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, <[email protected]>
   6  *
   7  * Changes:
   8  *
   9  * Eduardo J. Blanco <[email protected]> :990222: kmod support
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/kernel.h>
  15 #include <linux/string.h>
  16 #include <linux/errno.h>
  17 #include <linux/err.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/init.h>
  20 #include <linux/kmod.h>
  21 #include <linux/slab.h>
  22 #include <linux/idr.h>
  23 #include <linux/jhash.h>
  24 #include <linux/rculist.h>
  25 #include <net/net_namespace.h>
  26 #include <net/sock.h>
  27 #include <net/netlink.h>
  28 #include <net/pkt_sched.h>
  29 #include <net/pkt_cls.h>
  30 #include <net/tc_act/tc_pedit.h>
  31 #include <net/tc_act/tc_mirred.h>
  32 #include <net/tc_act/tc_vlan.h>
  33 #include <net/tc_act/tc_tunnel_key.h>
  34 #include <net/tc_act/tc_csum.h>
  35 #include <net/tc_act/tc_gact.h>
  36 #include <net/tc_act/tc_police.h>
  37 #include <net/tc_act/tc_sample.h>
  38 #include <net/tc_act/tc_skbedit.h>
  39 #include <net/tc_act/tc_ct.h>
  40 #include <net/tc_act/tc_mpls.h>
  41 #include <net/tc_act/tc_gate.h>
  42 #include <net/flow_offload.h>
  43
  44 extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1];
  45
  46 /* The list of all installed classifier types */
  47 static LIST_HEAD(tcf_proto_base);
  48
  49 /* Protects list of registered TC modules. It is pure SMP lock. */
  50 static DEFINE_RWLOCK(cls_mod_lock);
  51
  52 static u32 destroy_obj_hashfn(const struct tcf_proto *tp)
  53 {
  54         return jhash_3words(tp->chain->index, tp->prio,
  55                             (__force __u32)tp->protocol, 0);
  56 }
  57
  58 static void tcf_proto_signal_destroying(struct tcf_chain *chain,
  59                                         struct tcf_proto *tp)
  60 {
  61         struct tcf_block *block = chain->block;
  62
  63         mutex_lock(&block->proto_destroy_lock);
  64         hash_add_rcu(block->proto_destroy_ht, &tp->destroy_ht_node,
  65                      destroy_obj_hashfn(tp));
  66         mutex_unlock(&block->proto_destroy_lock);
  67 }
  68
  69 static bool tcf_proto_cmp(const struct tcf_proto *tp1,
  70                           const struct tcf_proto *tp2)
  71 {
  72         return tp1->chain->index == tp2->chain->index &&
  73                tp1->prio == tp2->prio &&
  74                tp1->protocol == tp2->protocol;
  75 }
  76
  77 static bool tcf_proto_exists_destroying(struct tcf_chain *chain,
  78                                         struct tcf_proto *tp)
  79 {
  80         u32 hash = destroy_obj_hashfn(tp);
  81         struct tcf_proto *iter;
  82         bool found = false;
  83
  84         rcu_read_lock();
  85         hash_for_each_possible_rcu(chain->block->proto_destroy_ht, iter,
  86                                    destroy_ht_node, hash) {
  87                 if (tcf_proto_cmp(tp, iter)) {
  88                         found = true;
  89                         break;
  90                 }
  91         }
  92         rcu_read_unlock();
  93
  94         return found;
  95 }
  96
  97 static void
  98 tcf_proto_signal_destroyed(struct tcf_chain *chain, struct tcf_proto *tp)
  99 {
 100         struct tcf_block *block = chain->block;
 101
 102         mutex_lock(&block->proto_destroy_lock);
 103         if (hash_hashed(&tp->destroy_ht_node))
 104                 hash_del_rcu(&tp->destroy_ht_node);
 105         mutex_unlock(&block->proto_destroy_lock);
 106 }
 107
 108 /* Find classifier type by string name */
 109
 110 static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
 111 {
 112         const struct tcf_proto_ops *t, *res = NULL;
 113
 114         if (kind) {
 115                 read_lock(&cls_mod_lock);
 116                 list_for_each_entry(t, &tcf_proto_base, head) {
 117                         if (strcmp(kind, t->kind) == 0) {
 118                                 if (try_module_get(t->owner))
 119                                         res = t;
 120                                 break;
 121                         }
 122                 }
 123                 read_unlock(&cls_mod_lock);
 124         }
 125         return res;
 126 }
 127
 128 static const struct tcf_proto_ops *
 129 tcf_proto_lookup_ops(const char *kind, bool rtnl_held,
 130                      struct netlink_ext_ack *extack)
 131 {
 132         const struct tcf_proto_ops *ops;
 133
 134         ops = __tcf_proto_lookup_ops(kind);
 135         if (ops)
 136                 return ops;
 137 #ifdef CONFIG_MODULES
 138         if (rtnl_held)
 139                 rtnl_unlock();
 140         request_module("cls_%s", kind);
 141         if (rtnl_held)
 142                 rtnl_lock();
 143         ops = __tcf_proto_lookup_ops(kind);
 144         /* We dropped the RTNL semaphore in order to perform
 145          * the module load. So, even if we succeeded in loading
 146          * the module we have to replay the request. We indicate
 147          * this using -EAGAIN.
 148          */
 149         if (ops) {
 150                 module_put(ops->owner);
 151                 return ERR_PTR(-EAGAIN);
 152         }
 153 #endif
 154         NL_SET_ERR_MSG(extack, "TC classifier not found");
 155         return ERR_PTR(-ENOENT);
 156 }
 157
 158 /* Register(unregister) new classifier type */
 159
 160 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
 161 {
 162         struct tcf_proto_ops *t;
 163         int rc = -EEXIST;
 164
 165         write_lock(&cls_mod_lock);
 166         list_for_each_entry(t, &tcf_proto_base, head)
 167                 if (!strcmp(ops->kind, t->kind))
 168                         goto out;
 169
 170         list_add_tail(&ops->head, &tcf_proto_base);
 171         rc = 0;
 172 out:
 173         write_unlock(&cls_mod_lock);
 174         return rc;
 175 }
 176 EXPORT_SYMBOL(register_tcf_proto_ops);
 177
 178 static struct workqueue_struct *tc_filter_wq;
 179
 180 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
 181 {
 182         struct tcf_proto_ops *t;
 183         int rc = -ENOENT;
 184
 185         /* Wait for outstanding call_rcu()s, if any, from a
 186          * tcf_proto_ops's destroy() handler.
 187          */
 188         rcu_barrier();
 189         flush_workqueue(tc_filter_wq);
 190
 191         write_lock(&cls_mod_lock);
 192         list_for_each_entry(t, &tcf_proto_base, head) {
 193                 if (t == ops) {
 194                         list_del(&t->head);
 195                         rc = 0;
 196                         break;
 197                 }
 198         }
 199         write_unlock(&cls_mod_lock);
 200         return rc;
 201 }
 202 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 203
 204 bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
 205 {
 206         INIT_RCU_WORK(rwork, func);
 207         return queue_rcu_work(tc_filter_wq, rwork);
 208 }
 209 EXPORT_SYMBOL(tcf_queue_work);
 210
 211 /* Select new prio value from the range, managed by kernel. */
 212
 213 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 214 {
 215         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 216
 217         if (tp)
 218                 first = tp->prio - 1;
 219
 220         return TC_H_MAJ(first);
 221 }
 222
 223 static bool tcf_proto_check_kind(struct nlattr *kind, char *name)
 224 {
 225         if (kind)
 226                 return nla_strscpy(name, kind, IFNAMSIZ) < 0;
 227         memset(name, 0, IFNAMSIZ);
 228         return false;
 229 }
 230
 231 static bool tcf_proto_is_unlocked(const char *kind)
 232 {
 233         const struct tcf_proto_ops *ops;
 234         bool ret;
 235
 236         if (strlen(kind) == 0)
 237                 return false;
 238
 239         ops = tcf_proto_lookup_ops(kind, false, NULL);
 240         /* On error return false to take rtnl lock. Proto lookup/create
 241          * functions will perform lookup again and properly handle errors.
 242          */
 243         if (IS_ERR(ops))
 244                 return false;
 245
 246         ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED);
 247         module_put(ops->owner);
 248         return ret;
 249 }
 250
 251 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 252                                           u32 prio, struct tcf_chain *chain,
 253                                           bool rtnl_held,
 254                                           struct netlink_ext_ack *extack)
 255 {
 256         struct tcf_proto *tp;
 257         int err;
 258
 259         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 260         if (!tp)
 261                 return ERR_PTR(-ENOBUFS);
 262
 263         tp->ops = tcf_proto_lookup_ops(kind, rtnl_held, extack);
 264         if (IS_ERR(tp->ops)) {
 265                 err = PTR_ERR(tp->ops);
 266                 goto errout;
 267         }
 268         tp->classify = tp->ops->classify;
 269         tp->protocol = protocol;
 270         tp->prio = prio;
 271         tp->chain = chain;
 272         spin_lock_init(&tp->lock);
 273         refcount_set(&tp->refcnt, 1);
 274
 275         err = tp->ops->init(tp);
 276         if (err) {
 277                 module_put(tp->ops->owner);
 278                 goto errout;
 279         }
 280         return tp;
 281
 282 errout:
 283         kfree(tp);
 284         return ERR_PTR(err);
 285 }
 286
 287 static void tcf_proto_get(struct tcf_proto *tp)
 288 {
 289         refcount_inc(&tp->refcnt);
 290 }
 291
 292 static void tcf_chain_put(struct tcf_chain *chain);
 293
 294 static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
 295                               bool sig_destroy, struct netlink_ext_ack *extack)
 296 {
 297         tp->ops->destroy(tp, rtnl_held, extack);
 298         if (sig_destroy)
 299                 tcf_proto_signal_destroyed(tp->chain, tp);
 300         tcf_chain_put(tp->chain);
 301         module_put(tp->ops->owner);
 302         kfree_rcu(tp, rcu);
 303 }
 304
 305 static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
 306                           struct netlink_ext_ack *extack)
 307 {
 308         if (refcount_dec_and_test(&tp->refcnt))
 309                 tcf_proto_destroy(tp, rtnl_held, true, extack);
 310 }
 311
 312 static bool tcf_proto_check_delete(struct tcf_proto *tp)
 313 {
 314         if (tp->ops->delete_empty)
 315                 return tp->ops->delete_empty(tp);
 316
 317         tp->deleting = true;
 318         return tp->deleting;
 319 }
 320
 321 static void tcf_proto_mark_delete(struct tcf_proto *tp)
 322 {
 323         spin_lock(&tp->lock);
 324         tp->deleting = true;
 325         spin_unlock(&tp->lock);
 326 }
 327
 328 static bool tcf_proto_is_deleting(struct tcf_proto *tp)
 329 {
 330         bool deleting;
 331
 332         spin_lock(&tp->lock);
 333         deleting = tp->deleting;
 334         spin_unlock(&tp->lock);
 335
 336         return deleting;
 337 }
 338
 339 #define ASSERT_BLOCK_LOCKED(block)                                      \
 340         lockdep_assert_held(&(block)->lock)
 341
 342 struct tcf_filter_chain_list_item {
 343         struct list_head list;
 344         tcf_chain_head_change_t *chain_head_change;
 345         void *chain_head_change_priv;
 346 };
 347
 348 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 349                                           u32 chain_index)
 350 {
 351         struct tcf_chain *chain;
 352
 353         ASSERT_BLOCK_LOCKED(block);
 354
 355         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 356         if (!chain)
 357                 return NULL;
 358         list_add_tail_rcu(&chain->list, &block->chain_list);
 359         mutex_init(&chain->filter_chain_lock);
 360         chain->block = block;
 361         chain->index = chain_index;
 362         chain->refcnt = 1;
 363         if (!chain->index)
 364                 block->chain0.chain = chain;
 365         return chain;
 366 }
 367
 368 static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
 369                                        struct tcf_proto *tp_head)
 370 {
 371         if (item->chain_head_change)
 372                 item->chain_head_change(tp_head, item->chain_head_change_priv);
 373 }
 374
 375 static void tcf_chain0_head_change(struct tcf_chain *chain,
 376                                    struct tcf_proto *tp_head)
 377 {
 378         struct tcf_filter_chain_list_item *item;
 379         struct tcf_block *block = chain->block;
 380
 381         if (chain->index)
 382                 return;
 383
 384         mutex_lock(&block->lock);
 385         list_for_each_entry(item, &block->chain0.filter_chain_list, list)
 386                 tcf_chain_head_change_item(item, tp_head);
 387         mutex_unlock(&block->lock);
 388 }
 389
 390 /* Returns true if block can be safely freed. */
 391
 392 static bool tcf_chain_detach(struct tcf_chain *chain)
 393 {
 394         struct tcf_block *block = chain->block;
 395
 396         ASSERT_BLOCK_LOCKED(block);
 397
 398         list_del_rcu(&chain->list);
 399         if (!chain->index)
 400                 block->chain0.chain = NULL;
 401
 402         if (list_empty(&block->chain_list) &&
 403             refcount_read(&block->refcnt) == 0)
 404                 return true;
 405
 406         return false;
 407 }
 408
 409 static void tcf_block_destroy(struct tcf_block *block)
 410 {
 411         mutex_destroy(&block->lock);
 412         mutex_destroy(&block->proto_destroy_lock);
 413         kfree_rcu(block, rcu);
 414 }
 415
 416 static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
 417 {
 418         struct tcf_block *block = chain->block;
 419
 420         mutex_destroy(&chain->filter_chain_lock);
 421         kfree_rcu(chain, rcu);
 422         if (free_block)
 423                 tcf_block_destroy(block);
 424 }
 425
 426 static void tcf_chain_hold(struct tcf_chain *chain)
 427 {
 428         ASSERT_BLOCK_LOCKED(chain->block);
 429
 430         ++chain->refcnt;
 431 }
 432
 433 static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain)
 434 {
 435         ASSERT_BLOCK_LOCKED(chain->block);
 436
 437         /* In case all the references are action references, this
 438          * chain should not be shown to the user.
 439          */
 440         return chain->refcnt == chain->action_refcnt;
 441 }
 442
 443 static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
 444                                           u32 chain_index)
 445 {
 446         struct tcf_chain *chain;
 447
 448         ASSERT_BLOCK_LOCKED(block);
 449
 450         list_for_each_entry(chain, &block->chain_list, list) {
 451                 if (chain->index == chain_index)
 452                         return chain;
 453         }
 454         return NULL;
 455 }
 456
 457 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 458 static struct tcf_chain *tcf_chain_lookup_rcu(const struct tcf_block *block,
 459                                               u32 chain_index)
 460 {
 461         struct tcf_chain *chain;
 462
 463         list_for_each_entry_rcu(chain, &block->chain_list, list) {
 464                 if (chain->index == chain_index)
 465                         return chain;
 466         }
 467         return NULL;
 468 }
 469 #endif
 470
 471 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 472                            u32 seq, u16 flags, int event, bool unicast);
 473
 474 static struct tcf_chain *__tcf_chain_get(struct tcf_block *block,
 475                                          u32 chain_index, bool create,
 476                                          bool by_act)
 477 {
 478         struct tcf_chain *chain = NULL;
 479         bool is_first_reference;
 480
 481         mutex_lock(&block->lock);
 482         chain = tcf_chain_lookup(block, chain_index);
 483         if (chain) {
 484                 tcf_chain_hold(chain);
 485         } else {
 486                 if (!create)
 487                         goto errout;
 488                 chain = tcf_chain_create(block, chain_index);
 489                 if (!chain)
 490                         goto errout;
 491         }
 492
 493         if (by_act)
 494                 ++chain->action_refcnt;
 495         is_first_reference = chain->refcnt - chain->action_refcnt == 1;
 496         mutex_unlock(&block->lock);
 497
 498         /* Send notification only in case we got the first
 499          * non-action reference. Until then, the chain acts only as
 500          * a placeholder for actions pointing to it and user ought
 501          * not know about them.
