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         bool                            tprot_set;
  23         u8                              tprot;
  24         /* for x_tables compatibility */
  25         struct xt_action_param          xt;
  26 };
  27
  28 static inline void nft_set_pktinfo(struct nft_pktinfo *pkt,
  29                                    struct sk_buff *skb,
  30                                    const struct nf_hook_state *state)
  31 {
  32         pkt->skb = skb;
  33         pkt->net = pkt->xt.net = state->net;
  34         pkt->in = pkt->xt.in = state->in;
  35         pkt->out = pkt->xt.out = state->out;
  36         pkt->hook = pkt->xt.hooknum = state->hook;
  37         pkt->pf = pkt->xt.family = state->pf;
  38 }
  39
  40 static inline void nft_set_pktinfo_proto_unspec(struct nft_pktinfo *pkt,
  41                                                 struct sk_buff *skb)
  42 {
  43         pkt->tprot_set = false;
  44         pkt->tprot = 0;
  45         pkt->xt.thoff = 0;
  46         pkt->xt.fragoff = 0;
  47 }
  48
  49 static inline void nft_set_pktinfo_unspec(struct nft_pktinfo *pkt,
  50                                           struct sk_buff *skb,
  51                                           const struct nf_hook_state *state)
  52 {
  53         nft_set_pktinfo(pkt, skb, state);
  54         nft_set_pktinfo_proto_unspec(pkt, skb);
  55 }
  56
  57 /**
  58  *      struct nft_verdict - nf_tables verdict
  59  *
  60  *      @code: nf_tables/netfilter verdict code
  61  *      @chain: destination chain for NFT_JUMP/NFT_GOTO
  62  */
  63 struct nft_verdict {
  64         u32                             code;
  65         struct nft_chain                *chain;
  66 };
  67
  68 struct nft_data {
  69         union {
  70                 u32                     data[4];
  71                 struct nft_verdict      verdict;
  72         };
  73 } __attribute__((aligned(__alignof__(u64))));
  74
  75 /**
  76  *      struct nft_regs - nf_tables register set
  77  *
  78  *      @data: data registers
  79  *      @verdict: verdict register
  80  *
  81  *      The first four data registers alias to the verdict register.
  82  */
  83 struct nft_regs {
  84         union {
  85                 u32                     data[20];
  86                 struct nft_verdict      verdict;
  87         };
  88 };
  89
  90 static inline void nft_data_copy(u32 *dst, const struct nft_data *src,
  91                                  unsigned int len)
  92 {
  93         memcpy(dst, src, len);
  94 }
  95
  96 static inline void nft_data_debug(const struct nft_data *data)
  97 {
  98         pr_debug("data[0]=%x data[1]=%x data[2]=%x data[3]=%x\n",
  99                  data->data[0], data->data[1],
 100                  data->data[2], data->data[3]);
 101 }
 102
 103 /**
 104  *      struct nft_ctx - nf_tables rule/set context
 105  *
 106  *      @net: net namespace
 107  *      @afi: address family info
 108  *      @table: the table the chain is contained in
 109  *      @chain: the chain the rule is contained in
 110  *      @nla: netlink attributes
 111  *      @portid: netlink portID of the original message
 112  *      @seq: netlink sequence number
 113  *      @report: notify via unicast netlink message
 114  */
 115 struct nft_ctx {
 116         struct net                      *net;
 117         struct nft_af_info              *afi;
 118         struct nft_table                *table;
 119         struct nft_chain                *chain;
 120         const struct nlattr * const     *nla;
 121         u32                             portid;
 122         u32                             seq;
 123         bool                            report;
 124 };
 125
 126 struct nft_data_desc {
 127         enum nft_data_types             type;
 128         unsigned int                    len;
 129 };
 130
 131 int nft_data_init(const struct nft_ctx *ctx,
 132                   struct nft_data *data, unsigned int size,
 133                   struct nft_data_desc *desc, const struct nlattr *nla);
 134 void nft_data_uninit(const struct nft_data *data, enum nft_data_types type);
 135 int nft_data_dump(struct sk_buff *skb, int attr, const struct nft_data *data,
 136                   enum nft_data_types type, unsigned int len);
 137
 138 static inline enum nft_data_types nft_dreg_to_type(enum nft_registers reg)
 139 {
 140         return reg == NFT_REG_VERDICT ? NFT_DATA_VERDICT : NFT_DATA_VALUE;
 141 }
 142
 143 static inline enum nft_registers nft_type_to_reg(enum nft_data_types type)
 144 {
 145         return type == NFT_DATA_VERDICT ? NFT_REG_VERDICT : NFT_REG_1 * NFT_REG_SIZE / NFT_REG32_SIZE;
 146 }
 147
 148 unsigned int nft_parse_register(const struct nlattr *attr);
 149 int nft_dump_register(struct sk_buff *skb, unsigned int attr, unsigned int reg);
 150
 151 int nft_validate_register_load(enum nft_registers reg, unsigned int len);
 152 int nft_validate_register_store(const struct nft_ctx *ctx,
 153                                 enum nft_registers reg,
 154                                 const struct nft_data *data,
 155                                 enum nft_data_types type, unsigned int len);
 156
 157 /**
 158  *      struct nft_userdata - user defined data associated with an object
 159  *
 160  *      @len: length of the data
 161  *      @data: content
 162  *
 163  *      The presence of user data is indicated in an object specific fashion,
 164  *      so a length of zero can't occur and the value "len" indicates data
 165  *      of length len + 1.
