1 /*
2 * 25-Jul-1998 Major changes to allow for ip chain table
3 *
4 * 3-Jan-2000 Named tables to allow packet selection for different uses.
5 */
6
7 /*
8 * Format of an IP firewall descriptor
9 *
10 * src, dst, src_mask, dst_mask are always stored in network byte order.
11 * flags are stored in host byte order (of course).
12 * Port numbers are stored in HOST byte order.
13 */
14
15 #ifndef _IPTABLES_H
16 #define _IPTABLES_H
17
18 #ifdef __KERNEL__
19 #include <linux/if.h>
20 #include <linux/in.h>
21 #include <linux/ip.h>
22 #include <linux/skbuff.h>
23 #endif
24 #include <linux/types.h>
25 #include <linux/compiler.h>
26 #include <linux/netfilter_ipv4.h>
27
28 #include <linux/netfilter/x_tables.h>
29
30 #ifndef __KERNEL__
31 #define IPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
32 #define IPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
33 #define ipt_match xt_match
34 #define ipt_target xt_target
35 #define ipt_table xt_table
36 #define ipt_get_revision xt_get_revision
37 #define ipt_entry_match xt_entry_match
38 #define ipt_entry_target xt_entry_target
39 #define ipt_standard_target xt_standard_target
40 #define ipt_error_target xt_error_target
41 #define ipt_counters xt_counters
42 #define IPT_CONTINUE XT_CONTINUE
43 #define IPT_RETURN XT_RETURN
44
45 /* This group is older than old (iptables < v1.4.0-rc1~89) */
46 #include <linux/netfilter/xt_tcpudp.h>
47 #define ipt_udp xt_udp
48 #define ipt_tcp xt_tcp
49 #define IPT_TCP_INV_SRCPT XT_TCP_INV_SRCPT
50 #define IPT_TCP_INV_DSTPT XT_TCP_INV_DSTPT
51 #define IPT_TCP_INV_FLAGS XT_TCP_INV_FLAGS
52 #define IPT_TCP_INV_OPTION XT_TCP_INV_OPTION
53 #define IPT_TCP_INV_MASK XT_TCP_INV_MASK
54 #define IPT_UDP_INV_SRCPT XT_UDP_INV_SRCPT
55 #define IPT_UDP_INV_DSTPT XT_UDP_INV_DSTPT
56 #define IPT_UDP_INV_MASK XT_UDP_INV_MASK
57
58 /* The argument to IPT_SO_ADD_COUNTERS. */
59 #define ipt_counters_info xt_counters_info
60 /* Standard return verdict, or do jump. */
61 #define IPT_STANDARD_TARGET XT_STANDARD_TARGET
62 /* Error verdict. */
63 #define IPT_ERROR_TARGET XT_ERROR_TARGET
64
65 /* fn returns 0 to continue iteration */
66 #define IPT_MATCH_ITERATE(e, fn, args...) \
67 XT_MATCH_ITERATE(struct ipt_entry, e, fn, ## args)
68
69 /* fn returns 0 to continue iteration */
70 #define IPT_ENTRY_ITERATE(entries, size, fn, args...) \
71 XT_ENTRY_ITERATE(struct ipt_entry, entries, size, fn, ## args)
72 #endif
73
74 /* Yes, Virginia, you have to zero the padding. */
75 struct ipt_ip {
76 /* Source and destination IP addr */
77 struct in_addr src, dst;
78 /* Mask for src and dest IP addr */
79 struct in_addr smsk, dmsk;
80 char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
81 unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
82
83 /* Protocol, 0 = ANY */
84 __u16 proto;
85
86 /* Flags word */
87 __u8 flags;
88 /* Inverse flags */
89 __u8 invflags;
90 };
91
92 /* Values for "flag" field in struct ipt_ip (general ip structure). */
93 #define IPT_F_FRAG 0x01 /* Set if rule is a fragment rule */
94 #define IPT_F_GOTO 0x02 /* Set if jump is a goto */
95 #define IPT_F_MASK 0x03 /* All possible flag bits mask. */
96
