target/linux/generic/pending-3.18/120-bridge_allow_receiption_on_disabled_port.patch

   1 From: Stephen Hemminger <stephen@networkplumber.org>
   2 Subject: bridge: allow receiption on disabled port
   3
   4 When an ethernet device is enslaved to a bridge, and the bridge STP
   5 detects loss of carrier (or operational state down), then normally
   6 packet receiption is blocked.
   7
   8 This breaks control applications like WPA which maybe expecting to
   9 receive packets to negotiate to bring link up. The bridge needs to
  10 block forwarding packets from these disabled ports, but there is no
  11 hard requirement to not allow local packet delivery.
  12
  13 Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
  14 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  15
  16 --- a/net/bridge/br_input.c
  17 +++ b/net/bridge/br_input.c
  18 @@ -146,11 +146,13 @@ EXPORT_SYMBOL_GPL(br_handle_frame_finish
  19  static int br_handle_local_finish(struct sk_buff *skb)
  20  {
  21         struct net_bridge_port *p = br_port_get_rcu(skb->dev);
  22 -       u16 vid = 0;
  23 +       if (p->state != BR_STATE_DISABLED) {
  24 +               u16 vid = 0;
  25
  26 -       /* check if vlan is allowed, to avoid spoofing */
  27 -       if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid))
  28 -               br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false);
  29 +               /* check if vlan is allowed, to avoid spoofing */
  30 +               if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid))
  31 +                       br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false);
  32 +       }
  33         return 0;        /* process further */
  34  }
  35
  36 @@ -224,6 +226,18 @@ rx_handler_result_t br_handle_frame(stru
  37
  38  forward:
  39         switch (p->state) {
  40 +       case BR_STATE_DISABLED:
  41 +               if (ether_addr_equal(p->br->dev->dev_addr, dest))
  42 +                       skb->pkt_type = PACKET_HOST;
  43 +
  44 +               if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
  45 +                       br_handle_local_finish))
  46 +                       break;
  47 +
  48 +               BR_INPUT_SKB_CB(skb)->brdev = p->br->dev;
  49 +               br_pass_frame_up(skb);
  50 +               break;
  51 +
  52         case BR_STATE_FORWARDING:
  53                 rhook = rcu_dereference(br_should_route_hook);
  54                 if (rhook) {