 166  */
 167 struct nft_userdata {
 168         u8                      len;
 169         unsigned char           data[0];
 170 };
 171
 172 /**
 173  *      struct nft_set_elem - generic representation of set elements
 174  *
 175  *      @key: element key
 176  *      @priv: element private data and extensions
 177  */
 178 struct nft_set_elem {
 179         union {
 180                 u32             buf[NFT_DATA_VALUE_MAXLEN / sizeof(u32)];
 181                 struct nft_data val;
 182         } key;
 183         void                    *priv;
 184 };
 185
 186 struct nft_set;
 187 struct nft_set_iter {
 188         u8              genmask;
 189         unsigned int    count;
 190         unsigned int    skip;
 191         int             err;
 192         int             (*fn)(const struct nft_ctx *ctx,
 193                               const struct nft_set *set,
 194                               const struct nft_set_iter *iter,
 195                               const struct nft_set_elem *elem);
 196 };
 197
 198 /**
 199  *      struct nft_set_desc - description of set elements
 200  *
 201  *      @klen: key length
 202  *      @dlen: data length
 203  *      @size: number of set elements
 204  */
 205 struct nft_set_desc {
 206         unsigned int            klen;
 207         unsigned int            dlen;
 208         unsigned int            size;
 209 };
 210
 211 /**
 212  *      enum nft_set_class - performance class
 213  *
 214  *      @NFT_LOOKUP_O_1: constant, O(1)
 215  *      @NFT_LOOKUP_O_LOG_N: logarithmic, O(log N)
 216  *      @NFT_LOOKUP_O_N: linear, O(N)
 217  */
 218 enum nft_set_class {
 219         NFT_SET_CLASS_O_1,
 220         NFT_SET_CLASS_O_LOG_N,
 221         NFT_SET_CLASS_O_N,
 222 };
 223
 224 /**
 225  *      struct nft_set_estimate - estimation of memory and performance
 226  *                                characteristics
 227  *
 228  *      @size: required memory
 229  *      @class: lookup performance class
 230  */
 231 struct nft_set_estimate {
 232         unsigned int            size;
 233         enum nft_set_class      class;
 234 };
 235
 236 struct nft_set_ext;
 237 struct nft_expr;
 238
 239 /**
 240  *      struct nft_set_ops - nf_tables set operations
 241  *
 242  *      @lookup: look up an element within the set
 243  *      @insert: insert new element into set
 244  *      @activate: activate new element in the next generation
 245  *      @deactivate: deactivate element in the next generation
 246  *      @remove: remove element from set
 247  *      @walk: iterate over all set elemeennts
 248  *      @privsize: function to return size of set private data
 249  *      @init: initialize private data of new set instance
 250  *      @destroy: destroy private data of set instance
 251  *      @list: nf_tables_set_ops list node
 252  *      @owner: module reference
 253  *      @elemsize: element private size
 254  *      @features: features supported by the implementation
 255  */
 256 struct nft_set_ops {
 257         bool                            (*lookup)(const struct net *net,
 258                                                   const struct nft_set *set,
 259                                                   const u32 *key,
 260                                                   const struct nft_set_ext **ext);
 261         bool                            (*update)(struct nft_set *set,
 262                                                   const u32 *key,
 263                                                   void *(*new)(struct nft_set *,
 264                                                                const struct nft_expr *,
 265                                                                struct nft_regs *),
 266                                                   const struct nft_expr *expr,
 267                                                   struct nft_regs *regs,
 268                                                   const struct nft_set_ext **ext);
 269
 270         int                             (*insert)(const struct net *net,
 271                                                   const struct nft_set *set,
 272                                                   const struct nft_set_elem *elem,
 273                                                   struct nft_set_ext **ext);
 274         void                            (*activate)(const struct net *net,
 275                                                     const struct nft_set *set,
 276                                                     const struct nft_set_elem *elem);
 277         void *                          (*deactivate)(const struct net *net,
 278                                                       const struct nft_set *set,
 279                                                       const struct nft_set_elem *elem);
 280         void                            (*remove)(const struct nft_set *set,
 281                                                   const struct nft_set_elem *elem);
 282         void                            (*walk)(const struct nft_ctx *ctx,
 283                                                 const struct nft_set *set,
 284                                                 struct nft_set_iter *iter);
 285
 286         unsigned int                    (*privsize)(const struct nlattr * const nla[]);
 287         bool                            (*estimate)(const struct nft_set_desc *desc,
 288                                                     u32 features,
 289                                                     struct nft_set_estimate *est);
 290         int                             (*init)(const struct nft_set *set,
 291                                                 const struct nft_set_desc *desc,
 292                                                 const struct nlattr * const nla[]);
