squashfs4: Add support for LZMA Magic to unsquashfs

Some vendor firmwares use a different super block magic to indicate LZMA
compression. This patches adds support for detecting this and enable
extraction for those firmware's root filesystems.

SVN-Revision: 28489

diff --git a/tools/squashfs4/patches/170-add_support_for_LZMA_MAGIC_to_unsqashfs.patch b/tools/squashfs4/patches/170-add_support_for_LZMA_MAGIC_to_unsqashfs.patch
new file mode 100644 (file)
index 0000000..ad69b19
--- /dev/null
+++ b/tools/squashfs4/patches/170-add_support_for_LZMA_MAGIC_to_unsqashfs.patch
@@ -0,0 +1,72 @@
+--- a/squashfs-tools/squashfs_fs.h
++++ b/squashfs-tools/squashfs_fs.h
+@@ -30,6 +30,13 @@
+ #define SQUASHFS_MAGIC_SWAP           0x68737173
+ #define SQUASHFS_START                        0
+ 
++/*
++ * Squashfs + LZMA
++ */
++
++#define SQUASHFS_MAGIC_LZMA           0x71736873
++#define SQUASHFS_MAGIC_LZMA_SWAP      0x73687371
++
+ /* size of metadata (inode and directory) blocks */
+ #define SQUASHFS_METADATA_SIZE                8192
+ #define SQUASHFS_METADATA_LOG         13
+--- a/squashfs-tools/unsquashfs.c
++++ b/squashfs-tools/unsquashfs.c
+@@ -1463,10 +1463,12 @@ int read_super(char *source)
+        */
+       read_fs_bytes(fd, SQUASHFS_START, sizeof(struct squashfs_super_block),
+               &sBlk_4);
+-      swap = sBlk_4.s_magic != SQUASHFS_MAGIC;
++      swap = (sBlk_4.s_magic != SQUASHFS_MAGIC &&
++              sBlk_4.s_magic != SQUASHFS_MAGIC_LZMA);
+       SQUASHFS_INSWAP_SUPER_BLOCK(&sBlk_4);
+ 
+-      if(sBlk_4.s_magic == SQUASHFS_MAGIC && sBlk_4.s_major == 4 &&
++      if((sBlk_4.s_magic == SQUASHFS_MAGIC || 
++         sBlk_4.s_magic == SQUASHFS_MAGIC_LZMA) && sBlk_4.s_major == 4 &&
+                       sBlk_4.s_minor == 0) {
+               s_ops.squashfs_opendir = squashfs_opendir_4;
+               s_ops.read_fragment = read_fragment_4;
+@@ -1479,7 +1481,11 @@ int read_super(char *source)
+               /*
+                * Check the compression type
+                */
+-              comp = lookup_compressor_id(sBlk.s.compression);
++              if (sBlk_4.s_magic == SQUASHFS_MAGIC_LZMA)
++                      comp = lookup_compressor("lzma");
++              else
++                      comp = lookup_compressor_id(sBlk.s.compression);
++
+               return TRUE;
+       }
+ 
+@@ -1494,8 +1500,10 @@ int read_super(char *source)
+        * Check it is a SQUASHFS superblock
+        */
+       swap = 0;
+-      if(sBlk_3.s_magic != SQUASHFS_MAGIC) {
+-              if(sBlk_3.s_magic == SQUASHFS_MAGIC_SWAP) {
++      if(sBlk_3.s_magic != SQUASHFS_MAGIC && 
++                      sBlk_3.s_magic != SQUASHFS_MAGIC_LZMA) {
++              if(sBlk_3.s_magic == SQUASHFS_MAGIC_SWAP || 
++                              sBlk_3.s_magic == SQUASHFS_MAGIC_LZMA_SWAP) {
+                       squashfs_super_block_3 sblk;
+                       ERROR("Reading a different endian SQUASHFS filesystem "
+                               "on %s\n", source);
+@@ -1573,7 +1581,11 @@ int read_super(char *source)
+       /*
+        * 1.x, 2.x and 3.x filesystems use gzip compression.
+        */
+-      comp = lookup_compressor("gzip");
++      if (sBlk.s.s_magic == SQUASHFS_MAGIC_LZMA)
++              comp = lookup_compressor("lzma");
++      else
++              comp = lookup_compressor("gzip");
++
+       return TRUE;
+ 
+ failed_mount: