include/linux/netfilter_bridge.h

   1 #ifndef __LINUX_BRIDGE_NETFILTER_H
   2 #define __LINUX_BRIDGE_NETFILTER_H
   3
   4 /* bridge-specific defines for netfilter.
   5  */
   6
   7 #include <linux/netfilter.h>
   8 #include <linux/if_ether.h>
   9 #include <linux/if_vlan.h>
  10 #include <linux/if_pppox.h>
  11
  12 /* Bridge Hooks */
  13 /* After promisc drops, checksum checks. */
  14 #define NF_BR_PRE_ROUTING       0
  15 /* If the packet is destined for this box. */
  16 #define NF_BR_LOCAL_IN          1
  17 /* If the packet is destined for another interface. */
  18 #define NF_BR_FORWARD           2
  19 /* Packets coming from a local process. */
  20 #define NF_BR_LOCAL_OUT         3
  21 /* Packets about to hit the wire. */
  22 #define NF_BR_POST_ROUTING      4
  23 /* Not really a hook, but used for the ebtables broute table */
  24 #define NF_BR_BROUTING          5
  25 #define NF_BR_NUMHOOKS          6
  26
  27 #ifdef __KERNEL__
  28
  29 enum nf_br_hook_priorities {
  30         NF_BR_PRI_FIRST = INT_MIN,
  31         NF_BR_PRI_NAT_DST_BRIDGED = -300,
  32         NF_BR_PRI_FILTER_BRIDGED = -200,
  33         NF_BR_PRI_BRNF = 0,
  34         NF_BR_PRI_NAT_DST_OTHER = 100,
  35         NF_BR_PRI_FILTER_OTHER = 200,
  36         NF_BR_PRI_NAT_SRC = 300,
  37         NF_BR_PRI_LAST = INT_MAX,
  38 };
  39
  40 #ifdef CONFIG_BRIDGE_NETFILTER
  41
  42 #define BRNF_PKT_TYPE                   0x01
  43 #define BRNF_BRIDGED_DNAT               0x02
  44 #define BRNF_BRIDGED                    0x04
  45 #define BRNF_NF_BRIDGE_PREROUTING       0x08
  46 #define BRNF_8021Q                      0x10
  47 #define BRNF_PPPoE                      0x20
  48
  49 /* Only used in br_forward.c */
  50 extern int nf_bridge_copy_header(struct sk_buff *skb);
  51 static inline int nf_bridge_maybe_copy_header(struct sk_buff *skb)
  52 {
  53         if (skb->nf_bridge &&
  54             skb->nf_bridge->mask & (BRNF_BRIDGED | BRNF_BRIDGED_DNAT))
  55                 return nf_bridge_copy_header(skb);
  56         return 0;
  57 }
  58
  59 static inline unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
  60 {
  61         switch (skb->protocol) {
  62         case __cpu_to_be16(ETH_P_8021Q):
  63                 return VLAN_HLEN;
  64         case __cpu_to_be16(ETH_P_PPP_SES):
  65                 return PPPOE_SES_HLEN;
  66         default:
  67                 return 0;
  68         }
  69 }
  70
  71 static inline unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
  72 {
  73         if (unlikely(skb->nf_bridge->mask & BRNF_PPPoE))
  74                 return PPPOE_SES_HLEN;
  75         return 0;
  76 }
  77
  78 extern int br_handle_frame_finish(struct sk_buff *skb);
  79 /* Only used in br_device.c */
  80 static inline int br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb)
  81 {
  82         struct nf_bridge_info *nf_bridge = skb->nf_bridge;
  83
  84         skb_pull(skb, ETH_HLEN);
  85         nf_bridge->mask ^= BRNF_BRIDGED_DNAT;
  86         skb_copy_to_linear_data_offset(skb, -(ETH_HLEN-ETH_ALEN),
  87                                        skb->nf_bridge->data, ETH_HLEN-ETH_ALEN);
  88         skb->dev = nf_bridge->physindev;
  89         return br_handle_frame_finish(skb);
  90 }
  91
  92 /* This is called by the IP fragmenting code and it ensures there is
  93  * enough room for the encapsulating header (if there is one). */
  94 static inline unsigned int nf_bridge_pad(const struct sk_buff *skb)
  95 {
  96         if (skb->nf_bridge)
  97                 return nf_bridge_encap_header_len(skb);
  98         return 0;
  99 }
 100
 101 struct bridge_skb_cb {
 102         union {
 103                 __be32 ipv4;
 104         } daddr;
 105 };
 106
 107 static inline void br_drop_fake_rtable(struct sk_buff *skb)
 108 {
 109         struct dst_entry *dst = skb_dst(skb);
 110
 111         if (dst && (dst->flags & DST_FAKE_RTABLE))
 112                 skb_dst_drop(skb);
 113 }
 114
 115 #else
 116 #define nf_bridge_maybe_copy_header(skb)        (0)
 117 #define nf_bridge_pad(skb)                      (0)
 118 #define br_drop_fake_rtable(skb)                do { } while (0)
 119 #endif /* CONFIG_BRIDGE_NETFILTER */
 120
 121 #endif /* __KERNEL__ */
 122 #endif