1 #ifndef _NET_NF_TABLES_H
2 #define _NET_NF_TABLES_H
3 
4 #include <linux/module.h>
5 #include <linux/list.h>
6 #include <linux/netfilter.h>
7 #include <linux/netfilter/nfnetlink.h>
8 #include <linux/netfilter/x_tables.h>
9 #include <linux/netfilter/nf_tables.h>
10 #include <linux/u64_stats_sync.h>
11 #include <net/netlink.h>
12 
13 #define NFT_JUMP_STACK_SIZE	16
14 
15 struct nft_pktinfo {
16 	struct sk_buff			*skb;
17 	struct net			*net;
18 	const struct net_device		*in;
19 	const struct net_device		*out;
20 	u8				pf;
21 	u8				hook;
22 	u8				tprot;
23 	/* for x_tables compatibility */
24 	struct xt_action_param		xt;
25 };
26 
27 static inline void nft_set_pktinfo(struct nft_pktinfo *pkt,
28 				   struct sk_buff *skb,
29 				   const struct nf_hook_state *state)
30 {
31 	pkt->skb = skb;
32 	pkt->net = pkt->xt.net = state->net;
33 	pkt->in = pkt->xt.in = state->in;
34 	pkt->out = pkt->xt.out = state->out;
35 	pkt->hook = pkt->xt.hooknum = state->hook;
36 	pkt->pf = pkt->xt.family = state->pf;
37 }
38 
39 /**
40  * 	struct nft_verdict - nf_tables verdict
41  *
42  * 	@code: nf_tables/netfilter verdict code
43  * 	@chain: destination chain for NFT_JUMP/NFT_GOTO
44  */
45 struct nft_verdict {
46 	u32				code;
47 	struct nft_chain		*chain;
48 };
49 
50 struct nft_data {
51 	union {
52 		u32			data[4];
53 		struct nft_verdict	verdict;
54 	};
55 } __attribute__((aligned(__alignof__(u64))));
56 
57 /**
58  *	struct nft_regs - nf_tables register set
59  *
60  *	@data: data registers
61  *	@verdict: verdict register
62  *
63  *	The first four data registers alias to the verdict register.
64  */
65 struct nft_regs {
66 	union {
67 		u32			data[20];
68 		struct nft_verdict	verdict;
69 	};
70 };
71 
72 static inline void nft_data_copy(u32 *dst, const struct nft_data *src,
73 				 unsigned int len)
74 {
75 	memcpy(dst, src, len);
76 }
77 
78 static inline void nft_data_debug(const struct nft_data *data)
79 {
80 	pr_debug("data[0]=%x data[1]=%x data[2]=%x data[3]=%x\n",
81 		 data->data[0], data->data[1],
82 		 data->data[2], data->data[3]);
83 }
84 
85 /**
86  *	struct nft_ctx - nf_tables rule/set context
87  *
88  *	@net: net namespace
89  * 	@afi: address family info
90  * 	@table: the table the chain is contained in
91  * 	@chain: the chain the rule is contained in
92  *	@nla: netlink attributes
93  *	@portid: netlink portID of the original message
94  *	@seq: netlink sequence number
95  *	@report: notify via unicast netlink message
96  */
97 struct nft_ctx {
98 	struct net			*net;
99 	struct nft_af_info		*afi;
100 	struct nft_table		*table;
101 	struct nft_chain		*chain;
102 	const struct nlattr * const 	*nla;
103 	u32				portid;
104 	u32				seq;
105 	bool				report;
106 };
107 
108 struct nft_data_desc {
109 	enum nft_data_types		type;
110 	unsigned int			len;
111 };
112 
113 int nft_data_init(const struct nft_ctx *ctx,
114 		  struct nft_data *data, unsigned int size,
115 		  struct nft_data_desc *desc, const struct nlattr *nla);
116 void nft_data_uninit(const struct nft_data *data, enum nft_data_types type);
117 int nft_data_dump(struct sk_buff *skb, int attr, const struct nft_data *data,
118 		  enum nft_data_types type, unsigned int len);
119 
120 static inline enum nft_data_types nft_dreg_to_type(enum nft_registers reg)
121 {
122 	return reg == NFT_REG_VERDICT ? NFT_DATA_VERDICT : NFT_DATA_VALUE;
123 }
124 
125 static inline enum nft_registers nft_type_to_reg(enum nft_data_types type)
126 {
127 	return type == NFT_DATA_VERDICT ? NFT_REG_VERDICT : NFT_REG_1 * NFT_REG_SIZE / NFT_REG32_SIZE;
128 }
129 
130 unsigned int nft_parse_register(const struct nlattr *attr);
131 int nft_dump_register(struct sk_buff *skb, unsigned int attr, unsigned int reg);
132 
133 int nft_validate_register_load(enum nft_registers reg, unsigned int len);
134 int nft_validate_register_store(const struct nft_ctx *ctx,
135 				enum nft_registers reg,
136 				const struct nft_data *data,
137 				enum nft_data_types type, unsigned int len);
138 
139 /**
140  *	struct nft_userdata - user defined data associated with an object
141  *
142  *	@len: length of the data
143  *	@data: content
144  *
145  *	The presence of user data is indicated in an object specific fashion,
146  *	so a length of zero can't occur and the value "len" indicates data
147  *	of length len + 1.
