net/sched/cls_api.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/cls_api.c  Packet classifier API.
   4  *
   5  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   6  *
   7  * Changes:
   8  *
   9  * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/kernel.h>
  15 #include <linux/string.h>
  16 #include <linux/errno.h>
  17 #include <linux/err.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/init.h>
  20 #include <linux/kmod.h>
  21 #include <linux/slab.h>
  22 #include <linux/idr.h>
  23 #include <linux/jhash.h>
  24 #include <linux/rculist.h>
  25 #include <linux/rhashtable.h>
  26 #include <net/net_namespace.h>
  27 #include <net/sock.h>
  28 #include <net/netlink.h>
  29 #include <net/pkt_sched.h>
  30 #include <net/pkt_cls.h>
  31 #include <net/tc_act/tc_pedit.h>
  32 #include <net/tc_act/tc_mirred.h>
  33 #include <net/tc_act/tc_vlan.h>
  34 #include <net/tc_act/tc_tunnel_key.h>
  35 #include <net/tc_act/tc_csum.h>
  36 #include <net/tc_act/tc_gact.h>
  37 #include <net/tc_act/tc_police.h>
  38 #include <net/tc_act/tc_sample.h>
  39 #include <net/tc_act/tc_skbedit.h>
  40 #include <net/tc_act/tc_ct.h>
  41 #include <net/tc_act/tc_mpls.h>
  42 #include <net/tc_act/tc_gate.h>
  43 #include <net/flow_offload.h>
  44 #include <net/tc_wrapper.h>
  45
  46 /* The list of all installed classifier types */
  47 static LIST_HEAD(tcf_proto_base);
  48
  49 /* Protects list of registered TC modules. It is pure SMP lock. */
  50 static DEFINE_RWLOCK(cls_mod_lock);
  51
  52 static struct xarray tcf_exts_miss_cookies_xa;
  53 struct tcf_exts_miss_cookie_node {
  54         const struct tcf_chain *chain;
  55         const struct tcf_proto *tp;
  56         const struct tcf_exts *exts;
  57         u32 chain_index;
  58         u32 tp_prio;
  59         u32 handle;
  60         u32 miss_cookie_base;
  61         struct rcu_head rcu;
  62 };
  63
  64 /* Each tc action entry cookie will be comprised of 32bit miss_cookie_base +
  65  * action index in the exts tc actions array.
  66  */
  67 union tcf_exts_miss_cookie {
  68         struct {
  69                 u32 miss_cookie_base;
  70                 u32 act_index;
  71         };
  72         u64 miss_cookie;
  73 };
  74
  75 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
  76 static int
  77 tcf_exts_miss_cookie_base_alloc(struct tcf_exts *exts, struct tcf_proto *tp,
  78                                 u32 handle)
  79 {
  80         struct tcf_exts_miss_cookie_node *n;
  81         static u32 next;
  82         int err;
  83
  84         if (WARN_ON(!handle || !tp->ops->get_exts))
  85                 return -EINVAL;
  86
  87         n = kzalloc(sizeof(*n), GFP_KERNEL);
  88         if (!n)
  89                 return -ENOMEM;
  90
  91         n->chain_index = tp->chain->index;
  92         n->chain = tp->chain;
  93         n->tp_prio = tp->prio;
  94         n->tp = tp;
  95         n->exts = exts;
  96         n->handle = handle;
  97
  98         err = xa_alloc_cyclic(&tcf_exts_miss_cookies_xa, &n->miss_cookie_base,
  99                               n, xa_limit_32b, &next, GFP_KERNEL);
 100         if (err)
 101                 goto err_xa_alloc;
 102
 103         exts->miss_cookie_node = n;
 104         return 0;
 105
 106 err_xa_alloc:
 107         kfree(n);
 108         return err;
 109 }
 110
 111 static void tcf_exts_miss_cookie_base_destroy(struct tcf_exts *exts)
 112 {
 113         struct tcf_exts_miss_cookie_node *n;
 114
 115         if (!exts->miss_cookie_node)
 116                 return;
 117
 118         n = exts->miss_cookie_node;
 119         xa_erase(&tcf_exts_miss_cookies_xa, n->miss_cookie_base);
 120         kfree_rcu(n, rcu);
 121 }
 122
 123 static struct tcf_exts_miss_cookie_node *
 124 tcf_exts_miss_cookie_lookup(u64 miss_cookie, int *act_index)
 125 {
 126         union tcf_exts_miss_cookie mc = { .miss_cookie = miss_cookie, };
 127
 128         *act_index = mc.act_index;
 129         return xa_load(&tcf_exts_miss_cookies_xa, mc.miss_cookie_base);
 130 }
 131 #else /* IS_ENABLED(CONFIG_NET_TC_SKB_EXT) */
 132 static int
 133 tcf_exts_miss_cookie_base_alloc(struct tcf_exts *exts, struct tcf_proto *tp,
 134                                 u32 handle)
 135 {
 136         return 0;
 137 }
 138
 139 static void tcf_exts_miss_cookie_base_destroy(struct tcf_exts *exts)
 140 {
 141 }
 142 #endif /* IS_ENABLED(CONFIG_NET_TC_SKB_EXT) */
 143
 144 static u64 tcf_exts_miss_cookie_get(u32 miss_cookie_base, int act_index)
 145 {
 146         union tcf_exts_miss_cookie mc = { .act_index = act_index, };
 147
 148         if (!miss_cookie_base)
 149                 return 0;
 150
 151         mc.miss_cookie_base = miss_cookie_base;
 152         return mc.miss_cookie;
 153 }
 154
 155 #ifdef CONFIG_NET_CLS_ACT
 156 DEFINE_STATIC_KEY_FALSE(tc_skb_ext_tc);
 157 EXPORT_SYMBOL(tc_skb_ext_tc);
 158
 159 void tc_skb_ext_tc_enable(void)
 160 {
 161         static_branch_inc(&tc_skb_ext_tc);
 162 }
 163 EXPORT_SYMBOL(tc_skb_ext_tc_enable);
 164
 165 void tc_skb_ext_tc_disable(void)
 166 {
 167         static_branch_dec(&tc_skb_ext_tc);
 168 }
 169 EXPORT_SYMBOL(tc_skb_ext_tc_disable);
 170 #endif
 171
 172 static u32 destroy_obj_hashfn(const struct tcf_proto *tp)
 173 {
 174         return jhash_3words(tp->chain->index, tp->prio,
 175                             (__force __u32)tp->protocol, 0);
 176 }
 177
 178 static void tcf_proto_signal_destroying(struct tcf_chain *chain,
 179                                         struct tcf_proto *tp)
 180 {
 181         struct tcf_block *block = chain->block;
 182
 183         mutex_lock(&block->proto_destroy_lock);
 184         hash_add_rcu(block->proto_destroy_ht, &tp->destroy_ht_node,
 185                      destroy_obj_hashfn(tp));
 186         mutex_unlock(&block->proto_destroy_lock);
 187 }
 188
 189 static bool tcf_proto_cmp(const struct tcf_proto *tp1,
 190                           const struct tcf_proto *tp2)
 191 {
 192         return tp1->chain->index == tp2->chain->index &&
 193                tp1->prio == tp2->prio &&
 194                tp1->protocol == tp2->protocol;
 195 }
 196
 197 static bool tcf_proto_exists_destroying(struct tcf_chain *chain,
 198                                         struct tcf_proto *tp)
 199 {
 200         u32 hash = destroy_obj_hashfn(tp);
 201         struct tcf_proto *iter;
 202         bool found = false;
 203
 204         rcu_read_lock();
 205         hash_for_each_possible_rcu(chain->block->proto_destroy_ht, iter,
 206                                    destroy_ht_node, hash) {
 207                 if (tcf_proto_cmp(tp, iter)) {
 208                         found = true;
 209                         break;
 210                 }
 211         }
 212         rcu_read_unlock();
 213
 214         return found;
 215 }
 216
 217 static void
 218 tcf_proto_signal_destroyed(struct tcf_chain *chain, struct tcf_proto *tp)
 219 {
 220         struct tcf_block *block = chain->block;
 221
 222         mutex_lock(&block->proto_destroy_lock);
 223         if (hash_hashed(&tp->destroy_ht_node))
 224                 hash_del_rcu(&tp->destroy_ht_node);
 225         mutex_unlock(&block->proto_destroy_lock);
 226 }
 227
 228 /* Find classifier type by string name */
 229
 230 static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
 231 {
 232         const struct tcf_proto_ops *t, *res = NULL;
 233
 234         if (kind) {
 235                 read_lock(&cls_mod_lock);
 236                 list_for_each_entry(t, &tcf_proto_base, head) {
 237                         if (strcmp(kind, t->kind) == 0) {
 238                                 if (try_module_get(t->owner))
 239                                         res = t;
 240                                 break;
 241                         }
 242                 }
 243                 read_unlock(&cls_mod_lock);
 244         }
 245         return res;
 246 }
 247
 248 static const struct tcf_proto_ops *
 249 tcf_proto_lookup_ops(const char *kind, bool rtnl_held,
 250                      struct netlink_ext_ack *extack)
 251 {
 252         const struct tcf_proto_ops *ops;
 253
 254         ops = __tcf_proto_lookup_ops(kind);
 255         if (ops)
 256                 return ops;
 257 #ifdef CONFIG_MODULES
 258         if (rtnl_held)
 259                 rtnl_unlock();
 260         request_module("cls_%s", kind);
 261         if (rtnl_held)
 262                 rtnl_lock();
 263         ops = __tcf_proto_lookup_ops(kind);
 264         /* We dropped the RTNL semaphore in order to perform
 265          * the module load. So, even if we succeeded in loading
 266          * the module we have to replay the request. We indicate
 267          * this using -EAGAIN.
 268          */
 269         if (ops) {
 270                 module_put(ops->owner);
 271                 return ERR_PTR(-EAGAIN);
 272         }
 273 #endif
 274         NL_SET_ERR_MSG(extack, "TC classifier not found");
 275         return ERR_PTR(-ENOENT);
 276 }
 277
 278 /* Register(unregister) new classifier type */
 279
 280 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
 281 {
 282         struct tcf_proto_ops *t;
 283         int rc = -EEXIST;
 284
 285         write_lock(&cls_mod_lock);
 286         list_for_each_entry(t, &tcf_proto_base, head)
 287                 if (!strcmp(ops->kind, t->kind))
 288                         goto out;
 289
 290         list_add_tail(&ops->head, &tcf_proto_base);
 291         rc = 0;
 292 out:
 293         write_unlock(&cls_mod_lock);
 294         return rc;
 295 }
 296 EXPORT_SYMBOL(register_tcf_proto_ops);
 297
 298 static struct workqueue_struct *tc_filter_wq;
 299
 300 void unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
 301 {
 302         struct tcf_proto_ops *t;
 303         int rc = -ENOENT;
 304
 305         /* Wait for outstanding call_rcu()s, if any, from a
 306          * tcf_proto_ops's destroy() handler.
 307          */
 308         rcu_barrier();
 309         flush_workqueue(tc_filter_wq);
 310
 311         write_lock(&cls_mod_lock);
 312         list_for_each_entry(t, &tcf_proto_base, head) {
 313                 if (t == ops) {
 314                         list_del(&t->head);
 315                         rc = 0;
 316                         break;
 317                 }
 318         }
 319         write_unlock(&cls_mod_lock);
 320
 321         WARN(rc, "unregister tc filter kind(%s) failed %d\n", ops->kind, rc);
 322 }
 323 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 324
 325 bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
 326 {
 327         INIT_RCU_WORK(rwork, func);
 328         return queue_rcu_work(tc_filter_wq, rwork);
 329 }
 330 EXPORT_SYMBOL(tcf_queue_work);
 331
 332 /* Select new prio value from the range, managed by kernel. */
 333
 334 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 335 {
 336         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 337
 338         if (tp)
 339                 first = tp->prio - 1;
 340
 341         return TC_H_MAJ(first);
 342 }
 343
 344 static bool tcf_proto_check_kind(struct nlattr *kind, char *name)
 345 {
 346         if (kind)
 347                 return nla_strscpy(name, kind, IFNAMSIZ) < 0;
 348         memset(name, 0, IFNAMSIZ);
 349         return false;
 350 }
 351
 352 static bool tcf_proto_is_unlocked(const char *kind)
 353 {
 354         const struct tcf_proto_ops *ops;
 355         bool ret;
 356
 357         if (strlen(kind) == 0)
 358                 return false;
 359
 360         ops = tcf_proto_lookup_ops(kind, false, NULL);
 361         /* On error return false to take rtnl lock. Proto lookup/create
 362          * functions will perform lookup again and properly handle errors.
 363          */
 364         if (IS_ERR(ops))
 365                 return false;
 366
 367         ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED);
 368         module_put(ops->owner);
 369         return ret;
 370 }
 371
 372 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 373                                           u32 prio, struct tcf_chain *chain,
 374                                           bool rtnl_held,
 375                                           struct netlink_ext_ack *extack)
 376 {
 377         struct tcf_proto *tp;
 378         int err;
 379
 380         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 381         if (!tp)
 382                 return ERR_PTR(-ENOBUFS);
 383
 384         tp->ops = tcf_proto_lookup_ops(kind, rtnl_held, extack);
 385         if (IS_ERR(tp->ops)) {
 386                 err = PTR_ERR(tp->ops);
 387                 goto errout;
 388         }
 389         tp->classify = tp->ops->classify;
 390         tp->protocol = protocol;
 391         tp->prio = prio;
 392         tp->chain = chain;
 393         spin_lock_init(&tp->lock);
 394         refcount_set(&tp->refcnt, 1);
 395
 396         err = tp->ops->init(tp);
 397         if (err) {
 398                 module_put(tp->ops->owner);
 399                 goto errout;
 400         }
 401         return tp;
 402
 403 errout:
 404         kfree(tp);
 405         return ERR_PTR(err);
 406 }
 407
 408 static void tcf_proto_get(struct tcf_proto *tp)
 409 {
 410         refcount_inc(&tp->refcnt);
 411 }
 412
 413 static void tcf_chain_put(struct tcf_chain *chain);
 414
 415 static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
 416                               bool sig_destroy, struct netlink_ext_ack *extack)
 417 {
 418         tp->ops->destroy(tp, rtnl_held, extack);
 419         if (sig_destroy)
 420                 tcf_proto_signal_destroyed(tp->chain, tp);
 421         tcf_chain_put(tp->chain);
 422         module_put(tp->ops->owner);
 423         kfree_rcu(tp, rcu);
 424 }
 425
 426 static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
 427                           struct netlink_ext_ack *extack)
 428 {
 429         if (refcount_dec_and_test(&tp->refcnt))
 430                 tcf_proto_destroy(tp, rtnl_held, true, extack);
 431 }
 432
 433 static bool tcf_proto_check_delete(struct tcf_proto *tp)
 434 {
 435         if (tp->ops->delete_empty)
 436                 return tp->ops->delete_empty(tp);
 437
 438         tp->deleting = true;
 439         return tp->deleting;
 440 }
 441
 442 static void tcf_proto_mark_delete(struct tcf_proto *tp)
 443 {
 444         spin_lock(&tp->lock);
 445         tp->deleting = true;
 446         spin_unlock(&tp->lock);
 447 }
 448
 449 static bool tcf_proto_is_deleting(struct tcf_proto *tp)
 450 {
 451         bool deleting;
 452
 453         spin_lock(&tp->lock);
 454         deleting = tp->deleting;
 455         spin_unlock(&tp->lock);
 456
 457         return deleting;
 458 }
 459
 460 #define ASSERT_BLOCK_LOCKED(block)                                      \
 461         lockdep_assert_held(&(block)->lock)
 462
 463 struct tcf_filter_chain_list_item {
 464         struct list_head list;
 465         tcf_chain_head_change_t *chain_head_change;
 466         void *chain_head_change_priv;
 467 };
 468
 469 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 470                                           u32 chain_index)
 471 {
 472         struct tcf_chain *chain;
 473
 474         ASSERT_BLOCK_LOCKED(block);
 475
 476         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 477         if (!chain)
 478                 return NULL;
 479         list_add_tail_rcu(&chain->list, &block->chain_list);
 480         mutex_init(&chain->filter_chain_lock);
 481         chain->block = block;
 482         chain->index = chain_index;
 483         chain->refcnt = 1;
 484         if (!chain->index)
 485                 block->chain0.chain = chain;
 486         return chain;
 487 }
 488
 489 static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
 490                                        struct tcf_proto *tp_head)
 491 {
 492         if (item->chain_head_change)
 493                 item->chain_head_change(tp_head, item->chain_head_change_priv);
 494 }
 495
 496 static void tcf_chain0_head_change(struct tcf_chain *chain,
 497                                    struct tcf_proto *tp_head)
 498 {
 499         struct tcf_filter_chain_list_item *item;
 500         struct tcf_block *block = chain->block;
 501
 502         if (chain->index)
 503                 return;
 504
 505         mutex_lock(&block->lock);
 506         list_for_each_entry(item, &block->chain0.filter_chain_list, list)
 507                 tcf_chain_head_change_item(item, tp_head);
 508         mutex_unlock(&block->lock);
 509 }
 510
 511 /* Returns true if block can be safely freed. */
 512
 513 static bool tcf_chain_detach(struct tcf_chain *chain)
 514 {
 515         struct tcf_block *block = chain->block;
 516
 517         ASSERT_BLOCK_LOCKED(block);
 518
 519         list_del_rcu(&chain->list);
 520         if (!chain->index)
 521                 block->chain0.chain = NULL;
 522
 523         if (list_empty(&block->chain_list) &&
 524             refcount_read(&block->refcnt) == 0)
 525                 return true;
 526
 527         return false;
 528 }
 529
 530 static void tcf_block_destroy(struct tcf_block *block)
 531 {
 532         mutex_destroy(&block->lock);
 533         mutex_destroy(&block->proto_destroy_lock);
 534         kfree_rcu(block, rcu);
 535 }
 536
 537 static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
 538 {
 539         struct tcf_block *block = chain->block;
 540
 541         mutex_destroy(&chain->filter_chain_lock);
 542         kfree_rcu(chain, rcu);
 543         if (free_block)
 544                 tcf_block_destroy(block);
 545 }
 546
 547 static void tcf_chain_hold(struct tcf_chain *chain)
 548 {
 549         ASSERT_BLOCK_LOCKED(chain->block);
 550
 551         ++chain->refcnt;
 552 }
 553
 554 static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain)
 555 {
 556         ASSERT_BLOCK_LOCKED(chain->block);
 557
 558         /* In case all the references are action references, this
 559          * chain should not be shown to the user.
