net/sched/cls_api.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/cls_api.c  Packet classifier API.
   4  *
   5  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   6  *
   7  * Changes:
   8  *
   9  * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/kernel.h>
  15 #include <linux/string.h>
  16 #include <linux/errno.h>
  17 #include <linux/err.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/init.h>
  20 #include <linux/kmod.h>
  21 #include <linux/slab.h>
  22 #include <linux/idr.h>
  23 #include <linux/jhash.h>
  24 #include <linux/rculist.h>
  25 #include <linux/rhashtable.h>
  26 #include <net/net_namespace.h>
  27 #include <net/sock.h>
  28 #include <net/netlink.h>
  29 #include <net/pkt_sched.h>
  30 #include <net/pkt_cls.h>
  31 #include <net/tc_act/tc_pedit.h>
  32 #include <net/tc_act/tc_mirred.h>
  33 #include <net/tc_act/tc_vlan.h>
  34 #include <net/tc_act/tc_tunnel_key.h>
  35 #include <net/tc_act/tc_csum.h>
  36 #include <net/tc_act/tc_gact.h>
  37 #include <net/tc_act/tc_police.h>
  38 #include <net/tc_act/tc_sample.h>
  39 #include <net/tc_act/tc_skbedit.h>
  40 #include <net/tc_act/tc_ct.h>
  41 #include <net/tc_act/tc_mpls.h>
  42 #include <net/tc_act/tc_gate.h>
  43 #include <net/flow_offload.h>
  44 #include <net/tc_wrapper.h>
  45
  46 /* 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 struct xarray tcf_exts_miss_cookies_xa;
  53 struct tcf_exts_miss_cookie_node {
  54         const struct tcf_chain *chain;
  55         const struct tcf_proto *tp;
  56         const struct tcf_exts *exts;
  57         u32 chain_index;
  58         u32 tp_prio;
  59         u32 handle;
  60         u32 miss_cookie_base;
  61         struct rcu_head rcu;
  62 };
  63
  64 /* Each tc action entry cookie will be comprised of 32bit miss_cookie_base +
  65  * action index in the exts tc actions array.
  66  */
  67 union tcf_exts_miss_cookie {
  68         struct {
  69                 u32 miss_cookie_base;
  70                 u32 act_index;
  71         };
  72         u64 miss_cookie;
  73 };
  74
  75 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
  76 static int
  77 tcf_exts_miss_cookie_base_alloc(struct tcf_exts *exts, struct tcf_proto *tp,
  78                                 u32 handle)
  79 {
  80         struct tcf_exts_miss_cookie_node *n;
  81         static u32 next;
  82         int err;
  83
  84         if (WARN_ON(!handle || !tp->ops->get_exts))
  85                 return -EINVAL;
  86
  87         n = kzalloc(sizeof(*n), GFP_KERNEL);
  88         if (!n)
  89                 return -ENOMEM;
  90
  91         n->chain_index = tp->chain->index;
  92         n->chain = tp->chain;
  93         n->tp_prio = tp->prio;
  94         n->tp = tp;
  95         n->exts = exts;
  96         n->handle = handle;
  97
  98         err = xa_alloc_cyclic(&tcf_exts_miss_cookies_xa, &n->miss_cookie_base,
  99                               n, xa_limit_32b, &next, GFP_KERNEL);
 100         if (err)
 101                 goto err_xa_alloc;
 102
 103         exts->miss_cookie_node = n;
 104         return 0;
 105
 106 err_xa_alloc:
 107         kfree(n);
 108         return err;
 109 }
 110
 111 static void tcf_exts_miss_cookie_base_destroy(struct tcf_exts *exts)
 112 {
 113         struct tcf_exts_miss_cookie_node *n;
 114
 115         if (!exts->miss_cookie_node)
 116                 return;
 117
 118         n = exts->miss_cookie_node;
 119         xa_erase(&tcf_exts_miss_cookies_xa, n->miss_cookie_base);
 120         kfree_rcu(n, rcu);
 121 }
 122
 123 static struct tcf_exts_miss_cookie_node *
 124 tcf_exts_miss_cookie_lookup(u64 miss_cookie, int *act_index)
 125 {
 126         union tcf_exts_miss_cookie mc = { .miss_cookie = miss_cookie, };
 127
 128         *act_index = mc.act_index;
 129         return xa_load(&tcf_exts_miss_cookies_xa, mc.miss_cookie_base);
 130 }
 131 #else /* IS_ENABLED(CONFIG_NET_TC_SKB_EXT) */
 132 static int
 133 tcf_exts_miss_cookie_base_alloc(struct tcf_exts *exts, struct tcf_proto *tp,
 134                                 u32 handle)
 135 {
 136         return 0;
 137 }
 138
 139 static void tcf_exts_miss_cookie_base_destroy(struct tcf_exts *exts)
 140 {
 141 }
 142 #endif /* IS_ENABLED(CONFIG_NET_TC_SKB_EXT) */
 143
 144 static u64 tcf_exts_miss_cookie_get(u32 miss_cookie_base, int act_index)
 145 {
 146         union tcf_exts_miss_cookie mc = { .act_index = act_index, };
 147
 148         if (!miss_cookie_base)
 149                 return 0;
 150
 151         mc.miss_cookie_base = miss_cookie_base;
 152         return mc.miss_cookie;
 153 }
 154
 155 #ifdef CONFIG_NET_CLS_ACT
 156 DEFINE_STATIC_KEY_FALSE(tc_skb_ext_tc);
 157 EXPORT_SYMBOL(tc_skb_ext_tc);
 158
 159 void tc_skb_ext_tc_enable(void)
 160 {
 161         static_branch_inc(&tc_skb_ext_tc);
 162 }
 163 EXPORT_SYMBOL(tc_skb_ext_tc_enable);
 164
 165 void tc_skb_ext_tc_disable(void)
 166 {
 167         static_branch_dec(&tc_skb_ext_tc);
 168 }
 169 EXPORT_SYMBOL(tc_skb_ext_tc_disable);
 170 #endif
 171
 172 static u32 destroy_obj_hashfn(const struct tcf_proto *tp)
 173 {
 174         return jhash_3words(tp->chain->index, tp->prio,
 175                             (__force __u32)tp->protocol, 0);
 176 }
 177
 178 static void tcf_proto_signal_destroying(struct tcf_chain *chain,
 179                                         struct tcf_proto *tp)
 180 {
 181         struct tcf_block *block = chain->block;
 182
 183         mutex_lock(&block->proto_destroy_lock);
 184         hash_add_rcu(block->proto_destroy_ht, &tp->destroy_ht_node,
 185                      destroy_obj_hashfn(tp));
 186         mutex_unlock(&block->proto_destroy_lock);
 187 }
 188
 189 static bool tcf_proto_cmp(const struct tcf_proto *tp1,
 190                           const struct tcf_proto *tp2)
 191 {
 192         return tp1->chain->index == tp2->chain->index &&
 193                tp1->prio == tp2->prio &&
 194                tp1->protocol == tp2->protocol;
 195 }
 196
 197 static bool tcf_proto_exists_destroying(struct tcf_chain *chain,
 198                                         struct tcf_proto *tp)
 199 {
 200         u32 hash = destroy_obj_hashfn(tp);
 201         struct tcf_proto *iter;
 202         bool found = false;
 203
 204         rcu_read_lock();
 205         hash_for_each_possible_rcu(chain->block->proto_destroy_ht, iter,
 206                                    destroy_ht_node, hash) {
 207                 if (tcf_proto_cmp(tp, iter)) {
 208                         found = true;
 209                         break;
 210                 }
 211         }
 212         rcu_read_unlock();
 213
 214         return found;
 215 }
 216
 217 static void
 218 tcf_proto_signal_destroyed(struct tcf_chain *chain, struct tcf_proto *tp)
 219 {
 220         struct tcf_block *block = chain->block;
 221
 222         mutex_lock(&block->proto_destroy_lock);
 223         if (hash_hashed(&tp->destroy_ht_node))
 224                 hash_del_rcu(&tp->destroy_ht_node);
 225         mutex_unlock(&block->proto_destroy_lock);
 226 }
 227
 228 /* Find classifier type by string name */
 229
 230 static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
 231 {
 232         const struct tcf_proto_ops *t, *res = NULL;
 233
 234         if (kind) {
 235                 read_lock(&cls_mod_lock);
 236                 list_for_each_entry(t, &tcf_proto_base, head) {
 237                         if (strcmp(kind, t->kind) == 0) {
 238                                 if (try_module_get(t->owner))
 239                                         res = t;
 240                                 break;
 241                         }
 242                 }
 243                 read_unlock(&cls_mod_lock);
 244         }
 245         return res;
 246 }
 247
 248 static const struct tcf_proto_ops *
 249 tcf_proto_lookup_ops(const char *kind, bool rtnl_held,
 250                      struct netlink_ext_ack *extack)
 251 {
 252         const struct tcf_proto_ops *ops;
 253
 254         ops = __tcf_proto_lookup_ops(kind);
 255         if (ops)
 256                 return ops;
 257 #ifdef CONFIG_MODULES
 258         if (rtnl_held)
 259                 rtnl_unlock();
 260         request_module("cls_%s", kind);
 261         if (rtnl_held)
 262                 rtnl_lock();
 263         ops = __tcf_proto_lookup_ops(kind);
 264         /* We dropped the RTNL semaphore in order to perform
 265          * the module load. So, even if we succeeded in loading
 266          * the module we have to replay the request. We indicate
 267          * this using -EAGAIN.
 268          */
 269         if (ops) {
 270                 module_put(ops->owner);
 271                 return ERR_PTR(-EAGAIN);
 272         }
 273 #endif
 274         NL_SET_ERR_MSG(extack, "TC classifier not found");
 275         return ERR_PTR(-ENOENT);
 276 }
 277
 278 /* Register(unregister) new classifier type */
 279
 280 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
 281 {
 282         struct tcf_proto_ops *t;
 283         int rc = -EEXIST;
 284
 285         write_lock(&cls_mod_lock);
 286         list_for_each_entry(t, &tcf_proto_base, head)
 287                 if (!strcmp(ops->kind, t->kind))
 288                         goto out;
 289
 290         list_add_tail(&ops->head, &tcf_proto_base);
 291         rc = 0;
 292 out:
 293         write_unlock(&cls_mod_lock);
 294         return rc;
 295 }
 296 EXPORT_SYMBOL(register_tcf_proto_ops);
 297
 298 static struct workqueue_struct *tc_filter_wq;
 299
 300 void unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
 301 {
 302         struct tcf_proto_ops *t;
 303         int rc = -ENOENT;
 304
 305         /* Wait for outstanding call_rcu()s, if any, from a
 306          * tcf_proto_ops's destroy() handler.
 307          */
 308         rcu_barrier();
 309         flush_workqueue(tc_filter_wq);
 310
 311         write_lock(&cls_mod_lock);
 312         list_for_each_entry(t, &tcf_proto_base, head) {
 313                 if (t == ops) {
 314                         list_del(&t->head);
 315                         rc = 0;
 316                         break;
 317                 }
 318         }
 319         write_unlock(&cls_mod_lock);
 320
 321         WARN(rc, "unregister tc filter kind(%s) failed %d\n", ops->kind, rc);
 322 }
 323 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 324
 325 bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
 326 {
 327         INIT_RCU_WORK(rwork, func);
 328         return queue_rcu_work(tc_filter_wq, rwork);
 329 }
 330 EXPORT_SYMBOL(tcf_queue_work);
 331
 332 /* Select new prio value from the range, managed by kernel. */
 333
 334 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 335 {
 336         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 337
 338         if (tp)
 339                 first = tp->prio - 1;
 340
 341         return TC_H_MAJ(first);
 342 }
 343
 344 static bool tcf_proto_check_kind(struct nlattr *kind, char *name)
 345 {
 346         if (kind)
 347                 return nla_strscpy(name, kind, IFNAMSIZ) < 0;
 348         memset(name, 0, IFNAMSIZ);
 349         return false;
 350 }
 351
 352 static bool tcf_proto_is_unlocked(const char *kind)
 353 {
 354         const struct tcf_proto_ops *ops;
 355         bool ret;
 356
 357         if (strlen(kind) == 0)
 358                 return false;
 359
 360         ops = tcf_proto_lookup_ops(kind, false, NULL);
 361         /* On error return false to take rtnl lock. Proto lookup/create
 362          * functions will perform lookup again and properly handle errors.
 363          */
 364         if (IS_ERR(ops))
 365                 return false;
 366
 367         ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED);
 368         module_put(ops->owner);
 369         return ret;
 370 }
 371
 372 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 373                                           u32 prio, struct tcf_chain *chain,
 374                                           bool rtnl_held,
 375                                           struct netlink_ext_ack *extack)
 376 {
 377         struct tcf_proto *tp;
 378         int err;
 379
 380         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 381         if (!tp)
 382                 return ERR_PTR(-ENOBUFS);
 383
 384         tp->ops = tcf_proto_lookup_ops(kind, rtnl_held, extack);
 385         if (IS_ERR(tp->ops)) {
 386                 err = PTR_ERR(tp->ops);
 387                 goto errout;
 388         }
 389         tp->classify = tp->ops->classify;
 390         tp->protocol = protocol;
 391         tp->prio = prio;
 392         tp->chain = chain;
 393         spin_lock_init(&tp->lock);
 394         refcount_set(&tp->refcnt, 1);
 395
 396         err = tp->ops->init(tp);
 397         if (err) {
 398                 module_put(tp->ops->owner);
 399                 goto errout;
 400         }
 401         return tp;
 402
 403 errout:
 404         kfree(tp);
 405         return ERR_PTR(err);
 406 }
 407
 408 static void tcf_proto_get(struct tcf_proto *tp)
 409 {
 410         refcount_inc(&tp->refcnt);
 411 }
 412
 413 static void tcf_chain_put(struct tcf_chain *chain);
 414
 415 static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
 416                               bool sig_destroy, struct netlink_ext_ack *extack)
 417 {
 418         tp->ops->destroy(tp, rtnl_held, extack);
 419         if (sig_destroy)
 420                 tcf_proto_signal_destroyed(tp->chain, tp);
 421         tcf_chain_put(tp->chain);
 422         module_put(tp->ops->owner);
 423         kfree_rcu(tp, rcu);
 424 }
 425
 426 static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
 427                           struct netlink_ext_ack *extack)
 428 {
 429         if (refcount_dec_and_test(&tp->refcnt))
 430                 tcf_proto_destroy(tp, rtnl_held, true, extack);
 431 }
 432
 433 static bool tcf_proto_check_delete(struct tcf_proto *tp)
 434 {
 435         if (tp->ops->delete_empty)
 436                 return tp->ops->delete_empty(tp);
 437
 438         tp->deleting = true;
 439         return tp->deleting;
 440 }
 441
 442 static void tcf_proto_mark_delete(struct tcf_proto *tp)
 443 {
 444         spin_lock(&tp->lock);
 445         tp->deleting = true;
 446         spin_unlock(&tp->lock);
 447 }
 448
 449 static bool tcf_proto_is_deleting(struct tcf_proto *tp)
 450 {
 451         bool deleting;
 452
 453         spin_lock(&tp->lock);
 454         deleting = tp->deleting;
 455         spin_unlock(&tp->lock);
 456
 457         return deleting;
 458 }
 459
 460 #define ASSERT_BLOCK_LOCKED(block)                                      \
 461         lockdep_assert_held(&(block)->lock)
 462
 463 struct tcf_filter_chain_list_item {
 464         struct list_head list;
 465         tcf_chain_head_change_t *chain_head_change;
 466         void *chain_head_change_priv;
 467 };
 468
 469 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 470                                           u32 chain_index)
 471 {
 472         struct tcf_chain *chain;
 473
 474         ASSERT_BLOCK_LOCKED(block);
 475
 476         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 477         if (!chain)
 478                 return NULL;
 479         list_add_tail_rcu(&chain->list, &block->chain_list);
 480         mutex_init(&chain->filter_chain_lock);
 481         chain->block = block;
 482         chain->index = chain_index;
 483         chain->refcnt = 1;
 484         if (!chain->index)
 485                 block->chain0.chain = chain;
 486         return chain;
 487 }
 488
 489 static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
 490                                        struct tcf_proto *tp_head)
 491 {
 492         if (item->chain_head_change)
 493                 item->chain_head_change(tp_head, item->chain_head_change_priv);
 494 }
 495
 496 static void tcf_chain0_head_change(struct tcf_chain *chain,
 497                                    struct tcf_proto *tp_head)
 498 {
 499         struct tcf_filter_chain_list_item *item;
 500         struct tcf_block *block = chain->block;
 501
 502         if (chain->index)
 503                 return;
 504
 505         mutex_lock(&block->lock);
 506         list_for_each_entry(item, &block->chain0.filter_chain_list, list)
 507                 tcf_chain_head_change_item(item, tp_head);
 508         mutex_unlock(&block->lock);
 509 }
 510
 511 /* Returns true if block can be safely freed. */
 512
 513 static bool tcf_chain_detach(struct tcf_chain *chain)
 514 {
 515         struct tcf_block *block = chain->block;
 516
 517         ASSERT_BLOCK_LOCKED(block);
 518
 519         list_del_rcu(&chain->list);
 520         if (!chain->index)
 521                 block->chain0.chain = NULL;
 522
 523         if (list_empty(&block->chain_list) &&
 524             refcount_read(&block->refcnt) == 0)
 525                 return true;
 526
 527         return false;
 528 }
 529
 530 static void tcf_block_destroy(struct tcf_block *block)
 531 {
 532         mutex_destroy(&block->lock);
 533         mutex_destroy(&block->proto_destroy_lock);
 534         kfree_rcu(block, rcu);
 535 }
 536
 537 static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
 538 {
 539         struct tcf_block *block = chain->block;
 540
 541         mutex_destroy(&chain->filter_chain_lock);
 542         kfree_rcu(chain, rcu);
 543         if (free_block)
 544                 tcf_block_destroy(block);
 545 }
 546
 547 static void tcf_chain_hold(struct tcf_chain *chain)
 548 {
 549         ASSERT_BLOCK_LOCKED(chain->block);
 550
 551         ++chain->refcnt;
 552 }
 553
 554 static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain)
 555 {
 556         ASSERT_BLOCK_LOCKED(chain->block);
 557
 558         /* In case all the references are action references, this
 559          * chain should not be shown to the user.
