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 /**
 124  *      struct nft_userdata - user defined data associated with an object
 125  *
 126  *      @len: length of the data
 127  *      @data: content
 128  *
 129  *      The presence of user data is indicated in an object specific fashion,
 130  *      so a length of zero can't occur and the value "len" indicates data
 131  *      of length len + 1.
 132  */
 133 struct nft_userdata {
 134         u8                      len;
 135         unsigned char           data[0];
 136 };
 137
 138 /**
 139  *      struct nft_set_elem - generic representation of set elements
 140  *
 141  *      @cookie: implementation specific element cookie
 142  *      @key: element key
 143  *      @data: element data (maps only)
 144  *      @flags: element flags (end of interval)
 145  *
 146  *      The cookie can be used to store a handle to the element for subsequent
 147  *      removal.
 148  */
 149 struct nft_set_elem {
 150         void                    *cookie;
 151         struct nft_data         key;
 152         struct nft_data         data;
 153         u32                     flags;
 154 };
 155
 156 struct nft_set;
 157 struct nft_set_iter {
 158         unsigned int    count;
 159         unsigned int    skip;
 160         int             err;
 161         int             (*fn)(const struct nft_ctx *ctx,
 162                               const struct nft_set *set,
 163                               const struct nft_set_iter *iter,
 164                               const struct nft_set_elem *elem);
 165 };
 166
 167 /**
 168  *      struct nft_set_desc - description of set elements
 169  *
 170  *      @klen: key length
 171  *      @dlen: data length
 172  *      @size: number of set elements
 173  */
 174 struct nft_set_desc {
 175         unsigned int            klen;
 176         unsigned int            dlen;
 177         unsigned int            size;
 178 };
 179
 180 /**
 181  *      enum nft_set_class - performance class
 182  *
 183  *      @NFT_LOOKUP_O_1: constant, O(1)
 184  *      @NFT_LOOKUP_O_LOG_N: logarithmic, O(log N)
 185  *      @NFT_LOOKUP_O_N: linear, O(N)
 186  */
 187 enum nft_set_class {
 188         NFT_SET_CLASS_O_1,
 189         NFT_SET_CLASS_O_LOG_N,
 190         NFT_SET_CLASS_O_N,
 191 };
 192
 193 /**
 194  *      struct nft_set_estimate - estimation of memory and performance
 195  *                                characteristics
 196  *
 197  *      @size: required memory
 198  *      @class: lookup performance class
 199  */
 200 struct nft_set_estimate {
 201         unsigned int            size;
 202         enum nft_set_class      class;
 203 };
 204
 205 /**
 206  *      struct nft_set_ops - nf_tables set operations
 207  *
 208  *      @lookup: look up an element within the set
 209  *      @insert: insert new element into set
 210  *      @remove: remove element from set
 211  *      @walk: iterate over all set elemeennts
 212  *      @privsize: function to return size of set private data
 213  *      @init: initialize private data of new set instance
 214  *      @destroy: destroy private data of set instance
 215  *      @list: nf_tables_set_ops list node
 216  *      @owner: module reference
 217  *      @features: features supported by the implementation
 218  */
 219 struct nft_set_ops {
 220         bool                            (*lookup)(const struct nft_set *set,
 221                                                   const struct nft_data *key,
 222                                                   struct nft_data *data);
 223         int                             (*get)(const struct nft_set *set,
 224                                                struct nft_set_elem *elem);
 225         int                             (*insert)(const struct nft_set *set,
 226                                                   const struct nft_set_elem *elem);
 227         void                            (*remove)(const struct nft_set *set,
 228                                                   const struct nft_set_elem *elem);
 229         void                            (*walk)(const struct nft_ctx *ctx,
 230                                                 const struct nft_set *set,
 231                                                 struct nft_set_iter *iter);
 232
 233         unsigned int                    (*privsize)(const struct nlattr * const nla[]);
