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 <net/net_namespace.h>
  26 #include <net/sock.h>
  27 #include <net/netlink.h>
  28 #include <net/pkt_sched.h>
  29 #include <net/pkt_cls.h>
  30 #include <net/tc_act/tc_pedit.h>
  31 #include <net/tc_act/tc_mirred.h>
  32 #include <net/tc_act/tc_vlan.h>
  33 #include <net/tc_act/tc_tunnel_key.h>
  34 #include <net/tc_act/tc_csum.h>
  35 #include <net/tc_act/tc_gact.h>
  36 #include <net/tc_act/tc_police.h>
  37 #include <net/tc_act/tc_sample.h>
  38 #include <net/tc_act/tc_skbedit.h>
  39 #include <net/tc_act/tc_ct.h>
  40 #include <net/tc_act/tc_mpls.h>
  41 #include <net/tc_act/tc_gate.h>
  42 #include <net/flow_offload.h>
  43
  44 extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1];
  45
  46 /* The list of all installed classifier types */
  47 static LIST_HEAD(tcf_proto_base);
  48
  49 /* Protects list of registered TC modules. It is pure SMP lock. */
  50 static DEFINE_RWLOCK(cls_mod_lock);
  51
  52 static u32 destroy_obj_hashfn(const struct tcf_proto *tp)
  53 {
  54         return jhash_3words(tp->chain->index, tp->prio,
  55                             (__force __u32)tp->protocol, 0);
  56 }
  57
  58 static void tcf_proto_signal_destroying(struct tcf_chain *chain,
  59                                         struct tcf_proto *tp)
  60 {
  61         struct tcf_block *block = chain->block;
  62
  63         mutex_lock(&block->proto_destroy_lock);
  64         hash_add_rcu(block->proto_destroy_ht, &tp->destroy_ht_node,
  65                      destroy_obj_hashfn(tp));
  66         mutex_unlock(&block->proto_destroy_lock);
  67 }
  68
  69 static bool tcf_proto_cmp(const struct tcf_proto *tp1,
  70                           const struct tcf_proto *tp2)
  71 {
  72         return tp1->chain->index == tp2->chain->index &&
  73                tp1->prio == tp2->prio &&
  74                tp1->protocol == tp2->protocol;
  75 }
  76
  77 static bool tcf_proto_exists_destroying(struct tcf_chain *chain,
  78                                         struct tcf_proto *tp)
  79 {
  80         u32 hash = destroy_obj_hashfn(tp);
  81         struct tcf_proto *iter;
  82         bool found = false;
  83
  84         rcu_read_lock();
  85         hash_for_each_possible_rcu(chain->block->proto_destroy_ht, iter,
  86                                    destroy_ht_node, hash) {
  87                 if (tcf_proto_cmp(tp, iter)) {
  88                         found = true;
  89                         break;
  90                 }
  91         }
  92         rcu_read_unlock();
  93
  94         return found;
  95 }
  96
  97 static void
  98 tcf_proto_signal_destroyed(struct tcf_chain *chain, struct tcf_proto *tp)
  99 {
 100         struct tcf_block *block = chain->block;
 101
 102         mutex_lock(&block->proto_destroy_lock);
 103         if (hash_hashed(&tp->destroy_ht_node))
 104                 hash_del_rcu(&tp->destroy_ht_node);
 105         mutex_unlock(&block->proto_destroy_lock);
 106 }
 107
 108 /* Find classifier type by string name */
 109
 110 static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
 111 {
 112         const struct tcf_proto_ops *t, *res = NULL;
 113
 114         if (kind) {
 115                 read_lock(&cls_mod_lock);
 116                 list_for_each_entry(t, &tcf_proto_base, head) {
 117                         if (strcmp(kind, t->kind) == 0) {
 118                                 if (try_module_get(t->owner))
 119                                         res = t;
 120                                 break;
 121                         }
 122                 }
 123                 read_unlock(&cls_mod_lock);
 124         }
 125         return res;
 126 }
 127
 128 static const struct tcf_proto_ops *
 129 tcf_proto_lookup_ops(const char *kind, bool rtnl_held,
 130                      struct netlink_ext_ack *extack)
 131 {
 132         const struct tcf_proto_ops *ops;
 133
 134         ops = __tcf_proto_lookup_ops(kind);
 135         if (ops)
 136                 return ops;
 137 #ifdef CONFIG_MODULES
 138         if (rtnl_held)
 139                 rtnl_unlock();
 140         request_module("cls_%s", kind);
 141         if (rtnl_held)
 142                 rtnl_lock();
 143         ops = __tcf_proto_lookup_ops(kind);
 144         /* We dropped the RTNL semaphore in order to perform
 145          * the module load. So, even if we succeeded in loading
 146          * the module we have to replay the request. We indicate
 147          * this using -EAGAIN.
 148          */
 149         if (ops) {
 150                 module_put(ops->owner);
 151                 return ERR_PTR(-EAGAIN);
 152         }
 153 #endif
 154         NL_SET_ERR_MSG(extack, "TC classifier not found");
 155         return ERR_PTR(-ENOENT);
 156 }
 157
 158 /* Register(unregister) new classifier type */
 159
 160 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
 161 {
 162         struct tcf_proto_ops *t;
 163         int rc = -EEXIST;
 164
 165         write_lock(&cls_mod_lock);
 166         list_for_each_entry(t, &tcf_proto_base, head)
 167                 if (!strcmp(ops->kind, t->kind))
 168                         goto out;
 169
 170         list_add_tail(&ops->head, &tcf_proto_base);
 171         rc = 0;
 172 out:
 173         write_unlock(&cls_mod_lock);
 174         return rc;
 175 }
 176 EXPORT_SYMBOL(register_tcf_proto_ops);
 177
 178 static struct workqueue_struct *tc_filter_wq;
 179
 180 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
 181 {
 182         struct tcf_proto_ops *t;
 183         int rc = -ENOENT;
 184
 185         /* Wait for outstanding call_rcu()s, if any, from a
 186          * tcf_proto_ops's destroy() handler.
 187          */
 188         rcu_barrier();
 189         flush_workqueue(tc_filter_wq);
 190
 191         write_lock(&cls_mod_lock);
 192         list_for_each_entry(t, &tcf_proto_base, head) {
 193                 if (t == ops) {
 194                         list_del(&t->head);
 195                         rc = 0;
 196                         break;
 197                 }
 198         }
 199         write_unlock(&cls_mod_lock);
 200         return rc;
 201 }
 202 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 203
 204 bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
 205 {
 206         INIT_RCU_WORK(rwork, func);
 207         return queue_rcu_work(tc_filter_wq, rwork);
 208 }
 209 EXPORT_SYMBOL(tcf_queue_work);
 210
 211 /* Select new prio value from the range, managed by kernel. */
 212
 213 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 214 {
 215         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 216
 217         if (tp)
 218                 first = tp->prio - 1;
 219
 220         return TC_H_MAJ(first);
 221 }
 222
 223 static bool tcf_proto_check_kind(struct nlattr *kind, char *name)
 224 {
 225         if (kind)
 226                 return nla_strscpy(name, kind, IFNAMSIZ) < 0;
 227         memset(name, 0, IFNAMSIZ);
 228         return false;
 229 }
 230
 231 static bool tcf_proto_is_unlocked(const char *kind)
 232 {
 233         const struct tcf_proto_ops *ops;
 234         bool ret;
 235
 236         if (strlen(kind) == 0)
 237                 return false;
 238
 239         ops = tcf_proto_lookup_ops(kind, false, NULL);
 240         /* On error return false to take rtnl lock. Proto lookup/create
 241          * functions will perform lookup again and properly handle errors.
 242          */
 243         if (IS_ERR(ops))
 244                 return false;
 245
 246         ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED);
 247         module_put(ops->owner);
 248         return ret;
 249 }
 250
 251 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 252                                           u32 prio, struct tcf_chain *chain,
 253                                           bool rtnl_held,
 254                                           struct netlink_ext_ack *extack)
 255 {
 256         struct tcf_proto *tp;
 257         int err;
 258
 259         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 260         if (!tp)
 261                 return ERR_PTR(-ENOBUFS);
 262
 263         tp->ops = tcf_proto_lookup_ops(kind, rtnl_held, extack);
 264         if (IS_ERR(tp->ops)) {
 265                 err = PTR_ERR(tp->ops);
 266                 goto errout;
 267         }
 268         tp->classify = tp->ops->classify;
 269         tp->protocol = protocol;
 270         tp->prio = prio;
 271         tp->chain = chain;
 272         spin_lock_init(&tp->lock);
 273         refcount_set(&tp->refcnt, 1);
 274
 275         err = tp->ops->init(tp);
 276         if (err) {
 277                 module_put(tp->ops->owner);
 278                 goto errout;
 279         }
 280         return tp;
 281
 282 errout:
 283         kfree(tp);
 284         return ERR_PTR(err);
 285 }
 286
 287 static void tcf_proto_get(struct tcf_proto *tp)
 288 {
 289         refcount_inc(&tp->refcnt);
 290 }
 291
 292 static void tcf_chain_put(struct tcf_chain *chain);
 293
 294 static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
 295                               bool sig_destroy, struct netlink_ext_ack *extack)
 296 {
 297         tp->ops->destroy(tp, rtnl_held, extack);
 298         if (sig_destroy)
 299                 tcf_proto_signal_destroyed(tp->chain, tp);
 300         tcf_chain_put(tp->chain);
 301         module_put(tp->ops->owner);
 302         kfree_rcu(tp, rcu);
 303 }
 304
 305 static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
 306                           struct netlink_ext_ack *extack)
 307 {
 308         if (refcount_dec_and_test(&tp->refcnt))
 309                 tcf_proto_destroy(tp, rtnl_held, true, extack);
 310 }
 311
 312 static bool tcf_proto_check_delete(struct tcf_proto *tp)
 313 {
 314         if (tp->ops->delete_empty)
 315                 return tp->ops->delete_empty(tp);
 316
 317         tp->deleting = true;
 318         return tp->deleting;
 319 }
 320
 321 static void tcf_proto_mark_delete(struct tcf_proto *tp)
 322 {
 323         spin_lock(&tp->lock);
 324         tp->deleting = true;
 325         spin_unlock(&tp->lock);
 326 }
 327
 328 static bool tcf_proto_is_deleting(struct tcf_proto *tp)
 329 {
 330         bool deleting;
 331
 332         spin_lock(&tp->lock);
 333         deleting = tp->deleting;
 334         spin_unlock(&tp->lock);
 335
 336         return deleting;
 337 }
 338
 339 #define ASSERT_BLOCK_LOCKED(block)                                      \
 340         lockdep_assert_held(&(block)->lock)
 341
 342 struct tcf_filter_chain_list_item {
 343         struct list_head list;
 344         tcf_chain_head_change_t *chain_head_change;
 345         void *chain_head_change_priv;
 346 };
 347
 348 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 349                                           u32 chain_index)
 350 {
 351         struct tcf_chain *chain;
 352
 353         ASSERT_BLOCK_LOCKED(block);
 354
 355         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 356         if (!chain)
 357                 return NULL;
 358         list_add_tail_rcu(&chain->list, &block->chain_list);
 359         mutex_init(&chain->filter_chain_lock);
 360         chain->block = block;
 361         chain->index = chain_index;
 362         chain->refcnt = 1;
 363         if (!chain->index)
 364                 block->chain0.chain = chain;
 365         return chain;
 366 }
 367
 368 static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
 369                                        struct tcf_proto *tp_head)
 370 {
 371         if (item->chain_head_change)
 372                 item->chain_head_change(tp_head, item->chain_head_change_priv);
 373 }
 374
 375 static void tcf_chain0_head_change(struct tcf_chain *chain,
 376                                    struct tcf_proto *tp_head)
 377 {
 378         struct tcf_filter_chain_list_item *item;
 379         struct tcf_block *block = chain->block;
 380
 381         if (chain->index)
 382                 return;
 383
 384         mutex_lock(&block->lock);
 385         list_for_each_entry(item, &block->chain0.filter_chain_list, list)
 386                 tcf_chain_head_change_item(item, tp_head);
 387         mutex_unlock(&block->lock);
 388 }
 389
 390 /* Returns true if block can be safely freed. */
 391
 392 static bool tcf_chain_detach(struct tcf_chain *chain)
 393 {
 394         struct tcf_block *block = chain->block;
 395
 396         ASSERT_BLOCK_LOCKED(block);
 397
 398         list_del_rcu(&chain->list);
 399         if (!chain->index)
 400                 block->chain0.chain = NULL;
 401
 402         if (list_empty(&block->chain_list) &&
 403             refcount_read(&block->refcnt) == 0)
 404                 return true;
 405
 406         return false;
 407 }
 408
 409 static void tcf_block_destroy(struct tcf_block *block)
 410 {
 411         mutex_destroy(&block->lock);
 412         mutex_destroy(&block->proto_destroy_lock);
 413         kfree_rcu(block, rcu);
 414 }
 415
 416 static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
 417 {
 418         struct tcf_block *block = chain->block;
 419
 420         mutex_destroy(&chain->filter_chain_lock);
 421         kfree_rcu(chain, rcu);
 422         if (free_block)
 423                 tcf_block_destroy(block);
 424 }
 425
 426 static void tcf_chain_hold(struct tcf_chain *chain)
 427 {
 428         ASSERT_BLOCK_LOCKED(chain->block);
 429
 430         ++chain->refcnt;
 431 }
 432
 433 static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain)
 434 {
 435         ASSERT_BLOCK_LOCKED(chain->block);
 436
 437         /* In case all the references are action references, this
 438          * chain should not be shown to the user.
 439          */
 440         return chain->refcnt == chain->action_refcnt;
 441 }
 442
 443 static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
 444                                           u32 chain_index)
 445 {
 446         struct tcf_chain *chain;
 447
 448         ASSERT_BLOCK_LOCKED(block);
 449
 450         list_for_each_entry(chain, &block->chain_list, list) {
 451                 if (chain->index == chain_index)
 452                         return chain;
 453         }
 454         return NULL;
 455 }
 456
 457 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 458 static struct tcf_chain *tcf_chain_lookup_rcu(const struct tcf_block *block,
 459                                               u32 chain_index)
 460 {
 461         struct tcf_chain *chain;
 462
 463         list_for_each_entry_rcu(chain, &block->chain_list, list) {
 464                 if (chain->index == chain_index)
 465                         return chain;
 466         }
 467         return NULL;
 468 }
 469 #endif
 470
 471 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 472                            u32 seq, u16 flags, int event, bool unicast);
 473
 474 static struct tcf_chain *__tcf_chain_get(struct tcf_block *block,
 475                                          u32 chain_index, bool create,
 476                                          bool by_act)
 477 {
 478         struct tcf_chain *chain = NULL;
 479         bool is_first_reference;
 480
 481         mutex_lock(&block->lock);
 482         chain = tcf_chain_lookup(block, chain_index);
 483         if (chain) {
 484                 tcf_chain_hold(chain);
 485         } else {
 486                 if (!create)
 487                         goto errout;
 488                 chain = tcf_chain_create(block, chain_index);
 489                 if (!chain)
 490                         goto errout;
 491         }
 492
 493         if (by_act)
 494                 ++chain->action_refcnt;
 495         is_first_reference = chain->refcnt - chain->action_refcnt == 1;
 496         mutex_unlock(&block->lock);
 497
 498         /* Send notification only in case we got the first
 499          * non-action reference. Until then, the chain acts only as
 500          * a placeholder for actions pointing to it and user ought
 501          * not know about them.
