Default to comparing all attributes if no oo_id_attrs defined

Since commit: "cache pickup: Avoid duplicates during cache pickup",
nfnl_ct_alloc_cache no longer properly fills the cache, as it doesn't
define oo_id_attrs so all items are considered duplicates.

Instead of adding a ~0 oo_id_attrs to ct_obj, this changes
nl_object_identical to default to comparing all attributes if
neither oo_id_attrs_get or oo_id_attrs are provided.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Handle -NLE_AGAIN in nl_cache_mngr_data_ready

Since commit "nl: Return -NLE_AGAIN if non-blocking socket would block",
nl_cache_mngr_data_ready returns -NLE_AGAIN to callers on non-blocking sockets.
Change it to consider -NLE_AGAIN as a non-error case as it is expected behavior
with the nl_recv changes.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
netfilter/queue: generalize nfnl_queue_msg_build_verdict()

Generalize netfilter/queue to allow sending batched verdicts
later.

Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
netfilter/queue: introduce nfnl_queue_msg_send_verdict_batch()

The batched verdict implicitely ACKs all queue packet IDs up to the
one send back, which reduces the number of verdict messages send
to the kernel.

Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: Thomas Graf <tgraf@suug.ch>