 234         bool                            (*estimate)(const struct nft_set_desc *desc,
 235                                                     u32 features,
 236                                                     struct nft_set_estimate *est);
 237         int                             (*init)(const struct nft_set *set,
 238                                                 const struct nft_set_desc *desc,
 239                                                 const struct nlattr * const nla[]);
 240         void                            (*destroy)(const struct nft_set *set);
 241
 242         struct list_head                list;
 243         struct module                   *owner;
 244         u32                             features;
 245 };
 246
 247 int nft_register_set(struct nft_set_ops *ops);
 248 void nft_unregister_set(struct nft_set_ops *ops);
 249
 250 /**
 251  *      struct nft_set - nf_tables set instance
 252  *
 253  *      @list: table set list node
 254  *      @bindings: list of set bindings
 255  *      @name: name of the set
 256  *      @ktype: key type (numeric type defined by userspace, not used in the kernel)
 257  *      @dtype: data type (verdict or numeric type defined by userspace)
 258  *      @size: maximum set size
 259  *      @nelems: number of elements
 260  *      @policy: set parameterization (see enum nft_set_policies)
 261  *      @ops: set ops
 262  *      @flags: set flags
 263  *      @klen: key length
 264  *      @dlen: data length
 265  *      @data: private set data
 266  */
 267 struct nft_set {
 268         struct list_head                list;
 269         struct list_head                bindings;
 270         char                            name[IFNAMSIZ];
 271         u32                             ktype;
 272         u32                             dtype;
 273         u32                             size;
 274         u32                             nelems;
 275         u16                             policy;
 276         /* runtime data below here */
 277         const struct nft_set_ops        *ops ____cacheline_aligned;
 278         u16                             flags;
 279         u8                              klen;
 280         u8                              dlen;
 281         unsigned char                   data[]
 282                 __attribute__((aligned(__alignof__(u64))));
 283 };
 284
 285 static inline void *nft_set_priv(const struct nft_set *set)
 286 {
 287         return (void *)set->data;
 288 }
 289
 290 struct nft_set *nf_tables_set_lookup(const struct nft_table *table,
 291                                      const struct nlattr *nla);
 292 struct nft_set *nf_tables_set_lookup_byid(const struct net *net,
 293                                           const struct nlattr *nla);
 294
 295 /**
 296  *      struct nft_set_binding - nf_tables set binding
 297  *
 298  *      @list: set bindings list node
 299  *      @chain: chain containing the rule bound to the set
 300  *
 301  *      A set binding contains all information necessary for validation
 302  *      of new elements added to a bound set.
 303  */
 304 struct nft_set_binding {
 305         struct list_head                list;
 306         const struct nft_chain          *chain;
 307 };
 308
 309 int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
 310                        struct nft_set_binding *binding);
 311 void nf_tables_unbind_set(const struct nft_ctx *ctx, struct nft_set *set,
 312                           struct nft_set_binding *binding);
 313
 314
 315 /**
 316  *      struct nft_expr_type - nf_tables expression type
 317  *
 318  *      @select_ops: function to select nft_expr_ops
 319  *      @ops: default ops, used when no select_ops functions is present
 320  *      @list: used internally
 321  *      @name: Identifier
 322  *      @owner: module reference
 323  *      @policy: netlink attribute policy
 324  *      @maxattr: highest netlink attribute number
 325  *      @family: address family for AF-specific types
 326  */
 327 struct nft_expr_type {
 328         const struct nft_expr_ops       *(*select_ops)(const struct nft_ctx *,
 329                                                        const struct nlattr * const tb[]);
 330         const struct nft_expr_ops       *ops;
 331         struct list_head                list;
 332         const char                      *name;
