include/net/netfilter/nf_tables.h

   1 #ifndef _NET_NF_TABLES_H
   2 #define _NET_NF_TABLES_H
   3
   4 #include <linux/list.h>
   5 #include <linux/netfilter.h>
   6 #include <linux/netfilter/nfnetlink.h>
   7 #include <linux/netfilter/x_tables.h>
   8 #include <linux/netfilter/nf_tables.h>
   9 #include <linux/u64_stats_sync.h>
  10 #include <net/netlink.h>
  11
  12 #define NFT_JUMP_STACK_SIZE     16
  13
  14 struct nft_pktinfo {
  15         struct sk_buff                  *skb;
  16         const struct net_device         *in;
  17         const struct net_device         *out;
  18         const struct nf_hook_ops        *ops;
  19         u8                              nhoff;
  20         u8                              thoff;
  21         u8                              tprot;
  22         /* for x_tables compatibility */
  23         struct xt_action_param          xt;
  24 };
  25
  26 static inline void nft_set_pktinfo(struct nft_pktinfo *pkt,
  27                                    const struct nf_hook_ops *ops,
  28                                    struct sk_buff *skb,
  29                                    const struct net_device *in,
  30                                    const struct net_device *out)
  31 {
  32         pkt->skb = skb;
  33         pkt->in = pkt->xt.in = in;
  34         pkt->out = pkt->xt.out = out;
  35         pkt->ops = ops;
  36         pkt->xt.hooknum = ops->hooknum;
  37         pkt->xt.family = ops->pf;
  38 }
  39
  40 struct nft_data {
  41         union {
  42                 u32                             data[4];
  43                 struct {
  44                         u32                     verdict;
  45                         struct nft_chain        *chain;
  46                 };
  47         };
  48 } __attribute__((aligned(__alignof__(u64))));
  49
  50 static inline int nft_data_cmp(const struct nft_data *d1,
  51                                const struct nft_data *d2,
  52                                unsigned int len)
  53 {
  54         return memcmp(d1->data, d2->data, len);
  55 }
  56
  57 static inline void nft_data_copy(struct nft_data *dst,
  58                                  const struct nft_data *src)
  59 {
  60         BUILD_BUG_ON(__alignof__(*dst) != __alignof__(u64));
  61         *(u64 *)&dst->data[0] = *(u64 *)&src->data[0];
  62         *(u64 *)&dst->data[2] = *(u64 *)&src->data[2];
  63 }
  64
  65 static inline void nft_data_debug(const struct nft_data *data)
  66 {
  67         pr_debug("data[0]=%x data[1]=%x data[2]=%x data[3]=%x\n",
  68                  data->data[0], data->data[1],
  69                  data->data[2], data->data[3]);
  70 }
  71
  72 /**
  73  *      struct nft_ctx - nf_tables rule/set context
  74  *
  75  *      @net: net namespace
  76  *      @afi: address family info
  77  *      @table: the table the chain is contained in
  78  *      @chain: the chain the rule is contained in
  79  *      @nla: netlink attributes
  80  *      @portid: netlink portID of the original message
  81  *      @seq: netlink sequence number
  82  *      @report: notify via unicast netlink message
  83  */
  84 struct nft_ctx {
  85         struct net                      *net;
  86         struct nft_af_info              *afi;
  87         struct nft_table                *table;
  88         struct nft_chain                *chain;
  89         const struct nlattr * const     *nla;
  90         u32                             portid;
  91         u32                             seq;
  92         bool                            report;
  93 };
  94
  95 struct nft_data_desc {
  96         enum nft_data_types             type;
  97         unsigned int                    len;
  98 };
  99
 100 int nft_data_init(const struct nft_ctx *ctx, struct nft_data *data,
 101                   struct nft_data_desc *desc, const struct nlattr *nla);
 102 void nft_data_uninit(const struct nft_data *data, enum nft_data_types type);
 103 int nft_data_dump(struct sk_buff *skb, int attr, const struct nft_data *data,
 104                   enum nft_data_types type, unsigned int len);
 105
 106 static inline enum nft_data_types nft_dreg_to_type(enum nft_registers reg)
 107 {
 108         return reg == NFT_REG_VERDICT ? NFT_DATA_VERDICT : NFT_DATA_VALUE;
 109 }
 110
 111 static inline enum nft_registers nft_type_to_reg(enum nft_data_types type)
 112 {
 113         return type == NFT_DATA_VERDICT ? NFT_REG_VERDICT : NFT_REG_1;
 114 }
 115
 116 int nft_validate_input_register(enum nft_registers reg);
 117 int nft_validate_output_register(enum nft_registers reg);
 118 int nft_validate_data_load(const struct nft_ctx *ctx, enum nft_registers reg,
 119                            const struct nft_data *data,
 120                            enum nft_data_types type);
 121
 122 /**
 123  *      struct nft_set_elem - generic representation of set elements
 124  *
 125  *      @cookie: implementation specific element cookie
 126  *      @key: element key
 127  *      @data: element data (maps only)
 128  *      @flags: element flags (end of interval)
 129  *
 130  *      The cookie can be used to store a handle to the element for subsequent
 131  *      removal.
