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Daniel Borkmann authored
Currently, NDA_FLAGS_EXT flags allow a maximum of 24 bits to be used for extended neighbor flags. These are eventually fed into neigh->flags by shifting with NTF_EXT_SHIFT as per commit 2c611ad9 ("net, neigh: Extend neigh->flags to 32 bit to allow for extensions"). If really ever needed in future, the full 32 bits from NDA_FLAGS_EXT can be used, it would only require to move neigh->flags from u32 to u64 inside the kernel. Add a build-time assertion such that when extending the NTF_EXT_MASK with new bits, we'll trigger an error once we surpass the 24th bit. This assumes that no bit holes in new NTF_EXT_* flags will slip in from UAPI, but I think this is reasonable to assume. Suggested-by:
David Ahern <dsahern@kernel.org> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Reviewed-by:
Jakub Kicinski <kuba@kernel.org>
507c2f1d
