net/sched/cls_api.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/cls_api.c  Packet classifier API.
   4  *
   5  * Authors:     Alexey Kuznetsov, <[email protected]>
   6  *
   7  * Changes:
   8  *
   9  * Eduardo J. Blanco <[email protected]> :990222: kmod support
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/kernel.h>
  15 #include <linux/string.h>
  16 #include <linux/errno.h>
  17 #include <linux/err.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/init.h>
  20 #include <linux/kmod.h>
  21 #include <linux/slab.h>
  22 #include <linux/idr.h>
  23 #include <linux/jhash.h>
  24 #include <linux/rculist.h>
  25 #include <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(NET_CLS_ALIAS_PREFIX "%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_maintain_bypass(struct tcf_block *block)
 414 {
 415         int filtercnt = atomic_read(&block->filtercnt);
 416         int skipswcnt = atomic_read(&block->skipswcnt);
 417         bool bypass_wanted = filtercnt > 0 && filtercnt == skipswcnt;
 418
 419         if (bypass_wanted != block->bypass_wanted) {
 420 #ifdef CONFIG_NET_CLS_ACT
 421                 if (bypass_wanted)
 422                         static_branch_inc(&tcf_bypass_check_needed_key);
 423                 else
 424                         static_branch_dec(&tcf_bypass_check_needed_key);
 425 #endif
 426                 block->bypass_wanted = bypass_wanted;
 427         }
 428 }
 429
 430 static void tcf_block_filter_cnt_update(struct tcf_block *block, bool *counted, bool add)
 431 {
 432         lockdep_assert_not_held(&block->cb_lock);
 433
 434         down_write(&block->cb_lock);
 435         if (*counted != add) {
 436                 if (add) {
 437                         atomic_inc(&block->filtercnt);
 438                         *counted = true;
 439                 } else {
 440                         atomic_dec(&block->filtercnt);
 441                         *counted = false;
 442                 }
 443         }
 444         tcf_maintain_bypass(block);
 445         up_write(&block->cb_lock);
 446 }
 447
 448 static void tcf_chain_put(struct tcf_chain *chain);
 449
 450 static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
 451                               bool sig_destroy, struct netlink_ext_ack *extack)
 452 {
 453         tp->ops->destroy(tp, rtnl_held, extack);
 454         tcf_block_filter_cnt_update(tp->chain->block, &tp->counted, false);
 455         if (sig_destroy)
 456                 tcf_proto_signal_destroyed(tp->chain, tp);
 457         tcf_chain_put(tp->chain);
 458         module_put(tp->ops->owner);
 459         kfree_rcu(tp, rcu);
 460 }
 461
 462 static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
 463                           struct netlink_ext_ack *extack)
 464 {
 465         if (refcount_dec_and_test(&tp->refcnt))
 466                 tcf_proto_destroy(tp, rtnl_held, true, extack);
 467 }
 468
 469 static bool tcf_proto_check_delete(struct tcf_proto *tp)
 470 {
 471         if (tp->ops->delete_empty)
 472                 return tp->ops->delete_empty(tp);
 473
 474         tp->deleting = true;
 475         return tp->deleting;
 476 }
 477
 478 static void tcf_proto_mark_delete(struct tcf_proto *tp)
 479 {
 480         spin_lock(&tp->lock);
 481         tp->deleting = true;
 482         spin_unlock(&tp->lock);
 483 }
 484
 485 static bool tcf_proto_is_deleting(struct tcf_proto *tp)
 486 {
 487         bool deleting;
 488
 489         spin_lock(&tp->lock);
 490         deleting = tp->deleting;
 491         spin_unlock(&tp->lock);
 492
 493         return deleting;
 494 }
 495
 496 #define ASSERT_BLOCK_LOCKED(block)                                      \
 497         lockdep_assert_held(&(block)->lock)
 498
 499 struct tcf_filter_chain_list_item {
 500         struct list_head list;
 501         tcf_chain_head_change_t *chain_head_change;
 502         void *chain_head_change_priv;
 503 };
 504
 505 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 506                                           u32 chain_index)
 507 {
 508         struct tcf_chain *chain;
 509
 510         ASSERT_BLOCK_LOCKED(block);
 511
 512         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 513         if (!chain)
 514                 return NULL;
 515         list_add_tail_rcu(&chain->list, &block->chain_list);
 516         mutex_init(&chain->filter_chain_lock);
 517         chain->block = block;
 518         chain->index = chain_index;
 519         chain->refcnt = 1;
 520         if (!chain->index)
 521                 block->chain0.chain = chain;
 522         return chain;
 523 }
 524
 525 static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
 526                                        struct tcf_proto *tp_head)
 527 {
 528         if (item->chain_head_change)
 529                 item->chain_head_change(tp_head, item->chain_head_change_priv);
 530 }
 531
 532 static void tcf_chain0_head_change(struct tcf_chain *chain,
 533                                    struct tcf_proto *tp_head)
 534 {
 535         struct tcf_filter_chain_list_item *item;
 536         struct tcf_block *block = chain->block;
 537
 538         if (chain->index)
 539                 return;
 540
 541         mutex_lock(&block->lock);
 542         list_for_each_entry(item, &block->chain0.filter_chain_list, list)
 543                 tcf_chain_head_change_item(item, tp_head);
 544         mutex_unlock(&block->lock);
 545 }
 546
 547 /* Returns true if block can be safely freed. */
 548
 549 static bool tcf_chain_detach(struct tcf_chain *chain)
 550 {
 551         struct tcf_block *block = chain->block;
 552
 553         ASSERT_BLOCK_LOCKED(block);
 554
 555         list_del_rcu(&chain->list);
 556         if (!chain->index)
 557                 block->chain0.chain = NULL;
 558
 559         if (list_empty(&block->chain_list) &&
 560             refcount_read(&block->refcnt) == 0)
 561                 return true;
 562
 563         return false;
 564 }
 565
 566 static void tcf_block_destroy(struct tcf_block *block)
 567 {
 568         mutex_destroy(&block->lock);
 569         mutex_destroy(&block->proto_destroy_lock);
 570         xa_destroy(&block->ports);
 571         kfree_rcu(block, rcu);
 572 }
 573
 574 static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
 575 {
 576         struct tcf_block *block = chain->block;
 577
 578         mutex_destroy(&chain->filter_chain_lock);
 579         kfree_rcu(chain, rcu);
 580         if (free_block)
 581                 tcf_block_destroy(block);
 582 }
 583
 584 static void tcf_chain_hold(struct tcf_chain *chain)
 585 {
 586         ASSERT_BLOCK_LOCKED(chain->block);
 587
 588         ++chain->refcnt;
 589 }
 590
 591 static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain)
 592 {
 593         ASSERT_BLOCK_LOCKED(chain->block);
 594
 595         /* In case all the references are action references, this
 596          * chain should not be shown to the user.
 597          */
 598         return chain->refcnt == chain->action_refcnt;
 599 }
 600
 601 static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
 602                                           u32 chain_index)
 603 {
 604         struct tcf_chain *chain;
 605
 606         ASSERT_BLOCK_LOCKED(block);
 607
 608         list_for_each_entry(chain, &block->chain_list, list) {
 609                 if (chain->index == chain_index)
 610                         return chain;
 611         }
 612         return NULL;
 613 }
 614
 615 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 616 static struct tcf_chain *tcf_chain_lookup_rcu(const struct tcf_block *block,
 617                                               u32 chain_index)
 618 {
 619         struct tcf_chain *chain;
 620
 621         list_for_each_entry_rcu(chain, &block->chain_list, list) {
 622                 if (chain->index == chain_index)
 623                         return chain;
 624         }
 625         return NULL;
 626 }
 627 #endif
 628
 629 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 630                            u32 seq, u16 flags, int event, bool unicast,
 631                            struct netlink_ext_ack *extack);
 632
 633 static struct tcf_chain *__tcf_chain_get(struct tcf_block *block,
 634                                          u32 chain_index, bool create,
 635                                          bool by_act)
 636 {
 637         struct tcf_chain *chain = NULL;
 638         bool is_first_reference;
 639
 640         mutex_lock(&block->lock);
 641         chain = tcf_chain_lookup(block, chain_index);
 642         if (chain) {
 643                 tcf_chain_hold(chain);
 644         } else {
 645                 if (!create)
 646                         goto errout;
 647                 chain = tcf_chain_create(block, chain_index);
 648                 if (!chain)
 649                         goto errout;
 650         }
 651
 652         if (by_act)
 653                 ++chain->action_refcnt;
 654         is_first_reference = chain->refcnt - chain->action_refcnt == 1;
 655         mutex_unlock(&block->lock);
 656
 657         /* Send notification only in case we got the first
 658          * non-action reference. Until then, the chain acts only as
 659          * a placeholder for actions pointing to it and user ought
 660          * not know about them.
 661          */
 662         if (is_first_reference && !by_act)
 663                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
 664                                 RTM_NEWCHAIN, false, NULL);
 665
 666         return chain;
 667
 668 errout:
 669         mutex_unlock(&block->lock);
 670         return chain;
 671 }
 672
 673 static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 674                                        bool create)
 675 {
 676         return __tcf_chain_get(block, chain_index, create, false);
 677 }
 678
 679 struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index)
 680 {
 681         return __tcf_chain_get(block, chain_index, true, true);
 682 }
 683 EXPORT_SYMBOL(tcf_chain_get_by_act);
 684
 685 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
 686                                void *tmplt_priv);
 687 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
 688                                   void *tmplt_priv, u32 chain_index,
 689                                   struct tcf_block *block, struct sk_buff *oskb,
 690                                   u32 seq, u16 flags);
 691
 692 static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
 693                             bool explicitly_created)
 694 {
 695         struct tcf_block *block = chain->block;
 696         const struct tcf_proto_ops *tmplt_ops;
 697         unsigned int refcnt, non_act_refcnt;
 698         bool free_block = false;
 699         void *tmplt_priv;
 700
 701         mutex_lock(&block->lock);
 702         if (explicitly_created) {
 703                 if (!chain->explicitly_created) {
 704                         mutex_unlock(&block->lock);
 705                         return;
 706                 }
 707                 chain->explicitly_created = false;
 708         }
 709
 710         if (by_act)
 711                 chain->action_refcnt--;
 712
 713         /* tc_chain_notify_delete can't be called while holding block lock.
 714          * However, when block is unlocked chain can be changed concurrently, so
 715          * save these to temporary variables.
 716          */
 717         refcnt = --chain->refcnt;
 718         non_act_refcnt = refcnt - chain->action_refcnt;
 719         tmplt_ops = chain->tmplt_ops;
 720         tmplt_priv = chain->tmplt_priv;
 721
 722         if (non_act_refcnt == chain->explicitly_created && !by_act) {
 723                 if (non_act_refcnt == 0)
 724                         tc_chain_notify_delete(tmplt_ops, tmplt_priv,
 725                                                chain->index, block, NULL, 0, 0);
 726                 /* Last reference to chain, no need to lock. */
 727                 chain->flushing = false;
 728         }
 729
 730         if (refcnt == 0)
 731                 free_block = tcf_chain_detach(chain);
 732         mutex_unlock(&block->lock);
 733
 734         if (refcnt == 0) {
 735                 tc_chain_tmplt_del(tmplt_ops, tmplt_priv);
 736                 tcf_chain_destroy(chain, free_block);
 737         }
 738 }
 739
 740 static void tcf_chain_put(struct tcf_chain *chain)
 741 {
 742         __tcf_chain_put(chain, false, false);
 743 }
 744
 745 void tcf_chain_put_by_act(struct tcf_chain *chain)
 746 {
 747         __tcf_chain_put(chain, true, false);
 748 }
 749 EXPORT_SYMBOL(tcf_chain_put_by_act);
 750
 751 static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 752 {
 753         __tcf_chain_put(chain, false, true);
 754 }
 755
 756 static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
 757 {
 758         struct tcf_proto *tp, *tp_next;
 759
 760         mutex_lock(&chain->filter_chain_lock);
 761         tp = tcf_chain_dereference(chain->filter_chain, chain);
 762         while (tp) {
 763                 tp_next = rcu_dereference_protected(tp->next, 1);
 764                 tcf_proto_signal_destroying(chain, tp);
 765                 tp = tp_next;
 766         }
 767         tp = tcf_chain_dereference(chain->filter_chain, chain);
 768         RCU_INIT_POINTER(chain->filter_chain, NULL);
 769         tcf_chain0_head_change(chain, NULL);
 770         chain->flushing = true;
 771         mutex_unlock(&chain->filter_chain_lock);
 772
 773         while (tp) {
 774                 tp_next = rcu_dereference_protected(tp->next, 1);
 775                 tcf_proto_put(tp, rtnl_held, NULL);
 776                 tp = tp_next;
 777         }
 778 }
 779
 780 static int tcf_block_setup(struct tcf_block *block,
 781                            struct flow_block_offload *bo);
 782
 783 static void tcf_block_offload_init(struct flow_block_offload *bo,
 784                                    struct net_device *dev, struct Qdisc *sch,
 785                                    enum flow_block_command command,
 786                                    enum flow_block_binder_type binder_type,
 787                                    struct flow_block *flow_block,
 788                                    bool shared, struct netlink_ext_ack *extack)
 789 {
 790         bo->net = dev_net(dev);
 791         bo->command = command;
 792         bo->binder_type = binder_type;
 793         bo->block = flow_block;
 794         bo->block_shared = shared;
 795         bo->extack = extack;
 796         bo->sch = sch;
 797         bo->cb_list_head = &flow_block->cb_list;
 798         INIT_LIST_HEAD(&bo->cb_list);
 799 }
 800
 801 static void tcf_block_unbind(struct tcf_block *block,
 802                              struct flow_block_offload *bo);
 803
 804 static void tc_block_indr_cleanup(struct flow_block_cb *block_cb)
 805 {
 806         struct tcf_block *block = block_cb->indr.data;
 807         struct net_device *dev = block_cb->indr.dev;
 808         struct Qdisc *sch = block_cb->indr.sch;
 809         struct netlink_ext_ack extack = {};
 810         struct flow_block_offload bo = {};
 811
 812         tcf_block_offload_init(&bo, dev, sch, FLOW_BLOCK_UNBIND,
 813                                block_cb->indr.binder_type,
 814                                &block->flow_block, tcf_block_shared(block),
 815                                &extack);
 816         rtnl_lock();
 817         down_write(&block->cb_lock);
 818         list_del(&block_cb->driver_list);
 819         list_move(&block_cb->list, &bo.cb_list);
 820         tcf_block_unbind(block, &bo);
 821         up_write(&block->cb_lock);
 822         rtnl_unlock();
 823 }
 824
 825 static bool tcf_block_offload_in_use(struct tcf_block *block)
 826 {
 827         return atomic_read(&block->offloadcnt);
 828 }
 829
 830 static int tcf_block_offload_cmd(struct tcf_block *block,
 831                                  struct net_device *dev, struct Qdisc *sch,
 832                                  struct tcf_block_ext_info *ei,
 833                                  enum flow_block_command command,
 834                                  struct netlink_ext_ack *extack)
 835 {
 836         struct flow_block_offload bo = {};
 837
 838         tcf_block_offload_init(&bo, dev, sch, command, ei->binder_type,
 839                                &block->flow_block, tcf_block_shared(block),
 840                                extack);
 841
 842         if (dev->netdev_ops->ndo_setup_tc) {
 843                 int err;
 844
 845                 err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 846                 if (err < 0) {
 847                         if (err != -EOPNOTSUPP)
 848                                 NL_SET_ERR_MSG(extack, "Driver ndo_setup_tc failed");
 849                         return err;
 850                 }
 851
 852                 return tcf_block_setup(block, &bo);
 853         }
 854
 855         flow_indr_dev_setup_offload(dev, sch, TC_SETUP_BLOCK, block, &bo,
 856                                     tc_block_indr_cleanup);
 857         tcf_block_setup(block, &bo);
 858
 859         return -EOPNOTSUPP;
 860 }
 861
 862 static int tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
 863                                   struct tcf_block_ext_info *ei,
 864                                   struct netlink_ext_ack *extack)
 865 {
 866         struct net_device *dev = q->dev_queue->dev;
 867         int err;
 868
 869         down_write(&block->cb_lock);
 870
 871         /* If tc offload feature is disabled and the block we try to bind
 872          * to already has some offloaded filters, forbid to bind.
