1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * ebtables
4 *
5 * Authors:
6 * Bart De Schuymer <bdschuym@pandora.be>
7 *
8 * ebtables.c,v 2.0, April, 2002
9 *
10 * This code is strongly inspired by the iptables code which is
11 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
12 */
13 #ifndef __LINUX_BRIDGE_EFF_H
14 #define __LINUX_BRIDGE_EFF_H
15
16 #include <linux/if.h>
17 #include <linux/if_ether.h>
18 #include <uapi/linux/netfilter_bridge/ebtables.h>
19
20 struct ebt_match {
21 struct list_head list;
22 const char name[EBT_FUNCTION_MAXNAMELEN];
23 bool (*match)(const struct sk_buff *skb, const struct net_device *in,
24 const struct net_device *out, const struct xt_match *match,
25 const void *matchinfo, int offset, unsigned int protoff,
26 bool *hotdrop);
27 bool (*checkentry)(const char *table, const void *entry,
28 const struct xt_match *match, void *matchinfo,
29 unsigned int hook_mask);
30 void (*destroy)(const struct xt_match *match, void *matchinfo);
31 unsigned int matchsize;
32 u_int8_t revision;
33 u_int8_t family;
34 struct module *me;
35 };
36
37 struct ebt_watcher {
38 struct list_head list;
39 const char name[EBT_FUNCTION_MAXNAMELEN];
40 unsigned int (*target)(struct sk_buff *skb,
41 const struct net_device *in, const struct net_device *out,
42 unsigned int hook_num, const struct xt_target *target,
43 const void *targinfo);
44 bool (*checkentry)(const char *table, const void *entry,
45 const struct xt_target *target, void *targinfo,
46 unsigned int hook_mask);
47 void (*destroy)(const struct xt_target *target, void *targinfo);
48 unsigned int targetsize;
49 u_int8_t revision;
50 u_int8_t family;
51 struct module *me;
52 };
53
54 struct ebt_target {
55 struct list_head list;
56 const char name[EBT_FUNCTION_MAXNAMELEN];
57 /* returns one of the standard EBT_* verdicts */
58 unsigned int (*target)(struct sk_buff *skb,
59 const struct net_device *in, const struct net_device *out,
60 unsigned int hook_num, const struct xt_target *target,
61 const void *targinfo);
62 bool (*checkentry)(const char *table, const void *entry,
63 const struct xt_target *target, void *targinfo,
64 unsigned int hook_mask);
65 void (*destroy)(const struct xt_target *target, void *targinfo);
66 unsigned int targetsize;
67 u_int8_t revision;
68 u_int8_t family;
69 struct module *me;
70 };
71
72 /* used for jumping from and into user defined chains (udc) */
73 struct ebt_chainstack {
74 struct ebt_entries *chaininfo; /* pointer to chain data */
75 struct ebt_entry *e; /* pointer to entry data */
76 unsigned int n; /* n'th entry */
77 };
78
79 struct ebt_table_info {
80 /* total size of the entries */
81 unsigned int entries_size;
82 unsigned int nentries;
83 /* pointers to the start of the chains */
84 struct ebt_entries *hook_entry[NF_BR_NUMHOOKS];
85 /* room to maintain the stack used for jumping from and into udc */
86 struct ebt_chainstack **chainstack;
87 char *entries;
88 struct ebt_counter counters[0] ____cacheline_aligned;
89 };
90
91 struct ebt_table {
92 struct list_head list;
93 char name[EBT_TABLE_MAXNAMELEN];
94 struct ebt_replace_kernel *table;
95 unsigned int valid_hooks;
96 rwlock_t lock;
97 /* e.g. could be the table explicitly only allows certain
98 * matches, targets, ... 0 == let it in */
99 int (*check)(const struct ebt_table_info *info,
100 unsigned int valid_hooks);
101 /* the data used by the kernel */
102 struct ebt_table_info *private;
103 struct module *me;
104 };
105
106 #define EBT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1)) & \
107 ~(__alignof__(struct _xt_align)-1))
108 extern int ebt_register_table(struct net *net,
109 const struct ebt_table *table,
110 const struct nf_hook_ops *ops,
111 struct ebt_table **res);
112 extern void ebt_unregister_table(struct net *net, struct ebt_table *table,
113 const struct nf_hook_ops *);
114 extern unsigned int ebt_do_table(struct sk_buff *skb,
115 const struct nf_hook_state *state,
116 struct ebt_table *table);
117
118 /* True if the hook mask denotes that the rule is in a base chain,
119 * used in the check() functions */
120 #define BASE_CHAIN (par->hook_mask & (1 << NF_BR_NUMHOOKS))
121 /* Clear the bit in the hook mask that tells if the rule is on a base chain */
122 #define CLEAR_BASE_CHAIN_BIT (par->hook_mask &= ~(1 << NF_BR_NUMHOOKS))
123
ebt_invalid_target(int target)124 static inline bool ebt_invalid_target(int target)
125 {
126 return (target < -NUM_STANDARD_TARGETS || target >= 0);
127 }
128
129 #endif
130
