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 /* return values for match() functions */
21 #define EBT_MATCH 0
22 #define EBT_NOMATCH 1
23
24 struct ebt_match {
25 struct list_head list;
26 const char name[EBT_FUNCTION_MAXNAMELEN];
27 bool (*match)(const struct sk_buff *skb, const struct net_device *in,
28 const struct net_device *out, const struct xt_match *match,
29 const void *matchinfo, int offset, unsigned int protoff,
30 bool *hotdrop);
31 bool (*checkentry)(const char *table, const void *entry,
32 const struct xt_match *match, void *matchinfo,
33 unsigned int hook_mask);
34 void (*destroy)(const struct xt_match *match, void *matchinfo);
35 unsigned int matchsize;
36 u_int8_t revision;
37 u_int8_t family;
38 struct module *me;
39 };
40
41 struct ebt_watcher {
42 struct list_head list;
43 const char name[EBT_FUNCTION_MAXNAMELEN];
44 unsigned int (*target)(struct sk_buff *skb,
45 const struct net_device *in, const struct net_device *out,
46 unsigned int hook_num, const struct xt_target *target,
47 const void *targinfo);
48 bool (*checkentry)(const char *table, const void *entry,
49 const struct xt_target *target, void *targinfo,
50 unsigned int hook_mask);
51 void (*destroy)(const struct xt_target *target, void *targinfo);
52 unsigned int targetsize;
53 u_int8_t revision;
54 u_int8_t family;
55 struct module *me;
56 };
57
58 struct ebt_target {
59 struct list_head list;
60 const char name[EBT_FUNCTION_MAXNAMELEN];
61 /* returns one of the standard EBT_* verdicts */
62 unsigned int (*target)(struct sk_buff *skb,
63 const struct net_device *in, const struct net_device *out,
64 unsigned int hook_num, const struct xt_target *target,
65 const void *targinfo);
66 bool (*checkentry)(const char *table, const void *entry,
67 const struct xt_target *target, void *targinfo,
68 unsigned int hook_mask);
69 void (*destroy)(const struct xt_target *target, void *targinfo);
70 unsigned int targetsize;
71 u_int8_t revision;
72 u_int8_t family;
73 struct module *me;
74 };
75
76 /* used for jumping from and into user defined chains (udc) */
77 struct ebt_chainstack {
78 struct ebt_entries *chaininfo; /* pointer to chain data */
79 struct ebt_entry *e; /* pointer to entry data */
80 unsigned int n; /* n'th entry */
81 };
82
83 struct ebt_table_info {
84 /* total size of the entries */
85 unsigned int entries_size;
86 unsigned int nentries;
87 /* pointers to the start of the chains */
88 struct ebt_entries *hook_entry[NF_BR_NUMHOOKS];
89 /* room to maintain the stack used for jumping from and into udc */
90 struct ebt_chainstack **chainstack;
91 char *entries;
92 struct ebt_counter counters[0] ____cacheline_aligned;
93 };
94
95 struct ebt_table {
96 struct list_head list;
97 char name[EBT_TABLE_MAXNAMELEN];
98 struct ebt_replace_kernel *table;
99 unsigned int valid_hooks;
100 rwlock_t lock;
101 /* e.g. could be the table explicitly only allows certain
102 * matches, targets, ... 0 == let it in */
103 int (*check)(const struct ebt_table_info *info,
104 unsigned int valid_hooks);
105 /* the data used by the kernel */
106 struct ebt_table_info *private;
107 struct module *me;
108 };
109
110 #define EBT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1)) & \
111 ~(__alignof__(struct _xt_align)-1))
112 extern int ebt_register_table(struct net *net,
113 const struct ebt_table *table,
114 const struct nf_hook_ops *ops,
115 struct ebt_table **res);
116 extern void ebt_unregister_table(struct net *net, struct ebt_table *table,
117 const struct nf_hook_ops *);
118 extern unsigned int ebt_do_table(struct sk_buff *skb,
119 const struct nf_hook_state *state,
120 struct ebt_table *table);
121
122 /* True if the hook mask denotes that the rule is in a base chain,
123 * used in the check() functions */
124 #define BASE_CHAIN (par->hook_mask & (1 << NF_BR_NUMHOOKS))
125 /* Clear the bit in the hook mask that tells if the rule is on a base chain */
126 #define CLEAR_BASE_CHAIN_BIT (par->hook_mask &= ~(1 << NF_BR_NUMHOOKS))
127
ebt_invalid_target(int target)128 static inline bool ebt_invalid_target(int target)
129 {
130 return (target < -NUM_STANDARD_TARGETS || target >= 0);
131 }
132
133 #endif
134