 873          */
 874         if (dev->netdev_ops->ndo_setup_tc &&
 875             !tc_can_offload(dev) &&
 876             tcf_block_offload_in_use(block)) {
 877                 NL_SET_ERR_MSG(extack, "Bind to offloaded block failed as dev has offload disabled");
 878                 err = -EOPNOTSUPP;
 879                 goto err_unlock;
 880         }
 881
 882         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_BIND, extack);
 883         if (err == -EOPNOTSUPP)
 884                 goto no_offload_dev_inc;
 885         if (err)
 886                 goto err_unlock;
 887
 888         up_write(&block->cb_lock);
 889         return 0;
 890
 891 no_offload_dev_inc:
 892         if (tcf_block_offload_in_use(block))
 893                 goto err_unlock;
 894
 895         err = 0;
 896         block->nooffloaddevcnt++;
 897 err_unlock:
 898         up_write(&block->cb_lock);
 899         return err;
 900 }
 901
 902 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
 903                                      struct tcf_block_ext_info *ei)
 904 {
 905         struct net_device *dev = q->dev_queue->dev;
 906         int err;
 907
 908         down_write(&block->cb_lock);
 909         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_UNBIND, NULL);
 910         if (err == -EOPNOTSUPP)
 911                 goto no_offload_dev_dec;
 912         up_write(&block->cb_lock);
 913         return;
 914
 915 no_offload_dev_dec:
 916         WARN_ON(block->nooffloaddevcnt-- == 0);
 917         up_write(&block->cb_lock);
 918 }
 919
 920 static int
 921 tcf_chain0_head_change_cb_add(struct tcf_block *block,
 922                               struct tcf_block_ext_info *ei,
 923                               struct netlink_ext_ack *extack)
 924 {
 925         struct tcf_filter_chain_list_item *item;
 926         struct tcf_chain *chain0;
 927
 928         item = kmalloc(sizeof(*item), GFP_KERNEL);
 929         if (!item) {
 930                 NL_SET_ERR_MSG(extack, "Memory allocation for head change callback item failed");
 931                 return -ENOMEM;
 932         }
 933         item->chain_head_change = ei->chain_head_change;
 934         item->chain_head_change_priv = ei->chain_head_change_priv;
 935
 936         mutex_lock(&block->lock);
 937         chain0 = block->chain0.chain;
 938         if (chain0)
 939                 tcf_chain_hold(chain0);
 940         else
 941                 list_add(&item->list, &block->chain0.filter_chain_list);
 942         mutex_unlock(&block->lock);
 943
 944         if (chain0) {
 945                 struct tcf_proto *tp_head;
 946
 947                 mutex_lock(&chain0->filter_chain_lock);
 948
 949                 tp_head = tcf_chain_dereference(chain0->filter_chain, chain0);
 950                 if (tp_head)
 951                         tcf_chain_head_change_item(item, tp_head);
 952
 953                 mutex_lock(&block->lock);
 954                 list_add(&item->list, &block->chain0.filter_chain_list);
 955                 mutex_unlock(&block->lock);
 956
 957                 mutex_unlock(&chain0->filter_chain_lock);
 958                 tcf_chain_put(chain0);
 959         }
 960
 961         return 0;
 962 }
 963
 964 static void
 965 tcf_chain0_head_change_cb_del(struct tcf_block *block,
 966                               struct tcf_block_ext_info *ei)
 967 {
 968         struct tcf_filter_chain_list_item *item;
 969
 970         mutex_lock(&block->lock);
 971         list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
 972                 if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
 973                     (item->chain_head_change == ei->chain_head_change &&
 974                      item->chain_head_change_priv == ei->chain_head_change_priv)) {
 975                         if (block->chain0.chain)
 976                                 tcf_chain_head_change_item(item, NULL);
 977                         list_del(&item->list);
 978                         mutex_unlock(&block->lock);
 979
 980                         kfree(item);
 981                         return;
 982                 }
 983         }
 984         mutex_unlock(&block->lock);
 985         WARN_ON(1);
 986 }
 987
 988 struct tcf_net {
 989         spinlock_t idr_lock; /* Protects idr */
 990         struct idr idr;
 991 };
 992
 993 static unsigned int tcf_net_id;
 994
 995 static int tcf_block_insert(struct tcf_block *block, struct net *net,
 996                             struct netlink_ext_ack *extack)
 997 {
 998         struct tcf_net *tn = net_generic(net, tcf_net_id);
 999         int err;
1000
1001         idr_preload(GFP_KERNEL);
1002         spin_lock(&tn->idr_lock);
1003         err = idr_alloc_u32(&tn->idr, block, &block->index, block->index,
1004                             GFP_NOWAIT);
1005         spin_unlock(&tn->idr_lock);
1006         idr_preload_end();
1007
1008         return err;
1009 }
1010
1011 static void tcf_block_remove(struct tcf_block *block, struct net *net)
1012 {
1013         struct tcf_net *tn = net_generic(net, tcf_net_id);
1014
1015         spin_lock(&tn->idr_lock);
1016         idr_remove(&tn->idr, block->index);
1017         spin_unlock(&tn->idr_lock);
1018 }
1019
1020 static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
1021                                           u32 block_index,
1022                                           struct netlink_ext_ack *extack)
1023 {
1024         struct tcf_block *block;
1025
1026         block = kzalloc(sizeof(*block), GFP_KERNEL);
1027         if (!block) {
1028                 NL_SET_ERR_MSG(extack, "Memory allocation for block failed");
1029                 return ERR_PTR(-ENOMEM);
1030         }
1031         mutex_init(&block->lock);
1032         mutex_init(&block->proto_destroy_lock);
1033         init_rwsem(&block->cb_lock);
1034         flow_block_init(&block->flow_block);
1035         INIT_LIST_HEAD(&block->chain_list);
1036         INIT_LIST_HEAD(&block->owner_list);
1037         INIT_LIST_HEAD(&block->chain0.filter_chain_list);
1038
1039         refcount_set(&block->refcnt, 1);
1040         block->net = net;
1041         block->index = block_index;
1042         xa_init(&block->ports);
1043
1044         /* Don't store q pointer for blocks which are shared */
1045         if (!tcf_block_shared(block))
1046                 block->q = q;
1047         return block;
1048 }
1049
1050 struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
1051 {
1052         struct tcf_net *tn = net_generic(net, tcf_net_id);
1053
1054         return idr_find(&tn->idr, block_index);
1055 }
1056 EXPORT_SYMBOL(tcf_block_lookup);
1057
1058 static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
1059 {
1060         struct tcf_block *block;
1061
1062         rcu_read_lock();
1063         block = tcf_block_lookup(net, block_index);
1064         if (block && !refcount_inc_not_zero(&block->refcnt))
1065                 block = NULL;
1066         rcu_read_unlock();
1067
1068         return block;
1069 }
1070
1071 static struct tcf_chain *
1072 __tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
1073 {
1074         mutex_lock(&block->lock);
1075         if (chain)
1076                 chain = list_is_last(&chain->list, &block->chain_list) ?
1077                         NULL : list_next_entry(chain, list);
1078         else
1079                 chain = list_first_entry_or_null(&block->chain_list,
1080                                                  struct tcf_chain, list);
1081
1082         /* skip all action-only chains */
1083         while (chain && tcf_chain_held_by_acts_only(chain))
1084                 chain = list_is_last(&chain->list, &block->chain_list) ?
1085                         NULL : list_next_entry(chain, list);
1086
1087         if (chain)
1088                 tcf_chain_hold(chain);
1089         mutex_unlock(&block->lock);
1090
1091         return chain;
1092 }
1093
1094 /* Function to be used by all clients that want to iterate over all chains on
1095  * block. It properly obtains block->lock and takes reference to chain before
1096  * returning it. Users of this function must be tolerant to concurrent chain
1097  * insertion/deletion or ensure that no concurrent chain modification is
1098  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1099  * consistent dump because rtnl lock is released each time skb is filled with
1100  * data and sent to user-space.
1101  */
1102
1103 struct tcf_chain *
1104 tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
1105 {
1106         struct tcf_chain *chain_next = __tcf_get_next_chain(block, chain);
1107
1108         if (chain)
1109                 tcf_chain_put(chain);
1110
1111         return chain_next;
1112 }
1113 EXPORT_SYMBOL(tcf_get_next_chain);
1114
1115 static struct tcf_proto *
1116 __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
1117 {
1118         u32 prio = 0;
1119
1120         ASSERT_RTNL();
1121         mutex_lock(&chain->filter_chain_lock);
1122
1123         if (!tp) {
1124                 tp = tcf_chain_dereference(chain->filter_chain, chain);
1125         } else if (tcf_proto_is_deleting(tp)) {
1126                 /* 'deleting' flag is set and chain->filter_chain_lock was
1127                  * unlocked, which means next pointer could be invalid. Restart
1128                  * search.
1129                  */
1130                 prio = tp->prio + 1;
1131                 tp = tcf_chain_dereference(chain->filter_chain, chain);
1132
1133                 for (; tp; tp = tcf_chain_dereference(tp->next, chain))
1134                         if (!tp->deleting && tp->prio >= prio)
1135                                 break;
1136         } else {
1137                 tp = tcf_chain_dereference(tp->next, chain);
1138         }
1139
1140         if (tp)
1141                 tcf_proto_get(tp);
1142
1143         mutex_unlock(&chain->filter_chain_lock);
1144
1145         return tp;
1146 }
1147
1148 /* Function to be used by all clients that want to iterate over all tp's on
1149  * chain. Users of this function must be tolerant to concurrent tp
1150  * insertion/deletion or ensure that no concurrent chain modification is
1151  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1152  * consistent dump because rtnl lock is released each time skb is filled with
1153  * data and sent to user-space.
1154  */
1155
1156 struct tcf_proto *
1157 tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
1158 {
1159         struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
1160
1161         if (tp)
1162                 tcf_proto_put(tp, true, NULL);
1163
1164         return tp_next;
1165 }
1166 EXPORT_SYMBOL(tcf_get_next_proto);
1167
1168 static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
1169 {
1170         struct tcf_chain *chain;
1171
1172         /* Last reference to block. At this point chains cannot be added or
1173          * removed concurrently.
1174          */
1175         for (chain = tcf_get_next_chain(block, NULL);
1176              chain;
1177              chain = tcf_get_next_chain(block, chain)) {
1178                 tcf_chain_put_explicitly_created(chain);
1179                 tcf_chain_flush(chain, rtnl_held);
1180         }
1181 }
1182
1183 /* Lookup Qdisc and increments its reference counter.
1184  * Set parent, if necessary.
1185  */
1186
1187 static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
1188                             u32 *parent, int ifindex, bool rtnl_held,
1189                             struct netlink_ext_ack *extack)
1190 {
1191         const struct Qdisc_class_ops *cops;
1192         struct net_device *dev;
1193         int err = 0;
1194
1195         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1196                 return 0;
1197
1198         rcu_read_lock();
1199
1200         /* Find link */
1201         dev = dev_get_by_index_rcu(net, ifindex);
1202         if (!dev) {
1203                 rcu_read_unlock();
1204                 return -ENODEV;
1205         }
1206
1207         /* Find qdisc */
1208         if (!*parent) {
1209                 *q = rcu_dereference(dev->qdisc);
1210                 *parent = (*q)->handle;
1211         } else {
1212                 *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
1213                 if (!*q) {
1214                         NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1215                         err = -EINVAL;
1216                         goto errout_rcu;
1217                 }
1218         }
1219
1220         *q = qdisc_refcount_inc_nz(*q);
1221         if (!*q) {
1222                 NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1223                 err = -EINVAL;
1224                 goto errout_rcu;
1225         }
1226
1227         /* Is it classful? */
1228         cops = (*q)->ops->cl_ops;
1229         if (!cops) {
1230                 NL_SET_ERR_MSG(extack, "Qdisc not classful");
1231                 err = -EINVAL;
1232                 goto errout_qdisc;
1233         }
1234
1235         if (!cops->tcf_block) {
1236                 NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
1237                 err = -EOPNOTSUPP;
1238                 goto errout_qdisc;
1239         }
1240
1241 errout_rcu:
1242         /* At this point we know that qdisc is not noop_qdisc,
1243          * which means that qdisc holds a reference to net_device
1244          * and we hold a reference to qdisc, so it is safe to release
1245          * rcu read lock.
1246          */
1247         rcu_read_unlock();
1248         return err;
1249
1250 errout_qdisc:
1251         rcu_read_unlock();
1252
1253         if (rtnl_held)
1254                 qdisc_put(*q);
1255         else
1256                 qdisc_put_unlocked(*q);
1257         *q = NULL;
1258
1259         return err;
1260 }
1261
1262 static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
1263                                int ifindex, struct netlink_ext_ack *extack)
1264 {
1265         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1266                 return 0;
1267
1268         /* Do we search for filter, attached to class? */
1269         if (TC_H_MIN(parent)) {
1270                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1271
1272                 *cl = cops->find(q, parent);
1273                 if (*cl == 0) {
1274                         NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
1275                         return -ENOENT;
1276                 }
1277         }
1278
1279         return 0;
1280 }
1281
1282 static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
1283                                           unsigned long cl, int ifindex,
1284                                           u32 block_index,
1285                                           struct netlink_ext_ack *extack)
1286 {
1287         struct tcf_block *block;
1288
1289         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
1290                 block = tcf_block_refcnt_get(net, block_index);
1291                 if (!block) {
1292                         NL_SET_ERR_MSG(extack, "Block of given index was not found");
1293                         return ERR_PTR(-EINVAL);
1294                 }
1295         } else {
1296                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1297
1298                 block = cops->tcf_block(q, cl, extack);
1299                 if (!block)
1300                         return ERR_PTR(-EINVAL);
1301
1302                 if (tcf_block_shared(block)) {
1303                         NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
1304                         return ERR_PTR(-EOPNOTSUPP);
1305                 }
1306
1307                 /* Always take reference to block in order to support execution
1308                  * of rules update path of cls API without rtnl lock. Caller
1309                  * must release block when it is finished using it. 'if' block
1310                  * of this conditional obtain reference to block by calling
1311                  * tcf_block_refcnt_get().
