5 #include <linux/netdevice.h>
6 #include <linux/static_key.h>
7 #include <uapi/linux/netfilter/x_tables.h>
10 * struct xt_action_param - parameters for matches/targets
12 * @match: the match extension
13 * @target: the target extension
14 * @matchinfo: per-match data
15 * @targetinfo: per-target data
16 * @in: input netdevice
17 * @out: output netdevice
18 * @fragoff: packet is a fragment, this is the data offset
19 * @thoff: position of transport header relative to skb->data
20 * @hook: hook number given packet came from
21 * @family: Actual NFPROTO_* through which the function is invoked
22 * (helpful when match->family == NFPROTO_UNSPEC)
24 * Fields written to by extensions:
26 * @hotdrop: drop packet if we had inspection problems
27 * Network namespace obtainable using dev_net(in/out)
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 net_device *in, *out;
46 * struct xt_mtchk_param - parameters for match extensions'
47 * checkentry functions
49 * @net: network namespace through which the check was invoked
50 * @table: table the rule is tried to be inserted into
51 * @entryinfo: the family-specific rule data
52 * (struct ipt_ip, ip6t_ip, arpt_arp or (note) ebt_entry)
53 * @match: struct xt_match through which this function was invoked
54 * @matchinfo: per-match data
55 * @hook_mask: via which hooks the new rule is reachable
56 * Other fields as above.
58 struct xt_mtchk_param {
61 const void *entryinfo;
62 const struct xt_match *match;
64 unsigned int hook_mask;
70 * struct xt_mdtor_param - match destructor parameters
73 struct xt_mtdtor_param {
75 const struct xt_match *match;
81 * struct xt_tgchk_param - parameters for target extensions'
82 * checkentry functions
84 * @entryinfo: the family-specific rule data
85 * (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
87 * Other fields see above.
89 struct xt_tgchk_param {
92 const void *entryinfo;
93 const struct xt_target *target;
95 unsigned int hook_mask;
100 /* Target destructor parameters */
101 struct xt_tgdtor_param {
103 const struct xt_target *target;
109 struct list_head list;
111 const char name[XT_EXTENSION_MAXNAMELEN];
114 /* Return true or false: return FALSE and set *hotdrop = 1 to
115 force immediate packet drop. */
116 /* Arguments changed since 2.6.9, as this must now handle
117 non-linear skb, using skb_header_pointer and
118 skb_ip_make_writable. */
119 bool (*match)(const struct sk_buff *skb,
120 struct xt_action_param *);
122 /* Called when user tries to insert an entry of this type. */
123 int (*checkentry)(const struct xt_mtchk_param *);
125 /* Called when entry of this type deleted. */
126 void (*destroy)(const struct xt_mtdtor_param *);
128 /* Called when userspace align differs from kernel space one */
129 void (*compat_from_user)(void *dst, const void *src);
130 int (*compat_to_user)(void __user *dst, const void *src);
132 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
136 unsigned int matchsize;
138 unsigned int compatsize;
141 unsigned short proto;
143 unsigned short family;
146 /* Registration hooks for targets. */
148 struct list_head list;
150 const char name[XT_EXTENSION_MAXNAMELEN];
153 /* Returns verdict. Argument order changed since 2.6.9, as this
154 must now handle non-linear skbs, using skb_copy_bits and
155 skb_ip_make_writable. */
156 unsigned int (*target)(struct sk_buff *skb,
157 const struct xt_action_param *);
159 /* Called when user tries to insert an entry of this type:
160 hook_mask is a bitmask of hooks from which it can be
162 /* Should return 0 on success or an error code otherwise (-Exxxx). */
163 int (*checkentry)(const struct xt_tgchk_param *);
165 /* Called when entry of this type deleted. */
166 void (*destroy)(const struct xt_tgdtor_param *);
168 /* Called when userspace align differs from kernel space one */
169 void (*compat_from_user)(void *dst, const void *src);
170 int (*compat_to_user)(void __user *dst, const void *src);
172 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
176 unsigned int targetsize;
178 unsigned int compatsize;
181 unsigned short proto;
183 unsigned short family;
186 /* Furniture shopping... */
188 struct list_head list;
190 /* What hooks you will enter on */
191 unsigned int valid_hooks;
193 /* Man behind the curtain... */
194 struct xt_table_info *private;
196 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
199 u_int8_t af; /* address/protocol family */
200 int priority; /* hook order */
202 /* A unique name... */
203 const char name[XT_TABLE_MAXNAMELEN];
206 #include <linux/netfilter_ipv4.h>
208 /* The table itself */
209 struct xt_table_info {
212 /* Number of entries: FIXME. --RR */
214 /* Initial number of entries. Needed for module usage count */
215 unsigned int initial_entries;
217 /* Entry points and underflows */
218 unsigned int hook_entry[NF_INET_NUMHOOKS];
219 unsigned int underflow[NF_INET_NUMHOOKS];
222 * Number of user chains. Since tables cannot have loops, at most
223 * @stacksize jumps (number of user chains) can possibly be made.
