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/rhashtable.h>
  24 #include <linux/jhash.h>
  25 #include <linux/rculist.h>
  26 #include <net/net_namespace.h>
  27 #include <net/sock.h>
  28 #include <net/netlink.h>
  29 #include <net/pkt_sched.h>
  30 #include <net/pkt_cls.h>
  31 #include <net/tc_act/tc_pedit.h>
  32 #include <net/tc_act/tc_mirred.h>
  33 #include <net/tc_act/tc_vlan.h>
  34 #include <net/tc_act/tc_tunnel_key.h>
  35 #include <net/tc_act/tc_csum.h>
  36 #include <net/tc_act/tc_gact.h>
  37 #include <net/tc_act/tc_police.h>
  38 #include <net/tc_act/tc_sample.h>
  39 #include <net/tc_act/tc_skbedit.h>
  40 #include <net/tc_act/tc_ct.h>
  41 #include <net/tc_act/tc_mpls.h>
  42 #include <net/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_strlcpy(name, kind, IFNAMSIZ) >= IFNAMSIZ;
 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 tc_indr_block_cmd(struct net_device *dev, struct tcf_block *block,
 624                               flow_indr_block_bind_cb_t *cb, void *cb_priv,
 625                               enum flow_block_command command, bool ingress)
 626 {
 627         struct flow_block_offload bo = {
 628                 .command        = command,
 629                 .binder_type    = ingress ?
 630                                   FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS :
 631                                   FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS,
 632                 .net            = dev_net(dev),
 633                 .block_shared   = tcf_block_non_null_shared(block),
 634         };
 635         INIT_LIST_HEAD(&bo.cb_list);
 636
 637         if (!block)
 638                 return;
 639
 640         bo.block = &block->flow_block;
 641
 642         down_write(&block->cb_lock);
 643         cb(dev, cb_priv, TC_SETUP_BLOCK, &bo);
 644
 645         tcf_block_setup(block, &bo);
 646         up_write(&block->cb_lock);
 647 }
 648
 649 static struct tcf_block *tc_dev_block(struct net_device *dev, bool ingress)
 650 {
 651         const struct Qdisc_class_ops *cops;
 652         const struct Qdisc_ops *ops;
 653         struct Qdisc *qdisc;
 654
 655         if (!dev_ingress_queue(dev))
 656                 return NULL;
 657
 658         qdisc = dev_ingress_queue(dev)->qdisc_sleeping;
 659         if (!qdisc)
 660                 return NULL;
 661
 662         ops = qdisc->ops;
 663         if (!ops)
 664                 return NULL;
 665
 666         if (!ingress && !strcmp("ingress", ops->id))
 667                 return NULL;
 668
 669         cops = ops->cl_ops;
 670         if (!cops)
 671                 return NULL;
 672
 673         if (!cops->tcf_block)
 674                 return NULL;
 675
 676         return cops->tcf_block(qdisc,
 677                                ingress ? TC_H_MIN_INGRESS : TC_H_MIN_EGRESS,
 678                                NULL);
 679 }
 680
 681 static void tc_indr_block_get_and_cmd(struct net_device *dev,
 682                                       flow_indr_block_bind_cb_t *cb,
 683                                       void *cb_priv,
 684                                       enum flow_block_command command)
 685 {
 686         struct tcf_block *block;
 687
 688         block = tc_dev_block(dev, true);
 689         tc_indr_block_cmd(dev, block, cb, cb_priv, command, true);
 690
 691         block = tc_dev_block(dev, false);
 692         tc_indr_block_cmd(dev, block, cb, cb_priv, command, false);
 693 }
 694
 695 static void tc_indr_block_call(struct tcf_block *block,
 696                                struct net_device *dev,
 697                                struct tcf_block_ext_info *ei,
 698                                enum flow_block_command command,
 699                                struct netlink_ext_ack *extack)
 700 {
 701         struct flow_block_offload bo = {
 702                 .command        = command,
 703                 .binder_type    = ei->binder_type,
 704                 .net            = dev_net(dev),
 705                 .block          = &block->flow_block,
 706                 .block_shared   = tcf_block_shared(block),
 707                 .extack         = extack,
 708         };
 709         INIT_LIST_HEAD(&bo.cb_list);
 710
 711         flow_indr_block_call(dev, &bo, command);
 712         tcf_block_setup(block, &bo);
 713 }
 714
 715 static bool tcf_block_offload_in_use(struct tcf_block *block)
 716 {
 717         return atomic_read(&block->offloadcnt);
 718 }
 719
 720 static int tcf_block_offload_cmd(struct tcf_block *block,
 721                                  struct net_device *dev,
 722                                  struct tcf_block_ext_info *ei,
 723                                  enum flow_block_command command,
 724                                  struct netlink_ext_ack *extack)
 725 {
 726         struct flow_block_offload bo = {};
 727         int err;
 728
 729         bo.net = dev_net(dev);
 730         bo.command = command;
 731         bo.binder_type = ei->binder_type;
 732         bo.block = &block->flow_block;
 733         bo.block_shared = tcf_block_shared(block);
 734         bo.extack = extack;
 735         INIT_LIST_HEAD(&bo.cb_list);
 736
 737         err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 738         if (err < 0)
 739                 return err;
 740
 741         return tcf_block_setup(block, &bo);
 742 }
 743
 744 static int tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
 745                                   struct tcf_block_ext_info *ei,
 746                                   struct netlink_ext_ack *extack)
 747 {
 748         struct net_device *dev = q->dev_queue->dev;
 749         int err;
 750
 751         down_write(&block->cb_lock);
 752         if (!dev->netdev_ops->ndo_setup_tc)
 753                 goto no_offload_dev_inc;
 754
 755         /* If tc offload feature is disabled and the block we try to bind
 756          * to already has some offloaded filters, forbid to bind.
 757          */
 758         if (!tc_can_offload(dev) && tcf_block_offload_in_use(block)) {
 759                 NL_SET_ERR_MSG(extack, "Bind to offloaded block failed as dev has offload disabled");
 760                 err = -EOPNOTSUPP;
 761                 goto err_unlock;
 762         }
 763
 764         err = tcf_block_offload_cmd(block, dev, ei, FLOW_BLOCK_BIND, extack);
 765         if (err == -EOPNOTSUPP)
 766                 goto no_offload_dev_inc;
 767         if (err)
 768                 goto err_unlock;
 769
 770         tc_indr_block_call(block, dev, ei, FLOW_BLOCK_BIND, extack);
 771         up_write(&block->cb_lock);
 772         return 0;
 773
 774 no_offload_dev_inc:
 775         if (tcf_block_offload_in_use(block)) {
 776                 err = -EOPNOTSUPP;
 777                 goto err_unlock;
 778         }
 779         err = 0;
 780         block->nooffloaddevcnt++;
 781         tc_indr_block_call(block, dev, ei, FLOW_BLOCK_BIND, extack);
 782 err_unlock:
 783         up_write(&block->cb_lock);
 784         return err;
 785 }
 786
 787 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
 788                                      struct tcf_block_ext_info *ei)
 789 {
 790         struct net_device *dev = q->dev_queue->dev;
 791         int err;
 792
 793         down_write(&block->cb_lock);
 794         tc_indr_block_call(block, dev, ei, FLOW_BLOCK_UNBIND, NULL);
 795
 796         if (!dev->netdev_ops->ndo_setup_tc)
 797                 goto no_offload_dev_dec;
 798         err = tcf_block_offload_cmd(block, dev, ei, FLOW_BLOCK_UNBIND, NULL);
 799         if (err == -EOPNOTSUPP)
 800                 goto no_offload_dev_dec;
 801         up_write(&block->cb_lock);
 802         return;
 803
 804 no_offload_dev_dec:
 805         WARN_ON(block->nooffloaddevcnt-- == 0);
 806         up_write(&block->cb_lock);
 807 }
 808
 809 static int
 810 tcf_chain0_head_change_cb_add(struct tcf_block *block,
 811                               struct tcf_block_ext_info *ei,
 812                               struct netlink_ext_ack *extack)
 813 {
 814         struct tcf_filter_chain_list_item *item;
 815         struct tcf_chain *chain0;
 816
 817         item = kmalloc(sizeof(*item), GFP_KERNEL);
 818         if (!item) {
 819                 NL_SET_ERR_MSG(extack, "Memory allocation for head change callback item failed");
 820                 return -ENOMEM;
 821         }
 822         item->chain_head_change = ei->chain_head_change;
 823         item->chain_head_change_priv = ei->chain_head_change_priv;
 824
 825         mutex_lock(&block->lock);
 826         chain0 = block->chain0.chain;
 827         if (chain0)
 828                 tcf_chain_hold(chain0);
 829         else
 830                 list_add(&item->list, &block->chain0.filter_chain_list);
 831         mutex_unlock(&block->lock);
 832
 833         if (chain0) {
 834                 struct tcf_proto *tp_head;
 835
 836                 mutex_lock(&chain0->filter_chain_lock);
 837
 838                 tp_head = tcf_chain_dereference(chain0->filter_chain, chain0);
 839                 if (tp_head)
 840                         tcf_chain_head_change_item(item, tp_head);
 841
 842                 mutex_lock(&block->lock);
 843                 list_add(&item->list, &block->chain0.filter_chain_list);
 844                 mutex_unlock(&block->lock);
 845
 846                 mutex_unlock(&chain0->filter_chain_lock);
 847                 tcf_chain_put(chain0);
 848         }
 849
 850         return 0;
 851 }
 852
 853 static void
 854 tcf_chain0_head_change_cb_del(struct tcf_block *block,
 855                               struct tcf_block_ext_info *ei)
 856 {
 857         struct tcf_filter_chain_list_item *item;
 858
 859         mutex_lock(&block->lock);
 860         list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
 861                 if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
 862                     (item->chain_head_change == ei->chain_head_change &&
 863                      item->chain_head_change_priv == ei->chain_head_change_priv)) {
 864                         if (block->chain0.chain)
 865                                 tcf_chain_head_change_item(item, NULL);
 866                         list_del(&item->list);
 867                         mutex_unlock(&block->lock);
 868
 869                         kfree(item);
 870                         return;
 871                 }
 872         }
 873         mutex_unlock(&block->lock);
 874         WARN_ON(1);
 875 }
 876
 877 struct tcf_net {
 878         spinlock_t idr_lock; /* Protects idr */
 879         struct idr idr;
 880 };
 881
 882 static unsigned int tcf_net_id;
 883
 884 static int tcf_block_insert(struct tcf_block *block, struct net *net,
 885                             struct netlink_ext_ack *extack)
 886 {
 887         struct tcf_net *tn = net_generic(net, tcf_net_id);
 888         int err;
 889
 890         idr_preload(GFP_KERNEL);
 891         spin_lock(&tn->idr_lock);
 892         err = idr_alloc_u32(&tn->idr, block, &block->index, block->index,
 893                             GFP_NOWAIT);
 894         spin_unlock(&tn->idr_lock);
 895         idr_preload_end();
 896
 897         return err;
 898 }
 899
 900 static void tcf_block_remove(struct tcf_block *block, struct net *net)
 901 {
 902         struct tcf_net *tn = net_generic(net, tcf_net_id);
 903
 904         spin_lock(&tn->idr_lock);
 905         idr_remove(&tn->idr, block->index);
 906         spin_unlock(&tn->idr_lock);
 907 }
 908
 909 static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 910                                           u32 block_index,
 911                                           struct netlink_ext_ack *extack)
 912 {
 913         struct tcf_block *block;
 914
 915         block = kzalloc(sizeof(*block), GFP_KERNEL);
 916         if (!block) {
 917                 NL_SET_ERR_MSG(extack, "Memory allocation for block failed");
 918                 return ERR_PTR(-ENOMEM);
 919         }
 920         mutex_init(&block->lock);
 921         mutex_init(&block->proto_destroy_lock);
 922         init_rwsem(&block->cb_lock);
 923         flow_block_init(&block->flow_block);
 924         INIT_LIST_HEAD(&block->chain_list);
 925         INIT_LIST_HEAD(&block->owner_list);
 926         INIT_LIST_HEAD(&block->chain0.filter_chain_list);
 927
 928         refcount_set(&block->refcnt, 1);
 929         block->net = net;
 930         block->index = block_index;
 931
 932         /* Don't store q pointer for blocks which are shared */
 933         if (!tcf_block_shared(block))
 934                 block->q = q;
 935         return block;
 936 }
 937
 938 static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
 939 {
 940         struct tcf_net *tn = net_generic(net, tcf_net_id);
 941
 942         return idr_find(&tn->idr, block_index);
 943 }
 944
 945 static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
 946 {
 947         struct tcf_block *block;
 948
 949         rcu_read_lock();
 950         block = tcf_block_lookup(net, block_index);
 951         if (block && !refcount_inc_not_zero(&block->refcnt))
 952                 block = NULL;
 953         rcu_read_unlock();
 954
 955         return block;
 956 }
 957
 958 static struct tcf_chain *
 959 __tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
 960 {
 961         mutex_lock(&block->lock);
 962         if (chain)
 963                 chain = list_is_last(&chain->list, &block->chain_list) ?