 333         struct module                   *owner;
 334         const struct nla_policy         *policy;
 335         unsigned int                    maxattr;
 336         u8                              family;
 337 };
 338
 339 /**
 340  *      struct nft_expr_ops - nf_tables expression operations
 341  *
 342  *      @eval: Expression evaluation function
 343  *      @size: full expression size, including private data size
 344  *      @init: initialization function
 345  *      @destroy: destruction function
 346  *      @dump: function to dump parameters
 347  *      @type: expression type
 348  *      @validate: validate expression, called during loop detection
 349  *      @data: extra data to attach to this expression operation
 350  */
 351 struct nft_expr;
 352 struct nft_expr_ops {
 353         void                            (*eval)(const struct nft_expr *expr,
 354                                                 struct nft_data data[NFT_REG_MAX + 1],
 355                                                 const struct nft_pktinfo *pkt);
 356         unsigned int                    size;
 357
 358         int                             (*init)(const struct nft_ctx *ctx,
 359                                                 const struct nft_expr *expr,
 360                                                 const struct nlattr * const tb[]);
 361         void                            (*destroy)(const struct nft_ctx *ctx,
 362                                                    const struct nft_expr *expr);
 363         int                             (*dump)(struct sk_buff *skb,
 364                                                 const struct nft_expr *expr);
 365         int                             (*validate)(const struct nft_ctx *ctx,
 366                                                     const struct nft_expr *expr,
 367                                                     const struct nft_data **data);
 368         const struct nft_expr_type      *type;
 369         void                            *data;
 370 };
 371
 372 #define NFT_EXPR_MAXATTR                16
 373 #define NFT_EXPR_SIZE(size)             (sizeof(struct nft_expr) + \
 374                                          ALIGN(size, __alignof__(struct nft_expr)))
 375
 376 /**
 377  *      struct nft_expr - nf_tables expression
 378  *
 379  *      @ops: expression ops
 380  *      @data: expression private data
 381  */
 382 struct nft_expr {
 383         const struct nft_expr_ops       *ops;
 384         unsigned char                   data[];
 385 };
 386
 387 static inline void *nft_expr_priv(const struct nft_expr *expr)
 388 {
 389         return (void *)expr->data;
 390 }
 391
 392 /**
 393  *      struct nft_rule - nf_tables rule
 394  *
 395  *      @list: used internally
 396  *      @handle: rule handle
 397  *      @genmask: generation mask
 398  *      @dlen: length of expression data
 399  *      @udata: user data is appended to the rule
 400  *      @data: expression data
 401  */
 402 struct nft_rule {
 403         struct list_head                list;
 404         u64                             handle:42,
 405                                         genmask:2,
 406                                         dlen:12,
 407                                         udata:1;
 408         unsigned char                   data[]
 409                 __attribute__((aligned(__alignof__(struct nft_expr))));
 410 };
 411
 412 /**
 413  *      struct nft_trans - nf_tables object update in transaction
 414  *
 415  *      @list: used internally
 416  *      @msg_type: message type
 417  *      @ctx: transaction context
 418  *      @data: internal information related to the transaction
 419  */
 420 struct nft_trans {
 421         struct list_head                list;
 422         int                             msg_type;
 423         struct nft_ctx                  ctx;
 424         char                            data[0];
 425 };
 426
 427 struct nft_trans_rule {
 428         struct nft_rule                 *rule;
 429 };
 430
 431 #define nft_trans_rule(trans)   \
 432         (((struct nft_trans_rule *)trans->data)->rule)
 433
 434 struct nft_trans_set {
 435         struct nft_set  *set;
 436         u32             set_id;
 437 };
 438
 439 #define nft_trans_set(trans)    \
 440         (((struct nft_trans_set *)trans->data)->set)
 441 #define nft_trans_set_id(trans) \
