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_NF_BRIDGE_PREROUTING	0x08
23 #define BRNF_8021Q			0x10
24 #define BRNF_PPPoE			0x20
25 
26 static inline unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
27 {
28 	switch (skb->protocol) {
29 	case __cpu_to_be16(ETH_P_8021Q):
30 		return VLAN_HLEN;
31 	case __cpu_to_be16(ETH_P_PPP_SES):
32 		return PPPOE_SES_HLEN;
33 	default:
34 		return 0;
35 	}
36 }
37 
38 static inline unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
39 {
40 	if (unlikely(skb->nf_bridge->mask & BRNF_PPPoE))
41 		return PPPOE_SES_HLEN;
42 	return 0;
43 }
44 
45 int br_handle_frame_finish(struct sk_buff *skb);
46 
47 /* This is called by the IP fragmenting code and it ensures there is
48  * enough room for the encapsulating header (if there is one). */
49 static inline unsigned int nf_bridge_pad(const struct sk_buff *skb)
50 {
51 	if (skb->nf_bridge)
52 		return nf_bridge_encap_header_len(skb);
53 	return 0;
54 }
55 
56 static inline void br_drop_fake_rtable(struct sk_buff *skb)
57 {
58 	struct dst_entry *dst = skb_dst(skb);
59 
60 	if (dst && (dst->flags & DST_FAKE_RTABLE))
61 		skb_dst_drop(skb);
62 }
63 
64 #else
65 #define nf_bridge_pad(skb)			(0)
66 #define br_drop_fake_rtable(skb)	        do { } while (0)
67 #endif /* CONFIG_BRIDGE_NETFILTER */
68 
69 #endif
70