 502          */
 503         if (is_first_reference && !by_act)
 504                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
 505                                 RTM_NEWCHAIN, false);
 506
 507         return chain;
 508
 509 errout:
 510         mutex_unlock(&block->lock);
 511         return chain;
 512 }
 513
 514 static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 515                                        bool create)
 516 {
 517         return __tcf_chain_get(block, chain_index, create, false);
 518 }
 519
 520 struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index)
 521 {
 522         return __tcf_chain_get(block, chain_index, true, true);
 523 }
 524 EXPORT_SYMBOL(tcf_chain_get_by_act);
 525
 526 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
 527                                void *tmplt_priv);
 528 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
 529                                   void *tmplt_priv, u32 chain_index,
 530                                   struct tcf_block *block, struct sk_buff *oskb,
 531                                   u32 seq, u16 flags, bool unicast);
 532
 533 static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
 534                             bool explicitly_created)
 535 {
 536         struct tcf_block *block = chain->block;
 537         const struct tcf_proto_ops *tmplt_ops;
 538         bool free_block = false;
 539         unsigned int refcnt;
 540         void *tmplt_priv;
 541
 542         mutex_lock(&block->lock);
 543         if (explicitly_created) {
 544                 if (!chain->explicitly_created) {
 545                         mutex_unlock(&block->lock);
 546                         return;
 547                 }
 548                 chain->explicitly_created = false;
 549         }
 550
 551         if (by_act)
 552                 chain->action_refcnt--;
 553
 554         /* tc_chain_notify_delete can't be called while holding block lock.
 555          * However, when block is unlocked chain can be changed concurrently, so
 556          * save these to temporary variables.
 557          */
 558         refcnt = --chain->refcnt;
 559         tmplt_ops = chain->tmplt_ops;
 560         tmplt_priv = chain->tmplt_priv;
 561
 562         /* The last dropped non-action reference will trigger notification. */
 563         if (refcnt - chain->action_refcnt == 0 && !by_act) {
 564                 tc_chain_notify_delete(tmplt_ops, tmplt_priv, chain->index,
 565                                        block, NULL, 0, 0, false);
 566                 /* Last reference to chain, no need to lock. */
 567                 chain->flushing = false;
 568         }
 569
 570         if (refcnt == 0)
 571                 free_block = tcf_chain_detach(chain);
 572         mutex_unlock(&block->lock);
 573
 574         if (refcnt == 0) {
 575                 tc_chain_tmplt_del(tmplt_ops, tmplt_priv);
 576                 tcf_chain_destroy(chain, free_block);
 577         }
 578 }
 579
 580 static void tcf_chain_put(struct tcf_chain *chain)
 581 {
 582         __tcf_chain_put(chain, false, false);
 583 }
 584
 585 void tcf_chain_put_by_act(struct tcf_chain *chain)
 586 {
 587         __tcf_chain_put(chain, true, false);
 588 }
 589 EXPORT_SYMBOL(tcf_chain_put_by_act);
 590
 591 static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 592 {
 593         __tcf_chain_put(chain, false, true);
 594 }
 595
 596 static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
 597 {
 598         struct tcf_proto *tp, *tp_next;
 599
 600         mutex_lock(&chain->filter_chain_lock);
 601         tp = tcf_chain_dereference(chain->filter_chain, chain);
 602         while (tp) {
 603                 tp_next = rcu_dereference_protected(tp->next, 1);
 604                 tcf_proto_signal_destroying(chain, tp);
 605                 tp = tp_next;
 606         }
 607         tp = tcf_chain_dereference(chain->filter_chain, chain);
 608         RCU_INIT_POINTER(chain->filter_chain, NULL);
 609         tcf_chain0_head_change(chain, NULL);
 610         chain->flushing = true;
 611         mutex_unlock(&chain->filter_chain_lock);
 612
 613         while (tp) {
 614                 tp_next = rcu_dereference_protected(tp->next, 1);
 615                 tcf_proto_put(tp, rtnl_held, NULL);
 616                 tp = tp_next;
 617         }
 618 }
 619
 620 static int tcf_block_setup(struct tcf_block *block,
 621                            struct flow_block_offload *bo);
 622
 623 static void tcf_block_offload_init(struct flow_block_offload *bo,
 624                                    struct net_device *dev, struct Qdisc *sch,
 625                                    enum flow_block_command command,
 626                                    enum flow_block_binder_type binder_type,
 627                                    struct flow_block *flow_block,
 628                                    bool shared, struct netlink_ext_ack *extack)
 629 {
 630         bo->net = dev_net(dev);
 631         bo->command = command;
 632         bo->binder_type = binder_type;
 633         bo->block = flow_block;
 634         bo->block_shared = shared;
 635         bo->extack = extack;
 636         bo->sch = sch;
 637         INIT_LIST_HEAD(&bo->cb_list);
 638 }
 639
 640 static void tcf_block_unbind(struct tcf_block *block,
 641                              struct flow_block_offload *bo);
 642
 643 static void tc_block_indr_cleanup(struct flow_block_cb *block_cb)
 644 {
 645         struct tcf_block *block = block_cb->indr.data;
 646         struct net_device *dev = block_cb->indr.dev;
 647         struct Qdisc *sch = block_cb->indr.sch;
 648         struct netlink_ext_ack extack = {};
 649         struct flow_block_offload bo = {};
 650
 651         tcf_block_offload_init(&bo, dev, sch, FLOW_BLOCK_UNBIND,
 652                                block_cb->indr.binder_type,
 653                                &block->flow_block, tcf_block_shared(block),
 654                                &extack);
 655         rtnl_lock();
 656         down_write(&block->cb_lock);
 657         list_del(&block_cb->driver_list);
 658         list_move(&block_cb->list, &bo.cb_list);
 659         tcf_block_unbind(block, &bo);
 660         up_write(&block->cb_lock);
 661         rtnl_unlock();
 662 }
 663
 664 static bool tcf_block_offload_in_use(struct tcf_block *block)
 665 {
 666         return atomic_read(&block->offloadcnt);
 667 }
 668
 669 static int tcf_block_offload_cmd(struct tcf_block *block,
 670                                  struct net_device *dev, struct Qdisc *sch,
 671                                  struct tcf_block_ext_info *ei,
 672                                  enum flow_block_command command,
 673                                  struct netlink_ext_ack *extack)
 674 {
 675         struct flow_block_offload bo = {};
 676
 677         tcf_block_offload_init(&bo, dev, sch, command, ei->binder_type,
 678                                &block->flow_block, tcf_block_shared(block),
 679                                extack);
 680
 681         if (dev->netdev_ops->ndo_setup_tc) {
 682                 int err;
 683
 684                 err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 685                 if (err < 0) {
 686                         if (err != -EOPNOTSUPP)
 687                                 NL_SET_ERR_MSG(extack, "Driver ndo_setup_tc failed");
 688                         return err;
 689                 }
 690
 691                 return tcf_block_setup(block, &bo);
 692         }
 693
 694         flow_indr_dev_setup_offload(dev, sch, TC_SETUP_BLOCK, block, &bo,
 695                                     tc_block_indr_cleanup);
 696         tcf_block_setup(block, &bo);
 697
 698         return -EOPNOTSUPP;
 699 }
 700
 701 static int tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
 702                                   struct tcf_block_ext_info *ei,
 703                                   struct netlink_ext_ack *extack)
 704 {
 705         struct net_device *dev = q->dev_queue->dev;
 706         int err;
 707
 708         down_write(&block->cb_lock);
 709
 710         /* If tc offload feature is disabled and the block we try to bind
 711          * to already has some offloaded filters, forbid to bind.
 712          */
 713         if (dev->netdev_ops->ndo_setup_tc &&
 714             !tc_can_offload(dev) &&
 715             tcf_block_offload_in_use(block)) {
 716                 NL_SET_ERR_MSG(extack, "Bind to offloaded block failed as dev has offload disabled");
 717                 err = -EOPNOTSUPP;
 718                 goto err_unlock;
 719         }
 720
 721         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_BIND, extack);
 722         if (err == -EOPNOTSUPP)
 723                 goto no_offload_dev_inc;
 724         if (err)
 725                 goto err_unlock;
 726
 727         up_write(&block->cb_lock);
 728         return 0;
 729
 730 no_offload_dev_inc:
 731         if (tcf_block_offload_in_use(block))
 732                 goto err_unlock;
 733
 734         err = 0;
 735         block->nooffloaddevcnt++;
 736 err_unlock:
 737         up_write(&block->cb_lock);
 738         return err;
 739 }
 740
 741 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
 742                                      struct tcf_block_ext_info *ei)
 743 {
 744         struct net_device *dev = q->dev_queue->dev;
 745         int err;
 746
 747         down_write(&block->cb_lock);
 748         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_UNBIND, NULL);
 749         if (err == -EOPNOTSUPP)
 750                 goto no_offload_dev_dec;
 751         up_write(&block->cb_lock);
 752         return;
 753
 754 no_offload_dev_dec:
 755         WARN_ON(block->nooffloaddevcnt-- == 0);
 756         up_write(&block->cb_lock);
 757 }
 758
 759 static int
 760 tcf_chain0_head_change_cb_add(struct tcf_block *block,
 761                               struct tcf_block_ext_info *ei,
 762                               struct netlink_ext_ack *extack)
 763 {
 764         struct tcf_filter_chain_list_item *item;
 765         struct tcf_chain *chain0;
 766
 767         item = kmalloc(sizeof(*item), GFP_KERNEL);
 768         if (!item) {
 769                 NL_SET_ERR_MSG(extack, "Memory allocation for head change callback item failed");
 770                 return -ENOMEM;
 771         }
 772         item->chain_head_change = ei->chain_head_change;
 773         item->chain_head_change_priv = ei->chain_head_change_priv;
 774
 775         mutex_lock(&block->lock);
 776         chain0 = block->chain0.chain;
 777         if (chain0)
 778                 tcf_chain_hold(chain0);
 779         else
 780                 list_add(&item->list, &block->chain0.filter_chain_list);
 781         mutex_unlock(&block->lock);
 782
 783         if (chain0) {
 784                 struct tcf_proto *tp_head;
 785
 786                 mutex_lock(&chain0->filter_chain_lock);
 787
 788                 tp_head = tcf_chain_dereference(chain0->filter_chain, chain0);
 789                 if (tp_head)
 790                         tcf_chain_head_change_item(item, tp_head);
 791
 792                 mutex_lock(&block->lock);
 793                 list_add(&item->list, &block->chain0.filter_chain_list);
 794                 mutex_unlock(&block->lock);
 795
 796                 mutex_unlock(&chain0->filter_chain_lock);
 797                 tcf_chain_put(chain0);
 798         }
 799
 800         return 0;
 801 }
 802
 803 static void
 804 tcf_chain0_head_change_cb_del(struct tcf_block *block,
 805                               struct tcf_block_ext_info *ei)
 806 {
 807         struct tcf_filter_chain_list_item *item;
 808
 809         mutex_lock(&block->lock);
 810         list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
 811                 if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
 812                     (item->chain_head_change == ei->chain_head_change &&
 813                      item->chain_head_change_priv == ei->chain_head_change_priv)) {
 814                         if (block->chain0.chain)
 815                                 tcf_chain_head_change_item(item, NULL);
 816                         list_del(&item->list);
 817                         mutex_unlock(&block->lock);
 818
 819                         kfree(item);
 820                         return;
 821                 }
 822         }
 823         mutex_unlock(&block->lock);
 824         WARN_ON(1);
 825 }
 826
 827 struct tcf_net {
 828         spinlock_t idr_lock; /* Protects idr */
 829         struct idr idr;
 830 };
 831
 832 static unsigned int tcf_net_id;
 833
 834 static int tcf_block_insert(struct tcf_block *block, struct net *net,
 835                             struct netlink_ext_ack *extack)
 836 {
 837         struct tcf_net *tn = net_generic(net, tcf_net_id);
 838         int err;
 839
 840         idr_preload(GFP_KERNEL);
 841         spin_lock(&tn->idr_lock);
 842         err = idr_alloc_u32(&tn->idr, block, &block->index, block->index,
 843                             GFP_NOWAIT);
 844         spin_unlock(&tn->idr_lock);
 845         idr_preload_end();
 846
 847         return err;
 848 }
 849
 850 static void tcf_block_remove(struct tcf_block *block, struct net *net)
 851 {
 852         struct tcf_net *tn = net_generic(net, tcf_net_id);
 853
 854         spin_lock(&tn->idr_lock);
 855         idr_remove(&tn->idr, block->index);
 856         spin_unlock(&tn->idr_lock);
 857 }
 858
 859 static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 860                                           u32 block_index,
 861                                           struct netlink_ext_ack *extack)
 862 {
 863         struct tcf_block *block;
 864
 865         block = kzalloc(sizeof(*block), GFP_KERNEL);
 866         if (!block) {
 867                 NL_SET_ERR_MSG(extack, "Memory allocation for block failed");
 868                 return ERR_PTR(-ENOMEM);
 869         }
 870         mutex_init(&block->lock);
 871         mutex_init(&block->proto_destroy_lock);
 872         init_rwsem(&block->cb_lock);
 873         flow_block_init(&block->flow_block);
 874         INIT_LIST_HEAD(&block->chain_list);
 875         INIT_LIST_HEAD(&block->owner_list);
 876         INIT_LIST_HEAD(&block->chain0.filter_chain_list);
 877
 878         refcount_set(&block->refcnt, 1);
 879         block->net = net;
 880         block->index = block_index;
 881
 882         /* Don't store q pointer for blocks which are shared */
 883         if (!tcf_block_shared(block))
 884                 block->q = q;
 885         return block;
 886 }
 887
 888 static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
 889 {
 890         struct tcf_net *tn = net_generic(net, tcf_net_id);
 891
 892         return idr_find(&tn->idr, block_index);
 893 }
 894
 895 static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
 896 {
 897         struct tcf_block *block;
 898
 899         rcu_read_lock();
 900         block = tcf_block_lookup(net, block_index);
 901         if (block && !refcount_inc_not_zero(&block->refcnt))
 902                 block = NULL;
 903         rcu_read_unlock();
 904
 905         return block;
 906 }
 907
 908 static struct tcf_chain *
 909 __tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
 910 {
 911         mutex_lock(&block->lock);
 912         if (chain)
 913                 chain = list_is_last(&chain->list, &block->chain_list) ?
 914                         NULL : list_next_entry(chain, list);
 915         else
 916                 chain = list_first_entry_or_null(&block->chain_list,
 917                                                  struct tcf_chain, list);
 918
 919         /* skip all action-only chains */
 920         while (chain && tcf_chain_held_by_acts_only(chain))
 921                 chain = list_is_last(&chain->list, &block->chain_list) ?
 922                         NULL : list_next_entry(chain, list);
 923
 924         if (chain)
 925                 tcf_chain_hold(chain);
 926         mutex_unlock(&block->lock);
 927
 928         return chain;
 929 }
 930
 931 /* Function to be used by all clients that want to iterate over all chains on
 932  * block. It properly obtains block->lock and takes reference to chain before
 933  * returning it. Users of this function must be tolerant to concurrent chain
 934  * insertion/deletion or ensure that no concurrent chain modification is
 935  * possible. Note that all netlink dump callbacks cannot guarantee to provide
 936  * consistent dump because rtnl lock is released each time skb is filled with
 937  * data and sent to user-space.
 938  */
 939
 940 struct tcf_chain *
 941 tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
 942 {
 943         struct tcf_chain *chain_next = __tcf_get_next_chain(block, chain);
 944
 945         if (chain)
 946                 tcf_chain_put(chain);
 947
 948         return chain_next;
 949 }
 950 EXPORT_SYMBOL(tcf_get_next_chain);
 951
 952 static struct tcf_proto *
 953 __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
 954 {
 955         u32 prio = 0;
 956
 957         ASSERT_RTNL();
 958         mutex_lock(&chain->filter_chain_lock);
 959
 960         if (!tp) {
 961                 tp = tcf_chain_dereference(chain->filter_chain, chain);
 962         } else if (tcf_proto_is_deleting(tp)) {
 963                 /* 'deleting' flag is set and chain->filter_chain_lock was
 964                  * unlocked, which means next pointer could be invalid. Restart
 965                  * search.
 966                  */
 967                 prio = tp->prio + 1;
 968                 tp = tcf_chain_dereference(chain->filter_chain, chain);
 969
 970                 for (; tp; tp = tcf_chain_dereference(tp->next, chain))
 971                         if (!tp->deleting && tp->prio >= prio)
 972                                 break;
 973         } else {
 974                 tp = tcf_chain_dereference(tp->next, chain);
 975         }
 976
 977         if (tp)
 978                 tcf_proto_get(tp);
 979
 980         mutex_unlock(&chain->filter_chain_lock);
 981
 982         return tp;
 983 }
 984
 985 /* Function to be used by all clients that want to iterate over all tp's on
 986  * chain. Users of this function must be tolerant to concurrent tp
 987  * insertion/deletion or ensure that no concurrent chain modification is
 988  * possible. Note that all netlink dump callbacks cannot guarantee to provide
 989  * consistent dump because rtnl lock is released each time skb is filled with
 990  * data and sent to user-space.
 991  */
 992
 993 struct tcf_proto *
 994 tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
 995 {
 996         struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
 997
 998         if (tp)
 999                 tcf_proto_put(tp, true, NULL);
1000
1001         return tp_next;
1002 }
1003 EXPORT_SYMBOL(tcf_get_next_proto);
1004
1005 static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
1006 {
1007         struct tcf_chain *chain;
1008
1009         /* Last reference to block. At this point chains cannot be added or
1010          * removed concurrently.
1011          */
1012         for (chain = tcf_get_next_chain(block, NULL);
1013              chain;
1014              chain = tcf_get_next_chain(block, chain)) {
1015                 tcf_chain_put_explicitly_created(chain);
1016                 tcf_chain_flush(chain, rtnl_held);
1017         }
1018 }
1019
1020 /* Lookup Qdisc and increments its reference counter.
1021  * Set parent, if necessary.
1022  */
1023
1024 static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
1025                             u32 *parent, int ifindex, bool rtnl_held,
1026                             struct netlink_ext_ack *extack)
1027 {
1028         const struct Qdisc_class_ops *cops;
1029         struct net_device *dev;
1030         int err = 0;
1031
1032         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1033                 return 0;
1034
1035         rcu_read_lock();
1036
1037         /* Find link */
1038         dev = dev_get_by_index_rcu(net, ifindex);
1039         if (!dev) {
1040                 rcu_read_unlock();
1041                 return -ENODEV;
1042         }
1043
1044         /* Find qdisc */
1045         if (!*parent) {
1046                 *q = dev->qdisc;
1047                 *parent = (*q)->handle;
1048         } else {
1049                 *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
1050                 if (!*q) {
1051                         NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1052                         err = -EINVAL;
1053                         goto errout_rcu;
1054                 }
1055         }
1056
1057         *q = qdisc_refcount_inc_nz(*q);
1058         if (!*q) {
1059                 NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1060                 err = -EINVAL;
1061                 goto errout_rcu;
1062         }
1063
1064         /* Is it classful? */
1065         cops = (*q)->ops->cl_ops;
1066         if (!cops) {
1067                 NL_SET_ERR_MSG(extack, "Qdisc not classful");
1068                 err = -EINVAL;
1069                 goto errout_qdisc;
1070         }
1071
1072         if (!cops->tcf_block) {
1073                 NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
1074                 err = -EOPNOTSUPP;
1075                 goto errout_qdisc;
1076         }
1077
1078 errout_rcu:
1079         /* At this point we know that qdisc is not noop_qdisc,
1080          * which means that qdisc holds a reference to net_device
1081          * and we hold a reference to qdisc, so it is safe to release
1082          * rcu read lock.
1083          */
1084         rcu_read_unlock();
1085         return err;
1086
1087 errout_qdisc:
1088         rcu_read_unlock();
1089
1090         if (rtnl_held)
1091                 qdisc_put(*q);
1092         else
1093                 qdisc_put_unlocked(*q);
1094         *q = NULL;
1095
1096         return err;
1097 }
1098
1099 static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
1100                                int ifindex, struct netlink_ext_ack *extack)
1101 {
1102         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1103                 return 0;
1104
1105         /* Do we search for filter, attached to class? */
1106         if (TC_H_MIN(parent)) {
1107                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1108
1109                 *cl = cops->find(q, parent);
1110                 if (*cl == 0) {
1111                         NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
1112                         return -ENOENT;
1113                 }
1114         }
1115
1116         return 0;
1117 }
1118
1119 static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
1120                                           unsigned long cl, int ifindex,
1121                                           u32 block_index,
1122                                           struct netlink_ext_ack *extack)
1123 {
1124         struct tcf_block *block;
1125
1126         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
1127                 block = tcf_block_refcnt_get(net, block_index);
1128                 if (!block) {
1129                         NL_SET_ERR_MSG(extack, "Block of given index was not found");
1130                         return ERR_PTR(-EINVAL);
1131                 }
1132         } else {
1133                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1134
1135                 block = cops->tcf_block(q, cl, extack);
1136                 if (!block)
1137                         return ERR_PTR(-EINVAL);
1138
1139                 if (tcf_block_shared(block)) {
1140                         NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
1141                         return ERR_PTR(-EOPNOTSUPP);
1142                 }
1143
1144                 /* Always take reference to block in order to support execution
1145                  * of rules update path of cls API without rtnl lock. Caller
1146                  * must release block when it is finished using it. 'if' block
1147                  * of this conditional obtain reference to block by calling
1148                  * tcf_block_refcnt_get().
1149                  */
1150                 refcount_inc(&block->refcnt);
1151         }
1152
1153         return block;
1154 }
1155
1156 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
1157                             struct tcf_block_ext_info *ei, bool rtnl_held)
1158 {
1159         if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
1160                 /* Flushing/putting all chains will cause the block to be
1161                  * deallocated when last chain is freed. However, if chain_list
1162                  * is empty, block has to be manually deallocated. After block
1163                  * reference counter reached 0, it is no longer possible to
1164                  * increment it or add new chains to block.
1165                  */
1166                 bool free_block = list_empty(&block->chain_list);
1167
1168                 mutex_unlock(&block->lock);
1169                 if (tcf_block_shared(block))
1170                         tcf_block_remove(block, block->net);
1171
1172                 if (q)
1173                         tcf_block_offload_unbind(block, q, ei);
1174
1175                 if (free_block)
1176                         tcf_block_destroy(block);
1177                 else
1178                         tcf_block_flush_all_chains(block, rtnl_held);
1179         } else if (q) {
1180                 tcf_block_offload_unbind(block, q, ei);
1181         }
1182 }
1183
1184 static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
1185 {
1186         __tcf_block_put(block, NULL, NULL, rtnl_held);
1187 }
1188
1189 /* Find tcf block.
1190  * Set q, parent, cl when appropriate.
1191  */
1192
1193 static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
1194                                         u32 *parent, unsigned long *cl,
1195                                         int ifindex, u32 block_index,
1196                                         struct netlink_ext_ack *extack)
1197 {
1198         struct tcf_block *block;
1199         int err = 0;
1200
1201         ASSERT_RTNL();
1202
1203         err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
1204         if (err)
1205                 goto errout;
1206
1207         err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
1208         if (err)
1209                 goto errout_qdisc;
1210
1211         block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
1212         if (IS_ERR(block)) {
1213                 err = PTR_ERR(block);
1214                 goto errout_qdisc;
1215         }
1216
1217         return block;
1218
1219 errout_qdisc:
1220         if (*q)
1221                 qdisc_put(*q);
1222 errout:
1223         *q = NULL;
1224         return ERR_PTR(err);
1225 }
1226
1227 static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
1228                               bool rtnl_held)
1229 {
1230         if (!IS_ERR_OR_NULL(block))
1231                 tcf_block_refcnt_put(block, rtnl_held);
1232
1233         if (q) {
1234                 if (rtnl_held)
1235                         qdisc_put(q);
1236                 else
1237                         qdisc_put_unlocked(q);
1238         }
1239 }
1240
1241 struct tcf_block_owner_item {
1242         struct list_head list;
1243         struct Qdisc *q;
1244         enum flow_block_binder_type binder_type;
1245 };
1246
1247 static void
1248 tcf_block_owner_netif_keep_dst(struct tcf_block *block,
1249                                struct Qdisc *q,
1250                                enum flow_block_binder_type binder_type)
1251 {
1252         if (block->keep_dst &&
1253             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS &&
1254             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
1255                 netif_keep_dst(qdisc_dev(q));
1256 }
1257
1258 void tcf_block_netif_keep_dst(struct tcf_block *block)
1259 {
1260         struct tcf_block_owner_item *item;
1261
1262         block->keep_dst = true;
1263         list_for_each_entry(item, &block->owner_list, list)
1264                 tcf_block_owner_netif_keep_dst(block, item->q,
1265                                                item->binder_type);
1266 }
1267 EXPORT_SYMBOL(tcf_block_netif_keep_dst);
1268
1269 static int tcf_block_owner_add(struct tcf_block *block,
1270                                struct Qdisc *q,
1271                                enum flow_block_binder_type binder_type)
1272 {
1273         struct tcf_block_owner_item *item;
1274
1275         item = kmalloc(sizeof(*item), GFP_KERNEL);
1276         if (!item)
1277                 return -ENOMEM;
1278         item->q = q;
1279         item->binder_type = binder_type;
1280         list_add(&item->list, &block->owner_list);
1281         return 0;
1282 }
1283
1284 static void tcf_block_owner_del(struct tcf_block *block,
1285                                 struct Qdisc *q,
1286                                 enum flow_block_binder_type binder_type)
1287 {
1288         struct tcf_block_owner_item *item;
1289
1290         list_for_each_entry(item, &block->owner_list, list) {
1291                 if (item->q == q && item->binder_type == binder_type) {
1292                         list_del(&item->list);
1293                         kfree(item);
1294                         return;
1295                 }
1296         }
1297         WARN_ON(1);
1298 }
1299
1300 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
1301                       struct tcf_block_ext_info *ei,
1302                       struct netlink_ext_ack *extack)
1303 {
1304         struct net *net = qdisc_net(q);
1305         struct tcf_block *block = NULL;
1306         int err;
1307
1308         if (ei->block_index)
1309                 /* block_index not 0 means the shared block is requested */
1310                 block = tcf_block_refcnt_get(net, ei->block_index);
1311
1312         if (!block) {
1313                 block = tcf_block_create(net, q, ei->block_index, extack);
1314                 if (IS_ERR(block))
1315                         return PTR_ERR(block);
1316                 if (tcf_block_shared(block)) {
1317                         err = tcf_block_insert(block, net, extack);
1318                         if (err)
1319                                 goto err_block_insert;
1320                 }
1321         }
1322
1323         err = tcf_block_owner_add(block, q, ei->binder_type);
1324         if (err)
1325                 goto err_block_owner_add;
1326
1327         tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
1328
1329         err = tcf_chain0_head_change_cb_add(block, ei, extack);
1330         if (err)
1331                 goto err_chain0_head_change_cb_add;
1332
1333         err = tcf_block_offload_bind(block, q, ei, extack);
1334         if (err)
1335                 goto err_block_offload_bind;
1336
1337         *p_block = block;
1338         return 0;
1339
1340 err_block_offload_bind:
1341         tcf_chain0_head_change_cb_del(block, ei);
1342 err_chain0_head_change_cb_add:
1343         tcf_block_owner_del(block, q, ei->binder_type);
1344 err_block_owner_add:
1345 err_block_insert:
1346         tcf_block_refcnt_put(block, true);
1347         return err;
1348 }
1349 EXPORT_SYMBOL(tcf_block_get_ext);
1350
1351 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
1352 {
1353         struct tcf_proto __rcu **p_filter_chain = priv;
1354
1355         rcu_assign_pointer(*p_filter_chain, tp_head);
1356 }
1357
1358 int tcf_block_get(struct tcf_block **p_block,
1359                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
1360                   struct netlink_ext_ack *extack)
1361 {
1362         struct tcf_block_ext_info ei = {
1363                 .chain_head_change = tcf_chain_head_change_dflt,
1364                 .chain_head_change_priv = p_filter_chain,
1365         };
1366
1367         WARN_ON(!p_filter_chain);
1368         return tcf_block_get_ext(p_block, q, &ei, extack);
1369 }
1370 EXPORT_SYMBOL(tcf_block_get);
1371
1372 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
1373  * actions should be all removed after flushing.
1374  */
1375 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
1376                        struct tcf_block_ext_info *ei)
1377 {
1378         if (!block)
1379                 return;
1380         tcf_chain0_head_change_cb_del(block, ei);
1381         tcf_block_owner_del(block, q, ei->binder_type);
1382
1383         __tcf_block_put(block, q, ei, true);
1384 }
1385 EXPORT_SYMBOL(tcf_block_put_ext);
1386
1387 void tcf_block_put(struct tcf_block *block)
1388 {
1389         struct tcf_block_ext_info ei = {0, };
1390
1391         if (!block)
1392                 return;
1393         tcf_block_put_ext(block, block->q, &ei);
1394 }
1395
1396 EXPORT_SYMBOL(tcf_block_put);
1397
1398 static int
1399 tcf_block_playback_offloads(struct tcf_block *block, flow_setup_cb_t *cb,
1400                             void *cb_priv, bool add, bool offload_in_use,
1401                             struct netlink_ext_ack *extack)
1402 {
1403         struct tcf_chain *chain, *chain_prev;
1404         struct tcf_proto *tp, *tp_prev;
1405         int err;
1406
1407         lockdep_assert_held(&block->cb_lock);
1408
1409         for (chain = __tcf_get_next_chain(block, NULL);
1410              chain;
1411              chain_prev = chain,
1412                      chain = __tcf_get_next_chain(block, chain),
1413                      tcf_chain_put(chain_prev)) {
1414                 for (tp = __tcf_get_next_proto(chain, NULL); tp;
1415                      tp_prev = tp,
1416                              tp = __tcf_get_next_proto(chain, tp),
1417                              tcf_proto_put(tp_prev, true, NULL)) {
1418                         if (tp->ops->reoffload) {
1419                                 err = tp->ops->reoffload(tp, add, cb, cb_priv,
1420                                                          extack);
1421                                 if (err && add)
1422                                         goto err_playback_remove;
1423                         } else if (add && offload_in_use) {
1424                                 err = -EOPNOTSUPP;
1425                                 NL_SET_ERR_MSG(extack, "Filter HW offload failed - classifier without re-offloading support");
1426                                 goto err_playback_remove;
1427                         }
1428                 }
1429         }
1430
1431         return 0;
1432
1433 err_playback_remove:
1434         tcf_proto_put(tp, true, NULL);
1435         tcf_chain_put(chain);
1436         tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
1437                                     extack);
1438         return err;
1439 }
1440
1441 static int tcf_block_bind(struct tcf_block *block,
1442                           struct flow_block_offload *bo)
1443 {
1444         struct flow_block_cb *block_cb, *next;
1445         int err, i = 0;
1446
1447         lockdep_assert_held(&block->cb_lock);
1448
1449         list_for_each_entry(block_cb, &bo->cb_list, list) {
1450                 err = tcf_block_playback_offloads(block, block_cb->cb,
1451                                                   block_cb->cb_priv, true,
1452                                                   tcf_block_offload_in_use(block),
1453                                                   bo->extack);
1454                 if (err)
1455                         goto err_unroll;
1456                 if (!bo->unlocked_driver_cb)
1457                         block->lockeddevcnt++;
1458
1459                 i++;
1460         }
1461         list_splice(&bo->cb_list, &block->flow_block.cb_list);
1462
1463         return 0;
1464
1465 err_unroll:
1466         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1467                 if (i-- > 0) {
1468                         list_del(&block_cb->list);
1469                         tcf_block_playback_offloads(block, block_cb->cb,
1470                                                     block_cb->cb_priv, false,
1471                                                     tcf_block_offload_in_use(block),
1472                                                     NULL);
1473                         if (!bo->unlocked_driver_cb)
1474                                 block->lockeddevcnt--;
1475                 }
1476                 flow_block_cb_free(block_cb);
1477         }
1478
1479         return err;
1480 }
1481
1482 static void tcf_block_unbind(struct tcf_block *block,
1483                              struct flow_block_offload *bo)
1484 {
1485         struct flow_block_cb *block_cb, *next;
1486
1487         lockdep_assert_held(&block->cb_lock);
1488
1489         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1490                 tcf_block_playback_offloads(block, block_cb->cb,
1491                                             block_cb->cb_priv, false,
1492                                             tcf_block_offload_in_use(block),
1493                                             NULL);
1494                 list_del(&block_cb->list);
1495                 flow_block_cb_free(block_cb);
1496                 if (!bo->unlocked_driver_cb)
1497                         block->lockeddevcnt--;
1498         }
1499 }
1500
1501 static int tcf_block_setup(struct tcf_block *block,
1502                            struct flow_block_offload *bo)
1503 {
1504         int err;
1505
1506         switch (bo->command) {
1507         case FLOW_BLOCK_BIND:
1508                 err = tcf_block_bind(block, bo);
1509                 break;
1510         case FLOW_BLOCK_UNBIND:
1511                 err = 0;
1512                 tcf_block_unbind(block, bo);
1513                 break;
1514         default:
1515                 WARN_ON_ONCE(1);
1516                 err = -EOPNOTSUPP;
1517         }
1518
1519         return err;
1520 }
1521
1522 /* Main classifier routine: scans classifier chain attached
1523  * to this qdisc, (optionally) tests for protocol and asks
1524  * specific classifiers.
