archival/libarchive/decompress_unxz.c

   1 /*
   2  * This file uses XZ Embedded library code which is written
   3  * by Lasse Collin <lasse.collin@tukaani.org>
   4  * and Igor Pavlov <http://7-zip.org/>
   5  *
   6  * See README file in unxz/ directory for more information.
   7  *
   8  * This file is:
   9  * Copyright (C) 2010 Denys Vlasenko <vda.linux@googlemail.com>
  10  * Licensed under GPLv2, see file LICENSE in this source tree.
  11  */
  12 #include "libbb.h"
  13 #include "bb_archive.h"
  14
  15 #define XZ_FUNC FAST_FUNC
  16 #define XZ_EXTERN static
  17
  18 #define XZ_DEC_DYNALLOC
  19
  20 /* Skip check (rather than fail) of unsupported hash functions */
  21 #define XZ_DEC_ANY_CHECK  1
  22
  23 /* We use our own crc32 function */
  24 #define XZ_INTERNAL_CRC32 0
  25 static uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
  26 {
  27         return ~crc32_block_endian0(~crc, buf, size, global_crc32_table);
  28 }
  29
  30 /* We use arch-optimized unaligned accessors */
  31 #define get_unaligned_le32(buf) ({ uint32_t v; move_from_unaligned32(v, buf); SWAP_LE32(v); })
  32 #define get_unaligned_be32(buf) ({ uint32_t v; move_from_unaligned32(v, buf); SWAP_BE32(v); })
  33 #define put_unaligned_le32(val, buf) move_to_unaligned32(buf, SWAP_LE32(val))
  34 #define put_unaligned_be32(val, buf) move_to_unaligned32(buf, SWAP_BE32(val))
  35
  36 #include "unxz/xz_dec_bcj.c"
  37 #include "unxz/xz_dec_lzma2.c"
  38 #include "unxz/xz_dec_stream.c"
  39
  40 IF_DESKTOP(long long) int FAST_FUNC
  41 unpack_xz_stream(transformer_state_t *xstate)
  42 {
  43         enum xz_ret xz_result;
  44         struct xz_buf iobuf;
  45         struct xz_dec *state;
  46         unsigned char *membuf;
  47         IF_DESKTOP(long long) int total = 0;
  48
  49         if (!global_crc32_table)
  50                 global_crc32_table = crc32_filltable(NULL, /*endian:*/ 0);
  51
  52         memset(&iobuf, 0, sizeof(iobuf));
  53         membuf = xmalloc(2 * BUFSIZ);
  54         iobuf.in = membuf;
  55         iobuf.out = membuf + BUFSIZ;
  56         iobuf.out_size = BUFSIZ;
  57
  58         if (!xstate || xstate->check_signature == 0) {
  59                 /* Preload XZ file signature */
  60                 strcpy((char*)membuf, HEADER_MAGIC);
  61                 iobuf.in_size = HEADER_MAGIC_SIZE;
  62         } /* else: let xz code read & check it */
  63
  64         /* Limit memory usage to about 64 MiB. */
  65         state = xz_dec_init(XZ_DYNALLOC, 64*1024*1024);
  66
  67         xz_result = X_OK;
  68         while (1) {
  69                 if (iobuf.in_pos == iobuf.in_size) {
  70                         int rd = safe_read(xstate->src_fd, membuf, BUFSIZ);
  71                         if (rd < 0) {
  72                                 bb_error_msg(bb_msg_read_error);
  73                                 total = -1;
  74                                 break;
  75                         }
  76                         if (rd == 0 && xz_result == XZ_STREAM_END)
  77                                 break;
  78                         iobuf.in_size = rd;
  79                         iobuf.in_pos = 0;
  80                 }
  81                 if (xz_result == XZ_STREAM_END) {
  82                         /*
  83                          * Try to start decoding next concatenated stream.
  84                          * Stream padding must always be a multiple of four
  85                          * bytes to preserve four-byte alignment. To keep the
  86                          * code slightly smaller, we aren't as strict here as
  87                          * the .xz spec requires. We just skip all zero-bytes
  88                          * without checking the alignment and thus can accept
  89                          * files that aren't valid, e.g. the XZ utils test
  90                          * files bad-0pad-empty.xz and bad-0catpad-empty.xz.
  91                          */
  92                         do {
  93                                 if (membuf[iobuf.in_pos] != 0) {
  94                                         xz_dec_reset(state);
  95                                         goto do_run;
  96                                 }
  97                                 iobuf.in_pos++;
  98                         } while (iobuf.in_pos < iobuf.in_size);
  99                 }
 100  do_run:
 101 //              bb_error_msg(">in pos:%d size:%d out pos:%d size:%d",
 102 //                              iobuf.in_pos, iobuf.in_size, iobuf.out_pos, iobuf.out_size);
 103                 xz_result = xz_dec_run(state, &iobuf);
 104 //              bb_error_msg("<in pos:%d size:%d out pos:%d size:%d r:%d",
 105 //                              iobuf.in_pos, iobuf.in_size, iobuf.out_pos, iobuf.out_size, xz_result);
 106                 if (iobuf.out_pos) {
 107                         xtransformer_write(xstate, iobuf.out, iobuf.out_pos);
 108                         IF_DESKTOP(total += iobuf.out_pos;)
 109                         iobuf.out_pos = 0;
 110                 }
 111                 if (xz_result == XZ_STREAM_END) {
 112                         /*
 113                          * Can just "break;" here, if not for concatenated
 114                          * .xz streams.
 115                          * Checking for padding may require buffer
 116                          * replenishment. Can't do it here.
 117                          */
 118                         continue;
 119                 }
 120                 if (xz_result != XZ_OK && xz_result != XZ_UNSUPPORTED_CHECK) {
 121                         bb_error_msg("corrupted data");
 122                         total = -1;
 123                         break;
 124                 }
 125         }
 126
 127         xz_dec_end(state);
 128         free(membuf);
 129
 130         return total;
 131 }