net/netfilter/nft_set_rbtree.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
   4  *
   5  * Development of this code funded by Astaro AG (http://www.astaro.com/)
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/init.h>
  10 #include <linux/module.h>
  11 #include <linux/list.h>
  12 #include <linux/rbtree.h>
  13 #include <linux/netlink.h>
  14 #include <linux/netfilter.h>
  15 #include <linux/netfilter/nf_tables.h>
  16 #include <net/netfilter/nf_tables_core.h>
  17
  18 struct nft_rbtree {
  19         struct rb_root          root;
  20         rwlock_t                lock;
  21         seqcount_rwlock_t       count;
  22         struct delayed_work     gc_work;
  23 };
  24
  25 struct nft_rbtree_elem {
  26         struct rb_node          node;
  27         struct nft_set_ext      ext;
  28 };
  29
  30 static bool nft_rbtree_interval_end(const struct nft_rbtree_elem *rbe)
  31 {
  32         return nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) &&
  33                (*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END);
  34 }
  35
  36 static bool nft_rbtree_interval_start(const struct nft_rbtree_elem *rbe)
  37 {
  38         return !nft_rbtree_interval_end(rbe);
  39 }
  40
  41 static bool nft_rbtree_equal(const struct nft_set *set, const void *this,
  42                              const struct nft_rbtree_elem *interval)
  43 {
  44         return memcmp(this, nft_set_ext_key(&interval->ext), set->klen) == 0;
  45 }
  46
  47 static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
  48                                 const u32 *key, const struct nft_set_ext **ext,
  49                                 unsigned int seq)
  50 {
  51         struct nft_rbtree *priv = nft_set_priv(set);
  52         const struct nft_rbtree_elem *rbe, *interval = NULL;
  53         u8 genmask = nft_genmask_cur(net);
  54         const struct rb_node *parent;
  55         const void *this;
  56         int d;
  57
  58         parent = rcu_dereference_raw(priv->root.rb_node);
  59         while (parent != NULL) {
  60                 if (read_seqcount_retry(&priv->count, seq))
  61                         return false;
  62
  63                 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
  64
  65                 this = nft_set_ext_key(&rbe->ext);
  66                 d = memcmp(this, key, set->klen);
  67                 if (d < 0) {
  68                         parent = rcu_dereference_raw(parent->rb_left);
  69                         if (interval &&
  70                             nft_rbtree_equal(set, this, interval) &&
  71                             nft_rbtree_interval_end(rbe) &&
  72                             nft_rbtree_interval_start(interval))
  73                                 continue;
  74                         interval = rbe;
  75                 } else if (d > 0)
  76                         parent = rcu_dereference_raw(parent->rb_right);
  77                 else {
  78                         if (!nft_set_elem_active(&rbe->ext, genmask)) {
  79                                 parent = rcu_dereference_raw(parent->rb_left);
  80                                 continue;
  81                         }
  82
  83                         if (nft_set_elem_expired(&rbe->ext))
  84                                 return false;
  85
  86                         if (nft_rbtree_interval_end(rbe)) {
  87                                 if (nft_set_is_anonymous(set))
  88                                         return false;
  89                                 parent = rcu_dereference_raw(parent->rb_left);
  90                                 interval = NULL;
  91                                 continue;
  92                         }
  93
  94                         *ext = &rbe->ext;
  95                         return true;
  96                 }
  97         }
  98
  99         if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
 100             nft_set_elem_active(&interval->ext, genmask) &&
 101             !nft_set_elem_expired(&interval->ext) &&
 102             nft_rbtree_interval_start(interval)) {
 103                 *ext = &interval->ext;
 104                 return true;
 105         }
 106
 107         return false;
 108 }
 109
 110 static bool nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
 111                               const u32 *key, const struct nft_set_ext **ext)
 112 {
 113         struct nft_rbtree *priv = nft_set_priv(set);
 114         unsigned int seq = read_seqcount_begin(&priv->count);
 115         bool ret;
 116
 117         ret = __nft_rbtree_lookup(net, set, key, ext, seq);
 118         if (ret || !read_seqcount_retry(&priv->count, seq))
 119                 return ret;
 120
 121         read_lock_bh(&priv->lock);
 122         seq = read_seqcount_begin(&priv->count);
 123         ret = __nft_rbtree_lookup(net, set, key, ext, seq);
 124         read_unlock_bh(&priv->lock);
 125
 126         return ret;
 127 }
 128
 129 static bool __nft_rbtree_get(const struct net *net, const struct nft_set *set,
