diff options
| author | Florian Westphal | 2022-04-25 15:15:44 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso | 2022-05-13 18:56:28 +0200 |
| commit | 8edc813111001e9be3cce066d3d4091d2ef04a1d (patch) | |
| tree | 178f82135ed388c543d2853de79635b1eda253ab | |
| parent | 90d1daa45849f272b701f29d6ca88b24743c7553 (diff) | |
netfilter: prefer extension check to pointer check
The pointer check usually results in a 'false positive': its likely
that the ctnetlink module is loaded but no event monitoring is enabled.
After recent change to autodetect ctnetlink usage and only allocate
the ecache extension if a listener is active, check if the extension
is present on a given conntrack.
If its not there, there is nothing to report and calls to the
notification framework can be elided.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | include/net/netfilter/nf_conntrack_core.h | 2 | ||||
| -rw-r--r-- | include/net/netfilter/nf_conntrack_ecache.h | 31 |
2 files changed, 16 insertions, 17 deletions
diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h index 13807ea94cd2..6406cfee34c2 100644 --- a/include/net/netfilter/nf_conntrack_core.h +++ b/include/net/netfilter/nf_conntrack_core.h @@ -60,7 +60,7 @@ static inline int nf_conntrack_confirm(struct sk_buff *skb) if (ct) { if (!nf_ct_is_confirmed(ct)) ret = __nf_conntrack_confirm(skb); - if (likely(ret == NF_ACCEPT)) + if (ret == NF_ACCEPT && nf_ct_ecache_exist(ct)) nf_ct_deliver_cached_events(ct); } return ret; diff --git a/include/net/netfilter/nf_conntrack_ecache.h b/include/net/netfilter/nf_conntrack_ecache.h index 2e3d58439e34..0c1dac318e02 100644 --- a/include/net/netfilter/nf_conntrack_ecache.h +++ b/include/net/netfilter/nf_conntrack_ecache.h @@ -36,6 +36,15 @@ nf_ct_ecache_find(const struct nf_conn *ct) #endif } +static inline bool nf_ct_ecache_exist(const struct nf_conn *ct) +{ +#ifdef CONFIG_NF_CONNTRACK_EVENTS + return nf_ct_ext_exist(ct, NF_CT_EXT_ECACHE); +#else + return false; +#endif +} + #ifdef CONFIG_NF_CONNTRACK_EVENTS /* This structure is passed to event handler */ @@ -108,30 +117,20 @@ nf_conntrack_event_report(enum ip_conntrack_events event, struct nf_conn *ct, u32 portid, int report) { #ifdef CONFIG_NF_CONNTRACK_EVENTS - const struct net *net = nf_ct_net(ct); - - if (!rcu_access_pointer(net->ct.nf_conntrack_event_cb)) - return 0; - - return nf_conntrack_eventmask_report(1 << event, ct, portid, report); -#else - return 0; + if (nf_ct_ecache_exist(ct)) + return nf_conntrack_eventmask_report(1 << event, ct, portid, report); #endif + return 0; } static inline int nf_conntrack_event(enum ip_conntrack_events event, struct nf_conn *ct) { #ifdef CONFIG_NF_CONNTRACK_EVENTS - const struct net *net = nf_ct_net(ct); - - if (!rcu_access_pointer(net->ct.nf_conntrack_event_cb)) - return 0; - - return nf_conntrack_eventmask_report(1 << event, ct, 0, 0); -#else - return 0; + if (nf_ct_ecache_exist(ct)) + return nf_conntrack_eventmask_report(1 << event, ct, 0, 0); #endif + return 0; } #ifdef CONFIG_NF_CONNTRACK_EVENTS |