net/sched/cls

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This source file includes following definitions.
destroy_obj_hashfn
tcf_proto_signal_destroying
tcf_proto_cmp
tcf_proto_exists_destroying
tcf_proto_signal_destroyed
__tcf_proto_lookup_ops
tcf_proto_lookup_ops
register_tcf_proto_ops
unregister_tcf_proto_ops
tcf_queue_work
tcf_auto_prio
tcf_proto_check_kind
tcf_proto_is_unlocked
tcf_proto_create
tcf_proto_get
tcf_proto_destroy
tcf_proto_put
tcf_proto_check_delete
tcf_proto_mark_delete
tcf_proto_is_deleting
tcf_chain_create
tcf_chain_head_change_item
tcf_chain0_head_change
tcf_chain_detach
tcf_block_destroy
tcf_chain_destroy
tcf_chain_hold
tcf_chain_held_by_acts_only
tcf_chain_lookup
__tcf_chain_get
tcf_chain_get
tcf_chain_get_by_act
__tcf_chain_put
tcf_chain_put
tcf_chain_put_by_act
tcf_chain_put_explicitly_created
tcf_chain_flush
tc_indr_block_cmd
tc_dev_block
tc_indr_block_get_and_cmd
tc_indr_block_call
tcf_block_offload_in_use
tcf_block_offload_cmd
tcf_block_offload_bind
tcf_block_offload_unbind
tcf_chain0_head_change_cb_add
tcf_chain0_head_change_cb_del
tcf_block_insert
tcf_block_remove
tcf_block_create
tcf_block_lookup
tcf_block_refcnt_get
__tcf_get_next_chain
tcf_get_next_chain
__tcf_get_next_proto
tcf_get_next_proto
tcf_block_flush_all_chains
__tcf_qdisc_find
__tcf_qdisc_cl_find
__tcf_block_find
__tcf_block_put
tcf_block_refcnt_put
tcf_block_find
tcf_block_release
tcf_block_owner_netif_keep_dst
tcf_block_netif_keep_dst
tcf_block_owner_add
tcf_block_owner_del
tcf_block_get_ext
tcf_chain_head_change_dflt
tcf_block_get
tcf_block_put_ext
tcf_block_put
tcf_block_playback_offloads
tcf_block_bind
tcf_block_unbind
tcf_block_setup
tcf_classify
tcf_chain_tp_prev
tcf_chain_tp_insert
tcf_chain_tp_remove
tcf_chain_tp_insert_unique
tcf_chain_tp_delete_empty
tcf_chain_tp_find
tcf_fill_node
tfilter_notify
tfilter_del_notify
tfilter_notify_chain
tfilter_put
tc_new_tfilter
tc_del_tfilter
tc_get_tfilter
tcf_node_dump
tcf_chain_dump
tc_dump_tfilter
tc_chain_fill_node
tc_chain_notify
tc_chain_notify_delete
tc_chain_tmplt_add
tc_chain_tmplt_del
tc_ctl_chain
tc_dump_chain
tcf_exts_destroy
tcf_exts_validate
tcf_exts_change
tcf_exts_first_act
tcf_exts_dump
tcf_exts_dump_stats
tcf_block_offload_inc
tcf_block_offload_dec
tc_cls_offload_cnt_update
tc_cls_offload_cnt_reset
__tc_setup_cb_call
tc_setup_cb_call
tc_setup_cb_add
tc_setup_cb_replace
tc_setup_cb_destroy
tc_setup_cb_reoffload
tc_cleanup_flow_action
tcf_mirred_get_dev
tcf_tunnel_encap_put_tunnel
tcf_tunnel_encap_get_tunnel
tcf_sample_get_group
tc_setup_flow_action
tcf_exts_num_actions
tcf_net_init
tcf_net_exit
tc_filter_init
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/cls_api.c  Packet classifier API.
   4  *
   5  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   6  *
   7  * Changes:
   8  *
   9  * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
  10  */
  11 
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/kernel.h>
  15 #include <linux/string.h>
  16 #include <linux/errno.h>
  17 #include <linux/err.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/init.h>
  20 #include <linux/kmod.h>
  21 #include <linux/slab.h>
  22 #include <linux/idr.h>
  23 #include <linux/rhashtable.h>
  24 #include <linux/jhash.h>
  25 #include <net/net_namespace.h>
  26 #include <net/sock.h>
  27 #include <net/netlink.h>
  28 #include <net/pkt_sched.h>
  29 #include <net/pkt_cls.h>
  30 #include <net/tc_act/tc_pedit.h>
  31 #include <net/tc_act/tc_mirred.h>
  32 #include <net/tc_act/tc_vlan.h>
  33 #include <net/tc_act/tc_tunnel_key.h>
  34 #include <net/tc_act/tc_csum.h>
  35 #include <net/tc_act/tc_gact.h>
  36 #include <net/tc_act/tc_police.h>
  37 #include <net/tc_act/tc_sample.h>
  38 #include <net/tc_act/tc_skbedit.h>
  39 #include <net/tc_act/tc_ct.h>
  40 #include <net/tc_act/tc_mpls.h>
  41 #include <net/flow_offload.h>
  42 
  43 extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1];
  44 
  45 /* The list of all installed classifier types */
  46 static LIST_HEAD(tcf_proto_base);
  47 
  48 /* Protects list of registered TC modules. It is pure SMP lock. */
  49 static DEFINE_RWLOCK(cls_mod_lock);
  50 
  51 static u32 destroy_obj_hashfn(const struct tcf_proto *tp)
  52 {
  53         return jhash_3words(tp->chain->index, tp->prio,
  54                             (__force __u32)tp->protocol, 0);
  55 }
  56 
  57 static void tcf_proto_signal_destroying(struct tcf_chain *chain,
  58                                         struct tcf_proto *tp)
  59 {
  60         struct tcf_block *block = chain->block;
  61 
  62         mutex_lock(&block->proto_destroy_lock);
  63         hash_add_rcu(block->proto_destroy_ht, &tp->destroy_ht_node,
  64                      destroy_obj_hashfn(tp));
  65         mutex_unlock(&block->proto_destroy_lock);
  66 }
  67 
  68 static bool tcf_proto_cmp(const struct tcf_proto *tp1,
  69                           const struct tcf_proto *tp2)
  70 {
  71         return tp1->chain->index == tp2->chain->index &&
  72                tp1->prio == tp2->prio &&
  73                tp1->protocol == tp2->protocol;
  74 }
  75 
  76 static bool tcf_proto_exists_destroying(struct tcf_chain *chain,
  77                                         struct tcf_proto *tp)
  78 {
  79         u32 hash = destroy_obj_hashfn(tp);
  80         struct tcf_proto *iter;
  81         bool found = false;
  82 
  83         rcu_read_lock();
  84         hash_for_each_possible_rcu(chain->block->proto_destroy_ht, iter,
  85                                    destroy_ht_node, hash) {
  86                 if (tcf_proto_cmp(tp, iter)) {
  87                         found = true;
  88                         break;
  89                 }
  90         }
  91         rcu_read_unlock();
  92 
  93         return found;
  94 }
  95 
  96 static void
  97 tcf_proto_signal_destroyed(struct tcf_chain *chain, struct tcf_proto *tp)
  98 {
  99         struct tcf_block *block = chain->block;
 100 
 101         mutex_lock(&block->proto_destroy_lock);
 102         if (hash_hashed(&tp->destroy_ht_node))
 103                 hash_del_rcu(&tp->destroy_ht_node);
 104         mutex_unlock(&block->proto_destroy_lock);
 105 }
 106 
 107 /* Find classifier type by string name */
 108 
 109 static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
 110 {
 111         const struct tcf_proto_ops *t, *res = NULL;
 112 
 113         if (kind) {
 114                 read_lock(&cls_mod_lock);
 115                 list_for_each_entry(t, &tcf_proto_base, head) {
 116                         if (strcmp(kind, t->kind) == 0) {
 117                                 if (try_module_get(t->owner))
 118                                         res = t;
 119                                 break;
 120                         }
 121                 }
 122                 read_unlock(&cls_mod_lock);
 123         }
 124         return res;
 125 }
 126 
 127 static const struct tcf_proto_ops *
 128 tcf_proto_lookup_ops(const char *kind, bool rtnl_held,
 129                      struct netlink_ext_ack *extack)
 130 {
 131         const struct tcf_proto_ops *ops;
 132 
 133         ops = __tcf_proto_lookup_ops(kind);
 134         if (ops)
 135                 return ops;
 136 #ifdef CONFIG_MODULES
 137         if (rtnl_held)
 138                 rtnl_unlock();
 139         request_module("cls_%s", kind);
 140         if (rtnl_held)
 141                 rtnl_lock();
 142         ops = __tcf_proto_lookup_ops(kind);
 143         /* We dropped the RTNL semaphore in order to perform
 144          * the module load. So, even if we succeeded in loading
 145          * the module we have to replay the request. We indicate
 146          * this using -EAGAIN.
 147          */
 148         if (ops) {
 149                 module_put(ops->owner);
 150                 return ERR_PTR(-EAGAIN);
 151         }
 152 #endif
 153         NL_SET_ERR_MSG(extack, "TC classifier not found");
 154         return ERR_PTR(-ENOENT);
 155 }
 156 
 157 /* Register(unregister) new classifier type */
 158 
 159 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
 160 {
 161         struct tcf_proto_ops *t;
 162         int rc = -EEXIST;
 163 
 164         write_lock(&cls_mod_lock);
 165         list_for_each_entry(t, &tcf_proto_base, head)
 166                 if (!strcmp(ops->kind, t->kind))
 167                         goto out;
 168 
 169         list_add_tail(&ops->head, &tcf_proto_base);
 170         rc = 0;
 171 out:
 172         write_unlock(&cls_mod_lock);
 173         return rc;
 174 }
 175 EXPORT_SYMBOL(register_tcf_proto_ops);
 176 
 177 static struct workqueue_struct *tc_filter_wq;
 178 
 179 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
 180 {
 181         struct tcf_proto_ops *t;
 182         int rc = -ENOENT;
 183 
 184         /* Wait for outstanding call_rcu()s, if any, from a
 185          * tcf_proto_ops's destroy() handler.
 186          */
 187         rcu_barrier();
 188         flush_workqueue(tc_filter_wq);
 189 
 190         write_lock(&cls_mod_lock);
 191         list_for_each_entry(t, &tcf_proto_base, head) {
 192                 if (t == ops) {
 193                         list_del(&t->head);
 194                         rc = 0;
 195                         break;
 196                 }
 197         }
 198         write_unlock(&cls_mod_lock);
 199         return rc;
 200 }
 201 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 202 
 203 bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
 204 {
 205         INIT_RCU_WORK(rwork, func);
 206         return queue_rcu_work(tc_filter_wq, rwork);
 207 }
 208 EXPORT_SYMBOL(tcf_queue_work);
 209 
 210 /* Select new prio value from the range, managed by kernel. */
 211 
 212 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 213 {
 214         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 215 
 216         if (tp)
 217                 first = tp->prio - 1;
 218 
 219         return TC_H_MAJ(first);
 220 }
 221 
 222 static bool tcf_proto_check_kind(struct nlattr *kind, char *name)
 223 {
 224         if (kind)
 225                 return nla_strlcpy(name, kind, IFNAMSIZ) >= IFNAMSIZ;
 226         memset(name, 0, IFNAMSIZ);
 227         return false;
 228 }
 229 
 230 static bool tcf_proto_is_unlocked(const char *kind)
 231 {
 232         const struct tcf_proto_ops *ops;
 233         bool ret;
 234 
 235         if (strlen(kind) == 0)
 236                 return false;
 237 
 238         ops = tcf_proto_lookup_ops(kind, false, NULL);
 239         /* On error return false to take rtnl lock. Proto lookup/create
 240          * functions will perform lookup again and properly handle errors.
 241          */
 242         if (IS_ERR(ops))
 243                 return false;
 244 
 245         ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED);
 246         module_put(ops->owner);
 247         return ret;
 248 }
 249 
 250 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 251                                           u32 prio, struct tcf_chain *chain,
 252                                           bool rtnl_held,
 253                                           struct netlink_ext_ack *extack)
 254 {
 255         struct tcf_proto *tp;
 256         int err;
 257 
 258         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 259         if (!tp)
 260                 return ERR_PTR(-ENOBUFS);
 261 
 262         tp->ops = tcf_proto_lookup_ops(kind, rtnl_held, extack);
 263         if (IS_ERR(tp->ops)) {
 264                 err = PTR_ERR(tp->ops);
 265                 goto errout;
 266         }
 267         tp->classify = tp->ops->classify;
 268         tp->protocol = protocol;
 269         tp->prio = prio;
 270         tp->chain = chain;
 271         spin_lock_init(&tp->lock);
 272         refcount_set(&tp->refcnt, 1);
 273 
 274         err = tp->ops->init(tp);
 275         if (err) {
 276                 module_put(tp->ops->owner);
 277                 goto errout;
 278         }
 279         return tp;
 280 
 281 errout:
 282         kfree(tp);
 283         return ERR_PTR(err);
 284 }
 285 
 286 static void tcf_proto_get(struct tcf_proto *tp)
 287 {
 288         refcount_inc(&tp->refcnt);
 289 }
 290 
 291 static void tcf_chain_put(struct tcf_chain *chain);
 292 
 293 static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
 294                               bool sig_destroy, struct netlink_ext_ack *extack)
 295 {
 296         tp->ops->destroy(tp, rtnl_held, extack);
 297         if (sig_destroy)
 298                 tcf_proto_signal_destroyed(tp->chain, tp);
 299         tcf_chain_put(tp->chain);
 300         module_put(tp->ops->owner);
 301         kfree_rcu(tp, rcu);
 302 }
 303 
 304 static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
 305                           struct netlink_ext_ack *extack)
 306 {
 307         if (refcount_dec_and_test(&tp->refcnt))
 308                 tcf_proto_destroy(tp, rtnl_held, true, extack);
 309 }
 310 
 311 static bool tcf_proto_check_delete(struct tcf_proto *tp)
 312 {
 313         if (tp->ops->delete_empty)
 314                 return tp->ops->delete_empty(tp);
 315 
 316         tp->deleting = true;
 317         return tp->deleting;
 318 }
 319 
 320 static void tcf_proto_mark_delete(struct tcf_proto *tp)
 321 {
 322         spin_lock(&tp->lock);
 323         tp->deleting = true;
 324         spin_unlock(&tp->lock);
 325 }
 326 
 327 static bool tcf_proto_is_deleting(struct tcf_proto *tp)
 328 {
 329         bool deleting;
 330 
 331         spin_lock(&tp->lock);
 332         deleting = tp->deleting;
 333         spin_unlock(&tp->lock);
 334 
 335         return deleting;
 336 }
 337 
 338 #define ASSERT_BLOCK_LOCKED(block)                                      \
 339         lockdep_assert_held(&(block)->lock)
 340 
 341 struct tcf_filter_chain_list_item {
 342         struct list_head list;
 343         tcf_chain_head_change_t *chain_head_change;
 344         void *chain_head_change_priv;
 345 };
 346 
 347 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 348                                           u32 chain_index)
 349 {
 350         struct tcf_chain *chain;
 351 
 352         ASSERT_BLOCK_LOCKED(block);
 353 
 354         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 355         if (!chain)
 356                 return NULL;
 357         list_add_tail(&chain->list, &block->chain_list);
 358         mutex_init(&chain->filter_chain_lock);
 359         chain->block = block;
 360         chain->index = chain_index;
 361         chain->refcnt = 1;
 362         if (!chain->index)
 363                 block->chain0.chain = chain;
 364         return chain;
 365 }
 366 
 367 static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
 368                                        struct tcf_proto *tp_head)
 369 {
 370         if (item->chain_head_change)
 371                 item->chain_head_change(tp_head, item->chain_head_change_priv);
 372 }
 373 
 374 static void tcf_chain0_head_change(struct tcf_chain *chain,
 375                                    struct tcf_proto *tp_head)
 376 {
 377         struct tcf_filter_chain_list_item *item;
 378         struct tcf_block *block = chain->block;
 379 
 380         if (chain->index)
 381                 return;
 382 
 383         mutex_lock(&block->lock);
 384         list_for_each_entry(item, &block->chain0.filter_chain_list, list)
 385                 tcf_chain_head_change_item(item, tp_head);
 386         mutex_unlock(&block->lock);
 387 }
 388 
 389 /* Returns true if block can be safely freed. */
 390 
 391 static bool tcf_chain_detach(struct tcf_chain *chain)
 392 {
 393         struct tcf_block *block = chain->block;
 394 
 395         ASSERT_BLOCK_LOCKED(block);
 396 
 397         list_del(&chain->list);
 398         if (!chain->index)
 399                 block->chain0.chain = NULL;
 400 
 401         if (list_empty(&block->chain_list) &&
 402             refcount_read(&block->refcnt) == 0)
 403                 return true;
 404 
 405         return false;
 406 }
 407 
 408 static void tcf_block_destroy(struct tcf_block *block)
 409 {
 410         mutex_destroy(&block->lock);
 411         mutex_destroy(&block->proto_destroy_lock);
 412         kfree_rcu(block, rcu);
 413 }
 414 
 415 static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
 416 {
 417         struct tcf_block *block = chain->block;
 418 
 419         mutex_destroy(&chain->filter_chain_lock);
 420         kfree_rcu(chain, rcu);
 421         if (free_block)
 422                 tcf_block_destroy(block);
 423 }
 424 
 425 static void tcf_chain_hold(struct tcf_chain *chain)
 426 {
 427         ASSERT_BLOCK_LOCKED(chain->block);
 428 
 429         ++chain->refcnt;
 430 }
 431 
 432 static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain)
 433 {
 434         ASSERT_BLOCK_LOCKED(chain->block);
 435 
 436         /* In case all the references are action references, this
 437          * chain should not be shown to the user.