 560          */
 561         return chain->refcnt == chain->action_refcnt;
 562 }
 563
 564 static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
 565                                           u32 chain_index)
 566 {
 567         struct tcf_chain *chain;
 568
 569         ASSERT_BLOCK_LOCKED(block);
 570
 571         list_for_each_entry(chain, &block->chain_list, list) {
 572                 if (chain->index == chain_index)
 573                         return chain;
 574         }
 575         return NULL;
 576 }
 577
 578 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 579 static struct tcf_chain *tcf_chain_lookup_rcu(const struct tcf_block *block,
 580                                               u32 chain_index)
 581 {
 582         struct tcf_chain *chain;
 583
 584         list_for_each_entry_rcu(chain, &block->chain_list, list) {
 585                 if (chain->index == chain_index)
 586                         return chain;
 587         }
 588         return NULL;
 589 }
 590 #endif
 591
 592 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 593                            u32 seq, u16 flags, int event, bool unicast,
 594                            struct netlink_ext_ack *extack);
 595
 596 static struct tcf_chain *__tcf_chain_get(struct tcf_block *block,
 597                                          u32 chain_index, bool create,
 598                                          bool by_act)
 599 {
 600         struct tcf_chain *chain = NULL;
 601         bool is_first_reference;
 602
 603         mutex_lock(&block->lock);
 604         chain = tcf_chain_lookup(block, chain_index);
 605         if (chain) {
 606                 tcf_chain_hold(chain);
 607         } else {
 608                 if (!create)
 609                         goto errout;
 610                 chain = tcf_chain_create(block, chain_index);
 611                 if (!chain)
 612                         goto errout;
 613         }
 614
 615         if (by_act)
 616                 ++chain->action_refcnt;
 617         is_first_reference = chain->refcnt - chain->action_refcnt == 1;
 618         mutex_unlock(&block->lock);
 619
 620         /* Send notification only in case we got the first
 621          * non-action reference. Until then, the chain acts only as
 622          * a placeholder for actions pointing to it and user ought
 623          * not know about them.
 624          */
 625         if (is_first_reference && !by_act)
 626                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
 627                                 RTM_NEWCHAIN, false, NULL);
 628
 629         return chain;
 630
 631 errout:
 632         mutex_unlock(&block->lock);
 633         return chain;
 634 }
 635
 636 static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 637                                        bool create)
 638 {
 639         return __tcf_chain_get(block, chain_index, create, false);
 640 }
 641
 642 struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index)
 643 {
 644         return __tcf_chain_get(block, chain_index, true, true);
 645 }
 646 EXPORT_SYMBOL(tcf_chain_get_by_act);
 647
 648 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
 649                                void *tmplt_priv);
 650 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
 651                                   void *tmplt_priv, u32 chain_index,
 652                                   struct tcf_block *block, struct sk_buff *oskb,
 653                                   u32 seq, u16 flags, bool unicast);
 654
 655 static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
 656                             bool explicitly_created)
 657 {
 658         struct tcf_block *block = chain->block;
 659         const struct tcf_proto_ops *tmplt_ops;
 660         unsigned int refcnt, non_act_refcnt;
 661         bool free_block = false;
 662         void *tmplt_priv;
 663
 664         mutex_lock(&block->lock);
 665         if (explicitly_created) {
 666                 if (!chain->explicitly_created) {
 667                         mutex_unlock(&block->lock);
 668                         return;
 669                 }
 670                 chain->explicitly_created = false;
 671         }
 672
 673         if (by_act)
 674                 chain->action_refcnt--;
 675
 676         /* tc_chain_notify_delete can't be called while holding block lock.
 677          * However, when block is unlocked chain can be changed concurrently, so
 678          * save these to temporary variables.
 679          */
 680         refcnt = --chain->refcnt;
 681         non_act_refcnt = refcnt - chain->action_refcnt;
 682         tmplt_ops = chain->tmplt_ops;
 683         tmplt_priv = chain->tmplt_priv;
 684
 685         if (non_act_refcnt == chain->explicitly_created && !by_act) {
 686                 if (non_act_refcnt == 0)
 687                         tc_chain_notify_delete(tmplt_ops, tmplt_priv,
 688                                                chain->index, block, NULL, 0, 0,
 689                                                false);
 690                 /* Last reference to chain, no need to lock. */
 691                 chain->flushing = false;
 692         }
 693
 694         if (refcnt == 0)
 695                 free_block = tcf_chain_detach(chain);
 696         mutex_unlock(&block->lock);
 697
 698         if (refcnt == 0) {
 699                 tc_chain_tmplt_del(tmplt_ops, tmplt_priv);
 700                 tcf_chain_destroy(chain, free_block);
 701         }
 702 }
 703
 704 static void tcf_chain_put(struct tcf_chain *chain)
 705 {
 706         __tcf_chain_put(chain, false, false);
 707 }
 708
 709 void tcf_chain_put_by_act(struct tcf_chain *chain)
 710 {
 711         __tcf_chain_put(chain, true, false);
 712 }
 713 EXPORT_SYMBOL(tcf_chain_put_by_act);
 714
 715 static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 716 {
 717         __tcf_chain_put(chain, false, true);
 718 }
 719
 720 static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
 721 {
 722         struct tcf_proto *tp, *tp_next;
 723
 724         mutex_lock(&chain->filter_chain_lock);
 725         tp = tcf_chain_dereference(chain->filter_chain, chain);
 726         while (tp) {
 727                 tp_next = rcu_dereference_protected(tp->next, 1);
 728                 tcf_proto_signal_destroying(chain, tp);
 729                 tp = tp_next;
 730         }
 731         tp = tcf_chain_dereference(chain->filter_chain, chain);
 732         RCU_INIT_POINTER(chain->filter_chain, NULL);
 733         tcf_chain0_head_change(chain, NULL);
 734         chain->flushing = true;
 735         mutex_unlock(&chain->filter_chain_lock);
 736
 737         while (tp) {
 738                 tp_next = rcu_dereference_protected(tp->next, 1);
 739                 tcf_proto_put(tp, rtnl_held, NULL);
 740                 tp = tp_next;
 741         }
 742 }
 743
 744 static int tcf_block_setup(struct tcf_block *block,
 745                            struct flow_block_offload *bo);
 746
 747 static void tcf_block_offload_init(struct flow_block_offload *bo,
 748                                    struct net_device *dev, struct Qdisc *sch,
 749                                    enum flow_block_command command,
 750                                    enum flow_block_binder_type binder_type,
 751                                    struct flow_block *flow_block,
 752                                    bool shared, struct netlink_ext_ack *extack)
 753 {
 754         bo->net = dev_net(dev);
 755         bo->command = command;
 756         bo->binder_type = binder_type;
 757         bo->block = flow_block;
 758         bo->block_shared = shared;
 759         bo->extack = extack;
 760         bo->sch = sch;
 761         bo->cb_list_head = &flow_block->cb_list;
 762         INIT_LIST_HEAD(&bo->cb_list);
 763 }
 764
 765 static void tcf_block_unbind(struct tcf_block *block,
 766                              struct flow_block_offload *bo);
 767
 768 static void tc_block_indr_cleanup(struct flow_block_cb *block_cb)
 769 {
 770         struct tcf_block *block = block_cb->indr.data;
 771         struct net_device *dev = block_cb->indr.dev;
 772         struct Qdisc *sch = block_cb->indr.sch;
 773         struct netlink_ext_ack extack = {};
 774         struct flow_block_offload bo = {};
 775
 776         tcf_block_offload_init(&bo, dev, sch, FLOW_BLOCK_UNBIND,
 777                                block_cb->indr.binder_type,
 778                                &block->flow_block, tcf_block_shared(block),
 779                                &extack);
 780         rtnl_lock();
 781         down_write(&block->cb_lock);
 782         list_del(&block_cb->driver_list);
 783         list_move(&block_cb->list, &bo.cb_list);
 784         tcf_block_unbind(block, &bo);
 785         up_write(&block->cb_lock);
 786         rtnl_unlock();
 787 }
 788
 789 static bool tcf_block_offload_in_use(struct tcf_block *block)
 790 {
 791         return atomic_read(&block->offloadcnt);
 792 }
 793
 794 static int tcf_block_offload_cmd(struct tcf_block *block,
 795                                  struct net_device *dev, struct Qdisc *sch,
 796                                  struct tcf_block_ext_info *ei,
 797                                  enum flow_block_command command,
 798                                  struct netlink_ext_ack *extack)
 799 {
 800         struct flow_block_offload bo = {};
 801
 802         tcf_block_offload_init(&bo, dev, sch, command, ei->binder_type,
 803                                &block->flow_block, tcf_block_shared(block),
 804                                extack);
 805
 806         if (dev->netdev_ops->ndo_setup_tc) {
 807                 int err;
 808
 809                 err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 810                 if (err < 0) {
 811                         if (err != -EOPNOTSUPP)
 812                                 NL_SET_ERR_MSG(extack, "Driver ndo_setup_tc failed");
 813                         return err;
 814                 }
 815
 816                 return tcf_block_setup(block, &bo);
 817         }
 818
 819         flow_indr_dev_setup_offload(dev, sch, TC_SETUP_BLOCK, block, &bo,
 820                                     tc_block_indr_cleanup);
 821         tcf_block_setup(block, &bo);
 822
 823         return -EOPNOTSUPP;
 824 }
 825
 826 static int tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
 827                                   struct tcf_block_ext_info *ei,
 828                                   struct netlink_ext_ack *extack)
 829 {
 830         struct net_device *dev = q->dev_queue->dev;
 831         int err;
 832
 833         down_write(&block->cb_lock);
 834
 835         /* If tc offload feature is disabled and the block we try to bind
 836          * to already has some offloaded filters, forbid to bind.
 837          */
 838         if (dev->netdev_ops->ndo_setup_tc &&
 839             !tc_can_offload(dev) &&
 840             tcf_block_offload_in_use(block)) {
 841                 NL_SET_ERR_MSG(extack, "Bind to offloaded block failed as dev has offload disabled");
 842                 err = -EOPNOTSUPP;
 843                 goto err_unlock;
 844         }
 845
 846         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_BIND, extack);
 847         if (err == -EOPNOTSUPP)
 848                 goto no_offload_dev_inc;
 849         if (err)
 850                 goto err_unlock;
 851
 852         up_write(&block->cb_lock);
 853         return 0;
 854
 855 no_offload_dev_inc:
 856         if (tcf_block_offload_in_use(block))
 857                 goto err_unlock;
 858
 859         err = 0;
 860         block->nooffloaddevcnt++;
 861 err_unlock:
 862         up_write(&block->cb_lock);
 863         return err;
 864 }
 865
 866 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
 867                                      struct tcf_block_ext_info *ei)
 868 {
 869         struct net_device *dev = q->dev_queue->dev;
 870         int err;
 871
 872         down_write(&block->cb_lock);
 873         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_UNBIND, NULL);
 874         if (err == -EOPNOTSUPP)
 875                 goto no_offload_dev_dec;
 876         up_write(&block->cb_lock);
 877         return;
 878
 879 no_offload_dev_dec:
 880         WARN_ON(block->nooffloaddevcnt-- == 0);
 881         up_write(&block->cb_lock);
 882 }
 883
 884 static int
 885 tcf_chain0_head_change_cb_add(struct tcf_block *block,
 886                               struct tcf_block_ext_info *ei,
 887                               struct netlink_ext_ack *extack)
 888 {
 889         struct tcf_filter_chain_list_item *item;
 890         struct tcf_chain *chain0;
 891
 892         item = kmalloc(sizeof(*item), GFP_KERNEL);
 893         if (!item) {
 894                 NL_SET_ERR_MSG(extack, "Memory allocation for head change callback item failed");
 895                 return -ENOMEM;
 896         }
 897         item->chain_head_change = ei->chain_head_change;
 898         item->chain_head_change_priv = ei->chain_head_change_priv;
 899
 900         mutex_lock(&block->lock);
 901         chain0 = block->chain0.chain;
 902         if (chain0)
 903                 tcf_chain_hold(chain0);
 904         else
 905                 list_add(&item->list, &block->chain0.filter_chain_list);
 906         mutex_unlock(&block->lock);
 907
 908         if (chain0) {
 909                 struct tcf_proto *tp_head;
 910
 911                 mutex_lock(&chain0->filter_chain_lock);
 912
 913                 tp_head = tcf_chain_dereference(chain0->filter_chain, chain0);
 914                 if (tp_head)
 915                         tcf_chain_head_change_item(item, tp_head);
 916
 917                 mutex_lock(&block->lock);
 918                 list_add(&item->list, &block->chain0.filter_chain_list);
 919                 mutex_unlock(&block->lock);
 920
 921                 mutex_unlock(&chain0->filter_chain_lock);
 922                 tcf_chain_put(chain0);
 923         }
 924
 925         return 0;
 926 }
 927
 928 static void
 929 tcf_chain0_head_change_cb_del(struct tcf_block *block,
 930                               struct tcf_block_ext_info *ei)
 931 {
 932         struct tcf_filter_chain_list_item *item;
 933
 934         mutex_lock(&block->lock);
 935         list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
 936                 if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
 937                     (item->chain_head_change == ei->chain_head_change &&
 938                      item->chain_head_change_priv == ei->chain_head_change_priv)) {
 939                         if (block->chain0.chain)
 940                                 tcf_chain_head_change_item(item, NULL);
 941                         list_del(&item->list);
 942                         mutex_unlock(&block->lock);
 943
 944                         kfree(item);
 945                         return;
 946                 }
 947         }
 948         mutex_unlock(&block->lock);
 949         WARN_ON(1);
 950 }
 951
 952 struct tcf_net {
 953         spinlock_t idr_lock; /* Protects idr */
 954         struct idr idr;
 955 };
 956
 957 static unsigned int tcf_net_id;
 958
 959 static int tcf_block_insert(struct tcf_block *block, struct net *net,
 960                             struct netlink_ext_ack *extack)
 961 {
 962         struct tcf_net *tn = net_generic(net, tcf_net_id);
 963         int err;
 964
 965         idr_preload(GFP_KERNEL);
 966         spin_lock(&tn->idr_lock);
 967         err = idr_alloc_u32(&tn->idr, block, &block->index, block->index,
 968                             GFP_NOWAIT);
 969         spin_unlock(&tn->idr_lock);
 970         idr_preload_end();
 971
 972         return err;
 973 }
 974
 975 static void tcf_block_remove(struct tcf_block *block, struct net *net)
 976 {
 977         struct tcf_net *tn = net_generic(net, tcf_net_id);
 978
 979         spin_lock(&tn->idr_lock);
 980         idr_remove(&tn->idr, block->index);
 981         spin_unlock(&tn->idr_lock);
 982 }
 983
 984 static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 985                                           u32 block_index,
 986                                           struct netlink_ext_ack *extack)
 987 {
 988         struct tcf_block *block;
 989
 990         block = kzalloc(sizeof(*block), GFP_KERNEL);
 991         if (!block) {
 992                 NL_SET_ERR_MSG(extack, "Memory allocation for block failed");
 993                 return ERR_PTR(-ENOMEM);
 994         }
 995         mutex_init(&block->lock);
 996         mutex_init(&block->proto_destroy_lock);
 997         init_rwsem(&block->cb_lock);
 998         flow_block_init(&block->flow_block);
 999         INIT_LIST_HEAD(&block->chain_list);
1000         INIT_LIST_HEAD(&block->owner_list);
1001         INIT_LIST_HEAD(&block->chain0.filter_chain_list);
1002
1003         refcount_set(&block->refcnt, 1);
1004         block->net = net;
1005         block->index = block_index;
1006
1007         /* Don't store q pointer for blocks which are shared */
1008         if (!tcf_block_shared(block))
1009                 block->q = q;
1010         return block;
1011 }
1012
1013 static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
1014 {
1015         struct tcf_net *tn = net_generic(net, tcf_net_id);
1016
1017         return idr_find(&tn->idr, block_index);
1018 }
1019
1020 static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
1021 {
1022         struct tcf_block *block;
1023
1024         rcu_read_lock();
1025         block = tcf_block_lookup(net, block_index);
1026         if (block && !refcount_inc_not_zero(&block->refcnt))
1027                 block = NULL;
1028         rcu_read_unlock();
1029
1030         return block;
1031 }
1032
1033 static struct tcf_chain *
1034 __tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
1035 {
1036         mutex_lock(&block->lock);
1037         if (chain)
1038                 chain = list_is_last(&chain->list, &block->chain_list) ?