 293         void                            (*destroy)(const struct nft_set *set);
 294
 295         struct list_head                list;
 296         struct module                   *owner;
 297         unsigned int                    elemsize;
 298         u32                             features;
 299 };
 300
 301 int nft_register_set(struct nft_set_ops *ops);
 302 void nft_unregister_set(struct nft_set_ops *ops);
 303
 304 /**
 305  *      struct nft_set - nf_tables set instance
 306  *
 307  *      @list: table set list node
 308  *      @bindings: list of set bindings
 309  *      @name: name of the set
 310  *      @ktype: key type (numeric type defined by userspace, not used in the kernel)
 311  *      @dtype: data type (verdict or numeric type defined by userspace)
 312  *      @size: maximum set size
 313  *      @nelems: number of elements
 314  *      @ndeact: number of deactivated elements queued for removal
 315  *      @timeout: default timeout value in msecs
 316  *      @gc_int: garbage collection interval in msecs
 317  *      @policy: set parameterization (see enum nft_set_policies)
 318  *      @udlen: user data length
 319  *      @udata: user data
 320  *      @ops: set ops
 321  *      @flags: set flags
 322  *      @genmask: generation mask
 323  *      @klen: key length
 324  *      @dlen: data length
 325  *      @data: private set data
 326  */
 327 struct nft_set {
 328         struct list_head                list;
 329         struct list_head                bindings;
 330         char                            name[NFT_SET_MAXNAMELEN];
 331         u32                             ktype;
 332         u32                             dtype;
 333         u32                             size;
 334         atomic_t                        nelems;
 335         u32                             ndeact;
 336         u64                             timeout;
 337         u32                             gc_int;
 338         u16                             policy;
 339         u16                             udlen;
 340         unsigned char                   *udata;
 341         /* runtime data below here */
 342         const struct nft_set_ops        *ops ____cacheline_aligned;
 343         u16                             flags:14,
 344                                         genmask:2;
 345         u8                              klen;
 346         u8                              dlen;
 347         unsigned char                   data[]
 348                 __attribute__((aligned(__alignof__(u64))));
 349 };
 350
 351 static inline void *nft_set_priv(const struct nft_set *set)
 352 {
 353         return (void *)set->data;
 354 }
 355
 356 static inline struct nft_set *nft_set_container_of(const void *priv)
 357 {
 358         return (void *)priv - offsetof(struct nft_set, data);
 359 }
 360
 361 struct nft_set *nf_tables_set_lookup(const struct nft_table *table,
 362                                      const struct nlattr *nla, u8 genmask);
 363 struct nft_set *nf_tables_set_lookup_byid(const struct net *net,
 364                                           const struct nlattr *nla, u8 genmask);
 365
 366 static inline unsigned long nft_set_gc_interval(const struct nft_set *set)
 367 {
 368         return set->gc_int ? msecs_to_jiffies(set->gc_int) : HZ;
 369 }
 370
 371 /**
 372  *      struct nft_set_binding - nf_tables set binding
 373  *
 374  *      @list: set bindings list node
 375  *      @chain: chain containing the rule bound to the set
 376  *      @flags: set action flags
 377  *
 378  *      A set binding contains all information necessary for validation
 379  *      of new elements added to a bound set.
 380  */
 381 struct nft_set_binding {
 382         struct list_head                list;
 383         const struct nft_chain          *chain;
 384         u32                             flags;
 385 };
 386
 387 int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
 388                        struct nft_set_binding *binding);
 389 void nf_tables_unbind_set(const struct nft_ctx *ctx, struct nft_set *set,
 390                           struct nft_set_binding *binding);
 391
 392 /**
 393  *      enum nft_set_extensions - set extension type IDs
 394  *
 395  *      @NFT_SET_EXT_KEY: element key
 396  *      @NFT_SET_EXT_DATA: mapping data
 397  *      @NFT_SET_EXT_FLAGS: element flags
 398  *      @NFT_SET_EXT_TIMEOUT: element timeout
 399  *      @NFT_SET_EXT_EXPIRATION: element expiration time
 400  *      @NFT_SET_EXT_USERDATA: user data associated with the element
 401  *      @NFT_SET_EXT_EXPR: expression assiociated with the element
 402  *      @NFT_SET_EXT_NUM: number of extension types
 403  */
 404 enum nft_set_extensions {
 405         NFT_SET_EXT_KEY,
 406         NFT_SET_EXT_DATA,
 407         NFT_SET_EXT_FLAGS,
 408         NFT_SET_EXT_TIMEOUT,
 409         NFT_SET_EXT_EXPIRATION,
 410         NFT_SET_EXT_USERDATA,
 411         NFT_SET_EXT_EXPR,
 412         NFT_SET_EXT_NUM
 413 };
 414
 415 /**
 416  *      struct nft_set_ext_type - set extension type
 417  *
 418  *      @len: fixed part length of the extension
 419  *      @align: alignment requirements of the extension
 420  */
 421 struct nft_set_ext_type {
 422         u8      len;
 423         u8      align;
 424 };
 425
 426 extern const struct nft_set_ext_type nft_set_ext_types[];
 427
 428 /**
 429  *      struct nft_set_ext_tmpl - set extension template
 430  *
 431  *      @len: length of extension area
 432  *      @offset: offsets of individual extension types
 433  */
 434 struct nft_set_ext_tmpl {
 435         u16     len;
 436         u8      offset[NFT_SET_EXT_NUM];
 437 };
 438
 439 /**
 440  *      struct nft_set_ext - set extensions
 441  *
 442  *      @genmask: generation mask
 443  *      @offset: offsets of individual extension types
 444  *      @data: beginning of extension data
 445  */
 446 struct nft_set_ext {