1525  */
1526 static inline int __tcf_classify(struct sk_buff *skb,
1527                                  const struct tcf_proto *tp,
1528                                  const struct tcf_proto *orig_tp,
1529                                  struct tcf_result *res,
1530                                  bool compat_mode,
1531                                  u32 *last_executed_chain)
1532 {
1533 #ifdef CONFIG_NET_CLS_ACT
1534         const int max_reclassify_loop = 4;
1535         const struct tcf_proto *first_tp;
1536         int limit = 0;
1537
1538 reclassify:
1539 #endif
1540         for (; tp; tp = rcu_dereference_bh(tp->next)) {
1541                 __be16 protocol = skb_protocol(skb, false);
1542                 int err;
1543
1544                 if (tp->protocol != protocol &&
1545                     tp->protocol != htons(ETH_P_ALL))
1546                         continue;
1547
1548                 err = tp->classify(skb, tp, res);
1549 #ifdef CONFIG_NET_CLS_ACT
1550                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
1551                         first_tp = orig_tp;
1552                         *last_executed_chain = first_tp->chain->index;
1553                         goto reset;
1554                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
1555                         first_tp = res->goto_tp;
1556                         *last_executed_chain = err & TC_ACT_EXT_VAL_MASK;
1557                         goto reset;
1558                 }
1559 #endif
1560                 if (err >= 0)
1561                         return err;
1562         }
1563
1564         return TC_ACT_UNSPEC; /* signal: continue lookup */
1565 #ifdef CONFIG_NET_CLS_ACT
1566 reset:
1567         if (unlikely(limit++ >= max_reclassify_loop)) {
1568                 net_notice_ratelimited("%u: reclassify loop, rule prio %u, protocol %02x\n",
1569                                        tp->chain->block->index,
1570                                        tp->prio & 0xffff,
1571                                        ntohs(tp->protocol));
1572                 return TC_ACT_SHOT;
1573         }
1574
1575         tp = first_tp;
1576         goto reclassify;
1577 #endif
1578 }
1579
1580 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1581                  struct tcf_result *res, bool compat_mode)
1582 {
1583         u32 last_executed_chain = 0;
1584
1585         return __tcf_classify(skb, tp, tp, res, compat_mode,
1586                               &last_executed_chain);
1587 }
1588 EXPORT_SYMBOL(tcf_classify);
1589
1590 int tcf_classify_ingress(struct sk_buff *skb,
1591                          const struct tcf_block *ingress_block,
1592                          const struct tcf_proto *tp,
1593                          struct tcf_result *res, bool compat_mode)
1594 {
1595 #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1596         u32 last_executed_chain = 0;
1597
1598         return __tcf_classify(skb, tp, tp, res, compat_mode,
1599                               &last_executed_chain);
1600 #else
1601         u32 last_executed_chain = tp ? tp->chain->index : 0;
1602         const struct tcf_proto *orig_tp = tp;
1603         struct tc_skb_ext *ext;
1604         int ret;
1605
1606         ext = skb_ext_find(skb, TC_SKB_EXT);
1607
1608         if (ext && ext->chain) {
1609                 struct tcf_chain *fchain;
1610
1611                 fchain = tcf_chain_lookup_rcu(ingress_block, ext->chain);
1612                 if (!fchain)
1613                         return TC_ACT_SHOT;
1614
1615                 /* Consume, so cloned/redirect skbs won't inherit ext */
1616                 skb_ext_del(skb, TC_SKB_EXT);
1617
1618                 tp = rcu_dereference_bh(fchain->filter_chain);
1619                 last_executed_chain = fchain->index;
1620         }
1621
1622         ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode,
1623                              &last_executed_chain);
1624
1625         /* If we missed on some chain */
1626         if (ret == TC_ACT_UNSPEC && last_executed_chain) {
1627                 ext = skb_ext_add(skb, TC_SKB_EXT);
1628                 if (WARN_ON_ONCE(!ext))
1629                         return TC_ACT_SHOT;
1630                 ext->chain = last_executed_chain;
1631                 ext->mru = qdisc_skb_cb(skb)->mru;
1632                 ext->post_ct = qdisc_skb_cb(skb)->post_ct;
1633         }
1634
1635         return ret;
1636 #endif
1637 }
1638 EXPORT_SYMBOL(tcf_classify_ingress);
1639
1640 struct tcf_chain_info {
1641         struct tcf_proto __rcu **pprev;
1642         struct tcf_proto __rcu *next;
1643 };
1644
1645 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
1646                                            struct tcf_chain_info *chain_info)
1647 {
1648         return tcf_chain_dereference(*chain_info->pprev, chain);
1649 }
1650
1651 static int tcf_chain_tp_insert(struct tcf_chain *chain,
1652                                struct tcf_chain_info *chain_info,
1653                                struct tcf_proto *tp)
1654 {
1655         if (chain->flushing)
1656                 return -EAGAIN;
1657
1658         if (*chain_info->pprev == chain->filter_chain)
1659                 tcf_chain0_head_change(chain, tp);
1660         tcf_proto_get(tp);
1661         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
1662         rcu_assign_pointer(*chain_info->pprev, tp);
1663
1664         return 0;
1665 }
1666
1667 static void tcf_chain_tp_remove(struct tcf_chain *chain,
1668                                 struct tcf_chain_info *chain_info,
1669                                 struct tcf_proto *tp)
1670 {
1671         struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
1672
1673         tcf_proto_mark_delete(tp);
1674         if (tp == chain->filter_chain)
1675                 tcf_chain0_head_change(chain, next);
1676         RCU_INIT_POINTER(*chain_info->pprev, next);
1677 }
1678
1679 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1680                                            struct tcf_chain_info *chain_info,
1681                                            u32 protocol, u32 prio,
1682                                            bool prio_allocate);
1683
1684 /* Try to insert new proto.
1685  * If proto with specified priority already exists, free new proto
1686  * and return existing one.
1687  */
1688
1689 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
1690                                                     struct tcf_proto *tp_new,
1691                                                     u32 protocol, u32 prio,
1692                                                     bool rtnl_held)
1693 {
1694         struct tcf_chain_info chain_info;
1695         struct tcf_proto *tp;
1696         int err = 0;
1697
1698         mutex_lock(&chain->filter_chain_lock);
1699
1700         if (tcf_proto_exists_destroying(chain, tp_new)) {
1701                 mutex_unlock(&chain->filter_chain_lock);
1702                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1703                 return ERR_PTR(-EAGAIN);
1704         }
1705
1706         tp = tcf_chain_tp_find(chain, &chain_info,
1707                                protocol, prio, false);
1708         if (!tp)
1709                 err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
1710         mutex_unlock(&chain->filter_chain_lock);
1711
1712         if (tp) {
1713                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1714                 tp_new = tp;
1715         } else if (err) {
1716                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1717                 tp_new = ERR_PTR(err);
1718         }
1719
1720         return tp_new;
1721 }
1722
1723 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
1724                                       struct tcf_proto *tp, bool rtnl_held,
1725                                       struct netlink_ext_ack *extack)
1726 {
1727         struct tcf_chain_info chain_info;
1728         struct tcf_proto *tp_iter;
1729         struct tcf_proto **pprev;
1730         struct tcf_proto *next;
1731
1732         mutex_lock(&chain->filter_chain_lock);
1733
1734         /* Atomically find and remove tp from chain. */
1735         for (pprev = &chain->filter_chain;
1736              (tp_iter = tcf_chain_dereference(*pprev, chain));
1737              pprev = &tp_iter->next) {
1738                 if (tp_iter == tp) {
1739                         chain_info.pprev = pprev;
1740                         chain_info.next = tp_iter->next;
1741                         WARN_ON(tp_iter->deleting);
1742                         break;
1743                 }
1744         }
1745         /* Verify that tp still exists and no new filters were inserted
1746          * concurrently.
1747          * Mark tp for deletion if it is empty.
1748          */
1749         if (!tp_iter || !tcf_proto_check_delete(tp)) {
1750                 mutex_unlock(&chain->filter_chain_lock);
1751                 return;
1752         }
1753
1754         tcf_proto_signal_destroying(chain, tp);
1755         next = tcf_chain_dereference(chain_info.next, chain);
1756         if (tp == chain->filter_chain)
1757                 tcf_chain0_head_change(chain, next);
1758         RCU_INIT_POINTER(*chain_info.pprev, next);
1759         mutex_unlock(&chain->filter_chain_lock);
1760
1761         tcf_proto_put(tp, rtnl_held, extack);
1762 }
1763
1764 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1765                                            struct tcf_chain_info *chain_info,
1766                                            u32 protocol, u32 prio,
1767                                            bool prio_allocate)
1768 {
1769         struct tcf_proto **pprev;
1770         struct tcf_proto *tp;
1771
1772         /* Check the chain for existence of proto-tcf with this priority */
1773         for (pprev = &chain->filter_chain;
1774              (tp = tcf_chain_dereference(*pprev, chain));
1775              pprev = &tp->next) {
1776                 if (tp->prio >= prio) {
1777                         if (tp->prio == prio) {
1778                                 if (prio_allocate ||
1779                                     (tp->protocol != protocol && protocol))
1780                                         return ERR_PTR(-EINVAL);
1781                         } else {
1782                                 tp = NULL;
1783                         }
1784                         break;
1785                 }
1786         }
1787         chain_info->pprev = pprev;
1788         if (tp) {
1789                 chain_info->next = tp->next;
1790                 tcf_proto_get(tp);
1791         } else {
1792                 chain_info->next = NULL;
1793         }
1794         return tp;
1795 }
1796
1797 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
1798                          struct tcf_proto *tp, struct tcf_block *block,
1799                          struct Qdisc *q, u32 parent, void *fh,
1800                          u32 portid, u32 seq, u16 flags, int event,
1801                          bool terse_dump, bool rtnl_held)
1802 {
1803         struct tcmsg *tcm;
1804         struct nlmsghdr  *nlh;
1805         unsigned char *b = skb_tail_pointer(skb);
1806
1807         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1808         if (!nlh)
1809                 goto out_nlmsg_trim;
1810         tcm = nlmsg_data(nlh);
1811         tcm->tcm_family = AF_UNSPEC;
1812         tcm->tcm__pad1 = 0;
1813         tcm->tcm__pad2 = 0;
1814         if (q) {
1815                 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1816                 tcm->tcm_parent = parent;
1817         } else {
1818                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
1819                 tcm->tcm_block_index = block->index;
1820         }
1821         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
1822         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
1823                 goto nla_put_failure;
1824         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
1825                 goto nla_put_failure;
1826         if (!fh) {
1827                 tcm->tcm_handle = 0;
1828         } else if (terse_dump) {
1829                 if (tp->ops->terse_dump) {
1830                         if (tp->ops->terse_dump(net, tp, fh, skb, tcm,
1831                                                 rtnl_held) < 0)
1832                                 goto nla_put_failure;
1833                 } else {
1834                         goto cls_op_not_supp;
1835                 }
1836         } else {
1837                 if (tp->ops->dump &&
1838                     tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
1839                         goto nla_put_failure;
1840         }
1841         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1842         return skb->len;
1843
1844 out_nlmsg_trim:
1845 nla_put_failure:
1846 cls_op_not_supp:
1847         nlmsg_trim(skb, b);
1848         return -1;
1849 }
1850
1851 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
1852                           struct nlmsghdr *n, struct tcf_proto *tp,
1853                           struct tcf_block *block, struct Qdisc *q,
1854                           u32 parent, void *fh, int event, bool unicast,
1855                           bool rtnl_held)
1856 {
1857         struct sk_buff *skb;
1858         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1859         int err = 0;
1860
1861         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1862         if (!skb)
1863                 return -ENOBUFS;
1864
1865         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1866                           n->nlmsg_seq, n->nlmsg_flags, event,
1867                           false, rtnl_held) <= 0) {
1868                 kfree_skb(skb);
1869                 return -EINVAL;
1870         }
1871
1872         if (unicast)
1873                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
1874         else
1875                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1876                                      n->nlmsg_flags & NLM_F_ECHO);
1877
1878         if (err > 0)
1879                 err = 0;
1880         return err;
1881 }
1882
1883 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
1884                               struct nlmsghdr *n, struct tcf_proto *tp,
1885                               struct tcf_block *block, struct Qdisc *q,
1886                               u32 parent, void *fh, bool unicast, bool *last,
1887                               bool rtnl_held, struct netlink_ext_ack *extack)
1888 {
1889         struct sk_buff *skb;
1890         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1891         int err;
1892
1893         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1894         if (!skb)
1895                 return -ENOBUFS;
1896
1897         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1898                           n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
1899                           false, rtnl_held) <= 0) {
1900                 NL_SET_ERR_MSG(extack, "Failed to build del event notification");
1901                 kfree_skb(skb);
1902                 return -EINVAL;
1903         }
1904
1905         err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
1906         if (err) {
1907                 kfree_skb(skb);
1908                 return err;
1909         }
1910
1911         if (unicast)
1912                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
1913         else
1914                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1915                                      n->nlmsg_flags & NLM_F_ECHO);
1916         if (err < 0)
1917                 NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
1918
1919         if (err > 0)
1920                 err = 0;
1921         return err;
1922 }
1923
1924 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
1925                                  struct tcf_block *block, struct Qdisc *q,
1926                                  u32 parent, struct nlmsghdr *n,
1927                                  struct tcf_chain *chain, int event)
1928 {
1929         struct tcf_proto *tp;
1930
1931         for (tp = tcf_get_next_proto(chain, NULL);
1932              tp; tp = tcf_get_next_proto(chain, tp))
1933                 tfilter_notify(net, oskb, n, tp, block,
1934                                q, parent, NULL, event, false, true);
1935 }
1936
1937 static void tfilter_put(struct tcf_proto *tp, void *fh)
1938 {
1939         if (tp->ops->put && fh)
1940                 tp->ops->put(tp, fh);
1941 }
1942
1943 static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
1944                           struct netlink_ext_ack *extack)
1945 {
1946         struct net *net = sock_net(skb->sk);
1947         struct nlattr *tca[TCA_MAX + 1];
1948         char name[IFNAMSIZ];
1949         struct tcmsg *t;
1950         u32 protocol;
1951         u32 prio;
1952         bool prio_allocate;
1953         u32 parent;
1954         u32 chain_index;
1955         struct Qdisc *q = NULL;
1956         struct tcf_chain_info chain_info;
1957         struct tcf_chain *chain = NULL;
1958         struct tcf_block *block;
1959         struct tcf_proto *tp;
1960         unsigned long cl;
1961         void *fh;
1962         int err;
1963         int tp_created;
1964         bool rtnl_held = false;
1965
1966         if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1967                 return -EPERM;
1968
1969 replay:
1970         tp_created = 0;
1971
1972         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
1973                                      rtm_tca_policy, extack);
1974         if (err < 0)
1975                 return err;
1976
1977         t = nlmsg_data(n);
1978         protocol = TC_H_MIN(t->tcm_info);
1979         prio = TC_H_MAJ(t->tcm_info);
1980         prio_allocate = false;
1981         parent = t->tcm_parent;
1982         tp = NULL;
1983         cl = 0;
1984         block = NULL;
1985
1986         if (prio == 0) {
1987                 /* If no priority is provided by the user,
1988                  * we allocate one.