1039                         NULL : list_next_entry(chain, list);
1040         else
1041                 chain = list_first_entry_or_null(&block->chain_list,
1042                                                  struct tcf_chain, list);
1043
1044         /* skip all action-only chains */
1045         while (chain && tcf_chain_held_by_acts_only(chain))
1046                 chain = list_is_last(&chain->list, &block->chain_list) ?
1047                         NULL : list_next_entry(chain, list);
1048
1049         if (chain)
1050                 tcf_chain_hold(chain);
1051         mutex_unlock(&block->lock);
1052
1053         return chain;
1054 }
1055
1056 /* Function to be used by all clients that want to iterate over all chains on
1057  * block. It properly obtains block->lock and takes reference to chain before
1058  * returning it. Users of this function must be tolerant to concurrent chain
1059  * insertion/deletion or ensure that no concurrent chain modification is
1060  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1061  * consistent dump because rtnl lock is released each time skb is filled with
1062  * data and sent to user-space.
1063  */
1064
1065 struct tcf_chain *
1066 tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
1067 {
1068         struct tcf_chain *chain_next = __tcf_get_next_chain(block, chain);
1069
1070         if (chain)
1071                 tcf_chain_put(chain);
1072
1073         return chain_next;
1074 }
1075 EXPORT_SYMBOL(tcf_get_next_chain);
1076
1077 static struct tcf_proto *
1078 __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
1079 {
1080         u32 prio = 0;
1081
1082         ASSERT_RTNL();
1083         mutex_lock(&chain->filter_chain_lock);
1084
1085         if (!tp) {
1086                 tp = tcf_chain_dereference(chain->filter_chain, chain);
1087         } else if (tcf_proto_is_deleting(tp)) {
1088                 /* 'deleting' flag is set and chain->filter_chain_lock was
1089                  * unlocked, which means next pointer could be invalid. Restart
1090                  * search.
1091                  */
1092                 prio = tp->prio + 1;
1093                 tp = tcf_chain_dereference(chain->filter_chain, chain);
1094
1095                 for (; tp; tp = tcf_chain_dereference(tp->next, chain))
1096                         if (!tp->deleting && tp->prio >= prio)
1097                                 break;
1098         } else {
1099                 tp = tcf_chain_dereference(tp->next, chain);
1100         }
1101
1102         if (tp)
1103                 tcf_proto_get(tp);
1104
1105         mutex_unlock(&chain->filter_chain_lock);
1106
1107         return tp;
1108 }
1109
1110 /* Function to be used by all clients that want to iterate over all tp's on
1111  * chain. Users of this function must be tolerant to concurrent tp
1112  * insertion/deletion or ensure that no concurrent chain modification is
1113  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1114  * consistent dump because rtnl lock is released each time skb is filled with
1115  * data and sent to user-space.
1116  */
1117
1118 struct tcf_proto *
1119 tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
1120 {
1121         struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
1122
1123         if (tp)
1124                 tcf_proto_put(tp, true, NULL);
1125
1126         return tp_next;
1127 }
1128 EXPORT_SYMBOL(tcf_get_next_proto);
1129
1130 static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
1131 {
1132         struct tcf_chain *chain;
1133
1134         /* Last reference to block. At this point chains cannot be added or
1135          * removed concurrently.
1136          */
1137         for (chain = tcf_get_next_chain(block, NULL);
1138              chain;
1139              chain = tcf_get_next_chain(block, chain)) {
1140                 tcf_chain_put_explicitly_created(chain);
1141                 tcf_chain_flush(chain, rtnl_held);
1142         }
1143 }
1144
1145 /* Lookup Qdisc and increments its reference counter.
1146  * Set parent, if necessary.
1147  */
1148
1149 static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
1150                             u32 *parent, int ifindex, bool rtnl_held,
1151                             struct netlink_ext_ack *extack)
1152 {
1153         const struct Qdisc_class_ops *cops;
1154         struct net_device *dev;
1155         int err = 0;
1156
1157         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1158                 return 0;
1159
1160         rcu_read_lock();
1161
1162         /* Find link */
1163         dev = dev_get_by_index_rcu(net, ifindex);
1164         if (!dev) {
1165                 rcu_read_unlock();
1166                 return -ENODEV;
1167         }
1168
1169         /* Find qdisc */
1170         if (!*parent) {
1171                 *q = rcu_dereference(dev->qdisc);
1172                 *parent = (*q)->handle;
1173         } else {
1174                 *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
1175                 if (!*q) {
1176                         NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1177                         err = -EINVAL;
1178                         goto errout_rcu;
1179                 }
1180         }
1181
1182         *q = qdisc_refcount_inc_nz(*q);
1183         if (!*q) {
1184                 NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1185                 err = -EINVAL;
1186                 goto errout_rcu;
1187         }
1188
1189         /* Is it classful? */
1190         cops = (*q)->ops->cl_ops;
1191         if (!cops) {
1192                 NL_SET_ERR_MSG(extack, "Qdisc not classful");
1193                 err = -EINVAL;
1194                 goto errout_qdisc;
1195         }
1196
1197         if (!cops->tcf_block) {
1198                 NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
1199                 err = -EOPNOTSUPP;
1200                 goto errout_qdisc;
1201         }
1202
1203 errout_rcu:
1204         /* At this point we know that qdisc is not noop_qdisc,
1205          * which means that qdisc holds a reference to net_device
1206          * and we hold a reference to qdisc, so it is safe to release
1207          * rcu read lock.
1208          */
1209         rcu_read_unlock();
1210         return err;
1211
1212 errout_qdisc:
1213         rcu_read_unlock();
1214
1215         if (rtnl_held)
1216                 qdisc_put(*q);
1217         else
1218                 qdisc_put_unlocked(*q);
1219         *q = NULL;
1220
1221         return err;
1222 }
1223
1224 static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
1225                                int ifindex, struct netlink_ext_ack *extack)
1226 {
1227         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1228                 return 0;
1229
1230         /* Do we search for filter, attached to class? */
1231         if (TC_H_MIN(parent)) {
1232                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1233
1234                 *cl = cops->find(q, parent);
1235                 if (*cl == 0) {
1236                         NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
1237                         return -ENOENT;
1238                 }
1239         }
1240
1241         return 0;
1242 }
1243
1244 static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
1245                                           unsigned long cl, int ifindex,
1246                                           u32 block_index,
1247                                           struct netlink_ext_ack *extack)
1248 {
1249         struct tcf_block *block;
1250
1251         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
1252                 block = tcf_block_refcnt_get(net, block_index);
1253                 if (!block) {
1254                         NL_SET_ERR_MSG(extack, "Block of given index was not found");
1255                         return ERR_PTR(-EINVAL);
1256                 }
1257         } else {
1258                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1259
1260                 block = cops->tcf_block(q, cl, extack);
1261                 if (!block)
1262                         return ERR_PTR(-EINVAL);
1263
1264                 if (tcf_block_shared(block)) {
1265                         NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
1266                         return ERR_PTR(-EOPNOTSUPP);
1267                 }
1268
1269                 /* Always take reference to block in order to support execution
1270                  * of rules update path of cls API without rtnl lock. Caller
1271                  * must release block when it is finished using it. 'if' block
1272                  * of this conditional obtain reference to block by calling
1273                  * tcf_block_refcnt_get().
1274                  */
1275                 refcount_inc(&block->refcnt);
1276         }
1277
1278         return block;
1279 }
1280
1281 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
1282                             struct tcf_block_ext_info *ei, bool rtnl_held)
1283 {
1284         if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
1285                 /* Flushing/putting all chains will cause the block to be
1286                  * deallocated when last chain is freed. However, if chain_list
1287                  * is empty, block has to be manually deallocated. After block
1288                  * reference counter reached 0, it is no longer possible to
1289                  * increment it or add new chains to block.
1290                  */
1291                 bool free_block = list_empty(&block->chain_list);
1292
1293                 mutex_unlock(&block->lock);
1294                 if (tcf_block_shared(block))
1295                         tcf_block_remove(block, block->net);
1296
1297                 if (q)
1298                         tcf_block_offload_unbind(block, q, ei);
1299
1300                 if (free_block)
1301                         tcf_block_destroy(block);
1302                 else
1303                         tcf_block_flush_all_chains(block, rtnl_held);
1304         } else if (q) {
1305                 tcf_block_offload_unbind(block, q, ei);
1306         }
1307 }
1308
1309 static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
1310 {
1311         __tcf_block_put(block, NULL, NULL, rtnl_held);
1312 }
1313
1314 /* Find tcf block.
1315  * Set q, parent, cl when appropriate.
1316  */
1317
1318 static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
1319                                         u32 *parent, unsigned long *cl,
1320                                         int ifindex, u32 block_index,
1321                                         struct netlink_ext_ack *extack)
1322 {
1323         struct tcf_block *block;
1324         int err = 0;
1325
1326         ASSERT_RTNL();
1327
1328         err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
1329         if (err)
1330                 goto errout;
1331
1332         err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
1333         if (err)
1334                 goto errout_qdisc;
1335
1336         block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
1337         if (IS_ERR(block)) {
1338                 err = PTR_ERR(block);
1339                 goto errout_qdisc;
1340         }
1341
1342         return block;
1343
1344 errout_qdisc:
1345         if (*q)
1346                 qdisc_put(*q);
1347 errout:
1348         *q = NULL;
1349         return ERR_PTR(err);
1350 }
1351
1352 static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
1353                               bool rtnl_held)
1354 {
1355         if (!IS_ERR_OR_NULL(block))
1356                 tcf_block_refcnt_put(block, rtnl_held);
1357
1358         if (q) {
1359                 if (rtnl_held)
1360                         qdisc_put(q);
1361                 else
1362                         qdisc_put_unlocked(q);
1363         }
1364 }
1365
1366 struct tcf_block_owner_item {
1367         struct list_head list;
1368         struct Qdisc *q;
1369         enum flow_block_binder_type binder_type;
1370 };
1371
1372 static void
1373 tcf_block_owner_netif_keep_dst(struct tcf_block *block,
1374                                struct Qdisc *q,
1375                                enum flow_block_binder_type binder_type)
1376 {
1377         if (block->keep_dst &&
1378             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS &&
1379             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
1380                 netif_keep_dst(qdisc_dev(q));
1381 }
1382
1383 void tcf_block_netif_keep_dst(struct tcf_block *block)
1384 {
1385         struct tcf_block_owner_item *item;
1386
1387         block->keep_dst = true;
1388         list_for_each_entry(item, &block->owner_list, list)
1389                 tcf_block_owner_netif_keep_dst(block, item->q,
1390                                                item->binder_type);
1391 }
1392 EXPORT_SYMBOL(tcf_block_netif_keep_dst);
1393
1394 static int tcf_block_owner_add(struct tcf_block *block,
1395                                struct Qdisc *q,
1396                                enum flow_block_binder_type binder_type)
1397 {
1398         struct tcf_block_owner_item *item;
1399
1400         item = kmalloc(sizeof(*item), GFP_KERNEL);
1401         if (!item)
1402                 return -ENOMEM;
1403         item->q = q;
1404         item->binder_type = binder_type;
1405         list_add(&item->list, &block->owner_list);
1406         return 0;
1407 }
1408
1409 static void tcf_block_owner_del(struct tcf_block *block,
1410                                 struct Qdisc *q,
1411                                 enum flow_block_binder_type binder_type)
1412 {
1413         struct tcf_block_owner_item *item;
1414
1415         list_for_each_entry(item, &block->owner_list, list) {
1416                 if (item->q == q && item->binder_type == binder_type) {
1417                         list_del(&item->list);
1418                         kfree(item);
1419                         return;
1420                 }
1421         }
1422         WARN_ON(1);
1423 }
1424
1425 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
1426                       struct tcf_block_ext_info *ei,
1427                       struct netlink_ext_ack *extack)
1428 {
1429         struct net *net = qdisc_net(q);
1430         struct tcf_block *block = NULL;
1431         int err;
1432
1433         if (ei->block_index)
1434                 /* block_index not 0 means the shared block is requested */
1435                 block = tcf_block_refcnt_get(net, ei->block_index);
1436
1437         if (!block) {
1438                 block = tcf_block_create(net, q, ei->block_index, extack);
1439                 if (IS_ERR(block))
1440                         return PTR_ERR(block);
1441                 if (tcf_block_shared(block)) {
1442                         err = tcf_block_insert(block, net, extack);
1443                         if (err)
1444                                 goto err_block_insert;
1445                 }
1446         }
1447
1448         err = tcf_block_owner_add(block, q, ei->binder_type);
1449         if (err)
1450                 goto err_block_owner_add;
1451
1452         tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
1453
1454         err = tcf_chain0_head_change_cb_add(block, ei, extack);
1455         if (err)
1456                 goto err_chain0_head_change_cb_add;
1457
1458         err = tcf_block_offload_bind(block, q, ei, extack);
1459         if (err)
1460                 goto err_block_offload_bind;
1461
1462         *p_block = block;
1463         return 0;
1464
1465 err_block_offload_bind:
1466         tcf_chain0_head_change_cb_del(block, ei);
1467 err_chain0_head_change_cb_add:
1468         tcf_block_owner_del(block, q, ei->binder_type);
1469 err_block_owner_add:
1470 err_block_insert:
1471         tcf_block_refcnt_put(block, true);
1472         return err;
1473 }
1474 EXPORT_SYMBOL(tcf_block_get_ext);
1475
1476 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
1477 {
1478         struct tcf_proto __rcu **p_filter_chain = priv;
1479
1480         rcu_assign_pointer(*p_filter_chain, tp_head);
1481 }
1482
1483 int tcf_block_get(struct tcf_block **p_block,
1484                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
1485                   struct netlink_ext_ack *extack)
1486 {
1487         struct tcf_block_ext_info ei = {
1488                 .chain_head_change = tcf_chain_head_change_dflt,
1489                 .chain_head_change_priv = p_filter_chain,
1490         };
1491
1492         WARN_ON(!p_filter_chain);
1493         return tcf_block_get_ext(p_block, q, &ei, extack);
1494 }
1495 EXPORT_SYMBOL(tcf_block_get);
1496
1497 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
1498  * actions should be all removed after flushing.
