ObjFW  Check-in [9db1965939]

 * Public License, either version 2 or 3, which can be found in the file
 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#import "OFObject.h"
#import "OFKernelEventObserver.h"
#import "OFString.h"
#import "OFTarArchiveEntry.h"

OF_ASSUME_NONNULL_BEGIN


@class OFStream;

/*!
 * @class OFTarArchive OFTarArchive.h ObjFW/OFTarArchive.h
 *
 * @brief A class for accessing and manipulating tar archives.
 */
@interface OFTarArchive: OFObject
{
	OF_KINDOF(OFStream *) _stream;
	enum {
		OF_TAR_ARCHIVE_MODE_READ,
		OF_TAR_ARCHIVE_MODE_WRITE,
		OF_TAR_ARCHIVE_MODE_APPEND
	} _mode;
	of_string_encoding_t _encoding;
	OF_KINDOF(OFStream *) _Nullable _lastReturnedStream;
}

/*!
 * @brief The encoding to use for the archive.
 */
@property (nonatomic) of_string_encoding_t encoding;

/*!
 * @brief A stream for reading the current entry
 *
 * @note This is only available in read mode.
 *
 * @note The returned stream only conforms to @ref OFReadyForReadingObserving if
 *	 the underlying stream does so, too.

}

- (instancetype)initWithStream: (OFStream *)stream
			 entry: (OFTarArchiveEntry *)entry;
@end

@implementation OFTarArchive: OFObject
@synthesize encoding = _encoding;

+ (instancetype)archiveWithStream: (OF_KINDOF(OFStream *))stream
			     mode: (OFString *)mode
{
	return [[[self alloc] initWithStream: stream
					mode: mode] autorelease];
}

			if (!empty)
				@throw [OFInvalidFormatException exception];

			[stream seekToOffset: -1024
				      whence: SEEK_END];
		}

		_encoding = OF_STRING_ENCODING_UTF_8;
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

			if (buffer.u32[i] != 0)
				@throw [OFInvalidFormatException exception];

		return nil;
	}

	entry = [[[OFTarArchiveEntry alloc]
	    of_initWithHeader: buffer.c
		     encoding: _encoding] autorelease];

	_lastReturnedStream = [[OFTarArchive_FileReadStream alloc]
	    initWithStream: _stream
		     entry: entry];

	return entry;
}

	pool = objc_autoreleasePoolPush();

	[_lastReturnedStream close];
	[_lastReturnedStream release];
	_lastReturnedStream = nil;

	[entry of_writeToStream: _stream
		       encoding: _encoding];

	_lastReturnedStream = [[OFTarArchive_FileWriteStream alloc]
	    initWithStream: _stream
		     entry: entry];

	objc_autoreleasePoolPop(pool);

 * Alternatively, it may be distributed under the terms of the GNU General
 * Public License, either version 2 or 3, which can be found in the file
 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#import "OFTarArchiveEntry.h"
#import "OFString.h"

OF_ASSUME_NONNULL_BEGIN

@class OFStream;

@interface OFTarArchiveEntry ()
- (instancetype)of_initWithHeader: (unsigned char [_Nonnull 512])header
			 encoding: (of_string_encoding_t)encoding
    OF_METHOD_FAMILY(init);
- (void)of_writeToStream: (OFStream *)stream
		encoding: (of_string_encoding_t)encoding;
@end

OF_ASSUME_NONNULL_END

#import "OFDate.h"
#import "OFStream.h"
#import "OFString.h"

#import "OFOutOfRangeException.h"

static OFString *
stringFromBuffer(const unsigned char *buffer, size_t length,
    of_string_encoding_t encoding)
{
	for (size_t i = 0; i < length; i++)
		if (buffer[i] == '\0')
			length = i;

	return [OFString stringWithCString: (const char *)buffer
				  encoding: encoding
				    length: length];
}

static void
stringToBuffer(unsigned char *buffer, OFString *string, size_t length,
    of_string_encoding_t encoding)
{
	size_t cStringLength = [string cStringLengthWithEncoding: encoding];

	if (cStringLength > length)
		@throw [OFOutOfRangeException exception];

	memcpy(buffer, [string cStringWithEncoding: encoding], cStringLength);

	for (size_t i = cStringLength; i < length; i++)
		buffer[i] = '\0';
}

static uintmax_t
octalValueFromBuffer(const unsigned char *buffer, size_t length, uintmax_t max)
{
	uintmax_t value = 0;

	if (length == 0)
		return 0;

	if (buffer[0] == 0x80) {
		for (size_t i = 1; i < length; i++)
			value = (value << 8) | buffer[i];
	} else
		value = [stringFromBuffer(buffer, length,
		    OF_STRING_ENCODING_ASCII) octalValue];

	if (value > max)
		@throw [OFOutOfRangeException exception];

	return value;
}

@implementation OFTarArchiveEntry
+ (instancetype)entryWithFileName: (OFString *)fileName
{
	return [[[self alloc] initWithFileName: fileName] autorelease];
}