1989                  */
1990                 if (n->nlmsg_flags & NLM_F_CREATE) {
1991                         prio = TC_H_MAKE(0x80000000U, 0U);
1992                         prio_allocate = true;
1993                 } else {
1994                         NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
1995                         return -ENOENT;
1996                 }
1997         }
1998
1999         /* Find head of filter chain. */
2000
2001         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2002         if (err)
2003                 return err;
2004
2005         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2006                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2007                 err = -EINVAL;
2008                 goto errout;
2009         }
2010
2011         /* Take rtnl mutex if rtnl_held was set to true on previous iteration,
2012          * block is shared (no qdisc found), qdisc is not unlocked, classifier
2013          * type is not specified, classifier is not unlocked.
2014          */
2015         if (rtnl_held ||
2016             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2017             !tcf_proto_is_unlocked(name)) {
2018                 rtnl_held = true;
2019                 rtnl_lock();
2020         }
2021
2022         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2023         if (err)
2024                 goto errout;
2025
2026         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2027                                  extack);
2028         if (IS_ERR(block)) {
2029                 err = PTR_ERR(block);
2030                 goto errout;
2031         }
2032         block->classid = parent;
2033
2034         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2035         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2036                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2037                 err = -EINVAL;
2038                 goto errout;
2039         }
2040         chain = tcf_chain_get(block, chain_index, true);
2041         if (!chain) {
2042                 NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
2043                 err = -ENOMEM;
2044                 goto errout;
2045         }
2046
2047         mutex_lock(&chain->filter_chain_lock);
2048         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2049                                prio, prio_allocate);
2050         if (IS_ERR(tp)) {
2051                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2052                 err = PTR_ERR(tp);
2053                 goto errout_locked;
2054         }
2055
2056         if (tp == NULL) {
2057                 struct tcf_proto *tp_new = NULL;
2058
2059                 if (chain->flushing) {
2060                         err = -EAGAIN;
2061                         goto errout_locked;
2062                 }
2063
2064                 /* Proto-tcf does not exist, create new one */
2065
2066                 if (tca[TCA_KIND] == NULL || !protocol) {
2067                         NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
2068                         err = -EINVAL;
2069                         goto errout_locked;
2070                 }
2071
2072                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2073                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2074                         err = -ENOENT;
2075                         goto errout_locked;
2076                 }
2077
2078                 if (prio_allocate)
2079                         prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
2080                                                                &chain_info));
2081
2082                 mutex_unlock(&chain->filter_chain_lock);
2083                 tp_new = tcf_proto_create(name, protocol, prio, chain,
2084                                           rtnl_held, extack);
2085                 if (IS_ERR(tp_new)) {
2086                         err = PTR_ERR(tp_new);
2087                         goto errout_tp;
2088                 }
2089
2090                 tp_created = 1;
2091                 tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
2092                                                 rtnl_held);
2093                 if (IS_ERR(tp)) {
2094                         err = PTR_ERR(tp);
2095                         goto errout_tp;
2096                 }
2097         } else {
2098                 mutex_unlock(&chain->filter_chain_lock);
2099         }
2100
2101         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2102                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2103                 err = -EINVAL;
2104                 goto errout;
2105         }
2106
2107         fh = tp->ops->get(tp, t->tcm_handle);
2108
2109         if (!fh) {
2110                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2111                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2112                         err = -ENOENT;
2113                         goto errout;
2114                 }
2115         } else if (n->nlmsg_flags & NLM_F_EXCL) {
2116                 tfilter_put(tp, fh);
2117                 NL_SET_ERR_MSG(extack, "Filter already exists");
2118                 err = -EEXIST;
2119                 goto errout;
2120         }
2121
2122         if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
2123                 NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
2124                 err = -EINVAL;
2125                 goto errout;
2126         }
2127
2128         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
2129                               n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
2130                               rtnl_held, extack);
2131         if (err == 0) {
2132                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2133                                RTM_NEWTFILTER, false, rtnl_held);
2134                 tfilter_put(tp, fh);
2135                 /* q pointer is NULL for shared blocks */
2136                 if (q)
2137                         q->flags &= ~TCQ_F_CAN_BYPASS;
2138         }
2139
2140 errout:
2141         if (err && tp_created)
2142                 tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
2143 errout_tp:
2144         if (chain) {
2145                 if (tp && !IS_ERR(tp))
2146                         tcf_proto_put(tp, rtnl_held, NULL);
2147                 if (!tp_created)
2148                         tcf_chain_put(chain);
2149         }
2150         tcf_block_release(q, block, rtnl_held);
2151
2152         if (rtnl_held)
2153                 rtnl_unlock();
2154
2155         if (err == -EAGAIN) {
2156                 /* Take rtnl lock in case EAGAIN is caused by concurrent flush
2157                  * of target chain.
2158                  */
2159                 rtnl_held = true;
2160                 /* Replay the request. */
2161                 goto replay;
2162         }
2163         return err;
2164
2165 errout_locked:
2166         mutex_unlock(&chain->filter_chain_lock);
2167         goto errout;
2168 }
2169
2170 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2171                           struct netlink_ext_ack *extack)
2172 {
2173         struct net *net = sock_net(skb->sk);
2174         struct nlattr *tca[TCA_MAX + 1];
2175         char name[IFNAMSIZ];
2176         struct tcmsg *t;
2177         u32 protocol;
2178         u32 prio;
2179         u32 parent;
2180         u32 chain_index;
2181         struct Qdisc *q = NULL;
2182         struct tcf_chain_info chain_info;
2183         struct tcf_chain *chain = NULL;
2184         struct tcf_block *block = NULL;
2185         struct tcf_proto *tp = NULL;
2186         unsigned long cl = 0;
2187         void *fh = NULL;
2188         int err;
2189         bool rtnl_held = false;
2190
2191         if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2192                 return -EPERM;
2193
2194         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2195                                      rtm_tca_policy, extack);
2196         if (err < 0)
2197                 return err;
2198
2199         t = nlmsg_data(n);
2200         protocol = TC_H_MIN(t->tcm_info);
2201         prio = TC_H_MAJ(t->tcm_info);
2202         parent = t->tcm_parent;
2203
2204         if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
2205                 NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
2206                 return -ENOENT;
2207         }
2208
2209         /* Find head of filter chain. */
2210
2211         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2212         if (err)
2213                 return err;
2214
2215         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2216                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2217                 err = -EINVAL;
2218                 goto errout;
2219         }
2220         /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
2221          * found), qdisc is not unlocked, classifier type is not specified,
2222          * classifier is not unlocked.
2223          */
2224         if (!prio ||
2225             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2226             !tcf_proto_is_unlocked(name)) {
2227                 rtnl_held = true;
2228                 rtnl_lock();
2229         }
2230
2231         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2232         if (err)
2233                 goto errout;
2234
2235         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2236                                  extack);
2237         if (IS_ERR(block)) {
2238                 err = PTR_ERR(block);
2239                 goto errout;
2240         }
2241
2242         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2243         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2244                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2245                 err = -EINVAL;
2246                 goto errout;
2247         }
2248         chain = tcf_chain_get(block, chain_index, false);
2249         if (!chain) {
2250                 /* User requested flush on non-existent chain. Nothing to do,
2251                  * so just return success.
2252                  */
2253                 if (prio == 0) {
2254                         err = 0;
2255                         goto errout;
2256                 }
2257                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2258                 err = -ENOENT;
2259                 goto errout;
2260         }
2261
2262         if (prio == 0) {
2263                 tfilter_notify_chain(net, skb, block, q, parent, n,
2264                                      chain, RTM_DELTFILTER);
2265                 tcf_chain_flush(chain, rtnl_held);
2266                 err = 0;
2267                 goto errout;
2268         }
2269
2270         mutex_lock(&chain->filter_chain_lock);
2271         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2272                                prio, false);
2273         if (!tp || IS_ERR(tp)) {
2274                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2275                 err = tp ? PTR_ERR(tp) : -ENOENT;
2276                 goto errout_locked;
2277         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2278                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2279                 err = -EINVAL;
2280                 goto errout_locked;
2281         } else if (t->tcm_handle == 0) {
2282                 tcf_proto_signal_destroying(chain, tp);
2283                 tcf_chain_tp_remove(chain, &chain_info, tp);
2284                 mutex_unlock(&chain->filter_chain_lock);
2285
2286                 tcf_proto_put(tp, rtnl_held, NULL);
2287                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2288                                RTM_DELTFILTER, false, rtnl_held);
2289                 err = 0;
2290                 goto errout;
2291         }
2292         mutex_unlock(&chain->filter_chain_lock);
2293
2294         fh = tp->ops->get(tp, t->tcm_handle);
2295
2296         if (!fh) {
2297                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2298                 err = -ENOENT;
2299         } else {
2300                 bool last;
2301
2302                 err = tfilter_del_notify(net, skb, n, tp, block,
2303                                          q, parent, fh, false, &last,
2304                                          rtnl_held, extack);
2305
2306                 if (err)
2307                         goto errout;
2308                 if (last)
2309                         tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
2310         }
2311
2312 errout:
2313         if (chain) {
2314                 if (tp && !IS_ERR(tp))
2315                         tcf_proto_put(tp, rtnl_held, NULL);
2316                 tcf_chain_put(chain);
2317         }
2318         tcf_block_release(q, block, rtnl_held);
2319
2320         if (rtnl_held)
2321                 rtnl_unlock();
2322
2323         return err;
2324
2325 errout_locked:
2326         mutex_unlock(&chain->filter_chain_lock);
2327         goto errout;
2328 }
2329
2330 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2331                           struct netlink_ext_ack *extack)
2332 {
2333         struct net *net = sock_net(skb->sk);
2334         struct nlattr *tca[TCA_MAX + 1];
2335         char name[IFNAMSIZ];
2336         struct tcmsg *t;
2337         u32 protocol;
2338         u32 prio;
2339         u32 parent;
2340         u32 chain_index;
2341         struct Qdisc *q = NULL;
2342         struct tcf_chain_info chain_info;
2343         struct tcf_chain *chain = NULL;
2344         struct tcf_block *block = NULL;
2345         struct tcf_proto *tp = NULL;
2346         unsigned long cl = 0;
2347         void *fh = NULL;
2348         int err;
2349         bool rtnl_held = false;
2350
2351         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2352                                      rtm_tca_policy, extack);
2353         if (err < 0)
2354                 return err;
2355
2356         t = nlmsg_data(n);
2357         protocol = TC_H_MIN(t->tcm_info);
2358         prio = TC_H_MAJ(t->tcm_info);
2359         parent = t->tcm_parent;
2360
2361         if (prio == 0) {
2362                 NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2363                 return -ENOENT;
2364         }
2365
2366         /* Find head of filter chain. */
2367
2368         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2369         if (err)
2370                 return err;
2371
2372         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2373                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2374                 err = -EINVAL;
2375                 goto errout;
2376         }
2377         /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
2378          * unlocked, classifier type is not specified, classifier is not
2379          * unlocked.
2380          */
2381         if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2382             !tcf_proto_is_unlocked(name)) {
2383                 rtnl_held = true;
2384                 rtnl_lock();
2385         }
2386
2387         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2388         if (err)
2389                 goto errout;
2390
2391         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2392                                  extack);
2393         if (IS_ERR(block)) {
2394                 err = PTR_ERR(block);
2395                 goto errout;
2396         }
2397
2398         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2399         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2400                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2401                 err = -EINVAL;
2402                 goto errout;
2403         }
2404         chain = tcf_chain_get(block, chain_index, false);
2405         if (!chain) {
2406                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2407                 err = -EINVAL;
2408                 goto errout;
2409         }
2410
2411         mutex_lock(&chain->filter_chain_lock);
2412         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2413                                prio, false);
2414         mutex_unlock(&chain->filter_chain_lock);
2415         if (!tp || IS_ERR(tp)) {
2416                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2417                 err = tp ? PTR_ERR(tp) : -ENOENT;
2418                 goto errout;
2419         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2420                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2421                 err = -EINVAL;
2422                 goto errout;
2423         }
2424
2425         fh = tp->ops->get(tp, t->tcm_handle);
2426
2427         if (!fh) {
2428                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2429                 err = -ENOENT;
2430         } else {
2431                 err = tfilter_notify(net, skb, n, tp, block, q, parent,
2432                                      fh, RTM_NEWTFILTER, true, rtnl_held);
2433                 if (err < 0)
2434                         NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
2435         }
2436
2437         tfilter_put(tp, fh);
2438 errout:
2439         if (chain) {
2440                 if (tp && !IS_ERR(tp))
2441                         tcf_proto_put(tp, rtnl_held, NULL);
2442                 tcf_chain_put(chain);
2443         }
2444         tcf_block_release(q, block, rtnl_held);
2445
2446         if (rtnl_held)
2447                 rtnl_unlock();
2448
2449         return err;
2450 }
2451
2452 struct tcf_dump_args {
2453         struct tcf_walker w;
2454         struct sk_buff *skb;
2455         struct netlink_callback *cb;
2456         struct tcf_block *block;
2457         struct Qdisc *q;
2458         u32 parent;
2459         bool terse_dump;
2460 };
2461
2462 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2463 {
2464         struct tcf_dump_args *a = (void *)arg;
2465         struct net *net = sock_net(a->skb->sk);
2466
2467         return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
2468                              n, NETLINK_CB(a->cb->skb).portid,
2469                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2470                              RTM_NEWTFILTER, a->terse_dump, true);
2471 }
2472
2473 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
2474                            struct sk_buff *skb, struct netlink_callback *cb,
2475                            long index_start, long *p_index, bool terse)
2476 {
2477         struct net *net = sock_net(skb->sk);
2478         struct tcf_block *block = chain->block;
2479         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2480         struct tcf_proto *tp, *tp_prev;
2481         struct tcf_dump_args arg;
2482
2483         for (tp = __tcf_get_next_proto(chain, NULL);
2484              tp;
2485              tp_prev = tp,
2486                      tp = __tcf_get_next_proto(chain, tp),
2487                      tcf_proto_put(tp_prev, true, NULL),
2488                      (*p_index)++) {
2489                 if (*p_index < index_start)
2490                         continue;
2491                 if (TC_H_MAJ(tcm->tcm_info) &&
2492                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
2493                         continue;
2494                 if (TC_H_MIN(tcm->tcm_info) &&
2495                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
2496                         continue;
2497                 if (*p_index > index_start)
2498                         memset(&cb->args[1], 0,
2499                                sizeof(cb->args) - sizeof(cb->args[0]));
2500                 if (cb->args[1] == 0) {
2501                         if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
2502                                           NETLINK_CB(cb->skb).portid,
2503                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
2504                                           RTM_NEWTFILTER, false, true) <= 0)
2505                                 goto errout;
2506                         cb->args[1] = 1;
2507                 }
2508                 if (!tp->ops->walk)
2509                         continue;
2510                 arg.w.fn = tcf_node_dump;
2511                 arg.skb = skb;
2512                 arg.cb = cb;
2513                 arg.block = block;
2514                 arg.q = q;
2515                 arg.parent = parent;
2516                 arg.w.stop = 0;
2517                 arg.w.skip = cb->args[1] - 1;
2518                 arg.w.count = 0;
2519                 arg.w.cookie = cb->args[2];
2520                 arg.terse_dump = terse;
2521                 tp->ops->walk(tp, &arg.w, true);
2522                 cb->args[2] = arg.w.cookie;
2523                 cb->args[1] = arg.w.count + 1;
2524                 if (arg.w.stop)
2525                         goto errout;
2526         }
2527         return true;
2528
2529 errout:
2530         tcf_proto_put(tp, true, NULL);
2531         return false;
2532 }
2533
2534 static const struct nla_policy tcf_tfilter_dump_policy[TCA_MAX + 1] = {
2535         [TCA_DUMP_FLAGS] = NLA_POLICY_BITFIELD32(TCA_DUMP_FLAGS_TERSE),
2536 };
2537
2538 /* called with RTNL */
2539 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
2540 {
2541         struct tcf_chain *chain, *chain_prev;
2542         struct net *net = sock_net(skb->sk);
2543         struct nlattr *tca[TCA_MAX + 1];
2544         struct Qdisc *q = NULL;
2545         struct tcf_block *block;
2546         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2547         bool terse_dump = false;
2548         long index_start;
2549         long index;
2550         u32 parent;
2551         int err;
2552
2553         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2554                 return skb->len;
2555
2556         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2557                                      tcf_tfilter_dump_policy, cb->extack);
2558         if (err)
2559                 return err;
2560
2561         if (tca[TCA_DUMP_FLAGS]) {
2562                 struct nla_bitfield32 flags =
2563                         nla_get_bitfield32(tca[TCA_DUMP_FLAGS]);
2564
2565                 terse_dump = flags.value & TCA_DUMP_FLAGS_TERSE;
2566         }
2567
2568         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2569                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2570                 if (!block)
2571                         goto out;
2572                 /* If we work with block index, q is NULL and parent value
2573                  * will never be used in the following code. The check
2574                  * in tcf_fill_node prevents it. However, compiler does not
2575                  * see that far, so set parent to zero to silence the warning
2576                  * about parent being uninitialized.
