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Linux/include/net/netfilter/nf_tables.h

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  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 net *net,
240                                                   const struct nft_set *set,
241                                                   const u32 *key,
242                                                   const struct nft_set_ext **ext);
243         bool                            (*update)(struct nft_set *set,
244                                                   const u32 *key,
245                                                   void *(*new)(struct nft_set *,
246                                                                const struct nft_expr *,
247                                                                struct nft_regs *),
248                                                   const struct nft_expr *expr,
249                                                   struct nft_regs *regs,
250                                                   const struct nft_set_ext **ext);
251 
252         int                             (*insert)(const struct net *net,
253                                                   const struct nft_set *set,
254                                                   const struct nft_set_elem *elem);
255         void                            (*activate)(const struct net *net,
256                                                     const struct nft_set *set,
257                                                     const struct nft_set_elem *elem);
258         void *                          (*deactivate)(const struct net *net,
259                                                       const struct nft_set *set,
260                                                       const struct nft_set_elem *elem);
261         void                            (*remove)(const struct nft_set *set,
262                                                   const struct nft_set_elem *elem);
263         void                            (*walk)(const struct nft_ctx *ctx,
264                                                 const struct nft_set *set,
265                                                 struct nft_set_iter *iter);
266 
267         unsigned int                    (*privsize)(const struct nlattr * const nla[]);
268         bool                            (*estimate)(const struct nft_set_desc *desc,
269                                                     u32 features,
270                                                     struct nft_set_estimate *est);
271         int                             (*init)(const struct nft_set *set,
272                                                 const struct nft_set_desc *desc,
273                                                 const struct nlattr * const nla[]);
274         void                            (*destroy)(const struct nft_set *set);
275 
276         struct list_head                list;
277         struct module                   *owner;
278         unsigned int                    elemsize;
279         u32                             features;
280 };
281 
282 int nft_register_set(struct nft_set_ops *ops);
283 void nft_unregister_set(struct nft_set_ops *ops);
284 
285 /**
286  *      struct nft_set - nf_tables set instance
287  *
288  *      @list: table set list node
289  *      @bindings: list of set bindings
290  *      @name: name of the set
291  *      @ktype: key type (numeric type defined by userspace, not used in the kernel)
292  *      @dtype: data type (verdict or numeric type defined by userspace)
293  *      @size: maximum set size
294  *      @nelems: number of elements
295  *      @ndeact: number of deactivated elements queued for removal
296  *      @timeout: default timeout value in msecs
297  *      @gc_int: garbage collection interval in msecs
298  *      @policy: set parameterization (see enum nft_set_policies)
299  *      @udlen: user data length
300  *      @udata: user data
301  *      @ops: set ops
302  *      @flags: set flags
303  *      @genmask: generation mask
304  *      @klen: key length
305  *      @dlen: data length
306  *      @data: private set data
307  */
308 struct nft_set {
309         struct list_head                list;
310         struct list_head                bindings;
311         char                            name[NFT_SET_MAXNAMELEN];
312         u32                             ktype;
313         u32                             dtype;
314         u32                             size;
315         atomic_t                        nelems;
316         u32                             ndeact;
317         u64                             timeout;
318         u32                             gc_int;
319         u16                             policy;
320         u16                             udlen;
321         unsigned char                   *udata;
322         /* runtime data below here */
323         const struct nft_set_ops        *ops ____cacheline_aligned;
324         u16                             flags:14,
325                                         genmask:2;
326         u8                              klen;
327         u8                              dlen;
328         unsigned char                   data[]
329                 __attribute__((aligned(__alignof__(u64))));
330 };
331 
332 static inline void *nft_set_priv(const struct nft_set *set)
333 {
334         return (void *)set->data;
335 }
336 
337 static inline struct nft_set *nft_set_container_of(const void *priv)
338 {
339         return (void *)priv - offsetof(struct nft_set, data);
340 }
341 
342 struct nft_set *nf_tables_set_lookup(const struct nft_table *table,
343                                      const struct nlattr *nla, u8 genmask);
344 struct nft_set *nf_tables_set_lookup_byid(const struct net *net,
345                                           const struct nlattr *nla, u8 genmask);
346 
347 static inline unsigned long nft_set_gc_interval(const struct nft_set *set)
348 {
349         return set->gc_int ? msecs_to_jiffies(set->gc_int) : HZ;
350 }
351 
352 /**
353  *      struct nft_set_binding - nf_tables set binding
354  *
355  *      @list: set bindings list node
356  *      @chain: chain containing the rule bound to the set
357  *      @flags: set action flags
358  *
359  *      A set binding contains all information necessary for validation
360  *      of new elements added to a bound set.