 964                         NULL : list_next_entry(chain, list);
 965         else
 966                 chain = list_first_entry_or_null(&block->chain_list,
 967                                                  struct tcf_chain, list);
 968
 969         /* skip all action-only chains */
 970         while (chain && tcf_chain_held_by_acts_only(chain))
 971                 chain = list_is_last(&chain->list, &block->chain_list) ?
 972                         NULL : list_next_entry(chain, list);
 973
 974         if (chain)
 975                 tcf_chain_hold(chain);
 976         mutex_unlock(&block->lock);
 977
 978         return chain;
 979 }
 980
 981 /* Function to be used by all clients that want to iterate over all chains on
 982  * block. It properly obtains block->lock and takes reference to chain before
 983  * returning it. Users of this function must be tolerant to concurrent chain
 984  * insertion/deletion or ensure that no concurrent chain modification is
 985  * possible. Note that all netlink dump callbacks cannot guarantee to provide
 986  * consistent dump because rtnl lock is released each time skb is filled with
 987  * data and sent to user-space.
 988  */
 989
 990 struct tcf_chain *
 991 tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
 992 {
 993         struct tcf_chain *chain_next = __tcf_get_next_chain(block, chain);
 994
 995         if (chain)
 996                 tcf_chain_put(chain);
 997
 998         return chain_next;
 999 }
1000 EXPORT_SYMBOL(tcf_get_next_chain);
1001
1002 static struct tcf_proto *
1003 __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
1004 {
1005         u32 prio = 0;
1006
1007         ASSERT_RTNL();
1008         mutex_lock(&chain->filter_chain_lock);
1009
1010         if (!tp) {
1011                 tp = tcf_chain_dereference(chain->filter_chain, chain);
1012         } else if (tcf_proto_is_deleting(tp)) {
1013                 /* 'deleting' flag is set and chain->filter_chain_lock was
1014                  * unlocked, which means next pointer could be invalid. Restart
1015                  * search.
1016                  */
1017                 prio = tp->prio + 1;
1018                 tp = tcf_chain_dereference(chain->filter_chain, chain);
1019
1020                 for (; tp; tp = tcf_chain_dereference(tp->next, chain))
1021                         if (!tp->deleting && tp->prio >= prio)
1022                                 break;
1023         } else {
1024                 tp = tcf_chain_dereference(tp->next, chain);
1025         }
1026
1027         if (tp)
1028                 tcf_proto_get(tp);
1029
1030         mutex_unlock(&chain->filter_chain_lock);
1031
1032         return tp;
1033 }
1034
1035 /* Function to be used by all clients that want to iterate over all tp's on
1036  * chain. Users of this function must be tolerant to concurrent tp
1037  * insertion/deletion or ensure that no concurrent chain modification is
1038  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1039  * consistent dump because rtnl lock is released each time skb is filled with
1040  * data and sent to user-space.
1041  */
1042
1043 struct tcf_proto *
1044 tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp,
1045                    bool rtnl_held)
1046 {
1047         struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
1048
1049         if (tp)
1050                 tcf_proto_put(tp, rtnl_held, NULL);
1051
1052         return tp_next;
1053 }
1054 EXPORT_SYMBOL(tcf_get_next_proto);
1055
1056 static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
1057 {
1058         struct tcf_chain *chain;
1059
1060         /* Last reference to block. At this point chains cannot be added or
1061          * removed concurrently.
1062          */
1063         for (chain = tcf_get_next_chain(block, NULL);
1064              chain;
1065              chain = tcf_get_next_chain(block, chain)) {
1066                 tcf_chain_put_explicitly_created(chain);
1067                 tcf_chain_flush(chain, rtnl_held);
1068         }
1069 }
1070
1071 /* Lookup Qdisc and increments its reference counter.
1072  * Set parent, if necessary.
1073  */
1074
1075 static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
1076                             u32 *parent, int ifindex, bool rtnl_held,
1077                             struct netlink_ext_ack *extack)
1078 {
1079         const struct Qdisc_class_ops *cops;
1080         struct net_device *dev;
1081         int err = 0;
1082
1083         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1084                 return 0;
1085
1086         rcu_read_lock();
1087
1088         /* Find link */
1089         dev = dev_get_by_index_rcu(net, ifindex);
1090         if (!dev) {
1091                 rcu_read_unlock();
1092                 return -ENODEV;
1093         }
1094
1095         /* Find qdisc */
1096         if (!*parent) {
1097                 *q = dev->qdisc;
1098                 *parent = (*q)->handle;
1099         } else {
1100                 *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
1101                 if (!*q) {
1102                         NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1103                         err = -EINVAL;
1104                         goto errout_rcu;
1105                 }
1106         }
1107
1108         *q = qdisc_refcount_inc_nz(*q);
1109         if (!*q) {
1110                 NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1111                 err = -EINVAL;
1112                 goto errout_rcu;
1113         }
1114
1115         /* Is it classful? */
1116         cops = (*q)->ops->cl_ops;
1117         if (!cops) {
1118                 NL_SET_ERR_MSG(extack, "Qdisc not classful");
1119                 err = -EINVAL;
1120                 goto errout_qdisc;
1121         }
1122
1123         if (!cops->tcf_block) {
1124                 NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
1125                 err = -EOPNOTSUPP;
1126                 goto errout_qdisc;
1127         }
1128
1129 errout_rcu:
1130         /* At this point we know that qdisc is not noop_qdisc,
1131          * which means that qdisc holds a reference to net_device
1132          * and we hold a reference to qdisc, so it is safe to release
1133          * rcu read lock.
1134          */
1135         rcu_read_unlock();
1136         return err;
1137
1138 errout_qdisc:
1139         rcu_read_unlock();
1140
1141         if (rtnl_held)
1142                 qdisc_put(*q);
1143         else
1144                 qdisc_put_unlocked(*q);
1145         *q = NULL;
1146
1147         return err;
1148 }
1149
1150 static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
1151                                int ifindex, struct netlink_ext_ack *extack)
1152 {
1153         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1154                 return 0;
1155
1156         /* Do we search for filter, attached to class? */
1157         if (TC_H_MIN(parent)) {
1158                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1159
1160                 *cl = cops->find(q, parent);
1161                 if (*cl == 0) {
1162                         NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
1163                         return -ENOENT;
1164                 }
1165         }
1166
1167         return 0;
1168 }
1169
1170 static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
1171                                           unsigned long cl, int ifindex,
1172                                           u32 block_index,
1173                                           struct netlink_ext_ack *extack)
1174 {
1175         struct tcf_block *block;
1176
1177         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
1178                 block = tcf_block_refcnt_get(net, block_index);
1179                 if (!block) {
1180                         NL_SET_ERR_MSG(extack, "Block of given index was not found");
1181                         return ERR_PTR(-EINVAL);
1182                 }
1183         } else {
1184                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1185
1186                 block = cops->tcf_block(q, cl, extack);
1187                 if (!block)
1188                         return ERR_PTR(-EINVAL);
1189
1190                 if (tcf_block_shared(block)) {
1191                         NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
1192                         return ERR_PTR(-EOPNOTSUPP);
1193                 }
1194
1195                 /* Always take reference to block in order to support execution
1196                  * of rules update path of cls API without rtnl lock. Caller
1197                  * must release block when it is finished using it. 'if' block
1198                  * of this conditional obtain reference to block by calling
1199                  * tcf_block_refcnt_get().
1200                  */
1201                 refcount_inc(&block->refcnt);
1202         }
1203
1204         return block;
1205 }
1206
1207 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
1208                             struct tcf_block_ext_info *ei, bool rtnl_held)
1209 {
1210         if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
1211                 /* Flushing/putting all chains will cause the block to be
1212                  * deallocated when last chain is freed. However, if chain_list
1213                  * is empty, block has to be manually deallocated. After block
1214                  * reference counter reached 0, it is no longer possible to
1215                  * increment it or add new chains to block.
1216                  */
1217                 bool free_block = list_empty(&block->chain_list);
1218
1219                 mutex_unlock(&block->lock);
1220                 if (tcf_block_shared(block))
1221                         tcf_block_remove(block, block->net);
1222
1223                 if (q)
1224                         tcf_block_offload_unbind(block, q, ei);
1225
1226                 if (free_block)
1227                         tcf_block_destroy(block);
1228                 else
1229                         tcf_block_flush_all_chains(block, rtnl_held);
1230         } else if (q) {
1231                 tcf_block_offload_unbind(block, q, ei);
1232         }
1233 }
1234
1235 static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
1236 {
1237         __tcf_block_put(block, NULL, NULL, rtnl_held);
1238 }
1239
1240 /* Find tcf block.
1241  * Set q, parent, cl when appropriate.
1242  */
1243
1244 static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
1245                                         u32 *parent, unsigned long *cl,
1246                                         int ifindex, u32 block_index,
1247                                         struct netlink_ext_ack *extack)
1248 {
1249         struct tcf_block *block;
1250         int err = 0;
1251
1252         ASSERT_RTNL();
1253
1254         err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
1255         if (err)
1256                 goto errout;
1257
1258         err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
1259         if (err)
1260                 goto errout_qdisc;
1261
1262         block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
1263         if (IS_ERR(block)) {
1264                 err = PTR_ERR(block);
1265                 goto errout_qdisc;
1266         }
1267
1268         return block;
1269
1270 errout_qdisc:
1271         if (*q)
1272                 qdisc_put(*q);
1273 errout:
1274         *q = NULL;
1275         return ERR_PTR(err);
1276 }
1277
1278 static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
1279                               bool rtnl_held)
1280 {
1281         if (!IS_ERR_OR_NULL(block))
1282                 tcf_block_refcnt_put(block, rtnl_held);
1283
1284         if (q) {
1285                 if (rtnl_held)
1286                         qdisc_put(q);
1287                 else
1288                         qdisc_put_unlocked(q);
1289         }
1290 }
1291
1292 struct tcf_block_owner_item {
1293         struct list_head list;
1294         struct Qdisc *q;
1295         enum flow_block_binder_type binder_type;
1296 };
1297
1298 static void
1299 tcf_block_owner_netif_keep_dst(struct tcf_block *block,
1300                                struct Qdisc *q,
1301                                enum flow_block_binder_type binder_type)
1302 {
1303         if (block->keep_dst &&
1304             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS &&
1305             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
1306                 netif_keep_dst(qdisc_dev(q));
1307 }
1308
1309 void tcf_block_netif_keep_dst(struct tcf_block *block)
1310 {
1311         struct tcf_block_owner_item *item;
1312
1313         block->keep_dst = true;
1314         list_for_each_entry(item, &block->owner_list, list)
1315                 tcf_block_owner_netif_keep_dst(block, item->q,
1316                                                item->binder_type);
1317 }
1318 EXPORT_SYMBOL(tcf_block_netif_keep_dst);
1319
1320 static int tcf_block_owner_add(struct tcf_block *block,
1321                                struct Qdisc *q,
1322                                enum flow_block_binder_type binder_type)
1323 {
1324         struct tcf_block_owner_item *item;
1325
1326         item = kmalloc(sizeof(*item), GFP_KERNEL);
1327         if (!item)
1328                 return -ENOMEM;
1329         item->q = q;
1330         item->binder_type = binder_type;
1331         list_add(&item->list, &block->owner_list);
1332         return 0;
1333 }
1334
1335 static void tcf_block_owner_del(struct tcf_block *block,
1336                                 struct Qdisc *q,
1337                                 enum flow_block_binder_type binder_type)
1338 {
1339         struct tcf_block_owner_item *item;
1340
1341         list_for_each_entry(item, &block->owner_list, list) {
1342                 if (item->q == q && item->binder_type == binder_type) {
1343                         list_del(&item->list);
1344                         kfree(item);
1345                         return;
1346                 }
1347         }
1348         WARN_ON(1);
1349 }
1350
1351 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
1352                       struct tcf_block_ext_info *ei,
1353                       struct netlink_ext_ack *extack)
1354 {
1355         struct net *net = qdisc_net(q);
1356         struct tcf_block *block = NULL;
1357         int err;
1358
1359         if (ei->block_index)
1360                 /* block_index not 0 means the shared block is requested */
1361                 block = tcf_block_refcnt_get(net, ei->block_index);
1362
1363         if (!block) {
1364                 block = tcf_block_create(net, q, ei->block_index, extack);
1365                 if (IS_ERR(block))
1366                         return PTR_ERR(block);
1367                 if (tcf_block_shared(block)) {
1368                         err = tcf_block_insert(block, net, extack);
1369                         if (err)
1370                                 goto err_block_insert;
1371                 }
1372         }
1373
1374         err = tcf_block_owner_add(block, q, ei->binder_type);
1375         if (err)
1376                 goto err_block_owner_add;
1377
1378         tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
1379
1380         err = tcf_chain0_head_change_cb_add(block, ei, extack);
1381         if (err)
1382                 goto err_chain0_head_change_cb_add;
1383
1384         err = tcf_block_offload_bind(block, q, ei, extack);
1385         if (err)
1386                 goto err_block_offload_bind;
1387
1388         *p_block = block;
1389         return 0;
1390
1391 err_block_offload_bind:
1392         tcf_chain0_head_change_cb_del(block, ei);
1393 err_chain0_head_change_cb_add:
1394         tcf_block_owner_del(block, q, ei->binder_type);
1395 err_block_owner_add:
1396 err_block_insert:
1397         tcf_block_refcnt_put(block, true);
1398         return err;
1399 }
1400 EXPORT_SYMBOL(tcf_block_get_ext);
1401
1402 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
1403 {
1404         struct tcf_proto __rcu **p_filter_chain = priv;
1405
1406         rcu_assign_pointer(*p_filter_chain, tp_head);
1407 }
1408
1409 int tcf_block_get(struct tcf_block **p_block,
1410                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
1411                   struct netlink_ext_ack *extack)
1412 {
1413         struct tcf_block_ext_info ei = {
1414                 .chain_head_change = tcf_chain_head_change_dflt,
1415                 .chain_head_change_priv = p_filter_chain,
1416         };
1417
1418         WARN_ON(!p_filter_chain);
1419         return tcf_block_get_ext(p_block, q, &ei, extack);
1420 }
1421 EXPORT_SYMBOL(tcf_block_get);
1422
1423 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
1424  * actions should be all removed after flushing.