1312                  */
1313                 refcount_inc(&block->refcnt);
1314         }
1315
1316         return block;
1317 }
1318
1319 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
1320                             struct tcf_block_ext_info *ei, bool rtnl_held)
1321 {
1322         if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
1323                 /* Flushing/putting all chains will cause the block to be
1324                  * deallocated when last chain is freed. However, if chain_list
1325                  * is empty, block has to be manually deallocated. After block
1326                  * reference counter reached 0, it is no longer possible to
1327                  * increment it or add new chains to block.
1328                  */
1329                 bool free_block = list_empty(&block->chain_list);
1330
1331                 mutex_unlock(&block->lock);
1332                 if (tcf_block_shared(block))
1333                         tcf_block_remove(block, block->net);
1334
1335                 if (q)
1336                         tcf_block_offload_unbind(block, q, ei);
1337
1338                 if (free_block)
1339                         tcf_block_destroy(block);
1340                 else
1341                         tcf_block_flush_all_chains(block, rtnl_held);
1342         } else if (q) {
1343                 tcf_block_offload_unbind(block, q, ei);
1344         }
1345 }
1346
1347 static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
1348 {
1349         __tcf_block_put(block, NULL, NULL, rtnl_held);
1350 }
1351
1352 /* Find tcf block.
1353  * Set q, parent, cl when appropriate.
1354  */
1355
1356 static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
1357                                         u32 *parent, unsigned long *cl,
1358                                         int ifindex, u32 block_index,
1359                                         struct netlink_ext_ack *extack)
1360 {
1361         struct tcf_block *block;
1362         int err = 0;
1363
1364         ASSERT_RTNL();
1365
1366         err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
1367         if (err)
1368                 goto errout;
1369
1370         err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
1371         if (err)
1372                 goto errout_qdisc;
1373
1374         block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
1375         if (IS_ERR(block)) {
1376                 err = PTR_ERR(block);
1377                 goto errout_qdisc;
1378         }
1379
1380         return block;
1381
1382 errout_qdisc:
1383         if (*q)
1384                 qdisc_put(*q);
1385 errout:
1386         *q = NULL;
1387         return ERR_PTR(err);
1388 }
1389
1390 static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
1391                               bool rtnl_held)
1392 {
1393         if (!IS_ERR_OR_NULL(block))
1394                 tcf_block_refcnt_put(block, rtnl_held);
1395
1396         if (q) {
1397                 if (rtnl_held)
1398                         qdisc_put(q);
1399                 else
1400                         qdisc_put_unlocked(q);
1401         }
1402 }
1403
1404 struct tcf_block_owner_item {
1405         struct list_head list;
1406         struct Qdisc *q;
1407         enum flow_block_binder_type binder_type;
1408 };
1409
1410 static void
1411 tcf_block_owner_netif_keep_dst(struct tcf_block *block,
1412                                struct Qdisc *q,
1413                                enum flow_block_binder_type binder_type)
1414 {
1415         if (block->keep_dst &&
1416             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS &&
1417             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
1418                 netif_keep_dst(qdisc_dev(q));
1419 }
1420
1421 void tcf_block_netif_keep_dst(struct tcf_block *block)
1422 {
1423         struct tcf_block_owner_item *item;
1424
1425         block->keep_dst = true;
1426         list_for_each_entry(item, &block->owner_list, list)
1427                 tcf_block_owner_netif_keep_dst(block, item->q,
1428                                                item->binder_type);
1429 }
1430 EXPORT_SYMBOL(tcf_block_netif_keep_dst);
1431
1432 static int tcf_block_owner_add(struct tcf_block *block,
1433                                struct Qdisc *q,
1434                                enum flow_block_binder_type binder_type)
1435 {
1436         struct tcf_block_owner_item *item;
1437
1438         item = kmalloc(sizeof(*item), GFP_KERNEL);
1439         if (!item)
1440                 return -ENOMEM;
1441         item->q = q;
1442         item->binder_type = binder_type;
1443         list_add(&item->list, &block->owner_list);
1444         return 0;
1445 }
1446
1447 static void tcf_block_owner_del(struct tcf_block *block,
1448                                 struct Qdisc *q,
1449                                 enum flow_block_binder_type binder_type)
1450 {
1451         struct tcf_block_owner_item *item;
1452
1453         list_for_each_entry(item, &block->owner_list, list) {
1454                 if (item->q == q && item->binder_type == binder_type) {
1455                         list_del(&item->list);
1456                         kfree(item);
1457                         return;
1458                 }
1459         }
1460         WARN_ON(1);
1461 }
1462
1463 static bool tcf_block_tracks_dev(struct tcf_block *block,
1464                                  struct tcf_block_ext_info *ei)
1465 {
1466         return tcf_block_shared(block) &&
1467                (ei->binder_type == FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS ||
1468                 ei->binder_type == FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS);
1469 }
1470
1471 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
1472                       struct tcf_block_ext_info *ei,
1473                       struct netlink_ext_ack *extack)
1474 {
1475         struct net_device *dev = qdisc_dev(q);
1476         struct net *net = qdisc_net(q);
1477         struct tcf_block *block = NULL;
1478         int err;
1479
1480         if (ei->block_index)
1481                 /* block_index not 0 means the shared block is requested */
1482                 block = tcf_block_refcnt_get(net, ei->block_index);
1483
1484         if (!block) {
1485                 block = tcf_block_create(net, q, ei->block_index, extack);
1486                 if (IS_ERR(block))
1487                         return PTR_ERR(block);
1488                 if (tcf_block_shared(block)) {
1489                         err = tcf_block_insert(block, net, extack);
1490                         if (err)
1491                                 goto err_block_insert;
1492                 }
1493         }
1494
1495         err = tcf_block_owner_add(block, q, ei->binder_type);
1496         if (err)
1497                 goto err_block_owner_add;
1498
1499         tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
1500
1501         err = tcf_chain0_head_change_cb_add(block, ei, extack);
1502         if (err)
1503                 goto err_chain0_head_change_cb_add;
1504
1505         err = tcf_block_offload_bind(block, q, ei, extack);
1506         if (err)
1507                 goto err_block_offload_bind;
1508
1509         if (tcf_block_tracks_dev(block, ei)) {
1510                 err = xa_insert(&block->ports, dev->ifindex, dev, GFP_KERNEL);
1511                 if (err) {
1512                         NL_SET_ERR_MSG(extack, "block dev insert failed");
1513                         goto err_dev_insert;
1514                 }
1515         }
1516
1517         *p_block = block;
1518         return 0;
1519
1520 err_dev_insert:
1521         tcf_block_offload_unbind(block, q, ei);
1522 err_block_offload_bind:
1523         tcf_chain0_head_change_cb_del(block, ei);
1524 err_chain0_head_change_cb_add:
1525         tcf_block_owner_del(block, q, ei->binder_type);
1526 err_block_owner_add:
1527 err_block_insert:
1528         tcf_block_refcnt_put(block, true);
1529         return err;
1530 }
1531 EXPORT_SYMBOL(tcf_block_get_ext);
1532
1533 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
1534 {
1535         struct tcf_proto __rcu **p_filter_chain = priv;
1536
1537         rcu_assign_pointer(*p_filter_chain, tp_head);
1538 }
1539
1540 int tcf_block_get(struct tcf_block **p_block,
1541                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
1542                   struct netlink_ext_ack *extack)
1543 {
1544         struct tcf_block_ext_info ei = {
1545                 .chain_head_change = tcf_chain_head_change_dflt,
1546                 .chain_head_change_priv = p_filter_chain,
1547         };
1548
1549         WARN_ON(!p_filter_chain);
1550         return tcf_block_get_ext(p_block, q, &ei, extack);
1551 }
1552 EXPORT_SYMBOL(tcf_block_get);
1553
1554 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
1555  * actions should be all removed after flushing.
1556  */
1557 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
1558                        struct tcf_block_ext_info *ei)
1559 {
1560         struct net_device *dev = qdisc_dev(q);
1561
1562         if (!block)
1563                 return;
1564         if (tcf_block_tracks_dev(block, ei))
1565                 xa_erase(&block->ports, dev->ifindex);
1566         tcf_chain0_head_change_cb_del(block, ei);
1567         tcf_block_owner_del(block, q, ei->binder_type);
1568
1569         __tcf_block_put(block, q, ei, true);
1570 }
1571 EXPORT_SYMBOL(tcf_block_put_ext);
1572
1573 void tcf_block_put(struct tcf_block *block)
1574 {
1575         struct tcf_block_ext_info ei = {0, };
1576
1577         if (!block)
1578                 return;
1579         tcf_block_put_ext(block, block->q, &ei);
1580 }
1581
1582 EXPORT_SYMBOL(tcf_block_put);
1583
1584 static int
1585 tcf_block_playback_offloads(struct tcf_block *block, flow_setup_cb_t *cb,
1586                             void *cb_priv, bool add, bool offload_in_use,
1587                             struct netlink_ext_ack *extack)
1588 {
1589         struct tcf_chain *chain, *chain_prev;
1590         struct tcf_proto *tp, *tp_prev;
1591         int err;
1592
1593         lockdep_assert_held(&block->cb_lock);
1594
1595         for (chain = __tcf_get_next_chain(block, NULL);
1596              chain;
1597              chain_prev = chain,
1598                      chain = __tcf_get_next_chain(block, chain),
1599                      tcf_chain_put(chain_prev)) {
1600                 if (chain->tmplt_ops && add)
1601                         chain->tmplt_ops->tmplt_reoffload(chain, true, cb,
1602                                                           cb_priv);
1603                 for (tp = __tcf_get_next_proto(chain, NULL); tp;
1604                      tp_prev = tp,
1605                              tp = __tcf_get_next_proto(chain, tp),
1606                              tcf_proto_put(tp_prev, true, NULL)) {
1607                         if (tp->ops->reoffload) {
1608                                 err = tp->ops->reoffload(tp, add, cb, cb_priv,
1609                                                          extack);
1610                                 if (err && add)
1611                                         goto err_playback_remove;
1612                         } else if (add && offload_in_use) {
1613                                 err = -EOPNOTSUPP;
1614                                 NL_SET_ERR_MSG(extack, "Filter HW offload failed - classifier without re-offloading support");
1615                                 goto err_playback_remove;
1616                         }
1617                 }
1618                 if (chain->tmplt_ops && !add)
1619                         chain->tmplt_ops->tmplt_reoffload(chain, false, cb,
1620                                                           cb_priv);
1621         }
1622
1623         return 0;
1624
1625 err_playback_remove:
1626         tcf_proto_put(tp, true, NULL);
1627         tcf_chain_put(chain);
1628         tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
1629                                     extack);
1630         return err;
1631 }
1632
1633 static int tcf_block_bind(struct tcf_block *block,
1634                           struct flow_block_offload *bo)
1635 {
1636         struct flow_block_cb *block_cb, *next;
1637         int err, i = 0;
1638
1639         lockdep_assert_held(&block->cb_lock);
1640
1641         list_for_each_entry(block_cb, &bo->cb_list, list) {
1642                 err = tcf_block_playback_offloads(block, block_cb->cb,
1643                                                   block_cb->cb_priv, true,
1644                                                   tcf_block_offload_in_use(block),
1645                                                   bo->extack);
1646                 if (err)
1647                         goto err_unroll;
1648                 if (!bo->unlocked_driver_cb)
1649                         block->lockeddevcnt++;
1650
1651                 i++;
1652         }
1653         list_splice(&bo->cb_list, &block->flow_block.cb_list);
1654
1655         return 0;
1656
1657 err_unroll:
1658         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1659                 list_del(&block_cb->driver_list);
1660                 if (i-- > 0) {
1661                         list_del(&block_cb->list);
1662                         tcf_block_playback_offloads(block, block_cb->cb,
1663                                                     block_cb->cb_priv, false,
1664                                                     tcf_block_offload_in_use(block),
1665                                                     NULL);
1666                         if (!bo->unlocked_driver_cb)
1667                                 block->lockeddevcnt--;
1668                 }
1669                 flow_block_cb_free(block_cb);
1670         }
1671
1672         return err;
1673 }
1674
1675 static void tcf_block_unbind(struct tcf_block *block,
1676                              struct flow_block_offload *bo)
1677 {
1678         struct flow_block_cb *block_cb, *next;
1679
1680         lockdep_assert_held(&block->cb_lock);
1681
1682         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1683                 tcf_block_playback_offloads(block, block_cb->cb,
1684                                             block_cb->cb_priv, false,
1685                                             tcf_block_offload_in_use(block),
1686                                             NULL);
1687                 list_del(&block_cb->list);
1688                 flow_block_cb_free(block_cb);
1689                 if (!bo->unlocked_driver_cb)
1690                         block->lockeddevcnt--;
1691         }
1692 }
1693
1694 static int tcf_block_setup(struct tcf_block *block,
1695                            struct flow_block_offload *bo)
1696 {
1697         int err;
1698
1699         switch (bo->command) {
1700         case FLOW_BLOCK_BIND:
1701                 err = tcf_block_bind(block, bo);
1702                 break;
1703         case FLOW_BLOCK_UNBIND:
1704                 err = 0;
1705                 tcf_block_unbind(block, bo);
1706                 break;
1707         default:
1708                 WARN_ON_ONCE(1);
1709                 err = -EOPNOTSUPP;
1710         }
1711
1712         return err;
1713 }
1714
1715 /* Main classifier routine: scans classifier chain attached
1716  * to this qdisc, (optionally) tests for protocol and asks
1717  * specific classifiers.
1718  */
1719 static inline int __tcf_classify(struct sk_buff *skb,
1720                                  const struct tcf_proto *tp,
1721                                  const struct tcf_proto *orig_tp,
1722                                  struct tcf_result *res,
1723                                  bool compat_mode,
1724                                  struct tcf_exts_miss_cookie_node *n,
1725                                  int act_index,
1726                                  u32 *last_executed_chain)
1727 {
1728 #ifdef CONFIG_NET_CLS_ACT
1729         const int max_reclassify_loop = 16;
1730         const struct tcf_proto *first_tp;
1731         int limit = 0;
1732
1733 reclassify:
1734 #endif
1735         for (; tp; tp = rcu_dereference_bh(tp->next)) {
1736                 __be16 protocol = skb_protocol(skb, false);
1737                 int err = 0;
1738
1739                 if (n) {
1740                         struct tcf_exts *exts;
1741
1742                         if (n->tp_prio != tp->prio)
1743                                 continue;
1744
1745                         /* We re-lookup the tp and chain based on index instead
1746                          * of having hard refs and locks to them, so do a sanity
1747                          * check if any of tp,chain,exts was replaced by the
1748                          * time we got here with a cookie from hardware.
