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1 #ifndef _X_TABLES_H
2 #define _X_TABLES_H
3 
4 #define XT_FUNCTION_MAXNAMELEN 30
5 #define XT_TABLE_MAXNAMELEN 32
6 
7 struct xt_entry_match
8 {
9 	union {
10 		struct {
11 			u_int16_t match_size;
12 
13 			/* Used by userspace */
14 			char name[XT_FUNCTION_MAXNAMELEN-1];
15 
16 			u_int8_t revision;
17 		} user;
18 		struct {
19 			u_int16_t match_size;
20 
21 			/* Used inside the kernel */
22 			struct xt_match *match;
23 		} kernel;
24 
25 		/* Total length */
26 		u_int16_t match_size;
27 	} u;
28 
29 	unsigned char data[0];
30 };
31 
32 struct xt_entry_target
33 {
34 	union {
35 		struct {
36 			u_int16_t target_size;
37 
38 			/* Used by userspace */
39 			char name[XT_FUNCTION_MAXNAMELEN-1];
40 
41 			u_int8_t revision;
42 		} user;
43 		struct {
44 			u_int16_t target_size;
45 
46 			/* Used inside the kernel */
47 			struct xt_target *target;
48 		} kernel;
49 
50 		/* Total length */
51 		u_int16_t target_size;
52 	} u;
53 
54 	unsigned char data[0];
55 };
56 
57 #define XT_TARGET_INIT(__name, __size)					       \
58 {									       \
59 	.target.u.user = {						       \
60 		.target_size	= XT_ALIGN(__size),			       \
61 		.name		= __name,				       \
62 	},								       \
63 }
64 
65 struct xt_standard_target
66 {
67 	struct xt_entry_target target;
68 	int verdict;
69 };
70 
71 /* The argument to IPT_SO_GET_REVISION_*.  Returns highest revision
72  * kernel supports, if >= revision. */
73 struct xt_get_revision
74 {
75 	char name[XT_FUNCTION_MAXNAMELEN-1];
76 
77 	u_int8_t revision;
78 };
79 
80 /* CONTINUE verdict for targets */
81 #define XT_CONTINUE 0xFFFFFFFF
82 
83 /* For standard target */
84 #define XT_RETURN (-NF_REPEAT - 1)
85 
86 /* this is a dummy structure to find out the alignment requirement for a struct
87  * containing all the fundamental data types that are used in ipt_entry,
88  * ip6t_entry and arpt_entry.  This sucks, and it is a hack.  It will be my
89  * personal pleasure to remove it -HW
90  */
91 struct _xt_align
92 {
93 	u_int8_t u8;
94 	u_int16_t u16;
95 	u_int32_t u32;
96 	u_int64_t u64;
97 };
98 
99 #define XT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1)) 	\
100 			& ~(__alignof__(struct _xt_align)-1))
101 
102 /* Standard return verdict, or do jump. */
103 #define XT_STANDARD_TARGET ""
104 /* Error verdict. */
105 #define XT_ERROR_TARGET "ERROR"
106 
107 #define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0)
108 #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
109 
110 struct xt_counters
111 {
112 	u_int64_t pcnt, bcnt;			/* Packet and byte counters */
113 };
114 
115 /* The argument to IPT_SO_ADD_COUNTERS. */
116 struct xt_counters_info
117 {
118 	/* Which table. */
119 	char name[XT_TABLE_MAXNAMELEN];
120 
121 	unsigned int num_counters;
122 
123 	/* The counters (actually `number' of these). */
124 	struct xt_counters counters[0];
125 };
126 
127 #define XT_INV_PROTO		0x40	/* Invert the sense of PROTO. */
128 
129 /* fn returns 0 to continue iteration */
130 #define XT_MATCH_ITERATE(type, e, fn, args...)			\
131 ({								\
132 	unsigned int __i;					\
133 	int __ret = 0;						\
134 	struct xt_entry_match *__m;				\
135 								\
136 	for (__i = sizeof(type);				\
137 	     __i < (e)->target_offset;				\
138 	     __i += __m->u.match_size) {			\
