ip_tables.h

  1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
  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
 16#ifndef _UAPI_IPTABLES_H
 17#define _UAPI_IPTABLES_H
 18
 19#include <linux/types.h>
 20#include <linux/compiler.h>
 21#include <linux/if.h>
 22#include <linux/netfilter_ipv4.h>
 23
 24#include <linux/netfilter/x_tables.h>
 25
 26#ifndef __KERNEL__
 27#define IPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
 28#define IPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
 29#define ipt_match xt_match
 30#define ipt_target xt_target
 31#define ipt_table xt_table
 32#define ipt_get_revision xt_get_revision
 33#define ipt_entry_match xt_entry_match
 34#define ipt_entry_target xt_entry_target
 35#define ipt_standard_target xt_standard_target
 36#define ipt_error_target xt_error_target
 37#define ipt_counters xt_counters
 38#define IPT_CONTINUE XT_CONTINUE
 39#define IPT_RETURN XT_RETURN
 40
 41/* This group is older than old (iptables < v1.4.0-rc1~89) */
 42#include <linux/netfilter/xt_tcpudp.h>
 43#define ipt_udp xt_udp
 44#define ipt_tcp xt_tcp
 45#define IPT_TCP_INV_SRCPT	XT_TCP_INV_SRCPT
 46#define IPT_TCP_INV_DSTPT	XT_TCP_INV_DSTPT
 47#define IPT_TCP_INV_FLAGS	XT_TCP_INV_FLAGS
 48#define IPT_TCP_INV_OPTION	XT_TCP_INV_OPTION
 49#define IPT_TCP_INV_MASK	XT_TCP_INV_MASK
 50#define IPT_UDP_INV_SRCPT	XT_UDP_INV_SRCPT
 51#define IPT_UDP_INV_DSTPT	XT_UDP_INV_DSTPT
 52#define IPT_UDP_INV_MASK	XT_UDP_INV_MASK
 53
 54/* The argument to IPT_SO_ADD_COUNTERS. */
 55#define ipt_counters_info xt_counters_info
 56/* Standard return verdict, or do jump. */
 57#define IPT_STANDARD_TARGET XT_STANDARD_TARGET
 58/* Error verdict. */
 59#define IPT_ERROR_TARGET XT_ERROR_TARGET
 60
 61/* fn returns 0 to continue iteration */
 62#define IPT_MATCH_ITERATE(e, fn, args...) \
 63	XT_MATCH_ITERATE(struct ipt_entry, e, fn, ## args)
 64
 65/* fn returns 0 to continue iteration */
 66#define IPT_ENTRY_ITERATE(entries, size, fn, args...) \
 67	XT_ENTRY_ITERATE(struct ipt_entry, entries, size, fn, ## args)
 68#endif
 69
 70/* Yes, Virginia, you have to zero the padding. */
 71struct ipt_ip {
 72	/* Source and destination IP addr */
 73	struct in_addr src, dst;
 74	/* Mask for src and dest IP addr */
 75	struct in_addr smsk, dmsk;
 76	char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
 77	unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
 78
 79	/* Protocol, 0 = ANY */
 80	__u16 proto;
 81
 82	/* Flags word */
 83	__u8 flags;
 84	/* Inverse flags */
 85	__u8 invflags;
 86};
 87
 88/* Values for "flag" field in struct ipt_ip (general ip structure). */
 89#define IPT_F_FRAG		0x01	/* Set if rule is a fragment rule */
 90#define IPT_F_GOTO		0x02	/* Set if jump is a goto */
 91#define IPT_F_MASK		0x03	/* All possible flag bits mask. */
 92
 93/* Values for "inv" field in struct ipt_ip. */
 94#define IPT_INV_VIA_IN		0x01	/* Invert the sense of IN IFACE. */
 95#define IPT_INV_VIA_OUT		0x02	/* Invert the sense of OUT IFACE */
 96#define IPT_INV_TOS		0x04	/* Invert the sense of TOS. */
 97#define IPT_INV_SRCIP		0x08	/* Invert the sense of SRC IP. */
 98#define IPT_INV_DSTIP		0x10	/* Invert the sense of DST OP. */
 99#define IPT_INV_FRAG		0x20	/* Invert the sense of FRAG. */
100#define IPT_INV_PROTO		XT_INV_PROTO
101#define IPT_INV_MASK		0x7F	/* All possible flag bits mask. */
102
103/* This structure defines each of the firewall rules.  Consists of 3
104   parts which are 1) general IP header stuff 2) match specific
105   stuff 3) the target to perform if the rule matches */
106struct ipt_entry {
107	struct ipt_ip ip;
108
109	/* Mark with fields that we care about. */
110	unsigned int nfcache;
111
112	/* Size of ipt_entry + matches */
113	__u16 target_offset;
114	/* Size of ipt_entry + matches + target */
115	__u16 next_offset;
116
117	/* Back pointer */
118	unsigned int comefrom;
119
120	/* Packet and byte counters. */
121	struct xt_counters counters;
122
123	/* The matches (if any), then the target. */
124	unsigned char elems[];
125};
126
127/*
128 * New IP firewall options for [gs]etsockopt at the RAW IP level.
