On 05/01, Breno Leitao wrote:

Add a single kselftest covering the proto_ops getsockopt_iter
conversions for AF_NETLINK and AF_VSOCK, using one fixture per protocol:

netlink:

NETLINK_PKTINFO covers the flag-style int path (exact size, oversize
clamp, undersize -EINVAL); NETLINK_LIST_MEMBERSHIPS covers the
size-discovery path that always reports the required buffer length back
via optlen, even when the user buffer is too small to receive any group
bits.

vsock:
SO_VM_SOCKETS_BUFFER_SIZE covers the u64 path (exact size, oversize
clamp, undersize -EINVAL).

Each fixture also exercises an unknown optname and a bogus level so
the returned-length / errno semantics preserved by the sockopt_t
conversion are pinned down.

Signed-off-by: Breno Leitao <leitao@debian.org>

A few nits if you happen to respin (or for similar tests in the future):
- add ASSERT_EQ(optlen, xxx), won't hurt
- christmas tree (although not sure how much we care, you'll have to move
   optlen = sizeof() assignment)

Acked-by: Stanislav Fomichev <sdf@fomichev.me>