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);
nf_bridge_maybe_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
nf_bridge_encap_header_len(const struct sk_buff * skb)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
nf_bridge_mtu_reduction(const struct sk_buff * skb)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 */
br_nf_pre_routing_finish_bridge_slow(struct sk_buff * skb)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). */
nf_bridge_pad(const struct sk_buff * skb)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 #else
108 #define nf_bridge_maybe_copy_header(skb) (0)
109 #define nf_bridge_pad(skb) (0)
110 #endif /* CONFIG_BRIDGE_NETFILTER */
111
112 #endif /* __KERNEL__ */
113 #endif
114