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1 /*
2  *  ebtables
3  *
4  *	Authors:
5  *	Bart De Schuymer		<bdschuym@pandora.be>
6  *
7  *  ebtables.c,v 2.0, April, 2002
8  *
9  *  This code is stongly inspired on the iptables code which is
10  *  Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
11  */
12 #ifndef __LINUX_BRIDGE_EFF_H
13 #define __LINUX_BRIDGE_EFF_H
14 
15 #include <uapi/linux/netfilter_bridge/ebtables.h>
16 
17 
18 /* return values for match() functions */
19 #define EBT_MATCH 0
20 #define EBT_NOMATCH 1
21 
22 struct ebt_match {
23 	struct list_head list;
24 	const char name[EBT_FUNCTION_MAXNAMELEN];
25 	bool (*match)(const struct sk_buff *skb, const struct net_device *in,
26 		const struct net_device *out, const struct xt_match *match,
27 		const void *matchinfo, int offset, unsigned int protoff,
28 		bool *hotdrop);
29 	bool (*checkentry)(const char *table, const void *entry,
30 		const struct xt_match *match, void *matchinfo,
31 		unsigned int hook_mask);
32 	void (*destroy)(const struct xt_match *match, void *matchinfo);
33 	unsigned int matchsize;
34 	u_int8_t revision;
35 	u_int8_t family;
36 	struct module *me;
37 };
38 
39 struct ebt_watcher {
40 	struct list_head list;
41 	const char name[EBT_FUNCTION_MAXNAMELEN];
42 	unsigned int (*target)(struct sk_buff *skb,
43 		const struct net_device *in, const struct net_device *out,
44 		unsigned int hook_num, const struct xt_target *target,
45 		const void *targinfo);
46 	bool (*checkentry)(const char *table, const void *entry,
47 		const struct xt_target *target, void *targinfo,
48 		unsigned int hook_mask);
49 	void (*destroy)(const struct xt_target *target, void *targinfo);
50 	unsigned int targetsize;
51 	u_int8_t revision;
52 	u_int8_t family;
53 	struct module *me;
54 };
55 
56 struct ebt_target {
57 	struct list_head list;
58 	const char name[EBT_FUNCTION_MAXNAMELEN];
59 	/* returns one of the standard EBT_* verdicts */
60 	unsigned int (*target)(struct sk_buff *skb,
61 		const struct net_device *in, const struct net_device *out,
62 		unsigned int hook_num, const struct xt_target *target,
63 		const void *targinfo);
64 	bool (*checkentry)(const char *table, const void *entry,
65 		const struct xt_target *target, void *targinfo,
66 		unsigned int hook_mask);
67 	void (*destroy)(const struct xt_target *target, void *targinfo);
68 	unsigned int targetsize;
69 	u_int8_t revision;
70 	u_int8_t family;
71 	struct module *me;
72 };
73 
74 /* used for jumping from and into user defined chains (udc) */
75 struct ebt_chainstack {
76 	struct ebt_entries *chaininfo; /* pointer to chain data */
77 	struct ebt_entry *e; /* pointer to entry data */
78 	unsigned int n; /* n'th entry */
79 };
80 
81 struct ebt_table_info {
82 	/* total size of the entries */
83 	unsigned int entries_size;
84 	unsigned int nentries;
85 	/* pointers to the start of the chains */
86 	struct ebt_entries *hook_entry[NF_BR_NUMHOOKS];
87 	/* room to maintain the stack used for jumping from and into udc */
88 	struct ebt_chainstack **chainstack;
89 	char *entries;
90 	struct ebt_counter counters[0] ____cacheline_aligned;
91 };
92 
93 struct ebt_table {
94 	struct list_head list;
95 	char name[EBT_TABLE_MAXNAMELEN];
96 	struct ebt_replace_kernel *table;
97 	unsigned int valid_hooks;
98 	rwlock_t lock;
99 	/* e.g. could be the table explicitly only allows certain
100 	 * matches, targets, ... 0 == let it in */
101 	int (*check)(const struct ebt_table_info *info,
102 	   unsigned int valid_hooks);
103 	/* the data used by the kernel */
104 	struct ebt_table_info *private;
105 	struct module *me;
106 };
107 
108 #define EBT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1)) & \
109 		     ~(__alignof__(struct _xt_align)-1))
110 extern struct ebt_table *ebt_register_table(struct net *net,
111 					    const struct ebt_table *table);
112 extern void ebt_unregister_table(struct net *net, struct ebt_table *table);
113 extern unsigned int ebt_do_table(unsigned int hook, struct sk_buff *skb,
114    const struct net_device *in, const struct net_device *out,
115    struct ebt_table *table);
116 
117 /* Used in the kernel match() functions */
118 #define FWINV(bool,invflg) ((bool) ^ !!(info->invflags & invflg))
119 /* True if the hook mask denotes that the rule is in a base chain,
120  * used in the check() functions */
121 #define BASE_CHAIN (par->hook_mask & (1 << NF_BR_NUMHOOKS))
122 /* Clear the bit in the hook mask that tells if the rule is on a base chain */
123 #define CLEAR_BASE_CHAIN_BIT (par->hook_mask &= ~(1 << NF_BR_NUMHOOKS))
124 /* True if the target is not a standard target */
125 #define INVALID_TARGET (info->target < -NUM_STANDARD_TARGETS || info->target >= 0)
126 
127 #endif
128