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#! /usr/bin/python3.9 #------------------------------------------------------------------- # tarfile.py #------------------------------------------------------------------- # Copyright (C) 2002 Lars Gustaebel <lars@gustaebel.de> # All rights reserved. # # Permission is hereby granted, free of charge, to any person # obtaining a copy of this software and associated documentation # files (the "Software"), to deal in the Software without # restriction, including without limitation the rights to use, # copy, modify, merge, publish, distribute, sublicense, and/or sell # copies of the Software, and to permit persons to whom the # Software is furnished to do so, subject to the following # conditions: # # The above copyright notice and this permission notice shall be # included in all copies or substantial portions of the Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES # OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR # OTHER DEALINGS IN THE SOFTWARE. # """Read from and write to tar format archives. """ version = "0.9.0" __author__ = "Lars Gust\u00e4bel (lars@gustaebel.de)" __credits__ = "Gustavo Niemeyer, Niels Gust\u00e4bel, Richard Townsend." #--------- # Imports #--------- from builtins import open as bltn_open import sys import os import io import shutil import stat import time import struct import copy import re import warnings try: import pwd except ImportError: pwd = None try: import grp except ImportError: grp = None # os.symlink on Windows prior to 6.0 raises NotImplementedError symlink_exception = (AttributeError, NotImplementedError) try: # OSError (winerror=1314) will be raised if the caller does not hold the # SeCreateSymbolicLinkPrivilege privilege symlink_exception += (OSError,) except NameError: pass # from tarfile import * __all__ = ["TarFile", "TarInfo", "is_tarfile", "TarError", "ReadError", "CompressionError", "StreamError", "ExtractError", "HeaderError", "ENCODING", "USTAR_FORMAT", "GNU_FORMAT", "PAX_FORMAT", "DEFAULT_FORMAT", "open"] # If true, use the safer (but backwards-incompatible) 'tar' extraction filter, # rather than 'fully_trusted', by default. # The emitted warning is changed to match. _RH_SAFER_DEFAULT = True # System-wide configuration file _CONFIG_FILENAME = '/etc/python/tarfile.cfg' #--------------------------------------------------------- # tar constants #--------------------------------------------------------- NUL = b"\0" # the null character BLOCKSIZE = 512 # length of processing blocks RECORDSIZE = BLOCKSIZE * 20 # length of records GNU_MAGIC = b"ustar \0" # magic gnu tar string POSIX_MAGIC = b"ustar\x0000" # magic posix tar string LENGTH_NAME = 100 # maximum length of a filename LENGTH_LINK = 100 # maximum length of a linkname LENGTH_PREFIX = 155 # maximum length of the prefix field REGTYPE = b"0" # regular file AREGTYPE = b"\0" # regular file LNKTYPE = b"1" # link (inside tarfile) SYMTYPE = b"2" # symbolic link CHRTYPE = b"3" # character special device BLKTYPE = b"4" # block special device DIRTYPE = b"5" # directory FIFOTYPE = b"6" # fifo special device CONTTYPE = b"7" # contiguous file GNUTYPE_LONGNAME = b"L" # GNU tar longname GNUTYPE_LONGLINK = b"K" # GNU tar longlink GNUTYPE_SPARSE = b"S" # GNU tar sparse file XHDTYPE = b"x" # POSIX.1-2001 extended header XGLTYPE = b"g" # POSIX.1-2001 global header SOLARIS_XHDTYPE = b"X" # Solaris extended header USTAR_FORMAT = 0 # POSIX.1-1988 (ustar) format GNU_FORMAT = 1 # GNU tar format PAX_FORMAT = 2 # POSIX.1-2001 (pax) format DEFAULT_FORMAT = PAX_FORMAT #--------------------------------------------------------- # tarfile constants #--------------------------------------------------------- # File types that tarfile supports: SUPPORTED_TYPES = (REGTYPE, AREGTYPE, LNKTYPE, SYMTYPE, DIRTYPE, FIFOTYPE, CONTTYPE, CHRTYPE, BLKTYPE, GNUTYPE_LONGNAME, GNUTYPE_LONGLINK, GNUTYPE_SPARSE) # File types that will be treated as a regular file. REGULAR_TYPES = (REGTYPE, AREGTYPE, CONTTYPE, GNUTYPE_SPARSE) # File types that are part of the GNU tar format. GNU_TYPES = (GNUTYPE_LONGNAME, GNUTYPE_LONGLINK, GNUTYPE_SPARSE) # Fields from a pax header that override a TarInfo attribute. PAX_FIELDS = ("path", "linkpath", "size", "mtime", "uid", "gid", "uname", "gname") # Fields from a pax header that are affected by hdrcharset. PAX_NAME_FIELDS = {"path", "linkpath", "uname", "gname"} # Fields in a pax header that are numbers, all other fields # are treated as strings. PAX_NUMBER_FIELDS = { "atime": float, "ctime": float, "mtime": float, "uid": int, "gid": int, "size": int } #--------------------------------------------------------- # initialization #--------------------------------------------------------- if os.name == "nt": ENCODING = "utf-8" else: ENCODING = sys.getfilesystemencoding() #--------------------------------------------------------- # Some useful functions #--------------------------------------------------------- def stn(s, length, encoding, errors): """Convert a string to a null-terminated bytes object. """ if s is None: raise ValueError("metadata cannot contain None") s = s.encode(encoding, errors) return s[:length] + (length - len(s)) * NUL def nts(s, encoding, errors): """Convert a null-terminated bytes object to a string. """ p = s.find(b"\0") if p != -1: s = s[:p] return s.decode(encoding, errors) def nti(s): """Convert a number field to a python number. """ # There are two possible encodings for a number field, see # itn() below. if s[0] in (0o200, 0o377): n = 0 for i in range(len(s) - 1): n <<= 8 n += s[i + 1] if s[0] == 0o377: n = -(256 ** (len(s) - 1) - n) else: try: s = nts(s, "ascii", "strict") n = int(s.strip() or "0", 8) except ValueError: raise InvalidHeaderError("invalid header") return n def itn(n, digits=8, format=DEFAULT_FORMAT): """Convert a python number to a number field. """ # POSIX 1003.1-1988 requires numbers to be encoded as a string of # octal digits followed by a null-byte, this allows values up to # (8**(digits-1))-1. GNU tar allows storing numbers greater than # that if necessary. A leading 0o200 or 0o377 byte indicate this # particular encoding, the following digits-1 bytes are a big-endian # base-256 representation. This allows values up to (256**(digits-1))-1. # A 0o200 byte indicates a positive number, a 0o377 byte a negative # number. n = int(n) if 0 <= n < 8 ** (digits - 1): s = bytes("%0*o" % (digits - 1, n), "ascii") + NUL elif format == GNU_FORMAT and -256 ** (digits - 1) <= n < 256 ** (digits - 1): if n >= 0: s = bytearray([0o200]) else: s = bytearray([0o377]) n = 256 ** digits + n for i in range(digits - 1): s.insert(1, n & 0o377) n >>= 8 else: raise ValueError("overflow in number field") return s def calc_chksums(buf): """Calculate the checksum for a member's header by summing up all characters except for the chksum field which is treated as if it was filled with spaces. According to the GNU tar sources, some tars (Sun and NeXT) calculate chksum with signed char, which will be different if there are chars in the buffer with the high bit set. So we calculate two checksums, unsigned and signed. """ unsigned_chksum = 256 + sum(struct.unpack_from("148B8x356B", buf)) signed_chksum = 256 + sum(struct.unpack_from("148b8x356b", buf)) return unsigned_chksum, signed_chksum def copyfileobj(src, dst, length=None, exception=OSError, bufsize=None): """Copy length bytes from fileobj src to fileobj dst. If length is None, copy the entire content. """ bufsize = bufsize or 16 * 1024 if length == 0: return if length is None: shutil.copyfileobj(src, dst, bufsize) return blocks, remainder = divmod(length, bufsize) for b in range(blocks): buf = src.read(bufsize) if len(buf) < bufsize: raise exception("unexpected end of data") dst.write(buf) if remainder != 0: buf = src.read(remainder) if len(buf) < remainder: raise exception("unexpected end of data") dst.write(buf) return def _safe_print(s): encoding = getattr(sys.stdout, 'encoding', None) if encoding is not None: s = s.encode(encoding, 'backslashreplace').decode(encoding) print(s, end=' ') class TarError(Exception): """Base exception.""" pass class ExtractError(TarError): """General exception for extract errors.""" pass class ReadError(TarError): """Exception for unreadable tar archives.""" pass class CompressionError(TarError): """Exception for unavailable compression methods.""" pass class StreamError(TarError): """Exception for unsupported operations on stream-like TarFiles.""" pass class HeaderError(TarError): """Base exception for header errors.""" pass class EmptyHeaderError(HeaderError): """Exception for empty headers.""" pass class TruncatedHeaderError(HeaderError): """Exception for truncated headers.""" pass class EOFHeaderError(HeaderError): """Exception for end of file headers.""" pass class InvalidHeaderError(HeaderError): """Exception for invalid headers.""" pass class SubsequentHeaderError(HeaderError): """Exception for missing and invalid extended headers.""" pass #--------------------------- # internal stream interface #--------------------------- class _LowLevelFile: """Low-level file object. Supports reading and writing. It is used instead of a regular file object for streaming access. """ def __init__(self, name, mode): mode = { "r": os.O_RDONLY, "w": os.O_WRONLY | os.O_CREAT | os.O_TRUNC, }[mode] if hasattr(os, "O_BINARY"): mode |= os.O_BINARY self.fd = os.open(name, mode, 0o666) def close(self): os.close(self.fd) def read(self, size): return os.read(self.fd, size) def write(self, s): os.write(self.fd, s) class _Stream: """Class that serves as an adapter between TarFile and a stream-like object. The stream-like object only needs to have a read() or write() method and is accessed blockwise. Use of gzip or bzip2 compression is possible. A stream-like object could be for example: sys.stdin, sys.stdout, a socket, a tape device etc. _Stream is intended to be used only internally. """ def __init__(self, name, mode, comptype, fileobj, bufsize): """Construct a _Stream object. """ self._extfileobj = True if fileobj is None: fileobj = _LowLevelFile(name, mode) self._extfileobj = False if comptype == '*': # Enable transparent compression detection for the # stream interface fileobj = _StreamProxy(fileobj) comptype = fileobj.getcomptype() self.name = name or "" self.mode = mode self.comptype = comptype self.fileobj = fileobj self.bufsize = bufsize self.buf = b"" self.pos = 0 self.closed = False try: if comptype == "gz": try: import zlib except ImportError: raise CompressionError("zlib module is not available") self.zlib = zlib self.crc = zlib.crc32(b"") if mode == "r": self._init_read_gz() self.exception = zlib.error else: self._init_write_gz() elif comptype == "bz2": try: import bz2 except ImportError: raise CompressionError("bz2 module is not available") if mode == "r": self.dbuf = b"" self.cmp = bz2.BZ2Decompressor() self.exception = OSError else: self.cmp = bz2.BZ2Compressor() elif comptype == "xz": try: import lzma except ImportError: raise CompressionError("lzma module is not available") if mode == "r": self.dbuf = b"" self.cmp = lzma.LZMADecompressor() self.exception = lzma.LZMAError else: self.cmp = lzma.LZMACompressor() elif comptype != "tar": raise CompressionError("unknown compression type %r" % comptype) except: if not self._extfileobj: self.fileobj.close() self.closed = True raise def __del__(self): if hasattr(self, "closed") and not self.closed: self.close() def _init_write_gz(self): """Initialize for writing with gzip compression. """ self.cmp = self.zlib.compressobj(9, self.zlib.DEFLATED, -self.zlib.MAX_WBITS, self.zlib.DEF_MEM_LEVEL, 0) timestamp = struct.pack("<L", int(time.time())) self.