3 #include <linux/kernel.h>
4 #include <linux/types.h>
6 #define XT_FUNCTION_MAXNAMELEN 30
7 #define XT_EXTENSION_MAXNAMELEN 29
8 #define XT_TABLE_MAXNAMELEN 32
10 struct xt_entry_match {
15 /* Used by userspace */
16 char name[XT_EXTENSION_MAXNAMELEN];
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_EXTENSION_MAXNAMELEN];
45 /* Used inside the kernel */
46 struct xt_target *target;
53 unsigned char data[0];
56 #define XT_TARGET_INIT(__name, __size) \
59 .target_size = XT_ALIGN(__size), \
64 struct xt_standard_target {
65 struct xt_entry_target target;
69 /* The argument to IPT_SO_GET_REVISION_*. Returns highest revision
70 * kernel supports, if >= revision. */
71 struct xt_get_revision {
72 char name[XT_EXTENSION_MAXNAMELEN];
76 /* CONTINUE verdict for targets */
77 #define XT_CONTINUE 0xFFFFFFFF
79 /* For standard target */
80 #define XT_RETURN (-NF_REPEAT - 1)
82 /* this is a dummy structure to find out the alignment requirement for a struct
83 * containing all the fundamental data types that are used in ipt_entry,
84 * ip6t_entry and arpt_entry. This sucks, and it is a hack. It will be my
85 * personal pleasure to remove it -HW
94 #define XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _xt_align))
96 /* Standard return verdict, or do jump. */
97 #define XT_STANDARD_TARGET ""
99 #define XT_ERROR_TARGET "ERROR"
101 #define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0)
102 #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
105 __u64 pcnt, bcnt; /* Packet and byte counters */
108 /* The argument to IPT_SO_ADD_COUNTERS. */
109 struct xt_counters_info {
111 char name[XT_TABLE_MAXNAMELEN];
113 unsigned int num_counters;
115 /* The counters (actually `number' of these). */
116 struct xt_counters counters[0];
119 #define XT_INV_PROTO 0x40 /* Invert the sense of PROTO. */
122 /* fn returns 0 to continue iteration */
123 #define XT_MATCH_ITERATE(type, e, fn, args...) \
127 struct xt_entry_match *__m; \
129 for (__i = sizeof(type); \
130 __i < (e)->target_offset; \
131 __i += __m->u.match_size) { \
132 __m = (void *)e + __i; \
134 __ret = fn(__m , ## args); \
141 /* fn returns 0 to continue iteration */
142 #define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
144 unsigned int __i, __n; \
148 for (__i = 0, __n = 0; __i < (size); \
149 __i += __entry->next_offset, __n++) { \
150 __entry = (void *)(entries) + __i; \
154 __ret = fn(__entry , ## args); \
161 /* fn returns 0 to continue iteration */
162 #define XT_ENTRY_ITERATE(type, entries, size, fn, args...) \
163 XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args)
165 #endif /* !__KERNEL__ */
167 /* pos is normally a struct ipt_entry/ip6t_entry/etc. */
168 #define xt_entry_foreach(pos, ehead, esize) \
169 for ((pos) = (typeof(pos))(ehead); \
170 (pos) < (typeof(pos))((char *)(ehead) + (esize)); \
171 (pos) = (typeof(pos))((char *)(pos) + (pos)->next_offset))
173 /* can only be xt_entry_match, so no use of typeof here */
174 #define xt_ematch_foreach(pos, entry) \
175 for ((pos) = (struct xt_entry_match *)entry->elems; \
176 (pos) < (struct xt_entry_match *)((char *)(entry) + \
177 (entry)->target_offset); \
178 (pos) = (struct xt_entry_match *)((char *)(pos) + \
179 (pos)->u.match_size))
183 #include <linux/netdevice.h>
185 #define xt_match_param xt_action_param
186 #define xt_target_param xt_action_param
188 * struct xt_action_param - parameters for matches/targets
190 * @match: the match extension
191 * @target: the target extension
192 * @matchinfo: per-match data
193 * @targetinfo: per-target data
194 * @in: input netdevice
195 * @out: output netdevice
196 * @fragoff: packet is a fragment, this is the data offset
197 * @thoff: position of transport header relative to skb->data
198 * @hook: hook number given packet came from
199 * @family: Actual NFPROTO_* through which the function is invoked
200 * (helpful when match->family == NFPROTO_UNSPEC)
201 * @hotdrop: drop packet if we had inspection problems
202 * Network namespace obtainable using dev_net(in/out)
204 struct xt_action_param {
206 const struct xt_match *match;
207 const struct xt_target *target;
210 const void *matchinfo, *targinfo;
212 const struct net_device *in, *out;
215 unsigned int hooknum;
221 * struct xt_mtchk_param - parameters for match extensions'
222 * checkentry functions
224 * @net: network namespace through which the check was invoked
225 * @table: table the rule is tried to be inserted into
226 * @entryinfo: the family-specific rule data
227 * (struct ipt_ip, ip6t_ip, arpt_arp or (note) ebt_entry)
228 * @match: struct xt_match through which this function was invoked
229 * @matchinfo: per-match data
230 * @hook_mask: via which hooks the new rule is reachable
231 * Other fields as above.