148  */
149 struct nft_userdata {
150 	u8			len;
151 	unsigned char		data[0];
152 };
153 
154 /**
155  *	struct nft_set_elem - generic representation of set elements
156  *
157  *	@key: element key
158  *	@priv: element private data and extensions
159  */
160 struct nft_set_elem {
161 	union {
162 		u32		buf[NFT_DATA_VALUE_MAXLEN / sizeof(u32)];
163 		struct nft_data	val;
164 	} key;
165 	void			*priv;
166 };
167 
168 struct nft_set;
169 struct nft_set_iter {
170 	u8		genmask;
171 	unsigned int	count;
172 	unsigned int	skip;
173 	int		err;
174 	int		(*fn)(const struct nft_ctx *ctx,
175 			      const struct nft_set *set,
176 			      const struct nft_set_iter *iter,
177 			      const struct nft_set_elem *elem);
178 };
179 
180 /**
181  *	struct nft_set_desc - description of set elements
182  *
183  *	@klen: key length
184  *	@dlen: data length
185  *	@size: number of set elements
186  */
187 struct nft_set_desc {
188 	unsigned int		klen;
189 	unsigned int		dlen;
190 	unsigned int		size;
191 };
192 
193 /**
194  *	enum nft_set_class - performance class
195  *
196  *	@NFT_LOOKUP_O_1: constant, O(1)
197  *	@NFT_LOOKUP_O_LOG_N: logarithmic, O(log N)
198  *	@NFT_LOOKUP_O_N: linear, O(N)
199  */
200 enum nft_set_class {
201 	NFT_SET_CLASS_O_1,
202 	NFT_SET_CLASS_O_LOG_N,
203 	NFT_SET_CLASS_O_N,
204 };
205 
206 /**
207  *	struct nft_set_estimate - estimation of memory and performance
208  *				  characteristics
209  *
210  *	@size: required memory
211  *	@class: lookup performance class
212  */
213 struct nft_set_estimate {
214 	unsigned int		size;
215 	enum nft_set_class	class;
216 };
217 
218 struct nft_set_ext;
219 struct nft_expr;
220 
221 /**
222  *	struct nft_set_ops - nf_tables set operations
223  *
224  *	@lookup: look up an element within the set
225  *	@insert: insert new element into set
226  *	@activate: activate new element in the next generation
227  *	@deactivate: deactivate element in the next generation
228  *	@remove: remove element from set
229  *	@walk: iterate over all set elemeennts
230  *	@privsize: function to return size of set private data
231  *	@init: initialize private data of new set instance
232  *	@destroy: destroy private data of set instance
233  *	@list: nf_tables_set_ops list node
234  *	@owner: module reference
235  *	@elemsize: element private size
236  *	@features: features supported by the implementation
237  */
238 struct nft_set_ops {
239 	bool				(*lookup)(const struct nft_set *set,
240 						  const u32 *key,
241 						  const struct nft_set_ext **ext);
242 	bool				(*update)(struct nft_set *set,
243 						  const u32 *key,
244 						  void *(*new)(struct nft_set *,
245 							       const struct nft_expr *,
246 							       struct nft_regs *),
247 						  const struct nft_expr *expr,
248 						  struct nft_regs *regs,
249 						  const struct nft_set_ext **ext);
250 
251 	int				(*insert)(const struct nft_set *set,
252 						  const struct nft_set_elem *elem);
253 	void				(*activate)(const struct nft_set *set,
254 						    const struct nft_set_elem *elem);
255 	void *				(*deactivate)(const struct nft_set *set,
256 						      const struct nft_set_elem *elem);
257 	void				(*remove)(const struct nft_set *set,
258 						  const struct nft_set_elem *elem);
259 	void				(*walk)(const struct nft_ctx *ctx,
260 						const struct nft_set *set,
261 						struct nft_set_iter *iter);
262 
263 	unsigned int			(*privsize)(const struct nlattr * const nla[]);
264 	bool				(*estimate)(const struct nft_set_desc *desc,
265 						    u32 features,
266 						    struct nft_set_estimate *est);
267 	int				(*init)(const struct nft_set *set,
268 						const struct nft_set_desc *desc,
269 						const struct nlattr * const nla[]);
270 	void				(*destroy)(const struct nft_set *set);
271 
272 	struct list_head		list;
273 	struct module			*owner;
274 	unsigned int			elemsize;
275 	u32				features;
276 };
277 
278 int nft_register_set(struct nft_set_ops *ops);
279 void nft_unregister_set(struct nft_set_ops *ops);
280 
281 /**
282  * 	struct nft_set - nf_tables set instance
283  *
284  *	@list: table set list node
285  *	@bindings: list of set bindings
286  * 	@name: name of the set
287  * 	@ktype: key type (numeric type defined by userspace, not used in the kernel)
288  * 	@dtype: data type (verdict or numeric type defined by userspace)
289  * 	@size: maximum set size
290  * 	@nelems: number of elements