__write(b"\037\213\010\010" + timestamp + b"\002\377") if self.name.endswith(".gz"): self.name = self.name[:-3] # Honor "directory components removed" from RFC1952 self.name = os.path.basename(self.name) # RFC1952 says we must use ISO-8859-1 for the FNAME field. self.__write(self.name.encode("iso-8859-1", "replace") + NUL) def write(self, s): """Write string s to the stream. """ if self.comptype == "gz": self.crc = self.zlib.crc32(s, self.crc) self.pos += len(s) if self.comptype != "tar": s = self.cmp.compress(s) self.__write(s) def __write(self, s): """Write string s to the stream if a whole new block is ready to be written. """ self.buf += s while len(self.buf) > self.bufsize: self.fileobj.write(self.buf[:self.bufsize]) self.buf = self.buf[self.bufsize:] def close(self): """Close the _Stream object. No operation should be done on it afterwards. """ if self.closed: return self.closed = True try: if self.mode == "w" and self.comptype != "tar": self.buf += self.cmp.flush() if self.mode == "w" and self.buf: self.fileobj.write(self.buf) self.buf = b"" if self.comptype == "gz": self.fileobj.write(struct.pack("<L", self.crc)) self.fileobj.write(struct.pack("<L", self.pos & 0xffffFFFF)) finally: if not self._extfileobj: self.fileobj.close() def _init_read_gz(self): """Initialize for reading a gzip compressed fileobj. """ self.cmp = self.zlib.decompressobj(-self.zlib.MAX_WBITS) self.dbuf = b"" # taken from gzip.GzipFile with some alterations if self.__read(2) != b"\037\213": raise ReadError("not a gzip file") if self.__read(1) != b"\010": raise CompressionError("unsupported compression method") flag = ord(self.__read(1)) self.__read(6) if flag & 4: xlen = ord(self.__read(1)) + 256 * ord(self.__read(1)) self.read(xlen) if flag & 8: while True: s = self.__read(1) if not s or s == NUL: break if flag & 16: while True: s = self.__read(1) if not s or s == NUL: break if flag & 2: self.__read(2) def tell(self): """Return the stream's file pointer position. """ return self.pos def seek(self, pos=0): """Set the stream's file pointer to pos. Negative seeking is forbidden. """ if pos - self.pos >= 0: blocks, remainder = divmod(pos - self.pos, self.bufsize) for i in range(blocks): self.read(self.bufsize) self.read(remainder) else: raise StreamError("seeking backwards is not allowed") return self.pos def read(self, size): """Return the next size number of bytes from the stream.""" assert size is not None buf = self._read(size) self.pos += len(buf) return buf def _read(self, size): """Return size bytes from the stream. """ if self.comptype == "tar": return self.__read(size) c = len(self.dbuf) t = [self.dbuf] while c < size: # Skip underlying buffer to avoid unaligned double buffering. if self.buf: buf = self.buf self.buf = b"" else: buf = self.fileobj.read(self.bufsize) if not buf: break try: buf = self.cmp.decompress(buf) except self.exception: raise ReadError("invalid compressed data") t.append(buf) c += len(buf) t = b"".join(t) self.dbuf = t[size:] return t[:size] def __read(self, size): """Return size bytes from stream. If internal buffer is empty, read another block from the stream. """ c = len(self.buf) t = [self.buf] while c < size: buf = self.fileobj.read(self.bufsize) if not buf: break t.append(buf) c += len(buf) t = b"".join(t) self.buf = t[size:] return t[:size] # class _Stream class _StreamProxy(object): """Small proxy class that enables transparent compression detection for the Stream interface (mode 'r|*'). """ def __init__(self, fileobj): self.fileobj = fileobj self.buf = self.fileobj.read(BLOCKSIZE) def read(self, size): self.read = self.fileobj.read return self.buf def getcomptype(self): if self.buf.startswith(b"\x1f\x8b\x08"): return "gz" elif self.buf[0:3] == b"BZh" and self.buf[4:10] == b"1AY&SY": return "bz2" elif self.buf.startswith((b"\x5d\x00\x00\x80", b"\xfd7zXZ")): return "xz" else: return "tar" def close(self): self.fileobj.close() # class StreamProxy #------------------------ # Extraction file object #------------------------ class _FileInFile(object): """A thin wrapper around an existing file object that provides a part of its data as an individual file object. """ def __init__(self, fileobj, offset, size, blockinfo=None): self.fileobj = fileobj self.offset = offset self.size = size self.position = 0 self.name = getattr(fileobj, "name", None) self.closed = False if blockinfo is None: blockinfo = [(0, size)] # Construct a map with data and zero blocks. self.map_index = 0 self.map = [] lastpos = 0 realpos = self.offset for offset, size in blockinfo: if offset > lastpos: self.map.append((False, lastpos, offset, None)) self.map.append((True, offset, offset + size, realpos)) realpos += size lastpos = offset + size if lastpos < self.size: self.map.append((False, lastpos, self.size, None)) def flush(self): pass def readable(self): return True def writable(self): return False def seekable(self): return self.fileobj.seekable() def tell(self): """Return the current file position. """ return self.position def seek(self, position, whence=io.SEEK_SET): """Seek to a position in the file. """ if whence == io.SEEK_SET: self.position = min(max(position, 0), self.size) elif whence == io.SEEK_CUR: if position < 0: self.position = max(self.position + position, 0) else: self.position = min(self.position + position, self.size) elif whence == io.SEEK_END: self.position = max(min(self.size + position, self.size), 0) else: raise ValueError("Invalid argument") return self.position def read(self, size=None): """Read data from the file. """ if size is None: size = self.size - self.position else: size = min(size, self.size - self.position) buf = b"" while size > 0: while True: data, start, stop, offset = self.map[self.map_index] if start <= self.position < stop: break else: self.map_index += 1 if self.map_index == len(self.map): self.map_index = 0 length = min(size, stop - self.position) if data: self.fileobj.seek(offset + (self.position - start)) b = self.fileobj.read(length) if len(b) != length: raise ReadError("unexpected end of data") buf += b else: buf += NUL * length size -= length self.position += length return buf def readinto(self, b): buf = self.read(len(b)) b[:len(buf)] = buf return len(buf) def close(self): self.closed = True #class _FileInFile class ExFileObject(io.BufferedReader): def __init__(self, tarfile, tarinfo): fileobj = _FileInFile(tarfile.fileobj, tarinfo.offset_data, tarinfo.size, tarinfo.sparse) super().__init__(fileobj) #class ExFileObject #----------------------------- # extraction filters (PEP 706) #----------------------------- class FilterError(TarError): pass class AbsolutePathError(FilterError): def __init__(self, tarinfo): self.tarinfo = tarinfo super().__init__(f'member {tarinfo.name!r} has an absolute path') class OutsideDestinationError(FilterError): def __init__(self, tarinfo, path): self.tarinfo = tarinfo self._path = path super().__init__(f'{tarinfo.name!r} would be extracted to {path!r}, ' + 'which is outside the destination') class SpecialFileError(FilterError): def __init__(self, tarinfo): self.tarinfo = tarinfo super().__init__(f'{tarinfo.name!r} is a special file') class AbsoluteLinkError(FilterError): def __init__(self, tarinfo): self.tarinfo = tarinfo super().__init__(f'{tarinfo.name!r} is a link to an absolute path') class LinkOutsideDestinationError(FilterError): def __init__(self, tarinfo, path): self.tarinfo = tarinfo self._path = path super().__init__(f'{tarinfo.name!r} would link to {path!r}, ' + 'which is outside the destination') class LinkFallbackError(FilterError): def __init__(self, tarinfo, path): self.tarinfo = tarinfo self._path = path super().__init__(f'link {tarinfo.name!r} would be extracted as a ' + f'copy of {path!r}, which was rejected') # Errors caused by filters -- both "fatal" and "non-fatal" -- that # we consider to be issues with the argument, rather than a bug in the # filter function _FILTER_ERRORS = (FilterError, OSError, ExtractError) def _get_filtered_attrs(member, dest_path, for_data=True): new_attrs = {} name = member.name dest_path = os.path.realpath(dest_path, strict=os.path.ALLOW_MISSING) # Strip leading / (tar's directory separator) from filenames. # Include os.sep (target OS directory separator) as well. if name.startswith(('/', os.sep)): name = new_attrs['name'] = member.path.lstrip('/' + os.sep) if os.path.isabs(name): # Path is absolute even after stripping. # For example, 'C:/foo' on Windows. raise AbsolutePathError(member) # Ensure we stay in the destination target_path = os.path.realpath(os.path.join(dest_path, name), strict=os.path.ALLOW_MISSING) if os.path.commonpath([target_path, dest_path]) != dest_path: raise OutsideDestinationError(member, target_path) # Limit permissions (no high bits, and go-w) mode = member.mode if mode is not None: # Strip high bits & group/other write bits mode = mode & 0o755 if for_data: # For data, handle permissions & file types if member.isreg() or member.islnk(): if not mode & 0o100: # Clear executable bits if not executable by user mode &= ~0o111 # Ensure owner can read & write mode |= 0o600 elif member.isdir() or member.issym(): # Ignore mode for directories & symlinks mode = None else: # Reject special files raise SpecialFileError(member) if mode != member.mode: new_attrs['mode'] = mode if for_data: # Ignore ownership for 'data' if member.uid is not None: new_attrs['uid'] = None if member.gid is not None: new_attrs['gid'] = None if member.uname is not None: new_attrs['uname'] = None if member.gname is not