target/linux/generic/backport-4.19/362-v4.18-netfilter-nf_flow_table-in-flow_offload_lookup-skip-.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Sun, 25 Feb 2018 15:39:56 +0100
   3 Subject: [PATCH] netfilter: nf_flow_table: in flow_offload_lookup, skip
   4  entries being deleted
   5
   6 Preparation for sending flows back to the slow path
   7
   8 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   9 ---
  10
  11 --- a/net/netfilter/nf_flow_table_core.c
  12 +++ b/net/netfilter/nf_flow_table_core.c
  13 @@ -184,8 +184,21 @@ struct flow_offload_tuple_rhash *
  14  flow_offload_lookup(struct nf_flowtable *flow_table,
  15                     struct flow_offload_tuple *tuple)
  16  {
  17 -       return rhashtable_lookup_fast(&flow_table->rhashtable, tuple,
  18 -                                     nf_flow_offload_rhash_params);
  19 +       struct flow_offload_tuple_rhash *tuplehash;
  20 +       struct flow_offload *flow;
  21 +       int dir;
  22 +
  23 +       tuplehash = rhashtable_lookup_fast(&flow_table->rhashtable, tuple,
  24 +                                          nf_flow_offload_rhash_params);
  25 +       if (!tuplehash)
  26 +               return NULL;
  27 +
  28 +       dir = tuplehash->tuple.dir;
  29 +       flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
  30 +       if (flow->flags & (FLOW_OFFLOAD_DYING | FLOW_OFFLOAD_TEARDOWN))
  31 +               return NULL;
  32 +
  33 +       return tuplehash;
  34  }
  35  EXPORT_SYMBOL_GPL(flow_offload_lookup);
  36