 132  */
 133 struct nft_set_elem {
 134         void                    *cookie;
 135         struct nft_data         key;
 136         struct nft_data         data;
 137         u32                     flags;
 138 };
 139
 140 struct nft_set;
 141 struct nft_set_iter {
 142         unsigned int    count;
 143         unsigned int    skip;
 144         int             err;
 145         int             (*fn)(const struct nft_ctx *ctx,
 146                               const struct nft_set *set,
 147                               const struct nft_set_iter *iter,
 148                               const struct nft_set_elem *elem);
 149 };
 150
 151 /**
 152  *      struct nft_set_desc - description of set elements
 153  *
 154  *      @klen: key length
 155  *      @dlen: data length
 156  *      @size: number of set elements
 157  */
 158 struct nft_set_desc {
 159         unsigned int            klen;
 160         unsigned int            dlen;
 161         unsigned int            size;
 162 };
 163
 164 /**
 165  *      enum nft_set_class - performance class
 166  *
 167  *      @NFT_LOOKUP_O_1: constant, O(1)
 168  *      @NFT_LOOKUP_O_LOG_N: logarithmic, O(log N)
 169  *      @NFT_LOOKUP_O_N: linear, O(N)
 170  */
 171 enum nft_set_class {
 172         NFT_SET_CLASS_O_1,
 173         NFT_SET_CLASS_O_LOG_N,
 174         NFT_SET_CLASS_O_N,
 175 };
 176
 177 /**
 178  *      struct nft_set_estimate - estimation of memory and performance
 179  *                                characteristics
 180  *
 181  *      @size: required memory
 182  *      @class: lookup performance class
 183  */
 184 struct nft_set_estimate {
 185         unsigned int            size;
 186         enum nft_set_class      class;
 187 };
 188
 189 /**
 190  *      struct nft_set_ops - nf_tables set operations
 191  *
 192  *      @lookup: look up an element within the set
 193  *      @insert: insert new element into set
 194  *      @remove: remove element from set
 195  *      @walk: iterate over all set elemeennts
 196  *      @privsize: function to return size of set private data
 197  *      @init: initialize private data of new set instance
 198  *      @destroy: destroy private data of set instance
 199  *      @list: nf_tables_set_ops list node
 200  *      @owner: module reference
 201  *      @features: features supported by the implementation
 202  */
 203 struct nft_set_ops {
 204         bool                            (*lookup)(const struct nft_set *set,
 205                                                   const struct nft_data *key,
 206                                                   struct nft_data *data);
 207         int                             (*get)(const struct nft_set *set,
 208                                                struct nft_set_elem *elem);
 209         int                             (*insert)(const struct nft_set *set,
 210                                                   const struct nft_set_elem *elem);
 211         void                            (*remove)(const struct nft_set *set,
 212                                                   const struct nft_set_elem *elem);
 213         void                            (*walk)(const struct nft_ctx *ctx,
 214                                                 const struct nft_set *set,
 215                                                 struct nft_set_iter *iter);
 216
 217         unsigned int                    (*privsize)(const struct nlattr * const nla[]);
 218         bool                            (*estimate)(const struct nft_set_desc *desc,
 219                                                     u32 features,
 220                                                     struct nft_set_estimate *est);
 221         int                             (*init)(const struct nft_set *set,
 222                                                 const struct nft_set_desc *desc,
 223                                                 const struct nlattr * const nla[]);
 224         void                            (*destroy)(const struct nft_set *set);
 225
 226         struct list_head                list;
 227         struct module                   *owner;
 228         u32                             features;
