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 static inline
  51 struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
  52 {
  53         struct nf_bridge_info **nf_bridge = &(skb->nf_bridge);
  54
  55         if ((*nf_bridge = kmalloc(sizeof(**nf_bridge), GFP_ATOMIC)) != NULL) {
  56                 atomic_set(&(*nf_bridge)->use, 1);
  57                 (*nf_bridge)->mask = 0;
  58                 (*nf_bridge)->physindev = (*nf_bridge)->physoutdev = NULL;
  59 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
  60                 (*nf_bridge)->netoutdev = NULL;
  61 #endif
  62         }
  63
  64         return *nf_bridge;
  65 }
  66
  67 /* Only used in br_forward.c */
  68 static inline int nf_bridge_maybe_copy_header(struct sk_buff *skb)
  69 {
  70         int err;
  71
  72         if (skb->nf_bridge) {
  73                 if (skb->protocol == __constant_htons(ETH_P_8021Q)) {
  74                         err = skb_cow(skb, 18);
  75                         if (err)
  76                                 return err;
  77                         memcpy(skb->data - 18, skb->nf_bridge->data, 18);
  78                         skb_push(skb, 4);
  79                 } else {
  80                         err = skb_cow(skb, 16);
  81                         if (err)
  82                                 return err;
  83                         memcpy(skb->data - 16, skb->nf_bridge->data, 16);
  84                 }
  85         }
  86         return 0;
  87 }
  88
  89 static inline
  90 void nf_bridge_save_header(struct sk_buff *skb)
  91 {
  92         int header_size = 16;
  93
  94         if (skb->protocol == __constant_htons(ETH_P_8021Q))
  95                 header_size = 18;
  96
  97         memcpy(skb->nf_bridge->data, skb->data - header_size, header_size);
  98 }
  99
 100 /* This is called by the IP fragmenting code and it ensures there is
 101  * enough room for the encapsulating header (if there is one). */
 102 static inline
 103 int nf_bridge_pad(struct sk_buff *skb)
 104 {
 105         if (skb->protocol == __constant_htons(ETH_P_IP))
 106                 return 0;
 107         if (skb->nf_bridge) {
 108                 if (skb->protocol == __constant_htons(ETH_P_8021Q))
 109                         return 4;
 110         }
 111         return 0;
 112 }
 113
 114 struct bridge_skb_cb {
 115         union {
 116                 __u32 ipv4;
 117         } daddr;
 118 };
 119 #endif /* CONFIG_BRIDGE_NETFILTER */
 120
 121 #endif /* __KERNEL__ */
 122 #endif