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         bool                            tprot_set;
  18         u8                              tprot;
  19         /* for x_tables compatibility */
  20         struct xt_action_param          xt;
  21 };
  22
  23 static inline struct net *nft_net(const struct nft_pktinfo *pkt)
  24 {
  25         return pkt->xt.state->net;
  26 }
  27
  28 static inline unsigned int nft_hook(const struct nft_pktinfo *pkt)
  29 {
  30         return pkt->xt.state->hook;
  31 }
  32
  33 static inline u8 nft_pf(const struct nft_pktinfo *pkt)
  34 {
  35         return pkt->xt.state->pf;
  36 }
  37
  38 static inline const struct net_device *nft_in(const struct nft_pktinfo *pkt)
  39 {
  40         return pkt->xt.state->in;
  41 }
  42
  43 static inline const struct net_device *nft_out(const struct nft_pktinfo *pkt)
  44 {
  45         return pkt->xt.state->out;
  46 }
  47
  48 static inline void nft_set_pktinfo(struct nft_pktinfo *pkt,
  49                                    struct sk_buff *skb,
  50                                    const struct nf_hook_state *state)
  51 {
  52         pkt->skb = skb;
  53         pkt->xt.state = state;
  54 }
  55
  56 static inline void nft_set_pktinfo_proto_unspec(struct nft_pktinfo *pkt,
  57                                                 struct sk_buff *skb)
  58 {
  59         pkt->tprot_set = false;
  60         pkt->tprot = 0;
  61         pkt->xt.thoff = 0;
  62         pkt->xt.fragoff = 0;
  63 }
  64
  65 static inline void nft_set_pktinfo_unspec(struct nft_pktinfo *pkt,
  66                                           struct sk_buff *skb,
  67                                           const struct nf_hook_state *state)
  68 {
  69         nft_set_pktinfo(pkt, skb, state);
  70         nft_set_pktinfo_proto_unspec(pkt, skb);
  71 }
  72
  73 /**
  74  *      struct nft_verdict - nf_tables verdict
  75  *
  76  *      @code: nf_tables/netfilter verdict code
  77  *      @chain: destination chain for NFT_JUMP/NFT_GOTO
  78  */
  79 struct nft_verdict {
  80         u32                             code;
  81         struct nft_chain                *chain;
  82 };
  83
  84 struct nft_data {
  85         union {
  86                 u32                     data[4];
  87                 struct nft_verdict      verdict;
  88         };
  89 } __attribute__((aligned(__alignof__(u64))));
  90
  91 /**
  92  *      struct nft_regs - nf_tables register set
  93  *
  94  *      @data: data registers
  95  *      @verdict: verdict register
  96  *
  97  *      The first four data registers alias to the verdict register.
  98  */
  99 struct nft_regs {
 100         union {
 101                 u32                     data[20];
 102                 struct nft_verdict      verdict;
 103         };
 104 };
 105
 106 static inline void nft_data_copy(u32 *dst, const struct nft_data *src,
 107                                  unsigned int len)
 108 {
 109         memcpy(dst, src, len);
 110 }
 111
 112 static inline void nft_data_debug(const struct nft_data *data)
 113 {
 114         pr_debug("data[0]=%x data[1]=%x data[2]=%x data[3]=%x\n",
 115                  data->data[0], data->data[1],
 116                  data->data[2], data->data[3]);
 117 }
 118
 119 /**
 120  *      struct nft_ctx - nf_tables rule/set context
 121  *
 122  *      @net: net namespace
 123  *      @afi: address family info
 124  *      @table: the table the chain is contained in
 125  *      @chain: the chain the rule is contained in
 126  *      @nla: netlink attributes
 127  *      @portid: netlink portID of the original message
 128  *      @seq: netlink sequence number
 129  *      @report: notify via unicast netlink message
 130  */
 131 struct nft_ctx {
 132         struct net                      *net;
 133         struct nft_af_info              *afi;
 134         struct nft_table                *table;
 135         struct nft_chain                *chain;
 136         const struct nlattr * const     *nla;
 137         u32                             portid;
 138         u32                             seq;
 139         bool                            report;
 140 };
 141
 142 struct nft_data_desc {
 143         enum nft_data_types             type;
 144         unsigned int                    len;
 145 };
 146
 147 int nft_data_init(const struct nft_ctx *ctx,
 148                   struct nft_data *data, unsigned int size,
 149                   struct nft_data_desc *desc, const struct nlattr *nla);
 150 void nft_data_uninit(const struct nft_data *data, enum nft_data_types type);
 151 int nft_data_dump(struct sk_buff *skb, int attr, const struct nft_data *data,
 152                   enum nft_data_types type, unsigned int len);
 153
 154 static inline enum nft_data_types nft_dreg_to_type(enum nft_registers reg)
 155 {
 156         return reg == NFT_REG_VERDICT ? NFT_DATA_VERDICT : NFT_DATA_VALUE;
 157 }
 158
 159 static inline enum nft_registers nft_type_to_reg(enum nft_data_types type)
 160 {
 161         return type == NFT_DATA_VERDICT ? NFT_REG_VERDICT : NFT_REG_1 * NFT_REG_SIZE / NFT_REG32_SIZE;
 162 }
 163
 164 int nft_parse_u32_check(const struct nlattr *attr, int max, u32 *dest);
 165 unsigned int nft_parse_register(const struct nlattr *attr);
 166 int nft_dump_register(struct sk_buff *skb, unsigned int attr, unsigned int reg);
 167
 168 int nft_validate_register_load(enum nft_registers reg, unsigned int len);
 169 int nft_validate_register_store(const struct nft_ctx *ctx,
 170                                 enum nft_registers reg,
 171                                 const struct nft_data *data,
 172                                 enum nft_data_types type, unsigned int len);
 173
 174 /**
 175  *      struct nft_userdata - user defined data associated with an object
 176  *
 177  *      @len: length of the data
 178  *      @data: content
 179  *
 180  *      The presence of user data is indicated in an object specific fashion,
 181  *      so a length of zero can't occur and the value "len" indicates data
 182  *      of length len + 1.