1749                          */
1750                         if (unlikely(n->tp != tp || n->tp->chain != n->chain ||
1751                                      !tp->ops->get_exts)) {
1752                                 tcf_set_drop_reason(skb,
1753                                                     SKB_DROP_REASON_TC_COOKIE_ERROR);
1754                                 return TC_ACT_SHOT;
1755                         }
1756
1757                         exts = tp->ops->get_exts(tp, n->handle);
1758                         if (unlikely(!exts || n->exts != exts)) {
1759                                 tcf_set_drop_reason(skb,
1760                                                     SKB_DROP_REASON_TC_COOKIE_ERROR);
1761                                 return TC_ACT_SHOT;
1762                         }
1763
1764                         n = NULL;
1765                         err = tcf_exts_exec_ex(skb, exts, act_index, res);
1766                 } else {
1767                         if (tp->protocol != protocol &&
1768                             tp->protocol != htons(ETH_P_ALL))
1769                                 continue;
1770
1771                         err = tc_classify(skb, tp, res);
1772                 }
1773 #ifdef CONFIG_NET_CLS_ACT
1774                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
1775                         first_tp = orig_tp;
1776                         *last_executed_chain = first_tp->chain->index;
1777                         goto reset;
1778                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
1779                         first_tp = res->goto_tp;
1780                         *last_executed_chain = err & TC_ACT_EXT_VAL_MASK;
1781                         goto reset;
1782                 }
1783 #endif
1784                 if (err >= 0)
1785                         return err;
1786         }
1787
1788         if (unlikely(n)) {
1789                 tcf_set_drop_reason(skb,
1790                                     SKB_DROP_REASON_TC_COOKIE_ERROR);
1791                 return TC_ACT_SHOT;
1792         }
1793
1794         return TC_ACT_UNSPEC; /* signal: continue lookup */
1795 #ifdef CONFIG_NET_CLS_ACT
1796 reset:
1797         if (unlikely(limit++ >= max_reclassify_loop)) {
1798                 net_notice_ratelimited("%u: reclassify loop, rule prio %u, protocol %02x\n",
1799                                        tp->chain->block->index,
1800                                        tp->prio & 0xffff,
1801                                        ntohs(tp->protocol));
1802                 tcf_set_drop_reason(skb,
1803                                     SKB_DROP_REASON_TC_RECLASSIFY_LOOP);
1804                 return TC_ACT_SHOT;
1805         }
1806
1807         tp = first_tp;
1808         goto reclassify;
1809 #endif
1810 }
1811
1812 int tcf_classify(struct sk_buff *skb,
1813                  const struct tcf_block *block,
1814                  const struct tcf_proto *tp,
1815                  struct tcf_result *res, bool compat_mode)
1816 {
1817 #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1818         u32 last_executed_chain = 0;
1819
1820         return __tcf_classify(skb, tp, tp, res, compat_mode, NULL, 0,
1821                               &last_executed_chain);
1822 #else
1823         u32 last_executed_chain = tp ? tp->chain->index : 0;
1824         struct tcf_exts_miss_cookie_node *n = NULL;
1825         const struct tcf_proto *orig_tp = tp;
1826         struct tc_skb_ext *ext;
1827         int act_index = 0;
1828         int ret;
1829
1830         if (block) {
1831                 ext = skb_ext_find(skb, TC_SKB_EXT);
1832
1833                 if (ext && (ext->chain || ext->act_miss)) {
1834                         struct tcf_chain *fchain;
1835                         u32 chain;
1836
1837                         if (ext->act_miss) {
1838                                 n = tcf_exts_miss_cookie_lookup(ext->act_miss_cookie,
1839                                                                 &act_index);
1840                                 if (!n) {
1841                                         tcf_set_drop_reason(skb,
1842                                                             SKB_DROP_REASON_TC_COOKIE_ERROR);
1843                                         return TC_ACT_SHOT;
1844                                 }
1845
1846                                 chain = n->chain_index;
1847                         } else {
1848                                 chain = ext->chain;
1849                         }
1850
1851                         fchain = tcf_chain_lookup_rcu(block, chain);
1852                         if (!fchain) {
1853                                 tcf_set_drop_reason(skb,
1854                                                     SKB_DROP_REASON_TC_CHAIN_NOTFOUND);
1855
1856                                 return TC_ACT_SHOT;
1857                         }
1858
1859                         /* Consume, so cloned/redirect skbs won't inherit ext */
1860                         skb_ext_del(skb, TC_SKB_EXT);
1861
1862                         tp = rcu_dereference_bh(fchain->filter_chain);
1863                         last_executed_chain = fchain->index;
1864                 }
1865         }
1866
1867         ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode, n, act_index,
1868                              &last_executed_chain);
1869
1870         if (tc_skb_ext_tc_enabled()) {
1871                 /* If we missed on some chain */
1872                 if (ret == TC_ACT_UNSPEC && last_executed_chain) {
1873                         struct tc_skb_cb *cb = tc_skb_cb(skb);
1874
1875                         ext = tc_skb_ext_alloc(skb);
1876                         if (WARN_ON_ONCE(!ext)) {
1877                                 tcf_set_drop_reason(skb, SKB_DROP_REASON_NOMEM);
1878                                 return TC_ACT_SHOT;
1879                         }
1880                         ext->chain = last_executed_chain;
1881                         ext->mru = cb->mru;
1882                         ext->post_ct = cb->post_ct;
1883                         ext->post_ct_snat = cb->post_ct_snat;
1884                         ext->post_ct_dnat = cb->post_ct_dnat;
1885                         ext->zone = cb->zone;
1886                 }
1887         }
1888
1889         return ret;
1890 #endif
1891 }
1892 EXPORT_SYMBOL(tcf_classify);
1893
1894 struct tcf_chain_info {
1895         struct tcf_proto __rcu **pprev;
1896         struct tcf_proto __rcu *next;
1897 };
1898
1899 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
1900                                            struct tcf_chain_info *chain_info)
1901 {
1902         return tcf_chain_dereference(*chain_info->pprev, chain);
1903 }
1904
1905 static int tcf_chain_tp_insert(struct tcf_chain *chain,
1906                                struct tcf_chain_info *chain_info,
1907                                struct tcf_proto *tp)
1908 {
1909         if (chain->flushing)
1910                 return -EAGAIN;
1911
1912         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
1913         if (*chain_info->pprev == chain->filter_chain)
1914                 tcf_chain0_head_change(chain, tp);
1915         tcf_proto_get(tp);
1916         rcu_assign_pointer(*chain_info->pprev, tp);
1917
1918         return 0;
1919 }
1920
1921 static void tcf_chain_tp_remove(struct tcf_chain *chain,
1922                                 struct tcf_chain_info *chain_info,
1923                                 struct tcf_proto *tp)
1924 {
1925         struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
1926
1927         tcf_proto_mark_delete(tp);
1928         if (tp == chain->filter_chain)
1929                 tcf_chain0_head_change(chain, next);
1930         RCU_INIT_POINTER(*chain_info->pprev, next);
1931 }
1932
1933 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1934                                            struct tcf_chain_info *chain_info,
1935                                            u32 protocol, u32 prio,
1936                                            bool prio_allocate,
1937                                            struct netlink_ext_ack *extack);
1938
1939 /* Try to insert new proto.
1940  * If proto with specified priority already exists, free new proto
1941  * and return existing one.
1942  */
1943
1944 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
1945                                                     struct tcf_proto *tp_new,
1946                                                     u32 protocol, u32 prio,
1947                                                     bool rtnl_held)
1948 {
1949         struct tcf_chain_info chain_info;
1950         struct tcf_proto *tp;
1951         int err = 0;
1952
1953         mutex_lock(&chain->filter_chain_lock);
1954
1955         if (tcf_proto_exists_destroying(chain, tp_new)) {
1956                 mutex_unlock(&chain->filter_chain_lock);
1957                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1958                 return ERR_PTR(-EAGAIN);
1959         }
1960
1961         tp = tcf_chain_tp_find(chain, &chain_info, protocol, prio, false, NULL);
1962         if (!tp)
1963                 err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
1964         mutex_unlock(&chain->filter_chain_lock);
1965
1966         if (tp) {
1967                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1968                 tp_new = tp;
1969         } else if (err) {
1970                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1971                 tp_new = ERR_PTR(err);
1972         }
1973
1974         return tp_new;
1975 }
1976
1977 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
1978                                       struct tcf_proto *tp, bool rtnl_held,
1979                                       struct netlink_ext_ack *extack)
1980 {
1981         struct tcf_chain_info chain_info;
1982         struct tcf_proto *tp_iter;
1983         struct tcf_proto **pprev;
1984         struct tcf_proto *next;
1985
1986         mutex_lock(&chain->filter_chain_lock);
1987
1988         /* Atomically find and remove tp from chain. */
1989         for (pprev = &chain->filter_chain;
1990              (tp_iter = tcf_chain_dereference(*pprev, chain));
1991              pprev = &tp_iter->next) {
1992                 if (tp_iter == tp) {
1993                         chain_info.pprev = pprev;
1994                         chain_info.next = tp_iter->next;
1995                         WARN_ON(tp_iter->deleting);
1996                         break;
1997                 }
1998         }
1999         /* Verify that tp still exists and no new filters were inserted
2000          * concurrently.
2001          * Mark tp for deletion if it is empty.
2002          */
2003         if (!tp_iter || !tcf_proto_check_delete(tp)) {
2004                 mutex_unlock(&chain->filter_chain_lock);
2005                 return;
2006         }
2007
2008         tcf_proto_signal_destroying(chain, tp);
2009         next = tcf_chain_dereference(chain_info.next, chain);
2010         if (tp == chain->filter_chain)
2011                 tcf_chain0_head_change(chain, next);
2012         RCU_INIT_POINTER(*chain_info.pprev, next);
2013         mutex_unlock(&chain->filter_chain_lock);
2014
2015         tcf_proto_put(tp, rtnl_held, extack);
2016 }
2017
2018 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
2019                                            struct tcf_chain_info *chain_info,
2020                                            u32 protocol, u32 prio,
2021                                            bool prio_allocate,
2022                                            struct netlink_ext_ack *extack)
2023 {
2024         struct tcf_proto **pprev;
2025         struct tcf_proto *tp;
2026
2027         /* Check the chain for existence of proto-tcf with this priority */
2028         for (pprev = &chain->filter_chain;
2029              (tp = tcf_chain_dereference(*pprev, chain));
2030              pprev = &tp->next) {
2031                 if (tp->prio >= prio) {
2032                         if (tp->prio == prio) {
2033                                 if (prio_allocate) {
2034                                         NL_SET_ERR_MSG(extack, "Lowest ID from auto-alloc range already in use");
2035                                         return ERR_PTR(-ENOSPC);
2036                                 }
2037                                 if (tp->protocol != protocol && protocol) {
2038                                         NL_SET_ERR_MSG(extack, "Protocol mismatch for filter with specified priority");
2039                                         return ERR_PTR(-EINVAL);
2040                                 }
2041                         } else {
2042                                 tp = NULL;
2043                         }
2044                         break;
2045                 }
2046         }
2047         chain_info->pprev = pprev;
2048         if (tp) {
2049                 chain_info->next = tp->next;
2050                 tcf_proto_get(tp);
2051         } else {
2052                 chain_info->next = NULL;
2053         }
2054         return tp;
2055 }
2056
2057 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
2058                          struct tcf_proto *tp, struct tcf_block *block,
2059                          struct Qdisc *q, u32 parent, void *fh,
2060                          u32 portid, u32 seq, u16 flags, int event,
2061                          bool terse_dump, bool rtnl_held,
2062                          struct netlink_ext_ack *extack)
2063 {
2064         struct tcmsg *tcm;
2065         struct nlmsghdr  *nlh;
2066         unsigned char *b = skb_tail_pointer(skb);
2067
2068         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2069         if (!nlh)
2070                 goto out_nlmsg_trim;
2071         tcm = nlmsg_data(nlh);
2072         tcm->tcm_family = AF_UNSPEC;
2073         tcm->tcm__pad1 = 0;
2074         tcm->tcm__pad2 = 0;
2075         if (q) {
2076                 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
2077                 tcm->tcm_parent = parent;
2078         } else {
2079                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2080                 tcm->tcm_block_index = block->index;
2081         }
2082         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
2083         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
2084                 goto nla_put_failure;
2085         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
2086                 goto nla_put_failure;
2087         if (!fh) {
2088                 tcm->tcm_handle = 0;
2089         } else if (terse_dump) {
2090                 if (tp->ops->terse_dump) {
2091                         if (tp->ops->terse_dump(net, tp, fh, skb, tcm,
2092                                                 rtnl_held) < 0)
2093                                 goto nla_put_failure;
2094                 } else {
2095                         goto cls_op_not_supp;
2096                 }
2097         } else {
2098                 if (tp->ops->dump &&
2099                     tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
2100                         goto nla_put_failure;
2101         }
2102
2103         if (extack && extack->_msg &&
2104             nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
2105                 goto nla_put_failure;
2106
2107         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2108
2109         return skb->len;
2110
2111 out_nlmsg_trim:
2112 nla_put_failure:
2113 cls_op_not_supp:
2114         nlmsg_trim(skb, b);
2115         return -1;
2116 }
2117
2118 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
2119                           struct nlmsghdr *n, struct tcf_proto *tp,
2120                           struct tcf_block *block, struct Qdisc *q,
2121                           u32 parent, void *fh, int event, bool unicast,
2122                           bool rtnl_held, struct netlink_ext_ack *extack)
2123 {
2124         struct sk_buff *skb;
2125         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2126         int err = 0;
2127
2128         if (!unicast && !rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
2129                 return 0;
2130
2131         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2132         if (!skb)
2133                 return -ENOBUFS;
2134
2135         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
2136                           n->nlmsg_seq, n->nlmsg_flags, event,
2137                           false, rtnl_held, extack) <= 0) {
2138                 kfree_skb(skb);
2139                 return -EINVAL;
2140         }
2141
2142         if (unicast)
2143                 err = rtnl_unicast(skb, net, portid);
2144         else
2145                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2146                                      n->nlmsg_flags & NLM_F_ECHO);
2147         return err;
2148 }
2149
2150 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
2151                               struct nlmsghdr *n, struct tcf_proto *tp,
2152                               struct tcf_block *block, struct Qdisc *q,
2153                               u32 parent, void *fh, bool *last, bool rtnl_held,
2154                               struct netlink_ext_ack *extack)
2155 {
2156         struct sk_buff *skb;
2157         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2158         int err;
2159
2160         if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
2161                 return tp->ops->delete(tp, fh, last, rtnl_held, extack);
2162
2163         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2164         if (!skb)
2165                 return -ENOBUFS;
2166
2167         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
2168                           n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
2169                           false, rtnl_held, extack) <= 0) {
2170                 NL_SET_ERR_MSG(extack, "Failed to build del event notification");
2171                 kfree_skb(skb);
2172                 return -EINVAL;
2173         }
2174
2175         err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
2176         if (err) {
2177                 kfree_skb(skb);
2178                 return err;
2179         }
2180
2181         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2182                              n->nlmsg_flags & NLM_F_ECHO);
2183         if (err < 0)
2184                 NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
2185
2186         return err;
2187 }
2188
2189 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
2190                                  struct tcf_block *block, struct Qdisc *q,
2191                                  u32 parent, struct nlmsghdr *n,
2192                                  struct tcf_chain *chain, int event,
2193                                  struct netlink_ext_ack *extack)
2194 {
2195         struct tcf_proto *tp;
2196
2197         for (tp = tcf_get_next_proto(chain, NULL);
2198              tp; tp = tcf_get_next_proto(chain, tp))
2199                 tfilter_notify(net, oskb, n, tp, block, q, parent, NULL,
2200                                event, false, true, extack);
2201 }
2202
2203 static void tfilter_put(struct tcf_proto *tp, void *fh)
2204 {
2205         if (tp->ops->put && fh)
2206                 tp->ops->put(tp, fh);
2207 }
2208
2209 static bool is_qdisc_ingress(__u32 classid)
2210 {
2211         return (TC_H_MIN(classid) == TC_H_MIN(TC_H_MIN_INGRESS));
2212 }
2213
2214 static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2215                           struct netlink_ext_ack *extack)
2216 {
2217         struct net *net = sock_net(skb->sk);
2218         struct nlattr *tca[TCA_MAX + 1];
2219         char name[IFNAMSIZ];
2220         struct tcmsg *t;
2221         u32 protocol;
2222         u32 prio;
2223         bool prio_allocate;
2224         u32 parent;
2225         u32 chain_index;
2226         struct Qdisc *q;
2227         struct tcf_chain_info chain_info;
2228         struct tcf_chain *chain;
2229         struct tcf_block *block;
2230         struct tcf_proto *tp;
2231         unsigned long cl;
2232         void *fh;
2233         int err;
2234         int tp_created;
2235         bool rtnl_held = false;
2236         u32 flags;
2237
2238 replay:
2239         tp_created = 0;
2240
2241         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2242                                      rtm_tca_policy, extack);
2243         if (err < 0)
2244                 return err;
2245
2246         t = nlmsg_data(n);
2247         protocol = TC_H_MIN(t->tcm_info);
2248         prio = TC_H_MAJ(t->tcm_info);
2249         prio_allocate = false;
2250         parent = t->tcm_parent;
2251         tp = NULL;
2252         cl = 0;
2253         block = NULL;
2254         q = NULL;
2255         chain = NULL;
2256         flags = 0;
2257
2258         if (prio == 0) {
2259                 /* If no priority is provided by the user,
2260                  * we allocate one.
