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 extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1];
  47
  48 /* The list of all installed classifier types */
  49 static LIST_HEAD(tcf_proto_base);
  50
  51 /* Protects list of registered TC modules. It is pure SMP lock. */
  52 static DEFINE_RWLOCK(cls_mod_lock);
  53
  54 static struct xarray tcf_exts_miss_cookies_xa;
  55 struct tcf_exts_miss_cookie_node {
  56         const struct tcf_chain *chain;
  57         const struct tcf_proto *tp;
  58         const struct tcf_exts *exts;
  59         u32 chain_index;
  60         u32 tp_prio;
  61         u32 handle;
  62         u32 miss_cookie_base;
  63         struct rcu_head rcu;
  64 };
  65
  66 /* Each tc action entry cookie will be comprised of 32bit miss_cookie_base +
  67  * action index in the exts tc actions array.
  68  */
  69 union tcf_exts_miss_cookie {
  70         struct {
  71                 u32 miss_cookie_base;
  72                 u32 act_index;
  73         };
  74         u64 miss_cookie;
  75 };
  76
  77 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
  78 static int
  79 tcf_exts_miss_cookie_base_alloc(struct tcf_exts *exts, struct tcf_proto *tp,
  80                                 u32 handle)
  81 {
  82         struct tcf_exts_miss_cookie_node *n;
  83         static u32 next;
  84         int err;
  85
  86         if (WARN_ON(!handle || !tp->ops->get_exts))
  87                 return -EINVAL;
  88
  89         n = kzalloc(sizeof(*n), GFP_KERNEL);
  90         if (!n)
  91                 return -ENOMEM;
  92
  93         n->chain_index = tp->chain->index;
  94         n->chain = tp->chain;
  95         n->tp_prio = tp->prio;
  96         n->tp = tp;
  97         n->exts = exts;
  98         n->handle = handle;
  99
 100         err = xa_alloc_cyclic(&tcf_exts_miss_cookies_xa, &n->miss_cookie_base,
 101                               n, xa_limit_32b, &next, GFP_KERNEL);
 102         if (err)
 103                 goto err_xa_alloc;
 104
 105         exts->miss_cookie_node = n;
 106         return 0;
 107
 108 err_xa_alloc:
 109         kfree(n);
 110         return err;
 111 }
 112
 113 static void tcf_exts_miss_cookie_base_destroy(struct tcf_exts *exts)
 114 {
 115         struct tcf_exts_miss_cookie_node *n;
 116
 117         if (!exts->miss_cookie_node)
 118                 return;
 119
 120         n = exts->miss_cookie_node;
 121         xa_erase(&tcf_exts_miss_cookies_xa, n->miss_cookie_base);
 122         kfree_rcu(n, rcu);
 123 }
 124
 125 static struct tcf_exts_miss_cookie_node *
 126 tcf_exts_miss_cookie_lookup(u64 miss_cookie, int *act_index)
 127 {
 128         union tcf_exts_miss_cookie mc = { .miss_cookie = miss_cookie, };
 129
 130         *act_index = mc.act_index;
 131         return xa_load(&tcf_exts_miss_cookies_xa, mc.miss_cookie_base);
 132 }
 133 #else /* IS_ENABLED(CONFIG_NET_TC_SKB_EXT) */
 134 static int
 135 tcf_exts_miss_cookie_base_alloc(struct tcf_exts *exts, struct tcf_proto *tp,
 136                                 u32 handle)
 137 {
 138         return 0;
 139 }
 140
 141 static void tcf_exts_miss_cookie_base_destroy(struct tcf_exts *exts)
 142 {
 143 }
 144 #endif /* IS_ENABLED(CONFIG_NET_TC_SKB_EXT) */
 145
 146 static u64 tcf_exts_miss_cookie_get(u32 miss_cookie_base, int act_index)
 147 {
 148         union tcf_exts_miss_cookie mc = { .act_index = act_index, };
 149
 150         if (!miss_cookie_base)
 151                 return 0;
 152
 153         mc.miss_cookie_base = miss_cookie_base;
 154         return mc.miss_cookie;
 155 }
 156
 157 #ifdef CONFIG_NET_CLS_ACT
 158 DEFINE_STATIC_KEY_FALSE(tc_skb_ext_tc);
 159 EXPORT_SYMBOL(tc_skb_ext_tc);
 160
 161 void tc_skb_ext_tc_enable(void)
 162 {
 163         static_branch_inc(&tc_skb_ext_tc);
 164 }
 165 EXPORT_SYMBOL(tc_skb_ext_tc_enable);
 166
 167 void tc_skb_ext_tc_disable(void)
 168 {
 169         static_branch_dec(&tc_skb_ext_tc);
 170 }
 171 EXPORT_SYMBOL(tc_skb_ext_tc_disable);
 172 #endif
 173
 174 static u32 destroy_obj_hashfn(const struct tcf_proto *tp)
 175 {
 176         return jhash_3words(tp->chain->index, tp->prio,
 177                             (__force __u32)tp->protocol, 0);
 178 }
 179
 180 static void tcf_proto_signal_destroying(struct tcf_chain *chain,
 181                                         struct tcf_proto *tp)
 182 {
 183         struct tcf_block *block = chain->block;
 184
 185         mutex_lock(&block->proto_destroy_lock);
 186         hash_add_rcu(block->proto_destroy_ht, &tp->destroy_ht_node,
 187                      destroy_obj_hashfn(tp));
 188         mutex_unlock(&block->proto_destroy_lock);
 189 }
 190
 191 static bool tcf_proto_cmp(const struct tcf_proto *tp1,
 192                           const struct tcf_proto *tp2)
 193 {
 194         return tp1->chain->index == tp2->chain->index &&
 195                tp1->prio == tp2->prio &&
 196                tp1->protocol == tp2->protocol;
 197 }
 198
 199 static bool tcf_proto_exists_destroying(struct tcf_chain *chain,
 200                                         struct tcf_proto *tp)
 201 {
 202         u32 hash = destroy_obj_hashfn(tp);
 203         struct tcf_proto *iter;
 204         bool found = false;
 205
 206         rcu_read_lock();
 207         hash_for_each_possible_rcu(chain->block->proto_destroy_ht, iter,
 208                                    destroy_ht_node, hash) {
 209                 if (tcf_proto_cmp(tp, iter)) {
 210                         found = true;
 211                         break;
 212                 }
 213         }
 214         rcu_read_unlock();
 215
 216         return found;
 217 }
 218
 219 static void
 220 tcf_proto_signal_destroyed(struct tcf_chain *chain, struct tcf_proto *tp)
 221 {
 222         struct tcf_block *block = chain->block;
 223
 224         mutex_lock(&block->proto_destroy_lock);
 225         if (hash_hashed(&tp->destroy_ht_node))
 226                 hash_del_rcu(&tp->destroy_ht_node);
 227         mutex_unlock(&block->proto_destroy_lock);
 228 }
 229
 230 /* Find classifier type by string name */
 231
 232 static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
 233 {
 234         const struct tcf_proto_ops *t, *res = NULL;
 235
 236         if (kind) {
 237                 read_lock(&cls_mod_lock);
 238                 list_for_each_entry(t, &tcf_proto_base, head) {
 239                         if (strcmp(kind, t->kind) == 0) {
 240                                 if (try_module_get(t->owner))
 241                                         res = t;
 242                                 break;
 243                         }
 244                 }
 245                 read_unlock(&cls_mod_lock);
 246         }
 247         return res;
 248 }
 249
 250 static const struct tcf_proto_ops *
 251 tcf_proto_lookup_ops(const char *kind, bool rtnl_held,
 252                      struct netlink_ext_ack *extack)
 253 {
 254         const struct tcf_proto_ops *ops;
 255
 256         ops = __tcf_proto_lookup_ops(kind);
 257         if (ops)
 258                 return ops;
 259 #ifdef CONFIG_MODULES
 260         if (rtnl_held)
 261                 rtnl_unlock();
 262         request_module("cls_%s", kind);
 263         if (rtnl_held)
 264                 rtnl_lock();
 265         ops = __tcf_proto_lookup_ops(kind);
 266         /* We dropped the RTNL semaphore in order to perform
 267          * the module load. So, even if we succeeded in loading
 268          * the module we have to replay the request. We indicate
 269          * this using -EAGAIN.
 270          */
 271         if (ops) {
 272                 module_put(ops->owner);
 273                 return ERR_PTR(-EAGAIN);
 274         }
 275 #endif
 276         NL_SET_ERR_MSG(extack, "TC classifier not found");
 277         return ERR_PTR(-ENOENT);
 278 }
 279
 280 /* Register(unregister) new classifier type */
 281
 282 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
 283 {
 284         struct tcf_proto_ops *t;
 285         int rc = -EEXIST;
 286
 287         write_lock(&cls_mod_lock);
 288         list_for_each_entry(t, &tcf_proto_base, head)
 289                 if (!strcmp(ops->kind, t->kind))
 290                         goto out;
 291
 292         list_add_tail(&ops->head, &tcf_proto_base);
 293         rc = 0;
 294 out:
 295         write_unlock(&cls_mod_lock);
 296         return rc;
 297 }
 298 EXPORT_SYMBOL(register_tcf_proto_ops);
 299
 300 static struct workqueue_struct *tc_filter_wq;
 301
 302 void unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
 303 {
 304         struct tcf_proto_ops *t;
 305         int rc = -ENOENT;
 306
 307         /* Wait for outstanding call_rcu()s, if any, from a
 308          * tcf_proto_ops's destroy() handler.
 309          */
 310         rcu_barrier();
 311         flush_workqueue(tc_filter_wq);
 312
 313         write_lock(&cls_mod_lock);
 314         list_for_each_entry(t, &tcf_proto_base, head) {
 315                 if (t == ops) {
 316                         list_del(&t->head);
 317                         rc = 0;
 318                         break;
 319                 }
 320         }
 321         write_unlock(&cls_mod_lock);
 322
 323         WARN(rc, "unregister tc filter kind(%s) failed %d\n", ops->kind, rc);
 324 }
 325 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 326
 327 bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
 328 {
 329         INIT_RCU_WORK(rwork, func);
 330         return queue_rcu_work(tc_filter_wq, rwork);
 331 }
 332 EXPORT_SYMBOL(tcf_queue_work);
 333
 334 /* Select new prio value from the range, managed by kernel. */
 335
 336 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 337 {
 338         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 339
 340         if (tp)
 341                 first = tp->prio - 1;
 342
 343         return TC_H_MAJ(first);
 344 }
 345
 346 static bool tcf_proto_check_kind(struct nlattr *kind, char *name)
 347 {
 348         if (kind)
 349                 return nla_strscpy(name, kind, IFNAMSIZ) < 0;
 350         memset(name, 0, IFNAMSIZ);
 351         return false;
 352 }
 353
 354 static bool tcf_proto_is_unlocked(const char *kind)
 355 {
 356         const struct tcf_proto_ops *ops;
 357         bool ret;
 358
 359         if (strlen(kind) == 0)
 360                 return false;
 361
 362         ops = tcf_proto_lookup_ops(kind, false, NULL);
 363         /* On error return false to take rtnl lock. Proto lookup/create
 364          * functions will perform lookup again and properly handle errors.