361  */
362 struct nft_set_binding {
363         struct list_head                list;
364         const struct nft_chain          *chain;
365         u32                             flags;
366 };
367 
368 int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
369                        struct nft_set_binding *binding);
370 void nf_tables_unbind_set(const struct nft_ctx *ctx, struct nft_set *set,
371                           struct nft_set_binding *binding);
372 
373 /**
374  *      enum nft_set_extensions - set extension type IDs
375  *
376  *      @NFT_SET_EXT_KEY: element key
377  *      @NFT_SET_EXT_DATA: mapping data
378  *      @NFT_SET_EXT_FLAGS: element flags
379  *      @NFT_SET_EXT_TIMEOUT: element timeout
380  *      @NFT_SET_EXT_EXPIRATION: element expiration time
381  *      @NFT_SET_EXT_USERDATA: user data associated with the element
382  *      @NFT_SET_EXT_EXPR: expression assiociated with the element
383  *      @NFT_SET_EXT_NUM: number of extension types
384  */
385 enum nft_set_extensions {
386         NFT_SET_EXT_KEY,
387         NFT_SET_EXT_DATA,
388         NFT_SET_EXT_FLAGS,
389         NFT_SET_EXT_TIMEOUT,
390         NFT_SET_EXT_EXPIRATION,
391         NFT_SET_EXT_USERDATA,
392         NFT_SET_EXT_EXPR,
393         NFT_SET_EXT_NUM
394 };
395 
396 /**
397  *      struct nft_set_ext_type - set extension type
398  *
399  *      @len: fixed part length of the extension
400  *      @align: alignment requirements of the extension
401  */
402 struct nft_set_ext_type {
403         u8      len;
404         u8      align;
405 };
406 
407 extern const struct nft_set_ext_type nft_set_ext_types[];
408 
409 /**
410  *      struct nft_set_ext_tmpl - set extension template
411  *
412  *      @len: length of extension area
413  *      @offset: offsets of individual extension types
414  */
415 struct nft_set_ext_tmpl {
416         u16     len;
417         u8      offset[NFT_SET_EXT_NUM];
418 };
419 
420 /**
421  *      struct nft_set_ext - set extensions
422  *
423  *      @genmask: generation mask
424  *      @offset: offsets of individual extension types
425  *      @data: beginning of extension data
426  */
427 struct nft_set_ext {
428         u8      genmask;
429         u8      offset[NFT_SET_EXT_NUM];
430         char    data[0];
431 };
432 
433 static inline void nft_set_ext_prepare(struct nft_set_ext_tmpl *tmpl)
434 {
435         memset(tmpl, 0, sizeof(*tmpl));
436         tmpl->len = sizeof(struct nft_set_ext);
437 }
438 
439 static inline void nft_set_ext_add_length(struct nft_set_ext_tmpl *tmpl, u8 id,
440                                           unsigned int len)
441 {
442         tmpl->len        = ALIGN(tmpl->len, nft_set_ext_types[id].align);
443         BUG_ON(tmpl->len > U8_MAX);
444         tmpl->offset[id] = tmpl->len;
445         tmpl->len       += nft_set_ext_types[id].len + len;
446 }
447 
448 static inline void nft_set_ext_add(struct nft_set_ext_tmpl *tmpl, u8 id)
449 {
450         nft_set_ext_add_length(tmpl, id, 0);
451 }
452 
453 static inline void nft_set_ext_init(struct nft_set_ext *ext,
454                                     const struct nft_set_ext_tmpl *tmpl)
455 {
456         memcpy(ext->offset, tmpl->offset, sizeof(ext->offset));
457 }
458 
459 static inline bool __nft_set_ext_exists(const struct nft_set_ext *ext, u8 id)
460 {
461         return !!ext->offset[id];
462 }
463 
464 static inline bool nft_set_ext_exists(const struct nft_set_ext *ext, u8 id)
465 {
466         return ext && __nft_set_ext_exists(ext, id);
467 }
468 
469 static inline void *nft_set_ext(const struct nft_set_ext *ext, u8 id)
470 {
471         return (void *)ext + ext->offset[id];
472 }
473 
474 static inline struct nft_data *nft_set_ext_key(const struct nft_set_ext *ext)
475 {
476         return nft_set_ext(ext, NFT_SET_EXT_KEY);
477 }
478 
479 static inline struct nft_data *nft_set_ext_data(const struct nft_set_ext *ext)
480 {
481         return nft_set_ext(ext, NFT_SET_EXT_DATA);
482 }
483 
484 static inline u8 *nft_set_ext_flags(const struct nft_set_ext *ext)
485 {
486         return nft_set_ext(ext, NFT_SET_EXT_FLAGS);
487 }
488 
