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 #ifdef 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 /* Only used in br_forward.c */
28 extern int nf_bridge_copy_header(struct sk_buff *skb);
29 static inline int nf_bridge_maybe_copy_header(struct sk_buff *skb)
30 {
31 	if (skb->nf_bridge &&
32 	    skb->nf_bridge->mask & (BRNF_BRIDGED | BRNF_BRIDGED_DNAT))
33 		return nf_bridge_copy_header(skb);
34   	return 0;
35 }
36 
37 static inline unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
38 {
39 	switch (skb->protocol) {
40 	case __cpu_to_be16(ETH_P_8021Q):
41 		return VLAN_HLEN;
42 	case __cpu_to_be16(ETH_P_PPP_SES):
43 		return PPPOE_SES_HLEN;
44 	default:
45 		return 0;
46 	}
47 }
48 
49 static inline unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
50 {
51 	if (unlikely(skb->nf_bridge->mask & BRNF_PPPoE))
52 		return PPPOE_SES_HLEN;
53 	return 0;
54 }
55 
56 extern int br_handle_frame_finish(struct sk_buff *skb);
57 /* Only used in br_device.c */
58 static inline int br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb)
59 {
60 	struct nf_bridge_info *nf_bridge = skb->nf_bridge;
61 
62 	skb_pull(skb, ETH_HLEN);
63 	nf_bridge->mask ^= BRNF_BRIDGED_DNAT;
64 	skb_copy_to_linear_data_offset(skb, -(ETH_HLEN-ETH_ALEN),
65 				       skb->nf_bridge->data, ETH_HLEN-ETH_ALEN);
66 	skb->dev = nf_bridge->physindev;
67 	return br_handle_frame_finish(skb);
68 }
69 
70 /* This is called by the IP fragmenting code and it ensures there is
71  * enough room for the encapsulating header (if there is one). */
72 static inline unsigned int nf_bridge_pad(const struct sk_buff *skb)
73 {
74 	if (skb->nf_bridge)
75 		return nf_bridge_encap_header_len(skb);
76 	return 0;
77 }
78 
79 struct bridge_skb_cb {
80 	union {
81 		__be32 ipv4;
82 	} daddr;
83 };
84 
85 static inline void br_drop_fake_rtable(struct sk_buff *skb)
86 {
87 	struct dst_entry *dst = skb_dst(skb);
88 
89 	if (dst && (dst->flags & DST_FAKE_RTABLE))
90 		skb_dst_drop(skb);
91 }
92 
93 #else
94 #define nf_bridge_maybe_copy_header(skb)	(0)
95 #define nf_bridge_pad(skb)			(0)
96 #define br_drop_fake_rtable(skb)	        do { } while (0)
97 #endif /* CONFIG_BRIDGE_NETFILTER */
98 
99 #endif
100