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Commit | Line | Data |
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1da177e4 LT |
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/types.h> | |
21 | #include <linux/in.h> | |
22 | #include <linux/ip.h> | |
23 | #include <linux/skbuff.h> | |
24 | #endif | |
25 | #include <linux/compiler.h> | |
26 | #include <linux/netfilter_ipv4.h> | |
27 | ||
28 | #define IPT_FUNCTION_MAXNAMELEN 30 | |
29 | #define IPT_TABLE_MAXNAMELEN 32 | |
30 | ||
31 | /* Yes, Virginia, you have to zero the padding. */ | |
32 | struct ipt_ip { | |
33 | /* Source and destination IP addr */ | |
34 | struct in_addr src, dst; | |
35 | /* Mask for src and dest IP addr */ | |
36 | struct in_addr smsk, dmsk; | |
37 | char iniface[IFNAMSIZ], outiface[IFNAMSIZ]; | |
38 | unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ]; | |
39 | ||
40 | /* Protocol, 0 = ANY */ | |
41 | u_int16_t proto; | |
42 | ||
43 | /* Flags word */ | |
44 | u_int8_t flags; | |
45 | /* Inverse flags */ | |
46 | u_int8_t invflags; | |
47 | }; | |
48 | ||
49 | struct ipt_entry_match | |
50 | { | |
51 | union { | |
52 | struct { | |
53 | u_int16_t match_size; | |
54 | ||
55 | /* Used by userspace */ | |
56 | char name[IPT_FUNCTION_MAXNAMELEN-1]; | |
57 | ||
58 | u_int8_t revision; | |
59 | } user; | |
60 | struct { | |
61 | u_int16_t match_size; | |
62 | ||
63 | /* Used inside the kernel */ | |
64 | struct ipt_match *match; | |
65 | } kernel; | |
66 | ||
67 | /* Total length */ | |
68 | u_int16_t match_size; | |
69 | } u; | |
70 | ||
71 | unsigned char data[0]; | |
72 | }; | |
73 | ||
74 | struct ipt_entry_target | |
75 | { | |
76 | union { | |
77 | struct { | |
78 | u_int16_t target_size; | |
79 | ||
80 | /* Used by userspace */ | |
81 | char name[IPT_FUNCTION_MAXNAMELEN-1]; | |
82 | ||
83 | u_int8_t revision; | |
84 | } user; | |
85 | struct { | |
86 | u_int16_t target_size; | |
87 | ||
88 | /* Used inside the kernel */ | |
89 | struct ipt_target *target; | |
90 | } kernel; | |
91 | ||
92 | /* Total length */ | |
93 | u_int16_t target_size; | |
94 | } u; | |
95 | ||
96 | unsigned char data[0]; | |
97 | }; | |
98 | ||
99 | struct ipt_standard_target | |
100 | { | |
101 | struct ipt_entry_target target; | |
102 | int verdict; | |
103 | }; | |
104 | ||
105 | struct ipt_counters | |
106 | { | |
107 | u_int64_t pcnt, bcnt; /* Packet and byte counters */ | |
108 | }; | |
109 | ||
110 | /* Values for "flag" field in struct ipt_ip (general ip structure). */ | |
111 | #define IPT_F_FRAG 0x01 /* Set if rule is a fragment rule */ | |
112 | #define IPT_F_MASK 0x01 /* All possible flag bits mask. */ | |
113 | ||
114 | /* Values for "inv" field in struct ipt_ip. */ | |
115 | #define IPT_INV_VIA_IN 0x01 /* Invert the sense of IN IFACE. */ | |
116 | #define IPT_INV_VIA_OUT 0x02 /* Invert the sense of OUT IFACE */ | |
117 | #define IPT_INV_TOS 0x04 /* Invert the sense of TOS. */ | |
118 | #define IPT_INV_SRCIP 0x08 /* Invert the sense of SRC IP. */ | |
119 | #define IPT_INV_DSTIP 0x10 /* Invert the sense of DST OP. */ | |
120 | #define IPT_INV_FRAG 0x20 /* Invert the sense of FRAG. */ | |
121 | #define IPT_INV_PROTO 0x40 /* Invert the sense of PROTO. */ | |