 229 };
 230
 231 int nft_register_set(struct nft_set_ops *ops);
 232 void nft_unregister_set(struct nft_set_ops *ops);
 233
 234 /**
 235  *      struct nft_set - nf_tables set instance
 236  *
 237  *      @list: table set list node
 238  *      @bindings: list of set bindings
 239  *      @name: name of the set
 240  *      @ktype: key type (numeric type defined by userspace, not used in the kernel)
 241  *      @dtype: data type (verdict or numeric type defined by userspace)
 242  *      @size: maximum set size
 243  *      @nelems: number of elements
 244  *      @policy: set parameterization (see enum nft_set_policies)
 245  *      @ops: set ops
 246  *      @flags: set flags
 247  *      @klen: key length
 248  *      @dlen: data length
 249  *      @data: private set data
 250  */
 251 struct nft_set {
 252         struct list_head                list;
 253         struct list_head                bindings;
 254         char                            name[IFNAMSIZ];
 255         u32                             ktype;
 256         u32                             dtype;
 257         u32                             size;
 258         u32                             nelems;
 259         u16                             policy;
 260         /* runtime data below here */
 261         const struct nft_set_ops        *ops ____cacheline_aligned;
 262         u16                             flags;
 263         u8                              klen;
 264         u8                              dlen;
 265         unsigned char                   data[]
 266                 __attribute__((aligned(__alignof__(u64))));
 267 };
 268
 269 static inline void *nft_set_priv(const struct nft_set *set)
 270 {
 271         return (void *)set->data;
 272 }
 273
 274 struct nft_set *nf_tables_set_lookup(const struct nft_table *table,
 275                                      const struct nlattr *nla);
 276 struct nft_set *nf_tables_set_lookup_byid(const struct net *net,
 277                                           const struct nlattr *nla);
 278
 279 /**
 280  *      struct nft_set_binding - nf_tables set binding
 281  *
 282  *      @list: set bindings list node
 283  *      @chain: chain containing the rule bound to the set
 284  *
 285  *      A set binding contains all information necessary for validation
 286  *      of new elements added to a bound set.
 287  */
 288 struct nft_set_binding {
 289         struct list_head                list;
 290         const struct nft_chain          *chain;
 291 };
 292
 293 int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
 294                        struct nft_set_binding *binding);
 295 void nf_tables_unbind_set(const struct nft_ctx *ctx, struct nft_set *set,
 296                           struct nft_set_binding *binding);
 297
 298
 299 /**
 300  *      struct nft_expr_type - nf_tables expression type
 301  *
 302  *      @select_ops: function to select nft_expr_ops
 303  *      @ops: default ops, used when no select_ops functions is present
 304  *      @list: used internally
 305  *      @name: Identifier
 306  *      @owner: module reference
 307  *      @policy: netlink attribute policy
 308  *      @maxattr: highest netlink attribute number
 309  *      @family: address family for AF-specific types
 310  */
 311 struct nft_expr_type {
 312         const struct nft_expr_ops       *(*select_ops)(const struct nft_ctx *,
 313                                                        const struct nlattr * const tb[]);
 314         const struct nft_expr_ops       *ops;
 315         struct list_head                list;
 316         const char                      *name;
 317         struct module                   *owner;
 318         const struct nla_policy         *policy;
 319         unsigned int                    maxattr;
 320         u8                              family;
 321 };
 322
 323 /**
 324  *      struct nft_expr_ops - nf_tables expression operations
 325  *
 326  *      @eval: Expression evaluation function
 327  *      @size: full expression size, including private data size
 328  *      @init: initialization function
 329  *      @destroy: destruction function
 330  *      @dump: function to dump parameters