None: new_attrs['gname'] = None # Check link destination for 'data' if member.islnk() or member.issym(): if os.path.isabs(member.linkname): raise AbsoluteLinkError(member) normalized = os.path.normpath(member.linkname) if normalized != member.linkname: new_attrs['linkname'] = normalized if member.issym(): target_path = os.path.join(dest_path, os.path.dirname(name), member.linkname) else: target_path = os.path.join(dest_path, member.linkname) target_path = os.path.realpath(target_path, strict=os.path.ALLOW_MISSING) if os.path.commonpath([target_path, dest_path]) != dest_path: raise LinkOutsideDestinationError(member, target_path) return new_attrs def fully_trusted_filter(member, dest_path): return member def tar_filter(member, dest_path): new_attrs = _get_filtered_attrs(member, dest_path, False) if new_attrs: return member.replace(**new_attrs, deep=False) return member def data_filter(member, dest_path): new_attrs = _get_filtered_attrs(member, dest_path, True) if new_attrs: return member.replace(**new_attrs, deep=False) return member _NAMED_FILTERS = { "fully_trusted": fully_trusted_filter, "tar": tar_filter, "data": data_filter, } #------------------ # Exported Classes #------------------ # Sentinel for replace() defaults, meaning "don't change the attribute" _KEEP = object() # Header length is digits followed by a space. _header_length_prefix_re = re.compile(br"([0-9]{1,20}) ") class TarInfo(object): """Informational class which holds the details about an archive member given by a tar header block. TarInfo objects are returned by TarFile.getmember(), TarFile.getmembers() and TarFile.gettarinfo() and are usually created internally. """ __slots__ = dict( name = 'Name of the archive member.', mode = 'Permission bits.', uid = 'User ID of the user who originally stored this member.', gid = 'Group ID of the user who originally stored this member.', size = 'Size in bytes.', mtime = 'Time of last modification.', chksum = 'Header checksum.', type = ('File type. type is usually one of these constants: ' 'REGTYPE, AREGTYPE, LNKTYPE, SYMTYPE, DIRTYPE, FIFOTYPE, ' 'CONTTYPE, CHRTYPE, BLKTYPE, GNUTYPE_SPARSE.'), linkname = ('Name of the target file name, which is only present ' 'in TarInfo objects of type LNKTYPE and SYMTYPE.'), uname = 'User name.', gname = 'Group name.', devmajor = 'Device major number.', devminor = 'Device minor number.', offset = 'The tar header starts here.', offset_data = "The file's data starts here.", pax_headers = ('A dictionary containing key-value pairs of an ' 'associated pax extended header.'), sparse = 'Sparse member information.', tarfile = None, _sparse_structs = None, _link_target = None, ) def __init__(self, name=""): """Construct a TarInfo object. name is the optional name of the member. """ self.name = name # member name self.mode = 0o644 # file permissions self.uid = 0 # user id self.gid = 0 # group id self.size = 0 # file size self.mtime = 0 # modification time self.chksum = 0 # header checksum self.type = REGTYPE # member type self.linkname = "" # link name self.uname = "" # user name self.gname = "" # group name self.devmajor = 0 # device major number self.devminor = 0 # device minor number self.offset = 0 # the tar header starts here self.offset_data = 0 # the file's data starts here self.sparse = None # sparse member information self.pax_headers = {} # pax header information @property def path(self): 'In pax headers, "name" is called "path".' return self.name @path.setter def path(self, name): self.name = name @property def linkpath(self): 'In pax headers, "linkname" is called "linkpath".' return self.linkname @linkpath.setter def linkpath(self, linkname): self.linkname = linkname def __repr__(self): return "<%s %r at %#x>" % (self.__class__.__name__,self.name,id(self)) def replace(self, *, name=_KEEP, mtime=_KEEP, mode=_KEEP, linkname=_KEEP, uid=_KEEP, gid=_KEEP, uname=_KEEP, gname=_KEEP, deep=True, _KEEP=_KEEP): """Return a deep copy of self with the given attributes replaced. """ if deep: result = copy.deepcopy(self) else: result = copy.copy(self) if name is not _KEEP: result.name = name if mtime is not _KEEP: result.mtime = mtime if mode is not _KEEP: result.mode = mode if linkname is not _KEEP: result.linkname = linkname if uid is not _KEEP: result.uid = uid if gid is not _KEEP: result.gid = gid if uname is not _KEEP: result.uname = uname if gname is not _KEEP: result.gname = gname return result def get_info(self): """Return the TarInfo's attributes as a dictionary. """ if self.mode is None: mode = None else: mode = self.mode & 0o7777 info = { "name": self.name, "mode": mode, "uid": self.uid, "gid": self.gid, "size": self.size, "mtime": self.mtime, "chksum": self.chksum, "type": self.type, "linkname": self.linkname, "uname": self.uname, "gname": self.gname, "devmajor": self.devmajor, "devminor": self.devminor } if info["type"] == DIRTYPE and not info["name"].endswith("/"): info["name"] += "/" return info def tobuf(self, format=DEFAULT_FORMAT, encoding=ENCODING, errors="surrogateescape"): """Return a tar header as a string of 512 byte blocks. """ info = self.get_info() for name, value in info.items(): if value is None: raise ValueError("%s may not be None" % name) if format == USTAR_FORMAT: return self.create_ustar_header(info, encoding, errors) elif format == GNU_FORMAT: return self.create_gnu_header(info, encoding, errors) elif format == PAX_FORMAT: return self.create_pax_header(info, encoding) else: raise ValueError("invalid format") def create_ustar_header(self, info, encoding, errors): """Return the object as a ustar header block. """ info["magic"] = POSIX_MAGIC if len(info["linkname"].encode(encoding, errors)) > LENGTH_LINK: raise ValueError("linkname is too long") if len(info["name"].encode(encoding, errors)) > LENGTH_NAME: info["prefix"], info["name"] = self._posix_split_name(info["name"], encoding, errors) return self._create_header(info, USTAR_FORMAT, encoding, errors) def create_gnu_header(self, info, encoding, errors): """Return the object as a GNU header block sequence. """ info["magic"] = GNU_MAGIC buf = b"" if len(info["linkname"].encode(encoding, errors)) > LENGTH_LINK: buf += self._create_gnu_long_header(info["linkname"], GNUTYPE_LONGLINK, encoding, errors) if len(info["name"].encode(encoding, errors)) > LENGTH_NAME: buf += self._create_gnu_long_header(info["name"], GNUTYPE_LONGNAME, encoding, errors) return buf + self._create_header(info, GNU_FORMAT, encoding, errors) def create_pax_header(self, info, encoding): """Return the object as a ustar header block. If it cannot be represented this way, prepend a pax extended header sequence with supplement information. """ info["magic"] = POSIX_MAGIC pax_headers = self.pax_headers.copy() # Test string fields for values that exceed the field length or cannot # be represented in ASCII encoding. for name, hname, length in ( ("name", "path", LENGTH_NAME), ("linkname", "linkpath", LENGTH_LINK), ("uname", "uname", 32), ("gname", "gname", 32)): if hname in pax_headers: # The pax header has priority. continue # Try to encode the string as ASCII. try: info[name].encode("ascii", "strict") except UnicodeEncodeError: pax_headers[hname] = info[name] continue if len(info[name]) > length: pax_headers[hname] = info[name] # Test number fields for values that exceed the field limit or values # that like to be stored as float. for name, digits in (("uid", 8), ("gid", 8), ("size", 12), ("mtime", 12)): needs_pax = False val = info[name] val_is_float = isinstance(val, float) val_int = round(val) if val_is_float else val if not 0 <= val_int < 8 ** (digits - 1): # Avoid overflow. info[name] = 0 needs_pax = True elif val_is_float: # Put rounded value in ustar header, and full # precision value in pax header. info[name] = val_int needs_pax = True # The existing pax header has priority. if needs_pax and name not in pax_headers: pax_headers[name] = str(val) # Create a pax extended header if necessary. if pax_headers: buf = self._create_pax_generic_header(pax_headers, XHDTYPE, encoding) else: buf = b"" return buf + self._create_header(info, USTAR_FORMAT, "ascii", "replace") @classmethod def create_pax_global_header(cls, pax_headers): """Return the object as a pax global header block sequence. """ return cls._create_pax_generic_header(pax_headers, XGLTYPE, "utf-8") def _posix_split_name(self, name, encoding, errors): """Split a name longer than 100 chars into a prefix and a name part. """ components = name.split("/") for i in range(1, len(components)): prefix = "/".join(components[:i]) name = "/".join(components[i:]) if len(prefix.encode(encoding, errors)) <= LENGTH_PREFIX and \ len(name.encode(encoding, errors)) <= LENGTH_NAME: break else: raise ValueError("name is too long") return prefix, name @staticmethod def _create_header(info, format, encoding, errors): """Return a header block. info is a dictionary with file information, format must be one of the *_FORMAT constants. """ has_device_fields = info.get("type") in (CHRTYPE, BLKTYPE) if has_device_fields: devmajor = itn(info.get("devmajor", 0), 8, format) devminor = itn(info.get("devminor", 0), 8, format) else: devmajor = stn("", 8, encoding, errors) devminor = stn("", 8, encoding, errors) # None values in metadata should cause ValueError. # itn()/stn() do this for all fields except type. filetype = info.get("type", REGTYPE) if filetype is None: raise ValueError("TarInfo.type must not be None") parts = [ stn(info.get("name", ""), 100, encoding, errors), itn(info.get("mode", 0) & 0o7777, 8, format), itn(info.get("uid", 0), 8, format), itn(info.get("gid", 0), 8, format), itn(info.get("size", 0), 12, format), itn(info.get("mtime", 0), 12, format), b" ", # checksum field filetype, stn(info.get("linkname", ""), 100, encoding, errors), info.get("magic", POSIX_MAGIC), stn(info.get("uname", ""), 32, encoding, errors), stn(info.get("gname", ""), 32, encoding, errors), devmajor, devminor, stn(info.get("prefix", ""), 155, encoding, errors) ] buf = struct.pack("%ds" % BLOCKSIZE, b"".join(parts)) chksum = calc_chksums(buf[-BLOCKSIZE:])[0] buf = buf[:-364] + bytes("%06o\0" % chksum, "ascii") + buf[-357:] return buf @staticmethod def _create_payload(payload): """Return the string payload filled with zero bytes up to the next 512 byte border. """ blocks, remainder = divmod(len(payload), BLOCKSIZE) if remainder > 0: payload += (BLOCKSIZE - remainder) * NUL return payload @classmethod def _create_gnu_long_header(cls, name, type, encoding, errors): """Return a GNUTYPE_LONGNAME or GNUTYPE_LONGLINK sequence for name. """ name = name.encode(encoding, errors) + NUL info = {} info["name"] = "././@LongLink" info["type"] = type info["size"] = len(name) info["magic"] = GNU_MAGIC # create extended header + name blocks. return cls._create_header(info, USTAR_FORMAT, encoding, errors) + \ cls._create_payload(name) @classmethod def _create_pax_generic_header(cls, pax_headers, type, encoding): """Return a POSIX.1-2008 extended or global header sequence that contains a list of keyword, value pairs. The values must be strings. """ # Check if one of the fields contains surrogate characters and thereby # forces hdrcharset=BINARY, see _proc_pax() for more information. binary = False for keyword, value in pax_headers.items(): try: value.encode("utf-8", "strict") except UnicodeEncodeError: binary = True break records = b"" if binary: # Put the hdrcharset field at the beginning of the header. records += b"21 hdrcharset=BINARY\n" for keyword, value in pax_headers.items(): keyword = keyword.encode("utf-8") if binary: # Try to restore the original byte representation of `value'. # Needless to say, that the encoding must match the string. value = value.encode(encoding, "surrogateescape") else: value = value.encode("utf-8") l = len(keyword) + len(value) + 3 # ' ' + '=' + '\n' n = p = 0 while True: n = l + len(str(p)) if n == p: break p = n records += bytes(str(p), "ascii") + b" " + keyword + b"=" + value + b"\n" # We use a hardcoded "././@PaxHeader" name like star does # instead of the one that POSIX recommends. info = {} info["name"] = "././@PaxHeader" info["type"] = type info["size"] = len(records) info["magic"] = POSIX_MAGIC # Create pax header + record blocks. return cls._create_header(info, USTAR_FORMAT, "ascii", "replace") + \ cls._create_payload(records) @classmethod def frombuf(cls, buf, encoding, errors): """Construct a TarInfo object from a 512 byte bytes object. """ if len(buf) == 0: raise EmptyHeaderError("empty header") if len(buf) != BLOCKSIZE: raise TruncatedHeaderError("truncated header") if buf.count(NUL) == BLOCKSIZE: raise EOFHeaderError("end of file header") chksum = nti(buf[148:156]) if chksum not in calc_chksums(buf): raise InvalidHeaderError("bad checksum") obj = cls() obj.name = nts(buf[0:100], encoding, errors) obj.mode = nti(buf[100:108]) obj.uid = nti(buf[108:116]) obj.gid = nti(buf[116:124]) obj.size = nti(buf[124:136]) obj.mtime = nti(buf[136:148]) obj.chksum = chksum obj.type = buf[156:157] obj.linkname = nts(buf[157:257], encoding, errors) obj.uname = nts(buf[265:297], encoding, errors) obj.gname = nts(buf[297:329], encoding, errors) obj.devmajor = nti(buf[329:337]) obj.devminor = nti(buf[337:345]) prefix = nts(buf[345:500], encoding, errors) # Old V7 tar format represents a directory as a regular # file with a trailing slash. if obj.type == AREGTYPE and obj.name.endswith("/"): obj.type = DIRTYPE # The old GNU sparse format occupies some of the unused # space in the buffer for up to 4 sparse structures. # Save them for later processing in _proc_sparse(). if obj.type == GNUTYPE_SPARSE: pos = 386 structs = [] for i in range(4): try: offset = nti(buf[pos:pos + 12]) numbytes = nti(buf[pos + 12:pos + 24]) except ValueError: break structs.append((offset, numbytes)) pos += 24 isextended = bool(buf[482]) origsize = nti(buf[483:495]) obj._sparse_structs = (structs, isextended, origsize) # Remove redundant slashes from directories. if obj.isdir(): obj.name = obj.name.rstrip("/") # Reconstruct a ustar longname. if prefix and obj.type not in GNU_TYPES: obj.name = prefix + "/" + obj.name return obj @classmethod def fromtarfile(cls, tarfile): """Return the next TarInfo object from TarFile object tarfile. """ buf = tarfile.fileobj.read(BLOCKSIZE) obj = cls.frombuf(buf, tarfile.encoding, tarfile.errors) obj.offset = tarfile.fileobj.tell() - BLOCKSIZE return obj._proc_member(tarfile) #-------------------------------------------------------------------------- # The following are methods that are called depending on the type of a # member. The entry point is _proc_member() which can be overridden in a # subclass to add custom _proc_*() methods. A _proc_*() method MUST # implement the following # operations: # 1. Set self.offset_data to the position where the data blocks begin, # if there is data that follows. # 2. Set tarfile.offset to the position where the next member's header will # begin. # 3. Return self or another valid TarInfo object. def _proc_member(self, tarfile): """Choose the right processing method depending on the type and call it. """ if self.type in (GNUTYPE_LONGNAME, GNUTYPE_LONGLINK): return self._proc_gnulong(tarfile) elif self.type == GNUTYPE_SPARSE: return self._proc_sparse(tarfile) elif self.type in (XHDTYPE, XGLTYPE, SOLARIS_XHDTYPE): return self._proc_pax(tarfile) else: return self._proc_builtin(tarfile) def _proc_builtin(self, tarfile): """Process a builtin type or an unknown type which will be treated as a regular file. """ self.offset_data = tarfile.fileobj.tell() offset = self.offset_data if self.isreg() or self.type not in SUPPORTED_TYPES: # Skip the following data blocks. offset += self._block(self.size) tarfile.offset = offset # Patch the TarInfo object with saved global # header information. self._apply_pax_info(tarfile.pax_headers, tarfile.encoding, tarfile.errors) return self def _proc_gnulong(self, tarfile): """Process the blocks that hold a GNU longname or longlink member. """ buf = tarfile.fileobj.read(self._block(self.size)) # Fetch the next header and process it. try: next = self.fromtarfile(tarfile) except HeaderError: raise SubsequentHeaderError("missing or bad subsequent header") # Patch the TarInfo object from the next header with # the longname information. next.offset = self.offset if self.type == GNUTYPE_LONGNAME: next.name = nts(buf, tarfile.encoding, tarfile.errors) elif self.type == GNUTYPE_LONGLINK: next.linkname = nts(buf, tarfile.encoding, tarfile.errors) return next def _proc_sparse(self, tarfile): """Process a GNU sparse header plus extra headers. """ # We already collected some sparse structures in frombuf(). structs, isextended, origsize = self._sparse_structs del self._sparse_structs # Collect sparse structures from extended header blocks. while isextended: buf = tarfile.fileobj.read(BLOCKSIZE) pos = 0 for i in range(21): try: offset = nti(buf[pos:pos + 12]) numbytes = nti(buf[pos + 12:pos + 24]) except ValueError: break if offset and numbytes: structs.append((offset, numbytes)) pos += 24 isextended = bool(buf[504]) self.sparse = structs self.offset_data = tarfile.fileobj.tell() tarfile.offset = self.offset_data + self._block(self.size) self.size = origsize return self def _proc_pax(self, tarfile): """Process an extended or global header as described in POSIX.1-2008. """ # Read the header information. buf = tarfile.fileobj.read(self._block(self.size)) # A pax header stores supplemental information for either # the following file (extended) or all following files # (global). if self.type == XGLTYPE: pax_headers = tarfile.pax_headers else: pax_headers = tarfile.pax_headers.copy() # Parse pax header information. A record looks like that: # "%d %s=%s\n" % (length, keyword, value). length is the size # of the complete record including the length field itself and # the newline. pos = 0 encoding = None raw_headers = [] while len(buf) > pos and buf[pos] != 0x00: if not (match := _header_length_prefix_re.match(buf, pos)): raise InvalidHeaderError("invalid header") try: length = int(match.group(1)) except ValueError: raise InvalidHeaderError("invalid header") # Headers must be at least 5 bytes, shortest being '5 x=\n'. # Value is allowed to be empty. if length < 5: raise InvalidHeaderError("invalid header") if pos + length > len(buf): raise InvalidHeaderError("invalid header") header_value_end_offset = match.start(1) + length - 1 # Last byte of the header keyword_and_value = buf[match.end(1) + 1:header_value_end_offset] raw_keyword, equals, raw_value = keyword_and_value.partition(b"=") # Check the framing of the header. The last character must be '\n' (0x0A) if not raw_keyword or equals != b"=" or buf[header_value_end_offset] != 0x0A: raise InvalidHeaderError("invalid header") raw_headers.append((length, raw_keyword, raw_value)) # Check if the pax header contains a hdrcharset field. This tells us # the encoding of the path, linkpath, uname and gname fields. Normally, # these fields are UTF-8 encoded but since POSIX.1-2008 tar # implementations are allowed to store them as raw binary strings if # the translation to UTF-8 fails. For the time being, we don't care about # anything other than "BINARY". The only other value that is currently # allowed by the standard is "ISO-IR 10646 2000 UTF-8" in other words UTF-8. # Note that we only follow the initial 'hdrcharset' setting to preserve # the initial behavior of the 'tarfile' module. if raw_keyword == b"hdrcharset" and encoding is None: if raw_value == b"BINARY": encoding = tarfile.encoding else: # This branch ensures only the first 'hdrcharset' header is used. encoding = "utf-8" pos += length # If no explicit hdrcharset is set, we use UTF-8 as a default. if encoding is None: encoding = "utf-8" # After parsing the raw headers we can decode them to text. for length, raw_keyword, raw_value in raw_headers: # Normally, we could just use "utf-8" as the encoding and "strict" # as the error handler, but we better not take the risk. For # example, GNU tar <= 1.23 is known to store filenames it cannot # translate to UTF-8 as raw strings (unfortunately without a # hdrcharset=BINARY header). # We first try the strict standard encoding, and if that fails we # fall back on the user's encoding and error handler. keyword = self._decode_pax_field(raw_keyword, "utf-8", "utf-8", tarfile.errors) if keyword in PAX_NAME_FIELDS: value = self._decode_pax_field(raw_value, encoding, tarfile.encoding, tarfile.errors) else: value = self._decode_pax_field(raw_value, "utf-8", "utf-8", tarfile.errors) pax_headers[keyword] = value # Fetch the next header. try: next = self.fromtarfile(tarfile) except HeaderError: raise SubsequentHeaderError("missing or bad subsequent header") # Process GNU sparse information. if "GNU.sparse.map" in pax_headers: # GNU extended sparse format version 0.1. self._proc_gnusparse_01(next, pax_headers) elif "GNU.sparse.size" in pax_headers: # GNU extended sparse format version 0.0. self._proc_gnusparse_00(next, raw_headers) elif pax_headers.get("GNU.sparse.major") == "1" and pax_headers.get("GNU.sparse.minor") == "0": # GNU extended sparse format version 1.0. self._proc_gnusparse_10(next, pax_headers, tarfile) if self.type in (XHDTYPE, SOLARIS_XHDTYPE): # Patch