 365          */
 366         if (IS_ERR(ops))
 367                 return false;
 368
 369         ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED);
 370         module_put(ops->owner);
 371         return ret;
 372 }
 373
 374 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 375                                           u32 prio, struct tcf_chain *chain,
 376                                           bool rtnl_held,
 377                                           struct netlink_ext_ack *extack)
 378 {
 379         struct tcf_proto *tp;
 380         int err;
 381
 382         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 383         if (!tp)
 384                 return ERR_PTR(-ENOBUFS);
 385
 386         tp->ops = tcf_proto_lookup_ops(kind, rtnl_held, extack);
 387         if (IS_ERR(tp->ops)) {
 388                 err = PTR_ERR(tp->ops);
 389                 goto errout;
 390         }
 391         tp->classify = tp->ops->classify;
 392         tp->protocol = protocol;
 393         tp->prio = prio;
 394         tp->chain = chain;
 395         spin_lock_init(&tp->lock);
 396         refcount_set(&tp->refcnt, 1);
 397
 398         err = tp->ops->init(tp);
 399         if (err) {
 400                 module_put(tp->ops->owner);
 401                 goto errout;
 402         }
 403         return tp;
 404
 405 errout:
 406         kfree(tp);
 407         return ERR_PTR(err);
 408 }
 409
 410 static void tcf_proto_get(struct tcf_proto *tp)
 411 {
 412         refcount_inc(&tp->refcnt);
 413 }
 414
 415 static void tcf_chain_put(struct tcf_chain *chain);
 416
 417 static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
 418                               bool sig_destroy, struct netlink_ext_ack *extack)
 419 {
 420         tp->ops->destroy(tp, rtnl_held, extack);
 421         if (sig_destroy)
 422                 tcf_proto_signal_destroyed(tp->chain, tp);
 423         tcf_chain_put(tp->chain);
 424         module_put(tp->ops->owner);
 425         kfree_rcu(tp, rcu);
 426 }
 427
 428 static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
 429                           struct netlink_ext_ack *extack)
 430 {
 431         if (refcount_dec_and_test(&tp->refcnt))
 432                 tcf_proto_destroy(tp, rtnl_held, true, extack);
 433 }
 434
 435 static bool tcf_proto_check_delete(struct tcf_proto *tp)
 436 {
 437         if (tp->ops->delete_empty)
 438                 return tp->ops->delete_empty(tp);
 439
 440         tp->deleting = true;
 441         return tp->deleting;
 442 }
 443
 444 static void tcf_proto_mark_delete(struct tcf_proto *tp)
 445 {
 446         spin_lock(&tp->lock);
 447         tp->deleting = true;
 448         spin_unlock(&tp->lock);
 449 }
 450
 451 static bool tcf_proto_is_deleting(struct tcf_proto *tp)
 452 {
 453         bool deleting;
 454
 455         spin_lock(&tp->lock);
 456         deleting = tp->deleting;
 457         spin_unlock(&tp->lock);
 458
 459         return deleting;
 460 }
 461
 462 #define ASSERT_BLOCK_LOCKED(block)                                      \
 463         lockdep_assert_held(&(block)->lock)
 464
 465 struct tcf_filter_chain_list_item {
 466         struct list_head list;
 467         tcf_chain_head_change_t *chain_head_change;
 468         void *chain_head_change_priv;
 469 };
 470
 471 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 472                                           u32 chain_index)
 473 {
 474         struct tcf_chain *chain;
 475
 476         ASSERT_BLOCK_LOCKED(block);
 477
 478         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 479         if (!chain)
 480                 return NULL;
 481         list_add_tail_rcu(&chain->list, &block->chain_list);
 482         mutex_init(&chain->filter_chain_lock);
 483         chain->block = block;
 484         chain->index = chain_index;
 485         chain->refcnt = 1;
 486         if (!chain->index)
 487                 block->chain0.chain = chain;
 488         return chain;
 489 }
 490
 491 static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
 492                                        struct tcf_proto *tp_head)
 493 {
 494         if (item->chain_head_change)
 495                 item->chain_head_change(tp_head, item->chain_head_change_priv);
 496 }
 497
 498 static void tcf_chain0_head_change(struct tcf_chain *chain,
 499                                    struct tcf_proto *tp_head)
 500 {
 501         struct tcf_filter_chain_list_item *item;
 502         struct tcf_block *block = chain->block;
 503
 504         if (chain->index)
 505                 return;
 506
 507         mutex_lock(&block->lock);
 508         list_for_each_entry(item, &block->chain0.filter_chain_list, list)
 509                 tcf_chain_head_change_item(item, tp_head);
 510         mutex_unlock(&block->lock);
 511 }
 512
 513 /* Returns true if block can be safely freed. */
 514
 515 static bool tcf_chain_detach(struct tcf_chain *chain)
 516 {
 517         struct tcf_block *block = chain->block;
 518
 519         ASSERT_BLOCK_LOCKED(block);
 520
 521         list_del_rcu(&chain->list);
 522         if (!chain->index)
 523                 block->chain0.chain = NULL;
 524
 525         if (list_empty(&block->chain_list) &&
 526             refcount_read(&block->refcnt) == 0)
 527                 return true;
 528
 529         return false;
 530 }
 531
 532 static void tcf_block_destroy(struct tcf_block *block)
 533 {
 534         mutex_destroy(&block->lock);
 535         mutex_destroy(&block->proto_destroy_lock);
 536         kfree_rcu(block, rcu);
 537 }
 538
 539 static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
 540 {
 541         struct tcf_block *block = chain->block;
 542
 543         mutex_destroy(&chain->filter_chain_lock);
 544         kfree_rcu(chain, rcu);
 545         if (free_block)
 546                 tcf_block_destroy(block);
 547 }
 548
 549 static void tcf_chain_hold(struct tcf_chain *chain)
 550 {
 551         ASSERT_BLOCK_LOCKED(chain->block);
 552
 553         ++chain->refcnt;
 554 }
 555
 556 static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain)
 557 {
 558         ASSERT_BLOCK_LOCKED(chain->block);
 559
 560         /* In case all the references are action references, this
 561          * chain should not be shown to the user.
 562          */
 563         return chain->refcnt == chain->action_refcnt;
 564 }
 565
 566 static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
 567                                           u32 chain_index)
 568 {
 569         struct tcf_chain *chain;
 570
 571         ASSERT_BLOCK_LOCKED(block);
 572
 573         list_for_each_entry(chain, &block->chain_list, list) {
 574                 if (chain->index == chain_index)
 575                         return chain;
 576         }
 577         return NULL;
 578 }
 579
 580 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 581 static struct tcf_chain *tcf_chain_lookup_rcu(const struct tcf_block *block,
 582                                               u32 chain_index)
 583 {
 584         struct tcf_chain *chain;
 585
 586         list_for_each_entry_rcu(chain, &block->chain_list, list) {
 587                 if (chain->index == chain_index)
 588                         return chain;
 589         }
 590         return NULL;
 591 }
 592 #endif
 593
 594 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 595                            u32 seq, u16 flags, int event, bool unicast,
 596                            struct netlink_ext_ack *extack);
 597
 598 static struct tcf_chain *__tcf_chain_get(struct tcf_block *block,
 599                                          u32 chain_index, bool create,
 600                                          bool by_act)
 601 {
 602         struct tcf_chain *chain = NULL;
 603         bool is_first_reference;
 604
 605         mutex_lock(&block->lock);
 606         chain = tcf_chain_lookup(block, chain_index);
 607         if (chain) {
 608                 tcf_chain_hold(chain);
 609         } else {
 610                 if (!create)
 611                         goto errout;
 612                 chain = tcf_chain_create(block, chain_index);
 613                 if (!chain)
 614                         goto errout;
 615         }
 616
 617         if (by_act)
 618                 ++chain->action_refcnt;
 619         is_first_reference = chain->refcnt - chain->action_refcnt == 1;
 620         mutex_unlock(&block->lock);
 621
 622         /* Send notification only in case we got the first
 623          * non-action reference. Until then, the chain acts only as
 624          * a placeholder for actions pointing to it and user ought
 625          * not know about them.
 626          */
 627         if (is_first_reference && !by_act)
 628                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
 629                                 RTM_NEWCHAIN, false, NULL);
 630
 631         return chain;
 632
 633 errout:
 634         mutex_unlock(&block->lock);
 635         return chain;
 636 }
 637
 638 static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 639                                        bool create)
 640 {
 641         return __tcf_chain_get(block, chain_index, create, false);
 642 }
 643
 644 struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index)
 645 {
 646         return __tcf_chain_get(block, chain_index, true, true);
 647 }
 648 EXPORT_SYMBOL(tcf_chain_get_by_act);
 649
 650 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
 651                                void *tmplt_priv);
 652 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
 653                                   void *tmplt_priv, u32 chain_index,
 654                                   struct tcf_block *block, struct sk_buff *oskb,
 655                                   u32 seq, u16 flags, bool unicast);
 656
 657 static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
 658                             bool explicitly_created)
 659 {
 660         struct tcf_block *block = chain->block;
 661         const struct tcf_proto_ops *tmplt_ops;
 662         bool free_block = false;
 663         unsigned int refcnt;
 664         void *tmplt_priv;
 665
 666         mutex_lock(&block->lock);
 667         if (explicitly_created) {
 668                 if (!chain->explicitly_created) {
 669                         mutex_unlock(&block->lock);
 670                         return;
 671                 }
 672                 chain->explicitly_created = false;
 673         }
 674
 675         if (by_act)
 676                 chain->action_refcnt--;
 677
 678         /* tc_chain_notify_delete can't be called while holding block lock.
 679          * However, when block is unlocked chain can be changed concurrently, so
 680          * save these to temporary variables.
 681          */
 682         refcnt = --chain->refcnt;
 683         tmplt_ops = chain->tmplt_ops;
 684         tmplt_priv = chain->tmplt_priv;
 685
 686         /* The last dropped non-action reference will trigger notification. */
 687         if (refcnt - chain->action_refcnt == 0 && !by_act) {
 688                 tc_chain_notify_delete(tmplt_ops, tmplt_priv, chain->index,
 689                                        block, NULL, 0, 0, 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                 if (i-- > 0) {
1593                         list_del(&block_cb->list);
1594                         tcf_block_playback_offloads(block, block_cb->cb,
1595                                                     block_cb->cb_priv, false,
1596                                                     tcf_block_offload_in_use(block),
1597                                                     NULL);
1598                         if (!bo->unlocked_driver_cb)
1599                                 block->lockeddevcnt--;
1600                 }
1601                 flow_block_cb_free(block_cb);
1602         }
1603
1604         return err;
1605 }
1606
1607 static void tcf_block_unbind(struct tcf_block *block,
1608                              struct flow_block_offload *bo)
1609 {
1610         struct flow_block_cb *block_cb, *next;
1611
1612         lockdep_assert_held(&block->cb_lock);
1613
1614         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1615                 tcf_block_playback_offloads(block, block_cb->cb,
1616                                             block_cb->cb_priv, false,
1617                                             tcf_block_offload_in_use(block),
1618                                             NULL);
1619                 list_del(&block_cb->list);
1620                 flow_block_cb_free(block_cb);
1621                 if (!bo->unlocked_driver_cb)
1622                         block->lockeddevcnt--;
1623         }
1624 }
1625
1626 static int tcf_block_setup(struct tcf_block *block,
1627                            struct flow_block_offload *bo)
1628 {
1629         int err;
1630
1631         switch (bo->command) {
1632         case FLOW_BLOCK_BIND:
1633                 err = tcf_block_bind(block, bo);
1634                 break;
1635         case FLOW_BLOCK_UNBIND:
1636                 err = 0;
1637                 tcf_block_unbind(block, bo);
1638                 break;
1639         default:
1640                 WARN_ON_ONCE(1);
1641                 err = -EOPNOTSUPP;
1642         }
1643
1644         return err;
1645 }
1646
1647 /* Main classifier routine: scans classifier chain attached
1648  * to this qdisc, (optionally) tests for protocol and asks
1649  * specific classifiers.
1650  */
1651 static inline int __tcf_classify(struct sk_buff *skb,
1652                                  const struct tcf_proto *tp,
1653                                  const struct tcf_proto *orig_tp,
1654                                  struct tcf_result *res,
1655                                  bool compat_mode,
1656                                  struct tcf_exts_miss_cookie_node *n,
1657                                  int act_index,
1658                                  u32 *last_executed_chain)
1659 {
1660 #ifdef CONFIG_NET_CLS_ACT
1661         const int max_reclassify_loop = 16;
1662         const struct tcf_proto *first_tp;
1663         int limit = 0;
1664
1665 reclassify:
1666 #endif
1667         for (; tp; tp = rcu_dereference_bh(tp->next)) {
1668                 __be16 protocol = skb_protocol(skb, false);
1669                 int err = 0;
1670
1671                 if (n) {
1672                         struct tcf_exts *exts;
1673
1674                         if (n->tp_prio != tp->prio)
1675                                 continue;
1676
1677                         /* We re-lookup the tp and chain based on index instead
1678                          * of having hard refs and locks to them, so do a sanity
1679                          * check if any of tp,chain,exts was replaced by the
1680                          * time we got here with a cookie from hardware.