129 * Unlike BSD Linux inherits IP options so you don't have to use a raw
130 * socket for this. Instead we check rights in the calls.
131 *
132 * ATTENTION: check linux/in.h before adding new number here.
133 */
134#define IPT_BASE_CTL		64
135
136#define IPT_SO_SET_REPLACE	(IPT_BASE_CTL)
137#define IPT_SO_SET_ADD_COUNTERS	(IPT_BASE_CTL + 1)
138#define IPT_SO_SET_MAX		IPT_SO_SET_ADD_COUNTERS
139
140#define IPT_SO_GET_INFO			(IPT_BASE_CTL)
141#define IPT_SO_GET_ENTRIES		(IPT_BASE_CTL + 1)
142#define IPT_SO_GET_REVISION_MATCH	(IPT_BASE_CTL + 2)
143#define IPT_SO_GET_REVISION_TARGET	(IPT_BASE_CTL + 3)
144#define IPT_SO_GET_MAX			IPT_SO_GET_REVISION_TARGET
145
146/* ICMP matching stuff */
147struct ipt_icmp {
148	__u8 type;				/* type to match */
149	__u8 code[2];				/* range of code */
150	__u8 invflags;				/* Inverse flags */
151};
152
153/* Values for "inv" field for struct ipt_icmp. */
154#define IPT_ICMP_INV	0x01	/* Invert the sense of type/code test */
155
156/* The argument to IPT_SO_GET_INFO */
157struct ipt_getinfo {
158	/* Which table: caller fills this in. */
159	char name[XT_TABLE_MAXNAMELEN];
160
161	/* Kernel fills these in. */
162	/* Which hook entry points are valid: bitmask */
163	unsigned int valid_hooks;
164
165	/* Hook entry points: one per netfilter hook. */
166	unsigned int hook_entry[NF_INET_NUMHOOKS];
167
168	/* Underflow points. */
169	unsigned int underflow[NF_INET_NUMHOOKS];
170
171	/* Number of entries */
172	unsigned int num_entries;
173
174	/* Size of entries. */
175	unsigned int size;
176};
177
178/* The argument to IPT_SO_SET_REPLACE. */
179struct ipt_replace {
180	/* Which table. */
181	char name[XT_TABLE_MAXNAMELEN];
182
183	/* Which hook entry points are valid: bitmask.  You can't
184           change this. */
185	unsigned int valid_hooks;
186
187	/* Number of entries */
188	unsigned int num_entries;
189
190	/* Total size of new entries */
191	unsigned int size;
192
193	/* Hook entry points. */
194	unsigned int hook_entry[NF_INET_NUMHOOKS];
195
196	/* Underflow points. */
197	unsigned int underflow[NF_INET_NUMHOOKS];
198
199	/* Information about old entries: */
200	/* Number of counters (must be equal to current number of entries). */
201	unsigned int num_counters;
202	/* The old entries' counters. */
203	struct xt_counters __user *counters;
204
205	/* The entries (hang off end: not really an array). */
206	struct ipt_entry entries[];
207};
208
209/* The argument to IPT_SO_GET_ENTRIES. */
210struct ipt_get_entries {
211	/* Which table: user fills this in. */
212	char name[XT_TABLE_MAXNAMELEN];
213
214	/* User fills this in: total entry size. */
215	unsigned int size;
216
217	/* The entries. */
218	struct ipt_entry entrytable[];
219};
220
221/* Helper functions */
222static __inline__ struct xt_entry_target *
223ipt_get_target(struct ipt_entry *e)
224{
225	return (struct xt_entry_target *)((char *)e + e->target_offset);
226}
227
228/*
229 *	Main firewall chains definitions and global var's definitions.
230 */
231#endif /* _UAPI_IPTABLES_H */