291  * 	@ndeact: number of deactivated elements queued for removal
292  * 	@timeout: default timeout value in msecs
293  * 	@gc_int: garbage collection interval in msecs
294  *	@policy: set parameterization (see enum nft_set_policies)
295  *	@udlen: user data length
296  *	@udata: user data
297  * 	@ops: set ops
298  * 	@pnet: network namespace
299  * 	@flags: set flags
300  * 	@klen: key length
301  * 	@dlen: data length
302  * 	@data: private set data
303  */
304 struct nft_set {
305 	struct list_head		list;
306 	struct list_head		bindings;
307 	char				name[NFT_SET_MAXNAMELEN];
308 	u32				ktype;
309 	u32				dtype;
310 	u32				size;
311 	atomic_t			nelems;
312 	u32				ndeact;
313 	u64				timeout;
314 	u32				gc_int;
315 	u16				policy;
316 	u16				udlen;
317 	unsigned char			*udata;
318 	/* runtime data below here */
319 	const struct nft_set_ops	*ops ____cacheline_aligned;
320 	possible_net_t			pnet;
321 	u16				flags;
322 	u8				klen;
323 	u8				dlen;
324 	unsigned char			data[]
325 		__attribute__((aligned(__alignof__(u64))));
326 };
327 
328 static inline void *nft_set_priv(const struct nft_set *set)
329 {
330 	return (void *)set->data;
331 }
332 
333 static inline struct nft_set *nft_set_container_of(const void *priv)
334 {
335 	return (void *)priv - offsetof(struct nft_set, data);
336 }
337 
338 struct nft_set *nf_tables_set_lookup(const struct nft_table *table,
339 				     const struct nlattr *nla);
340 struct nft_set *nf_tables_set_lookup_byid(const struct net *net,
341 					  const struct nlattr *nla);
342 
343 static inline unsigned long nft_set_gc_interval(const struct nft_set *set)
344 {
345 	return set->gc_int ? msecs_to_jiffies(set->gc_int) : HZ;
346 }
347 
348 /**
349  *	struct nft_set_binding - nf_tables set binding
350  *
351  *	@list: set bindings list node
352  *	@chain: chain containing the rule bound to the set
353  *	@flags: set action flags
354  *
355  *	A set binding contains all information necessary for validation
356  *	of new elements added to a bound set.
357  */
358 struct nft_set_binding {
359 	struct list_head		list;
360 	const struct nft_chain		*chain;
361 	u32				flags;
362 };
363 
364 int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
365 		       struct nft_set_binding *binding);
366 void nf_tables_unbind_set(const struct nft_ctx *ctx, struct nft_set *set,
367 			  struct nft_set_binding *binding);
368 
369 /**
370  *	enum nft_set_extensions - set extension type IDs
371  *
372  *	@NFT_SET_EXT_KEY: element key
373  *	@NFT_SET_EXT_DATA: mapping data
374  *	@NFT_SET_EXT_FLAGS: element flags
375  *	@NFT_SET_EXT_TIMEOUT: element timeout
376  *	@NFT_SET_EXT_EXPIRATION: element expiration time
377  *	@NFT_SET_EXT_USERDATA: user data associated with the element
378  *	@NFT_SET_EXT_EXPR: expression assiociated with the element
379  *	@NFT_SET_EXT_NUM: number of extension types
380  */
381 enum nft_set_extensions {
382 	NFT_SET_EXT_KEY,
383 	NFT_SET_EXT_DATA,
384 	NFT_SET_EXT_FLAGS,
385 	NFT_SET_EXT_TIMEOUT,
386 	NFT_SET_EXT_EXPIRATION,
387 	NFT_SET_EXT_USERDATA,
388 	NFT_SET_EXT_EXPR,
389 	NFT_SET_EXT_NUM
390 };
391 
392 /**
393  *	struct nft_set_ext_type - set extension type
394  *
395  * 	@len: fixed part length of the extension
396  * 	@align: alignment requirements of the extension
397  */
398 struct nft_set_ext_type {
399 	u8	len;
400 	u8	align;
401 };
402 
403 extern const struct nft_set_ext_type nft_set_ext_types[];
404 
405 /**
406  *	struct nft_set_ext_tmpl - set extension template
407  *
408  *	@len: length of extension area
409  *	@offset: offsets of individual extension types
410  */
411 struct nft_set_ext_tmpl {
412 	u16	len;
413 	u8	offset[NFT_SET_EXT_NUM];
414 };
415 
416 /**
417  *	struct nft_set_ext - set extensions
418  *
419  *	@genmask: generation mask
420  *	@offset: offsets of individual extension types
421  *	@data: beginning of extension data
422  */
423 struct nft_set_ext {
424 	u8	genmask;
425 	u8	offset[NFT_SET_EXT_NUM];
426 	char	data[0];
427 };
428 
429 static inline void nft_set_ext_prepare(struct nft_set_ext_tmpl *tmpl)
430 {
431 	memset(tmpl, 0, sizeof(*tmpl));
432 	tmpl->len = sizeof(struct nft_set_ext);
433 }
434 
435 static inline void nft_set_ext_add_length(struct nft_set_ext_tmpl *tmpl, u8 id,
436 					  unsigned int len)
437 {
438 	tmpl->len	 = ALIGN(tmpl->len, nft_set_ext_types[id].align);
439 	BUG_ON(tmpl->len > U8_MAX);