1499  */
1500 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
1501                        struct tcf_block_ext_info *ei)
1502 {
1503         if (!block)
1504                 return;
1505         tcf_chain0_head_change_cb_del(block, ei);
1506         tcf_block_owner_del(block, q, ei->binder_type);
1507
1508         __tcf_block_put(block, q, ei, true);
1509 }
1510 EXPORT_SYMBOL(tcf_block_put_ext);
1511
1512 void tcf_block_put(struct tcf_block *block)
1513 {
1514         struct tcf_block_ext_info ei = {0, };
1515
1516         if (!block)
1517                 return;
1518         tcf_block_put_ext(block, block->q, &ei);
1519 }
1520
1521 EXPORT_SYMBOL(tcf_block_put);
1522
1523 static int
1524 tcf_block_playback_offloads(struct tcf_block *block, flow_setup_cb_t *cb,
1525                             void *cb_priv, bool add, bool offload_in_use,
1526                             struct netlink_ext_ack *extack)
1527 {
1528         struct tcf_chain *chain, *chain_prev;
1529         struct tcf_proto *tp, *tp_prev;
1530         int err;
1531
1532         lockdep_assert_held(&block->cb_lock);
1533
1534         for (chain = __tcf_get_next_chain(block, NULL);
1535              chain;
1536              chain_prev = chain,
1537                      chain = __tcf_get_next_chain(block, chain),
1538                      tcf_chain_put(chain_prev)) {
1539                 for (tp = __tcf_get_next_proto(chain, NULL); tp;
1540                      tp_prev = tp,
1541                              tp = __tcf_get_next_proto(chain, tp),
1542                              tcf_proto_put(tp_prev, true, NULL)) {
1543                         if (tp->ops->reoffload) {
1544                                 err = tp->ops->reoffload(tp, add, cb, cb_priv,
1545                                                          extack);
1546                                 if (err && add)
1547                                         goto err_playback_remove;
1548                         } else if (add && offload_in_use) {
1549                                 err = -EOPNOTSUPP;
1550                                 NL_SET_ERR_MSG(extack, "Filter HW offload failed - classifier without re-offloading support");
1551                                 goto err_playback_remove;
1552                         }
1553                 }
1554         }
1555
1556         return 0;
1557
1558 err_playback_remove:
1559         tcf_proto_put(tp, true, NULL);
1560         tcf_chain_put(chain);
1561         tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
1562                                     extack);
1563         return err;
1564 }
1565
1566 static int tcf_block_bind(struct tcf_block *block,
1567                           struct flow_block_offload *bo)
1568 {
1569         struct flow_block_cb *block_cb, *next;
1570         int err, i = 0;
1571
1572         lockdep_assert_held(&block->cb_lock);
1573
1574         list_for_each_entry(block_cb, &bo->cb_list, list) {
1575                 err = tcf_block_playback_offloads(block, block_cb->cb,
1576                                                   block_cb->cb_priv, true,
1577                                                   tcf_block_offload_in_use(block),
1578                                                   bo->extack);
1579                 if (err)
1580                         goto err_unroll;
1581                 if (!bo->unlocked_driver_cb)
1582                         block->lockeddevcnt++;
1583
1584                 i++;
1585         }
1586         list_splice(&bo->cb_list, &block->flow_block.cb_list);
1587
1588         return 0;
1589
1590 err_unroll:
1591         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1592                 list_del(&block_cb->driver_list);
1593                 if (i-- > 0) {
1594                         list_del(&block_cb->list);
1595                         tcf_block_playback_offloads(block, block_cb->cb,
1596                                                     block_cb->cb_priv, false,
1597                                                     tcf_block_offload_in_use(block),
1598                                                     NULL);
1599                         if (!bo->unlocked_driver_cb)
1600                                 block->lockeddevcnt--;
1601                 }
1602                 flow_block_cb_free(block_cb);
1603         }
1604
1605         return err;
1606 }
1607
1608 static void tcf_block_unbind(struct tcf_block *block,
1609                              struct flow_block_offload *bo)
1610 {
1611         struct flow_block_cb *block_cb, *next;
1612
1613         lockdep_assert_held(&block->cb_lock);
1614
1615         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1616                 tcf_block_playback_offloads(block, block_cb->cb,
1617                                             block_cb->cb_priv, false,
1618                                             tcf_block_offload_in_use(block),
1619                                             NULL);
1620                 list_del(&block_cb->list);
1621                 flow_block_cb_free(block_cb);
1622                 if (!bo->unlocked_driver_cb)
1623                         block->lockeddevcnt--;
1624         }
1625 }
1626
1627 static int tcf_block_setup(struct tcf_block *block,
1628                            struct flow_block_offload *bo)
1629 {
1630         int err;
1631
1632         switch (bo->command) {
1633         case FLOW_BLOCK_BIND:
1634                 err = tcf_block_bind(block, bo);
1635                 break;
1636         case FLOW_BLOCK_UNBIND:
1637                 err = 0;
1638                 tcf_block_unbind(block, bo);
1639                 break;
1640         default:
1641                 WARN_ON_ONCE(1);
1642                 err = -EOPNOTSUPP;
1643         }
1644
1645         return err;
1646 }
1647
1648 /* Main classifier routine: scans classifier chain attached
1649  * to this qdisc, (optionally) tests for protocol and asks
1650  * specific classifiers.
1651  */
1652 static inline int __tcf_classify(struct sk_buff *skb,
1653                                  const struct tcf_proto *tp,
1654                                  const struct tcf_proto *orig_tp,
1655                                  struct tcf_result *res,
1656                                  bool compat_mode,
1657                                  struct tcf_exts_miss_cookie_node *n,
1658                                  int act_index,
1659                                  u32 *last_executed_chain)
1660 {
1661 #ifdef CONFIG_NET_CLS_ACT
1662         const int max_reclassify_loop = 16;
1663         const struct tcf_proto *first_tp;
1664         int limit = 0;
1665
1666 reclassify:
1667 #endif
1668         for (; tp; tp = rcu_dereference_bh(tp->next)) {
1669                 __be16 protocol = skb_protocol(skb, false);
1670                 int err = 0;
1671
1672                 if (n) {
1673                         struct tcf_exts *exts;
1674
1675                         if (n->tp_prio != tp->prio)
1676                                 continue;
1677
1678                         /* We re-lookup the tp and chain based on index instead
1679                          * of having hard refs and locks to them, so do a sanity
1680                          * check if any of tp,chain,exts was replaced by the
1681                          * time we got here with a cookie from hardware.
1682                          */
1683                         if (unlikely(n->tp != tp || n->tp->chain != n->chain ||
1684                                      !tp->ops->get_exts))
1685                                 return TC_ACT_SHOT;
1686
1687                         exts = tp->ops->get_exts(tp, n->handle);
1688                         if (unlikely(!exts || n->exts != exts))
1689                                 return TC_ACT_SHOT;
1690
1691                         n = NULL;
1692                         err = tcf_exts_exec_ex(skb, exts, act_index, res);
1693                 } else {
1694                         if (tp->protocol != protocol &&
1695                             tp->protocol != htons(ETH_P_ALL))
1696                                 continue;
1697
1698                         err = tc_classify(skb, tp, res);
1699                 }
1700 #ifdef CONFIG_NET_CLS_ACT
1701                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
1702                         first_tp = orig_tp;
1703                         *last_executed_chain = first_tp->chain->index;
1704                         goto reset;
1705                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
1706                         first_tp = res->goto_tp;
1707                         *last_executed_chain = err & TC_ACT_EXT_VAL_MASK;
1708                         goto reset;
1709                 }
1710 #endif
1711                 if (err >= 0)
1712                         return err;
1713         }
1714
1715         if (unlikely(n))
1716                 return TC_ACT_SHOT;
1717
1718         return TC_ACT_UNSPEC; /* signal: continue lookup */
1719 #ifdef CONFIG_NET_CLS_ACT
1720 reset:
1721         if (unlikely(limit++ >= max_reclassify_loop)) {
1722                 net_notice_ratelimited("%u: reclassify loop, rule prio %u, protocol %02x\n",
1723                                        tp->chain->block->index,
1724                                        tp->prio & 0xffff,
1725                                        ntohs(tp->protocol));
1726                 return TC_ACT_SHOT;
1727         }
1728
1729         tp = first_tp;
1730         goto reclassify;
1731 #endif
1732 }
1733
1734 int tcf_classify(struct sk_buff *skb,
1735                  const struct tcf_block *block,
1736                  const struct tcf_proto *tp,
1737                  struct tcf_result *res, bool compat_mode)
1738 {
1739 #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1740         u32 last_executed_chain = 0;
1741
1742         return __tcf_classify(skb, tp, tp, res, compat_mode, NULL, 0,
1743                               &last_executed_chain);
1744 #else
1745         u32 last_executed_chain = tp ? tp->chain->index : 0;
1746         struct tcf_exts_miss_cookie_node *n = NULL;
1747         const struct tcf_proto *orig_tp = tp;
1748         struct tc_skb_ext *ext;
1749         int act_index = 0;
1750         int ret;
1751
1752         if (block) {
1753                 ext = skb_ext_find(skb, TC_SKB_EXT);
1754
1755                 if (ext && (ext->chain || ext->act_miss)) {
1756                         struct tcf_chain *fchain;
1757                         u32 chain;
1758
1759                         if (ext->act_miss) {
1760                                 n = tcf_exts_miss_cookie_lookup(ext->act_miss_cookie,
1761                                                                 &act_index);
1762                                 if (!n)
1763                                         return TC_ACT_SHOT;
1764
1765                                 chain = n->chain_index;
1766                         } else {
1767                                 chain = ext->chain;
1768                         }
1769
1770                         fchain = tcf_chain_lookup_rcu(block, chain);
1771                         if (!fchain)
1772                                 return TC_ACT_SHOT;
1773
1774                         /* Consume, so cloned/redirect skbs won't inherit ext */
1775                         skb_ext_del(skb, TC_SKB_EXT);
1776
1777                         tp = rcu_dereference_bh(fchain->filter_chain);
1778                         last_executed_chain = fchain->index;
1779                 }
1780         }
1781
1782         ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode, n, act_index,
1783                              &last_executed_chain);
1784
1785         if (tc_skb_ext_tc_enabled()) {
1786                 /* If we missed on some chain */
1787                 if (ret == TC_ACT_UNSPEC && last_executed_chain) {
1788                         struct tc_skb_cb *cb = tc_skb_cb(skb);
1789
1790                         ext = tc_skb_ext_alloc(skb);
1791                         if (WARN_ON_ONCE(!ext))
1792                                 return TC_ACT_SHOT;
1793                         ext->chain = last_executed_chain;
1794                         ext->mru = cb->mru;
1795                         ext->post_ct = cb->post_ct;
1796                         ext->post_ct_snat = cb->post_ct_snat;
1797                         ext->post_ct_dnat = cb->post_ct_dnat;
1798                         ext->zone = cb->zone;
1799                 }
1800         }
1801
1802         return ret;
1803 #endif
1804 }
1805 EXPORT_SYMBOL(tcf_classify);
1806
1807 struct tcf_chain_info {
1808         struct tcf_proto __rcu **pprev;
1809         struct tcf_proto __rcu *next;
1810 };
1811
1812 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
1813                                            struct tcf_chain_info *chain_info)
1814 {
1815         return tcf_chain_dereference(*chain_info->pprev, chain);
1816 }
1817
1818 static int tcf_chain_tp_insert(struct tcf_chain *chain,
1819                                struct tcf_chain_info *chain_info,
1820                                struct tcf_proto *tp)
1821 {
1822         if (chain->flushing)
1823                 return -EAGAIN;
1824
1825         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
1826         if (*chain_info->pprev == chain->filter_chain)
1827                 tcf_chain0_head_change(chain, tp);
1828         tcf_proto_get(tp);
1829         rcu_assign_pointer(*chain_info->pprev, tp);
1830
1831         return 0;
1832 }
1833
1834 static void tcf_chain_tp_remove(struct tcf_chain *chain,
1835                                 struct tcf_chain_info *chain_info,
1836                                 struct tcf_proto *tp)
1837 {
1838         struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
1839
1840         tcf_proto_mark_delete(tp);
1841         if (tp == chain->filter_chain)
1842                 tcf_chain0_head_change(chain, next);
1843         RCU_INIT_POINTER(*chain_info->pprev, next);
1844 }
1845
1846 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1847                                            struct tcf_chain_info *chain_info,
1848                                            u32 protocol, u32 prio,
1849                                            bool prio_allocate);
1850
1851 /* Try to insert new proto.
1852  * If proto with specified priority already exists, free new proto
1853  * and return existing one.
1854  */
1855
1856 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
1857                                                     struct tcf_proto *tp_new,
1858                                                     u32 protocol, u32 prio,
1859                                                     bool rtnl_held)
1860 {
1861         struct tcf_chain_info chain_info;
1862         struct tcf_proto *tp;
1863         int err = 0;
1864
1865         mutex_lock(&chain->filter_chain_lock);
1866
1867         if (tcf_proto_exists_destroying(chain, tp_new)) {
1868                 mutex_unlock(&chain->filter_chain_lock);
1869                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1870                 return ERR_PTR(-EAGAIN);
1871         }
1872
1873         tp = tcf_chain_tp_find(chain, &chain_info,
1874                                protocol, prio, false);
1875         if (!tp)
1876                 err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
1877         mutex_unlock(&chain->filter_chain_lock);
1878
1879         if (tp) {
1880                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1881                 tp_new = tp;
1882         } else if (err) {
1883                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1884                 tp_new = ERR_PTR(err);
1885         }
1886
1887         return tp_new;
1888 }
1889
1890 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
1891                                       struct tcf_proto *tp, bool rtnl_held,
1892                                       struct netlink_ext_ack *extack)
1893 {
1894         struct tcf_chain_info chain_info;
1895         struct tcf_proto *tp_iter;
1896         struct tcf_proto **pprev;
1897         struct tcf_proto *next;
1898
1899         mutex_lock(&chain->filter_chain_lock);
1900
1901         /* Atomically find and remove tp from chain. */
1902         for (pprev = &chain->filter_chain;
1903              (tp_iter = tcf_chain_dereference(*pprev, chain));
1904              pprev = &tp_iter->next) {
1905                 if (tp_iter == tp) {
1906                         chain_info.pprev = pprev;
1907                         chain_info.next = tp_iter->next;
1908                         WARN_ON(tp_iter->deleting);
1909                         break;
1910                 }
1911         }
1912         /* Verify that tp still exists and no new filters were inserted
1913          * concurrently.
1914          * Mark tp for deletion if it is empty.