1425  */
1426 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
1427                        struct tcf_block_ext_info *ei)
1428 {
1429         if (!block)
1430                 return;
1431         tcf_chain0_head_change_cb_del(block, ei);
1432         tcf_block_owner_del(block, q, ei->binder_type);
1433
1434         __tcf_block_put(block, q, ei, true);
1435 }
1436 EXPORT_SYMBOL(tcf_block_put_ext);
1437
1438 void tcf_block_put(struct tcf_block *block)
1439 {
1440         struct tcf_block_ext_info ei = {0, };
1441
1442         if (!block)
1443                 return;
1444         tcf_block_put_ext(block, block->q, &ei);
1445 }
1446
1447 EXPORT_SYMBOL(tcf_block_put);
1448
1449 static int
1450 tcf_block_playback_offloads(struct tcf_block *block, flow_setup_cb_t *cb,
1451                             void *cb_priv, bool add, bool offload_in_use,
1452                             struct netlink_ext_ack *extack)
1453 {
1454         struct tcf_chain *chain, *chain_prev;
1455         struct tcf_proto *tp, *tp_prev;
1456         int err;
1457
1458         lockdep_assert_held(&block->cb_lock);
1459
1460         for (chain = __tcf_get_next_chain(block, NULL);
1461              chain;
1462              chain_prev = chain,
1463                      chain = __tcf_get_next_chain(block, chain),
1464                      tcf_chain_put(chain_prev)) {
1465                 for (tp = __tcf_get_next_proto(chain, NULL); tp;
1466                      tp_prev = tp,
1467                              tp = __tcf_get_next_proto(chain, tp),
1468                              tcf_proto_put(tp_prev, true, NULL)) {
1469                         if (tp->ops->reoffload) {
1470                                 err = tp->ops->reoffload(tp, add, cb, cb_priv,
1471                                                          extack);
1472                                 if (err && add)
1473                                         goto err_playback_remove;
1474                         } else if (add && offload_in_use) {
1475                                 err = -EOPNOTSUPP;
1476                                 NL_SET_ERR_MSG(extack, "Filter HW offload failed - classifier without re-offloading support");
1477                                 goto err_playback_remove;
1478                         }
1479                 }
1480         }
1481
1482         return 0;
1483
1484 err_playback_remove:
1485         tcf_proto_put(tp, true, NULL);
1486         tcf_chain_put(chain);
1487         tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
1488                                     extack);
1489         return err;
1490 }
1491
1492 static int tcf_block_bind(struct tcf_block *block,
1493                           struct flow_block_offload *bo)
1494 {
1495         struct flow_block_cb *block_cb, *next;
1496         int err, i = 0;
1497
1498         lockdep_assert_held(&block->cb_lock);
1499
1500         list_for_each_entry(block_cb, &bo->cb_list, list) {
1501                 err = tcf_block_playback_offloads(block, block_cb->cb,
1502                                                   block_cb->cb_priv, true,
1503                                                   tcf_block_offload_in_use(block),
1504                                                   bo->extack);
1505                 if (err)
1506                         goto err_unroll;
1507                 if (!bo->unlocked_driver_cb)
1508                         block->lockeddevcnt++;
1509
1510                 i++;
1511         }
1512         list_splice(&bo->cb_list, &block->flow_block.cb_list);
1513
1514         return 0;
1515
1516 err_unroll:
1517         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1518                 if (i-- > 0) {
1519                         list_del(&block_cb->list);
1520                         tcf_block_playback_offloads(block, block_cb->cb,
1521                                                     block_cb->cb_priv, false,
1522                                                     tcf_block_offload_in_use(block),
1523                                                     NULL);
1524                         if (!bo->unlocked_driver_cb)
1525                                 block->lockeddevcnt--;
1526                 }
1527                 flow_block_cb_free(block_cb);
1528         }
1529
1530         return err;
1531 }
1532
1533 static void tcf_block_unbind(struct tcf_block *block,
1534                              struct flow_block_offload *bo)
1535 {
1536         struct flow_block_cb *block_cb, *next;
1537
1538         lockdep_assert_held(&block->cb_lock);
1539
1540         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1541                 tcf_block_playback_offloads(block, block_cb->cb,
1542                                             block_cb->cb_priv, false,
1543                                             tcf_block_offload_in_use(block),
1544                                             NULL);
1545                 list_del(&block_cb->list);
1546                 flow_block_cb_free(block_cb);
1547                 if (!bo->unlocked_driver_cb)
1548                         block->lockeddevcnt--;
1549         }
1550 }
1551
1552 static int tcf_block_setup(struct tcf_block *block,
1553                            struct flow_block_offload *bo)
1554 {
1555         int err;
1556
1557         switch (bo->command) {
1558         case FLOW_BLOCK_BIND:
1559                 err = tcf_block_bind(block, bo);
1560                 break;
1561         case FLOW_BLOCK_UNBIND:
1562                 err = 0;
1563                 tcf_block_unbind(block, bo);
1564                 break;
1565         default:
1566                 WARN_ON_ONCE(1);
1567                 err = -EOPNOTSUPP;
1568         }
1569
1570         return err;
1571 }
1572
1573 /* Main classifier routine: scans classifier chain attached
1574  * to this qdisc, (optionally) tests for protocol and asks
1575  * specific classifiers.
1576  */
1577 static inline int __tcf_classify(struct sk_buff *skb,
1578                                  const struct tcf_proto *tp,
1579                                  const struct tcf_proto *orig_tp,
1580                                  struct tcf_result *res,
1581                                  bool compat_mode,
1582                                  u32 *last_executed_chain)
1583 {
1584 #ifdef CONFIG_NET_CLS_ACT
1585         const int max_reclassify_loop = 4;
1586         const struct tcf_proto *first_tp;
1587         int limit = 0;
1588
1589 reclassify:
1590 #endif
1591         for (; tp; tp = rcu_dereference_bh(tp->next)) {
1592                 __be16 protocol = tc_skb_protocol(skb);
1593                 int err;
1594
1595                 if (tp->protocol != protocol &&
1596                     tp->protocol != htons(ETH_P_ALL))
1597                         continue;
1598
1599                 err = tp->classify(skb, tp, res);
1600 #ifdef CONFIG_NET_CLS_ACT
1601                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
1602                         first_tp = orig_tp;
1603                         *last_executed_chain = first_tp->chain->index;
1604                         goto reset;
1605                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
1606                         first_tp = res->goto_tp;
1607                         *last_executed_chain = err & TC_ACT_EXT_VAL_MASK;
1608                         goto reset;
1609                 }
1610 #endif
1611                 if (err >= 0)
1612                         return err;
1613         }
1614
1615         return TC_ACT_UNSPEC; /* signal: continue lookup */
1616 #ifdef CONFIG_NET_CLS_ACT
1617 reset:
1618         if (unlikely(limit++ >= max_reclassify_loop)) {
1619                 net_notice_ratelimited("%u: reclassify loop, rule prio %u, protocol %02x\n",
1620                                        tp->chain->block->index,
1621                                        tp->prio & 0xffff,
1622                                        ntohs(tp->protocol));
1623                 return TC_ACT_SHOT;
1624         }
1625
1626         tp = first_tp;
1627         goto reclassify;
1628 #endif
1629 }
1630
1631 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1632                  struct tcf_result *res, bool compat_mode)
1633 {
1634         u32 last_executed_chain = 0;
1635
1636         return __tcf_classify(skb, tp, tp, res, compat_mode,
1637                               &last_executed_chain);
1638 }
1639 EXPORT_SYMBOL(tcf_classify);
1640
1641 int tcf_classify_ingress(struct sk_buff *skb,
1642                          const struct tcf_block *ingress_block,
1643                          const struct tcf_proto *tp,
1644                          struct tcf_result *res, bool compat_mode)
1645 {
1646 #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1647         u32 last_executed_chain = 0;
1648
1649         return __tcf_classify(skb, tp, tp, res, compat_mode,
1650                               &last_executed_chain);
1651 #else
1652         u32 last_executed_chain = tp ? tp->chain->index : 0;
1653         const struct tcf_proto *orig_tp = tp;
1654         struct tc_skb_ext *ext;
1655         int ret;
1656
1657         ext = skb_ext_find(skb, TC_SKB_EXT);
1658
1659         if (ext && ext->chain) {
1660                 struct tcf_chain *fchain;
1661
1662                 fchain = tcf_chain_lookup_rcu(ingress_block, ext->chain);
1663                 if (!fchain)
1664                         return TC_ACT_SHOT;
1665
1666                 /* Consume, so cloned/redirect skbs won't inherit ext */
1667                 skb_ext_del(skb, TC_SKB_EXT);
1668
1669                 tp = rcu_dereference_bh(fchain->filter_chain);
1670         }
1671
1672         ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode,
1673                              &last_executed_chain);
1674
1675         /* If we missed on some chain */
1676         if (ret == TC_ACT_UNSPEC && last_executed_chain) {
1677                 ext = skb_ext_add(skb, TC_SKB_EXT);
1678                 if (WARN_ON_ONCE(!ext))
1679                         return TC_ACT_SHOT;
1680                 ext->chain = last_executed_chain;
1681         }
1682
1683         return ret;
1684 #endif
1685 }
1686 EXPORT_SYMBOL(tcf_classify_ingress);
1687
1688 struct tcf_chain_info {
1689         struct tcf_proto __rcu **pprev;
1690         struct tcf_proto __rcu *next;
1691 };
1692
1693 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
1694                                            struct tcf_chain_info *chain_info)
1695 {
1696         return tcf_chain_dereference(*chain_info->pprev, chain);
1697 }
1698
1699 static int tcf_chain_tp_insert(struct tcf_chain *chain,
1700                                struct tcf_chain_info *chain_info,
1701                                struct tcf_proto *tp)
1702 {
1703         if (chain->flushing)
1704                 return -EAGAIN;
1705
1706         if (*chain_info->pprev == chain->filter_chain)
1707                 tcf_chain0_head_change(chain, tp);
1708         tcf_proto_get(tp);
1709         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
1710         rcu_assign_pointer(*chain_info->pprev, tp);
1711
1712         return 0;
1713 }
1714
1715 static void tcf_chain_tp_remove(struct tcf_chain *chain,
1716                                 struct tcf_chain_info *chain_info,
1717                                 struct tcf_proto *tp)
1718 {
1719         struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
1720
1721         tcf_proto_mark_delete(tp);
1722         if (tp == chain->filter_chain)
1723                 tcf_chain0_head_change(chain, next);
1724         RCU_INIT_POINTER(*chain_info->pprev, next);
1725 }
1726
1727 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1728                                            struct tcf_chain_info *chain_info,
1729                                            u32 protocol, u32 prio,
1730                                            bool prio_allocate);
1731
1732 /* Try to insert new proto.
1733  * If proto with specified priority already exists, free new proto
1734  * and return existing one.