1681                          */
1682                         if (unlikely(n->tp != tp || n->tp->chain != n->chain ||
1683                                      !tp->ops->get_exts))
1684                                 return TC_ACT_SHOT;
1685
1686                         exts = tp->ops->get_exts(tp, n->handle);
1687                         if (unlikely(!exts || n->exts != exts))
1688                                 return TC_ACT_SHOT;
1689
1690                         n = NULL;
1691                         err = tcf_exts_exec_ex(skb, exts, act_index, res);
1692                 } else {
1693                         if (tp->protocol != protocol &&
1694                             tp->protocol != htons(ETH_P_ALL))
1695                                 continue;
1696
1697                         err = tc_classify(skb, tp, res);
1698                 }
1699 #ifdef CONFIG_NET_CLS_ACT
1700                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
1701                         first_tp = orig_tp;
1702                         *last_executed_chain = first_tp->chain->index;
1703                         goto reset;
1704                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
1705                         first_tp = res->goto_tp;
1706                         *last_executed_chain = err & TC_ACT_EXT_VAL_MASK;
1707                         goto reset;
1708                 }
1709 #endif
1710                 if (err >= 0)
1711                         return err;
1712         }
1713
1714         if (unlikely(n))
1715                 return TC_ACT_SHOT;
1716
1717         return TC_ACT_UNSPEC; /* signal: continue lookup */
1718 #ifdef CONFIG_NET_CLS_ACT
1719 reset:
1720         if (unlikely(limit++ >= max_reclassify_loop)) {
1721                 net_notice_ratelimited("%u: reclassify loop, rule prio %u, protocol %02x\n",
1722                                        tp->chain->block->index,
1723                                        tp->prio & 0xffff,
1724                                        ntohs(tp->protocol));
1725                 return TC_ACT_SHOT;
1726         }
1727
1728         tp = first_tp;
1729         goto reclassify;
1730 #endif
1731 }
1732
1733 int tcf_classify(struct sk_buff *skb,
1734                  const struct tcf_block *block,
1735                  const struct tcf_proto *tp,
1736                  struct tcf_result *res, bool compat_mode)
1737 {
1738 #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1739         u32 last_executed_chain = 0;
1740
1741         return __tcf_classify(skb, tp, tp, res, compat_mode, NULL, 0,
1742                               &last_executed_chain);
1743 #else
1744         u32 last_executed_chain = tp ? tp->chain->index : 0;
1745         struct tcf_exts_miss_cookie_node *n = NULL;
1746         const struct tcf_proto *orig_tp = tp;
1747         struct tc_skb_ext *ext;
1748         int act_index = 0;
1749         int ret;
1750
1751         if (block) {
1752                 ext = skb_ext_find(skb, TC_SKB_EXT);
1753
1754                 if (ext && (ext->chain || ext->act_miss)) {
1755                         struct tcf_chain *fchain;
1756                         u32 chain;
1757
1758                         if (ext->act_miss) {
1759                                 n = tcf_exts_miss_cookie_lookup(ext->act_miss_cookie,
1760                                                                 &act_index);
1761                                 if (!n)
1762                                         return TC_ACT_SHOT;
1763
1764                                 chain = n->chain_index;
1765                         } else {
1766                                 chain = ext->chain;
1767                         }
1768
1769                         fchain = tcf_chain_lookup_rcu(block, chain);
1770                         if (!fchain)
1771                                 return TC_ACT_SHOT;
1772
1773                         /* Consume, so cloned/redirect skbs won't inherit ext */
1774                         skb_ext_del(skb, TC_SKB_EXT);
1775
1776                         tp = rcu_dereference_bh(fchain->filter_chain);
1777                         last_executed_chain = fchain->index;
1778                 }
1779         }
1780
1781         ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode, n, act_index,
1782                              &last_executed_chain);
1783
1784         if (tc_skb_ext_tc_enabled()) {
1785                 /* If we missed on some chain */
1786                 if (ret == TC_ACT_UNSPEC && last_executed_chain) {
1787                         struct tc_skb_cb *cb = tc_skb_cb(skb);
1788
1789                         ext = tc_skb_ext_alloc(skb);
1790                         if (WARN_ON_ONCE(!ext))
1791                                 return TC_ACT_SHOT;
1792                         ext->chain = last_executed_chain;
1793                         ext->mru = cb->mru;
1794                         ext->post_ct = cb->post_ct;
1795                         ext->post_ct_snat = cb->post_ct_snat;
1796                         ext->post_ct_dnat = cb->post_ct_dnat;
1797                         ext->zone = cb->zone;
1798                 }
1799         }
1800
1801         return ret;
1802 #endif
1803 }
1804 EXPORT_SYMBOL(tcf_classify);
1805
1806 struct tcf_chain_info {
1807         struct tcf_proto __rcu **pprev;
1808         struct tcf_proto __rcu *next;
1809 };
1810
1811 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
1812                                            struct tcf_chain_info *chain_info)
1813 {
1814         return tcf_chain_dereference(*chain_info->pprev, chain);
1815 }
1816
1817 static int tcf_chain_tp_insert(struct tcf_chain *chain,
1818                                struct tcf_chain_info *chain_info,
1819                                struct tcf_proto *tp)
1820 {
1821         if (chain->flushing)
1822                 return -EAGAIN;
1823
1824         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
1825         if (*chain_info->pprev == chain->filter_chain)
1826                 tcf_chain0_head_change(chain, tp);
1827         tcf_proto_get(tp);
1828         rcu_assign_pointer(*chain_info->pprev, tp);
1829
1830         return 0;
1831 }
1832
1833 static void tcf_chain_tp_remove(struct tcf_chain *chain,
1834                                 struct tcf_chain_info *chain_info,
1835                                 struct tcf_proto *tp)
1836 {
1837         struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
1838
1839         tcf_proto_mark_delete(tp);
1840         if (tp == chain->filter_chain)
1841                 tcf_chain0_head_change(chain, next);
1842         RCU_INIT_POINTER(*chain_info->pprev, next);
1843 }
1844
1845 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1846                                            struct tcf_chain_info *chain_info,
1847                                            u32 protocol, u32 prio,
1848                                            bool prio_allocate);
1849
1850 /* Try to insert new proto.
1851  * If proto with specified priority already exists, free new proto
1852  * and return existing one.
1853  */
1854
1855 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
1856                                                     struct tcf_proto *tp_new,
1857                                                     u32 protocol, u32 prio,
1858                                                     bool rtnl_held)
1859 {
1860         struct tcf_chain_info chain_info;
1861         struct tcf_proto *tp;
1862         int err = 0;
1863
1864         mutex_lock(&chain->filter_chain_lock);
1865
1866         if (tcf_proto_exists_destroying(chain, tp_new)) {
1867                 mutex_unlock(&chain->filter_chain_lock);
1868                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1869                 return ERR_PTR(-EAGAIN);
1870         }
1871
1872         tp = tcf_chain_tp_find(chain, &chain_info,
1873                                protocol, prio, false);
1874         if (!tp)
1875                 err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
1876         mutex_unlock(&chain->filter_chain_lock);
1877
1878         if (tp) {
1879                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1880                 tp_new = tp;
1881         } else if (err) {
1882                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1883                 tp_new = ERR_PTR(err);
1884         }
1885
1886         return tp_new;
1887 }
1888
1889 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
1890                                       struct tcf_proto *tp, bool rtnl_held,
1891                                       struct netlink_ext_ack *extack)
1892 {
1893         struct tcf_chain_info chain_info;
1894         struct tcf_proto *tp_iter;
1895         struct tcf_proto **pprev;
1896         struct tcf_proto *next;
1897
1898         mutex_lock(&chain->filter_chain_lock);
1899
1900         /* Atomically find and remove tp from chain. */
1901         for (pprev = &chain->filter_chain;
1902              (tp_iter = tcf_chain_dereference(*pprev, chain));
1903              pprev = &tp_iter->next) {
1904                 if (tp_iter == tp) {
1905                         chain_info.pprev = pprev;
1906                         chain_info.next = tp_iter->next;
1907                         WARN_ON(tp_iter->deleting);
1908                         break;
1909                 }
1910         }
1911         /* Verify that tp still exists and no new filters were inserted
1912          * concurrently.
1913          * Mark tp for deletion if it is empty.
1914          */
1915         if (!tp_iter || !tcf_proto_check_delete(tp)) {
1916                 mutex_unlock(&chain->filter_chain_lock);
1917                 return;
1918         }
1919
1920         tcf_proto_signal_destroying(chain, tp);
1921         next = tcf_chain_dereference(chain_info.next, chain);
1922         if (tp == chain->filter_chain)
1923                 tcf_chain0_head_change(chain, next);
1924         RCU_INIT_POINTER(*chain_info.pprev, next);
1925         mutex_unlock(&chain->filter_chain_lock);
1926
1927         tcf_proto_put(tp, rtnl_held, extack);
1928 }
1929
1930 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1931                                            struct tcf_chain_info *chain_info,
1932                                            u32 protocol, u32 prio,
1933                                            bool prio_allocate)
1934 {
1935         struct tcf_proto **pprev;
1936         struct tcf_proto *tp;
1937
1938         /* Check the chain for existence of proto-tcf with this priority */
1939         for (pprev = &chain->filter_chain;
1940              (tp = tcf_chain_dereference(*pprev, chain));
1941              pprev = &tp->next) {
1942                 if (tp->prio >= prio) {
1943                         if (tp->prio == prio) {
1944                                 if (prio_allocate ||
1945                                     (tp->protocol != protocol && protocol))
1946                                         return ERR_PTR(-EINVAL);
1947                         } else {
1948                                 tp = NULL;
1949                         }
1950                         break;
1951                 }
1952         }
1953         chain_info->pprev = pprev;
1954         if (tp) {
1955                 chain_info->next = tp->next;
1956                 tcf_proto_get(tp);
1957         } else {
1958                 chain_info->next = NULL;
1959         }
1960         return tp;
1961 }
1962
1963 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
1964                          struct tcf_proto *tp, struct tcf_block *block,
1965                          struct Qdisc *q, u32 parent, void *fh,
1966                          u32 portid, u32 seq, u16 flags, int event,
1967                          bool terse_dump, bool rtnl_held,
1968                          struct netlink_ext_ack *extack)
1969 {
1970         struct tcmsg *tcm;
1971         struct nlmsghdr  *nlh;
1972         unsigned char *b = skb_tail_pointer(skb);
1973
1974         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1975         if (!nlh)
1976                 goto out_nlmsg_trim;
1977         tcm = nlmsg_data(nlh);
1978         tcm->tcm_family = AF_UNSPEC;
1979         tcm->tcm__pad1 = 0;
1980         tcm->tcm__pad2 = 0;
1981         if (q) {
1982                 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1983                 tcm->tcm_parent = parent;
1984         } else {
1985                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
1986                 tcm->tcm_block_index = block->index;
1987         }
1988         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
1989         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
1990                 goto nla_put_failure;
1991         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
1992                 goto nla_put_failure;
1993         if (!fh) {
1994                 tcm->tcm_handle = 0;
1995         } else if (terse_dump) {
1996                 if (tp->ops->terse_dump) {
1997                         if (tp->ops->terse_dump(net, tp, fh, skb, tcm,
1998                                                 rtnl_held) < 0)
1999                                 goto nla_put_failure;
2000                 } else {
2001                         goto cls_op_not_supp;
2002                 }
2003         } else {
2004                 if (tp->ops->dump &&
2005                     tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
2006                         goto nla_put_failure;
2007         }
2008
2009         if (extack && extack->_msg &&
2010             nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
2011                 goto nla_put_failure;
2012
2013         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2014
2015         return skb->len;
2016
2017 out_nlmsg_trim:
2018 nla_put_failure:
2019 cls_op_not_supp:
2020         nlmsg_trim(skb, b);
2021         return -1;
2022 }
2023
2024 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
2025                           struct nlmsghdr *n, struct tcf_proto *tp,
2026                           struct tcf_block *block, struct Qdisc *q,
2027                           u32 parent, void *fh, int event, bool unicast,
2028                           bool rtnl_held, struct netlink_ext_ack *extack)
2029 {
2030         struct sk_buff *skb;
2031         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2032         int err = 0;
2033
2034         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2035         if (!skb)
2036                 return -ENOBUFS;
2037
2038         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
2039                           n->nlmsg_seq, n->nlmsg_flags, event,
2040                           false, rtnl_held, extack) <= 0) {
2041                 kfree_skb(skb);
2042                 return -EINVAL;
2043         }
2044
2045         if (unicast)
2046                 err = rtnl_unicast(skb, net, portid);
2047         else
2048                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2049                                      n->nlmsg_flags & NLM_F_ECHO);
2050         return err;
2051 }
2052
2053 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
2054                               struct nlmsghdr *n, struct tcf_proto *tp,
2055                               struct tcf_block *block, struct Qdisc *q,
2056                               u32 parent, void *fh, bool unicast, bool *last,
2057                               bool rtnl_held, struct netlink_ext_ack *extack)
2058 {
2059         struct sk_buff *skb;
2060         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2061         int err;
2062
2063         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2064         if (!skb)
2065                 return -ENOBUFS;
2066
2067         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
2068                           n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
2069                           false, rtnl_held, extack) <= 0) {
2070                 NL_SET_ERR_MSG(extack, "Failed to build del event notification");
2071                 kfree_skb(skb);
2072                 return -EINVAL;
2073         }
2074
2075         err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
2076         if (err) {
2077                 kfree_skb(skb);
2078                 return err;
2079         }
2080
2081         if (unicast)
2082                 err = rtnl_unicast(skb, net, portid);
2083         else
2084                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2085                                      n->nlmsg_flags & NLM_F_ECHO);
2086         if (err < 0)
2087                 NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
2088
2089         return err;
2090 }
2091
2092 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
2093                                  struct tcf_block *block, struct Qdisc *q,
2094                                  u32 parent, struct nlmsghdr *n,
2095                                  struct tcf_chain *chain, int event,
2096                                  struct netlink_ext_ack *extack)
2097 {
2098         struct tcf_proto *tp;
2099
2100         for (tp = tcf_get_next_proto(chain, NULL);
2101              tp; tp = tcf_get_next_proto(chain, tp))
2102                 tfilter_notify(net, oskb, n, tp, block, q, parent, NULL,
2103                                event, false, true, extack);
2104 }
2105
2106 static void tfilter_put(struct tcf_proto *tp, void *fh)
2107 {
2108         if (tp->ops->put && fh)
2109                 tp->ops->put(tp, fh);
2110 }
2111
2112 static bool is_qdisc_ingress(__u32 classid)
2113 {
2114         return (TC_H_MIN(classid) == TC_H_MIN(TC_H_MIN_INGRESS));
2115 }
2116
2117 static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2118                           struct netlink_ext_ack *extack)
2119 {
2120         struct net *net = sock_net(skb->sk);
2121         struct nlattr *tca[TCA_MAX + 1];
2122         char name[IFNAMSIZ];
2123         struct tcmsg *t;
2124         u32 protocol;
2125         u32 prio;
2126         bool prio_allocate;
2127         u32 parent;
2128         u32 chain_index;
2129         struct Qdisc *q;
2130         struct tcf_chain_info chain_info;
2131         struct tcf_chain *chain;
2132         struct tcf_block *block;
2133         struct tcf_proto *tp;
2134         unsigned long cl;
2135         void *fh;
2136         int err;
2137         int tp_created;
2138         bool rtnl_held = false;
2139         u32 flags;
2140
2141 replay:
2142         tp_created = 0;
2143
2144         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2145                                      rtm_tca_policy, extack);
2146         if (err < 0)
2147                 return err;
2148
2149         t = nlmsg_data(n);
2150         protocol = TC_H_MIN(t->tcm_info);
2151         prio = TC_H_MAJ(t->tcm_info);
2152         prio_allocate = false;
2153         parent = t->tcm_parent;
2154         tp = NULL;
2155         cl = 0;
2156         block = NULL;
2157         q = NULL;
2158         chain = NULL;
2159         flags = 0;
2160
2161         if (prio == 0) {
2162                 /* If no priority is provided by the user,
2163                  * we allocate one.