489 static inline u64 *nft_set_ext_timeout(const struct nft_set_ext *ext)
490 {
491         return nft_set_ext(ext, NFT_SET_EXT_TIMEOUT);
492 }
493 
494 static inline unsigned long *nft_set_ext_expiration(const struct nft_set_ext *ext)
495 {
496         return nft_set_ext(ext, NFT_SET_EXT_EXPIRATION);
497 }
498 
499 static inline struct nft_userdata *nft_set_ext_userdata(const struct nft_set_ext *ext)
500 {
501         return nft_set_ext(ext, NFT_SET_EXT_USERDATA);
502 }
503 
504 static inline struct nft_expr *nft_set_ext_expr(const struct nft_set_ext *ext)
505 {
506         return nft_set_ext(ext, NFT_SET_EXT_EXPR);
507 }
508 
509 static inline bool nft_set_elem_expired(const struct nft_set_ext *ext)
510 {
511         return nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION) &&
512                time_is_before_eq_jiffies(*nft_set_ext_expiration(ext));
513 }
514 
515 static inline struct nft_set_ext *nft_set_elem_ext(const struct nft_set *set,
516                                                    void *elem)
517 {
518         return elem + set->ops->elemsize;
519 }
520 
521 void *nft_set_elem_init(const struct nft_set *set,
522                         const struct nft_set_ext_tmpl *tmpl,
523                         const u32 *key, const u32 *data,
524                         u64 timeout, gfp_t gfp);
525 void nft_set_elem_destroy(const struct nft_set *set, void *elem);
526 
527 /**
528  *      struct nft_set_gc_batch_head - nf_tables set garbage collection batch
529  *
530  *      @rcu: rcu head
531  *      @set: set the elements belong to
532  *      @cnt: count of elements
533  */
534 struct nft_set_gc_batch_head {
535         struct rcu_head                 rcu;
536         const struct nft_set            *set;
537         unsigned int                    cnt;
538 };
539 
540 #define NFT_SET_GC_BATCH_SIZE   ((PAGE_SIZE -                             \
541                                   sizeof(struct nft_set_gc_batch_head)) / \
542                                  sizeof(void *))
543 
544 /**
545  *      struct nft_set_gc_batch - nf_tables set garbage collection batch
546  *
547  *      @head: GC batch head
548  *      @elems: garbage collection elements
549  */
550 struct nft_set_gc_batch {
551         struct nft_set_gc_batch_head    head;
552         void                            *elems[NFT_SET_GC_BATCH_SIZE];
553 };
554 
555 struct nft_set_gc_batch *nft_set_gc_batch_alloc(const struct nft_set *set,
556                                                 gfp_t gfp);
557 void nft_set_gc_batch_release(struct rcu_head *rcu);
558 
559 static inline void nft_set_gc_batch_complete(struct nft_set_gc_batch *gcb)
560 {
561         if (gcb != NULL)
562                 call_rcu(&gcb->head.rcu, nft_set_gc_batch_release);
563 }
564 
565 static inline struct nft_set_gc_batch *
566 nft_set_gc_batch_check(const struct nft_set *set, struct nft_set_gc_batch *gcb,
567                        gfp_t gfp)
568 {
569         if (gcb != NULL) {
570                 if (gcb->head.cnt + 1 < ARRAY_SIZE(gcb->elems))
571                         return gcb;
572                 nft_set_gc_batch_complete(gcb);
573         }
574         return nft_set_gc_batch_alloc(set, gfp);
575 }
576 
577 static inline void nft_set_gc_batch_add(struct nft_set_gc_batch *gcb,
578                                         void *elem)
579 {
580         gcb->elems[gcb->head.cnt++] = elem;
581 }
582 
583 /**
584  *      struct nft_expr_type - nf_tables expression type
585  *
586  *      @select_ops: function to select nft_expr_ops
587  *      @ops: default ops, used when no select_ops functions is present
588  *      @list: used internally
589  *      @name: Identifier
590  *      @owner: module reference
591  *      @policy: netlink attribute policy
592  *      @maxattr: highest netlink attribute number
593  *      @family: address family for AF-specific types
594  *      @flags: expression type flags
595  */
596 struct nft_expr_type {
597         const struct nft_expr_ops       *(*select_ops)(const struct nft_ctx *,
598                                                        const struct nlattr * const tb[]);
599         const struct nft_expr_ops       *ops;