1735  */
1736
1737 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
1738                                                     struct tcf_proto *tp_new,
1739                                                     u32 protocol, u32 prio,
1740                                                     bool rtnl_held)
1741 {
1742         struct tcf_chain_info chain_info;
1743         struct tcf_proto *tp;
1744         int err = 0;
1745
1746         mutex_lock(&chain->filter_chain_lock);
1747
1748         if (tcf_proto_exists_destroying(chain, tp_new)) {
1749                 mutex_unlock(&chain->filter_chain_lock);
1750                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1751                 return ERR_PTR(-EAGAIN);
1752         }
1753
1754         tp = tcf_chain_tp_find(chain, &chain_info,
1755                                protocol, prio, false);
1756         if (!tp)
1757                 err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
1758         mutex_unlock(&chain->filter_chain_lock);
1759
1760         if (tp) {
1761                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1762                 tp_new = tp;
1763         } else if (err) {
1764                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1765                 tp_new = ERR_PTR(err);
1766         }
1767
1768         return tp_new;
1769 }
1770
1771 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
1772                                       struct tcf_proto *tp, bool rtnl_held,
1773                                       struct netlink_ext_ack *extack)
1774 {
1775         struct tcf_chain_info chain_info;
1776         struct tcf_proto *tp_iter;
1777         struct tcf_proto **pprev;
1778         struct tcf_proto *next;
1779
1780         mutex_lock(&chain->filter_chain_lock);
1781
1782         /* Atomically find and remove tp from chain. */
1783         for (pprev = &chain->filter_chain;
1784              (tp_iter = tcf_chain_dereference(*pprev, chain));
1785              pprev = &tp_iter->next) {
1786                 if (tp_iter == tp) {
1787                         chain_info.pprev = pprev;
1788                         chain_info.next = tp_iter->next;
1789                         WARN_ON(tp_iter->deleting);
1790                         break;
1791                 }
1792         }
1793         /* Verify that tp still exists and no new filters were inserted
1794          * concurrently.
1795          * Mark tp for deletion if it is empty.
1796          */
1797         if (!tp_iter || !tcf_proto_check_delete(tp)) {
1798                 mutex_unlock(&chain->filter_chain_lock);
1799                 return;
1800         }
1801
1802         tcf_proto_signal_destroying(chain, tp);
1803         next = tcf_chain_dereference(chain_info.next, chain);
1804         if (tp == chain->filter_chain)
1805                 tcf_chain0_head_change(chain, next);
1806         RCU_INIT_POINTER(*chain_info.pprev, next);
1807         mutex_unlock(&chain->filter_chain_lock);
1808
1809         tcf_proto_put(tp, rtnl_held, extack);
1810 }
1811
1812 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1813                                            struct tcf_chain_info *chain_info,
1814                                            u32 protocol, u32 prio,
1815                                            bool prio_allocate)
1816 {
1817         struct tcf_proto **pprev;
1818         struct tcf_proto *tp;
1819
1820         /* Check the chain for existence of proto-tcf with this priority */
1821         for (pprev = &chain->filter_chain;
1822              (tp = tcf_chain_dereference(*pprev, chain));
1823              pprev = &tp->next) {
1824                 if (tp->prio >= prio) {
1825                         if (tp->prio == prio) {
1826                                 if (prio_allocate ||
1827                                     (tp->protocol != protocol && protocol))
1828                                         return ERR_PTR(-EINVAL);
1829                         } else {
1830                                 tp = NULL;
1831                         }
1832                         break;
1833                 }
1834         }
1835         chain_info->pprev = pprev;
1836         if (tp) {
1837                 chain_info->next = tp->next;
1838                 tcf_proto_get(tp);
1839         } else {
1840                 chain_info->next = NULL;
1841         }
1842         return tp;
1843 }
1844
1845 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
1846                          struct tcf_proto *tp, struct tcf_block *block,
1847                          struct Qdisc *q, u32 parent, void *fh,
1848                          u32 portid, u32 seq, u16 flags, int event,
1849                          bool rtnl_held)
1850 {
1851         struct tcmsg *tcm;
1852         struct nlmsghdr  *nlh;
1853         unsigned char *b = skb_tail_pointer(skb);
1854
1855         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1856         if (!nlh)
1857                 goto out_nlmsg_trim;
1858         tcm = nlmsg_data(nlh);
1859         tcm->tcm_family = AF_UNSPEC;
1860         tcm->tcm__pad1 = 0;
1861         tcm->tcm__pad2 = 0;
1862         if (q) {
1863                 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1864                 tcm->tcm_parent = parent;
1865         } else {
1866                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
1867                 tcm->tcm_block_index = block->index;
1868         }
1869         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
1870         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
1871                 goto nla_put_failure;
1872         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
1873                 goto nla_put_failure;
1874         if (!fh) {
1875                 tcm->tcm_handle = 0;
1876         } else {
1877                 if (tp->ops->dump &&
1878                     tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
1879                         goto nla_put_failure;
1880         }
1881         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1882         return skb->len;
1883
1884 out_nlmsg_trim:
1885 nla_put_failure:
1886         nlmsg_trim(skb, b);
1887         return -1;
1888 }
1889
1890 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
1891                           struct nlmsghdr *n, struct tcf_proto *tp,
1892                           struct tcf_block *block, struct Qdisc *q,
1893                           u32 parent, void *fh, int event, bool unicast,
1894                           bool rtnl_held)
1895 {
1896         struct sk_buff *skb;
1897         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1898         int err = 0;
1899
1900         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1901         if (!skb)
1902                 return -ENOBUFS;
1903
1904         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1905                           n->nlmsg_seq, n->nlmsg_flags, event,
1906                           rtnl_held) <= 0) {
1907                 kfree_skb(skb);
1908                 return -EINVAL;
1909         }
1910
1911         if (unicast)
1912                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
1913         else
1914                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1915                                      n->nlmsg_flags & NLM_F_ECHO);
1916
1917         if (err > 0)
1918                 err = 0;
1919         return err;
1920 }
1921
1922 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
1923                               struct nlmsghdr *n, struct tcf_proto *tp,
1924                               struct tcf_block *block, struct Qdisc *q,
1925                               u32 parent, void *fh, bool unicast, bool *last,
1926                               bool rtnl_held, struct netlink_ext_ack *extack)
1927 {
1928         struct sk_buff *skb;
1929         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1930         int err;
1931
1932         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1933         if (!skb)
1934                 return -ENOBUFS;
1935
1936         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1937                           n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
1938                           rtnl_held) <= 0) {
1939                 NL_SET_ERR_MSG(extack, "Failed to build del event notification");
1940                 kfree_skb(skb);
1941                 return -EINVAL;
1942         }
1943
1944         err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
1945         if (err) {
1946                 kfree_skb(skb);
1947                 return err;
1948         }
1949
1950         if (unicast)
1951                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
1952         else
1953                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1954                                      n->nlmsg_flags & NLM_F_ECHO);
1955         if (err < 0)
1956                 NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
1957
1958         if (err > 0)
1959                 err = 0;
1960         return err;
1961 }
1962
1963 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
1964                                  struct tcf_block *block, struct Qdisc *q,
1965                                  u32 parent, struct nlmsghdr *n,
1966                                  struct tcf_chain *chain, int event,
1967                                  bool rtnl_held)
1968 {
1969         struct tcf_proto *tp;
1970
1971         for (tp = tcf_get_next_proto(chain, NULL, rtnl_held);
1972              tp; tp = tcf_get_next_proto(chain, tp, rtnl_held))
1973                 tfilter_notify(net, oskb, n, tp, block,
1974                                q, parent, NULL, event, false, rtnl_held);
1975 }
1976
1977 static void tfilter_put(struct tcf_proto *tp, void *fh)
1978 {
1979         if (tp->ops->put && fh)
1980                 tp->ops->put(tp, fh);
1981 }
1982
1983 static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
1984                           struct netlink_ext_ack *extack)
1985 {
1986         struct net *net = sock_net(skb->sk);
1987         struct nlattr *tca[TCA_MAX + 1];
1988         char name[IFNAMSIZ];
1989         struct tcmsg *t;
1990         u32 protocol;
1991         u32 prio;
1992         bool prio_allocate;
1993         u32 parent;
1994         u32 chain_index;
1995         struct Qdisc *q = NULL;
1996         struct tcf_chain_info chain_info;
1997         struct tcf_chain *chain = NULL;
1998         struct tcf_block *block;
1999         struct tcf_proto *tp;
2000         unsigned long cl;
2001         void *fh;
2002         int err;
2003         int tp_created;
2004         bool rtnl_held = false;
2005
2006         if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2007                 return -EPERM;
2008
2009 replay:
2010         tp_created = 0;
2011
2012         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2013                                      rtm_tca_policy, extack);
2014         if (err < 0)
2015                 return err;
2016
2017         t = nlmsg_data(n);
2018         protocol = TC_H_MIN(t->tcm_info);
2019         prio = TC_H_MAJ(t->tcm_info);
2020         prio_allocate = false;
2021         parent = t->tcm_parent;
2022         tp = NULL;
2023         cl = 0;
2024         block = NULL;
2025
2026         if (prio == 0) {
2027                 /* If no priority is provided by the user,
2028                  * we allocate one.
2029                  */
2030                 if (n->nlmsg_flags & NLM_F_CREATE) {
2031                         prio = TC_H_MAKE(0x80000000U, 0U);
2032                         prio_allocate = true;
2033                 } else {
2034                         NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2035                         return -ENOENT;
2036                 }
2037         }
2038
2039         /* Find head of filter chain. */
2040
2041         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2042         if (err)
2043                 return err;
2044
2045         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2046                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2047                 err = -EINVAL;
2048                 goto errout;
2049         }
2050
2051         /* Take rtnl mutex if rtnl_held was set to true on previous iteration,
2052          * block is shared (no qdisc found), qdisc is not unlocked, classifier
2053          * type is not specified, classifier is not unlocked.
2054          */
2055         if (rtnl_held ||
2056             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2057             !tcf_proto_is_unlocked(name)) {
2058                 rtnl_held = true;
2059                 rtnl_lock();
2060         }
2061
2062         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2063         if (err)
2064                 goto errout;
2065
2066         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2067                                  extack);
2068         if (IS_ERR(block)) {
2069                 err = PTR_ERR(block);
2070                 goto errout;
2071         }
2072
2073         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2074         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2075                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2076                 err = -EINVAL;
2077                 goto errout;
2078         }
2079         chain = tcf_chain_get(block, chain_index, true);
2080         if (!chain) {
2081                 NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
2082                 err = -ENOMEM;
2083                 goto errout;
2084         }
2085
2086         mutex_lock(&chain->filter_chain_lock);
2087         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2088                                prio, prio_allocate);
2089         if (IS_ERR(tp)) {
2090                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2091                 err = PTR_ERR(tp);
2092                 goto errout_locked;
2093         }
2094
2095         if (tp == NULL) {
2096                 struct tcf_proto *tp_new = NULL;
2097
2098                 if (chain->flushing) {
2099                         err = -EAGAIN;
2100                         goto errout_locked;
2101                 }
2102
2103                 /* Proto-tcf does not exist, create new one */
2104
2105                 if (tca[TCA_KIND] == NULL || !protocol) {
2106                         NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
2107                         err = -EINVAL;
2108                         goto errout_locked;
2109                 }
2110
2111                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2112                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2113                         err = -ENOENT;
2114                         goto errout_locked;
2115                 }
2116
2117                 if (prio_allocate)
2118                         prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
2119                                                                &chain_info));
2120
2121                 mutex_unlock(&chain->filter_chain_lock);
2122                 tp_new = tcf_proto_create(name, protocol, prio, chain,
2123                                           rtnl_held, extack);
2124                 if (IS_ERR(tp_new)) {
2125                         err = PTR_ERR(tp_new);
2126                         goto errout_tp;
2127                 }
2128
2129                 tp_created = 1;
2130                 tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
2131                                                 rtnl_held);
2132                 if (IS_ERR(tp)) {
2133                         err = PTR_ERR(tp);
2134                         goto errout_tp;
2135                 }
2136         } else {
2137                 mutex_unlock(&chain->filter_chain_lock);
2138         }
2139
2140         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2141                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2142                 err = -EINVAL;
2143                 goto errout;
2144         }
2145
2146         fh = tp->ops->get(tp, t->tcm_handle);
2147
2148         if (!fh) {
2149                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2150                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2151                         err = -ENOENT;
2152                         goto errout;
2153                 }
2154         } else if (n->nlmsg_flags & NLM_F_EXCL) {
2155                 tfilter_put(tp, fh);
2156                 NL_SET_ERR_MSG(extack, "Filter already exists");
2157                 err = -EEXIST;
2158                 goto errout;
2159         }
2160
2161         if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
2162                 NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
2163                 err = -EINVAL;
2164                 goto errout;
2165         }
2166
2167         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
2168                               n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
2169                               rtnl_held, extack);
2170         if (err == 0) {
2171                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2172                                RTM_NEWTFILTER, false, rtnl_held);
2173                 tfilter_put(tp, fh);
2174                 /* q pointer is NULL for shared blocks */
2175                 if (q)
2176                         q->flags &= ~TCQ_F_CAN_BYPASS;
2177         }
2178
2179 errout:
2180         if (err && tp_created)
2181                 tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
2182 errout_tp:
2183         if (chain) {
2184                 if (tp && !IS_ERR(tp))
2185                         tcf_proto_put(tp, rtnl_held, NULL);
2186                 if (!tp_created)
2187                         tcf_chain_put(chain);
2188         }
2189         tcf_block_release(q, block, rtnl_held);
2190
2191         if (rtnl_held)
2192                 rtnl_unlock();
2193
2194         if (err == -EAGAIN) {
2195                 /* Take rtnl lock in case EAGAIN is caused by concurrent flush
2196                  * of target chain.