 560          */
 561         return chain->refcnt == chain->action_refcnt;
 562 }
 563
 564 static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
 565                                           u32 chain_index)
 566 {
 567         struct tcf_chain *chain;
 568
 569         ASSERT_BLOCK_LOCKED(block);
 570
 571         list_for_each_entry(chain, &block->chain_list, list) {
 572                 if (chain->index == chain_index)
 573                         return chain;
 574         }
 575         return NULL;
 576 }
 577
 578 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 579 static struct tcf_chain *tcf_chain_lookup_rcu(const struct tcf_block *block,
 580                                               u32 chain_index)
 581 {
 582         struct tcf_chain *chain;
 583
 584         list_for_each_entry_rcu(chain, &block->chain_list, list) {
 585                 if (chain->index == chain_index)
 586                         return chain;
 587         }
 588         return NULL;
 589 }
 590 #endif
 591
 592 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 593                            u32 seq, u16 flags, int event, bool unicast,
 594                            struct netlink_ext_ack *extack);
 595
 596 static struct tcf_chain *__tcf_chain_get(struct tcf_block *block,
 597                                          u32 chain_index, bool create,
 598                                          bool by_act)
 599 {
 600         struct tcf_chain *chain = NULL;
 601         bool is_first_reference;
 602
 603         mutex_lock(&block->lock);
 604         chain = tcf_chain_lookup(block, chain_index);
 605         if (chain) {
 606                 tcf_chain_hold(chain);
 607         } else {
 608                 if (!create)
 609                         goto errout;
 610                 chain = tcf_chain_create(block, chain_index);
 611                 if (!chain)
 612                         goto errout;
 613         }
 614
 615         if (by_act)
 616                 ++chain->action_refcnt;
 617         is_first_reference = chain->refcnt - chain->action_refcnt == 1;
 618         mutex_unlock(&block->lock);
 619
 620         /* Send notification only in case we got the first
 621          * non-action reference. Until then, the chain acts only as
 622          * a placeholder for actions pointing to it and user ought
 623          * not know about them.
 624          */
 625         if (is_first_reference && !by_act)
 626                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
 627                                 RTM_NEWCHAIN, false, NULL);
 628
 629         return chain;
 630
 631 errout:
 632         mutex_unlock(&block->lock);
 633         return chain;
 634 }
 635
 636 static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 637                                        bool create)
 638 {
 639         return __tcf_chain_get(block, chain_index, create, false);
 640 }
 641
 642 struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index)
 643 {
 644         return __tcf_chain_get(block, chain_index, true, true);
 645 }
 646 EXPORT_SYMBOL(tcf_chain_get_by_act);
 647
 648 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
 649                                void *tmplt_priv);
 650 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
 651                                   void *tmplt_priv, u32 chain_index,
 652                                   struct tcf_block *block, struct sk_buff *oskb,
 653                                   u32 seq, u16 flags, bool unicast);
 654
 655 static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
 656                             bool explicitly_created)
 657 {
 658         struct tcf_block *block = chain->block;
 659         const struct tcf_proto_ops *tmplt_ops;
 660         unsigned int refcnt, non_act_refcnt;
 661         bool free_block = false;
 662         void *tmplt_priv;
 663
 664         mutex_lock(&block->lock);
 665         if (explicitly_created) {
 666                 if (!chain->explicitly_created) {
 667                         mutex_unlock(&block->lock);
 668                         return;
 669                 }
 670                 chain->explicitly_created = false;
 671         }
 672
 673         if (by_act)
 674                 chain->action_refcnt--;
 675
 676         /* tc_chain_notify_delete can't be called while holding block lock.
 677          * However, when block is unlocked chain can be changed concurrently, so
 678          * save these to temporary variables.
 679          */
 680         refcnt = --chain->refcnt;
 681         non_act_refcnt = refcnt - chain->action_refcnt;
 682         tmplt_ops = chain->tmplt_ops;
 683         tmplt_priv = chain->tmplt_priv;
 684
 685         if (non_act_refcnt == chain->explicitly_created && !by_act) {
 686                 if (non_act_refcnt == 0)
 687                         tc_chain_notify_delete(tmplt_ops, tmplt_priv,
 688                                                chain->index, block, NULL, 0, 0,
 689                                                false);
 690                 /* Last reference to chain, no need to lock. */
 691                 chain->flushing = false;
 692         }
 693
 694         if (refcnt == 0)
 695                 free_block = tcf_chain_detach(chain);
 696         mutex_unlock(&block->lock);
 697
 698         if (refcnt == 0) {
 699                 tc_chain_tmplt_del(tmplt_ops, tmplt_priv);
 700                 tcf_chain_destroy(chain, free_block);
 701         }
 702 }
 703
 704 static void tcf_chain_put(struct tcf_chain *chain)
 705 {
 706         __tcf_chain_put(chain, false, false);
 707 }
 708
 709 void tcf_chain_put_by_act(struct tcf_chain *chain)
 710 {
 711         __tcf_chain_put(chain, true, false);
 712 }
 713 EXPORT_SYMBOL(tcf_chain_put_by_act);
 714
 715 static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 716 {
 717         __tcf_chain_put(chain, false, true);
 718 }
 719
 720 static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
 721 {
 722         struct tcf_proto *tp, *tp_next;
 723
 724         mutex_lock(&chain->filter_chain_lock);
 725         tp = tcf_chain_dereference(chain->filter_chain, chain);
 726         while (tp) {
 727                 tp_next = rcu_dereference_protected(tp->next, 1);
 728                 tcf_proto_signal_destroying(chain, tp);
 729                 tp = tp_next;
 730         }
 731         tp = tcf_chain_dereference(chain->filter_chain, chain);
 732         RCU_INIT_POINTER(chain->filter_chain, NULL);
 733         tcf_chain0_head_change(chain, NULL);
 734         chain->flushing = true;
 735         mutex_unlock(&chain->filter_chain_lock);
 736
 737         while (tp) {
 738                 tp_next = rcu_dereference_protected(tp->next, 1);
 739                 tcf_proto_put(tp, rtnl_held, NULL);
 740                 tp = tp_next;
 741         }
 742 }
 743
 744 static int tcf_block_setup(struct tcf_block *block,
 745                            struct flow_block_offload *bo);
 746
 747 static void tcf_block_offload_init(struct flow_block_offload *bo,
 748                                    struct net_device *dev, struct Qdisc *sch,
 749                                    enum flow_block_command command,
 750                                    enum flow_block_binder_type binder_type,
 751                                    struct flow_block *flow_block,
 752                                    bool shared, struct netlink_ext_ack *extack)
 753 {
 754         bo->net = dev_net(dev);
 755         bo->command = command;
 756         bo->binder_type = binder_type;
 757         bo->block = flow_block;
 758         bo->block_shared = shared;
 759         bo->extack = extack;
 760         bo->sch = sch;
 761         bo->cb_list_head = &flow_block->cb_list;
 762         INIT_LIST_HEAD(&bo->cb_list);
 763 }
 764
 765 static void tcf_block_unbind(struct tcf_block *block,
 766                              struct flow_block_offload *bo);
 767
 768 static void tc_block_indr_cleanup(struct flow_block_cb *block_cb)
 769 {
 770         struct tcf_block *block = block_cb->indr.data;
 771         struct net_device *dev = block_cb->indr.dev;
 772         struct Qdisc *sch = block_cb->indr.sch;
 773         struct netlink_ext_ack extack = {};
 774         struct flow_block_offload bo = {};
 775
 776         tcf_block_offload_init(&bo, dev, sch, FLOW_BLOCK_UNBIND,
 777                                block_cb->indr.binder_type,
 778                                &block->flow_block, tcf_block_shared(block),
 779                                &extack);
 780         rtnl_lock();
 781         down_write(&block->cb_lock);
 782         list_del(&block_cb->driver_list);
 783         list_move(&block_cb->list, &bo.cb_list);
 784         tcf_block_unbind(block, &bo);
 785         up_write(&block->cb_lock);
 786         rtnl_unlock();
 787 }
 788
 789 static bool tcf_block_offload_in_use(struct tcf_block *block)
 790 {
 791         return atomic_read(&block->offloadcnt);
 792 }
 793
 794 static int tcf_block_offload_cmd(struct tcf_block *block,
 795                                  struct net_device *dev, struct Qdisc *sch,
 796                                  struct tcf_block_ext_info *ei,
 797                                  enum flow_block_command command,
 798                                  struct netlink_ext_ack *extack)
 799 {
 800         struct flow_block_offload bo = {};
 801
 802         tcf_block_offload_init(&bo, dev, sch, command, ei->binder_type,
 803                                &block->flow_block, tcf_block_shared(block),
 804                                extack);
 805
 806         if (dev->netdev_ops->ndo_setup_tc) {
 807                 int err;
 808
 809                 err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 810                 if (err < 0) {
 811                         if (err != -EOPNOTSUPP)
 812                                 NL_SET_ERR_MSG(extack, "Driver ndo_setup_tc failed");
 813                         return err;
 814                 }
 815
 816                 return tcf_block_setup(block, &bo);
 817         }
 818
 819         flow_indr_dev_setup_offload(dev, sch, TC_SETUP_BLOCK, block, &bo,
 820                                     tc_block_indr_cleanup);
 821         tcf_block_setup(block, &bo);
 822
 823         return -EOPNOTSUPP;
 824 }
 825
 826 static int tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
 827                                   struct tcf_block_ext_info *ei,
 828                                   struct netlink_ext_ack *extack)
 829 {
 830         struct net_device *dev = q->dev_queue->dev;
 831         int err;
 832
 833         down_write(&block->cb_lock);
 834
 835         /* If tc offload feature is disabled and the block we try to bind
 836          * to already has some offloaded filters, forbid to bind.
 837          */
 838         if (dev->netdev_ops->ndo_setup_tc &&
 839             !tc_can_offload(dev) &&
 840             tcf_block_offload_in_use(block)) {
 841                 NL_SET_ERR_MSG(extack, "Bind to offloaded block failed as dev has offload disabled");
 842                 err = -EOPNOTSUPP;
 843                 goto err_unlock;
 844         }
 845
 846         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_BIND, extack);
 847         if (err == -EOPNOTSUPP)
 848                 goto no_offload_dev_inc;
 849         if (err)
 850                 goto err_unlock;
 851
 852         up_write(&block->cb_lock);
 853         return 0;
 854
 855 no_offload_dev_inc:
 856         if (tcf_block_offload_in_use(block))
 857                 goto err_unlock;
 858
 859         err = 0;
 860         block->nooffloaddevcnt++;
 861 err_unlock:
 862         up_write(&block->cb_lock);
 863         return err;
 864 }
 865
 866 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
 867                                      struct tcf_block_ext_info *ei)
 868 {
 869         struct net_device *dev = q->dev_queue->dev;
 870         int err;
 871
 872         down_write(&block->cb_lock);
 873         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_UNBIND, NULL);
 874         if (err == -EOPNOTSUPP)
 875                 goto no_offload_dev_dec;
 876         up_write(&block->cb_lock);
 877         return;
 878
 879 no_offload_dev_dec:
 880         WARN_ON(block->nooffloaddevcnt-- == 0);
 881         up_write(&block->cb_lock);
 882 }
 883
 884 static int
 885 tcf_chain0_head_change_cb_add(struct tcf_block *block,
 886                               struct tcf_block_ext_info *ei,
 887                               struct netlink_ext_ack *extack)
 888 {
 889         struct tcf_filter_chain_list_item *item;
 890         struct tcf_chain *chain0;
 891
 892         item = kmalloc(sizeof(*item), GFP_KERNEL);
 893         if (!item) {
 894                 NL_SET_ERR_MSG(extack, "Memory allocation for head change callback item failed");
 895                 return -ENOMEM;
 896         }
 897         item->chain_head_change = ei->chain_head_change;
 898         item->chain_head_change_priv = ei->chain_head_change_priv;
 899
 900         mutex_lock(&block->lock);
 901         chain0 = block->chain0.chain;
 902         if (chain0)
 903                 tcf_chain_hold(chain0);
 904         else
 905                 list_add(&item->list, &block->chain0.filter_chain_list);
 906         mutex_unlock(&block->lock);
 907
 908         if (chain0) {
 909                 struct tcf_proto *tp_head;
 910
 911                 mutex_lock(&chain0->filter_chain_lock);
 912
 913                 tp_head = tcf_chain_dereference(chain0->filter_chain, chain0);
 914                 if (tp_head)
 915                         tcf_chain_head_change_item(item, tp_head);
 916
 917                 mutex_lock(&block->lock);
 918                 list_add(&item->list, &block->chain0.filter_chain_list);
 919                 mutex_unlock(&block->lock);
 920
 921                 mutex_unlock(&chain0->filter_chain_lock);
 922                 tcf_chain_put(chain0);
 923         }
 924
 925         return 0;
 926 }
 927
 928 static void
 929 tcf_chain0_head_change_cb_del(struct tcf_block *block,
 930                               struct tcf_block_ext_info *ei)
 931 {
 932         struct tcf_filter_chain_list_item *item;
 933
 934         mutex_lock(&block->lock);
 935         list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
 936                 if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
 937                     (item->chain_head_change == ei->chain_head_change &&
 938                      item->chain_head_change_priv == ei->chain_head_change_priv)) {
 939                         if (block->chain0.chain)
 940                                 tcf_chain_head_change_item(item, NULL);
 941                         list_del(&item->list);
 942                         mutex_unlock(&block->lock);
 943
 944                         kfree(item);
 945                         return;
 946                 }
 947         }
 948         mutex_unlock(&block->lock);
 949         WARN_ON(1);
 950 }
 951
 952 struct tcf_net {
 953         spinlock_t idr_lock; /* Protects idr */
 954         struct idr idr;
 955 };
 956
 957 static unsigned int tcf_net_id;
 958
 959 static int tcf_block_insert(struct tcf_block *block, struct net *net,
 960                             struct netlink_ext_ack *extack)
 961 {
 962         struct tcf_net *tn = net_generic(net, tcf_net_id);
 963         int err;
 964
 965         idr_preload(GFP_KERNEL);
 966         spin_lock(&tn->idr_lock);
 967         err = idr_alloc_u32(&tn->idr, block, &block->index, block->index,
 968                             GFP_NOWAIT);
 969         spin_unlock(&tn->idr_lock);
 970         idr_preload_end();
 971
 972         return err;
 973 }
 974
 975 static void tcf_block_remove(struct tcf_block *block, struct net *net)
 976 {
 977         struct tcf_net *tn = net_generic(net, tcf_net_id);
 978
 979         spin_lock(&tn->idr_lock);
 980         idr_remove(&tn->idr, block->index);
 981         spin_unlock(&tn->idr_lock);
 982 }
 983
 984 static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 985                                           u32 block_index,
 986                                           struct netlink_ext_ack *extack)
 987 {
 988         struct tcf_block *block;
 989
 990         block = kzalloc(sizeof(*block), GFP_KERNEL);
 991         if (!block) {
 992                 NL_SET_ERR_MSG(extack, "Memory allocation for block failed");
 993                 return ERR_PTR(-ENOMEM);
 994         }
 995         mutex_init(&block->lock);
 996         mutex_init(&block->proto_destroy_lock);
 997         init_rwsem(&block->cb_lock);
 998         flow_block_init(&block->flow_block);
 999         INIT_LIST_HEAD(&block->chain_list);
1000         INIT_LIST_HEAD(&block->owner_list);
1001         INIT_LIST_HEAD(&block->chain0.filter_chain_list);
1002
1003         refcount_set(&block->refcnt, 1);
1004         block->net = net;
1005         block->index = block_index;
1006
1007         /* Don't store q pointer for blocks which are shared */
1008         if (!tcf_block_shared(block))
1009                 block->q = q;
1010         return block;
1011 }
1012
1013 static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
1014 {
1015         struct tcf_net *tn = net_generic(net, tcf_net_id);
1016
1017         return idr_find(&tn->idr, block_index);
1018 }
1019
1020 static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
1021 {
1022         struct tcf_block *block;
1023
1024         rcu_read_lock();
1025         block = tcf_block_lookup(net, block_index);
1026         if (block && !refcount_inc_not_zero(&block->refcnt))
1027                 block = NULL;
1028         rcu_read_unlock();
1029
1030         return block;
1031 }
1032
1033 static struct tcf_chain *
1034 __tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
1035 {
1036         mutex_lock(&block->lock);
1037         if (chain)
1038                 chain = list_is_last(&chain->list, &block->chain_list) ?
