5 #include <linux/netdevice.h>
6 #include <linux/locallock.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;
69 * struct xt_mdtor_param - match destructor parameters
72 struct xt_mtdtor_param {
74 const struct xt_match *match;
80 * struct xt_tgchk_param - parameters for target extensions'
81 * checkentry functions
83 * @entryinfo: the family-specific rule data
84 * (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
86 * Other fields see above.
88 struct xt_tgchk_param {
91 const void *entryinfo;
92 const struct xt_target *target;
94 unsigned int hook_mask;
98 /* Target destructor parameters */
99 struct xt_tgdtor_param {
101 const struct xt_target *target;
107 struct list_head list;
109 const char name[XT_EXTENSION_MAXNAMELEN];
112 /* Return true or false: return FALSE and set *hotdrop = 1 to
113 force immediate packet drop. */
114 /* Arguments changed since 2.6.9, as this must now handle
115 non-linear skb, using skb_header_pointer and
116 skb_ip_make_writable. */
117 bool (*match)(const struct sk_buff *skb,
118 struct xt_action_param *);
120 /* Called when user tries to insert an entry of this type. */
121 int (*checkentry)(const struct xt_mtchk_param *);
123 /* Called when entry of this type deleted. */
124 void (*destroy)(const struct xt_mtdtor_param *);
126 /* Called when userspace align differs from kernel space one */
127 void (*compat_from_user)(void *dst, const void *src);
128 int (*compat_to_user)(void __user *dst, const void *src);
130 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
134 unsigned int matchsize;
136 unsigned int compatsize;
139 unsigned short proto;
141 unsigned short family;
144 /* Registration hooks for targets. */
146 struct list_head list;
148 const char name[XT_EXTENSION_MAXNAMELEN];
151 /* Returns verdict. Argument order changed since 2.6.9, as this
152 must now handle non-linear skbs, using skb_copy_bits and
153 skb_ip_make_writable. */
154 unsigned int (*target)(struct sk_buff *skb,
155 const struct xt_action_param *);
157 /* Called when user tries to insert an entry of this type:
158 hook_mask is a bitmask of hooks from which it can be
160 /* Should return 0 on success or an error code otherwise (-Exxxx). */
161 int (*checkentry)(const struct xt_tgchk_param *);
163 /* Called when entry of this type deleted. */
164 void (*destroy)(const struct xt_tgdtor_param *);
166 /* Called when userspace align differs from kernel space one */
167 void (*compat_from_user)(void *dst, const void *src);
168 int (*compat_to_user)(void __user *dst, const void *src);
170 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
174 unsigned int targetsize;
176 unsigned int compatsize;
179 unsigned short proto;
181 unsigned short family;
184 /* Furniture shopping... */
186 struct list_head list;
188 /* What hooks you will enter on */
189 unsigned int valid_hooks;
191 /* Man behind the curtain... */
192 struct xt_table_info *private;
194 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
197 u_int8_t af; /* address/protocol family */
198 int priority; /* hook order */
200 /* A unique name... */
201 const char name[XT_TABLE_MAXNAMELEN];
204 #include <linux/netfilter_ipv4.h>
206 /* The table itself */
207 struct xt_table_info {
210 /* Number of entries: FIXME. --RR */
212 /* Initial number of entries. Needed for module usage count */
213 unsigned int initial_entries;
215 /* Entry points and underflows */
216 unsigned int hook_entry[NF_INET_NUMHOOKS];
217 unsigned int underflow[NF_INET_NUMHOOKS];
220 * Number of user chains. Since tables cannot have loops, at most
221 * @stacksize jumps (number of user chains) can possibly be made.
223 unsigned int stacksize;
224 unsigned int __percpu *stackptr;
226 /* ipt_entry tables: one per CPU */
227 /* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */
231 #define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \
232 + nr_cpu_ids * sizeof(char *))
233 int xt_register_target(struct xt_target *target);
234 void xt_unregister_target(struct xt_target *target);
235 int xt_register_targets(struct xt_target *target, unsigned int n);
236 void xt_unregister_targets(struct xt_target *target, unsigned int n);
238 int xt_register_match(struct xt_match *target);
239 void xt_unregister_match(struct xt_match *target);
240 int xt_register_matches(struct xt_match *match, unsigned int n);
241 void xt_unregister_matches(struct xt_match *match, unsigned int n);
243 int xt_check_match(struct xt_mtchk_param *, unsigned int size, u_int8_t proto,
245 int xt_check_target(struct xt_tgchk_param *, unsigned int size, u_int8_t proto,
248 struct xt_table *xt_register_table(struct net *net,
249 const struct xt_table *table,
250 struct xt_table_info *bootstrap,
251 struct xt_table_info *newinfo);
252 void *xt_unregister_table(struct xt_table *table);
254 struct xt_table_info *xt_replace_table(struct xt_table *table,
255 unsigned int num_counters,
256 struct xt_table_info *newinfo,
259 struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
260 struct xt_target *xt_find_target(u8 af, const char *name, u8 revision);
261 struct xt_match *xt_request_find_match(u8 af, const char *name, u8 revision);
262 struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision);
263 int xt_find_revision(u8 af, const char *name, u8 revision, int target,
266 struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
268 void xt_table_unlock(struct xt_table *t);
270 int xt_proto_init(struct net *net, u_int8_t af);
271 void xt_proto_fini(struct net *net, u_int8_t af);
273 struct xt_table_info *xt_alloc_table_info(unsigned int size);
274 void xt_free_table_info(struct xt_table_info *info);
277 * xt_recseq - recursive seqcount for netfilter use
279 * Packet processing changes the seqcount only if no recursion happened
280 * get_counters() can use read_seqcount_begin()/read_seqcount_retry(),
281 * because we use the normal seqcount convention :
282 * Low order bit set to 1 if a writer is active.