 438          */
 439         return chain->refcnt == chain->action_refcnt;
 440 }
 441 
 442 static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
 443                                           u32 chain_index)
 444 {
 445         struct tcf_chain *chain;
 446 
 447         ASSERT_BLOCK_LOCKED(block);
 448 
 449         list_for_each_entry(chain, &block->chain_list, list) {
 450                 if (chain->index == chain_index)
 451                         return chain;
 452         }
 453         return NULL;
 454 }
 455 
 456 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 457                            u32 seq, u16 flags, int event, bool unicast);
 458 
 459 static struct tcf_chain *__tcf_chain_get(struct tcf_block *block,
 460                                          u32 chain_index, bool create,
 461                                          bool by_act)
 462 {
 463         struct tcf_chain *chain = NULL;
 464         bool is_first_reference;
 465 
 466         mutex_lock(&block->lock);
 467         chain = tcf_chain_lookup(block, chain_index);
 468         if (chain) {
 469                 tcf_chain_hold(chain);
 470         } else {
 471                 if (!create)
 472                         goto errout;
 473                 chain = tcf_chain_create(block, chain_index);
 474                 if (!chain)
 475                         goto errout;
 476         }
 477 
 478         if (by_act)
 479                 ++chain->action_refcnt;
 480         is_first_reference = chain->refcnt - chain->action_refcnt == 1;
 481         mutex_unlock(&block->lock);
 482 
 483         /* Send notification only in case we got the first
 484          * non-action reference. Until then, the chain acts only as
 485          * a placeholder for actions pointing to it and user ought
 486          * not know about them.
 487          */
 488         if (is_first_reference && !by_act)
 489                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
 490                                 RTM_NEWCHAIN, false);
 491 
 492         return chain;
 493 
 494 errout:
 495         mutex_unlock(&block->lock);
 496         return chain;
 497 }
 498 
 499 static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 500                                        bool create)
 501 {
 502         return __tcf_chain_get(block, chain_index, create, false);
 503 }
 504 
 505 struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index)
 506 {
 507         return __tcf_chain_get(block, chain_index, true, true);
 508 }
 509 EXPORT_SYMBOL(tcf_chain_get_by_act);
 510 
 511 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
 512                                void *tmplt_priv);
 513 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
 514                                   void *tmplt_priv, u32 chain_index,
 515                                   struct tcf_block *block, struct sk_buff *oskb,
 516                                   u32 seq, u16 flags, bool unicast);
 517 
 518 static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
 519                             bool explicitly_created)
 520 {
 521         struct tcf_block *block = chain->block;
 522         const struct tcf_proto_ops *tmplt_ops;
 523         bool free_block = false;
 524         unsigned int refcnt;
 525         void *tmplt_priv;
 526 
 527         mutex_lock(&block->lock);
 528         if (explicitly_created) {
 529                 if (!chain->explicitly_created) {
 530                         mutex_unlock(&block->lock);
 531                         return;
 532                 }
 533                 chain->explicitly_created = false;
 534         }
 535 
 536         if (by_act)
 537                 chain->action_refcnt--;
 538 
 539         /* tc_chain_notify_delete can't be called while holding block lock.
 540          * However, when block is unlocked chain can be changed concurrently, so
 541          * save these to temporary variables.
 542          */
 543         refcnt = --chain->refcnt;
 544         tmplt_ops = chain->tmplt_ops;
 545         tmplt_priv = chain->tmplt_priv;
 546 
 547         /* The last dropped non-action reference will trigger notification. */
 548         if (refcnt - chain->action_refcnt == 0 && !by_act) {
 549                 tc_chain_notify_delete(tmplt_ops, tmplt_priv, chain->index,
 550                                        block, NULL, 0, 0, false);
 551                 /* Last reference to chain, no need to lock. */
 552                 chain->flushing = false;
 553         }
 554 
 555         if (refcnt == 0)
 556                 free_block = tcf_chain_detach(chain);
 557         mutex_unlock(&block->lock);
 558 
 559         if (refcnt == 0) {
 560                 tc_chain_tmplt_del(tmplt_ops, tmplt_priv);
 561                 tcf_chain_destroy(chain, free_block);
 562         }
 563 }
 564 
 565 static void tcf_chain_put(struct tcf_chain *chain)
 566 {
 567         __tcf_chain_put(chain, false, false);
 568 }
 569 
 570 void tcf_chain_put_by_act(struct tcf_chain *chain)
 571 {
 572         __tcf_chain_put(chain, true, false);
 573 }
 574 EXPORT_SYMBOL(tcf_chain_put_by_act);
 575 
 576 static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 577 {
 578         __tcf_chain_put(chain, false, true);
 579 }
 580 
 581 static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
 582 {
 583         struct tcf_proto *tp, *tp_next;
 584 
 585         mutex_lock(&chain->filter_chain_lock);
 586         tp = tcf_chain_dereference(chain->filter_chain, chain);
 587         while (tp) {
 588                 tp_next = rcu_dereference_protected(tp->next, 1);
 589                 tcf_proto_signal_destroying(chain, tp);
 590                 tp = tp_next;
 591         }
 592         tp = tcf_chain_dereference(chain->filter_chain, chain);
 593         RCU_INIT_POINTER(chain->filter_chain, NULL);
 594         tcf_chain0_head_change(chain, NULL);
 595         chain->flushing = true;
 596         mutex_unlock(&chain->filter_chain_lock);
 597 
 598         while (tp) {
 599                 tp_next = rcu_dereference_protected(tp->next, 1);
 600                 tcf_proto_put(tp, rtnl_held, NULL);
 601                 tp = tp_next;
 602         }
 603 }
 604 
 605 static int tcf_block_setup(struct tcf_block *block,
 606                            struct flow_block_offload *bo);
 607 
 608 static void tc_indr_block_cmd(struct net_device *dev, struct tcf_block *block,
 609                               flow_indr_block_bind_cb_t *cb, void *cb_priv,
 610                               enum flow_block_command command, bool ingress)
 611 {
 612         struct flow_block_offload bo = {
 613                 .command        = command,
 614                 .binder_type    = ingress ?
 615                                   FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS :
 616                                   FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS,
 617                 .net            = dev_net(dev),
 618                 .block_shared   = tcf_block_non_null_shared(block),
 619         };
 620         INIT_LIST_HEAD(&bo.cb_list);
 621 
 622         if (!block)
 623                 return;
 624 
 625         bo.block = &block->flow_block;
 626 
 627         down_write(&block->cb_lock);
 628         cb(dev, cb_priv, TC_SETUP_BLOCK, &bo);
 629 
 630         tcf_block_setup(block, &bo);
 631         up_write(&block->cb_lock);
 632 }
 633 
 634 static struct tcf_block *tc_dev_block(struct net_device *dev, bool ingress)
 635 {
 636         const struct Qdisc_class_ops *cops;
 637         const struct Qdisc_ops *ops;
 638         struct Qdisc *qdisc;
 639 
 640         if (!dev_ingress_queue(dev))
 641                 return NULL;
 642 
 643         qdisc = dev_ingress_queue(dev)->qdisc_sleeping;
 644         if (!qdisc)
 645                 return NULL;
 646 
 647         ops = qdisc->ops;
 648         if (!ops)
 649                 return NULL;
 650 
 651         if (!ingress && !strcmp("ingress", ops->id))
 652                 return NULL;
 653 
 654         cops = ops->cl_ops;
 655         if (!cops)
 656                 return NULL;
 657 
 658         if (!cops->tcf_block)
 659                 return NULL;
 660 
 661         return cops->tcf_block(qdisc,
 662                                ingress ? TC_H_MIN_INGRESS : TC_H_MIN_EGRESS,
 663                                NULL);
 664 }
 665 
 666 static void tc_indr_block_get_and_cmd(struct net_device *dev,
 667                                       flow_indr_block_bind_cb_t *cb,
 668                                       void *cb_priv,
 669                                       enum flow_block_command command)
 670 {
 671         struct tcf_block *block;
 672 
 673         block = tc_dev_block(dev, true);
 674         tc_indr_block_cmd(dev, block, cb, cb_priv, command, true);
 675 
 676         block = tc_dev_block(dev, false);
 677         tc_indr_block_cmd(dev, block, cb, cb_priv, command, false);
 678 }
 679 
 680 static void tc_indr_block_call(struct tcf_block *block,
 681                                struct net_device *dev,
 682                                struct tcf_block_ext_info *ei,
 683                                enum flow_block_command command,
 684                                struct netlink_ext_ack *extack)
 685 {
 686         struct flow_block_offload bo = {
 687                 .command        = command,
 688                 .binder_type    = ei->binder_type,
 689                 .net            = dev_net(dev),
 690                 .block          = &block->flow_block,
 691                 .block_shared   = tcf_block_shared(block),
 692                 .extack         = extack,
 693         };
 694         INIT_LIST_HEAD(&bo.cb_list);
 695 
 696         flow_indr_block_call(dev, &bo, command);
 697         tcf_block_setup(block, &bo);
 698 }
 699 
 700 static bool tcf_block_offload_in_use(struct tcf_block *block)
 701 {
 702         return atomic_read(&block->offloadcnt);
 703 }
 704 
 705 static int tcf_block_offload_cmd(struct tcf_block *block,
 706                                  struct net_device *dev,
 707                                  struct tcf_block_ext_info *ei,
 708                                  enum flow_block_command command,
 709                                  struct netlink_ext_ack *extack)
 710 {
 711         struct flow_block_offload bo = {};
 712         int err;
 713 
 714         bo.net = dev_net(dev);
 715         bo.command = command;
 716         bo.binder_type = ei->binder_type;
 717         bo.block = &block->flow_block;
 718         bo.block_shared = tcf_block_shared(block);
 719         bo.extack = extack;
 720         INIT_LIST_HEAD(&bo.cb_list);
 721 
 722         err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 723         if (err < 0)
 724                 return err;
 725 
 726         return tcf_block_setup(block, &bo);
 727 }
 728 
 729 static int tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
 730                                   struct tcf_block_ext_info *ei,
 731                                   struct netlink_ext_ack *extack)
 732 {
 733         struct net_device *dev = q->dev_queue->dev;
 734         int err;
 735 
 736         down_write(&block->cb_lock);
 737         if (!dev->netdev_ops->ndo_setup_tc)
 738                 goto no_offload_dev_inc;
 739 
 740         /* If tc offload feature is disabled and the block we try to bind
 741          * to already has some offloaded filters, forbid to bind.