225 unsigned int stacksize;
228 unsigned char entries[0] __aligned(8);
231 int xt_register_target(struct xt_target *target);
232 void xt_unregister_target(struct xt_target *target);
233 int xt_register_targets(struct xt_target *target, unsigned int n);
234 void xt_unregister_targets(struct xt_target *target, unsigned int n);
236 int xt_register_match(struct xt_match *target);
237 void xt_unregister_match(struct xt_match *target);
238 int xt_register_matches(struct xt_match *match, unsigned int n);
239 void xt_unregister_matches(struct xt_match *match, unsigned int n);
241 int xt_check_match(struct xt_mtchk_param *, unsigned int size, u_int8_t proto,
243 int xt_check_target(struct xt_tgchk_param *, unsigned int size, u_int8_t proto,
246 struct xt_table *xt_register_table(struct net *net,
247 const struct xt_table *table,
248 struct xt_table_info *bootstrap,
249 struct xt_table_info *newinfo);
250 void *xt_unregister_table(struct xt_table *table);
252 struct xt_table_info *xt_replace_table(struct xt_table *table,
253 unsigned int num_counters,
254 struct xt_table_info *newinfo,
257 struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
258 struct xt_target *xt_find_target(u8 af, const char *name, u8 revision);
259 struct xt_match *xt_request_find_match(u8 af, const char *name, u8 revision);
260 struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision);
261 int xt_find_revision(u8 af, const char *name, u8 revision, int target,
264 struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
266 void xt_table_unlock(struct xt_table *t);
268 int xt_proto_init(struct net *net, u_int8_t af);
269 void xt_proto_fini(struct net *net, u_int8_t af);
271 struct xt_table_info *xt_alloc_table_info(unsigned int size);
272 void xt_free_table_info(struct xt_table_info *info);
275 * xt_recseq - recursive seqcount for netfilter use
277 * Packet processing changes the seqcount only if no recursion happened
278 * get_counters() can use read_seqcount_begin()/read_seqcount_retry(),
279 * because we use the normal seqcount convention :
280 * Low order bit set to 1 if a writer is active.
282 DECLARE_PER_CPU(seqcount_t, xt_recseq);
284 /* xt_tee_enabled - true if x_tables needs to handle reentrancy
286 * Enabled if current ip(6)tables ruleset has at least one -j TEE rule.
288 extern struct static_key xt_tee_enabled;
291 * xt_write_recseq_begin - start of a write section
293 * Begin packet processing : all readers must wait the end
294 * 1) Must be called with preemption disabled
295 * 2) softirqs must be disabled too (or we should use this_cpu_add())
297 * 1 if no recursion on this cpu
298 * 0 if recursion detected
300 static inline unsigned int xt_write_recseq_begin(void)
305 * Low order bit of sequence is set if we already
306 * called xt_write_recseq_begin().
