5 #include <linux/netdevice.h>
6 #include <uapi/linux/netfilter/x_tables.h>
9 * struct xt_action_param - parameters for matches/targets
11 * @match: the match extension
12 * @target: the target extension
13 * @matchinfo: per-match data
14 * @targetinfo: per-target data
15 * @in: input netdevice
16 * @out: output netdevice
17 * @fragoff: packet is a fragment, this is the data offset
18 * @thoff: position of transport header relative to skb->data
19 * @hook: hook number given packet came from
20 * @family: Actual NFPROTO_* through which the function is invoked
21 * (helpful when match->family == NFPROTO_UNSPEC)
23 * Fields written to by extensions:
25 * @hotdrop: drop packet if we had inspection problems
26 * Network namespace obtainable using dev_net(in/out)
28 struct xt_action_param
{
30 const struct xt_match
*match
;
31 const struct xt_target
*target
;
34 const void *matchinfo
, *targinfo
;
36 const struct net_device
*in
, *out
;
45 * struct xt_mtchk_param - parameters for match extensions'
46 * checkentry functions
48 * @net: network namespace through which the check was invoked
49 * @table: table the rule is tried to be inserted into
50 * @entryinfo: the family-specific rule data
51 * (struct ipt_ip, ip6t_ip, arpt_arp or (note) ebt_entry)
52 * @match: struct xt_match through which this function was invoked
53 * @matchinfo: per-match data
54 * @hook_mask: via which hooks the new rule is reachable
55 * Other fields as above.
57 struct xt_mtchk_param
{
60 const void *entryinfo
;
61 const struct xt_match
*match
;
63 unsigned int hook_mask
;
68 * struct xt_mdtor_param - match destructor parameters
71 struct xt_mtdtor_param
{
73 const struct xt_match
*match
;
79 * struct xt_tgchk_param - parameters for target extensions'
80 * checkentry functions
82 * @entryinfo: the family-specific rule data
83 * (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
85 * Other fields see above.
87 struct xt_tgchk_param
{
90 const void *entryinfo
;
91 const struct xt_target
*target
;
93 unsigned int hook_mask
;
97 /* Target destructor parameters */
98 struct xt_tgdtor_param
{
100 const struct xt_target
*target
;
106 struct list_head list
;
108 const char name
[XT_EXTENSION_MAXNAMELEN
];
111 /* Return true or false: return FALSE and set *hotdrop = 1 to
112 force immediate packet drop. */
113 /* Arguments changed since 2.6.9, as this must now handle
114 non-linear skb, using skb_header_pointer and
115 skb_ip_make_writable. */
116 bool (*match
)(const struct sk_buff
*skb
,
117 struct xt_action_param
*);
119 /* Called when user tries to insert an entry of this type. */
120 int (*checkentry
)(const struct xt_mtchk_param
*);
122 /* Called when entry of this type deleted. */
123 void (*destroy
)(const struct xt_mtdtor_param
*);
125 /* Called when userspace align differs from kernel space one */
126 void (*compat_from_user
)(void *dst
, const void *src
);
127 int (*compat_to_user
)(void __user
*dst
, const void *src
);
129 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
133 unsigned int matchsize
;
135 unsigned int compatsize
;
138 unsigned short proto
;
140 unsigned short family
;
143 /* Registration hooks for targets. */
145 struct list_head list
;
147 const char name
[XT_EXTENSION_MAXNAMELEN
];
150 /* Returns verdict. Argument order changed since 2.6.9, as this
151 must now handle non-linear skbs, using skb_copy_bits and
152 skb_ip_make_writable. */
153 unsigned int (*target
)(struct sk_buff
*skb
,
154 const struct xt_action_param
*);
156 /* Called when user tries to insert an entry of this type:
157 hook_mask is a bitmask of hooks from which it can be
159 /* Should return 0 on success or an error code otherwise (-Exxxx). */
160 int (*checkentry
)(const struct xt_tgchk_param
*);
162 /* Called when entry of this type deleted. */
163 void (*destroy
)(const struct xt_tgdtor_param
*);
165 /* Called when userspace align differs from kernel space one */
166 void (*compat_from_user
)(void *dst
, const void *src
);
167 int (*compat_to_user
)(void __user
*dst
, const void *src
);
169 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
173 unsigned int targetsize
;
175 unsigned int compatsize
;
178 unsigned short proto
;
180 unsigned short family
;
183 /* Furniture shopping... */
185 struct list_head list
;
187 /* What hooks you will enter on */
188 unsigned int valid_hooks
;
190 /* Man behind the curtain... */
191 struct xt_table_info
*private;
193 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
196 u_int8_t af
; /* address/protocol family */
197 int priority
; /* hook order */
199 /* A unique name... */
200 const char name
[XT_TABLE_MAXNAMELEN
];
203 #include <linux/netfilter_ipv4.h>
205 /* The table itself */
206 struct xt_table_info
{
209 /* Number of entries: FIXME. --RR */
211 /* Initial number of entries. Needed for module usage count */
212 unsigned int initial_entries
;
214 /* Entry points and underflows */
215 unsigned int hook_entry
[NF_INET_NUMHOOKS
];
216 unsigned int underflow
[NF_INET_NUMHOOKS
];
219 * Number of user chains. Since tables cannot have loops, at most
220 * @stacksize jumps (number of user chains) can possibly be made.