 447         u8      genmask;
 448         u8      offset[NFT_SET_EXT_NUM];
 449         char    data[0];
 450 };
 451
 452 static inline void nft_set_ext_prepare(struct nft_set_ext_tmpl *tmpl)
 453 {
 454         memset(tmpl, 0, sizeof(*tmpl));
 455         tmpl->len = sizeof(struct nft_set_ext);
 456 }
 457
 458 static inline void nft_set_ext_add_length(struct nft_set_ext_tmpl *tmpl, u8 id,
 459                                           unsigned int len)
 460 {
 461         tmpl->len        = ALIGN(tmpl->len, nft_set_ext_types[id].align);
 462         BUG_ON(tmpl->len > U8_MAX);
 463         tmpl->offset[id] = tmpl->len;
 464         tmpl->len       += nft_set_ext_types[id].len + len;
 465 }
 466
 467 static inline void nft_set_ext_add(struct nft_set_ext_tmpl *tmpl, u8 id)
 468 {
 469         nft_set_ext_add_length(tmpl, id, 0);
 470 }
 471
 472 static inline void nft_set_ext_init(struct nft_set_ext *ext,
 473                                     const struct nft_set_ext_tmpl *tmpl)
 474 {
 475         memcpy(ext->offset, tmpl->offset, sizeof(ext->offset));
 476 }
 477
 478 static inline bool __nft_set_ext_exists(const struct nft_set_ext *ext, u8 id)
 479 {
 480         return !!ext->offset[id];
 481 }
 482
 483 static inline bool nft_set_ext_exists(const struct nft_set_ext *ext, u8 id)
 484 {
 485         return ext && __nft_set_ext_exists(ext, id);
 486 }
 487
 488 static inline void *nft_set_ext(const struct nft_set_ext *ext, u8 id)
 489 {
 490         return (void *)ext + ext->offset[id];
 491 }
 492
 493 static inline struct nft_data *nft_set_ext_key(const struct nft_set_ext *ext)
 494 {
 495         return nft_set_ext(ext, NFT_SET_EXT_KEY);
 496 }
 497
 498 static inline struct nft_data *nft_set_ext_data(const struct nft_set_ext *ext)
 499 {
 500         return nft_set_ext(ext, NFT_SET_EXT_DATA);
 501 }
 502
 503 static inline u8 *nft_set_ext_flags(const struct nft_set_ext *ext)
 504 {
 505         return nft_set_ext(ext, NFT_SET_EXT_FLAGS);
 506 }
 507
 508 static inline u64 *nft_set_ext_timeout(const struct nft_set_ext *ext)
 509 {
 510         return nft_set_ext(ext, NFT_SET_EXT_TIMEOUT);
 511 }
 512
 513 static inline unsigned long *nft_set_ext_expiration(const struct nft_set_ext *ext)
 514 {
 515         return nft_set_ext(ext, NFT_SET_EXT_EXPIRATION);
 516 }
 517
 518 static inline struct nft_userdata *nft_set_ext_userdata(const struct nft_set_ext *ext)
 519 {
 520         return nft_set_ext(ext, NFT_SET_EXT_USERDATA);
 521 }
 522
 523 static inline struct nft_expr *nft_set_ext_expr(const struct nft_set_ext *ext)
 524 {
 525         return nft_set_ext(ext, NFT_SET_EXT_EXPR);
 526 }
 527
 528 static inline bool nft_set_elem_expired(const struct nft_set_ext *ext)
 529 {
 530         return nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION) &&
 531                time_is_before_eq_jiffies(*nft_set_ext_expiration(ext));
 532 }
 533
 534 static inline struct nft_set_ext *nft_set_elem_ext(const struct nft_set *set,
 535                                                    void *elem)
 536 {
 537         return elem + set->ops->elemsize;
 538 }
 539
 540 void *nft_set_elem_init(const struct nft_set *set,
 541                         const struct nft_set_ext_tmpl *tmpl,
 542                         const u32 *key, const u32 *data,
 543                         u64 timeout, gfp_t gfp);
 544 void nft_set_elem_destroy(const struct nft_set *set, void *elem);
 545
 546 /**
 547  *      struct nft_set_gc_batch_head - nf_tables set garbage collection batch
 548  *
 549  *      @rcu: rcu head
 550  *      @set: set the elements belong to
 551  *      @cnt: count of elements
 552  */
 553 struct nft_set_gc_batch_head {
 554         struct rcu_head                 rcu;
 555         const struct nft_set            *set;
 556         unsigned int                    cnt;
 557 };
 558
 559 #define NFT_SET_GC_BATCH_SIZE   ((PAGE_SIZE -                             \
 560                                   sizeof(struct nft_set_gc_batch_head)) / \
 561                                  sizeof(void *))
 562
 563 /**
 564  *      struct nft_set_gc_batch - nf_tables set garbage collection batch
 565  *
 566  *      @head: GC batch head
 567  *      @elems: garbage collection elements
 568  */
 569 struct nft_set_gc_batch {
 570         struct nft_set_gc_batch_head    head;
 571         void                            *elems[NFT_SET_GC_BATCH_SIZE];
 572 };
 573
 574 struct nft_set_gc_batch *nft_set_gc_batch_alloc(const struct nft_set *set,
 575                                                 gfp_t gfp);
 576 void nft_set_gc_batch_release(struct rcu_head *rcu);
 577
 578 static inline void nft_set_gc_batch_complete(struct nft_set_gc_batch *gcb)
 579 {
 580         if (gcb != NULL)
 581                 call_rcu(&gcb->head.rcu, nft_set_gc_batch_release);
 582 }
 583
 584 static inline struct nft_set_gc_batch *
 585 nft_set_gc_batch_check(const struct nft_set *set, struct nft_set_gc_batch *gcb,
 586                        gfp_t gfp)
 587 {
 588         if (gcb != NULL) {
 589                 if (gcb->head.cnt + 1 < ARRAY_SIZE(gcb->elems))
 590                         return gcb;
 591                 nft_set_gc_batch_complete(gcb);
 592         }
 593         return nft_set_gc_batch_alloc(set, gfp);
 594 }
 595
 596 static inline void nft_set_gc_batch_add(struct nft_set_gc_batch *gcb,
 597                                         void *elem)
 598 {
 599         gcb->elems[gcb->head.cnt++] = elem;
 600 }
 601
 602 /**
 603  *      struct nft_expr_type - nf_tables expression type
 604  *
 605  *      @select_ops: function to select nft_expr_ops
 606  *      @ops: default ops, used when no select_ops functions is present
 607  *      @list: used internally
 608  *      @name: Identifier
 609  *      @owner: module reference
 610  *      @policy: netlink attribute policy
 611  *      @maxattr: highest netlink attribute number
