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 #define IPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
31 #define IPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
32 #define ipt_match xt_match
33 #define ipt_target xt_target
34 #define ipt_table xt_table
35 #define ipt_get_revision xt_get_revision
36
37 /* Yes, Virginia, you have to zero the padding. */
38 struct ipt_ip {
39 /* Source and destination IP addr */
40 struct in_addr src, dst;
41 /* Mask for src and dest IP addr */
42 struct in_addr smsk, dmsk;
43 char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
44 unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
45
46 /* Protocol, 0 = ANY */
47 u_int16_t proto;
48
49 /* Flags word */
50 u_int8_t flags;
51 /* Inverse flags */
52 u_int8_t invflags;
53 };
54
55 #define ipt_entry_match xt_entry_match
56 #define ipt_entry_target xt_entry_target
57 #define ipt_standard_target xt_standard_target
58
59 #define ipt_counters xt_counters
60
61 /* Values for "flag" field in struct ipt_ip (general ip structure). */
62 #define IPT_F_FRAG 0x01 /* Set if rule is a fragment rule */
63 #define IPT_F_GOTO 0x02 /* Set if jump is a goto */
64 #define IPT_F_MASK 0x03 /* All possible flag bits mask. */
65
66 /* Values for "inv" field in struct ipt_ip. */
67 #define IPT_INV_VIA_IN 0x01 /* Invert the sense of IN IFACE. */
68 #define IPT_INV_VIA_OUT 0x02 /* Invert the sense of OUT IFACE */
69 #define IPT_INV_TOS 0x04 /* Invert the sense of TOS. */
70 #define IPT_INV_SRCIP 0x08 /* Invert the sense of SRC IP. */
71 #define IPT_INV_DSTIP 0x10 /* Invert the sense of DST OP. */
72 #define IPT_INV_FRAG 0x20 /* Invert the sense of FRAG. */
73 #define IPT_INV_PROTO XT_INV_PROTO
74 #define IPT_INV_MASK 0x7F /* All possible flag bits mask. */
75
76 /* This structure defines each of the firewall rules. Consists of 3
77 parts which are 1) general IP header stuff 2) match specific
78 stuff 3) the target to perform if the rule matches */
79 struct ipt_entry
80 {
81 struct ipt_ip ip;
82
83 /* Mark with fields that we care about. */
84 unsigned int nfcache;
85
86 /* Size of ipt_entry + matches */
87 u_int16_t target_offset;
88 /* Size of ipt_entry + matches + target */
89 u_int16_t next_offset;
90
91 /* Back pointer */
92 unsigned int comefrom;
93
94 /* Packet and byte counters. */
95 struct xt_counters counters;
96
97 /* The matches (if any), then the target. */
98 unsigned char elems[0];
99 };
100
101 /*
102 * New IP firewall options for [gs]etsockopt at the RAW IP level.
103 * Unlike BSD Linux inherits IP options so you don't have to use a raw
104 * socket for this. Instead we check rights in the calls.
105 *
106 * ATTENTION: check linux/in.h before adding new number here.