 183  */
 184 struct nft_userdata {
 185         u8                      len;
 186         unsigned char           data[0];
 187 };
 188
 189 /**
 190  *      struct nft_set_elem - generic representation of set elements
 191  *
 192  *      @key: element key
 193  *      @priv: element private data and extensions
 194  */
 195 struct nft_set_elem {
 196         union {
 197                 u32             buf[NFT_DATA_VALUE_MAXLEN / sizeof(u32)];
 198                 struct nft_data val;
 199         } key;
 200         void                    *priv;
 201 };
 202
 203 struct nft_set;
 204 struct nft_set_iter {
 205         u8              genmask;
 206         unsigned int    count;
 207         unsigned int    skip;
 208         int             err;
 209         int             (*fn)(const struct nft_ctx *ctx,
 210                               const struct nft_set *set,
 211                               const struct nft_set_iter *iter,
 212                               const struct nft_set_elem *elem);
 213 };
 214
 215 /**
 216  *      struct nft_set_desc - description of set elements
 217  *
 218  *      @klen: key length
 219  *      @dlen: data length
 220  *      @size: number of set elements
 221  */
 222 struct nft_set_desc {
 223         unsigned int            klen;
 224         unsigned int            dlen;
 225         unsigned int            size;
 226 };
 227
 228 /**
 229  *      enum nft_set_class - performance class
 230  *
 231  *      @NFT_LOOKUP_O_1: constant, O(1)
 232  *      @NFT_LOOKUP_O_LOG_N: logarithmic, O(log N)
 233  *      @NFT_LOOKUP_O_N: linear, O(N)
 234  */
 235 enum nft_set_class {
 236         NFT_SET_CLASS_O_1,
 237         NFT_SET_CLASS_O_LOG_N,
 238         NFT_SET_CLASS_O_N,
 239 };
 240
 241 /**
 242  *      struct nft_set_estimate - estimation of memory and performance
 243  *                                characteristics
 244  *
 245  *      @size: required memory
 246  *      @class: lookup performance class
 247  */
 248 struct nft_set_estimate {
 249         unsigned int            size;
 250         enum nft_set_class      class;
 251 };
 252
 253 struct nft_set_ext;
 254 struct nft_expr;
 255
 256 /**
 257  *      struct nft_set_ops - nf_tables set operations
 258  *
 259  *      @lookup: look up an element within the set
 260  *      @insert: insert new element into set
 261  *      @activate: activate new element in the next generation
 262  *      @deactivate: lookup for element and deactivate it in the next generation
 263  *      @deactivate_one: deactivate element in the next generation
 264  *      @remove: remove element from set
 265  *      @walk: iterate over all set elemeennts
 266  *      @privsize: function to return size of set private data
 267  *      @init: initialize private data of new set instance
 268  *      @destroy: destroy private data of set instance
 269  *      @list: nf_tables_set_ops list node
 270  *      @owner: module reference
 271  *      @elemsize: element private size
 272  *      @features: features supported by the implementation
 273  */
 274 struct nft_set_ops {
 275         bool                            (*lookup)(const struct net *net,
 276                                                   const struct nft_set *set,
 277                                                   const u32 *key,
 278                                                   const struct nft_set_ext **ext);
 279         bool                            (*update)(struct nft_set *set,
 280                                                   const u32 *key,
 281                                                   void *(*new)(struct nft_set *,
 282                                                                const struct nft_expr *,
 283                                                                struct nft_regs *),
 284                                                   const struct nft_expr *expr,
 285                                                   struct nft_regs *regs,
 286                                                   const struct nft_set_ext **ext);
 287
 288         int                             (*insert)(const struct net *net,
 289                                                   const struct nft_set *set,
 290                                                   const struct nft_set_elem *elem,
 291                                                   struct nft_set_ext **ext);
 292         void                            (*activate)(const struct net *net,
 293                                                     const struct nft_set *set,
 294                                                     const struct nft_set_elem *elem);
 295         void *                          (*deactivate)(const struct net *net,
 296                                                       const struct nft_set *set,
 297                                                       const struct nft_set_elem *elem);
 298         bool                            (*deactivate_one)(const struct net *net,
 299                                                           const struct nft_set *set,
 300                                                           void *priv);
 301         void                            (*remove)(const struct nft_set *set,
 302                                                   const struct nft_set_elem *elem);
 303         void                            (*walk)(const struct nft_ctx *ctx,
 304                                                 const struct nft_set *set,
 305                                                 struct nft_set_iter *iter);
 306
 307         unsigned int                    (*privsize)(const struct nlattr * const nla[]);
 308         bool                            (*estimate)(const struct nft_set_desc *desc,
 309                                                     u32 features,
 310                                                     struct nft_set_estimate *est);
 311         int                             (*init)(const struct nft_set *set,
 312                                                 const struct nft_set_desc *desc,