 612  *      @family: address family for AF-specific types
 613  *      @flags: expression type flags
 614  */
 615 struct nft_expr_type {
 616         const struct nft_expr_ops       *(*select_ops)(const struct nft_ctx *,
 617                                                        const struct nlattr * const tb[]);
 618         const struct nft_expr_ops       *ops;
 619         struct list_head                list;
 620         const char                      *name;
 621         struct module                   *owner;
 622         const struct nla_policy         *policy;
 623         unsigned int                    maxattr;
 624         u8                              family;
 625         u8                              flags;
 626 };
 627
 628 #define NFT_EXPR_STATEFUL               0x1
 629
 630 /**
 631  *      struct nft_expr_ops - nf_tables expression operations
 632  *
 633  *      @eval: Expression evaluation function
 634  *      @size: full expression size, including private data size
 635  *      @init: initialization function
 636  *      @destroy: destruction function
 637  *      @dump: function to dump parameters
 638  *      @type: expression type
 639  *      @validate: validate expression, called during loop detection
 640  *      @data: extra data to attach to this expression operation
 641  */
 642 struct nft_expr;
 643 struct nft_expr_ops {
 644         void                            (*eval)(const struct nft_expr *expr,
 645                                                 struct nft_regs *regs,
 646                                                 const struct nft_pktinfo *pkt);
 647         int                             (*clone)(struct nft_expr *dst,
 648                                                  const struct nft_expr *src);
 649         unsigned int                    size;
 650
 651         int                             (*init)(const struct nft_ctx *ctx,
 652                                                 const struct nft_expr *expr,
 653                                                 const struct nlattr * const tb[]);
 654         void                            (*destroy)(const struct nft_ctx *ctx,
 655                                                    const struct nft_expr *expr);
 656         int                             (*dump)(struct sk_buff *skb,
 657                                                 const struct nft_expr *expr);
 658         int                             (*validate)(const struct nft_ctx *ctx,
 659                                                     const struct nft_expr *expr,
 660                                                     const struct nft_data **data);
 661         const struct nft_expr_type      *type;
 662         void                            *data;
 663 };
 664
 665 #define NFT_EXPR_MAXATTR                16
 666 #define NFT_EXPR_SIZE(size)             (sizeof(struct nft_expr) + \
 667                                          ALIGN(size, __alignof__(struct nft_expr)))
 668
 669 /**
 670  *      struct nft_expr - nf_tables expression
 671  *
 672  *      @ops: expression ops
 673  *      @data: expression private data
 674  */
 675 struct nft_expr {
 676         const struct nft_expr_ops       *ops;
 677         unsigned char                   data[];
 678 };
 679
 680 static inline void *nft_expr_priv(const struct nft_expr *expr)
 681 {
 682         return (void *)expr->data;
 683 }
 684
 685 struct nft_expr *nft_expr_init(const struct nft_ctx *ctx,
 686                                const struct nlattr *nla);
 687 void nft_expr_destroy(const struct nft_ctx *ctx, struct nft_expr *expr);
 688 int nft_expr_dump(struct sk_buff *skb, unsigned int attr,
 689                   const struct nft_expr *expr);
 690
 691 static inline int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
 692 {
 693         int err;
 694
 695         __module_get(src->ops->type->owner);
 696         if (src->ops->clone) {
 697                 dst->ops = src->ops;
 698                 err = src->ops->clone(dst, src);
 699                 if (err < 0)
 700                         return err;
 701         } else {
 702                 memcpy(dst, src, src->ops->size);
 703         }
 704         return 0;
 705 }
 706
 707 /**
 708  *      struct nft_rule - nf_tables rule
 709  *
 710  *      @list: used internally
 711  *      @handle: rule handle
 712  *      @genmask: generation mask
 713  *      @dlen: length of expression data
 714  *      @udata: user data is appended to the rule
 715  *      @data: expression data
 716  */
 717 struct nft_rule {
 718         struct list_head                list;
 719         u64                             handle:42,
 720                                         genmask:2,
 721                                         dlen:12,
 722                                         udata:1;
 723         unsigned char                   data[]
 724                 __attribute__((aligned(__alignof__(struct nft_expr))));
 725 };
 726
 727 static inline struct nft_expr *nft_expr_first(const struct nft_rule *rule)
 728 {
 729         return (struct nft_expr *)&rule->data[0];
 730 }
 731
 732 static inline struct nft_expr *nft_expr_next(const struct nft_expr *expr)
 733 {
 734         return ((void *)expr) + expr->ops->size;
 735 }
 736
 737 static inline struct nft_expr *nft_expr_last(const struct nft_rule *rule)
 738 {
 739         return (struct nft_expr *)&rule->data[rule->dlen];
 740 }
 741
 742 static inline struct nft_userdata *nft_userdata(const struct nft_rule *rule)
 743 {
 744         return (void *)&rule->data[rule->dlen];
 745 }
 746
 747 /*
 748  * The last pointer isn't really necessary, but the compiler isn't able to
 749  * determine that the result of nft_expr_last() is always the same since it
 750  * can't assume that the dlen value wasn't changed within calls in the loop.