 742          */
 743         if (!tc_can_offload(dev) && tcf_block_offload_in_use(block)) {
 744                 NL_SET_ERR_MSG(extack, "Bind to offloaded block failed as dev has offload disabled");
 745                 err = -EOPNOTSUPP;
 746                 goto err_unlock;
 747         }
 748 
 749         err = tcf_block_offload_cmd(block, dev, ei, FLOW_BLOCK_BIND, extack);
 750         if (err == -EOPNOTSUPP)
 751                 goto no_offload_dev_inc;
 752         if (err)
 753                 goto err_unlock;
 754 
 755         tc_indr_block_call(block, dev, ei, FLOW_BLOCK_BIND, extack);
 756         up_write(&block->cb_lock);
 757         return 0;
 758 
 759 no_offload_dev_inc:
 760         if (tcf_block_offload_in_use(block)) {
 761                 err = -EOPNOTSUPP;
 762                 goto err_unlock;
 763         }
 764         err = 0;
 765         block->nooffloaddevcnt++;
 766         tc_indr_block_call(block, dev, ei, FLOW_BLOCK_BIND, extack);
 767 err_unlock:
 768         up_write(&block->cb_lock);
 769         return err;
 770 }
 771 
 772 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
 773                                      struct tcf_block_ext_info *ei)
 774 {
 775         struct net_device *dev = q->dev_queue->dev;
 776         int err;
 777 
 778         down_write(&block->cb_lock);
 779         tc_indr_block_call(block, dev, ei, FLOW_BLOCK_UNBIND, NULL);
 780 
 781         if (!dev->netdev_ops->ndo_setup_tc)
 782                 goto no_offload_dev_dec;
 783         err = tcf_block_offload_cmd(block, dev, ei, FLOW_BLOCK_UNBIND, NULL);
 784         if (err == -EOPNOTSUPP)
 785                 goto no_offload_dev_dec;
 786         up_write(&block->cb_lock);
 787         return;
 788 
 789 no_offload_dev_dec:
 790         WARN_ON(block->nooffloaddevcnt-- == 0);
 791         up_write(&block->cb_lock);
 792 }
 793 
 794 static int
 795 tcf_chain0_head_change_cb_add(struct tcf_block *block,
 796                               struct tcf_block_ext_info *ei,
 797                               struct netlink_ext_ack *extack)
 798 {
 799         struct tcf_filter_chain_list_item *item;
 800         struct tcf_chain *chain0;
 801 
 802         item = kmalloc(sizeof(*item), GFP_KERNEL);
 803         if (!item) {
 804                 NL_SET_ERR_MSG(extack, "Memory allocation for head change callback item failed");
 805                 return -ENOMEM;
 806         }
 807         item->chain_head_change = ei->chain_head_change;
 808         item->chain_head_change_priv = ei->chain_head_change_priv;
 809 
 810         mutex_lock(&block->lock);
 811         chain0 = block->chain0.chain;
 812         if (chain0)
 813                 tcf_chain_hold(chain0);
 814         else
 815                 list_add(&item->list, &block->chain0.filter_chain_list);
 816         mutex_unlock(&block->lock);
 817 
 818         if (chain0) {
 819                 struct tcf_proto *tp_head;
 820 
 821                 mutex_lock(&chain0->filter_chain_lock);
 822 
 823                 tp_head = tcf_chain_dereference(chain0->filter_chain, chain0);
 824                 if (tp_head)
 825                         tcf_chain_head_change_item(item, tp_head);
 826 
 827                 mutex_lock(&block->lock);
 828                 list_add(&item->list, &block->chain0.filter_chain_list);
 829                 mutex_unlock(&block->lock);
 830 
 831                 mutex_unlock(&chain0->filter_chain_lock);
 832                 tcf_chain_put(chain0);
 833         }
 834 
 835         return 0;
 836 }
 837 
 838 static void
 839 tcf_chain0_head_change_cb_del(struct tcf_block *block,
 840                               struct tcf_block_ext_info *ei)
 841 {
 842         struct tcf_filter_chain_list_item *item;
 843 
 844         mutex_lock(&block->lock);
 845         list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
 846                 if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
 847                     (item->chain_head_change == ei->chain_head_change &&
 848                      item->chain_head_change_priv == ei->chain_head_change_priv)) {
 849                         if (block->chain0.chain)
 850                                 tcf_chain_head_change_item(item, NULL);
 851                         list_del(&item->list);
 852                         mutex_unlock(&block->lock);
 853 
 854                         kfree(item);
 855                         return;
 856                 }
 857         }
 858         mutex_unlock(&block->lock);
 859         WARN_ON(1);
 860 }
 861 
 862 struct tcf_net {
 863         spinlock_t idr_lock; /* Protects idr */
 864         struct idr idr;
 865 };
 866 
 867 static unsigned int tcf_net_id;
 868 
 869 static int tcf_block_insert(struct tcf_block *block, struct net *net,
 870                             struct netlink_ext_ack *extack)
 871 {
 872         struct tcf_net *tn = net_generic(net, tcf_net_id);
 873         int err;
 874 
 875         idr_preload(GFP_KERNEL);
 876         spin_lock(&tn->idr_lock);
 877         err = idr_alloc_u32(&tn->idr, block, &block->index, block->index,
 878                             GFP_NOWAIT);
 879         spin_unlock(&tn->idr_lock);
 880         idr_preload_end();
 881 
 882         return err;
 883 }
 884 
 885 static void tcf_block_remove(struct tcf_block *block, struct net *net)
 886 {
 887         struct tcf_net *tn = net_generic(net, tcf_net_id);
 888 
 889         spin_lock(&tn->idr_lock);
 890         idr_remove(&tn->idr, block->index);
 891         spin_unlock(&tn->idr_lock);
 892 }
 893 
 894 static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 895                                           u32 block_index,
 896                                           struct netlink_ext_ack *extack)
 897 {
 898         struct tcf_block *block;
 899 
 900         block = kzalloc(sizeof(*block), GFP_KERNEL);
 901         if (!block) {
 902                 NL_SET_ERR_MSG(extack, "Memory allocation for block failed");
 903                 return ERR_PTR(-ENOMEM);
 904         }
 905         mutex_init(&block->lock);
 906         mutex_init(&block->proto_destroy_lock);
 907         init_rwsem(&block->cb_lock);
 908         flow_block_init(&block->flow_block);
 909         INIT_LIST_HEAD(&block->chain_list);
 910         INIT_LIST_HEAD(&block->owner_list);
 911         INIT_LIST_HEAD(&block->chain0.filter_chain_list);
 912 
 913         refcount_set(&block->refcnt, 1);
 914         block->net = net;
 915         block->index = block_index;
 916 
 917         /* Don't store q pointer for blocks which are shared */
 918         if (!tcf_block_shared(block))
 919                 block->q = q;
 920         return block;
 921 }
 922 
 923 static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
 924 {
 925         struct tcf_net *tn = net_generic(net, tcf_net_id);
 926 
 927         return idr_find(&tn->idr, block_index);
 928 }
 929 
 930 static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
 931 {
 932         struct tcf_block *block;
 933 
 934         rcu_read_lock();
 935         block = tcf_block_lookup(net, block_index);
 936         if (block && !refcount_inc_not_zero(&block->refcnt))
 937                 block = NULL;
 938         rcu_read_unlock();
 939 
 940         return block;
 941 }
 942 
 943 static struct tcf_chain *
 944 __tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
 945 {
 946         mutex_lock(&block->lock);
 947         if (chain)
 948                 chain = list_is_last(&chain->list, &block->chain_list) ?
 949                         NULL : list_next_entry(chain, list);
 950         else
 951                 chain = list_first_entry_or_null(&block->chain_list,
 952                                                  struct tcf_chain, list);
 953 
 954         /* skip all action-only chains */
 955         while (chain && tcf_chain_held_by_acts_only(chain))
 956                 chain = list_is_last(&chain->list, &block->chain_list) ?
 957                         NULL : list_next_entry(chain, list);
 958 
 959         if (chain)
 960                 tcf_chain_hold(chain);
 961         mutex_unlock(&block->lock);
 962 
 963         return chain;
 964 }
 965 
 966 /* Function to be used by all clients that want to iterate over all chains on
 967  * block. It properly obtains block->lock and takes reference to chain before
 968  * returning it. Users of this function must be tolerant to concurrent chain
 969  * insertion/deletion or ensure that no concurrent chain modification is
 970  * possible. Note that all netlink dump callbacks cannot guarantee to provide
 971  * consistent dump because rtnl lock is released each time skb is filled with
 972  * data and sent to user-space.
 973  */
 974 
 975 struct tcf_chain *
 976 tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
 977 {
 978         struct tcf_chain *chain_next = __tcf_get_next_chain(block, chain);
 979 
 980         if (chain)
 981                 tcf_chain_put(chain);
 982 
 983         return chain_next;
 984 }
 985 EXPORT_SYMBOL(tcf_get_next_chain);
 986 
 987 static struct tcf_proto *
 988 __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
 989 {
 990         u32 prio = 0;
 991 
 992         ASSERT_RTNL();
 993         mutex_lock(&chain->filter_chain_lock);
 994 
 995         if (!tp) {
 996                 tp = tcf_chain_dereference(chain->filter_chain, chain);
 997         } else if (tcf_proto_is_deleting(tp)) {
 998                 /* 'deleting' flag is set and chain->filter_chain_lock was
 999                  * unlocked, which means next pointer could be invalid. Restart
1000                  * search.
1001                  */
1002                 prio = tp->prio + 1;
1003                 tp = tcf_chain_dereference(chain->filter_chain, chain);
1004 
1005                 for (; tp; tp = tcf_chain_dereference(tp->next, chain))
1006                         if (!tp->deleting && tp->prio >= prio)
1007                                 break;
1008         } else {
1009                 tp = tcf_chain_dereference(tp->next, chain);
1010         }
1011 
1012         if (tp)
1013                 tcf_proto_get(tp);
1014 
1015         mutex_unlock(&chain->filter_chain_lock);
1016 
1017         return tp;
1018 }
1019 
1020 /* Function to be used by all clients that want to iterate over all tp's on
1021  * chain. Users of this function must be tolerant to concurrent tp
1022  * insertion/deletion or ensure that no concurrent chain modification is
1023  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1024  * consistent dump because rtnl lock is released each time skb is filled with
1025  * data and sent to user-space.
1026  */
1027 
1028 struct tcf_proto *
1029 tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp,
1030                    bool rtnl_held)
1031 {
1032         struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
1033 
1034         if (tp)
1035                 tcf_proto_put(tp, rtnl_held, NULL);
1036 
1037         return tp_next;
1038 }
1039 EXPORT_SYMBOL(tcf_get_next_proto);
1040 
1041 static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
1042 {
1043         struct tcf_chain *chain;
1044 
1045         /* Last reference to block. At this point chains cannot be added or
1046          * removed concurrently.
1047          */
1048         for (chain = tcf_get_next_chain(block, NULL);
1049              chain;
1050              chain = tcf_get_next_chain(block, chain)) {
1051                 tcf_chain_put_explicitly_created(chain);
1052                 tcf_chain_flush(chain, rtnl_held);
1053         }
1054 }
1055 
1056 /* Lookup Qdisc and increments its reference counter.
1057  * Set parent, if necessary.
1058  */
1059 
1060 static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
1061                             u32 *parent, int ifindex, bool rtnl_held,
1062                             struct netlink_ext_ack *extack)
1063 {
1064         const struct Qdisc_class_ops *cops;
1065         struct net_device *dev;
1066         int err = 0;
1067 
1068         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1069                 return 0;
1070 
1071         rcu_read_lock();
1072 
1073         /* Find link */
1074         dev = dev_get_by_index_rcu(net, ifindex);
1075         if (!dev) {
1076                 rcu_read_unlock();
1077                 return -ENODEV;
1078         }
1079 
1080         /* Find qdisc */
1081         if (!*parent) {
1082                 *q = dev->qdisc;
1083                 *parent = (*q)->handle;
1084         } else {
1085                 *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
1086                 if (!*q) {
1087                         NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1088                         err = -EINVAL;
1089                         goto errout_rcu;
1090                 }
1091         }
1092 
1093         *q = qdisc_refcount_inc_nz(*q);
1094         if (!*q) {
1095                 NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1096                 err = -EINVAL;
1097                 goto errout_rcu;
1098         }
1099 
1100         /* Is it classful? */
1101         cops = (*q)->ops->cl_ops;
1102         if (!cops) {
1103                 NL_SET_ERR_MSG(extack, "Qdisc not classful");
1104                 err = -EINVAL;
1105                 goto errout_qdisc;
1106         }
1107 
1108         if (!cops->tcf_block) {
1109                 NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
1110                 err = -EOPNOTSUPP;
1111                 goto errout_qdisc;
1112         }
1113 
1114 errout_rcu:
1115         /* At this point we know that qdisc is not noop_qdisc,
1116          * which means that qdisc holds a reference to net_device
1117          * and we hold a reference to qdisc, so it is safe to release
1118          * rcu read lock.
1119          */
1120         rcu_read_unlock();
1121         return err;
1122 
1123 errout_qdisc:
1124         rcu_read_unlock();
1125 
1126         if (rtnl_held)
1127                 qdisc_put(*q);
1128         else
1129                 qdisc_put_unlocked(*q);
1130         *q = NULL;
1131 
1132         return err;
1133 }
1134 
1135 static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
1136                                int ifindex, struct netlink_ext_ack *extack)
1137 {
1138         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1139                 return 0;
1140 
1141         /* Do we search for filter, attached to class? */
1142         if (TC_H_MIN(parent)) {
1143                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1144 
1145                 *cl = cops->find(q, parent);
1146                 if (*cl == 0) {
1147                         NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
1148                         return -ENOENT;
1149                 }
1150         }
1151 
1152         return 0;
1153 }
1154 
1155 static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
1156                                           unsigned long cl, int ifindex,
1157                                           u32 block_index,
1158                                           struct netlink_ext_ack *extack)
1159 {
1160         struct tcf_block *block;
1161 
1162         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
1163                 block = tcf_block_refcnt_get(net, block_index);
1164                 if (!block) {
1165                         NL_SET_ERR_MSG(extack, "Block of given index was not found");
1166                         return ERR_PTR(-EINVAL);
1167                 }
1168         } else {
1169                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1170 
1171                 block = cops->tcf_block(q, cl, extack);
1172                 if (!block)
1173                         return ERR_PTR(-EINVAL);
1174 
1175                 if (tcf_block_shared(block)) {
1176                         NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
1177                         return ERR_PTR(-EOPNOTSUPP);
1178                 }
1179 
1180                 /* Always take reference to block in order to support execution
1181                  * of rules update path of cls API without rtnl lock. Caller
1182                  * must release block when it is finished using it. 'if' block
1183                  * of this conditional obtain reference to block by calling
1184                  * tcf_block_refcnt_get().
1185                  */
1186                 refcount_inc(&block->refcnt);
1187         }
1188 
1189         return block;
1190 }
1191 
1192 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
1193                             struct tcf_block_ext_info *ei, bool rtnl_held)
1194 {
1195         if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
1196                 /* Flushing/putting all chains will cause the block to be
1197                  * deallocated when last chain is freed. However, if chain_list
1198                  * is empty, block has to be manually deallocated. After block
1199                  * reference counter reached 0, it is no longer possible to
1200                  * increment it or add new chains to block.
1201                  */
1202                 bool free_block = list_empty(&block->chain_list);
1203 
1204                 mutex_unlock(&block->lock);
1205                 if (tcf_block_shared(block))
1206                         tcf_block_remove(block, block->net);
1207 
1208                 if (q)
1209                         tcf_block_offload_unbind(block, q, ei);
1210 
1211                 if (free_block)
1212                         tcf_block_destroy(block);
1213                 else
1214                         tcf_block_flush_all_chains(block, rtnl_held);
1215         } else if (q) {
1216                 tcf_block_offload_unbind(block, q, ei);
1217         }
1218 }
1219 
1220 static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
1221 {
1222         __tcf_block_put(block, NULL, NULL, rtnl_held);
1223 }
1224 
1225 /* Find tcf block.
1226  * Set q, parent, cl when appropriate.