1039                         NULL : list_next_entry(chain, list);
1040         else
1041                 chain = list_first_entry_or_null(&block->chain_list,
1042                                                  struct tcf_chain, list);
1043
1044         /* skip all action-only chains */
1045         while (chain && tcf_chain_held_by_acts_only(chain))
1046                 chain = list_is_last(&chain->list, &block->chain_list) ?
1047                         NULL : list_next_entry(chain, list);
1048
1049         if (chain)
1050                 tcf_chain_hold(chain);
1051         mutex_unlock(&block->lock);
1052
1053         return chain;
1054 }
1055
1056 /* Function to be used by all clients that want to iterate over all chains on
1057  * block. It properly obtains block->lock and takes reference to chain before
1058  * returning it. Users of this function must be tolerant to concurrent chain
1059  * insertion/deletion or ensure that no concurrent chain modification is
1060  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1061  * consistent dump because rtnl lock is released each time skb is filled with
1062  * data and sent to user-space.
1063  */
1064
1065 struct tcf_chain *
1066 tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
1067 {
1068         struct tcf_chain *chain_next = __tcf_get_next_chain(block, chain);
1069
1070         if (chain)
1071                 tcf_chain_put(chain);
1072
1073         return chain_next;
1074 }
1075 EXPORT_SYMBOL(tcf_get_next_chain);
1076
1077 static struct tcf_proto *
1078 __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
1079 {
1080         u32 prio = 0;
1081
1082         ASSERT_RTNL();
1083         mutex_lock(&chain->filter_chain_lock);
1084
1085         if (!tp) {
1086                 tp = tcf_chain_dereference(chain->filter_chain, chain);
1087         } else if (tcf_proto_is_deleting(tp)) {
1088                 /* 'deleting' flag is set and chain->filter_chain_lock was
1089                  * unlocked, which means next pointer could be invalid. Restart
1090                  * search.
1091                  */
1092                 prio = tp->prio + 1;
1093                 tp = tcf_chain_dereference(chain->filter_chain, chain);
1094
1095                 for (; tp; tp = tcf_chain_dereference(tp->next, chain))
1096                         if (!tp->deleting && tp->prio >= prio)
1097                                 break;
1098         } else {
1099                 tp = tcf_chain_dereference(tp->next, chain);
1100         }
1101
1102         if (tp)
1103                 tcf_proto_get(tp);
1104
1105         mutex_unlock(&chain->filter_chain_lock);
1106
1107         return tp;
1108 }
1109
1110 /* Function to be used by all clients that want to iterate over all tp's on
1111  * chain. Users of this function must be tolerant to concurrent tp
1112  * insertion/deletion or ensure that no concurrent chain modification is
1113  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1114  * consistent dump because rtnl lock is released each time skb is filled with
1115  * data and sent to user-space.
1116  */
1117
1118 struct tcf_proto *
1119 tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
1120 {
1121         struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
1122
1123         if (tp)
1124                 tcf_proto_put(tp, true, NULL);
1125
1126         return tp_next;
1127 }
1128 EXPORT_SYMBOL(tcf_get_next_proto);
1129
1130 static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
1131 {
1132         struct tcf_chain *chain;
1133
1134         /* Last reference to block. At this point chains cannot be added or
1135          * removed concurrently.
1136          */
1137         for (chain = tcf_get_next_chain(block, NULL);
1138              chain;
1139              chain = tcf_get_next_chain(block, chain)) {
1140                 tcf_chain_put_explicitly_created(chain);
1141                 tcf_chain_flush(chain, rtnl_held);
1142         }
1143 }
1144
1145 /* Lookup Qdisc and increments its reference counter.
1146  * Set parent, if necessary.
1147  */
1148
1149 static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
1150                             u32 *parent, int ifindex, bool rtnl_held,
1151                             struct netlink_ext_ack *extack)
1152 {
1153         const struct Qdisc_class_ops *cops;
1154         struct net_device *dev;
1155         int err = 0;
1156
1157         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1158                 return 0;
1159
1160         rcu_read_lock();
1161
1162         /* Find link */
1163         dev = dev_get_by_index_rcu(net, ifindex);
1164         if (!dev) {
1165                 rcu_read_unlock();
1166                 return -ENODEV;
1167         }
1168
1169         /* Find qdisc */
1170         if (!*parent) {
1171                 *q = rcu_dereference(dev->qdisc);
1172                 *parent = (*q)->handle;
1173         } else {
1174                 *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
1175                 if (!*q) {
1176                         NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1177                         err = -EINVAL;
1178                         goto errout_rcu;
1179                 }
1180         }
1181
1182         *q = qdisc_refcount_inc_nz(*q);
1183         if (!*q) {
1184                 NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1185                 err = -EINVAL;
1186                 goto errout_rcu;
1187         }
1188
1189         /* Is it classful? */
1190         cops = (*q)->ops->cl_ops;
1191         if (!cops) {
1192                 NL_SET_ERR_MSG(extack, "Qdisc not classful");
1193                 err = -EINVAL;
1194                 goto errout_qdisc;
1195         }
1196
1197         if (!cops->tcf_block) {
1198                 NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
1199                 err = -EOPNOTSUPP;
1200                 goto errout_qdisc;
1201         }
1202
1203 errout_rcu:
1204         /* At this point we know that qdisc is not noop_qdisc,
1205          * which means that qdisc holds a reference to net_device
1206          * and we hold a reference to qdisc, so it is safe to release
1207          * rcu read lock.
1208          */
1209         rcu_read_unlock();
1210         return err;
1211
1212 errout_qdisc:
1213         rcu_read_unlock();
1214
1215         if (rtnl_held)
1216                 qdisc_put(*q);
1217         else
1218                 qdisc_put_unlocked(*q);
1219         *q = NULL;
1220
1221         return err;
1222 }
1223
1224 static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
1225                                int ifindex, struct netlink_ext_ack *extack)
1226 {
1227         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1228                 return 0;
1229
1230         /* Do we search for filter, attached to class? */
1231         if (TC_H_MIN(parent)) {
1232                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1233
1234                 *cl = cops->find(q, parent);
1235                 if (*cl == 0) {
1236                         NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
1237                         return -ENOENT;
1238                 }
1239         }
1240
1241         return 0;
1242 }
1243
1244 static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
1245                                           unsigned long cl, int ifindex,
1246                                           u32 block_index,
1247                                           struct netlink_ext_ack *extack)
1248 {
1249         struct tcf_block *block;
1250
1251         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
1252                 block = tcf_block_refcnt_get(net, block_index);
1253                 if (!block) {
1254                         NL_SET_ERR_MSG(extack, "Block of given index was not found");
1255                         return ERR_PTR(-EINVAL);
1256                 }
1257         } else {
1258                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1259
1260                 block = cops->tcf_block(q, cl, extack);
1261                 if (!block)
1262                         return ERR_PTR(-EINVAL);
1263
1264                 if (tcf_block_shared(block)) {
1265                         NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
1266                         return ERR_PTR(-EOPNOTSUPP);
1267                 }
1268
1269                 /* Always take reference to block in order to support execution
1270                  * of rules update path of cls API without rtnl lock. Caller
1271                  * must release block when it is finished using it. 'if' block
1272                  * of this conditional obtain reference to block by calling
1273                  * tcf_block_refcnt_get().
1274                  */
1275                 refcount_inc(&block->refcnt);
1276         }
1277
1278         return block;
1279 }
1280
1281 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
1282                             struct tcf_block_ext_info *ei, bool rtnl_held)
1283 {
1284         if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
1285                 /* Flushing/putting all chains will cause the block to be
1286                  * deallocated when last chain is freed. However, if chain_list
1287                  * is empty, block has to be manually deallocated. After block
1288                  * reference counter reached 0, it is no longer possible to
1289                  * increment it or add new chains to block.
1290                  */
1291                 bool free_block = list_empty(&block->chain_list);
1292
1293                 mutex_unlock(&block->lock);
1294                 if (tcf_block_shared(block))
1295                         tcf_block_remove(block, block->net);
1296
1297                 if (q)
1298                         tcf_block_offload_unbind(block, q, ei);
1299
1300                 if (free_block)
1301                         tcf_block_destroy(block);
1302                 else
1303                         tcf_block_flush_all_chains(block, rtnl_held);
1304         } else if (q) {
1305                 tcf_block_offload_unbind(block, q, ei);
1306         }
1307 }
1308
1309 static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
1310 {
1311         __tcf_block_put(block, NULL, NULL, rtnl_held);
1312 }
1313
1314 /* Find tcf block.
1315  * Set q, parent, cl when appropriate.
1316  */
1317
1318 static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
1319                                         u32 *parent, unsigned long *cl,
1320                                         int ifindex, u32 block_index,
1321                                         struct netlink_ext_ack *extack)
1322 {
1323         struct tcf_block *block;
1324         int err = 0;
1325
1326         ASSERT_RTNL();
1327
1328         err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
1329         if (err)
1330                 goto errout;
1331
1332         err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
1333         if (err)
1334                 goto errout_qdisc;
1335
1336         block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
1337         if (IS_ERR(block)) {
1338                 err = PTR_ERR(block);
1339                 goto errout_qdisc;
1340         }
1341
1342         return block;
1343
1344 errout_qdisc:
1345         if (*q)
1346                 qdisc_put(*q);
1347 errout:
1348         *q = NULL;
1349         return ERR_PTR(err);
1350 }
1351
1352 static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
1353                               bool rtnl_held)
1354 {
1355         if (!IS_ERR_OR_NULL(block))
1356                 tcf_block_refcnt_put(block, rtnl_held);
1357
1358         if (q) {
1359                 if (rtnl_held)
1360                         qdisc_put(q);
1361                 else
1362                         qdisc_put_unlocked(q);
1363         }
1364 }
1365
1366 struct tcf_block_owner_item {
1367         struct list_head list;
1368         struct Qdisc *q;
1369         enum flow_block_binder_type binder_type;
1370 };
1371
1372 static void
1373 tcf_block_owner_netif_keep_dst(struct tcf_block *block,
1374                                struct Qdisc *q,
1375                                enum flow_block_binder_type binder_type)
1376 {
1377         if (block->keep_dst &&
1378             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS &&
1379             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
1380                 netif_keep_dst(qdisc_dev(q));
1381 }
1382
1383 void tcf_block_netif_keep_dst(struct tcf_block *block)
1384 {
1385         struct tcf_block_owner_item *item;
1386
1387         block->keep_dst = true;
1388         list_for_each_entry(item, &block->owner_list, list)
1389                 tcf_block_owner_netif_keep_dst(block, item->q,
1390                                                item->binder_type);
1391 }
1392 EXPORT_SYMBOL(tcf_block_netif_keep_dst);
1393
1394 static int tcf_block_owner_add(struct tcf_block *block,
1395                                struct Qdisc *q,
1396                                enum flow_block_binder_type binder_type)
1397 {
1398         struct tcf_block_owner_item *item;
1399
1400         item = kmalloc(sizeof(*item), GFP_KERNEL);
1401         if (!item)
1402                 return -ENOMEM;
1403         item->q = q;
1404         item->binder_type = binder_type;
1405         list_add(&item->list, &block->owner_list);
1406         return 0;
1407 }
1408
1409 static void tcf_block_owner_del(struct tcf_block *block,
1410                                 struct Qdisc *q,
1411                                 enum flow_block_binder_type binder_type)
1412 {
1413         struct tcf_block_owner_item *item;
1414
1415         list_for_each_entry(item, &block->owner_list, list) {
1416                 if (item->q == q && item->binder_type == binder_type) {
1417                         list_del(&item->list);
1418                         kfree(item);
1419                         return;
1420                 }
1421         }
1422         WARN_ON(1);
1423 }
1424
1425 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
1426                       struct tcf_block_ext_info *ei,
1427                       struct netlink_ext_ack *extack)
1428 {
1429         struct net *net = qdisc_net(q);
1430         struct tcf_block *block = NULL;
1431         int err;
1432
1433         if (ei->block_index)
1434                 /* block_index not 0 means the shared block is requested */
1435                 block = tcf_block_refcnt_get(net, ei->block_index);
1436
1437         if (!block) {
1438                 block = tcf_block_create(net, q, ei->block_index, extack);
1439                 if (IS_ERR(block))
1440                         return PTR_ERR(block);
1441                 if (tcf_block_shared(block)) {
1442                         err = tcf_block_insert(block, net, extack);
1443                         if (err)
1444                                 goto err_block_insert;
1445                 }
1446         }
1447
1448         err = tcf_block_owner_add(block, q, ei->binder_type);
1449         if (err)
1450                 goto err_block_owner_add;
1451
1452         tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
1453
1454         err = tcf_chain0_head_change_cb_add(block, ei, extack);
1455         if (err)
1456                 goto err_chain0_head_change_cb_add;
1457
1458         err = tcf_block_offload_bind(block, q, ei, extack);
1459         if (err)
1460                 goto err_block_offload_bind;
1461
1462         *p_block = block;
1463         return 0;
1464
1465 err_block_offload_bind:
1466         tcf_chain0_head_change_cb_del(block, ei);
1467 err_chain0_head_change_cb_add:
1468         tcf_block_owner_del(block, q, ei->binder_type);
1469 err_block_owner_add:
1470 err_block_insert:
1471         tcf_block_refcnt_put(block, true);
1472         return err;
1473 }
1474 EXPORT_SYMBOL(tcf_block_get_ext);
1475
1476 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
1477 {
1478         struct tcf_proto __rcu **p_filter_chain = priv;
1479
1480         rcu_assign_pointer(*p_filter_chain, tp_head);
1481 }
1482
1483 int tcf_block_get(struct tcf_block **p_block,
1484                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
1485                   struct netlink_ext_ack *extack)
1486 {
1487         struct tcf_block_ext_info ei = {
1488                 .chain_head_change = tcf_chain_head_change_dflt,
1489                 .chain_head_change_priv = p_filter_chain,
1490         };
1491
1492         WARN_ON(!p_filter_chain);
1493         return tcf_block_get_ext(p_block, q, &ei, extack);
1494 }
1495 EXPORT_SYMBOL(tcf_block_get);
1496
1497 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
1498  * actions should be all removed after flushing.
