1 /* SPDX-License-Identifier: GPL-2.0 */
6 #include <linux/netdevice.h>
7 #include <linux/static_key.h>
8 #include <linux/netfilter.h>
9 #include <uapi/linux/netfilter/x_tables.h>
11 /* Test a struct->invflags and a boolean for inequality */
12 #define NF_INVF(ptr, flag, boolean) \
13 ((boolean) ^ !!((ptr)->invflags & (flag)))
16 * struct xt_action_param - parameters for matches/targets
18 * @match: the match extension
19 * @target: the target extension
20 * @matchinfo: per-match data
21 * @targetinfo: per-target data
22 * @state: pointer to hook state this packet came from
23 * @fragoff: packet is a fragment, this is the data offset
24 * @thoff: position of transport header relative to skb->data
26 * Fields written to by extensions:
28 * @hotdrop: drop packet if we had inspection problems
30 struct xt_action_param {
32 const struct xt_match *match;
33 const struct xt_target *target;
36 const void *matchinfo, *targinfo;
38 const struct nf_hook_state *state;
44 static inline struct net *xt_net(const struct xt_action_param *par)
46 return par->state->net;
49 static inline struct net_device *xt_in(const struct xt_action_param *par)
51 return par->state->in;
54 static inline const char *xt_inname(const struct xt_action_param *par)
56 return par->state->in->name;
59 static inline struct net_device *xt_out(const struct xt_action_param *par)
61 return par->state->out;
64 static inline const char *xt_outname(const struct xt_action_param *par)
66 return par->state->out->name;
69 static inline unsigned int xt_hooknum(const struct xt_action_param *par)
71 return par->state->hook;
74 static inline u_int8_t xt_family(const struct xt_action_param *par)
76 return par->state->pf;
80 * struct xt_mtchk_param - parameters for match extensions'
81 * checkentry functions
83 * @net: network namespace through which the check was invoked
84 * @table: table the rule is tried to be inserted into
85 * @entryinfo: the family-specific rule data
86 * (struct ipt_ip, ip6t_ip, arpt_arp or (note) ebt_entry)
87 * @match: struct xt_match through which this function was invoked
88 * @matchinfo: per-match data
89 * @hook_mask: via which hooks the new rule is reachable
90 * Other fields as above.
92 struct xt_mtchk_param {
95 const void *entryinfo;
96 const struct xt_match *match;
98 unsigned int hook_mask;
104 * struct xt_mdtor_param - match destructor parameters
107 struct xt_mtdtor_param {
109 const struct xt_match *match;
115 * struct xt_tgchk_param - parameters for target extensions'
116 * checkentry functions
118 * @entryinfo: the family-specific rule data
119 * (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
121 * Other fields see above.
123 struct xt_tgchk_param {
126 const void *entryinfo;
127 const struct xt_target *target;
129 unsigned int hook_mask;
134 /* Target destructor parameters */
135 struct xt_tgdtor_param {
137 const struct xt_target *target;
143 struct list_head list;
145 const char name[XT_EXTENSION_MAXNAMELEN];
148 /* Return true or false: return FALSE and set *hotdrop = 1 to
149 force immediate packet drop. */
150 /* Arguments changed since 2.6.9, as this must now handle
151 non-linear skb, using skb_header_pointer and
152 skb_ip_make_writable. */
153 bool (*match)(const struct sk_buff *skb,
154 struct xt_action_param *);
156 /* Called when user tries to insert an entry of this type. */
157 int (*checkentry)(const struct xt_mtchk_param *);
159 /* Called when entry of this type deleted. */
160 void (*destroy)(const struct xt_mtdtor_param *);
162 /* Called when userspace align differs from kernel space one */
163 void (*compat_from_user)(void *dst, const void *src);
164 int (*compat_to_user)(void __user *dst, const void *src);
166 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
170 unsigned int matchsize;
171 unsigned int usersize;
173 unsigned int compatsize;
176 unsigned short proto;
178 unsigned short family;
181 /* Registration hooks for targets. */
183 struct list_head list;
185 const char name[XT_EXTENSION_MAXNAMELEN];
188 /* Returns verdict. Argument order changed since 2.6.9, as this
189 must now handle non-linear skbs, using skb_copy_bits and
190 skb_ip_make_writable. */
191 unsigned int (*target)(struct sk_buff *skb,
192 const struct xt_action_param *);
194 /* Called when user tries to insert an entry of this type:
195 hook_mask is a bitmask of hooks from which it can be
197 /* Should return 0 on success or an error code otherwise (-Exxxx). */
198 int (*checkentry)(const struct xt_tgchk_param *);
200 /* Called when entry of this type deleted. */
201 void (*destroy)(const struct xt_tgdtor_param *);
203 /* Called when userspace align differs from kernel space one */
204 void (*compat_from_user)(void *dst, const void *src);
205 int (*compat_to_user)(void __user *dst, const void *src);
207 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
211 unsigned int targetsize;
212 unsigned int usersize;
214 unsigned int compatsize;
217 unsigned short proto;
219 unsigned short family;
222 /* Furniture shopping... */
224 struct list_head list;
226 /* What hooks you will enter on */
227 unsigned int valid_hooks;
229 /* Man behind the curtain... */
230 struct xt_table_info *private;
232 /* Set this to THIS_MODULE if you are a module, otherwise NULL */
235 u_int8_t af; /* address/protocol family */
236 int priority; /* hook order */
238 /* called when table is needed in the given netns */
239 int (*table_init)(struct net *net);
241 /* A unique name... */
242 const char name[XT_TABLE_MAXNAMELEN];
245 #include <linux/netfilter_ipv4.h>
247 /* The table itself */
248 struct xt_table_info {
251 /* Number of entries: FIXME. --RR */
253 /* Initial number of entries. Needed for module usage count */
254 unsigned int initial_entries;
256 /* Entry points and underflows */
257 unsigned int hook_entry[NF_INET_NUMHOOKS];
258 unsigned int underflow[NF_INET_NUMHOOKS];
261 * Number of user chains. Since tables cannot have loops, at most
262 * @stacksize jumps (number of user chains) can possibly be made.