308 addend = (__this_cpu_read(xt_recseq.sequence) + 1) & 1;
311 * This is kind of a write_seqcount_begin(), but addend is 0 or 1
312 * We dont check addend value to avoid a test and conditional jump,
313 * since addend is most likely 1
315 __this_cpu_add(xt_recseq.sequence, addend);
322 * xt_write_recseq_end - end of a write section
323 * @addend: return value from previous xt_write_recseq_begin()
325 * End packet processing : all readers can proceed
326 * 1) Must be called with preemption disabled
327 * 2) softirqs must be disabled too (or we should use this_cpu_add())
329 static inline void xt_write_recseq_end(unsigned int addend)
331 /* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
333 __this_cpu_add(xt_recseq.sequence, addend);
337 * This helper is performance critical and must be inlined
339 static inline unsigned long ifname_compare_aligned(const char *_a,
343 const unsigned long *a = (const unsigned long *)_a;
344 const unsigned long *b = (const unsigned long *)_b;
345 const unsigned long *mask = (const unsigned long *)_mask;
348 ret = (a[0] ^ b[0]) & mask[0];
349 if (IFNAMSIZ > sizeof(unsigned long))
350 ret |= (a[1] ^ b[1]) & mask[1];
351 if (IFNAMSIZ > 2 * sizeof(unsigned long))
352 ret |= (a[2] ^ b[2]) & mask[2];
353 if (IFNAMSIZ > 3 * sizeof(unsigned long))
354 ret |= (a[3] ^ b[3]) & mask[3];
355 BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
360 /* On SMP, ip(6)t_entry->counters.pcnt holds address of the
361 * real (percpu) counter. On !SMP, its just the packet count,
362 * so nothing needs to be done there.
364 * xt_percpu_counter_alloc returns the address of the percpu
365 * counter, or 0 on !SMP. We force an alignment of 16 bytes
366 * so that bytes/packets share a common cache line.
368 * Hence caller must use IS_ERR_VALUE to check for error, this
369 * allows us to return 0 for single core systems without forcing
370 * callers to deal with SMP vs. NONSMP issues.
372 static inline u64 xt_percpu_counter_alloc(void)
374 if (nr_cpu_ids > 1) {
375 void __percpu *res = __alloc_percpu(sizeof(struct xt_counters),
376 sizeof(struct xt_counters));
379 return (u64) -ENOMEM;
381 return (u64) (__force unsigned long) res;
386 static inline void xt_percpu_counter_free(u64 pcnt)
389 free_percpu((void __percpu *) (unsigned long) pcnt);
392 static inline struct xt_counters *
393 xt_get_this_cpu_counter(struct xt_counters *cnt)
396 return this_cpu_ptr((void __percpu *) (unsigned long) cnt->pcnt);
401 static inline struct xt_counters *
402 xt_get_per_cpu_counter(struct xt_counters *cnt, unsigned int cpu)
405 return per_cpu_ptr((void __percpu *) (unsigned long) cnt->pcnt, cpu);
410 struct nf_hook_ops *xt_hook_link(const struct xt_table *, nf_hookfn *);
411 void xt_hook_unlink(const struct xt_table *, struct nf_hook_ops *);
414 #include <net/compat.h>
416 struct compat_xt_entry_match {
419 u_int16_t match_size;
420 char name[XT_FUNCTION_MAXNAMELEN - 1];
424 u_int16_t match_size;
427 u_int16_t match_size;
429 unsigned char data[0];
432 struct compat_xt_entry_target {
435 u_int16_t target_size;
436 char name[XT_FUNCTION_MAXNAMELEN - 1];
440 u_int16_t target_size;
441 compat_uptr_t target;
443 u_int16_t target_size;
445 unsigned char data[0];
448 /* FIXME: this works only on 32 bit tasks
449 * need to change whole approach in order to calculate align as function of
450 * current task alignment */
452 struct compat_xt_counters {
453 compat_u64 pcnt, bcnt; /* Packet and byte counters */
456 struct compat_xt_counters_info {
457 char name[XT_TABLE_MAXNAMELEN];
458 compat_uint_t num_counters;
459 struct compat_xt_counters counters[0];
462 struct _compat_xt_align {
469 #define COMPAT_XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _compat_xt_align))
471 void xt_compat_lock(u_int8_t af);
472 void xt_compat_unlock(u_int8_t af);
474 int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta);
475 void xt_compat_flush_offsets(u_int8_t af);
476 void xt_compat_init_offsets(u_int8_t af, unsigned int number);
477 int xt_compat_calc_jump(u_int8_t af, unsigned int offset);
479 int xt_compat_match_offset(const struct xt_match *match);
480 int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
482 int xt_compat_match_to_user(const struct xt_entry_match *m,
483 void __user **dstptr, unsigned int *size);
485 int xt_compat_target_offset(const struct xt_target *target);
486 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
488 int xt_compat_target_to_user(const struct xt_entry_target *t,
489 void __user **dstptr, unsigned int *size);
491 #endif /* CONFIG_COMPAT */
492 #endif /* _X_TABLES_H */