222 unsigned int stacksize
;
223 unsigned int __percpu
*stackptr
;
225 /* ipt_entry tables: one per CPU */
226 /* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */
230 #define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \
231 + nr_cpu_ids * sizeof(char *))
232 extern int xt_register_target(struct xt_target
*target
);
233 extern void xt_unregister_target(struct xt_target
*target
);
234 extern int xt_register_targets(struct xt_target
*target
, unsigned int n
);
235 extern void xt_unregister_targets(struct xt_target
*target
, unsigned int n
);
237 extern int xt_register_match(struct xt_match
*target
);
238 extern void xt_unregister_match(struct xt_match
*target
);
239 extern int xt_register_matches(struct xt_match
*match
, unsigned int n
);
240 extern void xt_unregister_matches(struct xt_match
*match
, unsigned int n
);
242 extern int xt_check_match(struct xt_mtchk_param
*,
243 unsigned int size
, u_int8_t proto
, bool inv_proto
);
244 extern int xt_check_target(struct xt_tgchk_param
*,
245 unsigned int size
, u_int8_t proto
, bool inv_proto
);
247 extern struct xt_table
*xt_register_table(struct net
*net
,
248 const struct xt_table
*table
,
249 struct xt_table_info
*bootstrap
,
250 struct xt_table_info
*newinfo
);
251 extern void *xt_unregister_table(struct xt_table
*table
);
253 extern struct xt_table_info
*xt_replace_table(struct xt_table
*table
,
254 unsigned int num_counters
,
255 struct xt_table_info
*newinfo
,
258 extern struct xt_match
*xt_find_match(u8 af
, const char *name
, u8 revision
);
259 extern struct xt_target
*xt_find_target(u8 af
, const char *name
, u8 revision
);
260 extern struct xt_match
*xt_request_find_match(u8 af
, const char *name
,
262 extern struct xt_target
*xt_request_find_target(u8 af
, const char *name
,
264 extern int xt_find_revision(u8 af
, const char *name
, u8 revision
,
265 int target
, int *err
);
267 extern struct xt_table
*xt_find_table_lock(struct net
*net
, u_int8_t af
,
269 extern void xt_table_unlock(struct xt_table
*t
);
271 extern int xt_proto_init(struct net
*net
, u_int8_t af
);
272 extern void xt_proto_fini(struct net
*net
, u_int8_t af
);
274 extern struct xt_table_info
*xt_alloc_table_info(unsigned int size
);
275 extern void xt_free_table_info(struct xt_table_info
*info
);
278 * xt_recseq - recursive seqcount for netfilter use
280 * Packet processing changes the seqcount only if no recursion happened
281 * get_counters() can use read_seqcount_begin()/read_seqcount_retry(),
282 * because we use the normal seqcount convention :
283 * Low order bit set to 1 if a writer is active.
285 DECLARE_PER_CPU(seqcount_t
, xt_recseq
);
288 * xt_write_recseq_begin - start of a write section
290 * Begin packet processing : all readers must wait the end
291 * 1) Must be called with preemption disabled
292 * 2) softirqs must be disabled too (or we should use this_cpu_add())
294 * 1 if no recursion on this cpu
295 * 0 if recursion detected
297 static inline unsigned int xt_write_recseq_begin(void)
302 * Low order bit of sequence is set if we already
303 * called xt_write_recseq_begin().
