5 #include <linux/netdevice.h>
6 #include <linux/static_key.h>
7 #include <linux/netfilter.h>
8 #include <uapi/linux/netfilter/x_tables.h>
10 /* Test a struct->invflags and a boolean for inequality */
11 #define NF_INVF(ptr, flag, boolean) \
12 ((boolean) ^ !!((ptr)->invflags & (flag)))
15 * struct xt_action_param - parameters for matches/targets
17 * @match: the match extension
18 * @target: the target extension
19 * @matchinfo: per-match data
20 * @targetinfo: per-target data
21 * @state: pointer to hook state this packet came from
22 * @fragoff: packet is a fragment, this is the data offset
23 * @thoff: position of transport header relative to skb->data
25 * Fields written to by extensions:
27 * @hotdrop: drop packet if we had inspection problems
29 struct xt_action_param
{
31 const struct xt_match
*match
;
32 const struct xt_target
*target
;
35 const void *matchinfo
, *targinfo
;
37 const struct nf_hook_state
*state
;
43 static inline struct net
*xt_net(const struct xt_action_param
*par
)
45 return par
->state
->net
;
48 static inline struct net_device
*xt_in(const struct xt_action_param
*par
)
50 return par
->state
->in
;
53 static inline const char *xt_inname(const struct xt_action_param
*par
)
55 return par
->state
->in
->name
;
58 static inline struct net_device
*xt_out(const struct xt_action_param
*par
)
60 return par
->state
->out
;
63 static inline const char *xt_outname(const struct xt_action_param
*par
)
65 return par
->state
->out
->name
;
68 static inline unsigned int xt_hooknum(const struct xt_action_param
*par
)
70 return par
->state
->hook
;
73 static inline u_int8_t
xt_family(const struct xt_action_param
*par
)
75 return par
->state
->pf
;
79 * struct xt_mtchk_param - parameters for match extensions'
80 * checkentry functions
82 * @net: network namespace through which the check was invoked
83 * @table: table the rule is tried to be inserted into
84 * @entryinfo: the family-specific rule data
85 * (struct ipt_ip, ip6t_ip, arpt_arp or (note) ebt_entry)
86 * @match: struct xt_match through which this function was invoked
87 * @matchinfo: per-match data
88 * @hook_mask: via which hooks the new rule is reachable
89 * Other fields as above.
91 struct xt_mtchk_param
{
94 const void *entryinfo
;
95 const struct xt_match
*match
;
97 unsigned int hook_mask
;
103 * struct xt_mdtor_param - match destructor parameters
106 struct xt_mtdtor_param
{
108 const struct xt_match
*match
;
114 * struct xt_tgchk_param - parameters for target extensions'
115 * checkentry functions
117 * @entryinfo: the family-specific rule data
118 * (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
120 * Other fields see above.
