On Tue, Feb 21, 2023 at 3:45 PM Daniel Müller <deso@xxxxxxxxxx> wrote: > > This change implements support for reading zip archives, including > opening an archive, finding an entry based on its path and name in it, > and closing it. > The code was copied from https://github.com/iovisor/bcc/pull/4440, which > implements similar functionality for bcc. The author confirmed that he > is fine with this usage and the corresponding relicensing. I adjusted it > to adhere to libbpf coding standards. > > Signed-off-by: Daniel Müller <deso@xxxxxxxxxx> > Acked-by: Michał Gregorczyk <michalgr@xxxxxxxx> > --- > tools/lib/bpf/Build | 2 +- > tools/lib/bpf/zip.c | 326 ++++++++++++++++++++++++++++++++++++++++++++ > tools/lib/bpf/zip.h | 47 +++++++ > 3 files changed, 374 insertions(+), 1 deletion(-) > create mode 100644 tools/lib/bpf/zip.c > create mode 100644 tools/lib/bpf/zip.h > [...] > + > +static int find_cd(struct zip_archive *archive) > +{ > + __u32 offset; > + int64_t limit; > + int rc = -1; > + > + if (archive->size <= sizeof(struct end_of_cd_record)) > + return -EINVAL; > + > + /* Because the end of central directory ends with a variable length array of > + * up to 0xFFFF bytes we can't know exactly where it starts and need to > + * search for it at the end of the file, scanning the (limit, offset] range. > + */ > + offset = archive->size - sizeof(struct end_of_cd_record); > + limit = (int64_t)offset - (1 << 16); > + > + for (; offset >= 0 && offset > limit && rc == -1; offset--) rc != 0 here to handle -EINVAL? It will keep going for -ENOTSUP, though, which is probably not right, so maybe (rc != 0 && rc != -ENOTSUP)? but with the latter it feels better to just have explicit if with return inside the for loop > + rc = try_parse_end_of_cd(archive, offset); > + > + return rc; > +} > + [...]