 130                              const u32 *key, struct nft_rbtree_elem **elem,
 131                              unsigned int seq, unsigned int flags, u8 genmask)
 132 {
 133         struct nft_rbtree_elem *rbe, *interval = NULL;
 134         struct nft_rbtree *priv = nft_set_priv(set);
 135         const struct rb_node *parent;
 136         const void *this;
 137         int d;
 138
 139         parent = rcu_dereference_raw(priv->root.rb_node);
 140         while (parent != NULL) {
 141                 if (read_seqcount_retry(&priv->count, seq))
 142                         return false;
 143
 144                 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 145
 146                 this = nft_set_ext_key(&rbe->ext);
 147                 d = memcmp(this, key, set->klen);
 148                 if (d < 0) {
 149                         parent = rcu_dereference_raw(parent->rb_left);
 150                         if (!(flags & NFT_SET_ELEM_INTERVAL_END))
 151                                 interval = rbe;
 152                 } else if (d > 0) {
 153                         parent = rcu_dereference_raw(parent->rb_right);
 154                         if (flags & NFT_SET_ELEM_INTERVAL_END)
 155                                 interval = rbe;
 156                 } else {
 157                         if (!nft_set_elem_active(&rbe->ext, genmask)) {
 158                                 parent = rcu_dereference_raw(parent->rb_left);
 159                                 continue;
 160                         }
 161
 162                         if (nft_set_elem_expired(&rbe->ext))
 163                                 return false;
 164
 165                         if (!nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) ||
 166                             (*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END) ==
 167                             (flags & NFT_SET_ELEM_INTERVAL_END)) {
 168                                 *elem = rbe;
 169                                 return true;
 170                         }
 171
 172                         if (nft_rbtree_interval_end(rbe))
 173                                 interval = NULL;
 174
 175                         parent = rcu_dereference_raw(parent->rb_left);
 176                 }
 177         }
 178
 179         if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
 180             nft_set_elem_active(&interval->ext, genmask) &&
 181             !nft_set_elem_expired(&interval->ext) &&
 182             ((!nft_rbtree_interval_end(interval) &&
 183               !(flags & NFT_SET_ELEM_INTERVAL_END)) ||
 184              (nft_rbtree_interval_end(interval) &&
 185               (flags & NFT_SET_ELEM_INTERVAL_END)))) {
 186                 *elem = interval;
 187                 return true;
 188         }
 189
 190         return false;
 191 }
 192
 193 static void *nft_rbtree_get(const struct net *net, const struct nft_set *set,
 194                             const struct nft_set_elem *elem, unsigned int flags)
 195 {
 196         struct nft_rbtree *priv = nft_set_priv(set);
 197         unsigned int seq = read_seqcount_begin(&priv->count);
 198         struct nft_rbtree_elem *rbe = ERR_PTR(-ENOENT);
 199         const u32 *key = (const u32 *)&elem->key.val;
 200         u8 genmask = nft_genmask_cur(net);
 201         bool ret;
 202
 203         ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask);
 204         if (ret || !read_seqcount_retry(&priv->count, seq))
 205                 return rbe;
 206
 207         read_lock_bh(&priv->lock);
 208         seq = read_seqcount_begin(&priv->count);
 209         ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask);
 210         if (!ret)
 211                 rbe = ERR_PTR(-ENOENT);
 212         read_unlock_bh(&priv->lock);
 213
 214         return rbe;
 215 }
 216
 217 static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 218                                struct nft_rbtree_elem *new,
 219                                struct nft_set_ext **ext)
 220 {
 221         bool overlap = false, dup_end_left = false, dup_end_right = false;
 222         struct nft_rbtree *priv = nft_set_priv(set);
 223         u8 genmask = nft_genmask_next(net);
 224         struct nft_rbtree_elem *rbe;
 225         struct rb_node *parent, **p;
 226         int d;
 227
 228         /* Detect overlaps as we descend the tree. Set the flag in these cases:
 229          *
 230          * a1. _ _ __>|  ?_ _ __|  (insert end before existing end)
 231          * a2. _ _ ___|  ?_ _ _>|  (insert end after existing end)
 232          * a3. _ _ ___? >|_ _ __|  (insert start before existing end)
 233          *
 234          * and clear it later on, as we eventually reach the points indicated by
 235          * '?' above, in the cases described below. We'll always meet these
 236          * later, locally, due to tree ordering, and overlaps for the intervals
 237          * that are the closest together are always evaluated last.