 331  *      @type: expression type
 332  *      @validate: validate expression, called during loop detection
 333  *      @data: extra data to attach to this expression operation
 334  */
 335 struct nft_expr;
 336 struct nft_expr_ops {
 337         void                            (*eval)(const struct nft_expr *expr,
 338                                                 struct nft_data data[NFT_REG_MAX + 1],
 339                                                 const struct nft_pktinfo *pkt);
 340         unsigned int                    size;
 341
 342         int                             (*init)(const struct nft_ctx *ctx,
 343                                                 const struct nft_expr *expr,
 344                                                 const struct nlattr * const tb[]);
 345         void                            (*destroy)(const struct nft_ctx *ctx,
 346                                                    const struct nft_expr *expr);
 347         int                             (*dump)(struct sk_buff *skb,
 348                                                 const struct nft_expr *expr);
 349         int                             (*validate)(const struct nft_ctx *ctx,
 350                                                     const struct nft_expr *expr,
 351                                                     const struct nft_data **data);
 352         const struct nft_expr_type      *type;
 353         void                            *data;
 354 };
 355
 356 #define NFT_EXPR_MAXATTR                16
 357 #define NFT_EXPR_SIZE(size)             (sizeof(struct nft_expr) + \
 358                                          ALIGN(size, __alignof__(struct nft_expr)))
 359
 360 /**
 361  *      struct nft_expr - nf_tables expression
 362  *
 363  *      @ops: expression ops
 364  *      @data: expression private data
 365  */
 366 struct nft_expr {
 367         const struct nft_expr_ops       *ops;
 368         unsigned char                   data[];
 369 };
 370
 371 static inline void *nft_expr_priv(const struct nft_expr *expr)
 372 {
 373         return (void *)expr->data;
 374 }
 375
 376 /**
 377  *      struct nft_rule - nf_tables rule
 378  *
 379  *      @list: used internally
 380  *      @handle: rule handle
 381  *      @genmask: generation mask
 382  *      @dlen: length of expression data
 383  *      @ulen: length of user data (used for comments)
 384  *      @data: expression data
 385  */
 386 struct nft_rule {
 387         struct list_head                list;
 388         u64                             handle:42,
 389                                         genmask:2,
 390                                         dlen:12,
 391                                         ulen:8;
 392         unsigned char                   data[]
 393                 __attribute__((aligned(__alignof__(struct nft_expr))));
 394 };
 395
 396 /**
 397  *      struct nft_trans - nf_tables object update in transaction
 398  *
 399  *      @list: used internally
 400  *      @msg_type: message type
 401  *      @ctx: transaction context
 402  *      @data: internal information related to the transaction
 403  */
 404 struct nft_trans {
 405         struct list_head                list;
 406         int                             msg_type;
 407         struct nft_ctx                  ctx;
 408         char                            data[0];
 409 };
 410
 411 struct nft_trans_rule {
 412         struct nft_rule                 *rule;
 413 };
 414
 415 #define nft_trans_rule(trans)   \
 416         (((struct nft_trans_rule *)trans->data)->rule)
 417
 418 struct nft_trans_set {
 419         struct nft_set  *set;
 420         u32             set_id;
 421 };
 422
 423 #define nft_trans_set(trans)    \
 424         (((struct nft_trans_set *)trans->data)->set)
 425 #define nft_trans_set_id(trans) \
 426         (((struct nft_trans_set *)trans->data)->set_id)
 427
 428 struct nft_trans_chain {
 429         bool            update;
 430         char            name[NFT_CHAIN_MAXNAMELEN];
 431         struct nft_stats __percpu *stats;
 432         u8              policy;
 433 };
 434
 435 #define nft_trans_chain_update(trans)   \
 436         (((struct nft_trans_chain *)trans->data)->update)
