4 #include <linux/types.h>
6 #define XT_FUNCTION_MAXNAMELEN 30
7 #define XT_TABLE_MAXNAMELEN 32
9 struct xt_entry_match {
14 /* Used by userspace */
15 char name[XT_FUNCTION_MAXNAMELEN-1];
22 /* Used inside the kernel */
23 struct xt_match *match;
30 unsigned char data[0];
33 struct xt_entry_target {
38 /* Used by userspace */
39 char name[XT_FUNCTION_MAXNAMELEN-1];
46 /* Used inside the kernel */
47 struct xt_target *target;
54 unsigned char data[0];
57 #define XT_TARGET_INIT(__name, __size) \
60 .target_size = XT_ALIGN(__size), \
65 struct xt_standard_target {
66 struct xt_entry_target target;
70 /* The argument to IPT_SO_GET_REVISION_*. Returns highest revision
71 * kernel supports, if >= revision. */
72 struct xt_get_revision {
73 char name[XT_FUNCTION_MAXNAMELEN-1];
78 /* CONTINUE verdict for targets */
79 #define XT_CONTINUE 0xFFFFFFFF
81 /* For standard target */
82 #define XT_RETURN (-NF_REPEAT - 1)
84 /* this is a dummy structure to find out the alignment requirement for a struct
85 * containing all the fundamental data types that are used in ipt_entry,
86 * ip6t_entry and arpt_entry. This sucks, and it is a hack. It will be my
87 * personal pleasure to remove it -HW
96 #define XT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1)) \
97 & ~(__alignof__(struct _xt_align)-1))
99 /* Standard return verdict, or do jump. */
100 #define XT_STANDARD_TARGET ""
102 #define XT_ERROR_TARGET "ERROR"
104 #define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0)
105 #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
108 __u64 pcnt, bcnt; /* Packet and byte counters */
111 /* The argument to IPT_SO_ADD_COUNTERS. */
112 struct xt_counters_info {
114 char name[XT_TABLE_MAXNAMELEN];
116 unsigned int num_counters;
118 /* The counters (actually `number' of these). */
119 struct xt_counters counters[0];
122 #define XT_INV_PROTO 0x40 /* Invert the sense of PROTO. */
124 /* fn returns 0 to continue iteration */
125 #define XT_MATCH_ITERATE(type, e, fn, args...) \
129 struct xt_entry_match *__m; \
131 for (__i = sizeof(type); \
132 __i < (e)->target_offset; \
133 __i += __m->u.match_size) { \
134 __m = (void *)e + __i; \
136 __ret = fn(__m , ## args); \
143 /* fn returns 0 to continue iteration */
144 #define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
146 unsigned int __i, __n; \
150 for (__i = 0, __n = 0; __i < (size); \
151 __i += __entry->next_offset, __n++) { \
152 __entry = (void *)(entries) + __i; \
156 __ret = fn(__entry , ## args); \
163 /* fn returns 0 to continue iteration */
164 #define XT_ENTRY_ITERATE(type, entries, size, fn, args...) \
165 XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args)
169 #include <linux/netdevice.h>
172 * struct xt_match_param - parameters for match extensions' match functions
174 * @in: input netdevice
175 * @out: output netdevice
176 * @match: struct xt_match through which this function was invoked
177 * @matchinfo: per-match data
178 * @fragoff: packet is a fragment, this is the data offset
179 * @thoff: position of transport header relative to skb->data
180 * @hook: hook number given packet came from
181 * @family: Actual NFPROTO_* through which the function is invoked
182 * (helpful when match->family == NFPROTO_UNSPEC)
183 * @hotdrop: drop packet if we had inspection problems
185 struct xt_match_param {
186 const struct net_device *in, *out;
187 const struct xt_match *match;
188 const void *matchinfo;
191 unsigned int hooknum;
197 * struct xt_mtchk_param - parameters for match extensions'
198 * checkentry functions
200 * @table: table the rule is tried to be inserted into
201 * @entryinfo: the family-specific rule data
202 * (struct ipt_ip, ip6t_ip, ebt_entry)
203 * @match: struct xt_match through which this function was invoked
204 * @matchinfo: per-match data
205 * @hook_mask: via which hooks the new rule is reachable
207 struct xt_mtchk_param {
210 const void *entryinfo;
211 const struct xt_match *match;
213 unsigned int hook_mask;
217 /* Match destructor parameters */
218 struct xt_mtdtor_param {
219 const struct xt_match *match;
225 * struct xt_target_param - parameters for target extensions' target functions
227 * @hooknum: hook through which this target was invoked
228 * @target: struct xt_target through which this function was invoked
229 * @targinfo: per-target data
231 * Other fields see above.
233 struct xt_target_param {
234 const struct net_device *in, *out;
235 const struct xt_target *target;
236 const void *targinfo;
237 unsigned int hooknum;
242 * struct xt_tgchk_param - parameters for target extensions'
243 * checkentry functions
245 * @entryinfo: the family-specific rule data
246 * (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
248 * Other fields see above.
