LXR busybox/archival/libarchive/decompress

   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
  25static 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
  40IF_DESKTOP(long long) int FAST_FUNC
  41unpack_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}
 132