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, TC_SETUP_BLOCK);
 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                 last_executed_chain = fchain->index;
1671         }
1672
1673         ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode,
1674                              &last_executed_chain);
1675
1676         /* If we missed on some chain */
1677         if (ret == TC_ACT_UNSPEC && last_executed_chain) {
1678                 ext = skb_ext_add(skb, TC_SKB_EXT);
1679                 if (WARN_ON_ONCE(!ext))
1680                         return TC_ACT_SHOT;
1681                 ext->chain = last_executed_chain;
1682         }
1683
1684         return ret;
1685 #endif
1686 }
1687 EXPORT_SYMBOL(tcf_classify_ingress);
1688
1689 struct tcf_chain_info {
1690         struct tcf_proto __rcu **pprev;
1691         struct tcf_proto __rcu *next;
1692 };
1693
1694 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
1695                                            struct tcf_chain_info *chain_info)
1696 {
1697         return tcf_chain_dereference(*chain_info->pprev, chain);
1698 }
1699
1700 static int tcf_chain_tp_insert(struct tcf_chain *chain,
1701                                struct tcf_chain_info *chain_info,
1702                                struct tcf_proto *tp)
1703 {
1704         if (chain->flushing)
1705                 return -EAGAIN;
1706
1707         if (*chain_info->pprev == chain->filter_chain)
1708                 tcf_chain0_head_change(chain, tp);
1709         tcf_proto_get(tp);
1710         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
1711         rcu_assign_pointer(*chain_info->pprev, tp);
1712
1713         return 0;
1714 }
1715
1716 static void tcf_chain_tp_remove(struct tcf_chain *chain,
1717                                 struct tcf_chain_info *chain_info,
1718                                 struct tcf_proto *tp)
1719 {
1720         struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
1721
1722         tcf_proto_mark_delete(tp);
1723         if (tp == chain->filter_chain)
1724                 tcf_chain0_head_change(chain, next);
1725         RCU_INIT_POINTER(*chain_info->pprev, next);
1726 }
1727
1728 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1729                                            struct tcf_chain_info *chain_info,
1730                                            u32 protocol, u32 prio,
1731                                            bool prio_allocate);
1732
1733 /* Try to insert new proto.
1734  * If proto with specified priority already exists, free new proto
1735  * and return existing one.
1736  */
1737
1738 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
1739                                                     struct tcf_proto *tp_new,
1740                                                     u32 protocol, u32 prio,
1741                                                     bool rtnl_held)
1742 {
1743         struct tcf_chain_info chain_info;
1744         struct tcf_proto *tp;
1745         int err = 0;
1746
1747         mutex_lock(&chain->filter_chain_lock);
1748
1749         if (tcf_proto_exists_destroying(chain, tp_new)) {
1750                 mutex_unlock(&chain->filter_chain_lock);
1751                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1752                 return ERR_PTR(-EAGAIN);
1753         }
1754
1755         tp = tcf_chain_tp_find(chain, &chain_info,
1756                                protocol, prio, false);
1757         if (!tp)
1758                 err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
1759         mutex_unlock(&chain->filter_chain_lock);
1760
1761         if (tp) {
1762                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1763                 tp_new = tp;
1764         } else if (err) {
1765                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1766                 tp_new = ERR_PTR(err);
1767         }
1768
1769         return tp_new;
1770 }
1771
1772 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
1773                                       struct tcf_proto *tp, bool rtnl_held,
1774                                       struct netlink_ext_ack *extack)
1775 {
1776         struct tcf_chain_info chain_info;
1777         struct tcf_proto *tp_iter;
1778         struct tcf_proto **pprev;
1779         struct tcf_proto *next;
1780
1781         mutex_lock(&chain->filter_chain_lock);
1782
1783         /* Atomically find and remove tp from chain. */
1784         for (pprev = &chain->filter_chain;
1785              (tp_iter = tcf_chain_dereference(*pprev, chain));
1786              pprev = &tp_iter->next) {
1787                 if (tp_iter == tp) {
1788                         chain_info.pprev = pprev;
1789                         chain_info.next = tp_iter->next;
1790                         WARN_ON(tp_iter->deleting);
1791                         break;
1792                 }
1793         }
1794         /* Verify that tp still exists and no new filters were inserted
1795          * concurrently.
1796          * Mark tp for deletion if it is empty.
1797          */
1798         if (!tp_iter || !tcf_proto_check_delete(tp)) {
1799                 mutex_unlock(&chain->filter_chain_lock);
1800                 return;
1801         }
1802
1803         tcf_proto_signal_destroying(chain, tp);
1804         next = tcf_chain_dereference(chain_info.next, chain);
1805         if (tp == chain->filter_chain)
1806                 tcf_chain0_head_change(chain, next);
1807         RCU_INIT_POINTER(*chain_info.pprev, next);
1808         mutex_unlock(&chain->filter_chain_lock);
1809
1810         tcf_proto_put(tp, rtnl_held, extack);
1811 }
1812
1813 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1814                                            struct tcf_chain_info *chain_info,
1815                                            u32 protocol, u32 prio,
1816                                            bool prio_allocate)
1817 {
1818         struct tcf_proto **pprev;
1819         struct tcf_proto *tp;
1820
1821         /* Check the chain for existence of proto-tcf with this priority */
1822         for (pprev = &chain->filter_chain;
1823              (tp = tcf_chain_dereference(*pprev, chain));
1824              pprev = &tp->next) {
1825                 if (tp->prio >= prio) {
1826                         if (tp->prio == prio) {
1827                                 if (prio_allocate ||
1828                                     (tp->protocol != protocol && protocol))
1829                                         return ERR_PTR(-EINVAL);
1830                         } else {
1831                                 tp = NULL;
1832                         }
1833                         break;
1834                 }
1835         }
1836         chain_info->pprev = pprev;
1837         if (tp) {
1838                 chain_info->next = tp->next;
1839                 tcf_proto_get(tp);
1840         } else {
1841                 chain_info->next = NULL;
1842         }
1843         return tp;
1844 }
1845
1846 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
1847                          struct tcf_proto *tp, struct tcf_block *block,
1848                          struct Qdisc *q, u32 parent, void *fh,
1849                          u32 portid, u32 seq, u16 flags, int event,
1850                          bool rtnl_held)
1851 {
1852         struct tcmsg *tcm;
1853         struct nlmsghdr  *nlh;
1854         unsigned char *b = skb_tail_pointer(skb);
1855
1856         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1857         if (!nlh)
1858                 goto out_nlmsg_trim;
1859         tcm = nlmsg_data(nlh);
1860         tcm->tcm_family = AF_UNSPEC;
1861         tcm->tcm__pad1 = 0;
1862         tcm->tcm__pad2 = 0;
1863         if (q) {
1864                 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1865                 tcm->tcm_parent = parent;
1866         } else {
1867                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
1868                 tcm->tcm_block_index = block->index;
1869         }
1870         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
1871         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
1872                 goto nla_put_failure;
1873         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
1874                 goto nla_put_failure;
1875         if (!fh) {
1876                 tcm->tcm_handle = 0;
1877         } else {
1878                 if (tp->ops->dump &&
1879                     tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
1880                         goto nla_put_failure;
1881         }
1882         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1883         return skb->len;
1884
1885 out_nlmsg_trim:
1886 nla_put_failure:
1887         nlmsg_trim(skb, b);
1888         return -1;
1889 }
1890
1891 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
1892                           struct nlmsghdr *n, struct tcf_proto *tp,
1893                           struct tcf_block *block, struct Qdisc *q,
1894                           u32 parent, void *fh, int event, bool unicast,
1895                           bool rtnl_held)
1896 {
1897         struct sk_buff *skb;
1898         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1899         int err = 0;
1900
1901         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1902         if (!skb)
1903                 return -ENOBUFS;
1904
1905         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1906                           n->nlmsg_seq, n->nlmsg_flags, event,
1907                           rtnl_held) <= 0) {
1908                 kfree_skb(skb);
1909                 return -EINVAL;
1910         }
1911
1912         if (unicast)
1913                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
1914         else
1915                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1916                                      n->nlmsg_flags & NLM_F_ECHO);
1917
1918         if (err > 0)
1919                 err = 0;
1920         return err;
1921 }
1922
1923 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
1924                               struct nlmsghdr *n, struct tcf_proto *tp,
1925                               struct tcf_block *block, struct Qdisc *q,
1926                               u32 parent, void *fh, bool unicast, bool *last,
1927                               bool rtnl_held, struct netlink_ext_ack *extack)
1928 {
1929         struct sk_buff *skb;
1930         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1931         int err;
1932
1933         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1934         if (!skb)
1935                 return -ENOBUFS;
1936
1937         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1938                           n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
1939                           rtnl_held) <= 0) {
1940                 NL_SET_ERR_MSG(extack, "Failed to build del event notification");
1941                 kfree_skb(skb);
1942                 return -EINVAL;
1943         }
1944
1945         err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
1946         if (err) {
1947                 kfree_skb(skb);
1948                 return err;
1949         }
1950
1951         if (unicast)
1952                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
1953         else
1954                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1955                                      n->nlmsg_flags & NLM_F_ECHO);
1956         if (err < 0)