 238          *
 239          * b1. _ _ __>|  !_ _ __|  (insert end before existing start)
 240          * b2. _ _ ___|  !_ _ _>|  (insert end after existing start)
 241          * b3. _ _ ___! >|_ _ __|  (insert start after existing end, as a leaf)
 242          *            '--' no nodes falling in this range
 243          * b4.          >|_ _   !  (insert start before existing start)
 244          *
 245          * Case a3. resolves to b3.:
 246          * - if the inserted start element is the leftmost, because the '0'
 247          *   element in the tree serves as end element
 248          * - otherwise, if an existing end is found immediately to the left. If
 249          *   there are existing nodes in between, we need to further descend the
 250          *   tree before we can conclude the new start isn't causing an overlap
 251          *
 252          * or to b4., which, preceded by a3., means we already traversed one or
 253          * more existing intervals entirely, from the right.
 254          *
 255          * For a new, rightmost pair of elements, we'll hit cases b3. and b2.,
 256          * in that order.
 257          *
 258          * The flag is also cleared in two special cases:
 259          *
 260          * b5. |__ _ _!|<_ _ _   (insert start right before existing end)
 261          * b6. |__ _ >|!__ _ _   (insert end right after existing start)
 262          *
 263          * which always happen as last step and imply that no further
 264          * overlapping is possible.
 265          *
 266          * Another special case comes from the fact that start elements matching
 267          * an already existing start element are allowed: insertion is not
 268          * performed but we return -EEXIST in that case, and the error will be
 269          * cleared by the caller if NLM_F_EXCL is not present in the request.
 270          * This way, request for insertion of an exact overlap isn't reported as
 271          * error to userspace if not desired.
 272          *
 273          * However, if the existing start matches a pre-existing start, but the
 274          * end element doesn't match the corresponding pre-existing end element,
 275          * we need to report a partial overlap. This is a local condition that
 276          * can be noticed without need for a tracking flag, by checking for a
 277          * local duplicated end for a corresponding start, from left and right,
 278          * separately.