1915          */
1916         if (!tp_iter || !tcf_proto_check_delete(tp)) {
1917                 mutex_unlock(&chain->filter_chain_lock);
1918                 return;
1919         }
1920
1921         tcf_proto_signal_destroying(chain, tp);
1922         next = tcf_chain_dereference(chain_info.next, chain);
1923         if (tp == chain->filter_chain)
1924                 tcf_chain0_head_change(chain, next);
1925         RCU_INIT_POINTER(*chain_info.pprev, next);
1926         mutex_unlock(&chain->filter_chain_lock);
1927
1928         tcf_proto_put(tp, rtnl_held, extack);
1929 }
1930
1931 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1932                                            struct tcf_chain_info *chain_info,
1933                                            u32 protocol, u32 prio,
1934                                            bool prio_allocate)
1935 {
1936         struct tcf_proto **pprev;
1937         struct tcf_proto *tp;
1938
1939         /* Check the chain for existence of proto-tcf with this priority */
1940         for (pprev = &chain->filter_chain;
1941              (tp = tcf_chain_dereference(*pprev, chain));
1942              pprev = &tp->next) {
1943                 if (tp->prio >= prio) {
1944                         if (tp->prio == prio) {
1945                                 if (prio_allocate ||
1946                                     (tp->protocol != protocol && protocol))
1947                                         return ERR_PTR(-EINVAL);
1948                         } else {
1949                                 tp = NULL;
1950                         }
1951                         break;
1952                 }
1953         }
1954         chain_info->pprev = pprev;
1955         if (tp) {
1956                 chain_info->next = tp->next;
1957                 tcf_proto_get(tp);
1958         } else {
1959                 chain_info->next = NULL;
1960         }
1961         return tp;
1962 }
1963
1964 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
1965                          struct tcf_proto *tp, struct tcf_block *block,
1966                          struct Qdisc *q, u32 parent, void *fh,
1967                          u32 portid, u32 seq, u16 flags, int event,
1968                          bool terse_dump, bool rtnl_held,
1969                          struct netlink_ext_ack *extack)
1970 {
1971         struct tcmsg *tcm;
1972         struct nlmsghdr  *nlh;
1973         unsigned char *b = skb_tail_pointer(skb);
1974
1975         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1976         if (!nlh)
1977                 goto out_nlmsg_trim;
1978         tcm = nlmsg_data(nlh);
1979         tcm->tcm_family = AF_UNSPEC;
1980         tcm->tcm__pad1 = 0;
1981         tcm->tcm__pad2 = 0;
1982         if (q) {
1983                 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1984                 tcm->tcm_parent = parent;
1985         } else {
1986                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
1987                 tcm->tcm_block_index = block->index;
1988         }
1989         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
1990         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
1991                 goto nla_put_failure;
1992         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
1993                 goto nla_put_failure;
1994         if (!fh) {
1995                 tcm->tcm_handle = 0;
1996         } else if (terse_dump) {
1997                 if (tp->ops->terse_dump) {
1998                         if (tp->ops->terse_dump(net, tp, fh, skb, tcm,
1999                                                 rtnl_held) < 0)
2000                                 goto nla_put_failure;
2001                 } else {
2002                         goto cls_op_not_supp;
2003                 }
2004         } else {
2005                 if (tp->ops->dump &&
2006                     tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
2007                         goto nla_put_failure;
2008         }
2009
2010         if (extack && extack->_msg &&
2011             nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
2012                 goto nla_put_failure;
2013
2014         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2015
2016         return skb->len;
2017
2018 out_nlmsg_trim:
2019 nla_put_failure:
2020 cls_op_not_supp:
2021         nlmsg_trim(skb, b);
2022         return -1;
2023 }
2024
2025 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
2026                           struct nlmsghdr *n, struct tcf_proto *tp,
2027                           struct tcf_block *block, struct Qdisc *q,
2028                           u32 parent, void *fh, int event, bool unicast,
2029                           bool rtnl_held, struct netlink_ext_ack *extack)
2030 {
2031         struct sk_buff *skb;
2032         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2033         int err = 0;
2034
2035         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2036         if (!skb)
2037                 return -ENOBUFS;
2038
2039         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
2040                           n->nlmsg_seq, n->nlmsg_flags, event,
2041                           false, rtnl_held, extack) <= 0) {
2042                 kfree_skb(skb);
2043                 return -EINVAL;
2044         }
2045
2046         if (unicast)
2047                 err = rtnl_unicast(skb, net, portid);
2048         else
2049                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2050                                      n->nlmsg_flags & NLM_F_ECHO);
2051         return err;
2052 }
2053
2054 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
2055                               struct nlmsghdr *n, struct tcf_proto *tp,
2056                               struct tcf_block *block, struct Qdisc *q,
2057                               u32 parent, void *fh, bool unicast, bool *last,
2058                               bool rtnl_held, struct netlink_ext_ack *extack)
2059 {
2060         struct sk_buff *skb;
2061         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2062         int err;
2063
2064         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2065         if (!skb)
2066                 return -ENOBUFS;
2067
2068         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
2069                           n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
2070                           false, rtnl_held, extack) <= 0) {
2071                 NL_SET_ERR_MSG(extack, "Failed to build del event notification");
2072                 kfree_skb(skb);
2073                 return -EINVAL;
2074         }
2075
2076         err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
2077         if (err) {
2078                 kfree_skb(skb);
2079                 return err;
2080         }
2081
2082         if (unicast)
2083                 err = rtnl_unicast(skb, net, portid);
2084         else
2085                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2086                                      n->nlmsg_flags & NLM_F_ECHO);
2087         if (err < 0)
2088                 NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
2089
2090         return err;
2091 }
2092
2093 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
2094                                  struct tcf_block *block, struct Qdisc *q,
2095                                  u32 parent, struct nlmsghdr *n,
2096                                  struct tcf_chain *chain, int event,
2097                                  struct netlink_ext_ack *extack)
2098 {
2099         struct tcf_proto *tp;
2100
2101         for (tp = tcf_get_next_proto(chain, NULL);
2102              tp; tp = tcf_get_next_proto(chain, tp))
2103                 tfilter_notify(net, oskb, n, tp, block, q, parent, NULL,
2104                                event, false, true, extack);
2105 }
2106
2107 static void tfilter_put(struct tcf_proto *tp, void *fh)
2108 {
2109         if (tp->ops->put && fh)
2110                 tp->ops->put(tp, fh);
2111 }
2112
2113 static bool is_qdisc_ingress(__u32 classid)
2114 {
2115         return (TC_H_MIN(classid) == TC_H_MIN(TC_H_MIN_INGRESS));
2116 }
2117
2118 static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2119                           struct netlink_ext_ack *extack)
2120 {
2121         struct net *net = sock_net(skb->sk);
2122         struct nlattr *tca[TCA_MAX + 1];
2123         char name[IFNAMSIZ];
2124         struct tcmsg *t;
2125         u32 protocol;
2126         u32 prio;
2127         bool prio_allocate;
2128         u32 parent;
2129         u32 chain_index;
2130         struct Qdisc *q;
2131         struct tcf_chain_info chain_info;
2132         struct tcf_chain *chain;
2133         struct tcf_block *block;
2134         struct tcf_proto *tp;
2135         unsigned long cl;
2136         void *fh;
2137         int err;
2138         int tp_created;
2139         bool rtnl_held = false;
2140         u32 flags;
2141
2142 replay:
2143         tp_created = 0;
2144
2145         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2146                                      rtm_tca_policy, extack);
2147         if (err < 0)
2148                 return err;
2149
2150         t = nlmsg_data(n);
2151         protocol = TC_H_MIN(t->tcm_info);
2152         prio = TC_H_MAJ(t->tcm_info);
2153         prio_allocate = false;
2154         parent = t->tcm_parent;
2155         tp = NULL;
2156         cl = 0;
2157         block = NULL;
2158         q = NULL;
2159         chain = NULL;
2160         flags = 0;
2161
2162         if (prio == 0) {
2163                 /* If no priority is provided by the user,
2164                  * we allocate one.
2165                  */
2166                 if (n->nlmsg_flags & NLM_F_CREATE) {
2167                         prio = TC_H_MAKE(0x80000000U, 0U);
2168                         prio_allocate = true;
2169                 } else {
2170                         NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2171                         return -ENOENT;
2172                 }
2173         }
2174
2175         /* Find head of filter chain. */
2176
2177         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2178         if (err)
2179                 return err;
2180
2181         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2182                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2183                 err = -EINVAL;
2184                 goto errout;
2185         }
2186
2187         /* Take rtnl mutex if rtnl_held was set to true on previous iteration,
2188          * block is shared (no qdisc found), qdisc is not unlocked, classifier
2189          * type is not specified, classifier is not unlocked.
2190          */
2191         if (rtnl_held ||
2192             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2193             !tcf_proto_is_unlocked(name)) {
2194                 rtnl_held = true;
2195                 rtnl_lock();
2196         }
2197
2198         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2199         if (err)
2200                 goto errout;
2201
2202         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2203                                  extack);
2204         if (IS_ERR(block)) {
2205                 err = PTR_ERR(block);
2206                 goto errout;
2207         }
2208         block->classid = parent;
2209
2210         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2211         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2212                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2213                 err = -EINVAL;
2214                 goto errout;
2215         }
2216         chain = tcf_chain_get(block, chain_index, true);
2217         if (!chain) {
2218                 NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
2219                 err = -ENOMEM;
2220                 goto errout;
2221         }
2222
2223         mutex_lock(&chain->filter_chain_lock);
2224         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2225                                prio, prio_allocate);
2226         if (IS_ERR(tp)) {
2227                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2228                 err = PTR_ERR(tp);
2229                 goto errout_locked;
2230         }
2231
2232         if (tp == NULL) {
2233                 struct tcf_proto *tp_new = NULL;
2234
2235                 if (chain->flushing) {
2236                         err = -EAGAIN;
2237                         goto errout_locked;
2238                 }
2239
2240                 /* Proto-tcf does not exist, create new one */
2241
2242                 if (tca[TCA_KIND] == NULL || !protocol) {
2243                         NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
2244                         err = -EINVAL;
2245                         goto errout_locked;
2246                 }
2247
2248                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2249                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2250                         err = -ENOENT;
2251                         goto errout_locked;
2252                 }
2253
2254                 if (prio_allocate)
2255                         prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
2256                                                                &chain_info));
2257
2258                 mutex_unlock(&chain->filter_chain_lock);
2259                 tp_new = tcf_proto_create(name, protocol, prio, chain,
2260                                           rtnl_held, extack);
2261                 if (IS_ERR(tp_new)) {
2262                         err = PTR_ERR(tp_new);
2263                         goto errout_tp;
2264                 }
2265
2266                 tp_created = 1;
2267                 tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
2268                                                 rtnl_held);
2269                 if (IS_ERR(tp)) {
2270                         err = PTR_ERR(tp);
2271                         goto errout_tp;
2272                 }
2273         } else {
2274                 mutex_unlock(&chain->filter_chain_lock);
2275         }
2276
2277         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2278                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2279                 err = -EINVAL;
2280                 goto errout;
2281         }
2282
2283         fh = tp->ops->get(tp, t->tcm_handle);
2284
2285         if (!fh) {
2286                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2287                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2288                         err = -ENOENT;
2289                         goto errout;
2290                 }
2291         } else if (n->nlmsg_flags & NLM_F_EXCL) {
2292                 tfilter_put(tp, fh);
2293                 NL_SET_ERR_MSG(extack, "Filter already exists");
2294                 err = -EEXIST;
2295                 goto errout;
2296         }
2297
2298         if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
2299                 tfilter_put(tp, fh);
2300                 NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
2301                 err = -EINVAL;
2302                 goto errout;
2303         }
2304
2305         if (!(n->nlmsg_flags & NLM_F_CREATE))
2306                 flags |= TCA_ACT_FLAGS_REPLACE;
2307         if (!rtnl_held)
2308                 flags |= TCA_ACT_FLAGS_NO_RTNL;
2309         if (is_qdisc_ingress(parent))
2310                 flags |= TCA_ACT_FLAGS_AT_INGRESS;
2311         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
2312                               flags, extack);
2313         if (err == 0) {
2314                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2315                                RTM_NEWTFILTER, false, rtnl_held, extack);
2316                 tfilter_put(tp, fh);
2317                 /* q pointer is NULL for shared blocks */
2318                 if (q)
2319                         q->flags &= ~TCQ_F_CAN_BYPASS;
2320         }
2321
2322 errout:
2323         if (err && tp_created)
2324                 tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
2325 errout_tp:
2326         if (chain) {
2327                 if (tp && !IS_ERR(tp))
2328                         tcf_proto_put(tp, rtnl_held, NULL);
2329                 if (!tp_created)
2330                         tcf_chain_put(chain);
2331         }
2332         tcf_block_release(q, block, rtnl_held);
2333
2334         if (rtnl_held)
2335                 rtnl_unlock();
2336
2337         if (err == -EAGAIN) {
2338                 /* Take rtnl lock in case EAGAIN is caused by concurrent flush
2339                  * of target chain.
2340                  */
2341                 rtnl_held = true;
2342                 /* Replay the request. */
2343                 goto replay;
2344         }
2345         return err;
2346
2347 errout_locked:
2348         mutex_unlock(&chain->filter_chain_lock);
2349         goto errout;
2350 }
2351
2352 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2353                           struct netlink_ext_ack *extack)
2354 {
2355         struct net *net = sock_net(skb->sk);
2356         struct nlattr *tca[TCA_MAX + 1];
2357         char name[IFNAMSIZ];
2358         struct tcmsg *t;
2359         u32 protocol;
2360         u32 prio;
2361         u32 parent;
2362         u32 chain_index;
2363         struct Qdisc *q = NULL;
2364         struct tcf_chain_info chain_info;
2365         struct tcf_chain *chain = NULL;
2366         struct tcf_block *block = NULL;
2367         struct tcf_proto *tp = NULL;
2368         unsigned long cl = 0;
2369         void *fh = NULL;
2370         int err;
2371         bool rtnl_held = false;
2372
2373         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2374                                      rtm_tca_policy, extack);
2375         if (err < 0)
2376                 return err;
2377
2378         t = nlmsg_data(n);
2379         protocol = TC_H_MIN(t->tcm_info);
2380         prio = TC_H_MAJ(t->tcm_info);
2381         parent = t->tcm_parent;
2382
2383         if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
2384                 NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
2385                 return -ENOENT;
2386         }
2387
2388         /* Find head of filter chain. */
2389
2390         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2391         if (err)
2392                 return err;
2393
2394         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2395                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2396                 err = -EINVAL;
2397                 goto errout;
2398         }
2399         /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
2400          * found), qdisc is not unlocked, classifier type is not specified,
2401          * classifier is not unlocked.
2402          */
2403         if (!prio ||
2404             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2405             !tcf_proto_is_unlocked(name)) {
2406                 rtnl_held = true;
2407                 rtnl_lock();
2408         }
2409
2410         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2411         if (err)
2412                 goto errout;
2413
2414         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2415                                  extack);
2416         if (IS_ERR(block)) {
2417                 err = PTR_ERR(block);
2418                 goto errout;
2419         }
2420
2421         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2422         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2423                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2424                 err = -EINVAL;
2425                 goto errout;
2426         }
2427         chain = tcf_chain_get(block, chain_index, false);
2428         if (!chain) {
2429                 /* User requested flush on non-existent chain. Nothing to do,
2430                  * so just return success.
