include/net/netfilter/nf_tables.h

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