1957                 NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
1958
1959         if (err > 0)
1960                 err = 0;
1961         return err;
1962 }
1963
1964 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
1965                                  struct tcf_block *block, struct Qdisc *q,
1966                                  u32 parent, struct nlmsghdr *n,
1967                                  struct tcf_chain *chain, int event,
1968                                  bool rtnl_held)
1969 {
1970         struct tcf_proto *tp;
1971
1972         for (tp = tcf_get_next_proto(chain, NULL, rtnl_held);
1973              tp; tp = tcf_get_next_proto(chain, tp, rtnl_held))
1974                 tfilter_notify(net, oskb, n, tp, block,
1975                                q, parent, NULL, event, false, rtnl_held);
1976 }
1977
1978 static void tfilter_put(struct tcf_proto *tp, void *fh)
1979 {
1980         if (tp->ops->put && fh)
1981                 tp->ops->put(tp, fh);
1982 }
1983
1984 static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
1985                           struct netlink_ext_ack *extack)
1986 {
1987         struct net *net = sock_net(skb->sk);
1988         struct nlattr *tca[TCA_MAX + 1];
1989         char name[IFNAMSIZ];
1990         struct tcmsg *t;
1991         u32 protocol;
1992         u32 prio;
1993         bool prio_allocate;
1994         u32 parent;
1995         u32 chain_index;
1996         struct Qdisc *q = NULL;
1997         struct tcf_chain_info chain_info;
1998         struct tcf_chain *chain = NULL;
1999         struct tcf_block *block;
2000         struct tcf_proto *tp;
2001         unsigned long cl;
2002         void *fh;
2003         int err;
2004         int tp_created;
2005         bool rtnl_held = false;
2006
2007         if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2008                 return -EPERM;
2009
2010 replay:
2011         tp_created = 0;
2012
2013         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2014                                      rtm_tca_policy, extack);
2015         if (err < 0)
2016                 return err;
2017
2018         t = nlmsg_data(n);
2019         protocol = TC_H_MIN(t->tcm_info);
2020         prio = TC_H_MAJ(t->tcm_info);
2021         prio_allocate = false;
2022         parent = t->tcm_parent;
2023         tp = NULL;
2024         cl = 0;
2025         block = NULL;
2026
2027         if (prio == 0) {
2028                 /* If no priority is provided by the user,
2029                  * we allocate one.
2030                  */
2031                 if (n->nlmsg_flags & NLM_F_CREATE) {
2032                         prio = TC_H_MAKE(0x80000000U, 0U);
2033                         prio_allocate = true;
2034                 } else {
2035                         NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2036                         return -ENOENT;
2037                 }
2038         }
2039
2040         /* Find head of filter chain. */
2041
2042         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2043         if (err)
2044                 return err;
2045
2046         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2047                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2048                 err = -EINVAL;
2049                 goto errout;
2050         }
2051
2052         /* Take rtnl mutex if rtnl_held was set to true on previous iteration,
2053          * block is shared (no qdisc found), qdisc is not unlocked, classifier
2054          * type is not specified, classifier is not unlocked.
2055          */
2056         if (rtnl_held ||
2057             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2058             !tcf_proto_is_unlocked(name)) {
2059                 rtnl_held = true;
2060                 rtnl_lock();
2061         }
2062
2063         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2064         if (err)
2065                 goto errout;
2066
2067         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2068                                  extack);
2069         if (IS_ERR(block)) {
2070                 err = PTR_ERR(block);
2071                 goto errout;
2072         }
2073
2074         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2075         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2076                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2077                 err = -EINVAL;
2078                 goto errout;
2079         }
2080         chain = tcf_chain_get(block, chain_index, true);
2081         if (!chain) {
2082                 NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
2083                 err = -ENOMEM;
2084                 goto errout;
2085         }
2086
2087         mutex_lock(&chain->filter_chain_lock);
2088         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2089                                prio, prio_allocate);
2090         if (IS_ERR(tp)) {
2091                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2092                 err = PTR_ERR(tp);
2093                 goto errout_locked;
2094         }
2095
2096         if (tp == NULL) {
2097                 struct tcf_proto *tp_new = NULL;
2098
2099                 if (chain->flushing) {
2100                         err = -EAGAIN;
2101                         goto errout_locked;
2102                 }
2103
2104                 /* Proto-tcf does not exist, create new one */
2105
2106                 if (tca[TCA_KIND] == NULL || !protocol) {
2107                         NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
2108                         err = -EINVAL;
2109                         goto errout_locked;
2110                 }
2111
2112                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2113                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2114                         err = -ENOENT;
2115                         goto errout_locked;
2116                 }
2117
2118                 if (prio_allocate)
2119                         prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
2120                                                                &chain_info));
2121
2122                 mutex_unlock(&chain->filter_chain_lock);
2123                 tp_new = tcf_proto_create(name, protocol, prio, chain,
2124                                           rtnl_held, extack);
2125                 if (IS_ERR(tp_new)) {
2126                         err = PTR_ERR(tp_new);
2127                         goto errout_tp;
2128                 }
2129
2130                 tp_created = 1;
2131                 tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
2132                                                 rtnl_held);
2133                 if (IS_ERR(tp)) {
2134                         err = PTR_ERR(tp);
2135                         goto errout_tp;
2136                 }
2137         } else {
2138                 mutex_unlock(&chain->filter_chain_lock);
2139         }
2140
2141         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2142                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2143                 err = -EINVAL;
2144                 goto errout;
2145         }
2146
2147         fh = tp->ops->get(tp, t->tcm_handle);
2148
2149         if (!fh) {
2150                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2151                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2152                         err = -ENOENT;
2153                         goto errout;
2154                 }
2155         } else if (n->nlmsg_flags & NLM_F_EXCL) {
2156                 tfilter_put(tp, fh);
2157                 NL_SET_ERR_MSG(extack, "Filter already exists");
2158                 err = -EEXIST;
2159                 goto errout;
2160         }
2161
2162         if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
2163                 NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
2164                 err = -EINVAL;
2165                 goto errout;
2166         }
2167
2168         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
2169                               n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
2170                               rtnl_held, extack);
2171         if (err == 0) {
2172                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2173                                RTM_NEWTFILTER, false, rtnl_held);
2174                 tfilter_put(tp, fh);
2175                 /* q pointer is NULL for shared blocks */
2176                 if (q)
2177                         q->flags &= ~TCQ_F_CAN_BYPASS;
2178         }
2179
2180 errout:
2181         if (err && tp_created)
2182                 tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
2183 errout_tp:
2184         if (chain) {
2185                 if (tp && !IS_ERR(tp))
2186                         tcf_proto_put(tp, rtnl_held, NULL);
2187                 if (!tp_created)
2188                         tcf_chain_put(chain);
2189         }
2190         tcf_block_release(q, block, rtnl_held);
2191
2192         if (rtnl_held)
2193                 rtnl_unlock();
2194
2195         if (err == -EAGAIN) {
2196                 /* Take rtnl lock in case EAGAIN is caused by concurrent flush
2197                  * of target chain.
2198                  */
2199                 rtnl_held = true;
2200                 /* Replay the request. */
2201                 goto replay;
2202         }
2203         return err;
2204
2205 errout_locked:
2206         mutex_unlock(&chain->filter_chain_lock);
2207         goto errout;
2208 }
2209
2210 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2211                           struct netlink_ext_ack *extack)
2212 {
2213         struct net *net = sock_net(skb->sk);
2214         struct nlattr *tca[TCA_MAX + 1];
2215         char name[IFNAMSIZ];
2216         struct tcmsg *t;
2217         u32 protocol;
2218         u32 prio;
2219         u32 parent;
2220         u32 chain_index;
2221         struct Qdisc *q = NULL;
2222         struct tcf_chain_info chain_info;
2223         struct tcf_chain *chain = NULL;
2224         struct tcf_block *block = NULL;
2225         struct tcf_proto *tp = NULL;
2226         unsigned long cl = 0;
2227         void *fh = NULL;
2228         int err;
2229         bool rtnl_held = false;
2230
2231         if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2232                 return -EPERM;
2233
2234         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2235                                      rtm_tca_policy, extack);
2236         if (err < 0)
2237                 return err;
2238
2239         t = nlmsg_data(n);
2240         protocol = TC_H_MIN(t->tcm_info);
2241         prio = TC_H_MAJ(t->tcm_info);
2242         parent = t->tcm_parent;
2243
2244         if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
2245                 NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
2246                 return -ENOENT;
2247         }
2248
2249         /* Find head of filter chain. */
2250
2251         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2252         if (err)
2253                 return err;
2254
2255         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2256                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2257                 err = -EINVAL;
2258                 goto errout;
2259         }
2260         /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
2261          * found), qdisc is not unlocked, classifier type is not specified,
2262          * classifier is not unlocked.