122 struct xt_tgchk_param
{
125 const void *entryinfo
;
126 const struct xt_target
*target
;
128 unsigned int hook_mask
;
133 /* Target destructor parameters */
134 struct xt_tgdtor_param
{
136 const struct xt_target
*target
;
142 struct list_head list
;
144 const char name
[XT_EXTENSION_MAXNAMELEN
];
147 /* Return true or false: return FALSE and set *hotdrop = 1 to
148 force immediate packet drop. */
149 /* Arguments changed since 2.6.9, as this must now handle
150 non-linear skb, using skb_header_pointer and
151 skb_ip_make_writable. */
152 bool (*match
)(const struct sk_buff
*skb
,
153 struct xt_action_param
*);
155 /* Called when user tries to insert an entry of this type. */
156 int (*checkentry
)(const struct xt_mtchk_param
*);
158 /* Called when entry of this type deleted. */
159 void (*destroy
)(const struct xt_mtdtor_param
*);
161 /* Called when userspace align differs from kernel space one */
162 void (*compat_from_user
)(void *dst
, const void *src
);
163 int (*compat_to_user
)(void __user
*dst
, const void *src
);
165 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
169 unsigned int matchsize
;
171 unsigned int compatsize
;
174 unsigned short proto
;
176 unsigned short family
;
179 /* Registration hooks for targets. */
181 struct list_head list
;
183 const char name
[XT_EXTENSION_MAXNAMELEN
];
186 /* Returns verdict. Argument order changed since 2.6.9, as this
187 must now handle non-linear skbs, using skb_copy_bits and
188 skb_ip_make_writable. */
189 unsigned int (*target
)(struct sk_buff
*skb
,
190 const struct xt_action_param
*);
192 /* Called when user tries to insert an entry of this type:
193 hook_mask is a bitmask of hooks from which it can be
195 /* Should return 0 on success or an error code otherwise (-Exxxx). */
196 int (*checkentry
)(const struct xt_tgchk_param
*);
198 /* Called when entry of this type deleted. */
199 void (*destroy
)(const struct xt_tgdtor_param
*);
201 /* Called when userspace align differs from kernel space one */
202 void (*compat_from_user
)(void *dst
, const void *src
);
203 int (*compat_to_user
)(void __user
*dst
, const void *src
);
205 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
209 unsigned int targetsize
;
211 unsigned int compatsize
;
214 unsigned short proto
;
216 unsigned short family
;
219 /* Furniture shopping... */
221 struct list_head list
;
223 /* What hooks you will enter on */
224 unsigned int valid_hooks
;
226 /* Man behind the curtain... */
227 struct xt_table_info
*private;
229 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
232 u_int8_t af
; /* address/protocol family */
233 int priority
; /* hook order */
235 /* called when table is needed in the given netns */
236 int (*table_init
)(struct net
*net
);
238 /* A unique name... */
239 const char name
[XT_TABLE_MAXNAMELEN
];
242 #include <linux/netfilter_ipv4.h>
244 /* The table itself */
245 struct xt_table_info
{
248 /* Number of entries: FIXME. --RR */
250 /* Initial number of entries. Needed for module usage count */
251 unsigned int initial_entries
;
253 /* Entry points and underflows */
254 unsigned int hook_entry
[NF_INET_NUMHOOKS
];
255 unsigned int underflow
[NF_INET_NUMHOOKS
];
258 * Number of user chains. Since tables cannot have loops, at most
259 * @stacksize jumps (number of user chains) can possibly be made.
261 unsigned int stacksize
;
264 unsigned char entries
[0] __aligned(8);
267 int xt_register_target(struct xt_target
*target
);
268 void xt_unregister_target(struct xt_target
*target
);
269 int xt_register_targets(struct xt_target
*target
, unsigned int n
);
270 void xt_unregister_targets(struct xt_target
*target
, unsigned int n
);
272 int xt_register_match(struct xt_match
*target
);
273 void xt_unregister_match(struct xt_match
*target
);
274 int xt_register_matches(struct xt_match
*match
, unsigned int n
);
275 void xt_unregister_matches(struct xt_match
*match
, unsigned int n
);
277 int xt_check_entry_offsets(const void *base
, const char *elems
,
278 unsigned int target_offset
,
279 unsigned int next_offset
);
281 unsigned int *xt_alloc_entry_offsets(unsigned int size
);