 751  */
 752 #define nft_rule_for_each_expr(expr, last, rule) \
 753         for ((expr) = nft_expr_first(rule), (last) = nft_expr_last(rule); \
 754              (expr) != (last); \
 755              (expr) = nft_expr_next(expr))
 756
 757 enum nft_chain_flags {
 758         NFT_BASE_CHAIN                  = 0x1,
 759 };
 760
 761 /**
 762  *      struct nft_chain - nf_tables chain
 763  *
 764  *      @rules: list of rules in the chain
 765  *      @list: used internally
 766  *      @table: table that this chain belongs to
 767  *      @handle: chain handle
 768  *      @use: number of jump references to this chain
 769  *      @level: length of longest path to this chain
 770  *      @flags: bitmask of enum nft_chain_flags
 771  *      @name: name of the chain
 772  */
 773 struct nft_chain {
 774         struct list_head                rules;
 775         struct list_head                list;
 776         struct nft_table                *table;
 777         u64                             handle;
 778         u32                             use;
 779         u16                             level;
 780         u8                              flags:6,
 781                                         genmask:2;
 782         char                            name[NFT_CHAIN_MAXNAMELEN];
 783 };
 784
 785 enum nft_chain_type {
 786         NFT_CHAIN_T_DEFAULT = 0,
 787         NFT_CHAIN_T_ROUTE,
 788         NFT_CHAIN_T_NAT,
 789         NFT_CHAIN_T_MAX
 790 };
 791
 792 /**
 793  *      struct nf_chain_type - nf_tables chain type info
 794  *
 795  *      @name: name of the type
 796  *      @type: numeric identifier
 797  *      @family: address family
 798  *      @owner: module owner
 799  *      @hook_mask: mask of valid hooks
 800  *      @hooks: hookfn overrides
 801  */
 802 struct nf_chain_type {
 803         const char                      *name;
 804         enum nft_chain_type             type;
 805         int                             family;
 806         struct module                   *owner;
 807         unsigned int                    hook_mask;
 808         nf_hookfn                       *hooks[NF_MAX_HOOKS];
 809 };
 810
 811 int nft_chain_validate_dependency(const struct nft_chain *chain,
 812                                   enum nft_chain_type type);
 813 int nft_chain_validate_hooks(const struct nft_chain *chain,
 814                              unsigned int hook_flags);
 815
 816 struct nft_stats {
 817         u64                     bytes;
 818         u64                     pkts;
 819         struct u64_stats_sync   syncp;
 820 };
 821
 822 #define NFT_HOOK_OPS_MAX                2
 823
 824 /**
 825  *      struct nft_base_chain - nf_tables base chain
 826  *
 827  *      @ops: netfilter hook ops
 828  *      @type: chain type
 829  *      @policy: default policy
 830  *      @stats: per-cpu chain stats
 831  *      @chain: the chain
 832  *      @dev_name: device name that this base chain is attached to (if any)
 833  */
 834 struct nft_base_chain {
 835         struct nf_hook_ops              ops[NFT_HOOK_OPS_MAX];
 836         const struct nf_chain_type      *type;
 837         u8                              policy;
 838         u8                              flags;
 839         struct nft_stats __percpu       *stats;
 840         struct nft_chain                chain;
 841         char                            dev_name[IFNAMSIZ];
 842 };
 843
 844 static inline struct nft_base_chain *nft_base_chain(const struct nft_chain *chain)
 845 {
 846         return container_of(chain, struct nft_base_chain, chain);
 847 }
 848
 849 int __nft_release_basechain(struct nft_ctx *ctx);
 850
 851 unsigned int nft_do_chain(struct nft_pktinfo *pkt, void *priv);
 852
 853 /**
 854  *      struct nft_table - nf_tables table
 855  *
 856  *      @list: used internally
 857  *      @chains: chains in the table
 858  *      @sets: sets in the table
 859  *      @hgenerator: handle generator state
 860  *      @use: number of chain references to this table
 861  *      @flags: table flag (see enum nft_table_flags)
 862  *      @genmask: generation mask
 863  *      @name: name of the table
 864  */
 865 struct nft_table {
 866         struct list_head                list;
 867         struct list_head                chains;
 868         struct list_head                sets;
 869         u64                             hgenerator;
 870         u32                             use;
