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 {
220 const struct xt_match *match;
226 * struct xt_target_param - parameters for target extensions' target functions
228 * @hooknum: hook through which this target was invoked
229 * @target: struct xt_target through which this function was invoked
230 * @targinfo: per-target data
232 * Other fields see above.
234 struct xt_target_param {
235 const struct net_device *in, *out;
236 const struct xt_target *target;
237 const void *targinfo;
238 unsigned int hooknum;
243 * struct xt_tgchk_param - parameters for target extensions'
244 * checkentry functions
246 * @entryinfo: the family-specific rule data
247 * (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
249 * Other fields see above.
251 struct xt_tgchk_param {
254 const void *entryinfo;
255 const struct xt_target *target;
257 unsigned int hook_mask;
261 /* Target destructor parameters */
262 struct xt_tgdtor_param {
264 const struct xt_target *target;
270 struct list_head list;
272 const char name[XT_FUNCTION_MAXNAMELEN-1];
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 *);
283 /* Called when user tries to insert an entry of this type. */
284 bool (*checkentry)(const struct xt_mtchk_param *);
286 /* Called when entry of this type deleted. */
287 void (*destroy)(const struct xt_mtdtor_param *);
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);
293 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
296 /* Free to use by each match */
300 unsigned int matchsize;
302 unsigned int compatsize;
305 unsigned short proto;
307 unsigned short family;
310 /* Registration hooks for targets. */
312 struct list_head list;
314 const char name[XT_FUNCTION_MAXNAMELEN-1];
316 /* Returns verdict. Argument order changed since 2.6.9, as this
317 must now handle non-linear skbs, using skb_copy_bits and
318 skb_ip_make_writable. */
319 unsigned int (*target)(struct sk_buff *skb,
320 const struct xt_target_param *);
322 /* Called when user tries to insert an entry of this type:
323 hook_mask is a bitmask of hooks from which it can be
325 /* Should return true or false. */
326 bool (*checkentry)(const struct xt_tgchk_param *);
328 /* Called when entry of this type deleted. */
329 void (*destroy)(const struct xt_tgdtor_param *);
331 /* Called when userspace align differs from kernel space one */
332 void (*compat_from_user)(void *dst, void *src);
333 int (*compat_to_user)(void __user *dst, void *src);
335 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
339 unsigned int targetsize;
341 unsigned int compatsize;
344 unsigned short proto;
346 unsigned short family;
350 /* Furniture shopping... */
352 struct list_head list;
354 /* What hooks you will enter on */
355 unsigned int valid_hooks;
357 /* Man behind the curtain... */
358 struct xt_table_info *private;
360 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
363 u_int8_t af; /* address/protocol family */
364 int priority; /* hook order */
366 /* A unique name... */
367 const char name[XT_TABLE_MAXNAMELEN];
370 #include <linux/netfilter_ipv4.h>
372 /* The table itself */
373 struct xt_table_info {
376 /* Number of entries: FIXME. --RR */
378 /* Initial number of entries. Needed for module usage count */
379 unsigned int initial_entries;
381 /* Entry points and underflows */
382 unsigned int hook_entry[NF_INET_NUMHOOKS];
383 unsigned int underflow[NF_INET_NUMHOOKS];
385 /* ipt_entry tables: one per CPU */
386 /* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */
390 #define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \
391 + nr_cpu_ids * sizeof(char *))
392 extern int xt_register_target(struct xt_target *target);
393 extern void xt_unregister_target(struct xt_target *target);
394 extern int xt_register_targets(struct xt_target *target, unsigned int n);
395 extern void xt_unregister_targets(struct xt_target *target, unsigned int n);
397 extern int xt_register_match(struct xt_match *target);
398 extern void xt_unregister_match(struct xt_match *target);
399 extern int xt_register_matches(struct xt_match *match, unsigned int n);
400 extern void xt_unregister_matches(struct xt_match *match, unsigned int n);
402 extern int xt_check_match(struct xt_mtchk_param *,
403 unsigned int size, u_int8_t proto, bool inv_proto);
404 extern int xt_check_target(struct xt_tgchk_param *,
405 unsigned int size, u_int8_t proto, bool inv_proto);
407 extern struct xt_table *xt_register_table(struct net *net,
408 const struct xt_table *table,
409 struct xt_table_info *bootstrap,
410 struct xt_table_info *newinfo);
411 extern void *xt_unregister_table(struct xt_table *table);
413 extern struct xt_table_info *xt_replace_table(struct xt_table *table,
414 unsigned int num_counters,
415 struct xt_table_info *newinfo,
418 extern struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
419 extern struct xt_target *xt_find_target(u8 af, const char *name, u8 revision);
420 extern struct xt_target *xt_request_find_target(u8 af, const char *name,
422 extern int xt_find_revision(u8 af, const char *name, u8 revision,
423 int target, int *err);
425 extern struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
427 extern void xt_table_unlock(struct xt_table *t);
429 extern int xt_proto_init(struct net *net, u_int8_t af);
430 extern void xt_proto_fini(struct net *net, u_int8_t af);
432 extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
433 extern void xt_free_table_info(struct xt_table_info *info);
436 * Per-CPU spinlock associated with per-cpu table entries, and
437 * with a counter for the "reading" side that allows a recursive
438 * reader to avoid taking the lock and deadlocking.