2263          */
2264         if (!prio ||
2265             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2266             !tcf_proto_is_unlocked(name)) {
2267                 rtnl_held = true;
2268                 rtnl_lock();
2269         }
2270
2271         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2272         if (err)
2273                 goto errout;
2274
2275         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2276                                  extack);
2277         if (IS_ERR(block)) {
2278                 err = PTR_ERR(block);
2279                 goto errout;
2280         }
2281
2282         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2283         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2284                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2285                 err = -EINVAL;
2286                 goto errout;
2287         }
2288         chain = tcf_chain_get(block, chain_index, false);
2289         if (!chain) {
2290                 /* User requested flush on non-existent chain. Nothing to do,
2291                  * so just return success.
2292                  */
2293                 if (prio == 0) {
2294                         err = 0;
2295                         goto errout;
2296                 }
2297                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2298                 err = -ENOENT;
2299                 goto errout;
2300         }
2301
2302         if (prio == 0) {
2303                 tfilter_notify_chain(net, skb, block, q, parent, n,
2304                                      chain, RTM_DELTFILTER, rtnl_held);
2305                 tcf_chain_flush(chain, rtnl_held);
2306                 err = 0;
2307                 goto errout;
2308         }
2309
2310         mutex_lock(&chain->filter_chain_lock);
2311         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2312                                prio, false);
2313         if (!tp || IS_ERR(tp)) {
2314                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2315                 err = tp ? PTR_ERR(tp) : -ENOENT;
2316                 goto errout_locked;
2317         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2318                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2319                 err = -EINVAL;
2320                 goto errout_locked;
2321         } else if (t->tcm_handle == 0) {
2322                 tcf_proto_signal_destroying(chain, tp);
2323                 tcf_chain_tp_remove(chain, &chain_info, tp);
2324                 mutex_unlock(&chain->filter_chain_lock);
2325
2326                 tcf_proto_put(tp, rtnl_held, NULL);
2327                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2328                                RTM_DELTFILTER, false, rtnl_held);
2329                 err = 0;
2330                 goto errout;
2331         }
2332         mutex_unlock(&chain->filter_chain_lock);
2333
2334         fh = tp->ops->get(tp, t->tcm_handle);
2335
2336         if (!fh) {
2337                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2338                 err = -ENOENT;
2339         } else {
2340                 bool last;
2341
2342                 err = tfilter_del_notify(net, skb, n, tp, block,
2343                                          q, parent, fh, false, &last,
2344                                          rtnl_held, extack);
2345
2346                 if (err)
2347                         goto errout;
2348                 if (last)
2349                         tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
2350         }
2351
2352 errout:
2353         if (chain) {
2354                 if (tp && !IS_ERR(tp))
2355                         tcf_proto_put(tp, rtnl_held, NULL);
2356                 tcf_chain_put(chain);
2357         }
2358         tcf_block_release(q, block, rtnl_held);
2359
2360         if (rtnl_held)
2361                 rtnl_unlock();
2362
2363         return err;
2364
2365 errout_locked:
2366         mutex_unlock(&chain->filter_chain_lock);
2367         goto errout;
2368 }
2369
2370 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2371                           struct netlink_ext_ack *extack)
2372 {
2373         struct net *net = sock_net(skb->sk);
2374         struct nlattr *tca[TCA_MAX + 1];
2375         char name[IFNAMSIZ];
2376         struct tcmsg *t;
2377         u32 protocol;
2378         u32 prio;
2379         u32 parent;
2380         u32 chain_index;
2381         struct Qdisc *q = NULL;
2382         struct tcf_chain_info chain_info;
2383         struct tcf_chain *chain = NULL;
2384         struct tcf_block *block = NULL;
2385         struct tcf_proto *tp = NULL;
2386         unsigned long cl = 0;
2387         void *fh = NULL;
2388         int err;
2389         bool rtnl_held = false;
2390
2391         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2392                                      rtm_tca_policy, extack);
2393         if (err < 0)
2394                 return err;
2395
2396         t = nlmsg_data(n);
2397         protocol = TC_H_MIN(t->tcm_info);
2398         prio = TC_H_MAJ(t->tcm_info);
2399         parent = t->tcm_parent;
2400
2401         if (prio == 0) {
2402                 NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2403                 return -ENOENT;
2404         }
2405
2406         /* Find head of filter chain. */
2407
2408         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2409         if (err)
2410                 return err;
2411
2412         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2413                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2414                 err = -EINVAL;
2415                 goto errout;
2416         }
2417         /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
2418          * unlocked, classifier type is not specified, classifier is not
2419          * unlocked.
2420          */
2421         if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2422             !tcf_proto_is_unlocked(name)) {
2423                 rtnl_held = true;
2424                 rtnl_lock();
2425         }
2426
2427         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2428         if (err)
2429                 goto errout;
2430
2431         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2432                                  extack);
2433         if (IS_ERR(block)) {
2434                 err = PTR_ERR(block);
2435                 goto errout;
2436         }
2437
2438         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2439         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2440                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2441                 err = -EINVAL;
2442                 goto errout;
2443         }
2444         chain = tcf_chain_get(block, chain_index, false);
2445         if (!chain) {
2446                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2447                 err = -EINVAL;
2448                 goto errout;
2449         }
2450
2451         mutex_lock(&chain->filter_chain_lock);
2452         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2453                                prio, false);
2454         mutex_unlock(&chain->filter_chain_lock);
2455         if (!tp || IS_ERR(tp)) {
2456                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2457                 err = tp ? PTR_ERR(tp) : -ENOENT;
2458                 goto errout;
2459         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2460                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2461                 err = -EINVAL;
2462                 goto errout;
2463         }
2464
2465         fh = tp->ops->get(tp, t->tcm_handle);
2466
2467         if (!fh) {
2468                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2469                 err = -ENOENT;
2470         } else {
2471                 err = tfilter_notify(net, skb, n, tp, block, q, parent,
2472                                      fh, RTM_NEWTFILTER, true, rtnl_held);
2473                 if (err < 0)
2474                         NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
2475         }
2476
2477         tfilter_put(tp, fh);
2478 errout:
2479         if (chain) {
2480                 if (tp && !IS_ERR(tp))
2481                         tcf_proto_put(tp, rtnl_held, NULL);
2482                 tcf_chain_put(chain);
2483         }
2484         tcf_block_release(q, block, rtnl_held);
2485
2486         if (rtnl_held)
2487                 rtnl_unlock();
2488
2489         return err;
2490 }
2491
2492 struct tcf_dump_args {
2493         struct tcf_walker w;
2494         struct sk_buff *skb;
2495         struct netlink_callback *cb;
2496         struct tcf_block *block;
2497         struct Qdisc *q;
2498         u32 parent;
2499 };
2500
2501 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2502 {
2503         struct tcf_dump_args *a = (void *)arg;
2504         struct net *net = sock_net(a->skb->sk);
2505
2506         return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
2507                              n, NETLINK_CB(a->cb->skb).portid,
2508                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2509                              RTM_NEWTFILTER, true);
2510 }
2511
2512 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
2513                            struct sk_buff *skb, struct netlink_callback *cb,
2514                            long index_start, long *p_index)
2515 {
2516         struct net *net = sock_net(skb->sk);
2517         struct tcf_block *block = chain->block;
2518         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2519         struct tcf_proto *tp, *tp_prev;
2520         struct tcf_dump_args arg;
2521
2522         for (tp = __tcf_get_next_proto(chain, NULL);
2523              tp;
2524              tp_prev = tp,
2525                      tp = __tcf_get_next_proto(chain, tp),
2526                      tcf_proto_put(tp_prev, true, NULL),
2527                      (*p_index)++) {
2528                 if (*p_index < index_start)
2529                         continue;
2530                 if (TC_H_MAJ(tcm->tcm_info) &&
2531                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
2532                         continue;
2533                 if (TC_H_MIN(tcm->tcm_info) &&
2534                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
2535                         continue;
2536                 if (*p_index > index_start)
2537                         memset(&cb->args[1], 0,
2538                                sizeof(cb->args) - sizeof(cb->args[0]));
2539                 if (cb->args[1] == 0) {
2540                         if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
2541                                           NETLINK_CB(cb->skb).portid,
2542                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
2543                                           RTM_NEWTFILTER, true) <= 0)
2544                                 goto errout;
2545                         cb->args[1] = 1;
2546                 }
2547                 if (!tp->ops->walk)
2548                         continue;
2549                 arg.w.fn = tcf_node_dump;
2550                 arg.skb = skb;
2551                 arg.cb = cb;
2552                 arg.block = block;
2553                 arg.q = q;
2554                 arg.parent = parent;
2555                 arg.w.stop = 0;
2556                 arg.w.skip = cb->args[1] - 1;
2557                 arg.w.count = 0;
2558                 arg.w.cookie = cb->args[2];
2559                 tp->ops->walk(tp, &arg.w, true);
2560                 cb->args[2] = arg.w.cookie;
2561                 cb->args[1] = arg.w.count + 1;
2562                 if (arg.w.stop)
2563                         goto errout;
2564         }
2565         return true;
2566
2567 errout:
2568         tcf_proto_put(tp, true, NULL);
2569         return false;
2570 }
2571
2572 /* called with RTNL */
2573 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
2574 {
2575         struct tcf_chain *chain, *chain_prev;
2576         struct net *net = sock_net(skb->sk);
2577         struct nlattr *tca[TCA_MAX + 1];
2578         struct Qdisc *q = NULL;
2579         struct tcf_block *block;
2580         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2581         long index_start;
2582         long index;
2583         u32 parent;
2584         int err;
2585
2586         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2587                 return skb->len;
2588
2589         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2590                                      NULL, cb->extack);
2591         if (err)
2592                 return err;
2593
2594         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2595                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2596                 if (!block)
2597                         goto out;
2598                 /* If we work with block index, q is NULL and parent value
2599                  * will never be used in the following code. The check
2600                  * in tcf_fill_node prevents it. However, compiler does not
2601                  * see that far, so set parent to zero to silence the warning
2602                  * about parent being uninitialized.