 442         (((struct nft_trans_set *)trans->data)->set_id)
 443
 444 struct nft_trans_chain {
 445         bool            update;
 446         char            name[NFT_CHAIN_MAXNAMELEN];
 447         struct nft_stats __percpu *stats;
 448         u8              policy;
 449 };
 450
 451 #define nft_trans_chain_update(trans)   \
 452         (((struct nft_trans_chain *)trans->data)->update)
 453 #define nft_trans_chain_name(trans)     \
 454         (((struct nft_trans_chain *)trans->data)->name)
 455 #define nft_trans_chain_stats(trans)    \
 456         (((struct nft_trans_chain *)trans->data)->stats)
 457 #define nft_trans_chain_policy(trans)   \
 458         (((struct nft_trans_chain *)trans->data)->policy)
 459
 460 struct nft_trans_table {
 461         bool            update;
 462         bool            enable;
 463 };
 464
 465 #define nft_trans_table_update(trans)   \
 466         (((struct nft_trans_table *)trans->data)->update)
 467 #define nft_trans_table_enable(trans)   \
 468         (((struct nft_trans_table *)trans->data)->enable)
 469
 470 struct nft_trans_elem {
 471         struct nft_set          *set;
 472         struct nft_set_elem     elem;
 473 };
 474
 475 #define nft_trans_elem_set(trans)       \
 476         (((struct nft_trans_elem *)trans->data)->set)
 477 #define nft_trans_elem(trans)   \
 478         (((struct nft_trans_elem *)trans->data)->elem)
 479
 480 static inline struct nft_expr *nft_expr_first(const struct nft_rule *rule)
 481 {
 482         return (struct nft_expr *)&rule->data[0];
 483 }
 484
 485 static inline struct nft_expr *nft_expr_next(const struct nft_expr *expr)
 486 {
 487         return ((void *)expr) + expr->ops->size;
 488 }
 489
 490 static inline struct nft_expr *nft_expr_last(const struct nft_rule *rule)
 491 {
 492         return (struct nft_expr *)&rule->data[rule->dlen];
 493 }
 494
 495 static inline struct nft_userdata *nft_userdata(const struct nft_rule *rule)
 496 {
 497         return (void *)&rule->data[rule->dlen];
 498 }
 499
 500 /*
 501  * The last pointer isn't really necessary, but the compiler isn't able to
 502  * determine that the result of nft_expr_last() is always the same since it
 503  * can't assume that the dlen value wasn't changed within calls in the loop.
 504  */
 505 #define nft_rule_for_each_expr(expr, last, rule) \
 506         for ((expr) = nft_expr_first(rule), (last) = nft_expr_last(rule); \
 507              (expr) != (last); \
 508              (expr) = nft_expr_next(expr))
 509
 510 enum nft_chain_flags {
 511         NFT_BASE_CHAIN                  = 0x1,
 512         NFT_CHAIN_INACTIVE              = 0x2,
 513 };
 514
 515 /**
 516  *      struct nft_chain - nf_tables chain
 517  *
 518  *      @rules: list of rules in the chain
 519  *      @list: used internally
 520  *      @net: net namespace that this chain belongs to
 521  *      @table: table that this chain belongs to
 522  *      @handle: chain handle
 523  *      @use: number of jump references to this chain
 524  *      @level: length of longest path to this chain
 525  *      @flags: bitmask of enum nft_chain_flags
 526  *      @name: name of the chain
 527  */
 528 struct nft_chain {
 529         struct list_head                rules;
 530         struct list_head                list;
 531         struct net                      *net;
 532         struct nft_table                *table;
 533         u64                             handle;
 534         u32                             use;
 535         u16                             level;
 536         u8                              flags;
 537         char                            name[NFT_CHAIN_MAXNAMELEN];
 538 };
 539
 540 enum nft_chain_type {
 541         NFT_CHAIN_T_DEFAULT = 0,
 542         NFT_CHAIN_T_ROUTE,
 543         NFT_CHAIN_T_NAT,
 544         NFT_CHAIN_T_MAX
 545 };
 546
 547 int nft_chain_validate_dependency(const struct nft_chain *chain,
 548                                   enum nft_chain_type type);
 549 int nft_chain_validate_hooks(const struct nft_chain *chain,
 550                              unsigned int hook_flags);
 551
 552 struct nft_stats {
 553         u64                     bytes;
 554         u64                     pkts;
 555         struct u64_stats_sync   syncp;
 556 };
 557
 558 #define NFT_HOOK_OPS_MAX                2
 559
 560 /**
 561  *      struct nft_base_chain - nf_tables base chain
 562  *