 502          */
 503         if (is_first_reference && !by_act)
 504                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
 505                                 RTM_NEWCHAIN, false);
 506
 507         return chain;
 508
 509 errout:
 510         mutex_unlock(&block->lock);
 511         return chain;
 512 }
 513
 514 static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 515                                        bool create)
 516 {
 517         return __tcf_chain_get(block, chain_index, create, false);
 518 }
 519
 520 struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index)
 521 {
 522         return __tcf_chain_get(block, chain_index, true, true);
 523 }
 524 EXPORT_SYMBOL(tcf_chain_get_by_act);
 525
 526 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
 527                                void *tmplt_priv);
 528 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
 529                                   void *tmplt_priv, u32 chain_index,
 530                                   struct tcf_block *block, struct sk_buff *oskb,
 531                                   u32 seq, u16 flags, bool unicast);
 532
 533 static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
 534                             bool explicitly_created)
 535 {
 536         struct tcf_block *block = chain->block;
 537         const struct tcf_proto_ops *tmplt_ops;
 538         bool free_block = false;
 539         unsigned int refcnt;
 540         void *tmplt_priv;
 541
 542         mutex_lock(&block->lock);
 543         if (explicitly_created) {
 544                 if (!chain->explicitly_created) {
 545                         mutex_unlock(&block->lock);
 546                         return;
 547                 }
 548                 chain->explicitly_created = false;
 549         }
 550
 551         if (by_act)
 552                 chain->action_refcnt--;
 553
 554         /* tc_chain_notify_delete can't be called while holding block lock.
 555          * However, when block is unlocked chain can be changed concurrently, so
 556          * save these to temporary variables.
 557          */
 558         refcnt = --chain->refcnt;
 559         tmplt_ops = chain->tmplt_ops;
 560         tmplt_priv = chain->tmplt_priv;
 561
 562         /* The last dropped non-action reference will trigger notification. */
 563         if (refcnt - chain->action_refcnt == 0 && !by_act) {
 564                 tc_chain_notify_delete(tmplt_ops, tmplt_priv, chain->index,
 565                                        block, NULL, 0, 0, false);
 566                 /* Last reference to chain, no need to lock. */
 567                 chain->flushing = false;
 568         }
 569
 570         if (refcnt == 0)
 571                 free_block = tcf_chain_detach(chain);
 572         mutex_unlock(&block->lock);
 573
 574         if (refcnt == 0) {
 575                 tc_chain_tmplt_del(tmplt_ops, tmplt_priv);
 576                 tcf_chain_destroy(chain, free_block);
 577         }
 578 }
 579
 580 static void tcf_chain_put(struct tcf_chain *chain)
 581 {
 582         __tcf_chain_put(chain, false, false);
 583 }
 584
 585 void tcf_chain_put_by_act(struct tcf_chain *chain)
 586 {
 587         __tcf_chain_put(chain, true, false);
 588 }
 589 EXPORT_SYMBOL(tcf_chain_put_by_act);
 590
 591 static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 592 {
 593         __tcf_chain_put(chain, false, true);
 594 }
 595
 596 static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
 597 {
 598         struct tcf_proto *tp, *tp_next;
 599
 600         mutex_lock(&chain->filter_chain_lock);
 601         tp = tcf_chain_dereference(chain->filter_chain, chain);
 602         while (tp) {
 603                 tp_next = rcu_dereference_protected(tp->next, 1);
 604                 tcf_proto_signal_destroying(chain, tp);
 605                 tp = tp_next;
 606         }
 607         tp = tcf_chain_dereference(chain->filter_chain, chain);
 608         RCU_INIT_POINTER(chain->filter_chain, NULL);
 609         tcf_chain0_head_change(chain, NULL);
 610         chain->flushing = true;
 611         mutex_unlock(&chain->filter_chain_lock);
 612
 613         while (tp) {
 614                 tp_next = rcu_dereference_protected(tp->next, 1);
 615                 tcf_proto_put(tp, rtnl_held, NULL);
 616                 tp = tp_next;
 617         }
 618 }
 619
 620 static int tcf_block_setup(struct tcf_block *block,
 621                            struct flow_block_offload *bo);
 622
 623 static void tcf_block_offload_init(struct flow_block_offload *bo,
 624                                    struct net_device *dev, struct Qdisc *sch,
 625                                    enum flow_block_command command,
 626                                    enum flow_block_binder_type binder_type,
 627                                    struct flow_block *flow_block,
 628                                    bool shared, struct netlink_ext_ack *extack)
 629 {
 630         bo->net = dev_net(dev);
 631         bo->command = command;
 632         bo->binder_type = binder_type;
 633         bo->block = flow_block;
 634         bo->block_shared = shared;
 635         bo->extack = extack;
 636         bo->sch = sch;
 637         bo->cb_list_head = &flow_block->cb_list;
 638         INIT_LIST_HEAD(&bo->cb_list);
 639 }
 640
 641 static void tcf_block_unbind(struct tcf_block *block,
 642                              struct flow_block_offload *bo);
 643
 644 static void tc_block_indr_cleanup(struct flow_block_cb *block_cb)
 645 {
 646         struct tcf_block *block = block_cb->indr.data;
 647         struct net_device *dev = block_cb->indr.dev;
 648         struct Qdisc *sch = block_cb->indr.sch;
 649         struct netlink_ext_ack extack = {};
 650         struct flow_block_offload bo = {};
 651
 652         tcf_block_offload_init(&bo, dev, sch, FLOW_BLOCK_UNBIND,
 653                                block_cb->indr.binder_type,
 654                                &block->flow_block, tcf_block_shared(block),
 655                                &extack);
 656         rtnl_lock();
 657         down_write(&block->cb_lock);
 658         list_del(&block_cb->driver_list);
 659         list_move(&block_cb->list, &bo.cb_list);
 660         tcf_block_unbind(block, &bo);
 661         up_write(&block->cb_lock);
 662         rtnl_unlock();
 663 }
 664
 665 static bool tcf_block_offload_in_use(struct tcf_block *block)
 666 {
 667         return atomic_read(&block->offloadcnt);
 668 }
 669
 670 static int tcf_block_offload_cmd(struct tcf_block *block,
 671                                  struct net_device *dev, struct Qdisc *sch,
 672                                  struct tcf_block_ext_info *ei,
 673                                  enum flow_block_command command,
 674                                  struct netlink_ext_ack *extack)
 675 {
 676         struct flow_block_offload bo = {};
 677
 678         tcf_block_offload_init(&bo, dev, sch, command, ei->binder_type,
 679                                &block->flow_block, tcf_block_shared(block),
 680                                extack);
 681
 682         if (dev->netdev_ops->ndo_setup_tc) {
 683                 int err;
 684
 685                 err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 686                 if (err < 0) {
 687                         if (err != -EOPNOTSUPP)
 688                                 NL_SET_ERR_MSG(extack, "Driver ndo_setup_tc failed");
 689                         return err;
 690                 }
 691
 692                 return tcf_block_setup(block, &bo);
 693         }
 694
 695         flow_indr_dev_setup_offload(dev, sch, TC_SETUP_BLOCK, block, &bo,
 696                                     tc_block_indr_cleanup);
 697         tcf_block_setup(block, &bo);
 698
 699         return -EOPNOTSUPP;
 700 }
 701
 702 static int tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
 703                                   struct tcf_block_ext_info *ei,
 704                                   struct netlink_ext_ack *extack)
 705 {
 706         struct net_device *dev = q->dev_queue->dev;
 707         int err;
 708
 709         down_write(&block->cb_lock);
 710
 711         /* If tc offload feature is disabled and the block we try to bind
 712          * to already has some offloaded filters, forbid to bind.
 713          */
 714         if (dev->netdev_ops->ndo_setup_tc &&
 715             !tc_can_offload(dev) &&
 716             tcf_block_offload_in_use(block)) {
 717                 NL_SET_ERR_MSG(extack, "Bind to offloaded block failed as dev has offload disabled");
 718                 err = -EOPNOTSUPP;
 719                 goto err_unlock;
 720         }
 721
 722         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_BIND, extack);
 723         if (err == -EOPNOTSUPP)
 724                 goto no_offload_dev_inc;
 725         if (err)
 726                 goto err_unlock;
 727
 728         up_write(&block->cb_lock);
 729         return 0;
 730
 731 no_offload_dev_inc:
 732         if (tcf_block_offload_in_use(block))
 733                 goto err_unlock;
 734
 735         err = 0;
 736         block->nooffloaddevcnt++;
 737 err_unlock:
 738         up_write(&block->cb_lock);
 739         return err;
 740 }
 741
 742 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
 743                                      struct tcf_block_ext_info *ei)
 744 {
 745         struct net_device *dev = q->dev_queue->dev;
 746         int err;
 747
 748         down_write(&block->cb_lock);
 749         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_UNBIND, NULL);
 750         if (err == -EOPNOTSUPP)
 751                 goto no_offload_dev_dec;
 752         up_write(&block->cb_lock);
 753         return;
 754
 755 no_offload_dev_dec:
 756         WARN_ON(block->nooffloaddevcnt-- == 0);
 757         up_write(&block->cb_lock);
 758 }
 759
 760 static int
 761 tcf_chain0_head_change_cb_add(struct tcf_block *block,
 762                               struct tcf_block_ext_info *ei,
 763                               struct netlink_ext_ack *extack)
 764 {
 765         struct tcf_filter_chain_list_item *item;
 766         struct tcf_chain *chain0;
 767
 768         item = kmalloc(sizeof(*item), GFP_KERNEL);
 769         if (!item) {
 770                 NL_SET_ERR_MSG(extack, "Memory allocation for head change callback item failed");
 771                 return -ENOMEM;
 772         }
 773         item->chain_head_change = ei->chain_head_change;
 774         item->chain_head_change_priv = ei->chain_head_change_priv;
 775
 776         mutex_lock(&block->lock);
 777         chain0 = block->chain0.chain;
 778         if (chain0)
 779                 tcf_chain_hold(chain0);
 780         else
 781                 list_add(&item->list, &block->chain0.filter_chain_list);
 782         mutex_unlock(&block->lock);
 783
 784         if (chain0) {
 785                 struct tcf_proto *tp_head;
 786
 787                 mutex_lock(&chain0->filter_chain_lock);
 788
 789                 tp_head = tcf_chain_dereference(chain0->filter_chain, chain0);
 790                 if (tp_head)
 791                         tcf_chain_head_change_item(item, tp_head);
 792
 793                 mutex_lock(&block->lock);
 794                 list_add(&item->list, &block->chain0.filter_chain_list);
 795                 mutex_unlock(&block->lock);
 796
 797                 mutex_unlock(&chain0->filter_chain_lock);
 798                 tcf_chain_put(chain0);
 799         }
 800
 801         return 0;
 802 }
 803
 804 static void
 805 tcf_chain0_head_change_cb_del(struct tcf_block *block,
 806                               struct tcf_block_ext_info *ei)
 807 {
 808         struct tcf_filter_chain_list_item *item;
 809
 810         mutex_lock(&block->lock);
 811         list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
 812                 if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
 813                     (item->chain_head_change == ei->chain_head_change &&
 814                      item->chain_head_change_priv == ei->chain_head_change_priv)) {
 815                         if (block->chain0.chain)
 816                                 tcf_chain_head_change_item(item, NULL);
 817                         list_del(&item->list);
 818                         mutex_unlock(&block->lock);
 819
 820                         kfree(item);
 821                         return;
 822                 }
 823         }
 824         mutex_unlock(&block->lock);
 825         WARN_ON(1);
 826 }
 827
 828 struct tcf_net {
 829         spinlock_t idr_lock; /* Protects idr */
 830         struct idr idr;
 831 };
 832
 833 static unsigned int tcf_net_id;
 834
 835 static int tcf_block_insert(struct tcf_block *block, struct net *net,
 836                             struct netlink_ext_ack *extack)
 837 {
 838         struct tcf_net *tn = net_generic(net, tcf_net_id);
 839         int err;
 840
 841         idr_preload(GFP_KERNEL);
 842         spin_lock(&tn->idr_lock);
 843         err = idr_alloc_u32(&tn->idr, block, &block->index, block->index,
 844                             GFP_NOWAIT);
 845         spin_unlock(&tn->idr_lock);
 846         idr_preload_end();
 847
 848         return err;
 849 }
 850
 851 static void tcf_block_remove(struct tcf_block *block, struct net *net)
 852 {
 853         struct tcf_net *tn = net_generic(net, tcf_net_id);
 854
 855         spin_lock(&tn->idr_lock);
 856         idr_remove(&tn->idr, block->index);
 857         spin_unlock(&tn->idr_lock);
 858 }
 859
 860 static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 861                                           u32 block_index,
 862                                           struct netlink_ext_ack *extack)
 863 {
 864         struct tcf_block *block;
 865
 866         block = kzalloc(sizeof(*block), GFP_KERNEL);
 867         if (!block) {
 868                 NL_SET_ERR_MSG(extack, "Memory allocation for block failed");
 869                 return ERR_PTR(-ENOMEM);
 870         }
 871         mutex_init(&block->lock);
 872         mutex_init(&block->proto_destroy_lock);
 873         init_rwsem(&block->cb_lock);
 874         flow_block_init(&block->flow_block);
 875         INIT_LIST_HEAD(&block->chain_list);
 876         INIT_LIST_HEAD(&block->owner_list);
 877         INIT_LIST_HEAD(&block->chain0.filter_chain_list);
 878
 879         refcount_set(&block->refcnt, 1);
 880         block->net = net;
 881         block->index = block_index;
 882
 883         /* Don't store q pointer for blocks which are shared */
 884         if (!tcf_block_shared(block))
 885                 block->q = q;
 886         return block;
 887 }
 888
 889 static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
 890 {
 891         struct tcf_net *tn = net_generic(net, tcf_net_id);
 892
 893         return idr_find(&tn->idr, block_index);
 894 }
 895
 896 static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
 897 {
 898         struct tcf_block *block;
 899
 900         rcu_read_lock();
 901         block = tcf_block_lookup(net, block_index);
 902         if (block && !refcount_inc_not_zero(&block->refcnt))
 903                 block = NULL;
 904         rcu_read_unlock();
 905
 906         return block;
 907 }
 908
 909 static struct tcf_chain *
 910 __tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
 911 {
 912         mutex_lock(&block->lock);
 913         if (chain)
 914                 chain = list_is_last(&chain->list, &block->chain_list) ?
 915                         NULL : list_next_entry(chain, list);
 916         else
 917                 chain = list_first_entry_or_null(&block->chain_list,
 918                                                  struct tcf_chain, list);
 919
 920         /* skip all action-only chains */
 921         while (chain && tcf_chain_held_by_acts_only(chain))
 922                 chain = list_is_last(&chain->list, &block->chain_list) ?
 923                         NULL : list_next_entry(chain, list);
 924
 925         if (chain)
 926                 tcf_chain_hold(chain);
 927         mutex_unlock(&block->lock);
 928
 929         return chain;
 930 }
 931
 932 /* Function to be used by all clients that want to iterate over all chains on
 933  * block. It properly obtains block->lock and takes reference to chain before
 934  * returning it. Users of this function must be tolerant to concurrent chain
 935  * insertion/deletion or ensure that no concurrent chain modification is
 936  * possible. Note that all netlink dump callbacks cannot guarantee to provide
 937  * consistent dump because rtnl lock is released each time skb is filled with
 938  * data and sent to user-space.
 939  */
 940
 941 struct tcf_chain *
 942 tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
 943 {
 944         struct tcf_chain *chain_next = __tcf_get_next_chain(block, chain);
 945
 946         if (chain)
 947                 tcf_chain_put(chain);
 948
 949         return chain_next;
 950 }
 951 EXPORT_SYMBOL(tcf_get_next_chain);
 952
 953 static struct tcf_proto *
 954 __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
 955 {
 956         u32 prio = 0;
 957
 958         ASSERT_RTNL();
 959         mutex_lock(&chain->filter_chain_lock);
 960
 961         if (!tp) {
 962                 tp = tcf_chain_dereference(chain->filter_chain, chain);
 963         } else if (tcf_proto_is_deleting(tp)) {
 964                 /* 'deleting' flag is set and chain->filter_chain_lock was
 965                  * unlocked, which means next pointer could be invalid. Restart
 966                  * search.