139 		__m = (void *)e + __i;				\
140 								\
141 		__ret = fn(__m , ## args);			\
142 		if (__ret != 0)					\
143 			break;					\
144 	}							\
145 	__ret;							\
146 })
147 
148 /* fn returns 0 to continue iteration */
149 #define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
150 ({								\
151 	unsigned int __i, __n;					\
152 	int __ret = 0;						\
153 	type *__entry;						\
154 								\
155 	for (__i = 0, __n = 0; __i < (size);			\
156 	     __i += __entry->next_offset, __n++) { 		\
157 		__entry = (void *)(entries) + __i;		\
158 		if (__n < n)					\
159 			continue;				\
160 								\
161 		__ret = fn(__entry , ## args);			\
162 		if (__ret != 0)					\
163 			break;					\
164 	}							\
165 	__ret;							\
166 })
167 
168 /* fn returns 0 to continue iteration */
169 #define XT_ENTRY_ITERATE(type, entries, size, fn, args...) \
170 	XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args)
171 
172 #ifdef __KERNEL__
173 
174 #include <linux/netdevice.h>
175 
176 /**
177  * struct xt_match_param - parameters for match extensions' match functions
178  *
179  * @in:		input netdevice
180  * @out:	output netdevice
181  * @match:	struct xt_match through which this function was invoked
182  * @matchinfo:	per-match data
183  * @fragoff:	packet is a fragment, this is the data offset
184  * @thoff:	position of transport header relative to skb->data
185  * @hotdrop:	drop packet if we had inspection problems
186  * @family:	Actual NFPROTO_* through which the function is invoked
187  * 		(helpful when match->family == NFPROTO_UNSPEC)
188  */
189 struct xt_match_param {
190 	const struct net_device *in, *out;
191 	const struct xt_match *match;
192 	const void *matchinfo;
193 	int fragoff;
194 	unsigned int thoff;
195 	bool *hotdrop;
196 	u_int8_t family;
197 };
198 
199 /**
200  * struct xt_mtchk_param - parameters for match extensions'
201  * checkentry functions
202  *
203  * @table:	table the rule is tried to be inserted into
204  * @entryinfo:	the family-specific rule data
205  * 		(struct ipt_ip, ip6t_ip, ebt_entry)
206  * @match:	struct xt_match through which this function was invoked
207  * @matchinfo:	per-match data
208  * @hook_mask:	via which hooks the new rule is reachable
209  */
210 struct xt_mtchk_param {
211 	const char *table;
212 	const void *entryinfo;
213 	const struct xt_match *match;
214 	void *matchinfo;
215 	unsigned int hook_mask;
216 	u_int8_t family;
217 };
218 
219 /* Match destructor parameters */
220 struct xt_mtdtor_param {
221 	const struct xt_match *match;
222 	void *matchinfo;
223 	u_int8_t family;
224 };
225 
226 /**
227  * struct xt_target_param - parameters for target extensions' target functions
228  *
229  * @hooknum:	hook through which this target was invoked
230  * @target:	struct xt_target through which this function was invoked
231  * @targinfo:	per-target data
232  *
233  * Other fields see above.
234  */
235 struct xt_target_param {
236 	const struct net_device *in, *out;
237 	unsigned int hooknum;
238 	const struct xt_target *target;
239 	const void *targinfo;
240 	u_int8_t family;
241 };
242 
243 /**
244  * struct xt_tgchk_param - parameters for target extensions'
245  * checkentry functions
246  *
247  * @entryinfo:	the family-specific rule data
248  * 		(struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
249  *
250  * Other fields see above.
