netfilter: ctnetlink: group errors into logical errno sets
netfilter: ctnetlink: group errors into logical errno sets

This patch groups ctnetlink errors into three logical sets:

* Malformed messages: if ctnetlink receives a message without some mandatory
attribute, then it returns EINVAL.
* Unsupported operations: if userspace tries to perform an unsupported
operation, then it returns EOPNOTSUPP.
* Unchangeable: if userspace tries to change some attribute of the
conntrack object that can only be set once, then it returns EBUSY.

This patch reduces the number of -EINVAL from 23 to 14 and it results in
5 -EBUSY and 6 -EOPNOTSUPP.

Signed-off-by: Pablo Neira Ayuso <707d14912bb250caf67dfe0ea4035681fbfc4f56@netfilter.org>
Signed-off-by: Patrick McHardy <3a4d625ce225e891399f98db96a382ac4a84080b@trash.net>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas