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         unsigned long           last_gc;
  23 };
  24
  25 struct nft_rbtree_elem {
  26         struct nft_elem_priv    priv;
  27         struct rb_node          node;
  28         struct nft_set_ext      ext;
  29 };
  30
  31 static bool nft_rbtree_interval_end(const struct nft_rbtree_elem *rbe)
  32 {
  33         return nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) &&
  34                (*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END);
  35 }
  36
  37 static bool nft_rbtree_interval_start(const struct nft_rbtree_elem *rbe)
  38 {
  39         return !nft_rbtree_interval_end(rbe);
  40 }
  41
  42 static int nft_rbtree_cmp(const struct nft_set *set,
  43                           const struct nft_rbtree_elem *e1,
  44                           const struct nft_rbtree_elem *e2)
  45 {
  46         return memcmp(nft_set_ext_key(&e1->ext), nft_set_ext_key(&e2->ext),
  47                       set->klen);
  48 }
  49
  50 static bool nft_rbtree_elem_expired(const struct nft_rbtree_elem *rbe)
  51 {
  52         return nft_set_elem_expired(&rbe->ext);
  53 }
  54
  55 static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
  56                                 const u32 *key, const struct nft_set_ext **ext,
  57                                 unsigned int seq)
  58 {
  59         struct nft_rbtree *priv = nft_set_priv(set);
  60         const struct nft_rbtree_elem *rbe, *interval = NULL;
  61         u8 genmask = nft_genmask_cur(net);
  62         const struct rb_node *parent;
  63         int d;
  64
  65         parent = rcu_dereference_raw(priv->root.rb_node);
  66         while (parent != NULL) {
  67                 if (read_seqcount_retry(&priv->count, seq))
  68                         return false;
  69
  70                 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
  71
  72                 d = memcmp(nft_set_ext_key(&rbe->ext), key, set->klen);
  73                 if (d < 0) {
  74                         parent = rcu_dereference_raw(parent->rb_left);
  75                         if (interval &&
  76                             !nft_rbtree_cmp(set, rbe, interval) &&
  77                             nft_rbtree_interval_end(rbe) &&
  78                             nft_rbtree_interval_start(interval))
  79                                 continue;
  80                         interval = rbe;
  81                 } else if (d > 0)
  82                         parent = rcu_dereference_raw(parent->rb_right);
  83                 else {
  84                         if (!nft_set_elem_active(&rbe->ext, genmask)) {
  85                                 parent = rcu_dereference_raw(parent->rb_left);
  86                                 continue;
  87                         }
  88
  89                         if (nft_rbtree_elem_expired(rbe))
  90                                 return false;
  91
  92                         if (nft_rbtree_interval_end(rbe)) {
  93                                 if (nft_set_is_anonymous(set))
  94                                         return false;
  95                                 parent = rcu_dereference_raw(parent->rb_left);
  96                                 interval = NULL;
  97                                 continue;
  98                         }
  99
 100                         *ext = &rbe->ext;
 101                         return true;
 102                 }
 103         }
 104
 105         if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
 106             nft_set_elem_active(&interval->ext, genmask) &&
 107             !nft_rbtree_elem_expired(interval) &&
 108             nft_rbtree_interval_start(interval)) {
 109                 *ext = &interval->ext;
 110                 return true;
 111         }
 112
 113         return false;
 114 }
 115
 116 INDIRECT_CALLABLE_SCOPE
 117 bool nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
 118                        const u32 *key, const struct nft_set_ext **ext)
 119 {
 120         struct nft_rbtree *priv = nft_set_priv(set);
 121         unsigned int seq = read_seqcount_begin(&priv->count);
 122         bool ret;
 123
 124         ret = __nft_rbtree_lookup(net, set, key, ext, seq);
 125         if (ret || !read_seqcount_retry(&priv->count, seq))
 126                 return ret;
 127
 128         read_lock_bh(&priv->lock);
 129         seq = read_seqcount_begin(&priv->count);
 130         ret = __nft_rbtree_lookup(net, set, key, ext, seq);
 131         read_unlock_bh(&priv->lock);
 132
 133         return ret;
 134 }
 135
 136 static bool __nft_rbtree_get(const struct net *net, const struct nft_set *set,
 137                              const u32 *key, struct nft_rbtree_elem **elem,