2261                  */
2262                 if (n->nlmsg_flags & NLM_F_CREATE) {
2263                         prio = TC_H_MAKE(0x80000000U, 0U);
2264                         prio_allocate = true;
2265                 } else {
2266                         NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2267                         return -ENOENT;
2268                 }
2269         }
2270
2271         /* Find head of filter chain. */
2272
2273         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2274         if (err)
2275                 return err;
2276
2277         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2278                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2279                 err = -EINVAL;
2280                 goto errout;
2281         }
2282
2283         /* Take rtnl mutex if rtnl_held was set to true on previous iteration,
2284          * block is shared (no qdisc found), qdisc is not unlocked, classifier
2285          * type is not specified, classifier is not unlocked.
2286          */
2287         if (rtnl_held ||
2288             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2289             !tcf_proto_is_unlocked(name)) {
2290                 rtnl_held = true;
2291                 rtnl_lock();
2292         }
2293
2294         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2295         if (err)
2296                 goto errout;
2297
2298         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2299                                  extack);
2300         if (IS_ERR(block)) {
2301                 err = PTR_ERR(block);
2302                 goto errout;
2303         }
2304         block->classid = parent;
2305
2306         chain_index = nla_get_u32_default(tca[TCA_CHAIN], 0);
2307         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2308                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2309                 err = -EINVAL;
2310                 goto errout;
2311         }
2312         chain = tcf_chain_get(block, chain_index, true);
2313         if (!chain) {
2314                 NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
2315                 err = -ENOMEM;
2316                 goto errout;
2317         }
2318
2319         mutex_lock(&chain->filter_chain_lock);
2320         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2321                                prio, prio_allocate, extack);
2322         if (IS_ERR(tp)) {
2323                 err = PTR_ERR(tp);
2324                 goto errout_locked;
2325         }
2326
2327         if (tp == NULL) {
2328                 struct tcf_proto *tp_new = NULL;
2329
2330                 if (chain->flushing) {
2331                         err = -EAGAIN;
2332                         goto errout_locked;
2333                 }
2334
2335                 /* Proto-tcf does not exist, create new one */
2336
2337                 if (tca[TCA_KIND] == NULL || !protocol) {
2338                         NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
2339                         err = -EINVAL;
2340                         goto errout_locked;
2341                 }
2342
2343                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2344                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2345                         err = -ENOENT;
2346                         goto errout_locked;
2347                 }
2348
2349                 if (prio_allocate)
2350                         prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
2351                                                                &chain_info));
2352
2353                 mutex_unlock(&chain->filter_chain_lock);
2354                 tp_new = tcf_proto_create(name, protocol, prio, chain,
2355                                           rtnl_held, extack);
2356                 if (IS_ERR(tp_new)) {
2357                         err = PTR_ERR(tp_new);
2358                         goto errout_tp;
2359                 }
2360
2361                 tp_created = 1;
2362                 tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
2363                                                 rtnl_held);
2364                 if (IS_ERR(tp)) {
2365                         err = PTR_ERR(tp);
2366                         goto errout_tp;
2367                 }
2368         } else {
2369                 mutex_unlock(&chain->filter_chain_lock);
2370         }
2371
2372         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2373                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2374                 err = -EINVAL;
2375                 goto errout;
2376         }
2377
2378         fh = tp->ops->get(tp, t->tcm_handle);
2379
2380         if (!fh) {
2381                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2382                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2383                         err = -ENOENT;
2384                         goto errout;
2385                 }
2386         } else if (n->nlmsg_flags & NLM_F_EXCL) {
2387                 tfilter_put(tp, fh);
2388                 NL_SET_ERR_MSG(extack, "Filter already exists");
2389                 err = -EEXIST;
2390                 goto errout;
2391         }
2392
2393         if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
2394                 tfilter_put(tp, fh);
2395                 NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
2396                 err = -EINVAL;
2397                 goto errout;
2398         }
2399
2400         if (!(n->nlmsg_flags & NLM_F_CREATE))
2401                 flags |= TCA_ACT_FLAGS_REPLACE;
2402         if (!rtnl_held)
2403                 flags |= TCA_ACT_FLAGS_NO_RTNL;
2404         if (is_qdisc_ingress(parent))
2405                 flags |= TCA_ACT_FLAGS_AT_INGRESS;
2406         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
2407                               flags, extack);
2408         if (err == 0) {
2409                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2410                                RTM_NEWTFILTER, false, rtnl_held, extack);
2411                 tfilter_put(tp, fh);
2412                 tcf_block_filter_cnt_update(block, &tp->counted, true);
2413                 /* q pointer is NULL for shared blocks */
2414                 if (q)
2415                         q->flags &= ~TCQ_F_CAN_BYPASS;
2416         }
2417
2418 errout:
2419         if (err && tp_created)
2420                 tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
2421 errout_tp:
2422         if (chain) {
2423                 if (tp && !IS_ERR(tp))
2424                         tcf_proto_put(tp, rtnl_held, NULL);
2425                 if (!tp_created)
2426                         tcf_chain_put(chain);
2427         }
2428         tcf_block_release(q, block, rtnl_held);
2429
2430         if (rtnl_held)
2431                 rtnl_unlock();
2432
2433         if (err == -EAGAIN) {
2434                 /* Take rtnl lock in case EAGAIN is caused by concurrent flush
2435                  * of target chain.
2436                  */
2437                 rtnl_held = true;
2438                 /* Replay the request. */
2439                 goto replay;
2440         }
2441         return err;
2442
2443 errout_locked:
2444         mutex_unlock(&chain->filter_chain_lock);
2445         goto errout;
2446 }
2447
2448 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2449                           struct netlink_ext_ack *extack)
2450 {
2451         struct net *net = sock_net(skb->sk);
2452         struct nlattr *tca[TCA_MAX + 1];
2453         char name[IFNAMSIZ];
2454         struct tcmsg *t;
2455         u32 protocol;
2456         u32 prio;
2457         u32 parent;
2458         u32 chain_index;
2459         struct Qdisc *q = NULL;
2460         struct tcf_chain_info chain_info;
2461         struct tcf_chain *chain = NULL;
2462         struct tcf_block *block = NULL;
2463         struct tcf_proto *tp = NULL;
2464         unsigned long cl = 0;
2465         void *fh = NULL;
2466         int err;
2467         bool rtnl_held = false;
2468
2469         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2470                                      rtm_tca_policy, extack);
2471         if (err < 0)
2472                 return err;
2473
2474         t = nlmsg_data(n);
2475         protocol = TC_H_MIN(t->tcm_info);
2476         prio = TC_H_MAJ(t->tcm_info);
2477         parent = t->tcm_parent;
2478
2479         if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
2480                 NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
2481                 return -ENOENT;
2482         }
2483
2484         /* Find head of filter chain. */
2485
2486         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2487         if (err)
2488                 return err;
2489
2490         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2491                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2492                 err = -EINVAL;
2493                 goto errout;
2494         }
2495         /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
2496          * found), qdisc is not unlocked, classifier type is not specified,
2497          * classifier is not unlocked.
2498          */
2499         if (!prio ||
2500             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2501             !tcf_proto_is_unlocked(name)) {
2502                 rtnl_held = true;
2503                 rtnl_lock();
2504         }
2505
2506         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2507         if (err)
2508                 goto errout;
2509
2510         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2511                                  extack);
2512         if (IS_ERR(block)) {
2513                 err = PTR_ERR(block);
2514                 goto errout;
2515         }
2516
2517         chain_index = nla_get_u32_default(tca[TCA_CHAIN], 0);
2518         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2519                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2520                 err = -EINVAL;
2521                 goto errout;
2522         }
2523         chain = tcf_chain_get(block, chain_index, false);
2524         if (!chain) {
2525                 /* User requested flush on non-existent chain. Nothing to do,
2526                  * so just return success.
2527                  */
2528                 if (prio == 0) {
2529                         err = 0;
2530                         goto errout;
2531                 }
2532                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2533                 err = -ENOENT;
2534                 goto errout;
2535         }
2536
2537         if (prio == 0) {
2538                 tfilter_notify_chain(net, skb, block, q, parent, n,
2539                                      chain, RTM_DELTFILTER, extack);
2540                 tcf_chain_flush(chain, rtnl_held);
2541                 err = 0;
2542                 goto errout;
2543         }
2544
2545         mutex_lock(&chain->filter_chain_lock);
2546         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2547                                prio, false, extack);
2548         if (!tp) {
2549                 err = -ENOENT;
2550                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2551                 goto errout_locked;
2552         } else if (IS_ERR(tp)) {
2553                 err = PTR_ERR(tp);
2554                 goto errout_locked;
2555         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2556                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2557                 err = -EINVAL;
2558                 goto errout_locked;
2559         } else if (t->tcm_handle == 0) {
2560                 tcf_proto_signal_destroying(chain, tp);
2561                 tcf_chain_tp_remove(chain, &chain_info, tp);
2562                 mutex_unlock(&chain->filter_chain_lock);
2563
2564                 tcf_proto_put(tp, rtnl_held, NULL);
2565                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2566                                RTM_DELTFILTER, false, rtnl_held, extack);
2567                 err = 0;
2568                 goto errout;
2569         }
2570         mutex_unlock(&chain->filter_chain_lock);
2571
2572         fh = tp->ops->get(tp, t->tcm_handle);
2573
2574         if (!fh) {
2575                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2576                 err = -ENOENT;
2577         } else {
2578                 bool last;
2579
2580                 err = tfilter_del_notify(net, skb, n, tp, block, q, parent, fh,
2581                                          &last, rtnl_held, extack);
2582
2583                 if (err)
2584                         goto errout;
2585                 if (last)
2586                         tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
2587         }
2588
2589 errout:
2590         if (chain) {
2591                 if (tp && !IS_ERR(tp))
2592                         tcf_proto_put(tp, rtnl_held, NULL);
2593                 tcf_chain_put(chain);
2594         }
2595         tcf_block_release(q, block, rtnl_held);
2596
2597         if (rtnl_held)
2598                 rtnl_unlock();
2599
2600         return err;
2601
2602 errout_locked:
2603         mutex_unlock(&chain->filter_chain_lock);
2604         goto errout;
2605 }
2606
2607 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2608                           struct netlink_ext_ack *extack)
2609 {
2610         struct net *net = sock_net(skb->sk);
2611         struct nlattr *tca[TCA_MAX + 1];
2612         char name[IFNAMSIZ];
2613         struct tcmsg *t;
2614         u32 protocol;
2615         u32 prio;
2616         u32 parent;
2617         u32 chain_index;
2618         struct Qdisc *q = NULL;
2619         struct tcf_chain_info chain_info;
2620         struct tcf_chain *chain = NULL;
2621         struct tcf_block *block = NULL;
2622         struct tcf_proto *tp = NULL;
2623         unsigned long cl = 0;
2624         void *fh = NULL;
2625         int err;
2626         bool rtnl_held = false;
2627
2628         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2629                                      rtm_tca_policy, extack);
2630         if (err < 0)
2631                 return err;
2632
2633         t = nlmsg_data(n);
2634         protocol = TC_H_MIN(t->tcm_info);
2635         prio = TC_H_MAJ(t->tcm_info);
2636         parent = t->tcm_parent;
2637
2638         if (prio == 0) {
2639                 NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2640                 return -ENOENT;
2641         }
2642
2643         /* Find head of filter chain. */
2644
2645         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2646         if (err)
2647                 return err;
2648
2649         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2650                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2651                 err = -EINVAL;
2652                 goto errout;
2653         }
2654         /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
2655          * unlocked, classifier type is not specified, classifier is not
2656          * unlocked.