2164                  */
2165                 if (n->nlmsg_flags & NLM_F_CREATE) {
2166                         prio = TC_H_MAKE(0x80000000U, 0U);
2167                         prio_allocate = true;
2168                 } else {
2169                         NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2170                         return -ENOENT;
2171                 }
2172         }
2173
2174         /* Find head of filter chain. */
2175
2176         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2177         if (err)
2178                 return err;
2179
2180         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2181                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2182                 err = -EINVAL;
2183                 goto errout;
2184         }
2185
2186         /* Take rtnl mutex if rtnl_held was set to true on previous iteration,
2187          * block is shared (no qdisc found), qdisc is not unlocked, classifier
2188          * type is not specified, classifier is not unlocked.
2189          */
2190         if (rtnl_held ||
2191             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2192             !tcf_proto_is_unlocked(name)) {
2193                 rtnl_held = true;
2194                 rtnl_lock();
2195         }
2196
2197         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2198         if (err)
2199                 goto errout;
2200
2201         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2202                                  extack);
2203         if (IS_ERR(block)) {
2204                 err = PTR_ERR(block);
2205                 goto errout;
2206         }
2207         block->classid = parent;
2208
2209         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2210         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2211                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2212                 err = -EINVAL;
2213                 goto errout;
2214         }
2215         chain = tcf_chain_get(block, chain_index, true);
2216         if (!chain) {
2217                 NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
2218                 err = -ENOMEM;
2219                 goto errout;
2220         }
2221
2222         mutex_lock(&chain->filter_chain_lock);
2223         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2224                                prio, prio_allocate);
2225         if (IS_ERR(tp)) {
2226                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2227                 err = PTR_ERR(tp);
2228                 goto errout_locked;
2229         }
2230
2231         if (tp == NULL) {
2232                 struct tcf_proto *tp_new = NULL;
2233
2234                 if (chain->flushing) {
2235                         err = -EAGAIN;
2236                         goto errout_locked;
2237                 }
2238
2239                 /* Proto-tcf does not exist, create new one */
2240
2241                 if (tca[TCA_KIND] == NULL || !protocol) {
2242                         NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
2243                         err = -EINVAL;
2244                         goto errout_locked;
2245                 }
2246
2247                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2248                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2249                         err = -ENOENT;
2250                         goto errout_locked;
2251                 }
2252
2253                 if (prio_allocate)
2254                         prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
2255                                                                &chain_info));
2256
2257                 mutex_unlock(&chain->filter_chain_lock);
2258                 tp_new = tcf_proto_create(name, protocol, prio, chain,
2259                                           rtnl_held, extack);
2260                 if (IS_ERR(tp_new)) {
2261                         err = PTR_ERR(tp_new);
2262                         goto errout_tp;
2263                 }
2264
2265                 tp_created = 1;
2266                 tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
2267                                                 rtnl_held);
2268                 if (IS_ERR(tp)) {
2269                         err = PTR_ERR(tp);
2270                         goto errout_tp;
2271                 }
2272         } else {
2273                 mutex_unlock(&chain->filter_chain_lock);
2274         }
2275
2276         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2277                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2278                 err = -EINVAL;
2279                 goto errout;
2280         }
2281
2282         fh = tp->ops->get(tp, t->tcm_handle);
2283
2284         if (!fh) {
2285                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2286                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2287                         err = -ENOENT;
2288                         goto errout;
2289                 }
2290         } else if (n->nlmsg_flags & NLM_F_EXCL) {
2291                 tfilter_put(tp, fh);
2292                 NL_SET_ERR_MSG(extack, "Filter already exists");
2293                 err = -EEXIST;
2294                 goto errout;
2295         }
2296
2297         if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
2298                 tfilter_put(tp, fh);
2299                 NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
2300                 err = -EINVAL;
2301                 goto errout;
2302         }
2303
2304         if (!(n->nlmsg_flags & NLM_F_CREATE))
2305                 flags |= TCA_ACT_FLAGS_REPLACE;
2306         if (!rtnl_held)
2307                 flags |= TCA_ACT_FLAGS_NO_RTNL;
2308         if (is_qdisc_ingress(parent))
2309                 flags |= TCA_ACT_FLAGS_AT_INGRESS;
2310         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
2311                               flags, extack);
2312         if (err == 0) {
2313                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2314                                RTM_NEWTFILTER, false, rtnl_held, extack);
2315                 tfilter_put(tp, fh);
2316                 /* q pointer is NULL for shared blocks */
2317                 if (q)
2318                         q->flags &= ~TCQ_F_CAN_BYPASS;
2319         }
2320
2321 errout:
2322         if (err && tp_created)
2323                 tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
2324 errout_tp:
2325         if (chain) {
2326                 if (tp && !IS_ERR(tp))
2327                         tcf_proto_put(tp, rtnl_held, NULL);
2328                 if (!tp_created)
2329                         tcf_chain_put(chain);
2330         }
2331         tcf_block_release(q, block, rtnl_held);
2332
2333         if (rtnl_held)
2334                 rtnl_unlock();
2335
2336         if (err == -EAGAIN) {
2337                 /* Take rtnl lock in case EAGAIN is caused by concurrent flush
2338                  * of target chain.
2339                  */
2340                 rtnl_held = true;
2341                 /* Replay the request. */
2342                 goto replay;
2343         }
2344         return err;
2345
2346 errout_locked:
2347         mutex_unlock(&chain->filter_chain_lock);
2348         goto errout;
2349 }
2350
2351 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2352                           struct netlink_ext_ack *extack)
2353 {
2354         struct net *net = sock_net(skb->sk);
2355         struct nlattr *tca[TCA_MAX + 1];
2356         char name[IFNAMSIZ];
2357         struct tcmsg *t;
2358         u32 protocol;
2359         u32 prio;
2360         u32 parent;
2361         u32 chain_index;
2362         struct Qdisc *q = NULL;
2363         struct tcf_chain_info chain_info;
2364         struct tcf_chain *chain = NULL;
2365         struct tcf_block *block = NULL;
2366         struct tcf_proto *tp = NULL;
2367         unsigned long cl = 0;
2368         void *fh = NULL;
2369         int err;
2370         bool rtnl_held = false;
2371
2372         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2373                                      rtm_tca_policy, extack);
2374         if (err < 0)
2375                 return err;
2376
2377         t = nlmsg_data(n);
2378         protocol = TC_H_MIN(t->tcm_info);
2379         prio = TC_H_MAJ(t->tcm_info);
2380         parent = t->tcm_parent;
2381
2382         if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
2383                 NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
2384                 return -ENOENT;
2385         }
2386
2387         /* Find head of filter chain. */
2388
2389         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2390         if (err)
2391                 return err;
2392
2393         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2394                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2395                 err = -EINVAL;
2396                 goto errout;
2397         }
2398         /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
2399          * found), qdisc is not unlocked, classifier type is not specified,
2400          * classifier is not unlocked.
2401          */
2402         if (!prio ||
2403             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2404             !tcf_proto_is_unlocked(name)) {
2405                 rtnl_held = true;
2406                 rtnl_lock();
2407         }
2408
2409         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2410         if (err)
2411                 goto errout;
2412
2413         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2414                                  extack);
2415         if (IS_ERR(block)) {
2416                 err = PTR_ERR(block);
2417                 goto errout;
2418         }
2419
2420         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2421         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2422                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2423                 err = -EINVAL;
2424                 goto errout;
2425         }
2426         chain = tcf_chain_get(block, chain_index, false);
2427         if (!chain) {
2428                 /* User requested flush on non-existent chain. Nothing to do,
2429                  * so just return success.