440 * "reading" is used by ip/arp/ip6 tables rule processing which runs per-cpu.
441 * It needs to ensure that the rules are not being changed while the packet
442 * is being processed. In some cases, the read lock will be acquired
443 * twice on the same CPU; this is okay because of the count.
445 * "writing" is used when reading counters.
446 * During replace any readers that are using the old tables have to complete
447 * before freeing the old table. This is handled by the write locking
448 * necessary for reading the counters.
450 struct xt_info_lock {
452 unsigned char readers;
454 DECLARE_PER_CPU(struct xt_info_lock, xt_info_locks);
457 * Note: we need to ensure that preemption is disabled before acquiring
458 * the per-cpu-variable, so we do it as a two step process rather than
459 * using "spin_lock_bh()".
461 * We _also_ need to disable bottom half processing before updating our
462 * nesting count, to make sure that the only kind of re-entrancy is this
463 * code being called by itself: since the count+lock is not an atomic
464 * operation, we can allow no races.
466 * _Only_ that special combination of being per-cpu and never getting
467 * re-entered asynchronously means that the count is safe.
469 static inline void xt_info_rdlock_bh(void)
471 struct xt_info_lock *lock;
474 lock = &__get_cpu_var(xt_info_locks);
475 if (likely(!lock->readers++))
476 spin_lock(&lock->lock);
479 static inline void xt_info_rdunlock_bh(void)
481 struct xt_info_lock *lock = &__get_cpu_var(xt_info_locks);
483 if (likely(!--lock->readers))
484 spin_unlock(&lock->lock);
489 * The "writer" side needs to get exclusive access to the lock,
490 * regardless of readers. This must be called with bottom half
491 * processing (and thus also preemption) disabled.
493 static inline void xt_info_wrlock(unsigned int cpu)
495 spin_lock(&per_cpu(xt_info_locks, cpu).lock);
498 static inline void xt_info_wrunlock(unsigned int cpu)
500 spin_unlock(&per_cpu(xt_info_locks, cpu).lock);
504 * This helper is performance critical and must be inlined
506 static inline unsigned long ifname_compare_aligned(const char *_a,
510 const unsigned long *a = (const unsigned long *)_a;
511 const unsigned long *b = (const unsigned long *)_b;
512 const unsigned long *mask = (const unsigned long *)_mask;
515 ret = (a[0] ^ b[0]) & mask[0];
516 if (IFNAMSIZ > sizeof(unsigned long))
517 ret |= (a[1] ^ b[1]) & mask[1];
518 if (IFNAMSIZ > 2 * sizeof(unsigned long))
519 ret |= (a[2] ^ b[2]) & mask[2];
520 if (IFNAMSIZ > 3 * sizeof(unsigned long))
521 ret |= (a[3] ^ b[3]) & mask[3];
522 BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
526 extern struct nf_hook_ops *xt_hook_link(const struct xt_table *, nf_hookfn *);
527 extern void xt_hook_unlink(const struct xt_table *, struct nf_hook_ops *);
530 #include <net/compat.h>
532 struct compat_xt_entry_match {
535 u_int16_t match_size;
536 char name[XT_FUNCTION_MAXNAMELEN - 1];
540 u_int16_t match_size;
543 u_int16_t match_size;
545 unsigned char data[0];
548 struct compat_xt_entry_target {
551 u_int16_t target_size;
552 char name[XT_FUNCTION_MAXNAMELEN - 1];
556 u_int16_t target_size;
557 compat_uptr_t target;
559 u_int16_t target_size;
561 unsigned char data[0];
564 /* FIXME: this works only on 32 bit tasks
565 * need to change whole approach in order to calculate align as function of
566 * current task alignment */
568 struct compat_xt_counters {
569 #if defined(CONFIG_X86_64) || defined(CONFIG_IA64)
576 struct compat_xt_counters_info {
577 char name[XT_TABLE_MAXNAMELEN];
578 compat_uint_t num_counters;
579 struct compat_xt_counters counters[0];
582 #define COMPAT_XT_ALIGN(s) (((s) + (__alignof__(struct compat_xt_counters)-1)) \
583 & ~(__alignof__(struct compat_xt_counters)-1))
585 extern void xt_compat_lock(u_int8_t af);
586 extern void xt_compat_unlock(u_int8_t af);
588 extern int xt_compat_add_offset(u_int8_t af, unsigned int offset, short delta);
589 extern void xt_compat_flush_offsets(u_int8_t af);
590 extern short xt_compat_calc_jump(u_int8_t af, unsigned int offset);
592 extern int xt_compat_match_offset(const struct xt_match *match);
593 extern int xt_compat_match_from_user(struct xt_entry_match *m,
594 void **dstptr, unsigned int *size);
595 extern int xt_compat_match_to_user(struct xt_entry_match *m,
596 void __user **dstptr, unsigned int *size);
598 extern int xt_compat_target_offset(const struct xt_target *target);
599 extern void xt_compat_target_from_user(struct xt_entry_target *t,
600 void **dstptr, unsigned int *size);
601 extern int xt_compat_target_to_user(struct xt_entry_target *t,
602 void __user **dstptr, unsigned int *size);
604 #endif /* CONFIG_COMPAT */
605 #endif /* __KERNEL__ */
607 #endif /* _X_TABLES_H */