include/linux/netfilter_bridge.h

   1 #ifndef __LINUX_BRIDGE_NETFILTER_H
   2 #define __LINUX_BRIDGE_NETFILTER_H
   3
   4 #include <uapi/linux/netfilter_bridge.h>
   5
   6
   7 enum nf_br_hook_priorities {
   8         NF_BR_PRI_FIRST = INT_MIN,
   9         NF_BR_PRI_NAT_DST_BRIDGED = -300,
  10         NF_BR_PRI_FILTER_BRIDGED = -200,
  11         NF_BR_PRI_BRNF = 0,
  12         NF_BR_PRI_NAT_DST_OTHER = 100,
  13         NF_BR_PRI_FILTER_OTHER = 200,
  14         NF_BR_PRI_NAT_SRC = 300,
  15         NF_BR_PRI_LAST = INT_MAX,
  16 };
  17
  18 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
  19
  20 #define BRNF_PKT_TYPE                   0x01
  21 #define BRNF_BRIDGED_DNAT               0x02
  22 #define BRNF_BRIDGED                    0x04
  23 #define BRNF_NF_BRIDGE_PREROUTING       0x08
  24 #define BRNF_8021Q                      0x10
  25 #define BRNF_PPPoE                      0x20
  26
  27 static inline unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
  28 {
  29         switch (skb->protocol) {
  30         case __cpu_to_be16(ETH_P_8021Q):
  31                 return VLAN_HLEN;
  32         case __cpu_to_be16(ETH_P_PPP_SES):
  33                 return PPPOE_SES_HLEN;
  34         default:
  35                 return 0;
  36         }
  37 }
  38
  39 static inline void nf_bridge_update_protocol(struct sk_buff *skb)
  40 {
  41         if (skb->nf_bridge->mask & BRNF_8021Q)
  42                 skb->protocol = htons(ETH_P_8021Q);
  43         else if (skb->nf_bridge->mask & BRNF_PPPoE)
  44                 skb->protocol = htons(ETH_P_PPP_SES);
  45 }
  46
  47 static inline unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
  48 {
  49         if (unlikely(skb->nf_bridge->mask & BRNF_PPPoE))
  50                 return PPPOE_SES_HLEN;
  51         return 0;
  52 }
  53
  54 int br_handle_frame_finish(struct sk_buff *skb);
  55 /* Only used in br_device.c */
  56 static inline int br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb)
  57 {
  58         struct nf_bridge_info *nf_bridge = skb->nf_bridge;
  59
  60         skb_pull(skb, ETH_HLEN);
  61         nf_bridge->mask ^= BRNF_BRIDGED_DNAT;
  62         skb_copy_to_linear_data_offset(skb, -(ETH_HLEN-ETH_ALEN),
  63                                        skb->nf_bridge->data, ETH_HLEN-ETH_ALEN);
  64         skb->dev = nf_bridge->physindev;
  65         return br_handle_frame_finish(skb);
  66 }
  67
  68 /* This is called by the IP fragmenting code and it ensures there is
  69  * enough room for the encapsulating header (if there is one). */
  70 static inline unsigned int nf_bridge_pad(const struct sk_buff *skb)
  71 {
  72         if (skb->nf_bridge)
  73                 return nf_bridge_encap_header_len(skb);
  74         return 0;
  75 }
  76
  77 struct bridge_skb_cb {
  78         union {
  79                 __be32 ipv4;
  80         } daddr;
  81 };
  82
  83 static inline void br_drop_fake_rtable(struct sk_buff *skb)
  84 {
  85         struct dst_entry *dst = skb_dst(skb);
  86
  87         if (dst && (dst->flags & DST_FAKE_RTABLE))
  88                 skb_dst_drop(skb);
  89 }
  90
  91 #else
  92 #define nf_bridge_pad(skb)                      (0)
  93 #define br_drop_fake_rtable(skb)                do { } while (0)
  94 #endif /* CONFIG_BRIDGE_NETFILTER */
  95
  96 #endif