1227  */
1228 
1229 static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
1230                                         u32 *parent, unsigned long *cl,
1231                                         int ifindex, u32 block_index,
1232                                         struct netlink_ext_ack *extack)
1233 {
1234         struct tcf_block *block;
1235         int err = 0;
1236 
1237         ASSERT_RTNL();
1238 
1239         err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
1240         if (err)
1241                 goto errout;
1242 
1243         err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
1244         if (err)
1245                 goto errout_qdisc;
1246 
1247         block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
1248         if (IS_ERR(block)) {
1249                 err = PTR_ERR(block);
1250                 goto errout_qdisc;
1251         }
1252 
1253         return block;
1254 
1255 errout_qdisc:
1256         if (*q)
1257                 qdisc_put(*q);
1258 errout:
1259         *q = NULL;
1260         return ERR_PTR(err);
1261 }
1262 
1263 static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
1264                               bool rtnl_held)
1265 {
1266         if (!IS_ERR_OR_NULL(block))
1267                 tcf_block_refcnt_put(block, rtnl_held);
1268 
1269         if (q) {
1270                 if (rtnl_held)
1271                         qdisc_put(q);
1272                 else
1273                         qdisc_put_unlocked(q);
1274         }
1275 }
1276 
1277 struct tcf_block_owner_item {
1278         struct list_head list;
1279         struct Qdisc *q;
1280         enum flow_block_binder_type binder_type;
1281 };
1282 
1283 static void
1284 tcf_block_owner_netif_keep_dst(struct tcf_block *block,
1285                                struct Qdisc *q,
1286                                enum flow_block_binder_type binder_type)
1287 {
1288         if (block->keep_dst &&
1289             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS &&
1290             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
1291                 netif_keep_dst(qdisc_dev(q));
1292 }
1293 
1294 void tcf_block_netif_keep_dst(struct tcf_block *block)
1295 {
1296         struct tcf_block_owner_item *item;
1297 
1298         block->keep_dst = true;
1299         list_for_each_entry(item, &block->owner_list, list)
1300                 tcf_block_owner_netif_keep_dst(block, item->q,
1301                                                item->binder_type);
1302 }
1303 EXPORT_SYMBOL(tcf_block_netif_keep_dst);
1304 
1305 static int tcf_block_owner_add(struct tcf_block *block,
1306                                struct Qdisc *q,
1307                                enum flow_block_binder_type binder_type)
1308 {
1309         struct tcf_block_owner_item *item;
1310 
1311         item = kmalloc(sizeof(*item), GFP_KERNEL);
1312         if (!item)
1313                 return -ENOMEM;
1314         item->q = q;
1315         item->binder_type = binder_type;
1316         list_add(&item->list, &block->owner_list);
1317         return 0;
1318 }
1319 
1320 static void tcf_block_owner_del(struct tcf_block *block,
1321                                 struct Qdisc *q,
1322                                 enum flow_block_binder_type binder_type)
1323 {
1324         struct tcf_block_owner_item *item;
1325 
1326         list_for_each_entry(item, &block->owner_list, list) {
1327                 if (item->q == q && item->binder_type == binder_type) {
1328                         list_del(&item->list);
1329                         kfree(item);
1330                         return;
1331                 }
1332         }
1333         WARN_ON(1);
1334 }
1335 
1336 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
1337                       struct tcf_block_ext_info *ei,
1338                       struct netlink_ext_ack *extack)
1339 {
1340         struct net *net = qdisc_net(q);
1341         struct tcf_block *block = NULL;
1342         int err;
1343 
1344         if (ei->block_index)
1345                 /* block_index not 0 means the shared block is requested */
1346                 block = tcf_block_refcnt_get(net, ei->block_index);
1347 
1348         if (!block) {
1349                 block = tcf_block_create(net, q, ei->block_index, extack);
1350                 if (IS_ERR(block))
1351                         return PTR_ERR(block);
1352                 if (tcf_block_shared(block)) {
1353                         err = tcf_block_insert(block, net, extack);
1354                         if (err)
1355                                 goto err_block_insert;
1356                 }
1357         }
1358 
1359         err = tcf_block_owner_add(block, q, ei->binder_type);
1360         if (err)
1361                 goto err_block_owner_add;
1362 
1363         tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
1364 
1365         err = tcf_chain0_head_change_cb_add(block, ei, extack);
1366         if (err)
1367                 goto err_chain0_head_change_cb_add;
1368 
1369         err = tcf_block_offload_bind(block, q, ei, extack);
1370         if (err)
1371                 goto err_block_offload_bind;
1372 
1373         *p_block = block;
1374         return 0;
1375 
1376 err_block_offload_bind:
1377         tcf_chain0_head_change_cb_del(block, ei);
1378 err_chain0_head_change_cb_add:
1379         tcf_block_owner_del(block, q, ei->binder_type);
1380 err_block_owner_add:
1381 err_block_insert:
1382         tcf_block_refcnt_put(block, true);
1383         return err;
1384 }
1385 EXPORT_SYMBOL(tcf_block_get_ext);
1386 
1387 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
1388 {
1389         struct tcf_proto __rcu **p_filter_chain = priv;
1390 
1391         rcu_assign_pointer(*p_filter_chain, tp_head);
1392 }
1393 
1394 int tcf_block_get(struct tcf_block **p_block,
1395                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
1396                   struct netlink_ext_ack *extack)
1397 {
1398         struct tcf_block_ext_info ei = {
1399                 .chain_head_change = tcf_chain_head_change_dflt,
1400                 .chain_head_change_priv = p_filter_chain,
1401         };
1402 
1403         WARN_ON(!p_filter_chain);
1404         return tcf_block_get_ext(p_block, q, &ei, extack);
1405 }
1406 EXPORT_SYMBOL(tcf_block_get);
1407 
1408 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
1409  * actions should be all removed after flushing.
1410  */
1411 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
1412                        struct tcf_block_ext_info *ei)
1413 {
1414         if (!block)
1415                 return;
1416         tcf_chain0_head_change_cb_del(block, ei);
1417         tcf_block_owner_del(block, q, ei->binder_type);
1418 
1419         __tcf_block_put(block, q, ei, true);
1420 }
1421 EXPORT_SYMBOL(tcf_block_put_ext);
1422 
1423 void tcf_block_put(struct tcf_block *block)
1424 {
1425         struct tcf_block_ext_info ei = {0, };
1426 
1427         if (!block)
1428                 return;
1429         tcf_block_put_ext(block, block->q, &ei);
1430 }
1431 
1432 EXPORT_SYMBOL(tcf_block_put);
1433 
1434 static int
1435 tcf_block_playback_offloads(struct tcf_block *block, flow_setup_cb_t *cb,
1436                             void *cb_priv, bool add, bool offload_in_use,
1437                             struct netlink_ext_ack *extack)
1438 {
1439         struct tcf_chain *chain, *chain_prev;
1440         struct tcf_proto *tp, *tp_prev;
1441         int err;
1442 
1443         lockdep_assert_held(&block->cb_lock);
1444 
1445         for (chain = __tcf_get_next_chain(block, NULL);
1446              chain;
1447              chain_prev = chain,
1448                      chain = __tcf_get_next_chain(block, chain),
1449                      tcf_chain_put(chain_prev)) {
1450                 for (tp = __tcf_get_next_proto(chain, NULL); tp;
1451                      tp_prev = tp,
1452                              tp = __tcf_get_next_proto(chain, tp),
1453                              tcf_proto_put(tp_prev, true, NULL)) {
1454                         if (tp->ops->reoffload) {
1455                                 err = tp->ops->reoffload(tp, add, cb, cb_priv,
1456                                                          extack);
1457                                 if (err && add)
1458                                         goto err_playback_remove;
1459                         } else if (add && offload_in_use) {
1460                                 err = -EOPNOTSUPP;
1461                                 NL_SET_ERR_MSG(extack, "Filter HW offload failed - classifier without re-offloading support");
1462                                 goto err_playback_remove;
1463                         }
1464                 }
1465         }
1466 
1467         return 0;
1468 
1469 err_playback_remove:
1470         tcf_proto_put(tp, true, NULL);
1471         tcf_chain_put(chain);
1472         tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
1473                                     extack);
1474         return err;
1475 }
1476 
1477 static int tcf_block_bind(struct tcf_block *block,
1478                           struct flow_block_offload *bo)
1479 {
1480         struct flow_block_cb *block_cb, *next;
1481         int err, i = 0;
1482 
1483         lockdep_assert_held(&block->cb_lock);
1484 
1485         list_for_each_entry(block_cb, &bo->cb_list, list) {
1486                 err = tcf_block_playback_offloads(block, block_cb->cb,
1487                                                   block_cb->cb_priv, true,
1488                                                   tcf_block_offload_in_use(block),
1489                                                   bo->extack);
1490                 if (err)
1491                         goto err_unroll;
1492                 if (!bo->unlocked_driver_cb)
1493                         block->lockeddevcnt++;
1494 
1495                 i++;
1496         }
1497         list_splice(&bo->cb_list, &block->flow_block.cb_list);
1498 
1499         return 0;
1500 
1501 err_unroll:
1502         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1503                 if (i-- > 0) {
1504                         list_del(&block_cb->list);
1505                         tcf_block_playback_offloads(block, block_cb->cb,
1506                                                     block_cb->cb_priv, false,
1507                                                     tcf_block_offload_in_use(block),
1508                                                     NULL);
1509                         if (!bo->unlocked_driver_cb)
1510                                 block->lockeddevcnt--;
1511                 }
1512                 flow_block_cb_free(block_cb);
1513         }
1514 
1515         return err;
1516 }
1517 
1518 static void tcf_block_unbind(struct tcf_block *block,
1519                              struct flow_block_offload *bo)
1520 {
1521         struct flow_block_cb *block_cb, *next;
1522 
1523         lockdep_assert_held(&block->cb_lock);
1524 
1525         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1526                 tcf_block_playback_offloads(block, block_cb->cb,
1527                                             block_cb->cb_priv, false,
1528                                             tcf_block_offload_in_use(block),
1529                                             NULL);
1530                 list_del(&block_cb->list);
1531                 flow_block_cb_free(block_cb);
1532                 if (!bo->unlocked_driver_cb)
1533                         block->lockeddevcnt--;
1534         }
1535 }
1536 
1537 static int tcf_block_setup(struct tcf_block *block,
1538                            struct flow_block_offload *bo)
1539 {
1540         int err;
1541 
1542         switch (bo->command) {
1543         case FLOW_BLOCK_BIND:
1544                 err = tcf_block_bind(block, bo);
1545                 break;
1546         case FLOW_BLOCK_UNBIND:
1547                 err = 0;
1548                 tcf_block_unbind(block, bo);
1549                 break;
1550         default:
1551                 WARN_ON_ONCE(1);
1552                 err = -EOPNOTSUPP;
1553         }
1554 
1555         return err;
1556 }
1557 
1558 /* Main classifier routine: scans classifier chain attached
1559  * to this qdisc, (optionally) tests for protocol and asks
1560  * specific classifiers.
1561  */
1562 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1563                  struct tcf_result *res, bool compat_mode)
1564 {
1565 #ifdef CONFIG_NET_CLS_ACT
1566         const int max_reclassify_loop = 4;
1567         const struct tcf_proto *orig_tp = tp;
1568         const struct tcf_proto *first_tp;
1569         int limit = 0;
1570 
1571 reclassify:
1572 #endif
1573         for (; tp; tp = rcu_dereference_bh(tp->next)) {
1574                 __be16 protocol = tc_skb_protocol(skb);
1575                 int err;
1576 
1577                 if (tp->protocol != protocol &&
1578                     tp->protocol != htons(ETH_P_ALL))
1579                         continue;
1580 
1581                 err = tp->classify(skb, tp, res);
1582 #ifdef CONFIG_NET_CLS_ACT
1583                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
1584                         first_tp = orig_tp;
1585                         goto reset;
1586                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
1587                         first_tp = res->goto_tp;
1588 
1589 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1590                         {
1591                                 struct tc_skb_ext *ext;
1592 
1593                                 ext = skb_ext_add(skb, TC_SKB_EXT);
1594                                 if (WARN_ON_ONCE(!ext))
1595                                         return TC_ACT_SHOT;
1596 
1597                                 ext->chain = err & TC_ACT_EXT_VAL_MASK;
1598                         }
1599 #endif
1600                         goto reset;
1601                 }
1602 #endif
1603                 if (err >= 0)
1604                         return err;
1605         }
1606 
1607         return TC_ACT_UNSPEC; /* signal: continue lookup */
1608 #ifdef CONFIG_NET_CLS_ACT
1609 reset:
1610         if (unlikely(limit++ >= max_reclassify_loop)) {
1611                 net_notice_ratelimited("%u: reclassify loop, rule prio %u, protocol %02x\n",
1612                                        tp->chain->block->index,
1613                                        tp->prio & 0xffff,
1614                                        ntohs(tp->protocol));
1615                 return TC_ACT_SHOT;
1616         }
1617 
1618         tp = first_tp;
1619         goto reclassify;
1620 #endif
1621 }
1622 EXPORT_SYMBOL(tcf_classify);
1623 
1624 struct tcf_chain_info {
1625         struct tcf_proto __rcu **pprev;
1626         struct tcf_proto __rcu *next;
1627 };
1628 
1629 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
1630                                            struct tcf_chain_info *chain_info)
1631 {
1632         return tcf_chain_dereference(*chain_info->pprev, chain);
1633 }
1634 
1635 static int tcf_chain_tp_insert(struct tcf_chain *chain,
1636                                struct tcf_chain_info *chain_info,
1637                                struct tcf_proto *tp)
1638 {
1639         if (chain->flushing)
1640                 return -EAGAIN;
1641 
1642         if (*chain_info->pprev == chain->filter_chain)
1643                 tcf_chain0_head_change(chain, tp);
1644         tcf_proto_get(tp);
1645         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
1646         rcu_assign_pointer(*chain_info->pprev, tp);
1647 
1648         return 0;
1649 }
1650 
1651 static void tcf_chain_tp_remove(struct tcf_chain *chain,
1652                                 struct tcf_chain_info *chain_info,
1653                                 struct tcf_proto *tp)
1654 {
1655         struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
1656 
1657         tcf_proto_mark_delete(tp);
1658         if (tp == chain->filter_chain)
1659                 tcf_chain0_head_change(chain, next);
1660         RCU_INIT_POINTER(*chain_info->pprev, next);
1661 }
1662 
1663 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1664                                            struct tcf_chain_info *chain_info,
1665                                            u32 protocol, u32 prio,
1666                                            bool prio_allocate);
1667 
1668 /* Try to insert new proto.
1669  * If proto with specified priority already exists, free new proto
1670  * and return existing one.
1671  */
1672 
1673 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
1674                                                     struct tcf_proto *tp_new,
1675                                                     u32 protocol, u32 prio,
1676                                                     bool rtnl_held)
1677 {
1678         struct tcf_chain_info chain_info;
1679         struct tcf_proto *tp;
1680         int err = 0;
1681 
1682         mutex_lock(&chain->filter_chain_lock);
1683 
1684         if (tcf_proto_exists_destroying(chain, tp_new)) {
1685                 mutex_unlock(&chain->filter_chain_lock);
1686                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1687                 return ERR_PTR(-EAGAIN);
1688         }
1689 
1690         tp = tcf_chain_tp_find(chain, &chain_info,
1691                                protocol, prio, false);
1692         if (!tp)
1693                 err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
1694         mutex_unlock(&chain->filter_chain_lock);
1695 
1696         if (tp) {
1697                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1698                 tp_new = tp;
1699         } else if (err) {
1700                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1701                 tp_new = ERR_PTR(err);
1702         }
1703 
1704         return tp_new;
1705 }
1706 
1707 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
1708                                       struct tcf_proto *tp, bool rtnl_held,
1709                                       struct netlink_ext_ack *extack)
1710 {
1711         struct tcf_chain_info chain_info;
1712         struct tcf_proto *tp_iter;
1713         struct tcf_proto **pprev;
1714         struct tcf_proto *next;
1715 
1716         mutex_lock(&chain->filter_chain_lock);
1717 
1718         /* Atomically find and remove tp from chain. */
1719         for (pprev = &chain->filter_chain;
1720              (tp_iter = tcf_chain_dereference(*pprev, chain));
1721              pprev = &tp_iter->next) {
1722                 if (tp_iter == tp) {
1723                         chain_info.pprev = pprev;
1724                         chain_info.next = tp_iter->next;
1725                         WARN_ON(tp_iter->deleting);
1726                         break;
1727                 }
1728         }
1729         /* Verify that tp still exists and no new filters were inserted
1730          * concurrently.
1731          * Mark tp for deletion if it is empty.