 967                  */
 968                 prio = tp->prio + 1;
 969                 tp = tcf_chain_dereference(chain->filter_chain, chain);
 970
 971                 for (; tp; tp = tcf_chain_dereference(tp->next, chain))
 972                         if (!tp->deleting && tp->prio >= prio)
 973                                 break;
 974         } else {
 975                 tp = tcf_chain_dereference(tp->next, chain);
 976         }
 977
 978         if (tp)
 979                 tcf_proto_get(tp);
 980
 981         mutex_unlock(&chain->filter_chain_lock);
 982
 983         return tp;
 984 }
 985
 986 /* Function to be used by all clients that want to iterate over all tp's on
 987  * chain. Users of this function must be tolerant to concurrent tp
 988  * insertion/deletion or ensure that no concurrent chain modification is
 989  * possible. Note that all netlink dump callbacks cannot guarantee to provide
 990  * consistent dump because rtnl lock is released each time skb is filled with
 991  * data and sent to user-space.
 992  */
 993
 994 struct tcf_proto *
 995 tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
 996 {
 997         struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
 998
 999         if (tp)
1000                 tcf_proto_put(tp, true, NULL);
1001
1002         return tp_next;
1003 }
1004 EXPORT_SYMBOL(tcf_get_next_proto);
1005
1006 static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
1007 {
1008         struct tcf_chain *chain;
1009
1010         /* Last reference to block. At this point chains cannot be added or
1011          * removed concurrently.
1012          */
1013         for (chain = tcf_get_next_chain(block, NULL);
1014              chain;
1015              chain = tcf_get_next_chain(block, chain)) {
1016                 tcf_chain_put_explicitly_created(chain);
1017                 tcf_chain_flush(chain, rtnl_held);
1018         }
1019 }
1020
1021 /* Lookup Qdisc and increments its reference counter.
1022  * Set parent, if necessary.
1023  */
1024
1025 static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
1026                             u32 *parent, int ifindex, bool rtnl_held,
1027                             struct netlink_ext_ack *extack)
1028 {
1029         const struct Qdisc_class_ops *cops;
1030         struct net_device *dev;
1031         int err = 0;
1032
1033         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1034                 return 0;
1035
1036         rcu_read_lock();
1037
1038         /* Find link */
1039         dev = dev_get_by_index_rcu(net, ifindex);
1040         if (!dev) {
1041                 rcu_read_unlock();
1042                 return -ENODEV;
1043         }
1044
1045         /* Find qdisc */
1046         if (!*parent) {
1047                 *q = dev->qdisc;
1048                 *parent = (*q)->handle;
1049         } else {
1050                 *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
1051                 if (!*q) {
1052                         NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1053                         err = -EINVAL;
1054                         goto errout_rcu;
1055                 }
1056         }
1057
1058         *q = qdisc_refcount_inc_nz(*q);
1059         if (!*q) {
1060                 NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1061                 err = -EINVAL;
1062                 goto errout_rcu;
1063         }
1064
1065         /* Is it classful? */
1066         cops = (*q)->ops->cl_ops;
1067         if (!cops) {
1068                 NL_SET_ERR_MSG(extack, "Qdisc not classful");
1069                 err = -EINVAL;
1070                 goto errout_qdisc;
1071         }
1072
1073         if (!cops->tcf_block) {
1074                 NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
1075                 err = -EOPNOTSUPP;
1076                 goto errout_qdisc;
1077         }
1078
1079 errout_rcu:
1080         /* At this point we know that qdisc is not noop_qdisc,
1081          * which means that qdisc holds a reference to net_device
1082          * and we hold a reference to qdisc, so it is safe to release
1083          * rcu read lock.
1084          */
1085         rcu_read_unlock();
1086         return err;
1087
1088 errout_qdisc:
1089         rcu_read_unlock();
1090
1091         if (rtnl_held)
1092                 qdisc_put(*q);
1093         else
1094                 qdisc_put_unlocked(*q);
1095         *q = NULL;
1096
1097         return err;
1098 }
1099
1100 static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
1101                                int ifindex, struct netlink_ext_ack *extack)
1102 {
1103         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1104                 return 0;
1105
1106         /* Do we search for filter, attached to class? */
1107         if (TC_H_MIN(parent)) {
1108                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1109
1110                 *cl = cops->find(q, parent);
1111                 if (*cl == 0) {
1112                         NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
1113                         return -ENOENT;
1114                 }
1115         }
1116
1117         return 0;
1118 }
1119
1120 static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
1121                                           unsigned long cl, int ifindex,
1122                                           u32 block_index,
1123                                           struct netlink_ext_ack *extack)
1124 {
1125         struct tcf_block *block;
1126
1127         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
1128                 block = tcf_block_refcnt_get(net, block_index);
1129                 if (!block) {
1130                         NL_SET_ERR_MSG(extack, "Block of given index was not found");
1131                         return ERR_PTR(-EINVAL);
1132                 }
1133         } else {
1134                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1135
1136                 block = cops->tcf_block(q, cl, extack);
1137                 if (!block)
1138                         return ERR_PTR(-EINVAL);
1139
1140                 if (tcf_block_shared(block)) {
1141                         NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
1142                         return ERR_PTR(-EOPNOTSUPP);
1143                 }
1144
1145                 /* Always take reference to block in order to support execution
1146                  * of rules update path of cls API without rtnl lock. Caller
1147                  * must release block when it is finished using it. 'if' block
1148                  * of this conditional obtain reference to block by calling
1149                  * tcf_block_refcnt_get().
1150                  */
1151                 refcount_inc(&block->refcnt);
1152         }
1153
1154         return block;
1155 }
1156
1157 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
1158                             struct tcf_block_ext_info *ei, bool rtnl_held)
1159 {
1160         if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
1161                 /* Flushing/putting all chains will cause the block to be
1162                  * deallocated when last chain is freed. However, if chain_list
1163                  * is empty, block has to be manually deallocated. After block
1164                  * reference counter reached 0, it is no longer possible to
1165                  * increment it or add new chains to block.
1166                  */
1167                 bool free_block = list_empty(&block->chain_list);
1168
1169                 mutex_unlock(&block->lock);
1170                 if (tcf_block_shared(block))
1171                         tcf_block_remove(block, block->net);
1172
1173                 if (q)
1174                         tcf_block_offload_unbind(block, q, ei);
1175
1176                 if (free_block)
1177                         tcf_block_destroy(block);
1178                 else
1179                         tcf_block_flush_all_chains(block, rtnl_held);
1180         } else if (q) {
1181                 tcf_block_offload_unbind(block, q, ei);
1182         }
1183 }
1184
1185 static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
1186 {
1187         __tcf_block_put(block, NULL, NULL, rtnl_held);
1188 }
1189
1190 /* Find tcf block.
1191  * Set q, parent, cl when appropriate.
1192  */
1193
1194 static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
1195                                         u32 *parent, unsigned long *cl,
1196                                         int ifindex, u32 block_index,
1197                                         struct netlink_ext_ack *extack)
1198 {
1199         struct tcf_block *block;
1200         int err = 0;
1201
1202         ASSERT_RTNL();
1203
1204         err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
1205         if (err)
1206                 goto errout;
1207
1208         err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
1209         if (err)
1210                 goto errout_qdisc;
1211
1212         block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
1213         if (IS_ERR(block)) {
1214                 err = PTR_ERR(block);
1215                 goto errout_qdisc;
1216         }
1217
1218         return block;
1219
1220 errout_qdisc:
1221         if (*q)
1222                 qdisc_put(*q);
1223 errout:
1224         *q = NULL;
1225         return ERR_PTR(err);
1226 }
1227
1228 static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
1229                               bool rtnl_held)
1230 {
1231         if (!IS_ERR_OR_NULL(block))
1232                 tcf_block_refcnt_put(block, rtnl_held);
1233
1234         if (q) {
1235                 if (rtnl_held)
1236                         qdisc_put(q);
1237                 else
1238                         qdisc_put_unlocked(q);
1239         }
1240 }
1241
1242 struct tcf_block_owner_item {
1243         struct list_head list;
1244         struct Qdisc *q;
1245         enum flow_block_binder_type binder_type;
1246 };
1247
1248 static void
1249 tcf_block_owner_netif_keep_dst(struct tcf_block *block,
1250                                struct Qdisc *q,
1251                                enum flow_block_binder_type binder_type)
1252 {
1253         if (block->keep_dst &&
1254             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS &&
1255             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
1256                 netif_keep_dst(qdisc_dev(q));
1257 }
1258
1259 void tcf_block_netif_keep_dst(struct tcf_block *block)
1260 {
1261         struct tcf_block_owner_item *item;
1262
1263         block->keep_dst = true;
1264         list_for_each_entry(item, &block->owner_list, list)
1265                 tcf_block_owner_netif_keep_dst(block, item->q,
1266                                                item->binder_type);
1267 }
1268 EXPORT_SYMBOL(tcf_block_netif_keep_dst);
1269
1270 static int tcf_block_owner_add(struct tcf_block *block,
1271                                struct Qdisc *q,
1272                                enum flow_block_binder_type binder_type)
1273 {
1274         struct tcf_block_owner_item *item;
1275
1276         item = kmalloc(sizeof(*item), GFP_KERNEL);
1277         if (!item)
1278                 return -ENOMEM;
1279         item->q = q;
1280         item->binder_type = binder_type;
1281         list_add(&item->list, &block->owner_list);
1282         return 0;
1283 }
1284
1285 static void tcf_block_owner_del(struct tcf_block *block,
1286                                 struct Qdisc *q,
1287                                 enum flow_block_binder_type binder_type)
1288 {
1289         struct tcf_block_owner_item *item;
1290
1291         list_for_each_entry(item, &block->owner_list, list) {
1292                 if (item->q == q && item->binder_type == binder_type) {
1293                         list_del(&item->list);
1294                         kfree(item);
1295                         return;
1296                 }
1297         }
1298         WARN_ON(1);
1299 }
1300
1301 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
1302                       struct tcf_block_ext_info *ei,
1303                       struct netlink_ext_ack *extack)
1304 {
1305         struct net *net = qdisc_net(q);
1306         struct tcf_block *block = NULL;
1307         int err;
1308
1309         if (ei->block_index)
1310                 /* block_index not 0 means the shared block is requested */
1311                 block = tcf_block_refcnt_get(net, ei->block_index);
1312
1313         if (!block) {
1314                 block = tcf_block_create(net, q, ei->block_index, extack);
1315                 if (IS_ERR(block))
1316                         return PTR_ERR(block);
1317                 if (tcf_block_shared(block)) {
1318                         err = tcf_block_insert(block, net, extack);
1319                         if (err)
1320                                 goto err_block_insert;
1321                 }
1322         }
1323
1324         err = tcf_block_owner_add(block, q, ei->binder_type);
1325         if (err)
1326                 goto err_block_owner_add;
1327
1328         tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
1329
1330         err = tcf_chain0_head_change_cb_add(block, ei, extack);
1331         if (err)
1332                 goto err_chain0_head_change_cb_add;
1333
1334         err = tcf_block_offload_bind(block, q, ei, extack);
1335         if (err)
1336                 goto err_block_offload_bind;
1337
1338         *p_block = block;
1339         return 0;
1340
1341 err_block_offload_bind:
1342         tcf_chain0_head_change_cb_del(block, ei);
1343 err_chain0_head_change_cb_add:
1344         tcf_block_owner_del(block, q, ei->binder_type);
1345 err_block_owner_add:
1346 err_block_insert:
1347         tcf_block_refcnt_put(block, true);
1348         return err;
1349 }
1350 EXPORT_SYMBOL(tcf_block_get_ext);
1351
1352 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
1353 {
1354         struct tcf_proto __rcu **p_filter_chain = priv;
1355
1356         rcu_assign_pointer(*p_filter_chain, tp_head);
1357 }
1358
1359 int tcf_block_get(struct tcf_block **p_block,
1360                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
1361                   struct netlink_ext_ack *extack)
1362 {
1363         struct tcf_block_ext_info ei = {
1364                 .chain_head_change = tcf_chain_head_change_dflt,
1365                 .chain_head_change_priv = p_filter_chain,
1366         };
1367
1368         WARN_ON(!p_filter_chain);
1369         return tcf_block_get_ext(p_block, q, &ei, extack);
1370 }
1371 EXPORT_SYMBOL(tcf_block_get);
1372
1373 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
1374  * actions should be all removed after flushing.
1375  */
1376 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
1377                        struct tcf_block_ext_info *ei)
1378 {
1379         if (!block)
1380                 return;
1381         tcf_chain0_head_change_cb_del(block, ei);
1382         tcf_block_owner_del(block, q, ei->binder_type);
1383
1384         __tcf_block_put(block, q, ei, true);
1385 }
1386 EXPORT_SYMBOL(tcf_block_put_ext);
1387
1388 void tcf_block_put(struct tcf_block *block)
1389 {
1390         struct tcf_block_ext_info ei = {0, };
1391
1392         if (!block)
1393                 return;
1394         tcf_block_put_ext(block, block->q, &ei);
1395 }
1396
1397 EXPORT_SYMBOL(tcf_block_put);
1398
1399 static int
1400 tcf_block_playback_offloads(struct tcf_block *block, flow_setup_cb_t *cb,
1401                             void *cb_priv, bool add, bool offload_in_use,
1402                             struct netlink_ext_ack *extack)
1403 {
1404         struct tcf_chain *chain, *chain_prev;
1405         struct tcf_proto *tp, *tp_prev;
1406         int err;
1407
1408         lockdep_assert_held(&block->cb_lock);
1409
1410         for (chain = __tcf_get_next_chain(block, NULL);
1411              chain;
1412              chain_prev = chain,
1413                      chain = __tcf_get_next_chain(block, chain),
1414                      tcf_chain_put(chain_prev)) {
1415                 for (tp = __tcf_get_next_proto(chain, NULL); tp;
1416                      tp_prev = tp,
1417                              tp = __tcf_get_next_proto(chain, tp),
1418                              tcf_proto_put(tp_prev, true, NULL)) {
1419                         if (tp->ops->reoffload) {
1420                                 err = tp->ops->reoffload(tp, add, cb, cb_priv,
1421                                                          extack);
1422                                 if (err && add)
1423                                         goto err_playback_remove;
1424                         } else if (add && offload_in_use) {
1425                                 err = -EOPNOTSUPP;
1426                                 NL_SET_ERR_MSG(extack, "Filter HW offload failed - classifier without re-offloading support");
1427                                 goto err_playback_remove;
1428                         }
1429                 }
1430         }
1431
1432         return 0;
1433
1434 err_playback_remove:
1435         tcf_proto_put(tp, true, NULL);
1436         tcf_chain_put(chain);
1437         tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
1438                                     extack);
1439         return err;
1440 }
1441
1442 static int tcf_block_bind(struct tcf_block *block,
1443                           struct flow_block_offload *bo)
1444 {
1445         struct flow_block_cb *block_cb, *next;
1446         int err, i = 0;
1447
1448         lockdep_assert_held(&block->cb_lock);
1449
1450         list_for_each_entry(block_cb, &bo->cb_list, list) {
1451                 err = tcf_block_playback_offloads(block, block_cb->cb,
1452                                                   block_cb->cb_priv, true,
1453                                                   tcf_block_offload_in_use(block),
1454                                                   bo->extack);
1455                 if (err)
1456                         goto err_unroll;
1457                 if (!bo->unlocked_driver_cb)
1458                         block->lockeddevcnt++;
1459
1460                 i++;
1461         }
1462         list_splice(&bo->cb_list, &block->flow_block.cb_list);
1463
1464         return 0;
1465
1466 err_unroll:
1467         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1468                 if (i-- > 0) {
1469                         list_del(&block_cb->list);
1470                         tcf_block_playback_offloads(block, block_cb->cb,
1471                                                     block_cb->cb_priv, false,
1472                                                     tcf_block_offload_in_use(block),
1473                                                     NULL);
1474                         if (!bo->unlocked_driver_cb)
1475                                 block->lockeddevcnt--;
1476                 }
1477                 flow_block_cb_free(block_cb);
1478         }
1479
1480         return err;
1481 }
1482
1483 static void tcf_block_unbind(struct tcf_block *block,
1484                              struct flow_block_offload *bo)
1485 {
1486         struct flow_block_cb *block_cb, *next;
1487
1488         lockdep_assert_held(&block->cb_lock);
1489
1490         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1491                 tcf_block_playback_offloads(block, block_cb->cb,
1492                                             block_cb->cb_priv, false,
1493                                             tcf_block_offload_in_use(block),
1494                                             NULL);
1495                 list_del(&block_cb->list);
1496                 flow_block_cb_free(block_cb);
1497                 if (!bo->unlocked_driver_cb)
1498                         block->lockeddevcnt--;
1499         }
1500 }
1501
1502 static int tcf_block_setup(struct tcf_block *block,
1503                            struct flow_block_offload *bo)
1504 {
1505         int err;
1506
1507         switch (bo->command) {
1508         case FLOW_BLOCK_BIND:
1509                 err = tcf_block_bind(block, bo);
1510                 break;
1511         case FLOW_BLOCK_UNBIND:
1512                 err = 0;
1513                 tcf_block_unbind(block, bo);
1514                 break;
1515         default:
1516                 WARN_ON_ONCE(1);
1517                 err = -EOPNOTSUPP;
1518         }
1519
1520         return err;
1521 }
1522
1523 /* Main classifier routine: scans classifier chain attached
1524  * to this qdisc, (optionally) tests for protocol and asks
1525  * specific classifiers.