 313                                                 const struct nlattr * const nla[]);
 314         void                            (*destroy)(const struct nft_set *set);
 315
 316         struct list_head                list;
 317         struct module                   *owner;
 318         unsigned int                    elemsize;
 319         u32                             features;
 320 };
 321
 322 int nft_register_set(struct nft_set_ops *ops);
 323 void nft_unregister_set(struct nft_set_ops *ops);
 324
 325 /**
 326  *      struct nft_set - nf_tables set instance
 327  *
 328  *      @list: table set list node
 329  *      @bindings: list of set bindings
 330  *      @name: name of the set
 331  *      @ktype: key type (numeric type defined by userspace, not used in the kernel)
 332  *      @dtype: data type (verdict or numeric type defined by userspace)
 333  *      @objtype: object type (see NFT_OBJECT_* definitions)
 334  *      @size: maximum set size
 335  *      @nelems: number of elements
 336  *      @ndeact: number of deactivated elements queued for removal
 337  *      @timeout: default timeout value in jiffies
 338  *      @gc_int: garbage collection interval in msecs
 339  *      @policy: set parameterization (see enum nft_set_policies)
 340  *      @udlen: user data length
 341  *      @udata: user data
 342  *      @ops: set ops
 343  *      @flags: set flags
 344  *      @genmask: generation mask
 345  *      @klen: key length
 346  *      @dlen: data length
 347  *      @data: private set data
 348  */
 349 struct nft_set {
 350         struct list_head                list;
 351         struct list_head                bindings;
 352         char                            name[NFT_SET_MAXNAMELEN];
 353         u32                             ktype;
 354         u32                             dtype;
 355         u32                             objtype;
 356         u32                             size;
 357         atomic_t                        nelems;
 358         u32                             ndeact;
 359         u64                             timeout;
 360         u32                             gc_int;
 361         u16                             policy;
 362         u16                             udlen;
 363         unsigned char                   *udata;
 364         /* runtime data below here */
 365         const struct nft_set_ops        *ops ____cacheline_aligned;
 366         u16                             flags:14,
 367                                         genmask:2;
 368         u8                              klen;
 369         u8                              dlen;
 370         unsigned char                   data[]
 371                 __attribute__((aligned(__alignof__(u64))));
 372 };
 373
 374 static inline void *nft_set_priv(const struct nft_set *set)
 375 {
 376         return (void *)set->data;
 377 }
 378
 379 static inline struct nft_set *nft_set_container_of(const void *priv)
 380 {
 381         return (void *)priv - offsetof(struct nft_set, data);
 382 }
 383
 384 struct nft_set *nf_tables_set_lookup(const struct nft_table *table,
 385                                      const struct nlattr *nla, u8 genmask);
 386 struct nft_set *nf_tables_set_lookup_byid(const struct net *net,
 387                                           const struct nlattr *nla, u8 genmask);
 388
 389 static inline unsigned long nft_set_gc_interval(const struct nft_set *set)
 390 {
 391         return set->gc_int ? msecs_to_jiffies(set->gc_int) : HZ;
 392 }
 393
 394 /**
 395  *      struct nft_set_binding - nf_tables set binding
 396  *
 397  *      @list: set bindings list node
 398  *      @chain: chain containing the rule bound to the set
 399  *      @flags: set action flags
 400  *
 401  *      A set binding contains all information necessary for validation
 402  *      of new elements added to a bound set.
 403  */
 404 struct nft_set_binding {
 405         struct list_head                list;
 406         const struct nft_chain          *chain;
 407         u32                             flags;
 408 };
 409
 410 int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
 411                        struct nft_set_binding *binding);
 412 void nf_tables_unbind_set(const struct nft_ctx *ctx, struct nft_set *set,
 413                           struct nft_set_binding *binding);
 414
 415 /**
 416  *      enum nft_set_extensions - set extension type IDs
 417  *
 418  *      @NFT_SET_EXT_KEY: element key
 419  *      @NFT_SET_EXT_DATA: mapping data
 420  *      @NFT_SET_EXT_FLAGS: element flags
 421  *      @NFT_SET_EXT_TIMEOUT: element timeout
 422  *      @NFT_SET_EXT_EXPIRATION: element expiration time
 423  *      @NFT_SET_EXT_USERDATA: user data associated with the element
 424  *      @NFT_SET_EXT_EXPR: expression assiociated with the element
 425  *      @NFT_SET_EXT_OBJREF: stateful object reference associated with element
 426  *      @NFT_SET_EXT_NUM: number of extension types
 427  */
 428 enum nft_set_extensions {
 429         NFT_SET_EXT_KEY,
 430         NFT_SET_EXT_DATA,
 431         NFT_SET_EXT_FLAGS,
 432         NFT_SET_EXT_TIMEOUT,
 433         NFT_SET_EXT_EXPIRATION,
 434         NFT_SET_EXT_USERDATA,
 435         NFT_SET_EXT_EXPR,
 436         NFT_SET_EXT_OBJREF,
 437         NFT_SET_EXT_NUM
 438 };
 439
 440 /**
 441  *      struct nft_set_ext_type - set extension type
 442  *
 443  *      @len: fixed part length of the extension
 444  *      @align: alignment requirements of the extension
 445  */
 446 struct nft_set_ext_type {
 447         u8      len;
 448         u8      align;
 449 };
 450
 451 extern const struct nft_set_ext_type nft_set_ext_types[];
 452
 453 /**
 454  *      struct nft_set_ext_tmpl - set extension template
 455  *
 456  *      @len: length of extension area
 457  *      @offset: offsets of individual extension types
 458  */
 459 struct nft_set_ext_tmpl {
 460         u16     len;
 461         u8      offset[NFT_SET_EXT_NUM];
 462 };
 463
 464 /**
 465  *      struct nft_set_ext - set extensions
