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2019-08-23Check against format limits in meta_reader_read_dir_headerDavid Oberhollenzer
The SquashFS kernel implementation insists that a directory header is followed by no more than an upper bound of entries, way less than what the filed itself actually supports. This commit makes sure that the meta_reader_read_dir_header function also enforces that same limit. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-23Size accounting + alloc() overflow checking, round #2David Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-23Do bounds checking in metadata readerDavid Oberhollenzer
In all cases where metadata blocks are read, we can roughly (in some cases even preciesly) say in what range those metadata blocks will be, so it makes sense to throw an error if an attempt is made to wander outside this range. Furthermore, when reading from an uncompressed block, it is more reasonable to check against the actual block bounds than to padd it with 0 bytes. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-23Some simple search/replace cases for allocationDavid Oberhollenzer
This commit exchanges some malloc(x + y * z) patterns that can be found with a simple git grep and are obvious for the new wrappers. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-22deserialize_tree: filter out directory loopsDavid Oberhollenzer
The tree deserializer does a recursive depth-first search to populate the directory tree, moving back and forth between the directory listing containing the inode references and the inode table pointing to the list of child inodes. It is completely unaware of hard links and creates duplicate nodes instead. It is possible to create a malicious SquashFS image that contains a directory that contains as child a reference to its own inode. This can also be done transitively (i.e. directory contains its own parent or grand parent), leading to infinite recursion (actually finite, since it terminates once all stack memory is exhausted). This commit adds a simple check to see if a node has the same inode number as any of its would-be parents. If it does, the node is discarded and a warning message is emitted. Other cases with arbitrary layers of indirection could be constructed as well (e.g. dir 'a' contains hard link to 'b' and 'b' one back to 'a'), but the sub hierarchies are always expanded, this check should catch that too. Reported-by: Zachary Dremann <dremann@gmail.com> Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-21Fix "no attributes" sentinel value for xattr readerDavid Oberhollenzer
An inode can be of extended type for reasons other than having extended attributes and simply set the xattr ID to 0xFFFFFFFF to indicate that it doesn't have extended attributes. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-19Fix memory leak in data writer fragment deduplicationDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-19Fix memory leak in data writer error code pathsDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-18Replace update_crc32 helper function with crc32 from zlibDavid Oberhollenzer
It is optimized to the maximum and if we already use zlib anyway, why not use zlib crc32? This also makes zlib a hard dependency which also means the whole "do we have a compressor" sanity check in the build system can be removed. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-18Make data writer use block processorDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-18Restructure data writer around passing block_t structuresDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-18Minor interface change to data writerDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-18cleanup: internalize deduplication list in data_writerDavid Oberhollenzer
This change removes the need for passing a list of files around for deduplication. Also the deduplication code no longer needs to worry about order, since the file being deduplicated is only added after deduplication is done. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-16Fix: don't try to read xattrs if there are noneDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-07Add pread(2) like function to data_readerDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-07Fix forward seek when unpacking sparse filesDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-07Fix zero padding of extracted data blocksDavid Oberhollenzer
Only padd it if the *extracted* size is less then block size. Doing it with the compressed size results in garbled blocks. Especially because most of them are less than block size when compressed. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-05cleanup data readerDavid Oberhollenzer
- Split block reading code out from "dump_blocks" into precache_data_block, similar to precache_fragment_block - Merge the code paths for fragment/data block reading and uncompression Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-05cleanup: unify all the code that reads squashfs imagesDavid Oberhollenzer
This commit creates a new data structure called 'sqfs_reader_t' that takes care of all the repetetive tasks like opening the file, reading the super block, creating the compressor, deserializing an fstree and creating a data reader. This in turn makes it possible to remove all the duplicate code from rdsquashfs and sqfs2tar. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-02Fix explicit NULL dereference in deserialize_fstree failure pathDavid Oberhollenzer
If we failed to create the root node, we don't need to cleanup the fstree_t which would attempt to recursively cleanup the root node. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-02cleanup: merge error paths in xattr reader restore_kv_pairsDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-02Fix potential double free of xattr reader id_block_startsDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-01Add option to restore xattrs to deserialize_fstreeDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-01Add xattr reader implementation to recover xattrs from squashfsDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-01Fix xattr writer size accountingDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-01Fix super block flags: clear "no xattr" flag when writing xattrsDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-08-01Fix xattr OOL positionDavid Oberhollenzer