1526  */
1527 static inline int __tcf_classify(struct sk_buff *skb,
1528                                  const struct tcf_proto *tp,
1529                                  const struct tcf_proto *orig_tp,
1530                                  struct tcf_result *res,
1531                                  bool compat_mode,
1532                                  u32 *last_executed_chain)
1533 {
1534 #ifdef CONFIG_NET_CLS_ACT
1535         const int max_reclassify_loop = 16;
1536         const struct tcf_proto *first_tp;
1537         int limit = 0;
1538
1539 reclassify:
1540 #endif
1541         for (; tp; tp = rcu_dereference_bh(tp->next)) {
1542                 __be16 protocol = skb_protocol(skb, false);
1543                 int err;
1544
1545                 if (tp->protocol != protocol &&
1546                     tp->protocol != htons(ETH_P_ALL))
1547                         continue;
1548
1549                 err = tp->classify(skb, tp, res);
1550 #ifdef CONFIG_NET_CLS_ACT
1551                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
1552                         first_tp = orig_tp;
1553                         *last_executed_chain = first_tp->chain->index;
1554                         goto reset;
1555                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
1556                         first_tp = res->goto_tp;
1557                         *last_executed_chain = err & TC_ACT_EXT_VAL_MASK;
1558                         goto reset;
1559                 }
1560 #endif
1561                 if (err >= 0)
1562                         return err;
1563         }
1564
1565         return TC_ACT_UNSPEC; /* signal: continue lookup */
1566 #ifdef CONFIG_NET_CLS_ACT
1567 reset:
1568         if (unlikely(limit++ >= max_reclassify_loop)) {
1569                 net_notice_ratelimited("%u: reclassify loop, rule prio %u, protocol %02x\n",
1570                                        tp->chain->block->index,
1571                                        tp->prio & 0xffff,
1572                                        ntohs(tp->protocol));
1573                 return TC_ACT_SHOT;
1574         }
1575
1576         tp = first_tp;
1577         goto reclassify;
1578 #endif
1579 }
1580
1581 int tcf_classify(struct sk_buff *skb,
1582                  const struct tcf_block *block,
1583                  const struct tcf_proto *tp,
1584                  struct tcf_result *res, bool compat_mode)
1585 {
1586 #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1587         u32 last_executed_chain = 0;
1588
1589         return __tcf_classify(skb, tp, tp, res, compat_mode,
1590                               &last_executed_chain);
1591 #else
1592         u32 last_executed_chain = tp ? tp->chain->index : 0;
1593         const struct tcf_proto *orig_tp = tp;
1594         struct tc_skb_ext *ext;
1595         int ret;
1596
1597         if (block) {
1598                 ext = skb_ext_find(skb, TC_SKB_EXT);
1599
1600                 if (ext && ext->chain) {
1601                         struct tcf_chain *fchain;
1602
1603                         fchain = tcf_chain_lookup_rcu(block, ext->chain);
1604                         if (!fchain)
1605                                 return TC_ACT_SHOT;
1606
1607                         /* Consume, so cloned/redirect skbs won't inherit ext */
1608                         skb_ext_del(skb, TC_SKB_EXT);
1609
1610                         tp = rcu_dereference_bh(fchain->filter_chain);
1611                         last_executed_chain = fchain->index;
1612                 }
1613         }
1614
1615         ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode,
1616                              &last_executed_chain);
1617
1618         /* If we missed on some chain */
1619         if (ret == TC_ACT_UNSPEC && last_executed_chain) {
1620                 ext = tc_skb_ext_alloc(skb);
1621                 if (WARN_ON_ONCE(!ext))
1622                         return TC_ACT_SHOT;
1623                 ext->chain = last_executed_chain;
1624                 ext->mru = qdisc_skb_cb(skb)->mru;
1625                 ext->post_ct = qdisc_skb_cb(skb)->post_ct;
1626         }
1627
1628         return ret;
1629 #endif
1630 }
1631 EXPORT_SYMBOL(tcf_classify);
1632
1633 struct tcf_chain_info {
1634         struct tcf_proto __rcu **pprev;
1635         struct tcf_proto __rcu *next;
1636 };
1637
1638 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
1639                                            struct tcf_chain_info *chain_info)
1640 {
1641         return tcf_chain_dereference(*chain_info->pprev, chain);
1642 }
1643
1644 static int tcf_chain_tp_insert(struct tcf_chain *chain,
1645                                struct tcf_chain_info *chain_info,
1646                                struct tcf_proto *tp)
1647 {
1648         if (chain->flushing)
1649                 return -EAGAIN;
1650
1651         if (*chain_info->pprev == chain->filter_chain)
1652                 tcf_chain0_head_change(chain, tp);
1653         tcf_proto_get(tp);
1654         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
1655         rcu_assign_pointer(*chain_info->pprev, tp);
1656
1657         return 0;
1658 }
1659
1660 static void tcf_chain_tp_remove(struct tcf_chain *chain,
1661                                 struct tcf_chain_info *chain_info,
1662                                 struct tcf_proto *tp)
1663 {
1664         struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
1665
1666         tcf_proto_mark_delete(tp);
1667         if (tp == chain->filter_chain)
1668                 tcf_chain0_head_change(chain, next);
1669         RCU_INIT_POINTER(*chain_info->pprev, next);
1670 }
1671
1672 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1673                                            struct tcf_chain_info *chain_info,
1674                                            u32 protocol, u32 prio,
1675                                            bool prio_allocate);
1676
1677 /* Try to insert new proto.
1678  * If proto with specified priority already exists, free new proto
1679  * and return existing one.
1680  */
1681
1682 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
1683                                                     struct tcf_proto *tp_new,
1684                                                     u32 protocol, u32 prio,
1685                                                     bool rtnl_held)
1686 {
1687         struct tcf_chain_info chain_info;
1688         struct tcf_proto *tp;
1689         int err = 0;
1690
1691         mutex_lock(&chain->filter_chain_lock);
1692
1693         if (tcf_proto_exists_destroying(chain, tp_new)) {
1694                 mutex_unlock(&chain->filter_chain_lock);
1695                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1696                 return ERR_PTR(-EAGAIN);
1697         }
1698
1699         tp = tcf_chain_tp_find(chain, &chain_info,
1700                                protocol, prio, false);
1701         if (!tp)
1702                 err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
1703         mutex_unlock(&chain->filter_chain_lock);
1704
1705         if (tp) {
1706                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1707                 tp_new = tp;
1708         } else if (err) {
1709                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1710                 tp_new = ERR_PTR(err);
1711         }
1712
1713         return tp_new;
1714 }
1715
1716 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
1717                                       struct tcf_proto *tp, bool rtnl_held,
1718                                       struct netlink_ext_ack *extack)
1719 {
1720         struct tcf_chain_info chain_info;
1721         struct tcf_proto *tp_iter;
1722         struct tcf_proto **pprev;
1723         struct tcf_proto *next;
1724
1725         mutex_lock(&chain->filter_chain_lock);
1726
1727         /* Atomically find and remove tp from chain. */
1728         for (pprev = &chain->filter_chain;
1729              (tp_iter = tcf_chain_dereference(*pprev, chain));
1730              pprev = &tp_iter->next) {
1731                 if (tp_iter == tp) {
1732                         chain_info.pprev = pprev;
1733                         chain_info.next = tp_iter->next;
1734                         WARN_ON(tp_iter->deleting);
1735                         break;
1736                 }
1737         }
1738         /* Verify that tp still exists and no new filters were inserted
1739          * concurrently.
1740          * Mark tp for deletion if it is empty.
1741          */
1742         if (!tp_iter || !tcf_proto_check_delete(tp)) {
1743                 mutex_unlock(&chain->filter_chain_lock);
1744                 return;
1745         }
1746
1747         tcf_proto_signal_destroying(chain, tp);
1748         next = tcf_chain_dereference(chain_info.next, chain);
1749         if (tp == chain->filter_chain)
1750                 tcf_chain0_head_change(chain, next);
1751         RCU_INIT_POINTER(*chain_info.pprev, next);
1752         mutex_unlock(&chain->filter_chain_lock);
1753
1754         tcf_proto_put(tp, rtnl_held, extack);
1755 }
1756
1757 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1758                                            struct tcf_chain_info *chain_info,
1759                                            u32 protocol, u32 prio,
1760                                            bool prio_allocate)
1761 {
1762         struct tcf_proto **pprev;
1763         struct tcf_proto *tp;
1764
1765         /* Check the chain for existence of proto-tcf with this priority */
1766         for (pprev = &chain->filter_chain;
1767              (tp = tcf_chain_dereference(*pprev, chain));
1768              pprev = &tp->next) {
1769                 if (tp->prio >= prio) {
1770                         if (tp->prio == prio) {
1771                                 if (prio_allocate ||
1772                                     (tp->protocol != protocol && protocol))
1773                                         return ERR_PTR(-EINVAL);
1774                         } else {
1775                                 tp = NULL;
1776                         }
1777                         break;
1778                 }
1779         }
1780         chain_info->pprev = pprev;
1781         if (tp) {
1782                 chain_info->next = tp->next;
1783                 tcf_proto_get(tp);
1784         } else {
1785                 chain_info->next = NULL;
1786         }
1787         return tp;
1788 }
1789
1790 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
1791                          struct tcf_proto *tp, struct tcf_block *block,
1792                          struct Qdisc *q, u32 parent, void *fh,
1793                          u32 portid, u32 seq, u16 flags, int event,
1794                          bool terse_dump, bool rtnl_held)
1795 {
1796         struct tcmsg *tcm;
1797         struct nlmsghdr  *nlh;
1798         unsigned char *b = skb_tail_pointer(skb);
1799
1800         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1801         if (!nlh)
1802                 goto out_nlmsg_trim;
1803         tcm = nlmsg_data(nlh);
1804         tcm->tcm_family = AF_UNSPEC;
1805         tcm->tcm__pad1 = 0;
1806         tcm->tcm__pad2 = 0;
1807         if (q) {
1808                 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1809                 tcm->tcm_parent = parent;
1810         } else {
1811                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
1812                 tcm->tcm_block_index = block->index;
1813         }
1814         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
1815         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
1816                 goto nla_put_failure;
1817         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
1818                 goto nla_put_failure;
1819         if (!fh) {
1820                 tcm->tcm_handle = 0;
1821         } else if (terse_dump) {
1822                 if (tp->ops->terse_dump) {
1823                         if (tp->ops->terse_dump(net, tp, fh, skb, tcm,
1824                                                 rtnl_held) < 0)
1825                                 goto nla_put_failure;
1826                 } else {
1827                         goto cls_op_not_supp;
1828                 }
1829         } else {
1830                 if (tp->ops->dump &&
1831                     tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
1832                         goto nla_put_failure;
1833         }
1834         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1835         return skb->len;
1836
1837 out_nlmsg_trim:
1838 nla_put_failure:
1839 cls_op_not_supp:
1840         nlmsg_trim(skb, b);
1841         return -1;
1842 }
1843
1844 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
1845                           struct nlmsghdr *n, struct tcf_proto *tp,
1846                           struct tcf_block *block, struct Qdisc *q,
1847                           u32 parent, void *fh, int event, bool unicast,
1848                           bool rtnl_held)
1849 {
1850         struct sk_buff *skb;
1851         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1852         int err = 0;
1853
1854         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1855         if (!skb)
1856                 return -ENOBUFS;
1857
1858         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1859                           n->nlmsg_seq, n->nlmsg_flags, event,
1860                           false, rtnl_held) <= 0) {
1861                 kfree_skb(skb);
1862                 return -EINVAL;
1863         }
1864
1865         if (unicast)
1866                 err = rtnl_unicast(skb, net, portid);
1867         else
1868                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1869                                      n->nlmsg_flags & NLM_F_ECHO);
1870         return err;
1871 }
1872
1873 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
1874                               struct nlmsghdr *n, struct tcf_proto *tp,
1875                               struct tcf_block *block, struct Qdisc *q,
1876                               u32 parent, void *fh, bool unicast, bool *last,
1877                               bool rtnl_held, struct netlink_ext_ack *extack)
1878 {
1879         struct sk_buff *skb;
1880         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1881         int err;
1882
1883         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1884         if (!skb)
1885                 return -ENOBUFS;
1886
1887         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1888                           n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
1889                           false, rtnl_held) <= 0) {
1890                 NL_SET_ERR_MSG(extack, "Failed to build del event notification");
1891                 kfree_skb(skb);
1892                 return -EINVAL;
1893         }
1894
1895         err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
1896         if (err) {
1897                 kfree_skb(skb);
1898                 return err;
1899         }
1900
1901         if (unicast)
1902                 err = rtnl_unicast(skb, net, portid);
1903         else
1904                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1905                                      n->nlmsg_flags & NLM_F_ECHO);
1906         if (err < 0)
1907                 NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
1908
1909         return err;
1910 }
1911
1912 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
1913                                  struct tcf_block *block, struct Qdisc *q,
1914                                  u32 parent, struct nlmsghdr *n,
1915                                  struct tcf_chain *chain, int event)
1916 {
1917         struct tcf_proto *tp;
1918
1919         for (tp = tcf_get_next_proto(chain, NULL);
1920              tp; tp = tcf_get_next_proto(chain, tp))
1921                 tfilter_notify(net, oskb, n, tp, block,
1922                                q, parent, NULL, event, false, true);
1923 }
1924
1925 static void tfilter_put(struct tcf_proto *tp, void *fh)
1926 {
1927         if (tp->ops->put && fh)
1928                 tp->ops->put(tp, fh);
1929 }
1930
1931 static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
1932                           struct netlink_ext_ack *extack)
1933 {
1934         struct net *net = sock_net(skb->sk);
1935         struct nlattr *tca[TCA_MAX + 1];
1936         char name[IFNAMSIZ];
1937         struct tcmsg *t;
1938         u32 protocol;
1939         u32 prio;
1940         bool prio_allocate;
1941         u32 parent;
1942         u32 chain_index;
1943         struct Qdisc *q = NULL;
1944         struct tcf_chain_info chain_info;
1945         struct tcf_chain *chain = NULL;
1946         struct tcf_block *block;
1947         struct tcf_proto *tp;
1948         unsigned long cl;
1949         void *fh;
1950         int err;
1951         int tp_created;
1952         bool rtnl_held = false;
1953         u32 flags;
1954
1955         if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1956                 return -EPERM;
1957
1958 replay:
1959         tp_created = 0;
1960
1961         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
1962                                      rtm_tca_policy, extack);
1963         if (err < 0)
1964                 return err;
1965
1966         t = nlmsg_data(n);
1967         protocol = TC_H_MIN(t->tcm_info);
1968         prio = TC_H_MAJ(t->tcm_info);
1969         prio_allocate = false;
1970         parent = t->tcm_parent;
1971         tp = NULL;
1972         cl = 0;
1973         block = NULL;
1974         flags = 0;
1975
1976         if (prio == 0) {
1977                 /* If no priority is provided by the user,
1978                  * we allocate one.
1979                  */
1980                 if (n->nlmsg_flags & NLM_F_CREATE) {
1981                         prio = TC_H_MAKE(0x80000000U, 0U);
1982                         prio_allocate = true;
1983                 } else {
1984                         NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
1985                         return -ENOENT;
1986                 }
1987         }
1988
1989         /* Find head of filter chain. */
1990
1991         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
1992         if (err)
1993                 return err;
1994
1995         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
1996                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
1997                 err = -EINVAL;
1998                 goto errout;
1999         }
2000
2001         /* Take rtnl mutex if rtnl_held was set to true on previous iteration,
2002          * block is shared (no qdisc found), qdisc is not unlocked, classifier
2003          * type is not specified, classifier is not unlocked.
2004          */
2005         if (rtnl_held ||
2006             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2007             !tcf_proto_is_unlocked(name)) {
2008                 rtnl_held = true;
2009                 rtnl_lock();
2010         }
2011
2012         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2013         if (err)
2014                 goto errout;
2015
2016         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2017                                  extack);
2018         if (IS_ERR(block)) {
2019                 err = PTR_ERR(block);
2020                 goto errout;
2021         }
2022         block->classid = parent;
2023
2024         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2025         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2026                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2027                 err = -EINVAL;
2028                 goto errout;
2029         }
2030         chain = tcf_chain_get(block, chain_index, true);
2031         if (!chain) {
2032                 NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
2033                 err = -ENOMEM;
2034                 goto errout;
2035         }
2036
2037         mutex_lock(&chain->filter_chain_lock);
2038         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2039                                prio, prio_allocate);
2040         if (IS_ERR(tp)) {
2041                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2042                 err = PTR_ERR(tp);
2043                 goto errout_locked;
2044         }
2045
2046         if (tp == NULL) {
2047                 struct tcf_proto *tp_new = NULL;
2048
2049                 if (chain->flushing) {
2050                         err = -EAGAIN;
2051                         goto errout_locked;
2052                 }
2053
2054                 /* Proto-tcf does not exist, create new one */
2055
2056                 if (tca[TCA_KIND] == NULL || !protocol) {
2057                         NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
2058                         err = -EINVAL;
2059                         goto errout_locked;
2060                 }
2061
2062                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2063                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2064                         err = -ENOENT;
2065                         goto errout_locked;
2066                 }
2067
2068                 if (prio_allocate)
2069                         prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
2070                                                                &chain_info));
2071
2072                 mutex_unlock(&chain->filter_chain_lock);
2073                 tp_new = tcf_proto_create(name, protocol, prio, chain,
2074                                           rtnl_held, extack);
2075                 if (IS_ERR(tp_new)) {
2076                         err = PTR_ERR(tp_new);
2077                         goto errout_tp;
2078                 }
2079
2080                 tp_created = 1;
2081                 tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
2082                                                 rtnl_held);
2083                 if (IS_ERR(tp)) {
2084                         err = PTR_ERR(tp);
2085                         goto errout_tp;
2086                 }
2087         } else {
2088                 mutex_unlock(&chain->filter_chain_lock);
2089         }
2090
2091         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2092                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2093                 err = -EINVAL;
2094                 goto errout;
2095         }
2096
2097         fh = tp->ops->get(tp, t->tcm_handle);
2098
2099         if (!fh) {
2100                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2101                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2102                         err = -ENOENT;
2103                         goto errout;
2104                 }
2105         } else if (n->nlmsg_flags & NLM_F_EXCL) {
2106                 tfilter_put(tp, fh);
2107                 NL_SET_ERR_MSG(extack, "Filter already exists");
2108                 err = -EEXIST;
2109                 goto errout;
2110         }
2111
2112         if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
2113                 NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
2114                 err = -EINVAL;
2115                 goto errout;
2116         }
2117
2118         if (!(n->nlmsg_flags & NLM_F_CREATE))
2119                 flags |= TCA_ACT_FLAGS_REPLACE;
2120         if (!rtnl_held)
2121                 flags |= TCA_ACT_FLAGS_NO_RTNL;
2122         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
2123                               flags, extack);
2124         if (err == 0) {
2125                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2126                                RTM_NEWTFILTER, false, rtnl_held);
2127                 tfilter_put(tp, fh);
2128                 /* q pointer is NULL for shared blocks */
2129                 if (q)
2130                         q->flags &= ~TCQ_F_CAN_BYPASS;
2131         }
2132
2133 errout:
2134         if (err && tp_created)
2135                 tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
2136 errout_tp:
2137         if (chain) {
2138                 if (tp && !IS_ERR(tp))
2139                         tcf_proto_put(tp, rtnl_held, NULL);
2140                 if (!tp_created)
2141                         tcf_chain_put(chain);
2142         }
2143         tcf_block_release(q, block, rtnl_held);
2144
2145         if (rtnl_held)
2146                 rtnl_unlock();
2147
2148         if (err == -EAGAIN) {
2149                 /* Take rtnl lock in case EAGAIN is caused by concurrent flush
2150                  * of target chain.
2151                  */
2152                 rtnl_held = true;
2153                 /* Replay the request. */
2154                 goto replay;
2155         }
2156         return err;
2157
2158 errout_locked:
2159         mutex_unlock(&chain->filter_chain_lock);
2160         goto errout;
2161 }
2162
2163 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2164                           struct netlink_ext_ack *extack)
2165 {
2166         struct net *net = sock_net(skb->sk);
2167         struct nlattr *tca[TCA_MAX + 1];
2168         char name[IFNAMSIZ];
2169         struct tcmsg *t;
2170         u32 protocol;
2171         u32 prio;
2172         u32 parent;
2173         u32 chain_index;
2174         struct Qdisc *q = NULL;
2175         struct tcf_chain_info chain_info;
2176         struct tcf_chain *chain = NULL;
2177         struct tcf_block *block = NULL;
2178         struct tcf_proto *tp = NULL;
2179         unsigned long cl = 0;
2180         void *fh = NULL;
2181         int err;
2182         bool rtnl_held = false;
2183
2184         if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2185                 return -EPERM;
2186
2187         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2188                                      rtm_tca_policy, extack);
2189         if (err < 0)
2190                 return err;
2191
2192         t = nlmsg_data(n);
2193         protocol = TC_H_MIN(t->tcm_info);
2194         prio = TC_H_MAJ(t->tcm_info);
2195         parent = t->tcm_parent;
2196
2197         if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
2198                 NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
2199                 return -ENOENT;
2200         }
2201
2202         /* Find head of filter chain. */
2203
2204         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2205         if (err)
2206                 return err;
2207
2208         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2209                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2210                 err = -EINVAL;
2211                 goto errout;
2212         }
2213         /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
2214          * found), qdisc is not unlocked, classifier type is not specified,
2215          * classifier is not unlocked.
2216          */
2217         if (!prio ||
2218             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2219             !tcf_proto_is_unlocked(name)) {
2220                 rtnl_held = true;
2221                 rtnl_lock();
2222         }
2223
2224         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2225         if (err)
2226                 goto errout;
2227
2228         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2229                                  extack);
2230         if (IS_ERR(block)) {
2231                 err = PTR_ERR(block);
2232                 goto errout;
2233         }
2234
2235         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2236         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2237                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2238                 err = -EINVAL;
2239                 goto errout;
2240         }
2241         chain = tcf_chain_get(block, chain_index, false);
2242         if (!chain) {
2243                 /* User requested flush on non-existent chain. Nothing to do,
2244                  * so just return success.
2245                  */
2246                 if (prio == 0) {
2247                         err = 0;
2248                         goto errout;
2249                 }
2250                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2251                 err = -ENOENT;
2252                 goto errout;
2253         }
2254
2255         if (prio == 0) {
2256                 tfilter_notify_chain(net, skb, block, q, parent, n,
2257                                      chain, RTM_DELTFILTER);
2258                 tcf_chain_flush(chain, rtnl_held);
2259                 err = 0;
2260                 goto errout;
2261         }
2262
2263         mutex_lock(&chain->filter_chain_lock);
2264         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2265                                prio, false);
2266         if (!tp || IS_ERR(tp)) {
2267                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2268                 err = tp ? PTR_ERR(tp) : -ENOENT;
2269                 goto errout_locked;
2270         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2271                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2272                 err = -EINVAL;
2273                 goto errout_locked;
2274         } else if (t->tcm_handle == 0) {
2275                 tcf_proto_signal_destroying(chain, tp);
2276                 tcf_chain_tp_remove(chain, &chain_info, tp);
2277                 mutex_unlock(&chain->filter_chain_lock);
2278
2279                 tcf_proto_put(tp, rtnl_held, NULL);
2280                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2281                                RTM_DELTFILTER, false, rtnl_held);
2282                 err = 0;
2283                 goto errout;
2284         }
2285         mutex_unlock(&chain->filter_chain_lock);
2286
2287         fh = tp->ops->get(tp, t->tcm_handle);
2288
2289         if (!fh) {
2290                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2291                 err = -ENOENT;
2292         } else {
2293                 bool last;
2294
2295                 err = tfilter_del_notify(net, skb, n, tp, block,
2296                                          q, parent, fh, false, &last,
2297                                          rtnl_held, extack);
2298
2299                 if (err)
2300                         goto errout;
2301                 if (last)
2302                         tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
2303         }
2304
2305 errout:
2306         if (chain) {
2307                 if (tp && !IS_ERR(tp))
2308                         tcf_proto_put(tp, rtnl_held, NULL);
2309                 tcf_chain_put(chain);
2310         }
2311         tcf_block_release(q, block, rtnl_held);
2312
2313         if (rtnl_held)
2314                 rtnl_unlock();
2315
2316         return err;
2317
2318 errout_locked:
2319         mutex_unlock(&chain->filter_chain_lock);
2320         goto errout;
2321 }
2322
2323 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2324                           struct netlink_ext_ack *extack)
2325 {
2326         struct net *net = sock_net(skb->sk);
2327         struct nlattr *tca[TCA_MAX + 1];
2328         char name[IFNAMSIZ];
2329         struct tcmsg *t;
2330         u32 protocol;
2331         u32 prio;
2332         u32 parent;
2333         u32 chain_index;
2334         struct Qdisc *q = NULL;
2335         struct tcf_chain_info chain_info;
2336         struct tcf_chain *chain = NULL;
2337         struct tcf_block *block = NULL;
2338         struct tcf_proto *tp = NULL;
2339         unsigned long cl = 0;
2340         void *fh = NULL;
2341         int err;
2342         bool rtnl_held = false;
2343
2344         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2345                                      rtm_tca_policy, extack);
2346         if (err < 0)
2347                 return err;
2348
2349         t = nlmsg_data(n);
2350         protocol = TC_H_MIN(t->tcm_info);
2351         prio = TC_H_MAJ(t->tcm_info);
2352         parent = t->tcm_parent;
2353
2354         if (prio == 0) {
2355                 NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2356                 return -ENOENT;
2357         }
2358
2359         /* Find head of filter chain. */
2360
2361         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2362         if (err)
2363                 return err;
2364
2365         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2366                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2367                 err = -EINVAL;
2368                 goto errout;
2369         }
2370         /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
2371          * unlocked, classifier type is not specified, classifier is not
2372          * unlocked.
2373          */
2374         if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2375             !tcf_proto_is_unlocked(name)) {
2376                 rtnl_held = true;
2377                 rtnl_lock();
2378         }
2379
2380         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2381         if (err)
2382                 goto errout;
2383
2384         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2385                                  extack);
2386         if (IS_ERR(block)) {
2387                 err = PTR_ERR(block);
2388                 goto errout;
2389         }
2390
2391         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2392         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2393                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2394                 err = -EINVAL;
2395                 goto errout;
2396         }
2397         chain = tcf_chain_get(block, chain_index, false);
2398         if (!chain) {
2399                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2400                 err = -EINVAL;
2401                 goto errout;
2402         }
2403
2404         mutex_lock(&chain->filter_chain_lock);
2405         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2406                                prio, false);
2407         mutex_unlock(&chain->filter_chain_lock);
2408         if (!tp || IS_ERR(tp)) {
2409                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2410                 err = tp ? PTR_ERR(tp) : -ENOENT;
2411                 goto errout;
2412         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2413                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2414                 err = -EINVAL;
2415                 goto errout;
2416         }
2417
2418         fh = tp->ops->get(tp, t->tcm_handle);
2419
2420         if (!fh) {
2421                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2422                 err = -ENOENT;
2423         } else {
2424                 err = tfilter_notify(net, skb, n, tp, block, q, parent,
2425                                      fh, RTM_NEWTFILTER, true, rtnl_held);
2426                 if (err < 0)
2427                         NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
2428         }
2429
2430         tfilter_put(tp, fh);
2431 errout:
2432         if (chain) {
2433                 if (tp && !IS_ERR(tp))
2434                         tcf_proto_put(tp, rtnl_held, NULL);
2435                 tcf_chain_put(chain);
2436         }
2437         tcf_block_release(q, block, rtnl_held);
2438
2439         if (rtnl_held)
2440                 rtnl_unlock();
2441
2442         return err;
2443 }
2444
2445 struct tcf_dump_args {
2446         struct tcf_walker w;
2447         struct sk_buff *skb;
2448         struct netlink_callback *cb;
2449         struct tcf_block *block;
2450         struct Qdisc *q;
2451         u32 parent;
2452         bool terse_dump;
2453 };
2454
2455 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2456 {
2457         struct tcf_dump_args *a = (void *)arg;
2458         struct net *net = sock_net(a->skb->sk);
2459
2460         return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
2461                              n, NETLINK_CB(a->cb->skb).portid,
2462                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2463                              RTM_NEWTFILTER, a->terse_dump, true);
2464 }
2465
2466 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
2467                            struct sk_buff *skb, struct netlink_callback *cb,
2468                            long index_start, long *p_index, bool terse)
2469 {
2470         struct net *net = sock_net(skb->sk);
2471         struct tcf_block *block = chain->block;
2472         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2473         struct tcf_proto *tp, *tp_prev;
2474         struct tcf_dump_args arg;
2475
2476         for (tp = __tcf_get_next_proto(chain, NULL);
2477              tp;
2478              tp_prev = tp,
2479                      tp = __tcf_get_next_proto(chain, tp),
2480                      tcf_proto_put(tp_prev, true, NULL),
2481                      (*p_index)++) {
2482                 if (*p_index < index_start)
2483                         continue;
2484                 if (TC_H_MAJ(tcm->tcm_info) &&
2485                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
2486                         continue;
2487                 if (TC_H_MIN(tcm->tcm_info) &&
2488                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
2489                         continue;
2490                 if (*p_index > index_start)
2491                         memset(&cb->args[1], 0,
2492                                sizeof(cb->args) - sizeof(cb->args[0]));
2493                 if (cb->args[1] == 0) {
2494                         if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
2495                                           NETLINK_CB(cb->skb).portid,
2496                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
2497                                           RTM_NEWTFILTER, false, true) <= 0)
2498                                 goto errout;
2499                         cb->args[1] = 1;
2500                 }
2501                 if (!tp->ops->walk)
2502                         continue;
2503                 arg.w.fn = tcf_node_dump;
2504                 arg.skb = skb;
2505                 arg.cb = cb;
2506                 arg.block = block;
2507                 arg.q = q;
2508                 arg.parent = parent;
2509                 arg.w.stop = 0;
2510                 arg.w.skip = cb->args[1] - 1;
2511                 arg.w.count = 0;
2512                 arg.w.cookie = cb->args[2];
2513                 arg.terse_dump = terse;
2514                 tp->ops->walk(tp, &arg.w, true);
2515                 cb->args[2] = arg.w.cookie;
2516                 cb->args[1] = arg.w.count + 1;
2517                 if (arg.w.stop)
2518                         goto errout;
2519         }
2520         return true;
2521
2522 errout:
2523         tcf_proto_put(tp, true, NULL);
2524         return false;
2525 }
2526
2527 static const struct nla_policy tcf_tfilter_dump_policy[TCA_MAX + 1] = {
2528         [TCA_DUMP_FLAGS] = NLA_POLICY_BITFIELD32(TCA_DUMP_FLAGS_TERSE),
2529 };
2530
2531 /* called with RTNL */
2532 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
2533 {
2534         struct tcf_chain *chain, *chain_prev;
2535         struct net *net = sock_net(skb->sk);
2536         struct nlattr *tca[TCA_MAX + 1];
2537         struct Qdisc *q = NULL;
2538         struct tcf_block *block;
2539         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2540         bool terse_dump = false;
2541         long index_start;
2542         long index;
2543         u32 parent;
2544         int err;
2545
2546         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2547                 return skb->len;
2548
2549         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2550                                      tcf_tfilter_dump_policy, cb->extack);
2551         if (err)
2552                 return err;
2553
2554         if (tca[TCA_DUMP_FLAGS]) {
2555                 struct nla_bitfield32 flags =
2556                         nla_get_bitfield32(tca[TCA_DUMP_FLAGS]);
2557
2558                 terse_dump = flags.value & TCA_DUMP_FLAGS_TERSE;
2559         }
2560
2561         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2562                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2563                 if (!block)
2564                         goto out;
2565                 /* If we work with block index, q is NULL and parent value
2566                  * will never be used in the following code. The check
2567                  * in tcf_fill_node prevents it. However, compiler does not
2568                  * see that far, so set parent to zero to silence the warning
2569                  * about parent being uninitialized.