1499  */
1500 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
1501                        struct tcf_block_ext_info *ei)
1502 {
1503         if (!block)
1504                 return;
1505         tcf_chain0_head_change_cb_del(block, ei);
1506         tcf_block_owner_del(block, q, ei->binder_type);
1507
1508         __tcf_block_put(block, q, ei, true);
1509 }
1510 EXPORT_SYMBOL(tcf_block_put_ext);
1511
1512 void tcf_block_put(struct tcf_block *block)
1513 {
1514         struct tcf_block_ext_info ei = {0, };
1515
1516         if (!block)
1517                 return;
1518         tcf_block_put_ext(block, block->q, &ei);
1519 }
1520
1521 EXPORT_SYMBOL(tcf_block_put);
1522
1523 static int
1524 tcf_block_playback_offloads(struct tcf_block *block, flow_setup_cb_t *cb,
1525                             void *cb_priv, bool add, bool offload_in_use,
1526                             struct netlink_ext_ack *extack)
1527 {
1528         struct tcf_chain *chain, *chain_prev;
1529         struct tcf_proto *tp, *tp_prev;
1530         int err;
1531
1532         lockdep_assert_held(&block->cb_lock);
1533
1534         for (chain = __tcf_get_next_chain(block, NULL);
1535              chain;
1536              chain_prev = chain,
1537                      chain = __tcf_get_next_chain(block, chain),
1538                      tcf_chain_put(chain_prev)) {
1539                 if (chain->tmplt_ops && add)
1540                         chain->tmplt_ops->tmplt_reoffload(chain, true, cb,
1541                                                           cb_priv);
1542                 for (tp = __tcf_get_next_proto(chain, NULL); tp;
1543                      tp_prev = tp,
1544                              tp = __tcf_get_next_proto(chain, tp),
1545                              tcf_proto_put(tp_prev, true, NULL)) {
1546                         if (tp->ops->reoffload) {
1547                                 err = tp->ops->reoffload(tp, add, cb, cb_priv,
1548                                                          extack);
1549                                 if (err && add)
1550                                         goto err_playback_remove;
1551                         } else if (add && offload_in_use) {
1552                                 err = -EOPNOTSUPP;
1553                                 NL_SET_ERR_MSG(extack, "Filter HW offload failed - classifier without re-offloading support");
1554                                 goto err_playback_remove;
1555                         }
1556                 }
1557                 if (chain->tmplt_ops && !add)
1558                         chain->tmplt_ops->tmplt_reoffload(chain, false, cb,
1559                                                           cb_priv);
1560         }
1561
1562         return 0;
1563
1564 err_playback_remove:
1565         tcf_proto_put(tp, true, NULL);
1566         tcf_chain_put(chain);
1567         tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
1568                                     extack);
1569         return err;
1570 }
1571
1572 static int tcf_block_bind(struct tcf_block *block,
1573                           struct flow_block_offload *bo)
1574 {
1575         struct flow_block_cb *block_cb, *next;
1576         int err, i = 0;
1577
1578         lockdep_assert_held(&block->cb_lock);
1579
1580         list_for_each_entry(block_cb, &bo->cb_list, list) {
1581                 err = tcf_block_playback_offloads(block, block_cb->cb,
1582                                                   block_cb->cb_priv, true,
1583                                                   tcf_block_offload_in_use(block),
1584                                                   bo->extack);
1585                 if (err)
1586                         goto err_unroll;
1587                 if (!bo->unlocked_driver_cb)
1588                         block->lockeddevcnt++;
1589
1590                 i++;
1591         }
1592         list_splice(&bo->cb_list, &block->flow_block.cb_list);
1593
1594         return 0;
1595
1596 err_unroll:
1597         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1598                 list_del(&block_cb->driver_list);
1599                 if (i-- > 0) {
1600                         list_del(&block_cb->list);
1601                         tcf_block_playback_offloads(block, block_cb->cb,
1602                                                     block_cb->cb_priv, false,
1603                                                     tcf_block_offload_in_use(block),
1604                                                     NULL);
1605                         if (!bo->unlocked_driver_cb)
1606                                 block->lockeddevcnt--;
1607                 }
1608                 flow_block_cb_free(block_cb);
1609         }
1610
1611         return err;
1612 }
1613
1614 static void tcf_block_unbind(struct tcf_block *block,
1615                              struct flow_block_offload *bo)
1616 {
1617         struct flow_block_cb *block_cb, *next;
1618
1619         lockdep_assert_held(&block->cb_lock);
1620
1621         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1622                 tcf_block_playback_offloads(block, block_cb->cb,
1623                                             block_cb->cb_priv, false,
1624                                             tcf_block_offload_in_use(block),
1625                                             NULL);
1626                 list_del(&block_cb->list);
1627                 flow_block_cb_free(block_cb);
1628                 if (!bo->unlocked_driver_cb)
1629                         block->lockeddevcnt--;
1630         }
1631 }
1632
1633 static int tcf_block_setup(struct tcf_block *block,
1634                            struct flow_block_offload *bo)
1635 {
1636         int err;
1637
1638         switch (bo->command) {
1639         case FLOW_BLOCK_BIND:
1640                 err = tcf_block_bind(block, bo);
1641                 break;
1642         case FLOW_BLOCK_UNBIND:
1643                 err = 0;
1644                 tcf_block_unbind(block, bo);
1645                 break;
1646         default:
1647                 WARN_ON_ONCE(1);
1648                 err = -EOPNOTSUPP;
1649         }
1650
1651         return err;
1652 }
1653
1654 /* Main classifier routine: scans classifier chain attached
1655  * to this qdisc, (optionally) tests for protocol and asks
1656  * specific classifiers.
1657  */
1658 static inline int __tcf_classify(struct sk_buff *skb,
1659                                  const struct tcf_proto *tp,
1660                                  const struct tcf_proto *orig_tp,
1661                                  struct tcf_result *res,
1662                                  bool compat_mode,
1663                                  struct tcf_exts_miss_cookie_node *n,
1664                                  int act_index,
1665                                  u32 *last_executed_chain)
1666 {
1667 #ifdef CONFIG_NET_CLS_ACT
1668         const int max_reclassify_loop = 16;
1669         const struct tcf_proto *first_tp;
1670         int limit = 0;
1671
1672 reclassify:
1673 #endif
1674         for (; tp; tp = rcu_dereference_bh(tp->next)) {
1675                 __be16 protocol = skb_protocol(skb, false);
1676                 int err = 0;
1677
1678                 if (n) {
1679                         struct tcf_exts *exts;
1680
1681                         if (n->tp_prio != tp->prio)
1682                                 continue;
1683
1684                         /* We re-lookup the tp and chain based on index instead
1685                          * of having hard refs and locks to them, so do a sanity
1686                          * check if any of tp,chain,exts was replaced by the
1687                          * time we got here with a cookie from hardware.
1688                          */
1689                         if (unlikely(n->tp != tp || n->tp->chain != n->chain ||
1690                                      !tp->ops->get_exts))
1691                                 return TC_ACT_SHOT;
1692
1693                         exts = tp->ops->get_exts(tp, n->handle);
1694                         if (unlikely(!exts || n->exts != exts))
1695                                 return TC_ACT_SHOT;
1696
1697                         n = NULL;
1698                         err = tcf_exts_exec_ex(skb, exts, act_index, res);
1699                 } else {
1700                         if (tp->protocol != protocol &&
1701                             tp->protocol != htons(ETH_P_ALL))
1702                                 continue;
1703
1704                         err = tc_classify(skb, tp, res);
1705                 }
1706 #ifdef CONFIG_NET_CLS_ACT
1707                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
1708                         first_tp = orig_tp;
1709                         *last_executed_chain = first_tp->chain->index;
1710                         goto reset;
1711                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
1712                         first_tp = res->goto_tp;
1713                         *last_executed_chain = err & TC_ACT_EXT_VAL_MASK;
1714                         goto reset;
1715                 }
1716 #endif
1717                 if (err >= 0)
1718                         return err;
1719         }
1720
1721         if (unlikely(n))
1722                 return TC_ACT_SHOT;
1723
1724         return TC_ACT_UNSPEC; /* signal: continue lookup */
1725 #ifdef CONFIG_NET_CLS_ACT
1726 reset:
1727         if (unlikely(limit++ >= max_reclassify_loop)) {
1728                 net_notice_ratelimited("%u: reclassify loop, rule prio %u, protocol %02x\n",
1729                                        tp->chain->block->index,
1730                                        tp->prio & 0xffff,
1731                                        ntohs(tp->protocol));
1732                 return TC_ACT_SHOT;
1733         }
1734
1735         tp = first_tp;
1736         goto reclassify;
1737 #endif
1738 }
1739
1740 int tcf_classify(struct sk_buff *skb,
1741                  const struct tcf_block *block,
1742                  const struct tcf_proto *tp,
1743                  struct tcf_result *res, bool compat_mode)
1744 {
1745 #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1746         u32 last_executed_chain = 0;
1747
1748         return __tcf_classify(skb, tp, tp, res, compat_mode, NULL, 0,
1749                               &last_executed_chain);
1750 #else
1751         u32 last_executed_chain = tp ? tp->chain->index : 0;
1752         struct tcf_exts_miss_cookie_node *n = NULL;
1753         const struct tcf_proto *orig_tp = tp;
1754         struct tc_skb_ext *ext;
1755         int act_index = 0;
1756         int ret;
1757
1758         if (block) {
1759                 ext = skb_ext_find(skb, TC_SKB_EXT);
1760
1761                 if (ext && (ext->chain || ext->act_miss)) {
1762                         struct tcf_chain *fchain;
1763                         u32 chain;
1764
1765                         if (ext->act_miss) {
1766                                 n = tcf_exts_miss_cookie_lookup(ext->act_miss_cookie,
1767                                                                 &act_index);
1768                                 if (!n)
1769                                         return TC_ACT_SHOT;
1770
1771                                 chain = n->chain_index;
1772                         } else {
1773                                 chain = ext->chain;
1774                         }
1775
1776                         fchain = tcf_chain_lookup_rcu(block, chain);
1777                         if (!fchain)
1778                                 return TC_ACT_SHOT;
1779
1780                         /* Consume, so cloned/redirect skbs won't inherit ext */
1781                         skb_ext_del(skb, TC_SKB_EXT);
1782
1783                         tp = rcu_dereference_bh(fchain->filter_chain);
1784                         last_executed_chain = fchain->index;
1785                 }
1786         }
1787
1788         ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode, n, act_index,
1789                              &last_executed_chain);
1790
1791         if (tc_skb_ext_tc_enabled()) {
1792                 /* If we missed on some chain */
1793                 if (ret == TC_ACT_UNSPEC && last_executed_chain) {
1794                         struct tc_skb_cb *cb = tc_skb_cb(skb);
1795
1796                         ext = tc_skb_ext_alloc(skb);
1797                         if (WARN_ON_ONCE(!ext))
1798                                 return TC_ACT_SHOT;
1799                         ext->chain = last_executed_chain;
1800                         ext->mru = cb->mru;
1801                         ext->post_ct = cb->post_ct;
1802                         ext->post_ct_snat = cb->post_ct_snat;
1803                         ext->post_ct_dnat = cb->post_ct_dnat;
1804                         ext->zone = cb->zone;
1805                 }
1806         }
1807
1808         return ret;
1809 #endif
1810 }
1811 EXPORT_SYMBOL(tcf_classify);
1812
1813 struct tcf_chain_info {
1814         struct tcf_proto __rcu **pprev;
1815         struct tcf_proto __rcu *next;
1816 };
1817
1818 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
1819                                            struct tcf_chain_info *chain_info)
1820 {
1821         return tcf_chain_dereference(*chain_info->pprev, chain);
1822 }
1823
1824 static int tcf_chain_tp_insert(struct tcf_chain *chain,
1825                                struct tcf_chain_info *chain_info,
1826                                struct tcf_proto *tp)
1827 {
1828         if (chain->flushing)
1829                 return -EAGAIN;
1830
1831         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
1832         if (*chain_info->pprev == chain->filter_chain)
1833                 tcf_chain0_head_change(chain, tp);
1834         tcf_proto_get(tp);
1835         rcu_assign_pointer(*chain_info->pprev, tp);
1836
1837         return 0;
1838 }
1839
1840 static void tcf_chain_tp_remove(struct tcf_chain *chain,
1841                                 struct tcf_chain_info *chain_info,
1842                                 struct tcf_proto *tp)
1843 {
1844         struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
1845
1846         tcf_proto_mark_delete(tp);
1847         if (tp == chain->filter_chain)
1848                 tcf_chain0_head_change(chain, next);
1849         RCU_INIT_POINTER(*chain_info->pprev, next);
1850 }
1851
1852 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1853                                            struct tcf_chain_info *chain_info,
1854                                            u32 protocol, u32 prio,
1855                                            bool prio_allocate);
1856
1857 /* Try to insert new proto.
1858  * If proto with specified priority already exists, free new proto
1859  * and return existing one.
1860  */
1861
1862 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
1863                                                     struct tcf_proto *tp_new,
1864                                                     u32 protocol, u32 prio,
1865                                                     bool rtnl_held)
1866 {
1867         struct tcf_chain_info chain_info;
1868         struct tcf_proto *tp;
1869         int err = 0;
1870
1871         mutex_lock(&chain->filter_chain_lock);
1872
1873         if (tcf_proto_exists_destroying(chain, tp_new)) {
1874                 mutex_unlock(&chain->filter_chain_lock);
1875                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1876                 return ERR_PTR(-EAGAIN);
1877         }
1878
1879         tp = tcf_chain_tp_find(chain, &chain_info,
1880                                protocol, prio, false);
1881         if (!tp)
1882                 err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
1883         mutex_unlock(&chain->filter_chain_lock);
1884
1885         if (tp) {
1886                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1887                 tp_new = tp;
1888         } else if (err) {
1889                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1890                 tp_new = ERR_PTR(err);
1891         }
1892
1893         return tp_new;
1894 }
1895
1896 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
1897                                       struct tcf_proto *tp, bool rtnl_held,
1898                                       struct netlink_ext_ack *extack)
1899 {
1900         struct tcf_chain_info chain_info;
1901         struct tcf_proto *tp_iter;
1902         struct tcf_proto **pprev;
1903         struct tcf_proto *next;
1904
1905         mutex_lock(&chain->filter_chain_lock);
1906
1907         /* Atomically find and remove tp from chain. */
1908         for (pprev = &chain->filter_chain;
1909              (tp_iter = tcf_chain_dereference(*pprev, chain));
1910              pprev = &tp_iter->next) {
1911                 if (tp_iter == tp) {
1912                         chain_info.pprev = pprev;
1913                         chain_info.next = tp_iter->next;
1914                         WARN_ON(tp_iter->deleting);
1915                         break;
1916                 }
1917         }
1918         /* Verify that tp still exists and no new filters were inserted
1919          * concurrently.
1920          * Mark tp for deletion if it is empty.