2197                  */
2198                 rtnl_held = true;
2199                 /* Replay the request. */
2200                 goto replay;
2201         }
2202         return err;
2203
2204 errout_locked:
2205         mutex_unlock(&chain->filter_chain_lock);
2206         goto errout;
2207 }
2208
2209 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2210                           struct netlink_ext_ack *extack)
2211 {
2212         struct net *net = sock_net(skb->sk);
2213         struct nlattr *tca[TCA_MAX + 1];
2214         char name[IFNAMSIZ];
2215         struct tcmsg *t;
2216         u32 protocol;
2217         u32 prio;
2218         u32 parent;
2219         u32 chain_index;
2220         struct Qdisc *q = NULL;
2221         struct tcf_chain_info chain_info;
2222         struct tcf_chain *chain = NULL;
2223         struct tcf_block *block = NULL;
2224         struct tcf_proto *tp = NULL;
2225         unsigned long cl = 0;
2226         void *fh = NULL;
2227         int err;
2228         bool rtnl_held = false;
2229
2230         if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2231                 return -EPERM;
2232
2233         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2234                                      rtm_tca_policy, extack);
2235         if (err < 0)
2236                 return err;
2237
2238         t = nlmsg_data(n);
2239         protocol = TC_H_MIN(t->tcm_info);
2240         prio = TC_H_MAJ(t->tcm_info);
2241         parent = t->tcm_parent;
2242
2243         if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
2244                 NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
2245                 return -ENOENT;
2246         }
2247
2248         /* Find head of filter chain. */
2249
2250         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2251         if (err)
2252                 return err;
2253
2254         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2255                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2256                 err = -EINVAL;
2257                 goto errout;
2258         }
2259         /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
2260          * found), qdisc is not unlocked, classifier type is not specified,
2261          * classifier is not unlocked.
2262          */
2263         if (!prio ||
2264             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2265             !tcf_proto_is_unlocked(name)) {
2266                 rtnl_held = true;
2267                 rtnl_lock();
2268         }
2269
2270         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2271         if (err)
2272                 goto errout;
2273
2274         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2275                                  extack);
2276         if (IS_ERR(block)) {
2277                 err = PTR_ERR(block);
2278                 goto errout;
2279         }
2280
2281         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2282         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2283                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2284                 err = -EINVAL;
2285                 goto errout;
2286         }
2287         chain = tcf_chain_get(block, chain_index, false);
2288         if (!chain) {
2289                 /* User requested flush on non-existent chain. Nothing to do,
2290                  * so just return success.
2291                  */
2292                 if (prio == 0) {
2293                         err = 0;
2294                         goto errout;
2295                 }
2296                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2297                 err = -ENOENT;
2298                 goto errout;
2299         }
2300
2301         if (prio == 0) {
2302                 tfilter_notify_chain(net, skb, block, q, parent, n,
2303                                      chain, RTM_DELTFILTER, rtnl_held);
2304                 tcf_chain_flush(chain, rtnl_held);
2305                 err = 0;
2306                 goto errout;
2307         }
2308
2309         mutex_lock(&chain->filter_chain_lock);
2310         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2311                                prio, false);
2312         if (!tp || IS_ERR(tp)) {
2313                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2314                 err = tp ? PTR_ERR(tp) : -ENOENT;
2315                 goto errout_locked;
2316         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2317                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2318                 err = -EINVAL;
2319                 goto errout_locked;
2320         } else if (t->tcm_handle == 0) {
2321                 tcf_proto_signal_destroying(chain, tp);
2322                 tcf_chain_tp_remove(chain, &chain_info, tp);
2323                 mutex_unlock(&chain->filter_chain_lock);
2324
2325                 tcf_proto_put(tp, rtnl_held, NULL);
2326                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2327                                RTM_DELTFILTER, false, rtnl_held);
2328                 err = 0;
2329                 goto errout;
2330         }
2331         mutex_unlock(&chain->filter_chain_lock);
2332
2333         fh = tp->ops->get(tp, t->tcm_handle);
2334
2335         if (!fh) {
2336                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2337                 err = -ENOENT;
2338         } else {
2339                 bool last;
2340
2341                 err = tfilter_del_notify(net, skb, n, tp, block,
2342                                          q, parent, fh, false, &last,
2343                                          rtnl_held, extack);
2344
2345                 if (err)
2346                         goto errout;
2347                 if (last)
2348                         tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
2349         }
2350
2351 errout:
2352         if (chain) {
2353                 if (tp && !IS_ERR(tp))
2354                         tcf_proto_put(tp, rtnl_held, NULL);
2355                 tcf_chain_put(chain);
2356         }
2357         tcf_block_release(q, block, rtnl_held);
2358
2359         if (rtnl_held)
2360                 rtnl_unlock();
2361
2362         return err;
2363
2364 errout_locked:
2365         mutex_unlock(&chain->filter_chain_lock);
2366         goto errout;
2367 }
2368
2369 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2370                           struct netlink_ext_ack *extack)
2371 {
2372         struct net *net = sock_net(skb->sk);
2373         struct nlattr *tca[TCA_MAX + 1];
2374         char name[IFNAMSIZ];
2375         struct tcmsg *t;
2376         u32 protocol;
2377         u32 prio;
2378         u32 parent;
2379         u32 chain_index;
2380         struct Qdisc *q = NULL;
2381         struct tcf_chain_info chain_info;
2382         struct tcf_chain *chain = NULL;
2383         struct tcf_block *block = NULL;
2384         struct tcf_proto *tp = NULL;
2385         unsigned long cl = 0;
2386         void *fh = NULL;
2387         int err;
2388         bool rtnl_held = false;
2389
2390         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2391                                      rtm_tca_policy, extack);
2392         if (err < 0)
2393                 return err;
2394
2395         t = nlmsg_data(n);
2396         protocol = TC_H_MIN(t->tcm_info);
2397         prio = TC_H_MAJ(t->tcm_info);
2398         parent = t->tcm_parent;
2399
2400         if (prio == 0) {
2401                 NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2402                 return -ENOENT;
2403         }
2404
2405         /* Find head of filter chain. */
2406
2407         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2408         if (err)
2409                 return err;
2410
2411         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2412                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2413                 err = -EINVAL;
2414                 goto errout;
2415         }
2416         /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
2417          * unlocked, classifier type is not specified, classifier is not
2418          * unlocked.
2419          */
2420         if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2421             !tcf_proto_is_unlocked(name)) {
2422                 rtnl_held = true;
2423                 rtnl_lock();
2424         }
2425
2426         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2427         if (err)
2428                 goto errout;
2429
2430         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2431                                  extack);
2432         if (IS_ERR(block)) {
2433                 err = PTR_ERR(block);
2434                 goto errout;
2435         }
2436
2437         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2438         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2439                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2440                 err = -EINVAL;
2441                 goto errout;
2442         }
2443         chain = tcf_chain_get(block, chain_index, false);
2444         if (!chain) {
2445                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2446                 err = -EINVAL;
2447                 goto errout;
2448         }
2449
2450         mutex_lock(&chain->filter_chain_lock);
2451         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2452                                prio, false);
2453         mutex_unlock(&chain->filter_chain_lock);
2454         if (!tp || IS_ERR(tp)) {
2455                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2456                 err = tp ? PTR_ERR(tp) : -ENOENT;
2457                 goto errout;
2458         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2459                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2460                 err = -EINVAL;
2461                 goto errout;
2462         }
2463
2464         fh = tp->ops->get(tp, t->tcm_handle);
2465
2466         if (!fh) {
2467                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2468                 err = -ENOENT;
2469         } else {
2470                 err = tfilter_notify(net, skb, n, tp, block, q, parent,
2471                                      fh, RTM_NEWTFILTER, true, rtnl_held);
2472                 if (err < 0)
2473                         NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
2474         }
2475
2476         tfilter_put(tp, fh);
2477 errout:
2478         if (chain) {
2479                 if (tp && !IS_ERR(tp))
2480                         tcf_proto_put(tp, rtnl_held, NULL);
2481                 tcf_chain_put(chain);
2482         }
2483         tcf_block_release(q, block, rtnl_held);
2484
2485         if (rtnl_held)
2486                 rtnl_unlock();
2487
2488         return err;
2489 }
2490
2491 struct tcf_dump_args {
2492         struct tcf_walker w;
2493         struct sk_buff *skb;
2494         struct netlink_callback *cb;
2495         struct tcf_block *block;
2496         struct Qdisc *q;
2497         u32 parent;
2498 };
2499
2500 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2501 {
2502         struct tcf_dump_args *a = (void *)arg;
2503         struct net *net = sock_net(a->skb->sk);
2504
2505         return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
2506                              n, NETLINK_CB(a->cb->skb).portid,
2507                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2508                              RTM_NEWTFILTER, true);
2509 }
2510
2511 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
2512                            struct sk_buff *skb, struct netlink_callback *cb,
2513                            long index_start, long *p_index)
2514 {
2515         struct net *net = sock_net(skb->sk);
2516         struct tcf_block *block = chain->block;
2517         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2518         struct tcf_proto *tp, *tp_prev;
2519         struct tcf_dump_args arg;
2520
2521         for (tp = __tcf_get_next_proto(chain, NULL);
2522              tp;
2523              tp_prev = tp,
2524                      tp = __tcf_get_next_proto(chain, tp),
2525                      tcf_proto_put(tp_prev, true, NULL),
2526                      (*p_index)++) {
2527                 if (*p_index < index_start)
2528                         continue;
2529                 if (TC_H_MAJ(tcm->tcm_info) &&
2530                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
2531                         continue;
2532                 if (TC_H_MIN(tcm->tcm_info) &&
2533                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
2534                         continue;
2535                 if (*p_index > index_start)
2536                         memset(&cb->args[1], 0,
2537                                sizeof(cb->args) - sizeof(cb->args[0]));
2538                 if (cb->args[1] == 0) {
2539                         if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
2540                                           NETLINK_CB(cb->skb).portid,
2541                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
2542                                           RTM_NEWTFILTER, true) <= 0)
2543                                 goto errout;
2544                         cb->args[1] = 1;
2545                 }
2546                 if (!tp->ops->walk)
2547                         continue;
2548                 arg.w.fn = tcf_node_dump;
2549                 arg.skb = skb;
2550                 arg.cb = cb;
2551                 arg.block = block;
2552                 arg.q = q;
2553                 arg.parent = parent;
2554                 arg.w.stop = 0;
2555                 arg.w.skip = cb->args[1] - 1;
2556                 arg.w.count = 0;
2557                 arg.w.cookie = cb->args[2];
2558                 tp->ops->walk(tp, &arg.w, true);
2559                 cb->args[2] = arg.w.cookie;
2560                 cb->args[1] = arg.w.count + 1;
2561                 if (arg.w.stop)
2562                         goto errout;
2563         }
2564         return true;
2565
2566 errout:
2567         tcf_proto_put(tp, true, NULL);
2568         return false;
2569 }
2570
2571 /* called with RTNL */
2572 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
2573 {
2574         struct tcf_chain *chain, *chain_prev;
2575         struct net *net = sock_net(skb->sk);
2576         struct nlattr *tca[TCA_MAX + 1];
2577         struct Qdisc *q = NULL;
2578         struct tcf_block *block;
2579         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2580         long index_start;
2581         long index;
2582         u32 parent;
2583         int err;
2584
2585         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2586                 return skb->len;
2587
2588         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2589                                      NULL, cb->extack);
2590         if (err)
2591                 return err;
2592
2593         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2594                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2595                 if (!block)
2596                         goto out;
2597                 /* If we work with block index, q is NULL and parent value
2598                  * will never be used in the following code. The check
2599                  * in tcf_fill_node prevents it. However, compiler does not
2600                  * see that far, so set parent to zero to silence the warning
2601                  * about parent being uninitialized.