2577                  */
2578                 parent = 0;
2579         } else {
2580                 const struct Qdisc_class_ops *cops;
2581                 struct net_device *dev;
2582                 unsigned long cl = 0;
2583
2584                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2585                 if (!dev)
2586                         return skb->len;
2587
2588                 parent = tcm->tcm_parent;
2589                 if (!parent)
2590                         q = dev->qdisc;
2591                 else
2592                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2593                 if (!q)
2594                         goto out;
2595                 cops = q->ops->cl_ops;
2596                 if (!cops)
2597                         goto out;
2598                 if (!cops->tcf_block)
2599                         goto out;
2600                 if (TC_H_MIN(tcm->tcm_parent)) {
2601                         cl = cops->find(q, tcm->tcm_parent);
2602                         if (cl == 0)
2603                                 goto out;
2604                 }
2605                 block = cops->tcf_block(q, cl, NULL);
2606                 if (!block)
2607                         goto out;
2608                 parent = block->classid;
2609                 if (tcf_block_shared(block))
2610                         q = NULL;
2611         }
2612
2613         index_start = cb->args[0];
2614         index = 0;
2615
2616         for (chain = __tcf_get_next_chain(block, NULL);
2617              chain;
2618              chain_prev = chain,
2619                      chain = __tcf_get_next_chain(block, chain),
2620                      tcf_chain_put(chain_prev)) {
2621                 if (tca[TCA_CHAIN] &&
2622                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
2623                         continue;
2624                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
2625                                     index_start, &index, terse_dump)) {
2626                         tcf_chain_put(chain);
2627                         err = -EMSGSIZE;
2628                         break;
2629                 }
2630         }
2631
2632         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2633                 tcf_block_refcnt_put(block, true);
2634         cb->args[0] = index;
2635
2636 out:
2637         /* If we did no progress, the error (EMSGSIZE) is real */
2638         if (skb->len == 0 && err)
2639                 return err;
2640         return skb->len;
2641 }
2642
2643 static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
2644                               void *tmplt_priv, u32 chain_index,
2645                               struct net *net, struct sk_buff *skb,
2646                               struct tcf_block *block,
2647                               u32 portid, u32 seq, u16 flags, int event)
2648 {
2649         unsigned char *b = skb_tail_pointer(skb);
2650         const struct tcf_proto_ops *ops;
2651         struct nlmsghdr *nlh;
2652         struct tcmsg *tcm;
2653         void *priv;
2654
2655         ops = tmplt_ops;
2656         priv = tmplt_priv;
2657
2658         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2659         if (!nlh)
2660                 goto out_nlmsg_trim;
2661         tcm = nlmsg_data(nlh);
2662         tcm->tcm_family = AF_UNSPEC;
2663         tcm->tcm__pad1 = 0;
2664         tcm->tcm__pad2 = 0;
2665         tcm->tcm_handle = 0;
2666         if (block->q) {
2667                 tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
2668                 tcm->tcm_parent = block->q->handle;
2669         } else {
2670                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2671                 tcm->tcm_block_index = block->index;
2672         }
2673
2674         if (nla_put_u32(skb, TCA_CHAIN, chain_index))
2675                 goto nla_put_failure;
2676
2677         if (ops) {
2678                 if (nla_put_string(skb, TCA_KIND, ops->kind))
2679                         goto nla_put_failure;
2680                 if (ops->tmplt_dump(skb, net, priv) < 0)
2681                         goto nla_put_failure;
2682         }
2683
2684         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2685         return skb->len;
2686
2687 out_nlmsg_trim:
2688 nla_put_failure:
2689         nlmsg_trim(skb, b);
2690         return -EMSGSIZE;
2691 }
2692
2693 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
2694                            u32 seq, u16 flags, int event, bool unicast)
2695 {
2696         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2697         struct tcf_block *block = chain->block;
2698         struct net *net = block->net;
2699         struct sk_buff *skb;
2700         int err = 0;
2701
2702         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2703         if (!skb)
2704                 return -ENOBUFS;
2705
2706         if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2707                                chain->index, net, skb, block, portid,
2708                                seq, flags, event) <= 0) {
2709                 kfree_skb(skb);
2710                 return -EINVAL;
2711         }
2712
2713         if (unicast)
2714                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
2715         else
2716                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2717                                      flags & NLM_F_ECHO);
2718
2719         if (err > 0)
2720                 err = 0;
2721         return err;
2722 }
2723
2724 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
2725                                   void *tmplt_priv, u32 chain_index,
2726                                   struct tcf_block *block, struct sk_buff *oskb,
2727                                   u32 seq, u16 flags, bool unicast)
2728 {
2729         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2730         struct net *net = block->net;
2731         struct sk_buff *skb;
2732
2733         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2734         if (!skb)
2735                 return -ENOBUFS;
2736
2737         if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
2738                                block, portid, seq, flags, RTM_DELCHAIN) <= 0) {
2739                 kfree_skb(skb);
2740                 return -EINVAL;
2741         }
2742
2743         if (unicast)
2744                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
2745
2746         return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
2747 }
2748
2749 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
2750                               struct nlattr **tca,
2751                               struct netlink_ext_ack *extack)
2752 {
2753         const struct tcf_proto_ops *ops;
2754         char name[IFNAMSIZ];
2755         void *tmplt_priv;
2756
2757         /* If kind is not set, user did not specify template. */
2758         if (!tca[TCA_KIND])
2759                 return 0;
2760
2761         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2762                 NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
2763                 return -EINVAL;
2764         }
2765
2766         ops = tcf_proto_lookup_ops(name, true, extack);
2767         if (IS_ERR(ops))
2768                 return PTR_ERR(ops);
2769         if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
2770                 NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
2771                 return -EOPNOTSUPP;
2772         }
2773
2774         tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
2775         if (IS_ERR(tmplt_priv)) {
2776                 module_put(ops->owner);
2777                 return PTR_ERR(tmplt_priv);
2778         }
2779         chain->tmplt_ops = ops;
2780         chain->tmplt_priv = tmplt_priv;
2781         return 0;
2782 }
2783
2784 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
2785                                void *tmplt_priv)
2786 {
2787         /* If template ops are set, no work to do for us. */
2788         if (!tmplt_ops)
2789                 return;
2790
2791         tmplt_ops->tmplt_destroy(tmplt_priv);
2792         module_put(tmplt_ops->owner);
2793 }
2794
2795 /* Add/delete/get a chain */
2796
2797 static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
2798                         struct netlink_ext_ack *extack)
2799 {
2800         struct net *net = sock_net(skb->sk);
2801         struct nlattr *tca[TCA_MAX + 1];
2802         struct tcmsg *t;
2803         u32 parent;
2804         u32 chain_index;
2805         struct Qdisc *q = NULL;
2806         struct tcf_chain *chain = NULL;
2807         struct tcf_block *block;
2808         unsigned long cl;
2809         int err;
2810
2811         if (n->nlmsg_type != RTM_GETCHAIN &&
2812             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2813                 return -EPERM;
2814
2815 replay:
2816         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2817                                      rtm_tca_policy, extack);
2818         if (err < 0)
2819                 return err;
2820
2821         t = nlmsg_data(n);
2822         parent = t->tcm_parent;
2823         cl = 0;
2824
2825         block = tcf_block_find(net, &q, &parent, &cl,
2826                                t->tcm_ifindex, t->tcm_block_index, extack);
2827         if (IS_ERR(block))
2828                 return PTR_ERR(block);
2829
2830         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2831         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2832                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2833                 err = -EINVAL;
2834                 goto errout_block;
2835         }
2836
2837         mutex_lock(&block->lock);
2838         chain = tcf_chain_lookup(block, chain_index);
2839         if (n->nlmsg_type == RTM_NEWCHAIN) {
2840                 if (chain) {
2841                         if (tcf_chain_held_by_acts_only(chain)) {
2842                                 /* The chain exists only because there is
2843                                  * some action referencing it.
2844                                  */
2845                                 tcf_chain_hold(chain);
2846                         } else {
2847                                 NL_SET_ERR_MSG(extack, "Filter chain already exists");
2848                                 err = -EEXIST;
2849                                 goto errout_block_locked;
2850                         }
2851                 } else {
2852                         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2853                                 NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
2854                                 err = -ENOENT;
2855                                 goto errout_block_locked;
2856                         }
2857                         chain = tcf_chain_create(block, chain_index);
2858                         if (!chain) {
2859                                 NL_SET_ERR_MSG(extack, "Failed to create filter chain");
2860                                 err = -ENOMEM;
2861                                 goto errout_block_locked;
2862                         }
2863                 }
2864         } else {
2865                 if (!chain || tcf_chain_held_by_acts_only(chain)) {
2866                         NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2867                         err = -EINVAL;
2868                         goto errout_block_locked;
2869                 }
2870                 tcf_chain_hold(chain);
2871         }
2872
2873         if (n->nlmsg_type == RTM_NEWCHAIN) {
2874                 /* Modifying chain requires holding parent block lock. In case
2875                  * the chain was successfully added, take a reference to the
2876                  * chain. This ensures that an empty chain does not disappear at
2877                  * the end of this function.
2878                  */
2879                 tcf_chain_hold(chain);
2880                 chain->explicitly_created = true;
2881         }
2882         mutex_unlock(&block->lock);
2883
2884         switch (n->nlmsg_type) {
2885         case RTM_NEWCHAIN:
2886                 err = tc_chain_tmplt_add(chain, net, tca, extack);
2887                 if (err) {
2888                         tcf_chain_put_explicitly_created(chain);
2889                         goto errout;
2890                 }
2891
2892                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
2893                                 RTM_NEWCHAIN, false);
2894                 break;
2895         case RTM_DELCHAIN:
2896                 tfilter_notify_chain(net, skb, block, q, parent, n,
2897                                      chain, RTM_DELTFILTER);
2898                 /* Flush the chain first as the user requested chain removal. */
2899                 tcf_chain_flush(chain, true);
2900                 /* In case the chain was successfully deleted, put a reference
2901                  * to the chain previously taken during addition.