440 	tmpl->offset[id] = tmpl->len;
441 	tmpl->len	+= nft_set_ext_types[id].len + len;
442 }
443 
444 static inline void nft_set_ext_add(struct nft_set_ext_tmpl *tmpl, u8 id)
445 {
446 	nft_set_ext_add_length(tmpl, id, 0);
447 }
448 
449 static inline void nft_set_ext_init(struct nft_set_ext *ext,
450 				    const struct nft_set_ext_tmpl *tmpl)
451 {
452 	memcpy(ext->offset, tmpl->offset, sizeof(ext->offset));
453 }
454 
455 static inline bool __nft_set_ext_exists(const struct nft_set_ext *ext, u8 id)
456 {
457 	return !!ext->offset[id];
458 }
459 
460 static inline bool nft_set_ext_exists(const struct nft_set_ext *ext, u8 id)
461 {
462 	return ext && __nft_set_ext_exists(ext, id);
463 }
464 
465 static inline void *nft_set_ext(const struct nft_set_ext *ext, u8 id)
466 {
467 	return (void *)ext + ext->offset[id];
468 }
469 
470 static inline struct nft_data *nft_set_ext_key(const struct nft_set_ext *ext)
471 {
472 	return nft_set_ext(ext, NFT_SET_EXT_KEY);
473 }
474 
475 static inline struct nft_data *nft_set_ext_data(const struct nft_set_ext *ext)
476 {
477 	return nft_set_ext(ext, NFT_SET_EXT_DATA);
478 }
479 
480 static inline u8 *nft_set_ext_flags(const struct nft_set_ext *ext)
481 {
482 	return nft_set_ext(ext, NFT_SET_EXT_FLAGS);
483 }
484 
485 static inline u64 *nft_set_ext_timeout(const struct nft_set_ext *ext)
486 {
487 	return nft_set_ext(ext, NFT_SET_EXT_TIMEOUT);
488 }
489 
490 static inline unsigned long *nft_set_ext_expiration(const struct nft_set_ext *ext)
491 {
492 	return nft_set_ext(ext, NFT_SET_EXT_EXPIRATION);
493 }
494 
495 static inline struct nft_userdata *nft_set_ext_userdata(const struct nft_set_ext *ext)
496 {
497 	return nft_set_ext(ext, NFT_SET_EXT_USERDATA);
498 }
499 
500 static inline struct nft_expr *nft_set_ext_expr(const struct nft_set_ext *ext)
501 {
502 	return nft_set_ext(ext, NFT_SET_EXT_EXPR);
503 }
504 
505 static inline bool nft_set_elem_expired(const struct nft_set_ext *ext)
506 {
507 	return nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION) &&
508 	       time_is_before_eq_jiffies(*nft_set_ext_expiration(ext));
509 }
510 
511 static inline struct nft_set_ext *nft_set_elem_ext(const struct nft_set *set,
512 						   void *elem)
513 {
514 	return elem + set->ops->elemsize;
515 }
516 
517 void *nft_set_elem_init(const struct nft_set *set,
518 			const struct nft_set_ext_tmpl *tmpl,
519 			const u32 *key, const u32 *data,
520 			u64 timeout, gfp_t gfp);
521 void nft_set_elem_destroy(const struct nft_set *set, void *elem);
522 
523 /**
524  *	struct nft_set_gc_batch_head - nf_tables set garbage collection batch
525  *
526  *	@rcu: rcu head
527  *	@set: set the elements belong to
528  *	@cnt: count of elements
529  */
530 struct nft_set_gc_batch_head {
531 	struct rcu_head			rcu;
532 	const struct nft_set		*set;
533 	unsigned int			cnt;
534 };
535 
536 #define NFT_SET_GC_BATCH_SIZE	((PAGE_SIZE -				  \
537 				  sizeof(struct nft_set_gc_batch_head)) / \
538 				 sizeof(void *))
539 
540 /**
541  *	struct nft_set_gc_batch - nf_tables set garbage collection batch
542  *
543  * 	@head: GC batch head
544  * 	@elems: garbage collection elements
545  */
546 struct nft_set_gc_batch {
547 	struct nft_set_gc_batch_head	head;
548 	void				*elems[NFT_SET_GC_BATCH_SIZE];
549 };
550 
551 struct nft_set_gc_batch *nft_set_gc_batch_alloc(const struct nft_set *set,
552 						gfp_t gfp);
553 void nft_set_gc_batch_release(struct rcu_head *rcu);
554 
555 static inline void nft_set_gc_batch_complete(struct nft_set_gc_batch *gcb)
556 {
557 	if (gcb != NULL)
558 		call_rcu(&gcb->head.rcu, nft_set_gc_batch_release);
559 }
560 
561 static inline struct nft_set_gc_batch *
562 nft_set_gc_batch_check(const struct nft_set *set, struct nft_set_gc_batch *gcb,
563 		       gfp_t gfp)
564 {
565 	if (gcb != NULL) {
566 		if (gcb->head.cnt + 1 < ARRAY_SIZE(gcb->elems))
567 			return gcb;
568 		nft_set_gc_batch_complete(gcb);
569 	}
570 	return nft_set_gc_batch_alloc(set, gfp);
571 }
572 
573 static inline void nft_set_gc_batch_add(struct nft_set_gc_batch *gcb,
574 					void *elem)
575 {
576 	gcb->elems[gcb->head.cnt++] = elem;
577 }
578 
579 /**
580  *	struct nft_expr_type - nf_tables expression type
581  *
582  *	@select_ops: function to select nft_expr_ops
583  *	@ops: default ops, used when no select_ops functions is present
584  *	@list: used internally
585  *	@name: Identifier
