userns: net: make many network capable calls targeted

When privilege is protected a namespaced network resource, then having
the required privilege targed toward the user namespace which owns the
resource suffices.

As with other patches, a big concern here is that we be cleanly separating
the cases where privilege protects a network resource from cases where
privilege can lead to laxer constraints on input and, subsequently,
the ability to corrupt, crash, or own the host kernel.

Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
18 files changed