 466  *
 467  *      @genmask: generation mask
 468  *      @offset: offsets of individual extension types
 469  *      @data: beginning of extension data
 470  */
 471 struct nft_set_ext {
 472         u8      genmask;
 473         u8      offset[NFT_SET_EXT_NUM];
 474         char    data[0];
 475 };
 476
 477 static inline void nft_set_ext_prepare(struct nft_set_ext_tmpl *tmpl)
 478 {
 479         memset(tmpl, 0, sizeof(*tmpl));
 480         tmpl->len = sizeof(struct nft_set_ext);
 481 }
 482
 483 static inline void nft_set_ext_add_length(struct nft_set_ext_tmpl *tmpl, u8 id,
 484                                           unsigned int len)
 485 {
 486         tmpl->len        = ALIGN(tmpl->len, nft_set_ext_types[id].align);
 487         BUG_ON(tmpl->len > U8_MAX);
 488         tmpl->offset[id] = tmpl->len;
 489         tmpl->len       += nft_set_ext_types[id].len + len;
 490 }
 491
 492 static inline void nft_set_ext_add(struct nft_set_ext_tmpl *tmpl, u8 id)
 493 {
 494         nft_set_ext_add_length(tmpl, id, 0);
 495 }
 496
 497 static inline void nft_set_ext_init(struct nft_set_ext *ext,
 498                                     const struct nft_set_ext_tmpl *tmpl)
 499 {
 500         memcpy(ext->offset, tmpl->offset, sizeof(ext->offset));
 501 }
 502
 503 static inline bool __nft_set_ext_exists(const struct nft_set_ext *ext, u8 id)
 504 {
 505         return !!ext->offset[id];
 506 }
 507
 508 static inline bool nft_set_ext_exists(const struct nft_set_ext *ext, u8 id)
 509 {
 510         return ext && __nft_set_ext_exists(ext, id);
 511 }
 512
 513 static inline void *nft_set_ext(const struct nft_set_ext *ext, u8 id)
 514 {
 515         return (void *)ext + ext->offset[id];
 516 }
 517
 518 static inline struct nft_data *nft_set_ext_key(const struct nft_set_ext *ext)
 519 {
 520         return nft_set_ext(ext, NFT_SET_EXT_KEY);
 521 }
 522
 523 static inline struct nft_data *nft_set_ext_data(const struct nft_set_ext *ext)
 524 {
 525         return nft_set_ext(ext, NFT_SET_EXT_DATA);
 526 }
 527
 528 static inline u8 *nft_set_ext_flags(const struct nft_set_ext *ext)
 529 {
 530         return nft_set_ext(ext, NFT_SET_EXT_FLAGS);
 531 }
 532
 533 static inline u64 *nft_set_ext_timeout(const struct nft_set_ext *ext)
 534 {
 535         return nft_set_ext(ext, NFT_SET_EXT_TIMEOUT);
 536 }
 537
 538 static inline unsigned long *nft_set_ext_expiration(const struct nft_set_ext *ext)
 539 {
 540         return nft_set_ext(ext, NFT_SET_EXT_EXPIRATION);
 541 }
 542
 543 static inline struct nft_userdata *nft_set_ext_userdata(const struct nft_set_ext *ext)
 544 {
 545         return nft_set_ext(ext, NFT_SET_EXT_USERDATA);
 546 }
 547
 548 static inline struct nft_expr *nft_set_ext_expr(const struct nft_set_ext *ext)
 549 {
 550         return nft_set_ext(ext, NFT_SET_EXT_EXPR);
 551 }
 552
 553 static inline bool nft_set_elem_expired(const struct nft_set_ext *ext)
 554 {
 555         return nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION) &&
 556                time_is_before_eq_jiffies(*nft_set_ext_expiration(ext));
 557 }
 558
 559 static inline struct nft_set_ext *nft_set_elem_ext(const struct nft_set *set,
 560                                                    void *elem)
 561 {
 562         return elem + set->ops->elemsize;
 563 }
 564
 565 static inline struct nft_object **nft_set_ext_obj(const struct nft_set_ext *ext)
 566 {
 567         return nft_set_ext(ext, NFT_SET_EXT_OBJREF);
 568 }
 569
 570 void *nft_set_elem_init(const struct nft_set *set,
 571                         const struct nft_set_ext_tmpl *tmpl,
 572                         const u32 *key, const u32 *data,
 573                         u64 timeout, gfp_t gfp);
 574 void nft_set_elem_destroy(const struct nft_set *set, void *elem,
 575                           bool destroy_expr);
 576
 577 /**
 578  *      struct nft_set_gc_batch_head - nf_tables set garbage collection batch
 579  *
 580  *      @rcu: rcu head
 581  *      @set: set the elements belong to
 582  *      @cnt: count of elements
 583  */
 584 struct nft_set_gc_batch_head {
 585         struct rcu_head                 rcu;
 586         const struct nft_set            *set;
 587         unsigned int                    cnt;
 588 };
 589
 590 #define NFT_SET_GC_BATCH_SIZE   ((PAGE_SIZE -                             \
 591                                   sizeof(struct nft_set_gc_batch_head)) / \
 592                                  sizeof(void *))
 593
 594 /**
 595  *      struct nft_set_gc_batch - nf_tables set garbage collection batch
 596  *
 597  *      @head: GC batch head
 598  *      @elems: garbage collection elements
 599  */
 600 struct nft_set_gc_batch {
 601         struct nft_set_gc_batch_head    head;
 602         void                            *elems[NFT_SET_GC_BATCH_SIZE];
 603 };
 604
 605 struct nft_set_gc_batch *nft_set_gc_batch_alloc(const struct nft_set *set,
 606                                                 gfp_t gfp);
 607 void nft_set_gc_batch_release(struct rcu_head *rcu);
 608
 609 static inline void nft_set_gc_batch_complete(struct nft_set_gc_batch *gcb)
 610 {
 611         if (gcb != NULL)
 612                 call_rcu(&gcb->head.rcu, nft_set_gc_batch_release);
 613 }
 614
 615 static inline struct nft_set_gc_batch *
 616 nft_set_gc_batch_check(const struct nft_set *set, struct nft_set_gc_batch *gcb,
 617                        gfp_t gfp)
 618 {
 619         if (gcb != NULL) {
 620                 if (gcb->head.cnt + 1 < ARRAY_SIZE(gcb->elems))
 621                         return gcb;
 622                 nft_set_gc_batch_complete(gcb);
 623         }
 624         return nft_set_gc_batch_alloc(set, gfp);
 625 }
 626
 627 static inline void nft_set_gc_batch_add(struct nft_set_gc_batch *gcb,
 628                                         void *elem)
 629 {
 630         gcb->elems[gcb->head.cnt++] = elem;
 631 }
 632
 633 /**
 634  *      struct nft_expr_type - nf_tables expression type
 635  *
 636  *      @select_ops: function to select nft_expr_ops
 637  *      @ops: default ops, used when no select_ops functions is present