600         struct list_head                list;
601         const char                      *name;
602         struct module                   *owner;
603         const struct nla_policy         *policy;
604         unsigned int                    maxattr;
605         u8                              family;
606         u8                              flags;
607 };
608 
609 #define NFT_EXPR_STATEFUL               0x1
610 
611 /**
612  *      struct nft_expr_ops - nf_tables expression operations
613  *
614  *      @eval: Expression evaluation function
615  *      @size: full expression size, including private data size
616  *      @init: initialization function
617  *      @destroy: destruction function
618  *      @dump: function to dump parameters
619  *      @type: expression type
620  *      @validate: validate expression, called during loop detection
621  *      @data: extra data to attach to this expression operation
622  */
623 struct nft_expr;
624 struct nft_expr_ops {
625         void                            (*eval)(const struct nft_expr *expr,
626                                                 struct nft_regs *regs,
627                                                 const struct nft_pktinfo *pkt);
628         int                             (*clone)(struct nft_expr *dst,
629                                                  const struct nft_expr *src);
630         unsigned int                    size;
631 
632         int                             (*init)(const struct nft_ctx *ctx,
633                                                 const struct nft_expr *expr,
634                                                 const struct nlattr * const tb[]);
635         void                            (*destroy)(const struct nft_ctx *ctx,
636                                                    const struct nft_expr *expr);
637         int                             (*dump)(struct sk_buff *skb,
638                                                 const struct nft_expr *expr);
639         int                             (*validate)(const struct nft_ctx *ctx,
640                                                     const struct nft_expr *expr,
641                                                     const struct nft_data **data);
642         const struct nft_expr_type      *type;
643         void                            *data;
644 };
645 
646 #define NFT_EXPR_MAXATTR                16
647 #define NFT_EXPR_SIZE(size)             (sizeof(struct nft_expr) + \
648                                          ALIGN(size, __alignof__(struct nft_expr)))
649 
650 /**
651  *      struct nft_expr - nf_tables expression
652  *
653  *      @ops: expression ops
654  *      @data: expression private data
655  */
656 struct nft_expr {
657         const struct nft_expr_ops       *ops;
658         unsigned char                   data[];
659 };
660 
661 static inline void *nft_expr_priv(const struct nft_expr *expr)
662 {
663         return (void *)expr->data;
664 }
665 
666 struct nft_expr *nft_expr_init(const struct nft_ctx *ctx,
667                                const struct nlattr *nla);
668 void nft_expr_destroy(const struct nft_ctx *ctx, struct nft_expr *expr);
669 int nft_expr_dump(struct sk_buff *skb, unsigned int attr,
670                   const struct nft_expr *expr);
671 
672 static inline int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
673 {
674         int err;
675 
676         __module_get(src->ops->type->owner);
677         if (src->ops->clone) {
678                 dst->ops = src->ops;
679                 err = src->ops->clone(dst, src);
680                 if (err < 0)
681                         return err;
682         } else {
683                 memcpy(dst, src, src->ops->size);
684         }
685         return 0;
686 }
687 
688 /**
689  *      struct nft_rule - nf_tables rule
690  *
691  *      @list: used internally
692  *      @handle: rule handle
693  *      @genmask: generation mask
694  *      @dlen: length of expression data
695  *      @udata: user data is appended to the rule
696  *      @data: expression data
697  */
698 struct nft_rule {
