Ensure future compatibility, drop old code (v1/v2 support) #1
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kolyshkin
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In case kernel folks will ever release capability v4, the chances are high v3 is still supported. Therefore, we should not error out upon seeing an unknown version from the kernel, but assume we can go with v3. While at it, treat the uninitialized capVers as an error. Before this patch, it was still treated as an error, but "unknown capability version" is not exactly what the error is, so let's be more specific. Reported-by: Andrei Vagin <avagin@google.com> Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Capabilities v3 API was added by the Linux kernel 2.6.26. Since go 1.18 (no longer supported as of go 1.20 release), the minimum Linux kernel requirement is 2.6.32 (see [1]). So, it does not make sense to support capabilities v1 and v2 any more. Drop the support, returning the appropriate error message. [1] https://tip.golang.org/doc/go1.18#linux Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
kolyshkin
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Aug 1, 2024
Earlier commit (see #1) made sure we don't error out if the kernel capability version is unknown; this ensures compatibility with future kernels. Looking at the code, I realized p.hdr.version should be initialized to linuxCapVer3 in that case, not the version returned by the kernel, otherwise we supply v3 data structure with (say) v4 version set in header. Practically, this was not a real bug (yet) because v4 is not (yet) available, but if it will ever be introduced later, this fix makes us ready. Fixes: 5584105 ("Fix future version compatibility")
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This PR does two things.
Make sure that once (if ever) Linux kernel will start supporting capabilities v4, this library won't stop working. This relies on the assumption that v3 will still be supported.
Drops v1 and v2 API.
v3 API is used since the Linux kernel 2.6.26.
Since go 1.18 (no longer supported as of go 1.20 release), the minimum Linux kernel requirement is 2.6.32 (see 1). So, it does not make sense to support capabilities v1 and v2 any more.
Drop the support.
Same as syndtr#23