2657          */
2658         if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2659             !tcf_proto_is_unlocked(name)) {
2660                 rtnl_held = true;
2661                 rtnl_lock();
2662         }
2663
2664         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2665         if (err)
2666                 goto errout;
2667
2668         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2669                                  extack);
2670         if (IS_ERR(block)) {
2671                 err = PTR_ERR(block);
2672                 goto errout;
2673         }
2674
2675         chain_index = nla_get_u32_default(tca[TCA_CHAIN], 0);
2676         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2677                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2678                 err = -EINVAL;
2679                 goto errout;
2680         }
2681         chain = tcf_chain_get(block, chain_index, false);
2682         if (!chain) {
2683                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2684                 err = -EINVAL;
2685                 goto errout;
2686         }
2687
2688         mutex_lock(&chain->filter_chain_lock);
2689         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2690                                prio, false, extack);
2691         mutex_unlock(&chain->filter_chain_lock);
2692         if (!tp) {
2693                 err = -ENOENT;
2694                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2695                 goto errout;
2696         } else if (IS_ERR(tp)) {
2697                 err = PTR_ERR(tp);
2698                 goto errout;
2699         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2700                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2701                 err = -EINVAL;
2702                 goto errout;
2703         }
2704
2705         fh = tp->ops->get(tp, t->tcm_handle);
2706
2707         if (!fh) {
2708                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2709                 err = -ENOENT;
2710         } else {
2711                 err = tfilter_notify(net, skb, n, tp, block, q, parent,
2712                                      fh, RTM_NEWTFILTER, true, rtnl_held, NULL);
2713                 if (err < 0)
2714                         NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
2715         }
2716
2717         tfilter_put(tp, fh);
2718 errout:
2719         if (chain) {
2720                 if (tp && !IS_ERR(tp))
2721                         tcf_proto_put(tp, rtnl_held, NULL);
2722                 tcf_chain_put(chain);
2723         }
2724         tcf_block_release(q, block, rtnl_held);
2725
2726         if (rtnl_held)
2727                 rtnl_unlock();
2728
2729         return err;
2730 }
2731
2732 struct tcf_dump_args {
2733         struct tcf_walker w;
2734         struct sk_buff *skb;
2735         struct netlink_callback *cb;
2736         struct tcf_block *block;
2737         struct Qdisc *q;
2738         u32 parent;
2739         bool terse_dump;
2740 };
2741
2742 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2743 {
2744         struct tcf_dump_args *a = (void *)arg;
2745         struct net *net = sock_net(a->skb->sk);
2746
2747         return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
2748                              n, NETLINK_CB(a->cb->skb).portid,
2749                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2750                              RTM_NEWTFILTER, a->terse_dump, true, NULL);
2751 }
2752
2753 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
2754                            struct sk_buff *skb, struct netlink_callback *cb,
2755                            long index_start, long *p_index, bool terse)
2756 {
2757         struct net *net = sock_net(skb->sk);
2758         struct tcf_block *block = chain->block;
2759         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2760         struct tcf_proto *tp, *tp_prev;
2761         struct tcf_dump_args arg;
2762
2763         for (tp = __tcf_get_next_proto(chain, NULL);
2764              tp;
2765              tp_prev = tp,
2766                      tp = __tcf_get_next_proto(chain, tp),
2767                      tcf_proto_put(tp_prev, true, NULL),
2768                      (*p_index)++) {
2769                 if (*p_index < index_start)
2770                         continue;
2771                 if (TC_H_MAJ(tcm->tcm_info) &&
2772                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
2773                         continue;
2774                 if (TC_H_MIN(tcm->tcm_info) &&
2775                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
2776                         continue;
2777                 if (*p_index > index_start)
2778                         memset(&cb->args[1], 0,
2779                                sizeof(cb->args) - sizeof(cb->args[0]));
2780                 if (cb->args[1] == 0) {
2781                         if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
2782                                           NETLINK_CB(cb->skb).portid,
2783                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
2784                                           RTM_NEWTFILTER, false, true, NULL) <= 0)
2785                                 goto errout;
2786                         cb->args[1] = 1;
2787                 }
2788                 if (!tp->ops->walk)
2789                         continue;
2790                 arg.w.fn = tcf_node_dump;
2791                 arg.skb = skb;
2792                 arg.cb = cb;
2793                 arg.block = block;
2794                 arg.q = q;
2795                 arg.parent = parent;
2796                 arg.w.stop = 0;
2797                 arg.w.skip = cb->args[1] - 1;
2798                 arg.w.count = 0;
2799                 arg.w.cookie = cb->args[2];
2800                 arg.terse_dump = terse;
2801                 tp->ops->walk(tp, &arg.w, true);
2802                 cb->args[2] = arg.w.cookie;
2803                 cb->args[1] = arg.w.count + 1;
2804                 if (arg.w.stop)
2805                         goto errout;
2806         }
2807         return true;
2808
2809 errout:
2810         tcf_proto_put(tp, true, NULL);
2811         return false;
2812 }
2813
2814 static const struct nla_policy tcf_tfilter_dump_policy[TCA_MAX + 1] = {
2815         [TCA_CHAIN]      = { .type = NLA_U32 },
2816         [TCA_DUMP_FLAGS] = NLA_POLICY_BITFIELD32(TCA_DUMP_FLAGS_TERSE),
2817 };
2818
2819 /* called with RTNL */
2820 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
2821 {
2822         struct tcf_chain *chain, *chain_prev;
2823         struct net *net = sock_net(skb->sk);
2824         struct nlattr *tca[TCA_MAX + 1];
2825         struct Qdisc *q = NULL;
2826         struct tcf_block *block;
2827         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2828         bool terse_dump = false;
2829         long index_start;
2830         long index;
2831         u32 parent;
2832         int err;
2833
2834         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2835                 return skb->len;
2836
2837         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2838                                      tcf_tfilter_dump_policy, cb->extack);
2839         if (err)
2840                 return err;
2841
2842         if (tca[TCA_DUMP_FLAGS]) {
2843                 struct nla_bitfield32 flags =
2844                         nla_get_bitfield32(tca[TCA_DUMP_FLAGS]);
2845
2846                 terse_dump = flags.value & TCA_DUMP_FLAGS_TERSE;
2847         }
2848
2849         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2850                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2851                 if (!block)
2852                         goto out;
2853                 /* If we work with block index, q is NULL and parent value
2854                  * will never be used in the following code. The check
2855                  * in tcf_fill_node prevents it. However, compiler does not
2856                  * see that far, so set parent to zero to silence the warning
2857                  * about parent being uninitialized.
2858                  */
2859                 parent = 0;
2860         } else {
2861                 const struct Qdisc_class_ops *cops;
2862                 struct net_device *dev;
2863                 unsigned long cl = 0;
2864
2865                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2866                 if (!dev)
2867                         return skb->len;
2868
2869                 parent = tcm->tcm_parent;
2870                 if (!parent)
2871                         q = rtnl_dereference(dev->qdisc);
2872                 else
2873                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2874                 if (!q)
2875                         goto out;
2876                 cops = q->ops->cl_ops;
2877                 if (!cops)
2878                         goto out;
2879                 if (!cops->tcf_block)
2880                         goto out;
2881                 if (TC_H_MIN(tcm->tcm_parent)) {
2882                         cl = cops->find(q, tcm->tcm_parent);
2883                         if (cl == 0)
2884                                 goto out;
2885                 }
2886                 block = cops->tcf_block(q, cl, NULL);
2887                 if (!block)
2888                         goto out;
2889                 parent = block->classid;
2890                 if (tcf_block_shared(block))
2891                         q = NULL;
2892         }
2893
2894         index_start = cb->args[0];
2895         index = 0;
2896
2897         for (chain = __tcf_get_next_chain(block, NULL);
2898              chain;
2899              chain_prev = chain,
2900                      chain = __tcf_get_next_chain(block, chain),
2901                      tcf_chain_put(chain_prev)) {
2902                 if (tca[TCA_CHAIN] &&
2903                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
2904                         continue;
2905                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
2906                                     index_start, &index, terse_dump)) {
2907                         tcf_chain_put(chain);
2908                         err = -EMSGSIZE;
2909                         break;
2910                 }
2911         }
2912
2913         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2914                 tcf_block_refcnt_put(block, true);
2915         cb->args[0] = index;
2916
2917 out:
2918         /* If we did no progress, the error (EMSGSIZE) is real */
2919         if (skb->len == 0 && err)
2920                 return err;
2921         return skb->len;
2922 }
2923
2924 static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
2925                               void *tmplt_priv, u32 chain_index,
2926                               struct net *net, struct sk_buff *skb,
2927                               struct tcf_block *block,
2928                               u32 portid, u32 seq, u16 flags, int event,
2929                               struct netlink_ext_ack *extack)
2930 {
2931         unsigned char *b = skb_tail_pointer(skb);
2932         const struct tcf_proto_ops *ops;
2933         struct nlmsghdr *nlh;
2934         struct tcmsg *tcm;
2935         void *priv;
2936
2937         ops = tmplt_ops;
2938         priv = tmplt_priv;
2939
2940         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2941         if (!nlh)
2942                 goto out_nlmsg_trim;
2943         tcm = nlmsg_data(nlh);
2944         tcm->tcm_family = AF_UNSPEC;
2945         tcm->tcm__pad1 = 0;
2946         tcm->tcm__pad2 = 0;
2947         tcm->tcm_handle = 0;
2948         if (block->q) {
2949                 tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
2950                 tcm->tcm_parent = block->q->handle;
2951         } else {
2952                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2953                 tcm->tcm_block_index = block->index;
2954         }
2955
2956         if (nla_put_u32(skb, TCA_CHAIN, chain_index))
2957                 goto nla_put_failure;
2958
2959         if (ops) {
2960                 if (nla_put_string(skb, TCA_KIND, ops->kind))
2961                         goto nla_put_failure;
2962                 if (ops->tmplt_dump(skb, net, priv) < 0)
2963                         goto nla_put_failure;
2964         }
2965
2966         if (extack && extack->_msg &&
2967             nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
2968                 goto out_nlmsg_trim;
2969
2970         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2971
2972         return skb->len;
2973
2974 out_nlmsg_trim:
2975 nla_put_failure:
2976         nlmsg_trim(skb, b);
2977         return -EMSGSIZE;
2978 }
2979
2980 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
2981                            u32 seq, u16 flags, int event, bool unicast,
2982                            struct netlink_ext_ack *extack)
2983 {
2984         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2985         struct tcf_block *block = chain->block;
2986         struct net *net = block->net;
2987         struct sk_buff *skb;
2988         int err = 0;
2989
2990         if (!unicast && !rtnl_notify_needed(net, flags, RTNLGRP_TC))
2991                 return 0;
2992
2993         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2994         if (!skb)
2995                 return -ENOBUFS;
2996
2997         if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2998                                chain->index, net, skb, block, portid,
2999                                seq, flags, event, extack) <= 0) {
3000                 kfree_skb(skb);
3001                 return -EINVAL;
3002         }
3003
3004         if (unicast)
3005                 err = rtnl_unicast(skb, net, portid);
3006         else
3007                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
3008                                      flags & NLM_F_ECHO);
3009
3010         return err;
3011 }
3012
3013 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
3014                                   void *tmplt_priv, u32 chain_index,
3015                                   struct tcf_block *block, struct sk_buff *oskb,
3016                                   u32 seq, u16 flags)
3017 {
3018         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
3019         struct net *net = block->net;
3020         struct sk_buff *skb;
3021
3022         if (!rtnl_notify_needed(net, flags, RTNLGRP_TC))
3023                 return 0;
3024
3025         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3026         if (!skb)
3027                 return -ENOBUFS;
3028
3029         if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
3030                                block, portid, seq, flags, RTM_DELCHAIN, NULL) <= 0) {
3031                 kfree_skb(skb);
3032                 return -EINVAL;
3033         }
3034
3035         return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
3036 }
3037
3038 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
3039                               struct nlattr **tca,
3040                               struct netlink_ext_ack *extack)
3041 {
3042         const struct tcf_proto_ops *ops;
3043         char name[IFNAMSIZ];
3044         void *tmplt_priv;
3045
3046         /* If kind is not set, user did not specify template. */
3047         if (!tca[TCA_KIND])
3048                 return 0;
3049
3050         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
3051                 NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
3052                 return -EINVAL;
3053         }
3054
3055         ops = tcf_proto_lookup_ops(name, true, extack);
3056         if (IS_ERR(ops))
3057                 return PTR_ERR(ops);
3058         if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump ||
3059             !ops->tmplt_reoffload) {
3060                 NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
3061                 module_put(ops->owner);
3062                 return -EOPNOTSUPP;
3063         }
3064
3065         tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
3066         if (IS_ERR(tmplt_priv)) {
3067                 module_put(ops->owner);
3068                 return PTR_ERR(tmplt_priv);
3069         }
3070         chain->tmplt_ops = ops;
3071         chain->tmplt_priv = tmplt_priv;
3072         return 0;
3073 }
3074
3075 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
3076                                void *tmplt_priv)
3077 {
3078         /* If template ops are set, no work to do for us. */
3079         if (!tmplt_ops)
3080                 return;
3081
3082         tmplt_ops->tmplt_destroy(tmplt_priv);
3083         module_put(tmplt_ops->owner);
3084 }
3085
3086 /* Add/delete/get a chain */
3087
3088 static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
3089                         struct netlink_ext_ack *extack)
3090 {
3091         struct net *net = sock_net(skb->sk);
3092         struct nlattr *tca[TCA_MAX + 1];
3093         struct tcmsg *t;
3094         u32 parent;
3095         u32 chain_index;
3096         struct Qdisc *q;
3097         struct tcf_chain *chain;
3098         struct tcf_block *block;
3099         unsigned long cl;
3100         int err;
3101
3102 replay:
3103         q = NULL;
3104         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
3105                                      rtm_tca_policy, extack);
3106         if (err < 0)
3107                 return err;
3108
3109         t = nlmsg_data(n);
3110         parent = t->tcm_parent;
3111         cl = 0;
3112
3113         block = tcf_block_find(net, &q, &parent, &cl,
3114                                t->tcm_ifindex, t->tcm_block_index, extack);
3115         if (IS_ERR(block))
3116                 return PTR_ERR(block);
3117
3118         chain_index = nla_get_u32_default(tca[TCA_CHAIN], 0);
3119         if (chain_index > TC_ACT_EXT_VAL_MASK) {
3120                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
3121                 err = -EINVAL;
3122                 goto errout_block;
3123         }
3124
3125         mutex_lock(&block->lock);
3126         chain = tcf_chain_lookup(block, chain_index);
3127         if (n->nlmsg_type == RTM_NEWCHAIN) {
3128                 if (chain) {
3129                         if (tcf_chain_held_by_acts_only(chain)) {
3130                                 /* The chain exists only because there is
3131                                  * some action referencing it.
3132                                  */
3133                                 tcf_chain_hold(chain);
3134                         } else {
3135                                 NL_SET_ERR_MSG(extack, "Filter chain already exists");
3136                                 err = -EEXIST;
3137                                 goto errout_block_locked;
3138                         }
3139                 } else {
3140                         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
3141                                 NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
3142                                 err = -ENOENT;
3143                                 goto errout_block_locked;
3144                         }
3145                         chain = tcf_chain_create(block, chain_index);
3146                         if (!chain) {
3147                                 NL_SET_ERR_MSG(extack, "Failed to create filter chain");
3148                                 err = -ENOMEM;
3149                                 goto errout_block_locked;
3150                         }
3151                 }
3152         } else {
3153                 if (!chain || tcf_chain_held_by_acts_only(chain)) {
3154                         NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
3155                         err = -EINVAL;
3156                         goto errout_block_locked;
3157                 }
3158                 tcf_chain_hold(chain);
3159         }
3160
3161         if (n->nlmsg_type == RTM_NEWCHAIN) {
3162                 /* Modifying chain requires holding parent block lock. In case
3163                  * the chain was successfully added, take a reference to the
3164                  * chain. This ensures that an empty chain does not disappear at
3165                  * the end of this function.
3166                  */
3167                 tcf_chain_hold(chain);
3168                 chain->explicitly_created = true;
3169         }
3170         mutex_unlock(&block->lock);
3171
3172         switch (n->nlmsg_type) {
3173         case RTM_NEWCHAIN:
3174                 err = tc_chain_tmplt_add(chain, net, tca, extack);
3175                 if (err) {
3176                         tcf_chain_put_explicitly_created(chain);
3177                         goto errout;
3178                 }
3179
3180                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
3181                                 RTM_NEWCHAIN, false, extack);
3182                 break;
3183         case RTM_DELCHAIN:
3184                 tfilter_notify_chain(net, skb, block, q, parent, n,
3185                                      chain, RTM_DELTFILTER, extack);
3186                 /* Flush the chain first as the user requested chain removal. */
3187                 tcf_chain_flush(chain, true);
3188                 /* In case the chain was successfully deleted, put a reference
3189                  * to the chain previously taken during addition.
