netfilter: nf_flow_table: in flow_offload_lookup, skip entries being deleted

Preparation for sending flows back to the slow path

Signed-off-by: Felix Fietkau <nbd@nbd.name>
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 5a81e4f..ff5e17a 100644 (file)
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -184,8 +184,21 @@ struct flow_offload_tuple_rhash *
 flow_offload_lookup(struct nf_flowtable *flow_table,
                    struct flow_offload_tuple *tuple)
 {
-       return rhashtable_lookup_fast(&flow_table->rhashtable, tuple,
-                                     nf_flow_offload_rhash_params);
+       struct flow_offload_tuple_rhash *tuplehash;
+       struct flow_offload *flow;
+       int dir;
+
+       tuplehash = rhashtable_lookup_fast(&flow_table->rhashtable, tuple,
+                                          nf_flow_offload_rhash_params);
+       if (!tuplehash)
+               return NULL;
+
+       dir = tuplehash->tuple.dir;
+       flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
+       if (flow->flags & (FLOW_OFFLOAD_DYING | FLOW_OFFLOAD_TEARDOWN))
+               return NULL;
+
+       return tuplehash;
 }
 EXPORT_SYMBOL_GPL(flow_offload_lookup);