 279          */
 280
 281         parent = NULL;
 282         p = &priv->root.rb_node;
 283         while (*p != NULL) {
 284                 parent = *p;
 285                 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 286                 d = memcmp(nft_set_ext_key(&rbe->ext),
 287                            nft_set_ext_key(&new->ext),
 288                            set->klen);
 289                 if (d < 0) {
 290                         p = &parent->rb_left;
 291
 292                         if (nft_rbtree_interval_start(new)) {
 293                                 if (nft_rbtree_interval_end(rbe) &&
 294                                     nft_set_elem_active(&rbe->ext, genmask) &&
 295                                     !nft_set_elem_expired(&rbe->ext) && !*p)
 296                                         overlap = false;
 297                         } else {
 298                                 if (dup_end_left && !*p)
 299                                         return -ENOTEMPTY;
 300
 301                                 overlap = nft_rbtree_interval_end(rbe) &&
 302                                           nft_set_elem_active(&rbe->ext,
 303                                                               genmask) &&
 304                                           !nft_set_elem_expired(&rbe->ext);
 305
 306                                 if (overlap) {
 307                                         dup_end_right = true;
 308                                         continue;
 309                                 }
 310                         }
 311                 } else if (d > 0) {
 312                         p = &parent->rb_right;
 313
 314                         if (nft_rbtree_interval_end(new)) {
 315                                 if (dup_end_right && !*p)
 316                                         return -ENOTEMPTY;
 317
 318                                 overlap = nft_rbtree_interval_end(rbe) &&
 319                                           nft_set_elem_active(&rbe->ext,
 320                                                               genmask) &&
 321                                           !nft_set_elem_expired(&rbe->ext);
 322
 323                                 if (overlap) {
 324                                         dup_end_left = true;
 325                                         continue;
 326                                 }
 327                         } else if (nft_set_elem_active(&rbe->ext, genmask) &&
 328                                    !nft_set_elem_expired(&rbe->ext)) {
 329                                 overlap = nft_rbtree_interval_end(rbe);
 330                         }
 331                 } else {
 332                         if (nft_rbtree_interval_end(rbe) &&
 333                             nft_rbtree_interval_start(new)) {
 334                                 p = &parent->rb_left;
 335
 336                                 if (nft_set_elem_active(&rbe->ext, genmask) &&
 337                                     !nft_set_elem_expired(&rbe->ext))
 338                                         overlap = false;
 339                         } else if (nft_rbtree_interval_start(rbe) &&
 340                                    nft_rbtree_interval_end(new)) {
 341                                 p = &parent->rb_right;
 342
 343                                 if (nft_set_elem_active(&rbe->ext, genmask) &&
 344                                     !nft_set_elem_expired(&rbe->ext))
 345                                         overlap = false;
 346                         } else if (nft_set_elem_active(&rbe->ext, genmask) &&
 347                                    !nft_set_elem_expired(&rbe->ext)) {
 348                                 *ext = &rbe->ext;
 349                                 return -EEXIST;
 350                         } else {
 351                                 p = &parent->rb_left;
 352                         }
 353                 }
 354
 355                 dup_end_left = dup_end_right = false;
 356         }
 357
 358         if (overlap)
 359                 return -ENOTEMPTY;
 360
 361         rb_link_node_rcu(&new->node, parent, p);
 362         rb_insert_color(&new->node, &priv->root);
 363         return 0;
 364 }
 365
 366 static int nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 367                              const struct nft_set_elem *elem,
 368                              struct nft_set_ext **ext)
 369 {
 370         struct nft_rbtree *priv = nft_set_priv(set);
 371         struct nft_rbtree_elem *rbe = elem->priv;
 372         int err;
 373
 374         write_lock_bh(&priv->lock);
 375         write_seqcount_begin(&priv->count);
 376         err = __nft_rbtree_insert(net, set, rbe, ext);
 377         write_seqcount_end(&priv->count);
 378         write_unlock_bh(&priv->lock);
 379
 380         return err;
 381 }
 382