 638  *      @list: used internally
 639  *      @name: Identifier
 640  *      @owner: module reference
 641  *      @policy: netlink attribute policy
 642  *      @maxattr: highest netlink attribute number
 643  *      @family: address family for AF-specific types
 644  *      @flags: expression type flags
 645  */
 646 struct nft_expr_type {
 647         const struct nft_expr_ops       *(*select_ops)(const struct nft_ctx *,
 648                                                        const struct nlattr * const tb[]);
 649         const struct nft_expr_ops       *ops;
 650         struct list_head                list;
 651         const char                      *name;
 652         struct module                   *owner;
 653         const struct nla_policy         *policy;
 654         unsigned int                    maxattr;
 655         u8                              family;
 656         u8                              flags;
 657 };
 658
 659 #define NFT_EXPR_STATEFUL               0x1
 660
 661 /**
 662  *      struct nft_expr_ops - nf_tables expression operations
 663  *
 664  *      @eval: Expression evaluation function
 665  *      @size: full expression size, including private data size
 666  *      @init: initialization function
 667  *      @destroy: destruction function
 668  *      @dump: function to dump parameters
 669  *      @type: expression type
 670  *      @validate: validate expression, called during loop detection
 671  *      @data: extra data to attach to this expression operation
 672  */
 673 struct nft_expr;
 674 struct nft_expr_ops {
 675         void                            (*eval)(const struct nft_expr *expr,
 676                                                 struct nft_regs *regs,
 677                                                 const struct nft_pktinfo *pkt);
 678         int                             (*clone)(struct nft_expr *dst,
 679                                                  const struct nft_expr *src);
 680         unsigned int                    size;
 681
 682         int                             (*init)(const struct nft_ctx *ctx,
 683                                                 const struct nft_expr *expr,
 684                                                 const struct nlattr * const tb[]);
 685         void                            (*destroy)(const struct nft_ctx *ctx,
 686                                                    const struct nft_expr *expr);
 687         int                             (*dump)(struct sk_buff *skb,
 688                                                 const struct nft_expr *expr);
 689         int                             (*validate)(const struct nft_ctx *ctx,
 690                                                     const struct nft_expr *expr,
 691                                                     const struct nft_data **data);
 692         const struct nft_expr_type      *type;
 693         void                            *data;
 694 };
 695
 696 #define NFT_EXPR_MAXATTR                16
 697 #define NFT_EXPR_SIZE(size)             (sizeof(struct nft_expr) + \
 698                                          ALIGN(size, __alignof__(struct nft_expr)))
 699
 700 /**
 701  *      struct nft_expr - nf_tables expression
 702  *
 703  *      @ops: expression ops
 704  *      @data: expression private data
 705  */
 706 struct nft_expr {
 707         const struct nft_expr_ops       *ops;
 708         unsigned char                   data[];
 709 };
 710
 711 static inline void *nft_expr_priv(const struct nft_expr *expr)
 712 {
 713         return (void *)expr->data;
 714 }
 715
 716 struct nft_expr *nft_expr_init(const struct nft_ctx *ctx,
 717                                const struct nlattr *nla);
 718 void nft_expr_destroy(const struct nft_ctx *ctx, struct nft_expr *expr);
 719 int nft_expr_dump(struct sk_buff *skb, unsigned int attr,
 720                   const struct nft_expr *expr);
 721
 722 static inline int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
 723 {
 724         int err;
 725
 726         if (src->ops->clone) {
 727                 dst->ops = src->ops;
 728                 err = src->ops->clone(dst, src);
 729                 if (err < 0)
 730                         return err;
 731         } else {
 732                 memcpy(dst, src, src->ops->size);
 733         }
 734
 735         __module_get(src->ops->type->owner);
 736         return 0;
 737 }
 738
 739 /**
 740  *      struct nft_rule - nf_tables rule
 741  *
 742  *      @list: used internally
 743  *      @handle: rule handle
 744  *      @genmask: generation mask
 745  *      @dlen: length of expression data
 746  *      @udata: user data is appended to the rule
 747  *      @data: expression data
 748  */
 749 struct nft_rule {
 750         struct list_head                list;
 751         u64                             handle:42,
 752                                         genmask:2,
 753                                         dlen:12,
 754                                         udata:1;
 755         unsigned char                   data[]
 756                 __attribute__((aligned(__alignof__(struct nft_expr))));
 757 };
 758
 759 static inline struct nft_expr *nft_expr_first(const struct nft_rule *rule)
 760 {
 761         return (struct nft_expr *)&rule->data[0];
 762 }
 763
 764 static inline struct nft_expr *nft_expr_next(const struct nft_expr *expr)
 765 {
 766         return ((void *)expr) + expr->ops->size;
 767 }
 768
 769 static inline struct nft_expr *nft_expr_last(const struct nft_rule *rule)
 770 {
 771         return (struct nft_expr *)&rule->data[rule->dlen];
 772 }
 773
 774 static inline struct nft_userdata *nft_userdata(const struct nft_rule *rule)
 775 {
 776         return (void *)&rule->data[rule->dlen];
 777 }
 778
 779 /*
 780  * The last pointer isn't really necessary, but the compiler isn't able to
 781  * determine that the result of nft_expr_last() is always the same since it
 782  * can't assume that the dlen value wasn't changed within calls in the loop.