699         struct list_head                list;
700         u64                             handle:42,
701                                         genmask:2,
702                                         dlen:12,
703                                         udata:1;
704         unsigned char                   data[]
705                 __attribute__((aligned(__alignof__(struct nft_expr))));
706 };
707 
708 static inline struct nft_expr *nft_expr_first(const struct nft_rule *rule)
709 {
710         return (struct nft_expr *)&rule->data[0];
711 }
712 
713 static inline struct nft_expr *nft_expr_next(const struct nft_expr *expr)
714 {
715         return ((void *)expr) + expr->ops->size;
716 }
717 
718 static inline struct nft_expr *nft_expr_last(const struct nft_rule *rule)
719 {
720         return (struct nft_expr *)&rule->data[rule->dlen];
721 }
722 
723 static inline struct nft_userdata *nft_userdata(const struct nft_rule *rule)
724 {
725         return (void *)&rule->data[rule->dlen];
726 }
727 
728 /*
729  * The last pointer isn't really necessary, but the compiler isn't able to
730  * determine that the result of nft_expr_last() is always the same since it
731  * can't assume that the dlen value wasn't changed within calls in the loop.
732  */
733 #define nft_rule_for_each_expr(expr, last, rule) \
734         for ((expr) = nft_expr_first(rule), (last) = nft_expr_last(rule); \
735              (expr) != (last); \
736              (expr) = nft_expr_next(expr))
737 
738 enum nft_chain_flags {
739         NFT_BASE_CHAIN                  = 0x1,
740 };
741 
742 /**
743  *      struct nft_chain - nf_tables chain
744  *
745  *      @rules: list of rules in the chain
746  *      @list: used internally
747  *      @table: table that this chain belongs to
748  *      @handle: chain handle
749  *      @use: number of jump references to this chain
750  *      @level: length of longest path to this chain
751  *      @flags: bitmask of enum nft_chain_flags
752  *      @name: name of the chain
753  */
754 struct nft_chain {
755         struct list_head                rules;
756         struct list_head                list;
757         struct nft_table                *table;
758         u64                             handle;
759         u32                             use;
760         u16                             level;
761         u8                              flags:6,
762                                         genmask:2;
763         char                            name[NFT_CHAIN_MAXNAMELEN];
764 };
765 
766 enum nft_chain_type {
767         NFT_CHAIN_T_DEFAULT = 0,
768         NFT_CHAIN_T_ROUTE,
769         NFT_CHAIN_T_NAT,
770         NFT_CHAIN_T_MAX
771 };
772 
773 /**
774  *      struct nf_chain_type - nf_tables chain type info
775  *
776  *      @name: name of the type
777  *      @type: numeric identifier
778  *      @family: address family
779  *      @owner: module owner
780  *      @hook_mask: mask of valid hooks
781  *      @hooks: hookfn overrides
782  */
783 struct nf_chain_type {
784         const char                      *name;
785         enum nft_chain_type             type;
786         int                             family;
787         struct module                   *owner;
788         unsigned int                    hook_mask;
789         nf_hookfn                       *hooks[NF_MAX_HOOKS];
790 };
791 
792 int nft_chain_validate_dependency(const struct nft_chain *chain,
793                                   enum nft_chain_type type);
794 int nft_chain_validate_hooks(const struct nft_chain *chain,
795                              unsigned int hook_flags);
796 
797 struct nft_stats {
798         u64                     bytes;
799         u64                     pkts;
800         struct u64_stats_sync   syncp;
801 };
802 
803 #define NFT_HOOK_OPS_MAX                2
804 
805 /**
806  *      struct nft_base_chain - nf_tables base chain
807  *
808  *      @ops: netfilter hook ops
809  *      @type: chain type
810  *      @policy: default policy
811  *      @stats: per-cpu chain stats
812  *      @chain: the chain
813  *      @dev_name: device name that this base chain is attached to (if any)