2602                  */
2603                 parent = 0;
2604         } else {
2605                 const struct Qdisc_class_ops *cops;
2606                 struct net_device *dev;
2607                 unsigned long cl = 0;
2608
2609                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2610                 if (!dev)
2611                         return skb->len;
2612
2613                 parent = tcm->tcm_parent;
2614                 if (!parent) {
2615                         q = dev->qdisc;
2616                         parent = q->handle;
2617                 } else {
2618                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2619                 }
2620                 if (!q)
2621                         goto out;
2622                 cops = q->ops->cl_ops;
2623                 if (!cops)
2624                         goto out;
2625                 if (!cops->tcf_block)
2626                         goto out;
2627                 if (TC_H_MIN(tcm->tcm_parent)) {
2628                         cl = cops->find(q, tcm->tcm_parent);
2629                         if (cl == 0)
2630                                 goto out;
2631                 }
2632                 block = cops->tcf_block(q, cl, NULL);
2633                 if (!block)
2634                         goto out;
2635                 if (tcf_block_shared(block))
2636                         q = NULL;
2637         }
2638
2639         index_start = cb->args[0];
2640         index = 0;
2641
2642         for (chain = __tcf_get_next_chain(block, NULL);
2643              chain;
2644              chain_prev = chain,
2645                      chain = __tcf_get_next_chain(block, chain),
2646                      tcf_chain_put(chain_prev)) {
2647                 if (tca[TCA_CHAIN] &&
2648                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
2649                         continue;
2650                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
2651                                     index_start, &index)) {
2652                         tcf_chain_put(chain);
2653                         err = -EMSGSIZE;
2654                         break;
2655                 }
2656         }
2657
2658         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2659                 tcf_block_refcnt_put(block, true);
2660         cb->args[0] = index;
2661
2662 out:
2663         /* If we did no progress, the error (EMSGSIZE) is real */
2664         if (skb->len == 0 && err)
2665                 return err;
2666         return skb->len;
2667 }
2668
2669 static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
2670                               void *tmplt_priv, u32 chain_index,
2671                               struct net *net, struct sk_buff *skb,
2672                               struct tcf_block *block,
2673                               u32 portid, u32 seq, u16 flags, int event)
2674 {
2675         unsigned char *b = skb_tail_pointer(skb);
2676         const struct tcf_proto_ops *ops;
2677         struct nlmsghdr *nlh;
2678         struct tcmsg *tcm;
2679         void *priv;
2680
2681         ops = tmplt_ops;
2682         priv = tmplt_priv;
2683
2684         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2685         if (!nlh)
2686                 goto out_nlmsg_trim;
2687         tcm = nlmsg_data(nlh);
2688         tcm->tcm_family = AF_UNSPEC;
2689         tcm->tcm__pad1 = 0;
2690         tcm->tcm__pad2 = 0;
2691         tcm->tcm_handle = 0;
2692         if (block->q) {
2693                 tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
2694                 tcm->tcm_parent = block->q->handle;
2695         } else {
2696                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2697                 tcm->tcm_block_index = block->index;
2698         }
2699
2700         if (nla_put_u32(skb, TCA_CHAIN, chain_index))
2701                 goto nla_put_failure;
2702
2703         if (ops) {
2704                 if (nla_put_string(skb, TCA_KIND, ops->kind))
2705                         goto nla_put_failure;
2706                 if (ops->tmplt_dump(skb, net, priv) < 0)
2707                         goto nla_put_failure;
2708         }
2709
2710         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2711         return skb->len;
2712
2713 out_nlmsg_trim:
2714 nla_put_failure:
2715         nlmsg_trim(skb, b);
2716         return -EMSGSIZE;
2717 }
2718
2719 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
2720                            u32 seq, u16 flags, int event, bool unicast)
2721 {
2722         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2723         struct tcf_block *block = chain->block;
2724         struct net *net = block->net;
2725         struct sk_buff *skb;
2726         int err = 0;
2727
2728         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2729         if (!skb)
2730                 return -ENOBUFS;
2731
2732         if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2733                                chain->index, net, skb, block, portid,
2734                                seq, flags, event) <= 0) {
2735                 kfree_skb(skb);
2736                 return -EINVAL;
2737         }
2738
2739         if (unicast)
2740                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
2741         else
2742                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2743                                      flags & NLM_F_ECHO);
2744
2745         if (err > 0)
2746                 err = 0;
2747         return err;
2748 }
2749
2750 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
2751                                   void *tmplt_priv, u32 chain_index,
2752                                   struct tcf_block *block, struct sk_buff *oskb,
2753                                   u32 seq, u16 flags, bool unicast)
2754 {
2755         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2756         struct net *net = block->net;
2757         struct sk_buff *skb;
2758
2759         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2760         if (!skb)
2761                 return -ENOBUFS;
2762
2763         if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
2764                                block, portid, seq, flags, RTM_DELCHAIN) <= 0) {
2765                 kfree_skb(skb);
2766                 return -EINVAL;
2767         }
2768
2769         if (unicast)
2770                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
2771
2772         return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
2773 }
2774
2775 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
2776                               struct nlattr **tca,
2777                               struct netlink_ext_ack *extack)
2778 {
2779         const struct tcf_proto_ops *ops;
2780         char name[IFNAMSIZ];
2781         void *tmplt_priv;
2782
2783         /* If kind is not set, user did not specify template. */
2784         if (!tca[TCA_KIND])
2785                 return 0;
2786
2787         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2788                 NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
2789                 return -EINVAL;
2790         }
2791
2792         ops = tcf_proto_lookup_ops(name, true, extack);
2793         if (IS_ERR(ops))
2794                 return PTR_ERR(ops);
2795         if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
2796                 NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
2797                 return -EOPNOTSUPP;
2798         }
2799
2800         tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
2801         if (IS_ERR(tmplt_priv)) {
2802                 module_put(ops->owner);
2803                 return PTR_ERR(tmplt_priv);
2804         }
2805         chain->tmplt_ops = ops;
2806         chain->tmplt_priv = tmplt_priv;
2807         return 0;
2808 }
2809
2810 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
2811                                void *tmplt_priv)
2812 {
2813         /* If template ops are set, no work to do for us. */
2814         if (!tmplt_ops)
2815                 return;
2816
2817         tmplt_ops->tmplt_destroy(tmplt_priv);
2818         module_put(tmplt_ops->owner);
2819 }
2820
2821 /* Add/delete/get a chain */
2822
2823 static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
2824                         struct netlink_ext_ack *extack)
2825 {
2826         struct net *net = sock_net(skb->sk);
2827         struct nlattr *tca[TCA_MAX + 1];
2828         struct tcmsg *t;
2829         u32 parent;
2830         u32 chain_index;
2831         struct Qdisc *q = NULL;
2832         struct tcf_chain *chain = NULL;
2833         struct tcf_block *block;
2834         unsigned long cl;
2835         int err;
2836
2837         if (n->nlmsg_type != RTM_GETCHAIN &&
2838             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2839                 return -EPERM;
2840
2841 replay:
2842         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2843                                      rtm_tca_policy, extack);
2844         if (err < 0)
2845                 return err;
2846
2847         t = nlmsg_data(n);
2848         parent = t->tcm_parent;
2849         cl = 0;
2850
2851         block = tcf_block_find(net, &q, &parent, &cl,
2852                                t->tcm_ifindex, t->tcm_block_index, extack);
2853         if (IS_ERR(block))
2854                 return PTR_ERR(block);
2855
2856         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2857         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2858                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2859                 err = -EINVAL;
2860                 goto errout_block;
2861         }
2862
2863         mutex_lock(&block->lock);
2864         chain = tcf_chain_lookup(block, chain_index);
2865         if (n->nlmsg_type == RTM_NEWCHAIN) {
2866                 if (chain) {
2867                         if (tcf_chain_held_by_acts_only(chain)) {
2868                                 /* The chain exists only because there is
2869                                  * some action referencing it.
2870                                  */
2871                                 tcf_chain_hold(chain);
2872                         } else {
2873                                 NL_SET_ERR_MSG(extack, "Filter chain already exists");
2874                                 err = -EEXIST;
2875                                 goto errout_block_locked;
2876                         }
2877                 } else {
2878                         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2879                                 NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
2880                                 err = -ENOENT;
2881                                 goto errout_block_locked;
2882                         }
2883                         chain = tcf_chain_create(block, chain_index);
2884                         if (!chain) {
2885                                 NL_SET_ERR_MSG(extack, "Failed to create filter chain");
2886                                 err = -ENOMEM;
2887                                 goto errout_block_locked;
2888                         }
2889                 }
2890         } else {
2891                 if (!chain || tcf_chain_held_by_acts_only(chain)) {
2892                         NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2893                         err = -EINVAL;
2894                         goto errout_block_locked;
2895                 }
2896                 tcf_chain_hold(chain);
2897         }
2898
2899         if (n->nlmsg_type == RTM_NEWCHAIN) {
2900                 /* Modifying chain requires holding parent block lock. In case
2901                  * the chain was successfully added, take a reference to the
2902                  * chain. This ensures that an empty chain does not disappear at
2903                  * the end of this function.
2904                  */
2905                 tcf_chain_hold(chain);
2906                 chain->explicitly_created = true;
2907         }
2908         mutex_unlock(&block->lock);
2909
2910         switch (n->nlmsg_type) {
2911         case RTM_NEWCHAIN:
2912                 err = tc_chain_tmplt_add(chain, net, tca, extack);
2913                 if (err) {
2914                         tcf_chain_put_explicitly_created(chain);
2915                         goto errout;
2916                 }
2917
2918                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
2919                                 RTM_NEWCHAIN, false);
2920                 break;
2921         case RTM_DELCHAIN:
2922                 tfilter_notify_chain(net, skb, block, q, parent, n,
2923                                      chain, RTM_DELTFILTER, true);
2924                 /* Flush the chain first as the user requested chain removal. */
2925                 tcf_chain_flush(chain, true);
2926                 /* In case the chain was successfully deleted, put a reference
2927                  * to the chain previously taken during addition.
2928                  */
2929                 tcf_chain_put_explicitly_created(chain);
2930                 break;
2931         case RTM_GETCHAIN:
2932                 err = tc_chain_notify(chain, skb, n->nlmsg_seq,
2933                                       n->nlmsg_seq, n->nlmsg_type, true);
2934                 if (err < 0)
2935                         NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
2936                 break;
2937         default:
2938                 err = -EOPNOTSUPP;
2939                 NL_SET_ERR_MSG(extack, "Unsupported message type");
2940                 goto errout;
2941         }
2942
2943 errout:
2944         tcf_chain_put(chain);
2945 errout_block:
2946         tcf_block_release(q, block, true);
2947         if (err == -EAGAIN)
2948                 /* Replay the request. */
2949                 goto replay;
2950         return err;
2951
2952 errout_block_locked:
2953         mutex_unlock(&block->lock);
2954         goto errout_block;
2955 }
2956
2957 /* called with RTNL */
2958 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
2959 {
2960         struct net *net = sock_net(skb->sk);
2961         struct nlattr *tca[TCA_MAX + 1];
2962         struct Qdisc *q = NULL;
2963         struct tcf_block *block;
2964         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2965         struct tcf_chain *chain;
2966         long index_start;
2967         long index;
2968         u32 parent;
2969         int err;
2970
2971         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2972                 return skb->len;
2973
2974         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2975                                      rtm_tca_policy, cb->extack);
2976         if (err)
2977                 return err;
2978
2979         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2980                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2981                 if (!block)
2982                         goto out;
2983                 /* If we work with block index, q is NULL and parent value
2984                  * will never be used in the following code. The check
2985                  * in tcf_fill_node prevents it. However, compiler does not
2986                  * see that far, so set parent to zero to silence the warning
2987                  * about parent being uninitialized.
