patches/squashfs-tools/0004-unsquashfs-add-support-for-LZMA-magics.patch

   1 From c2dc60a94b01a1fff4a22db1c0569651afa6c959 Mon Sep 17 00:00:00 2001
   2 From: Jonas Gorski <jonas.gorski@gmail.com>
   3 Date: Wed, 19 Oct 2011 11:44:57 +0200
   4 Subject: [PATCH] unsquashfs: add support for LZMA magics
   5 X-Face: z*RaLf`X<@C75u6Ig9}{oW$H;1_\2t5)({*|jhM<pyWR#k60!#=#>/Vb;]yA5<GWI5`6u&+
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   7  !pE^+iDQQ1yC6^,)YDKkxDd!T>\I~93>J<_`<4)A{':UrE
   8
   9 Some vendor (e.g. Thomson/Technicolor) use a different super block magic
  10 to indicate LZMA compression:
  11
  12   qshs (0x71736873) - LZMA compression
  13   shsq (0x73687371) - LZMA compression, SWAPPED fields
  14
  15 Add support for detecting this and enable extraction for filesystems
  16 from those firmwares.
  17
  18 Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
  19 Tested-by: Antonio Ospite <ospite@studenti.unina.it>
  20 ---
  21  squashfs-tools/squashfs_fs.h |    6 ++++++
  22  squashfs-tools/unsquashfs.c  |   24 ++++++++++++++++++------
  23  2 files changed, 24 insertions(+), 6 deletions(-)
  24
  25 diff --git a/squashfs-tools/squashfs_fs.h b/squashfs-tools/squashfs_fs.h
  26 index d4fba1b..8462a6b 100644
  27 --- a/squashfs-tools/squashfs_fs.h
  28 +++ b/squashfs-tools/squashfs_fs.h
  29 @@ -31,6 +31,12 @@
  30  #define SQUASHFS_MAGIC_SWAP            0x68737173
  31  #define SQUASHFS_START                 0
  32
  33 +/*
  34 + * Squashfs + LZMA
  35 + */
  36 +#define SQUASHFS_MAGIC_LZMA            0x71736873
  37 +#define SQUASHFS_MAGIC_LZMA_SWAP       0x73687371
  38 +
  39  /* size of metadata (inode and directory) blocks */
  40  #define SQUASHFS_METADATA_SIZE         8192
  41  #define SQUASHFS_METADATA_LOG          13
  42 diff --git a/squashfs-tools/unsquashfs.c b/squashfs-tools/unsquashfs.c
  43 index 320bead..7869a38 100644
  44 --- a/squashfs-tools/unsquashfs.c
  45 +++ b/squashfs-tools/unsquashfs.c
  46 @@ -1783,10 +1783,12 @@ int read_super(char *source)
  47          */
  48         read_fs_bytes(fd, SQUASHFS_START, sizeof(struct squashfs_super_block),
  49                 &sBlk_4);
  50 -       swap = sBlk_4.s_magic != SQUASHFS_MAGIC;
  51 +       swap = (sBlk_4.s_magic != SQUASHFS_MAGIC &&
  52 +               sBlk_4.s_magic != SQUASHFS_MAGIC_LZMA);
  53         SQUASHFS_INSWAP_SUPER_BLOCK(&sBlk_4);
  54
  55 -       if(sBlk_4.s_magic == SQUASHFS_MAGIC && sBlk_4.s_major == 4 &&
  56 +       if((sBlk_4.s_magic == SQUASHFS_MAGIC ||
  57 +                       sBlk_4.s_magic == SQUASHFS_MAGIC_LZMA) && sBlk_4.s_major == 4 &&
  58                         sBlk_4.s_minor == 0) {
  59                 s_ops.squashfs_opendir = squashfs_opendir_4;
  60                 s_ops.read_fragment = read_fragment_4;
  61 @@ -1799,7 +1801,11 @@ int read_super(char *source)
  62                 /*
  63                  * Check the compression type
  64                  */
  65 -               comp = lookup_compressor_id(sBlk.s.compression);
  66 +               if (sBlk_4.s_magic == SQUASHFS_MAGIC_LZMA)
  67 +                       comp = lookup_compressor("lzma");
  68 +               else
  69 +                       comp = lookup_compressor_id(sBlk.s.compression);
  70 +
  71                 return TRUE;
  72         }
  73
  74 @@ -1814,8 +1820,10 @@ int read_super(char *source)
  75          * Check it is a SQUASHFS superblock
  76          */
  77         swap = 0;
  78 -       if(sBlk_3.s_magic != SQUASHFS_MAGIC) {
  79 -               if(sBlk_3.s_magic == SQUASHFS_MAGIC_SWAP) {
  80 +       if(sBlk_3.s_magic != SQUASHFS_MAGIC &&
  81 +                       sBlk_3.s_magic != SQUASHFS_MAGIC_LZMA) {
  82 +               if(sBlk_3.s_magic == SQUASHFS_MAGIC_SWAP ||
  83 +                               sBlk_3.s_magic == SQUASHFS_MAGIC_LZMA_SWAP) {
  84                         squashfs_super_block_3 sblk;
  85                         ERROR("Reading a different endian SQUASHFS filesystem "
  86                                 "on %s\n", source);
  87 @@ -1893,7 +1901,11 @@ int read_super(char *source)
  88         /*
  89          * 1.x, 2.x and 3.x filesystems use gzip compression.
  90          */
  91 -       comp = lookup_compressor("gzip");
  92 +       if (sBlk.s.s_magic == SQUASHFS_MAGIC_LZMA)
  93 +               comp = lookup_compressor("lzma");
  94 +       else
  95 +               comp = lookup_compressor("gzip");
  96 +
  97         return TRUE;
  98
  99  failed_mount:
 100 --
 101 1.7.10.4
 102