2570                  */
2571                 parent = 0;
2572         } else {
2573                 const struct Qdisc_class_ops *cops;
2574                 struct net_device *dev;
2575                 unsigned long cl = 0;
2576
2577                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2578                 if (!dev)
2579                         return skb->len;
2580
2581                 parent = tcm->tcm_parent;
2582                 if (!parent)
2583                         q = dev->qdisc;
2584                 else
2585                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2586                 if (!q)
2587                         goto out;
2588                 cops = q->ops->cl_ops;
2589                 if (!cops)
2590                         goto out;
2591                 if (!cops->tcf_block)
2592                         goto out;
2593                 if (TC_H_MIN(tcm->tcm_parent)) {
2594                         cl = cops->find(q, tcm->tcm_parent);
2595                         if (cl == 0)
2596                                 goto out;
2597                 }
2598                 block = cops->tcf_block(q, cl, NULL);
2599                 if (!block)
2600                         goto out;
2601                 parent = block->classid;
2602                 if (tcf_block_shared(block))
2603                         q = NULL;
2604         }
2605
2606         index_start = cb->args[0];
2607         index = 0;
2608
2609         for (chain = __tcf_get_next_chain(block, NULL);
2610              chain;
2611              chain_prev = chain,
2612                      chain = __tcf_get_next_chain(block, chain),
2613                      tcf_chain_put(chain_prev)) {
2614                 if (tca[TCA_CHAIN] &&
2615                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
2616                         continue;
2617                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
2618                                     index_start, &index, terse_dump)) {
2619                         tcf_chain_put(chain);
2620                         err = -EMSGSIZE;
2621                         break;
2622                 }
2623         }
2624
2625         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2626                 tcf_block_refcnt_put(block, true);
2627         cb->args[0] = index;
2628
2629 out:
2630         /* If we did no progress, the error (EMSGSIZE) is real */
2631         if (skb->len == 0 && err)
2632                 return err;
2633         return skb->len;
2634 }
2635
2636 static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
2637                               void *tmplt_priv, u32 chain_index,
2638                               struct net *net, struct sk_buff *skb,
2639                               struct tcf_block *block,
2640                               u32 portid, u32 seq, u16 flags, int event)
2641 {
2642         unsigned char *b = skb_tail_pointer(skb);
2643         const struct tcf_proto_ops *ops;
2644         struct nlmsghdr *nlh;
2645         struct tcmsg *tcm;
2646         void *priv;
2647
2648         ops = tmplt_ops;
2649         priv = tmplt_priv;
2650
2651         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2652         if (!nlh)
2653                 goto out_nlmsg_trim;
2654         tcm = nlmsg_data(nlh);
2655         tcm->tcm_family = AF_UNSPEC;
2656         tcm->tcm__pad1 = 0;
2657         tcm->tcm__pad2 = 0;
2658         tcm->tcm_handle = 0;
2659         if (block->q) {
2660                 tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
2661                 tcm->tcm_parent = block->q->handle;
2662         } else {
2663                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2664                 tcm->tcm_block_index = block->index;
2665         }
2666
2667         if (nla_put_u32(skb, TCA_CHAIN, chain_index))
2668                 goto nla_put_failure;
2669
2670         if (ops) {
2671                 if (nla_put_string(skb, TCA_KIND, ops->kind))
2672                         goto nla_put_failure;
2673                 if (ops->tmplt_dump(skb, net, priv) < 0)
2674                         goto nla_put_failure;
2675         }
2676
2677         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2678         return skb->len;
2679
2680 out_nlmsg_trim:
2681 nla_put_failure:
2682         nlmsg_trim(skb, b);
2683         return -EMSGSIZE;
2684 }
2685
2686 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
2687                            u32 seq, u16 flags, int event, bool unicast)
2688 {
2689         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2690         struct tcf_block *block = chain->block;
2691         struct net *net = block->net;
2692         struct sk_buff *skb;
2693         int err = 0;
2694
2695         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2696         if (!skb)
2697                 return -ENOBUFS;
2698
2699         if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2700                                chain->index, net, skb, block, portid,
2701                                seq, flags, event) <= 0) {
2702                 kfree_skb(skb);
2703                 return -EINVAL;
2704         }
2705
2706         if (unicast)
2707                 err = rtnl_unicast(skb, net, portid);
2708         else
2709                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2710                                      flags & NLM_F_ECHO);
2711
2712         return err;
2713 }
2714
2715 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
2716                                   void *tmplt_priv, u32 chain_index,
2717                                   struct tcf_block *block, struct sk_buff *oskb,
2718                                   u32 seq, u16 flags, bool unicast)
2719 {
2720         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2721         struct net *net = block->net;
2722         struct sk_buff *skb;
2723
2724         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2725         if (!skb)
2726                 return -ENOBUFS;
2727
2728         if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
2729                                block, portid, seq, flags, RTM_DELCHAIN) <= 0) {
2730                 kfree_skb(skb);
2731                 return -EINVAL;
2732         }
2733
2734         if (unicast)
2735                 return rtnl_unicast(skb, net, portid);
2736
2737         return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
2738 }
2739
2740 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
2741                               struct nlattr **tca,
2742                               struct netlink_ext_ack *extack)
2743 {
2744         const struct tcf_proto_ops *ops;
2745         char name[IFNAMSIZ];
2746         void *tmplt_priv;
2747
2748         /* If kind is not set, user did not specify template. */
2749         if (!tca[TCA_KIND])
2750                 return 0;
2751
2752         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2753                 NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
2754                 return -EINVAL;
2755         }
2756
2757         ops = tcf_proto_lookup_ops(name, true, extack);
2758         if (IS_ERR(ops))
2759                 return PTR_ERR(ops);
2760         if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
2761                 NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
2762                 return -EOPNOTSUPP;
2763         }
2764
2765         tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
2766         if (IS_ERR(tmplt_priv)) {
2767                 module_put(ops->owner);
2768                 return PTR_ERR(tmplt_priv);
2769         }
2770         chain->tmplt_ops = ops;
2771         chain->tmplt_priv = tmplt_priv;
2772         return 0;
2773 }
2774
2775 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
2776                                void *tmplt_priv)
2777 {
2778         /* If template ops are set, no work to do for us. */
2779         if (!tmplt_ops)
2780                 return;
2781
2782         tmplt_ops->tmplt_destroy(tmplt_priv);
2783         module_put(tmplt_ops->owner);
2784 }
2785
2786 /* Add/delete/get a chain */
2787
2788 static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
2789                         struct netlink_ext_ack *extack)
2790 {
2791         struct net *net = sock_net(skb->sk);
2792         struct nlattr *tca[TCA_MAX + 1];
2793         struct tcmsg *t;
2794         u32 parent;
2795         u32 chain_index;
2796         struct Qdisc *q = NULL;
2797         struct tcf_chain *chain = NULL;
2798         struct tcf_block *block;
2799         unsigned long cl;
2800         int err;
2801
2802         if (n->nlmsg_type != RTM_GETCHAIN &&
2803             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2804                 return -EPERM;
2805
2806 replay:
2807         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2808                                      rtm_tca_policy, extack);
2809         if (err < 0)
2810                 return err;
2811
2812         t = nlmsg_data(n);
2813         parent = t->tcm_parent;
2814         cl = 0;
2815
2816         block = tcf_block_find(net, &q, &parent, &cl,
2817                                t->tcm_ifindex, t->tcm_block_index, extack);
2818         if (IS_ERR(block))
2819                 return PTR_ERR(block);
2820
2821         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2822         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2823                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2824                 err = -EINVAL;
2825                 goto errout_block;
2826         }
2827
2828         mutex_lock(&block->lock);
2829         chain = tcf_chain_lookup(block, chain_index);
2830         if (n->nlmsg_type == RTM_NEWCHAIN) {
2831                 if (chain) {
2832                         if (tcf_chain_held_by_acts_only(chain)) {
2833                                 /* The chain exists only because there is
2834                                  * some action referencing it.
2835                                  */
2836                                 tcf_chain_hold(chain);
2837                         } else {
2838                                 NL_SET_ERR_MSG(extack, "Filter chain already exists");
2839                                 err = -EEXIST;
2840                                 goto errout_block_locked;
2841                         }
2842                 } else {
2843                         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2844                                 NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
2845                                 err = -ENOENT;
2846                                 goto errout_block_locked;
2847                         }
2848                         chain = tcf_chain_create(block, chain_index);
2849                         if (!chain) {
2850                                 NL_SET_ERR_MSG(extack, "Failed to create filter chain");
2851                                 err = -ENOMEM;
2852                                 goto errout_block_locked;
2853                         }
2854                 }
2855         } else {
2856                 if (!chain || tcf_chain_held_by_acts_only(chain)) {
2857                         NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2858                         err = -EINVAL;
2859                         goto errout_block_locked;
2860                 }
2861                 tcf_chain_hold(chain);
2862         }
2863
2864         if (n->nlmsg_type == RTM_NEWCHAIN) {
2865                 /* Modifying chain requires holding parent block lock. In case
2866                  * the chain was successfully added, take a reference to the
2867                  * chain. This ensures that an empty chain does not disappear at
2868                  * the end of this function.
2869                  */
2870                 tcf_chain_hold(chain);
2871                 chain->explicitly_created = true;
2872         }
2873         mutex_unlock(&block->lock);
2874
2875         switch (n->nlmsg_type) {
2876         case RTM_NEWCHAIN:
2877                 err = tc_chain_tmplt_add(chain, net, tca, extack);
2878                 if (err) {
2879                         tcf_chain_put_explicitly_created(chain);
2880                         goto errout;
2881                 }
2882
2883                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
2884                                 RTM_NEWCHAIN, false);
2885                 break;
2886         case RTM_DELCHAIN:
2887                 tfilter_notify_chain(net, skb, block, q, parent, n,
2888                                      chain, RTM_DELTFILTER);
2889                 /* Flush the chain first as the user requested chain removal. */
2890                 tcf_chain_flush(chain, true);
2891                 /* In case the chain was successfully deleted, put a reference
2892                  * to the chain previously taken during addition.