 783  */
 784 #define nft_rule_for_each_expr(expr, last, rule) \
 785         for ((expr) = nft_expr_first(rule), (last) = nft_expr_last(rule); \
 786              (expr) != (last); \
 787              (expr) = nft_expr_next(expr))
 788
 789 enum nft_chain_flags {
 790         NFT_BASE_CHAIN                  = 0x1,
 791 };
 792
 793 /**
 794  *      struct nft_chain - nf_tables chain
 795  *
 796  *      @rules: list of rules in the chain
 797  *      @list: used internally
 798  *      @table: table that this chain belongs to
 799  *      @handle: chain handle
 800  *      @use: number of jump references to this chain
 801  *      @level: length of longest path to this chain
 802  *      @flags: bitmask of enum nft_chain_flags
 803  *      @name: name of the chain
 804  */
 805 struct nft_chain {
 806         struct list_head                rules;
 807         struct list_head                list;
 808         struct nft_table                *table;
 809         u64                             handle;
 810         u32                             use;
 811         u16                             level;
 812         u8                              flags:6,
 813                                         genmask:2;
 814         char                            name[NFT_CHAIN_MAXNAMELEN];
 815 };
 816
 817 enum nft_chain_type {
 818         NFT_CHAIN_T_DEFAULT = 0,
 819         NFT_CHAIN_T_ROUTE,
 820         NFT_CHAIN_T_NAT,
 821         NFT_CHAIN_T_MAX
 822 };
 823
 824 /**
 825  *      struct nf_chain_type - nf_tables chain type info
 826  *
 827  *      @name: name of the type
 828  *      @type: numeric identifier
 829  *      @family: address family
 830  *      @owner: module owner
 831  *      @hook_mask: mask of valid hooks
 832  *      @hooks: hookfn overrides
 833  */
 834 struct nf_chain_type {
 835         const char                      *name;
 836         enum nft_chain_type             type;
 837         int                             family;
 838         struct module                   *owner;
 839         unsigned int                    hook_mask;
 840         nf_hookfn                       *hooks[NF_MAX_HOOKS];
 841 };
 842
 843 int nft_chain_validate_dependency(const struct nft_chain *chain,
 844                                   enum nft_chain_type type);
 845 int nft_chain_validate_hooks(const struct nft_chain *chain,
 846                              unsigned int hook_flags);
 847
 848 struct nft_stats {
 849         u64                     bytes;
 850         u64                     pkts;
 851         struct u64_stats_sync   syncp;
 852 };
 853
 854 #define NFT_HOOK_OPS_MAX                2
 855
 856 /**
 857  *      struct nft_base_chain - nf_tables base chain
 858  *
 859  *      @ops: netfilter hook ops
 860  *      @type: chain type
 861  *      @policy: default policy
 862  *      @stats: per-cpu chain stats
 863  *      @chain: the chain
 864  *      @dev_name: device name that this base chain is attached to (if any)
 865  */
 866 struct nft_base_chain {
 867         struct nf_hook_ops              ops[NFT_HOOK_OPS_MAX];
 868         const struct nf_chain_type      *type;
 869         u8                              policy;
 870         u8                              flags;
 871         struct nft_stats __percpu       *stats;
 872         struct nft_chain                chain;
 873         char                            dev_name[IFNAMSIZ];
 874 };
 875
 876 static inline struct nft_base_chain *nft_base_chain(const struct nft_chain *chain)
 877 {
 878         return container_of(chain, struct nft_base_chain, chain);
 879 }
 880
 881 int __nft_release_basechain(struct nft_ctx *ctx);
 882
 883 unsigned int nft_do_chain(struct nft_pktinfo *pkt, void *priv);
 884
 885 /**
 886  *      struct nft_table - nf_tables table
 887  *
 888  *      @list: used internally
 889  *      @chains: chains in the table
 890  *      @sets: sets in the table
 891  *      @objects: stateful objects in the table
 892  *      @hgenerator: handle generator state
 893  *      @use: number of chain references to this table
 894  *      @flags: table flag (see enum nft_table_flags)
 895  *      @genmask: generation mask
 896  *      @name: name of the table
 897  */
 898 struct nft_table {
 899         struct list_head                list;
 900         struct list_head                chains;
 901         struct list_head                sets;
 902         struct list_head                objects;
 903         u64                             hgenerator;
 904         u32                             use;
 905         u16                             flags:14,
 906                                         genmask:2;
 907         char                            name[NFT_TABLE_MAXNAMELEN];
 908 };
 909
 910 enum nft_af_flags {
 911         NFT_AF_NEEDS_DEV        = (1 << 0),
 912 };
 913
 914 /**
 915  *      struct nft_af_info - nf_tables address family info
 916  *
 917  *      @list: used internally
 918  *      @family: address family
 919  *      @nhooks: number of hooks in this family
 920  *      @owner: module owner
 921  *      @tables: used internally
 922  *      @flags: family flags
 923  *      @nops: number of hook ops in this family
 924  *      @hook_ops_init: initialization function for chain hook ops
 925  *      @hooks: hookfn overrides for packet validation
 926  */
 927 struct nft_af_info {
 928         struct list_head                list;
 929         int                             family;
 930         unsigned int                    nhooks;
 931         struct module                   *owner;
 932         struct list_head                tables;
 933         u32                             flags;
 934         unsigned int                    nops;
 935         void                            (*hook_ops_init)(struct nf_hook_ops *,
 936                                                          unsigned int);
 937         nf_hookfn                       *hooks[NF_MAX_HOOKS];
 938 };
 939
 940 int nft_register_afinfo(struct net *, struct nft_af_info *);
 941 void nft_unregister_afinfo(struct net *, struct nft_af_info *);
 942
 943 int nft_register_chain_type(const struct nf_chain_type *);
 944 void nft_unregister_chain_type(const struct nf_chain_type *);
 945
 946 int nft_register_expr(struct nft_expr_type *);
