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.
Signed-off-by: Jonas Gorski <jonas.gorski+open...@gmail.com>
---
I chose to only add this to unsquashfs to make inspecting vendor
firmwares easier, so creating them isn't support (but would be easy to
implement)
tools/squashfs4/patches/160-lzma_magic.patch | 87 ++++++++++++++++++++++++++
1 files changed, 87 insertions(+), 0 deletions(-)
create mode 100644 tools/squashfs4/patches/160-lzma_magic.patch
diff --git a/tools/squashfs4/patches/160-lzma_magic.patch
b/tools/squashfs4/patches/160-lzma_magic.patch
new file mode 100644
index 0000000..40fad9e
--- /dev/null
+++ b/tools/squashfs4/patches/160-lzma_magic.patch
@@ -0,0 +1,87 @@
+--- 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
+@@ -1437,11 +1437,13 @@ int read_super(char *source)
+ */
+ read_bytes(SQUASHFS_START, sizeof(squashfs_super_block),
+ (char *) &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 &&
+- sBlk_4.s_minor == 0) {
++ 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;
+ s_ops.read_fragment_table = read_fragment_table_4;
+@@ -1453,7 +1455,11 @@ int read_super(char *source)
+ /*
+ * Check the compression type
+ */
+- comp = lookup_compressor_id(sBlk.compression);
++ if (sBlk_4.s_magic == SQUASHFS_MAGIC_LZMA)
++ comp = lookup_compressor("lzma");
++ else
++ comp = lookup_compressor_id(sBlk.compression);
++
+ if(!comp->supported) {
+ ERROR("Filesystem uses %s compression, this is "
+ "unsupported by this version\n", comp->name);
+@@ -1475,8 +1481,10 @@ 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);
+@@ -1550,11 +1558,20 @@ int read_super(char *source)
+ goto failed_mount;
+ }
+
+- /*
+- * 1.x, 2.x and 3.x filesystems use gzip compression. Gzip is always
+- * suppported.
+- */
+- comp = lookup_compressor("gzip");
++ if (sBlk.s_magic == SQUASHFS_MAGIC_LZMA) {
++ /* Check for availability */
++ comp = lookup_compressor("lzma");
++ if(!comp->supported) {
++ ERROR("Filesystem uses lzma compression, this is "
++ "unsupported by this version\n");
++ ERROR("Decompressors available:\n");
++ display_compressors("", "");
++ goto failed_mount;
++ }
++ } else {
++ /* Gzip is always supported */
++ comp = lookup_compressor("gzip");
++ }
+ return TRUE;
+
+ failed_mount:
--
1.5.6.5
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