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/config.h>
   8 #include <linux/netfilter.h>
   9 #if defined(__KERNEL__) && defined(CONFIG_BRIDGE_NETFILTER)
  10 #include <asm/atomic.h>
  11 #include <linux/if_ether.h>
  12 #endif
  13
  14 /* Bridge Hooks */
  15 /* After promisc drops, checksum checks. */
  16 #define NF_BR_PRE_ROUTING       0
  17 /* If the packet is destined for this box. */
  18 #define NF_BR_LOCAL_IN          1
  19 /* If the packet is destined for another interface. */
  20 #define NF_BR_FORWARD           2
  21 /* Packets coming from a local process. */
  22 #define NF_BR_LOCAL_OUT         3
  23 /* Packets about to hit the wire. */
  24 #define NF_BR_POST_ROUTING      4
  25 /* Not really a hook, but used for the ebtables broute table */
  26 #define NF_BR_BROUTING          5
  27 #define NF_BR_NUMHOOKS          6
  28
  29 #ifdef __KERNEL__
  30
  31 enum nf_br_hook_priorities {
  32         NF_BR_PRI_FIRST = INT_MIN,
  33         NF_BR_PRI_NAT_DST_BRIDGED = -300,
  34         NF_BR_PRI_FILTER_BRIDGED = -200,
  35         NF_BR_PRI_BRNF = 0,
  36         NF_BR_PRI_NAT_DST_OTHER = 100,
  37         NF_BR_PRI_FILTER_OTHER = 200,
  38         NF_BR_PRI_NAT_SRC = 300,
  39         NF_BR_PRI_LAST = INT_MAX,
  40 };
  41
  42 #ifdef CONFIG_BRIDGE_NETFILTER
  43
  44 #define BRNF_PKT_TYPE                   0x01
  45 #define BRNF_BRIDGED_DNAT               0x02
  46 #define BRNF_DONT_TAKE_PARENT           0x04
  47 #define BRNF_BRIDGED                    0x08
  48 #define BRNF_NF_BRIDGE_PREROUTING       0x10
  49
  50 /* Only used in br_forward.c */
  51 static inline int nf_bridge_maybe_copy_header(struct sk_buff *skb)
  52 {
  53         int err;
  54
  55         if (skb->nf_bridge) {
  56                 if (skb->protocol == __constant_htons(ETH_P_8021Q)) {
  57                         err = skb_cow(skb, 18);
  58                         if (err)
  59                                 return err;
  60                         memcpy(skb->data - 18, skb->nf_bridge->data, 18);
  61                         skb_push(skb, 4);
  62                 } else {
  63                         err = skb_cow(skb, 16);
  64                         if (err)
  65                                 return err;
  66                         memcpy(skb->data - 16, skb->nf_bridge->data, 16);
  67                 }
  68         }
  69         return 0;
  70 }
  71
  72 /* This is called by the IP fragmenting code and it ensures there is
  73  * enough room for the encapsulating header (if there is one). */
  74 static inline
  75 int nf_bridge_pad(struct sk_buff *skb)
  76 {
  77         if (skb->protocol == __constant_htons(ETH_P_IP))
  78                 return 0;
  79         if (skb->nf_bridge) {
  80                 if (skb->protocol == __constant_htons(ETH_P_8021Q))
  81                         return 4;
  82         }
  83         return 0;
  84 }
  85
  86 struct bridge_skb_cb {
  87         union {
  88                 __u32 ipv4;
  89         } daddr;
  90 };
  91 #endif /* CONFIG_BRIDGE_NETFILTER */
  92
  93 #endif /* __KERNEL__ */
  94 #endif