 383 static void nft_rbtree_remove(const struct net *net,
 384                               const struct nft_set *set,
 385                               const struct nft_set_elem *elem)
 386 {
 387         struct nft_rbtree *priv = nft_set_priv(set);
 388         struct nft_rbtree_elem *rbe = elem->priv;
 389
 390         write_lock_bh(&priv->lock);
 391         write_seqcount_begin(&priv->count);
 392         rb_erase(&rbe->node, &priv->root);
 393         write_seqcount_end(&priv->count);
 394         write_unlock_bh(&priv->lock);
 395 }
 396
 397 static void nft_rbtree_activate(const struct net *net,
 398                                 const struct nft_set *set,
 399                                 const struct nft_set_elem *elem)
 400 {
 401         struct nft_rbtree_elem *rbe = elem->priv;
 402
 403         nft_set_elem_change_active(net, set, &rbe->ext);
 404         nft_set_elem_clear_busy(&rbe->ext);
 405 }
 406
 407 static bool nft_rbtree_flush(const struct net *net,
 408                              const struct nft_set *set, void *priv)
 409 {
 410         struct nft_rbtree_elem *rbe = priv;
 411
 412         if (!nft_set_elem_mark_busy(&rbe->ext) ||
 413             !nft_is_active(net, &rbe->ext)) {
 414                 nft_set_elem_change_active(net, set, &rbe->ext);
 415                 return true;
 416         }
 417         return false;
 418 }
 419
 420 static void *nft_rbtree_deactivate(const struct net *net,
 421                                    const struct nft_set *set,
 422                                    const struct nft_set_elem *elem)
 423 {
 424         const struct nft_rbtree *priv = nft_set_priv(set);
 425         const struct rb_node *parent = priv->root.rb_node;
 426         struct nft_rbtree_elem *rbe, *this = elem->priv;
 427         u8 genmask = nft_genmask_next(net);
 428         int d;
 429
 430         while (parent != NULL) {
 431                 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 432
 433                 d = memcmp(nft_set_ext_key(&rbe->ext), &elem->key.val,
 434                                            set->klen);
 435                 if (d < 0)
 436                         parent = parent->rb_left;
 437                 else if (d > 0)
 438                         parent = parent->rb_right;
 439                 else {
 440                         if (nft_rbtree_interval_end(rbe) &&
 441                             nft_rbtree_interval_start(this)) {
 442                                 parent = parent->rb_left;
 443                                 continue;
 444                         } else if (nft_rbtree_interval_start(rbe) &&
 445                                    nft_rbtree_interval_end(this)) {
 446                                 parent = parent->rb_right;
 447                                 continue;
 448                         } else if (!nft_set_elem_active(&rbe->ext, genmask)) {
 449                                 parent = parent->rb_left;
 450                                 continue;
 451                         }
 452                         nft_rbtree_flush(net, set, rbe);
 453                         return rbe;
 454                 }
 455         }
 456         return NULL;
 457 }
 458
 459 static void nft_rbtree_walk(const struct nft_ctx *ctx,
 460                             struct nft_set *set,
 461                             struct nft_set_iter *iter)
 462 {
 463         struct nft_rbtree *priv = nft_set_priv(set);
 464         struct nft_rbtree_elem *rbe;
 465         struct nft_set_elem elem;
 466         struct rb_node *node;
 467
 468         read_lock_bh(&priv->lock);
 469         for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
 470                 rbe = rb_entry(node, struct nft_rbtree_elem, node);
 471
 472                 if (iter->count < iter->skip)
 473                         goto cont;
 474                 if (nft_set_elem_expired(&rbe->ext))
 475                         goto cont;
 476                 if (!nft_set_elem_active(&rbe->ext, iter->genmask))
 477                         goto cont;
 478
 479                 elem.priv = rbe;
 480
 481                 iter->err = iter->fn(ctx, set, iter, &elem);
 482                 if (iter->err < 0) {
 483                         read_unlock_bh(&priv->lock);
 484                         return;
 485                 }
 486 cont:
 487                 iter->count++;
 488         }
 489         read_unlock_bh(&priv->lock);
 490 }
 491
 492 static void nft_rbtree_gc(struct work_struct *work)
 493 {
 494         struct nft_rbtree_elem *rbe, *rbe_end = NULL, *rbe_prev = NULL;
 495         struct nft_set_gc_batch *gcb = NULL;
 496         struct nft_rbtree *priv;
 497         struct rb_node *node;
 498         struct nft_set *set;
 499
 500         priv = container_of(work, struct nft_rbtree, gc_work.work);
 501         set  = nft_set_container_of(priv);
 502