2893                  */
2894                 tcf_chain_put_explicitly_created(chain);
2895                 break;
2896         case RTM_GETCHAIN:
2897                 err = tc_chain_notify(chain, skb, n->nlmsg_seq,
2898                                       n->nlmsg_flags, n->nlmsg_type, true);
2899                 if (err < 0)
2900                         NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
2901                 break;
2902         default:
2903                 err = -EOPNOTSUPP;
2904                 NL_SET_ERR_MSG(extack, "Unsupported message type");
2905                 goto errout;
2906         }
2907
2908 errout:
2909         tcf_chain_put(chain);
2910 errout_block:
2911         tcf_block_release(q, block, true);
2912         if (err == -EAGAIN)
2913                 /* Replay the request. */
2914                 goto replay;
2915         return err;
2916
2917 errout_block_locked:
2918         mutex_unlock(&block->lock);
2919         goto errout_block;
2920 }
2921
2922 /* called with RTNL */
2923 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
2924 {
2925         struct net *net = sock_net(skb->sk);
2926         struct nlattr *tca[TCA_MAX + 1];
2927         struct Qdisc *q = NULL;
2928         struct tcf_block *block;
2929         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2930         struct tcf_chain *chain;
2931         long index_start;
2932         long index;
2933         int err;
2934
2935         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2936                 return skb->len;
2937
2938         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2939                                      rtm_tca_policy, cb->extack);
2940         if (err)
2941                 return err;
2942
2943         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2944                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2945                 if (!block)
2946                         goto out;
2947         } else {
2948                 const struct Qdisc_class_ops *cops;
2949                 struct net_device *dev;
2950                 unsigned long cl = 0;
2951
2952                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2953                 if (!dev)
2954                         return skb->len;
2955
2956                 if (!tcm->tcm_parent)
2957                         q = dev->qdisc;
2958                 else
2959                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2960
2961                 if (!q)
2962                         goto out;
2963                 cops = q->ops->cl_ops;
2964                 if (!cops)
2965                         goto out;
2966                 if (!cops->tcf_block)
2967                         goto out;
2968                 if (TC_H_MIN(tcm->tcm_parent)) {
2969                         cl = cops->find(q, tcm->tcm_parent);
2970                         if (cl == 0)
2971                                 goto out;
2972                 }
2973                 block = cops->tcf_block(q, cl, NULL);
2974                 if (!block)
2975                         goto out;
2976                 if (tcf_block_shared(block))
2977                         q = NULL;
2978         }
2979
2980         index_start = cb->args[0];
2981         index = 0;
2982
2983         mutex_lock(&block->lock);
2984         list_for_each_entry(chain, &block->chain_list, list) {
2985                 if ((tca[TCA_CHAIN] &&
2986                      nla_get_u32(tca[TCA_CHAIN]) != chain->index))
2987                         continue;
2988                 if (index < index_start) {
2989                         index++;
2990                         continue;
2991                 }
2992                 if (tcf_chain_held_by_acts_only(chain))
2993                         continue;
2994                 err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2995                                          chain->index, net, skb, block,
2996                                          NETLINK_CB(cb->skb).portid,
2997                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
2998                                          RTM_NEWCHAIN);
2999                 if (err <= 0)
3000                         break;
3001                 index++;
3002         }
3003         mutex_unlock(&block->lock);
3004
3005         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
3006                 tcf_block_refcnt_put(block, true);
3007         cb->args[0] = index;
3008
3009 out:
3010         /* If we did no progress, the error (EMSGSIZE) is real */
3011         if (skb->len == 0 && err)
3012                 return err;
3013         return skb->len;
3014 }
3015
3016 void tcf_exts_destroy(struct tcf_exts *exts)
3017 {
3018 #ifdef CONFIG_NET_CLS_ACT
3019         if (exts->actions) {
3020                 tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
3021                 kfree(exts->actions);
3022         }
3023         exts->nr_actions = 0;
3024 #endif
3025 }
3026 EXPORT_SYMBOL(tcf_exts_destroy);
3027
3028 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3029                       struct nlattr *rate_tlv, struct tcf_exts *exts,
3030                       u32 flags, struct netlink_ext_ack *extack)
3031 {
3032 #ifdef CONFIG_NET_CLS_ACT
3033         {
3034                 int init_res[TCA_ACT_MAX_PRIO] = {};
3035                 struct tc_action *act;
3036                 size_t attr_size = 0;
3037
3038                 if (exts->police && tb[exts->police]) {
3039                         struct tc_action_ops *a_o;
3040
3041                         a_o = tc_action_load_ops(tb[exts->police], true,
3042                                                  !(flags & TCA_ACT_FLAGS_NO_RTNL),
3043                                                  extack);
3044                         if (IS_ERR(a_o))
3045                                 return PTR_ERR(a_o);
3046                         flags |= TCA_ACT_FLAGS_POLICE | TCA_ACT_FLAGS_BIND;
3047                         act = tcf_action_init_1(net, tp, tb[exts->police],
3048                                                 rate_tlv, a_o, init_res, flags,
3049                                                 extack);
3050                         module_put(a_o->owner);
3051                         if (IS_ERR(act))
3052                                 return PTR_ERR(act);
3053
3054                         act->type = exts->type = TCA_OLD_COMPAT;
3055                         exts->actions[0] = act;
3056                         exts->nr_actions = 1;
3057                         tcf_idr_insert_many(exts->actions);
3058                 } else if (exts->action && tb[exts->action]) {
3059                         int err;
3060
3061                         flags |= TCA_ACT_FLAGS_BIND;
3062                         err = tcf_action_init(net, tp, tb[exts->action],
3063                                               rate_tlv, exts->actions, init_res,
3064                                               &attr_size, flags, extack);
3065                         if (err < 0)
3066                                 return err;
3067                         exts->nr_actions = err;
3068                 }
3069         }
3070 #else
3071         if ((exts->action && tb[exts->action]) ||
3072             (exts->police && tb[exts->police])) {
3073                 NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
3074                 return -EOPNOTSUPP;
3075         }
3076 #endif
3077
3078         return 0;
3079 }
3080 EXPORT_SYMBOL(tcf_exts_validate);
3081
3082 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
3083 {
3084 #ifdef CONFIG_NET_CLS_ACT
3085         struct tcf_exts old = *dst;
3086
3087         *dst = *src;
3088         tcf_exts_destroy(&old);
3089 #endif
3090 }
3091 EXPORT_SYMBOL(tcf_exts_change);
3092
3093 #ifdef CONFIG_NET_CLS_ACT
3094 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
3095 {
3096         if (exts->nr_actions == 0)
3097                 return NULL;
3098         else
3099                 return exts->actions[0];
3100 }
3101 #endif
3102
3103 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
3104 {
3105 #ifdef CONFIG_NET_CLS_ACT
3106         struct nlattr *nest;
3107
3108         if (exts->action && tcf_exts_has_actions(exts)) {
3109                 /*
3110                  * again for backward compatible mode - we want
3111                  * to work with both old and new modes of entering
3112                  * tc data even if iproute2  was newer - jhs
3113                  */
3114                 if (exts->type != TCA_OLD_COMPAT) {
3115                         nest = nla_nest_start_noflag(skb, exts->action);
3116                         if (nest == NULL)
3117                                 goto nla_put_failure;
3118
3119                         if (tcf_action_dump(skb, exts->actions, 0, 0, false)
3120                             < 0)
3121                                 goto nla_put_failure;
3122                         nla_nest_end(skb, nest);
3123                 } else if (exts->police) {
3124                         struct tc_action *act = tcf_exts_first_act(exts);
3125                         nest = nla_nest_start_noflag(skb, exts->police);
3126                         if (nest == NULL || !act)
3127                                 goto nla_put_failure;
3128                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
3129                                 goto nla_put_failure;
3130                         nla_nest_end(skb, nest);
3131                 }
3132         }
3133         return 0;
3134
3135 nla_put_failure:
3136         nla_nest_cancel(skb, nest);
3137         return -1;
3138 #else
3139         return 0;
3140 #endif
3141 }
3142 EXPORT_SYMBOL(tcf_exts_dump);
3143
3144 int tcf_exts_terse_dump(struct sk_buff *skb, struct tcf_exts *exts)
3145 {
3146 #ifdef CONFIG_NET_CLS_ACT
3147         struct nlattr *nest;
3148
3149         if (!exts->action || !tcf_exts_has_actions(exts))
3150                 return 0;
3151
3152         nest = nla_nest_start_noflag(skb, exts->action);
3153         if (!nest)
3154                 goto nla_put_failure;
3155
3156         if (tcf_action_dump(skb, exts->actions, 0, 0, true) < 0)
3157                 goto nla_put_failure;
3158         nla_nest_end(skb, nest);
3159         return 0;
3160
3161 nla_put_failure:
3162         nla_nest_cancel(skb, nest);
3163         return -1;
3164 #else
3165         return 0;
3166 #endif
3167 }
3168 EXPORT_SYMBOL(tcf_exts_terse_dump);
3169
3170 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
3171 {
3172 #ifdef CONFIG_NET_CLS_ACT
3173         struct tc_action *a = tcf_exts_first_act(exts);
3174         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
3175                 return -1;
3176 #endif
3177         return 0;
3178 }
3179 EXPORT_SYMBOL(tcf_exts_dump_stats);
3180
3181 static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
3182 {
3183         if (*flags & TCA_CLS_FLAGS_IN_HW)
3184                 return;
3185         *flags |= TCA_CLS_FLAGS_IN_HW;
3186         atomic_inc(&block->offloadcnt);
3187 }
3188
3189 static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
3190 {
3191         if (!(*flags & TCA_CLS_FLAGS_IN_HW))
3192                 return;
3193         *flags &= ~TCA_CLS_FLAGS_IN_HW;
3194         atomic_dec(&block->offloadcnt);
3195 }
3196
3197 static void tc_cls_offload_cnt_update(struct tcf_block *block,
3198                                       struct tcf_proto *tp, u32 *cnt,
3199                                       u32 *flags, u32 diff, bool add)
3200 {
3201         lockdep_assert_held(&block->cb_lock);
3202
3203         spin_lock(&tp->lock);
3204         if (add) {
3205                 if (!*cnt)
3206                         tcf_block_offload_inc(block, flags);
3207                 *cnt += diff;
3208         } else {
3209                 *cnt -= diff;
3210                 if (!*cnt)
3211                         tcf_block_offload_dec(block, flags);
3212         }
3213         spin_unlock(&tp->lock);
3214 }
3215
3216 static void
3217 tc_cls_offload_cnt_reset(struct tcf_block *block, struct tcf_proto *tp,
3218                          u32 *cnt, u32 *flags)
3219 {
3220         lockdep_assert_held(&block->cb_lock);
3221
3222         spin_lock(&tp->lock);
3223         tcf_block_offload_dec(block, flags);
3224         *cnt = 0;
3225         spin_unlock(&tp->lock);
3226 }
3227
3228 static int
3229 __tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3230                    void *type_data, bool err_stop)
3231 {
3232         struct flow_block_cb *block_cb;
3233         int ok_count = 0;
3234         int err;
3235
3236         list_for_each_entry(block_cb, &block->flow_block.cb_list, list) {
3237                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
3238                 if (err) {
3239                         if (err_stop)
3240                                 return err;
3241                 } else {
3242                         ok_count++;
3243                 }
3244         }
3245         return ok_count;
3246 }
3247
3248 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3249                      void *type_data, bool err_stop, bool rtnl_held)
3250 {
3251         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3252         int ok_count;
3253
3254 retry:
3255         if (take_rtnl)
3256                 rtnl_lock();
3257         down_read(&block->cb_lock);
3258         /* Need to obtain rtnl lock if block is bound to devs that require it.
3259          * In block bind code cb_lock is obtained while holding rtnl, so we must
3260          * obtain the locks in same order here.
3261          */
3262         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3263                 up_read(&block->cb_lock);
3264                 take_rtnl = true;
3265                 goto retry;
3266         }
3267
3268         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3269
3270         up_read(&block->cb_lock);
3271         if (take_rtnl)
3272                 rtnl_unlock();
3273         return ok_count;
3274 }
3275 EXPORT_SYMBOL(tc_setup_cb_call);
3276
3277 /* Non-destructive filter add. If filter that wasn't already in hardware is
3278  * successfully offloaded, increment block offloads counter. On failure,
3279  * previously offloaded filter is considered to be intact and offloads counter
3280  * is not decremented.
3281  */
3282
3283 int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
3284                     enum tc_setup_type type, void *type_data, bool err_stop,
3285                     u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3286 {
3287         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3288         int ok_count;
3289
3290 retry:
3291         if (take_rtnl)
3292                 rtnl_lock();
3293         down_read(&block->cb_lock);
3294         /* Need to obtain rtnl lock if block is bound to devs that require it.
3295          * In block bind code cb_lock is obtained while holding rtnl, so we must
3296          * obtain the locks in same order here.
3297          */
3298         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3299                 up_read(&block->cb_lock);
3300                 take_rtnl = true;
3301                 goto retry;
3302         }
3303
3304         /* Make sure all netdevs sharing this block are offload-capable. */
3305         if (block->nooffloaddevcnt && err_stop) {
3306                 ok_count = -EOPNOTSUPP;
3307                 goto err_unlock;
3308         }
3309
3310         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3311         if (ok_count < 0)
3312                 goto err_unlock;
3313
3314         if (tp->ops->hw_add)
3315                 tp->ops->hw_add(tp, type_data);
3316         if (ok_count > 0)
3317                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
3318                                           ok_count, true);
3319 err_unlock:
3320         up_read(&block->cb_lock);
3321         if (take_rtnl)
3322                 rtnl_unlock();
3323         return ok_count < 0 ? ok_count : 0;
3324 }
3325 EXPORT_SYMBOL(tc_setup_cb_add);
3326
3327 /* Destructive filter replace. If filter that wasn't already in hardware is
3328  * successfully offloaded, increment block offload counter. On failure,
3329  * previously offloaded filter is considered to be destroyed and offload counter
3330  * is decremented.
3331  */
3332
3333 int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
3334                         enum tc_setup_type type, void *type_data, bool err_stop,
3335                         u32 *old_flags, unsigned int *old_in_hw_count,
3336                         u32 *new_flags, unsigned int *new_in_hw_count,
3337                         bool rtnl_held)
3338 {
3339         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3340         int ok_count;
3341
3342 retry:
3343         if (take_rtnl)
3344                 rtnl_lock();
3345         down_read(&block->cb_lock);
3346         /* Need to obtain rtnl lock if block is bound to devs that require it.
3347          * In block bind code cb_lock is obtained while holding rtnl, so we must
3348          * obtain the locks in same order here.
3349          */
3350         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3351                 up_read(&block->cb_lock);
3352                 take_rtnl = true;
3353                 goto retry;
3354         }
3355
3356         /* Make sure all netdevs sharing this block are offload-capable. */
3357         if (block->nooffloaddevcnt && err_stop) {
3358                 ok_count = -EOPNOTSUPP;
3359                 goto err_unlock;
3360         }
3361
3362         tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
3363         if (tp->ops->hw_del)
3364                 tp->ops->hw_del(tp, type_data);
3365
3366         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3367         if (ok_count < 0)
3368                 goto err_unlock;
3369
3370         if (tp->ops->hw_add)
3371                 tp->ops->hw_add(tp, type_data);
3372         if (ok_count > 0)
3373                 tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
3374                                           new_flags, ok_count, true);
3375 err_unlock:
3376         up_read(&block->cb_lock);
3377         if (take_rtnl)
3378                 rtnl_unlock();
3379         return ok_count < 0 ? ok_count : 0;
3380 }
3381 EXPORT_SYMBOL(tc_setup_cb_replace);
3382
3383 /* Destroy filter and decrement block offload counter, if filter was previously
3384  * offloaded.
3385  */
3386
3387 int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
3388                         enum tc_setup_type type, void *type_data, bool err_stop,
3389                         u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3390 {
3391         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3392         int ok_count;
3393
3394 retry:
3395         if (take_rtnl)
3396                 rtnl_lock();
3397         down_read(&block->cb_lock);
3398         /* Need to obtain rtnl lock if block is bound to devs that require it.
3399          * In block bind code cb_lock is obtained while holding rtnl, so we must
3400          * obtain the locks in same order here.