284 DECLARE_PER_CPU(seqcount_t, xt_recseq);
286 DECLARE_LOCAL_IRQ_LOCK(xt_write_lock);
289 * xt_write_recseq_begin - start of a write section
291 * Begin packet processing : all readers must wait the end
292 * 1) Must be called with preemption disabled
293 * 2) softirqs must be disabled too (or we should use this_cpu_add())
295 * 1 if no recursion on this cpu
296 * 0 if recursion detected
298 static inline unsigned int xt_write_recseq_begin(void)
303 local_lock(xt_write_lock);
306 * Low order bit of sequence is set if we already
307 * called xt_write_recseq_begin().
309 addend = (__this_cpu_read(xt_recseq.sequence) + 1) & 1;
312 * This is kind of a write_seqcount_begin(), but addend is 0 or 1
313 * We dont check addend value to avoid a test and conditional jump,
314 * since addend is most likely 1
316 __this_cpu_add(xt_recseq.sequence, addend);
323 * xt_write_recseq_end - end of a write section
324 * @addend: return value from previous xt_write_recseq_begin()
326 * End packet processing : all readers can proceed
327 * 1) Must be called with preemption disabled
328 * 2) softirqs must be disabled too (or we should use this_cpu_add())
330 static inline void xt_write_recseq_end(unsigned int addend)
332 /* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
334 __this_cpu_add(xt_recseq.sequence, addend);
335 local_unlock(xt_write_lock);
339 * This helper is performance critical and must be inlined
341 static inline unsigned long ifname_compare_aligned(const char *_a,
345 const unsigned long *a = (const unsigned long *)_a;
346 const unsigned long *b = (const unsigned long *)_b;
347 const unsigned long *mask = (const unsigned long *)_mask;
350 ret = (a[0] ^ b[0]) & mask[0];
351 if (IFNAMSIZ > sizeof(unsigned long))
352 ret |= (a[1] ^ b[1]) & mask[1];
353 if (IFNAMSIZ > 2 * sizeof(unsigned long))
354 ret |= (a[2] ^ b[2]) & mask[2];
355 if (IFNAMSIZ > 3 * sizeof(unsigned long))
356 ret |= (a[3] ^ b[3]) & mask[3];
357 BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
361 struct nf_hook_ops *xt_hook_link(const struct xt_table *, nf_hookfn *);
362 void xt_hook_unlink(const struct xt_table *, struct nf_hook_ops *);
365 #include <net/compat.h>
367 struct compat_xt_entry_match {
370 u_int16_t match_size;
371 char name[XT_FUNCTION_MAXNAMELEN - 1];
375 u_int16_t match_size;
378 u_int16_t match_size;
380 unsigned char data[0];
383 struct compat_xt_entry_target {
386 u_int16_t target_size;
387 char name[XT_FUNCTION_MAXNAMELEN - 1];
391 u_int16_t target_size;
392 compat_uptr_t target;
394 u_int16_t target_size;
396 unsigned char data[0];
399 /* FIXME: this works only on 32 bit tasks
400 * need to change whole approach in order to calculate align as function of
401 * current task alignment */
403 struct compat_xt_counters {
404 compat_u64 pcnt, bcnt; /* Packet and byte counters */
407 struct compat_xt_counters_info {
408 char name[XT_TABLE_MAXNAMELEN];
409 compat_uint_t num_counters;
410 struct compat_xt_counters counters[0];
413 struct _compat_xt_align {
420 #define COMPAT_XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _compat_xt_align))
422 void xt_compat_lock(u_int8_t af);
423 void xt_compat_unlock(u_int8_t af);
425 int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta);
426 void xt_compat_flush_offsets(u_int8_t af);
427 void xt_compat_init_offsets(u_int8_t af, unsigned int number);
428 int xt_compat_calc_jump(u_int8_t af, unsigned int offset);
430 int xt_compat_match_offset(const struct xt_match *match);
431 int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
433 int xt_compat_match_to_user(const struct xt_entry_match *m,
434 void __user **dstptr, unsigned int *size);
436 int xt_compat_target_offset(const struct xt_target *target);
437 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
439 int xt_compat_target_to_user(const struct xt_entry_target *t,
440 void __user **dstptr, unsigned int *size);
442 #endif /* CONFIG_COMPAT */
443 #endif /* _X_TABLES_H */