2431                  */
2432                 if (prio == 0) {
2433                         err = 0;
2434                         goto errout;
2435                 }
2436                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2437                 err = -ENOENT;
2438                 goto errout;
2439         }
2440
2441         if (prio == 0) {
2442                 tfilter_notify_chain(net, skb, block, q, parent, n,
2443                                      chain, RTM_DELTFILTER, extack);
2444                 tcf_chain_flush(chain, rtnl_held);
2445                 err = 0;
2446                 goto errout;
2447         }
2448
2449         mutex_lock(&chain->filter_chain_lock);
2450         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2451                                prio, false);
2452         if (!tp || IS_ERR(tp)) {
2453                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2454                 err = tp ? PTR_ERR(tp) : -ENOENT;
2455                 goto errout_locked;
2456         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2457                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2458                 err = -EINVAL;
2459                 goto errout_locked;
2460         } else if (t->tcm_handle == 0) {
2461                 tcf_proto_signal_destroying(chain, tp);
2462                 tcf_chain_tp_remove(chain, &chain_info, tp);
2463                 mutex_unlock(&chain->filter_chain_lock);
2464
2465                 tcf_proto_put(tp, rtnl_held, NULL);
2466                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2467                                RTM_DELTFILTER, false, rtnl_held, extack);
2468                 err = 0;
2469                 goto errout;
2470         }
2471         mutex_unlock(&chain->filter_chain_lock);
2472
2473         fh = tp->ops->get(tp, t->tcm_handle);
2474
2475         if (!fh) {
2476                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2477                 err = -ENOENT;
2478         } else {
2479                 bool last;
2480
2481                 err = tfilter_del_notify(net, skb, n, tp, block,
2482                                          q, parent, fh, false, &last,
2483                                          rtnl_held, extack);
2484
2485                 if (err)
2486                         goto errout;
2487                 if (last)
2488                         tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
2489         }
2490
2491 errout:
2492         if (chain) {
2493                 if (tp && !IS_ERR(tp))
2494                         tcf_proto_put(tp, rtnl_held, NULL);
2495                 tcf_chain_put(chain);
2496         }
2497         tcf_block_release(q, block, rtnl_held);
2498
2499         if (rtnl_held)
2500                 rtnl_unlock();
2501
2502         return err;
2503
2504 errout_locked:
2505         mutex_unlock(&chain->filter_chain_lock);
2506         goto errout;
2507 }
2508
2509 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2510                           struct netlink_ext_ack *extack)
2511 {
2512         struct net *net = sock_net(skb->sk);
2513         struct nlattr *tca[TCA_MAX + 1];
2514         char name[IFNAMSIZ];
2515         struct tcmsg *t;
2516         u32 protocol;
2517         u32 prio;
2518         u32 parent;
2519         u32 chain_index;
2520         struct Qdisc *q = NULL;
2521         struct tcf_chain_info chain_info;
2522         struct tcf_chain *chain = NULL;
2523         struct tcf_block *block = NULL;
2524         struct tcf_proto *tp = NULL;
2525         unsigned long cl = 0;
2526         void *fh = NULL;
2527         int err;
2528         bool rtnl_held = false;
2529
2530         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2531                                      rtm_tca_policy, extack);
2532         if (err < 0)
2533                 return err;
2534
2535         t = nlmsg_data(n);
2536         protocol = TC_H_MIN(t->tcm_info);
2537         prio = TC_H_MAJ(t->tcm_info);
2538         parent = t->tcm_parent;
2539
2540         if (prio == 0) {
2541                 NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2542                 return -ENOENT;
2543         }
2544
2545         /* Find head of filter chain. */
2546
2547         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2548         if (err)
2549                 return err;
2550
2551         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2552                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2553                 err = -EINVAL;
2554                 goto errout;
2555         }
2556         /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
2557          * unlocked, classifier type is not specified, classifier is not
2558          * unlocked.
2559          */
2560         if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2561             !tcf_proto_is_unlocked(name)) {
2562                 rtnl_held = true;
2563                 rtnl_lock();
2564         }
2565
2566         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2567         if (err)
2568                 goto errout;
2569
2570         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2571                                  extack);
2572         if (IS_ERR(block)) {
2573                 err = PTR_ERR(block);
2574                 goto errout;
2575         }
2576
2577         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2578         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2579                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2580                 err = -EINVAL;
2581                 goto errout;
2582         }
2583         chain = tcf_chain_get(block, chain_index, false);
2584         if (!chain) {
2585                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2586                 err = -EINVAL;
2587                 goto errout;
2588         }
2589
2590         mutex_lock(&chain->filter_chain_lock);
2591         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2592                                prio, false);
2593         mutex_unlock(&chain->filter_chain_lock);
2594         if (!tp || IS_ERR(tp)) {
2595                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2596                 err = tp ? PTR_ERR(tp) : -ENOENT;
2597                 goto errout;
2598         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2599                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2600                 err = -EINVAL;
2601                 goto errout;
2602         }
2603
2604         fh = tp->ops->get(tp, t->tcm_handle);
2605
2606         if (!fh) {
2607                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2608                 err = -ENOENT;
2609         } else {
2610                 err = tfilter_notify(net, skb, n, tp, block, q, parent,
2611                                      fh, RTM_NEWTFILTER, true, rtnl_held, NULL);
2612                 if (err < 0)
2613                         NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
2614         }
2615
2616         tfilter_put(tp, fh);
2617 errout:
2618         if (chain) {
2619                 if (tp && !IS_ERR(tp))
2620                         tcf_proto_put(tp, rtnl_held, NULL);
2621                 tcf_chain_put(chain);
2622         }
2623         tcf_block_release(q, block, rtnl_held);
2624
2625         if (rtnl_held)
2626                 rtnl_unlock();
2627
2628         return err;
2629 }
2630
2631 struct tcf_dump_args {
2632         struct tcf_walker w;
2633         struct sk_buff *skb;
2634         struct netlink_callback *cb;
2635         struct tcf_block *block;
2636         struct Qdisc *q;
2637         u32 parent;
2638         bool terse_dump;
2639 };
2640
2641 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2642 {
2643         struct tcf_dump_args *a = (void *)arg;
2644         struct net *net = sock_net(a->skb->sk);
2645
2646         return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
2647                              n, NETLINK_CB(a->cb->skb).portid,
2648                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2649                              RTM_NEWTFILTER, a->terse_dump, true, NULL);
2650 }
2651
2652 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
2653                            struct sk_buff *skb, struct netlink_callback *cb,
2654                            long index_start, long *p_index, bool terse)
2655 {
2656         struct net *net = sock_net(skb->sk);
2657         struct tcf_block *block = chain->block;
2658         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2659         struct tcf_proto *tp, *tp_prev;
2660         struct tcf_dump_args arg;
2661
2662         for (tp = __tcf_get_next_proto(chain, NULL);
2663              tp;
2664              tp_prev = tp,
2665                      tp = __tcf_get_next_proto(chain, tp),
2666                      tcf_proto_put(tp_prev, true, NULL),
2667                      (*p_index)++) {
2668                 if (*p_index < index_start)
2669                         continue;
2670                 if (TC_H_MAJ(tcm->tcm_info) &&
2671                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
2672                         continue;
2673                 if (TC_H_MIN(tcm->tcm_info) &&
2674                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
2675                         continue;
2676                 if (*p_index > index_start)
2677                         memset(&cb->args[1], 0,
2678                                sizeof(cb->args) - sizeof(cb->args[0]));
2679                 if (cb->args[1] == 0) {
2680                         if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
2681                                           NETLINK_CB(cb->skb).portid,
2682                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
2683                                           RTM_NEWTFILTER, false, true, NULL) <= 0)
2684                                 goto errout;
2685                         cb->args[1] = 1;
2686                 }
2687                 if (!tp->ops->walk)
2688                         continue;
2689                 arg.w.fn = tcf_node_dump;
2690                 arg.skb = skb;
2691                 arg.cb = cb;
2692                 arg.block = block;
2693                 arg.q = q;
2694                 arg.parent = parent;
2695                 arg.w.stop = 0;
2696                 arg.w.skip = cb->args[1] - 1;
2697                 arg.w.count = 0;
2698                 arg.w.cookie = cb->args[2];
2699                 arg.terse_dump = terse;
2700                 tp->ops->walk(tp, &arg.w, true);
2701                 cb->args[2] = arg.w.cookie;
2702                 cb->args[1] = arg.w.count + 1;
2703                 if (arg.w.stop)
2704                         goto errout;
2705         }
2706         return true;
2707
2708 errout:
2709         tcf_proto_put(tp, true, NULL);
2710         return false;
2711 }
2712
2713 static const struct nla_policy tcf_tfilter_dump_policy[TCA_MAX + 1] = {
2714         [TCA_DUMP_FLAGS] = NLA_POLICY_BITFIELD32(TCA_DUMP_FLAGS_TERSE),
2715 };
2716
2717 /* called with RTNL */
2718 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
2719 {
2720         struct tcf_chain *chain, *chain_prev;
2721         struct net *net = sock_net(skb->sk);
2722         struct nlattr *tca[TCA_MAX + 1];
2723         struct Qdisc *q = NULL;
2724         struct tcf_block *block;
2725         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2726         bool terse_dump = false;
2727         long index_start;
2728         long index;
2729         u32 parent;
2730         int err;
2731
2732         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2733                 return skb->len;
2734
2735         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2736                                      tcf_tfilter_dump_policy, cb->extack);
2737         if (err)
2738                 return err;
2739
2740         if (tca[TCA_DUMP_FLAGS]) {
2741                 struct nla_bitfield32 flags =
2742                         nla_get_bitfield32(tca[TCA_DUMP_FLAGS]);
2743
2744                 terse_dump = flags.value & TCA_DUMP_FLAGS_TERSE;
2745         }
2746
2747         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2748                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2749                 if (!block)
2750                         goto out;
2751                 /* If we work with block index, q is NULL and parent value
2752                  * will never be used in the following code. The check
2753                  * in tcf_fill_node prevents it. However, compiler does not
2754                  * see that far, so set parent to zero to silence the warning
2755                  * about parent being uninitialized.
2756                  */
2757                 parent = 0;
2758         } else {
2759                 const struct Qdisc_class_ops *cops;
2760                 struct net_device *dev;
2761                 unsigned long cl = 0;
2762
2763                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2764                 if (!dev)
2765                         return skb->len;
2766
2767                 parent = tcm->tcm_parent;
2768                 if (!parent)
2769                         q = rtnl_dereference(dev->qdisc);
2770                 else
2771                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2772                 if (!q)
2773                         goto out;
2774                 cops = q->ops->cl_ops;
2775                 if (!cops)
2776                         goto out;
2777                 if (!cops->tcf_block)
2778                         goto out;
2779                 if (TC_H_MIN(tcm->tcm_parent)) {
2780                         cl = cops->find(q, tcm->tcm_parent);
2781                         if (cl == 0)
2782                                 goto out;
2783                 }
2784                 block = cops->tcf_block(q, cl, NULL);
2785                 if (!block)
2786                         goto out;
2787                 parent = block->classid;
2788                 if (tcf_block_shared(block))
2789                         q = NULL;
2790         }
2791
2792         index_start = cb->args[0];
2793         index = 0;
2794
2795         for (chain = __tcf_get_next_chain(block, NULL);
2796              chain;
2797              chain_prev = chain,
2798                      chain = __tcf_get_next_chain(block, chain),
2799                      tcf_chain_put(chain_prev)) {
2800                 if (tca[TCA_CHAIN] &&
2801                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
2802                         continue;
2803                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
2804                                     index_start, &index, terse_dump)) {
2805                         tcf_chain_put(chain);
2806                         err = -EMSGSIZE;
2807                         break;
2808                 }
2809         }
2810
2811         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2812                 tcf_block_refcnt_put(block, true);
2813         cb->args[0] = index;
2814
2815 out:
2816         /* If we did no progress, the error (EMSGSIZE) is real */
2817         if (skb->len == 0 && err)
2818                 return err;
2819         return skb->len;
2820 }
2821
2822 static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
2823                               void *tmplt_priv, u32 chain_index,
2824                               struct net *net, struct sk_buff *skb,
2825                               struct tcf_block *block,
2826                               u32 portid, u32 seq, u16 flags, int event,
2827                               struct netlink_ext_ack *extack)
2828 {
2829         unsigned char *b = skb_tail_pointer(skb);
2830         const struct tcf_proto_ops *ops;
2831         struct nlmsghdr *nlh;
2832         struct tcmsg *tcm;
2833         void *priv;
2834
2835         ops = tmplt_ops;
2836         priv = tmplt_priv;
2837
2838         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2839         if (!nlh)
2840                 goto out_nlmsg_trim;
2841         tcm = nlmsg_data(nlh);
2842         tcm->tcm_family = AF_UNSPEC;
2843         tcm->tcm__pad1 = 0;
2844         tcm->tcm__pad2 = 0;
2845         tcm->tcm_handle = 0;
2846         if (block->q) {
2847                 tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
2848                 tcm->tcm_parent = block->q->handle;
2849         } else {
2850                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2851                 tcm->tcm_block_index = block->index;
2852         }
2853
2854         if (nla_put_u32(skb, TCA_CHAIN, chain_index))
2855                 goto nla_put_failure;
2856
2857         if (ops) {
2858                 if (nla_put_string(skb, TCA_KIND, ops->kind))
2859                         goto nla_put_failure;
2860                 if (ops->tmplt_dump(skb, net, priv) < 0)
2861                         goto nla_put_failure;
2862         }
2863
2864         if (extack && extack->_msg &&
2865             nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
2866                 goto out_nlmsg_trim;
2867
2868         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2869
2870         return skb->len;
2871
2872 out_nlmsg_trim:
2873 nla_put_failure:
2874         nlmsg_trim(skb, b);
2875         return -EMSGSIZE;
2876 }
2877
2878 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
2879                            u32 seq, u16 flags, int event, bool unicast,
2880                            struct netlink_ext_ack *extack)
2881 {
2882         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2883         struct tcf_block *block = chain->block;
2884         struct net *net = block->net;
2885         struct sk_buff *skb;
2886         int err = 0;
2887
2888         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2889         if (!skb)
2890                 return -ENOBUFS;
2891
2892         if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2893                                chain->index, net, skb, block, portid,
2894                                seq, flags, event, extack) <= 0) {
2895                 kfree_skb(skb);
2896                 return -EINVAL;
2897         }
2898
2899         if (unicast)
2900                 err = rtnl_unicast(skb, net, portid);
2901         else
2902                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2903                                      flags & NLM_F_ECHO);
2904
2905         return err;
2906 }
2907
2908 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
2909                                   void *tmplt_priv, u32 chain_index,
2910                                   struct tcf_block *block, struct sk_buff *oskb,
2911                                   u32 seq, u16 flags, bool unicast)
2912 {
2913         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2914         struct net *net = block->net;
2915         struct sk_buff *skb;
2916
2917         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2918         if (!skb)
2919                 return -ENOBUFS;
2920
2921         if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
2922                                block, portid, seq, flags, RTM_DELCHAIN, NULL) <= 0) {
2923                 kfree_skb(skb);
2924                 return -EINVAL;
2925         }
2926
2927         if (unicast)
2928                 return rtnl_unicast(skb, net, portid);
2929
2930         return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
2931 }
2932
2933 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
2934                               struct nlattr **tca,
2935                               struct netlink_ext_ack *extack)
2936 {
2937         const struct tcf_proto_ops *ops;
2938         char name[IFNAMSIZ];
2939         void *tmplt_priv;
2940
2941         /* If kind is not set, user did not specify template. */
2942         if (!tca[TCA_KIND])
2943                 return 0;
2944
2945         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2946                 NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
2947                 return -EINVAL;
2948         }
2949
2950         ops = tcf_proto_lookup_ops(name, true, extack);
2951         if (IS_ERR(ops))
2952                 return PTR_ERR(ops);
2953         if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
2954                 NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
2955                 module_put(ops->owner);
2956                 return -EOPNOTSUPP;
2957         }
2958
2959         tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
2960         if (IS_ERR(tmplt_priv)) {
2961                 module_put(ops->owner);
2962                 return PTR_ERR(tmplt_priv);
2963         }
2964         chain->tmplt_ops = ops;
2965         chain->tmplt_priv = tmplt_priv;
2966         return 0;
2967 }
2968
2969 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
2970                                void *tmplt_priv)
2971 {
2972         /* If template ops are set, no work to do for us. */
2973         if (!tmplt_ops)
2974                 return;
2975
2976         tmplt_ops->tmplt_destroy(tmplt_priv);
2977         module_put(tmplt_ops->owner);
2978 }
2979
2980 /* Add/delete/get a chain */
2981
2982 static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
2983                         struct netlink_ext_ack *extack)
2984 {
2985         struct net *net = sock_net(skb->sk);
2986         struct nlattr *tca[TCA_MAX + 1];
2987         struct tcmsg *t;
2988         u32 parent;
2989         u32 chain_index;
2990         struct Qdisc *q;
2991         struct tcf_chain *chain;
2992         struct tcf_block *block;
2993         unsigned long cl;
2994         int err;
2995
2996 replay:
2997         q = NULL;
2998         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2999                                      rtm_tca_policy, extack);
3000         if (err < 0)
3001                 return err;
3002
3003         t = nlmsg_data(n);
3004         parent = t->tcm_parent;
3005         cl = 0;
3006
3007         block = tcf_block_find(net, &q, &parent, &cl,
3008                                t->tcm_ifindex, t->tcm_block_index, extack);
3009         if (IS_ERR(block))
3010                 return PTR_ERR(block);
3011
3012         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
3013         if (chain_index > TC_ACT_EXT_VAL_MASK) {
3014                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
3015                 err = -EINVAL;
3016                 goto errout_block;
3017         }
3018
3019         mutex_lock(&block->lock);
3020         chain = tcf_chain_lookup(block, chain_index);
3021         if (n->nlmsg_type == RTM_NEWCHAIN) {
3022                 if (chain) {
3023                         if (tcf_chain_held_by_acts_only(chain)) {
3024                                 /* The chain exists only because there is
3025                                  * some action referencing it.