586  *	@owner: module reference
587  *	@policy: netlink attribute policy
588  *	@maxattr: highest netlink attribute number
589  *	@family: address family for AF-specific types
590  *	@flags: expression type flags
591  */
592 struct nft_expr_type {
593 	const struct nft_expr_ops	*(*select_ops)(const struct nft_ctx *,
594 						       const struct nlattr * const tb[]);
595 	const struct nft_expr_ops	*ops;
596 	struct list_head		list;
597 	const char			*name;
598 	struct module			*owner;
599 	const struct nla_policy		*policy;
600 	unsigned int			maxattr;
601 	u8				family;
602 	u8				flags;
603 };
604 
605 #define NFT_EXPR_STATEFUL		0x1
606 
607 /**
608  *	struct nft_expr_ops - nf_tables expression operations
609  *
610  *	@eval: Expression evaluation function
611  *	@size: full expression size, including private data size
612  *	@init: initialization function
613  *	@destroy: destruction function
614  *	@dump: function to dump parameters
615  *	@type: expression type
616  *	@validate: validate expression, called during loop detection
617  *	@data: extra data to attach to this expression operation
618  */
619 struct nft_expr;
620 struct nft_expr_ops {
621 	void				(*eval)(const struct nft_expr *expr,
622 						struct nft_regs *regs,
623 						const struct nft_pktinfo *pkt);
624 	int				(*clone)(struct nft_expr *dst,
625 						 const struct nft_expr *src);
626 	unsigned int			size;
627 
628 	int				(*init)(const struct nft_ctx *ctx,
629 						const struct nft_expr *expr,
630 						const struct nlattr * const tb[]);
631 	void				(*destroy)(const struct nft_ctx *ctx,
632 						   const struct nft_expr *expr);
633 	int				(*dump)(struct sk_buff *skb,
634 						const struct nft_expr *expr);
635 	int				(*validate)(const struct nft_ctx *ctx,
636 						    const struct nft_expr *expr,
637 						    const struct nft_data **data);
638 	const struct nft_expr_type	*type;
639 	void				*data;
640 };
641 
642 #define NFT_EXPR_MAXATTR		16
643 #define NFT_EXPR_SIZE(size)		(sizeof(struct nft_expr) + \
644 					 ALIGN(size, __alignof__(struct nft_expr)))
645 
646 /**
647  *	struct nft_expr - nf_tables expression
648  *
649  *	@ops: expression ops
650  *	@data: expression private data
651  */
652 struct nft_expr {
653 	const struct nft_expr_ops	*ops;
654 	unsigned char			data[];
655 };
656 
657 static inline void *nft_expr_priv(const struct nft_expr *expr)
658 {
659 	return (void *)expr->data;
660 }
661 
662 struct nft_expr *nft_expr_init(const struct nft_ctx *ctx,
663 			       const struct nlattr *nla);
664 void nft_expr_destroy(const struct nft_ctx *ctx, struct nft_expr *expr);
665 int nft_expr_dump(struct sk_buff *skb, unsigned int attr,
666 		  const struct nft_expr *expr);
667 
668 static inline int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
669 {
670 	int err;
671 
672 	__module_get(src->ops->type->owner);
673 	if (src->ops->clone) {
674 		dst->ops = src->ops;
675 		err = src->ops->clone(dst, src);
676 		if (err < 0)
677 			return err;
678 	} else {
679 		memcpy(dst, src, src->ops->size);
680 	}
681 	return 0;
682 }
683 
684 /**
685  *	struct nft_rule - nf_tables rule
686  *
687  *	@list: used internally
688  *	@handle: rule handle
689  *	@genmask: generation mask
690  *	@dlen: length of expression data
691  *	@udata: user data is appended to the rule
692  *	@data: expression data
693  */
694 struct nft_rule {
695 	struct list_head		list;
696 	u64				handle:42,
697 					genmask:2,
698 					dlen:12,
699 					udata:1;
700 	unsigned char			data[]
701 		__attribute__((aligned(__alignof__(struct nft_expr))));
702 };
703 
704 static inline struct nft_expr *nft_expr_first(const struct nft_rule *rule)
705 {
706 	return (struct nft_expr *)&rule->data[0];
707 }
708 
709 static inline struct nft_expr *nft_expr_next(const struct nft_expr *expr)
710 {
711 	return ((void *)expr) + expr->ops->size;
712 }
713 
714 static inline struct nft_expr *nft_expr_last(const struct nft_rule *rule)
715 {
716 	return (struct nft_expr *)&rule->data[rule->dlen];
717 }
718 
719 static inline struct nft_userdata *nft_userdata(const struct nft_rule *rule)
720 {
721 	return (void *)&rule->data[rule->dlen];
722 }
723 
724 /*
725  * The last pointer isn't really necessary, but the compiler isn't able to
726  * determine that the result of nft_expr_last() is always the same since it
727  * can't assume that the dlen value wasn't changed within calls in the loop.
