The caller assumes that < 0 means that skb was stolen (or free'd).
All other return values continue skb processing.
nf_hook_slow returns 3 different return value types:
A) a (negative) errno value: the skb was dropped (NF_DROP, e.g.
by iptables '-j DROP' rule).
B) 0. The skb was stolen by the hook or queued to userspace.
C) 1. all hooks returned NF_ACCEPT so the caller should invoke
the okfn so packet processing can continue.
nft ingress facility currently doesn't have the 'okfn' that
the NF_HOOK() macros use; there is no nfqueue support either.
So 1 means that nf_hook_ingress() caller should go on processing the skb.
In order to allow use of NF_STOLEN from ingress we need to translate
this to an errno number, else we'd crash because we continue with
already-free'd (or about to be free-d) skb.
The errno value isn't checked, its just important that its less than 0,
so return -1.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
df122f58b8