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GeezerVison is showing github.com — cpython/Lib/tarfile.py at 3.10 · python/cpython Expand file tree/ Copy pathtarfile.pyMore file actions executable file ·3065 lines (2680 loc) · 111 KB / Copy pathtarfile.pyFile metadata and controlsexecutable file ·3065 lines (2680 loc) · 111 KB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 #!/usr/bin/env python3 #------------------------------------------------------------------- # tarfile.py #------------------------------------------------------------------- # Copyright (C) 2002 Lars Gustaebel <[email protected]> # 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" __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"] #--------------------------------------------------------- # 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. original_n = n 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") from None 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") from None 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") from None 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): data = self.read(self.bufsize) if not data: break 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 as e: raise ReadError("invalid compressed data") from e 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 if '..' in name.replace(os.sep, '/').split('/'): # Directories are created from the name as given, so a name that # leaves the destination part-way through would create them # outside it even if the resolved path stays inside. normalized = os.path.normpath(name) if normalized != name: name = new_attrs['name'] = normalized 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) # A link member that resolves to the destination directory itself # would replace it with a (sym)link, redirecting the destination # for all subsequent members. if target_path == dest_path: raise OutsideDestinationError(member, target_path) normalized = os.path.normpath(member.linkname) if normalized != member.linkname: new_attrs['linkname'] = normalized if member.issym(): # The symlink is created at `name` with trailing separators # stripped, so its target is relative to the directory # containing that path. link_dir = os.path.dirname(name.rstrip('/' + os.sep)) target_path = os.path.join(dest_path, link_dir, normalized) else: target_path = os.path.join(dest_path, normalized) 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, |
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