decompress_unlzo.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    1 /*
    2  * LZO decompressor for the Linux kernel. Code borrowed from the lzo
    3  * implementation by Markus Franz Xaver Johannes Oberhumer.
    4  *
    5  * Linux kernel adaptation:
    6  * Copyright (C) 2009
    7  * Albin Tonnerre, Free Electrons <albin.tonnerre@free-electrons.com>
    8  *
    9  * Original code:
   10  * Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
   11  * All Rights Reserved.
   12  *
   13  * lzop and the LZO library are free software; you can redistribute them
   14  * and/or modify them under the terms of the GNU General Public License as
   15  * published by the Free Software Foundation; either version 2 of
   16  * the License, or (at your option) any later version.
   17  *
   18  * This program is distributed in the hope that it will be useful,
   19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   21  * GNU General Public License for more details.
   22  *
   23  * You should have received a copy of the GNU General Public License
   24  * along with this program; see the file COPYING.
   25  * If not, write to the Free Software Foundation, Inc.,
   26  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   27  *
   28  * Markus F.X.J. Oberhumer
   29  * <markus@oberhumer.com>
   30  * http://www.oberhumer.com/opensource/lzop/
   31  */
   32 
   33 #ifdef STATIC
   34 #include "lzo/lzo1x_decompress.c"
   35 #else
   36 #include <linux/decompress/unlzo.h>
   37 #endif
   38 
   39 #include <linux/types.h>
   40 #include <linux/lzo.h>
   41 #include <linux/decompress/mm.h>
   42 
   43 #include <linux/compiler.h>
   44 #include <asm/unaligned.h>
   45 
   46 static const unsigned char lzop_magic[] = {
   47         0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a };
   48 
   49 #define LZO_BLOCK_SIZE        (256*1024l)
   50 #define HEADER_HAS_FILTER      0x00000800L
   51 #define HEADER_SIZE_MIN       (9 + 7     + 4 + 8     + 1       + 4)
   52 #define HEADER_SIZE_MAX       (9 + 7 + 1 + 8 + 8 + 4 + 1 + 255 + 4)
   53 
   54 STATIC inline int INIT parse_header(u8 *input, int *skip, int in_len)
   55 {
   56         int l;
   57         u8 *parse = input;
   58         u8 *end = input + in_len;
   59         u8 level = 0;
   60         u16 version;
   61 
   62         /*
   63          * Check that there's enough input to possibly have a valid header.
   64          * Then it is possible to parse several fields until the minimum
   65          * size may have been used.
   66          */
   67         if (in_len < HEADER_SIZE_MIN)
   68                 return 0;
   69 
   70         /* read magic: 9 first bits */
   71         for (l = 0; l < 9; l++) {
   72                 if (*parse++ != lzop_magic[l])
   73                         return 0;
   74         }
   75         /* get version (2bytes), skip library version (2),
   76          * 'need to be extracted' version (2) and
   77          * method (1) */
   78         version = get_unaligned_be16(parse);
   79         parse += 7;
   80         if (version >= 0x0940)
   81                 level = *parse++;
   82         if (get_unaligned_be32(parse) & HEADER_HAS_FILTER)
   83                 parse += 8; /* flags + filter info */
   84         else
   85                 parse += 4; /* flags */
   86 
   87         /*
   88          * At least mode, mtime_low, filename length, and checksum must
   89          * be left to be parsed. If also mtime_high is present, it's OK
   90          * because the next input buffer check is after reading the
   91          * filename length.
   92          */
   93         if (end - parse < 8 + 1 + 4)
   94                 return 0;
   95 
   96         /* skip mode and mtime_low */
   97         parse += 8;
   98         if (version >= 0x0940)
   99                 parse += 4;     /* skip mtime_high */
  100 
  101         l = *parse++;
  102         /* don't care about the file name, and skip checksum */
  103         if (end - parse < l + 4)
  104                 return 0;
  105         parse += l + 4;
  106 
  107         *skip = parse - input;
  108         return 1;
  109 }
  110 
  111 STATIC inline int INIT unlzo(u8 *input, int in_len,
  112                                 int (*fill) (void *, unsigned int),
  113                                 int (*flush) (void *, unsigned int),
  114                                 u8 *output, int *posp,
  115                                 void (*error) (char *x))
  116 {
  117         u8 r = 0;
  118         int skip = 0;
  119         u32 src_len, dst_len;
  120         size_t tmp;
  121         u8 *in_buf, *in_buf_save, *out_buf;
  122         int ret = -1;
  123 
  124         if (output) {
  125                 out_buf = output;
  126         } else if (!flush) {
  127                 error("NULL output pointer and no flush function provided");
  128                 goto exit;
  129         } else {
  130                 out_buf = malloc(LZO_BLOCK_SIZE);
  131                 if (!out_buf) {
  132                         error("Could not allocate output buffer");
  133                         goto exit;
  134                 }
  135         }
  136 
  137         if (input && fill) {
  138                 error("Both input pointer and fill function provided, don't know what to do");
  139                 goto exit_1;
  140         } else if (input) {
  141                 in_buf = input;
  142         } else if (!fill) {
  143                 error("NULL input pointer and missing fill function");
  144                 goto exit_1;
  145         } else {
  146                 in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE));
  147                 if (!in_buf) {
  148                         error("Could not allocate input buffer");
  149                         goto exit_1;
  150                 }
  151         }
  152         in_buf_save = in_buf;
  153 
  154         if (posp)
  155                 *posp = 0;
  156 
  157         if (fill) {
  158                 /*
  159                  * Start from in_buf + HEADER_SIZE_MAX to make it possible
  160                  * to use memcpy() to copy the unused data to the beginning
  161                  * of the buffer. This way memmove() isn't needed which
  162                  * is missing from pre-boot environments of most archs.