1921          */
1922         if (!tp_iter || !tcf_proto_check_delete(tp)) {
1923                 mutex_unlock(&chain->filter_chain_lock);
1924                 return;
1925         }
1926
1927         tcf_proto_signal_destroying(chain, tp);
1928         next = tcf_chain_dereference(chain_info.next, chain);
1929         if (tp == chain->filter_chain)
1930                 tcf_chain0_head_change(chain, next);
1931         RCU_INIT_POINTER(*chain_info.pprev, next);
1932         mutex_unlock(&chain->filter_chain_lock);
1933
1934         tcf_proto_put(tp, rtnl_held, extack);
1935 }
1936
1937 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1938                                            struct tcf_chain_info *chain_info,
1939                                            u32 protocol, u32 prio,
1940                                            bool prio_allocate)
1941 {
1942         struct tcf_proto **pprev;
1943         struct tcf_proto *tp;
1944
1945         /* Check the chain for existence of proto-tcf with this priority */
1946         for (pprev = &chain->filter_chain;
1947              (tp = tcf_chain_dereference(*pprev, chain));
1948              pprev = &tp->next) {
1949                 if (tp->prio >= prio) {
1950                         if (tp->prio == prio) {
1951                                 if (prio_allocate ||
1952                                     (tp->protocol != protocol && protocol))
1953                                         return ERR_PTR(-EINVAL);
1954                         } else {
1955                                 tp = NULL;
1956                         }
1957                         break;
1958                 }
1959         }
1960         chain_info->pprev = pprev;
1961         if (tp) {
1962                 chain_info->next = tp->next;
1963                 tcf_proto_get(tp);
1964         } else {
1965                 chain_info->next = NULL;
1966         }
1967         return tp;
1968 }
1969
1970 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
1971                          struct tcf_proto *tp, struct tcf_block *block,
1972                          struct Qdisc *q, u32 parent, void *fh,
1973                          u32 portid, u32 seq, u16 flags, int event,
1974                          bool terse_dump, bool rtnl_held,
1975                          struct netlink_ext_ack *extack)
1976 {
1977         struct tcmsg *tcm;
1978         struct nlmsghdr  *nlh;
1979         unsigned char *b = skb_tail_pointer(skb);
1980
1981         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1982         if (!nlh)
1983                 goto out_nlmsg_trim;
1984         tcm = nlmsg_data(nlh);
1985         tcm->tcm_family = AF_UNSPEC;
1986         tcm->tcm__pad1 = 0;
1987         tcm->tcm__pad2 = 0;
1988         if (q) {
1989                 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1990                 tcm->tcm_parent = parent;
1991         } else {
1992                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
1993                 tcm->tcm_block_index = block->index;
1994         }
1995         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
1996         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
1997                 goto nla_put_failure;
1998         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
1999                 goto nla_put_failure;
2000         if (!fh) {
2001                 tcm->tcm_handle = 0;
2002         } else if (terse_dump) {
2003                 if (tp->ops->terse_dump) {
2004                         if (tp->ops->terse_dump(net, tp, fh, skb, tcm,
2005                                                 rtnl_held) < 0)
2006                                 goto nla_put_failure;
2007                 } else {
2008                         goto cls_op_not_supp;
2009                 }
2010         } else {
2011                 if (tp->ops->dump &&
2012                     tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
2013                         goto nla_put_failure;
2014         }
2015
2016         if (extack && extack->_msg &&
2017             nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
2018                 goto nla_put_failure;
2019
2020         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2021
2022         return skb->len;
2023
2024 out_nlmsg_trim:
2025 nla_put_failure:
2026 cls_op_not_supp:
2027         nlmsg_trim(skb, b);
2028         return -1;
2029 }
2030
2031 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
2032                           struct nlmsghdr *n, struct tcf_proto *tp,
2033                           struct tcf_block *block, struct Qdisc *q,
2034                           u32 parent, void *fh, int event, bool unicast,
2035                           bool rtnl_held, struct netlink_ext_ack *extack)
2036 {
2037         struct sk_buff *skb;
2038         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2039         int err = 0;
2040
2041         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2042         if (!skb)
2043                 return -ENOBUFS;
2044
2045         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
2046                           n->nlmsg_seq, n->nlmsg_flags, event,
2047                           false, rtnl_held, extack) <= 0) {
2048                 kfree_skb(skb);
2049                 return -EINVAL;
2050         }
2051
2052         if (unicast)
2053                 err = rtnl_unicast(skb, net, portid);
2054         else
2055                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2056                                      n->nlmsg_flags & NLM_F_ECHO);
2057         return err;
2058 }
2059
2060 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
2061                               struct nlmsghdr *n, struct tcf_proto *tp,
2062                               struct tcf_block *block, struct Qdisc *q,
2063                               u32 parent, void *fh, bool unicast, bool *last,
2064                               bool rtnl_held, struct netlink_ext_ack *extack)
2065 {
2066         struct sk_buff *skb;
2067         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2068         int err;
2069
2070         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2071         if (!skb)
2072                 return -ENOBUFS;
2073
2074         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
2075                           n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
2076                           false, rtnl_held, extack) <= 0) {
2077                 NL_SET_ERR_MSG(extack, "Failed to build del event notification");
2078                 kfree_skb(skb);
2079                 return -EINVAL;
2080         }
2081
2082         err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
2083         if (err) {
2084                 kfree_skb(skb);
2085                 return err;
2086         }
2087
2088         if (unicast)
2089                 err = rtnl_unicast(skb, net, portid);
2090         else
2091                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2092                                      n->nlmsg_flags & NLM_F_ECHO);
2093         if (err < 0)
2094                 NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
2095
2096         return err;
2097 }
2098
2099 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
2100                                  struct tcf_block *block, struct Qdisc *q,
2101                                  u32 parent, struct nlmsghdr *n,
2102                                  struct tcf_chain *chain, int event,
2103                                  struct netlink_ext_ack *extack)
2104 {
2105         struct tcf_proto *tp;
2106
2107         for (tp = tcf_get_next_proto(chain, NULL);
2108              tp; tp = tcf_get_next_proto(chain, tp))
2109                 tfilter_notify(net, oskb, n, tp, block, q, parent, NULL,
2110                                event, false, true, extack);
2111 }
2112
2113 static void tfilter_put(struct tcf_proto *tp, void *fh)
2114 {
2115         if (tp->ops->put && fh)
2116                 tp->ops->put(tp, fh);
2117 }
2118
2119 static bool is_qdisc_ingress(__u32 classid)
2120 {
2121         return (TC_H_MIN(classid) == TC_H_MIN(TC_H_MIN_INGRESS));
2122 }
2123
2124 static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2125                           struct netlink_ext_ack *extack)
2126 {
2127         struct net *net = sock_net(skb->sk);
2128         struct nlattr *tca[TCA_MAX + 1];
2129         char name[IFNAMSIZ];
2130         struct tcmsg *t;
2131         u32 protocol;
2132         u32 prio;
2133         bool prio_allocate;
2134         u32 parent;
2135         u32 chain_index;
2136         struct Qdisc *q;
2137         struct tcf_chain_info chain_info;
2138         struct tcf_chain *chain;
2139         struct tcf_block *block;
2140         struct tcf_proto *tp;
2141         unsigned long cl;
2142         void *fh;
2143         int err;
2144         int tp_created;
2145         bool rtnl_held = false;
2146         u32 flags;
2147
2148 replay:
2149         tp_created = 0;
2150
2151         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2152                                      rtm_tca_policy, extack);
2153         if (err < 0)
2154                 return err;
2155
2156         t = nlmsg_data(n);
2157         protocol = TC_H_MIN(t->tcm_info);
2158         prio = TC_H_MAJ(t->tcm_info);
2159         prio_allocate = false;
2160         parent = t->tcm_parent;
2161         tp = NULL;
2162         cl = 0;
2163         block = NULL;
2164         q = NULL;
2165         chain = NULL;
2166         flags = 0;
2167
2168         if (prio == 0) {
2169                 /* If no priority is provided by the user,
2170                  * we allocate one.
2171                  */
2172                 if (n->nlmsg_flags & NLM_F_CREATE) {
2173                         prio = TC_H_MAKE(0x80000000U, 0U);
2174                         prio_allocate = true;
2175                 } else {
2176                         NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2177                         return -ENOENT;
2178                 }
2179         }
2180
2181         /* Find head of filter chain. */
2182
2183         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2184         if (err)
2185                 return err;
2186
2187         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2188                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2189                 err = -EINVAL;
2190                 goto errout;
2191         }
2192
2193         /* Take rtnl mutex if rtnl_held was set to true on previous iteration,
2194          * block is shared (no qdisc found), qdisc is not unlocked, classifier
2195          * type is not specified, classifier is not unlocked.
2196          */
2197         if (rtnl_held ||
2198             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2199             !tcf_proto_is_unlocked(name)) {
2200                 rtnl_held = true;
2201                 rtnl_lock();
2202         }
2203
2204         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2205         if (err)
2206                 goto errout;
2207
2208         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2209                                  extack);
2210         if (IS_ERR(block)) {
2211                 err = PTR_ERR(block);
2212                 goto errout;
2213         }
2214         block->classid = parent;
2215
2216         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2217         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2218                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2219                 err = -EINVAL;
2220                 goto errout;
2221         }
2222         chain = tcf_chain_get(block, chain_index, true);
2223         if (!chain) {
2224                 NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
2225                 err = -ENOMEM;
2226                 goto errout;
2227         }
2228
2229         mutex_lock(&chain->filter_chain_lock);
2230         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2231                                prio, prio_allocate);
2232         if (IS_ERR(tp)) {
2233                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2234                 err = PTR_ERR(tp);
2235                 goto errout_locked;
2236         }
2237
2238         if (tp == NULL) {
2239                 struct tcf_proto *tp_new = NULL;
2240
2241                 if (chain->flushing) {
2242                         err = -EAGAIN;
2243                         goto errout_locked;
2244                 }
2245
2246                 /* Proto-tcf does not exist, create new one */
2247
2248                 if (tca[TCA_KIND] == NULL || !protocol) {
2249                         NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
2250                         err = -EINVAL;
2251                         goto errout_locked;
2252                 }
2253
2254                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2255                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2256                         err = -ENOENT;
2257                         goto errout_locked;
2258                 }
2259
2260                 if (prio_allocate)
2261                         prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
2262                                                                &chain_info));
2263
2264                 mutex_unlock(&chain->filter_chain_lock);
2265                 tp_new = tcf_proto_create(name, protocol, prio, chain,
2266                                           rtnl_held, extack);
2267                 if (IS_ERR(tp_new)) {
2268                         err = PTR_ERR(tp_new);
2269                         goto errout_tp;
2270                 }
2271
2272                 tp_created = 1;
2273                 tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
2274                                                 rtnl_held);
2275                 if (IS_ERR(tp)) {
2276                         err = PTR_ERR(tp);
2277                         goto errout_tp;
2278                 }
2279         } else {
2280                 mutex_unlock(&chain->filter_chain_lock);
2281         }
2282
2283         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2284                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2285                 err = -EINVAL;
2286                 goto errout;
2287         }
2288
2289         fh = tp->ops->get(tp, t->tcm_handle);
2290
2291         if (!fh) {
2292                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2293                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2294                         err = -ENOENT;
2295                         goto errout;
2296                 }
2297         } else if (n->nlmsg_flags & NLM_F_EXCL) {
2298                 tfilter_put(tp, fh);
2299                 NL_SET_ERR_MSG(extack, "Filter already exists");
2300                 err = -EEXIST;
2301                 goto errout;
2302         }
2303
2304         if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
2305                 tfilter_put(tp, fh);
2306                 NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
2307                 err = -EINVAL;
2308                 goto errout;
2309         }
2310
2311         if (!(n->nlmsg_flags & NLM_F_CREATE))
2312                 flags |= TCA_ACT_FLAGS_REPLACE;
2313         if (!rtnl_held)
2314                 flags |= TCA_ACT_FLAGS_NO_RTNL;
2315         if (is_qdisc_ingress(parent))
2316                 flags |= TCA_ACT_FLAGS_AT_INGRESS;
2317         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
2318                               flags, extack);
2319         if (err == 0) {
2320                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2321                                RTM_NEWTFILTER, false, rtnl_held, extack);
2322                 tfilter_put(tp, fh);
2323                 /* q pointer is NULL for shared blocks */
2324                 if (q)
2325                         q->flags &= ~TCQ_F_CAN_BYPASS;
2326         }
2327
2328 errout:
2329         if (err && tp_created)
2330                 tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
2331 errout_tp:
2332         if (chain) {
2333                 if (tp && !IS_ERR(tp))
2334                         tcf_proto_put(tp, rtnl_held, NULL);
2335                 if (!tp_created)
2336                         tcf_chain_put(chain);
2337         }
2338         tcf_block_release(q, block, rtnl_held);
2339
2340         if (rtnl_held)
2341                 rtnl_unlock();
2342
2343         if (err == -EAGAIN) {
2344                 /* Take rtnl lock in case EAGAIN is caused by concurrent flush
2345                  * of target chain.
2346                  */
2347                 rtnl_held = true;
2348                 /* Replay the request. */
2349                 goto replay;
2350         }
2351         return err;
2352
2353 errout_locked:
2354         mutex_unlock(&chain->filter_chain_lock);
2355         goto errout;
2356 }
2357
2358 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2359                           struct netlink_ext_ack *extack)
2360 {
2361         struct net *net = sock_net(skb->sk);
2362         struct nlattr *tca[TCA_MAX + 1];
2363         char name[IFNAMSIZ];
2364         struct tcmsg *t;
2365         u32 protocol;
2366         u32 prio;
2367         u32 parent;
2368         u32 chain_index;
2369         struct Qdisc *q = NULL;
2370         struct tcf_chain_info chain_info;
2371         struct tcf_chain *chain = NULL;
2372         struct tcf_block *block = NULL;
2373         struct tcf_proto *tp = NULL;
2374         unsigned long cl = 0;
2375         void *fh = NULL;
2376         int err;
2377         bool rtnl_held = false;
2378
2379         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2380                                      rtm_tca_policy, extack);
2381         if (err < 0)
2382                 return err;
2383
2384         t = nlmsg_data(n);
2385         protocol = TC_H_MIN(t->tcm_info);
2386         prio = TC_H_MAJ(t->tcm_info);
2387         parent = t->tcm_parent;
2388
2389         if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
2390                 NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
2391                 return -ENOENT;
2392         }
2393
2394         /* Find head of filter chain. */
2395
2396         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2397         if (err)
2398                 return err;
2399
2400         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2401                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2402                 err = -EINVAL;
2403                 goto errout;
2404         }
2405         /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
2406          * found), qdisc is not unlocked, classifier type is not specified,
2407          * classifier is not unlocked.
2408          */
2409         if (!prio ||
2410             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2411             !tcf_proto_is_unlocked(name)) {
2412                 rtnl_held = true;
2413                 rtnl_lock();
2414         }
2415
2416         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2417         if (err)
2418                 goto errout;
2419
2420         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2421                                  extack);
2422         if (IS_ERR(block)) {
2423                 err = PTR_ERR(block);
2424                 goto errout;
2425         }
2426
2427         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2428         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2429                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2430                 err = -EINVAL;
2431                 goto errout;
2432         }
2433         chain = tcf_chain_get(block, chain_index, false);
2434         if (!chain) {
2435                 /* User requested flush on non-existent chain. Nothing to do,
2436                  * so just return success.
