1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * 25-Jul-1998 Major changes to allow for ip chain table
4  *
5  * 3-Jan-2000 Named tables to allow packet selection for different uses.
6  */
7 
8 /*
9  * 	Format of an IP firewall descriptor
10  *
11  * 	src, dst, src_mask, dst_mask are always stored in network byte order.
12  * 	flags are stored in host byte order (of course).
13  * 	Port numbers are stored in HOST byte order.
14  */
15 #ifndef _IPTABLES_H
16 #define _IPTABLES_H
17 
18 #include <linux/if.h>
19 #include <linux/in.h>
20 #include <linux/ip.h>
21 #include <linux/skbuff.h>
22 
23 #include <linux/init.h>
24 #include <uapi/linux/netfilter_ipv4/ip_tables.h>
25 
26 extern void ipt_init(void) __init;
27 
28 int ipt_register_table(struct net *net, const struct xt_table *table,
29 		       const struct ipt_replace *repl,
30 		       const struct nf_hook_ops *ops, struct xt_table **res);
31 void ipt_unregister_table(struct net *net, struct xt_table *table,
32 			  const struct nf_hook_ops *ops);
33 
34 /* Standard entry. */
35 struct ipt_standard {
36 	struct ipt_entry entry;
37 	struct xt_standard_target target;
38 };
39 
40 struct ipt_error {
41 	struct ipt_entry entry;
42 	struct xt_error_target target;
43 };
44 
45 #define IPT_ENTRY_INIT(__size)						       \
46 {									       \
47 	.target_offset	= sizeof(struct ipt_entry),			       \
48 	.next_offset	= (__size),					       \
49 }
50 
51 #define IPT_STANDARD_INIT(__verdict)					       \
52 {									       \
53 	.entry		= IPT_ENTRY_INIT(sizeof(struct ipt_standard)),	       \
54 	.target		= XT_TARGET_INIT(XT_STANDARD_TARGET,		       \
55 					 sizeof(struct xt_standard_target)),   \
56 	.target.verdict	= -(__verdict) - 1,				       \
57 }
58 
59 #define IPT_ERROR_INIT							       \
60 {									       \
61 	.entry		= IPT_ENTRY_INIT(sizeof(struct ipt_error)),	       \
62 	.target		= XT_TARGET_INIT(XT_ERROR_TARGET,		       \
63 					 sizeof(struct xt_error_target)),      \
64 	.target.errorname = "ERROR",					       \
65 }
66 
67 extern void *ipt_alloc_initial_table(const struct xt_table *);
68 extern unsigned int ipt_do_table(struct sk_buff *skb,
69 				 const struct nf_hook_state *state,
70 				 struct xt_table *table);
71 
72 #ifdef CONFIG_COMPAT
73 #include <net/compat.h>
74 
75 struct compat_ipt_entry {
76 	struct ipt_ip ip;
77 	compat_uint_t nfcache;
78 	__u16 target_offset;
79 	__u16 next_offset;
80 	compat_uint_t comefrom;
81 	struct compat_xt_counters counters;
82 	unsigned char elems[0];
83 };
84 
85 /* Helper functions */
86 static inline struct xt_entry_target *
87 compat_ipt_get_target(struct compat_ipt_entry *e)
88 {
89 	return (void *)e + e->target_offset;
90 }
91 
92 #endif /* CONFIG_COMPAT */
93 #endif /* _IPTABLES_H */
94