1732          */
1733         if (!tp_iter || !tcf_proto_check_delete(tp)) {
1734                 mutex_unlock(&chain->filter_chain_lock);
1735                 return;
1736         }
1737 
1738         tcf_proto_signal_destroying(chain, tp);
1739         next = tcf_chain_dereference(chain_info.next, chain);
1740         if (tp == chain->filter_chain)
1741                 tcf_chain0_head_change(chain, next);
1742         RCU_INIT_POINTER(*chain_info.pprev, next);
1743         mutex_unlock(&chain->filter_chain_lock);
1744 
1745         tcf_proto_put(tp, rtnl_held, extack);
1746 }
1747 
1748 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1749                                            struct tcf_chain_info *chain_info,
1750                                            u32 protocol, u32 prio,
1751                                            bool prio_allocate)
1752 {
1753         struct tcf_proto **pprev;
1754         struct tcf_proto *tp;
1755 
1756         /* Check the chain for existence of proto-tcf with this priority */
1757         for (pprev = &chain->filter_chain;
1758              (tp = tcf_chain_dereference(*pprev, chain));
1759              pprev = &tp->next) {
1760                 if (tp->prio >= prio) {
1761                         if (tp->prio == prio) {
1762                                 if (prio_allocate ||
1763                                     (tp->protocol != protocol && protocol))
1764                                         return ERR_PTR(-EINVAL);
1765                         } else {
1766                                 tp = NULL;
1767                         }
1768                         break;
1769                 }
1770         }
1771         chain_info->pprev = pprev;
1772         if (tp) {
1773                 chain_info->next = tp->next;
1774                 tcf_proto_get(tp);
1775         } else {
1776                 chain_info->next = NULL;
1777         }
1778         return tp;
1779 }
1780 
1781 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
1782                          struct tcf_proto *tp, struct tcf_block *block,
1783                          struct Qdisc *q, u32 parent, void *fh,
1784                          u32 portid, u32 seq, u16 flags, int event,
1785                          bool rtnl_held)
1786 {
1787         struct tcmsg *tcm;
1788         struct nlmsghdr  *nlh;
1789         unsigned char *b = skb_tail_pointer(skb);
1790 
1791         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1792         if (!nlh)
1793                 goto out_nlmsg_trim;
1794         tcm = nlmsg_data(nlh);
1795         tcm->tcm_family = AF_UNSPEC;
1796         tcm->tcm__pad1 = 0;
1797         tcm->tcm__pad2 = 0;
1798         if (q) {
1799                 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1800                 tcm->tcm_parent = parent;
1801         } else {
1802                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
1803                 tcm->tcm_block_index = block->index;
1804         }
1805         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
1806         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
1807                 goto nla_put_failure;
1808         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
1809                 goto nla_put_failure;
1810         if (!fh) {
1811                 tcm->tcm_handle = 0;
1812         } else {
1813                 if (tp->ops->dump &&
1814                     tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
1815                         goto nla_put_failure;
1816         }
1817         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1818         return skb->len;
1819 
1820 out_nlmsg_trim:
1821 nla_put_failure:
1822         nlmsg_trim(skb, b);
1823         return -1;
1824 }
1825 
1826 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
1827                           struct nlmsghdr *n, struct tcf_proto *tp,
1828                           struct tcf_block *block, struct Qdisc *q,
1829                           u32 parent, void *fh, int event, bool unicast,
1830                           bool rtnl_held)
1831 {
1832         struct sk_buff *skb;
1833         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1834         int err = 0;
1835 
1836         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1837         if (!skb)
1838                 return -ENOBUFS;
1839 
1840         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1841                           n->nlmsg_seq, n->nlmsg_flags, event,
1842                           rtnl_held) <= 0) {
1843                 kfree_skb(skb);
1844                 return -EINVAL;
1845         }
1846 
1847         if (unicast)
1848                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
1849         else
1850                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1851                                      n->nlmsg_flags & NLM_F_ECHO);
1852 
1853         if (err > 0)
1854                 err = 0;
1855         return err;
1856 }
1857 
1858 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
1859                               struct nlmsghdr *n, struct tcf_proto *tp,
1860                               struct tcf_block *block, struct Qdisc *q,
1861                               u32 parent, void *fh, bool unicast, bool *last,
1862                               bool rtnl_held, struct netlink_ext_ack *extack)
1863 {
1864         struct sk_buff *skb;
1865         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1866         int err;
1867 
1868         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1869         if (!skb)
1870                 return -ENOBUFS;
1871 
1872         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1873                           n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
1874                           rtnl_held) <= 0) {
1875                 NL_SET_ERR_MSG(extack, "Failed to build del event notification");
1876                 kfree_skb(skb);
1877                 return -EINVAL;
1878         }
1879 
1880         err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
1881         if (err) {
1882                 kfree_skb(skb);
1883                 return err;
1884         }
1885 
1886         if (unicast)
1887                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
1888         else
1889                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1890                                      n->nlmsg_flags & NLM_F_ECHO);
1891         if (err < 0)
1892                 NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
1893 
1894         if (err > 0)
1895                 err = 0;
1896         return err;
1897 }
1898 
1899 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
1900                                  struct tcf_block *block, struct Qdisc *q,
1901                                  u32 parent, struct nlmsghdr *n,
1902                                  struct tcf_chain *chain, int event,
1903                                  bool rtnl_held)
1904 {
1905         struct tcf_proto *tp;
1906 
1907         for (tp = tcf_get_next_proto(chain, NULL, rtnl_held);
1908              tp; tp = tcf_get_next_proto(chain, tp, rtnl_held))
1909                 tfilter_notify(net, oskb, n, tp, block,
1910                                q, parent, NULL, event, false, rtnl_held);
1911 }
1912 
1913 static void tfilter_put(struct tcf_proto *tp, void *fh)
1914 {
1915         if (tp->ops->put && fh)
1916                 tp->ops->put(tp, fh);
1917 }
1918 
1919 static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
1920                           struct netlink_ext_ack *extack)
1921 {
1922         struct net *net = sock_net(skb->sk);
1923         struct nlattr *tca[TCA_MAX + 1];
1924         char name[IFNAMSIZ];
1925         struct tcmsg *t;
1926         u32 protocol;
1927         u32 prio;
1928         bool prio_allocate;
1929         u32 parent;
1930         u32 chain_index;
1931         struct Qdisc *q = NULL;
1932         struct tcf_chain_info chain_info;
1933         struct tcf_chain *chain = NULL;
1934         struct tcf_block *block;
1935         struct tcf_proto *tp;
1936         unsigned long cl;
1937         void *fh;
1938         int err;
1939         int tp_created;
1940         bool rtnl_held = false;
1941 
1942         if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1943                 return -EPERM;
1944 
1945 replay:
1946         tp_created = 0;
1947 
1948         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
1949                                      rtm_tca_policy, extack);
1950         if (err < 0)
1951                 return err;
1952 
1953         t = nlmsg_data(n);
1954         protocol = TC_H_MIN(t->tcm_info);
1955         prio = TC_H_MAJ(t->tcm_info);
1956         prio_allocate = false;
1957         parent = t->tcm_parent;
1958         tp = NULL;
1959         cl = 0;
1960         block = NULL;
1961 
1962         if (prio == 0) {
1963                 /* If no priority is provided by the user,
1964                  * we allocate one.
1965                  */
1966                 if (n->nlmsg_flags & NLM_F_CREATE) {
1967                         prio = TC_H_MAKE(0x80000000U, 0U);
1968                         prio_allocate = true;
1969                 } else {
1970                         NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
1971                         return -ENOENT;
1972                 }
1973         }
1974 
1975         /* Find head of filter chain. */
1976 
1977         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
1978         if (err)
1979                 return err;
1980 
1981         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
1982                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
1983                 err = -EINVAL;
1984                 goto errout;
1985         }
1986 
1987         /* Take rtnl mutex if rtnl_held was set to true on previous iteration,
1988          * block is shared (no qdisc found), qdisc is not unlocked, classifier
1989          * type is not specified, classifier is not unlocked.
1990          */
1991         if (rtnl_held ||
1992             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
1993             !tcf_proto_is_unlocked(name)) {
1994                 rtnl_held = true;
1995                 rtnl_lock();
1996         }
1997 
1998         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
1999         if (err)
2000                 goto errout;
2001 
2002         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2003                                  extack);
2004         if (IS_ERR(block)) {
2005                 err = PTR_ERR(block);
2006                 goto errout;
2007         }
2008         block->classid = parent;
2009 
2010         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2011         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2012                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2013                 err = -EINVAL;
2014                 goto errout;
2015         }
2016         chain = tcf_chain_get(block, chain_index, true);
2017         if (!chain) {
2018                 NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
2019                 err = -ENOMEM;
2020                 goto errout;
2021         }
2022 
2023         mutex_lock(&chain->filter_chain_lock);
2024         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2025                                prio, prio_allocate);
2026         if (IS_ERR(tp)) {
2027                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2028                 err = PTR_ERR(tp);
2029                 goto errout_locked;
2030         }
2031 
2032         if (tp == NULL) {
2033                 struct tcf_proto *tp_new = NULL;
2034 
2035                 if (chain->flushing) {
2036                         err = -EAGAIN;
2037                         goto errout_locked;
2038                 }
2039 
2040                 /* Proto-tcf does not exist, create new one */
2041 
2042                 if (tca[TCA_KIND] == NULL || !protocol) {
2043                         NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
2044                         err = -EINVAL;
2045                         goto errout_locked;
2046                 }
2047 
2048                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2049                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2050                         err = -ENOENT;
2051                         goto errout_locked;
2052                 }
2053 
2054                 if (prio_allocate)
2055                         prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
2056                                                                &chain_info));
2057 
2058                 mutex_unlock(&chain->filter_chain_lock);
2059                 tp_new = tcf_proto_create(name, protocol, prio, chain,
2060                                           rtnl_held, extack);
2061                 if (IS_ERR(tp_new)) {
2062                         err = PTR_ERR(tp_new);
2063                         goto errout_tp;
2064                 }
2065 
2066                 tp_created = 1;
2067                 tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
2068                                                 rtnl_held);
2069                 if (IS_ERR(tp)) {
2070                         err = PTR_ERR(tp);
2071                         goto errout_tp;
2072                 }
2073         } else {
2074                 mutex_unlock(&chain->filter_chain_lock);
2075         }
2076 
2077         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2078                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2079                 err = -EINVAL;
2080                 goto errout;
2081         }
2082 
2083         fh = tp->ops->get(tp, t->tcm_handle);
2084 
2085         if (!fh) {
2086                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2087                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2088                         err = -ENOENT;
2089                         goto errout;
2090                 }
2091         } else if (n->nlmsg_flags & NLM_F_EXCL) {
2092                 tfilter_put(tp, fh);
2093                 NL_SET_ERR_MSG(extack, "Filter already exists");
2094                 err = -EEXIST;
2095                 goto errout;
2096         }
2097 
2098         if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
2099                 NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
2100                 err = -EINVAL;
2101                 goto errout;
2102         }
2103 
2104         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
2105                               n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
2106                               rtnl_held, extack);
2107         if (err == 0) {
2108                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2109                                RTM_NEWTFILTER, false, rtnl_held);
2110                 tfilter_put(tp, fh);
2111                 /* q pointer is NULL for shared blocks */
2112                 if (q)
2113                         q->flags &= ~TCQ_F_CAN_BYPASS;
2114         }
2115 
2116 errout:
2117         if (err && tp_created)
2118                 tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
2119 errout_tp:
2120         if (chain) {
2121                 if (tp && !IS_ERR(tp))
2122                         tcf_proto_put(tp, rtnl_held, NULL);
2123                 if (!tp_created)
2124                         tcf_chain_put(chain);
2125         }
2126         tcf_block_release(q, block, rtnl_held);
2127 
2128         if (rtnl_held)
2129                 rtnl_unlock();
2130 
2131         if (err == -EAGAIN) {
2132                 /* Take rtnl lock in case EAGAIN is caused by concurrent flush
2133                  * of target chain.
2134                  */
2135                 rtnl_held = true;
2136                 /* Replay the request. */
2137                 goto replay;
2138         }
2139         return err;
2140 
2141 errout_locked:
2142         mutex_unlock(&chain->filter_chain_lock);
2143         goto errout;
2144 }
2145 
2146 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2147                           struct netlink_ext_ack *extack)
2148 {
2149         struct net *net = sock_net(skb->sk);
2150         struct nlattr *tca[TCA_MAX + 1];
2151         char name[IFNAMSIZ];
2152         struct tcmsg *t;
2153         u32 protocol;
2154         u32 prio;
2155         u32 parent;
2156         u32 chain_index;
2157         struct Qdisc *q = NULL;
2158         struct tcf_chain_info chain_info;
2159         struct tcf_chain *chain = NULL;
2160         struct tcf_block *block = NULL;
2161         struct tcf_proto *tp = NULL;
2162         unsigned long cl = 0;
2163         void *fh = NULL;
2164         int err;
2165         bool rtnl_held = false;
2166 
2167         if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2168                 return -EPERM;
2169 
2170         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2171                                      rtm_tca_policy, extack);
2172         if (err < 0)
2173                 return err;
2174 
2175         t = nlmsg_data(n);
2176         protocol = TC_H_MIN(t->tcm_info);
2177         prio = TC_H_MAJ(t->tcm_info);
2178         parent = t->tcm_parent;
2179 
2180         if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
2181                 NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
2182                 return -ENOENT;
2183         }
2184 
2185         /* Find head of filter chain. */
2186 
2187         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2188         if (err)
2189                 return err;
2190 
2191         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2192                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2193                 err = -EINVAL;
2194                 goto errout;
2195         }
2196         /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
2197          * found), qdisc is not unlocked, classifier type is not specified,
2198          * classifier is not unlocked.
2199          */
2200         if (!prio ||
2201             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2202             !tcf_proto_is_unlocked(name)) {
2203                 rtnl_held = true;
2204                 rtnl_lock();
2205         }
2206 
2207         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2208         if (err)
2209                 goto errout;
2210 
2211         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2212                                  extack);
2213         if (IS_ERR(block)) {
2214                 err = PTR_ERR(block);
2215                 goto errout;
2216         }
2217 
2218         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2219         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2220                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2221                 err = -EINVAL;
2222                 goto errout;
2223         }
2224         chain = tcf_chain_get(block, chain_index, false);
2225         if (!chain) {
2226                 /* User requested flush on non-existent chain. Nothing to do,
2227                  * so just return success.