2430                  */
2431                 if (prio == 0) {
2432                         err = 0;
2433                         goto errout;
2434                 }
2435                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2436                 err = -ENOENT;
2437                 goto errout;
2438         }
2439
2440         if (prio == 0) {
2441                 tfilter_notify_chain(net, skb, block, q, parent, n,
2442                                      chain, RTM_DELTFILTER, extack);
2443                 tcf_chain_flush(chain, rtnl_held);
2444                 err = 0;
2445                 goto errout;
2446         }
2447
2448         mutex_lock(&chain->filter_chain_lock);
2449         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2450                                prio, false);
2451         if (!tp || IS_ERR(tp)) {
2452                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2453                 err = tp ? PTR_ERR(tp) : -ENOENT;
2454                 goto errout_locked;
2455         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2456                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2457                 err = -EINVAL;
2458                 goto errout_locked;
2459         } else if (t->tcm_handle == 0) {
2460                 tcf_proto_signal_destroying(chain, tp);
2461                 tcf_chain_tp_remove(chain, &chain_info, tp);
2462                 mutex_unlock(&chain->filter_chain_lock);
2463
2464                 tcf_proto_put(tp, rtnl_held, NULL);
2465                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2466                                RTM_DELTFILTER, false, rtnl_held, extack);
2467                 err = 0;
2468                 goto errout;
2469         }
2470         mutex_unlock(&chain->filter_chain_lock);
2471
2472         fh = tp->ops->get(tp, t->tcm_handle);
2473
2474         if (!fh) {
2475                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2476                 err = -ENOENT;
2477         } else {
2478                 bool last;
2479
2480                 err = tfilter_del_notify(net, skb, n, tp, block,
2481                                          q, parent, fh, false, &last,
2482                                          rtnl_held, extack);
2483
2484                 if (err)
2485                         goto errout;
2486                 if (last)
2487                         tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
2488         }
2489
2490 errout:
2491         if (chain) {
2492                 if (tp && !IS_ERR(tp))
2493                         tcf_proto_put(tp, rtnl_held, NULL);
2494                 tcf_chain_put(chain);
2495         }
2496         tcf_block_release(q, block, rtnl_held);
2497
2498         if (rtnl_held)
2499                 rtnl_unlock();
2500
2501         return err;
2502
2503 errout_locked:
2504         mutex_unlock(&chain->filter_chain_lock);
2505         goto errout;
2506 }
2507
2508 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2509                           struct netlink_ext_ack *extack)
2510 {
2511         struct net *net = sock_net(skb->sk);
2512         struct nlattr *tca[TCA_MAX + 1];
2513         char name[IFNAMSIZ];
2514         struct tcmsg *t;
2515         u32 protocol;
2516         u32 prio;
2517         u32 parent;
2518         u32 chain_index;
2519         struct Qdisc *q = NULL;
2520         struct tcf_chain_info chain_info;
2521         struct tcf_chain *chain = NULL;
2522         struct tcf_block *block = NULL;
2523         struct tcf_proto *tp = NULL;
2524         unsigned long cl = 0;
2525         void *fh = NULL;
2526         int err;
2527         bool rtnl_held = false;
2528
2529         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2530                                      rtm_tca_policy, extack);
2531         if (err < 0)
2532                 return err;
2533
2534         t = nlmsg_data(n);
2535         protocol = TC_H_MIN(t->tcm_info);
2536         prio = TC_H_MAJ(t->tcm_info);
2537         parent = t->tcm_parent;
2538
2539         if (prio == 0) {
2540                 NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2541                 return -ENOENT;
2542         }
2543
2544         /* Find head of filter chain. */
2545
2546         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2547         if (err)
2548                 return err;
2549
2550         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2551                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2552                 err = -EINVAL;
2553                 goto errout;
2554         }
2555         /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
2556          * unlocked, classifier type is not specified, classifier is not
2557          * unlocked.
2558          */
2559         if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2560             !tcf_proto_is_unlocked(name)) {
2561                 rtnl_held = true;
2562                 rtnl_lock();
2563         }
2564
2565         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2566         if (err)
2567                 goto errout;
2568
2569         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2570                                  extack);
2571         if (IS_ERR(block)) {
2572                 err = PTR_ERR(block);
2573                 goto errout;
2574         }
2575
2576         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2577         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2578                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2579                 err = -EINVAL;
2580                 goto errout;
2581         }
2582         chain = tcf_chain_get(block, chain_index, false);
2583         if (!chain) {
2584                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2585                 err = -EINVAL;
2586                 goto errout;
2587         }
2588
2589         mutex_lock(&chain->filter_chain_lock);
2590         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2591                                prio, false);
2592         mutex_unlock(&chain->filter_chain_lock);
2593         if (!tp || IS_ERR(tp)) {
2594                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2595                 err = tp ? PTR_ERR(tp) : -ENOENT;
2596                 goto errout;
2597         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2598                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2599                 err = -EINVAL;
2600                 goto errout;
2601         }
2602
2603         fh = tp->ops->get(tp, t->tcm_handle);
2604
2605         if (!fh) {
2606                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2607                 err = -ENOENT;
2608         } else {
2609                 err = tfilter_notify(net, skb, n, tp, block, q, parent,
2610                                      fh, RTM_NEWTFILTER, true, rtnl_held, NULL);
2611                 if (err < 0)
2612                         NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
2613         }
2614
2615         tfilter_put(tp, fh);
2616 errout:
2617         if (chain) {
2618                 if (tp && !IS_ERR(tp))
2619                         tcf_proto_put(tp, rtnl_held, NULL);
2620                 tcf_chain_put(chain);
2621         }
2622         tcf_block_release(q, block, rtnl_held);
2623
2624         if (rtnl_held)
2625                 rtnl_unlock();
2626
2627         return err;
2628 }
2629
2630 struct tcf_dump_args {
2631         struct tcf_walker w;
2632         struct sk_buff *skb;
2633         struct netlink_callback *cb;
2634         struct tcf_block *block;
2635         struct Qdisc *q;
2636         u32 parent;
2637         bool terse_dump;
2638 };
2639
2640 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2641 {
2642         struct tcf_dump_args *a = (void *)arg;
2643         struct net *net = sock_net(a->skb->sk);
2644
2645         return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
2646                              n, NETLINK_CB(a->cb->skb).portid,
2647                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2648                              RTM_NEWTFILTER, a->terse_dump, true, NULL);
2649 }
2650
2651 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
2652                            struct sk_buff *skb, struct netlink_callback *cb,
2653                            long index_start, long *p_index, bool terse)
2654 {
2655         struct net *net = sock_net(skb->sk);
2656         struct tcf_block *block = chain->block;
2657         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2658         struct tcf_proto *tp, *tp_prev;
2659         struct tcf_dump_args arg;
2660
2661         for (tp = __tcf_get_next_proto(chain, NULL);
2662              tp;
2663              tp_prev = tp,
2664                      tp = __tcf_get_next_proto(chain, tp),
2665                      tcf_proto_put(tp_prev, true, NULL),
2666                      (*p_index)++) {
2667                 if (*p_index < index_start)
2668                         continue;
2669                 if (TC_H_MAJ(tcm->tcm_info) &&
2670                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
2671                         continue;
2672                 if (TC_H_MIN(tcm->tcm_info) &&
2673                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
2674                         continue;
2675                 if (*p_index > index_start)
2676                         memset(&cb->args[1], 0,
2677                                sizeof(cb->args) - sizeof(cb->args[0]));
2678                 if (cb->args[1] == 0) {
2679                         if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
2680                                           NETLINK_CB(cb->skb).portid,
2681                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
2682                                           RTM_NEWTFILTER, false, true, NULL) <= 0)
2683                                 goto errout;
2684                         cb->args[1] = 1;
2685                 }
2686                 if (!tp->ops->walk)
2687                         continue;
2688                 arg.w.fn = tcf_node_dump;
2689                 arg.skb = skb;
2690                 arg.cb = cb;
2691                 arg.block = block;
2692                 arg.q = q;
2693                 arg.parent = parent;
2694                 arg.w.stop = 0;
2695                 arg.w.skip = cb->args[1] - 1;
2696                 arg.w.count = 0;
2697                 arg.w.cookie = cb->args[2];
2698                 arg.terse_dump = terse;
2699                 tp->ops->walk(tp, &arg.w, true);
2700                 cb->args[2] = arg.w.cookie;
2701                 cb->args[1] = arg.w.count + 1;
2702                 if (arg.w.stop)
2703                         goto errout;
2704         }
2705         return true;
2706
2707 errout:
2708         tcf_proto_put(tp, true, NULL);
2709         return false;
2710 }
2711
2712 static const struct nla_policy tcf_tfilter_dump_policy[TCA_MAX + 1] = {
2713         [TCA_DUMP_FLAGS] = NLA_POLICY_BITFIELD32(TCA_DUMP_FLAGS_TERSE),
2714 };
2715
2716 /* called with RTNL */
2717 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
2718 {
2719         struct tcf_chain *chain, *chain_prev;
2720         struct net *net = sock_net(skb->sk);
2721         struct nlattr *tca[TCA_MAX + 1];
2722         struct Qdisc *q = NULL;
2723         struct tcf_block *block;
2724         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2725         bool terse_dump = false;
2726         long index_start;
2727         long index;
2728         u32 parent;
2729         int err;
2730
2731         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2732                 return skb->len;
2733
2734         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2735                                      tcf_tfilter_dump_policy, cb->extack);
2736         if (err)
2737                 return err;
2738
2739         if (tca[TCA_DUMP_FLAGS]) {
2740                 struct nla_bitfield32 flags =
2741                         nla_get_bitfield32(tca[TCA_DUMP_FLAGS]);
2742
2743                 terse_dump = flags.value & TCA_DUMP_FLAGS_TERSE;
2744         }
2745
2746         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2747                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2748                 if (!block)
2749                         goto out;
2750                 /* If we work with block index, q is NULL and parent value
2751                  * will never be used in the following code. The check
2752                  * in tcf_fill_node prevents it. However, compiler does not
2753                  * see that far, so set parent to zero to silence the warning
2754                  * about parent being uninitialized.