 437 #define nft_trans_chain_name(trans)     \
 438         (((struct nft_trans_chain *)trans->data)->name)
 439 #define nft_trans_chain_stats(trans)    \
 440         (((struct nft_trans_chain *)trans->data)->stats)
 441 #define nft_trans_chain_policy(trans)   \
 442         (((struct nft_trans_chain *)trans->data)->policy)
 443
 444 struct nft_trans_table {
 445         bool            update;
 446         bool            enable;
 447 };
 448
 449 #define nft_trans_table_update(trans)   \
 450         (((struct nft_trans_table *)trans->data)->update)
 451 #define nft_trans_table_enable(trans)   \
 452         (((struct nft_trans_table *)trans->data)->enable)
 453
 454 struct nft_trans_elem {
 455         struct nft_set          *set;
 456         struct nft_set_elem     elem;
 457 };
 458
 459 #define nft_trans_elem_set(trans)       \
 460         (((struct nft_trans_elem *)trans->data)->set)
 461 #define nft_trans_elem(trans)   \
 462         (((struct nft_trans_elem *)trans->data)->elem)
 463
 464 static inline struct nft_expr *nft_expr_first(const struct nft_rule *rule)
 465 {
 466         return (struct nft_expr *)&rule->data[0];
 467 }
 468
 469 static inline struct nft_expr *nft_expr_next(const struct nft_expr *expr)
 470 {
 471         return ((void *)expr) + expr->ops->size;
 472 }
 473
 474 static inline struct nft_expr *nft_expr_last(const struct nft_rule *rule)
 475 {
 476         return (struct nft_expr *)&rule->data[rule->dlen];
 477 }
 478
 479 static inline void *nft_userdata(const struct nft_rule *rule)
 480 {
 481         return (void *)&rule->data[rule->dlen];
 482 }
 483
 484 /*
 485  * The last pointer isn't really necessary, but the compiler isn't able to
 486  * determine that the result of nft_expr_last() is always the same since it
 487  * can't assume that the dlen value wasn't changed within calls in the loop.
 488  */
 489 #define nft_rule_for_each_expr(expr, last, rule) \
 490         for ((expr) = nft_expr_first(rule), (last) = nft_expr_last(rule); \
 491              (expr) != (last); \
 492              (expr) = nft_expr_next(expr))
 493
 494 enum nft_chain_flags {
 495         NFT_BASE_CHAIN                  = 0x1,
 496         NFT_CHAIN_INACTIVE              = 0x2,
 497 };
 498
 499 /**
 500  *      struct nft_chain - nf_tables chain
 501  *
 502  *      @rules: list of rules in the chain
 503  *      @list: used internally
 504  *      @net: net namespace that this chain belongs to
 505  *      @table: table that this chain belongs to
 506  *      @handle: chain handle
 507  *      @use: number of jump references to this chain
 508  *      @level: length of longest path to this chain
 509  *      @flags: bitmask of enum nft_chain_flags
 510  *      @name: name of the chain
 511  */
 512 struct nft_chain {
 513         struct list_head                rules;
 514         struct list_head                list;
 515         struct net                      *net;
 516         struct nft_table                *table;
 517         u64                             handle;
 518         u32                             use;
 519         u16                             level;
 520         u8                              flags;
 521         char                            name[NFT_CHAIN_MAXNAMELEN];
 522 };
 523
 524 enum nft_chain_type {
 525         NFT_CHAIN_T_DEFAULT = 0,
 526         NFT_CHAIN_T_ROUTE,
 527         NFT_CHAIN_T_NAT,
 528         NFT_CHAIN_T_MAX
 529 };
 530
 531 int nft_chain_validate_dependency(const struct nft_chain *chain,
 532                                   enum nft_chain_type type);
 533 int nft_chain_validate_hooks(const struct nft_chain *chain,
 534                              unsigned int hook_flags);
 535
 536 struct nft_stats {
 537         u64                     bytes;
 538         u64                     pkts;
 539         struct u64_stats_sync   syncp;
 540 };
 541
 542 #define NFT_HOOK_OPS_MAX                2
 543
 544 /**
 545  *      struct nft_base_chain - nf_tables base chain
 546  *
 547  *      @ops: netfilter hook ops
 548  *      @type: chain type
 549  *      @policy: default policy
 550  *      @stats: per-cpu chain stats
 551  *      @chain: the chain
 552  */