We need to get the position _before_ writing the header, otherwise the reader has no way to know the length of the value. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-30Add propper copyright headers to all source filesDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-29Fix order of data block deduplicationDavid Oberhollenzer
Data blocks need to be deduplicated before attempting to write a fragment. In the current attempt if the data blocks are found to be duplicates but the fragment isn't, the flushed fragments are purged as well, possibly damaging other files. Also, when the deduplication happens, the HAS_FRAGMENT flag needs to be set, otherwise the deduplication code thinks that there is one more block than there actually is. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-29Cleanup: move deduplication code from data writer to fstreeDavid Oberhollenzer
Since it is actually completely independend of libsqfs and only works on file_info_t lists, it can be safely moved over to libfstree and the data writer becomes less cluttered as a result. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Fix duplicate file accountingDavid Oberhollenzer
A file is a complete duplicate if: - It has no blocks, only a single fragment and that is a duplicate - It has blocks but no fragment and the blocks are duplicate - It has blocks and a fragment and both are duplicate The previous version only counted the last one. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Fix used bytes accounting when deduplicating file blocksDavid Oberhollenzer
If an entire file is eliminated, we need to reset the "used_bytes" counter, otherwise, ALL the table positions are way off. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Fix free() of stack pointer in id_table_read error pathDavid Oberhollenzer
We didn't allocate the ID table, so we don't need to free() it when reading from disk fails. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Fix: return the correct value from data_reader_createDavid Oberhollenzer
Cut & paste misshap after mergining with fragment reader: If there are no fragments, data_reader_create should return the data reader, not 0! Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Add some nice statistics output to tar2sqfs and gensquashfsDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Add general purpose flags field to file_info_tDavid Oberhollenzer
Simplifies some task if we can just add a flag that a file has a framgent or that it has already been detected as a duplicate. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Implement data block deduplicationDavid Oberhollenzer
The strategy is as follows: - At the beginning of every file, remember the current position - Once a file is done scan the list of existing files for the following: - Look for an existing file that has a block with the same size and checksum as the first non-sparse block of the current file - After that, every block in the current file has to match in size and checksum the ones in the file that we found, from that point onward - sparse blocks in either file are skipped - If we found a match, we update the current file to point to the first matching block and rewind the squashfs image to remove the newly written data This strategy should in theory be able to find an existing file where the on-disk data *contains* the on-disk data of the current file. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Implement fragment deduplication in data writerDavid Oberhollenzer
The strategy is simple: - The data writer function that write data/fragment blocks get access to the list files. - When writing a fragment, we look for an already written file that has a fragment with the same size and checksum. - If we find one, we throw away the fragment and reuse the existing one. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Unify common file start/end code from data writer in helper functionsDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Compute per-block and per-fragment checksums in data wrtierDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Add fragment and block checksum fields to file_info_tDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Merge remaining code of fragment reader into data readerDavid Oberhollenzer
After the table read unification, there wasn't much left of the fragment reader and the remains could easily be moved over to the data reader. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-28Split data_reader_dump_file into smaller functionsDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-25Fix potential resource leak in deserialize_treeDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-25Fix checks of super block block sizeDavid Oberhollenzer
Make sure range is checked when reading a block and that the check is made correctly. Also make the block log check a little more strict. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-25Fix acciedental usage of left over local variable instead struct memberDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-25Add generic read_table function similar to write_tableDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-25Cleanup sqfs_write_tableDavid Oberhollenzer
This commit attempts to make the generic table writer more readable. A few changes are made, including heap allocation of the block list. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-25Rename table.c to write_table.c in accordance to function it containsDavid Oberhollenzer
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
2019-07-25Fix fragment reader out of bounds read when loading tableDavid Oberhollenzer
This commit fixes a bug in the fragment table reader where the reader tries to read data into an out of bounds location due to an oversight in size calculation. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
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