2755                  */
2756                 parent = 0;
2757         } else {
2758                 const struct Qdisc_class_ops *cops;
2759                 struct net_device *dev;
2760                 unsigned long cl = 0;
2761
2762                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2763                 if (!dev)
2764                         return skb->len;
2765
2766                 parent = tcm->tcm_parent;
2767                 if (!parent)
2768                         q = rtnl_dereference(dev->qdisc);
2769                 else
2770                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2771                 if (!q)
2772                         goto out;
2773                 cops = q->ops->cl_ops;
2774                 if (!cops)
2775                         goto out;
2776                 if (!cops->tcf_block)
2777                         goto out;
2778                 if (TC_H_MIN(tcm->tcm_parent)) {
2779                         cl = cops->find(q, tcm->tcm_parent);
2780                         if (cl == 0)
2781                                 goto out;
2782                 }
2783                 block = cops->tcf_block(q, cl, NULL);
2784                 if (!block)
2785                         goto out;
2786                 parent = block->classid;
2787                 if (tcf_block_shared(block))
2788                         q = NULL;
2789         }
2790
2791         index_start = cb->args[0];
2792         index = 0;
2793
2794         for (chain = __tcf_get_next_chain(block, NULL);
2795              chain;
2796              chain_prev = chain,
2797                      chain = __tcf_get_next_chain(block, chain),
2798                      tcf_chain_put(chain_prev)) {
2799                 if (tca[TCA_CHAIN] &&
2800                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
2801                         continue;
2802                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
2803                                     index_start, &index, terse_dump)) {
2804                         tcf_chain_put(chain);
2805                         err = -EMSGSIZE;
2806                         break;
2807                 }
2808         }
2809
2810         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2811                 tcf_block_refcnt_put(block, true);
2812         cb->args[0] = index;
2813
2814 out:
2815         /* If we did no progress, the error (EMSGSIZE) is real */
2816         if (skb->len == 0 && err)
2817                 return err;
2818         return skb->len;
2819 }
2820
2821 static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
2822                               void *tmplt_priv, u32 chain_index,
2823                               struct net *net, struct sk_buff *skb,
2824                               struct tcf_block *block,
2825                               u32 portid, u32 seq, u16 flags, int event,
2826                               struct netlink_ext_ack *extack)
2827 {
2828         unsigned char *b = skb_tail_pointer(skb);
2829         const struct tcf_proto_ops *ops;
2830         struct nlmsghdr *nlh;
2831         struct tcmsg *tcm;
2832         void *priv;
2833
2834         ops = tmplt_ops;
2835         priv = tmplt_priv;
2836
2837         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2838         if (!nlh)
2839                 goto out_nlmsg_trim;
2840         tcm = nlmsg_data(nlh);
2841         tcm->tcm_family = AF_UNSPEC;
2842         tcm->tcm__pad1 = 0;
2843         tcm->tcm__pad2 = 0;
2844         tcm->tcm_handle = 0;
2845         if (block->q) {
2846                 tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
2847                 tcm->tcm_parent = block->q->handle;
2848         } else {
2849                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2850                 tcm->tcm_block_index = block->index;
2851         }
2852
2853         if (nla_put_u32(skb, TCA_CHAIN, chain_index))
2854                 goto nla_put_failure;
2855
2856         if (ops) {
2857                 if (nla_put_string(skb, TCA_KIND, ops->kind))
2858                         goto nla_put_failure;
2859                 if (ops->tmplt_dump(skb, net, priv) < 0)
2860                         goto nla_put_failure;
2861         }
2862
2863         if (extack && extack->_msg &&
2864             nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
2865                 goto out_nlmsg_trim;
2866
2867         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2868
2869         return skb->len;
2870
2871 out_nlmsg_trim:
2872 nla_put_failure:
2873         nlmsg_trim(skb, b);
2874         return -EMSGSIZE;
2875 }
2876
2877 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
2878                            u32 seq, u16 flags, int event, bool unicast,
2879                            struct netlink_ext_ack *extack)
2880 {
2881         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2882         struct tcf_block *block = chain->block;
2883         struct net *net = block->net;
2884         struct sk_buff *skb;
2885         int err = 0;
2886
2887         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2888         if (!skb)
2889                 return -ENOBUFS;
2890
2891         if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2892                                chain->index, net, skb, block, portid,
2893                                seq, flags, event, extack) <= 0) {
2894                 kfree_skb(skb);
2895                 return -EINVAL;
2896         }
2897
2898         if (unicast)
2899                 err = rtnl_unicast(skb, net, portid);
2900         else
2901                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2902                                      flags & NLM_F_ECHO);
2903
2904         return err;
2905 }
2906
2907 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
2908                                   void *tmplt_priv, u32 chain_index,
2909                                   struct tcf_block *block, struct sk_buff *oskb,
2910                                   u32 seq, u16 flags, bool unicast)
2911 {
2912         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2913         struct net *net = block->net;
2914         struct sk_buff *skb;
2915
2916         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2917         if (!skb)
2918                 return -ENOBUFS;
2919
2920         if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
2921                                block, portid, seq, flags, RTM_DELCHAIN, NULL) <= 0) {
2922                 kfree_skb(skb);
2923                 return -EINVAL;
2924         }
2925
2926         if (unicast)
2927                 return rtnl_unicast(skb, net, portid);
2928
2929         return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
2930 }
2931
2932 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
2933                               struct nlattr **tca,
2934                               struct netlink_ext_ack *extack)
2935 {
2936         const struct tcf_proto_ops *ops;
2937         char name[IFNAMSIZ];
2938         void *tmplt_priv;
2939
2940         /* If kind is not set, user did not specify template. */
2941         if (!tca[TCA_KIND])
2942                 return 0;
2943
2944         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2945                 NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
2946                 return -EINVAL;
2947         }
2948
2949         ops = tcf_proto_lookup_ops(name, true, extack);
2950         if (IS_ERR(ops))
2951                 return PTR_ERR(ops);
2952         if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
2953                 NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
2954                 return -EOPNOTSUPP;
2955         }
2956
2957         tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
2958         if (IS_ERR(tmplt_priv)) {
2959                 module_put(ops->owner);
2960                 return PTR_ERR(tmplt_priv);
2961         }
2962         chain->tmplt_ops = ops;
2963         chain->tmplt_priv = tmplt_priv;
2964         return 0;
2965 }
2966
2967 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
2968                                void *tmplt_priv)
2969 {
2970         /* If template ops are set, no work to do for us. */
2971         if (!tmplt_ops)
2972                 return;
2973
2974         tmplt_ops->tmplt_destroy(tmplt_priv);
2975         module_put(tmplt_ops->owner);
2976 }
2977
2978 /* Add/delete/get a chain */
2979
2980 static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
2981                         struct netlink_ext_ack *extack)
2982 {
2983         struct net *net = sock_net(skb->sk);
2984         struct nlattr *tca[TCA_MAX + 1];
2985         struct tcmsg *t;
2986         u32 parent;
2987         u32 chain_index;
2988         struct Qdisc *q;
2989         struct tcf_chain *chain;
2990         struct tcf_block *block;
2991         unsigned long cl;
2992         int err;
2993
2994 replay:
2995         q = NULL;
2996         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2997                                      rtm_tca_policy, extack);
2998         if (err < 0)
2999                 return err;
3000
3001         t = nlmsg_data(n);
3002         parent = t->tcm_parent;
3003         cl = 0;
3004
3005         block = tcf_block_find(net, &q, &parent, &cl,
3006                                t->tcm_ifindex, t->tcm_block_index, extack);
3007         if (IS_ERR(block))
3008                 return PTR_ERR(block);
3009
3010         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
3011         if (chain_index > TC_ACT_EXT_VAL_MASK) {
3012                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
3013                 err = -EINVAL;
3014                 goto errout_block;
3015         }
3016
3017         mutex_lock(&block->lock);
3018         chain = tcf_chain_lookup(block, chain_index);
3019         if (n->nlmsg_type == RTM_NEWCHAIN) {
3020                 if (chain) {
3021                         if (tcf_chain_held_by_acts_only(chain)) {
3022                                 /* The chain exists only because there is
3023                                  * some action referencing it.
3024                                  */
3025                                 tcf_chain_hold(chain);
3026                         } else {
3027                                 NL_SET_ERR_MSG(extack, "Filter chain already exists");
3028                                 err = -EEXIST;
3029                                 goto errout_block_locked;
3030                         }
3031                 } else {
3032                         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
3033                                 NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
3034                                 err = -ENOENT;
3035                                 goto errout_block_locked;
3036                         }
3037                         chain = tcf_chain_create(block, chain_index);
3038                         if (!chain) {
3039                                 NL_SET_ERR_MSG(extack, "Failed to create filter chain");
3040                                 err = -ENOMEM;
3041                                 goto errout_block_locked;
3042                         }
3043                 }
3044         } else {
3045                 if (!chain || tcf_chain_held_by_acts_only(chain)) {
3046                         NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
3047                         err = -EINVAL;
3048                         goto errout_block_locked;
3049                 }
3050                 tcf_chain_hold(chain);
3051         }
3052
3053         if (n->nlmsg_type == RTM_NEWCHAIN) {
3054                 /* Modifying chain requires holding parent block lock. In case
3055                  * the chain was successfully added, take a reference to the
3056                  * chain. This ensures that an empty chain does not disappear at
3057                  * the end of this function.
3058                  */
3059                 tcf_chain_hold(chain);
3060                 chain->explicitly_created = true;
3061         }
3062         mutex_unlock(&block->lock);
3063
3064         switch (n->nlmsg_type) {
3065         case RTM_NEWCHAIN:
3066                 err = tc_chain_tmplt_add(chain, net, tca, extack);
3067                 if (err) {
3068                         tcf_chain_put_explicitly_created(chain);
3069                         goto errout;
3070                 }
3071
3072                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
3073                                 RTM_NEWCHAIN, false, extack);
3074                 break;
3075         case RTM_DELCHAIN:
3076                 tfilter_notify_chain(net, skb, block, q, parent, n,
3077                                      chain, RTM_DELTFILTER, extack);
3078                 /* Flush the chain first as the user requested chain removal. */
3079                 tcf_chain_flush(chain, true);
3080                 /* In case the chain was successfully deleted, put a reference
3081                  * to the chain previously taken during addition.
3082                  */
3083                 tcf_chain_put_explicitly_created(chain);
3084                 break;
3085         case RTM_GETCHAIN:
3086                 err = tc_chain_notify(chain, skb, n->nlmsg_seq,
3087                                       n->nlmsg_flags, n->nlmsg_type, true, extack);
3088                 if (err < 0)
3089                         NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
3090                 break;
3091         default:
3092                 err = -EOPNOTSUPP;
3093                 NL_SET_ERR_MSG(extack, "Unsupported message type");
3094                 goto errout;
3095         }
3096
3097 errout:
3098         tcf_chain_put(chain);
3099 errout_block:
3100         tcf_block_release(q, block, true);
3101         if (err == -EAGAIN)
3102                 /* Replay the request. */
3103                 goto replay;
3104         return err;
3105
3106 errout_block_locked:
3107         mutex_unlock(&block->lock);
3108         goto errout_block;
3109 }
3110
3111 /* called with RTNL */
3112 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
3113 {
3114         struct net *net = sock_net(skb->sk);
3115         struct nlattr *tca[TCA_MAX + 1];
3116         struct Qdisc *q = NULL;
3117         struct tcf_block *block;
3118         struct tcmsg *tcm = nlmsg_data(cb->nlh);
3119         struct tcf_chain *chain;
3120         long index_start;
3121         long index;
3122         int err;
3123
3124         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
3125                 return skb->len;
3126
3127         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
3128                                      rtm_tca_policy, cb->extack);
3129         if (err)
3130                 return err;
3131
3132         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
3133                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
3134                 if (!block)
3135                         goto out;
3136         } else {
3137                 const struct Qdisc_class_ops *cops;
3138                 struct net_device *dev;
3139                 unsigned long cl = 0;
3140
3141                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
3142                 if (!dev)
3143                         return skb->len;
3144
3145                 if (!tcm->tcm_parent)
3146                         q = rtnl_dereference(dev->qdisc);
3147                 else
3148                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
3149
3150                 if (!q)
3151                         goto out;
3152                 cops = q->ops->cl_ops;
3153                 if (!cops)
3154                         goto out;
3155                 if (!cops->tcf_block)
3156                         goto out;
3157                 if (TC_H_MIN(tcm->tcm_parent)) {
3158                         cl = cops->find(q, tcm->tcm_parent);
3159                         if (cl == 0)
3160                                 goto out;
3161                 }
3162                 block = cops->tcf_block(q, cl, NULL);
3163                 if (!block)
3164                         goto out;
3165                 if (tcf_block_shared(block))
3166                         q = NULL;
3167         }
3168
3169         index_start = cb->args[0];
3170         index = 0;
3171
3172         mutex_lock(&block->lock);
3173         list_for_each_entry(chain, &block->chain_list, list) {
3174                 if ((tca[TCA_CHAIN] &&
3175                      nla_get_u32(tca[TCA_CHAIN]) != chain->index))
3176                         continue;
3177                 if (index < index_start) {
3178                         index++;
3179                         continue;
3180                 }
3181                 if (tcf_chain_held_by_acts_only(chain))
3182                         continue;
3183                 err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
3184                                          chain->index, net, skb, block,
3185                                          NETLINK_CB(cb->skb).portid,
3186                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
3187                                          RTM_NEWCHAIN, NULL);
3188                 if (err <= 0)
3189                         break;
3190                 index++;
3191         }
3192         mutex_unlock(&block->lock);
3193
3194         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
3195                 tcf_block_refcnt_put(block, true);
3196         cb->args[0] = index;
3197
3198 out:
3199         /* If we did no progress, the error (EMSGSIZE) is real */
3200         if (skb->len == 0 && err)
3201                 return err;
3202         return skb->len;
3203 }
3204
3205 int tcf_exts_init_ex(struct tcf_exts *exts, struct net *net, int action,
3206                      int police, struct tcf_proto *tp, u32 handle,
3207                      bool use_action_miss)
3208 {
3209         int err = 0;
3210
3211 #ifdef CONFIG_NET_CLS_ACT
3212         exts->type = 0;
3213         exts->nr_actions = 0;
3214         exts->miss_cookie_node = NULL;
3215         /* Note: we do not own yet a reference on net.
3216          * This reference might be taken later from tcf_exts_get_net().