97 /* Values for "inv" field in struct ipt_ip. */
98 #define IPT_INV_VIA_IN 0x01 /* Invert the sense of IN IFACE. */
99 #define IPT_INV_VIA_OUT 0x02 /* Invert the sense of OUT IFACE */
100 #define IPT_INV_TOS 0x04 /* Invert the sense of TOS. */
101 #define IPT_INV_SRCIP 0x08 /* Invert the sense of SRC IP. */
102 #define IPT_INV_DSTIP 0x10 /* Invert the sense of DST OP. */
103 #define IPT_INV_FRAG 0x20 /* Invert the sense of FRAG. */
104 #define IPT_INV_PROTO XT_INV_PROTO
105 #define IPT_INV_MASK 0x7F /* All possible flag bits mask. */
106
107 /* This structure defines each of the firewall rules. Consists of 3
108 parts which are 1) general IP header stuff 2) match specific
109 stuff 3) the target to perform if the rule matches */
110 struct ipt_entry {
111 struct ipt_ip ip;
112
113 /* Mark with fields that we care about. */
114 unsigned int nfcache;
115
116 /* Size of ipt_entry + matches */
117 __u16 target_offset;
118 /* Size of ipt_entry + matches + target */
119 __u16 next_offset;
120
121 /* Back pointer */
122 unsigned int comefrom;
123
124 /* Packet and byte counters. */
125 struct xt_counters counters;
126
127 /* The matches (if any), then the target. */
128 unsigned char elems[0];
129 };
130
131 /*
132 * New IP firewall options for [gs]etsockopt at the RAW IP level.
133 * Unlike BSD Linux inherits IP options so you don't have to use a raw
134 * socket for this. Instead we check rights in the calls.
135 *
136 * ATTENTION: check linux/in.h before adding new number here.
137 */
138 #define IPT_BASE_CTL 64
139
140 #define IPT_SO_SET_REPLACE (IPT_BASE_CTL)
141 #define IPT_SO_SET_ADD_COUNTERS (IPT_BASE_CTL + 1)
142 #define IPT_SO_SET_MAX IPT_SO_SET_ADD_COUNTERS
143
144 #define IPT_SO_GET_INFO (IPT_BASE_CTL)
145 #define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1)
146 #define IPT_SO_GET_REVISION_MATCH (IPT_BASE_CTL + 2)
147 #define IPT_SO_GET_REVISION_TARGET (IPT_BASE_CTL + 3)
148 #define IPT_SO_GET_MAX IPT_SO_GET_REVISION_TARGET
149
150 /* ICMP matching stuff */
151 struct ipt_icmp {
152 __u8 type; /* type to match */
153 __u8 code[2]; /* range of code */
154 __u8 invflags; /* Inverse flags */
155 };
156
157 /* Values for "inv" field for struct ipt_icmp. */
158 #define IPT_ICMP_INV 0x01 /* Invert the sense of type/code test */
159
160 /* The argument to IPT_SO_GET_INFO */
161 struct ipt_getinfo {
162 /* Which table: caller fills this in. */
163 char name[XT_TABLE_MAXNAMELEN];
164
165 /* Kernel fills these in. */
166 /* Which hook entry points are valid: bitmask */
167 unsigned int valid_hooks;
168
169 /* Hook entry points: one per netfilter hook. */
170 unsigned int hook_entry[NF_INET_NUMHOOKS];
171
172 /* Underflow points. */
173 unsigned int underflow[NF_INET_NUMHOOKS];
174
175 /* Number of entries */
176 unsigned int num_entries;
177
178 /* Size of entries. */
179 unsigned int size;
180 };
181
182 /* The argument to IPT_SO_SET_REPLACE. */
183 struct ipt_replace {
184 /* Which table. */
185 char name[XT_TABLE_MAXNAMELEN];
186
187 /* Which hook entry points are valid: bitmask. You can't
188 change this. */
189 unsigned int valid_hooks;
190
191 /* Number of entries */
192 unsigned int num_entries;
193
