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         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 */