diff options
| author | Florian Westphal | 2016-11-28 11:40:05 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso | 2016-12-06 21:48:21 +0100 |
| commit | df122f58b834b24c27d7e2ac02a4910d3e56f6ae (patch) | |
| tree | af3a2ec7d16644f9d84ac5779a5c7a3d15c43cbe | |
| parent | 1ed9887ee31a38f265124c963f8e5b8a1ffb02e3 (diff) | |
netfilter: ingress: translate 0 nf_hook_slow retval to -1
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>
| -rw-r--r-- | include/linux/netfilter_ingress.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/netfilter_ingress.h b/include/linux/netfilter_ingress.h index 2dc3b49b804a..59476061de86 100644 --- a/include/linux/netfilter_ingress.h +++ b/include/linux/netfilter_ingress.h @@ -19,6 +19,7 @@ static inline int nf_hook_ingress(struct sk_buff *skb) { struct nf_hook_entry *e = rcu_dereference(skb->dev->nf_hooks_ingress); struct nf_hook_state state; + int ret; /* Must recheck the ingress hook head, in the event it became NULL * after the check in nf_hook_ingress_active evaluated to true. @@ -29,7 +30,11 @@ static inline int nf_hook_ingress(struct sk_buff *skb) nf_hook_state_init(&state, NF_NETDEV_INGRESS, NFPROTO_NETDEV, skb->dev, NULL, NULL, dev_net(skb->dev), NULL); - return nf_hook_slow(skb, &state, e); + ret = nf_hook_slow(skb, &state, e); + if (ret == 0) + return -1; + + return ret; } static inline void nf_hook_ingress_init(struct net_device *dev) |