 138                              unsigned int seq, unsigned int flags, u8 genmask)
 139 {
 140         struct nft_rbtree_elem *rbe, *interval = NULL;
 141         struct nft_rbtree *priv = nft_set_priv(set);
 142         const struct rb_node *parent;
 143         const void *this;
 144         int d;
 145
 146         parent = rcu_dereference_raw(priv->root.rb_node);
 147         while (parent != NULL) {
 148                 if (read_seqcount_retry(&priv->count, seq))
 149                         return false;
 150
 151                 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 152
 153                 this = nft_set_ext_key(&rbe->ext);
 154                 d = memcmp(this, key, set->klen);
 155                 if (d < 0) {
 156                         parent = rcu_dereference_raw(parent->rb_left);
 157                         if (!(flags & NFT_SET_ELEM_INTERVAL_END))
 158                                 interval = rbe;
 159                 } else if (d > 0) {
 160                         parent = rcu_dereference_raw(parent->rb_right);
 161                         if (flags & NFT_SET_ELEM_INTERVAL_END)
 162                                 interval = rbe;
 163                 } else {
 164                         if (!nft_set_elem_active(&rbe->ext, genmask)) {
 165                                 parent = rcu_dereference_raw(parent->rb_left);
 166                                 continue;
 167                         }
 168
 169                         if (nft_set_elem_expired(&rbe->ext))
 170                                 return false;
 171
 172                         if (!nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) ||
 173                             (*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END) ==
 174                             (flags & NFT_SET_ELEM_INTERVAL_END)) {
 175                                 *elem = rbe;
 176                                 return true;
 177                         }
 178
 179                         if (nft_rbtree_interval_end(rbe))
 180                                 interval = NULL;
 181
 182                         parent = rcu_dereference_raw(parent->rb_left);
 183                 }
 184         }
 185
 186         if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
 187             nft_set_elem_active(&interval->ext, genmask) &&
 188             !nft_set_elem_expired(&interval->ext) &&
 189             ((!nft_rbtree_interval_end(interval) &&
 190               !(flags & NFT_SET_ELEM_INTERVAL_END)) ||
 191              (nft_rbtree_interval_end(interval) &&
 192               (flags & NFT_SET_ELEM_INTERVAL_END)))) {
 193                 *elem = interval;
 194                 return true;
 195         }
 196
 197         return false;
 198 }
 199
 200 static struct nft_elem_priv *
 201 nft_rbtree_get(const struct net *net, const struct nft_set *set,
 202                const struct nft_set_elem *elem, unsigned int flags)
 203 {
 204         struct nft_rbtree *priv = nft_set_priv(set);
 205         unsigned int seq = read_seqcount_begin(&priv->count);
 206         struct nft_rbtree_elem *rbe = ERR_PTR(-ENOENT);
 207         const u32 *key = (const u32 *)&elem->key.val;
 208         u8 genmask = nft_genmask_cur(net);
 209         bool ret;
 210
 211         ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask);
 212         if (ret || !read_seqcount_retry(&priv->count, seq))
 213                 return &rbe->priv;
 214
 215         read_lock_bh(&priv->lock);
 216         seq = read_seqcount_begin(&priv->count);
 217         ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask);
 218         read_unlock_bh(&priv->lock);
 219
 220         if (!ret)
 221                 return ERR_PTR(-ENOENT);
 222
 223         return &rbe->priv;
 224 }
 225
 226 static void nft_rbtree_gc_elem_remove(struct net *net, struct nft_set *set,
 227                                       struct nft_rbtree *priv,
 228                                       struct nft_rbtree_elem *rbe)
 229 {
 230         lockdep_assert_held_write(&priv->lock);
 231         nft_setelem_data_deactivate(net, set, &rbe->priv);
 232         rb_erase(&rbe->node, &priv->root);
 233 }
 234
 235 static const struct nft_rbtree_elem *
 236 nft_rbtree_gc_elem(const struct nft_set *__set, struct nft_rbtree *priv,
 237                    struct nft_rbtree_elem *rbe, u8 genmask)
 238 {
 239         struct nft_set *set = (struct nft_set *)__set;
 240         struct rb_node *prev = rb_prev(&rbe->node);
 241         struct net *net = read_pnet(&set->net);
 242         struct nft_rbtree_elem *rbe_prev;
 243         struct nft_trans_gc *gc;
 244
 245         gc = nft_trans_gc_alloc(set, 0, GFP_ATOMIC);
 246         if (!gc)
 247                 return ERR_PTR(-ENOMEM);
 248
 249         /* search for end interval coming before this element.