  163                  */
  164                 in_buf += HEADER_SIZE_MAX;
  165                 in_len = fill(in_buf, HEADER_SIZE_MAX);
  166         }
  167 
  168         if (!parse_header(in_buf, &skip, in_len)) {
  169                 error("invalid header");
  170                 goto exit_2;
  171         }
  172         in_buf += skip;
  173         in_len -= skip;
  174 
  175         if (fill) {
  176                 /* Move the unused data to the beginning of the buffer. */
  177                 memcpy(in_buf_save, in_buf, in_len);
  178                 in_buf = in_buf_save;
  179         }
  180 
  181         if (posp)
  182                 *posp = skip;
  183 
  184         for (;;) {
  185                 /* read uncompressed block size */
  186                 if (fill && in_len < 4) {
  187                         skip = fill(in_buf + in_len, 4 - in_len);
  188                         if (skip > 0)
  189                                 in_len += skip;
  190                 }
  191                 if (in_len < 4) {
  192                         error("file corrupted");
  193                         goto exit_2;
  194                 }
  195                 dst_len = get_unaligned_be32(in_buf);
  196                 in_buf += 4;
  197                 in_len -= 4;
  198 
  199                 /* exit if last block */
  200                 if (dst_len == 0) {
  201                         if (posp)
  202                                 *posp += 4;
  203                         break;
  204                 }
  205 
  206                 if (dst_len > LZO_BLOCK_SIZE) {
  207                         error("dest len longer than block size");
  208                         goto exit_2;
  209                 }
  210 
  211                 /* read compressed block size, and skip block checksum info */
  212                 if (fill && in_len < 8) {
  213                         skip = fill(in_buf + in_len, 8 - in_len);
  214                         if (skip > 0)
  215                                 in_len += skip;
  216                 }
  217                 if (in_len < 8) {
  218                         error("file corrupted");
  219                         goto exit_2;
  220                 }
  221                 src_len = get_unaligned_be32(in_buf);
  222                 in_buf += 8;
  223                 in_len -= 8;
  224 
  225                 if (src_len <= 0 || src_len > dst_len) {
  226                         error("file corrupted");
  227                         goto exit_2;
  228                 }
  229 
  230                 /* decompress */
  231                 if (fill && in_len < src_len) {
  232                         skip = fill(in_buf + in_len, src_len - in_len);
  233                         if (skip > 0)
  234                                 in_len += skip;
  235                 }
  236                 if (in_len < src_len) {
  237                         error("file corrupted");
  238                         goto exit_2;
  239                 }
  240                 tmp = dst_len;
  241 
  242                 /* When the input data is not compressed at all,
  243                  * lzo1x_decompress_safe will fail, so call memcpy()
  244                  * instead */
  245                 if (unlikely(dst_len == src_len))
  246                         memcpy(out_buf, in_buf, src_len);
  247                 else {
  248                         r = lzo1x_decompress_safe((u8 *) in_buf, src_len,
  249                                                 out_buf, &tmp);
  250 
  251                         if (r != LZO_E_OK || dst_len != tmp) {
  252                                 error("Compressed data violation");
  253                                 goto exit_2;
  254                         }
  255                 }
  256 
  257                 if (flush && flush(out_buf, dst_len) != dst_len)
  258                         goto exit_2;
  259                 if (output)
  260                         out_buf += dst_len;
  261                 if (posp)
  262                         *posp += src_len + 12;
  263 
  264                 in_buf += src_len;
  265                 in_len -= src_len;
  266                 if (fill) {
  267                         /*
  268                          * If there happens to still be unused data left in
  269                          * in_buf, move it to the beginning of the buffer.
  270                          * Use a loop to avoid memmove() dependency.
  271                          */
  272                         if (in_len > 0)
  273                                 for (skip = 0; skip < in_len; ++skip)
  274                                         in_buf_save[skip] = in_buf[skip];
  275                         in_buf = in_buf_save;
  276                 }
  277         }
  278 
  279         ret = 0;
  280 exit_2:
  281         if (!input)
  282                 free(in_buf_save);
  283 exit_1:
  284         if (!output)
  285                 free(out_buf);
  286 exit:
  287         return ret;
  288 }
  289 
  290 #define decompress unlzo
Cache object: f62f299e43594cc4927846e4bbe5f58a
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/lib/decompress_unlzo.c

FreeBSD/Linux Kernel Cross Reference
sys/lib/decompress_unlzo.c