3190                  */
3191                 tcf_chain_put_explicitly_created(chain);
3192                 break;
3193         case RTM_GETCHAIN:
3194                 err = tc_chain_notify(chain, skb, n->nlmsg_seq,
3195                                       n->nlmsg_flags, n->nlmsg_type, true, extack);
3196                 if (err < 0)
3197                         NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
3198                 break;
3199         default:
3200                 err = -EOPNOTSUPP;
3201                 NL_SET_ERR_MSG(extack, "Unsupported message type");
3202                 goto errout;
3203         }
3204
3205 errout:
3206         tcf_chain_put(chain);
3207 errout_block:
3208         tcf_block_release(q, block, true);
3209         if (err == -EAGAIN)
3210                 /* Replay the request. */
3211                 goto replay;
3212         return err;
3213
3214 errout_block_locked:
3215         mutex_unlock(&block->lock);
3216         goto errout_block;
3217 }
3218
3219 /* called with RTNL */
3220 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
3221 {
3222         struct net *net = sock_net(skb->sk);
3223         struct nlattr *tca[TCA_MAX + 1];
3224         struct Qdisc *q = NULL;
3225         struct tcf_block *block;
3226         struct tcmsg *tcm = nlmsg_data(cb->nlh);
3227         struct tcf_chain *chain;
3228         long index_start;
3229         long index;
3230         int err;
3231
3232         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
3233                 return skb->len;
3234
3235         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
3236                                      rtm_tca_policy, cb->extack);
3237         if (err)
3238                 return err;
3239
3240         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
3241                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
3242                 if (!block)
3243                         goto out;
3244         } else {
3245                 const struct Qdisc_class_ops *cops;
3246                 struct net_device *dev;
3247                 unsigned long cl = 0;
3248
3249                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
3250                 if (!dev)
3251                         return skb->len;
3252
3253                 if (!tcm->tcm_parent)
3254                         q = rtnl_dereference(dev->qdisc);
3255                 else
3256                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
3257
3258                 if (!q)
3259                         goto out;
3260                 cops = q->ops->cl_ops;
3261                 if (!cops)
3262                         goto out;
3263                 if (!cops->tcf_block)
3264                         goto out;
3265                 if (TC_H_MIN(tcm->tcm_parent)) {
3266                         cl = cops->find(q, tcm->tcm_parent);
3267                         if (cl == 0)
3268                                 goto out;
3269                 }
3270                 block = cops->tcf_block(q, cl, NULL);
3271                 if (!block)
3272                         goto out;
3273                 if (tcf_block_shared(block))
3274                         q = NULL;
3275         }
3276
3277         index_start = cb->args[0];
3278         index = 0;
3279
3280         mutex_lock(&block->lock);
3281         list_for_each_entry(chain, &block->chain_list, list) {
3282                 if ((tca[TCA_CHAIN] &&
3283                      nla_get_u32(tca[TCA_CHAIN]) != chain->index))
3284                         continue;
3285                 if (index < index_start) {
3286                         index++;
3287                         continue;
3288                 }
3289                 if (tcf_chain_held_by_acts_only(chain))
3290                         continue;
3291                 err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
3292                                          chain->index, net, skb, block,
3293                                          NETLINK_CB(cb->skb).portid,
3294                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
3295                                          RTM_NEWCHAIN, NULL);
3296                 if (err <= 0)
3297                         break;
3298                 index++;
3299         }
3300         mutex_unlock(&block->lock);
3301
3302         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
3303                 tcf_block_refcnt_put(block, true);
3304         cb->args[0] = index;
3305
3306 out:
3307         /* If we did no progress, the error (EMSGSIZE) is real */
3308         if (skb->len == 0 && err)
3309                 return err;
3310         return skb->len;
3311 }
3312
3313 int tcf_exts_init_ex(struct tcf_exts *exts, struct net *net, int action,
3314                      int police, struct tcf_proto *tp, u32 handle,
3315                      bool use_action_miss)
3316 {
3317         int err = 0;
3318
3319 #ifdef CONFIG_NET_CLS_ACT
3320         exts->type = 0;
3321         exts->nr_actions = 0;
3322         exts->miss_cookie_node = NULL;
3323         /* Note: we do not own yet a reference on net.
3324          * This reference might be taken later from tcf_exts_get_net().
3325          */
3326         exts->net = net;
3327         exts->actions = kcalloc(TCA_ACT_MAX_PRIO, sizeof(struct tc_action *),
3328                                 GFP_KERNEL);
3329         if (!exts->actions)
3330                 return -ENOMEM;
3331 #endif
3332
3333         exts->action = action;
3334         exts->police = police;
3335
3336         if (!use_action_miss)
3337                 return 0;
3338
3339         err = tcf_exts_miss_cookie_base_alloc(exts, tp, handle);
3340         if (err)
3341                 goto err_miss_alloc;
3342
3343         return 0;
3344
3345 err_miss_alloc:
3346         tcf_exts_destroy(exts);
3347 #ifdef CONFIG_NET_CLS_ACT
3348         exts->actions = NULL;
3349 #endif
3350         return err;
3351 }
3352 EXPORT_SYMBOL(tcf_exts_init_ex);
3353
3354 void tcf_exts_destroy(struct tcf_exts *exts)
3355 {
3356         tcf_exts_miss_cookie_base_destroy(exts);
3357
3358 #ifdef CONFIG_NET_CLS_ACT
3359         if (exts->actions) {
3360                 tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
3361                 kfree(exts->actions);
3362         }
3363         exts->nr_actions = 0;
3364 #endif
3365 }
3366 EXPORT_SYMBOL(tcf_exts_destroy);
3367
3368 int tcf_exts_validate_ex(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3369                          struct nlattr *rate_tlv, struct tcf_exts *exts,
3370                          u32 flags, u32 fl_flags, struct netlink_ext_ack *extack)
3371 {
3372 #ifdef CONFIG_NET_CLS_ACT
3373         {
3374                 int init_res[TCA_ACT_MAX_PRIO] = {};
3375                 struct tc_action *act;
3376                 size_t attr_size = 0;
3377
3378                 if (exts->police && tb[exts->police]) {
3379                         struct tc_action_ops *a_o;
3380
3381                         flags |= TCA_ACT_FLAGS_POLICE | TCA_ACT_FLAGS_BIND;
3382                         a_o = tc_action_load_ops(tb[exts->police], flags,
3383                                                  extack);
3384                         if (IS_ERR(a_o))
3385                                 return PTR_ERR(a_o);
3386                         act = tcf_action_init_1(net, tp, tb[exts->police],
3387                                                 rate_tlv, a_o, init_res, flags,
3388                                                 extack);
3389                         module_put(a_o->owner);
3390                         if (IS_ERR(act))
3391                                 return PTR_ERR(act);
3392
3393                         act->type = exts->type = TCA_OLD_COMPAT;
3394                         exts->actions[0] = act;
3395                         exts->nr_actions = 1;
3396                         tcf_idr_insert_many(exts->actions, init_res);
3397                 } else if (exts->action && tb[exts->action]) {
3398                         int err;
3399
3400                         flags |= TCA_ACT_FLAGS_BIND;
3401                         err = tcf_action_init(net, tp, tb[exts->action],
3402                                               rate_tlv, exts->actions, init_res,
3403                                               &attr_size, flags, fl_flags,
3404                                               extack);
3405                         if (err < 0)
3406                                 return err;
3407                         exts->nr_actions = err;
3408                 }
3409         }
3410 #else
3411         if ((exts->action && tb[exts->action]) ||
3412             (exts->police && tb[exts->police])) {
3413                 NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
3414                 return -EOPNOTSUPP;
3415         }
3416 #endif
3417
3418         return 0;
3419 }
3420 EXPORT_SYMBOL(tcf_exts_validate_ex);
3421
3422 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3423                       struct nlattr *rate_tlv, struct tcf_exts *exts,
3424                       u32 flags, struct netlink_ext_ack *extack)
3425 {
3426         return tcf_exts_validate_ex(net, tp, tb, rate_tlv, exts,
3427                                     flags, 0, extack);
3428 }
3429 EXPORT_SYMBOL(tcf_exts_validate);
3430
3431 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
3432 {
3433 #ifdef CONFIG_NET_CLS_ACT
3434         struct tcf_exts old = *dst;
3435
3436         *dst = *src;
3437         tcf_exts_destroy(&old);
3438 #endif
3439 }
3440 EXPORT_SYMBOL(tcf_exts_change);
3441
3442 #ifdef CONFIG_NET_CLS_ACT
3443 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
3444 {
3445         if (exts->nr_actions == 0)
3446                 return NULL;
3447         else
3448                 return exts->actions[0];
3449 }
3450 #endif
3451
3452 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
3453 {
3454 #ifdef CONFIG_NET_CLS_ACT
3455         struct nlattr *nest;
3456
3457         if (exts->action && tcf_exts_has_actions(exts)) {
3458                 /*
3459                  * again for backward compatible mode - we want
3460                  * to work with both old and new modes of entering
3461                  * tc data even if iproute2  was newer - jhs
3462                  */
3463                 if (exts->type != TCA_OLD_COMPAT) {
3464                         nest = nla_nest_start_noflag(skb, exts->action);
3465                         if (nest == NULL)
3466                                 goto nla_put_failure;
3467
3468                         if (tcf_action_dump(skb, exts->actions, 0, 0, false)
3469                             < 0)
3470                                 goto nla_put_failure;
3471                         nla_nest_end(skb, nest);
3472                 } else if (exts->police) {
3473                         struct tc_action *act = tcf_exts_first_act(exts);
3474                         nest = nla_nest_start_noflag(skb, exts->police);
3475                         if (nest == NULL || !act)
3476                                 goto nla_put_failure;
3477                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
3478                                 goto nla_put_failure;
3479                         nla_nest_end(skb, nest);
3480                 }
3481         }
3482         return 0;
3483
3484 nla_put_failure:
3485         nla_nest_cancel(skb, nest);
3486         return -1;
3487 #else
3488         return 0;
3489 #endif
3490 }
3491 EXPORT_SYMBOL(tcf_exts_dump);
3492
3493 int tcf_exts_terse_dump(struct sk_buff *skb, struct tcf_exts *exts)
3494 {
3495 #ifdef CONFIG_NET_CLS_ACT
3496         struct nlattr *nest;
3497
3498         if (!exts->action || !tcf_exts_has_actions(exts))
3499                 return 0;
3500
3501         nest = nla_nest_start_noflag(skb, exts->action);
3502         if (!nest)
3503                 goto nla_put_failure;
3504
3505         if (tcf_action_dump(skb, exts->actions, 0, 0, true) < 0)
3506                 goto nla_put_failure;
3507         nla_nest_end(skb, nest);
3508         return 0;
3509
3510 nla_put_failure:
3511         nla_nest_cancel(skb, nest);
3512         return -1;
3513 #else
3514         return 0;
3515 #endif
3516 }
3517 EXPORT_SYMBOL(tcf_exts_terse_dump);
3518
3519 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
3520 {
3521 #ifdef CONFIG_NET_CLS_ACT
3522         struct tc_action *a = tcf_exts_first_act(exts);
3523         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
3524                 return -1;
3525 #endif
3526         return 0;
3527 }
3528 EXPORT_SYMBOL(tcf_exts_dump_stats);
3529
3530 static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
3531 {
3532         if (*flags & TCA_CLS_FLAGS_IN_HW)
3533                 return;
3534         *flags |= TCA_CLS_FLAGS_IN_HW;
3535         if (tc_skip_sw(*flags))
3536                 atomic_inc(&block->skipswcnt);
3537         atomic_inc(&block->offloadcnt);
3538 }
3539
3540 static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
3541 {
3542         if (!(*flags & TCA_CLS_FLAGS_IN_HW))
3543                 return;
3544         *flags &= ~TCA_CLS_FLAGS_IN_HW;
3545         if (tc_skip_sw(*flags))
3546                 atomic_dec(&block->skipswcnt);
3547         atomic_dec(&block->offloadcnt);
3548 }
3549
3550 static void tc_cls_offload_cnt_update(struct tcf_block *block,
3551                                       struct tcf_proto *tp, u32 *cnt,
3552                                       u32 *flags, u32 diff, bool add)
3553 {
3554         lockdep_assert_held(&block->cb_lock);
3555
3556         spin_lock(&tp->lock);
3557         if (add) {
3558                 if (!*cnt)
3559                         tcf_block_offload_inc(block, flags);
3560                 *cnt += diff;
3561         } else {
3562                 *cnt -= diff;
3563                 if (!*cnt)
3564                         tcf_block_offload_dec(block, flags);
3565         }
3566         spin_unlock(&tp->lock);
3567 }
3568
3569 static void
3570 tc_cls_offload_cnt_reset(struct tcf_block *block, struct tcf_proto *tp,
3571                          u32 *cnt, u32 *flags)
3572 {
3573         lockdep_assert_held(&block->cb_lock);
3574
3575         spin_lock(&tp->lock);
3576         tcf_block_offload_dec(block, flags);
3577         *cnt = 0;
3578         spin_unlock(&tp->lock);
3579 }
3580
3581 static int
3582 __tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3583                    void *type_data, bool err_stop)
3584 {
3585         struct flow_block_cb *block_cb;
3586         int ok_count = 0;
3587         int err;
3588
3589         list_for_each_entry(block_cb, &block->flow_block.cb_list, list) {
3590                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
3591                 if (err) {
3592                         if (err_stop)
3593                                 return err;
3594                 } else {
3595                         ok_count++;
3596                 }
3597         }
3598         return ok_count;
3599 }
3600
3601 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3602                      void *type_data, bool err_stop, bool rtnl_held)
3603 {
3604         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3605         int ok_count;
3606
3607 retry:
3608         if (take_rtnl)
3609                 rtnl_lock();
3610         down_read(&block->cb_lock);
3611         /* Need to obtain rtnl lock if block is bound to devs that require it.
3612          * In block bind code cb_lock is obtained while holding rtnl, so we must
3613          * obtain the locks in same order here.
3614          */
3615         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3616                 up_read(&block->cb_lock);
3617                 take_rtnl = true;
3618                 goto retry;
3619         }
3620
3621         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3622
3623         up_read(&block->cb_lock);
3624         if (take_rtnl)
3625                 rtnl_unlock();
3626         return ok_count;
3627 }
3628 EXPORT_SYMBOL(tc_setup_cb_call);
3629
3630 /* Non-destructive filter add. If filter that wasn't already in hardware is
3631  * successfully offloaded, increment block offloads counter. On failure,
3632  * previously offloaded filter is considered to be intact and offloads counter
3633  * is not decremented.
3634  */
3635
3636 int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
3637                     enum tc_setup_type type, void *type_data, bool err_stop,
3638                     u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3639 {
3640         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3641         int ok_count;
3642
3643 retry:
3644         if (take_rtnl)
3645                 rtnl_lock();
3646         down_read(&block->cb_lock);
3647         /* Need to obtain rtnl lock if block is bound to devs that require it.
3648          * In block bind code cb_lock is obtained while holding rtnl, so we must
3649          * obtain the locks in same order here.
3650          */
3651         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3652                 up_read(&block->cb_lock);
3653                 take_rtnl = true;
3654                 goto retry;
3655         }
3656
3657         /* Make sure all netdevs sharing this block are offload-capable. */
3658         if (block->nooffloaddevcnt && err_stop) {
3659                 ok_count = -EOPNOTSUPP;
3660                 goto err_unlock;
3661         }
3662
3663         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3664         if (ok_count < 0)
3665                 goto err_unlock;
3666
3667         if (tp->ops->hw_add)
3668                 tp->ops->hw_add(tp, type_data);
3669         if (ok_count > 0)
3670                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
3671                                           ok_count, true);
3672 err_unlock:
3673         up_read(&block->cb_lock);
3674         if (take_rtnl)
3675                 rtnl_unlock();
3676         return min(ok_count, 0);
3677 }
3678 EXPORT_SYMBOL(tc_setup_cb_add);
3679
3680 /* Destructive filter replace. If filter that wasn't already in hardware is
3681  * successfully offloaded, increment block offload counter. On failure,
3682  * previously offloaded filter is considered to be destroyed and offload counter
3683  * is decremented.
