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/init.h>
21 #include <linux/ip.h>
22 #include <linux/skbuff.h>
23 #include <uapi/linux/netfilter_ipv4/ip_tables.h>
24 
25 int ipt_register_table(struct net *net, const struct xt_table *table,
26 		       const struct ipt_replace *repl,
27 		       const struct nf_hook_ops *ops, struct xt_table **res);
28 void ipt_unregister_table(struct net *net, struct xt_table *table,
29 			  const struct nf_hook_ops *ops);
30 
31 /* Standard entry. */
32 struct ipt_standard {
33 	struct ipt_entry entry;
34 	struct xt_standard_target target;
35 };
36 
37 struct ipt_error {
38 	struct ipt_entry entry;
39 	struct xt_error_target target;
40 };
41 
42 #define IPT_ENTRY_INIT(__size)						       \
43 {									       \
44 	.target_offset	= sizeof(struct ipt_entry),			       \
45 	.next_offset	= (__size),					       \
46 }
47 
48 #define IPT_STANDARD_INIT(__verdict)					       \
49 {									       \
50 	.entry		= IPT_ENTRY_INIT(sizeof(struct ipt_standard)),	       \
51 	.target		= XT_TARGET_INIT(XT_STANDARD_TARGET,		       \
52 					 sizeof(struct xt_standard_target)),   \
53 	.target.verdict	= -(__verdict) - 1,				       \
54 }
55 
56 #define IPT_ERROR_INIT							       \
57 {									       \
58 	.entry		= IPT_ENTRY_INIT(sizeof(struct ipt_error)),	       \
59 	.target		= XT_TARGET_INIT(XT_ERROR_TARGET,		       \
60 					 sizeof(struct xt_error_target)),      \
61 	.target.errorname = "ERROR",					       \
62 }
63 
64 extern void *ipt_alloc_initial_table(const struct xt_table *);
65 extern unsigned int ipt_do_table(struct sk_buff *skb,
66 				 const struct nf_hook_state *state,
67 				 struct xt_table *table);
68 
69 #ifdef CONFIG_COMPAT
70 #include <net/compat.h>
71 
72 struct compat_ipt_entry {
73 	struct ipt_ip ip;
74 	compat_uint_t nfcache;
75 	__u16 target_offset;
76 	__u16 next_offset;
77 	compat_uint_t comefrom;
78 	struct compat_xt_counters counters;
79 	unsigned char elems[0];
80 };
81 
82 /* Helper functions */
83 static inline struct xt_entry_target *
84 compat_ipt_get_target(struct compat_ipt_entry *e)
85 {
86 	return (void *)e + e->target_offset;
87 }
88 
89 #endif /* CONFIG_COMPAT */
90 #endif /* _IPTABLES_H */
91