the TarInfo object with the extended header info. next._apply_pax_info(pax_headers, tarfile.encoding, tarfile.errors) next.offset = self.offset if "size" in pax_headers: # If the extended header replaces the size field, # we need to recalculate the offset where the next # header starts. offset = next.offset_data if next.isreg() or next.type not in SUPPORTED_TYPES: offset += next._block(next.size) tarfile.offset = offset return next def _proc_gnusparse_00(self, next, raw_headers): """Process a GNU tar extended sparse header, version 0.0. """ offsets = [] numbytes = [] for _, keyword, value in raw_headers: if keyword == b"GNU.sparse.offset": try: offsets.append(int(value.decode())) except ValueError: raise InvalidHeaderError("invalid header") elif keyword == b"GNU.sparse.numbytes": try: numbytes.append(int(value.decode())) except ValueError: raise InvalidHeaderError("invalid header") next.sparse = list(zip(offsets, numbytes)) def _proc_gnusparse_01(self, next, pax_headers): """Process a GNU tar extended sparse header, version 0.1. """ sparse = [int(x) for x in pax_headers["GNU.sparse.map"].split(",")] next.sparse = list(zip(sparse[::2], sparse[1::2])) def _proc_gnusparse_10(self, next, pax_headers, tarfile): """Process a GNU tar extended sparse header, version 1.0. """ fields = None sparse = [] buf = tarfile.fileobj.read(BLOCKSIZE) fields, buf = buf.split(b"\n", 1) fields = int(fields) while len(sparse) < fields * 2: if b"\n" not in buf: buf += tarfile.fileobj.read(BLOCKSIZE) number, buf = buf.split(b"\n", 1) sparse.append(int(number)) next.offset_data = tarfile.fileobj.tell() next.sparse = list(zip(sparse[::2], sparse[1::2])) def _apply_pax_info(self, pax_headers, encoding, errors): """Replace fields with supplemental information from a previous pax extended or global header. """ for keyword, value in pax_headers.items(): if keyword == "GNU.sparse.name": setattr(self, "path", value) elif keyword == "GNU.sparse.size": setattr(self, "size", int(value)) elif keyword == "GNU.sparse.realsize": setattr(self, "size", int(value)) elif keyword in PAX_FIELDS: if keyword in PAX_NUMBER_FIELDS: try: value = PAX_NUMBER_FIELDS[keyword](value) except ValueError: value = 0 if keyword == "path": value = value.rstrip("/") setattr(self, keyword, value) self.pax_headers = pax_headers.copy() def _decode_pax_field(self, value, encoding, fallback_encoding, fallback_errors): """Decode a single field from a pax record. """ try: return value.decode(encoding, "strict") except UnicodeDecodeError: return value.decode(fallback_encoding, fallback_errors) def _block(self, count): """Round up a byte count by BLOCKSIZE and return it, e.g. _block(834) => 1024. """ # Only non-negative offsets are allowed if count < 0: raise InvalidHeaderError("invalid offset") blocks, remainder = divmod(count, BLOCKSIZE) if remainder: blocks += 1 return blocks * BLOCKSIZE def isreg(self): 'Return True if the Tarinfo object is a regular file.' return self.type in REGULAR_TYPES def isfile(self): 'Return True if the Tarinfo object is a regular file.' return self.isreg() def isdir(self): 'Return True if it is a directory.' return self.type == DIRTYPE def issym(self): 'Return True if it is a symbolic link.' return self.type == SYMTYPE def islnk(self): 'Return True if it is a hard link.' return self.type == LNKTYPE def ischr(self): 'Return True if it is a character device.' return self.type == CHRTYPE def isblk(self): 'Return True if it is a block device.' return self.type == BLKTYPE def isfifo(self): 'Return True if it is a FIFO.' return self.type == FIFOTYPE def issparse(self): return self.sparse is not None def isdev(self): 'Return True if it is one of character device, block device or FIFO.' return self.type in (CHRTYPE, BLKTYPE, FIFOTYPE) # class TarInfo class TarFile(object): """The TarFile Class provides an interface to tar archives. """ debug = 0 # May be set from 0 (no msgs) to 3 (all msgs) dereference = False # If true, add content of linked file to the # tar file, else the link. ignore_zeros = False # If true, skips empty or invalid blocks and # continues processing. errorlevel = 1 # If 0, fatal errors only appear in debug # messages (if debug >= 0). If > 0, errors # are passed to the caller as exceptions. format = DEFAULT_FORMAT # The format to use when creating an archive. encoding = ENCODING # Encoding for 8-bit character strings. errors = None # Error handler for unicode conversion. tarinfo = TarInfo # The default TarInfo class to use. fileobject = ExFileObject # The file-object for extractfile(). extraction_filter = None # The default filter for extraction. def __init__(self, name=None, mode="r", fileobj=None, format=None, tarinfo=None, dereference=None, ignore_zeros=None, encoding=None, errors="surrogateescape", pax_headers=None, debug=None, errorlevel=None, copybufsize=None): """Open an (uncompressed) tar archive `name'. `mode' is either 'r' to read from an existing archive, 'a' to append data to an existing file or 'w' to create a new file overwriting an existing one. `mode' defaults to 'r'. If `fileobj' is given, it is used for reading or writing data. If it can be determined, `mode' is overridden by `fileobj's mode. `fileobj' is not closed, when TarFile is closed. """ modes = {"r": "rb", "a": "r+b", "w": "wb", "x": "xb"} if mode not in modes: raise ValueError("mode must be 'r', 'a', 'w' or 'x'") self.mode = mode self._mode = modes[mode] if not fileobj: if self.mode == "a" and not os.path.exists(name): # Create nonexistent files in append mode. self.mode = "w" self._mode = "wb" fileobj = bltn_open(name, self._mode) self._extfileobj = False else: if (name is None and hasattr(fileobj, "name") and isinstance(fileobj.name, (str, bytes))): name = fileobj.name if hasattr(fileobj, "mode"): self._mode = fileobj.mode self._extfileobj = True self.name = os.path.abspath(name) if name else None self.fileobj = fileobj # Init attributes. if format is not None: self.format = format if tarinfo is not None: self.tarinfo = tarinfo if dereference is not None: self.dereference = dereference if ignore_zeros is not None: self.ignore_zeros = ignore_zeros if encoding is not None: self.encoding = encoding self.errors = errors if pax_headers is not None and self.format == PAX_FORMAT: self.pax_headers = pax_headers else: self.pax_headers = {} if debug is not None: self.debug = debug if errorlevel is not None: self.errorlevel = errorlevel # Init datastructures. self.copybufsize = copybufsize self.closed = False self.members = [] # list of members as TarInfo objects self._loaded = False # flag if all members have been read self.offset = self.fileobj.tell() # current position in the archive file self.inodes = {} # dictionary caching the inodes of # archive members already added try: if self.mode == "r": self.firstmember = None self.firstmember = self.next() if self.mode == "a": # Move to the end of the archive, # before the first empty block. while True: self.fileobj.seek(self.offset) try: tarinfo = self.tarinfo.fromtarfile(self) self.members.append(tarinfo) except EOFHeaderError: self.fileobj.seek(self.offset) break except HeaderError as e: raise ReadError(str(e)) if self.mode in ("a", "w", "x"): self._loaded = True if self.pax_headers: buf = self.tarinfo.create_pax_global_header(self.pax_headers.copy()) self.fileobj.write(buf) self.offset += len(buf) except: if not self._extfileobj: self.fileobj.close() self.closed = True raise #-------------------------------------------------------------------------- # Below are the classmethods which act as alternate constructors to the # TarFile class. The open() method is the only one that is needed for # public use; it is the "super"-constructor and is able to select an # adequate "sub"-constructor for a particular compression using the mapping # from OPEN_METH. # # This concept allows one to subclass TarFile without losing the comfort of # the super-constructor. A sub-constructor is registered and made available # by adding it to the mapping in OPEN_METH. @classmethod def open(cls, name=None, mode="r", fileobj=None, bufsize=RECORDSIZE, **kwargs): """Open a tar archive for reading, writing or appending. Return an appropriate TarFile class. mode: 'r' or 'r:*' open for reading with transparent compression 'r:' open for reading exclusively uncompressed 'r:gz' open for reading with gzip compression 'r:bz2' open for reading with bzip2 compression 'r:xz' open for reading with lzma compression 'a' or 'a:' open for appending, creating the file if necessary 'w' or 'w:' open for writing without compression 'w:gz' open for writing with gzip compression 'w:bz2' open for writing with bzip2 compression 'w:xz' open for writing with lzma compression 'x' or 'x:' create a tarfile exclusively without compression, raise an exception if the file is already created 'x:gz' create a gzip compressed tarfile, raise an exception if the file is already created 'x:bz2' create a bzip2 compressed tarfile, raise an exception if the file is already created 'x:xz' create an lzma compressed tarfile, raise an exception if the file is already created 'r|*' open a stream of tar blocks with transparent compression 'r|' open an uncompressed stream of tar blocks for reading 'r|gz' open a gzip compressed stream of tar blocks 'r|bz2' open a bzip2 compressed stream of tar blocks 'r|xz' open an lzma compressed stream of tar blocks 'w|' open an uncompressed stream for writing 'w|gz' open a gzip compressed stream for writing 'w|bz2' open a bzip2 compressed stream for writing 'w|xz' open an lzma compressed stream for writing """ if not name and not fileobj: raise ValueError("nothing to open") if mode in ("r", "r:*"): # Find out which *open() is appropriate for opening the file. def not_compressed(comptype): return cls.OPEN_METH[comptype] == 'taropen' for comptype in sorted(cls.OPEN_METH, key=not_compressed): func = getattr(cls, cls.OPEN_METH[comptype]) if fileobj is not None: saved_pos = fileobj.tell() try: return func(name, "r", fileobj, **kwargs) except (ReadError, CompressionError): if fileobj is not None: fileobj.seek(saved_pos) continue raise ReadError("file could not be opened successfully") elif ":" in mode: filemode, comptype = mode.split(":", 1) filemode = filemode or "r" comptype = comptype or "tar" # Select the *open() function according to # given compression. if comptype in cls.OPEN_METH: func = getattr(cls, cls.OPEN_METH[comptype]) else: raise CompressionError("unknown compression type %r" % comptype) return func(name, filemode, fileobj, **kwargs) elif "|" in mode: filemode, comptype = mode.split("|", 1) filemode = filemode