107 */
108 #define IPT_BASE_CTL 64
109
110 #define IPT_SO_SET_REPLACE (IPT_BASE_CTL)
111 #define IPT_SO_SET_ADD_COUNTERS (IPT_BASE_CTL + 1)
112 #define IPT_SO_SET_MAX IPT_SO_SET_ADD_COUNTERS
113
114 #define IPT_SO_GET_INFO (IPT_BASE_CTL)
115 #define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1)
116 #define IPT_SO_GET_REVISION_MATCH (IPT_BASE_CTL + 2)
117 #define IPT_SO_GET_REVISION_TARGET (IPT_BASE_CTL + 3)
118 #define IPT_SO_GET_MAX IPT_SO_GET_REVISION_TARGET
119
120 #define IPT_CONTINUE XT_CONTINUE
121 #define IPT_RETURN XT_RETURN
122
123 #include <linux/netfilter/xt_tcpudp.h>
124 #define ipt_udp xt_udp
125 #define ipt_tcp xt_tcp
126
127 #define IPT_TCP_INV_SRCPT XT_TCP_INV_SRCPT
128 #define IPT_TCP_INV_DSTPT XT_TCP_INV_DSTPT
129 #define IPT_TCP_INV_FLAGS XT_TCP_INV_FLAGS
130 #define IPT_TCP_INV_OPTION XT_TCP_INV_OPTION
131 #define IPT_TCP_INV_MASK XT_TCP_INV_MASK
132
133 #define IPT_UDP_INV_SRCPT XT_UDP_INV_SRCPT
134 #define IPT_UDP_INV_DSTPT XT_UDP_INV_DSTPT
135 #define IPT_UDP_INV_MASK XT_UDP_INV_MASK
136
137 /* ICMP matching stuff */
138 struct ipt_icmp
139 {
140 u_int8_t type; /* type to match */
141 u_int8_t code[2]; /* range of code */
142 u_int8_t invflags; /* Inverse flags */
143 };
144
145 /* Values for "inv" field for struct ipt_icmp. */
146 #define IPT_ICMP_INV 0x01 /* Invert the sense of type/code test */
147
148 /* The argument to IPT_SO_GET_INFO */
149 struct ipt_getinfo
150 {
151 /* Which table: caller fills this in. */
152 char name[IPT_TABLE_MAXNAMELEN];
153
154 /* Kernel fills these in. */
155 /* Which hook entry points are valid: bitmask */
156 unsigned int valid_hooks;
157
158 /* Hook entry points: one per netfilter hook. */
159 unsigned int hook_entry[NF_INET_NUMHOOKS];
160
161 /* Underflow points. */
162 unsigned int underflow[NF_INET_NUMHOOKS];
163
164 /* Number of entries */
165 unsigned int num_entries;
166
167 /* Size of entries. */
168 unsigned int size;
169 };
170
171 /* The argument to IPT_SO_SET_REPLACE. */
172 struct ipt_replace
173 {
174 /* Which table. */
175 char name[IPT_TABLE_MAXNAMELEN];
176
177 /* Which hook entry points are valid: bitmask. You can't
178 change this. */
179 unsigned int valid_hooks;
180
181 /* Number of entries */
182 unsigned int num_entries;
183
184 /* Total size of new entries */
185 unsigned int size;
186
187 /* Hook entry points. */
188 unsigned int hook_entry[NF_INET_NUMHOOKS];
189
190 /* Underflow points. */
191 unsigned int underflow[NF_INET_NUMHOOKS];
192
193 /* Information about old entries: */
194 /* Number of counters (must be equal to current number of entries). */
195 unsigned int num_counters;
196 /* The old entries' counters. */
197 struct xt_counters __user *counters;
198
199 /* The entries (hang off end: not really an array). */
200 struct ipt_entry entries[0];
201 };
202
203 /* The argument to IPT_SO_ADD_COUNTERS. */
204 #define ipt_counters_info xt_counters_info
205
206 /* The argument to IPT_SO_GET_ENTRIES. */
207 struct ipt_get_entries
208 {
209 /* Which table: user fills this in. */
210 char name[IPT_TABLE_MAXNAMELEN];
211
212 /* User fills this in: total entry size. */
213 unsigned int size;
214
215 /* The entries. */
216 struct ipt_entry entrytable[0];
217 };
218
219 /* Standard return verdict, or do jump. */
220 #define IPT_STANDARD_TARGET XT_STANDARD_TARGET
221 /* Error verdict. */
222 #define IPT_ERROR_TARGET XT_ERROR_TARGET
223
224 /* Helper functions */
225 static __inline__ struct ipt_entry_target *
ipt_get_target(struct ipt_entry * e)226 ipt_get_target(struct ipt_entry *e)
227 {
228 return (void *)e + e->target_offset;
229 }
230
231 /* fn returns 0 to continue iteration */
232 #define IPT_MATCH_ITERATE(e, fn, args...) \
233 XT_MATCH_ITERATE(struct ipt_entry, e, fn, ## args)
234
235 /* fn returns 0 to continue iteration */
236 #define IPT_ENTRY_ITERATE(entries, size, fn, args...) \
237 XT_ENTRY_ITERATE(struct ipt_entry, entries, size, fn, ## args)
238
239 /*
240 * Main firewall chains definitions and global var's definitions.