 871         u16                             flags:14,
 872                                         genmask:2;
 873         char                            name[NFT_TABLE_MAXNAMELEN];
 874 };
 875
 876 enum nft_af_flags {
 877         NFT_AF_NEEDS_DEV        = (1 << 0),
 878 };
 879
 880 /**
 881  *      struct nft_af_info - nf_tables address family info
 882  *
 883  *      @list: used internally
 884  *      @family: address family
 885  *      @nhooks: number of hooks in this family
 886  *      @owner: module owner
 887  *      @tables: used internally
 888  *      @flags: family flags
 889  *      @nops: number of hook ops in this family
 890  *      @hook_ops_init: initialization function for chain hook ops
 891  *      @hooks: hookfn overrides for packet validation
 892  */
 893 struct nft_af_info {
 894         struct list_head                list;
 895         int                             family;
 896         unsigned int                    nhooks;
 897         struct module                   *owner;
 898         struct list_head                tables;
 899         u32                             flags;
 900         unsigned int                    nops;
 901         void                            (*hook_ops_init)(struct nf_hook_ops *,
 902                                                          unsigned int);
 903         nf_hookfn                       *hooks[NF_MAX_HOOKS];
 904 };
 905
 906 int nft_register_afinfo(struct net *, struct nft_af_info *);
 907 void nft_unregister_afinfo(struct net *, struct nft_af_info *);
 908
 909 int nft_register_chain_type(const struct nf_chain_type *);
 910 void nft_unregister_chain_type(const struct nf_chain_type *);
 911
 912 int nft_register_expr(struct nft_expr_type *);
 913 void nft_unregister_expr(struct nft_expr_type *);
 914
 915 int nft_verdict_dump(struct sk_buff *skb, int type,
 916                      const struct nft_verdict *v);
 917
 918 /**
 919  *      struct nft_traceinfo - nft tracing information and state
 920  *
 921  *      @pkt: pktinfo currently processed
 922  *      @basechain: base chain currently processed
 923  *      @chain: chain currently processed
 924  *      @rule:  rule that was evaluated
 925  *      @verdict: verdict given by rule
 926  *      @type: event type (enum nft_trace_types)
 927  *      @packet_dumped: packet headers sent in a previous traceinfo message
 928  *      @trace: other struct members are initialised
 929  */
 930 struct nft_traceinfo {
 931         const struct nft_pktinfo        *pkt;
 932         const struct nft_base_chain     *basechain;
 933         const struct nft_chain          *chain;
 934         const struct nft_rule           *rule;
 935         const struct nft_verdict        *verdict;
 936         enum nft_trace_types            type;
 937         bool                            packet_dumped;
 938         bool                            trace;
 939 };
 940
 941 void nft_trace_init(struct nft_traceinfo *info, const struct nft_pktinfo *pkt,
 942                     const struct nft_verdict *verdict,
 943                     const struct nft_chain *basechain);
 944
 945 void nft_trace_notify(struct nft_traceinfo *info);
 946
 947 #define nft_dereference(p)                                      \
 948         nfnl_dereference(p, NFNL_SUBSYS_NFTABLES)
 949
 950 #define MODULE_ALIAS_NFT_FAMILY(family) \
 951         MODULE_ALIAS("nft-afinfo-" __stringify(family))
 952
 953 #define MODULE_ALIAS_NFT_CHAIN(family, name) \
 954         MODULE_ALIAS("nft-chain-" __stringify(family) "-" name)
 955
 956 #define MODULE_ALIAS_NFT_AF_EXPR(family, name) \
 957         MODULE_ALIAS("nft-expr-" __stringify(family) "-" name)
 958
 959 #define MODULE_ALIAS_NFT_EXPR(name) \
 960         MODULE_ALIAS("nft-expr-" name)
 961
 962 #define MODULE_ALIAS_NFT_SET() \
 963         MODULE_ALIAS("nft-set")
 964
 965 /*
 966  * The gencursor defines two generations, the currently active and the
 967  * next one. Objects contain a bitmask of 2 bits specifying the generations
 968  * they're active in. A set bit means they're inactive in the generation
 969  * represented by that bit.
 970  *
 971  * New objects start out as inactive in the current and active in the
 972  * next generation. When committing the ruleset the bitmask is cleared,
 973  * meaning they're active in all generations. When removing an object,
 974  * it is set inactive in the next generation. After committing the ruleset,
 975  * the objects are removed.