3026                                  */
3027                                 tcf_chain_hold(chain);
3028                         } else {
3029                                 NL_SET_ERR_MSG(extack, "Filter chain already exists");
3030                                 err = -EEXIST;
3031                                 goto errout_block_locked;
3032                         }
3033                 } else {
3034                         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
3035                                 NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
3036                                 err = -ENOENT;
3037                                 goto errout_block_locked;
3038                         }
3039                         chain = tcf_chain_create(block, chain_index);
3040                         if (!chain) {
3041                                 NL_SET_ERR_MSG(extack, "Failed to create filter chain");
3042                                 err = -ENOMEM;
3043                                 goto errout_block_locked;
3044                         }
3045                 }
3046         } else {
3047                 if (!chain || tcf_chain_held_by_acts_only(chain)) {
3048                         NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
3049                         err = -EINVAL;
3050                         goto errout_block_locked;
3051                 }
3052                 tcf_chain_hold(chain);
3053         }
3054
3055         if (n->nlmsg_type == RTM_NEWCHAIN) {
3056                 /* Modifying chain requires holding parent block lock. In case
3057                  * the chain was successfully added, take a reference to the
3058                  * chain. This ensures that an empty chain does not disappear at
3059                  * the end of this function.
3060                  */
3061                 tcf_chain_hold(chain);
3062                 chain->explicitly_created = true;
3063         }
3064         mutex_unlock(&block->lock);
3065
3066         switch (n->nlmsg_type) {
3067         case RTM_NEWCHAIN:
3068                 err = tc_chain_tmplt_add(chain, net, tca, extack);
3069                 if (err) {
3070                         tcf_chain_put_explicitly_created(chain);
3071                         goto errout;
3072                 }
3073
3074                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
3075                                 RTM_NEWCHAIN, false, extack);
3076                 break;
3077         case RTM_DELCHAIN:
3078                 tfilter_notify_chain(net, skb, block, q, parent, n,
3079                                      chain, RTM_DELTFILTER, extack);
3080                 /* Flush the chain first as the user requested chain removal. */
3081                 tcf_chain_flush(chain, true);
3082                 /* In case the chain was successfully deleted, put a reference
3083                  * to the chain previously taken during addition.
3084                  */
3085                 tcf_chain_put_explicitly_created(chain);
3086                 break;
3087         case RTM_GETCHAIN:
3088                 err = tc_chain_notify(chain, skb, n->nlmsg_seq,
3089                                       n->nlmsg_flags, n->nlmsg_type, true, extack);
3090                 if (err < 0)
3091                         NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
3092                 break;
3093         default:
3094                 err = -EOPNOTSUPP;
3095                 NL_SET_ERR_MSG(extack, "Unsupported message type");
3096                 goto errout;
3097         }
3098
3099 errout:
3100         tcf_chain_put(chain);
3101 errout_block:
3102         tcf_block_release(q, block, true);
3103         if (err == -EAGAIN)
3104                 /* Replay the request. */
3105                 goto replay;
3106         return err;
3107
3108 errout_block_locked:
3109         mutex_unlock(&block->lock);
3110         goto errout_block;
3111 }
3112
3113 /* called with RTNL */
3114 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
3115 {
3116         struct net *net = sock_net(skb->sk);
3117         struct nlattr *tca[TCA_MAX + 1];
3118         struct Qdisc *q = NULL;
3119         struct tcf_block *block;
3120         struct tcmsg *tcm = nlmsg_data(cb->nlh);
3121         struct tcf_chain *chain;
3122         long index_start;
3123         long index;
3124         int err;
3125
3126         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
3127                 return skb->len;
3128
3129         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
3130                                      rtm_tca_policy, cb->extack);
3131         if (err)
3132                 return err;
3133
3134         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
3135                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
3136                 if (!block)
3137                         goto out;
3138         } else {
3139                 const struct Qdisc_class_ops *cops;
3140                 struct net_device *dev;
3141                 unsigned long cl = 0;
3142
3143                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
3144                 if (!dev)
3145                         return skb->len;
3146
3147                 if (!tcm->tcm_parent)
3148                         q = rtnl_dereference(dev->qdisc);
3149                 else
3150                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
3151
3152                 if (!q)
3153                         goto out;
3154                 cops = q->ops->cl_ops;
3155                 if (!cops)
3156                         goto out;
3157                 if (!cops->tcf_block)
3158                         goto out;
3159                 if (TC_H_MIN(tcm->tcm_parent)) {
3160                         cl = cops->find(q, tcm->tcm_parent);
3161                         if (cl == 0)
3162                                 goto out;
3163                 }
3164                 block = cops->tcf_block(q, cl, NULL);
3165                 if (!block)
3166                         goto out;
3167                 if (tcf_block_shared(block))
3168                         q = NULL;
3169         }
3170
3171         index_start = cb->args[0];
3172         index = 0;
3173
3174         mutex_lock(&block->lock);
3175         list_for_each_entry(chain, &block->chain_list, list) {
3176                 if ((tca[TCA_CHAIN] &&
3177                      nla_get_u32(tca[TCA_CHAIN]) != chain->index))
3178                         continue;
3179                 if (index < index_start) {
3180                         index++;
3181                         continue;
3182                 }
3183                 if (tcf_chain_held_by_acts_only(chain))
3184                         continue;
3185                 err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
3186                                          chain->index, net, skb, block,
3187                                          NETLINK_CB(cb->skb).portid,
3188                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
3189                                          RTM_NEWCHAIN, NULL);
3190                 if (err <= 0)
3191                         break;
3192                 index++;
3193         }
3194         mutex_unlock(&block->lock);
3195
3196         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
3197                 tcf_block_refcnt_put(block, true);
3198         cb->args[0] = index;
3199
3200 out:
3201         /* If we did no progress, the error (EMSGSIZE) is real */
3202         if (skb->len == 0 && err)
3203                 return err;
3204         return skb->len;
3205 }
3206
3207 int tcf_exts_init_ex(struct tcf_exts *exts, struct net *net, int action,
3208                      int police, struct tcf_proto *tp, u32 handle,
3209                      bool use_action_miss)
3210 {
3211         int err = 0;
3212
3213 #ifdef CONFIG_NET_CLS_ACT
3214         exts->type = 0;
3215         exts->nr_actions = 0;
3216         exts->miss_cookie_node = NULL;
3217         /* Note: we do not own yet a reference on net.
3218          * This reference might be taken later from tcf_exts_get_net().
3219          */
3220         exts->net = net;
3221         exts->actions = kcalloc(TCA_ACT_MAX_PRIO, sizeof(struct tc_action *),
3222                                 GFP_KERNEL);
3223         if (!exts->actions)
3224                 return -ENOMEM;
3225 #endif
3226
3227         exts->action = action;
3228         exts->police = police;
3229
3230         if (!use_action_miss)
3231                 return 0;
3232
3233         err = tcf_exts_miss_cookie_base_alloc(exts, tp, handle);
3234         if (err)
3235                 goto err_miss_alloc;
3236
3237         return 0;
3238
3239 err_miss_alloc:
3240         tcf_exts_destroy(exts);
3241 #ifdef CONFIG_NET_CLS_ACT
3242         exts->actions = NULL;
3243 #endif
3244         return err;
3245 }
3246 EXPORT_SYMBOL(tcf_exts_init_ex);
3247
3248 void tcf_exts_destroy(struct tcf_exts *exts)
3249 {
3250         tcf_exts_miss_cookie_base_destroy(exts);
3251
3252 #ifdef CONFIG_NET_CLS_ACT
3253         if (exts->actions) {
3254                 tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
3255                 kfree(exts->actions);
3256         }
3257         exts->nr_actions = 0;
3258 #endif
3259 }
3260 EXPORT_SYMBOL(tcf_exts_destroy);
3261
3262 int tcf_exts_validate_ex(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3263                          struct nlattr *rate_tlv, struct tcf_exts *exts,
3264                          u32 flags, u32 fl_flags, struct netlink_ext_ack *extack)
3265 {
3266 #ifdef CONFIG_NET_CLS_ACT
3267         {
3268                 int init_res[TCA_ACT_MAX_PRIO] = {};
3269                 struct tc_action *act;
3270                 size_t attr_size = 0;
3271
3272                 if (exts->police && tb[exts->police]) {
3273                         struct tc_action_ops *a_o;
3274
3275                         a_o = tc_action_load_ops(tb[exts->police], true,
3276                                                  !(flags & TCA_ACT_FLAGS_NO_RTNL),
3277                                                  extack);
3278                         if (IS_ERR(a_o))
3279                                 return PTR_ERR(a_o);
3280                         flags |= TCA_ACT_FLAGS_POLICE | TCA_ACT_FLAGS_BIND;
3281                         act = tcf_action_init_1(net, tp, tb[exts->police],
3282                                                 rate_tlv, a_o, init_res, flags,
3283                                                 extack);
3284                         module_put(a_o->owner);
3285                         if (IS_ERR(act))
3286                                 return PTR_ERR(act);
3287
3288                         act->type = exts->type = TCA_OLD_COMPAT;
3289                         exts->actions[0] = act;
3290                         exts->nr_actions = 1;
3291                         tcf_idr_insert_many(exts->actions);
3292                 } else if (exts->action && tb[exts->action]) {
3293                         int err;
3294
3295                         flags |= TCA_ACT_FLAGS_BIND;
3296                         err = tcf_action_init(net, tp, tb[exts->action],
3297                                               rate_tlv, exts->actions, init_res,
3298                                               &attr_size, flags, fl_flags,
3299                                               extack);
3300                         if (err < 0)
3301                                 return err;
3302                         exts->nr_actions = err;
3303                 }
3304         }
3305 #else
3306         if ((exts->action && tb[exts->action]) ||
3307             (exts->police && tb[exts->police])) {
3308                 NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
3309                 return -EOPNOTSUPP;
3310         }
3311 #endif
3312
3313         return 0;
3314 }
3315 EXPORT_SYMBOL(tcf_exts_validate_ex);
3316
3317 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3318                       struct nlattr *rate_tlv, struct tcf_exts *exts,
3319                       u32 flags, struct netlink_ext_ack *extack)
3320 {
3321         return tcf_exts_validate_ex(net, tp, tb, rate_tlv, exts,
3322                                     flags, 0, extack);
3323 }
3324 EXPORT_SYMBOL(tcf_exts_validate);
3325
3326 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
3327 {
3328 #ifdef CONFIG_NET_CLS_ACT
3329         struct tcf_exts old = *dst;
3330
3331         *dst = *src;
3332         tcf_exts_destroy(&old);
3333 #endif
3334 }
3335 EXPORT_SYMBOL(tcf_exts_change);
3336
3337 #ifdef CONFIG_NET_CLS_ACT
3338 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
3339 {
3340         if (exts->nr_actions == 0)
3341                 return NULL;
3342         else
3343                 return exts->actions[0];
3344 }
3345 #endif
3346
3347 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
3348 {
3349 #ifdef CONFIG_NET_CLS_ACT
3350         struct nlattr *nest;
3351
3352         if (exts->action && tcf_exts_has_actions(exts)) {
3353                 /*
3354                  * again for backward compatible mode - we want
3355                  * to work with both old and new modes of entering
3356                  * tc data even if iproute2  was newer - jhs
3357                  */
3358                 if (exts->type != TCA_OLD_COMPAT) {
3359                         nest = nla_nest_start_noflag(skb, exts->action);
3360                         if (nest == NULL)
3361                                 goto nla_put_failure;
3362
3363                         if (tcf_action_dump(skb, exts->actions, 0, 0, false)
3364                             < 0)
3365                                 goto nla_put_failure;
3366                         nla_nest_end(skb, nest);
3367                 } else if (exts->police) {
3368                         struct tc_action *act = tcf_exts_first_act(exts);
3369                         nest = nla_nest_start_noflag(skb, exts->police);
3370                         if (nest == NULL || !act)
3371                                 goto nla_put_failure;
3372                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
3373                                 goto nla_put_failure;
3374                         nla_nest_end(skb, nest);
3375                 }
3376         }
3377         return 0;
3378
3379 nla_put_failure:
3380         nla_nest_cancel(skb, nest);
3381         return -1;
3382 #else
3383         return 0;
3384 #endif
3385 }
3386 EXPORT_SYMBOL(tcf_exts_dump);
3387
3388 int tcf_exts_terse_dump(struct sk_buff *skb, struct tcf_exts *exts)
3389 {
3390 #ifdef CONFIG_NET_CLS_ACT
3391         struct nlattr *nest;
3392
3393         if (!exts->action || !tcf_exts_has_actions(exts))
3394                 return 0;
3395
3396         nest = nla_nest_start_noflag(skb, exts->action);
3397         if (!nest)
3398                 goto nla_put_failure;
3399
3400         if (tcf_action_dump(skb, exts->actions, 0, 0, true) < 0)
3401                 goto nla_put_failure;
3402         nla_nest_end(skb, nest);
3403         return 0;
3404
3405 nla_put_failure:
3406         nla_nest_cancel(skb, nest);
3407         return -1;
3408 #else
3409         return 0;
3410 #endif
3411 }
3412 EXPORT_SYMBOL(tcf_exts_terse_dump);
3413
3414 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
3415 {
3416 #ifdef CONFIG_NET_CLS_ACT
3417         struct tc_action *a = tcf_exts_first_act(exts);
3418         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
3419                 return -1;
3420 #endif
3421         return 0;
3422 }
3423 EXPORT_SYMBOL(tcf_exts_dump_stats);
3424
3425 static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
3426 {
3427         if (*flags & TCA_CLS_FLAGS_IN_HW)
3428                 return;
3429         *flags |= TCA_CLS_FLAGS_IN_HW;
3430         atomic_inc(&block->offloadcnt);
3431 }
3432
3433 static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
3434 {
3435         if (!(*flags & TCA_CLS_FLAGS_IN_HW))
3436                 return;
3437         *flags &= ~TCA_CLS_FLAGS_IN_HW;
3438         atomic_dec(&block->offloadcnt);
3439 }
3440
3441 static void tc_cls_offload_cnt_update(struct tcf_block *block,
3442                                       struct tcf_proto *tp, u32 *cnt,
3443                                       u32 *flags, u32 diff, bool add)
3444 {
3445         lockdep_assert_held(&block->cb_lock);
3446
3447         spin_lock(&tp->lock);
3448         if (add) {
3449                 if (!*cnt)
3450                         tcf_block_offload_inc(block, flags);
3451                 *cnt += diff;
3452         } else {
3453                 *cnt -= diff;
3454                 if (!*cnt)
3455                         tcf_block_offload_dec(block, flags);
3456         }
3457         spin_unlock(&tp->lock);
3458 }
3459
3460 static void
3461 tc_cls_offload_cnt_reset(struct tcf_block *block, struct tcf_proto *tp,
3462                          u32 *cnt, u32 *flags)
3463 {
3464         lockdep_assert_held(&block->cb_lock);
3465
3466         spin_lock(&tp->lock);
3467         tcf_block_offload_dec(block, flags);
3468         *cnt = 0;
3469         spin_unlock(&tp->lock);
3470 }
3471
3472 static int
3473 __tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3474                    void *type_data, bool err_stop)
3475 {
3476         struct flow_block_cb *block_cb;
3477         int ok_count = 0;
3478         int err;
3479
3480         list_for_each_entry(block_cb, &block->flow_block.cb_list, list) {
3481                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
3482                 if (err) {
3483                         if (err_stop)
3484                                 return err;
3485                 } else {
3486                         ok_count++;
3487                 }
3488         }
3489         return ok_count;
3490 }
3491
3492 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3493                      void *type_data, bool err_stop, bool rtnl_held)
3494 {
3495         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3496         int ok_count;
3497
3498 retry:
3499         if (take_rtnl)
3500                 rtnl_lock();
3501         down_read(&block->cb_lock);
3502         /* Need to obtain rtnl lock if block is bound to devs that require it.
3503          * In block bind code cb_lock is obtained while holding rtnl, so we must
3504          * obtain the locks in same order here.