2228                  */
2229                 if (prio == 0) {
2230                         err = 0;
2231                         goto errout;
2232                 }
2233                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2234                 err = -ENOENT;
2235                 goto errout;
2236         }
2237 
2238         if (prio == 0) {
2239                 tfilter_notify_chain(net, skb, block, q, parent, n,
2240                                      chain, RTM_DELTFILTER, rtnl_held);
2241                 tcf_chain_flush(chain, rtnl_held);
2242                 err = 0;
2243                 goto errout;
2244         }
2245 
2246         mutex_lock(&chain->filter_chain_lock);
2247         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2248                                prio, false);
2249         if (!tp || IS_ERR(tp)) {
2250                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2251                 err = tp ? PTR_ERR(tp) : -ENOENT;
2252                 goto errout_locked;
2253         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2254                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2255                 err = -EINVAL;
2256                 goto errout_locked;
2257         } else if (t->tcm_handle == 0) {
2258                 tcf_proto_signal_destroying(chain, tp);
2259                 tcf_chain_tp_remove(chain, &chain_info, tp);
2260                 mutex_unlock(&chain->filter_chain_lock);
2261 
2262                 tcf_proto_put(tp, rtnl_held, NULL);
2263                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2264                                RTM_DELTFILTER, false, rtnl_held);
2265                 err = 0;
2266                 goto errout;
2267         }
2268         mutex_unlock(&chain->filter_chain_lock);
2269 
2270         fh = tp->ops->get(tp, t->tcm_handle);
2271 
2272         if (!fh) {
2273                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2274                 err = -ENOENT;
2275         } else {
2276                 bool last;
2277 
2278                 err = tfilter_del_notify(net, skb, n, tp, block,
2279                                          q, parent, fh, false, &last,
2280                                          rtnl_held, extack);
2281 
2282                 if (err)
2283                         goto errout;
2284                 if (last)
2285                         tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
2286         }
2287 
2288 errout:
2289         if (chain) {
2290                 if (tp && !IS_ERR(tp))
2291                         tcf_proto_put(tp, rtnl_held, NULL);
2292                 tcf_chain_put(chain);
2293         }
2294         tcf_block_release(q, block, rtnl_held);
2295 
2296         if (rtnl_held)
2297                 rtnl_unlock();
2298 
2299         return err;
2300 
2301 errout_locked:
2302         mutex_unlock(&chain->filter_chain_lock);
2303         goto errout;
2304 }
2305 
2306 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2307                           struct netlink_ext_ack *extack)
2308 {
2309         struct net *net = sock_net(skb->sk);
2310         struct nlattr *tca[TCA_MAX + 1];
2311         char name[IFNAMSIZ];
2312         struct tcmsg *t;
2313         u32 protocol;
2314         u32 prio;
2315         u32 parent;
2316         u32 chain_index;
2317         struct Qdisc *q = NULL;
2318         struct tcf_chain_info chain_info;
2319         struct tcf_chain *chain = NULL;
2320         struct tcf_block *block = NULL;
2321         struct tcf_proto *tp = NULL;
2322         unsigned long cl = 0;
2323         void *fh = NULL;
2324         int err;
2325         bool rtnl_held = false;
2326 
2327         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2328                                      rtm_tca_policy, extack);
2329         if (err < 0)
2330                 return err;
2331 
2332         t = nlmsg_data(n);
2333         protocol = TC_H_MIN(t->tcm_info);
2334         prio = TC_H_MAJ(t->tcm_info);
2335         parent = t->tcm_parent;
2336 
2337         if (prio == 0) {
2338                 NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2339                 return -ENOENT;
2340         }
2341 
2342         /* Find head of filter chain. */
2343 
2344         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2345         if (err)
2346                 return err;
2347 
2348         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2349                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2350                 err = -EINVAL;
2351                 goto errout;
2352         }
2353         /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
2354          * unlocked, classifier type is not specified, classifier is not
2355          * unlocked.
2356          */
2357         if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2358             !tcf_proto_is_unlocked(name)) {
2359                 rtnl_held = true;
2360                 rtnl_lock();
2361         }
2362 
2363         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2364         if (err)
2365                 goto errout;
2366 
2367         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2368                                  extack);
2369         if (IS_ERR(block)) {
2370                 err = PTR_ERR(block);
2371                 goto errout;
2372         }
2373 
2374         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2375         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2376                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2377                 err = -EINVAL;
2378                 goto errout;
2379         }
2380         chain = tcf_chain_get(block, chain_index, false);
2381         if (!chain) {
2382                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2383                 err = -EINVAL;
2384                 goto errout;
2385         }
2386 
2387         mutex_lock(&chain->filter_chain_lock);
2388         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2389                                prio, false);
2390         mutex_unlock(&chain->filter_chain_lock);
2391         if (!tp || IS_ERR(tp)) {
2392                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2393                 err = tp ? PTR_ERR(tp) : -ENOENT;
2394                 goto errout;
2395         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2396                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2397                 err = -EINVAL;
2398                 goto errout;
2399         }
2400 
2401         fh = tp->ops->get(tp, t->tcm_handle);
2402 
2403         if (!fh) {
2404                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2405                 err = -ENOENT;
2406         } else {
2407                 err = tfilter_notify(net, skb, n, tp, block, q, parent,
2408                                      fh, RTM_NEWTFILTER, true, rtnl_held);
2409                 if (err < 0)
2410                         NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
2411         }
2412 
2413         tfilter_put(tp, fh);
2414 errout:
2415         if (chain) {
2416                 if (tp && !IS_ERR(tp))
2417                         tcf_proto_put(tp, rtnl_held, NULL);
2418                 tcf_chain_put(chain);
2419         }
2420         tcf_block_release(q, block, rtnl_held);
2421 
2422         if (rtnl_held)
2423                 rtnl_unlock();
2424 
2425         return err;
2426 }
2427 
2428 struct tcf_dump_args {
2429         struct tcf_walker w;
2430         struct sk_buff *skb;
2431         struct netlink_callback *cb;
2432         struct tcf_block *block;
2433         struct Qdisc *q;
2434         u32 parent;
2435 };
2436 
2437 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2438 {
2439         struct tcf_dump_args *a = (void *)arg;
2440         struct net *net = sock_net(a->skb->sk);
2441 
2442         return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
2443                              n, NETLINK_CB(a->cb->skb).portid,
2444                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2445                              RTM_NEWTFILTER, true);
2446 }
2447 
2448 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
2449                            struct sk_buff *skb, struct netlink_callback *cb,
2450                            long index_start, long *p_index)
2451 {
2452         struct net *net = sock_net(skb->sk);
2453         struct tcf_block *block = chain->block;
2454         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2455         struct tcf_proto *tp, *tp_prev;
2456         struct tcf_dump_args arg;
2457 
2458         for (tp = __tcf_get_next_proto(chain, NULL);
2459              tp;
2460              tp_prev = tp,
2461                      tp = __tcf_get_next_proto(chain, tp),
2462                      tcf_proto_put(tp_prev, true, NULL),
2463                      (*p_index)++) {
2464                 if (*p_index < index_start)
2465                         continue;
2466                 if (TC_H_MAJ(tcm->tcm_info) &&
2467                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
2468                         continue;
2469                 if (TC_H_MIN(tcm->tcm_info) &&
2470                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
2471                         continue;
2472                 if (*p_index > index_start)
2473                         memset(&cb->args[1], 0,
2474                                sizeof(cb->args) - sizeof(cb->args[0]));
2475                 if (cb->args[1] == 0) {
2476                         if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
2477                                           NETLINK_CB(cb->skb).portid,
2478                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
2479                                           RTM_NEWTFILTER, true) <= 0)
2480                                 goto errout;
2481                         cb->args[1] = 1;
2482                 }
2483                 if (!tp->ops->walk)
2484                         continue;
2485                 arg.w.fn = tcf_node_dump;
2486                 arg.skb = skb;
2487                 arg.cb = cb;
2488                 arg.block = block;
2489                 arg.q = q;
2490                 arg.parent = parent;
2491                 arg.w.stop = 0;
2492                 arg.w.skip = cb->args[1] - 1;
2493                 arg.w.count = 0;
2494                 arg.w.cookie = cb->args[2];
2495                 tp->ops->walk(tp, &arg.w, true);
2496                 cb->args[2] = arg.w.cookie;
2497                 cb->args[1] = arg.w.count + 1;
2498                 if (arg.w.stop)
2499                         goto errout;
2500         }
2501         return true;
2502 
2503 errout:
2504         tcf_proto_put(tp, true, NULL);
2505         return false;
2506 }
2507 
2508 /* called with RTNL */
2509 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
2510 {
2511         struct tcf_chain *chain, *chain_prev;
2512         struct net *net = sock_net(skb->sk);
2513         struct nlattr *tca[TCA_MAX + 1];
2514         struct Qdisc *q = NULL;
2515         struct tcf_block *block;
2516         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2517         long index_start;
2518         long index;
2519         u32 parent;
2520         int err;
2521 
2522         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2523                 return skb->len;
2524 
2525         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2526                                      NULL, cb->extack);
2527         if (err)
2528                 return err;
2529 
2530         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2531                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2532                 if (!block)
2533                         goto out;
2534                 /* If we work with block index, q is NULL and parent value
2535                  * will never be used in the following code. The check
2536                  * in tcf_fill_node prevents it. However, compiler does not
2537                  * see that far, so set parent to zero to silence the warning
2538                  * about parent being uninitialized.
2539                  */
2540                 parent = 0;
2541         } else {
2542                 const struct Qdisc_class_ops *cops;
2543                 struct net_device *dev;
2544                 unsigned long cl = 0;
2545 
2546                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2547                 if (!dev)
2548                         return skb->len;
2549 
2550                 parent = tcm->tcm_parent;
2551                 if (!parent)
2552                         q = dev->qdisc;
2553                 else
2554                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2555                 if (!q)
2556                         goto out;
2557                 cops = q->ops->cl_ops;
2558                 if (!cops)
2559                         goto out;
2560                 if (!cops->tcf_block)
2561                         goto out;
2562                 if (TC_H_MIN(tcm->tcm_parent)) {
2563                         cl = cops->find(q, tcm->tcm_parent);
2564                         if (cl == 0)
2565                                 goto out;
2566                 }
2567                 block = cops->tcf_block(q, cl, NULL);
2568                 if (!block)
2569                         goto out;
2570                 parent = block->classid;
2571                 if (tcf_block_shared(block))
2572                         q = NULL;
2573         }
2574 
2575         index_start = cb->args[0];
2576         index = 0;
2577 
2578         for (chain = __tcf_get_next_chain(block, NULL);
2579              chain;
2580              chain_prev = chain,
2581                      chain = __tcf_get_next_chain(block, chain),
2582                      tcf_chain_put(chain_prev)) {
2583                 if (tca[TCA_CHAIN] &&
2584                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
2585                         continue;
2586                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
2587                                     index_start, &index)) {
2588                         tcf_chain_put(chain);
2589                         err = -EMSGSIZE;
2590                         break;
2591                 }
2592         }
2593 
2594         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2595                 tcf_block_refcnt_put(block, true);
2596         cb->args[0] = index;
2597 
2598 out:
2599         /* If we did no progress, the error (EMSGSIZE) is real */
2600         if (skb->len == 0 && err)
2601                 return err;
2602         return skb->len;
2603 }
2604 
2605 static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
2606                               void *tmplt_priv, u32 chain_index,
2607                               struct net *net, struct sk_buff *skb,
2608                               struct tcf_block *block,
2609                               u32 portid, u32 seq, u16 flags, int event)
2610 {
2611         unsigned char *b = skb_tail_pointer(skb);
2612         const struct tcf_proto_ops *ops;
2613         struct nlmsghdr *nlh;
2614         struct tcmsg *tcm;
2615         void *priv;
2616 
2617         ops = tmplt_ops;
2618         priv = tmplt_priv;
2619 
2620         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2621         if (!nlh)
2622                 goto out_nlmsg_trim;
2623         tcm = nlmsg_data(nlh);
2624         tcm->tcm_family = AF_UNSPEC;
2625         tcm->tcm__pad1 = 0;
2626         tcm->tcm__pad2 = 0;
2627         tcm->tcm_handle = 0;
2628         if (block->q) {
2629                 tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
2630                 tcm->tcm_parent = block->q->handle;
2631         } else {
2632                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2633                 tcm->tcm_block_index = block->index;
2634         }
2635 
2636         if (nla_put_u32(skb, TCA_CHAIN, chain_index))
2637                 goto nla_put_failure;
2638 
2639         if (ops) {
2640                 if (nla_put_string(skb, TCA_KIND, ops->kind))
2641                         goto nla_put_failure;
2642                 if (ops->tmplt_dump(skb, net, priv) < 0)
2643                         goto nla_put_failure;
2644         }
2645 
2646         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2647         return skb->len;
2648 
2649 out_nlmsg_trim:
2650 nla_put_failure:
2651         nlmsg_trim(skb, b);
2652         return -EMSGSIZE;
2653 }
2654 
2655 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
2656                            u32 seq, u16 flags, int event, bool unicast)
2657 {
2658         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2659         struct tcf_block *block = chain->block;
2660         struct net *net = block->net;
2661         struct sk_buff *skb;
2662         int err = 0;
2663 
2664         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2665         if (!skb)
2666                 return -ENOBUFS;
2667 
2668         if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2669                                chain->index, net, skb, block, portid,
2670                                seq, flags, event) <= 0) {
2671                 kfree_skb(skb);
2672                 return -EINVAL;
2673         }
2674 
2675         if (unicast)
2676                 err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
2677         else
2678                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2679                                      flags & NLM_F_ECHO);
2680 
2681         if (err > 0)
2682                 err = 0;
2683         return err;
2684 }
2685 
2686 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
2687                                   void *tmplt_priv, u32 chain_index,
2688                                   struct tcf_block *block, struct sk_buff *oskb,
2689                                   u32 seq, u16 flags, bool unicast)
2690 {
2691         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2692         struct net *net = block->net;
2693         struct sk_buff *skb;
2694 
2695         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2696         if (!skb)
2697                 return -ENOBUFS;
2698 
2699         if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
2700                                block, portid, seq, flags, RTM_DELCHAIN) <= 0) {
2701                 kfree_skb(skb);
2702                 return -EINVAL;
2703         }
2704 
2705         if (unicast)
2706                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
2707 
2708         return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
2709 }
2710 
2711 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
2712                               struct nlattr **tca,
2713                               struct netlink_ext_ack *extack)
2714 {
2715         const struct tcf_proto_ops *ops;
2716         char name[IFNAMSIZ];
2717         void *tmplt_priv;
2718 
2719         /* If kind is not set, user did not specify template. */
2720         if (!tca[TCA_KIND])
2721                 return 0;
2722 
2723         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2724                 NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
2725                 return -EINVAL;
2726         }
2727 
2728         ops = tcf_proto_lookup_ops(name, true, extack);
2729         if (IS_ERR(ops))
2730                 return PTR_ERR(ops);
2731         if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
2732                 NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
2733                 return -EOPNOTSUPP;
2734         }
2735 
2736         tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
2737         if (IS_ERR(tmplt_priv)) {
2738                 module_put(ops->owner);
2739                 return PTR_ERR(tmplt_priv);
2740         }
2741         chain->tmplt_ops = ops;
2742         chain->tmplt_priv = tmplt_priv;
2743         return 0;
2744 }
2745 
2746 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
2747                                void *tmplt_priv)
2748 {
2749         /* If template ops are set, no work to do for us. */
2750         if (!tmplt_ops)
2751                 return;
2752 
2753         tmplt_ops->tmplt_destroy(tmplt_priv);
2754         module_put(tmplt_ops->owner);
2755 }
2756 
2757 /* Add/delete/get a chain */
2758 
2759 static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
2760                         struct netlink_ext_ack *extack)
2761 {
2762         struct net *net = sock_net(skb->sk);
2763         struct nlattr *tca[TCA_MAX + 1];
2764         struct tcmsg *t;
2765         u32 parent;
2766         u32 chain_index;
2767         struct Qdisc *q = NULL;
2768         struct tcf_chain *chain = NULL;
2769         struct tcf_block *block;
2770         unsigned long cl;
2771         int err;
2772 
2773         if (n->nlmsg_type != RTM_GETCHAIN &&
2774             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2775                 return -EPERM;
2776 
2777 replay:
2778         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2779                                      rtm_tca_policy, extack);
2780         if (err < 0)
2781                 return err;
2782 
2783         t = nlmsg_data(n);
2784         parent = t->tcm_parent;
2785         cl = 0;
2786 
2787         block = tcf_block_find(net, &q, &parent, &cl,
2788                                t->tcm_ifindex, t->tcm_block_index, extack);
2789         if (IS_ERR(block))
2790                 return PTR_ERR(block);
2791 
2792         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2793         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2794                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2795                 err = -EINVAL;
2796                 goto errout_block;
2797         }
2798 
2799         mutex_lock(&block->lock);
2800         chain = tcf_chain_lookup(block, chain_index);
2801         if (n->nlmsg_type == RTM_NEWCHAIN) {
2802                 if (chain) {
2803                         if (tcf_chain_held_by_acts_only(chain)) {
2804                                 /* The chain exists only because there is
2805                                  * some action referencing it.