251  */
252 struct xt_tgchk_param {
253 	const char *table;
254 	const void *entryinfo;
255 	const struct xt_target *target;
256 	void *targinfo;
257 	unsigned int hook_mask;
258 	u_int8_t family;
259 };
260 
261 /* Target destructor parameters */
262 struct xt_tgdtor_param {
263 	const struct xt_target *target;
264 	void *targinfo;
265 	u_int8_t family;
266 };
267 
268 struct xt_match
269 {
270 	struct list_head list;
271 
272 	const char name[XT_FUNCTION_MAXNAMELEN-1];
273 	u_int8_t revision;
274 
275 	/* Return true or false: return FALSE and set *hotdrop = 1 to
276            force immediate packet drop. */
277 	/* Arguments changed since 2.6.9, as this must now handle
278 	   non-linear skb, using skb_header_pointer and
279 	   skb_ip_make_writable. */
280 	bool (*match)(const struct sk_buff *skb,
281 		      const struct xt_match_param *);
282 
283 	/* Called when user tries to insert an entry of this type. */
284 	bool (*checkentry)(const struct xt_mtchk_param *);
285 
286 	/* Called when entry of this type deleted. */
287 	void (*destroy)(const struct xt_mtdtor_param *);
288 
289 	/* Called when userspace align differs from kernel space one */
290 	void (*compat_from_user)(void *dst, void *src);
291 	int (*compat_to_user)(void __user *dst, void *src);
292 
293 	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
294 	struct module *me;
295 
296 	/* Free to use by each match */
297 	unsigned long data;
298 
299 	const char *table;
300 	unsigned int matchsize;
301 	unsigned int compatsize;
302 	unsigned int hooks;
303 	unsigned short proto;
304 
305 	unsigned short family;
306 };
307 
308 /* Registration hooks for targets. */
309 struct xt_target
310 {
311 	struct list_head list;
312 
313 	const char name[XT_FUNCTION_MAXNAMELEN-1];
314 
315 	/* Returns verdict. Argument order changed since 2.6.9, as this
316 	   must now handle non-linear skbs, using skb_copy_bits and
317 	   skb_ip_make_writable. */
318 	unsigned int (*target)(struct sk_buff *skb,
319 			       const struct xt_target_param *);
320 
321 	/* Called when user tries to insert an entry of this type:
322            hook_mask is a bitmask of hooks from which it can be
323            called. */
324 	/* Should return true or false. */
325 	bool (*checkentry)(const struct xt_tgchk_param *);
326 
327 	/* Called when entry of this type deleted. */
328 	void (*destroy)(const struct xt_tgdtor_param *);
329 
330 	/* Called when userspace align differs from kernel space one */
331 	void (*compat_from_user)(void *dst, void *src);
332 	int (*compat_to_user)(void __user *dst, void *src);
333 
334 	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
335 	struct module *me;
336 
337 	const char *table;
338 	unsigned int targetsize;
339 	unsigned int compatsize;
340 	unsigned int hooks;
341 	unsigned short proto;
342 
343 	unsigned short family;
344 	u_int8_t revision;
345 };
346 
347 /* Furniture shopping... */
348 struct xt_table
349 {
350 	struct list_head list;
351 
352 	/* A unique name... */
353 	const char name[XT_TABLE_MAXNAMELEN];
354 
355 	/* What hooks you will enter on */
356 	unsigned int valid_hooks;
357 
358 	/* Lock for the curtain */
359 	rwlock_t lock;
360 
361 	/* Man behind the curtain... */
362 	//struct ip6t_table_info *private;
363 	void *private;
364 
365 	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
366 	struct module *me;
367 
368 	u_int8_t af;		/* address/protocol family */
369 };
370 
371 #include <linux/netfilter_ipv4.h>
372 
373 /* The table itself */
374 struct xt_table_info
375 {
376 	/* Size per table */
377 	unsigned int size;
378 	/* Number of entries: FIXME. --RR */
379 	unsigned int number;
380 	/* Initial number of entries. Needed for module usage count */
381 	unsigned int initial_entries;
382 
383 	/* Entry points and underflows */
384 	unsigned int hook_entry[NF_INET_NUMHOOKS];
385 	unsigned int underflow[NF_INET_NUMHOOKS];
386 
387 	/* ipt_entry tables: one per CPU */
388 	/* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */
389 	char *entries[1];
390 };
391 
392 #define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \
393 			  + nr_cpu_ids * sizeof(char *))
394 extern int xt_register_target(struct xt_target *target);
395 extern void xt_unregister_target(struct xt_target *target);