2603                  */
2604                 parent = 0;
2605         } else {
2606                 const struct Qdisc_class_ops *cops;
2607                 struct net_device *dev;
2608                 unsigned long cl = 0;
2609
2610                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2611                 if (!dev)
2612                         return skb->len;
2613
2614                 parent = tcm->tcm_parent;
2615                 if (!parent) {
2616                         q = dev->qdisc;
2617                         parent = q->handle;
2618                 } else {
2619                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2620                 }
2621                 if (!q)
2622                         goto out;
2623                 cops = q->ops->cl_ops;
2624                 if (!cops)
2625                         goto out;
2626                 if (!cops->tcf_block)
2627                         goto out;
2628                 if (TC_H_MIN(tcm->tcm_parent)) {
2629                         cl = cops->find(q, tcm->tcm_parent);
2630                         if (cl == 0)
2631                                 goto out;
2632                 }
2633                 block = cops->tcf_block(q, cl, NULL);
2634                 if (!block)
2635                         goto out;
2636                 if (tcf_block_shared(block))
2637                         q = NULL;
2638         }
2639
2640         index_start = cb->args[0];
2641         index = 0;
2642
2643         for (chain = __tcf_get_next_chain(block, NULL);
2644              chain;
2645              chain_prev = chain,
2646                      chain = __tcf_get_next_chain(block, chain),
2647                      tcf_chain_put(chain_prev)) {
2648                 if (tca[TCA_CHAIN] &&
2649                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
2650                         continue;
2651                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
2652                                     index_start, &index)) {
2653                         tcf_chain_put(chain);
2654                         err = -EMSGSIZE;
2655                         break;
2656                 }
2657         }
2658
2659         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2660                 tcf_block_refcnt_put(block, true);
2661         cb->args[0] = index;
2662
2663 out:
2664         /* If we did no progress, the error (EMSGSIZE) is real */
2665         if (skb->len == 0 && err)
2666                 return err;
2667         return skb->len;
2668 }
2669
2670 static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
2671                               void *tmplt_priv, u32 chain_index,
2672                               struct net *net, struct sk_buff *skb,
2673                               struct tcf_block *block,
2674                               u32 portid, u32 seq, u16 flags, int event)
2675 {
2676         unsigned char *b = skb_tail_pointer(skb);
2677         const struct tcf_proto_ops *ops;
2678         struct nlmsghdr *nlh;
2679         struct tcmsg *tcm;
2680         void *priv;
2681
2682         ops = tmplt_ops;
2683         priv = tmplt_priv;
2684
2685         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2686         if (!nlh)
2687                 goto out_nlmsg_trim;
2688         tcm = nlmsg_data(nlh);
2689         tcm->tcm_family = AF_UNSPEC;
2690         tcm->tcm__pad1 = 0;
2691         tcm->tcm__pad2 = 0;
2692         tcm->tcm_handle = 0;
2693         if (block->q) {
2694                 tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
2695                 tcm->tcm_parent = block->q->handle;
2696         } else {
2697                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2698                 tcm->tcm_block_index = block->index;
2699         }
2700
2701         if (nla_put_u32(skb, TCA_CHAIN, chain_index))
2702                 goto nla_put_failure;
2703
2704         if (ops) {
2705                 if (nla_put_string(skb, TCA_KIND, ops->kind))
2706                         goto nla_put_failure;
2707                 if (ops->tmplt_dump(skb, net, priv) < 0)
2708                         goto nla_put_failure;
2709         }
2710
2711         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2712         return skb->len;
2713
2714 out_nlmsg_trim:
2715 nla_put_failure:
2716         nlmsg_trim(skb, b);
2717         return -EMSGSIZE;
2718 }
2719
2720 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
2721                            u32 seq, u16 flags, int event, bool unicast)
2722 {
2723         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2724         struct tcf_block *block = chain->block;
2725         struct net *net = block->net;
2726         struct sk_buff *skb;
2727         int err = 0;
2728
2729         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2730         if (!skb)
2731                 return -ENOBUFS;
2732
2733         if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2734                                chain->index, net, skb, block, portid,
2735                                seq, flags, event) <= 0) {
2736                 kfree_skb(skb);
2737                 return -EINVAL;
2738         }
2739
2740         if (unicast)
2741                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
2742         else
2743                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2744                                      flags & NLM_F_ECHO);
2745
2746         if (err > 0)
2747                 err = 0;
2748         return err;
2749 }
2750
2751 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
2752                                   void *tmplt_priv, u32 chain_index,
2753                                   struct tcf_block *block, struct sk_buff *oskb,
2754                                   u32 seq, u16 flags, bool unicast)
2755 {
2756         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2757         struct net *net = block->net;
2758         struct sk_buff *skb;
2759
2760         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2761         if (!skb)
2762                 return -ENOBUFS;
2763
2764         if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
2765                                block, portid, seq, flags, RTM_DELCHAIN) <= 0) {
2766                 kfree_skb(skb);
2767                 return -EINVAL;
2768         }
2769
2770         if (unicast)
2771                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
2772
2773         return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
2774 }
2775
2776 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
2777                               struct nlattr **tca,
2778                               struct netlink_ext_ack *extack)
2779 {
2780         const struct tcf_proto_ops *ops;
2781         char name[IFNAMSIZ];
2782         void *tmplt_priv;
2783
2784         /* If kind is not set, user did not specify template. */
2785         if (!tca[TCA_KIND])
2786                 return 0;
2787
2788         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2789                 NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
2790                 return -EINVAL;
2791         }
2792
2793         ops = tcf_proto_lookup_ops(name, true, extack);
2794         if (IS_ERR(ops))
2795                 return PTR_ERR(ops);
2796         if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
2797                 NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
2798                 return -EOPNOTSUPP;
2799         }
2800
2801         tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
2802         if (IS_ERR(tmplt_priv)) {
2803                 module_put(ops->owner);
2804                 return PTR_ERR(tmplt_priv);
2805         }
2806         chain->tmplt_ops = ops;
2807         chain->tmplt_priv = tmplt_priv;
2808         return 0;
2809 }
2810
2811 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
2812                                void *tmplt_priv)
2813 {
2814         /* If template ops are set, no work to do for us. */
2815         if (!tmplt_ops)
2816                 return;
2817
2818         tmplt_ops->tmplt_destroy(tmplt_priv);
2819         module_put(tmplt_ops->owner);
2820 }
2821
2822 /* Add/delete/get a chain */
2823
2824 static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
2825                         struct netlink_ext_ack *extack)
2826 {
2827         struct net *net = sock_net(skb->sk);
2828         struct nlattr *tca[TCA_MAX + 1];
2829         struct tcmsg *t;
2830         u32 parent;
2831         u32 chain_index;
2832         struct Qdisc *q = NULL;
2833         struct tcf_chain *chain = NULL;
2834         struct tcf_block *block;
2835         unsigned long cl;
2836         int err;
2837
2838         if (n->nlmsg_type != RTM_GETCHAIN &&
2839             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2840                 return -EPERM;
2841
2842 replay:
2843         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2844                                      rtm_tca_policy, extack);
2845         if (err < 0)
2846                 return err;
2847
2848         t = nlmsg_data(n);
2849         parent = t->tcm_parent;
2850         cl = 0;
2851
2852         block = tcf_block_find(net, &q, &parent, &cl,
2853                                t->tcm_ifindex, t->tcm_block_index, extack);
2854         if (IS_ERR(block))
2855                 return PTR_ERR(block);
2856
2857         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2858         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2859                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2860                 err = -EINVAL;
2861                 goto errout_block;
2862         }
2863
2864         mutex_lock(&block->lock);
2865         chain = tcf_chain_lookup(block, chain_index);
2866         if (n->nlmsg_type == RTM_NEWCHAIN) {
2867                 if (chain) {
2868                         if (tcf_chain_held_by_acts_only(chain)) {
2869                                 /* The chain exists only because there is
2870                                  * some action referencing it.