 503         write_lock_bh(&priv->lock);
 504         write_seqcount_begin(&priv->count);
 505         for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
 506                 rbe = rb_entry(node, struct nft_rbtree_elem, node);
 507
 508                 if (nft_rbtree_interval_end(rbe)) {
 509                         rbe_end = rbe;
 510                         continue;
 511                 }
 512                 if (!nft_set_elem_expired(&rbe->ext))
 513                         continue;
 514                 if (nft_set_elem_mark_busy(&rbe->ext))
 515                         continue;
 516
 517                 if (rbe_prev) {
 518                         rb_erase(&rbe_prev->node, &priv->root);
 519                         rbe_prev = NULL;
 520                 }
 521                 gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
 522                 if (!gcb)
 523                         break;
 524
 525                 atomic_dec(&set->nelems);
 526                 nft_set_gc_batch_add(gcb, rbe);
 527                 rbe_prev = rbe;
 528
 529                 if (rbe_end) {
 530                         atomic_dec(&set->nelems);
 531                         nft_set_gc_batch_add(gcb, rbe_end);
 532                         rb_erase(&rbe_end->node, &priv->root);
 533                         rbe_end = NULL;
 534                 }
 535                 node = rb_next(node);
 536                 if (!node)
 537                         break;
 538         }
 539         if (rbe_prev)
 540                 rb_erase(&rbe_prev->node, &priv->root);
 541         write_seqcount_end(&priv->count);
 542         write_unlock_bh(&priv->lock);
 543
 544         nft_set_gc_batch_complete(gcb);
 545
 546         queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
 547                            nft_set_gc_interval(set));
 548 }
 549
 550 static u64 nft_rbtree_privsize(const struct nlattr * const nla[],
 551                                const struct nft_set_desc *desc)
 552 {
 553         return sizeof(struct nft_rbtree);
 554 }
 555
 556 static int nft_rbtree_init(const struct nft_set *set,
 557                            const struct nft_set_desc *desc,
 558                            const struct nlattr * const nla[])
 559 {
 560         struct nft_rbtree *priv = nft_set_priv(set);
 561
 562         rwlock_init(&priv->lock);
 563         seqcount_rwlock_init(&priv->count, &priv->lock);
 564         priv->root = RB_ROOT;
 565
 566         INIT_DEFERRABLE_WORK(&priv->gc_work, nft_rbtree_gc);
 567         if (set->flags & NFT_SET_TIMEOUT)
 568                 queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
 569                                    nft_set_gc_interval(set));
 570
 571         return 0;
 572 }
 573
 574 static void nft_rbtree_destroy(const struct nft_set *set)
 575 {
 576         struct nft_rbtree *priv = nft_set_priv(set);
 577         struct nft_rbtree_elem *rbe;
 578         struct rb_node *node;
 579
 580         cancel_delayed_work_sync(&priv->gc_work);
 581         rcu_barrier();
 582         while ((node = priv->root.rb_node) != NULL) {
 583                 rb_erase(node, &priv->root);
 584                 rbe = rb_entry(node, struct nft_rbtree_elem, node);
 585                 nft_set_elem_destroy(set, rbe, true);
 586         }
 587 }
 588
 589 static bool nft_rbtree_estimate(const struct nft_set_desc *desc, u32 features,
 590                                 struct nft_set_estimate *est)
 591 {
 592         if (desc->field_count > 1)
 593                 return false;
 594
 595         if (desc->size)
 596                 est->size = sizeof(struct nft_rbtree) +
 597                             desc->size * sizeof(struct nft_rbtree_elem);
 598         else
 599                 est->size = ~0;
 600
 601         est->lookup = NFT_SET_CLASS_O_LOG_N;
 602         est->space  = NFT_SET_CLASS_O_N;
 603
 604         return true;
 605 }
 606
 607 const struct nft_set_type nft_set_rbtree_type = {
 608         .features       = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT | NFT_SET_TIMEOUT,
 609         .ops            = {
 610                 .privsize       = nft_rbtree_privsize,
 611                 .elemsize       = offsetof(struct nft_rbtree_elem, ext),
 612                 .estimate       = nft_rbtree_estimate,
 613                 .init           = nft_rbtree_init,
 614                 .destroy        = nft_rbtree_destroy,
 615                 .insert         = nft_rbtree_insert,
 616                 .remove         = nft_rbtree_remove,
 617                 .deactivate     = nft_rbtree_deactivate,
 618                 .flush          = nft_rbtree_flush,
 619                 .activate       = nft_rbtree_activate,
 620                 .lookup         = nft_rbtree_lookup,
 621                 .walk           = nft_rbtree_walk,
 622                 .get            = nft_rbtree_get,
 623         },
 624 };