241 */
242 #ifdef __KERNEL__
243
244 #include <linux/init.h>
245 extern void ipt_init(void) __init;
246
247 extern struct xt_table *ipt_register_table(struct net *net,
248 struct xt_table *table,
249 const struct ipt_replace *repl);
250 extern void ipt_unregister_table(struct xt_table *table);
251
252 /* Standard entry. */
253 struct ipt_standard
254 {
255 struct ipt_entry entry;
256 struct ipt_standard_target target;
257 };
258
259 struct ipt_error_target
260 {
261 struct ipt_entry_target target;
262 char errorname[IPT_FUNCTION_MAXNAMELEN];
263 };
264
265 struct ipt_error
266 {
267 struct ipt_entry entry;
268 struct ipt_error_target target;
269 };
270
271 #define IPT_ENTRY_INIT(__size) \
272 { \
273 .target_offset = sizeof(struct ipt_entry), \
274 .next_offset = (__size), \
275 }
276
277 #define IPT_STANDARD_INIT(__verdict) \
278 { \
279 .entry = IPT_ENTRY_INIT(sizeof(struct ipt_standard)), \
280 .target = XT_TARGET_INIT(IPT_STANDARD_TARGET, \
281 sizeof(struct xt_standard_target)), \
282 .target.verdict = -(__verdict) - 1, \
283 }
284
285 #define IPT_ERROR_INIT \
286 { \
287 .entry = IPT_ENTRY_INIT(sizeof(struct ipt_error)), \
288 .target = XT_TARGET_INIT(IPT_ERROR_TARGET, \
289 sizeof(struct ipt_error_target)), \
290 .target.errorname = "ERROR", \
291 }
292
293 extern unsigned int ipt_do_table(struct sk_buff *skb,
294 unsigned int hook,
295 const struct net_device *in,
296 const struct net_device *out,
297 struct xt_table *table);
298
299 #define IPT_ALIGN(s) XT_ALIGN(s)
300
301 #ifdef CONFIG_COMPAT
302 #include <net/compat.h>
303
304 struct compat_ipt_entry
305 {
306 struct ipt_ip ip;
307 compat_uint_t nfcache;
308 u_int16_t target_offset;
309 u_int16_t next_offset;
310 compat_uint_t comefrom;
311 struct compat_xt_counters counters;
312 unsigned char elems[0];
313 };
314
315 /* Helper functions */
316 static inline struct ipt_entry_target *
compat_ipt_get_target(struct compat_ipt_entry * e)317 compat_ipt_get_target(struct compat_ipt_entry *e)
318 {
319 return (void *)e + e->target_offset;
320 }
321
322 #define COMPAT_IPT_ALIGN(s) COMPAT_XT_ALIGN(s)
323
324 /* fn returns 0 to continue iteration */
325 #define COMPAT_IPT_MATCH_ITERATE(e, fn, args...) \
326 XT_MATCH_ITERATE(struct compat_ipt_entry, e, fn, ## args)
327
328 /* fn returns 0 to continue iteration */
329 #define COMPAT_IPT_ENTRY_ITERATE(entries, size, fn, args...) \
330 XT_ENTRY_ITERATE(struct compat_ipt_entry, entries, size, fn, ## args)
331
332 /* fn returns 0 to continue iteration */
333 #define COMPAT_IPT_ENTRY_ITERATE_CONTINUE(entries, size, n, fn, args...) \
334 XT_ENTRY_ITERATE_CONTINUE(struct compat_ipt_entry, entries, size, n, \
335 fn, ## args)
336
337 #endif /* CONFIG_COMPAT */
338 #endif /*__KERNEL__*/
339 #endif /* _IPTABLES_H */
340