2871                                  */
2872                                 tcf_chain_hold(chain);
2873                         } else {
2874                                 NL_SET_ERR_MSG(extack, "Filter chain already exists");
2875                                 err = -EEXIST;
2876                                 goto errout_block_locked;
2877                         }
2878                 } else {
2879                         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2880                                 NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
2881                                 err = -ENOENT;
2882                                 goto errout_block_locked;
2883                         }
2884                         chain = tcf_chain_create(block, chain_index);
2885                         if (!chain) {
2886                                 NL_SET_ERR_MSG(extack, "Failed to create filter chain");
2887                                 err = -ENOMEM;
2888                                 goto errout_block_locked;
2889                         }
2890                 }
2891         } else {
2892                 if (!chain || tcf_chain_held_by_acts_only(chain)) {
2893                         NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2894                         err = -EINVAL;
2895                         goto errout_block_locked;
2896                 }
2897                 tcf_chain_hold(chain);
2898         }
2899
2900         if (n->nlmsg_type == RTM_NEWCHAIN) {
2901                 /* Modifying chain requires holding parent block lock. In case
2902                  * the chain was successfully added, take a reference to the
2903                  * chain. This ensures that an empty chain does not disappear at
2904                  * the end of this function.
2905                  */
2906                 tcf_chain_hold(chain);
2907                 chain->explicitly_created = true;
2908         }
2909         mutex_unlock(&block->lock);
2910
2911         switch (n->nlmsg_type) {
2912         case RTM_NEWCHAIN:
2913                 err = tc_chain_tmplt_add(chain, net, tca, extack);
2914                 if (err) {
2915                         tcf_chain_put_explicitly_created(chain);
2916                         goto errout;
2917                 }
2918
2919                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
2920                                 RTM_NEWCHAIN, false);
2921                 break;
2922         case RTM_DELCHAIN:
2923                 tfilter_notify_chain(net, skb, block, q, parent, n,
2924                                      chain, RTM_DELTFILTER, true);
2925                 /* Flush the chain first as the user requested chain removal. */
2926                 tcf_chain_flush(chain, true);
2927                 /* In case the chain was successfully deleted, put a reference
2928                  * to the chain previously taken during addition.
2929                  */
2930                 tcf_chain_put_explicitly_created(chain);
2931                 break;
2932         case RTM_GETCHAIN:
2933                 err = tc_chain_notify(chain, skb, n->nlmsg_seq,
2934                                       n->nlmsg_seq, n->nlmsg_type, true);
2935                 if (err < 0)
2936                         NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
2937                 break;
2938         default:
2939                 err = -EOPNOTSUPP;
2940                 NL_SET_ERR_MSG(extack, "Unsupported message type");
2941                 goto errout;
2942         }
2943
2944 errout:
2945         tcf_chain_put(chain);
2946 errout_block:
2947         tcf_block_release(q, block, true);
2948         if (err == -EAGAIN)
2949                 /* Replay the request. */
2950                 goto replay;
2951         return err;
2952
2953 errout_block_locked:
2954         mutex_unlock(&block->lock);
2955         goto errout_block;
2956 }
2957
2958 /* called with RTNL */
2959 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
2960 {
2961         struct net *net = sock_net(skb->sk);
2962         struct nlattr *tca[TCA_MAX + 1];
2963         struct Qdisc *q = NULL;
2964         struct tcf_block *block;
2965         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2966         struct tcf_chain *chain;
2967         long index_start;
2968         long index;
2969         u32 parent;
2970         int err;
2971
2972         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2973                 return skb->len;
2974
2975         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2976                                      rtm_tca_policy, cb->extack);
2977         if (err)
2978                 return err;
2979
2980         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2981                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2982                 if (!block)
2983                         goto out;
2984                 /* If we work with block index, q is NULL and parent value
2985                  * will never be used in the following code. The check
2986                  * in tcf_fill_node prevents it. However, compiler does not
2987                  * see that far, so set parent to zero to silence the warning
2988                  * about parent being uninitialized.
2989                  */
2990                 parent = 0;
2991         } else {
2992                 const struct Qdisc_class_ops *cops;
2993                 struct net_device *dev;
2994                 unsigned long cl = 0;
2995
2996                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2997                 if (!dev)
2998                         return skb->len;
2999
3000                 parent = tcm->tcm_parent;
3001                 if (!parent) {
3002                         q = dev->qdisc;
3003                         parent = q->handle;
3004                 } else {
3005                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
3006                 }
3007                 if (!q)
3008                         goto out;
3009                 cops = q->ops->cl_ops;
3010                 if (!cops)
3011                         goto out;
3012                 if (!cops->tcf_block)
3013                         goto out;
3014                 if (TC_H_MIN(tcm->tcm_parent)) {
3015                         cl = cops->find(q, tcm->tcm_parent);
3016                         if (cl == 0)
3017                                 goto out;
3018                 }
3019                 block = cops->tcf_block(q, cl, NULL);
3020                 if (!block)
3021                         goto out;
3022                 if (tcf_block_shared(block))
3023                         q = NULL;
3024         }
3025
3026         index_start = cb->args[0];
3027         index = 0;
3028
3029         mutex_lock(&block->lock);
3030         list_for_each_entry(chain, &block->chain_list, list) {
3031                 if ((tca[TCA_CHAIN] &&
3032                      nla_get_u32(tca[TCA_CHAIN]) != chain->index))
3033                         continue;
3034                 if (index < index_start) {
3035                         index++;
3036                         continue;
3037                 }
3038                 if (tcf_chain_held_by_acts_only(chain))
3039                         continue;
3040                 err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
3041                                          chain->index, net, skb, block,
3042                                          NETLINK_CB(cb->skb).portid,
3043                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
3044                                          RTM_NEWCHAIN);
3045                 if (err <= 0)
3046                         break;
3047                 index++;
3048         }
3049         mutex_unlock(&block->lock);
3050
3051         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
3052                 tcf_block_refcnt_put(block, true);
3053         cb->args[0] = index;
3054
3055 out:
3056         /* If we did no progress, the error (EMSGSIZE) is real */
3057         if (skb->len == 0 && err)
3058                 return err;
3059         return skb->len;
3060 }
3061
3062 void tcf_exts_destroy(struct tcf_exts *exts)
3063 {
3064 #ifdef CONFIG_NET_CLS_ACT
3065         if (exts->actions) {
3066                 tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
3067                 kfree(exts->actions);
3068         }
3069         exts->nr_actions = 0;
3070 #endif
3071 }
3072 EXPORT_SYMBOL(tcf_exts_destroy);
3073
3074 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3075                       struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr,
3076                       bool rtnl_held, struct netlink_ext_ack *extack)
3077 {
3078 #ifdef CONFIG_NET_CLS_ACT
3079         {
3080                 struct tc_action *act;
3081                 size_t attr_size = 0;
3082
3083                 if (exts->police && tb[exts->police]) {
3084                         act = tcf_action_init_1(net, tp, tb[exts->police],
3085                                                 rate_tlv, "police", ovr,
3086                                                 TCA_ACT_BIND, rtnl_held,
3087                                                 extack);
3088                         if (IS_ERR(act))
3089                                 return PTR_ERR(act);
3090
3091                         act->type = exts->type = TCA_OLD_COMPAT;
3092                         exts->actions[0] = act;
3093                         exts->nr_actions = 1;
3094                 } else if (exts->action && tb[exts->action]) {