728  */
729 #define nft_rule_for_each_expr(expr, last, rule) \
730 	for ((expr) = nft_expr_first(rule), (last) = nft_expr_last(rule); \
731 	     (expr) != (last); \
732 	     (expr) = nft_expr_next(expr))
733 
734 enum nft_chain_flags {
735 	NFT_BASE_CHAIN			= 0x1,
736 	NFT_CHAIN_INACTIVE		= 0x2,
737 };
738 
739 /**
740  *	struct nft_chain - nf_tables chain
741  *
742  *	@rules: list of rules in the chain
743  *	@list: used internally
744  *	@table: table that this chain belongs to
745  *	@handle: chain handle
746  *	@use: number of jump references to this chain
747  *	@level: length of longest path to this chain
748  *	@flags: bitmask of enum nft_chain_flags
749  *	@name: name of the chain
750  */
751 struct nft_chain {
752 	struct list_head		rules;
753 	struct list_head		list;
754 	struct nft_table		*table;
755 	u64				handle;
756 	u32				use;
757 	u16				level;
758 	u8				flags;
759 	char				name[NFT_CHAIN_MAXNAMELEN];
760 };
761 
762 enum nft_chain_type {
763 	NFT_CHAIN_T_DEFAULT = 0,
764 	NFT_CHAIN_T_ROUTE,
765 	NFT_CHAIN_T_NAT,
766 	NFT_CHAIN_T_MAX
767 };
768 
769 /**
770  * 	struct nf_chain_type - nf_tables chain type info
771  *
772  * 	@name: name of the type
773  * 	@type: numeric identifier
774  * 	@family: address family
775  * 	@owner: module owner
776  * 	@hook_mask: mask of valid hooks
777  * 	@hooks: hookfn overrides
778  */
779 struct nf_chain_type {
780 	const char			*name;
781 	enum nft_chain_type		type;
782 	int				family;
783 	struct module			*owner;
784 	unsigned int			hook_mask;
785 	nf_hookfn			*hooks[NF_MAX_HOOKS];
786 };
787 
788 int nft_chain_validate_dependency(const struct nft_chain *chain,
789 				  enum nft_chain_type type);
790 int nft_chain_validate_hooks(const struct nft_chain *chain,
791                              unsigned int hook_flags);
792 
793 struct nft_stats {
794 	u64			bytes;
795 	u64			pkts;
796 	struct u64_stats_sync	syncp;
797 };
798 
799 #define NFT_HOOK_OPS_MAX		2
800 #define NFT_BASECHAIN_DISABLED		(1 << 0)
801 
802 /**
803  *	struct nft_base_chain - nf_tables base chain
804  *
805  *	@ops: netfilter hook ops
806  *	@pnet: net namespace that this chain belongs to
807  *	@type: chain type
808  *	@policy: default policy
809  *	@stats: per-cpu chain stats
810  *	@chain: the chain
811  *	@dev_name: device name that this base chain is attached to (if any)
812  */
813 struct nft_base_chain {
814 	struct nf_hook_ops		ops[NFT_HOOK_OPS_MAX];
815 	possible_net_t			pnet;
816 	const struct nf_chain_type	*type;
817 	u8				policy;
818 	u8				flags;
819 	struct nft_stats __percpu	*stats;
820 	struct nft_chain		chain;
821 	char 				dev_name[IFNAMSIZ];
822 };
823 
824 static inline struct nft_base_chain *nft_base_chain(const struct nft_chain *chain)
825 {
826 	return container_of(chain, struct nft_base_chain, chain);
827 }
828 
829 int __nft_release_basechain(struct nft_ctx *ctx);
830 
831 unsigned int nft_do_chain(struct nft_pktinfo *pkt, void *priv);
832 
833 /**
834  *	struct nft_table - nf_tables table
835  *
836  *	@list: used internally
837  *	@chains: chains in the table
838  *	@sets: sets in the table
839  *	@hgenerator: handle generator state
840  *	@use: number of chain references to this table
841  *	@flags: table flag (see enum nft_table_flags)
842  *	@name: name of the table
843  */
844 struct nft_table {
845 	struct list_head		list;
846 	struct list_head		chains;
847 	struct list_head		sets;
848 	u64				hgenerator;
849 	u32				use;
850 	u16				flags;
851 	char				name[NFT_TABLE_MAXNAMELEN];
852 };
853 
854 enum nft_af_flags {