250 struct xt_tgchk_param {
252 const void *entryinfo;
253 const struct xt_target *target;
255 unsigned int hook_mask;
259 /* Target destructor parameters */
260 struct xt_tgdtor_param {
261 const struct xt_target *target;
267 struct list_head list;
269 const char name[XT_FUNCTION_MAXNAMELEN-1];
272 /* Return true or false: return FALSE and set *hotdrop = 1 to
273 force immediate packet drop. */
274 /* Arguments changed since 2.6.9, as this must now handle
275 non-linear skb, using skb_header_pointer and
276 skb_ip_make_writable. */
277 bool (*match)(const struct sk_buff *skb,
278 const struct xt_match_param *);
280 /* Called when user tries to insert an entry of this type. */
281 bool (*checkentry)(const struct xt_mtchk_param *);
283 /* Called when entry of this type deleted. */
284 void (*destroy)(const struct xt_mtdtor_param *);
286 /* Called when userspace align differs from kernel space one */
287 void (*compat_from_user)(void *dst, void *src);
288 int (*compat_to_user)(void __user *dst, void *src);
290 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
293 /* Free to use by each match */
297 unsigned int matchsize;
298 unsigned int compatsize;
300 unsigned short proto;
302 unsigned short family;
305 /* Registration hooks for targets. */
307 struct list_head list;
309 const char name[XT_FUNCTION_MAXNAMELEN-1];
311 /* Returns verdict. Argument order changed since 2.6.9, as this
312 must now handle non-linear skbs, using skb_copy_bits and
313 skb_ip_make_writable. */
314 unsigned int (*target)(struct sk_buff *skb,
315 const struct xt_target_param *);
317 /* Called when user tries to insert an entry of this type:
318 hook_mask is a bitmask of hooks from which it can be
320 /* Should return true or false. */
321 bool (*checkentry)(const struct xt_tgchk_param *);
323 /* Called when entry of this type deleted. */
324 void (*destroy)(const struct xt_tgdtor_param *);
326 /* Called when userspace align differs from kernel space one */
327 void (*compat_from_user)(void *dst, void *src);
328 int (*compat_to_user)(void __user *dst, void *src);
330 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
334 unsigned int targetsize;
335 unsigned int compatsize;
337 unsigned short proto;
339 unsigned short family;
343 /* Furniture shopping... */
345 struct list_head list;
347 /* What hooks you will enter on */
348 unsigned int valid_hooks;
350 /* Man behind the curtain... */
351 struct xt_table_info *private;
353 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
356 u_int8_t af; /* address/protocol family */
358 /* A unique name... */
359 const char name[XT_TABLE_MAXNAMELEN];
362 #include <linux/netfilter_ipv4.h>
364 /* The table itself */
365 struct xt_table_info {
368 /* Number of entries: FIXME. --RR */
370 /* Initial number of entries. Needed for module usage count */
371 unsigned int initial_entries;
373 /* Entry points and underflows */
374 unsigned int hook_entry[NF_INET_NUMHOOKS];
375 unsigned int underflow[NF_INET_NUMHOOKS];
377 /* ipt_entry tables: one per CPU */
378 /* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */
382 #define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \
383 + nr_cpu_ids * sizeof(char *))
384 extern int xt_register_target(struct xt_target *target);
385 extern void xt_unregister_target(struct xt_target *target);
386 extern int xt_register_targets(struct xt_target *target, unsigned int n);
387 extern void xt_unregister_targets(struct xt_target *target, unsigned int n);
389 extern int xt_register_match(struct xt_match *target);
390 extern void xt_unregister_match(struct xt_match *target);
391 extern int xt_register_matches(struct xt_match *match, unsigned int n);
392 extern void xt_unregister_matches(struct xt_match *match, unsigned int n);
394 extern int xt_check_match(struct xt_mtchk_param *,
395 unsigned int size, u_int8_t proto, bool inv_proto);
396 extern int xt_check_target(struct xt_tgchk_param *,
397 unsigned int size, u_int8_t proto, bool inv_proto);
399 extern struct xt_table *xt_register_table(struct net *net,
400 const struct xt_table *table,
401 struct xt_table_info *bootstrap,
402 struct xt_table_info *newinfo);
403 extern void *xt_unregister_table(struct xt_table *table);
405 extern struct xt_table_info *xt_replace_table(struct xt_table *table,
406 unsigned int num_counters,
407 struct xt_table_info *newinfo,
410 extern struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
411 extern struct xt_target *xt_find_target(u8 af, const char *name, u8 revision);
412 extern struct xt_target *xt_request_find_target(u8 af, const char *name,
414 extern int xt_find_revision(u8 af, const char *name, u8 revision,
415 int target, int *err);
417 extern struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
419 extern void xt_table_unlock(struct xt_table *t);
421 extern int xt_proto_init(struct net *net, u_int8_t af);
422 extern void xt_proto_fini(struct net *net, u_int8_t af);
424 extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
425 extern void xt_free_table_info(struct xt_table_info *info);
428 * Per-CPU spinlock associated with per-cpu table entries, and
429 * with a counter for the "reading" side that allows a recursive
430 * reader to avoid taking the lock and deadlocking.
