netfilter: nf_flow_table: do not flow offload deleted conntrack entries

Conntrack entries can be deleted by the masquerade module. In that case,
flow offload should be deleted too, but GC and data-path of flow offload
do not check for conntrack status bits, hence flow offload entries will
be removed only by the timeout.

Update garbage collector and data-path to check for ct->status. If
IPS_DYING_BIT is set, garbage collector removes flow offload entries and
data-path routine ignores them.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index a9e4f74b1ff6efaf96d6591200d2a0264094ec42..4469519a48790aff617c15581d7472fed59939cb 100644 (file)
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -243,6 +243,7 @@ flow_offload_lookup(struct nf_flowtable *flow_table,
 {
        struct flow_offload_tuple_rhash *tuplehash;
        struct flow_offload *flow;
+       struct flow_offload_entry *e;
        int dir;
 
        tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
@@ -255,6 +256,10 @@ flow_offload_lookup(struct nf_flowtable *flow_table,
        if (flow->flags & (FLOW_OFFLOAD_DYING | FLOW_OFFLOAD_TEARDOWN))
                return NULL;
 
+       e = container_of(flow, struct flow_offload_entry, flow);
+       if (unlikely(nf_ct_is_dying(e->ct)))
+               return NULL;
+
        return tuplehash;
 }
 EXPORT_SYMBOL_GPL(flow_offload_lookup);
@@ -301,8 +306,10 @@ static inline bool nf_flow_has_expired(const struct flow_offload *flow)
 static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
 {
        struct nf_flowtable *flow_table = data;
+       struct flow_offload_entry *e;
 
-       if (nf_flow_has_expired(flow) ||
+       e = container_of(flow, struct flow_offload_entry, flow);
+       if (nf_flow_has_expired(flow) || nf_ct_is_dying(e->ct) ||
            (flow->flags & (FLOW_OFFLOAD_DYING | FLOW_OFFLOAD_TEARDOWN)))
                flow_offload_del(flow_table, flow);
 }