814  */
815 struct nft_base_chain {
816         struct nf_hook_ops              ops[NFT_HOOK_OPS_MAX];
817         const struct nf_chain_type      *type;
818         u8                              policy;
819         u8                              flags;
820         struct nft_stats __percpu       *stats;
821         struct nft_chain                chain;
822         char                            dev_name[IFNAMSIZ];
823 };
824 
825 static inline struct nft_base_chain *nft_base_chain(const struct nft_chain *chain)
826 {
827         return container_of(chain, struct nft_base_chain, chain);
828 }
829 
830 int __nft_release_basechain(struct nft_ctx *ctx);
831 
832 unsigned int nft_do_chain(struct nft_pktinfo *pkt, void *priv);
833 
834 /**
835  *      struct nft_table - nf_tables table
836  *
837  *      @list: used internally
838  *      @chains: chains in the table
839  *      @sets: sets in the table
840  *      @hgenerator: handle generator state
841  *      @use: number of chain references to this table
842  *      @flags: table flag (see enum nft_table_flags)
843  *      @genmask: generation mask
844  *      @name: name of the table
845  */
846 struct nft_table {
847         struct list_head                list;
848         struct list_head                chains;
849         struct list_head                sets;
850         u64                             hgenerator;
851         u32                             use;
852         u16                             flags:14,
853                                         genmask:2;
854         char                            name[NFT_TABLE_MAXNAMELEN];
855 };
856 
857 enum nft_af_flags {
858         NFT_AF_NEEDS_DEV        = (1 << 0),
859 };
860 
861 /**
862  *      struct nft_af_info - nf_tables address family info
863  *
864  *      @list: used internally
865  *      @family: address family
866  *      @nhooks: number of hooks in this family
867  *      @owner: module owner
868  *      @tables: used internally
869  *      @flags: family flags
870  *      @nops: number of hook ops in this family
871  *      @hook_ops_init: initialization function for chain hook ops
872  *      @hooks: hookfn overrides for packet validation
873  */
874 struct nft_af_info {
875         struct list_head                list;
876         int                             family;
877         unsigned int                    nhooks;
878         struct module                   *owner;
879         struct list_head                tables;
880         u32                             flags;
881         unsigned int                    nops;
882         void                            (*hook_ops_init)(struct nf_hook_ops *,
883                                                          unsigned int);
884         nf_hookfn                       *hooks[NF_MAX_HOOKS];
885 };
886 
887 int nft_register_afinfo(struct net *, struct nft_af_info *);
888 void nft_unregister_afinfo(struct net *, struct nft_af_info *);
889 
890 int nft_register_chain_type(const struct nf_chain_type *);
891 void nft_unregister_chain_type(const struct nf_chain_type *);
892 
893 int nft_register_expr(struct nft_expr_type *);
894 void nft_unregister_expr(struct nft_expr_type *);
895 
896 int nft_verdict_dump(struct sk_buff *skb, int type,
897                      const struct nft_verdict *v);
898 
899 /**
900  *      struct nft_traceinfo - nft tracing information and state
901  *
902  *      @pkt: pktinfo currently processed
903  *      @basechain: base chain currently processed
904  *      @chain: chain currently processed
905  *      @rule:  rule that was evaluated
906  *      @verdict: verdict given by rule
907  *      @type: event type (enum nft_trace_types)
908  *      @packet_dumped: packet headers sent in a previous traceinfo message
909  *      @trace: other struct members are initialised
910  */
911 struct nft_traceinfo {
912         const struct nft_pktinfo        *pkt;
913         const struct nft_base_chain     *basechain;
914         const struct nft_chain          *chain;
915         const struct nft_rule           *rule;
916         const struct nft_verdict        *verdict;