122 | #define IPT_INV_MASK 0x7F /* All possible flag bits mask. */ | |
123 | ||
124 | /* This structure defines each of the firewall rules. Consists of 3 | |
125 | parts which are 1) general IP header stuff 2) match specific | |
126 | stuff 3) the target to perform if the rule matches */ | |
127 | struct ipt_entry | |
128 | { | |
129 | struct ipt_ip ip; | |
130 | ||
131 | /* Mark with fields that we care about. */ | |
132 | unsigned int nfcache; | |
133 | ||
134 | /* Size of ipt_entry + matches */ | |
135 | u_int16_t target_offset; | |
136 | /* Size of ipt_entry + matches + target */ | |
137 | u_int16_t next_offset; | |
138 | ||
139 | /* Back pointer */ | |
140 | unsigned int comefrom; | |
141 | ||
142 | /* Packet and byte counters. */ | |
143 | struct ipt_counters counters; | |
144 | ||
145 | /* The matches (if any), then the target. */ | |
146 | unsigned char elems[0]; | |
147 | }; | |
148 | ||
149 | /* | |
150 | * New IP firewall options for [gs]etsockopt at the RAW IP level. | |
151 | * Unlike BSD Linux inherits IP options so you don't have to use a raw | |
152 | * socket for this. Instead we check rights in the calls. */ | |
153 | #define IPT_BASE_CTL 64 /* base for firewall socket options */ | |
154 | ||
155 | #define IPT_SO_SET_REPLACE (IPT_BASE_CTL) | |
156 | #define IPT_SO_SET_ADD_COUNTERS (IPT_BASE_CTL + 1) | |
157 | #define IPT_SO_SET_MAX IPT_SO_SET_ADD_COUNTERS | |
158 | ||
159 | #define IPT_SO_GET_INFO (IPT_BASE_CTL) | |
160 | #define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1) | |
161 | #define IPT_SO_GET_REVISION_MATCH (IPT_BASE_CTL + 2) | |
162 | #define IPT_SO_GET_REVISION_TARGET (IPT_BASE_CTL + 3) | |
163 | #define IPT_SO_GET_MAX IPT_SO_GET_REVISION_TARGET | |
164 | ||
165 | /* CONTINUE verdict for targets */ | |
166 | #define IPT_CONTINUE 0xFFFFFFFF | |
167 | ||
168 | /* For standard target */ | |
169 | #define IPT_RETURN (-NF_REPEAT - 1) | |
170 | ||
171 | /* TCP matching stuff */ | |
172 | struct ipt_tcp | |
173 | { | |
174 | u_int16_t spts[2]; /* Source port range. */ | |
175 | u_int16_t dpts[2]; /* Destination port range. */ | |
176 | u_int8_t option; /* TCP Option iff non-zero*/ | |
177 | u_int8_t flg_mask; /* TCP flags mask byte */ | |
178 | u_int8_t flg_cmp; /* TCP flags compare byte */ | |
179 | u_int8_t invflags; /* Inverse flags */ | |
180 | }; | |
181 | ||
182 | /* Values for "inv" field in struct ipt_tcp. */ | |
183 | #define IPT_TCP_INV_SRCPT 0x01 /* Invert the sense of source ports. */ | |
184 | #define IPT_TCP_INV_DSTPT 0x02 /* Invert the sense of dest ports. */ | |
185 | #define IPT_TCP_INV_FLAGS 0x04 /* Invert the sense of TCP flags. */ | |
186 | #define IPT_TCP_INV_OPTION 0x08 /* Invert the sense of option test. */ | |
187 | #define IPT_TCP_INV_MASK 0x0F /* All possible flags. */ | |
188 | ||
189 | /* UDP matching stuff */ | |
190 | struct ipt_udp | |
191 | { | |
192 | u_int16_t spts[2]; /* Source port range. */ | |
193 | u_int16_t dpts[2]; /* Destination port range. */ | |
194 | u_int8_t invflags; /* Inverse flags */ | |
195 | }; | |
196 | ||
197 | /* Values for "invflags" field in struct ipt_udp. */ | |
198 | #define IPT_UDP_INV_SRCPT 0x01 /* Invert the sense of source ports. */ | |