2437                  */
2438                 if (prio == 0) {
2439                         err = 0;
2440                         goto errout;
2441                 }
2442                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2443                 err = -ENOENT;
2444                 goto errout;
2445         }
2446
2447         if (prio == 0) {
2448                 tfilter_notify_chain(net, skb, block, q, parent, n,
2449                                      chain, RTM_DELTFILTER, extack);
2450                 tcf_chain_flush(chain, rtnl_held);
2451                 err = 0;
2452                 goto errout;
2453         }
2454
2455         mutex_lock(&chain->filter_chain_lock);
2456         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2457                                prio, false);
2458         if (!tp || IS_ERR(tp)) {
2459                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2460                 err = tp ? PTR_ERR(tp) : -ENOENT;
2461                 goto errout_locked;
2462         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2463                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2464                 err = -EINVAL;
2465                 goto errout_locked;
2466         } else if (t->tcm_handle == 0) {
2467                 tcf_proto_signal_destroying(chain, tp);
2468                 tcf_chain_tp_remove(chain, &chain_info, tp);
2469                 mutex_unlock(&chain->filter_chain_lock);
2470
2471                 tcf_proto_put(tp, rtnl_held, NULL);
2472                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2473                                RTM_DELTFILTER, false, rtnl_held, extack);
2474                 err = 0;
2475                 goto errout;
2476         }
2477         mutex_unlock(&chain->filter_chain_lock);
2478
2479         fh = tp->ops->get(tp, t->tcm_handle);
2480
2481         if (!fh) {
2482                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2483                 err = -ENOENT;
2484         } else {
2485                 bool last;
2486
2487                 err = tfilter_del_notify(net, skb, n, tp, block,
2488                                          q, parent, fh, false, &last,
2489                                          rtnl_held, extack);
2490
2491                 if (err)
2492                         goto errout;
2493                 if (last)
2494                         tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
2495         }
2496
2497 errout:
2498         if (chain) {
2499                 if (tp && !IS_ERR(tp))
2500                         tcf_proto_put(tp, rtnl_held, NULL);
2501                 tcf_chain_put(chain);
2502         }
2503         tcf_block_release(q, block, rtnl_held);
2504
2505         if (rtnl_held)
2506                 rtnl_unlock();
2507
2508         return err;
2509
2510 errout_locked:
2511         mutex_unlock(&chain->filter_chain_lock);
2512         goto errout;
2513 }
2514
2515 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2516                           struct netlink_ext_ack *extack)
2517 {
2518         struct net *net = sock_net(skb->sk);
2519         struct nlattr *tca[TCA_MAX + 1];
2520         char name[IFNAMSIZ];
2521         struct tcmsg *t;
2522         u32 protocol;
2523         u32 prio;
2524         u32 parent;
2525         u32 chain_index;
2526         struct Qdisc *q = NULL;
2527         struct tcf_chain_info chain_info;
2528         struct tcf_chain *chain = NULL;
2529         struct tcf_block *block = NULL;
2530         struct tcf_proto *tp = NULL;
2531         unsigned long cl = 0;
2532         void *fh = NULL;
2533         int err;
2534         bool rtnl_held = false;
2535
2536         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2537                                      rtm_tca_policy, extack);
2538         if (err < 0)
2539                 return err;
2540
2541         t = nlmsg_data(n);
2542         protocol = TC_H_MIN(t->tcm_info);
2543         prio = TC_H_MAJ(t->tcm_info);
2544         parent = t->tcm_parent;
2545
2546         if (prio == 0) {
2547                 NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2548                 return -ENOENT;
2549         }
2550
2551         /* Find head of filter chain. */
2552
2553         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2554         if (err)
2555                 return err;
2556
2557         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2558                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2559                 err = -EINVAL;
2560                 goto errout;
2561         }
2562         /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
2563          * unlocked, classifier type is not specified, classifier is not
2564          * unlocked.
2565          */
2566         if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2567             !tcf_proto_is_unlocked(name)) {
2568                 rtnl_held = true;
2569                 rtnl_lock();
2570         }
2571
2572         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2573         if (err)
2574                 goto errout;
2575
2576         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2577                                  extack);
2578         if (IS_ERR(block)) {
2579                 err = PTR_ERR(block);
2580                 goto errout;
2581         }
2582
2583         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2584         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2585                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2586                 err = -EINVAL;
2587                 goto errout;
2588         }
2589         chain = tcf_chain_get(block, chain_index, false);
2590         if (!chain) {
2591                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2592                 err = -EINVAL;
2593                 goto errout;
2594         }
2595
2596         mutex_lock(&chain->filter_chain_lock);
2597         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2598                                prio, false);
2599         mutex_unlock(&chain->filter_chain_lock);
2600         if (!tp || IS_ERR(tp)) {
2601                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2602                 err = tp ? PTR_ERR(tp) : -ENOENT;
2603                 goto errout;
2604         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2605                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2606                 err = -EINVAL;
2607                 goto errout;
2608         }
2609
2610         fh = tp->ops->get(tp, t->tcm_handle);
2611
2612         if (!fh) {
2613                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2614                 err = -ENOENT;
2615         } else {
2616                 err = tfilter_notify(net, skb, n, tp, block, q, parent,
2617                                      fh, RTM_NEWTFILTER, true, rtnl_held, NULL);
2618                 if (err < 0)
2619                         NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
2620         }
2621
2622         tfilter_put(tp, fh);
2623 errout:
2624         if (chain) {
2625                 if (tp && !IS_ERR(tp))
2626                         tcf_proto_put(tp, rtnl_held, NULL);
2627                 tcf_chain_put(chain);
2628         }
2629         tcf_block_release(q, block, rtnl_held);
2630
2631         if (rtnl_held)
2632                 rtnl_unlock();
2633
2634         return err;
2635 }
2636
2637 struct tcf_dump_args {
2638         struct tcf_walker w;
2639         struct sk_buff *skb;
2640         struct netlink_callback *cb;
2641         struct tcf_block *block;
2642         struct Qdisc *q;
2643         u32 parent;
2644         bool terse_dump;
2645 };
2646
2647 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2648 {
2649         struct tcf_dump_args *a = (void *)arg;
2650         struct net *net = sock_net(a->skb->sk);
2651
2652         return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
2653                              n, NETLINK_CB(a->cb->skb).portid,
2654                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2655                              RTM_NEWTFILTER, a->terse_dump, true, NULL);
2656 }
2657
2658 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
2659                            struct sk_buff *skb, struct netlink_callback *cb,
2660                            long index_start, long *p_index, bool terse)
2661 {
2662         struct net *net = sock_net(skb->sk);
2663         struct tcf_block *block = chain->block;
2664         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2665         struct tcf_proto *tp, *tp_prev;
2666         struct tcf_dump_args arg;
2667
2668         for (tp = __tcf_get_next_proto(chain, NULL);
2669              tp;
2670              tp_prev = tp,
2671                      tp = __tcf_get_next_proto(chain, tp),
2672                      tcf_proto_put(tp_prev, true, NULL),
2673                      (*p_index)++) {
2674                 if (*p_index < index_start)
2675                         continue;
2676                 if (TC_H_MAJ(tcm->tcm_info) &&
2677                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
2678                         continue;
2679                 if (TC_H_MIN(tcm->tcm_info) &&
2680                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
2681                         continue;
2682                 if (*p_index > index_start)
2683                         memset(&cb->args[1], 0,
2684                                sizeof(cb->args) - sizeof(cb->args[0]));
2685                 if (cb->args[1] == 0) {
2686                         if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
2687                                           NETLINK_CB(cb->skb).portid,
2688                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
2689                                           RTM_NEWTFILTER, false, true, NULL) <= 0)
2690                                 goto errout;
2691                         cb->args[1] = 1;
2692                 }
2693                 if (!tp->ops->walk)
2694                         continue;
2695                 arg.w.fn = tcf_node_dump;
2696                 arg.skb = skb;
2697                 arg.cb = cb;
2698                 arg.block = block;
2699                 arg.q = q;
2700                 arg.parent = parent;
2701                 arg.w.stop = 0;
2702                 arg.w.skip = cb->args[1] - 1;
2703                 arg.w.count = 0;
2704                 arg.w.cookie = cb->args[2];
2705                 arg.terse_dump = terse;
2706                 tp->ops->walk(tp, &arg.w, true);
2707                 cb->args[2] = arg.w.cookie;
2708                 cb->args[1] = arg.w.count + 1;
2709                 if (arg.w.stop)
2710                         goto errout;
2711         }
2712         return true;
2713
2714 errout:
2715         tcf_proto_put(tp, true, NULL);
2716         return false;
2717 }
2718
2719 static const struct nla_policy tcf_tfilter_dump_policy[TCA_MAX + 1] = {
2720         [TCA_DUMP_FLAGS] = NLA_POLICY_BITFIELD32(TCA_DUMP_FLAGS_TERSE),
2721 };
2722
2723 /* called with RTNL */
2724 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
2725 {
2726         struct tcf_chain *chain, *chain_prev;
2727         struct net *net = sock_net(skb->sk);
2728         struct nlattr *tca[TCA_MAX + 1];
2729         struct Qdisc *q = NULL;
2730         struct tcf_block *block;
2731         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2732         bool terse_dump = false;
2733         long index_start;
2734         long index;
2735         u32 parent;
2736         int err;
2737
2738         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2739                 return skb->len;
2740
2741         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2742                                      tcf_tfilter_dump_policy, cb->extack);
2743         if (err)
2744                 return err;
2745
2746         if (tca[TCA_DUMP_FLAGS]) {
2747                 struct nla_bitfield32 flags =
2748                         nla_get_bitfield32(tca[TCA_DUMP_FLAGS]);
2749
2750                 terse_dump = flags.value & TCA_DUMP_FLAGS_TERSE;
2751         }
2752
2753         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2754                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2755                 if (!block)
2756                         goto out;
2757                 /* If we work with block index, q is NULL and parent value
2758                  * will never be used in the following code. The check
2759                  * in tcf_fill_node prevents it. However, compiler does not
2760                  * see that far, so set parent to zero to silence the warning
2761                  * about parent being uninitialized.
2762                  */
2763                 parent = 0;
2764         } else {
2765                 const struct Qdisc_class_ops *cops;
2766                 struct net_device *dev;
2767                 unsigned long cl = 0;
2768
2769                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2770                 if (!dev)
2771                         return skb->len;
2772
2773                 parent = tcm->tcm_parent;
2774                 if (!parent)
2775                         q = rtnl_dereference(dev->qdisc);
2776                 else
2777                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2778                 if (!q)
2779                         goto out;
2780                 cops = q->ops->cl_ops;
2781                 if (!cops)
2782                         goto out;
2783                 if (!cops->tcf_block)
2784                         goto out;
2785                 if (TC_H_MIN(tcm->tcm_parent)) {
2786                         cl = cops->find(q, tcm->tcm_parent);
2787                         if (cl == 0)
2788                                 goto out;
2789                 }
2790                 block = cops->tcf_block(q, cl, NULL);
2791                 if (!block)
2792                         goto out;
2793                 parent = block->classid;
2794                 if (tcf_block_shared(block))
2795                         q = NULL;
2796         }
2797
2798         index_start = cb->args[0];
2799         index = 0;
2800
2801         for (chain = __tcf_get_next_chain(block, NULL);
2802              chain;
2803              chain_prev = chain,
2804                      chain = __tcf_get_next_chain(block, chain),
2805                      tcf_chain_put(chain_prev)) {
2806                 if (tca[TCA_CHAIN] &&
2807                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
2808                         continue;
2809                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
2810                                     index_start, &index, terse_dump)) {
2811                         tcf_chain_put(chain);
2812                         err = -EMSGSIZE;
2813                         break;
2814                 }
2815         }
2816
2817         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2818                 tcf_block_refcnt_put(block, true);
2819         cb->args[0] = index;
2820
2821 out:
2822         /* If we did no progress, the error (EMSGSIZE) is real */
2823         if (skb->len == 0 && err)
2824                 return err;
2825         return skb->len;
2826 }
2827
2828 static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
2829                               void *tmplt_priv, u32 chain_index,
2830                               struct net *net, struct sk_buff *skb,
2831                               struct tcf_block *block,
2832                               u32 portid, u32 seq, u16 flags, int event,
2833                               struct netlink_ext_ack *extack)
2834 {
2835         unsigned char *b = skb_tail_pointer(skb);
2836         const struct tcf_proto_ops *ops;
2837         struct nlmsghdr *nlh;
2838         struct tcmsg *tcm;
2839         void *priv;
2840
2841         ops = tmplt_ops;
2842         priv = tmplt_priv;
2843
2844         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2845         if (!nlh)
2846                 goto out_nlmsg_trim;
2847         tcm = nlmsg_data(nlh);
2848         tcm->tcm_family = AF_UNSPEC;
2849         tcm->tcm__pad1 = 0;
2850         tcm->tcm__pad2 = 0;
2851         tcm->tcm_handle = 0;
2852         if (block->q) {
2853                 tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
2854                 tcm->tcm_parent = block->q->handle;
2855         } else {
2856                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2857                 tcm->tcm_block_index = block->index;
2858         }
2859
2860         if (nla_put_u32(skb, TCA_CHAIN, chain_index))
2861                 goto nla_put_failure;
2862
2863         if (ops) {
2864                 if (nla_put_string(skb, TCA_KIND, ops->kind))
2865                         goto nla_put_failure;
2866                 if (ops->tmplt_dump(skb, net, priv) < 0)
2867                         goto nla_put_failure;
2868         }
2869
2870         if (extack && extack->_msg &&
2871             nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
2872                 goto out_nlmsg_trim;
2873
2874         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2875
2876         return skb->len;
2877
2878 out_nlmsg_trim:
2879 nla_put_failure:
2880         nlmsg_trim(skb, b);
2881         return -EMSGSIZE;
2882 }
2883
2884 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
2885                            u32 seq, u16 flags, int event, bool unicast,
2886                            struct netlink_ext_ack *extack)
2887 {
2888         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2889         struct tcf_block *block = chain->block;
2890         struct net *net = block->net;
2891         struct sk_buff *skb;
2892         int err = 0;
2893
2894         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2895         if (!skb)
2896                 return -ENOBUFS;
2897
2898         if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2899                                chain->index, net, skb, block, portid,
2900                                seq, flags, event, extack) <= 0) {
2901                 kfree_skb(skb);
2902                 return -EINVAL;
2903         }
2904
2905         if (unicast)
2906                 err = rtnl_unicast(skb, net, portid);
2907         else
2908                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2909                                      flags & NLM_F_ECHO);
2910
2911         return err;
2912 }
2913
2914 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
2915                                   void *tmplt_priv, u32 chain_index,
2916                                   struct tcf_block *block, struct sk_buff *oskb,
2917                                   u32 seq, u16 flags, bool unicast)
2918 {
2919         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2920         struct net *net = block->net;
2921         struct sk_buff *skb;
2922
2923         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2924         if (!skb)
2925                 return -ENOBUFS;
2926
2927         if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
2928                                block, portid, seq, flags, RTM_DELCHAIN, NULL) <= 0) {
2929                 kfree_skb(skb);
2930                 return -EINVAL;
2931         }
2932
2933         if (unicast)
2934                 return rtnl_unicast(skb, net, portid);
2935
2936         return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
2937 }
2938
2939 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
2940                               struct nlattr **tca,
2941                               struct netlink_ext_ack *extack)
2942 {
2943         const struct tcf_proto_ops *ops;
2944         char name[IFNAMSIZ];
2945         void *tmplt_priv;
2946
2947         /* If kind is not set, user did not specify template. */
2948         if (!tca[TCA_KIND])
2949                 return 0;
2950
2951         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2952                 NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
2953                 return -EINVAL;
2954         }
2955
2956         ops = tcf_proto_lookup_ops(name, true, extack);
2957         if (IS_ERR(ops))
2958                 return PTR_ERR(ops);
2959         if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump ||
2960             !ops->tmplt_reoffload) {
2961                 NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
2962                 module_put(ops->owner);
2963                 return -EOPNOTSUPP;
2964         }
2965
2966         tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
2967         if (IS_ERR(tmplt_priv)) {
2968                 module_put(ops->owner);
2969                 return PTR_ERR(tmplt_priv);
2970         }
2971         chain->tmplt_ops = ops;
2972         chain->tmplt_priv = tmplt_priv;
2973         return 0;
2974 }
2975
2976 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
2977                                void *tmplt_priv)
2978 {
2979         /* If template ops are set, no work to do for us. */
2980         if (!tmplt_ops)
2981                 return;
2982
2983         tmplt_ops->tmplt_destroy(tmplt_priv);
2984         module_put(tmplt_ops->owner);
2985 }
2986
2987 /* Add/delete/get a chain */
2988
2989 static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
2990                         struct netlink_ext_ack *extack)
2991 {
2992         struct net *net = sock_net(skb->sk);
2993         struct nlattr *tca[TCA_MAX + 1];
2994         struct tcmsg *t;
2995         u32 parent;
2996         u32 chain_index;
2997         struct Qdisc *q;
2998         struct tcf_chain *chain;
2999         struct tcf_block *block;
3000         unsigned long cl;
3001         int err;
3002
3003 replay:
3004         q = NULL;
3005         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
3006                                      rtm_tca_policy, extack);
3007         if (err < 0)
3008                 return err;
3009
3010         t = nlmsg_data(n);
3011         parent = t->tcm_parent;
3012         cl = 0;
3013
3014         block = tcf_block_find(net, &q, &parent, &cl,
3015                                t->tcm_ifindex, t->tcm_block_index, extack);
3016         if (IS_ERR(block))
3017                 return PTR_ERR(block);
3018
3019         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
3020         if (chain_index > TC_ACT_EXT_VAL_MASK) {
3021                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
3022                 err = -EINVAL;
3023                 goto errout_block;
3024         }
3025
3026         mutex_lock(&block->lock);
3027         chain = tcf_chain_lookup(block, chain_index);
3028         if (n->nlmsg_type == RTM_NEWCHAIN) {
3029                 if (chain) {
3030                         if (tcf_chain_held_by_acts_only(chain)) {
3031                                 /* The chain exists only because there is
3032                                  * some action referencing it.