233 struct xt_mtchk_param {
236 const void *entryinfo;
237 const struct xt_match *match;
239 unsigned int hook_mask;
244 * struct xt_mdtor_param - match destructor parameters
247 struct xt_mtdtor_param {
249 const struct xt_match *match;
255 * struct xt_tgchk_param - parameters for target extensions'
256 * checkentry functions
258 * @entryinfo: the family-specific rule data
259 * (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
261 * Other fields see above.
263 struct xt_tgchk_param {
266 const void *entryinfo;
267 const struct xt_target *target;
269 unsigned int hook_mask;
273 /* Target destructor parameters */
274 struct xt_tgdtor_param {
276 const struct xt_target *target;
282 struct list_head list;
284 const char name[XT_EXTENSION_MAXNAMELEN];
287 /* Return true or false: return FALSE and set *hotdrop = 1 to
288 force immediate packet drop. */
289 /* Arguments changed since 2.6.9, as this must now handle
290 non-linear skb, using skb_header_pointer and
291 skb_ip_make_writable. */
292 bool (*match)(const struct sk_buff *skb,
293 const struct xt_action_param *);
295 /* Called when user tries to insert an entry of this type. */
296 int (*checkentry)(const struct xt_mtchk_param *);
298 /* Called when entry of this type deleted. */
299 void (*destroy)(const struct xt_mtdtor_param *);
301 /* Called when userspace align differs from kernel space one */
302 void (*compat_from_user)(void *dst, const void *src);
303 int (*compat_to_user)(void __user *dst, const void *src);
305 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
309 unsigned int matchsize;
311 unsigned int compatsize;
314 unsigned short proto;
316 unsigned short family;
319 /* Registration hooks for targets. */
321 struct list_head list;
323 const char name[XT_EXTENSION_MAXNAMELEN];
326 /* Returns verdict. Argument order changed since 2.6.9, as this
327 must now handle non-linear skbs, using skb_copy_bits and
328 skb_ip_make_writable. */
329 unsigned int (*target)(struct sk_buff *skb,
330 const struct xt_action_param *);
332 /* Called when user tries to insert an entry of this type:
333 hook_mask is a bitmask of hooks from which it can be
335 /* Should return true or false, or an error code (-Exxxx). */
336 int (*checkentry)(const struct xt_tgchk_param *);
338 /* Called when entry of this type deleted. */
339 void (*destroy)(const struct xt_tgdtor_param *);
341 /* Called when userspace align differs from kernel space one */
342 void (*compat_from_user)(void *dst, const void *src);
343 int (*compat_to_user)(void __user *dst, const void *src);
345 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
349 unsigned int targetsize;
351 unsigned int compatsize;
354 unsigned short proto;
356 unsigned short family;
359 /* Furniture shopping... */
361 struct list_head list;
363 /* What hooks you will enter on */
364 unsigned int valid_hooks;
366 /* Man behind the curtain... */
367 struct xt_table_info *private;
369 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
372 u_int8_t af; /* address/protocol family */
373 int priority; /* hook order */
375 /* A unique name... */
376 const char name[XT_TABLE_MAXNAMELEN];
379 #include <linux/netfilter_ipv4.h>
381 /* The table itself */
382 struct xt_table_info {
385 /* Number of entries: FIXME. --RR */
387 /* Initial number of entries. Needed for module usage count */
388 unsigned int initial_entries;
390 /* Entry points and underflows */
391 unsigned int hook_entry[NF_INET_NUMHOOKS];
392 unsigned int underflow[NF_INET_NUMHOOKS];
395 * Number of user chains. Since tables cannot have loops, at most
396 * @stacksize jumps (number of user chains) can possibly be made.