199 | #define IPT_UDP_INV_DSTPT 0x02 /* Invert the sense of dest ports. */ | |
200 | #define IPT_UDP_INV_MASK 0x03 /* All possible flags. */ | |
201 | ||
202 | /* ICMP matching stuff */ | |
203 | struct ipt_icmp | |
204 | { | |
205 | u_int8_t type; /* type to match */ | |
206 | u_int8_t code[2]; /* range of code */ | |
207 | u_int8_t invflags; /* Inverse flags */ | |
208 | }; | |
209 | ||
210 | /* Values for "inv" field for struct ipt_icmp. */ | |
211 | #define IPT_ICMP_INV 0x01 /* Invert the sense of type/code test */ | |
212 | ||
213 | /* The argument to IPT_SO_GET_INFO */ | |
214 | struct ipt_getinfo | |
215 | { | |
216 | /* Which table: caller fills this in. */ | |
217 | char name[IPT_TABLE_MAXNAMELEN]; | |
218 | ||
219 | /* Kernel fills these in. */ | |
220 | /* Which hook entry points are valid: bitmask */ | |
221 | unsigned int valid_hooks; | |
222 | ||
223 | /* Hook entry points: one per netfilter hook. */ | |
224 | unsigned int hook_entry[NF_IP_NUMHOOKS]; | |
225 | ||
226 | /* Underflow points. */ | |
227 | unsigned int underflow[NF_IP_NUMHOOKS]; | |
228 | ||
229 | /* Number of entries */ | |
230 | unsigned int num_entries; | |
231 | ||
232 | /* Size of entries. */ | |
233 | unsigned int size; | |
234 | }; | |
235 | ||
236 | /* The argument to IPT_SO_SET_REPLACE. */ | |
237 | struct ipt_replace | |
238 | { | |
239 | /* Which table. */ | |
240 | char name[IPT_TABLE_MAXNAMELEN]; | |
241 | ||
242 | /* Which hook entry points are valid: bitmask. You can't | |
243 | change this. */ | |
244 | unsigned int valid_hooks; | |
245 | ||
246 | /* Number of entries */ | |
247 | unsigned int num_entries; | |
248 | ||
249 | /* Total size of new entries */ | |
250 | unsigned int size; | |
251 | ||
252 | /* Hook entry points. */ | |
253 | unsigned int hook_entry[NF_IP_NUMHOOKS]; | |
254 | ||
255 | /* Underflow points. */ | |
256 | unsigned int underflow[NF_IP_NUMHOOKS]; | |
257 | ||
258 | /* Information about old entries: */ | |
259 | /* Number of counters (must be equal to current number of entries). */ | |
260 | unsigned int num_counters; | |
261 | /* The old entries' counters. */ | |
262 | struct ipt_counters __user *counters; | |
263 | ||
264 | /* The entries (hang off end: not really an array). */ | |
265 | struct ipt_entry entries[0]; | |
266 | }; | |
267 | ||
268 | /* The argument to IPT_SO_ADD_COUNTERS. */ | |
269 | struct ipt_counters_info | |
270 | { | |
271 | /* Which table. */ | |
272 | char name[IPT_TABLE_MAXNAMELEN]; | |
273 | ||
274 | unsigned int num_counters; | |
275 | ||
276 | /* The counters (actually `number' of these). */ | |
277 | struct ipt_counters counters[0]; | |
278 | }; | |
279 | ||
280 | /* The argument to IPT_SO_GET_ENTRIES. */ | |
281 | struct ipt_get_entries | |
282 | { | |
283 | /* Which table: user fills this in. */ | |
284 | char name[IPT_TABLE_MAXNAMELEN]; | |
285 | ||
286 | /* User fills this in: total entry size. */ | |
287 | unsigned int size; | |
288 | ||
289 | /* The entries. */ | |
290 | struct ipt_entry entrytable[0]; | |
291 | }; | |
292 | ||
293 | /* The argument to IPT_SO_GET_REVISION_*. Returns highest revision | |
294 | * kernel supports, if >= revision. */ | |
295 | struct ipt_get_revision | |