3095                         int err;
3096
3097                         err = tcf_action_init(net, tp, tb[exts->action],
3098                                               rate_tlv, NULL, ovr, TCA_ACT_BIND,
3099                                               exts->actions, &attr_size,
3100                                               rtnl_held, extack);
3101                         if (err < 0)
3102                                 return err;
3103                         exts->nr_actions = err;
3104                 }
3105         }
3106 #else
3107         if ((exts->action && tb[exts->action]) ||
3108             (exts->police && tb[exts->police])) {
3109                 NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
3110                 return -EOPNOTSUPP;
3111         }
3112 #endif
3113
3114         return 0;
3115 }
3116 EXPORT_SYMBOL(tcf_exts_validate);
3117
3118 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
3119 {
3120 #ifdef CONFIG_NET_CLS_ACT
3121         struct tcf_exts old = *dst;
3122
3123         *dst = *src;
3124         tcf_exts_destroy(&old);
3125 #endif
3126 }
3127 EXPORT_SYMBOL(tcf_exts_change);
3128
3129 #ifdef CONFIG_NET_CLS_ACT
3130 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
3131 {
3132         if (exts->nr_actions == 0)
3133                 return NULL;
3134         else
3135                 return exts->actions[0];
3136 }
3137 #endif
3138
3139 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
3140 {
3141 #ifdef CONFIG_NET_CLS_ACT
3142         struct nlattr *nest;
3143
3144         if (exts->action && tcf_exts_has_actions(exts)) {
3145                 /*
3146                  * again for backward compatible mode - we want
3147                  * to work with both old and new modes of entering
3148                  * tc data even if iproute2  was newer - jhs
3149                  */
3150                 if (exts->type != TCA_OLD_COMPAT) {
3151                         nest = nla_nest_start_noflag(skb, exts->action);
3152                         if (nest == NULL)
3153                                 goto nla_put_failure;
3154
3155                         if (tcf_action_dump(skb, exts->actions, 0, 0) < 0)
3156                                 goto nla_put_failure;
3157                         nla_nest_end(skb, nest);
3158                 } else if (exts->police) {
3159                         struct tc_action *act = tcf_exts_first_act(exts);
3160                         nest = nla_nest_start_noflag(skb, exts->police);
3161                         if (nest == NULL || !act)
3162                                 goto nla_put_failure;
3163                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
3164                                 goto nla_put_failure;
3165                         nla_nest_end(skb, nest);
3166                 }
3167         }
3168         return 0;
3169
3170 nla_put_failure:
3171         nla_nest_cancel(skb, nest);
3172         return -1;
3173 #else
3174         return 0;
3175 #endif
3176 }
3177 EXPORT_SYMBOL(tcf_exts_dump);
3178
3179
3180 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
3181 {
3182 #ifdef CONFIG_NET_CLS_ACT
3183         struct tc_action *a = tcf_exts_first_act(exts);
3184         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
3185                 return -1;
3186 #endif
3187         return 0;
3188 }
3189 EXPORT_SYMBOL(tcf_exts_dump_stats);
3190
3191 static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
3192 {
3193         if (*flags & TCA_CLS_FLAGS_IN_HW)
3194                 return;
3195         *flags |= TCA_CLS_FLAGS_IN_HW;
3196         atomic_inc(&block->offloadcnt);
3197 }
3198
3199 static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
3200 {
3201         if (!(*flags & TCA_CLS_FLAGS_IN_HW))
3202                 return;
3203         *flags &= ~TCA_CLS_FLAGS_IN_HW;
3204         atomic_dec(&block->offloadcnt);
3205 }
3206
3207 static void tc_cls_offload_cnt_update(struct tcf_block *block,
3208                                       struct tcf_proto *tp, u32 *cnt,
3209                                       u32 *flags, u32 diff, bool add)
3210 {
3211         lockdep_assert_held(&block->cb_lock);
3212
3213         spin_lock(&tp->lock);
3214         if (add) {
3215                 if (!*cnt)
3216                         tcf_block_offload_inc(block, flags);
3217                 *cnt += diff;
3218         } else {
3219                 *cnt -= diff;
3220                 if (!*cnt)
3221                         tcf_block_offload_dec(block, flags);
3222         }
3223         spin_unlock(&tp->lock);
3224 }
3225
3226 static void
3227 tc_cls_offload_cnt_reset(struct tcf_block *block, struct tcf_proto *tp,
3228                          u32 *cnt, u32 *flags)
3229 {
3230         lockdep_assert_held(&block->cb_lock);
3231
3232         spin_lock(&tp->lock);
3233         tcf_block_offload_dec(block, flags);
3234         *cnt = 0;
3235         spin_unlock(&tp->lock);
3236 }
3237
3238 static int
3239 __tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3240                    void *type_data, bool err_stop)
3241 {
3242         struct flow_block_cb *block_cb;
3243         int ok_count = 0;
3244         int err;
3245
3246         list_for_each_entry(block_cb, &block->flow_block.cb_list, list) {
3247                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
3248                 if (err) {
3249                         if (err_stop)
3250                                 return err;
3251                 } else {
3252                         ok_count++;
3253                 }
3254         }
3255         return ok_count;
3256 }
3257
3258 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3259                      void *type_data, bool err_stop, bool rtnl_held)
3260 {
3261         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3262         int ok_count;
3263
3264 retry:
3265         if (take_rtnl)
3266                 rtnl_lock();
3267         down_read(&block->cb_lock);
3268         /* Need to obtain rtnl lock if block is bound to devs that require it.
3269          * In block bind code cb_lock is obtained while holding rtnl, so we must
3270          * obtain the locks in same order here.
3271          */
3272         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3273                 up_read(&block->cb_lock);
3274                 take_rtnl = true;
3275                 goto retry;
3276         }
3277
3278         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3279
3280         up_read(&block->cb_lock);
3281         if (take_rtnl)
3282                 rtnl_unlock();
3283         return ok_count;
3284 }
3285 EXPORT_SYMBOL(tc_setup_cb_call);
3286
3287 /* Non-destructive filter add. If filter that wasn't already in hardware is
3288  * successfully offloaded, increment block offloads counter. On failure,
3289  * previously offloaded filter is considered to be intact and offloads counter
3290  * is not decremented.
3291  */
3292
3293 int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
3294                     enum tc_setup_type type, void *type_data, bool err_stop,
3295                     u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3296 {
3297         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3298         int ok_count;
3299
3300 retry:
3301         if (take_rtnl)
3302                 rtnl_lock();
3303         down_read(&block->cb_lock);
3304         /* Need to obtain rtnl lock if block is bound to devs that require it.
3305          * In block bind code cb_lock is obtained while holding rtnl, so we must
3306          * obtain the locks in same order here.
3307          */
3308         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3309                 up_read(&block->cb_lock);
3310                 take_rtnl = true;
3311                 goto retry;
3312         }
3313
3314         /* Make sure all netdevs sharing this block are offload-capable. */
3315         if (block->nooffloaddevcnt && err_stop) {
3316                 ok_count = -EOPNOTSUPP;
3317                 goto err_unlock;
3318         }
3319
3320         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3321         if (ok_count < 0)
3322                 goto err_unlock;
3323
3324         if (tp->ops->hw_add)
3325                 tp->ops->hw_add(tp, type_data);
3326         if (ok_count > 0)
3327                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
3328                                           ok_count, true);
3329 err_unlock:
3330         up_read(&block->cb_lock);
3331         if (take_rtnl)
3332                 rtnl_unlock();
3333         return ok_count < 0 ? ok_count : 0;
3334 }
3335 EXPORT_SYMBOL(tc_setup_cb_add);
3336
3337 /* Destructive filter replace. If filter that wasn't already in hardware is
3338  * successfully offloaded, increment block offload counter. On failure,
3339  * previously offloaded filter is considered to be destroyed and offload counter
3340  * is decremented.
3341  */
3342
3343 int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
3344                         enum tc_setup_type type, void *type_data, bool err_stop,
3345                         u32 *old_flags, unsigned int *old_in_hw_count,
3346                         u32 *new_flags, unsigned int *new_in_hw_count,
3347                         bool rtnl_held)
3348 {
3349         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3350         int ok_count;
3351
3352 retry:
3353         if (take_rtnl)
3354                 rtnl_lock();
3355         down_read(&block->cb_lock);
3356         /* Need to obtain rtnl lock if block is bound to devs that require it.