396 extern int xt_register_targets(struct xt_target *target, unsigned int n);
397 extern void xt_unregister_targets(struct xt_target *target, unsigned int n);
398 
399 extern int xt_register_match(struct xt_match *target);
400 extern void xt_unregister_match(struct xt_match *target);
401 extern int xt_register_matches(struct xt_match *match, unsigned int n);
402 extern void xt_unregister_matches(struct xt_match *match, unsigned int n);
403 
404 extern int xt_check_match(struct xt_mtchk_param *,
405 			  unsigned int size, u_int8_t proto, bool inv_proto);
406 extern int xt_check_target(struct xt_tgchk_param *,
407 			   unsigned int size, u_int8_t proto, bool inv_proto);
408 
409 extern struct xt_table *xt_register_table(struct net *net,
410 					  struct xt_table *table,
411 					  struct xt_table_info *bootstrap,
412 					  struct xt_table_info *newinfo);
413 extern void *xt_unregister_table(struct xt_table *table);
414 
415 extern struct xt_table_info *xt_replace_table(struct xt_table *table,
416 					      unsigned int num_counters,
417 					      struct xt_table_info *newinfo,
418 					      int *error);
419 
420 extern struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
421 extern struct xt_target *xt_find_target(u8 af, const char *name, u8 revision);
422 extern struct xt_target *xt_request_find_target(u8 af, const char *name,
423 						u8 revision);
424 extern int xt_find_revision(u8 af, const char *name, u8 revision,
425 			    int target, int *err);
426 
427 extern struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
428 					   const char *name);
429 extern void xt_table_unlock(struct xt_table *t);
430 
431 extern int xt_proto_init(struct net *net, u_int8_t af);
432 extern void xt_proto_fini(struct net *net, u_int8_t af);
433 
434 extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
435 extern void xt_free_table_info(struct xt_table_info *info);
436 
437 #ifdef CONFIG_COMPAT
438 #include <net/compat.h>
439 
440 struct compat_xt_entry_match
441 {
442 	union {
443 		struct {
444 			u_int16_t match_size;
445 			char name[XT_FUNCTION_MAXNAMELEN - 1];
446 			u_int8_t revision;
447 		} user;
448 		struct {
449 			u_int16_t match_size;
450 			compat_uptr_t match;
451 		} kernel;
452 		u_int16_t match_size;
453 	} u;
454 	unsigned char data[0];
455 };
456 
457 struct compat_xt_entry_target
458 {
459 	union {
460 		struct {
461 			u_int16_t target_size;
462 			char name[XT_FUNCTION_MAXNAMELEN - 1];
463 			u_int8_t revision;
464 		} user;
465 		struct {
466 			u_int16_t target_size;
467 			compat_uptr_t target;
468 		} kernel;
469 		u_int16_t target_size;
470 	} u;
471 	unsigned char data[0];
472 };
473 
474 /* FIXME: this works only on 32 bit tasks
475  * need to change whole approach in order to calculate align as function of
476  * current task alignment */
477 
478 struct compat_xt_counters
479 {
480 #if defined(CONFIG_X86_64) || defined(CONFIG_IA64)
481 	u_int32_t cnt[4];
482 #else
483 	u_int64_t cnt[2];
484 #endif
485 };
486 
487 struct compat_xt_counters_info
488 {
489 	char name[XT_TABLE_MAXNAMELEN];
490 	compat_uint_t num_counters;
491 	struct compat_xt_counters counters[0];
492 };
493 
494 #define COMPAT_XT_ALIGN(s) (((s) + (__alignof__(struct compat_xt_counters)-1)) \
495 		& ~(__alignof__(struct compat_xt_counters)-1))
496 
497 extern void xt_compat_lock(u_int8_t af);
498 extern void xt_compat_unlock(u_int8_t af);
499 
500 extern int xt_compat_add_offset(u_int8_t af, unsigned int offset, short delta);
501 extern void xt_compat_flush_offsets(u_int8_t af);
502 extern short xt_compat_calc_jump(u_int8_t af, unsigned int offset);
503 
504 extern int xt_compat_match_offset(const struct xt_match *match);
505 extern int xt_compat_match_from_user(struct xt_entry_match *m,
506 				     void **dstptr, unsigned int *size);
507 extern int xt_compat_match_to_user(struct xt_entry_match *m,
508 				   void __user **dstptr, unsigned int *size);
509 
510 extern int xt_compat_target_offset(const struct xt_target *target);
511 extern void xt_compat_target_from_user(struct xt_entry_target *t,
512 				       void **dstptr, unsigned int *size);
513 extern int xt_compat_target_to_user(struct xt_entry_target *t,
514 				    void __user **dstptr, unsigned int *size);
515 
516 #endif /* CONFIG_COMPAT */
517 #endif /* __KERNEL__ */
518 
519 #endif /* _X_TABLES_H */
520