264 unsigned int stacksize;
267 unsigned char entries[0] __aligned(8);
270 int xt_register_target(struct xt_target *target);
271 void xt_unregister_target(struct xt_target *target);
272 int xt_register_targets(struct xt_target *target, unsigned int n);
273 void xt_unregister_targets(struct xt_target *target, unsigned int n);
275 int xt_register_match(struct xt_match *target);
276 void xt_unregister_match(struct xt_match *target);
277 int xt_register_matches(struct xt_match *match, unsigned int n);
278 void xt_unregister_matches(struct xt_match *match, unsigned int n);
280 int xt_check_entry_offsets(const void *base, const char *elems,
281 unsigned int target_offset,
282 unsigned int next_offset);
284 unsigned int *xt_alloc_entry_offsets(unsigned int size);
285 bool xt_find_jump_offset(const unsigned int *offsets,
286 unsigned int target, unsigned int size);
288 int xt_check_match(struct xt_mtchk_param *, unsigned int size, u_int8_t proto,
290 int xt_check_target(struct xt_tgchk_param *, unsigned int size, u_int8_t proto,
293 int xt_match_to_user(const struct xt_entry_match *m,
294 struct xt_entry_match __user *u);
295 int xt_target_to_user(const struct xt_entry_target *t,
296 struct xt_entry_target __user *u);
297 int xt_data_to_user(void __user *dst, const void *src,
298 int usersize, int size, int aligned_size);
300 void *xt_copy_counters_from_user(const void __user *user, unsigned int len,
301 struct xt_counters_info *info, bool compat);
303 struct xt_table *xt_register_table(struct net *net,
304 const struct xt_table *table,
305 struct xt_table_info *bootstrap,
306 struct xt_table_info *newinfo);
307 void *xt_unregister_table(struct xt_table *table);
309 struct xt_table_info *xt_replace_table(struct xt_table *table,
310 unsigned int num_counters,
311 struct xt_table_info *newinfo,
314 struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
315 struct xt_target *xt_find_target(u8 af, const char *name, u8 revision);
316 struct xt_match *xt_request_find_match(u8 af, const char *name, u8 revision);
317 struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision);
318 int xt_find_revision(u8 af, const char *name, u8 revision, int target,
321 struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
323 struct xt_table *xt_request_find_table_lock(struct net *net, u_int8_t af,
325 void xt_table_unlock(struct xt_table *t);
327 int xt_proto_init(struct net *net, u_int8_t af);
328 void xt_proto_fini(struct net *net, u_int8_t af);
330 struct xt_table_info *xt_alloc_table_info(unsigned int size);
331 void xt_free_table_info(struct xt_table_info *info);
334 * xt_recseq - recursive seqcount for netfilter use
336 * Packet processing changes the seqcount only if no recursion happened
337 * get_counters() can use read_seqcount_begin()/read_seqcount_retry(),
338 * because we use the normal seqcount convention :
339 * Low order bit set to 1 if a writer is active.
341 DECLARE_PER_CPU(seqcount_t, xt_recseq);
343 /* xt_tee_enabled - true if x_tables needs to handle reentrancy
345 * Enabled if current ip(6)tables ruleset has at least one -j TEE rule.