or "r" comptype = comptype or "tar" if filemode not in ("r", "w"): raise ValueError("mode must be 'r' or 'w'") stream = _Stream(name, filemode, comptype, fileobj, bufsize) try: t = cls(name, filemode, stream, **kwargs) except: stream.close() raise t._extfileobj = False return t elif mode in ("a", "w", "x"): return cls.taropen(name, mode, fileobj, **kwargs) raise ValueError("undiscernible mode") @classmethod def taropen(cls, name, mode="r", fileobj=None, **kwargs): """Open uncompressed tar archive name for reading or writing. """ if mode not in ("r", "a", "w", "x"): raise ValueError("mode must be 'r', 'a', 'w' or 'x'") return cls(name, mode, fileobj, **kwargs) @classmethod def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs): """Open gzip compressed tar archive name for reading or writing. Appending is not allowed. """ if mode not in ("r", "w", "x"): raise ValueError("mode must be 'r', 'w' or 'x'") try: from gzip import GzipFile except ImportError: raise CompressionError("gzip module is not available") try: fileobj = GzipFile(name, mode + "b", compresslevel, fileobj) except OSError: if fileobj is not None and mode == 'r': raise ReadError("not a gzip file") raise try: t = cls.taropen(name, mode, fileobj, **kwargs) except OSError: fileobj.close() if mode == 'r': raise ReadError("not a gzip file") raise except: fileobj.close() raise t._extfileobj = False return t @classmethod def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs): """Open bzip2 compressed tar archive name for reading or writing. Appending is not allowed. """ if mode not in ("r", "w", "x"): raise ValueError("mode must be 'r', 'w' or 'x'") try: from bz2 import BZ2File except ImportError: raise CompressionError("bz2 module is not available") fileobj = BZ2File(fileobj or name, mode, compresslevel=compresslevel) try: t = cls.taropen(name, mode, fileobj, **kwargs) except (OSError, EOFError): fileobj.close() if mode == 'r': raise ReadError("not a bzip2 file") raise except: fileobj.close() raise t._extfileobj = False return t @classmethod def xzopen(cls, name, mode="r", fileobj=None, preset=None, **kwargs): """Open lzma compressed tar archive name for reading or writing. Appending is not allowed. """ if mode not in ("r", "w", "x"): raise ValueError("mode must be 'r', 'w' or 'x'") try: from lzma import LZMAFile, LZMAError except ImportError: raise CompressionError("lzma module is not available") fileobj = LZMAFile(fileobj or name, mode, preset=preset) try: t = cls.taropen(name, mode, fileobj, **kwargs) except (LZMAError, EOFError): fileobj.close() if mode == 'r': raise ReadError("not an lzma file") raise except: fileobj.close() raise t._extfileobj = False return t # All *open() methods are registered here. OPEN_METH = { "tar": "taropen", # uncompressed tar "gz": "gzopen", # gzip compressed tar "bz2": "bz2open", # bzip2 compressed tar "xz": "xzopen" # lzma compressed tar } #-------------------------------------------------------------------------- # The public methods which TarFile provides: def close(self): """Close the TarFile. In write-mode, two finishing zero blocks are appended to the archive. """ if self.closed: return self.closed = True try: if self.mode in ("a", "w", "x"): self.fileobj.write(NUL * (BLOCKSIZE * 2)) self.offset += (BLOCKSIZE * 2) # fill up the end with zero-blocks # (like option -b20 for tar does) blocks, remainder = divmod(self.offset, RECORDSIZE) if remainder > 0: self.fileobj.write(NUL * (RECORDSIZE - remainder)) finally: if not self._extfileobj: self.fileobj.close() def getmember(self, name): """Return a TarInfo object for member `name'. If `name' can not be found in the archive, KeyError is raised. If a member occurs more than once in the archive, its last occurrence is assumed to be the most up-to-date version. """ tarinfo = self._getmember(name.rstrip('/')) if tarinfo is None: raise KeyError("filename %r not found" % name) return tarinfo def getmembers(self): """Return the members of the archive as a list of TarInfo objects. The list has the same order as the members in the archive. """ self._check() if not self._loaded: # if we want to obtain a list of self._load() # all members, we first have to # scan the whole archive. return self.members def getnames(self): """Return the members of the archive as a list of their names. It has the same order as the list returned by getmembers(). """ return [tarinfo.name for tarinfo in self.getmembers()] def gettarinfo(self, name=None, arcname=None, fileobj=None): """Create a TarInfo object from the result of os.stat or equivalent on an existing file. The file is either named by `name', or specified as a file object `fileobj' with a file descriptor. If given, `arcname' specifies an alternative name for the file in the archive, otherwise, the name is taken from the 'name' attribute of 'fileobj', or the 'name' argument. The name should be a text string. """ self._check("awx") # When fileobj is given, replace name by # fileobj's real name. if fileobj is not None: name = fileobj.name # Building the name of the member in the archive. # Backward slashes are converted to forward slashes, # Absolute paths are turned to relative paths. if arcname is None: arcname = name drv, arcname = os.path.splitdrive(arcname) arcname = arcname.replace(os.sep, "/") arcname = arcname.lstrip("/") # Now, fill the TarInfo object with # information specific for the file. tarinfo = self.tarinfo() tarinfo.tarfile = self # Not needed # Use os.stat or os.lstat, depending on if symlinks shall be resolved. if fileobj is None: if not self.dereference: statres = os.lstat(name) else: statres = os.stat(name) else: statres = os.fstat(fileobj.fileno()) linkname = "" stmd = statres.st_mode if stat.S_ISREG(stmd): inode = (statres.st_ino, statres.st_dev) if not self.dereference and statres.st_nlink > 1 and \ inode in self.inodes and arcname != self.inodes[inode]: # Is it a hardlink to an already # archived file? type = LNKTYPE linkname = self.inodes[inode] else: # The inode is added only if its valid. # For win32 it is always 0. type = REGTYPE if inode[0]: self.inodes[inode] = arcname elif stat.S_ISDIR(stmd): type = DIRTYPE elif stat.S_ISFIFO(stmd): type = FIFOTYPE elif stat.S_ISLNK(stmd): type = SYMTYPE linkname = os.readlink(name) elif stat.S_ISCHR(stmd): type = CHRTYPE elif stat.S_ISBLK(stmd): type = BLKTYPE else: return None # Fill the TarInfo object with all # information we can get. tarinfo.name = arcname tarinfo.mode = stmd tarinfo.uid = statres.st_uid tarinfo.gid = statres.st_gid if type == REGTYPE: tarinfo.size = statres.st_size else: tarinfo.size = 0 tarinfo.mtime = statres.st_mtime tarinfo.type = type tarinfo.linkname = linkname if pwd: try: tarinfo.uname = pwd.getpwuid(tarinfo.uid)[0] except KeyError: pass if grp: try: tarinfo.gname = grp.getgrgid(tarinfo.gid)[0] except KeyError: pass if type in (CHRTYPE, BLKTYPE): if hasattr(os, "major") and hasattr(os, "minor"): tarinfo.devmajor = os.major(statres.st_rdev) tarinfo.devminor = os.minor(statres.st_rdev) return tarinfo def list(self, verbose=True, *, members=None): """Print a table of contents to sys.stdout. If `verbose' is False, only the names of the members are printed. If it is True, an `ls -l'-like output is produced. `members' is optional and must be a subset of the list returned by getmembers(). """ self._check() if members is None: members = self for tarinfo in members: if verbose: if tarinfo.mode is None: _safe_print("??????????") else: _safe_print(stat.filemode(tarinfo.mode)) _safe_print("%s/%s" % (tarinfo.uname or tarinfo.uid, tarinfo.gname or tarinfo.gid)) if tarinfo.ischr() or tarinfo.isblk(): _safe_print("%10s" % ("%d,%d" % (tarinfo.devmajor, tarinfo.devminor))) else: _safe_print("%10d" % tarinfo.size) if tarinfo.mtime is None: _safe_print("????-??-?? ??:??:??") else: _safe_print("%d-%02d-%02d %02d:%02d:%02d" \ % time.localtime(tarinfo.mtime)[:6]) _safe_print(tarinfo.name + ("/" if tarinfo.isdir() else "")) if verbose: if tarinfo.issym(): _safe_print("-> " + tarinfo.linkname) if tarinfo.islnk(): _safe_print("link to " + tarinfo.linkname) print() def add(self, name, arcname=None, recursive=True, *, filter=None): """Add the file `name' to the archive. `name' may be any type of file (directory, fifo, symbolic link, etc.). If given, `arcname' specifies an alternative name for the file in the archive. Directories are added recursively by default. This can be avoided by setting `recursive' to False. `filter' is a function that expects a TarInfo object argument and returns the changed TarInfo object, if it returns None the TarInfo object will be excluded from the archive. """ self._check("awx") if arcname is None: arcname = name # Skip if somebody tries to archive the archive... if self.name is not None and os.path.abspath(name) == self.name: self._dbg(2, "tarfile: Skipped %r" % name) return self._dbg(1, name) # Create a TarInfo object from the file. tarinfo = self.gettarinfo(name, arcname) if tarinfo is None: self._dbg(1, "tarfile: Unsupported type %r" % name) return # Change or exclude the TarInfo object. if filter is not None: tarinfo = filter(tarinfo) if tarinfo is None: self._dbg(2, "tarfile: Excluded %r" % name) return # Append the tar header and data to the archive. if tarinfo.isreg(): with bltn_open(name, "rb") as f: self.addfile(tarinfo, f) elif tarinfo.isdir(): self.addfile(tarinfo) if recursive: for f in sorted(os.listdir(name)): self.add(os.path.join(name, f), os.path.join(arcname, f), recursive, filter=filter) else: self.addfile(tarinfo) def addfile(self, tarinfo, fileobj=None): """Add the TarInfo object `tarinfo' to the archive. If `fileobj' is given, it should be a binary file, and tarinfo.size bytes are read from it and added to the archive. You can create TarInfo objects directly, or by using gettarinfo(). """ self._check("awx") tarinfo = copy.copy(tarinfo) buf = tarinfo.tobuf(self.format, self.encoding, self.errors) self.fileobj.write(buf) self.offset += len(buf) bufsize=self.copybufsize # If there's data to follow, append it. if fileobj is not None: copyfileobj(fileobj, self.fileobj, tarinfo.size, bufsize=bufsize) blocks, remainder = divmod(tarinfo.size, BLOCKSIZE) if remainder > 0: self.fileobj.write(NUL * (BLOCKSIZE - remainder)) blocks += 1 self.offset += blocks * BLOCKSIZE self.members.append(tarinfo) def _get_filter_function(self, filter): if filter is None: filter = self.extraction_filter if filter is None: name = os.environ.get('PYTHON_TARFILE_EXTRACTION_FILTER') if name is None: try: file = bltn_open(_CONFIG_FILENAME) except FileNotFoundError: pass else: import configparser conf = configparser.ConfigParser( interpolation=None, comment_prefixes=('#', ), ) with file: conf.read_file(file) name = conf.get('tarfile', 'PYTHON_TARFILE_EXTRACTION_FILTER', fallback='') if name: try: filter = _NAMED_FILTERS[name] except KeyError: raise ValueError(f"filter {filter!r} not found") from None self.extraction_filter = filter return filter if _RH_SAFER_DEFAULT: warnings.warn( 'The default behavior of tarfile extraction has been ' + 'changed to disallow common exploits ' + '(including CVE-2007-4559). ' + 'By default, absolute/parent paths are disallowed ' + 'and some mode bits are cleared. ' + 'See https://access.redhat.com/articles/7004769 ' + 'for more details.', RuntimeWarning) return tar_filter return fully_trusted_filter if isinstance(filter, str): raise TypeError( 'String names are not supported for ' + 'TarFile.extraction_filter. Use a function such as ' + 'tarfile.data_filter directly.') return filter if callable(filter): return filter try: return _NAMED_FILTERS[filter] except KeyError: raise ValueError(f"filter {filter!r} not found") from None def extractall(self, path=".", members=None, *, numeric_owner=False, filter=None): """Extract all members from the archive to the current working directory and set owner, modification time and permissions on directories afterwards. `path' specifies a different directory to extract to. `members' is optional and must be a subset of the list returned by getmembers(). If `numeric_owner` is True, only the numbers for user/group names are used and not the names. The `filter` function will be called on each member just before extraction. It can return a changed TarInfo or None to skip the member. String names of common filters are accepted. """ directories = [] filter_function = self._get_filter_function(filter) if members is None: members = self for member in members: tarinfo, unfiltered = self._get_extract_tarinfo( member, filter_function, path) if tarinfo is None: continue if tarinfo.isdir(): # For directories, delay setting attributes until later, # since permissions can interfere with extraction and # extracting contents can reset mtime. directories.append(unfiltered) self._extract_one(tarinfo, path, set_attrs=not tarinfo.isdir(), numeric_owner=numeric_owner, filter_function=filter_function) # Reverse sort directories. directories.sort(key=lambda a: a.name, reverse=True) # Set correct owner, mtime and filemode on directories. for unfiltered in directories: try: # Need to re-apply any filter, to take the *current* filesystem # state into account. try: tarinfo = filter_function(unfiltered, path) except _FILTER_ERRORS as exc: self._log_no_directory_fixup(unfiltered, repr(exc)) continue if tarinfo is None: self._log_no_directory_fixup(unfiltered, 'excluded by filter') continue dirpath = os.path.join(path, tarinfo.name) try: lstat = os.lstat(dirpath) except FileNotFoundError: self._log_no_directory_fixup(tarinfo, 'missing') continue if not stat.S_ISDIR(lstat.st_mode): # This is no longer a directory; presumably a later # member overwrote the entry. self._log_no_directory_fixup(tarinfo, 'not a directory') continue self.chown(tarinfo, dirpath, numeric_owner=numeric_owner) self.utime(tarinfo, dirpath) self.chmod(tarinfo, dirpath) except ExtractError as e: self._handle_nonfatal_error(e) def _log_no_directory_fixup(self, member, reason): self._dbg(2, "tarfile: Not fixing up directory %r (%s)" % (member.name, reason)) def extract(self, member, path="", set_attrs=True, *, numeric_owner=False, filter=None): """Extract a member from the archive to the current working directory, using its full name. Its file information is extracted as accurately as possible. `member' may be a filename or a TarInfo object. You can specify a different directory using `path'. File attributes (owner, mtime, mode) are set unless `set_attrs' is False. If `numeric_owner` is True, only the numbers for user/group names are used and not the names. The `filter` function will be called before extraction. It can return a changed TarInfo or None to skip the member. String names of common filters are accepted. """ filter_function = self._get_filter_function(filter) tarinfo, unfiltered = self._get_extract_tarinfo( member, filter_function, path) if tarinfo is not None: self._extract_one(tarinfo, path, set_attrs, numeric_owner) def _get_extract_tarinfo(self, member, filter_function, path): """Get (filtered, unfiltered) TarInfos from *member* *member* might be a string. Return (None, None) if not found. """ if isinstance(member, str): unfiltered = self.getmember(member) else: unfiltered = member filtered = None try: filtered = filter_function(unfiltered, path) except (OSError, FilterError) as e: self._handle_fatal_error(e) except ExtractError as e: self._handle_nonfatal_error(e) if filtered is None: self._dbg(2, "tarfile: Excluded %r" % unfiltered.name) return None, None # Prepare the link target for makelink(). if filtered.islnk(): filtered = copy.copy(filtered) filtered._link_target = os.path.join(path, filtered.linkname) return filtered, unfiltered def _extract_one(self, tarinfo, path, set_attrs, numeric_owner, filter_function=None): """Extract from filtered tarinfo to disk. filter_function is only used when extracting a *different* member (e.g. as fallback to creating a symlink) """ self._check("r") try: self._extract_member(tarinfo, os.path.join(path, tarinfo.name), set_attrs=set_attrs, numeric_owner=numeric_owner, filter_function=filter_function, extraction_root=path) except OSError as e: self._handle_fatal_error(e) except ExtractError as e: self._handle_nonfatal_error(e) def _handle_nonfatal_error(self, e): """Handle non-fatal error (ExtractError) according to errorlevel""" if self.errorlevel > 1: raise else: self._dbg(1, "tarfile: %s" % e) def _handle_fatal_error(self, e): """Handle "fatal" error according to self.errorlevel""" if self.errorlevel > 0: raise elif isinstance(e, OSError): if e.filename is None: self._dbg(1, "tarfile: %s" % e.strerror) else: self._dbg(1, "tarfile: %s %r" % (e.strerror, e.filename)) else: self._dbg(1, "tarfile: %s %s" % (type(e).__name__, e)) def extractfile(self, member): """Extract a member from the archive as a file object. `member' may be a filename or a TarInfo object. If `member' is a regular file or a link, an io.BufferedReader object is returned. For all other existing members, None is returned. If `member' does not appear in the archive, KeyError is raised. """ self._check("r") if isinstance(member, str): tarinfo = self.getmember(member) else: tarinfo = member if tarinfo.isreg() or tarinfo.type not in SUPPORTED_TYPES: # Members with unknown types are treated as regular files. return self.fileobject(self, tarinfo) elif tarinfo.islnk() or tarinfo.issym(): if isinstance(self.fileobj, _Stream): # A small but ugly workaround for the case that someone tries # to extract a (sym)link as a file-object from a non-seekable # stream of tar blocks. raise StreamError("cannot extract (sym)link as file object") else: # A (sym)link's file object is its target's file object. return self.extractfile(self._find_link_target(tarinfo)) else: # If there's no data associated with the member (directory, chrdev, # blkdev, etc.), return None instead of a file object. return None def _extract_member(self, tarinfo, targetpath, set_attrs=True, numeric_owner=False, *, filter_function=None, extraction_root=None): """Extract the filtered TarInfo object tarinfo to a physical file called targetpath. filter_function is only used when extracting a *different* member (e.g. as fallback to creating a symlink) """ # Fetch the TarInfo object for the given name # and build the destination pathname, replacing # forward slashes to platform specific separators. targetpath = targetpath.rstrip("/") targetpath = targetpath.replace("/", os.sep) # Create all upper directories. upperdirs = os.path.dirname(targetpath) if upperdirs and not os.path.exists(upperdirs): # Create directories that are not part of the archive with # default permissions. os.makedirs(upperdirs) if tarinfo.islnk() or tarinfo.issym(): self._dbg(1, "%s -> %s" % (tarinfo.name, tarinfo.linkname)) else: self._dbg(1, tarinfo.name) if tarinfo.isreg(): self.makefile(tarinfo, targetpath) elif tarinfo.isdir(): self.makedir(tarinfo, targetpath) elif tarinfo.isfifo(): self.makefifo(tarinfo, targetpath) elif tarinfo.ischr() or tarinfo.isblk(): self.makedev(tarinfo, targetpath) elif tarinfo.islnk() or tarinfo.issym(): self.makelink_with_filter( tarinfo, targetpath, filter_function=filter_function, extraction_root=extraction_root) elif tarinfo.type not in SUPPORTED_TYPES: self.makeunknown(tarinfo, targetpath) else: self.makefile(tarinfo, targetpath) if set_attrs: self.chown(tarinfo, targetpath, numeric_owner) if not tarinfo.issym(): self.chmod(tarinfo, targetpath) self.utime(tarinfo, targetpath) #-------------------------------------------------------------------------- # Below are the different file methods. They are called via # _extract_member() when extract() is called. They can be replaced in a # subclass to implement other functionality. def makedir(self, tarinfo, targetpath): """Make a directory called targetpath. """ try: if tarinfo.mode is None: # Use the system's default mode os.mkdir(targetpath) else: # Use a safe mode for the directory, the real mode is set # later in _extract_member(). os.mkdir(targetpath, 0o700) except FileExistsError: pass def makefile(self, tarinfo, targetpath): """Make a file called targetpath. """ source = self.fileobj source.seek(tarinfo.offset_data) bufsize = self.copybufsize with bltn_open(targetpath, "wb") as target: if tarinfo.sparse is not None: for offset, size in tarinfo.sparse: target.seek(offset) copyfileobj(source, target, size, ReadError, bufsize) target.seek(tarinfo.size) target.truncate() else: copyfileobj(source, target, tarinfo.size, ReadError, bufsize) def makeunknown(self, tarinfo, targetpath): """Make a file from a TarInfo object with an unknown type at targetpath. """ self.makefile(tarinfo, targetpath) self._dbg(1, "tarfile: Unknown file type %r, " \ "extracted as regular file." % tarinfo.type) def makefifo(self, tarinfo, targetpath): """Make a fifo called targetpath. """ if hasattr(os, "mkfifo"): os.mkfifo(targetpath) else: raise ExtractError("fifo not supported by system") def makedev(self, tarinfo, targetpath): """Make a character or block device called targetpath. """ if not hasattr(os, "mknod") or not hasattr(os, "makedev"): raise ExtractError("special devices not supported by system") mode = tarinfo.mode if mode is None: # Use mknod's default mode = 0o600 