282 bool xt_find_jump_offset(const unsigned int *offsets
,
283 unsigned int target
, unsigned int size
);
285 int xt_check_match(struct xt_mtchk_param
*, unsigned int size
, u_int8_t proto
,
287 int xt_check_target(struct xt_tgchk_param
*, unsigned int size
, u_int8_t proto
,
290 void *xt_copy_counters_from_user(const void __user
*user
, unsigned int len
,
291 struct xt_counters_info
*info
, bool compat
);
293 struct xt_table
*xt_register_table(struct net
*net
,
294 const struct xt_table
*table
,
295 struct xt_table_info
*bootstrap
,
296 struct xt_table_info
*newinfo
);
297 void *xt_unregister_table(struct xt_table
*table
);
299 struct xt_table_info
*xt_replace_table(struct xt_table
*table
,
300 unsigned int num_counters
,
301 struct xt_table_info
*newinfo
,
304 struct xt_match
*xt_find_match(u8 af
, const char *name
, u8 revision
);
305 struct xt_target
*xt_find_target(u8 af
, const char *name
, u8 revision
);
306 struct xt_match
*xt_request_find_match(u8 af
, const char *name
, u8 revision
);
307 struct xt_target
*xt_request_find_target(u8 af
, const char *name
, u8 revision
);
308 int xt_find_revision(u8 af
, const char *name
, u8 revision
, int target
,
311 struct xt_table
*xt_find_table_lock(struct net
*net
, u_int8_t af
,
313 void xt_table_unlock(struct xt_table
*t
);
315 int xt_proto_init(struct net
*net
, u_int8_t af
);
316 void xt_proto_fini(struct net
*net
, u_int8_t af
);
318 struct xt_table_info
*xt_alloc_table_info(unsigned int size
);
319 void xt_free_table_info(struct xt_table_info
*info
);
322 * xt_recseq - recursive seqcount for netfilter use
324 * Packet processing changes the seqcount only if no recursion happened
325 * get_counters() can use read_seqcount_begin()/read_seqcount_retry(),
326 * because we use the normal seqcount convention :
327 * Low order bit set to 1 if a writer is active.
329 DECLARE_PER_CPU(seqcount_t
, xt_recseq
);
331 /* xt_tee_enabled - true if x_tables needs to handle reentrancy
333 * Enabled if current ip(6)tables ruleset has at least one -j TEE rule.
335 extern struct static_key xt_tee_enabled
;
338 * xt_write_recseq_begin - start of a write section
340 * Begin packet processing : all readers must wait the end
341 * 1) Must be called with preemption disabled
342 * 2) softirqs must be disabled too (or we should use this_cpu_add())
344 * 1 if no recursion on this cpu
345 * 0 if recursion detected
347 static inline unsigned int xt_write_recseq_begin(void)
352 * Low order bit of sequence is set if we already
353 * called xt_write_recseq_begin().
355 addend
= (__this_cpu_read(xt_recseq
.sequence
) + 1) & 1;
358 * This is kind of a write_seqcount_begin(), but addend is 0 or 1
359 * We dont check addend value to avoid a test and conditional jump,
360 * since addend is most likely 1
362 __this_cpu_add(xt_recseq
.sequence
, addend
);
369 * xt_write_recseq_end - end of a write section
370 * @addend: return value from previous xt_write_recseq_begin()
372 * End packet processing : all readers can proceed
373 * 1) Must be called with preemption disabled
374 * 2) softirqs must be disabled too (or we should use this_cpu_add())
376 static inline void xt_write_recseq_end(unsigned int addend
)
378 /* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
380 __this_cpu_add(xt_recseq
.sequence
, addend
);
384 * This helper is performance critical and must be inlined
386 static inline unsigned long ifname_compare_aligned(const char *_a
,
390 const unsigned long *a
= (const unsigned long *)_a
;
391 const unsigned long *b
= (const unsigned long *)_b
;
392 const unsigned long *mask
= (const unsigned long *)_mask
;
395 ret
= (a
[0] ^ b
[0]) & mask
[0];
396 if (IFNAMSIZ
> sizeof(unsigned long))
397 ret
|= (a
[1] ^ b
[1]) & mask
[1];
398 if (IFNAMSIZ
> 2 * sizeof(unsigned long))
399 ret
|= (a
[2] ^ b
[2]) & mask
[2];
400 if (IFNAMSIZ
> 3 * sizeof(unsigned long))
401 ret
|= (a
[3] ^ b
[3]) & mask
[3];
402 BUILD_BUG_ON(IFNAMSIZ
> 4 * sizeof(unsigned long));
407 /* On SMP, ip(6)t_entry->counters.pcnt holds address of the
408 * real (percpu) counter. On !SMP, its just the packet count,
409 * so nothing needs to be done there.