347 extern struct static_key xt_tee_enabled;
350 * xt_write_recseq_begin - start of a write section
352 * Begin packet processing : all readers must wait the end
353 * 1) Must be called with preemption disabled
354 * 2) softirqs must be disabled too (or we should use this_cpu_add())
356 * 1 if no recursion on this cpu
357 * 0 if recursion detected
359 static inline unsigned int xt_write_recseq_begin(void)
364 * Low order bit of sequence is set if we already
365 * called xt_write_recseq_begin().
367 addend = (__this_cpu_read(xt_recseq.sequence) + 1) & 1;
370 * This is kind of a write_seqcount_begin(), but addend is 0 or 1
371 * We dont check addend value to avoid a test and conditional jump,
372 * since addend is most likely 1
374 __this_cpu_add(xt_recseq.sequence, addend);
381 * xt_write_recseq_end - end of a write section
382 * @addend: return value from previous xt_write_recseq_begin()
384 * End packet processing : all readers can proceed
385 * 1) Must be called with preemption disabled
386 * 2) softirqs must be disabled too (or we should use this_cpu_add())
388 static inline void xt_write_recseq_end(unsigned int addend)
390 /* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
392 __this_cpu_add(xt_recseq.sequence, addend);
396 * This helper is performance critical and must be inlined
398 static inline unsigned long ifname_compare_aligned(const char *_a,
402 const unsigned long *a = (const unsigned long *)_a;
403 const unsigned long *b = (const unsigned long *)_b;
404 const unsigned long *mask = (const unsigned long *)_mask;
407 ret = (a[0] ^ b[0]) & mask[0];
408 if (IFNAMSIZ > sizeof(unsigned long))
409 ret |= (a[1] ^ b[1]) & mask[1];
410 if (IFNAMSIZ > 2 * sizeof(unsigned long))
411 ret |= (a[2] ^ b[2]) & mask[2];
412 if (IFNAMSIZ > 3 * sizeof(unsigned long))
413 ret |= (a[3] ^ b[3]) & mask[3];
414 BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
418 struct xt_percpu_counter_alloc_state {
420 const char __percpu *mem;
423 bool xt_percpu_counter_alloc(struct xt_percpu_counter_alloc_state *state,
424 struct xt_counters *counter);
425 void xt_percpu_counter_free(struct xt_counters *cnt);
427 static inline struct xt_counters *
428 xt_get_this_cpu_counter(struct xt_counters *cnt)
431 return this_cpu_ptr((void __percpu *) (unsigned long) cnt->pcnt);
436 static inline struct xt_counters *
437 xt_get_per_cpu_counter(struct xt_counters *cnt, unsigned int cpu)
440 return per_cpu_ptr((void __percpu *) (unsigned long) cnt->pcnt, cpu);
445 struct nf_hook_ops *xt_hook_ops_alloc(const struct xt_table *, nf_hookfn *);
448 #include <net/compat.h>
450 struct compat_xt_entry_match {
453 u_int16_t match_size;
454 char name[XT_FUNCTION_MAXNAMELEN - 1];
458 u_int16_t match_size;
461 u_int16_t match_size;
463 unsigned char data[0];
466 struct compat_xt_entry_target {
469 u_int16_t target_size;
470 char name[XT_FUNCTION_MAXNAMELEN - 1];
474 u_int16_t target_size;
475 compat_uptr_t target;
477 u_int16_t target_size;
479 unsigned char data[0];
482 /* FIXME: this works only on 32 bit tasks
483 * need to change whole approach in order to calculate align as function of
484 * current task alignment */
486 struct compat_xt_counters {
487 compat_u64 pcnt, bcnt; /* Packet and byte counters */
490 struct compat_xt_counters_info {
491 char name[XT_TABLE_MAXNAMELEN];
492 compat_uint_t num_counters;
493 struct compat_xt_counters counters[0];
496 struct _compat_xt_align {
503 #define COMPAT_XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _compat_xt_align))
505 void xt_compat_lock(u_int8_t af);
506 void xt_compat_unlock(u_int8_t af);
508 int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta);
509 void xt_compat_flush_offsets(u_int8_t af);
510 void xt_compat_init_offsets(u_int8_t af, unsigned int number);
511 int xt_compat_calc_jump(u_int8_t af, unsigned int offset);
513 int xt_compat_match_offset(const struct xt_match *match);
514 void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
516 int xt_compat_match_to_user(const struct xt_entry_match *m,
517 void __user **dstptr, unsigned int *size);
519 int xt_compat_target_offset(const struct xt_target *target);
520 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
522 int xt_compat_target_to_user(const struct xt_entry_target *t,
523 void __user **dstptr, unsigned int *size);
524 int xt_compat_check_entry_offsets(const void *base, const char *elems,
525 unsigned int target_offset,
526 unsigned int next_offset);
528 #endif /* CONFIG_COMPAT */
529 #endif /* _X_TABLES_H */