2902                  */
2903                 tcf_chain_put_explicitly_created(chain);
2904                 break;
2905         case RTM_GETCHAIN:
2906                 err = tc_chain_notify(chain, skb, n->nlmsg_seq,
2907                                       n->nlmsg_seq, n->nlmsg_type, true);
2908                 if (err < 0)
2909                         NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
2910                 break;
2911         default:
2912                 err = -EOPNOTSUPP;
2913                 NL_SET_ERR_MSG(extack, "Unsupported message type");
2914                 goto errout;
2915         }
2916
2917 errout:
2918         tcf_chain_put(chain);
2919 errout_block:
2920         tcf_block_release(q, block, true);
2921         if (err == -EAGAIN)
2922                 /* Replay the request. */
2923                 goto replay;
2924         return err;
2925
2926 errout_block_locked:
2927         mutex_unlock(&block->lock);
2928         goto errout_block;
2929 }
2930
2931 /* called with RTNL */
2932 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
2933 {
2934         struct net *net = sock_net(skb->sk);
2935         struct nlattr *tca[TCA_MAX + 1];
2936         struct Qdisc *q = NULL;
2937         struct tcf_block *block;
2938         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2939         struct tcf_chain *chain;
2940         long index_start;
2941         long index;
2942         int err;
2943
2944         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2945                 return skb->len;
2946
2947         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2948                                      rtm_tca_policy, cb->extack);
2949         if (err)
2950                 return err;
2951
2952         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2953                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2954                 if (!block)
2955                         goto out;
2956         } else {
2957                 const struct Qdisc_class_ops *cops;
2958                 struct net_device *dev;
2959                 unsigned long cl = 0;
2960
2961                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2962                 if (!dev)
2963                         return skb->len;
2964
2965                 if (!tcm->tcm_parent)
2966                         q = dev->qdisc;
2967                 else
2968                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2969
2970                 if (!q)
2971                         goto out;
2972                 cops = q->ops->cl_ops;
2973                 if (!cops)
2974                         goto out;
2975                 if (!cops->tcf_block)
2976                         goto out;
2977                 if (TC_H_MIN(tcm->tcm_parent)) {
2978                         cl = cops->find(q, tcm->tcm_parent);
2979                         if (cl == 0)
2980                                 goto out;
2981                 }
2982                 block = cops->tcf_block(q, cl, NULL);
2983                 if (!block)
2984                         goto out;
2985                 if (tcf_block_shared(block))
2986                         q = NULL;
2987         }
2988
2989         index_start = cb->args[0];
2990         index = 0;
2991
2992         mutex_lock(&block->lock);
2993         list_for_each_entry(chain, &block->chain_list, list) {
2994                 if ((tca[TCA_CHAIN] &&
2995                      nla_get_u32(tca[TCA_CHAIN]) != chain->index))
2996                         continue;
2997                 if (index < index_start) {
2998                         index++;
2999                         continue;
3000                 }
3001                 if (tcf_chain_held_by_acts_only(chain))
3002                         continue;
3003                 err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
3004                                          chain->index, net, skb, block,
3005                                          NETLINK_CB(cb->skb).portid,
3006                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
3007                                          RTM_NEWCHAIN);
3008                 if (err <= 0)
3009                         break;
3010                 index++;
3011         }
3012         mutex_unlock(&block->lock);
3013
3014         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
3015                 tcf_block_refcnt_put(block, true);
3016         cb->args[0] = index;
3017
3018 out:
3019         /* If we did no progress, the error (EMSGSIZE) is real */
3020         if (skb->len == 0 && err)
3021                 return err;
3022         return skb->len;
3023 }
3024
3025 void tcf_exts_destroy(struct tcf_exts *exts)
3026 {
3027 #ifdef CONFIG_NET_CLS_ACT
3028         if (exts->actions) {
3029                 tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
3030                 kfree(exts->actions);
3031         }
3032         exts->nr_actions = 0;
3033 #endif
3034 }
3035 EXPORT_SYMBOL(tcf_exts_destroy);
3036
3037 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3038                       struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr,
3039                       bool rtnl_held, struct netlink_ext_ack *extack)
3040 {
3041 #ifdef CONFIG_NET_CLS_ACT
3042         {
3043                 struct tc_action *act;
3044                 size_t attr_size = 0;
3045
3046                 if (exts->police && tb[exts->police]) {
3047                         struct tc_action_ops *a_o;
3048
3049                         a_o = tc_action_load_ops("police", tb[exts->police], rtnl_held, extack);
3050                         if (IS_ERR(a_o))
3051                                 return PTR_ERR(a_o);
3052                         act = tcf_action_init_1(net, tp, tb[exts->police],
3053                                                 rate_tlv, "police", ovr,
3054                                                 TCA_ACT_BIND, a_o, rtnl_held,
3055                                                 extack);
3056                         if (IS_ERR(act)) {
3057                                 module_put(a_o->owner);
3058                                 return PTR_ERR(act);
3059                         }
3060
3061                         act->type = exts->type = TCA_OLD_COMPAT;
3062                         exts->actions[0] = act;
3063                         exts->nr_actions = 1;
3064                         tcf_idr_insert_many(exts->actions);
3065                 } else if (exts->action && tb[exts->action]) {
3066                         int err;
3067
3068                         err = tcf_action_init(net, tp, tb[exts->action],
3069                                               rate_tlv, NULL, ovr, TCA_ACT_BIND,
3070                                               exts->actions, &attr_size,
3071                                               rtnl_held, extack);
3072                         if (err < 0)
3073                                 return err;
3074                         exts->nr_actions = err;
3075                 }
3076         }
3077 #else
3078         if ((exts->action && tb[exts->action]) ||
3079             (exts->police && tb[exts->police])) {
3080                 NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
3081                 return -EOPNOTSUPP;
3082         }
3083 #endif
3084
3085         return 0;
3086 }
3087 EXPORT_SYMBOL(tcf_exts_validate);
3088
3089 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
3090 {
3091 #ifdef CONFIG_NET_CLS_ACT
3092         struct tcf_exts old = *dst;
3093
3094         *dst = *src;
3095         tcf_exts_destroy(&old);
3096 #endif
3097 }
3098 EXPORT_SYMBOL(tcf_exts_change);
3099
3100 #ifdef CONFIG_NET_CLS_ACT
3101 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
3102 {
3103         if (exts->nr_actions == 0)
3104                 return NULL;
3105         else
3106                 return exts->actions[0];
3107 }
3108 #endif
3109
3110 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
3111 {
3112 #ifdef CONFIG_NET_CLS_ACT
3113         struct nlattr *nest;
3114
3115         if (exts->action && tcf_exts_has_actions(exts)) {
3116                 /*
3117                  * again for backward compatible mode - we want
3118                  * to work with both old and new modes of entering
3119                  * tc data even if iproute2  was newer - jhs
3120                  */
3121                 if (exts->type != TCA_OLD_COMPAT) {
3122                         nest = nla_nest_start_noflag(skb, exts->action);
3123                         if (nest == NULL)
3124                                 goto nla_put_failure;
3125
3126                         if (tcf_action_dump(skb, exts->actions, 0, 0, false)
3127                             < 0)
3128                                 goto nla_put_failure;
3129                         nla_nest_end(skb, nest);
3130                 } else if (exts->police) {
3131                         struct tc_action *act = tcf_exts_first_act(exts);
3132                         nest = nla_nest_start_noflag(skb, exts->police);
3133                         if (nest == NULL || !act)
3134                                 goto nla_put_failure;
3135                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
3136                                 goto nla_put_failure;
3137                         nla_nest_end(skb, nest);
3138                 }
3139         }
3140         return 0;
3141
3142 nla_put_failure:
3143         nla_nest_cancel(skb, nest);
3144         return -1;
3145 #else
3146         return 0;
3147 #endif
3148 }
3149 EXPORT_SYMBOL(tcf_exts_dump);
3150
3151 int tcf_exts_terse_dump(struct sk_buff *skb, struct tcf_exts *exts)
3152 {
3153 #ifdef CONFIG_NET_CLS_ACT
3154         struct nlattr *nest;
3155
3156         if (!exts->action || !tcf_exts_has_actions(exts))
3157                 return 0;
3158
3159         nest = nla_nest_start_noflag(skb, exts->action);
3160         if (!nest)
3161                 goto nla_put_failure;
3162
3163         if (tcf_action_dump(skb, exts->actions, 0, 0, true) < 0)
3164                 goto nla_put_failure;
3165         nla_nest_end(skb, nest);
3166         return 0;
3167
3168 nla_put_failure:
3169         nla_nest_cancel(skb, nest);
3170         return -1;
3171 #else
3172         return 0;
3173 #endif
3174 }
3175 EXPORT_SYMBOL(tcf_exts_terse_dump);
3176
3177 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
3178 {
3179 #ifdef CONFIG_NET_CLS_ACT
3180         struct tc_action *a = tcf_exts_first_act(exts);
3181         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
3182                 return -1;
3183 #endif
3184         return 0;
3185 }
3186 EXPORT_SYMBOL(tcf_exts_dump_stats);
3187
3188 static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
3189 {
3190         if (*flags & TCA_CLS_FLAGS_IN_HW)
3191                 return;
3192         *flags |= TCA_CLS_FLAGS_IN_HW;
3193         atomic_inc(&block->offloadcnt);
3194 }
3195
3196 static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
3197 {
3198         if (!(*flags & TCA_CLS_FLAGS_IN_HW))
3199                 return;
3200         *flags &= ~TCA_CLS_FLAGS_IN_HW;
3201         atomic_dec(&block->offloadcnt);
3202 }
3203
3204 static void tc_cls_offload_cnt_update(struct tcf_block *block,
3205                                       struct tcf_proto *tp, u32 *cnt,
3206                                       u32 *flags, u32 diff, bool add)
3207 {
3208         lockdep_assert_held(&block->cb_lock);
3209
3210         spin_lock(&tp->lock);
3211         if (add) {
3212                 if (!*cnt)
3213                         tcf_block_offload_inc(block, flags);
3214                 *cnt += diff;
3215         } else {
3216                 *cnt -= diff;
3217                 if (!*cnt)
3218                         tcf_block_offload_dec(block, flags);
3219         }
3220         spin_unlock(&tp->lock);
3221 }
3222
3223 static void
3224 tc_cls_offload_cnt_reset(struct tcf_block *block, struct tcf_proto *tp,
3225                          u32 *cnt, u32 *flags)
3226 {
3227         lockdep_assert_held(&block->cb_lock);
3228
3229         spin_lock(&tp->lock);
3230         tcf_block_offload_dec(block, flags);
3231         *cnt = 0;
3232         spin_unlock(&tp->lock);
3233 }
3234
3235 static int
3236 __tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3237                    void *type_data, bool err_stop)
3238 {
3239         struct flow_block_cb *block_cb;
3240         int ok_count = 0;
3241         int err;
3242
3243         list_for_each_entry(block_cb, &block->flow_block.cb_list, list) {
3244                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
3245                 if (err) {
3246                         if (err_stop)
3247                                 return err;
3248                 } else {
3249                         ok_count++;
3250                 }
3251         }
3252         return ok_count;
3253 }
3254
3255 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3256                      void *type_data, bool err_stop, bool rtnl_held)
3257 {
3258         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3259         int ok_count;
3260
3261 retry:
3262         if (take_rtnl)
3263                 rtnl_lock();
3264         down_read(&block->cb_lock);
3265         /* Need to obtain rtnl lock if block is bound to devs that require it.
3266          * In block bind code cb_lock is obtained while holding rtnl, so we must
3267          * obtain the locks in same order here.
3268          */
3269         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3270                 up_read(&block->cb_lock);
3271                 take_rtnl = true;
3272                 goto retry;
3273         }
3274
3275         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3276
3277         up_read(&block->cb_lock);
3278         if (take_rtnl)
3279                 rtnl_unlock();
3280         return ok_count;
3281 }
3282 EXPORT_SYMBOL(tc_setup_cb_call);
3283
3284 /* Non-destructive filter add. If filter that wasn't already in hardware is
3285  * successfully offloaded, increment block offloads counter. On failure,
3286  * previously offloaded filter is considered to be intact and offloads counter
3287  * is not decremented.
3288  */
3289
3290 int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
3291                     enum tc_setup_type type, void *type_data, bool err_stop,
3292                     u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3293 {
3294         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3295         int ok_count;
3296
3297 retry:
3298         if (take_rtnl)
3299                 rtnl_lock();
3300         down_read(&block->cb_lock);
3301         /* Need to obtain rtnl lock if block is bound to devs that require it.
3302          * In block bind code cb_lock is obtained while holding rtnl, so we must
3303          * obtain the locks in same order here.
3304          */
3305         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3306                 up_read(&block->cb_lock);
3307                 take_rtnl = true;
3308                 goto retry;
3309         }
3310
3311         /* Make sure all netdevs sharing this block are offload-capable. */
3312         if (block->nooffloaddevcnt && err_stop) {
3313                 ok_count = -EOPNOTSUPP;
3314                 goto err_unlock;
3315         }
3316
3317         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3318         if (ok_count < 0)
3319                 goto err_unlock;
3320
3321         if (tp->ops->hw_add)
3322                 tp->ops->hw_add(tp, type_data);
3323         if (ok_count > 0)
3324                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
3325                                           ok_count, true);
3326 err_unlock:
3327         up_read(&block->cb_lock);
3328         if (take_rtnl)
3329                 rtnl_unlock();
3330         return ok_count < 0 ? ok_count : 0;
3331 }
3332 EXPORT_SYMBOL(tc_setup_cb_add);
3333
3334 /* Destructive filter replace. If filter that wasn't already in hardware is
3335  * successfully offloaded, increment block offload counter. On failure,
3336  * previously offloaded filter is considered to be destroyed and offload counter
3337  * is decremented.
3338  */
3339
3340 int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
3341                         enum tc_setup_type type, void *type_data, bool err_stop,
3342                         u32 *old_flags, unsigned int *old_in_hw_count,
3343                         u32 *new_flags, unsigned int *new_in_hw_count,
3344                         bool rtnl_held)
3345 {
3346         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3347         int ok_count;
3348
3349 retry:
3350         if (take_rtnl)
3351                 rtnl_lock();
3352         down_read(&block->cb_lock);
3353         /* Need to obtain rtnl lock if block is bound to devs that require it.
3354          * In block bind code cb_lock is obtained while holding rtnl, so we must
3355          * obtain the locks in same order here.
3356          */
3357         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3358                 up_read(&block->cb_lock);
3359                 take_rtnl = true;
3360                 goto retry;
3361         }
3362
3363         /* Make sure all netdevs sharing this block are offload-capable. */
3364         if (block->nooffloaddevcnt && err_stop) {
3365                 ok_count = -EOPNOTSUPP;
3366                 goto err_unlock;
3367         }
3368
3369         tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
3370         if (tp->ops->hw_del)
3371                 tp->ops->hw_del(tp, type_data);
3372
3373         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3374         if (ok_count < 0)
3375                 goto err_unlock;
3376
3377         if (tp->ops->hw_add)
3378                 tp->ops->hw_add(tp, type_data);
3379         if (ok_count > 0)
3380                 tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
3381                                           new_flags, ok_count, true);
3382 err_unlock:
3383         up_read(&block->cb_lock);
3384         if (take_rtnl)
3385                 rtnl_unlock();
3386         return ok_count < 0 ? ok_count : 0;
3387 }
3388 EXPORT_SYMBOL(tc_setup_cb_replace);
3389
3390 /* Destroy filter and decrement block offload counter, if filter was previously
3391  * offloaded.
3392  */
3393
3394 int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
3395                         enum tc_setup_type type, void *type_data, bool err_stop,
3396                         u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3397 {
3398         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3399         int ok_count;
3400
3401 retry:
3402         if (take_rtnl)
3403                 rtnl_lock();
3404         down_read(&block->cb_lock);
3405         /* Need to obtain rtnl lock if block is bound to devs that require it.
3406          * In block bind code cb_lock is obtained while holding rtnl, so we must
3407          * obtain the locks in same order here.