3357          * In block bind code cb_lock is obtained while holding rtnl, so we must
3358          * obtain the locks in same order here.
3359          */
3360         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3361                 up_read(&block->cb_lock);
3362                 take_rtnl = true;
3363                 goto retry;
3364         }
3365
3366         /* Make sure all netdevs sharing this block are offload-capable. */
3367         if (block->nooffloaddevcnt && err_stop) {
3368                 ok_count = -EOPNOTSUPP;
3369                 goto err_unlock;
3370         }
3371
3372         tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
3373         if (tp->ops->hw_del)
3374                 tp->ops->hw_del(tp, type_data);
3375
3376         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3377         if (ok_count < 0)
3378                 goto err_unlock;
3379
3380         if (tp->ops->hw_add)
3381                 tp->ops->hw_add(tp, type_data);
3382         if (ok_count > 0)
3383                 tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
3384                                           new_flags, ok_count, true);
3385 err_unlock:
3386         up_read(&block->cb_lock);
3387         if (take_rtnl)
3388                 rtnl_unlock();
3389         return ok_count < 0 ? ok_count : 0;
3390 }
3391 EXPORT_SYMBOL(tc_setup_cb_replace);
3392
3393 /* Destroy filter and decrement block offload counter, if filter was previously
3394  * offloaded.
3395  */
3396
3397 int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
3398                         enum tc_setup_type type, void *type_data, bool err_stop,
3399                         u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3400 {
3401         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3402         int ok_count;
3403
3404 retry:
3405         if (take_rtnl)
3406                 rtnl_lock();
3407         down_read(&block->cb_lock);
3408         /* Need to obtain rtnl lock if block is bound to devs that require it.
3409          * In block bind code cb_lock is obtained while holding rtnl, so we must
3410          * obtain the locks in same order here.
3411          */
3412         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3413                 up_read(&block->cb_lock);
3414                 take_rtnl = true;
3415                 goto retry;
3416         }
3417
3418         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3419
3420         tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
3421         if (tp->ops->hw_del)
3422                 tp->ops->hw_del(tp, type_data);
3423
3424         up_read(&block->cb_lock);
3425         if (take_rtnl)
3426                 rtnl_unlock();
3427         return ok_count < 0 ? ok_count : 0;
3428 }
3429 EXPORT_SYMBOL(tc_setup_cb_destroy);
3430
3431 int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
3432                           bool add, flow_setup_cb_t *cb,
3433                           enum tc_setup_type type, void *type_data,
3434                           void *cb_priv, u32 *flags, unsigned int *in_hw_count)
3435 {
3436         int err = cb(type, type_data, cb_priv);
3437
3438         if (err) {
3439                 if (add && tc_skip_sw(*flags))
3440                         return err;
3441         } else {
3442                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags, 1,
3443                                           add);
3444         }
3445
3446         return 0;
3447 }
3448 EXPORT_SYMBOL(tc_setup_cb_reoffload);
3449
3450 static int tcf_act_get_cookie(struct flow_action_entry *entry,
3451                               const struct tc_action *act)
3452 {
3453         struct tc_cookie *cookie;
3454         int err = 0;
3455
3456         rcu_read_lock();
3457         cookie = rcu_dereference(act->act_cookie);
3458         if (cookie) {
3459                 entry->cookie = flow_action_cookie_create(cookie->data,
3460                                                           cookie->len,
3461                                                           GFP_ATOMIC);
3462                 if (!entry->cookie)
3463                         err = -ENOMEM;
3464         }
3465         rcu_read_unlock();
3466         return err;
3467 }
3468
3469 static void tcf_act_put_cookie(struct flow_action_entry *entry)
3470 {
3471         flow_action_cookie_destroy(entry->cookie);
3472 }
3473
3474 void tc_cleanup_flow_action(struct flow_action *flow_action)
3475 {
3476         struct flow_action_entry *entry;
3477         int i;
3478
3479         flow_action_for_each(i, entry, flow_action) {
3480                 tcf_act_put_cookie(entry);
3481                 if (entry->destructor)
3482                         entry->destructor(entry->destructor_priv);
3483         }
3484 }
3485 EXPORT_SYMBOL(tc_cleanup_flow_action);
3486
3487 static void tcf_mirred_get_dev(struct flow_action_entry *entry,
3488                                const struct tc_action *act)
3489 {
3490 #ifdef CONFIG_NET_CLS_ACT
3491         entry->dev = act->ops->get_dev(act, &entry->destructor);
3492         if (!entry->dev)
3493                 return;
3494         entry->destructor_priv = entry->dev;
3495 #endif
3496 }
3497
3498 static void tcf_tunnel_encap_put_tunnel(void *priv)
3499 {
3500         struct ip_tunnel_info *tunnel = priv;
3501
3502         kfree(tunnel);
3503 }
3504
3505 static int tcf_tunnel_encap_get_tunnel(struct flow_action_entry *entry,
3506                                        const struct tc_action *act)
3507 {
3508         entry->tunnel = tcf_tunnel_info_copy(act);
3509         if (!entry->tunnel)
3510                 return -ENOMEM;
3511         entry->destructor = tcf_tunnel_encap_put_tunnel;
3512         entry->destructor_priv = entry->tunnel;
3513         return 0;
3514 }
3515
3516 static void tcf_sample_get_group(struct flow_action_entry *entry,
3517                                  const struct tc_action *act)
3518 {
3519 #ifdef CONFIG_NET_CLS_ACT
3520         entry->sample.psample_group =
3521                 act->ops->get_psample_group(act, &entry->destructor);
3522         entry->destructor_priv = entry->sample.psample_group;
3523 #endif
3524 }
3525
3526 int tc_setup_flow_action(struct flow_action *flow_action,
3527                          const struct tcf_exts *exts)
3528 {
3529         struct tc_action *act;
3530         int i, j, k, err = 0;
3531
3532         BUILD_BUG_ON(TCA_ACT_HW_STATS_ANY != FLOW_ACTION_HW_STATS_ANY);
3533         BUILD_BUG_ON(TCA_ACT_HW_STATS_IMMEDIATE != FLOW_ACTION_HW_STATS_IMMEDIATE);
3534         BUILD_BUG_ON(TCA_ACT_HW_STATS_DELAYED != FLOW_ACTION_HW_STATS_DELAYED);
3535
3536         if (!exts)
3537                 return 0;
3538
3539         j = 0;
3540         tcf_exts_for_each_action(i, act, exts) {
3541                 struct flow_action_entry *entry;
3542
3543                 entry = &flow_action->entries[j];
3544                 spin_lock_bh(&act->tcfa_lock);
3545                 err = tcf_act_get_cookie(entry, act);
3546                 if (err)
3547                         goto err_out_locked;
3548
3549                 entry->hw_stats = act->hw_stats;
3550
3551                 if (is_tcf_gact_ok(act)) {
3552                         entry->id = FLOW_ACTION_ACCEPT;
3553                 } else if (is_tcf_gact_shot(act)) {
3554                         entry->id = FLOW_ACTION_DROP;
3555                 } else if (is_tcf_gact_trap(act)) {
3556                         entry->id = FLOW_ACTION_TRAP;
3557                 } else if (is_tcf_gact_goto_chain(act)) {
3558                         entry->id = FLOW_ACTION_GOTO;
3559                         entry->chain_index = tcf_gact_goto_chain_index(act);
3560                 } else if (is_tcf_mirred_egress_redirect(act)) {
3561                         entry->id = FLOW_ACTION_REDIRECT;
3562                         tcf_mirred_get_dev(entry, act);
3563                 } else if (is_tcf_mirred_egress_mirror(act)) {
3564                         entry->id = FLOW_ACTION_MIRRED;
3565                         tcf_mirred_get_dev(entry, act);
3566                 } else if (is_tcf_mirred_ingress_redirect(act)) {
3567                         entry->id = FLOW_ACTION_REDIRECT_INGRESS;
3568                         tcf_mirred_get_dev(entry, act);
3569                 } else if (is_tcf_mirred_ingress_mirror(act)) {
3570                         entry->id = FLOW_ACTION_MIRRED_INGRESS;
3571                         tcf_mirred_get_dev(entry, act);
3572                 } else if (is_tcf_vlan(act)) {
3573                         switch (tcf_vlan_action(act)) {
3574                         case TCA_VLAN_ACT_PUSH:
3575                                 entry->id = FLOW_ACTION_VLAN_PUSH;
3576                                 entry->vlan.vid = tcf_vlan_push_vid(act);
3577                                 entry->vlan.proto = tcf_vlan_push_proto(act);
3578                                 entry->vlan.prio = tcf_vlan_push_prio(act);
3579                                 break;