 947 void nft_unregister_expr(struct nft_expr_type *);
 948
 949 int nft_verdict_dump(struct sk_buff *skb, int type,
 950                      const struct nft_verdict *v);
 951
 952 /**
 953  *      struct nft_object - nf_tables stateful object
 954  *
 955  *      @list: table stateful object list node
 956  *      @table: table this object belongs to
 957  *      @type: pointer to object type
 958  *      @data: pointer to object data
 959  *      @name: name of this stateful object
 960  *      @genmask: generation mask
 961  *      @use: number of references to this stateful object
 962  *      @data: object data, layout depends on type
 963  */
 964 struct nft_object {
 965         struct list_head                list;
 966         char                            name[NFT_OBJ_MAXNAMELEN];
 967         struct nft_table                *table;
 968         u32                             genmask:2,
 969                                         use:30;
 970         /* runtime data below here */
 971         const struct nft_object_type    *type ____cacheline_aligned;
 972         unsigned char                   data[]
 973                 __attribute__((aligned(__alignof__(u64))));
 974 };
 975
 976 static inline void *nft_obj_data(const struct nft_object *obj)
 977 {
 978         return (void *)obj->data;
 979 }
 980
 981 #define nft_expr_obj(expr)      *((struct nft_object **)nft_expr_priv(expr))
 982
 983 struct nft_object *nf_tables_obj_lookup(const struct nft_table *table,
 984                                         const struct nlattr *nla, u32 objtype,
 985                                         u8 genmask);
 986
 987 int nft_obj_notify(struct net *net, struct nft_table *table,
 988                    struct nft_object *obj, u32 portid, u32 seq,
 989                    int event, int family, int report, gfp_t gfp);
 990
 991 /**
 992  *      struct nft_object_type - stateful object type
 993  *
 994  *      @eval: stateful object evaluation function
 995  *      @list: list node in list of object types
 996  *      @type: stateful object numeric type
 997  *      @size: stateful object size
 998  *      @owner: module owner
 999  *      @maxattr: maximum netlink attribute
1000  *      @policy: netlink attribute policy
1001  *      @init: initialize object from netlink attributes
1002  *      @destroy: release existing stateful object
1003  *      @dump: netlink dump stateful object
1004  */
1005 struct nft_object_type {
1006         void                            (*eval)(struct nft_object *obj,
1007                                                 struct nft_regs *regs,
1008                                                 const struct nft_pktinfo *pkt);
1009         struct list_head                list;
1010         u32                             type;
1011         unsigned int                    size;
1012         unsigned int                    maxattr;
1013         struct module                   *owner;
1014         const struct nla_policy         *policy;
1015         int                             (*init)(const struct nlattr * const tb[],
1016                                                 struct nft_object *obj);
1017         void                            (*destroy)(struct nft_object *obj);
1018         int                             (*dump)(struct sk_buff *skb,
1019                                                 struct nft_object *obj,
1020                                                 bool reset);
1021 };
1022
1023 int nft_register_obj(struct nft_object_type *obj_type);
1024 void nft_unregister_obj(struct nft_object_type *obj_type);
1025
1026 /**
1027  *      struct nft_traceinfo - nft tracing information and state
1028  *
1029  *      @pkt: pktinfo currently processed
1030  *      @basechain: base chain currently processed
1031  *      @chain: chain currently processed
1032  *      @rule:  rule that was evaluated
1033  *      @verdict: verdict given by rule
1034  *      @type: event type (enum nft_trace_types)
1035  *      @packet_dumped: packet headers sent in a previous traceinfo message
1036  *      @trace: other struct members are initialised
1037  */
1038 struct nft_traceinfo {
1039         const struct nft_pktinfo        *pkt;
1040         const struct nft_base_chain     *basechain;
1041         const struct nft_chain          *chain;
1042         const struct nft_rule           *rule;
1043         const struct nft_verdict        *verdict;
1044         enum nft_trace_types            type;
1045         bool                            packet_dumped;
1046         bool                            trace;
1047 };
1048
1049 void nft_trace_init(struct nft_traceinfo *info, const struct nft_pktinfo *pkt,
1050                     const struct nft_verdict *verdict,
1051                     const struct nft_chain *basechain);
1052
1053 void nft_trace_notify(struct nft_traceinfo *info);
1054
1055 #define nft_dereference(p)                                      \
1056         nfnl_dereference(p, NFNL_SUBSYS_NFTABLES)
1057
1058 #define MODULE_ALIAS_NFT_FAMILY(family) \
1059         MODULE_ALIAS("nft-afinfo-" __stringify(family))
1060
1061 #define MODULE_ALIAS_NFT_CHAIN(family, name) \
1062         MODULE_ALIAS("nft-chain-" __stringify(family) "-" name)
1063
1064 #define MODULE_ALIAS_NFT_AF_EXPR(family, name) \
1065         MODULE_ALIAS("nft-expr-" __stringify(family) "-" name)
1066
1067 #define MODULE_ALIAS_NFT_EXPR(name) \
1068         MODULE_ALIAS("nft-expr-" name)
1069
1070 #define MODULE_ALIAS_NFT_SET() \
1071         MODULE_ALIAS("nft-set")
1072
1073 #define MODULE_ALIAS_NFT_OBJ(type) \
1074         MODULE_ALIAS("nft-obj-" __stringify(type))
1075
1076 /*
1077  * The gencursor defines two generations, the currently active and the
1078  * next one. Objects contain a bitmask of 2 bits specifying the generations
1079  * they're active in. A set bit means they're inactive in the generation
1080  * represented by that bit.
1081  *
1082  * New objects start out as inactive in the current and active in the
1083  * next generation. When committing the ruleset the bitmask is cleared,
1084  * meaning they're active in all generations. When removing an object,
1085  * it is set inactive in the next generation. After committing the ruleset,
1086  * the objects are removed.