3408          */
3409         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3410                 up_read(&block->cb_lock);
3411                 take_rtnl = true;
3412                 goto retry;
3413         }
3414
3415         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3416
3417         tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
3418         if (tp->ops->hw_del)
3419                 tp->ops->hw_del(tp, type_data);
3420
3421         up_read(&block->cb_lock);
3422         if (take_rtnl)
3423                 rtnl_unlock();
3424         return ok_count < 0 ? ok_count : 0;
3425 }
3426 EXPORT_SYMBOL(tc_setup_cb_destroy);
3427
3428 int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
3429                           bool add, flow_setup_cb_t *cb,
3430                           enum tc_setup_type type, void *type_data,
3431                           void *cb_priv, u32 *flags, unsigned int *in_hw_count)
3432 {
3433         int err = cb(type, type_data, cb_priv);
3434
3435         if (err) {
3436                 if (add && tc_skip_sw(*flags))
3437                         return err;
3438         } else {
3439                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags, 1,
3440                                           add);
3441         }
3442
3443         return 0;
3444 }
3445 EXPORT_SYMBOL(tc_setup_cb_reoffload);
3446
3447 static int tcf_act_get_cookie(struct flow_action_entry *entry,
3448                               const struct tc_action *act)
3449 {
3450         struct tc_cookie *cookie;
3451         int err = 0;
3452
3453         rcu_read_lock();
3454         cookie = rcu_dereference(act->act_cookie);
3455         if (cookie) {
3456                 entry->cookie = flow_action_cookie_create(cookie->data,
3457                                                           cookie->len,
3458                                                           GFP_ATOMIC);
3459                 if (!entry->cookie)
3460                         err = -ENOMEM;
3461         }
3462         rcu_read_unlock();
3463         return err;
3464 }
3465
3466 static void tcf_act_put_cookie(struct flow_action_entry *entry)
3467 {
3468         flow_action_cookie_destroy(entry->cookie);
3469 }
3470
3471 void tc_cleanup_flow_action(struct flow_action *flow_action)
3472 {
3473         struct flow_action_entry *entry;
3474         int i;
3475
3476         flow_action_for_each(i, entry, flow_action) {
3477                 tcf_act_put_cookie(entry);
3478                 if (entry->destructor)
3479                         entry->destructor(entry->destructor_priv);
3480         }
3481 }
3482 EXPORT_SYMBOL(tc_cleanup_flow_action);
3483
3484 static void tcf_mirred_get_dev(struct flow_action_entry *entry,
3485                                const struct tc_action *act)
3486 {
3487 #ifdef CONFIG_NET_CLS_ACT
3488         entry->dev = act->ops->get_dev(act, &entry->destructor);
3489         if (!entry->dev)
3490                 return;
3491         entry->destructor_priv = entry->dev;
3492 #endif
3493 }
3494
3495 static void tcf_tunnel_encap_put_tunnel(void *priv)
3496 {
3497         struct ip_tunnel_info *tunnel = priv;
3498
3499         kfree(tunnel);
3500 }
3501
3502 static int tcf_tunnel_encap_get_tunnel(struct flow_action_entry *entry,
3503                                        const struct tc_action *act)
3504 {
3505         entry->tunnel = tcf_tunnel_info_copy(act);
3506         if (!entry->tunnel)
3507                 return -ENOMEM;
3508         entry->destructor = tcf_tunnel_encap_put_tunnel;
3509         entry->destructor_priv = entry->tunnel;
3510         return 0;
3511 }
3512
3513 static void tcf_sample_get_group(struct flow_action_entry *entry,
3514                                  const struct tc_action *act)
3515 {
3516 #ifdef CONFIG_NET_CLS_ACT
3517         entry->sample.psample_group =
3518                 act->ops->get_psample_group(act, &entry->destructor);
3519         entry->destructor_priv = entry->sample.psample_group;
3520 #endif
3521 }
3522
3523 static void tcf_gate_entry_destructor(void *priv)
3524 {
3525         struct action_gate_entry *oe = priv;
3526
3527         kfree(oe);
3528 }
3529
3530 static int tcf_gate_get_entries(struct flow_action_entry *entry,
3531                                 const struct tc_action *act)
3532 {
3533         entry->gate.entries = tcf_gate_get_list(act);
3534
3535         if (!entry->gate.entries)
3536                 return -EINVAL;
3537
3538         entry->destructor = tcf_gate_entry_destructor;
3539         entry->destructor_priv = entry->gate.entries;
3540
3541         return 0;
3542 }
3543
3544 static enum flow_action_hw_stats tc_act_hw_stats(u8 hw_stats)
3545 {
3546         if (WARN_ON_ONCE(hw_stats > TCA_ACT_HW_STATS_ANY))
3547                 return FLOW_ACTION_HW_STATS_DONT_CARE;
3548         else if (!hw_stats)
3549                 return FLOW_ACTION_HW_STATS_DISABLED;
3550
3551         return hw_stats;
3552 }
3553
3554 int tc_setup_flow_action(struct flow_action *flow_action,
3555                          const struct tcf_exts *exts)
3556 {
3557         struct tc_action *act;
3558         int i, j, k, err = 0;
3559
3560         BUILD_BUG_ON(TCA_ACT_HW_STATS_ANY != FLOW_ACTION_HW_STATS_ANY);
3561         BUILD_BUG_ON(TCA_ACT_HW_STATS_IMMEDIATE != FLOW_ACTION_HW_STATS_IMMEDIATE);
3562         BUILD_BUG_ON(TCA_ACT_HW_STATS_DELAYED != FLOW_ACTION_HW_STATS_DELAYED);
3563
3564         if (!exts)
3565                 return 0;
3566
3567         j = 0;
3568         tcf_exts_for_each_action(i, act, exts) {
3569                 struct flow_action_entry *entry;
3570
3571                 entry = &flow_action->entries[j];
3572                 spin_lock_bh(&act->tcfa_lock);
3573                 err = tcf_act_get_cookie(entry, act);
3574                 if (err)
3575                         goto err_out_locked;
3576
3577                 entry->hw_stats = tc_act_hw_stats(act->hw_stats);
3578
3579                 if (is_tcf_gact_ok(act)) {
3580                         entry->id = FLOW_ACTION_ACCEPT;
3581                 } else if (is_tcf_gact_shot(act)) {
3582                         entry->id = FLOW_ACTION_DROP;
3583                 } else if (is_tcf_gact_trap(act)) {
3584                         entry->id = FLOW_ACTION_TRAP;
3585                 } else if (is_tcf_gact_goto_chain(act)) {
3586                         entry->id = FLOW_ACTION_GOTO;
3587                         entry->chain_index = tcf_gact_goto_chain_index(act);
3588                 } else if (is_tcf_mirred_egress_redirect(act)) {
3589                         entry->id = FLOW_ACTION_REDIRECT;
3590                         tcf_mirred_get_dev(entry, act);
3591                 } else if (is_tcf_mirred_egress_mirror(act)) {
3592                         entry->id = FLOW_ACTION_MIRRED;
3593                         tcf_mirred_get_dev(entry, act);
3594                 } else if (is_tcf_mirred_ingress_redirect(act)) {
3595                         entry->id = FLOW_ACTION_REDIRECT_INGRESS;
3596                         tcf_mirred_get_dev(entry, act);
3597                 } else if (is_tcf_mirred_ingress_mirror(act)) {
3598                         entry->id = FLOW_ACTION_MIRRED_INGRESS;
3599                         tcf_mirred_get_dev(entry, act);
3600                 } else if (is_tcf_vlan(act)) {
3601                         switch (tcf_vlan_action(act)) {
3602                         case TCA_VLAN_ACT_PUSH:
3603                                 entry->id = FLOW_ACTION_VLAN_PUSH;
3604                                 entry->vlan.vid = tcf_vlan_push_vid(act);
3605                                 entry->vlan.proto = tcf_vlan_push_proto(act);
3606                                 entry->vlan.prio = tcf_vlan_push_prio(act);
3607                                 break;
3608                         case TCA_VLAN_ACT_POP:
3609                                 entry->id = FLOW_ACTION_VLAN_POP;
3610                                 break;
3611                         case TCA_VLAN_ACT_MODIFY:
3612                                 entry->id = FLOW_ACTION_VLAN_MANGLE;
3613                                 entry->vlan.vid = tcf_vlan_push_vid(act);
3614                                 entry->vlan.proto = tcf_vlan_push_proto(act);
3615                                 entry->vlan.prio = tcf_vlan_push_prio(act);
3616                                 break;
3617                         default:
3618                                 err = -EOPNOTSUPP;
3619                                 goto err_out_locked;
3620                         }
3621                 } else if (is_tcf_tunnel_set(act)) {
3622                         entry->id = FLOW_ACTION_TUNNEL_ENCAP;
3623                         err = tcf_tunnel_encap_get_tunnel(entry, act);
3624                         if (err)
3625                                 goto err_out_locked;
3626                 } else if (is_tcf_tunnel_release(act)) {
3627                         entry->id = FLOW_ACTION_TUNNEL_DECAP;
3628                 } else if (is_tcf_pedit(act)) {
3629                         for (k = 0; k < tcf_pedit_nkeys(act); k++) {
3630                                 switch (tcf_pedit_cmd(act, k)) {
3631                                 case TCA_PEDIT_KEY_EX_CMD_SET:
3632                                         entry->id = FLOW_ACTION_MANGLE;
3633                                         break;
3634                                 case TCA_PEDIT_KEY_EX_CMD_ADD:
3635                                         entry->id = FLOW_ACTION_ADD;
3636                                         break;
3637                                 default:
3638                                         err = -EOPNOTSUPP;
3639                                         goto err_out_locked;
3640                                 }
3641                                 entry->mangle.htype = tcf_pedit_htype(act, k);
3642                                 entry->mangle.mask = tcf_pedit_mask(act, k);
3643                                 entry->mangle.val = tcf_pedit_val(act, k);
3644                                 entry->mangle.offset = tcf_pedit_offset(act, k);
3645                                 entry->hw_stats = tc_act_hw_stats(act->hw_stats);
3646                                 entry = &flow_action->entries[++j];
3647                         }
3648                 } else if (is_tcf_csum(act)) {
3649                         entry->id = FLOW_ACTION_CSUM;
3650                         entry->csum_flags = tcf_csum_update_flags(act);
3651                 } else if (is_tcf_skbedit_mark(act)) {
3652                         entry->id = FLOW_ACTION_MARK;
3653                         entry->mark = tcf_skbedit_mark(act);
3654                 } else if (is_tcf_sample(act)) {
3655                         entry->id = FLOW_ACTION_SAMPLE;
3656                         entry->sample.trunc_size = tcf_sample_trunc_size(act);
3657                         entry->sample.truncate = tcf_sample_truncate(act);
3658                         entry->sample.rate = tcf_sample_rate(act);
3659                         tcf_sample_get_group(entry, act);
3660                 } else if (is_tcf_police(act)) {
3661                         entry->id = FLOW_ACTION_POLICE;
3662                         entry->police.burst = tcf_police_burst(act);
3663                         entry->police.rate_bytes_ps =
3664                                 tcf_police_rate_bytes_ps(act);
3665                         entry->police.mtu = tcf_police_tcfp_mtu(act);
3666                         entry->police.index = act->tcfa_index;
3667                 } else if (is_tcf_ct(act)) {
3668                         entry->id = FLOW_ACTION_CT;
3669                         entry->ct.action = tcf_ct_action(act);
3670                         entry->ct.zone = tcf_ct_zone(act);
3671                         entry->ct.flow_table = tcf_ct_ft(act);
3672                 } else if (is_tcf_mpls(act)) {
3673                         switch (tcf_mpls_action(act)) {
3674                         case TCA_MPLS_ACT_PUSH:
3675                                 entry->id = FLOW_ACTION_MPLS_PUSH;
3676                                 entry->mpls_push.proto = tcf_mpls_proto(act);
3677                                 entry->mpls_push.label = tcf_mpls_label(act);
3678                                 entry->mpls_push.tc = tcf_mpls_tc(act);
3679                                 entry->mpls_push.bos = tcf_mpls_bos(act);
3680                                 entry->mpls_push.ttl = tcf_mpls_ttl(act);
3681                                 break;
3682                         case TCA_MPLS_ACT_POP:
3683                                 entry->id = FLOW_ACTION_MPLS_POP;
3684                                 entry->mpls_pop.proto = tcf_mpls_proto(act);
3685                                 break;
3686                         case TCA_MPLS_ACT_MODIFY:
3687                                 entry->id = FLOW_ACTION_MPLS_MANGLE;
3688                                 entry->mpls_mangle.label = tcf_mpls_label(act);
3689                                 entry->mpls_mangle.tc = tcf_mpls_tc(act);
3690                                 entry->mpls_mangle.bos = tcf_mpls_bos(act);
3691                                 entry->mpls_mangle.ttl = tcf_mpls_ttl(act);
3692                                 break;
3693                         default:
3694                                 goto err_out_locked;
3695                         }
3696                 } else if (is_tcf_skbedit_ptype(act)) {
3697                         entry->id = FLOW_ACTION_PTYPE;
3698                         entry->ptype = tcf_skbedit_ptype(act);
3699                 } else if (is_tcf_skbedit_priority(act)) {
3700                         entry->id = FLOW_ACTION_PRIORITY;
3701                         entry->priority = tcf_skbedit_priority(act);
3702                 } else if (is_tcf_gate(act)) {
3703                         entry->id = FLOW_ACTION_GATE;
3704                         entry->gate.index = tcf_gate_index(act);
3705                         entry->gate.prio = tcf_gate_prio(act);
3706                         entry->gate.basetime = tcf_gate_basetime(act);
3707                         entry->gate.cycletime = tcf_gate_cycletime(act);
3708                         entry->gate.cycletimeext = tcf_gate_cycletimeext(act);
3709                         entry->gate.num_entries = tcf_gate_num_entries(act);
3710                         err = tcf_gate_get_entries(entry, act);
3711                         if (err)
3712                                 goto err_out_locked;
3713                 } else {
3714                         err = -EOPNOTSUPP;
3715                         goto err_out_locked;
3716                 }
3717                 spin_unlock_bh(&act->tcfa_lock);
3718
3719                 if (!is_tcf_pedit(act))
3720                         j++;
3721         }
3722
3723 err_out:
3724         if (err)
3725                 tc_cleanup_flow_action(flow_action);
3726
3727         return err;
3728 err_out_locked:
3729         spin_unlock_bh(&act->tcfa_lock);
3730         goto err_out;
3731 }
3732 EXPORT_SYMBOL(tc_setup_flow_action);
3733
3734 unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
3735 {
3736         unsigned int num_acts = 0;
3737         struct tc_action *act;
3738         int i;
3739
3740         tcf_exts_for_each_action(i, act, exts) {
3741                 if (is_tcf_pedit(act))
3742                         num_acts += tcf_pedit_nkeys(act);
3743                 else
3744                         num_acts++;
3745         }
3746         return num_acts;
3747 }
3748 EXPORT_SYMBOL(tcf_exts_num_actions);
3749
3750 #ifdef CONFIG_NET_CLS_ACT
3751 static int tcf_qevent_parse_block_index(struct nlattr *block_index_attr,
3752                                         u32 *p_block_index,
3753                                         struct netlink_ext_ack *extack)
3754 {
3755         *p_block_index = nla_get_u32(block_index_attr);
3756         if (!*p_block_index) {
3757                 NL_SET_ERR_MSG(extack, "Block number may not be zero");
3758                 return -EINVAL;
3759         }
3760
3761         return 0;
3762 }
3763
3764 int tcf_qevent_init(struct tcf_qevent *qe, struct Qdisc *sch,
3765                     enum flow_block_binder_type binder_type,
3766                     struct nlattr *block_index_attr,
3767                     struct netlink_ext_ack *extack)
3768 {
3769         u32 block_index;
3770         int err;
3771
3772         if (!block_index_attr)
3773                 return 0;
3774
3775         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3776         if (err)
3777                 return err;
3778
3779         if (!block_index)
3780                 return 0;
3781
3782         qe->info.binder_type = binder_type;
3783         qe->info.chain_head_change = tcf_chain_head_change_dflt;
3784         qe->info.chain_head_change_priv = &qe->filter_chain;
3785         qe->info.block_index = block_index;
3786
3787         return tcf_block_get_ext(&qe->block, sch, &qe->info, extack);
3788 }
3789 EXPORT_SYMBOL(tcf_qevent_init);
3790
3791 void tcf_qevent_destroy(struct tcf_qevent *qe, struct Qdisc *sch)
3792 {
3793         if (qe->info.block_index)
3794                 tcf_block_put_ext(qe->block, sch, &qe->info);
3795 }
3796 EXPORT_SYMBOL(tcf_qevent_destroy);
3797
3798 int tcf_qevent_validate_change(struct tcf_qevent *qe, struct nlattr *block_index_attr,
3799                                struct netlink_ext_ack *extack)
3800 {
3801         u32 block_index;
3802         int err;
3803
3804         if (!block_index_attr)
3805                 return 0;
3806
3807         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3808         if (err)
3809                 return err;
3810
3811         /* Bounce newly-configured block or change in block. */
3812         if (block_index != qe->info.block_index) {
3813                 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
3814                 return -EINVAL;
3815         }
3816
3817         return 0;
3818 }
3819 EXPORT_SYMBOL(tcf_qevent_validate_change);
3820
3821 struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
3822                                   struct sk_buff **to_free, int *ret)
3823 {
3824         struct tcf_result cl_res;
3825         struct tcf_proto *fl;
3826
3827         if (!qe->info.block_index)
3828                 return skb;
3829
3830         fl = rcu_dereference_bh(qe->filter_chain);
3831
3832         switch (tcf_classify(skb, fl, &cl_res, false)) {
3833         case TC_ACT_SHOT:
3834                 qdisc_qstats_drop(sch);
3835                 __qdisc_drop(skb, to_free);
3836                 *ret = __NET_XMIT_BYPASS;
3837                 return NULL;
3838         case TC_ACT_STOLEN:
3839         case TC_ACT_QUEUED:
3840         case TC_ACT_TRAP:
3841                 __qdisc_drop(skb, to_free);
3842                 *ret = __NET_XMIT_STOLEN;
3843                 return NULL;
3844         case TC_ACT_REDIRECT:
3845                 skb_do_redirect(skb);
3846                 *ret = __NET_XMIT_STOLEN;
3847                 return NULL;
3848         }
3849
3850         return skb;
3851 }
3852 EXPORT_SYMBOL(tcf_qevent_handle);
3853
3854 int tcf_qevent_dump(struct sk_buff *skb, int attr_name, struct tcf_qevent *qe)
3855 {
3856         if (!qe->info.block_index)
3857                 return 0;
3858         return nla_put_u32(skb, attr_name, qe->info.block_index);
3859 }
3860 EXPORT_SYMBOL(tcf_qevent_dump);
3861 #endif
3862
3863 static __net_init int tcf_net_init(struct net *net)
3864 {
3865         struct tcf_net *tn = net_generic(net, tcf_net_id);
3866
3867         spin_lock_init(&tn->idr_lock);
3868         idr_init(&tn->idr);
3869         return 0;
3870 }
3871
3872 static void __net_exit tcf_net_exit(struct net *net)
3873 {
3874         struct tcf_net *tn = net_generic(net, tcf_net_id);
3875
3876         idr_destroy(&tn->idr);
3877 }
3878
3879 static struct pernet_operations tcf_net_ops = {
3880         .init = tcf_net_init,
3881         .exit = tcf_net_exit,
3882         .id   = &tcf_net_id,
3883         .size = sizeof(struct tcf_net),
3884 };
3885
3886 static int __init tc_filter_init(void)
3887 {
3888         int err;
3889
3890         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
3891         if (!tc_filter_wq)
3892                 return -ENOMEM;
3893
3894         err = register_pernet_subsys(&tcf_net_ops);
3895         if (err)
3896                 goto err_register_pernet_subsys;
3897
3898         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
3899                       RTNL_FLAG_DOIT_UNLOCKED);
3900         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
3901                       RTNL_FLAG_DOIT_UNLOCKED);
3902         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
3903                       tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
3904         rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
3905         rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
3906         rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
3907                       tc_dump_chain, 0);
3908
3909         return 0;
3910
3911 err_register_pernet_subsys:
3912         destroy_workqueue(tc_filter_wq);
3913         return err;
3914 }
3915
3916 subsys_initcall(tc_filter_init);