 250          * end intervals don't carry a timeout extension, they
 251          * are coupled with the interval start element.
 252          */
 253         while (prev) {
 254                 rbe_prev = rb_entry(prev, struct nft_rbtree_elem, node);
 255                 if (nft_rbtree_interval_end(rbe_prev) &&
 256                     nft_set_elem_active(&rbe_prev->ext, genmask))
 257                         break;
 258
 259                 prev = rb_prev(prev);
 260         }
 261
 262         rbe_prev = NULL;
 263         if (prev) {
 264                 rbe_prev = rb_entry(prev, struct nft_rbtree_elem, node);
 265                 nft_rbtree_gc_elem_remove(net, set, priv, rbe_prev);
 266
 267                 /* There is always room in this trans gc for this element,
 268                  * memory allocation never actually happens, hence, the warning
 269                  * splat in such case. No need to set NFT_SET_ELEM_DEAD_BIT,
 270                  * this is synchronous gc which never fails.
 271                  */
 272                 gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
 273                 if (WARN_ON_ONCE(!gc))
 274                         return ERR_PTR(-ENOMEM);
 275
 276                 nft_trans_gc_elem_add(gc, rbe_prev);
 277         }
 278
 279         nft_rbtree_gc_elem_remove(net, set, priv, rbe);
 280         gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
 281         if (WARN_ON_ONCE(!gc))
 282                 return ERR_PTR(-ENOMEM);
 283
 284         nft_trans_gc_elem_add(gc, rbe);
 285
 286         nft_trans_gc_queue_sync_done(gc);
 287
 288         return rbe_prev;
 289 }
 290
 291 static bool nft_rbtree_update_first(const struct nft_set *set,
 292                                     struct nft_rbtree_elem *rbe,
 293                                     struct rb_node *first)
 294 {
 295         struct nft_rbtree_elem *first_elem;
 296
 297         first_elem = rb_entry(first, struct nft_rbtree_elem, node);
 298         /* this element is closest to where the new element is to be inserted:
 299          * update the first element for the node list path.
 300          */
 301         if (nft_rbtree_cmp(set, rbe, first_elem) < 0)
 302                 return true;
 303
 304         return false;
 305 }
 306
 307 static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 308                                struct nft_rbtree_elem *new,
 309                                struct nft_set_ext **ext)
 310 {
 311         struct nft_rbtree_elem *rbe, *rbe_le = NULL, *rbe_ge = NULL;
 312         struct rb_node *node, *next, *parent, **p, *first = NULL;
 313         struct nft_rbtree *priv = nft_set_priv(set);
 314         u8 cur_genmask = nft_genmask_cur(net);
 315         u8 genmask = nft_genmask_next(net);
 316         int d;
 317
 318         /* Descend the tree to search for an existing element greater than the
 319          * key value to insert that is greater than the new element. This is the
 320          * first element to walk the ordered elements to find possible overlap.
 321          */
 322         parent = NULL;
 323         p = &priv->root.rb_node;
 324         while (*p != NULL) {
 325                 parent = *p;
 326                 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 327                 d = nft_rbtree_cmp(set, rbe, new);
 328
 329                 if (d < 0) {
 330                         p = &parent->rb_left;
 331                 } else if (d > 0) {
 332                         if (!first ||
 333                             nft_rbtree_update_first(set, rbe, first))
 334                                 first = &rbe->node;
 335
 336                         p = &parent->rb_right;
 337                 } else {
 338                         if (nft_rbtree_interval_end(rbe))
 339                                 p = &parent->rb_left;
 340                         else
 341                                 p = &parent->rb_right;
 342                 }
 343         }
 344
 345         if (!first)
 346                 first = rb_first(&priv->root);
 347
 348         /* Detect overlap by going through the list of valid tree nodes.