398 unsigned int stacksize;
399 unsigned int *stackptr;
401 /* ipt_entry tables: one per CPU */
402 /* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */
406 #define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \
407 + nr_cpu_ids * sizeof(char *))
408 extern int xt_register_target(struct xt_target *target);
409 extern void xt_unregister_target(struct xt_target *target);
410 extern int xt_register_targets(struct xt_target *target, unsigned int n);
411 extern void xt_unregister_targets(struct xt_target *target, unsigned int n);
413 extern int xt_register_match(struct xt_match *target);
414 extern void xt_unregister_match(struct xt_match *target);
415 extern int xt_register_matches(struct xt_match *match, unsigned int n);
416 extern void xt_unregister_matches(struct xt_match *match, unsigned int n);
418 extern int xt_check_match(struct xt_mtchk_param *,
419 unsigned int size, u_int8_t proto, bool inv_proto);
420 extern int xt_check_target(struct xt_tgchk_param *,
421 unsigned int size, u_int8_t proto, bool inv_proto);
423 extern struct xt_table *xt_register_table(struct net *net,
424 const struct xt_table *table,
425 struct xt_table_info *bootstrap,
426 struct xt_table_info *newinfo);
427 extern void *xt_unregister_table(struct xt_table *table);
429 extern struct xt_table_info *xt_replace_table(struct xt_table *table,
430 unsigned int num_counters,
431 struct xt_table_info *newinfo,
434 extern struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
435 extern struct xt_target *xt_find_target(u8 af, const char *name, u8 revision);
436 extern struct xt_match *xt_request_find_match(u8 af, const char *name,
438 extern struct xt_target *xt_request_find_target(u8 af, const char *name,
440 extern int xt_find_revision(u8 af, const char *name, u8 revision,
441 int target, int *err);
443 extern struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
445 extern void xt_table_unlock(struct xt_table *t);
447 extern int xt_proto_init(struct net *net, u_int8_t af);
448 extern void xt_proto_fini(struct net *net, u_int8_t af);
450 extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
451 extern void xt_free_table_info(struct xt_table_info *info);
454 * Per-CPU spinlock associated with per-cpu table entries, and
455 * with a counter for the "reading" side that allows a recursive
456 * reader to avoid taking the lock and deadlocking.
458 * "reading" is used by ip/arp/ip6 tables rule processing which runs per-cpu.
459 * It needs to ensure that the rules are not being changed while the packet
460 * is being processed. In some cases, the read lock will be acquired
461 * twice on the same CPU; this is okay because of the count.
463 * "writing" is used when reading counters.
464 * During replace any readers that are using the old tables have to complete
465 * before freeing the old table. This is handled by the write locking
466 * necessary for reading the counters.
468 struct xt_info_lock {
470 unsigned char readers;
472 DECLARE_PER_CPU(struct xt_info_lock, xt_info_locks);
475 * Note: we need to ensure that preemption is disabled before acquiring
476 * the per-cpu-variable, so we do it as a two step process rather than
477 * using "spin_lock_bh()".
479 * We _also_ need to disable bottom half processing before updating our
480 * nesting count, to make sure that the only kind of re-entrancy is this
481 * code being called by itself: since the count+lock is not an atomic
482 * operation, we can allow no races.
484 * _Only_ that special combination of being per-cpu and never getting
485 * re-entered asynchronously means that the count is safe.