2806                                  */
2807                                 tcf_chain_hold(chain);
2808                         } else {
2809                                 NL_SET_ERR_MSG(extack, "Filter chain already exists");
2810                                 err = -EEXIST;
2811                                 goto errout_block_locked;
2812                         }
2813                 } else {
2814                         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2815                                 NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
2816                                 err = -ENOENT;
2817                                 goto errout_block_locked;
2818                         }
2819                         chain = tcf_chain_create(block, chain_index);
2820                         if (!chain) {
2821                                 NL_SET_ERR_MSG(extack, "Failed to create filter chain");
2822                                 err = -ENOMEM;
2823                                 goto errout_block_locked;
2824                         }
2825                 }
2826         } else {
2827                 if (!chain || tcf_chain_held_by_acts_only(chain)) {
2828                         NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2829                         err = -EINVAL;
2830                         goto errout_block_locked;
2831                 }
2832                 tcf_chain_hold(chain);
2833         }
2834 
2835         if (n->nlmsg_type == RTM_NEWCHAIN) {
2836                 /* Modifying chain requires holding parent block lock. In case
2837                  * the chain was successfully added, take a reference to the
2838                  * chain. This ensures that an empty chain does not disappear at
2839                  * the end of this function.
2840                  */
2841                 tcf_chain_hold(chain);
2842                 chain->explicitly_created = true;
2843         }
2844         mutex_unlock(&block->lock);
2845 
2846         switch (n->nlmsg_type) {
2847         case RTM_NEWCHAIN:
2848                 err = tc_chain_tmplt_add(chain, net, tca, extack);
2849                 if (err) {
2850                         tcf_chain_put_explicitly_created(chain);
2851                         goto errout;
2852                 }
2853 
2854                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
2855                                 RTM_NEWCHAIN, false);
2856                 break;
2857         case RTM_DELCHAIN:
2858                 tfilter_notify_chain(net, skb, block, q, parent, n,
2859                                      chain, RTM_DELTFILTER, true);
2860                 /* Flush the chain first as the user requested chain removal. */
2861                 tcf_chain_flush(chain, true);
2862                 /* In case the chain was successfully deleted, put a reference
2863                  * to the chain previously taken during addition.
2864                  */
2865                 tcf_chain_put_explicitly_created(chain);
2866                 break;
2867         case RTM_GETCHAIN:
2868                 err = tc_chain_notify(chain, skb, n->nlmsg_seq,
2869                                       n->nlmsg_seq, n->nlmsg_type, true);
2870                 if (err < 0)
2871                         NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
2872                 break;
2873         default:
2874                 err = -EOPNOTSUPP;
2875                 NL_SET_ERR_MSG(extack, "Unsupported message type");
2876                 goto errout;
2877         }
2878 
2879 errout:
2880         tcf_chain_put(chain);
2881 errout_block:
2882         tcf_block_release(q, block, true);
2883         if (err == -EAGAIN)
2884                 /* Replay the request. */
2885                 goto replay;
2886         return err;
2887 
2888 errout_block_locked:
2889         mutex_unlock(&block->lock);
2890         goto errout_block;
2891 }
2892 
2893 /* called with RTNL */
2894 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
2895 {
2896         struct net *net = sock_net(skb->sk);
2897         struct nlattr *tca[TCA_MAX + 1];
2898         struct Qdisc *q = NULL;
2899         struct tcf_block *block;
2900         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2901         struct tcf_chain *chain;
2902         long index_start;
2903         long index;
2904         u32 parent;
2905         int err;
2906 
2907         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2908                 return skb->len;
2909 
2910         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2911                                      rtm_tca_policy, cb->extack);
2912         if (err)
2913                 return err;
2914 
2915         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2916                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2917                 if (!block)
2918                         goto out;
2919                 /* If we work with block index, q is NULL and parent value
2920                  * will never be used in the following code. The check
2921                  * in tcf_fill_node prevents it. However, compiler does not
2922                  * see that far, so set parent to zero to silence the warning
2923                  * about parent being uninitialized.
2924                  */
2925                 parent = 0;
2926         } else {
2927                 const struct Qdisc_class_ops *cops;
2928                 struct net_device *dev;
2929                 unsigned long cl = 0;
2930 
2931                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2932                 if (!dev)
2933                         return skb->len;
2934 
2935                 parent = tcm->tcm_parent;
2936                 if (!parent) {
2937                         q = dev->qdisc;
2938                         parent = q->handle;
2939                 } else {
2940                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2941                 }
2942                 if (!q)
2943                         goto out;
2944                 cops = q->ops->cl_ops;
2945                 if (!cops)
2946                         goto out;
2947                 if (!cops->tcf_block)
2948                         goto out;
2949                 if (TC_H_MIN(tcm->tcm_parent)) {
2950                         cl = cops->find(q, tcm->tcm_parent);
2951                         if (cl == 0)
2952                                 goto out;
2953                 }
2954                 block = cops->tcf_block(q, cl, NULL);
2955                 if (!block)
2956                         goto out;
2957                 if (tcf_block_shared(block))
2958                         q = NULL;
2959         }
2960 
2961         index_start = cb->args[0];
2962         index = 0;
2963 
2964         mutex_lock(&block->lock);
2965         list_for_each_entry(chain, &block->chain_list, list) {
2966                 if ((tca[TCA_CHAIN] &&
2967                      nla_get_u32(tca[TCA_CHAIN]) != chain->index))
2968                         continue;
2969                 if (index < index_start) {
2970                         index++;
2971                         continue;
2972                 }
2973                 if (tcf_chain_held_by_acts_only(chain))
2974                         continue;
2975                 err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2976                                          chain->index, net, skb, block,
2977                                          NETLINK_CB(cb->skb).portid,
2978                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
2979                                          RTM_NEWCHAIN);
2980                 if (err <= 0)
2981                         break;
2982                 index++;
2983         }
2984         mutex_unlock(&block->lock);
2985 
2986         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2987                 tcf_block_refcnt_put(block, true);
2988         cb->args[0] = index;
2989 
2990 out:
2991         /* If we did no progress, the error (EMSGSIZE) is real */
2992         if (skb->len == 0 && err)
2993                 return err;
2994         return skb->len;
2995 }
2996 
2997 void tcf_exts_destroy(struct tcf_exts *exts)
2998 {
2999 #ifdef CONFIG_NET_CLS_ACT
3000         if (exts->actions) {
3001                 tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
3002                 kfree(exts->actions);
3003         }
3004         exts->nr_actions = 0;
3005 #endif
3006 }
3007 EXPORT_SYMBOL(tcf_exts_destroy);
3008 
3009 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3010                       struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr,
3011                       bool rtnl_held, struct netlink_ext_ack *extack)
3012 {
3013 #ifdef CONFIG_NET_CLS_ACT
3014         {
3015                 struct tc_action *act;
3016                 size_t attr_size = 0;
3017 
3018                 if (exts->police && tb[exts->police]) {
3019                         act = tcf_action_init_1(net, tp, tb[exts->police],
3020                                                 rate_tlv, "police", ovr,
3021                                                 TCA_ACT_BIND, rtnl_held,
3022                                                 extack);
3023                         if (IS_ERR(act))
3024                                 return PTR_ERR(act);
3025 
3026                         act->type = exts->type = TCA_OLD_COMPAT;
3027                         exts->actions[0] = act;
3028                         exts->nr_actions = 1;
3029                 } else if (exts->action && tb[exts->action]) {
3030                         int err;
3031 
3032                         err = tcf_action_init(net, tp, tb[exts->action],
3033                                               rate_tlv, NULL, ovr, TCA_ACT_BIND,
3034                                               exts->actions, &attr_size,
3035                                               rtnl_held, extack);
3036                         if (err < 0)
3037                                 return err;
3038                         exts->nr_actions = err;
3039                 }
3040         }
3041 #else
3042         if ((exts->action && tb[exts->action]) ||
3043             (exts->police && tb[exts->police])) {
3044                 NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
3045                 return -EOPNOTSUPP;
3046         }
3047 #endif
3048 
3049         return 0;
3050 }
3051 EXPORT_SYMBOL(tcf_exts_validate);
3052 
3053 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
3054 {
3055 #ifdef CONFIG_NET_CLS_ACT
3056         struct tcf_exts old = *dst;
3057 
3058         *dst = *src;
3059         tcf_exts_destroy(&old);
3060 #endif
3061 }
3062 EXPORT_SYMBOL(tcf_exts_change);
3063 
3064 #ifdef CONFIG_NET_CLS_ACT
3065 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
3066 {
3067         if (exts->nr_actions == 0)
3068                 return NULL;
3069         else
3070                 return exts->actions[0];
3071 }
3072 #endif
3073 
3074 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
3075 {
3076 #ifdef CONFIG_NET_CLS_ACT
3077         struct nlattr *nest;
3078 
3079         if (exts->action && tcf_exts_has_actions(exts)) {
3080                 /*
3081                  * again for backward compatible mode - we want
3082                  * to work with both old and new modes of entering
3083                  * tc data even if iproute2  was newer - jhs
3084                  */
3085                 if (exts->type != TCA_OLD_COMPAT) {
3086                         nest = nla_nest_start_noflag(skb, exts->action);
3087                         if (nest == NULL)
3088                                 goto nla_put_failure;
3089 
3090                         if (tcf_action_dump(skb, exts->actions, 0, 0) < 0)
3091                                 goto nla_put_failure;
3092                         nla_nest_end(skb, nest);
3093                 } else if (exts->police) {
3094                         struct tc_action *act = tcf_exts_first_act(exts);
3095                         nest = nla_nest_start_noflag(skb, exts->police);
3096                         if (nest == NULL || !act)
3097                                 goto nla_put_failure;
3098                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
3099                                 goto nla_put_failure;
3100                         nla_nest_end(skb, nest);
3101                 }
3102         }
3103         return 0;
3104 
3105 nla_put_failure:
3106         nla_nest_cancel(skb, nest);
3107         return -1;
3108 #else
3109         return 0;
3110 #endif
3111 }
3112 EXPORT_SYMBOL(tcf_exts_dump);
3113 
3114 
3115 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
3116 {
3117 #ifdef CONFIG_NET_CLS_ACT
3118         struct tc_action *a = tcf_exts_first_act(exts);
3119         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
3120                 return -1;
3121 #endif
3122         return 0;
3123 }
3124 EXPORT_SYMBOL(tcf_exts_dump_stats);
3125 
3126 static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
3127 {
3128         if (*flags & TCA_CLS_FLAGS_IN_HW)
3129                 return;
3130         *flags |= TCA_CLS_FLAGS_IN_HW;
3131         atomic_inc(&block->offloadcnt);
3132 }
3133 
3134 static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
3135 {
3136         if (!(*flags & TCA_CLS_FLAGS_IN_HW))
3137                 return;
3138         *flags &= ~TCA_CLS_FLAGS_IN_HW;
3139         atomic_dec(&block->offloadcnt);
3140 }
3141 
3142 static void tc_cls_offload_cnt_update(struct tcf_block *block,
3143                                       struct tcf_proto *tp, u32 *cnt,
3144                                       u32 *flags, u32 diff, bool add)
3145 {
3146         lockdep_assert_held(&block->cb_lock);
3147 
3148         spin_lock(&tp->lock);
3149         if (add) {
3150                 if (!*cnt)
3151                         tcf_block_offload_inc(block, flags);
3152                 *cnt += diff;
3153         } else {
3154                 *cnt -= diff;
3155                 if (!*cnt)
3156                         tcf_block_offload_dec(block, flags);
3157         }
3158         spin_unlock(&tp->lock);
3159 }
3160 
3161 static void
3162 tc_cls_offload_cnt_reset(struct tcf_block *block, struct tcf_proto *tp,
3163                          u32 *cnt, u32 *flags)
3164 {
3165         lockdep_assert_held(&block->cb_lock);
3166 
3167         spin_lock(&tp->lock);
3168         tcf_block_offload_dec(block, flags);
3169         *cnt = 0;
3170         spin_unlock(&tp->lock);
3171 }
3172 
3173 static int
3174 __tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3175                    void *type_data, bool err_stop)
3176 {
3177         struct flow_block_cb *block_cb;
3178         int ok_count = 0;
3179         int err;
3180 
3181         list_for_each_entry(block_cb, &block->flow_block.cb_list, list) {
3182                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
3183                 if (err) {
3184                         if (err_stop)
3185                                 return err;
3186                 } else {
3187                         ok_count++;
3188                 }
3189         }
3190         return ok_count;
3191 }
3192 
3193 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3194                      void *type_data, bool err_stop, bool rtnl_held)
3195 {
3196         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3197         int ok_count;
3198 
3199 retry:
3200         if (take_rtnl)
3201                 rtnl_lock();
3202         down_read(&block->cb_lock);
3203         /* Need to obtain rtnl lock if block is bound to devs that require it.
3204          * In block bind code cb_lock is obtained while holding rtnl, so we must
3205          * obtain the locks in same order here.
3206          */
3207         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3208                 up_read(&block->cb_lock);
3209                 take_rtnl = true;
3210                 goto retry;
3211         }
3212 
3213         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3214 
3215         up_read(&block->cb_lock);
3216         if (take_rtnl)
3217                 rtnl_unlock();
3218         return ok_count;
3219 }
3220 EXPORT_SYMBOL(tc_setup_cb_call);
3221 
3222 /* Non-destructive filter add. If filter that wasn't already in hardware is
3223  * successfully offloaded, increment block offloads counter. On failure,
3224  * previously offloaded filter is considered to be intact and offloads counter
3225  * is not decremented.
3226  */
3227 
3228 int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
3229                     enum tc_setup_type type, void *type_data, bool err_stop,
3230                     u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3231 {
3232         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3233         int ok_count;
3234 
3235 retry:
3236         if (take_rtnl)
3237                 rtnl_lock();
3238         down_read(&block->cb_lock);
3239         /* Need to obtain rtnl lock if block is bound to devs that require it.
3240          * In block bind code cb_lock is obtained while holding rtnl, so we must
3241          * obtain the locks in same order here.
3242          */
3243         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3244                 up_read(&block->cb_lock);
3245                 take_rtnl = true;
3246                 goto retry;
3247         }
3248 
3249         /* Make sure all netdevs sharing this block are offload-capable. */
3250         if (block->nooffloaddevcnt && err_stop) {
3251                 ok_count = -EOPNOTSUPP;
3252                 goto err_unlock;
3253         }
3254 
3255         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3256         if (ok_count < 0)
3257                 goto err_unlock;
3258 
3259         if (tp->ops->hw_add)
3260                 tp->ops->hw_add(tp, type_data);
3261         if (ok_count > 0)
3262                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
3263                                           ok_count, true);
3264 err_unlock:
3265         up_read(&block->cb_lock);
3266         if (take_rtnl)
3267                 rtnl_unlock();
3268         return ok_count < 0 ? ok_count : 0;
3269 }
3270 EXPORT_SYMBOL(tc_setup_cb_add);
3271 
3272 /* Destructive filter replace. If filter that wasn't already in hardware is
3273  * successfully offloaded, increment block offload counter. On failure,
3274  * previously offloaded filter is considered to be destroyed and offload counter
3275  * is decremented.