 349          * Values stored in the tree are in reversed order, starting from
 350          * highest to lowest value.
 351          */
 352         for (node = first; node != NULL; node = next) {
 353                 next = rb_next(node);
 354
 355                 rbe = rb_entry(node, struct nft_rbtree_elem, node);
 356
 357                 if (!nft_set_elem_active(&rbe->ext, genmask))
 358                         continue;
 359
 360                 /* perform garbage collection to avoid bogus overlap reports
 361                  * but skip new elements in this transaction.
 362                  */
 363                 if (nft_set_elem_expired(&rbe->ext) &&
 364                     nft_set_elem_active(&rbe->ext, cur_genmask)) {
 365                         const struct nft_rbtree_elem *removed_end;
 366
 367                         removed_end = nft_rbtree_gc_elem(set, priv, rbe, genmask);
 368                         if (IS_ERR(removed_end))
 369                                 return PTR_ERR(removed_end);
 370
 371                         if (removed_end == rbe_le || removed_end == rbe_ge)
 372                                 return -EAGAIN;
 373
 374                         continue;
 375                 }
 376
 377                 d = nft_rbtree_cmp(set, rbe, new);
 378                 if (d == 0) {
 379                         /* Matching end element: no need to look for an
 380                          * overlapping greater or equal element.
 381                          */
 382                         if (nft_rbtree_interval_end(rbe)) {
 383                                 rbe_le = rbe;
 384                                 break;
 385                         }
 386
 387                         /* first element that is greater or equal to key value. */
 388                         if (!rbe_ge) {
 389                                 rbe_ge = rbe;
 390                                 continue;
 391                         }
 392
 393                         /* this is a closer more or equal element, update it. */
 394                         if (nft_rbtree_cmp(set, rbe_ge, new) != 0) {
 395                                 rbe_ge = rbe;
 396                                 continue;
 397                         }
 398
 399                         /* element is equal to key value, make sure flags are
 400                          * the same, an existing more or equal start element
 401                          * must not be replaced by more or equal end element.
 402                          */
 403                         if ((nft_rbtree_interval_start(new) &&
 404                              nft_rbtree_interval_start(rbe_ge)) ||
 405                             (nft_rbtree_interval_end(new) &&
 406                              nft_rbtree_interval_end(rbe_ge))) {
 407                                 rbe_ge = rbe;
 408                                 continue;
 409                         }
 410                 } else if (d > 0) {
 411                         /* annotate element greater than the new element. */
 412                         rbe_ge = rbe;
 413                         continue;
 414                 } else if (d < 0) {
 415                         /* annotate element less than the new element. */
 416                         rbe_le = rbe;
 417                         break;
 418                 }
 419         }
 420
 421         /* - new start element matching existing start element: full overlap
 422          *   reported as -EEXIST, cleared by caller if NLM_F_EXCL is not given.
 423          */
 424         if (rbe_ge && !nft_rbtree_cmp(set, new, rbe_ge) &&
 425             nft_rbtree_interval_start(rbe_ge) == nft_rbtree_interval_start(new)) {
 426                 *ext = &rbe_ge->ext;
 427                 return -EEXIST;
 428         }
 429
 430         /* - new end element matching existing end element: full overlap
 431          *   reported as -EEXIST, cleared by caller if NLM_F_EXCL is not given.
 432          */
 433         if (rbe_le && !nft_rbtree_cmp(set, new, rbe_le) &&
 434             nft_rbtree_interval_end(rbe_le) == nft_rbtree_interval_end(new)) {
 435                 *ext = &rbe_le->ext;
 436                 return -EEXIST;
 437         }
 438
 439         /* - new start element with existing closest, less or equal key value
 440          *   being a start element: partial overlap, reported as -ENOTEMPTY.
 441          *   Anonymous sets allow for two consecutive start element since they
 442          *   are constant, skip them to avoid bogus overlap reports.
 443          */
 444         if (!nft_set_is_anonymous(set) && rbe_le &&
 445             nft_rbtree_interval_start(rbe_le) && nft_rbtree_interval_start(new))
 446                 return -ENOTEMPTY;
 447
 448         /* - new end element with existing closest, less or equal key value
 449          *   being a end element: partial overlap, reported as -ENOTEMPTY.
