target/linux/generic/patches-3.18/644-bridge_optimize_netfilter_hooks.patch

   1 From: Felix Fietkau <nbd@openwrt.org>
   2 Subject: [PATCH] bridge: optimize netfilter hooks
   3
   4 Bypass all netfilter hooks if the sysctls for that functionality have
   5 been disabled - eliminates the overhead of enabling
   6 CONFIG_BRIDGE_NETFILTER in the kernel config
   7 ---
   8 --- a/net/bridge/br_forward.c
   9 +++ b/net/bridge/br_forward.c
  10 @@ -53,7 +53,7 @@ EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit
  11
  12  int br_forward_finish(struct sk_buff *skb)
  13  {
  14 -       return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
  15 +       return BR_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
  16                        br_dev_queue_push_xmit);
  17
  18  }
  19 @@ -77,7 +77,7 @@ static void __br_deliver(const struct ne
  20                 return;
  21         }
  22
  23 -       NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
  24 +       BR_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
  25                 br_forward_finish);
  26  }
  27
  28 @@ -98,7 +98,7 @@ static void __br_forward(const struct ne
  29         skb->dev = to->dev;
  30         skb_forward_csum(skb);
  31
  32 -       NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
  33 +       BR_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
  34                 br_forward_finish);
  35  }
  36
  37 --- a/net/bridge/br_input.c
  38 +++ b/net/bridge/br_input.c
  39 @@ -53,7 +53,7 @@ static int br_pass_frame_up(struct sk_bu
  40         if (!skb)
  41                 return NET_RX_DROP;
  42
  43 -       return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
  44 +       return BR_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
  45                        netif_receive_skb);
  46  }
  47
  48 @@ -219,7 +219,7 @@ rx_handler_result_t br_handle_frame(stru
  49                 }
  50
  51                 /* Deliver packet to local host only */
  52 -               if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
  53 +               if (BR_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
  54                             NULL, br_handle_local_finish)) {
  55                         return RX_HANDLER_CONSUMED; /* consumed by filter */
  56                 } else {
  57 @@ -234,7 +234,7 @@ forward:
  58                 if (ether_addr_equal(p->br->dev->dev_addr, dest))
  59                         skb->pkt_type = PACKET_HOST;
  60
  61 -               if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
  62 +               if (BR_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
  63                         br_handle_local_finish))
  64                         break;
  65
  66 @@ -256,7 +256,7 @@ forward:
  67                 if (ether_addr_equal(p->br->dev->dev_addr, dest))
  68                         skb->pkt_type = PACKET_HOST;
  69
  70 -               NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
  71 +               BR_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
  72                         br_handle_frame_finish);
  73                 break;
  74         default:
  75 --- a/net/bridge/br_multicast.c
  76 +++ b/net/bridge/br_multicast.c
  77 @@ -814,7 +814,7 @@ static void __br_multicast_send_query(st
  78
  79         if (port) {
  80                 skb->dev = port->dev;
  81 -               NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
  82 +               BR_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
  83                         br_dev_queue_push_xmit);
  84         } else {
  85                 br_multicast_select_own_querier(br, ip, skb);
  86 --- a/net/bridge/br_netfilter.c
  87 +++ b/net/bridge/br_netfilter.c
  88 @@ -73,6 +73,15 @@ static int brnf_pass_vlan_indev __read_m
  89  #define IS_ARP(skb) \
  90         (!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_ARP))
  91
  92 +int brnf_call_ebtables __read_mostly = 0;
  93 +EXPORT_SYMBOL_GPL(brnf_call_ebtables);
  94 +
  95 +bool br_netfilter_run_hooks(void)
  96 +{
  97 +       return brnf_call_iptables | brnf_call_ip6tables | brnf_call_arptables |
  98 +              brnf_call_ebtables;
  99 +}
 100 +
 101  static inline __be16 vlan_proto(const struct sk_buff *skb)
 102  {
 103         if (vlan_tx_tag_present(skb))
 104 --- a/net/bridge/br_private.h
 105 +++ b/net/bridge/br_private.h
 106 @@ -778,6 +778,24 @@ static inline void br_nf_core_fini(void)
 107  #define br_netfilter_rtable_init(x)
 108  #endif
 109
 110 +#if IS_BUILTIN(CONFIG_BRIDGE_NETFILTER)
 111 +extern int brnf_call_ebtables;
 112 +bool br_netfilter_run_hooks(void);
 113 +#else
 114 +#define br_netfilter_run_hooks()       false
 115 +#endif
 116 +
 117 +static inline int
 118 +BR_HOOK(uint8_t pf, unsigned int hook, struct sk_buff *skb,
 119 +       struct net_device *in, struct net_device *out,
 120 +       int (*okfn)(struct sk_buff *))
 121 +{
 122 +       if (!br_netfilter_run_hooks())
 123 +               return okfn(skb);
 124 +
 125 +       return NF_HOOK(pf, hook, skb, in, out, okfn);
 126 +}
 127 +
 128  /* br_stp.c */
 129  void br_log_state(const struct net_bridge_port *p);
 130  void br_set_state(struct net_bridge_port *p, unsigned int state);
 131 --- a/net/bridge/br_stp_bpdu.c
 132 +++ b/net/bridge/br_stp_bpdu.c
 133 @@ -54,7 +54,7 @@ static void br_send_bpdu(struct net_brid
 134
 135         skb_reset_mac_header(skb);
 136
 137 -       NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
 138 +       BR_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
 139                 dev_queue_xmit);
 140  }
 141
 142 --- a/net/bridge/netfilter/ebtables.c
 143 +++ b/net/bridge/netfilter/ebtables.c
 144 @@ -2414,11 +2414,19 @@ static int __init ebtables_init(void)
 145         }
 146
 147         printk(KERN_INFO "Ebtables v2.0 registered\n");
 148 +
 149 +#if IS_BUILTIN(CONFIG_BRIDGE_NETFILTER)
 150 +       brnf_call_ebtables = 1;
 151 +#endif
 152 +
 153         return 0;
 154  }
 155
 156  static void __exit ebtables_fini(void)
 157  {
 158 +#if IS_BUILTIN(CONFIG_BRIDGE_NETFILTER)
 159 +       brnf_call_ebtables = 0;
 160 +#endif
 161         nf_unregister_sockopt(&ebt_sockopts);
 162         xt_unregister_target(&ebt_standard_target);
 163         printk(KERN_INFO "Ebtables v2.0 unregistered\n");
 164 --- a/net/Kconfig
 165 +++ b/net/Kconfig
 166 @@ -177,11 +177,11 @@ config NETFILTER_ADVANCED
 167           If unsure, say Y.
 168
 169  config BRIDGE_NETFILTER
 170 -       tristate "Bridged IP/ARP packets filtering"
 171 +       bool "Bridged IP/ARP packets filtering"
 172         depends on BRIDGE
 173         depends on NETFILTER && INET
 174         depends on NETFILTER_ADVANCED
 175 -       default m
 176 +       default y
 177         ---help---
 178           Enabling this option will let arptables resp. iptables see bridged
 179           ARP resp. IP traffic. If you want a bridging firewall, you probably