if tarinfo.isblk(): mode |= stat.S_IFBLK else: mode |= stat.S_IFCHR os.mknod(targetpath, mode, os.makedev(tarinfo.devmajor, tarinfo.devminor)) def makelink(self, tarinfo, targetpath): return self.makelink_with_filter(tarinfo, targetpath, None, None) def makelink_with_filter(self, tarinfo, targetpath, filter_function, extraction_root): """Make a (symbolic) link called targetpath. If it cannot be created (platform limitation), we try to make a copy of the referenced file instead of a link. filter_function is only used when extracting a *different* member (e.g. as fallback to creating a link). """ keyerror_to_extracterror = False try: # For systems that support symbolic and hard links. if tarinfo.issym(): if os.path.lexists(targetpath): # Avoid FileExistsError on following os.symlink. os.unlink(targetpath) os.symlink(tarinfo.linkname, targetpath) return else: if os.path.exists(tarinfo._link_target): os.link(tarinfo._link_target, targetpath) return except symlink_exception: keyerror_to_extracterror = True try: unfiltered = self._find_link_target(tarinfo) except KeyError: if keyerror_to_extracterror: raise ExtractError( "unable to resolve link inside archive") else: raise if filter_function is None: filtered = unfiltered else: if extraction_root is None: raise ExtractError( "makelink_with_filter: if filter_function is not None, " + "extraction_root must also not be None") try: filter_function( unfiltered.replace(name=tarinfo.name, deep=False), extraction_root) filtered = filter_function(unfiltered, extraction_root) except _FILTER_ERRORS as cause: raise LinkFallbackError(tarinfo, unfiltered.name) from cause if filtered is not None: self._extract_member(filtered, targetpath, filter_function=filter_function, extraction_root=extraction_root) def chown(self, tarinfo, targetpath, numeric_owner): """Set owner of targetpath according to tarinfo. If numeric_owner is True, use .gid/.uid instead of .gname/.uname. If numeric_owner is False, fall back to .gid/.uid when the search based on name fails. """ if hasattr(os, "geteuid") and os.geteuid() == 0: # We have to be root to do so. g = tarinfo.gid u = tarinfo.uid if not numeric_owner: try: if grp and tarinfo.gname: g = grp.getgrnam(tarinfo.gname)[2] except KeyError: pass try: if pwd and tarinfo.uname: u = pwd.getpwnam(tarinfo.uname)[2] except KeyError: pass if g is None: g = -1 if u is None: u = -1 try: if tarinfo.issym() and hasattr(os, "lchown"): os.lchown(targetpath, u, g) else: os.chown(targetpath, u, g) except OSError: raise ExtractError("could not change owner") def chmod(self, tarinfo, targetpath): """Set file permissions of targetpath according to tarinfo. """ if tarinfo.mode is None: return try: os.chmod(targetpath, tarinfo.mode) except OSError: raise ExtractError("could not change mode") def utime(self, tarinfo, targetpath): """Set modification time of targetpath according to tarinfo. """ mtime = tarinfo.mtime if mtime is None: return if not hasattr(os, 'utime'): return try: os.utime(targetpath, (mtime, mtime)) except OSError: raise ExtractError("could not change modification time") #-------------------------------------------------------------------------- def next(self): """Return the next member of the archive as a TarInfo object, when TarFile is opened for reading. Return None if there is no more available. """ self._check("ra") if self.firstmember is not None: m = self.firstmember self.firstmember = None return m # Advance the file pointer. if self.offset != self.fileobj.tell(): self.fileobj.seek(self.offset - 1) if not self.fileobj.read(1): raise ReadError("unexpected end of data") # Read the next block. tarinfo = None while True: try: tarinfo = self.tarinfo.fromtarfile(self) except EOFHeaderError as e: if self.ignore_zeros: self._dbg(2, "0x%X: %s" % (self.offset, e)) self.offset += BLOCKSIZE continue except InvalidHeaderError as e: if self.ignore_zeros: self._dbg(2, "0x%X: %s" % (self.offset, e)) self.offset += BLOCKSIZE continue elif self.offset == 0: raise ReadError(str(e)) except EmptyHeaderError: if self.offset == 0: raise ReadError("empty file") except TruncatedHeaderError as e: if self.offset == 0: raise ReadError(str(e)) except SubsequentHeaderError as e: raise ReadError(str(e)) except Exception as e: try: import zlib if isinstance(e, zlib.error): raise ReadError(f'zlib error: {e}') else: raise e except ImportError: raise e break if tarinfo is not None: self.members.append(tarinfo) else: self._loaded = True return tarinfo #-------------------------------------------------------------------------- # Little helper methods: def _getmember(self, name, tarinfo=None, normalize=False): """Find an archive member by name from bottom to top. If tarinfo is given, it is used as the starting point. """ # Ensure that all members have been loaded. members = self.getmembers() # Limit the member search list up to tarinfo. skipping = False if tarinfo is not None: try: index = members.index(tarinfo) except ValueError: # The given starting point might be a (modified) copy. # We'll later skip members until we find an equivalent. skipping = True else: # Happy fast path members = members[:index] if normalize: name = os.path.normpath(name) for member in reversed(members): if skipping: if tarinfo.offset == member.offset: skipping = False continue if normalize: member_name = os.path.normpath(member.name) else: member_name = member.name if name == member_name: return member if skipping: # Starting point was not found raise ValueError(tarinfo) def _load(self): """Read through the entire archive file and look for readable members. """ while True: tarinfo = self.next() if tarinfo is None: break self._loaded = True def _check(self, mode=None): """Check if TarFile is still open, and if the operation's mode corresponds to TarFile's mode. """ if self.closed: raise OSError("%s is closed" % self.__class__.__name__) if mode is not None and self.mode not in mode: raise OSError("bad operation for mode %r" % self.mode) def _find_link_target(self, tarinfo): """Find the target member of a symlink or hardlink member in the archive. """ if tarinfo.issym(): # Always search the entire archive. linkname = "/".join(filter(None, (os.path.dirname(tarinfo.name), tarinfo.linkname))) limit = None else: # Search the archive before the link, because a hard link is # just a reference to an already archived file. linkname = tarinfo.linkname limit = tarinfo member = self._getmember(linkname, tarinfo=limit, normalize=True) if member is None: raise KeyError("linkname %r not found" % linkname) return member def __iter__(self): """Provide an iterator object. """ if self._loaded: yield from self.members return # Yield items using TarFile's next() method. # When all members have been read, set TarFile as _loaded. index = 0 # Fix for SF #1100429: Under rare circumstances it can # happen that getmembers() is called during iteration, # which will have already exhausted the next() method. if self.firstmember is not None: tarinfo = self.next() index += 1 yield tarinfo while True: if index < len(self.members): tarinfo = self.members[index] elif not self._loaded: tarinfo = self.next() if not tarinfo: self._loaded = True return else: return index += 1 yield tarinfo def _dbg(self, level, msg): """Write debugging output to sys.stderr. """ if level <= self.debug: print(msg, file=sys.stderr) def __enter__(self): self._check() return self def __exit__(self, type, value, traceback): if type is None: self.close() else: # An exception occurred. We must not call close() because # it would try to write end-of-archive blocks and padding. if not self._extfileobj: self.fileobj.close() self.closed = True #-------------------- # exported functions #-------------------- def is_tarfile(name): """Return True if name points to a tar archive that we are able to handle, else return False. 'name' should be a string, file, or file-like object. """ try: if hasattr(name, "read"): t = open(fileobj=name) else: t = open(name) t.close() return True except TarError: return False open = TarFile.open def main(): import argparse description = 'A simple command-line interface for tarfile module.' parser = argparse.ArgumentParser(description=description) parser.add_argument('-v', '--verbose', action='store_true', default=False, help='Verbose output') parser.add_argument('--filter', metavar='<filtername>', choices=_NAMED_FILTERS, help='Filter for extraction') group = parser.add_mutually_exclusive_group(required=True) group.add_argument('-l', '--list', metavar='<tarfile>', help='Show listing of a tarfile') group.add_argument('-e', '--extract', nargs='+', metavar=('<tarfile>', '<output_dir>'), help='Extract tarfile into target dir') group.add_argument('-c', '--create', nargs='+', metavar=('<name>', '<file>'), help='Create tarfile from sources') group.add_argument('-t', '--test', metavar='<tarfile>', help='Test if a tarfile is valid') args = parser.parse_args() if args.filter and args.extract is None: parser.exit(1, '--filter is only valid for extraction\n') if args.test is not None: src = args.test if is_tarfile(src): with open(src, 'r') as tar: tar.getmembers() print(tar.getmembers(), file=sys.stderr) if args.verbose: print('{!r} is a tar archive.'.format(src)) else: parser.exit(1, '{!r} is not a tar archive.\n'.format(src)) elif args.list is not None: src = args.list if is_tarfile(src): with TarFile.open(src, 'r:*') as tf: tf.list(verbose=args.verbose) else: parser.exit(1, '{!r} is not a tar archive.\n'.format(src)) elif args.extract is not None: if len(args.extract) == 1: src = args.extract[0] curdir = os.curdir elif len(args.extract) == 2: src, curdir = args.extract else: parser.exit(1, parser.format_help()) if is_tarfile(src): with TarFile.open(src, 'r:*') as tf: tf.extractall(path=curdir, filter=args.filter) if args.verbose: if curdir == '.': msg = '{!r} file is extracted.'.format(src) else: msg = ('{!r} file is extracted ' 'into {!r} directory.').format(src, curdir) print(msg) else: parser.exit(1, '{!r} is not a tar archive.\n'.format(src)) elif args.create is not None: tar_name = args.create.pop(0) _, ext = os.path.splitext(tar_name) compressions = { # gz '.gz': 'gz', '.tgz': 'gz', # xz '.xz': 'xz', '.txz': 'xz', # bz2 '.bz2': 'bz2', '.tbz': 'bz2', '.tbz2': 'bz2', '.tb2': 'bz2', } tar_mode = 'w:' + compressions[ext] if ext in compressions else 'w' tar_files = args.create with TarFile.open(tar_name, tar_mode) as tf: for file_name in tar_files: tf.add(file_name) if args.verbose: print('{!r} file created.'.format(tar_name)) if __name__ == '__main__': main()
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