 450          */
 451         if (rbe_le &&
 452             nft_rbtree_interval_end(rbe_le) && nft_rbtree_interval_end(new))
 453                 return -ENOTEMPTY;
 454
 455         /* - new end element with existing closest, greater or equal key value
 456          *   being an end element: partial overlap, reported as -ENOTEMPTY
 457          */
 458         if (rbe_ge &&
 459             nft_rbtree_interval_end(rbe_ge) && nft_rbtree_interval_end(new))
 460                 return -ENOTEMPTY;
 461
 462         /* Accepted element: pick insertion point depending on key value */
 463         parent = NULL;
 464         p = &priv->root.rb_node;
 465         while (*p != NULL) {
 466                 parent = *p;
 467                 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 468                 d = nft_rbtree_cmp(set, rbe, new);
 469
 470                 if (d < 0)
 471                         p = &parent->rb_left;
 472                 else if (d > 0)
 473                         p = &parent->rb_right;
 474                 else if (nft_rbtree_interval_end(rbe))
 475                         p = &parent->rb_left;
 476                 else
 477                         p = &parent->rb_right;
 478         }
 479
 480         rb_link_node_rcu(&new->node, parent, p);
 481         rb_insert_color(&new->node, &priv->root);
 482         return 0;
 483 }
 484
 485 static int nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 486                              const struct nft_set_elem *elem,
 487                              struct nft_set_ext **ext)
 488 {
 489         struct nft_rbtree_elem *rbe = nft_elem_priv_cast(elem->priv);
 490         struct nft_rbtree *priv = nft_set_priv(set);
 491         int err;
 492
 493         do {
 494                 if (fatal_signal_pending(current))
 495                         return -EINTR;
 496
 497                 cond_resched();
 498
 499                 write_lock_bh(&priv->lock);
 500                 write_seqcount_begin(&priv->count);
 501                 err = __nft_rbtree_insert(net, set, rbe, ext);
 502                 write_seqcount_end(&priv->count);
 503                 write_unlock_bh(&priv->lock);
 504         } while (err == -EAGAIN);
 505
 506         return err;
 507 }
 508
 509 static void nft_rbtree_erase(struct nft_rbtree *priv, struct nft_rbtree_elem *rbe)
 510 {
 511         write_lock_bh(&priv->lock);
 512         write_seqcount_begin(&priv->count);
 513         rb_erase(&rbe->node, &priv->root);
 514         write_seqcount_end(&priv->count);
 515         write_unlock_bh(&priv->lock);
 516 }
 517
 518 static void nft_rbtree_remove(const struct net *net,
 519                               const struct nft_set *set,
 520                               struct nft_elem_priv *elem_priv)
 521 {
 522         struct nft_rbtree_elem *rbe = nft_elem_priv_cast(elem_priv);
 523         struct nft_rbtree *priv = nft_set_priv(set);
 524
 525         nft_rbtree_erase(priv, rbe);
 526 }
 527
 528 static void nft_rbtree_activate(const struct net *net,
 529                                 const struct nft_set *set,
 530                                 struct nft_elem_priv *elem_priv)
 531 {
 532         struct nft_rbtree_elem *rbe = nft_elem_priv_cast(elem_priv);
 533
 534         nft_set_elem_change_active(net, set, &rbe->ext);
 535 }
 536
 537 static void nft_rbtree_flush(const struct net *net,
 538                              const struct nft_set *set,
 539                              struct nft_elem_priv *elem_priv)
 540 {
 541         struct nft_rbtree_elem *rbe = nft_elem_priv_cast(elem_priv);
 542
 543         nft_set_elem_change_active(net, set, &rbe->ext);
 544 }
 545
 546 static struct nft_elem_priv *
 547 nft_rbtree_deactivate(const struct net *net, const struct nft_set *set,
 548                       const struct nft_set_elem *elem)
 549 {
 550         struct nft_rbtree_elem *rbe, *this = nft_elem_priv_cast(elem->priv);
 551         const struct nft_rbtree *priv = nft_set_priv(set);
 552         const struct rb_node *parent = priv->root.rb_node;
 553         u8 genmask = nft_genmask_next(net);
 554         int d;
 555
 556         while (parent != NULL) {
 557                 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 558