 976  */
 977 static inline unsigned int nft_gencursor_next(const struct net *net)
 978 {
 979         return net->nft.gencursor + 1 == 1 ? 1 : 0;
 980 }
 981
 982 static inline u8 nft_genmask_next(const struct net *net)
 983 {
 984         return 1 << nft_gencursor_next(net);
 985 }
 986
 987 static inline u8 nft_genmask_cur(const struct net *net)
 988 {
 989         /* Use ACCESS_ONCE() to prevent refetching the value for atomicity */
 990         return 1 << ACCESS_ONCE(net->nft.gencursor);
 991 }
 992
 993 #define NFT_GENMASK_ANY         ((1 << 0) | (1 << 1))
 994
 995 /*
 996  * Generic transaction helpers
 997  */
 998
 999 /* Check if this object is currently active. */
1000 #define nft_is_active(__net, __obj)                             \
1001         (((__obj)->genmask & nft_genmask_cur(__net)) == 0)
1002
1003 /* Check if this object is active in the next generation. */
1004 #define nft_is_active_next(__net, __obj)                        \
1005         (((__obj)->genmask & nft_genmask_next(__net)) == 0)
1006
1007 /* This object becomes active in the next generation. */
1008 #define nft_activate_next(__net, __obj)                         \
1009         (__obj)->genmask = nft_genmask_cur(__net)
1010
1011 /* This object becomes inactive in the next generation. */
1012 #define nft_deactivate_next(__net, __obj)                       \
1013         (__obj)->genmask = nft_genmask_next(__net)
1014
1015 /* After committing the ruleset, clear the stale generation bit. */
1016 #define nft_clear(__net, __obj)                                 \
1017         (__obj)->genmask &= ~nft_genmask_next(__net)
1018 #define nft_active_genmask(__obj, __genmask)                    \
1019         !((__obj)->genmask & __genmask)
1020
1021 /*
1022  * Set element transaction helpers
1023  */
1024
1025 static inline bool nft_set_elem_active(const struct nft_set_ext *ext,
1026                                        u8 genmask)
1027 {
1028         return !(ext->genmask & genmask);
1029 }
1030
1031 static inline void nft_set_elem_change_active(const struct net *net,
1032                                               const struct nft_set *set,
1033                                               struct nft_set_ext *ext)
1034 {
1035         ext->genmask ^= nft_genmask_next(net);
1036 }
1037
1038 /*
1039  * We use a free bit in the genmask field to indicate the element
1040  * is busy, meaning it is currently being processed either by
1041  * the netlink API or GC.
1042  *
1043  * Even though the genmask is only a single byte wide, this works
1044  * because the extension structure if fully constant once initialized,
1045  * so there are no non-atomic write accesses unless it is already
1046  * marked busy.
1047  */
1048 #define NFT_SET_ELEM_BUSY_MASK  (1 << 2)
1049
1050 #if defined(__LITTLE_ENDIAN_BITFIELD)
1051 #define NFT_SET_ELEM_BUSY_BIT   2
1052 #elif defined(__BIG_ENDIAN_BITFIELD)
1053 #define NFT_SET_ELEM_BUSY_BIT   (BITS_PER_LONG - BITS_PER_BYTE + 2)
1054 #else
1055 #error
1056 #endif
1057
1058 static inline int nft_set_elem_mark_busy(struct nft_set_ext *ext)
1059 {
1060         unsigned long *word = (unsigned long *)ext;
1061
1062         BUILD_BUG_ON(offsetof(struct nft_set_ext, genmask) != 0);
1063         return test_and_set_bit(NFT_SET_ELEM_BUSY_BIT, word);
1064 }
1065
1066 static inline void nft_set_elem_clear_busy(struct nft_set_ext *ext)
1067 {
1068         unsigned long *word = (unsigned long *)ext;
1069
1070         clear_bit(NFT_SET_ELEM_BUSY_BIT, word);
1071 }
1072
1073 /**
1074  *      struct nft_trans - nf_tables object update in transaction
1075  *
1076  *      @list: used internally
1077  *      @msg_type: message type
1078  *      @ctx: transaction context
1079  *      @data: internal information related to the transaction
1080  */
1081 struct nft_trans {
1082         struct list_head                list;
1083         int                             msg_type;
1084         struct nft_ctx                  ctx;
1085         char                            data[0];
1086 };
1087
1088 struct nft_trans_rule {
1089         struct nft_rule                 *rule;
1090 };
1091
1092 #define nft_trans_rule(trans)   \
1093         (((struct nft_trans_rule *)trans->data)->rule)
1094
1095 struct nft_trans_set {
1096         struct nft_set                  *set;
1097         u32                             set_id;
1098 };
1099
1100 #define nft_trans_set(trans)    \
1101         (((struct nft_trans_set *)trans->data)->set)
1102 #define nft_trans_set_id(trans) \
1103         (((struct nft_trans_set *)trans->data)->set_id)
1104
1105 struct nft_trans_chain {
1106         bool                            update;
1107         char                            name[NFT_CHAIN_MAXNAMELEN];
1108         struct nft_stats __percpu       *stats;
1109         u8                              policy;
1110 };
1111
1112 #define nft_trans_chain_update(trans)   \
1113         (((struct nft_trans_chain *)trans->data)->update)
1114 #define nft_trans_chain_name(trans)     \
1115         (((struct nft_trans_chain *)trans->data)->name)
1116 #define nft_trans_chain_stats(trans)    \
1117         (((struct nft_trans_chain *)trans->data)->stats)
1118 #define nft_trans_chain_policy(trans)   \
1119         (((struct nft_trans_chain *)trans->data)->policy)
1120
1121 struct nft_trans_table {
1122         bool                            update;
1123         bool                            enable;
1124 };
1125
1126 #define nft_trans_table_update(trans)   \
1127         (((struct nft_trans_table *)trans->data)->update)
1128 #define nft_trans_table_enable(trans)   \
1129         (((struct nft_trans_table *)trans->data)->enable)
1130
1131 struct nft_trans_elem {
1132         struct nft_set                  *set;
1133         struct nft_set_elem             elem;
1134 };
1135
1136 #define nft_trans_elem_set(trans)       \
1137         (((struct nft_trans_elem *)trans->data)->set)
1138 #define nft_trans_elem(trans)   \
1139         (((struct nft_trans_elem *)trans->data)->elem)
1140
1141 #endif /* _NET_NF_TABLES_H */