bytes to check
* @return true, if this stream is a tar archive stream, false otherwise
*/
public static boolean matches(final byte[] signature, final int length) {
if (length < TarConstants.VERSION_OFFSET+TarConstants.VERSIONLEN) {
return false;
}
if (ArchiveUtils.matchAsciiBuffer(TarConstants.MAGIC_POSIX,
signature, TarConstants.MAGIC_OFFSET, TarConstants.MAGICLEN)
&&
ArchiveUtils.matchAsciiBuffer(TarConstants.VERSION_POSIX,
signature, TarConstants.VERSION_OFFSET, TarConstants.VERSIONLEN)
){
return true;
}
if (ArchiveUtils.matchAsciiBuffer(TarConstants.MAGIC_GNU,
signature, TarConstants.MAGIC_OFFSET, TarConstants.MAGICLEN)
&&
(
ArchiveUtils.matchAsciiBuffer(TarConstants.VERSION_GNU_SPACE,
signature, TarConstants.VERSION_OFFSET, TarConstants.VERSIONLEN)
||
ArchiveUtils.matchAsciiBuffer(TarConstants.VERSION_GNU_ZERO,
signature, TarConstants.VERSION_OFFSET, TarConstants.VERSIONLEN)
)
){
return true;
}
// COMPRESS-107 - recognise Ant tar files
if (ArchiveUtils.matchAsciiBuffer(TarConstants.MAGIC_ANT,
signature, TarConstants.MAGIC_OFFSET, TarConstants.MAGICLEN)
&&
ArchiveUtils.matchAsciiBuffer(TarConstants.VERSION_ANT,
signature, TarConstants.VERSION_OFFSET, TarConstants.VERSIONLEN)
){
return true;
}
return false;
}
}