 559                 d = memcmp(nft_set_ext_key(&rbe->ext), &elem->key.val,
 560                                            set->klen);
 561                 if (d < 0)
 562                         parent = parent->rb_left;
 563                 else if (d > 0)
 564                         parent = parent->rb_right;
 565                 else {
 566                         if (nft_rbtree_interval_end(rbe) &&
 567                             nft_rbtree_interval_start(this)) {
 568                                 parent = parent->rb_left;
 569                                 continue;
 570                         } else if (nft_rbtree_interval_start(rbe) &&
 571                                    nft_rbtree_interval_end(this)) {
 572                                 parent = parent->rb_right;
 573                                 continue;
 574                         } else if (nft_set_elem_expired(&rbe->ext)) {
 575                                 break;
 576                         } else if (!nft_set_elem_active(&rbe->ext, genmask)) {
 577                                 parent = parent->rb_left;
 578                                 continue;
 579                         }
 580                         nft_rbtree_flush(net, set, &rbe->priv);
 581                         return &rbe->priv;
 582                 }
 583         }
 584         return NULL;
 585 }
 586
 587 static void nft_rbtree_walk(const struct nft_ctx *ctx,
 588                             struct nft_set *set,
 589                             struct nft_set_iter *iter)
 590 {
 591         struct nft_rbtree *priv = nft_set_priv(set);
 592         struct nft_rbtree_elem *rbe;
 593         struct rb_node *node;
 594
 595         read_lock_bh(&priv->lock);
 596         for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
 597                 rbe = rb_entry(node, struct nft_rbtree_elem, node);
 598
 599                 if (iter->count < iter->skip)
 600                         goto cont;
 601                 if (!nft_set_elem_active(&rbe->ext, iter->genmask))
 602                         goto cont;
 603
 604                 iter->err = iter->fn(ctx, set, iter, &rbe->priv);
 605                 if (iter->err < 0) {
 606                         read_unlock_bh(&priv->lock);
 607                         return;
 608                 }
 609 cont:
 610                 iter->count++;
 611         }
 612         read_unlock_bh(&priv->lock);
 613 }
 614
 615 static void nft_rbtree_gc_remove(struct net *net, struct nft_set *set,
 616                                  struct nft_rbtree *priv,
 617                                  struct nft_rbtree_elem *rbe)
 618 {
 619         nft_setelem_data_deactivate(net, set, &rbe->priv);
 620         nft_rbtree_erase(priv, rbe);
 621 }
 622
 623 static void nft_rbtree_gc(struct nft_set *set)
 624 {
 625         struct nft_rbtree *priv = nft_set_priv(set);
 626         struct nft_rbtree_elem *rbe, *rbe_end = NULL;
 627         struct nftables_pernet *nft_net;
 628         struct rb_node *node, *next;
 629         struct nft_trans_gc *gc;
 630         struct net *net;
 631
 632         set  = nft_set_container_of(priv);
 633         net  = read_pnet(&set->net);
 634         nft_net = nft_pernet(net);
 635
 636         gc = nft_trans_gc_alloc(set, 0, GFP_KERNEL);
 637         if (!gc)
 638                 return;
 639
 640         for (node = rb_first(&priv->root); node ; node = next) {
 641                 next = rb_next(node);
 642
 643                 rbe = rb_entry(node, struct nft_rbtree_elem, node);
 644
 645                 /* elements are reversed in the rbtree for historical reasons,
 646                  * from highest to lowest value, that is why end element is
 647                  * always visited before the start element.
 648                  */
 649                 if (nft_rbtree_interval_end(rbe)) {
 650                         rbe_end = rbe;
 651                         continue;
 652                 }
 653                 if (!nft_set_elem_expired(&rbe->ext))
 654                         continue;
 655
 656                 gc = nft_trans_gc_queue_sync(gc, GFP_KERNEL);
 657                 if (!gc)
 658                         goto try_later;
 659
 660                 /* end element needs to be removed first, it has
 661                  * no timeout extension.