3580                         case TCA_VLAN_ACT_POP:
3581                                 entry->id = FLOW_ACTION_VLAN_POP;
3582                                 break;
3583                         case TCA_VLAN_ACT_MODIFY:
3584                                 entry->id = FLOW_ACTION_VLAN_MANGLE;
3585                                 entry->vlan.vid = tcf_vlan_push_vid(act);
3586                                 entry->vlan.proto = tcf_vlan_push_proto(act);
3587                                 entry->vlan.prio = tcf_vlan_push_prio(act);
3588                                 break;
3589                         default:
3590                                 err = -EOPNOTSUPP;
3591                                 goto err_out_locked;
3592                         }
3593                 } else if (is_tcf_tunnel_set(act)) {
3594                         entry->id = FLOW_ACTION_TUNNEL_ENCAP;
3595                         err = tcf_tunnel_encap_get_tunnel(entry, act);
3596                         if (err)
3597                                 goto err_out_locked;
3598                 } else if (is_tcf_tunnel_release(act)) {
3599                         entry->id = FLOW_ACTION_TUNNEL_DECAP;
3600                 } else if (is_tcf_pedit(act)) {
3601                         for (k = 0; k < tcf_pedit_nkeys(act); k++) {
3602                                 switch (tcf_pedit_cmd(act, k)) {
3603                                 case TCA_PEDIT_KEY_EX_CMD_SET:
3604                                         entry->id = FLOW_ACTION_MANGLE;
3605                                         break;
3606                                 case TCA_PEDIT_KEY_EX_CMD_ADD:
3607                                         entry->id = FLOW_ACTION_ADD;
3608                                         break;
3609                                 default:
3610                                         err = -EOPNOTSUPP;
3611                                         goto err_out_locked;
3612                                 }
3613                                 entry->mangle.htype = tcf_pedit_htype(act, k);
3614                                 entry->mangle.mask = tcf_pedit_mask(act, k);
3615                                 entry->mangle.val = tcf_pedit_val(act, k);
3616                                 entry->mangle.offset = tcf_pedit_offset(act, k);
3617                                 entry->hw_stats = act->hw_stats;
3618                                 entry = &flow_action->entries[++j];
3619                         }
3620                 } else if (is_tcf_csum(act)) {
3621                         entry->id = FLOW_ACTION_CSUM;
3622                         entry->csum_flags = tcf_csum_update_flags(act);
3623                 } else if (is_tcf_skbedit_mark(act)) {
3624                         entry->id = FLOW_ACTION_MARK;
3625                         entry->mark = tcf_skbedit_mark(act);
3626                 } else if (is_tcf_sample(act)) {
3627                         entry->id = FLOW_ACTION_SAMPLE;
3628                         entry->sample.trunc_size = tcf_sample_trunc_size(act);
3629                         entry->sample.truncate = tcf_sample_truncate(act);
3630                         entry->sample.rate = tcf_sample_rate(act);
3631                         tcf_sample_get_group(entry, act);
3632                 } else if (is_tcf_police(act)) {
3633                         entry->id = FLOW_ACTION_POLICE;
3634                         entry->police.burst = tcf_police_tcfp_burst(act);
3635                         entry->police.rate_bytes_ps =
3636                                 tcf_police_rate_bytes_ps(act);
3637                 } else if (is_tcf_ct(act)) {
3638                         entry->id = FLOW_ACTION_CT;
3639                         entry->ct.action = tcf_ct_action(act);
3640                         entry->ct.zone = tcf_ct_zone(act);
3641                         entry->ct.flow_table = tcf_ct_ft(act);
3642                 } else if (is_tcf_mpls(act)) {
3643                         switch (tcf_mpls_action(act)) {
3644                         case TCA_MPLS_ACT_PUSH:
3645                                 entry->id = FLOW_ACTION_MPLS_PUSH;
3646                                 entry->mpls_push.proto = tcf_mpls_proto(act);
3647                                 entry->mpls_push.label = tcf_mpls_label(act);
3648                                 entry->mpls_push.tc = tcf_mpls_tc(act);
3649                                 entry->mpls_push.bos = tcf_mpls_bos(act);
3650                                 entry->mpls_push.ttl = tcf_mpls_ttl(act);
3651                                 break;
3652                         case TCA_MPLS_ACT_POP:
3653                                 entry->id = FLOW_ACTION_MPLS_POP;
3654                                 entry->mpls_pop.proto = tcf_mpls_proto(act);
3655                                 break;
3656                         case TCA_MPLS_ACT_MODIFY:
3657                                 entry->id = FLOW_ACTION_MPLS_MANGLE;
3658                                 entry->mpls_mangle.label = tcf_mpls_label(act);
3659                                 entry->mpls_mangle.tc = tcf_mpls_tc(act);
3660                                 entry->mpls_mangle.bos = tcf_mpls_bos(act);
3661                                 entry->mpls_mangle.ttl = tcf_mpls_ttl(act);
3662                                 break;
3663                         default:
3664                                 goto err_out_locked;
3665                         }
3666                 } else if (is_tcf_skbedit_ptype(act)) {
3667                         entry->id = FLOW_ACTION_PTYPE;
3668                         entry->ptype = tcf_skbedit_ptype(act);
3669                 } else if (is_tcf_skbedit_priority(act)) {
3670                         entry->id = FLOW_ACTION_PRIORITY;
3671                         entry->priority = tcf_skbedit_priority(act);
3672                 } else {
3673                         err = -EOPNOTSUPP;
3674                         goto err_out_locked;
3675                 }
3676                 spin_unlock_bh(&act->tcfa_lock);
3677
3678                 if (!is_tcf_pedit(act))
3679                         j++;
3680         }
3681
3682 err_out:
3683         if (err)
3684                 tc_cleanup_flow_action(flow_action);
3685
3686         return err;
3687 err_out_locked:
3688         spin_unlock_bh(&act->tcfa_lock);
3689         goto err_out;
3690 }
3691 EXPORT_SYMBOL(tc_setup_flow_action);
3692
3693 unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
3694 {
3695         unsigned int num_acts = 0;
3696         struct tc_action *act;
3697         int i;
3698
3699         tcf_exts_for_each_action(i, act, exts) {
3700                 if (is_tcf_pedit(act))
3701                         num_acts += tcf_pedit_nkeys(act);
3702                 else
3703                         num_acts++;
3704         }
3705         return num_acts;
3706 }
3707 EXPORT_SYMBOL(tcf_exts_num_actions);
3708
3709 static __net_init int tcf_net_init(struct net *net)
3710 {
3711         struct tcf_net *tn = net_generic(net, tcf_net_id);
3712
3713         spin_lock_init(&tn->idr_lock);
3714         idr_init(&tn->idr);
3715         return 0;
3716 }
3717
3718 static void __net_exit tcf_net_exit(struct net *net)
3719 {
3720         struct tcf_net *tn = net_generic(net, tcf_net_id);
3721
3722         idr_destroy(&tn->idr);
3723 }
3724
3725 static struct pernet_operations tcf_net_ops = {
3726         .init = tcf_net_init,
3727         .exit = tcf_net_exit,
3728         .id   = &tcf_net_id,
3729         .size = sizeof(struct tcf_net),
3730 };
3731
3732 static struct flow_indr_block_entry block_entry = {
3733         .cb = tc_indr_block_get_and_cmd,
3734         .list = LIST_HEAD_INIT(block_entry.list),
3735 };
3736
3737 static int __init tc_filter_init(void)
3738 {
3739         int err;
3740
3741         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
3742         if (!tc_filter_wq)
3743                 return -ENOMEM;
3744
3745         err = register_pernet_subsys(&tcf_net_ops);
3746         if (err)
3747                 goto err_register_pernet_subsys;
3748
3749         flow_indr_add_block_cb(&block_entry);
3750
3751         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
3752                       RTNL_FLAG_DOIT_UNLOCKED);
3753         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
3754                       RTNL_FLAG_DOIT_UNLOCKED);
3755         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
3756                       tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
3757         rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
3758         rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
3759         rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
3760                       tc_dump_chain, 0);
3761
3762         return 0;
3763
3764 err_register_pernet_subsys:
3765         destroy_workqueue(tc_filter_wq);
3766         return err;
3767 }
3768
3769 subsys_initcall(tc_filter_init);