3033                                  */
3034                                 tcf_chain_hold(chain);
3035                         } else {
3036                                 NL_SET_ERR_MSG(extack, "Filter chain already exists");
3037                                 err = -EEXIST;
3038                                 goto errout_block_locked;
3039                         }
3040                 } else {
3041                         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
3042                                 NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
3043                                 err = -ENOENT;
3044                                 goto errout_block_locked;
3045                         }
3046                         chain = tcf_chain_create(block, chain_index);
3047                         if (!chain) {
3048                                 NL_SET_ERR_MSG(extack, "Failed to create filter chain");
3049                                 err = -ENOMEM;
3050                                 goto errout_block_locked;
3051                         }
3052                 }
3053         } else {
3054                 if (!chain || tcf_chain_held_by_acts_only(chain)) {
3055                         NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
3056                         err = -EINVAL;
3057                         goto errout_block_locked;
3058                 }
3059                 tcf_chain_hold(chain);
3060         }
3061
3062         if (n->nlmsg_type == RTM_NEWCHAIN) {
3063                 /* Modifying chain requires holding parent block lock. In case
3064                  * the chain was successfully added, take a reference to the
3065                  * chain. This ensures that an empty chain does not disappear at
3066                  * the end of this function.
3067                  */
3068                 tcf_chain_hold(chain);
3069                 chain->explicitly_created = true;
3070         }
3071         mutex_unlock(&block->lock);
3072
3073         switch (n->nlmsg_type) {
3074         case RTM_NEWCHAIN:
3075                 err = tc_chain_tmplt_add(chain, net, tca, extack);
3076                 if (err) {
3077                         tcf_chain_put_explicitly_created(chain);
3078                         goto errout;
3079                 }
3080
3081                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
3082                                 RTM_NEWCHAIN, false, extack);
3083                 break;
3084         case RTM_DELCHAIN:
3085                 tfilter_notify_chain(net, skb, block, q, parent, n,
3086                                      chain, RTM_DELTFILTER, extack);
3087                 /* Flush the chain first as the user requested chain removal. */
3088                 tcf_chain_flush(chain, true);
3089                 /* In case the chain was successfully deleted, put a reference
3090                  * to the chain previously taken during addition.
3091                  */
3092                 tcf_chain_put_explicitly_created(chain);
3093                 break;
3094         case RTM_GETCHAIN:
3095                 err = tc_chain_notify(chain, skb, n->nlmsg_seq,
3096                                       n->nlmsg_flags, n->nlmsg_type, true, extack);
3097                 if (err < 0)
3098                         NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
3099                 break;
3100         default:
3101                 err = -EOPNOTSUPP;
3102                 NL_SET_ERR_MSG(extack, "Unsupported message type");
3103                 goto errout;
3104         }
3105
3106 errout:
3107         tcf_chain_put(chain);
3108 errout_block:
3109         tcf_block_release(q, block, true);
3110         if (err == -EAGAIN)
3111                 /* Replay the request. */
3112                 goto replay;
3113         return err;
3114
3115 errout_block_locked:
3116         mutex_unlock(&block->lock);
3117         goto errout_block;
3118 }
3119
3120 /* called with RTNL */
3121 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
3122 {
3123         struct net *net = sock_net(skb->sk);
3124         struct nlattr *tca[TCA_MAX + 1];
3125         struct Qdisc *q = NULL;
3126         struct tcf_block *block;
3127         struct tcmsg *tcm = nlmsg_data(cb->nlh);
3128         struct tcf_chain *chain;
3129         long index_start;
3130         long index;
3131         int err;
3132
3133         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
3134                 return skb->len;
3135
3136         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
3137                                      rtm_tca_policy, cb->extack);
3138         if (err)
3139                 return err;
3140
3141         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
3142                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
3143                 if (!block)
3144                         goto out;
3145         } else {
3146                 const struct Qdisc_class_ops *cops;
3147                 struct net_device *dev;
3148                 unsigned long cl = 0;
3149
3150                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
3151                 if (!dev)
3152                         return skb->len;
3153
3154                 if (!tcm->tcm_parent)
3155                         q = rtnl_dereference(dev->qdisc);
3156                 else
3157                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
3158
3159                 if (!q)
3160                         goto out;
3161                 cops = q->ops->cl_ops;
3162                 if (!cops)
3163                         goto out;
3164                 if (!cops->tcf_block)
3165                         goto out;
3166                 if (TC_H_MIN(tcm->tcm_parent)) {
3167                         cl = cops->find(q, tcm->tcm_parent);
3168                         if (cl == 0)
3169                                 goto out;
3170                 }
3171                 block = cops->tcf_block(q, cl, NULL);
3172                 if (!block)
3173                         goto out;
3174                 if (tcf_block_shared(block))
3175                         q = NULL;
3176         }
3177
3178         index_start = cb->args[0];
3179         index = 0;
3180
3181         mutex_lock(&block->lock);
3182         list_for_each_entry(chain, &block->chain_list, list) {
3183                 if ((tca[TCA_CHAIN] &&
3184                      nla_get_u32(tca[TCA_CHAIN]) != chain->index))
3185                         continue;
3186                 if (index < index_start) {
3187                         index++;
3188                         continue;
3189                 }
3190                 if (tcf_chain_held_by_acts_only(chain))
3191                         continue;
3192                 err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
3193                                          chain->index, net, skb, block,
3194                                          NETLINK_CB(cb->skb).portid,
3195                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
3196                                          RTM_NEWCHAIN, NULL);
3197                 if (err <= 0)
3198                         break;
3199                 index++;
3200         }
3201         mutex_unlock(&block->lock);
3202
3203         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
3204                 tcf_block_refcnt_put(block, true);
3205         cb->args[0] = index;
3206
3207 out:
3208         /* If we did no progress, the error (EMSGSIZE) is real */
3209         if (skb->len == 0 && err)
3210                 return err;
3211         return skb->len;
3212 }
3213
3214 int tcf_exts_init_ex(struct tcf_exts *exts, struct net *net, int action,
3215                      int police, struct tcf_proto *tp, u32 handle,
3216                      bool use_action_miss)
3217 {
3218         int err = 0;
3219
3220 #ifdef CONFIG_NET_CLS_ACT
3221         exts->type = 0;
3222         exts->nr_actions = 0;
3223         exts->miss_cookie_node = NULL;
3224         /* Note: we do not own yet a reference on net.
3225          * This reference might be taken later from tcf_exts_get_net().
3226          */
3227         exts->net = net;
3228         exts->actions = kcalloc(TCA_ACT_MAX_PRIO, sizeof(struct tc_action *),
3229                                 GFP_KERNEL);
3230         if (!exts->actions)
3231                 return -ENOMEM;
3232 #endif
3233
3234         exts->action = action;
3235         exts->police = police;
3236
3237         if (!use_action_miss)
3238                 return 0;
3239
3240         err = tcf_exts_miss_cookie_base_alloc(exts, tp, handle);
3241         if (err)
3242                 goto err_miss_alloc;
3243
3244         return 0;
3245
3246 err_miss_alloc:
3247         tcf_exts_destroy(exts);
3248 #ifdef CONFIG_NET_CLS_ACT
3249         exts->actions = NULL;
3250 #endif
3251         return err;
3252 }
3253 EXPORT_SYMBOL(tcf_exts_init_ex);
3254
3255 void tcf_exts_destroy(struct tcf_exts *exts)
3256 {
3257         tcf_exts_miss_cookie_base_destroy(exts);
3258
3259 #ifdef CONFIG_NET_CLS_ACT
3260         if (exts->actions) {
3261                 tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
3262                 kfree(exts->actions);
3263         }
3264         exts->nr_actions = 0;
3265 #endif
3266 }
3267 EXPORT_SYMBOL(tcf_exts_destroy);
3268
3269 int tcf_exts_validate_ex(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3270                          struct nlattr *rate_tlv, struct tcf_exts *exts,
3271                          u32 flags, u32 fl_flags, struct netlink_ext_ack *extack)
3272 {
3273 #ifdef CONFIG_NET_CLS_ACT
3274         {
3275                 int init_res[TCA_ACT_MAX_PRIO] = {};
3276                 struct tc_action *act;
3277                 size_t attr_size = 0;
3278
3279                 if (exts->police && tb[exts->police]) {
3280                         struct tc_action_ops *a_o;
3281
3282                         a_o = tc_action_load_ops(tb[exts->police], true,
3283                                                  !(flags & TCA_ACT_FLAGS_NO_RTNL),
3284                                                  extack);
3285                         if (IS_ERR(a_o))
3286                                 return PTR_ERR(a_o);
3287                         flags |= TCA_ACT_FLAGS_POLICE | TCA_ACT_FLAGS_BIND;
3288                         act = tcf_action_init_1(net, tp, tb[exts->police],
3289                                                 rate_tlv, a_o, init_res, flags,
3290                                                 extack);
3291                         module_put(a_o->owner);
3292                         if (IS_ERR(act))
3293                                 return PTR_ERR(act);
3294
3295                         act->type = exts->type = TCA_OLD_COMPAT;
3296                         exts->actions[0] = act;
3297                         exts->nr_actions = 1;
3298                         tcf_idr_insert_many(exts->actions);
3299                 } else if (exts->action && tb[exts->action]) {
3300                         int err;
3301
3302                         flags |= TCA_ACT_FLAGS_BIND;
3303                         err = tcf_action_init(net, tp, tb[exts->action],
3304                                               rate_tlv, exts->actions, init_res,
3305                                               &attr_size, flags, fl_flags,
3306                                               extack);
3307                         if (err < 0)
3308                                 return err;
3309                         exts->nr_actions = err;
3310                 }
3311         }
3312 #else
3313         if ((exts->action && tb[exts->action]) ||
3314             (exts->police && tb[exts->police])) {
3315                 NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
3316                 return -EOPNOTSUPP;
3317         }
3318 #endif
3319
3320         return 0;
3321 }
3322 EXPORT_SYMBOL(tcf_exts_validate_ex);
3323
3324 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3325                       struct nlattr *rate_tlv, struct tcf_exts *exts,
3326                       u32 flags, struct netlink_ext_ack *extack)
3327 {
3328         return tcf_exts_validate_ex(net, tp, tb, rate_tlv, exts,
3329                                     flags, 0, extack);
3330 }
3331 EXPORT_SYMBOL(tcf_exts_validate);
3332
3333 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
3334 {
3335 #ifdef CONFIG_NET_CLS_ACT
3336         struct tcf_exts old = *dst;
3337
3338         *dst = *src;
3339         tcf_exts_destroy(&old);
3340 #endif
3341 }
3342 EXPORT_SYMBOL(tcf_exts_change);
3343
3344 #ifdef CONFIG_NET_CLS_ACT
3345 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
3346 {
3347         if (exts->nr_actions == 0)
3348                 return NULL;
3349         else
3350                 return exts->actions[0];
3351 }
3352 #endif
3353
3354 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
3355 {
3356 #ifdef CONFIG_NET_CLS_ACT
3357         struct nlattr *nest;
3358
3359         if (exts->action && tcf_exts_has_actions(exts)) {
3360                 /*
3361                  * again for backward compatible mode - we want
3362                  * to work with both old and new modes of entering
3363                  * tc data even if iproute2  was newer - jhs
3364                  */
3365                 if (exts->type != TCA_OLD_COMPAT) {
3366                         nest = nla_nest_start_noflag(skb, exts->action);
3367                         if (nest == NULL)
3368                                 goto nla_put_failure;
3369
3370                         if (tcf_action_dump(skb, exts->actions, 0, 0, false)
3371                             < 0)
3372                                 goto nla_put_failure;
3373                         nla_nest_end(skb, nest);
3374                 } else if (exts->police) {
3375                         struct tc_action *act = tcf_exts_first_act(exts);
3376                         nest = nla_nest_start_noflag(skb, exts->police);
3377                         if (nest == NULL || !act)
3378                                 goto nla_put_failure;
3379                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
3380                                 goto nla_put_failure;
3381                         nla_nest_end(skb, nest);
3382                 }
3383         }
3384         return 0;
3385
3386 nla_put_failure:
3387         nla_nest_cancel(skb, nest);
3388         return -1;
3389 #else
3390         return 0;
3391 #endif
3392 }
3393 EXPORT_SYMBOL(tcf_exts_dump);
3394
3395 int tcf_exts_terse_dump(struct sk_buff *skb, struct tcf_exts *exts)
3396 {
3397 #ifdef CONFIG_NET_CLS_ACT
3398         struct nlattr *nest;
3399
3400         if (!exts->action || !tcf_exts_has_actions(exts))
3401                 return 0;
3402
3403         nest = nla_nest_start_noflag(skb, exts->action);
3404         if (!nest)
3405                 goto nla_put_failure;
3406
3407         if (tcf_action_dump(skb, exts->actions, 0, 0, true) < 0)
3408                 goto nla_put_failure;
3409         nla_nest_end(skb, nest);
3410         return 0;
3411
3412 nla_put_failure:
3413         nla_nest_cancel(skb, nest);
3414         return -1;
3415 #else
3416         return 0;
3417 #endif
3418 }
3419 EXPORT_SYMBOL(tcf_exts_terse_dump);
3420
3421 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
3422 {
3423 #ifdef CONFIG_NET_CLS_ACT
3424         struct tc_action *a = tcf_exts_first_act(exts);
3425         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
3426                 return -1;
3427 #endif
3428         return 0;
3429 }
3430 EXPORT_SYMBOL(tcf_exts_dump_stats);
3431
3432 static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
3433 {
3434         if (*flags & TCA_CLS_FLAGS_IN_HW)
3435                 return;
3436         *flags |= TCA_CLS_FLAGS_IN_HW;
3437         atomic_inc(&block->offloadcnt);
3438 }
3439
3440 static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
3441 {
3442         if (!(*flags & TCA_CLS_FLAGS_IN_HW))
3443                 return;
3444         *flags &= ~TCA_CLS_FLAGS_IN_HW;
3445         atomic_dec(&block->offloadcnt);
3446 }
3447
3448 static void tc_cls_offload_cnt_update(struct tcf_block *block,
3449                                       struct tcf_proto *tp, u32 *cnt,
3450                                       u32 *flags, u32 diff, bool add)
3451 {
3452         lockdep_assert_held(&block->cb_lock);
3453
3454         spin_lock(&tp->lock);
3455         if (add) {
3456                 if (!*cnt)
3457                         tcf_block_offload_inc(block, flags);
3458                 *cnt += diff;
3459         } else {
3460                 *cnt -= diff;
3461                 if (!*cnt)
3462                         tcf_block_offload_dec(block, flags);
3463         }
3464         spin_unlock(&tp->lock);
3465 }
3466
3467 static void
3468 tc_cls_offload_cnt_reset(struct tcf_block *block, struct tcf_proto *tp,
3469                          u32 *cnt, u32 *flags)
3470 {
3471         lockdep_assert_held(&block->cb_lock);
3472
3473         spin_lock(&tp->lock);
3474         tcf_block_offload_dec(block, flags);
3475         *cnt = 0;
3476         spin_unlock(&tp->lock);
3477 }
3478
3479 static int
3480 __tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3481                    void *type_data, bool err_stop)
3482 {
3483         struct flow_block_cb *block_cb;
3484         int ok_count = 0;
3485         int err;
3486
3487         list_for_each_entry(block_cb, &block->flow_block.cb_list, list) {
3488                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
3489                 if (err) {
3490                         if (err_stop)
3491                                 return err;
3492                 } else {
3493                         ok_count++;
3494                 }
3495         }
3496         return ok_count;
3497 }
3498
3499 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3500                      void *type_data, bool err_stop, bool rtnl_held)
3501 {
3502         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3503         int ok_count;
3504
3505 retry:
3506         if (take_rtnl)
3507                 rtnl_lock();
3508         down_read(&block->cb_lock);
3509         /* Need to obtain rtnl lock if block is bound to devs that require it.
3510          * In block bind code cb_lock is obtained while holding rtnl, so we must
3511          * obtain the locks in same order here.