487 static inline void xt_info_rdlock_bh(void)
489 struct xt_info_lock *lock;
492 lock = &__get_cpu_var(xt_info_locks);
493 if (likely(!lock->readers++))
494 spin_lock(&lock->lock);
497 static inline void xt_info_rdunlock_bh(void)
499 struct xt_info_lock *lock = &__get_cpu_var(xt_info_locks);
501 if (likely(!--lock->readers))
502 spin_unlock(&lock->lock);
507 * The "writer" side needs to get exclusive access to the lock,
508 * regardless of readers. This must be called with bottom half
509 * processing (and thus also preemption) disabled.
511 static inline void xt_info_wrlock(unsigned int cpu)
513 spin_lock(&per_cpu(xt_info_locks, cpu).lock);
516 static inline void xt_info_wrunlock(unsigned int cpu)
518 spin_unlock(&per_cpu(xt_info_locks, cpu).lock);
522 * This helper is performance critical and must be inlined
524 static inline unsigned long ifname_compare_aligned(const char *_a,
528 const unsigned long *a = (const unsigned long *)_a;
529 const unsigned long *b = (const unsigned long *)_b;
530 const unsigned long *mask = (const unsigned long *)_mask;
533 ret = (a[0] ^ b[0]) & mask[0];
534 if (IFNAMSIZ > sizeof(unsigned long))
535 ret |= (a[1] ^ b[1]) & mask[1];
536 if (IFNAMSIZ > 2 * sizeof(unsigned long))
537 ret |= (a[2] ^ b[2]) & mask[2];
538 if (IFNAMSIZ > 3 * sizeof(unsigned long))
539 ret |= (a[3] ^ b[3]) & mask[3];
540 BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
544 extern struct nf_hook_ops *xt_hook_link(const struct xt_table *, nf_hookfn *);
545 extern void xt_hook_unlink(const struct xt_table *, struct nf_hook_ops *);
548 #include <net/compat.h>
550 struct compat_xt_entry_match {
553 u_int16_t match_size;
554 char name[XT_FUNCTION_MAXNAMELEN - 1];
558 u_int16_t match_size;
561 u_int16_t match_size;
563 unsigned char data[0];
566 struct compat_xt_entry_target {
569 u_int16_t target_size;
570 char name[XT_FUNCTION_MAXNAMELEN - 1];
574 u_int16_t target_size;
575 compat_uptr_t target;
577 u_int16_t target_size;
579 unsigned char data[0];
582 /* FIXME: this works only on 32 bit tasks
583 * need to change whole approach in order to calculate align as function of
584 * current task alignment */
586 struct compat_xt_counters {
587 compat_u64 pcnt, bcnt; /* Packet and byte counters */
590 struct compat_xt_counters_info {
591 char name[XT_TABLE_MAXNAMELEN];
592 compat_uint_t num_counters;
593 struct compat_xt_counters counters[0];
596 struct _compat_xt_align {
603 #define COMPAT_XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _compat_xt_align))
605 extern void xt_compat_lock(u_int8_t af);
606 extern void xt_compat_unlock(u_int8_t af);
608 extern int xt_compat_add_offset(u_int8_t af, unsigned int offset, short delta);
609 extern void xt_compat_flush_offsets(u_int8_t af);
610 extern int xt_compat_calc_jump(u_int8_t af, unsigned int offset);
612 extern int xt_compat_match_offset(const struct xt_match *match);
613 extern int xt_compat_match_from_user(struct xt_entry_match *m,
614 void **dstptr, unsigned int *size);
615 extern int xt_compat_match_to_user(const struct xt_entry_match *m,
616 void __user **dstptr, unsigned int *size);
618 extern int xt_compat_target_offset(const struct xt_target *target);
619 extern void xt_compat_target_from_user(struct xt_entry_target *t,
620 void **dstptr, unsigned int *size);
621 extern int xt_compat_target_to_user(const struct xt_entry_target *t,
622 void __user **dstptr, unsigned int *size);
624 #endif /* CONFIG_COMPAT */
625 #endif /* __KERNEL__ */
627 #endif /* _X_TABLES_H */