1 #ifndef __LINUX_BRIDGE_NETFILTER_H
2 #define __LINUX_BRIDGE_NETFILTER_H
3 
4 /* bridge-specific defines for netfilter.
5  */
6 
7 #include <linux/config.h>
8 #include <linux/netfilter.h>
9 #if defined(__KERNEL__) && defined(CONFIG_BRIDGE_NETFILTER)
10 #include <asm/atomic.h>
11 #include <linux/if_ether.h>
12 #endif
13 
14 /* Bridge Hooks */
15 /* After promisc drops, checksum checks. */
16 #define NF_BR_PRE_ROUTING	0
17 /* If the packet is destined for this box. */
18 #define NF_BR_LOCAL_IN		1
19 /* If the packet is destined for another interface. */
20 #define NF_BR_FORWARD		2
21 /* Packets coming from a local process. */
22 #define NF_BR_LOCAL_OUT		3
23 /* Packets about to hit the wire. */
24 #define NF_BR_POST_ROUTING	4
25 /* Not really a hook, but used for the ebtables broute table */
26 #define NF_BR_BROUTING		5
27 #define NF_BR_NUMHOOKS		6
28 
29 #ifdef __KERNEL__
30 
31 enum nf_br_hook_priorities {
32 	NF_BR_PRI_FIRST = INT_MIN,
33 	NF_BR_PRI_NAT_DST_BRIDGED = -300,
34 	NF_BR_PRI_FILTER_BRIDGED = -200,
35 	NF_BR_PRI_BRNF = 0,
36 	NF_BR_PRI_NAT_DST_OTHER = 100,
37 	NF_BR_PRI_FILTER_OTHER = 200,
38 	NF_BR_PRI_NAT_SRC = 300,
39 	NF_BR_PRI_LAST = INT_MAX,
40 };
41 
42 #ifdef CONFIG_BRIDGE_NETFILTER
43 
44 #define BRNF_PKT_TYPE			0x01
45 #define BRNF_BRIDGED_DNAT		0x02
46 #define BRNF_DONT_TAKE_PARENT		0x04
47 #define BRNF_BRIDGED			0x08
48 #define BRNF_NF_BRIDGE_PREROUTING	0x10
49 
50 static inline
51 struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
52 {
53 	struct nf_bridge_info **nf_bridge = &(skb->nf_bridge);
54 
55 	if ((*nf_bridge = kmalloc(sizeof(**nf_bridge), GFP_ATOMIC)) != NULL) {
56 		atomic_set(&(*nf_bridge)->use, 1);
57 		(*nf_bridge)->mask = 0;
58 		(*nf_bridge)->physindev = (*nf_bridge)->physoutdev = NULL;
59 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
60 		(*nf_bridge)->netoutdev = NULL;
61 #endif
62 	}
63 
64 	return *nf_bridge;
65 }
66 
67 /* Only used in br_forward.c */
68 static inline
69 void nf_bridge_maybe_copy_header(struct sk_buff *skb)
70 {
71 	if (skb->nf_bridge) {
72 		if (skb->protocol == __constant_htons(ETH_P_8021Q)) {
73 			memcpy(skb->data - 18, skb->nf_bridge->data, 18);
74 			skb_push(skb, 4);
75 		} else
76 			memcpy(skb->data - 16, skb->nf_bridge->data, 16);
77 	}
78 }
79 
80 static inline
81 void nf_bridge_save_header(struct sk_buff *skb)
82 {
83         int header_size = 16;
84 
85 	if (skb->protocol == __constant_htons(ETH_P_8021Q))
86 		header_size = 18;
87 
88 	memcpy(skb->nf_bridge->data, skb->data - header_size, header_size);
89 }
90 
91 /* This is called by the IP fragmenting code and it ensures there is
92  * enough room for the encapsulating header (if there is one). */
93 static inline
94 int nf_bridge_pad(struct sk_buff *skb)
95 {
96 	if (skb->protocol == __constant_htons(ETH_P_IP))
97 		return 0;
98 	if (skb->nf_bridge) {
99 		if (skb->protocol == __constant_htons(ETH_P_8021Q))
100 			return 4;
101 	}
102 	return 0;
103 }
104 
105 struct bridge_skb_cb {
106 	union {
107 		__u32 ipv4;
108 	} daddr;
109 };
110 #endif /* CONFIG_BRIDGE_NETFILTER */
111 
112 #endif /* __KERNEL__ */
113 #endif
114