squashfs-tools-ng.git/lib/tar, branch v1.1.0

Remodel libtar/tar2sqfs to read data from an istream_t

2020-09-16T07:34:35+00:00

Signed-off-by: David Oberhollenzer

Remodel file extraction tools to use libfstream

2020-09-16T07:34:35+00:00

This commit rewrites the libtar write paths to use libfstream insead of a FILE pointer. Also, the libcommon file extraction function is remodeled to use libfstream. In accordance, rdsquashfs, sqfs2tar and sqfsdiff have some minor adjustments made to work with the ported libtar and libcommon. Signed-off-by: David Oberhollenzer

Fix integer bounds checking in GNU tar sparse format 1.0 parser

2020-09-03T16:28:09+00:00

- Make sure the file actually has that many records before trying to read one and fail if not. - Use the helper macros for size_t overflow checking instead of assuming size_t == uint64_t. - Impose a "reasonable" upper bound on the number of data segments and insist that there is at least one entry. Signed-off-by: David Oberhollenzer

Fix nonexistant gnu tar sparse format 1.0 support

2020-09-02T09:19:11+00:00

Contrary to previous claims, support for the GNU tar sparse format 1.0 was missing entirely (the newest of their 3 different sparse mapping formats). This oversight wasn't caught, because the unit test was compiling the wrong source file and tar2sqfs had no problem processing the test file because it is still a valid POSIX-ish tar archive (but the sparse part was missing and the mapping embedded in the file). Signed-off-by: David Oberhollenzer

Fix libtar treatment of link targets that fill the header field

2020-08-16T11:03:17+00:00

The tar header has a 100 byte field for symlink and hard link targets. If the target is longer than 100 bytes, an extension header has to be used. However, it is perfectly valid to fill all 100 bytes to the brim without adding a null terminator. In case of a symlink, this can result in garbage link targets, while for hard links it results in an immediate error since the target cannot be resolved later on. This commit attempts to fix the problem by replacing the strdup of the link target with an strndup that copies at most the size of the target header field. Signed-off-by: David Oberhollenzer

Cleanup: sqfs2tar: break up and simplify the repacking code

2020-05-30T15:49:40+00:00

- Move the xattr extraction and repacking to xattr.c - Don't on-the-fly delete the tar xattr list, use the function from libtar.a - Split minor tasks into static helper functions - creating a libtar xattr struct from libsqfs xattr data - finding a hard link entry from current path and inode number Signed-off-by: David Oberhollenzer

libtar: fix size computation of PAX line length

2020-05-18T12:00:31+00:00

This commit attempts to fix the following two problems: - The number of digits computation returning an off-by-one result if the number is 10, or the resulting digit string starts with "10". This results in one-too-many padding bytes, corrupting the rest of the archive since the headers now don't start at multiples of 512 anymore. - Adding the line length prefix affects the line length (duh). If it grows far enough to require more digits, the result is a similar problem. This is a converging series that we need to compute the limit of. Unit tests for this still need to be added. Or maybe I can convince a bored undergrad student to provide an induction proof. Signed-off-by: David Oberhollenzer

Skip PAX global headers

2020-04-22T12:22:44+00:00

Tar archives can contain set two kinds of PAX headers: - local headers that modify the attributes of the next file - global headers that set defaults for all files The later is used "... not widely used", according to tar(5) and has been deliberately not implemented. Some programs (e.g. git-archive) *do* generate them (in the case of git, it stores the commit hash). This commit adds a code path that skips a PAX global header entirely and resumes tar parsing, instead of erroneusly reporting it as an entry. Signed-off-by: David Oberhollenzer

Remove some configure time sizeof checks

2020-04-17T21:52:52+00:00

In libtar, the sizeof time_t checked when trying to store a time value. It is pointless using the preprocessor here, as we can simply do an if (sizeof(time_t) < ...) check and the compiler will take care optimizing away one or the other branch. After changing the libtar check and the corresponding unit tests, the sizeof check can be removed from configure.ac, along with other unused sizeof checks. Signed-off-by: David Oberhollenzer

Cleanup: split read_header.c in libtar.a

2020-04-17T21:31:32+00:00

Simply moving the pax header decoding to a separate file and splitting out the common helper functions should be a good start. Signed-off-by: David Oberhollenzer