 662                  */
 663                 if (rbe_end) {
 664                         nft_rbtree_gc_remove(net, set, priv, rbe_end);
 665                         nft_trans_gc_elem_add(gc, rbe_end);
 666                         rbe_end = NULL;
 667                 }
 668
 669                 gc = nft_trans_gc_queue_sync(gc, GFP_KERNEL);
 670                 if (!gc)
 671                         goto try_later;
 672
 673                 nft_rbtree_gc_remove(net, set, priv, rbe);
 674                 nft_trans_gc_elem_add(gc, rbe);
 675         }
 676
 677 try_later:
 678
 679         if (gc) {
 680                 gc = nft_trans_gc_catchall_sync(gc);
 681                 nft_trans_gc_queue_sync_done(gc);
 682                 priv->last_gc = jiffies;
 683         }
 684 }
 685
 686 static u64 nft_rbtree_privsize(const struct nlattr * const nla[],
 687                                const struct nft_set_desc *desc)
 688 {
 689         return sizeof(struct nft_rbtree);
 690 }
 691
 692 static int nft_rbtree_init(const struct nft_set *set,
 693                            const struct nft_set_desc *desc,
 694                            const struct nlattr * const nla[])
 695 {
 696         struct nft_rbtree *priv = nft_set_priv(set);
 697
 698         BUILD_BUG_ON(offsetof(struct nft_rbtree_elem, priv) != 0);
 699
 700         rwlock_init(&priv->lock);
 701         seqcount_rwlock_init(&priv->count, &priv->lock);
 702         priv->root = RB_ROOT;
 703
 704         return 0;
 705 }
 706
 707 static void nft_rbtree_destroy(const struct nft_ctx *ctx,
 708                                const struct nft_set *set)
 709 {
 710         struct nft_rbtree *priv = nft_set_priv(set);
 711         struct nft_rbtree_elem *rbe;
 712         struct rb_node *node;
 713
 714         while ((node = priv->root.rb_node) != NULL) {
 715                 rb_erase(node, &priv->root);
 716                 rbe = rb_entry(node, struct nft_rbtree_elem, node);
 717                 nf_tables_set_elem_destroy(ctx, set, &rbe->priv);
 718         }
 719 }
 720
 721 static bool nft_rbtree_estimate(const struct nft_set_desc *desc, u32 features,
 722                                 struct nft_set_estimate *est)
 723 {
 724         if (desc->field_count > 1)
 725                 return false;
 726
 727         if (desc->size)
 728                 est->size = sizeof(struct nft_rbtree) +
 729                             desc->size * sizeof(struct nft_rbtree_elem);
 730         else
 731                 est->size = ~0;
 732
 733         est->lookup = NFT_SET_CLASS_O_LOG_N;
 734         est->space  = NFT_SET_CLASS_O_N;
 735
 736         return true;
 737 }
 738
 739 static void nft_rbtree_commit(struct nft_set *set)
 740 {
 741         struct nft_rbtree *priv = nft_set_priv(set);
 742
 743         if (time_after_eq(jiffies, priv->last_gc + nft_set_gc_interval(set)))
 744                 nft_rbtree_gc(set);
 745 }
 746
 747 static void nft_rbtree_gc_init(const struct nft_set *set)
 748 {
 749         struct nft_rbtree *priv = nft_set_priv(set);
 750
 751         priv->last_gc = jiffies;
 752 }
 753
 754 const struct nft_set_type nft_set_rbtree_type = {
 755         .features       = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT | NFT_SET_TIMEOUT,
 756         .ops            = {
 757                 .privsize       = nft_rbtree_privsize,
 758                 .elemsize       = offsetof(struct nft_rbtree_elem, ext),
 759                 .estimate       = nft_rbtree_estimate,
 760                 .init           = nft_rbtree_init,
 761                 .destroy        = nft_rbtree_destroy,
 762                 .insert         = nft_rbtree_insert,
 763                 .remove         = nft_rbtree_remove,
 764                 .deactivate     = nft_rbtree_deactivate,
 765                 .flush          = nft_rbtree_flush,
 766                 .activate       = nft_rbtree_activate,
 767                 .commit         = nft_rbtree_commit,
 768                 .gc_init        = nft_rbtree_gc_init,
 769                 .lookup         = nft_rbtree_lookup,
 770                 .walk           = nft_rbtree_walk,
 771                 .get            = nft_rbtree_get,
 772         },
 773 };