2988                  */
2989                 parent = 0;
2990         } else {
2991                 const struct Qdisc_class_ops *cops;
2992                 struct net_device *dev;
2993                 unsigned long cl = 0;
2994
2995                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2996                 if (!dev)
2997                         return skb->len;
2998
2999                 parent = tcm->tcm_parent;
3000                 if (!parent) {
3001                         q = dev->qdisc;
3002                         parent = q->handle;
3003                 } else {
3004                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
3005                 }
3006                 if (!q)
3007                         goto out;
3008                 cops = q->ops->cl_ops;
3009                 if (!cops)
3010                         goto out;
3011                 if (!cops->tcf_block)
3012                         goto out;
3013                 if (TC_H_MIN(tcm->tcm_parent)) {
3014                         cl = cops->find(q, tcm->tcm_parent);
3015                         if (cl == 0)
3016                                 goto out;
3017                 }
3018                 block = cops->tcf_block(q, cl, NULL);
3019                 if (!block)
3020                         goto out;
3021                 if (tcf_block_shared(block))
3022                         q = NULL;
3023         }
3024
3025         index_start = cb->args[0];
3026         index = 0;
3027
3028         mutex_lock(&block->lock);
3029         list_for_each_entry(chain, &block->chain_list, list) {
3030                 if ((tca[TCA_CHAIN] &&
3031                      nla_get_u32(tca[TCA_CHAIN]) != chain->index))
3032                         continue;
3033                 if (index < index_start) {
3034                         index++;
3035                         continue;
3036                 }
3037                 if (tcf_chain_held_by_acts_only(chain))
3038                         continue;
3039                 err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
3040                                          chain->index, net, skb, block,
3041                                          NETLINK_CB(cb->skb).portid,
3042                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
3043                                          RTM_NEWCHAIN);
3044                 if (err <= 0)
3045                         break;
3046                 index++;
3047         }
3048         mutex_unlock(&block->lock);
3049
3050         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
3051                 tcf_block_refcnt_put(block, true);
3052         cb->args[0] = index;
3053
3054 out:
3055         /* If we did no progress, the error (EMSGSIZE) is real */
3056         if (skb->len == 0 && err)
3057                 return err;
3058         return skb->len;
3059 }
3060
3061 void tcf_exts_destroy(struct tcf_exts *exts)
3062 {
3063 #ifdef CONFIG_NET_CLS_ACT
3064         if (exts->actions) {
3065                 tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
3066                 kfree(exts->actions);
3067         }
3068         exts->nr_actions = 0;
3069 #endif
3070 }
3071 EXPORT_SYMBOL(tcf_exts_destroy);
3072
3073 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3074                       struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr,
3075                       bool rtnl_held, struct netlink_ext_ack *extack)
3076 {
3077 #ifdef CONFIG_NET_CLS_ACT
3078         {
3079                 struct tc_action *act;
3080                 size_t attr_size = 0;
3081
3082                 if (exts->police && tb[exts->police]) {
3083                         act = tcf_action_init_1(net, tp, tb[exts->police],
3084                                                 rate_tlv, "police", ovr,
3085                                                 TCA_ACT_BIND, rtnl_held,
3086                                                 extack);
3087                         if (IS_ERR(act))
3088                                 return PTR_ERR(act);
3089
3090                         act->type = exts->type = TCA_OLD_COMPAT;
3091                         exts->actions[0] = act;
3092                         exts->nr_actions = 1;
3093                 } else if (exts->action && tb[exts->action]) {
3094                         int err;
3095
3096                         err = tcf_action_init(net, tp, tb[exts->action],
3097                                               rate_tlv, NULL, ovr, TCA_ACT_BIND,
3098                                               exts->actions, &attr_size,
3099                                               rtnl_held, extack);
3100                         if (err < 0)
3101                                 return err;
3102                         exts->nr_actions = err;
3103                 }
3104         }
3105 #else
3106         if ((exts->action && tb[exts->action]) ||
3107             (exts->police && tb[exts->police])) {
3108                 NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
3109                 return -EOPNOTSUPP;
3110         }
3111 #endif
3112
3113         return 0;
3114 }
3115 EXPORT_SYMBOL(tcf_exts_validate);
3116
3117 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
3118 {
3119 #ifdef CONFIG_NET_CLS_ACT
3120         struct tcf_exts old = *dst;
3121
3122         *dst = *src;
3123         tcf_exts_destroy(&old);
3124 #endif
3125 }
3126 EXPORT_SYMBOL(tcf_exts_change);
3127
3128 #ifdef CONFIG_NET_CLS_ACT
3129 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
3130 {
3131         if (exts->nr_actions == 0)
3132                 return NULL;
3133         else
3134                 return exts->actions[0];
3135 }
3136 #endif
3137
3138 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
3139 {
3140 #ifdef CONFIG_NET_CLS_ACT
3141         struct nlattr *nest;
3142
3143         if (exts->action && tcf_exts_has_actions(exts)) {
3144                 /*
3145                  * again for backward compatible mode - we want
3146                  * to work with both old and new modes of entering
3147                  * tc data even if iproute2  was newer - jhs
3148                  */
3149                 if (exts->type != TCA_OLD_COMPAT) {
3150                         nest = nla_nest_start_noflag(skb, exts->action);
3151                         if (nest == NULL)
3152                                 goto nla_put_failure;
3153
3154                         if (tcf_action_dump(skb, exts->actions, 0, 0) < 0)
3155                                 goto nla_put_failure;
3156                         nla_nest_end(skb, nest);
3157                 } else if (exts->police) {
3158                         struct tc_action *act = tcf_exts_first_act(exts);
3159                         nest = nla_nest_start_noflag(skb, exts->police);
3160                         if (nest == NULL || !act)
3161                                 goto nla_put_failure;
3162                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
3163                                 goto nla_put_failure;
3164                         nla_nest_end(skb, nest);
3165                 }
3166         }
3167         return 0;
3168
3169 nla_put_failure:
3170         nla_nest_cancel(skb, nest);
3171         return -1;
3172 #else
3173         return 0;
3174 #endif
3175 }
3176 EXPORT_SYMBOL(tcf_exts_dump);
3177
3178
3179 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
3180 {
3181 #ifdef CONFIG_NET_CLS_ACT
3182         struct tc_action *a = tcf_exts_first_act(exts);
3183         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
3184                 return -1;
3185 #endif
3186         return 0;
3187 }
3188 EXPORT_SYMBOL(tcf_exts_dump_stats);
3189
3190 static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
3191 {
3192         if (*flags & TCA_CLS_FLAGS_IN_HW)
3193                 return;
3194         *flags |= TCA_CLS_FLAGS_IN_HW;
3195         atomic_inc(&block->offloadcnt);
3196 }
3197
3198 static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
3199 {
3200         if (!(*flags & TCA_CLS_FLAGS_IN_HW))
3201                 return;
3202         *flags &= ~TCA_CLS_FLAGS_IN_HW;
3203         atomic_dec(&block->offloadcnt);
3204 }
3205
3206 static void tc_cls_offload_cnt_update(struct tcf_block *block,
3207                                       struct tcf_proto *tp, u32 *cnt,
3208                                       u32 *flags, u32 diff, bool add)
3209 {
3210         lockdep_assert_held(&block->cb_lock);
3211
3212         spin_lock(&tp->lock);
3213         if (add) {
3214                 if (!*cnt)
3215                         tcf_block_offload_inc(block, flags);
3216                 *cnt += diff;
3217         } else {
3218                 *cnt -= diff;
3219                 if (!*cnt)
3220                         tcf_block_offload_dec(block, flags);
3221         }
3222         spin_unlock(&tp->lock);
3223 }
3224
3225 static void
3226 tc_cls_offload_cnt_reset(struct tcf_block *block, struct tcf_proto *tp,
3227                          u32 *cnt, u32 *flags)
3228 {
3229         lockdep_assert_held(&block->cb_lock);
3230
3231         spin_lock(&tp->lock);
3232         tcf_block_offload_dec(block, flags);
3233         *cnt = 0;
3234         spin_unlock(&tp->lock);
3235 }
3236
3237 static int
3238 __tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3239                    void *type_data, bool err_stop)
3240 {
3241         struct flow_block_cb *block_cb;
3242         int ok_count = 0;
3243         int err;
3244
3245         list_for_each_entry(block_cb, &block->flow_block.cb_list, list) {
3246                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
3247                 if (err) {
3248                         if (err_stop)
3249                                 return err;
3250                 } else {
3251                         ok_count++;
3252                 }
3253         }
3254         return ok_count;
3255 }
3256
3257 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3258                      void *type_data, bool err_stop, bool rtnl_held)
3259 {
3260         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3261         int ok_count;
3262
3263 retry:
3264         if (take_rtnl)
3265                 rtnl_lock();
3266         down_read(&block->cb_lock);
3267         /* Need to obtain rtnl lock if block is bound to devs that require it.
3268          * In block bind code cb_lock is obtained while holding rtnl, so we must
3269          * obtain the locks in same order here.
3270          */
3271         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3272                 up_read(&block->cb_lock);
3273                 take_rtnl = true;
3274                 goto retry;
3275         }
3276
3277         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3278
3279         up_read(&block->cb_lock);
3280         if (take_rtnl)
3281                 rtnl_unlock();
3282         return ok_count;
3283 }
3284 EXPORT_SYMBOL(tc_setup_cb_call);
3285
3286 /* Non-destructive filter add. If filter that wasn't already in hardware is
3287  * successfully offloaded, increment block offloads counter. On failure,
3288  * previously offloaded filter is considered to be intact and offloads counter
3289  * is not decremented.
3290  */
3291
3292 int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
3293                     enum tc_setup_type type, void *type_data, bool err_stop,
3294                     u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3295 {
3296         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3297         int ok_count;
3298
3299 retry:
3300         if (take_rtnl)
3301                 rtnl_lock();
3302         down_read(&block->cb_lock);
3303         /* Need to obtain rtnl lock if block is bound to devs that require it.
3304          * In block bind code cb_lock is obtained while holding rtnl, so we must
3305          * obtain the locks in same order here.
3306          */
3307         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3308                 up_read(&block->cb_lock);
3309                 take_rtnl = true;
3310                 goto retry;
3311         }
3312
3313         /* Make sure all netdevs sharing this block are offload-capable. */
3314         if (block->nooffloaddevcnt && err_stop) {
3315                 ok_count = -EOPNOTSUPP;
3316                 goto err_unlock;
3317         }
3318
3319         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3320         if (ok_count < 0)
3321                 goto err_unlock;
3322
3323         if (tp->ops->hw_add)
3324                 tp->ops->hw_add(tp, type_data);
3325         if (ok_count > 0)
3326                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
3327                                           ok_count, true);
3328 err_unlock:
3329         up_read(&block->cb_lock);
3330         if (take_rtnl)
3331                 rtnl_unlock();
3332         return ok_count < 0 ? ok_count : 0;
3333 }
3334 EXPORT_SYMBOL(tc_setup_cb_add);
3335
3336 /* Destructive filter replace. If filter that wasn't already in hardware is
3337  * successfully offloaded, increment block offload counter. On failure,
3338  * previously offloaded filter is considered to be destroyed and offload counter
3339  * is decremented.
3340  */
3341
3342 int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
3343                         enum tc_setup_type type, void *type_data, bool err_stop,
3344                         u32 *old_flags, unsigned int *old_in_hw_count,
3345                         u32 *new_flags, unsigned int *new_in_hw_count,
3346                         bool rtnl_held)
3347 {
3348         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3349         int ok_count;
3350
3351 retry:
3352         if (take_rtnl)
3353                 rtnl_lock();
3354         down_read(&block->cb_lock);
3355         /* Need to obtain rtnl lock if block is bound to devs that require it.
3356          * In block bind code cb_lock is obtained while holding rtnl, so we must
3357          * obtain the locks in same order here.
3358          */
3359         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3360                 up_read(&block->cb_lock);
3361                 take_rtnl = true;
3362                 goto retry;
3363         }
3364
3365         /* Make sure all netdevs sharing this block are offload-capable. */
3366         if (block->nooffloaddevcnt && err_stop) {
3367                 ok_count = -EOPNOTSUPP;
3368                 goto err_unlock;
3369         }
3370
3371         tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
3372         if (tp->ops->hw_del)
3373                 tp->ops->hw_del(tp, type_data);
3374
3375         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3376         if (ok_count < 0)
3377                 goto err_unlock;
3378
3379         if (tp->ops->hw_add)
3380                 tp->ops->hw_add(tp, type_data);
3381         if (ok_count > 0)
3382                 tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
3383                                           new_flags, ok_count, true);
3384 err_unlock:
3385         up_read(&block->cb_lock);
3386         if (take_rtnl)
3387                 rtnl_unlock();
3388         return ok_count < 0 ? ok_count : 0;
3389 }
3390 EXPORT_SYMBOL(tc_setup_cb_replace);
3391
3392 /* Destroy filter and decrement block offload counter, if filter was previously
3393  * offloaded.
3394  */
3395
3396 int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
3397                         enum tc_setup_type type, void *type_data, bool err_stop,
3398                         u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3399 {
3400         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3401         int ok_count;
3402
3403 retry:
3404         if (take_rtnl)
3405                 rtnl_lock();
3406         down_read(&block->cb_lock);
3407         /* Need to obtain rtnl lock if block is bound to devs that require it.
3408          * In block bind code cb_lock is obtained while holding rtnl, so we must
3409          * obtain the locks in same order here.