3401          */
3402         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3403                 up_read(&block->cb_lock);
3404                 take_rtnl = true;
3405                 goto retry;
3406         }
3407
3408         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3409
3410         tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
3411         if (tp->ops->hw_del)
3412                 tp->ops->hw_del(tp, type_data);
3413
3414         up_read(&block->cb_lock);
3415         if (take_rtnl)
3416                 rtnl_unlock();
3417         return ok_count < 0 ? ok_count : 0;
3418 }
3419 EXPORT_SYMBOL(tc_setup_cb_destroy);
3420
3421 int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
3422                           bool add, flow_setup_cb_t *cb,
3423                           enum tc_setup_type type, void *type_data,
3424                           void *cb_priv, u32 *flags, unsigned int *in_hw_count)
3425 {
3426         int err = cb(type, type_data, cb_priv);
3427
3428         if (err) {
3429                 if (add && tc_skip_sw(*flags))
3430                         return err;
3431         } else {
3432                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags, 1,
3433                                           add);
3434         }
3435
3436         return 0;
3437 }
3438 EXPORT_SYMBOL(tc_setup_cb_reoffload);
3439
3440 static int tcf_act_get_cookie(struct flow_action_entry *entry,
3441                               const struct tc_action *act)
3442 {
3443         struct tc_cookie *cookie;
3444         int err = 0;
3445
3446         rcu_read_lock();
3447         cookie = rcu_dereference(act->act_cookie);
3448         if (cookie) {
3449                 entry->cookie = flow_action_cookie_create(cookie->data,
3450                                                           cookie->len,
3451                                                           GFP_ATOMIC);
3452                 if (!entry->cookie)
3453                         err = -ENOMEM;
3454         }
3455         rcu_read_unlock();
3456         return err;
3457 }
3458
3459 static void tcf_act_put_cookie(struct flow_action_entry *entry)
3460 {
3461         flow_action_cookie_destroy(entry->cookie);
3462 }
3463
3464 void tc_cleanup_flow_action(struct flow_action *flow_action)
3465 {
3466         struct flow_action_entry *entry;
3467         int i;
3468
3469         flow_action_for_each(i, entry, flow_action) {
3470                 tcf_act_put_cookie(entry);
3471                 if (entry->destructor)
3472                         entry->destructor(entry->destructor_priv);
3473         }
3474 }
3475 EXPORT_SYMBOL(tc_cleanup_flow_action);
3476
3477 static void tcf_mirred_get_dev(struct flow_action_entry *entry,
3478                                const struct tc_action *act)
3479 {
3480 #ifdef CONFIG_NET_CLS_ACT
3481         entry->dev = act->ops->get_dev(act, &entry->destructor);
3482         if (!entry->dev)
3483                 return;
3484         entry->destructor_priv = entry->dev;
3485 #endif
3486 }
3487
3488 static void tcf_tunnel_encap_put_tunnel(void *priv)
3489 {
3490         struct ip_tunnel_info *tunnel = priv;
3491
3492         kfree(tunnel);
3493 }
3494
3495 static int tcf_tunnel_encap_get_tunnel(struct flow_action_entry *entry,
3496                                        const struct tc_action *act)
3497 {
3498         entry->tunnel = tcf_tunnel_info_copy(act);
3499         if (!entry->tunnel)
3500                 return -ENOMEM;
3501         entry->destructor = tcf_tunnel_encap_put_tunnel;
3502         entry->destructor_priv = entry->tunnel;
3503         return 0;
3504 }
3505
3506 static void tcf_sample_get_group(struct flow_action_entry *entry,
3507                                  const struct tc_action *act)
3508 {
3509 #ifdef CONFIG_NET_CLS_ACT
3510         entry->sample.psample_group =
3511                 act->ops->get_psample_group(act, &entry->destructor);
3512         entry->destructor_priv = entry->sample.psample_group;
3513 #endif
3514 }
3515
3516 static void tcf_gate_entry_destructor(void *priv)
3517 {
3518         struct action_gate_entry *oe = priv;
3519
3520         kfree(oe);
3521 }
3522
3523 static int tcf_gate_get_entries(struct flow_action_entry *entry,
3524                                 const struct tc_action *act)
3525 {
3526         entry->gate.entries = tcf_gate_get_list(act);
3527
3528         if (!entry->gate.entries)
3529                 return -EINVAL;
3530
3531         entry->destructor = tcf_gate_entry_destructor;
3532         entry->destructor_priv = entry->gate.entries;
3533
3534         return 0;
3535 }
3536
3537 static enum flow_action_hw_stats tc_act_hw_stats(u8 hw_stats)
3538 {
3539         if (WARN_ON_ONCE(hw_stats > TCA_ACT_HW_STATS_ANY))
3540                 return FLOW_ACTION_HW_STATS_DONT_CARE;
3541         else if (!hw_stats)
3542                 return FLOW_ACTION_HW_STATS_DISABLED;
3543
3544         return hw_stats;
3545 }
3546
3547 int tc_setup_flow_action(struct flow_action *flow_action,
3548                          const struct tcf_exts *exts)
3549 {
3550         struct tc_action *act;
3551         int i, j, k, err = 0;
3552
3553         BUILD_BUG_ON(TCA_ACT_HW_STATS_ANY != FLOW_ACTION_HW_STATS_ANY);
3554         BUILD_BUG_ON(TCA_ACT_HW_STATS_IMMEDIATE != FLOW_ACTION_HW_STATS_IMMEDIATE);
3555         BUILD_BUG_ON(TCA_ACT_HW_STATS_DELAYED != FLOW_ACTION_HW_STATS_DELAYED);
3556
3557         if (!exts)
3558                 return 0;
3559
3560         j = 0;
3561         tcf_exts_for_each_action(i, act, exts) {
3562                 struct flow_action_entry *entry;
3563
3564                 entry = &flow_action->entries[j];
3565                 spin_lock_bh(&act->tcfa_lock);
3566                 err = tcf_act_get_cookie(entry, act);
3567                 if (err)
3568                         goto err_out_locked;
3569
3570                 entry->hw_stats = tc_act_hw_stats(act->hw_stats);
3571
3572                 if (is_tcf_gact_ok(act)) {
3573                         entry->id = FLOW_ACTION_ACCEPT;
3574                 } else if (is_tcf_gact_shot(act)) {
3575                         entry->id = FLOW_ACTION_DROP;
3576                 } else if (is_tcf_gact_trap(act)) {
3577                         entry->id = FLOW_ACTION_TRAP;
3578                 } else if (is_tcf_gact_goto_chain(act)) {
3579                         entry->id = FLOW_ACTION_GOTO;
3580                         entry->chain_index = tcf_gact_goto_chain_index(act);
3581                 } else if (is_tcf_mirred_egress_redirect(act)) {
3582                         entry->id = FLOW_ACTION_REDIRECT;
3583                         tcf_mirred_get_dev(entry, act);
3584                 } else if (is_tcf_mirred_egress_mirror(act)) {
3585                         entry->id = FLOW_ACTION_MIRRED;
3586                         tcf_mirred_get_dev(entry, act);
3587                 } else if (is_tcf_mirred_ingress_redirect(act)) {
3588                         entry->id = FLOW_ACTION_REDIRECT_INGRESS;
3589                         tcf_mirred_get_dev(entry, act);
3590                 } else if (is_tcf_mirred_ingress_mirror(act)) {
3591                         entry->id = FLOW_ACTION_MIRRED_INGRESS;
3592                         tcf_mirred_get_dev(entry, act);
3593                 } else if (is_tcf_vlan(act)) {
3594                         switch (tcf_vlan_action(act)) {
3595                         case TCA_VLAN_ACT_PUSH:
3596                                 entry->id = FLOW_ACTION_VLAN_PUSH;
3597                                 entry->vlan.vid = tcf_vlan_push_vid(act);
3598                                 entry->vlan.proto = tcf_vlan_push_proto(act);
3599                                 entry->vlan.prio = tcf_vlan_push_prio(act);
3600                                 break;
3601                         case TCA_VLAN_ACT_POP:
3602                                 entry->id = FLOW_ACTION_VLAN_POP;
3603                                 break;
3604                         case TCA_VLAN_ACT_MODIFY:
3605                                 entry->id = FLOW_ACTION_VLAN_MANGLE;
3606                                 entry->vlan.vid = tcf_vlan_push_vid(act);
3607                                 entry->vlan.proto = tcf_vlan_push_proto(act);
3608                                 entry->vlan.prio = tcf_vlan_push_prio(act);
3609                                 break;
3610                         default:
3611                                 err = -EOPNOTSUPP;
3612                                 goto err_out_locked;
3613                         }
3614                 } else if (is_tcf_tunnel_set(act)) {
3615                         entry->id = FLOW_ACTION_TUNNEL_ENCAP;
3616                         err = tcf_tunnel_encap_get_tunnel(entry, act);
3617                         if (err)
3618                                 goto err_out_locked;
3619                 } else if (is_tcf_tunnel_release(act)) {
3620                         entry->id = FLOW_ACTION_TUNNEL_DECAP;
3621                 } else if (is_tcf_pedit(act)) {
3622                         for (k = 0; k < tcf_pedit_nkeys(act); k++) {
3623                                 switch (tcf_pedit_cmd(act, k)) {
3624                                 case TCA_PEDIT_KEY_EX_CMD_SET:
3625                                         entry->id = FLOW_ACTION_MANGLE;
3626                                         break;
3627                                 case TCA_PEDIT_KEY_EX_CMD_ADD:
3628                                         entry->id = FLOW_ACTION_ADD;
3629                                         break;
3630                                 default:
3631                                         err = -EOPNOTSUPP;
3632                                         goto err_out_locked;
3633                                 }
3634                                 entry->mangle.htype = tcf_pedit_htype(act, k);
3635                                 entry->mangle.mask = tcf_pedit_mask(act, k);
3636                                 entry->mangle.val = tcf_pedit_val(act, k);
3637                                 entry->mangle.offset = tcf_pedit_offset(act, k);
3638                                 entry->hw_stats = tc_act_hw_stats(act->hw_stats);
3639                                 entry = &flow_action->entries[++j];
3640                         }
3641                 } else if (is_tcf_csum(act)) {
3642                         entry->id = FLOW_ACTION_CSUM;
3643                         entry->csum_flags = tcf_csum_update_flags(act);
3644                 } else if (is_tcf_skbedit_mark(act)) {
3645                         entry->id = FLOW_ACTION_MARK;
3646                         entry->mark = tcf_skbedit_mark(act);
3647                 } else if (is_tcf_sample(act)) {
3648                         entry->id = FLOW_ACTION_SAMPLE;
3649                         entry->sample.trunc_size = tcf_sample_trunc_size(act);
3650                         entry->sample.truncate = tcf_sample_truncate(act);
3651                         entry->sample.rate = tcf_sample_rate(act);
3652                         tcf_sample_get_group(entry, act);
3653                 } else if (is_tcf_police(act)) {
3654                         entry->id = FLOW_ACTION_POLICE;
3655                         entry->police.burst = tcf_police_burst(act);
3656                         entry->police.rate_bytes_ps =
3657                                 tcf_police_rate_bytes_ps(act);
3658                         entry->police.burst_pkt = tcf_police_burst_pkt(act);
3659                         entry->police.rate_pkt_ps =
3660                                 tcf_police_rate_pkt_ps(act);
3661                         entry->police.mtu = tcf_police_tcfp_mtu(act);
3662                         entry->police.index = act->tcfa_index;
3663                 } else if (is_tcf_ct(act)) {
3664                         entry->id = FLOW_ACTION_CT;
3665                         entry->ct.action = tcf_ct_action(act);
3666                         entry->ct.zone = tcf_ct_zone(act);
3667                         entry->ct.flow_table = tcf_ct_ft(act);
3668                 } else if (is_tcf_mpls(act)) {
3669                         switch (tcf_mpls_action(act)) {
3670                         case TCA_MPLS_ACT_PUSH:
3671                                 entry->id = FLOW_ACTION_MPLS_PUSH;
3672                                 entry->mpls_push.proto = tcf_mpls_proto(act);
3673                                 entry->mpls_push.label = tcf_mpls_label(act);
3674                                 entry->mpls_push.tc = tcf_mpls_tc(act);
3675                                 entry->mpls_push.bos = tcf_mpls_bos(act);
3676                                 entry->mpls_push.ttl = tcf_mpls_ttl(act);
3677                                 break;
3678                         case TCA_MPLS_ACT_POP:
3679                                 entry->id = FLOW_ACTION_MPLS_POP;
3680                                 entry->mpls_pop.proto = tcf_mpls_proto(act);
3681                                 break;
3682                         case TCA_MPLS_ACT_MODIFY:
3683                                 entry->id = FLOW_ACTION_MPLS_MANGLE;
3684                                 entry->mpls_mangle.label = tcf_mpls_label(act);
3685                                 entry->mpls_mangle.tc = tcf_mpls_tc(act);
3686                                 entry->mpls_mangle.bos = tcf_mpls_bos(act);
3687                                 entry->mpls_mangle.ttl = tcf_mpls_ttl(act);
3688                                 break;
3689                         default:
3690                                 goto err_out_locked;
3691                         }
3692                 } else if (is_tcf_skbedit_ptype(act)) {
3693                         entry->id = FLOW_ACTION_PTYPE;
3694                         entry->ptype = tcf_skbedit_ptype(act);
3695                 } else if (is_tcf_skbedit_priority(act)) {
3696                         entry->id = FLOW_ACTION_PRIORITY;
3697                         entry->priority = tcf_skbedit_priority(act);
3698                 } else if (is_tcf_gate(act)) {
3699                         entry->id = FLOW_ACTION_GATE;
3700                         entry->gate.index = tcf_gate_index(act);
3701                         entry->gate.prio = tcf_gate_prio(act);
3702                         entry->gate.basetime = tcf_gate_basetime(act);
3703                         entry->gate.cycletime = tcf_gate_cycletime(act);
3704                         entry->gate.cycletimeext = tcf_gate_cycletimeext(act);
3705                         entry->gate.num_entries = tcf_gate_num_entries(act);
3706                         err = tcf_gate_get_entries(entry, act);
3707                         if (err)
3708                                 goto err_out_locked;
3709                 } else {
3710                         err = -EOPNOTSUPP;
3711                         goto err_out_locked;
3712                 }
3713                 spin_unlock_bh(&act->tcfa_lock);
3714
3715                 if (!is_tcf_pedit(act))
3716                         j++;
3717         }
3718
3719 err_out:
3720         if (err)
3721                 tc_cleanup_flow_action(flow_action);
3722
3723         return err;
3724 err_out_locked:
3725         spin_unlock_bh(&act->tcfa_lock);
3726         goto err_out;
3727 }
3728 EXPORT_SYMBOL(tc_setup_flow_action);
3729
3730 unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
3731 {
3732         unsigned int num_acts = 0;
3733         struct tc_action *act;
3734         int i;
3735
3736         tcf_exts_for_each_action(i, act, exts) {
3737                 if (is_tcf_pedit(act))
3738                         num_acts += tcf_pedit_nkeys(act);
3739                 else
3740                         num_acts++;
3741         }
3742         return num_acts;
3743 }
3744 EXPORT_SYMBOL(tcf_exts_num_actions);
3745
3746 #ifdef CONFIG_NET_CLS_ACT
3747 static int tcf_qevent_parse_block_index(struct nlattr *block_index_attr,
3748                                         u32 *p_block_index,
3749                                         struct netlink_ext_ack *extack)
3750 {
3751         *p_block_index = nla_get_u32(block_index_attr);
3752         if (!*p_block_index) {
3753                 NL_SET_ERR_MSG(extack, "Block number may not be zero");
3754                 return -EINVAL;
3755         }
3756
3757         return 0;
3758 }
3759
3760 int tcf_qevent_init(struct tcf_qevent *qe, struct Qdisc *sch,
3761                     enum flow_block_binder_type binder_type,
3762                     struct nlattr *block_index_attr,
3763                     struct netlink_ext_ack *extack)
3764 {
3765         u32 block_index;
3766         int err;
3767
3768         if (!block_index_attr)
3769                 return 0;
3770
3771         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3772         if (err)
3773                 return err;
3774
3775         if (!block_index)
3776                 return 0;
3777
3778         qe->info.binder_type = binder_type;
3779         qe->info.chain_head_change = tcf_chain_head_change_dflt;
3780         qe->info.chain_head_change_priv = &qe->filter_chain;
3781         qe->info.block_index = block_index;
3782
3783         return tcf_block_get_ext(&qe->block, sch, &qe->info, extack);
3784 }
3785 EXPORT_SYMBOL(tcf_qevent_init);
3786
3787 void tcf_qevent_destroy(struct tcf_qevent *qe, struct Qdisc *sch)
3788 {
3789         if (qe->info.block_index)
3790                 tcf_block_put_ext(qe->block, sch, &qe->info);
3791 }
3792 EXPORT_SYMBOL(tcf_qevent_destroy);
3793
3794 int tcf_qevent_validate_change(struct tcf_qevent *qe, struct nlattr *block_index_attr,
3795                                struct netlink_ext_ack *extack)
3796 {
3797         u32 block_index;
3798         int err;
3799
3800         if (!block_index_attr)
3801                 return 0;
3802
3803         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3804         if (err)
3805                 return err;
3806
3807         /* Bounce newly-configured block or change in block. */
3808         if (block_index != qe->info.block_index) {
3809                 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
3810                 return -EINVAL;
3811         }
3812
3813         return 0;
3814 }
3815 EXPORT_SYMBOL(tcf_qevent_validate_change);
3816
3817 struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
3818                                   struct sk_buff **to_free, int *ret)
3819 {
3820         struct tcf_result cl_res;
3821         struct tcf_proto *fl;
3822
3823         if (!qe->info.block_index)
3824                 return skb;
3825
3826         fl = rcu_dereference_bh(qe->filter_chain);
3827
3828         switch (tcf_classify(skb, NULL, fl, &cl_res, false)) {
3829         case TC_ACT_SHOT:
3830                 qdisc_qstats_drop(sch);
3831                 __qdisc_drop(skb, to_free);
3832                 *ret = __NET_XMIT_BYPASS;
3833                 return NULL;
3834         case TC_ACT_STOLEN:
3835         case TC_ACT_QUEUED:
3836         case TC_ACT_TRAP:
3837                 __qdisc_drop(skb, to_free);
3838                 *ret = __NET_XMIT_STOLEN;
3839                 return NULL;
3840         case TC_ACT_REDIRECT:
3841                 skb_do_redirect(skb);
3842                 *ret = __NET_XMIT_STOLEN;
3843                 return NULL;
3844         }
3845
3846         return skb;
3847 }
3848 EXPORT_SYMBOL(tcf_qevent_handle);
3849
3850 int tcf_qevent_dump(struct sk_buff *skb, int attr_name, struct tcf_qevent *qe)
3851 {
3852         if (!qe->info.block_index)
3853                 return 0;
3854         return nla_put_u32(skb, attr_name, qe->info.block_index);
3855 }
3856 EXPORT_SYMBOL(tcf_qevent_dump);
3857 #endif
3858
3859 static __net_init int tcf_net_init(struct net *net)
3860 {
3861         struct tcf_net *tn = net_generic(net, tcf_net_id);
3862
3863         spin_lock_init(&tn->idr_lock);
3864         idr_init(&tn->idr);
3865         return 0;
3866 }
3867
3868 static void __net_exit tcf_net_exit(struct net *net)
3869 {
3870         struct tcf_net *tn = net_generic(net, tcf_net_id);
3871
3872         idr_destroy(&tn->idr);
3873 }
3874
3875 static struct pernet_operations tcf_net_ops = {
3876         .init = tcf_net_init,
3877         .exit = tcf_net_exit,
3878         .id   = &tcf_net_id,
3879         .size = sizeof(struct tcf_net),
3880 };
3881
3882 static int __init tc_filter_init(void)
3883 {
3884         int err;
3885
3886         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
3887         if (!tc_filter_wq)
3888                 return -ENOMEM;
3889
3890         err = register_pernet_subsys(&tcf_net_ops);
3891         if (err)
3892                 goto err_register_pernet_subsys;
3893
3894         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
3895                       RTNL_FLAG_DOIT_UNLOCKED);
3896         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
3897                       RTNL_FLAG_DOIT_UNLOCKED);
3898         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
3899                       tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
3900         rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
3901         rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
3902         rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
3903                       tc_dump_chain, 0);
3904
3905         return 0;
3906
3907 err_register_pernet_subsys:
3908         destroy_workqueue(tc_filter_wq);
3909         return err;
3910 }
3911
3912 subsys_initcall(tc_filter_init);