855 	NFT_AF_NEEDS_DEV	= (1 << 0),
856 };
857 
858 /**
859  *	struct nft_af_info - nf_tables address family info
860  *
861  *	@list: used internally
862  *	@family: address family
863  *	@nhooks: number of hooks in this family
864  *	@owner: module owner
865  *	@tables: used internally
866  *	@flags: family flags
867  *	@nops: number of hook ops in this family
868  *	@hook_ops_init: initialization function for chain hook ops
869  *	@hooks: hookfn overrides for packet validation
870  */
871 struct nft_af_info {
872 	struct list_head		list;
873 	int				family;
874 	unsigned int			nhooks;
875 	struct module			*owner;
876 	struct list_head		tables;
877 	u32				flags;
878 	unsigned int			nops;
879 	void				(*hook_ops_init)(struct nf_hook_ops *,
880 							 unsigned int);
881 	nf_hookfn			*hooks[NF_MAX_HOOKS];
882 };
883 
884 int nft_register_afinfo(struct net *, struct nft_af_info *);
885 void nft_unregister_afinfo(struct net *, struct nft_af_info *);
886 
887 int nft_register_chain_type(const struct nf_chain_type *);
888 void nft_unregister_chain_type(const struct nf_chain_type *);
889 
890 int nft_register_expr(struct nft_expr_type *);
891 void nft_unregister_expr(struct nft_expr_type *);
892 
893 int nft_verdict_dump(struct sk_buff *skb, int type,
894 		     const struct nft_verdict *v);
895 
896 /**
897  *	struct nft_traceinfo - nft tracing information and state
898  *
899  *	@pkt: pktinfo currently processed
900  *	@basechain: base chain currently processed
901  *	@chain: chain currently processed
902  *	@rule:  rule that was evaluated
903  *	@verdict: verdict given by rule
904  *	@type: event type (enum nft_trace_types)
905  *	@packet_dumped: packet headers sent in a previous traceinfo message
906  *	@trace: other struct members are initialised
907  */
908 struct nft_traceinfo {
909 	const struct nft_pktinfo	*pkt;
910 	const struct nft_base_chain	*basechain;
911 	const struct nft_chain		*chain;
912 	const struct nft_rule		*rule;
913 	const struct nft_verdict	*verdict;
914 	enum nft_trace_types		type;
915 	bool				packet_dumped;
916 	bool				trace;
917 };
918 
919 void nft_trace_init(struct nft_traceinfo *info, const struct nft_pktinfo *pkt,
920 		    const struct nft_verdict *verdict,
921 		    const struct nft_chain *basechain);
922 
923 void nft_trace_notify(struct nft_traceinfo *info);
924 
925 #define nft_dereference(p)					\
926 	nfnl_dereference(p, NFNL_SUBSYS_NFTABLES)
927 
928 #define MODULE_ALIAS_NFT_FAMILY(family)	\
929 	MODULE_ALIAS("nft-afinfo-" __stringify(family))
930 
931 #define MODULE_ALIAS_NFT_CHAIN(family, name) \
932 	MODULE_ALIAS("nft-chain-" __stringify(family) "-" name)
933 
934 #define MODULE_ALIAS_NFT_AF_EXPR(family, name) \
935 	MODULE_ALIAS("nft-expr-" __stringify(family) "-" name)
936 
937 #define MODULE_ALIAS_NFT_EXPR(name) \
938 	MODULE_ALIAS("nft-expr-" name)
939 
940 #define MODULE_ALIAS_NFT_SET() \
941 	MODULE_ALIAS("nft-set")
942 
943 /*
944  * The gencursor defines two generations, the currently active and the
945  * next one. Objects contain a bitmask of 2 bits specifying the generations
946  * they're active in. A set bit means they're inactive in the generation
947  * represented by that bit.
948  *
949  * New objects start out as inactive in the current and active in the
950  * next generation. When committing the ruleset the bitmask is cleared,
951  * meaning they're active in all generations. When removing an object,
952  * it is set inactive in the next generation. After committing the ruleset,
953  * the objects are removed.