411 * xt_percpu_counter_alloc returns the address of the percpu
412 * counter, or 0 on !SMP. We force an alignment of 16 bytes
413 * so that bytes/packets share a common cache line.
415 * Hence caller must use IS_ERR_VALUE to check for error, this
416 * allows us to return 0 for single core systems without forcing
417 * callers to deal with SMP vs. NONSMP issues.
419 static inline unsigned long xt_percpu_counter_alloc(void)
421 if (nr_cpu_ids
> 1) {
422 void __percpu
*res
= __alloc_percpu(sizeof(struct xt_counters
),
423 sizeof(struct xt_counters
));
428 return (__force
unsigned long) res
;
433 static inline void xt_percpu_counter_free(u64 pcnt
)
436 free_percpu((void __percpu
*) (unsigned long) pcnt
);
439 static inline struct xt_counters
*
440 xt_get_this_cpu_counter(struct xt_counters
*cnt
)
443 return this_cpu_ptr((void __percpu
*) (unsigned long) cnt
->pcnt
);
448 static inline struct xt_counters
*
449 xt_get_per_cpu_counter(struct xt_counters
*cnt
, unsigned int cpu
)
452 return per_cpu_ptr((void __percpu
*) (unsigned long) cnt
->pcnt
, cpu
);
457 struct nf_hook_ops
*xt_hook_ops_alloc(const struct xt_table
*, nf_hookfn
*);
460 #include <net/compat.h>
462 struct compat_xt_entry_match
{
465 u_int16_t match_size
;
466 char name
[XT_FUNCTION_MAXNAMELEN
- 1];
470 u_int16_t match_size
;
473 u_int16_t match_size
;
475 unsigned char data
[0];
478 struct compat_xt_entry_target
{
481 u_int16_t target_size
;
482 char name
[XT_FUNCTION_MAXNAMELEN
- 1];
486 u_int16_t target_size
;
487 compat_uptr_t target
;
489 u_int16_t target_size
;
491 unsigned char data
[0];
494 /* FIXME: this works only on 32 bit tasks
495 * need to change whole approach in order to calculate align as function of
496 * current task alignment */
498 struct compat_xt_counters
{
499 compat_u64 pcnt
, bcnt
; /* Packet and byte counters */
502 struct compat_xt_counters_info
{
503 char name
[XT_TABLE_MAXNAMELEN
];
504 compat_uint_t num_counters
;
505 struct compat_xt_counters counters
[0];
508 struct _compat_xt_align
{
515 #define COMPAT_XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _compat_xt_align))
517 void xt_compat_lock(u_int8_t af
);
518 void xt_compat_unlock(u_int8_t af
);
520 int xt_compat_add_offset(u_int8_t af
, unsigned int offset
, int delta
);
521 void xt_compat_flush_offsets(u_int8_t af
);
522 void xt_compat_init_offsets(u_int8_t af
, unsigned int number
);
523 int xt_compat_calc_jump(u_int8_t af
, unsigned int offset
);
525 int xt_compat_match_offset(const struct xt_match
*match
);
526 void xt_compat_match_from_user(struct xt_entry_match
*m
, void **dstptr
,
528 int xt_compat_match_to_user(const struct xt_entry_match
*m
,
529 void __user
**dstptr
, unsigned int *size
);
531 int xt_compat_target_offset(const struct xt_target
*target
);
532 void xt_compat_target_from_user(struct xt_entry_target
*t
, void **dstptr
,
534 int xt_compat_target_to_user(const struct xt_entry_target
*t
,
535 void __user
**dstptr
, unsigned int *size
);
536 int xt_compat_check_entry_offsets(const void *base
, const char *elems
,
537 unsigned int target_offset
,
538 unsigned int next_offset
);
540 #endif /* CONFIG_COMPAT */
541 #endif /* _X_TABLES_H */