3410          */
3411         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3412                 up_read(&block->cb_lock);
3413                 take_rtnl = true;
3414                 goto retry;
3415         }
3416
3417         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3418
3419         tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
3420         if (tp->ops->hw_del)
3421                 tp->ops->hw_del(tp, type_data);
3422
3423         up_read(&block->cb_lock);
3424         if (take_rtnl)
3425                 rtnl_unlock();
3426         return ok_count < 0 ? ok_count : 0;
3427 }
3428 EXPORT_SYMBOL(tc_setup_cb_destroy);
3429
3430 int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
3431                           bool add, flow_setup_cb_t *cb,
3432                           enum tc_setup_type type, void *type_data,
3433                           void *cb_priv, u32 *flags, unsigned int *in_hw_count)
3434 {
3435         int err = cb(type, type_data, cb_priv);
3436
3437         if (err) {
3438                 if (add && tc_skip_sw(*flags))
3439                         return err;
3440         } else {
3441                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags, 1,
3442                                           add);
3443         }
3444
3445         return 0;
3446 }
3447 EXPORT_SYMBOL(tc_setup_cb_reoffload);
3448
3449 static int tcf_act_get_cookie(struct flow_action_entry *entry,
3450                               const struct tc_action *act)
3451 {
3452         struct tc_cookie *cookie;
3453         int err = 0;
3454
3455         rcu_read_lock();
3456         cookie = rcu_dereference(act->act_cookie);
3457         if (cookie) {
3458                 entry->cookie = flow_action_cookie_create(cookie->data,
3459                                                           cookie->len,
3460                                                           GFP_ATOMIC);
3461                 if (!entry->cookie)
3462                         err = -ENOMEM;
3463         }
3464         rcu_read_unlock();
3465         return err;
3466 }
3467
3468 static void tcf_act_put_cookie(struct flow_action_entry *entry)
3469 {
3470         flow_action_cookie_destroy(entry->cookie);
3471 }
3472
3473 void tc_cleanup_flow_action(struct flow_action *flow_action)
3474 {
3475         struct flow_action_entry *entry;
3476         int i;
3477
3478         flow_action_for_each(i, entry, flow_action) {
3479                 tcf_act_put_cookie(entry);
3480                 if (entry->destructor)
3481                         entry->destructor(entry->destructor_priv);
3482         }
3483 }
3484 EXPORT_SYMBOL(tc_cleanup_flow_action);
3485
3486 static void tcf_mirred_get_dev(struct flow_action_entry *entry,
3487                                const struct tc_action *act)
3488 {
3489 #ifdef CONFIG_NET_CLS_ACT
3490         entry->dev = act->ops->get_dev(act, &entry->destructor);
3491         if (!entry->dev)
3492                 return;
3493         entry->destructor_priv = entry->dev;
3494 #endif
3495 }
3496
3497 static void tcf_tunnel_encap_put_tunnel(void *priv)
3498 {
3499         struct ip_tunnel_info *tunnel = priv;
3500
3501         kfree(tunnel);
3502 }
3503
3504 static int tcf_tunnel_encap_get_tunnel(struct flow_action_entry *entry,
3505                                        const struct tc_action *act)
3506 {
3507         entry->tunnel = tcf_tunnel_info_copy(act);
3508         if (!entry->tunnel)
3509                 return -ENOMEM;
3510         entry->destructor = tcf_tunnel_encap_put_tunnel;
3511         entry->destructor_priv = entry->tunnel;
3512         return 0;
3513 }
3514
3515 static void tcf_sample_get_group(struct flow_action_entry *entry,
3516                                  const struct tc_action *act)
3517 {
3518 #ifdef CONFIG_NET_CLS_ACT
3519         entry->sample.psample_group =
3520                 act->ops->get_psample_group(act, &entry->destructor);
3521         entry->destructor_priv = entry->sample.psample_group;
3522 #endif
3523 }
3524
3525 int tc_setup_flow_action(struct flow_action *flow_action,
3526                          const struct tcf_exts *exts)
3527 {
3528         struct tc_action *act;
3529         int i, j, k, err = 0;
3530
3531         BUILD_BUG_ON(TCA_ACT_HW_STATS_ANY != FLOW_ACTION_HW_STATS_ANY);
3532         BUILD_BUG_ON(TCA_ACT_HW_STATS_IMMEDIATE != FLOW_ACTION_HW_STATS_IMMEDIATE);
3533         BUILD_BUG_ON(TCA_ACT_HW_STATS_DELAYED != FLOW_ACTION_HW_STATS_DELAYED);
3534
3535         if (!exts)
3536                 return 0;
3537
3538         j = 0;
3539         tcf_exts_for_each_action(i, act, exts) {
3540                 struct flow_action_entry *entry;
3541
3542                 entry = &flow_action->entries[j];
3543                 spin_lock_bh(&act->tcfa_lock);
3544                 err = tcf_act_get_cookie(entry, act);
3545                 if (err)
3546                         goto err_out_locked;
3547
3548                 entry->hw_stats = act->hw_stats;
3549
3550                 if (is_tcf_gact_ok(act)) {
3551                         entry->id = FLOW_ACTION_ACCEPT;
3552                 } else if (is_tcf_gact_shot(act)) {
3553                         entry->id = FLOW_ACTION_DROP;
3554                 } else if (is_tcf_gact_trap(act)) {
3555                         entry->id = FLOW_ACTION_TRAP;
3556                 } else if (is_tcf_gact_goto_chain(act)) {
3557                         entry->id = FLOW_ACTION_GOTO;
3558                         entry->chain_index = tcf_gact_goto_chain_index(act);
3559                 } else if (is_tcf_mirred_egress_redirect(act)) {
3560                         entry->id = FLOW_ACTION_REDIRECT;
3561                         tcf_mirred_get_dev(entry, act);
3562                 } else if (is_tcf_mirred_egress_mirror(act)) {
3563                         entry->id = FLOW_ACTION_MIRRED;
3564                         tcf_mirred_get_dev(entry, act);
3565                 } else if (is_tcf_mirred_ingress_redirect(act)) {
3566                         entry->id = FLOW_ACTION_REDIRECT_INGRESS;
3567                         tcf_mirred_get_dev(entry, act);
3568                 } else if (is_tcf_mirred_ingress_mirror(act)) {
3569                         entry->id = FLOW_ACTION_MIRRED_INGRESS;
3570                         tcf_mirred_get_dev(entry, act);
3571                 } else if (is_tcf_vlan(act)) {
3572                         switch (tcf_vlan_action(act)) {
3573                         case TCA_VLAN_ACT_PUSH:
3574                                 entry->id = FLOW_ACTION_VLAN_PUSH;
3575                                 entry->vlan.vid = tcf_vlan_push_vid(act);
3576                                 entry->vlan.proto = tcf_vlan_push_proto(act);
3577                                 entry->vlan.prio = tcf_vlan_push_prio(act);
3578                                 break;
3579                         case TCA_VLAN_ACT_POP:
3580                                 entry->id = FLOW_ACTION_VLAN_POP;
3581                                 break;
3582                         case TCA_VLAN_ACT_MODIFY:
3583                                 entry->id = FLOW_ACTION_VLAN_MANGLE;
3584                                 entry->vlan.vid = tcf_vlan_push_vid(act);
3585                                 entry->vlan.proto = tcf_vlan_push_proto(act);
3586                                 entry->vlan.prio = tcf_vlan_push_prio(act);
3587                                 break;
3588                         default:
3589                                 err = -EOPNOTSUPP;
3590                                 goto err_out_locked;
3591                         }
3592                 } else if (is_tcf_tunnel_set(act)) {
3593                         entry->id = FLOW_ACTION_TUNNEL_ENCAP;
3594                         err = tcf_tunnel_encap_get_tunnel(entry, act);
3595                         if (err)
3596                                 goto err_out_locked;
3597                 } else if (is_tcf_tunnel_release(act)) {
3598                         entry->id = FLOW_ACTION_TUNNEL_DECAP;
3599                 } else if (is_tcf_pedit(act)) {
3600                         for (k = 0; k < tcf_pedit_nkeys(act); k++) {
3601                                 switch (tcf_pedit_cmd(act, k)) {
3602                                 case TCA_PEDIT_KEY_EX_CMD_SET:
3603                                         entry->id = FLOW_ACTION_MANGLE;
3604                                         break;
3605                                 case TCA_PEDIT_KEY_EX_CMD_ADD:
3606                                         entry->id = FLOW_ACTION_ADD;
3607                                         break;
3608                                 default:
3609                                         err = -EOPNOTSUPP;
3610                                         goto err_out_locked;
3611                                 }
3612                                 entry->mangle.htype = tcf_pedit_htype(act, k);
3613                                 entry->mangle.mask = tcf_pedit_mask(act, k);
3614                                 entry->mangle.val = tcf_pedit_val(act, k);
3615                                 entry->mangle.offset = tcf_pedit_offset(act, k);
3616                                 entry->hw_stats = act->hw_stats;
3617                                 entry = &flow_action->entries[++j];
3618                         }
3619                 } else if (is_tcf_csum(act)) {
3620                         entry->id = FLOW_ACTION_CSUM;
3621                         entry->csum_flags = tcf_csum_update_flags(act);
3622                 } else if (is_tcf_skbedit_mark(act)) {
3623                         entry->id = FLOW_ACTION_MARK;
3624                         entry->mark = tcf_skbedit_mark(act);
3625                 } else if (is_tcf_sample(act)) {
3626                         entry->id = FLOW_ACTION_SAMPLE;
3627                         entry->sample.trunc_size = tcf_sample_trunc_size(act);
3628                         entry->sample.truncate = tcf_sample_truncate(act);
3629                         entry->sample.rate = tcf_sample_rate(act);
3630                         tcf_sample_get_group(entry, act);
3631                 } else if (is_tcf_police(act)) {
3632                         entry->id = FLOW_ACTION_POLICE;
3633                         entry->police.burst = tcf_police_tcfp_burst(act);
3634                         entry->police.rate_bytes_ps =
3635                                 tcf_police_rate_bytes_ps(act);
3636                 } else if (is_tcf_ct(act)) {
3637                         entry->id = FLOW_ACTION_CT;
3638                         entry->ct.action = tcf_ct_action(act);
3639                         entry->ct.zone = tcf_ct_zone(act);
3640                         entry->ct.flow_table = tcf_ct_ft(act);
3641                 } else if (is_tcf_mpls(act)) {
3642                         switch (tcf_mpls_action(act)) {
3643                         case TCA_MPLS_ACT_PUSH:
3644                                 entry->id = FLOW_ACTION_MPLS_PUSH;
3645                                 entry->mpls_push.proto = tcf_mpls_proto(act);
3646                                 entry->mpls_push.label = tcf_mpls_label(act);
3647                                 entry->mpls_push.tc = tcf_mpls_tc(act);
3648                                 entry->mpls_push.bos = tcf_mpls_bos(act);
3649                                 entry->mpls_push.ttl = tcf_mpls_ttl(act);
3650                                 break;
3651                         case TCA_MPLS_ACT_POP:
3652                                 entry->id = FLOW_ACTION_MPLS_POP;
3653                                 entry->mpls_pop.proto = tcf_mpls_proto(act);
3654                                 break;
3655                         case TCA_MPLS_ACT_MODIFY:
3656                                 entry->id = FLOW_ACTION_MPLS_MANGLE;
3657                                 entry->mpls_mangle.label = tcf_mpls_label(act);
3658                                 entry->mpls_mangle.tc = tcf_mpls_tc(act);
3659                                 entry->mpls_mangle.bos = tcf_mpls_bos(act);
3660                                 entry->mpls_mangle.ttl = tcf_mpls_ttl(act);
3661                                 break;
3662                         default:
3663                                 goto err_out_locked;
3664                         }
3665                 } else if (is_tcf_skbedit_ptype(act)) {
3666                         entry->id = FLOW_ACTION_PTYPE;
3667                         entry->ptype = tcf_skbedit_ptype(act);
3668                 } else if (is_tcf_skbedit_priority(act)) {
3669                         entry->id = FLOW_ACTION_PRIORITY;
3670                         entry->priority = tcf_skbedit_priority(act);
3671                 } else {
3672                         err = -EOPNOTSUPP;
3673                         goto err_out_locked;
3674                 }
3675                 spin_unlock_bh(&act->tcfa_lock);
3676
3677                 if (!is_tcf_pedit(act))
3678                         j++;
3679         }
3680
3681 err_out:
3682         if (err)
3683                 tc_cleanup_flow_action(flow_action);
3684
3685         return err;
3686 err_out_locked:
3687         spin_unlock_bh(&act->tcfa_lock);
3688         goto err_out;
3689 }
3690 EXPORT_SYMBOL(tc_setup_flow_action);
3691
3692 unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
3693 {
3694         unsigned int num_acts = 0;
3695         struct tc_action *act;
3696         int i;
3697
3698         tcf_exts_for_each_action(i, act, exts) {
3699                 if (is_tcf_pedit(act))
3700                         num_acts += tcf_pedit_nkeys(act);
3701                 else
3702                         num_acts++;
3703         }
3704         return num_acts;
3705 }
3706 EXPORT_SYMBOL(tcf_exts_num_actions);
3707
3708 static __net_init int tcf_net_init(struct net *net)
3709 {
3710         struct tcf_net *tn = net_generic(net, tcf_net_id);
3711
3712         spin_lock_init(&tn->idr_lock);
3713         idr_init(&tn->idr);
3714         return 0;
3715 }
3716
3717 static void __net_exit tcf_net_exit(struct net *net)
3718 {
3719         struct tcf_net *tn = net_generic(net, tcf_net_id);
3720
3721         idr_destroy(&tn->idr);
3722 }
3723
3724 static struct pernet_operations tcf_net_ops = {
3725         .init = tcf_net_init,
3726         .exit = tcf_net_exit,
3727         .id   = &tcf_net_id,
3728         .size = sizeof(struct tcf_net),
3729 };
3730
3731 static struct flow_indr_block_entry block_entry = {
3732         .cb = tc_indr_block_get_and_cmd,
3733         .list = LIST_HEAD_INIT(block_entry.list),
3734 };
3735
3736 static int __init tc_filter_init(void)
3737 {
3738         int err;
3739
3740         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
3741         if (!tc_filter_wq)
3742                 return -ENOMEM;
3743
3744         err = register_pernet_subsys(&tcf_net_ops);
3745         if (err)
3746                 goto err_register_pernet_subsys;
3747
3748         flow_indr_add_block_cb(&block_entry);
3749
3750         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
3751                       RTNL_FLAG_DOIT_UNLOCKED);
3752         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
3753                       RTNL_FLAG_DOIT_UNLOCKED);
3754         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
3755                       tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
3756         rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
3757         rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
3758         rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
3759                       tc_dump_chain, 0);
3760
3761         return 0;
3762
3763 err_register_pernet_subsys:
3764         destroy_workqueue(tc_filter_wq);
3765         return err;
3766 }
3767
3768 subsys_initcall(tc_filter_init);