305 addend
= (__this_cpu_read(xt_recseq
.sequence
) + 1) & 1;
308 * This is kind of a write_seqcount_begin(), but addend is 0 or 1
309 * We dont check addend value to avoid a test and conditional jump,
310 * since addend is most likely 1
312 __this_cpu_add(xt_recseq
.sequence
, addend
);
319 * xt_write_recseq_end - end of a write section
320 * @addend: return value from previous xt_write_recseq_begin()
322 * End packet processing : all readers can proceed
323 * 1) Must be called with preemption disabled
324 * 2) softirqs must be disabled too (or we should use this_cpu_add())
326 static inline void xt_write_recseq_end(unsigned int addend
)
328 /* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
330 __this_cpu_add(xt_recseq
.sequence
, addend
);
334 * This helper is performance critical and must be inlined
336 static inline unsigned long ifname_compare_aligned(const char *_a
,
340 const unsigned long *a
= (const unsigned long *)_a
;
341 const unsigned long *b
= (const unsigned long *)_b
;
342 const unsigned long *mask
= (const unsigned long *)_mask
;
345 ret
= (a
[0] ^ b
[0]) & mask
[0];
346 if (IFNAMSIZ
> sizeof(unsigned long))
347 ret
|= (a
[1] ^ b
[1]) & mask
[1];
348 if (IFNAMSIZ
> 2 * sizeof(unsigned long))
349 ret
|= (a
[2] ^ b
[2]) & mask
[2];
350 if (IFNAMSIZ
> 3 * sizeof(unsigned long))
351 ret
|= (a
[3] ^ b
[3]) & mask
[3];
352 BUILD_BUG_ON(IFNAMSIZ
> 4 * sizeof(unsigned long));
356 extern struct nf_hook_ops
*xt_hook_link(const struct xt_table
*, nf_hookfn
*);
357 extern void xt_hook_unlink(const struct xt_table
*, struct nf_hook_ops
*);
360 #include <net/compat.h>
362 struct compat_xt_entry_match
{
365 u_int16_t match_size
;
366 char name
[XT_FUNCTION_MAXNAMELEN
- 1];
370 u_int16_t match_size
;
373 u_int16_t match_size
;
375 unsigned char data
[0];
378 struct compat_xt_entry_target
{
381 u_int16_t target_size
;
382 char name
[XT_FUNCTION_MAXNAMELEN
- 1];
386 u_int16_t target_size
;
387 compat_uptr_t target
;
389 u_int16_t target_size
;
391 unsigned char data
[0];
394 /* FIXME: this works only on 32 bit tasks
395 * need to change whole approach in order to calculate align as function of
396 * current task alignment */
398 struct compat_xt_counters
{
399 compat_u64 pcnt
, bcnt
; /* Packet and byte counters */
402 struct compat_xt_counters_info
{
403 char name
[XT_TABLE_MAXNAMELEN
];
404 compat_uint_t num_counters
;
405 struct compat_xt_counters counters
[0];
408 struct _compat_xt_align
{
415 #define COMPAT_XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _compat_xt_align))
417 extern void xt_compat_lock(u_int8_t af
);
418 extern void xt_compat_unlock(u_int8_t af
);
420 extern int xt_compat_add_offset(u_int8_t af
, unsigned int offset
, int delta
);
421 extern void xt_compat_flush_offsets(u_int8_t af
);
422 extern void xt_compat_init_offsets(u_int8_t af
, unsigned int number
);
423 extern int xt_compat_calc_jump(u_int8_t af
, unsigned int offset
);
425 extern int xt_compat_match_offset(const struct xt_match
*match
);
426 extern int xt_compat_match_from_user(struct xt_entry_match
*m
,
427 void **dstptr
, unsigned int *size
);
428 extern int xt_compat_match_to_user(const struct xt_entry_match
*m
,
429 void __user
**dstptr
, unsigned int *size
);
431 extern int xt_compat_target_offset(const struct xt_target
*target
);
432 extern void xt_compat_target_from_user(struct xt_entry_target
*t
,
433 void **dstptr
, unsigned int *size
);
434 extern int xt_compat_target_to_user(const struct xt_entry_target
*t
,
435 void __user
**dstptr
, unsigned int *size
);
437 #endif /* CONFIG_COMPAT */
438 #endif /* _X_TABLES_H */