3276  */
3277 
3278 int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
3279                         enum tc_setup_type type, void *type_data, bool err_stop,
3280                         u32 *old_flags, unsigned int *old_in_hw_count,
3281                         u32 *new_flags, unsigned int *new_in_hw_count,
3282                         bool rtnl_held)
3283 {
3284         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3285         int ok_count;
3286 
3287 retry:
3288         if (take_rtnl)
3289                 rtnl_lock();
3290         down_read(&block->cb_lock);
3291         /* Need to obtain rtnl lock if block is bound to devs that require it.
3292          * In block bind code cb_lock is obtained while holding rtnl, so we must
3293          * obtain the locks in same order here.
3294          */
3295         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3296                 up_read(&block->cb_lock);
3297                 take_rtnl = true;
3298                 goto retry;
3299         }
3300 
3301         /* Make sure all netdevs sharing this block are offload-capable. */
3302         if (block->nooffloaddevcnt && err_stop) {
3303                 ok_count = -EOPNOTSUPP;
3304                 goto err_unlock;
3305         }
3306 
3307         tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
3308         if (tp->ops->hw_del)
3309                 tp->ops->hw_del(tp, type_data);
3310 
3311         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3312         if (ok_count < 0)
3313                 goto err_unlock;
3314 
3315         if (tp->ops->hw_add)
3316                 tp->ops->hw_add(tp, type_data);
3317         if (ok_count > 0)
3318                 tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
3319                                           new_flags, ok_count, true);
3320 err_unlock:
3321         up_read(&block->cb_lock);
3322         if (take_rtnl)
3323                 rtnl_unlock();
3324         return ok_count < 0 ? ok_count : 0;
3325 }
3326 EXPORT_SYMBOL(tc_setup_cb_replace);
3327 
3328 /* Destroy filter and decrement block offload counter, if filter was previously
3329  * offloaded.
3330  */
3331 
3332 int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
3333                         enum tc_setup_type type, void *type_data, bool err_stop,
3334                         u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3335 {
3336         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3337         int ok_count;
3338 
3339 retry:
3340         if (take_rtnl)
3341                 rtnl_lock();
3342         down_read(&block->cb_lock);
3343         /* Need to obtain rtnl lock if block is bound to devs that require it.
3344          * In block bind code cb_lock is obtained while holding rtnl, so we must
3345          * obtain the locks in same order here.
3346          */
3347         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3348                 up_read(&block->cb_lock);
3349                 take_rtnl = true;
3350                 goto retry;
3351         }
3352 
3353         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3354 
3355         tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
3356         if (tp->ops->hw_del)
3357                 tp->ops->hw_del(tp, type_data);
3358 
3359         up_read(&block->cb_lock);
3360         if (take_rtnl)
3361                 rtnl_unlock();
3362         return ok_count < 0 ? ok_count : 0;
3363 }
3364 EXPORT_SYMBOL(tc_setup_cb_destroy);
3365 
3366 int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
3367                           bool add, flow_setup_cb_t *cb,
3368                           enum tc_setup_type type, void *type_data,
3369                           void *cb_priv, u32 *flags, unsigned int *in_hw_count)
3370 {
3371         int err = cb(type, type_data, cb_priv);
3372 
3373         if (err) {
3374                 if (add && tc_skip_sw(*flags))
3375                         return err;
3376         } else {
3377                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags, 1,
3378                                           add);
3379         }
3380 
3381         return 0;
3382 }
3383 EXPORT_SYMBOL(tc_setup_cb_reoffload);
3384 
3385 void tc_cleanup_flow_action(struct flow_action *flow_action)
3386 {
3387         struct flow_action_entry *entry;
3388         int i;
3389 
3390         flow_action_for_each(i, entry, flow_action)
3391                 if (entry->destructor)
3392                         entry->destructor(entry->destructor_priv);
3393 }
3394 EXPORT_SYMBOL(tc_cleanup_flow_action);
3395 
3396 static void tcf_mirred_get_dev(struct flow_action_entry *entry,
3397                                const struct tc_action *act)
3398 {
3399 #ifdef CONFIG_NET_CLS_ACT
3400         entry->dev = act->ops->get_dev(act, &entry->destructor);
3401         if (!entry->dev)
3402                 return;
3403         entry->destructor_priv = entry->dev;
3404 #endif
3405 }
3406 
3407 static void tcf_tunnel_encap_put_tunnel(void *priv)
3408 {
3409         struct ip_tunnel_info *tunnel = priv;
3410 
3411         kfree(tunnel);
3412 }
3413 
3414 static int tcf_tunnel_encap_get_tunnel(struct flow_action_entry *entry,
3415                                        const struct tc_action *act)
3416 {
3417         entry->tunnel = tcf_tunnel_info_copy(act);
3418         if (!entry->tunnel)
3419                 return -ENOMEM;
3420         entry->destructor = tcf_tunnel_encap_put_tunnel;
3421         entry->destructor_priv = entry->tunnel;
3422         return 0;
3423 }
3424 
3425 static void tcf_sample_get_group(struct flow_action_entry *entry,
3426                                  const struct tc_action *act)
3427 {
3428 #ifdef CONFIG_NET_CLS_ACT
3429         entry->sample.psample_group =
3430                 act->ops->get_psample_group(act, &entry->destructor);
3431         entry->destructor_priv = entry->sample.psample_group;
3432 #endif
3433 }
3434 
3435 int tc_setup_flow_action(struct flow_action *flow_action,
3436                          const struct tcf_exts *exts, bool rtnl_held)
3437 {
3438         const struct tc_action *act;
3439         int i, j, k, err = 0;
3440 
3441         if (!exts)
3442                 return 0;
3443 
3444         if (!rtnl_held)
3445                 rtnl_lock();
3446 
3447         j = 0;
3448         tcf_exts_for_each_action(i, act, exts) {
3449                 struct flow_action_entry *entry;
3450 
3451                 entry = &flow_action->entries[j];
3452                 if (is_tcf_gact_ok(act)) {
3453                         entry->id = FLOW_ACTION_ACCEPT;
3454                 } else if (is_tcf_gact_shot(act)) {
3455                         entry->id = FLOW_ACTION_DROP;
3456                 } else if (is_tcf_gact_trap(act)) {
3457                         entry->id = FLOW_ACTION_TRAP;
3458                 } else if (is_tcf_gact_goto_chain(act)) {
3459                         entry->id = FLOW_ACTION_GOTO;
3460                         entry->chain_index = tcf_gact_goto_chain_index(act);
3461                 } else if (is_tcf_mirred_egress_redirect(act)) {
3462                         entry->id = FLOW_ACTION_REDIRECT;
3463                         tcf_mirred_get_dev(entry, act);
3464                 } else if (is_tcf_mirred_egress_mirror(act)) {
3465                         entry->id = FLOW_ACTION_MIRRED;
3466                         tcf_mirred_get_dev(entry, act);
3467                 } else if (is_tcf_mirred_ingress_redirect(act)) {
3468                         entry->id = FLOW_ACTION_REDIRECT_INGRESS;
3469                         tcf_mirred_get_dev(entry, act);
3470                 } else if (is_tcf_mirred_ingress_mirror(act)) {
3471                         entry->id = FLOW_ACTION_MIRRED_INGRESS;
3472                         tcf_mirred_get_dev(entry, act);
3473                 } else if (is_tcf_vlan(act)) {
3474                         switch (tcf_vlan_action(act)) {
3475                         case TCA_VLAN_ACT_PUSH:
3476                                 entry->id = FLOW_ACTION_VLAN_PUSH;
3477                                 entry->vlan.vid = tcf_vlan_push_vid(act);
3478                                 entry->vlan.proto = tcf_vlan_push_proto(act);
3479                                 entry->vlan.prio = tcf_vlan_push_prio(act);
3480                                 break;
3481                         case TCA_VLAN_ACT_POP:
3482                                 entry->id = FLOW_ACTION_VLAN_POP;
3483                                 break;
3484                         case TCA_VLAN_ACT_MODIFY:
3485                                 entry->id = FLOW_ACTION_VLAN_MANGLE;
3486                                 entry->vlan.vid = tcf_vlan_push_vid(act);
3487                                 entry->vlan.proto = tcf_vlan_push_proto(act);
3488                                 entry->vlan.prio = tcf_vlan_push_prio(act);
3489                                 break;
3490                         default:
3491                                 err = -EOPNOTSUPP;
3492                                 goto err_out;
3493                         }
3494                 } else if (is_tcf_tunnel_set(act)) {
3495                         entry->id = FLOW_ACTION_TUNNEL_ENCAP;
3496                         err = tcf_tunnel_encap_get_tunnel(entry, act);
3497                         if (err)
3498                                 goto err_out;
3499                 } else if (is_tcf_tunnel_release(act)) {
3500                         entry->id = FLOW_ACTION_TUNNEL_DECAP;
3501                 } else if (is_tcf_pedit(act)) {
3502                         for (k = 0; k < tcf_pedit_nkeys(act); k++) {
3503                                 switch (tcf_pedit_cmd(act, k)) {
3504                                 case TCA_PEDIT_KEY_EX_CMD_SET:
3505                                         entry->id = FLOW_ACTION_MANGLE;
3506                                         break;
3507                                 case TCA_PEDIT_KEY_EX_CMD_ADD:
3508                                         entry->id = FLOW_ACTION_ADD;
3509                                         break;
3510                                 default:
3511                                         err = -EOPNOTSUPP;
3512                                         goto err_out;
3513                                 }
3514                                 entry->mangle.htype = tcf_pedit_htype(act, k);
3515                                 entry->mangle.mask = tcf_pedit_mask(act, k);
3516                                 entry->mangle.val = tcf_pedit_val(act, k);
3517                                 entry->mangle.offset = tcf_pedit_offset(act, k);
3518                                 entry = &flow_action->entries[++j];
3519                         }
3520                 } else if (is_tcf_csum(act)) {
3521                         entry->id = FLOW_ACTION_CSUM;
3522                         entry->csum_flags = tcf_csum_update_flags(act);
3523                 } else if (is_tcf_skbedit_mark(act)) {
3524                         entry->id = FLOW_ACTION_MARK;
3525                         entry->mark = tcf_skbedit_mark(act);
3526                 } else if (is_tcf_sample(act)) {
3527                         entry->id = FLOW_ACTION_SAMPLE;
3528                         entry->sample.trunc_size = tcf_sample_trunc_size(act);
3529                         entry->sample.truncate = tcf_sample_truncate(act);
3530                         entry->sample.rate = tcf_sample_rate(act);
3531                         tcf_sample_get_group(entry, act);
3532                 } else if (is_tcf_police(act)) {
3533                         entry->id = FLOW_ACTION_POLICE;
3534                         entry->police.burst = tcf_police_tcfp_burst(act);
3535                         entry->police.rate_bytes_ps =
3536                                 tcf_police_rate_bytes_ps(act);
3537                 } else if (is_tcf_ct(act)) {
3538                         entry->id = FLOW_ACTION_CT;
3539                         entry->ct.action = tcf_ct_action(act);
3540                         entry->ct.zone = tcf_ct_zone(act);
3541                 } else if (is_tcf_mpls(act)) {
3542                         switch (tcf_mpls_action(act)) {
3543                         case TCA_MPLS_ACT_PUSH:
3544                                 entry->id = FLOW_ACTION_MPLS_PUSH;
3545                                 entry->mpls_push.proto = tcf_mpls_proto(act);
3546                                 entry->mpls_push.label = tcf_mpls_label(act);
3547                                 entry->mpls_push.tc = tcf_mpls_tc(act);
3548                                 entry->mpls_push.bos = tcf_mpls_bos(act);
3549                                 entry->mpls_push.ttl = tcf_mpls_ttl(act);
3550                                 break;
3551                         case TCA_MPLS_ACT_POP:
3552                                 entry->id = FLOW_ACTION_MPLS_POP;
3553                                 entry->mpls_pop.proto = tcf_mpls_proto(act);
3554                                 break;
3555                         case TCA_MPLS_ACT_MODIFY:
3556                                 entry->id = FLOW_ACTION_MPLS_MANGLE;
3557                                 entry->mpls_mangle.label = tcf_mpls_label(act);
3558                                 entry->mpls_mangle.tc = tcf_mpls_tc(act);
3559                                 entry->mpls_mangle.bos = tcf_mpls_bos(act);
3560                                 entry->mpls_mangle.ttl = tcf_mpls_ttl(act);
3561                                 break;
3562                         default:
3563                                 goto err_out;
3564                         }
3565                 } else if (is_tcf_skbedit_ptype(act)) {
3566                         entry->id = FLOW_ACTION_PTYPE;
3567                         entry->ptype = tcf_skbedit_ptype(act);
3568                 } else {
3569                         err = -EOPNOTSUPP;
3570                         goto err_out;
3571                 }
3572 
3573                 if (!is_tcf_pedit(act))
3574                         j++;
3575         }
3576 
3577 err_out:
3578         if (!rtnl_held)
3579                 rtnl_unlock();
3580 
3581         if (err)
3582                 tc_cleanup_flow_action(flow_action);
3583 
3584         return err;
3585 }
3586 EXPORT_SYMBOL(tc_setup_flow_action);
3587 
3588 unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
3589 {
3590         unsigned int num_acts = 0;
3591         struct tc_action *act;
3592         int i;
3593 
3594         tcf_exts_for_each_action(i, act, exts) {
3595                 if (is_tcf_pedit(act))
3596                         num_acts += tcf_pedit_nkeys(act);
3597                 else
3598                         num_acts++;
3599         }
3600         return num_acts;
3601 }
3602 EXPORT_SYMBOL(tcf_exts_num_actions);
3603 
3604 static __net_init int tcf_net_init(struct net *net)
3605 {
3606         struct tcf_net *tn = net_generic(net, tcf_net_id);
3607 
3608         spin_lock_init(&tn->idr_lock);
3609         idr_init(&tn->idr);
3610         return 0;
3611 }
3612 
3613 static void __net_exit tcf_net_exit(struct net *net)
3614 {
3615         struct tcf_net *tn = net_generic(net, tcf_net_id);
3616 
3617         idr_destroy(&tn->idr);
3618 }
3619 
3620 static struct pernet_operations tcf_net_ops = {
3621         .init = tcf_net_init,
3622         .exit = tcf_net_exit,
3623         .id   = &tcf_net_id,
3624         .size = sizeof(struct tcf_net),
3625 };
3626 
3627 static struct flow_indr_block_entry block_entry = {
3628         .cb = tc_indr_block_get_and_cmd,
3629         .list = LIST_HEAD_INIT(block_entry.list),
3630 };
3631 
3632 static int __init tc_filter_init(void)
3633 {
3634         int err;
3635 
3636         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
3637         if (!tc_filter_wq)
3638                 return -ENOMEM;
3639 
3640         err = register_pernet_subsys(&tcf_net_ops);
3641         if (err)
3642                 goto err_register_pernet_subsys;
3643 
3644         flow_indr_add_block_cb(&block_entry);
3645 
3646         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
3647                       RTNL_FLAG_DOIT_UNLOCKED);
3648         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
3649                       RTNL_FLAG_DOIT_UNLOCKED);
3650         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
3651                       tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
3652         rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
3653         rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
3654         rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
3655                       tc_dump_chain, 0);
3656 
3657         return 0;
3658 
3659 err_register_pernet_subsys:
3660         destroy_workqueue(tc_filter_wq);
3661         return err;
3662 }
3663 
3664 subsys_initcall(tc_filter_init);
/* [<][>][^][v][top][bottom][index][help] */
root/net/sched/cls_api.c

DEFINITIONS