194 /* Total size of new entries */
195 unsigned int size;
196
197 /* Hook entry points. */
198 unsigned int hook_entry[NF_INET_NUMHOOKS];
199
200 /* Underflow points. */
201 unsigned int underflow[NF_INET_NUMHOOKS];
202
203 /* Information about old entries: */
204 /* Number of counters (must be equal to current number of entries). */
205 unsigned int num_counters;
206 /* The old entries' counters. */
207 struct xt_counters __user *counters;
208
209 /* The entries (hang off end: not really an array). */
210 struct ipt_entry entries[0];
211 };
212
213 /* The argument to IPT_SO_GET_ENTRIES. */
214 struct ipt_get_entries {
215 /* Which table: user fills this in. */
216 char name[XT_TABLE_MAXNAMELEN];
217
218 /* User fills this in: total entry size. */
219 unsigned int size;
220
221 /* The entries. */
222 struct ipt_entry entrytable[0];
223 };
224
225 /* Helper functions */
226 static __inline__ struct xt_entry_target *
ipt_get_target(struct ipt_entry * e)227 ipt_get_target(struct ipt_entry *e)
228 {
229 return (void *)e + e->target_offset;
230 }
231
232 /*
233 * Main firewall chains definitions and global var's definitions.
234 */
235 #ifdef __KERNEL__
236
237 #include <linux/init.h>
238 extern void ipt_init(void) __init;
239
240 extern struct xt_table *ipt_register_table(struct net *net,
241 const struct xt_table *table,
242 const struct ipt_replace *repl);
243 extern void ipt_unregister_table(struct net *net, struct xt_table *table);
244
245 /* Standard entry. */
246 struct ipt_standard {
247 struct ipt_entry entry;
248 struct xt_standard_target target;
249 };
250
251 struct ipt_error {
252 struct ipt_entry entry;
253 struct xt_error_target target;
254 };
255
256 #define IPT_ENTRY_INIT(__size) \
257 { \
258 .target_offset = sizeof(struct ipt_entry), \
259 .next_offset = (__size), \
260 }
261
262 #define IPT_STANDARD_INIT(__verdict) \
263 { \
264 .entry = IPT_ENTRY_INIT(sizeof(struct ipt_standard)), \
265 .target = XT_TARGET_INIT(XT_STANDARD_TARGET, \
266 sizeof(struct xt_standard_target)), \
267 .target.verdict = -(__verdict) - 1, \
268 }
269
270 #define IPT_ERROR_INIT \
271 { \
272 .entry = IPT_ENTRY_INIT(sizeof(struct ipt_error)), \
273 .target = XT_TARGET_INIT(XT_ERROR_TARGET, \
274 sizeof(struct xt_error_target)), \
275 .target.errorname = "ERROR", \
276 }
277
278 extern void *ipt_alloc_initial_table(const struct xt_table *);
279 extern unsigned int ipt_do_table(struct sk_buff *skb,
280 unsigned int hook,
281 const struct net_device *in,
282 const struct net_device *out,
283 struct xt_table *table);
284
285 #ifdef CONFIG_COMPAT
286 #include <net/compat.h>
287
288 struct compat_ipt_entry {
289 struct ipt_ip ip;
290 compat_uint_t nfcache;
291 __u16 target_offset;
292 __u16 next_offset;
293 compat_uint_t comefrom;
294 struct compat_xt_counters counters;
295 unsigned char elems[0];
296 };
297
298 /* Helper functions */
299 static inline struct xt_entry_target *
compat_ipt_get_target(struct compat_ipt_entry * e)300 compat_ipt_get_target(struct compat_ipt_entry *e)
301 {
302 return (void *)e + e->target_offset;
303 }
304
305 #endif /* CONFIG_COMPAT */
306 #endif /*__KERNEL__*/
307 #endif /* _IPTABLES_H */
308