3217          */
3218         exts->net = net;
3219         exts->actions = kcalloc(TCA_ACT_MAX_PRIO, sizeof(struct tc_action *),
3220                                 GFP_KERNEL);
3221         if (!exts->actions)
3222                 return -ENOMEM;
3223 #endif
3224
3225         exts->action = action;
3226         exts->police = police;
3227
3228         if (!use_action_miss)
3229                 return 0;
3230
3231         err = tcf_exts_miss_cookie_base_alloc(exts, tp, handle);
3232         if (err)
3233                 goto err_miss_alloc;
3234
3235         return 0;
3236
3237 err_miss_alloc:
3238         tcf_exts_destroy(exts);
3239 #ifdef CONFIG_NET_CLS_ACT
3240         exts->actions = NULL;
3241 #endif
3242         return err;
3243 }
3244 EXPORT_SYMBOL(tcf_exts_init_ex);
3245
3246 void tcf_exts_destroy(struct tcf_exts *exts)
3247 {
3248         tcf_exts_miss_cookie_base_destroy(exts);
3249
3250 #ifdef CONFIG_NET_CLS_ACT
3251         if (exts->actions) {
3252                 tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
3253                 kfree(exts->actions);
3254         }
3255         exts->nr_actions = 0;
3256 #endif
3257 }
3258 EXPORT_SYMBOL(tcf_exts_destroy);
3259
3260 int tcf_exts_validate_ex(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3261                          struct nlattr *rate_tlv, struct tcf_exts *exts,
3262                          u32 flags, u32 fl_flags, struct netlink_ext_ack *extack)
3263 {
3264 #ifdef CONFIG_NET_CLS_ACT
3265         {
3266                 int init_res[TCA_ACT_MAX_PRIO] = {};
3267                 struct tc_action *act;
3268                 size_t attr_size = 0;
3269
3270                 if (exts->police && tb[exts->police]) {
3271                         struct tc_action_ops *a_o;
3272
3273                         a_o = tc_action_load_ops(tb[exts->police], true,
3274                                                  !(flags & TCA_ACT_FLAGS_NO_RTNL),
3275                                                  extack);
3276                         if (IS_ERR(a_o))
3277                                 return PTR_ERR(a_o);
3278                         flags |= TCA_ACT_FLAGS_POLICE | TCA_ACT_FLAGS_BIND;
3279                         act = tcf_action_init_1(net, tp, tb[exts->police],
3280                                                 rate_tlv, a_o, init_res, flags,
3281                                                 extack);
3282                         module_put(a_o->owner);
3283                         if (IS_ERR(act))
3284                                 return PTR_ERR(act);
3285
3286                         act->type = exts->type = TCA_OLD_COMPAT;
3287                         exts->actions[0] = act;
3288                         exts->nr_actions = 1;
3289                         tcf_idr_insert_many(exts->actions);
3290                 } else if (exts->action && tb[exts->action]) {
3291                         int err;
3292
3293                         flags |= TCA_ACT_FLAGS_BIND;
3294                         err = tcf_action_init(net, tp, tb[exts->action],
3295                                               rate_tlv, exts->actions, init_res,
3296                                               &attr_size, flags, fl_flags,
3297                                               extack);
3298                         if (err < 0)
3299                                 return err;
3300                         exts->nr_actions = err;
3301                 }
3302         }
3303 #else
3304         if ((exts->action && tb[exts->action]) ||
3305             (exts->police && tb[exts->police])) {
3306                 NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
3307                 return -EOPNOTSUPP;
3308         }
3309 #endif
3310
3311         return 0;
3312 }
3313 EXPORT_SYMBOL(tcf_exts_validate_ex);
3314
3315 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3316                       struct nlattr *rate_tlv, struct tcf_exts *exts,
3317                       u32 flags, struct netlink_ext_ack *extack)
3318 {
3319         return tcf_exts_validate_ex(net, tp, tb, rate_tlv, exts,
3320                                     flags, 0, extack);
3321 }
3322 EXPORT_SYMBOL(tcf_exts_validate);
3323
3324 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
3325 {
3326 #ifdef CONFIG_NET_CLS_ACT
3327         struct tcf_exts old = *dst;
3328
3329         *dst = *src;
3330         tcf_exts_destroy(&old);
3331 #endif
3332 }
3333 EXPORT_SYMBOL(tcf_exts_change);
3334
3335 #ifdef CONFIG_NET_CLS_ACT
3336 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
3337 {
3338         if (exts->nr_actions == 0)
3339                 return NULL;
3340         else
3341                 return exts->actions[0];
3342 }
3343 #endif
3344
3345 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
3346 {
3347 #ifdef CONFIG_NET_CLS_ACT
3348         struct nlattr *nest;
3349
3350         if (exts->action && tcf_exts_has_actions(exts)) {
3351                 /*
3352                  * again for backward compatible mode - we want
3353                  * to work with both old and new modes of entering
3354                  * tc data even if iproute2  was newer - jhs
3355                  */
3356                 if (exts->type != TCA_OLD_COMPAT) {
3357                         nest = nla_nest_start_noflag(skb, exts->action);
3358                         if (nest == NULL)
3359                                 goto nla_put_failure;
3360
3361                         if (tcf_action_dump(skb, exts->actions, 0, 0, false)
3362                             < 0)
3363                                 goto nla_put_failure;
3364                         nla_nest_end(skb, nest);
3365                 } else if (exts->police) {
3366                         struct tc_action *act = tcf_exts_first_act(exts);
3367                         nest = nla_nest_start_noflag(skb, exts->police);
3368                         if (nest == NULL || !act)
3369                                 goto nla_put_failure;
3370                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
3371                                 goto nla_put_failure;
3372                         nla_nest_end(skb, nest);
3373                 }
3374         }
3375         return 0;
3376
3377 nla_put_failure:
3378         nla_nest_cancel(skb, nest);
3379         return -1;
3380 #else
3381         return 0;
3382 #endif
3383 }
3384 EXPORT_SYMBOL(tcf_exts_dump);
3385
3386 int tcf_exts_terse_dump(struct sk_buff *skb, struct tcf_exts *exts)
3387 {
3388 #ifdef CONFIG_NET_CLS_ACT
3389         struct nlattr *nest;
3390
3391         if (!exts->action || !tcf_exts_has_actions(exts))
3392                 return 0;
3393
3394         nest = nla_nest_start_noflag(skb, exts->action);
3395         if (!nest)
3396                 goto nla_put_failure;
3397
3398         if (tcf_action_dump(skb, exts->actions, 0, 0, true) < 0)
3399                 goto nla_put_failure;
3400         nla_nest_end(skb, nest);
3401         return 0;
3402
3403 nla_put_failure:
3404         nla_nest_cancel(skb, nest);
3405         return -1;
3406 #else
3407         return 0;
3408 #endif
3409 }
3410 EXPORT_SYMBOL(tcf_exts_terse_dump);
3411
3412 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
3413 {
3414 #ifdef CONFIG_NET_CLS_ACT
3415         struct tc_action *a = tcf_exts_first_act(exts);
3416         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
3417                 return -1;
3418 #endif
3419         return 0;
3420 }
3421 EXPORT_SYMBOL(tcf_exts_dump_stats);
3422
3423 static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
3424 {
3425         if (*flags & TCA_CLS_FLAGS_IN_HW)
3426                 return;
3427         *flags |= TCA_CLS_FLAGS_IN_HW;
3428         atomic_inc(&block->offloadcnt);
3429 }
3430
3431 static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
3432 {
3433         if (!(*flags & TCA_CLS_FLAGS_IN_HW))
3434                 return;
3435         *flags &= ~TCA_CLS_FLAGS_IN_HW;
3436         atomic_dec(&block->offloadcnt);
3437 }
3438
3439 static void tc_cls_offload_cnt_update(struct tcf_block *block,
3440                                       struct tcf_proto *tp, u32 *cnt,
3441                                       u32 *flags, u32 diff, bool add)
3442 {
3443         lockdep_assert_held(&block->cb_lock);
3444
3445         spin_lock(&tp->lock);
3446         if (add) {
3447                 if (!*cnt)
3448                         tcf_block_offload_inc(block, flags);
3449                 *cnt += diff;
3450         } else {
3451                 *cnt -= diff;
3452                 if (!*cnt)
3453                         tcf_block_offload_dec(block, flags);
3454         }
3455         spin_unlock(&tp->lock);
3456 }
3457
3458 static void
3459 tc_cls_offload_cnt_reset(struct tcf_block *block, struct tcf_proto *tp,
3460                          u32 *cnt, u32 *flags)
3461 {
3462         lockdep_assert_held(&block->cb_lock);
3463
3464         spin_lock(&tp->lock);
3465         tcf_block_offload_dec(block, flags);
3466         *cnt = 0;
3467         spin_unlock(&tp->lock);
3468 }
3469
3470 static int
3471 __tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3472                    void *type_data, bool err_stop)
3473 {
3474         struct flow_block_cb *block_cb;
3475         int ok_count = 0;
3476         int err;
3477
3478         list_for_each_entry(block_cb, &block->flow_block.cb_list, list) {
3479                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
3480                 if (err) {
3481                         if (err_stop)
3482                                 return err;
3483                 } else {
3484                         ok_count++;
3485                 }
3486         }
3487         return ok_count;
3488 }
3489
3490 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3491                      void *type_data, bool err_stop, bool rtnl_held)
3492 {
3493         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3494         int ok_count;
3495
3496 retry:
3497         if (take_rtnl)
3498                 rtnl_lock();
3499         down_read(&block->cb_lock);
3500         /* Need to obtain rtnl lock if block is bound to devs that require it.
3501          * In block bind code cb_lock is obtained while holding rtnl, so we must
3502          * obtain the locks in same order here.
3503          */
3504         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3505                 up_read(&block->cb_lock);
3506                 take_rtnl = true;
3507                 goto retry;
3508         }
3509
3510         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3511
3512         up_read(&block->cb_lock);
3513         if (take_rtnl)
3514                 rtnl_unlock();
3515         return ok_count;
3516 }
3517 EXPORT_SYMBOL(tc_setup_cb_call);
3518
3519 /* Non-destructive filter add. If filter that wasn't already in hardware is
3520  * successfully offloaded, increment block offloads counter. On failure,
3521  * previously offloaded filter is considered to be intact and offloads counter
3522  * is not decremented.
3523  */
3524
3525 int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
3526                     enum tc_setup_type type, void *type_data, bool err_stop,
3527                     u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3528 {
3529         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3530         int ok_count;
3531
3532 retry:
3533         if (take_rtnl)
3534                 rtnl_lock();
3535         down_read(&block->cb_lock);
3536         /* Need to obtain rtnl lock if block is bound to devs that require it.
3537          * In block bind code cb_lock is obtained while holding rtnl, so we must
3538          * obtain the locks in same order here.
3539          */
3540         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3541                 up_read(&block->cb_lock);
3542                 take_rtnl = true;
3543                 goto retry;
3544         }
3545
3546         /* Make sure all netdevs sharing this block are offload-capable. */
3547         if (block->nooffloaddevcnt && err_stop) {
3548                 ok_count = -EOPNOTSUPP;
3549                 goto err_unlock;
3550         }
3551
3552         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3553         if (ok_count < 0)
3554                 goto err_unlock;
3555
3556         if (tp->ops->hw_add)
3557                 tp->ops->hw_add(tp, type_data);
3558         if (ok_count > 0)
3559                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
3560                                           ok_count, true);
3561 err_unlock:
3562         up_read(&block->cb_lock);
3563         if (take_rtnl)
3564                 rtnl_unlock();
3565         return min(ok_count, 0);
3566 }
3567 EXPORT_SYMBOL(tc_setup_cb_add);
3568
3569 /* Destructive filter replace. If filter that wasn't already in hardware is
3570  * successfully offloaded, increment block offload counter. On failure,
3571  * previously offloaded filter is considered to be destroyed and offload counter
3572  * is decremented.
3573  */
3574
3575 int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
3576                         enum tc_setup_type type, void *type_data, bool err_stop,
3577                         u32 *old_flags, unsigned int *old_in_hw_count,
3578                         u32 *new_flags, unsigned int *new_in_hw_count,
3579                         bool rtnl_held)
3580 {
3581         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3582         int ok_count;
3583
3584 retry:
3585         if (take_rtnl)
3586                 rtnl_lock();
3587         down_read(&block->cb_lock);
3588         /* Need to obtain rtnl lock if block is bound to devs that require it.
3589          * In block bind code cb_lock is obtained while holding rtnl, so we must
3590          * obtain the locks in same order here.
3591          */
3592         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3593                 up_read(&block->cb_lock);
3594                 take_rtnl = true;
3595                 goto retry;
3596         }
3597
3598         /* Make sure all netdevs sharing this block are offload-capable. */
3599         if (block->nooffloaddevcnt && err_stop) {
3600                 ok_count = -EOPNOTSUPP;
3601                 goto err_unlock;
3602         }
3603
3604         tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
3605         if (tp->ops->hw_del)
3606                 tp->ops->hw_del(tp, type_data);
3607
3608         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3609         if (ok_count < 0)
3610                 goto err_unlock;
3611
3612         if (tp->ops->hw_add)
3613                 tp->ops->hw_add(tp, type_data);
3614         if (ok_count > 0)
3615                 tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
3616                                           new_flags, ok_count, true);
3617 err_unlock:
3618         up_read(&block->cb_lock);
3619         if (take_rtnl)
3620                 rtnl_unlock();
3621         return min(ok_count, 0);
3622 }
3623 EXPORT_SYMBOL(tc_setup_cb_replace);
3624
3625 /* Destroy filter and decrement block offload counter, if filter was previously
3626  * offloaded.