 563  *      @ops: netfilter hook ops
 564  *      @type: chain type
 565  *      @policy: default policy
 566  *      @stats: per-cpu chain stats
 567  *      @chain: the chain
 568  */
 569 struct nft_base_chain {
 570         struct nf_hook_ops              ops[NFT_HOOK_OPS_MAX];
 571         const struct nf_chain_type      *type;
 572         u8                              policy;
 573         struct nft_stats __percpu       *stats;
 574         struct nft_chain                chain;
 575 };
 576
 577 static inline struct nft_base_chain *nft_base_chain(const struct nft_chain *chain)
 578 {
 579         return container_of(chain, struct nft_base_chain, chain);
 580 }
 581
 582 unsigned int nft_do_chain(struct nft_pktinfo *pkt,
 583                           const struct nf_hook_ops *ops);
 584
 585 /**
 586  *      struct nft_table - nf_tables table
 587  *
 588  *      @list: used internally
 589  *      @chains: chains in the table
 590  *      @sets: sets in the table
 591  *      @hgenerator: handle generator state
 592  *      @use: number of chain references to this table
 593  *      @flags: table flag (see enum nft_table_flags)
 594  *      @name: name of the table
 595  */
 596 struct nft_table {
 597         struct list_head                list;
 598         struct list_head                chains;
 599         struct list_head                sets;
 600         u64                             hgenerator;
 601         u32                             use;
 602         u16                             flags;
 603         char                            name[];
 604 };
 605
 606 /**
 607  *      struct nft_af_info - nf_tables address family info
 608  *
 609  *      @list: used internally
 610  *      @family: address family
 611  *      @nhooks: number of hooks in this family
 612  *      @owner: module owner
 613  *      @tables: used internally
 614  *      @nops: number of hook ops in this family
 615  *      @hook_ops_init: initialization function for chain hook ops
 616  *      @hooks: hookfn overrides for packet validation
 617  */
 618 struct nft_af_info {
 619         struct list_head                list;
 620         int                             family;
 621         unsigned int                    nhooks;
 622         struct module                   *owner;
 623         struct list_head                tables;
 624         unsigned int                    nops;
 625         void                            (*hook_ops_init)(struct nf_hook_ops *,
 626                                                          unsigned int);
 627         nf_hookfn                       *hooks[NF_MAX_HOOKS];
 628 };
 629
 630 int nft_register_afinfo(struct net *, struct nft_af_info *);
 631 void nft_unregister_afinfo(struct nft_af_info *);
 632
 633 /**
 634  *      struct nf_chain_type - nf_tables chain type info
 635  *
 636  *      @name: name of the type
 637  *      @type: numeric identifier
 638  *      @family: address family
 639  *      @owner: module owner
 640  *      @hook_mask: mask of valid hooks
 641  *      @hooks: hookfn overrides
 642  */
 643 struct nf_chain_type {
 644         const char                      *name;
 645         enum nft_chain_type             type;
 646         int                             family;
 647         struct module                   *owner;
 648         unsigned int                    hook_mask;
 649         nf_hookfn                       *hooks[NF_MAX_HOOKS];
 650 };
 651
 652 int nft_register_chain_type(const struct nf_chain_type *);
 653 void nft_unregister_chain_type(const struct nf_chain_type *);
 654
 655 int nft_register_expr(struct nft_expr_type *);
 656 void nft_unregister_expr(struct nft_expr_type *);
 657
 658 #define nft_dereference(p)                                      \
 659         nfnl_dereference(p, NFNL_SUBSYS_NFTABLES)
 660
 661 #define MODULE_ALIAS_NFT_FAMILY(family) \
 662         MODULE_ALIAS("nft-afinfo-" __stringify(family))
 663
 664 #define MODULE_ALIAS_NFT_CHAIN(family, name) \
 665         MODULE_ALIAS("nft-chain-" __stringify(family) "-" name)
 666
 667 #define MODULE_ALIAS_NFT_AF_EXPR(family, name) \
 668         MODULE_ALIAS("nft-expr-" __stringify(family) "-" name)
 669
 670 #define MODULE_ALIAS_NFT_EXPR(name) \
 671         MODULE_ALIAS("nft-expr-" name)
 672
 673 #define MODULE_ALIAS_NFT_SET() \
 674         MODULE_ALIAS("nft-set")
 675
 676 #endif /* _NET_NF_TABLES_H */