296 | { | |
297 | char name[IPT_FUNCTION_MAXNAMELEN-1]; | |
298 | ||
299 | u_int8_t revision; | |
300 | }; | |
301 | ||
302 | /* Standard return verdict, or do jump. */ | |
303 | #define IPT_STANDARD_TARGET "" | |
304 | /* Error verdict. */ | |
305 | #define IPT_ERROR_TARGET "ERROR" | |
306 | ||
307 | /* Helper functions */ | |
308 | static __inline__ struct ipt_entry_target * | |
309 | ipt_get_target(struct ipt_entry *e) | |
310 | { | |
311 | return (void *)e + e->target_offset; | |
312 | } | |
313 | ||
314 | /* fn returns 0 to continue iteration */ | |
315 | #define IPT_MATCH_ITERATE(e, fn, args...) \ | |
316 | ({ \ | |
317 | unsigned int __i; \ | |
318 | int __ret = 0; \ | |
319 | struct ipt_entry_match *__match; \ | |
320 | \ | |
321 | for (__i = sizeof(struct ipt_entry); \ | |
322 | __i < (e)->target_offset; \ | |
323 | __i += __match->u.match_size) { \ | |
324 | __match = (void *)(e) + __i; \ | |
325 | \ | |
326 | __ret = fn(__match , ## args); \ | |
327 | if (__ret != 0) \ | |
328 | break; \ | |
329 | } \ | |
330 | __ret; \ | |
331 | }) | |
332 | ||
333 | /* fn returns 0 to continue iteration */ | |
334 | #define IPT_ENTRY_ITERATE(entries, size, fn, args...) \ | |
335 | ({ \ | |
336 | unsigned int __i; \ | |
337 | int __ret = 0; \ | |
338 | struct ipt_entry *__entry; \ | |
339 | \ | |
340 | for (__i = 0; __i < (size); __i += __entry->next_offset) { \ | |
341 | __entry = (void *)(entries) + __i; \ | |
342 | \ | |
343 | __ret = fn(__entry , ## args); \ | |
344 | if (__ret != 0) \ | |
345 | break; \ | |
346 | } \ | |
347 | __ret; \ | |
348 | }) | |
349 | ||
350 | /* | |
351 | * Main firewall chains definitions and global var's definitions. | |
352 | */ | |
353 | #ifdef __KERNEL__ | |
354 | ||
355 | #include <linux/init.h> | |
356 | extern void ipt_init(void) __init; | |
357 | ||
358 | struct ipt_match | |
359 | { | |
360 | struct list_head list; | |
361 | ||
362 | const char name[IPT_FUNCTION_MAXNAMELEN-1]; | |
363 | ||
364 | u_int8_t revision; | |
365 | ||
366 | /* Return true or false: return FALSE and set *hotdrop = 1 to | |
367 | force immediate packet drop. */ | |
368 | /* Arguments changed since 2.4, as this must now handle | |
369 | non-linear skbs, using skb_copy_bits and | |
370 | skb_ip_make_writable. */ | |
371 | int (*match)(const struct sk_buff *skb, | |
372 | const struct net_device *in, | |
373 | const struct net_device *out, | |
374 | const void *matchinfo, | |
375 | int offset, | |
376 | int *hotdrop); | |
377 | ||
378 | /* Called when user tries to insert an entry of this type. */ | |
379 | /* Should return true or false. */ | |
380 | int (*checkentry)(const char *tablename, | |
381 | const struct ipt_ip *ip, | |
382 | void *matchinfo, | |
383 | unsigned int matchinfosize, | |
384 | unsigned int hook_mask); | |
385 | ||
386 | /* Called when entry of this type deleted. */ | |
387 | void (*destroy)(void *matchinfo, unsigned int matchinfosize); | |
388 | ||
389 | /* Set this to THIS_MODULE. */ | |
390 | struct module *me; | |
391 | }; | |
392 | ||
393 | /* Registration hooks for targets. */ | |
394 | struct ipt_target | |
395 | { | |
396 | struct list_head list; | |
397 | ||