1087  */
1088 static inline unsigned int nft_gencursor_next(const struct net *net)
1089 {
1090         return net->nft.gencursor + 1 == 1 ? 1 : 0;
1091 }
1092
1093 static inline u8 nft_genmask_next(const struct net *net)
1094 {
1095         return 1 << nft_gencursor_next(net);
1096 }
1097
1098 static inline u8 nft_genmask_cur(const struct net *net)
1099 {
1100         /* Use ACCESS_ONCE() to prevent refetching the value for atomicity */
1101         return 1 << ACCESS_ONCE(net->nft.gencursor);
1102 }
1103
1104 #define NFT_GENMASK_ANY         ((1 << 0) | (1 << 1))
1105
1106 /*
1107  * Generic transaction helpers
1108  */
1109
1110 /* Check if this object is currently active. */
1111 #define nft_is_active(__net, __obj)                             \
1112         (((__obj)->genmask & nft_genmask_cur(__net)) == 0)
1113
1114 /* Check if this object is active in the next generation. */
1115 #define nft_is_active_next(__net, __obj)                        \
1116         (((__obj)->genmask & nft_genmask_next(__net)) == 0)
1117
1118 /* This object becomes active in the next generation. */
1119 #define nft_activate_next(__net, __obj)                         \
1120         (__obj)->genmask = nft_genmask_cur(__net)
1121
1122 /* This object becomes inactive in the next generation. */
1123 #define nft_deactivate_next(__net, __obj)                       \
1124         (__obj)->genmask = nft_genmask_next(__net)
1125
1126 /* After committing the ruleset, clear the stale generation bit. */
1127 #define nft_clear(__net, __obj)                                 \
1128         (__obj)->genmask &= ~nft_genmask_next(__net)
1129 #define nft_active_genmask(__obj, __genmask)                    \
1130         !((__obj)->genmask & __genmask)
1131
1132 /*
1133  * Set element transaction helpers
1134  */
1135
1136 static inline bool nft_set_elem_active(const struct nft_set_ext *ext,
1137                                        u8 genmask)
1138 {
1139         return !(ext->genmask & genmask);
1140 }
1141
1142 static inline void nft_set_elem_change_active(const struct net *net,
1143                                               const struct nft_set *set,
1144                                               struct nft_set_ext *ext)
1145 {
1146         ext->genmask ^= nft_genmask_next(net);
1147 }
1148
1149 /*
1150  * We use a free bit in the genmask field to indicate the element
1151  * is busy, meaning it is currently being processed either by
1152  * the netlink API or GC.
1153  *
1154  * Even though the genmask is only a single byte wide, this works
1155  * because the extension structure if fully constant once initialized,
1156  * so there are no non-atomic write accesses unless it is already
1157  * marked busy.
1158  */
1159 #define NFT_SET_ELEM_BUSY_MASK  (1 << 2)
1160
1161 #if defined(__LITTLE_ENDIAN_BITFIELD)
1162 #define NFT_SET_ELEM_BUSY_BIT   2
1163 #elif defined(__BIG_ENDIAN_BITFIELD)
1164 #define NFT_SET_ELEM_BUSY_BIT   (BITS_PER_LONG - BITS_PER_BYTE + 2)
1165 #else
1166 #error
1167 #endif
1168
1169 static inline int nft_set_elem_mark_busy(struct nft_set_ext *ext)
1170 {
1171         unsigned long *word = (unsigned long *)ext;
1172
1173         BUILD_BUG_ON(offsetof(struct nft_set_ext, genmask) != 0);
1174         return test_and_set_bit(NFT_SET_ELEM_BUSY_BIT, word);
1175 }
1176
1177 static inline void nft_set_elem_clear_busy(struct nft_set_ext *ext)
1178 {
1179         unsigned long *word = (unsigned long *)ext;
1180
1181         clear_bit(NFT_SET_ELEM_BUSY_BIT, word);
1182 }
1183
1184 /**
1185  *      struct nft_trans - nf_tables object update in transaction
1186  *
1187  *      @list: used internally
1188  *      @msg_type: message type
1189  *      @ctx: transaction context
1190  *      @data: internal information related to the transaction
1191  */
1192 struct nft_trans {
1193         struct list_head                list;
1194         int                             msg_type;
1195         struct nft_ctx                  ctx;
1196         char                            data[0];
1197 };
1198
1199 struct nft_trans_rule {
1200         struct nft_rule                 *rule;
1201 };
1202
1203 #define nft_trans_rule(trans)   \
1204         (((struct nft_trans_rule *)trans->data)->rule)
1205
1206 struct nft_trans_set {
1207         struct nft_set                  *set;
1208         u32                             set_id;
1209 };
1210
1211 #define nft_trans_set(trans)    \
1212         (((struct nft_trans_set *)trans->data)->set)
1213 #define nft_trans_set_id(trans) \
1214         (((struct nft_trans_set *)trans->data)->set_id)
1215
1216 struct nft_trans_chain {
1217         bool                            update;
1218         char                            name[NFT_CHAIN_MAXNAMELEN];
1219         struct nft_stats __percpu       *stats;
1220         u8                              policy;
1221 };
1222
1223 #define nft_trans_chain_update(trans)   \
1224         (((struct nft_trans_chain *)trans->data)->update)
1225 #define nft_trans_chain_name(trans)     \
1226         (((struct nft_trans_chain *)trans->data)->name)
1227 #define nft_trans_chain_stats(trans)    \
1228         (((struct nft_trans_chain *)trans->data)->stats)
1229 #define nft_trans_chain_policy(trans)   \
1230         (((struct nft_trans_chain *)trans->data)->policy)
1231
1232 struct nft_trans_table {
1233         bool                            update;
1234         bool                            enable;
1235 };
1236
1237 #define nft_trans_table_update(trans)   \
1238         (((struct nft_trans_table *)trans->data)->update)
1239 #define nft_trans_table_enable(trans)   \
1240         (((struct nft_trans_table *)trans->data)->enable)
1241
1242 struct nft_trans_elem {
1243         struct nft_set                  *set;
1244         struct nft_set_elem             elem;
1245 };
1246
1247 #define nft_trans_elem_set(trans)       \
1248         (((struct nft_trans_elem *)trans->data)->set)
1249 #define nft_trans_elem(trans)   \
1250         (((struct nft_trans_elem *)trans->data)->elem)
1251
1252 struct nft_trans_obj {
1253         struct nft_object               *obj;
1254 };
1255
1256 #define nft_trans_obj(trans)    \
1257         (((struct nft_trans_obj *)trans->data)->obj)
1258
1259 #endif /* _NET_NF_TABLES_H */