954  */
955 static inline unsigned int nft_gencursor_next(const struct net *net)
956 {
957 	return net->nft.gencursor + 1 == 1 ? 1 : 0;
958 }
959 
960 static inline u8 nft_genmask_next(const struct net *net)
961 {
962 	return 1 << nft_gencursor_next(net);
963 }
964 
965 static inline u8 nft_genmask_cur(const struct net *net)
966 {
967 	/* Use ACCESS_ONCE() to prevent refetching the value for atomicity */
968 	return 1 << ACCESS_ONCE(net->nft.gencursor);
969 }
970 
971 #define NFT_GENMASK_ANY		((1 << 0) | (1 << 1))
972 
973 /*
974  * Set element transaction helpers
975  */
976 
977 static inline bool nft_set_elem_active(const struct nft_set_ext *ext,
978 				       u8 genmask)
979 {
980 	return !(ext->genmask & genmask);
981 }
982 
983 static inline void nft_set_elem_change_active(const struct nft_set *set,
984 					      struct nft_set_ext *ext)
985 {
986 	ext->genmask ^= nft_genmask_next(read_pnet(&set->pnet));
987 }
988 
989 /*
990  * We use a free bit in the genmask field to indicate the element
991  * is busy, meaning it is currently being processed either by
992  * the netlink API or GC.
993  *
994  * Even though the genmask is only a single byte wide, this works
995  * because the extension structure if fully constant once initialized,
996  * so there are no non-atomic write accesses unless it is already
997  * marked busy.
998  */
999 #define NFT_SET_ELEM_BUSY_MASK	(1 << 2)
1000 
1001 #if defined(__LITTLE_ENDIAN_BITFIELD)
1002 #define NFT_SET_ELEM_BUSY_BIT	2
1003 #elif defined(__BIG_ENDIAN_BITFIELD)
1004 #define NFT_SET_ELEM_BUSY_BIT	(BITS_PER_LONG - BITS_PER_BYTE + 2)
1005 #else
1006 #error
1007 #endif
1008 
1009 static inline int nft_set_elem_mark_busy(struct nft_set_ext *ext)
1010 {
1011 	unsigned long *word = (unsigned long *)ext;
1012 
1013 	BUILD_BUG_ON(offsetof(struct nft_set_ext, genmask) != 0);
1014 	return test_and_set_bit(NFT_SET_ELEM_BUSY_BIT, word);
1015 }
1016 
1017 static inline void nft_set_elem_clear_busy(struct nft_set_ext *ext)
1018 {
1019 	unsigned long *word = (unsigned long *)ext;
1020 
1021 	clear_bit(NFT_SET_ELEM_BUSY_BIT, word);
1022 }
1023 
1024 /**
1025  *	struct nft_trans - nf_tables object update in transaction
1026  *
1027  *	@list: used internally
1028  *	@msg_type: message type
1029  *	@ctx: transaction context
1030  *	@data: internal information related to the transaction
1031  */
1032 struct nft_trans {
1033 	struct list_head		list;
1034 	int				msg_type;
1035 	struct nft_ctx			ctx;
1036 	char				data[0];
1037 };
1038 
1039 struct nft_trans_rule {
1040 	struct nft_rule			*rule;
1041 };
1042 
1043 #define nft_trans_rule(trans)	\
1044 	(((struct nft_trans_rule *)trans->data)->rule)
1045 
1046 struct nft_trans_set {
1047 	struct nft_set			*set;
1048 	u32				set_id;
1049 };
1050 
1051 #define nft_trans_set(trans)	\
1052 	(((struct nft_trans_set *)trans->data)->set)
1053 #define nft_trans_set_id(trans)	\
1054 	(((struct nft_trans_set *)trans->data)->set_id)
1055 
1056 struct nft_trans_chain {
1057 	bool				update;
1058 	char				name[NFT_CHAIN_MAXNAMELEN];
1059 	struct nft_stats __percpu	*stats;
1060 	u8				policy;
1061 };
1062 
1063 #define nft_trans_chain_update(trans)	\
1064 	(((struct nft_trans_chain *)trans->data)->update)
1065 #define nft_trans_chain_name(trans)	\
1066 	(((struct nft_trans_chain *)trans->data)->name)
1067 #define nft_trans_chain_stats(trans)	\
1068 	(((struct nft_trans_chain *)trans->data)->stats)
1069 #define nft_trans_chain_policy(trans)	\
1070 	(((struct nft_trans_chain *)trans->data)->policy)
1071 
1072 struct nft_trans_table {
1073 	bool				update;
1074 	bool				enable;
1075 };
1076 
1077 #define nft_trans_table_update(trans)	\
1078 	(((struct nft_trans_table *)trans->data)->update)
1079 #define nft_trans_table_enable(trans)	\
1080 	(((struct nft_trans_table *)trans->data)->enable)
1081 
1082 struct nft_trans_elem {
1083 	struct nft_set			*set;
1084 	struct nft_set_elem		elem;
1085 };
1086 
1087 #define nft_trans_elem_set(trans)	\
1088 	(((struct nft_trans_elem *)trans->data)->set)
1089 #define nft_trans_elem(trans)	\
1090 	(((struct nft_trans_elem *)trans->data)->elem)
1091 
1092 #endif /* _NET_NF_TABLES_H */
1093