3684  */
3685
3686 int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
3687                         enum tc_setup_type type, void *type_data, bool err_stop,
3688                         u32 *old_flags, unsigned int *old_in_hw_count,
3689                         u32 *new_flags, unsigned int *new_in_hw_count,
3690                         bool rtnl_held)
3691 {
3692         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3693         int ok_count;
3694
3695 retry:
3696         if (take_rtnl)
3697                 rtnl_lock();
3698         down_read(&block->cb_lock);
3699         /* Need to obtain rtnl lock if block is bound to devs that require it.
3700          * In block bind code cb_lock is obtained while holding rtnl, so we must
3701          * obtain the locks in same order here.
3702          */
3703         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3704                 up_read(&block->cb_lock);
3705                 take_rtnl = true;
3706                 goto retry;
3707         }
3708
3709         /* Make sure all netdevs sharing this block are offload-capable. */
3710         if (block->nooffloaddevcnt && err_stop) {
3711                 ok_count = -EOPNOTSUPP;
3712                 goto err_unlock;
3713         }
3714
3715         tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
3716         if (tp->ops->hw_del)
3717                 tp->ops->hw_del(tp, type_data);
3718
3719         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3720         if (ok_count < 0)
3721                 goto err_unlock;
3722
3723         if (tp->ops->hw_add)
3724                 tp->ops->hw_add(tp, type_data);
3725         if (ok_count > 0)
3726                 tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
3727                                           new_flags, ok_count, true);
3728 err_unlock:
3729         up_read(&block->cb_lock);
3730         if (take_rtnl)
3731                 rtnl_unlock();
3732         return min(ok_count, 0);
3733 }
3734 EXPORT_SYMBOL(tc_setup_cb_replace);
3735
3736 /* Destroy filter and decrement block offload counter, if filter was previously
3737  * offloaded.
3738  */
3739
3740 int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
3741                         enum tc_setup_type type, void *type_data, bool err_stop,
3742                         u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3743 {
3744         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3745         int ok_count;
3746
3747 retry:
3748         if (take_rtnl)
3749                 rtnl_lock();
3750         down_read(&block->cb_lock);
3751         /* Need to obtain rtnl lock if block is bound to devs that require it.
3752          * In block bind code cb_lock is obtained while holding rtnl, so we must
3753          * obtain the locks in same order here.
3754          */
3755         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3756                 up_read(&block->cb_lock);
3757                 take_rtnl = true;
3758                 goto retry;
3759         }
3760
3761         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3762
3763         tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
3764         if (tp->ops->hw_del)
3765                 tp->ops->hw_del(tp, type_data);
3766
3767         up_read(&block->cb_lock);
3768         if (take_rtnl)
3769                 rtnl_unlock();
3770         return min(ok_count, 0);
3771 }
3772 EXPORT_SYMBOL(tc_setup_cb_destroy);
3773
3774 int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
3775                           bool add, flow_setup_cb_t *cb,
3776                           enum tc_setup_type type, void *type_data,
3777                           void *cb_priv, u32 *flags, unsigned int *in_hw_count)
3778 {
3779         int err = cb(type, type_data, cb_priv);
3780
3781         if (err) {
3782                 if (add && tc_skip_sw(*flags))
3783                         return err;
3784         } else {
3785                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags, 1,
3786                                           add);
3787         }
3788
3789         return 0;
3790 }
3791 EXPORT_SYMBOL(tc_setup_cb_reoffload);
3792
3793 static int tcf_act_get_user_cookie(struct flow_action_entry *entry,
3794                                    const struct tc_action *act)
3795 {
3796         struct tc_cookie *user_cookie;
3797         int err = 0;
3798
3799         rcu_read_lock();
3800         user_cookie = rcu_dereference(act->user_cookie);
3801         if (user_cookie) {
3802                 entry->user_cookie = flow_action_cookie_create(user_cookie->data,
3803                                                                user_cookie->len,
3804                                                                GFP_ATOMIC);
3805                 if (!entry->user_cookie)
3806                         err = -ENOMEM;
3807         }
3808         rcu_read_unlock();
3809         return err;
3810 }
3811
3812 static void tcf_act_put_user_cookie(struct flow_action_entry *entry)
3813 {
3814         flow_action_cookie_destroy(entry->user_cookie);
3815 }
3816
3817 void tc_cleanup_offload_action(struct flow_action *flow_action)
3818 {
3819         struct flow_action_entry *entry;
3820         int i;
3821
3822         flow_action_for_each(i, entry, flow_action) {
3823                 tcf_act_put_user_cookie(entry);
3824                 if (entry->destructor)
3825                         entry->destructor(entry->destructor_priv);
3826         }
3827 }
3828 EXPORT_SYMBOL(tc_cleanup_offload_action);
3829
3830 static int tc_setup_offload_act(struct tc_action *act,
3831                                 struct flow_action_entry *entry,
3832                                 u32 *index_inc,
3833                                 struct netlink_ext_ack *extack)
3834 {
3835 #ifdef CONFIG_NET_CLS_ACT
3836         if (act->ops->offload_act_setup) {
3837                 return act->ops->offload_act_setup(act, entry, index_inc, true,
3838                                                    extack);
3839         } else {
3840                 NL_SET_ERR_MSG(extack, "Action does not support offload");
3841                 return -EOPNOTSUPP;
3842         }
3843 #else
3844         return 0;
3845 #endif
3846 }
3847
3848 int tc_setup_action(struct flow_action *flow_action,
3849                     struct tc_action *actions[],
3850                     u32 miss_cookie_base,
3851                     struct netlink_ext_ack *extack)
3852 {
3853         int i, j, k, index, err = 0;
3854         struct tc_action *act;
3855
3856         BUILD_BUG_ON(TCA_ACT_HW_STATS_ANY != FLOW_ACTION_HW_STATS_ANY);
3857         BUILD_BUG_ON(TCA_ACT_HW_STATS_IMMEDIATE != FLOW_ACTION_HW_STATS_IMMEDIATE);
3858         BUILD_BUG_ON(TCA_ACT_HW_STATS_DELAYED != FLOW_ACTION_HW_STATS_DELAYED);
3859
3860         if (!actions)
3861                 return 0;
3862
3863         j = 0;
3864         tcf_act_for_each_action(i, act, actions) {
3865                 struct flow_action_entry *entry;
3866
3867                 entry = &flow_action->entries[j];
3868                 spin_lock_bh(&act->tcfa_lock);
3869                 err = tcf_act_get_user_cookie(entry, act);
3870                 if (err)
3871                         goto err_out_locked;
3872
3873                 index = 0;
3874                 err = tc_setup_offload_act(act, entry, &index, extack);
3875                 if (err)
3876                         goto err_out_locked;
3877
3878                 for (k = 0; k < index ; k++) {
3879                         entry[k].hw_stats = tc_act_hw_stats(act->hw_stats);
3880                         entry[k].hw_index = act->tcfa_index;
3881                         entry[k].cookie = (unsigned long)act;
3882                         entry[k].miss_cookie =
3883                                 tcf_exts_miss_cookie_get(miss_cookie_base, i);
3884                 }
3885
3886                 j += index;
3887
3888                 spin_unlock_bh(&act->tcfa_lock);
3889         }
3890
3891 err_out:
3892         if (err)
3893                 tc_cleanup_offload_action(flow_action);
3894
3895         return err;
3896 err_out_locked:
3897         spin_unlock_bh(&act->tcfa_lock);
3898         goto err_out;
3899 }
3900
3901 int tc_setup_offload_action(struct flow_action *flow_action,
3902                             const struct tcf_exts *exts,
3903                             struct netlink_ext_ack *extack)
3904 {
3905 #ifdef CONFIG_NET_CLS_ACT
3906         u32 miss_cookie_base;
3907
3908         if (!exts)
3909                 return 0;
3910
3911         miss_cookie_base = exts->miss_cookie_node ?
3912                            exts->miss_cookie_node->miss_cookie_base : 0;
3913         return tc_setup_action(flow_action, exts->actions, miss_cookie_base,
3914                                extack);
3915 #else
3916         return 0;
3917 #endif
3918 }
3919 EXPORT_SYMBOL(tc_setup_offload_action);
3920
3921 unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
3922 {
3923         unsigned int num_acts = 0;
3924         struct tc_action *act;
3925         int i;
3926
3927         tcf_exts_for_each_action(i, act, exts) {
3928                 if (is_tcf_pedit(act))
3929                         num_acts += tcf_pedit_nkeys(act);
3930                 else
3931                         num_acts++;
3932         }
3933         return num_acts;
3934 }
3935 EXPORT_SYMBOL(tcf_exts_num_actions);
3936
3937 #ifdef CONFIG_NET_CLS_ACT
3938 static int tcf_qevent_parse_block_index(struct nlattr *block_index_attr,
3939                                         u32 *p_block_index,
3940                                         struct netlink_ext_ack *extack)
3941 {
3942         *p_block_index = nla_get_u32(block_index_attr);
3943         if (!*p_block_index) {
3944                 NL_SET_ERR_MSG(extack, "Block number may not be zero");
3945                 return -EINVAL;
3946         }
3947
3948         return 0;
3949 }
3950
3951 int tcf_qevent_init(struct tcf_qevent *qe, struct Qdisc *sch,
3952                     enum flow_block_binder_type binder_type,
3953                     struct nlattr *block_index_attr,
3954                     struct netlink_ext_ack *extack)
3955 {
3956         u32 block_index;
3957         int err;
3958
3959         if (!block_index_attr)
3960                 return 0;
3961
3962         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3963         if (err)
3964                 return err;
3965
3966         qe->info.binder_type = binder_type;
3967         qe->info.chain_head_change = tcf_chain_head_change_dflt;
3968         qe->info.chain_head_change_priv = &qe->filter_chain;
3969         qe->info.block_index = block_index;
3970
3971         return tcf_block_get_ext(&qe->block, sch, &qe->info, extack);
3972 }
3973 EXPORT_SYMBOL(tcf_qevent_init);
3974
3975 void tcf_qevent_destroy(struct tcf_qevent *qe, struct Qdisc *sch)
3976 {
3977         if (qe->info.block_index)
3978                 tcf_block_put_ext(qe->block, sch, &qe->info);
3979 }
3980 EXPORT_SYMBOL(tcf_qevent_destroy);
3981
3982 int tcf_qevent_validate_change(struct tcf_qevent *qe, struct nlattr *block_index_attr,
3983                                struct netlink_ext_ack *extack)
3984 {
3985         u32 block_index;
3986         int err;
3987
3988         if (!block_index_attr)
3989                 return 0;
3990
3991         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3992         if (err)
3993                 return err;
3994
3995         /* Bounce newly-configured block or change in block. */
3996         if (block_index != qe->info.block_index) {
3997                 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
3998                 return -EINVAL;
3999         }
4000
4001         return 0;
4002 }
4003 EXPORT_SYMBOL(tcf_qevent_validate_change);
4004
4005 struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
4006                                   struct sk_buff **to_free, int *ret)
4007 {
4008         struct tcf_result cl_res;
4009         struct tcf_proto *fl;
4010
4011         if (!qe->info.block_index)
4012                 return skb;
4013
4014         fl = rcu_dereference_bh(qe->filter_chain);
4015
4016         switch (tcf_classify(skb, NULL, fl, &cl_res, false)) {
4017         case TC_ACT_SHOT:
4018                 qdisc_qstats_drop(sch);
4019                 __qdisc_drop(skb, to_free);
4020                 *ret = __NET_XMIT_BYPASS;
4021                 return NULL;
4022         case TC_ACT_STOLEN:
4023         case TC_ACT_QUEUED:
4024         case TC_ACT_TRAP:
4025                 __qdisc_drop(skb, to_free);
4026                 *ret = __NET_XMIT_STOLEN;
4027                 return NULL;
4028         case TC_ACT_REDIRECT:
4029                 skb_do_redirect(skb);
4030                 *ret = __NET_XMIT_STOLEN;
4031                 return NULL;
4032         }
4033
4034         return skb;
4035 }
4036 EXPORT_SYMBOL(tcf_qevent_handle);
4037
4038 int tcf_qevent_dump(struct sk_buff *skb, int attr_name, struct tcf_qevent *qe)
4039 {
4040         if (!qe->info.block_index)
4041                 return 0;
4042         return nla_put_u32(skb, attr_name, qe->info.block_index);
4043 }
4044 EXPORT_SYMBOL(tcf_qevent_dump);
4045 #endif
4046
4047 static __net_init int tcf_net_init(struct net *net)
4048 {
4049         struct tcf_net *tn = net_generic(net, tcf_net_id);
4050
4051         spin_lock_init(&tn->idr_lock);
4052         idr_init(&tn->idr);
4053         return 0;
4054 }
4055
4056 static void __net_exit tcf_net_exit(struct net *net)
4057 {
4058         struct tcf_net *tn = net_generic(net, tcf_net_id);
4059
4060         idr_destroy(&tn->idr);
4061 }
4062
4063 static struct pernet_operations tcf_net_ops = {
4064         .init = tcf_net_init,
4065         .exit = tcf_net_exit,
4066         .id   = &tcf_net_id,
4067         .size = sizeof(struct tcf_net),
4068 };
4069
4070 static const struct rtnl_msg_handler tc_filter_rtnl_msg_handlers[] __initconst = {
4071         {.msgtype = RTM_NEWTFILTER, .doit = tc_new_tfilter,
4072          .flags = RTNL_FLAG_DOIT_UNLOCKED},
4073         {.msgtype = RTM_DELTFILTER, .doit = tc_del_tfilter,
4074          .flags = RTNL_FLAG_DOIT_UNLOCKED},
4075         {.msgtype = RTM_GETTFILTER, .doit = tc_get_tfilter,
4076          .dumpit = tc_dump_tfilter, .flags = RTNL_FLAG_DOIT_UNLOCKED},
4077         {.msgtype = RTM_NEWCHAIN, .doit = tc_ctl_chain},
4078         {.msgtype = RTM_DELCHAIN, .doit = tc_ctl_chain},
4079         {.msgtype = RTM_GETCHAIN, .doit = tc_ctl_chain,
4080          .dumpit = tc_dump_chain},
4081 };
4082
4083 static int __init tc_filter_init(void)
4084 {
4085         int err;
4086
4087         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
4088         if (!tc_filter_wq)
4089                 return -ENOMEM;
4090
4091         err = register_pernet_subsys(&tcf_net_ops);
4092         if (err)
4093                 goto err_register_pernet_subsys;
4094
4095         xa_init_flags(&tcf_exts_miss_cookies_xa, XA_FLAGS_ALLOC1);
4096         rtnl_register_many(tc_filter_rtnl_msg_handlers);
4097
4098         return 0;
4099
4100 err_register_pernet_subsys:
4101         destroy_workqueue(tc_filter_wq);
4102         return err;
4103 }
4104
4105 subsys_initcall(tc_filter_init);