3512          */
3513         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3514                 up_read(&block->cb_lock);
3515                 take_rtnl = true;
3516                 goto retry;
3517         }
3518
3519         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3520
3521         up_read(&block->cb_lock);
3522         if (take_rtnl)
3523                 rtnl_unlock();
3524         return ok_count;
3525 }
3526 EXPORT_SYMBOL(tc_setup_cb_call);
3527
3528 /* Non-destructive filter add. If filter that wasn't already in hardware is
3529  * successfully offloaded, increment block offloads counter. On failure,
3530  * previously offloaded filter is considered to be intact and offloads counter
3531  * is not decremented.
3532  */
3533
3534 int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
3535                     enum tc_setup_type type, void *type_data, bool err_stop,
3536                     u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3537 {
3538         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3539         int ok_count;
3540
3541 retry:
3542         if (take_rtnl)
3543                 rtnl_lock();
3544         down_read(&block->cb_lock);
3545         /* Need to obtain rtnl lock if block is bound to devs that require it.
3546          * In block bind code cb_lock is obtained while holding rtnl, so we must
3547          * obtain the locks in same order here.
3548          */
3549         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3550                 up_read(&block->cb_lock);
3551                 take_rtnl = true;
3552                 goto retry;
3553         }
3554
3555         /* Make sure all netdevs sharing this block are offload-capable. */
3556         if (block->nooffloaddevcnt && err_stop) {
3557                 ok_count = -EOPNOTSUPP;
3558                 goto err_unlock;
3559         }
3560
3561         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3562         if (ok_count < 0)
3563                 goto err_unlock;
3564
3565         if (tp->ops->hw_add)
3566                 tp->ops->hw_add(tp, type_data);
3567         if (ok_count > 0)
3568                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
3569                                           ok_count, true);
3570 err_unlock:
3571         up_read(&block->cb_lock);
3572         if (take_rtnl)
3573                 rtnl_unlock();
3574         return min(ok_count, 0);
3575 }
3576 EXPORT_SYMBOL(tc_setup_cb_add);
3577
3578 /* Destructive filter replace. If filter that wasn't already in hardware is
3579  * successfully offloaded, increment block offload counter. On failure,
3580  * previously offloaded filter is considered to be destroyed and offload counter
3581  * is decremented.
3582  */
3583
3584 int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
3585                         enum tc_setup_type type, void *type_data, bool err_stop,
3586                         u32 *old_flags, unsigned int *old_in_hw_count,
3587                         u32 *new_flags, unsigned int *new_in_hw_count,
3588                         bool rtnl_held)
3589 {
3590         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3591         int ok_count;
3592
3593 retry:
3594         if (take_rtnl)
3595                 rtnl_lock();
3596         down_read(&block->cb_lock);
3597         /* Need to obtain rtnl lock if block is bound to devs that require it.
3598          * In block bind code cb_lock is obtained while holding rtnl, so we must
3599          * obtain the locks in same order here.
3600          */
3601         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3602                 up_read(&block->cb_lock);
3603                 take_rtnl = true;
3604                 goto retry;
3605         }
3606
3607         /* Make sure all netdevs sharing this block are offload-capable. */
3608         if (block->nooffloaddevcnt && err_stop) {
3609                 ok_count = -EOPNOTSUPP;
3610                 goto err_unlock;
3611         }
3612
3613         tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
3614         if (tp->ops->hw_del)
3615                 tp->ops->hw_del(tp, type_data);
3616
3617         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3618         if (ok_count < 0)
3619                 goto err_unlock;
3620
3621         if (tp->ops->hw_add)
3622                 tp->ops->hw_add(tp, type_data);
3623         if (ok_count > 0)
3624                 tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
3625                                           new_flags, ok_count, true);
3626 err_unlock:
3627         up_read(&block->cb_lock);
3628         if (take_rtnl)
3629                 rtnl_unlock();
3630         return min(ok_count, 0);
3631 }
3632 EXPORT_SYMBOL(tc_setup_cb_replace);
3633
3634 /* Destroy filter and decrement block offload counter, if filter was previously
3635  * offloaded.
3636  */
3637
3638 int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
3639                         enum tc_setup_type type, void *type_data, bool err_stop,
3640                         u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3641 {
3642         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3643         int ok_count;
3644
3645 retry:
3646         if (take_rtnl)
3647                 rtnl_lock();
3648         down_read(&block->cb_lock);
3649         /* Need to obtain rtnl lock if block is bound to devs that require it.
3650          * In block bind code cb_lock is obtained while holding rtnl, so we must
3651          * obtain the locks in same order here.
3652          */
3653         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3654                 up_read(&block->cb_lock);
3655                 take_rtnl = true;
3656                 goto retry;
3657         }
3658
3659         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3660
3661         tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
3662         if (tp->ops->hw_del)
3663                 tp->ops->hw_del(tp, type_data);
3664
3665         up_read(&block->cb_lock);
3666         if (take_rtnl)
3667                 rtnl_unlock();
3668         return min(ok_count, 0);
3669 }
3670 EXPORT_SYMBOL(tc_setup_cb_destroy);
3671
3672 int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
3673                           bool add, flow_setup_cb_t *cb,
3674                           enum tc_setup_type type, void *type_data,
3675                           void *cb_priv, u32 *flags, unsigned int *in_hw_count)
3676 {
3677         int err = cb(type, type_data, cb_priv);
3678
3679         if (err) {
3680                 if (add && tc_skip_sw(*flags))
3681                         return err;
3682         } else {
3683                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags, 1,
3684                                           add);
3685         }
3686
3687         return 0;
3688 }
3689 EXPORT_SYMBOL(tc_setup_cb_reoffload);
3690
3691 static int tcf_act_get_user_cookie(struct flow_action_entry *entry,
3692                                    const struct tc_action *act)
3693 {
3694         struct tc_cookie *user_cookie;
3695         int err = 0;
3696
3697         rcu_read_lock();
3698         user_cookie = rcu_dereference(act->user_cookie);
3699         if (user_cookie) {
3700                 entry->user_cookie = flow_action_cookie_create(user_cookie->data,
3701                                                                user_cookie->len,
3702                                                                GFP_ATOMIC);
3703                 if (!entry->user_cookie)
3704                         err = -ENOMEM;
3705         }
3706         rcu_read_unlock();
3707         return err;
3708 }
3709
3710 static void tcf_act_put_user_cookie(struct flow_action_entry *entry)
3711 {
3712         flow_action_cookie_destroy(entry->user_cookie);
3713 }
3714
3715 void tc_cleanup_offload_action(struct flow_action *flow_action)
3716 {
3717         struct flow_action_entry *entry;
3718         int i;
3719
3720         flow_action_for_each(i, entry, flow_action) {
3721                 tcf_act_put_user_cookie(entry);
3722                 if (entry->destructor)
3723                         entry->destructor(entry->destructor_priv);
3724         }
3725 }
3726 EXPORT_SYMBOL(tc_cleanup_offload_action);
3727
3728 static int tc_setup_offload_act(struct tc_action *act,
3729                                 struct flow_action_entry *entry,
3730                                 u32 *index_inc,
3731                                 struct netlink_ext_ack *extack)
3732 {
3733 #ifdef CONFIG_NET_CLS_ACT
3734         if (act->ops->offload_act_setup) {
3735                 return act->ops->offload_act_setup(act, entry, index_inc, true,
3736                                                    extack);
3737         } else {
3738                 NL_SET_ERR_MSG(extack, "Action does not support offload");
3739                 return -EOPNOTSUPP;
3740         }
3741 #else
3742         return 0;
3743 #endif
3744 }
3745
3746 int tc_setup_action(struct flow_action *flow_action,
3747                     struct tc_action *actions[],
3748                     u32 miss_cookie_base,
3749                     struct netlink_ext_ack *extack)
3750 {
3751         int i, j, k, index, err = 0;
3752         struct tc_action *act;
3753
3754         BUILD_BUG_ON(TCA_ACT_HW_STATS_ANY != FLOW_ACTION_HW_STATS_ANY);
3755         BUILD_BUG_ON(TCA_ACT_HW_STATS_IMMEDIATE != FLOW_ACTION_HW_STATS_IMMEDIATE);
3756         BUILD_BUG_ON(TCA_ACT_HW_STATS_DELAYED != FLOW_ACTION_HW_STATS_DELAYED);
3757
3758         if (!actions)
3759                 return 0;
3760
3761         j = 0;
3762         tcf_act_for_each_action(i, act, actions) {
3763                 struct flow_action_entry *entry;
3764
3765                 entry = &flow_action->entries[j];
3766                 spin_lock_bh(&act->tcfa_lock);
3767                 err = tcf_act_get_user_cookie(entry, act);
3768                 if (err)
3769                         goto err_out_locked;
3770
3771                 index = 0;
3772                 err = tc_setup_offload_act(act, entry, &index, extack);
3773                 if (err)
3774                         goto err_out_locked;
3775
3776                 for (k = 0; k < index ; k++) {
3777                         entry[k].hw_stats = tc_act_hw_stats(act->hw_stats);
3778                         entry[k].hw_index = act->tcfa_index;
3779                         entry[k].cookie = (unsigned long)act;
3780                         entry[k].miss_cookie =
3781                                 tcf_exts_miss_cookie_get(miss_cookie_base, i);
3782                 }
3783
3784                 j += index;
3785
3786                 spin_unlock_bh(&act->tcfa_lock);
3787         }
3788
3789 err_out:
3790         if (err)
3791                 tc_cleanup_offload_action(flow_action);
3792
3793         return err;
3794 err_out_locked:
3795         spin_unlock_bh(&act->tcfa_lock);
3796         goto err_out;
3797 }
3798
3799 int tc_setup_offload_action(struct flow_action *flow_action,
3800                             const struct tcf_exts *exts,
3801                             struct netlink_ext_ack *extack)
3802 {
3803 #ifdef CONFIG_NET_CLS_ACT
3804         u32 miss_cookie_base;
3805
3806         if (!exts)
3807                 return 0;
3808
3809         miss_cookie_base = exts->miss_cookie_node ?
3810                            exts->miss_cookie_node->miss_cookie_base : 0;
3811         return tc_setup_action(flow_action, exts->actions, miss_cookie_base,
3812                                extack);
3813 #else
3814         return 0;
3815 #endif
3816 }
3817 EXPORT_SYMBOL(tc_setup_offload_action);
3818
3819 unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
3820 {
3821         unsigned int num_acts = 0;
3822         struct tc_action *act;
3823         int i;
3824
3825         tcf_exts_for_each_action(i, act, exts) {
3826                 if (is_tcf_pedit(act))
3827                         num_acts += tcf_pedit_nkeys(act);
3828                 else
3829                         num_acts++;
3830         }
3831         return num_acts;
3832 }
3833 EXPORT_SYMBOL(tcf_exts_num_actions);
3834
3835 #ifdef CONFIG_NET_CLS_ACT
3836 static int tcf_qevent_parse_block_index(struct nlattr *block_index_attr,
3837                                         u32 *p_block_index,
3838                                         struct netlink_ext_ack *extack)
3839 {
3840         *p_block_index = nla_get_u32(block_index_attr);
3841         if (!*p_block_index) {
3842                 NL_SET_ERR_MSG(extack, "Block number may not be zero");
3843                 return -EINVAL;
3844         }
3845
3846         return 0;
3847 }
3848
3849 int tcf_qevent_init(struct tcf_qevent *qe, struct Qdisc *sch,
3850                     enum flow_block_binder_type binder_type,
3851                     struct nlattr *block_index_attr,
3852                     struct netlink_ext_ack *extack)
3853 {
3854         u32 block_index;
3855         int err;
3856
3857         if (!block_index_attr)
3858                 return 0;
3859
3860         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3861         if (err)
3862                 return err;
3863
3864         qe->info.binder_type = binder_type;
3865         qe->info.chain_head_change = tcf_chain_head_change_dflt;
3866         qe->info.chain_head_change_priv = &qe->filter_chain;
3867         qe->info.block_index = block_index;
3868
3869         return tcf_block_get_ext(&qe->block, sch, &qe->info, extack);
3870 }
3871 EXPORT_SYMBOL(tcf_qevent_init);
3872
3873 void tcf_qevent_destroy(struct tcf_qevent *qe, struct Qdisc *sch)
3874 {
3875         if (qe->info.block_index)
3876                 tcf_block_put_ext(qe->block, sch, &qe->info);
3877 }
3878 EXPORT_SYMBOL(tcf_qevent_destroy);
3879
3880 int tcf_qevent_validate_change(struct tcf_qevent *qe, struct nlattr *block_index_attr,
3881                                struct netlink_ext_ack *extack)
3882 {
3883         u32 block_index;
3884         int err;
3885
3886         if (!block_index_attr)
3887                 return 0;
3888
3889         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3890         if (err)
3891                 return err;
3892
3893         /* Bounce newly-configured block or change in block. */
3894         if (block_index != qe->info.block_index) {
3895                 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
3896                 return -EINVAL;
3897         }
3898
3899         return 0;
3900 }
3901 EXPORT_SYMBOL(tcf_qevent_validate_change);
3902
3903 struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
3904                                   struct sk_buff **to_free, int *ret)
3905 {
3906         struct tcf_result cl_res;
3907         struct tcf_proto *fl;
3908
3909         if (!qe->info.block_index)
3910                 return skb;
3911
3912         fl = rcu_dereference_bh(qe->filter_chain);
3913
3914         switch (tcf_classify(skb, NULL, fl, &cl_res, false)) {
3915         case TC_ACT_SHOT:
3916                 qdisc_qstats_drop(sch);
3917                 __qdisc_drop(skb, to_free);
3918                 *ret = __NET_XMIT_BYPASS;
3919                 return NULL;
3920         case TC_ACT_STOLEN:
3921         case TC_ACT_QUEUED:
3922         case TC_ACT_TRAP:
3923                 __qdisc_drop(skb, to_free);
3924                 *ret = __NET_XMIT_STOLEN;
3925                 return NULL;
3926         case TC_ACT_REDIRECT:
3927                 skb_do_redirect(skb);
3928                 *ret = __NET_XMIT_STOLEN;
3929                 return NULL;
3930         }
3931
3932         return skb;
3933 }
3934 EXPORT_SYMBOL(tcf_qevent_handle);
3935
3936 int tcf_qevent_dump(struct sk_buff *skb, int attr_name, struct tcf_qevent *qe)
3937 {
3938         if (!qe->info.block_index)
3939                 return 0;
3940         return nla_put_u32(skb, attr_name, qe->info.block_index);
3941 }
3942 EXPORT_SYMBOL(tcf_qevent_dump);
3943 #endif
3944
3945 static __net_init int tcf_net_init(struct net *net)
3946 {
3947         struct tcf_net *tn = net_generic(net, tcf_net_id);
3948
3949         spin_lock_init(&tn->idr_lock);
3950         idr_init(&tn->idr);
3951         return 0;
3952 }
3953
3954 static void __net_exit tcf_net_exit(struct net *net)
3955 {
3956         struct tcf_net *tn = net_generic(net, tcf_net_id);
3957
3958         idr_destroy(&tn->idr);
3959 }
3960
3961 static struct pernet_operations tcf_net_ops = {
3962         .init = tcf_net_init,
3963         .exit = tcf_net_exit,
3964         .id   = &tcf_net_id,
3965         .size = sizeof(struct tcf_net),
3966 };
3967
3968 static int __init tc_filter_init(void)
3969 {
3970         int err;
3971
3972         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
3973         if (!tc_filter_wq)
3974                 return -ENOMEM;
3975
3976         err = register_pernet_subsys(&tcf_net_ops);
3977         if (err)
3978                 goto err_register_pernet_subsys;
3979
3980         xa_init_flags(&tcf_exts_miss_cookies_xa, XA_FLAGS_ALLOC1);
3981
3982         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
3983                       RTNL_FLAG_DOIT_UNLOCKED);
3984         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
3985                       RTNL_FLAG_DOIT_UNLOCKED);
3986         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
3987                       tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
3988         rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
3989         rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
3990         rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
3991                       tc_dump_chain, 0);
3992
3993         return 0;
3994
3995 err_register_pernet_subsys:
3996         destroy_workqueue(tc_filter_wq);
3997         return err;
3998 }
3999
4000 subsys_initcall(tc_filter_init);