917         enum nft_trace_types            type;
918         bool                            packet_dumped;
919         bool                            trace;
920 };
921 
922 void nft_trace_init(struct nft_traceinfo *info, const struct nft_pktinfo *pkt,
923                     const struct nft_verdict *verdict,
924                     const struct nft_chain *basechain);
925 
926 void nft_trace_notify(struct nft_traceinfo *info);
927 
928 #define nft_dereference(p)                                      \
929         nfnl_dereference(p, NFNL_SUBSYS_NFTABLES)
930 
931 #define MODULE_ALIAS_NFT_FAMILY(family) \
932         MODULE_ALIAS("nft-afinfo-" __stringify(family))
933 
934 #define MODULE_ALIAS_NFT_CHAIN(family, name) \
935         MODULE_ALIAS("nft-chain-" __stringify(family) "-" name)
936 
937 #define MODULE_ALIAS_NFT_AF_EXPR(family, name) \
938         MODULE_ALIAS("nft-expr-" __stringify(family) "-" name)
939 
940 #define MODULE_ALIAS_NFT_EXPR(name) \
941         MODULE_ALIAS("nft-expr-" name)
942 
943 #define MODULE_ALIAS_NFT_SET() \
944         MODULE_ALIAS("nft-set")
945 
946 /*
947  * The gencursor defines two generations, the currently active and the
948  * next one. Objects contain a bitmask of 2 bits specifying the generations
949  * they're active in. A set bit means they're inactive in the generation
950  * represented by that bit.
951  *
952  * New objects start out as inactive in the current and active in the
953  * next generation. When committing the ruleset the bitmask is cleared,
954  * meaning they're active in all generations. When removing an object,
955  * it is set inactive in the next generation. After committing the ruleset,
956  * the objects are removed.
957  */
958 static inline unsigned int nft_gencursor_next(const struct net *net)
959 {
960         return net->nft.gencursor + 1 == 1 ? 1 : 0;
961 }
962 
963 static inline u8 nft_genmask_next(const struct net *net)
964 {
965         return 1 << nft_gencursor_next(net);
966 }
967 
968 static inline u8 nft_genmask_cur(const struct net *net)
969 {
970         /* Use ACCESS_ONCE() to prevent refetching the value for atomicity */
971         return 1 << ACCESS_ONCE(net->nft.gencursor);
972 }
973 
974 #define NFT_GENMASK_ANY         ((1 << 0) | (1 << 1))
975 
976 /*
977  * Generic transaction helpers
978  */
979 
980 /* Check if this object is currently active. */
981 #define nft_is_active(__net, __obj)                             \
982         (((__obj)->genmask & nft_genmask_cur(__net)) == 0)
983 
984 /* Check if this object is active in the next generation. */
985 #define nft_is_active_next(__net, __obj)                        \
986         (((__obj)->genmask & nft_genmask_next(__net)) == 0)
987 
988 /* This object becomes active in the next generation. */
989 #define nft_activate_next(__net, __obj)                         \
990         (__obj)->genmask = nft_genmask_cur(__net)
991 
992 /* This object becomes inactive in the next generation. */
993 #define nft_deactivate_next(__net, __obj)                       \
994         (__obj)->genmask = nft_genmask_next(__net)
995 
996 /* After committing the ruleset, clear the stale generation bit. */
997 #define nft_clear(__net, __obj)                                 \
998         (__obj)->genmask &= ~nft_genmask_next(__net)
999 #define nft_active_genmask(__obj, __genmask)                    \
1000         !((__obj)->genmask & __genmask)
1001 
1002 /*
1003  * Set element transaction helpers
1004  */
1005 
1006 static inline bool nft_set_elem_active(const struct nft_set_ext *ext,
1007                                        u8 genmask)
1008 {
1009         return !(ext->genmask & genmask);
1010 }
1011 
1012 static inline void nft_set_elem_change_active(const struct net *net,
1013                                               const struct nft_set *set,
1014                                               struct nft_set_ext *ext)
1015 {
1016         ext->genmask ^= nft_genmask_next(net);
1017 }
1018 
1019 /*
1020  * We use a free bit in the genmask field to indicate the element
1021  * is busy, meaning it is currently being processed either by
1022  * the netlink API or GC.