3627  */
3628
3629 int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
3630                         enum tc_setup_type type, void *type_data, bool err_stop,
3631                         u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3632 {
3633         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3634         int ok_count;
3635
3636 retry:
3637         if (take_rtnl)
3638                 rtnl_lock();
3639         down_read(&block->cb_lock);
3640         /* Need to obtain rtnl lock if block is bound to devs that require it.
3641          * In block bind code cb_lock is obtained while holding rtnl, so we must
3642          * obtain the locks in same order here.
3643          */
3644         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3645                 up_read(&block->cb_lock);
3646                 take_rtnl = true;
3647                 goto retry;
3648         }
3649
3650         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3651
3652         tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
3653         if (tp->ops->hw_del)
3654                 tp->ops->hw_del(tp, type_data);
3655
3656         up_read(&block->cb_lock);
3657         if (take_rtnl)
3658                 rtnl_unlock();
3659         return min(ok_count, 0);
3660 }
3661 EXPORT_SYMBOL(tc_setup_cb_destroy);
3662
3663 int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
3664                           bool add, flow_setup_cb_t *cb,
3665                           enum tc_setup_type type, void *type_data,
3666                           void *cb_priv, u32 *flags, unsigned int *in_hw_count)
3667 {
3668         int err = cb(type, type_data, cb_priv);
3669
3670         if (err) {
3671                 if (add && tc_skip_sw(*flags))
3672                         return err;
3673         } else {
3674                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags, 1,
3675                                           add);
3676         }
3677
3678         return 0;
3679 }
3680 EXPORT_SYMBOL(tc_setup_cb_reoffload);
3681
3682 static int tcf_act_get_user_cookie(struct flow_action_entry *entry,
3683                                    const struct tc_action *act)
3684 {
3685         struct tc_cookie *user_cookie;
3686         int err = 0;
3687
3688         rcu_read_lock();
3689         user_cookie = rcu_dereference(act->user_cookie);
3690         if (user_cookie) {
3691                 entry->user_cookie = flow_action_cookie_create(user_cookie->data,
3692                                                                user_cookie->len,
3693                                                                GFP_ATOMIC);
3694                 if (!entry->user_cookie)
3695                         err = -ENOMEM;
3696         }
3697         rcu_read_unlock();
3698         return err;
3699 }
3700
3701 static void tcf_act_put_user_cookie(struct flow_action_entry *entry)
3702 {
3703         flow_action_cookie_destroy(entry->user_cookie);
3704 }
3705
3706 void tc_cleanup_offload_action(struct flow_action *flow_action)
3707 {
3708         struct flow_action_entry *entry;
3709         int i;
3710
3711         flow_action_for_each(i, entry, flow_action) {
3712                 tcf_act_put_user_cookie(entry);
3713                 if (entry->destructor)
3714                         entry->destructor(entry->destructor_priv);
3715         }
3716 }
3717 EXPORT_SYMBOL(tc_cleanup_offload_action);
3718
3719 static int tc_setup_offload_act(struct tc_action *act,
3720                                 struct flow_action_entry *entry,
3721                                 u32 *index_inc,
3722                                 struct netlink_ext_ack *extack)
3723 {
3724 #ifdef CONFIG_NET_CLS_ACT
3725         if (act->ops->offload_act_setup) {
3726                 return act->ops->offload_act_setup(act, entry, index_inc, true,
3727                                                    extack);
3728         } else {
3729                 NL_SET_ERR_MSG(extack, "Action does not support offload");
3730                 return -EOPNOTSUPP;
3731         }
3732 #else
3733         return 0;
3734 #endif
3735 }
3736
3737 int tc_setup_action(struct flow_action *flow_action,
3738                     struct tc_action *actions[],
3739                     u32 miss_cookie_base,
3740                     struct netlink_ext_ack *extack)
3741 {
3742         int i, j, k, index, err = 0;
3743         struct tc_action *act;
3744
3745         BUILD_BUG_ON(TCA_ACT_HW_STATS_ANY != FLOW_ACTION_HW_STATS_ANY);
3746         BUILD_BUG_ON(TCA_ACT_HW_STATS_IMMEDIATE != FLOW_ACTION_HW_STATS_IMMEDIATE);
3747         BUILD_BUG_ON(TCA_ACT_HW_STATS_DELAYED != FLOW_ACTION_HW_STATS_DELAYED);
3748
3749         if (!actions)
3750                 return 0;
3751
3752         j = 0;
3753         tcf_act_for_each_action(i, act, actions) {
3754                 struct flow_action_entry *entry;
3755
3756                 entry = &flow_action->entries[j];
3757                 spin_lock_bh(&act->tcfa_lock);
3758                 err = tcf_act_get_user_cookie(entry, act);
3759                 if (err)
3760                         goto err_out_locked;
3761
3762                 index = 0;
3763                 err = tc_setup_offload_act(act, entry, &index, extack);
3764                 if (err)
3765                         goto err_out_locked;
3766
3767                 for (k = 0; k < index ; k++) {
3768                         entry[k].hw_stats = tc_act_hw_stats(act->hw_stats);
3769                         entry[k].hw_index = act->tcfa_index;
3770                         entry[k].cookie = (unsigned long)act;
3771                         entry[k].miss_cookie =
3772                                 tcf_exts_miss_cookie_get(miss_cookie_base, i);
3773                 }
3774
3775                 j += index;
3776
3777                 spin_unlock_bh(&act->tcfa_lock);
3778         }
3779
3780 err_out:
3781         if (err)
3782                 tc_cleanup_offload_action(flow_action);
3783
3784         return err;
3785 err_out_locked:
3786         spin_unlock_bh(&act->tcfa_lock);
3787         goto err_out;
3788 }
3789
3790 int tc_setup_offload_action(struct flow_action *flow_action,
3791                             const struct tcf_exts *exts,
3792                             struct netlink_ext_ack *extack)
3793 {
3794 #ifdef CONFIG_NET_CLS_ACT
3795         u32 miss_cookie_base;
3796
3797         if (!exts)
3798                 return 0;
3799
3800         miss_cookie_base = exts->miss_cookie_node ?
3801                            exts->miss_cookie_node->miss_cookie_base : 0;
3802         return tc_setup_action(flow_action, exts->actions, miss_cookie_base,
3803                                extack);
3804 #else
3805         return 0;
3806 #endif
3807 }
3808 EXPORT_SYMBOL(tc_setup_offload_action);
3809
3810 unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
3811 {
3812         unsigned int num_acts = 0;
3813         struct tc_action *act;
3814         int i;
3815
3816         tcf_exts_for_each_action(i, act, exts) {
3817                 if (is_tcf_pedit(act))
3818                         num_acts += tcf_pedit_nkeys(act);
3819                 else
3820                         num_acts++;
3821         }
3822         return num_acts;
3823 }
3824 EXPORT_SYMBOL(tcf_exts_num_actions);
3825
3826 #ifdef CONFIG_NET_CLS_ACT
3827 static int tcf_qevent_parse_block_index(struct nlattr *block_index_attr,
3828                                         u32 *p_block_index,
3829                                         struct netlink_ext_ack *extack)
3830 {
3831         *p_block_index = nla_get_u32(block_index_attr);
3832         if (!*p_block_index) {
3833                 NL_SET_ERR_MSG(extack, "Block number may not be zero");
3834                 return -EINVAL;
3835         }
3836
3837         return 0;
3838 }
3839
3840 int tcf_qevent_init(struct tcf_qevent *qe, struct Qdisc *sch,
3841                     enum flow_block_binder_type binder_type,
3842                     struct nlattr *block_index_attr,
3843                     struct netlink_ext_ack *extack)
3844 {
3845         u32 block_index;
3846         int err;
3847
3848         if (!block_index_attr)
3849                 return 0;
3850
3851         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3852         if (err)
3853                 return err;
3854
3855         qe->info.binder_type = binder_type;
3856         qe->info.chain_head_change = tcf_chain_head_change_dflt;
3857         qe->info.chain_head_change_priv = &qe->filter_chain;
3858         qe->info.block_index = block_index;
3859
3860         return tcf_block_get_ext(&qe->block, sch, &qe->info, extack);
3861 }
3862 EXPORT_SYMBOL(tcf_qevent_init);
3863
3864 void tcf_qevent_destroy(struct tcf_qevent *qe, struct Qdisc *sch)
3865 {
3866         if (qe->info.block_index)
3867                 tcf_block_put_ext(qe->block, sch, &qe->info);
3868 }
3869 EXPORT_SYMBOL(tcf_qevent_destroy);
3870
3871 int tcf_qevent_validate_change(struct tcf_qevent *qe, struct nlattr *block_index_attr,
3872                                struct netlink_ext_ack *extack)
3873 {
3874         u32 block_index;
3875         int err;
3876
3877         if (!block_index_attr)
3878                 return 0;
3879
3880         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3881         if (err)
3882                 return err;
3883
3884         /* Bounce newly-configured block or change in block. */
3885         if (block_index != qe->info.block_index) {
3886                 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
3887                 return -EINVAL;
3888         }
3889
3890         return 0;
3891 }
3892 EXPORT_SYMBOL(tcf_qevent_validate_change);
3893
3894 struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
3895                                   struct sk_buff **to_free, int *ret)
3896 {
3897         struct tcf_result cl_res;
3898         struct tcf_proto *fl;
3899
3900         if (!qe->info.block_index)
3901                 return skb;
3902
3903         fl = rcu_dereference_bh(qe->filter_chain);
3904
3905         switch (tcf_classify(skb, NULL, fl, &cl_res, false)) {
3906         case TC_ACT_SHOT:
3907                 qdisc_qstats_drop(sch);
3908                 __qdisc_drop(skb, to_free);
3909                 *ret = __NET_XMIT_BYPASS;
3910                 return NULL;
3911         case TC_ACT_STOLEN:
3912         case TC_ACT_QUEUED:
3913         case TC_ACT_TRAP:
3914                 __qdisc_drop(skb, to_free);
3915                 *ret = __NET_XMIT_STOLEN;
3916                 return NULL;
3917         case TC_ACT_REDIRECT:
3918                 skb_do_redirect(skb);
3919                 *ret = __NET_XMIT_STOLEN;
3920                 return NULL;
3921         }
3922
3923         return skb;
3924 }
3925 EXPORT_SYMBOL(tcf_qevent_handle);
3926
3927 int tcf_qevent_dump(struct sk_buff *skb, int attr_name, struct tcf_qevent *qe)
3928 {
3929         if (!qe->info.block_index)
3930                 return 0;
3931         return nla_put_u32(skb, attr_name, qe->info.block_index);
3932 }
3933 EXPORT_SYMBOL(tcf_qevent_dump);
3934 #endif
3935
3936 static __net_init int tcf_net_init(struct net *net)
3937 {
3938         struct tcf_net *tn = net_generic(net, tcf_net_id);
3939
3940         spin_lock_init(&tn->idr_lock);
3941         idr_init(&tn->idr);
3942         return 0;
3943 }
3944
3945 static void __net_exit tcf_net_exit(struct net *net)
3946 {
3947         struct tcf_net *tn = net_generic(net, tcf_net_id);
3948
3949         idr_destroy(&tn->idr);
3950 }
3951
3952 static struct pernet_operations tcf_net_ops = {
3953         .init = tcf_net_init,
3954         .exit = tcf_net_exit,
3955         .id   = &tcf_net_id,
3956         .size = sizeof(struct tcf_net),
3957 };
3958
3959 static int __init tc_filter_init(void)
3960 {
3961         int err;
3962
3963         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
3964         if (!tc_filter_wq)
3965                 return -ENOMEM;
3966
3967         err = register_pernet_subsys(&tcf_net_ops);
3968         if (err)
3969                 goto err_register_pernet_subsys;
3970
3971         xa_init_flags(&tcf_exts_miss_cookies_xa, XA_FLAGS_ALLOC1);
3972
3973         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
3974                       RTNL_FLAG_DOIT_UNLOCKED);
3975         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
3976                       RTNL_FLAG_DOIT_UNLOCKED);
3977         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
3978                       tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
3979         rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
3980         rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
3981         rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
3982                       tc_dump_chain, 0);
3983
3984         return 0;
3985
3986 err_register_pernet_subsys:
3987         destroy_workqueue(tc_filter_wq);
3988         return err;
3989 }
3990
3991 subsys_initcall(tc_filter_init);