3505          */
3506         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3507                 up_read(&block->cb_lock);
3508                 take_rtnl = true;
3509                 goto retry;
3510         }
3511
3512         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3513
3514         up_read(&block->cb_lock);
3515         if (take_rtnl)
3516                 rtnl_unlock();
3517         return ok_count;
3518 }
3519 EXPORT_SYMBOL(tc_setup_cb_call);
3520
3521 /* Non-destructive filter add. If filter that wasn't already in hardware is
3522  * successfully offloaded, increment block offloads counter. On failure,
3523  * previously offloaded filter is considered to be intact and offloads counter
3524  * is not decremented.
3525  */
3526
3527 int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
3528                     enum tc_setup_type type, void *type_data, bool err_stop,
3529                     u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3530 {
3531         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3532         int ok_count;
3533
3534 retry:
3535         if (take_rtnl)
3536                 rtnl_lock();
3537         down_read(&block->cb_lock);
3538         /* Need to obtain rtnl lock if block is bound to devs that require it.
3539          * In block bind code cb_lock is obtained while holding rtnl, so we must
3540          * obtain the locks in same order here.
3541          */
3542         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3543                 up_read(&block->cb_lock);
3544                 take_rtnl = true;
3545                 goto retry;
3546         }
3547
3548         /* Make sure all netdevs sharing this block are offload-capable. */
3549         if (block->nooffloaddevcnt && err_stop) {
3550                 ok_count = -EOPNOTSUPP;
3551                 goto err_unlock;
3552         }
3553
3554         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3555         if (ok_count < 0)
3556                 goto err_unlock;
3557
3558         if (tp->ops->hw_add)
3559                 tp->ops->hw_add(tp, type_data);
3560         if (ok_count > 0)
3561                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
3562                                           ok_count, true);
3563 err_unlock:
3564         up_read(&block->cb_lock);
3565         if (take_rtnl)
3566                 rtnl_unlock();
3567         return min(ok_count, 0);
3568 }
3569 EXPORT_SYMBOL(tc_setup_cb_add);
3570
3571 /* Destructive filter replace. If filter that wasn't already in hardware is
3572  * successfully offloaded, increment block offload counter. On failure,
3573  * previously offloaded filter is considered to be destroyed and offload counter
3574  * is decremented.
3575  */
3576
3577 int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
3578                         enum tc_setup_type type, void *type_data, bool err_stop,
3579                         u32 *old_flags, unsigned int *old_in_hw_count,
3580                         u32 *new_flags, unsigned int *new_in_hw_count,
3581                         bool rtnl_held)
3582 {
3583         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3584         int ok_count;
3585
3586 retry:
3587         if (take_rtnl)
3588                 rtnl_lock();
3589         down_read(&block->cb_lock);
3590         /* Need to obtain rtnl lock if block is bound to devs that require it.
3591          * In block bind code cb_lock is obtained while holding rtnl, so we must
3592          * obtain the locks in same order here.
3593          */
3594         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3595                 up_read(&block->cb_lock);
3596                 take_rtnl = true;
3597                 goto retry;
3598         }
3599
3600         /* Make sure all netdevs sharing this block are offload-capable. */
3601         if (block->nooffloaddevcnt && err_stop) {
3602                 ok_count = -EOPNOTSUPP;
3603                 goto err_unlock;
3604         }
3605
3606         tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
3607         if (tp->ops->hw_del)
3608                 tp->ops->hw_del(tp, type_data);
3609
3610         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3611         if (ok_count < 0)
3612                 goto err_unlock;
3613
3614         if (tp->ops->hw_add)
3615                 tp->ops->hw_add(tp, type_data);
3616         if (ok_count > 0)
3617                 tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
3618                                           new_flags, ok_count, true);
3619 err_unlock:
3620         up_read(&block->cb_lock);
3621         if (take_rtnl)
3622                 rtnl_unlock();
3623         return min(ok_count, 0);
3624 }
3625 EXPORT_SYMBOL(tc_setup_cb_replace);
3626
3627 /* Destroy filter and decrement block offload counter, if filter was previously
3628  * offloaded.
3629  */
3630
3631 int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
3632                         enum tc_setup_type type, void *type_data, bool err_stop,
3633                         u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3634 {
3635         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3636         int ok_count;
3637
3638 retry:
3639         if (take_rtnl)
3640                 rtnl_lock();
3641         down_read(&block->cb_lock);
3642         /* Need to obtain rtnl lock if block is bound to devs that require it.
3643          * In block bind code cb_lock is obtained while holding rtnl, so we must
3644          * obtain the locks in same order here.
3645          */
3646         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3647                 up_read(&block->cb_lock);
3648                 take_rtnl = true;
3649                 goto retry;
3650         }
3651
3652         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3653
3654         tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
3655         if (tp->ops->hw_del)
3656                 tp->ops->hw_del(tp, type_data);
3657
3658         up_read(&block->cb_lock);
3659         if (take_rtnl)
3660                 rtnl_unlock();
3661         return min(ok_count, 0);
3662 }
3663 EXPORT_SYMBOL(tc_setup_cb_destroy);
3664
3665 int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
3666                           bool add, flow_setup_cb_t *cb,
3667                           enum tc_setup_type type, void *type_data,
3668                           void *cb_priv, u32 *flags, unsigned int *in_hw_count)
3669 {
3670         int err = cb(type, type_data, cb_priv);
3671
3672         if (err) {
3673                 if (add && tc_skip_sw(*flags))
3674                         return err;
3675         } else {
3676                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags, 1,
3677                                           add);
3678         }
3679
3680         return 0;
3681 }
3682 EXPORT_SYMBOL(tc_setup_cb_reoffload);
3683
3684 static int tcf_act_get_user_cookie(struct flow_action_entry *entry,
3685                                    const struct tc_action *act)
3686 {
3687         struct tc_cookie *user_cookie;
3688         int err = 0;
3689
3690         rcu_read_lock();
3691         user_cookie = rcu_dereference(act->user_cookie);
3692         if (user_cookie) {
3693                 entry->user_cookie = flow_action_cookie_create(user_cookie->data,
3694                                                                user_cookie->len,
3695                                                                GFP_ATOMIC);
3696                 if (!entry->user_cookie)
3697                         err = -ENOMEM;
3698         }
3699         rcu_read_unlock();
3700         return err;
3701 }
3702
3703 static void tcf_act_put_user_cookie(struct flow_action_entry *entry)
3704 {
3705         flow_action_cookie_destroy(entry->user_cookie);
3706 }
3707
3708 void tc_cleanup_offload_action(struct flow_action *flow_action)
3709 {
3710         struct flow_action_entry *entry;
3711         int i;
3712
3713         flow_action_for_each(i, entry, flow_action) {
3714                 tcf_act_put_user_cookie(entry);
3715                 if (entry->destructor)
3716                         entry->destructor(entry->destructor_priv);
3717         }
3718 }
3719 EXPORT_SYMBOL(tc_cleanup_offload_action);
3720
3721 static int tc_setup_offload_act(struct tc_action *act,
3722                                 struct flow_action_entry *entry,
3723                                 u32 *index_inc,
3724                                 struct netlink_ext_ack *extack)
3725 {
3726 #ifdef CONFIG_NET_CLS_ACT
3727         if (act->ops->offload_act_setup) {
3728                 return act->ops->offload_act_setup(act, entry, index_inc, true,
3729                                                    extack);
3730         } else {
3731                 NL_SET_ERR_MSG(extack, "Action does not support offload");
3732                 return -EOPNOTSUPP;
3733         }
3734 #else
3735         return 0;
3736 #endif
3737 }
3738
3739 int tc_setup_action(struct flow_action *flow_action,
3740                     struct tc_action *actions[],
3741                     u32 miss_cookie_base,
3742                     struct netlink_ext_ack *extack)
3743 {
3744         int i, j, k, index, err = 0;
3745         struct tc_action *act;
3746
3747         BUILD_BUG_ON(TCA_ACT_HW_STATS_ANY != FLOW_ACTION_HW_STATS_ANY);
3748         BUILD_BUG_ON(TCA_ACT_HW_STATS_IMMEDIATE != FLOW_ACTION_HW_STATS_IMMEDIATE);
3749         BUILD_BUG_ON(TCA_ACT_HW_STATS_DELAYED != FLOW_ACTION_HW_STATS_DELAYED);
3750
3751         if (!actions)
3752                 return 0;
3753
3754         j = 0;
3755         tcf_act_for_each_action(i, act, actions) {
3756                 struct flow_action_entry *entry;
3757
3758                 entry = &flow_action->entries[j];
3759                 spin_lock_bh(&act->tcfa_lock);
3760                 err = tcf_act_get_user_cookie(entry, act);
3761                 if (err)
3762                         goto err_out_locked;
3763
3764                 index = 0;
3765                 err = tc_setup_offload_act(act, entry, &index, extack);
3766                 if (err)
3767                         goto err_out_locked;
3768
3769                 for (k = 0; k < index ; k++) {
3770                         entry[k].hw_stats = tc_act_hw_stats(act->hw_stats);
3771                         entry[k].hw_index = act->tcfa_index;
3772                         entry[k].cookie = (unsigned long)act;
3773                         entry[k].miss_cookie =
3774                                 tcf_exts_miss_cookie_get(miss_cookie_base, i);
3775                 }
3776
3777                 j += index;
3778
3779                 spin_unlock_bh(&act->tcfa_lock);
3780         }
3781
3782 err_out:
3783         if (err)
3784                 tc_cleanup_offload_action(flow_action);
3785
3786         return err;
3787 err_out_locked:
3788         spin_unlock_bh(&act->tcfa_lock);
3789         goto err_out;
3790 }
3791
3792 int tc_setup_offload_action(struct flow_action *flow_action,
3793                             const struct tcf_exts *exts,
3794                             struct netlink_ext_ack *extack)
3795 {
3796 #ifdef CONFIG_NET_CLS_ACT
3797         u32 miss_cookie_base;
3798
3799         if (!exts)
3800                 return 0;
3801
3802         miss_cookie_base = exts->miss_cookie_node ?
3803                            exts->miss_cookie_node->miss_cookie_base : 0;
3804         return tc_setup_action(flow_action, exts->actions, miss_cookie_base,
3805                                extack);
3806 #else
3807         return 0;
3808 #endif
3809 }
3810 EXPORT_SYMBOL(tc_setup_offload_action);
3811
3812 unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
3813 {
3814         unsigned int num_acts = 0;
3815         struct tc_action *act;
3816         int i;
3817
3818         tcf_exts_for_each_action(i, act, exts) {
3819                 if (is_tcf_pedit(act))
3820                         num_acts += tcf_pedit_nkeys(act);
3821                 else
3822                         num_acts++;
3823         }
3824         return num_acts;
3825 }
3826 EXPORT_SYMBOL(tcf_exts_num_actions);
3827
3828 #ifdef CONFIG_NET_CLS_ACT
3829 static int tcf_qevent_parse_block_index(struct nlattr *block_index_attr,
3830                                         u32 *p_block_index,
3831                                         struct netlink_ext_ack *extack)
3832 {
3833         *p_block_index = nla_get_u32(block_index_attr);
3834         if (!*p_block_index) {
3835                 NL_SET_ERR_MSG(extack, "Block number may not be zero");
3836                 return -EINVAL;
3837         }
3838
3839         return 0;
3840 }
3841
3842 int tcf_qevent_init(struct tcf_qevent *qe, struct Qdisc *sch,
3843                     enum flow_block_binder_type binder_type,
3844                     struct nlattr *block_index_attr,
3845                     struct netlink_ext_ack *extack)
3846 {
3847         u32 block_index;
3848         int err;
3849
3850         if (!block_index_attr)
3851                 return 0;
3852
3853         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3854         if (err)
3855                 return err;
3856
3857         qe->info.binder_type = binder_type;
3858         qe->info.chain_head_change = tcf_chain_head_change_dflt;
3859         qe->info.chain_head_change_priv = &qe->filter_chain;
3860         qe->info.block_index = block_index;
3861
3862         return tcf_block_get_ext(&qe->block, sch, &qe->info, extack);
3863 }
3864 EXPORT_SYMBOL(tcf_qevent_init);
3865
3866 void tcf_qevent_destroy(struct tcf_qevent *qe, struct Qdisc *sch)
3867 {
3868         if (qe->info.block_index)
3869                 tcf_block_put_ext(qe->block, sch, &qe->info);
3870 }
3871 EXPORT_SYMBOL(tcf_qevent_destroy);
3872
3873 int tcf_qevent_validate_change(struct tcf_qevent *qe, struct nlattr *block_index_attr,
3874                                struct netlink_ext_ack *extack)
3875 {
3876         u32 block_index;
3877         int err;
3878
3879         if (!block_index_attr)
3880                 return 0;
3881
3882         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3883         if (err)
3884                 return err;
3885
3886         /* Bounce newly-configured block or change in block. */
3887         if (block_index != qe->info.block_index) {
3888                 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
3889                 return -EINVAL;
3890         }
3891
3892         return 0;
3893 }
3894 EXPORT_SYMBOL(tcf_qevent_validate_change);
3895
3896 struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
3897                                   struct sk_buff **to_free, int *ret)
3898 {
3899         struct tcf_result cl_res;
3900         struct tcf_proto *fl;
3901
3902         if (!qe->info.block_index)
3903                 return skb;
3904
3905         fl = rcu_dereference_bh(qe->filter_chain);
3906
3907         switch (tcf_classify(skb, NULL, fl, &cl_res, false)) {
3908         case TC_ACT_SHOT:
3909                 qdisc_qstats_drop(sch);
3910                 __qdisc_drop(skb, to_free);
3911                 *ret = __NET_XMIT_BYPASS;
3912                 return NULL;
3913         case TC_ACT_STOLEN:
3914         case TC_ACT_QUEUED:
3915         case TC_ACT_TRAP:
3916                 __qdisc_drop(skb, to_free);
3917                 *ret = __NET_XMIT_STOLEN;
3918                 return NULL;
3919         case TC_ACT_REDIRECT:
3920                 skb_do_redirect(skb);
3921                 *ret = __NET_XMIT_STOLEN;
3922                 return NULL;
3923         }
3924
3925         return skb;
3926 }
3927 EXPORT_SYMBOL(tcf_qevent_handle);
3928
3929 int tcf_qevent_dump(struct sk_buff *skb, int attr_name, struct tcf_qevent *qe)
3930 {
3931         if (!qe->info.block_index)
3932                 return 0;
3933         return nla_put_u32(skb, attr_name, qe->info.block_index);
3934 }
3935 EXPORT_SYMBOL(tcf_qevent_dump);
3936 #endif
3937
3938 static __net_init int tcf_net_init(struct net *net)
3939 {
3940         struct tcf_net *tn = net_generic(net, tcf_net_id);
3941
3942         spin_lock_init(&tn->idr_lock);
3943         idr_init(&tn->idr);
3944         return 0;
3945 }
3946
3947 static void __net_exit tcf_net_exit(struct net *net)
3948 {
3949         struct tcf_net *tn = net_generic(net, tcf_net_id);
3950
3951         idr_destroy(&tn->idr);
3952 }
3953
3954 static struct pernet_operations tcf_net_ops = {
3955         .init = tcf_net_init,
3956         .exit = tcf_net_exit,
3957         .id   = &tcf_net_id,
3958         .size = sizeof(struct tcf_net),
3959 };
3960
3961 static int __init tc_filter_init(void)
3962 {
3963         int err;
3964
3965         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
3966         if (!tc_filter_wq)
3967                 return -ENOMEM;
3968
3969         err = register_pernet_subsys(&tcf_net_ops);
3970         if (err)
3971                 goto err_register_pernet_subsys;
3972
3973         xa_init_flags(&tcf_exts_miss_cookies_xa, XA_FLAGS_ALLOC1);
3974
3975         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
3976                       RTNL_FLAG_DOIT_UNLOCKED);
3977         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
3978                       RTNL_FLAG_DOIT_UNLOCKED);
3979         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
3980                       tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
3981         rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
3982         rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
3983         rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
3984                       tc_dump_chain, 0);
3985
3986         return 0;
3987
3988 err_register_pernet_subsys:
3989         destroy_workqueue(tc_filter_wq);
3990         return err;
3991 }
3992
3993 subsys_initcall(tc_filter_init);