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 int xt_register_target(struct xt_target *target);
233 void xt_unregister_target(struct xt_target *target);
234 int xt_register_targets(struct xt_target *target, unsigned int n);
235 void xt_unregister_targets(struct xt_target *target, unsigned int n);
237 int xt_register_match(struct xt_match *target);
238 void xt_unregister_match(struct xt_match *target);
239 int xt_register_matches(struct xt_match *match, unsigned int n);
240 void xt_unregister_matches(struct xt_match *match, unsigned int n);
242 int xt_check_entry_offsets(const void *base, const char *elems,
243 unsigned int target_offset,
244 unsigned int next_offset);
246 unsigned int *xt_alloc_entry_offsets(unsigned int size);
247 bool xt_find_jump_offset(const unsigned int *offsets,
248 unsigned int target, unsigned int size);
250 int xt_check_proc_name(const char *name, unsigned int size);
252 int xt_check_match(struct xt_mtchk_param *, unsigned int size, u_int8_t proto,
254 int xt_check_target(struct xt_tgchk_param *, unsigned int size, u_int8_t proto,
257 void *xt_copy_counters_from_user(const void __user *user, unsigned int len,
258 struct xt_counters_info *info, bool compat);
260 struct xt_table *xt_register_table(struct net *net,
261 const struct xt_table *table,
262 struct xt_table_info *bootstrap,
263 struct xt_table_info *newinfo);
264 void *xt_unregister_table(struct xt_table *table);
266 struct xt_table_info *xt_replace_table(struct xt_table *table,
267 unsigned int num_counters,
268 struct xt_table_info *newinfo,
271 struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
272 struct xt_target *xt_find_target(u8 af, const char *name, u8 revision);
273 struct xt_match *xt_request_find_match(u8 af, const char *name, u8 revision);
274 struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision);
275 int xt_find_revision(u8 af, const char *name, u8 revision, int target,
278 struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
280 void xt_table_unlock(struct xt_table *t);
282 int xt_proto_init(struct net *net, u_int8_t af);
283 void xt_proto_fini(struct net *net, u_int8_t af);
285 struct xt_table_info *xt_alloc_table_info(unsigned int size);
286 void xt_free_table_info(struct xt_table_info *info);
289 * xt_recseq - recursive seqcount for netfilter use
291 * Packet processing changes the seqcount only if no recursion happened
292 * get_counters() can use read_seqcount_begin()/read_seqcount_retry(),
293 * because we use the normal seqcount convention :
294 * Low order bit set to 1 if a writer is active.
296 DECLARE_PER_CPU(seqcount_t, xt_recseq);
299 * xt_write_recseq_begin - start of a write section
301 * Begin packet processing : all readers must wait the end
302 * 1) Must be called with preemption disabled
303 * 2) softirqs must be disabled too (or we should use this_cpu_add())
305 * 1 if no recursion on this cpu
306 * 0 if recursion detected
308 static inline unsigned int xt_write_recseq_begin(void)
313 * Low order bit of sequence is set if we already
314 * called xt_write_recseq_begin().
316 addend = (__this_cpu_read(xt_recseq.sequence) + 1) & 1;
319 * This is kind of a write_seqcount_begin(), but addend is 0 or 1
320 * We dont check addend value to avoid a test and conditional jump,
321 * since addend is most likely 1
323 __this_cpu_add(xt_recseq.sequence, addend);
330 * xt_write_recseq_end - end of a write section
331 * @addend: return value from previous xt_write_recseq_begin()
333 * End packet processing : all readers can proceed
334 * 1) Must be called with preemption disabled
335 * 2) softirqs must be disabled too (or we should use this_cpu_add())
337 static inline void xt_write_recseq_end(unsigned int addend)
339 /* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
341 __this_cpu_add(xt_recseq.sequence, addend);
345 * This helper is performance critical and must be inlined
347 static inline unsigned long ifname_compare_aligned(const char *_a,
351 const unsigned long *a = (const unsigned long *)_a;
352 const unsigned long *b = (const unsigned long *)_b;
353 const unsigned long *mask = (const unsigned long *)_mask;
356 ret = (a[0] ^ b[0]) & mask[0];
357 if (IFNAMSIZ > sizeof(unsigned long))
358 ret |= (a[1] ^ b[1]) & mask[1];
359 if (IFNAMSIZ > 2 * sizeof(unsigned long))
360 ret |= (a[2] ^ b[2]) & mask[2];
361 if (IFNAMSIZ > 3 * sizeof(unsigned long))
362 ret |= (a[3] ^ b[3]) & mask[3];
363 BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
367 struct nf_hook_ops *xt_hook_link(const struct xt_table *, nf_hookfn *);
368 void xt_hook_unlink(const struct xt_table *, struct nf_hook_ops *);
371 #include <net/compat.h>
373 struct compat_xt_entry_match {
376 u_int16_t match_size;
377 char name[XT_FUNCTION_MAXNAMELEN - 1];
381 u_int16_t match_size;
384 u_int16_t match_size;
386 unsigned char data[0];
389 struct compat_xt_entry_target {
392 u_int16_t target_size;
393 char name[XT_FUNCTION_MAXNAMELEN - 1];
397 u_int16_t target_size;
398 compat_uptr_t target;
400 u_int16_t target_size;
402 unsigned char data[0];
405 /* FIXME: this works only on 32 bit tasks
406 * need to change whole approach in order to calculate align as function of
407 * current task alignment */
409 struct compat_xt_counters {
410 compat_u64 pcnt, bcnt; /* Packet and byte counters */
413 struct compat_xt_counters_info {
414 char name[XT_TABLE_MAXNAMELEN];
415 compat_uint_t num_counters;
416 struct compat_xt_counters counters[0];
419 struct _compat_xt_align {
426 #define COMPAT_XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _compat_xt_align))
428 void xt_compat_lock(u_int8_t af);
429 void xt_compat_unlock(u_int8_t af);
431 int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta);
432 void xt_compat_flush_offsets(u_int8_t af);
433 void xt_compat_init_offsets(u_int8_t af, unsigned int number);
434 int xt_compat_calc_jump(u_int8_t af, unsigned int offset);
436 int xt_compat_match_offset(const struct xt_match *match);
437 void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
439 int xt_compat_match_to_user(const struct xt_entry_match *m,
440 void __user **dstptr, unsigned int *size);
442 int xt_compat_target_offset(const struct xt_target *target);
443 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
445 int xt_compat_target_to_user(const struct xt_entry_target *t,
446 void __user **dstptr, unsigned int *size);
447 int xt_compat_check_entry_offsets(const void *base, const char *elems,
448 unsigned int target_offset,
449 unsigned int next_offset);
451 #endif /* CONFIG_COMPAT */
452 #endif /* _X_TABLES_H */