 553 struct nft_base_chain {
 554         struct nf_hook_ops              ops[NFT_HOOK_OPS_MAX];
 555         const struct nf_chain_type      *type;
 556         u8                              policy;
 557         struct nft_stats __percpu       *stats;
 558         struct nft_chain                chain;
 559 };
 560
 561 static inline struct nft_base_chain *nft_base_chain(const struct nft_chain *chain)
 562 {
 563         return container_of(chain, struct nft_base_chain, chain);
 564 }
 565
 566 unsigned int nft_do_chain(struct nft_pktinfo *pkt,
 567                           const struct nf_hook_ops *ops);
 568
 569 /**
 570  *      struct nft_table - nf_tables table
 571  *
 572  *      @list: used internally
 573  *      @chains: chains in the table
 574  *      @sets: sets in the table
 575  *      @hgenerator: handle generator state
 576  *      @use: number of chain references to this table
 577  *      @flags: table flag (see enum nft_table_flags)
 578  *      @name: name of the table
 579  */
 580 struct nft_table {
 581         struct list_head                list;
 582         struct list_head                chains;
 583         struct list_head                sets;
 584         u64                             hgenerator;
 585         u32                             use;
 586         u16                             flags;
 587         char                            name[];
 588 };
 589
 590 /**
 591  *      struct nft_af_info - nf_tables address family info
 592  *
 593  *      @list: used internally
 594  *      @family: address family
 595  *      @nhooks: number of hooks in this family
 596  *      @owner: module owner
 597  *      @tables: used internally
 598  *      @nops: number of hook ops in this family
 599  *      @hook_ops_init: initialization function for chain hook ops
 600  *      @hooks: hookfn overrides for packet validation
 601  */
 602 struct nft_af_info {
 603         struct list_head                list;
 604         int                             family;
 605         unsigned int                    nhooks;
 606         struct module                   *owner;
 607         struct list_head                tables;
 608         unsigned int                    nops;
 609         void                            (*hook_ops_init)(struct nf_hook_ops *,
 610                                                          unsigned int);
 611         nf_hookfn                       *hooks[NF_MAX_HOOKS];
 612 };
 613
 614 int nft_register_afinfo(struct net *, struct nft_af_info *);
 615 void nft_unregister_afinfo(struct nft_af_info *);
 616
 617 /**
 618  *      struct nf_chain_type - nf_tables chain type info
 619  *
 620  *      @name: name of the type
 621  *      @type: numeric identifier
 622  *      @family: address family
 623  *      @owner: module owner
 624  *      @hook_mask: mask of valid hooks
 625  *      @hooks: hookfn overrides
 626  */
 627 struct nf_chain_type {
 628         const char                      *name;
 629         enum nft_chain_type             type;
 630         int                             family;
 631         struct module                   *owner;
 632         unsigned int                    hook_mask;
 633         nf_hookfn                       *hooks[NF_MAX_HOOKS];
 634 };
 635
 636 int nft_register_chain_type(const struct nf_chain_type *);
 637 void nft_unregister_chain_type(const struct nf_chain_type *);
 638
 639 int nft_register_expr(struct nft_expr_type *);
 640 void nft_unregister_expr(struct nft_expr_type *);
 641
 642 #define nft_dereference(p)                                      \
 643         nfnl_dereference(p, NFNL_SUBSYS_NFTABLES)
 644
 645 #define MODULE_ALIAS_NFT_FAMILY(family) \
 646         MODULE_ALIAS("nft-afinfo-" __stringify(family))
 647
 648 #define MODULE_ALIAS_NFT_CHAIN(family, name) \
 649         MODULE_ALIAS("nft-chain-" __stringify(family) "-" name)
 650
 651 #define MODULE_ALIAS_NFT_AF_EXPR(family, name) \
 652         MODULE_ALIAS("nft-expr-" __stringify(family) "-" name)
 653
 654 #define MODULE_ALIAS_NFT_EXPR(name) \
 655         MODULE_ALIAS("nft-expr-" name)
 656
 657 #define MODULE_ALIAS_NFT_SET() \
 658         MODULE_ALIAS("nft-set")
 659
 660 #endif /* _NET_NF_TABLES_H */