1023  *
1024  * Even though the genmask is only a single byte wide, this works
1025  * because the extension structure if fully constant once initialized,
1026  * so there are no non-atomic write accesses unless it is already
1027  * marked busy.
1028  */
1029 #define NFT_SET_ELEM_BUSY_MASK  (1 << 2)
1030 
1031 #if defined(__LITTLE_ENDIAN_BITFIELD)
1032 #define NFT_SET_ELEM_BUSY_BIT   2
1033 #elif defined(__BIG_ENDIAN_BITFIELD)
1034 #define NFT_SET_ELEM_BUSY_BIT   (BITS_PER_LONG - BITS_PER_BYTE + 2)
1035 #else
1036 #error
1037 #endif
1038 
1039 static inline int nft_set_elem_mark_busy(struct nft_set_ext *ext)
1040 {
1041         unsigned long *word = (unsigned long *)ext;
1042 
1043         BUILD_BUG_ON(offsetof(struct nft_set_ext, genmask) != 0);
1044         return test_and_set_bit(NFT_SET_ELEM_BUSY_BIT, word);
1045 }
1046 
1047 static inline void nft_set_elem_clear_busy(struct nft_set_ext *ext)
1048 {
1049         unsigned long *word = (unsigned long *)ext;
1050 
1051         clear_bit(NFT_SET_ELEM_BUSY_BIT, word);
1052 }
1053 
1054 /**
1055  *      struct nft_trans - nf_tables object update in transaction
1056  *
1057  *      @list: used internally
1058  *      @msg_type: message type
1059  *      @ctx: transaction context
1060  *      @data: internal information related to the transaction
1061  */
1062 struct nft_trans {
1063         struct list_head                list;
1064         int                             msg_type;
1065         struct nft_ctx                  ctx;
1066         char                            data[0];
1067 };
1068 
1069 struct nft_trans_rule {
1070         struct nft_rule                 *rule;
1071 };
1072 
1073 #define nft_trans_rule(trans)   \
1074         (((struct nft_trans_rule *)trans->data)->rule)
1075 
1076 struct nft_trans_set {
1077         struct nft_set                  *set;
1078         u32                             set_id;
1079 };
1080 
1081 #define nft_trans_set(trans)    \
1082         (((struct nft_trans_set *)trans->data)->set)
1083 #define nft_trans_set_id(trans) \
1084         (((struct nft_trans_set *)trans->data)->set_id)
1085 
1086 struct nft_trans_chain {
1087         bool                            update;
1088         char                            name[NFT_CHAIN_MAXNAMELEN];
1089         struct nft_stats __percpu       *stats;
1090         u8                              policy;
1091 };
1092 
1093 #define nft_trans_chain_update(trans)   \
1094         (((struct nft_trans_chain *)trans->data)->update)
1095 #define nft_trans_chain_name(trans)     \
1096         (((struct nft_trans_chain *)trans->data)->name)
1097 #define nft_trans_chain_stats(trans)    \
1098         (((struct nft_trans_chain *)trans->data)->stats)
1099 #define nft_trans_chain_policy(trans)   \
1100         (((struct nft_trans_chain *)trans->data)->policy)
1101 
1102 struct nft_trans_table {
1103         bool                            update;
1104         bool                            enable;
1105 };
1106 
1107 #define nft_trans_table_update(trans)   \
1108         (((struct nft_trans_table *)trans->data)->update)
1109 #define nft_trans_table_enable(trans)   \
1110         (((struct nft_trans_table *)trans->data)->enable)
1111 
1112 struct nft_trans_elem {
1113         struct nft_set                  *set;
1114         struct nft_set_elem             elem;
1115 };
1116 
1117 #define nft_trans_elem_set(trans)       \
1118         (((struct nft_trans_elem *)trans->data)->set)
1119 #define nft_trans_elem(trans)   \
1120         (((struct nft_trans_elem *)trans->data)->elem)
1121 
1122 #endif /* _NET_NF_TABLES_H */
1123 

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