432 * "reading" is used by ip/arp/ip6 tables rule processing which runs per-cpu.
433 * It needs to ensure that the rules are not being changed while the packet
434 * is being processed. In some cases, the read lock will be acquired
435 * twice on the same CPU; this is okay because of the count.
437 * "writing" is used when reading counters.
438 * During replace any readers that are using the old tables have to complete
439 * before freeing the old table. This is handled by the write locking
440 * necessary for reading the counters.
442 struct xt_info_lock {
444 unsigned char readers;
446 DECLARE_PER_CPU(struct xt_info_lock, xt_info_locks);
449 * Note: we need to ensure that preemption is disabled before acquiring
450 * the per-cpu-variable, so we do it as a two step process rather than
451 * using "spin_lock_bh()".
453 * We _also_ need to disable bottom half processing before updating our
454 * nesting count, to make sure that the only kind of re-entrancy is this
455 * code being called by itself: since the count+lock is not an atomic
456 * operation, we can allow no races.
458 * _Only_ that special combination of being per-cpu and never getting
459 * re-entered asynchronously means that the count is safe.
461 static inline void xt_info_rdlock_bh(void)
463 struct xt_info_lock *lock;
466 lock = &__get_cpu_var(xt_info_locks);
467 if (likely(!lock->readers++))
468 spin_lock(&lock->lock);
471 static inline void xt_info_rdunlock_bh(void)
473 struct xt_info_lock *lock = &__get_cpu_var(xt_info_locks);
475 if (likely(!--lock->readers))
476 spin_unlock(&lock->lock);
481 * The "writer" side needs to get exclusive access to the lock,
482 * regardless of readers. This must be called with bottom half
483 * processing (and thus also preemption) disabled.
485 static inline void xt_info_wrlock(unsigned int cpu)
487 spin_lock(&per_cpu(xt_info_locks, cpu).lock);
490 static inline void xt_info_wrunlock(unsigned int cpu)
492 spin_unlock(&per_cpu(xt_info_locks, cpu).lock);
496 * This helper is performance critical and must be inlined
498 static inline unsigned long ifname_compare_aligned(const char *_a,
502 const unsigned long *a = (const unsigned long *)_a;
503 const unsigned long *b = (const unsigned long *)_b;
504 const unsigned long *mask = (const unsigned long *)_mask;
507 ret = (a[0] ^ b[0]) & mask[0];
508 if (IFNAMSIZ > sizeof(unsigned long))
509 ret |= (a[1] ^ b[1]) & mask[1];
510 if (IFNAMSIZ > 2 * sizeof(unsigned long))
511 ret |= (a[2] ^ b[2]) & mask[2];
512 if (IFNAMSIZ > 3 * sizeof(unsigned long))
513 ret |= (a[3] ^ b[3]) & mask[3];
514 BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
519 #include <net/compat.h>
521 struct compat_xt_entry_match {
524 u_int16_t match_size;
525 char name[XT_FUNCTION_MAXNAMELEN - 1];
529 u_int16_t match_size;
532 u_int16_t match_size;
534 unsigned char data[0];
537 struct compat_xt_entry_target {
540 u_int16_t target_size;
541 char name[XT_FUNCTION_MAXNAMELEN - 1];
545 u_int16_t target_size;
546 compat_uptr_t target;
548 u_int16_t target_size;
550 unsigned char data[0];
553 /* FIXME: this works only on 32 bit tasks
554 * need to change whole approach in order to calculate align as function of
555 * current task alignment */
557 struct compat_xt_counters {
558 #if defined(CONFIG_X86_64) || defined(CONFIG_IA64)
565 struct compat_xt_counters_info {
566 char name[XT_TABLE_MAXNAMELEN];
567 compat_uint_t num_counters;
568 struct compat_xt_counters counters[0];
571 #define COMPAT_XT_ALIGN(s) (((s) + (__alignof__(struct compat_xt_counters)-1)) \
572 & ~(__alignof__(struct compat_xt_counters)-1))
574 extern void xt_compat_lock(u_int8_t af);
575 extern void xt_compat_unlock(u_int8_t af);
577 extern int xt_compat_add_offset(u_int8_t af, unsigned int offset, short delta);
578 extern void xt_compat_flush_offsets(u_int8_t af);
579 extern short xt_compat_calc_jump(u_int8_t af, unsigned int offset);
581 extern int xt_compat_match_offset(const struct xt_match *match);
582 extern int xt_compat_match_from_user(struct xt_entry_match *m,
583 void **dstptr, unsigned int *size);
584 extern int xt_compat_match_to_user(struct xt_entry_match *m,
585 void __user **dstptr, unsigned int *size);
587 extern int xt_compat_target_offset(const struct xt_target *target);
588 extern void xt_compat_target_from_user(struct xt_entry_target *t,
589 void **dstptr, unsigned int *size);
590 extern int xt_compat_target_to_user(struct xt_entry_target *t,
591 void __user **dstptr, unsigned int *size);
593 #endif /* CONFIG_COMPAT */
594 #endif /* __KERNEL__ */
596 #endif /* _X_TABLES_H */