398 | const char name[IPT_FUNCTION_MAXNAMELEN-1]; | |
399 | ||
400 | u_int8_t revision; | |
401 | ||
402 | /* Called when user tries to insert an entry of this type: | |
403 | hook_mask is a bitmask of hooks from which it can be | |
404 | called. */ | |
405 | /* Should return true or false. */ | |
406 | int (*checkentry)(const char *tablename, | |
407 | const struct ipt_entry *e, | |
408 | void *targinfo, | |
409 | unsigned int targinfosize, | |
410 | unsigned int hook_mask); | |
411 | ||
412 | /* Called when entry of this type deleted. */ | |
413 | void (*destroy)(void *targinfo, unsigned int targinfosize); | |
414 | ||
415 | /* Returns verdict. Argument order changed since 2.4, as this | |
416 | must now handle non-linear skbs, using skb_copy_bits and | |
417 | skb_ip_make_writable. */ | |
418 | unsigned int (*target)(struct sk_buff **pskb, | |
419 | const struct net_device *in, | |
420 | const struct net_device *out, | |
421 | unsigned int hooknum, | |
422 | const void *targinfo, | |
423 | void *userdata); | |
424 | ||
425 | /* Set this to THIS_MODULE. */ | |
426 | struct module *me; | |
427 | }; | |
428 | ||
429 | extern int ipt_register_target(struct ipt_target *target); | |
430 | extern void ipt_unregister_target(struct ipt_target *target); | |
431 | ||
432 | extern int ipt_register_match(struct ipt_match *match); | |
433 | extern void ipt_unregister_match(struct ipt_match *match); | |
434 | ||
435 | /* Furniture shopping... */ | |
436 | struct ipt_table | |
437 | { | |
438 | struct list_head list; | |
439 | ||
440 | /* A unique name... */ | |
441 | char name[IPT_TABLE_MAXNAMELEN]; | |
442 | ||
443 | /* What hooks you will enter on */ | |
444 | unsigned int valid_hooks; | |
445 | ||
446 | /* Lock for the curtain */ | |
447 | rwlock_t lock; | |
448 | ||
449 | /* Man behind the curtain... */ | |
450 | struct ipt_table_info *private; | |
451 | ||
452 | /* Set to THIS_MODULE. */ | |
453 | struct module *me; | |
454 | }; | |
455 | ||
456 | /* net/sched/ipt.c: Gimme access to your targets! Gets target->me. */ | |
457 | extern struct ipt_target *ipt_find_target(const char *name, u8 revision); | |
458 | ||
459 | /* Standard entry. */ | |
460 | struct ipt_standard | |
461 | { | |
462 | struct ipt_entry entry; | |
463 | struct ipt_standard_target target; | |
464 | }; | |
465 | ||
466 | struct ipt_error_target | |
467 | { | |
468 | struct ipt_entry_target target; | |
469 | char errorname[IPT_FUNCTION_MAXNAMELEN]; | |
470 | }; | |
471 | ||
472 | struct ipt_error | |
473 | { | |
474 | struct ipt_entry entry; | |
475 | struct ipt_error_target target; | |
476 | }; | |
477 | ||
478 | extern int ipt_register_table(struct ipt_table *table, | |
479 | const struct ipt_replace *repl); | |
480 | extern void ipt_unregister_table(struct ipt_table *table); | |
481 | extern unsigned int ipt_do_table(struct sk_buff **pskb, | |
482 | unsigned int hook, | |
483 | const struct net_device *in, | |
484 | const struct net_device *out, | |
485 | struct ipt_table *table, | |
486 | void *userdata); | |
487 | ||
488 | #define IPT_ALIGN(s) (((s) + (__alignof__(struct ipt_entry)-1)) & ~(__alignof__(struct ipt_entry)-1)) | |
489 | #endif /*__KERNEL__*/ | |
490 | #endif /* _IPTABLES_H */ |