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 unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
40 {
41 	if (unlikely(skb->nf_bridge->mask & BRNF_PPPoE))
42 		return PPPOE_SES_HLEN;
43 	return 0;
44 }
45 
46 int br_handle_frame_finish(struct sk_buff *skb);
47 
48 /* This is called by the IP fragmenting code and it ensures there is
49  * enough room for the encapsulating header (if there is one). */
50 static inline unsigned int nf_bridge_pad(const struct sk_buff *skb)
51 {
52 	if (skb->nf_bridge)
53 		return nf_bridge_encap_header_len(skb);
54 	return 0;
55 }
56 
57 struct bridge_skb_cb {
58 	union {
59 		__be32 ipv4;
60 	} daddr;
61 };
62 
63 static inline void br_drop_fake_rtable(struct sk_buff *skb)
64 {
65 	struct dst_entry *dst = skb_dst(skb);
66 
67 	if (dst && (dst->flags & DST_FAKE_RTABLE))
68 		skb_dst_drop(skb);
69 }
70 
71 #else
72 #define nf_bridge_pad(skb)			(0)
73 #define br_drop_fake_rtable(skb)	        do { } while (0)
74 #endif /* CONFIG_BRIDGE_NETFILTER */
75 
76 #endif
77