- (instancetype)init
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)of_initWithHeader: (unsigned char [512])header
			 encoding: (of_string_encoding_t)encoding
{
	self = [super init];

	@try {
		void *pool = objc_autoreleasePoolPush();
		OFString *targetFileName;

		_fileName = [stringFromBuffer(header, 100, encoding) copy];
		_mode = (uint32_t)octalValueFromBuffer(
		    header + 100, 8, UINT32_MAX);
		_UID = (uint32_t)octalValueFromBuffer(
		    header + 108, 8, UINT32_MAX);
		_GID = (uint32_t)octalValueFromBuffer(
		    header + 116, 8, UINT32_MAX);
		_size = (uint64_t)octalValueFromBuffer(
		    header + 124, 12, UINT64_MAX);
		_modificationDate = [[OFDate alloc]
		    initWithTimeIntervalSince1970:
		    (of_time_interval_t)octalValueFromBuffer(
		    header + 136, 12, UINTMAX_MAX)];
		_type = header[156];

		targetFileName = stringFromBuffer(header + 157, 100, encoding);
		if ([targetFileName length] > 0)
			_targetFileName = [targetFileName copy];

		if (_type == '\0')
			_type = OF_TAR_ARCHIVE_ENTRY_TYPE_FILE;

		if (memcmp(header + 257, "ustar\0" "00", 8) == 0) {
			OFString *prefix;

			_owner = [stringFromBuffer(header + 265, 32, encoding)
			    copy];
			_group = [stringFromBuffer(header + 297, 32, encoding)
			    copy];

			_deviceMajor = (uint32_t)octalValueFromBuffer(
			    header + 329, 8, UINT32_MAX);
			_deviceMinor = (uint32_t)octalValueFromBuffer(
			    header + 337, 8, UINT32_MAX);

			prefix = stringFromBuffer(header + 345, 155, encoding);
			if ([prefix length] > 0) {
				OFString *fileName = [OFString
				    stringWithFormat: @"%@/%@",
						      prefix, _fileName];
				[_fileName release];
				_fileName = [fileName copy];
			}

	objc_autoreleasePoolPop(pool);

	return [ret autorelease];
}

- (void)of_writeToStream: (OFStream *)stream
		encoding: (of_string_encoding_t)encoding
{
	unsigned char buffer[512];
	uint64_t modificationDate;
	uint16_t checksum = 0;

	stringToBuffer(buffer, _fileName, 100, encoding);
	stringToBuffer(buffer + 100,
	    [OFString stringWithFormat: @"%06" PRIo16 " ", _mode], 8,
	    OF_STRING_ENCODING_ASCII);
	stringToBuffer(buffer + 108,
	    [OFString stringWithFormat: @"%06" PRIo16 " ", _UID], 8,
	    OF_STRING_ENCODING_ASCII);
	stringToBuffer(buffer + 116,
	    [OFString stringWithFormat: @"%06" PRIo16 " ", _GID], 8,
	    OF_STRING_ENCODING_ASCII);
	stringToBuffer(buffer + 124,
	    [OFString stringWithFormat: @"%011" PRIo64 " ", _size], 12,
	    OF_STRING_ENCODING_ASCII);
	modificationDate = [_modificationDate timeIntervalSince1970];
	stringToBuffer(buffer + 136,
	    [OFString stringWithFormat: @"%011" PRIo64 " ", modificationDate],
	    12, OF_STRING_ENCODING_ASCII);

	/*
	 * During checksumming, the checksum field is expected to be set to 8
	 * spaces.
	 */
	memset(buffer + 148, ' ', 8);

	buffer[156] = _type;
	stringToBuffer(buffer + 157, _targetFileName, 100, encoding);

	/* ustar */
	memcpy(buffer + 257, "ustar\0" "00", 8);
	stringToBuffer(buffer + 265, _owner, 32, encoding);
	stringToBuffer(buffer + 297, _group, 32, encoding);
	stringToBuffer(buffer + 329,
	    [OFString stringWithFormat: @"%06" PRIo32 " ", _deviceMajor], 8,
	    OF_STRING_ENCODING_ASCII);
	stringToBuffer(buffer + 337,
	    [OFString stringWithFormat: @"%06" PRIo32 " ", _deviceMinor], 8,
	    OF_STRING_ENCODING_ASCII);
	memset(buffer + 345, '\0', 155 + 12);

	/* Fill in the checksum */
	for (size_t i = 0; i < 500; i++)
		checksum += buffer[i];
	stringToBuffer(buffer + 148,
	    [OFString stringWithFormat: @"%06" PRIo16, checksum], 7,
	    OF_STRING_ENCODING_ASCII);

	[stream writeBuffer: buffer
		     length: sizeof(buffer)];
}
@end