net/sched/act_api.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/act_api.c  Packet action API.
   4  *
   5  * Author:      Jamal Hadi Salim
   6  */
   7
   8 #include <linux/types.h>
   9 #include <linux/kernel.h>
  10 #include <linux/string.h>
  11 #include <linux/errno.h>
  12 #include <linux/slab.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/init.h>
  15 #include <linux/kmod.h>
  16 #include <linux/err.h>
  17 #include <linux/module.h>
  18 #include <net/net_namespace.h>
  19 #include <net/sock.h>
  20 #include <net/sch_generic.h>
  21 #include <net/pkt_cls.h>
  22 #include <net/act_api.h>
  23 #include <net/netlink.h>
  24
  25 static void tcf_action_goto_chain_exec(const struct tc_action *a,
  26                                        struct tcf_result *res)
  27 {
  28         const struct tcf_chain *chain = rcu_dereference_bh(a->goto_chain);
  29
  30         res->goto_tp = rcu_dereference_bh(chain->filter_chain);
  31 }
  32
  33 static void tcf_free_cookie_rcu(struct rcu_head *p)
  34 {
  35         struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
  36
  37         kfree(cookie->data);
  38         kfree(cookie);
  39 }
  40
  41 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
  42                                   struct tc_cookie *new_cookie)
  43 {
  44         struct tc_cookie *old;
  45
  46         old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
  47         if (old)
  48                 call_rcu(&old->rcu, tcf_free_cookie_rcu);
  49 }
  50
  51 int tcf_action_check_ctrlact(int action, struct tcf_proto *tp,
  52                              struct tcf_chain **newchain,
  53                              struct netlink_ext_ack *extack)
  54 {
  55         int opcode = TC_ACT_EXT_OPCODE(action), ret = -EINVAL;
  56         u32 chain_index;
  57
  58         if (!opcode)
  59                 ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;
  60         else if (opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC)
  61                 ret = 0;
  62         if (ret) {
  63                 NL_SET_ERR_MSG(extack, "invalid control action");
  64                 goto end;
  65         }
  66
  67         if (TC_ACT_EXT_CMP(action, TC_ACT_GOTO_CHAIN)) {
  68                 chain_index = action & TC_ACT_EXT_VAL_MASK;
  69                 if (!tp || !newchain) {
  70                         ret = -EINVAL;
  71                         NL_SET_ERR_MSG(extack,
  72                                        "can't goto NULL proto/chain");
  73                         goto end;
  74                 }
  75                 *newchain = tcf_chain_get_by_act(tp->chain->block, chain_index);
  76                 if (!*newchain) {
  77                         ret = -ENOMEM;
  78                         NL_SET_ERR_MSG(extack,
  79                                        "can't allocate goto_chain");
  80                 }
  81         }
  82 end:
  83         return ret;
  84 }
  85 EXPORT_SYMBOL(tcf_action_check_ctrlact);
  86
  87 struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,
  88                                          struct tcf_chain *goto_chain)
  89 {
  90         a->tcfa_action = action;
  91         rcu_swap_protected(a->goto_chain, goto_chain, 1);
  92         return goto_chain;
  93 }
  94 EXPORT_SYMBOL(tcf_action_set_ctrlact);
  95
  96 /* XXX: For standalone actions, we don't need a RCU grace period either, because
  97  * actions are always connected to filters and filters are already destroyed in
  98  * RCU callbacks, so after a RCU grace period actions are already disconnected
  99  * from filters. Readers later can not find us.
 100  */
 101 static void free_tcf(struct tc_action *p)
 102 {
 103         struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
 104
 105         free_percpu(p->cpu_bstats);
 106         free_percpu(p->cpu_bstats_hw);
 107         free_percpu(p->cpu_qstats);
 108
 109         tcf_set_action_cookie(&p->act_cookie, NULL);
 110         if (chain)
 111                 tcf_chain_put_by_act(chain);
 112
 113         kfree(p);
 114 }
 115
 116 static void tcf_action_cleanup(struct tc_action *p)
 117 {
 118         if (p->ops->cleanup)
 119                 p->ops->cleanup(p);
 120
 121         gen_kill_estimator(&p->tcfa_rate_est);
 122         free_tcf(p);
 123 }
 124
 125 static int __tcf_action_put(struct tc_action *p, bool bind)
 126 {
 127         struct tcf_idrinfo *idrinfo = p->idrinfo;
 128
 129         if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
 130                 if (bind)
 131                         atomic_dec(&p->tcfa_bindcnt);
 132                 idr_remove(&idrinfo->action_idr, p->tcfa_index);
 133                 mutex_unlock(&idrinfo->lock);
 134
 135                 tcf_action_cleanup(p);
 136                 return 1;
 137         }
 138
 139         if (bind)
 140                 atomic_dec(&p->tcfa_bindcnt);
 141
 142         return 0;
 143 }
 144
 145 int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
 146 {
 147         int ret = 0;
 148
 149         /* Release with strict==1 and bind==0 is only called through act API
 150          * interface (classifiers always bind). Only case when action with
 151          * positive reference count and zero bind count can exist is when it was
 152          * also created with act API (unbinding last classifier will destroy the
 153          * action if it was created by classifier). So only case when bind count
 154          * can be changed after initial check is when unbound action is
 155          * destroyed by act API while classifier binds to action with same id
 156          * concurrently. This result either creation of new action(same behavior
 157          * as before), or reusing existing action if concurrent process
 158          * increments reference count before action is deleted. Both scenarios
 159          * are acceptable.
 160          */
 161         if (p) {
 162                 if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
 163                         return -EPERM;
 164
 165                 if (__tcf_action_put(p, bind))
 166                         ret = ACT_P_DELETED;
 167         }
 168
 169         return ret;
 170 }
 171 EXPORT_SYMBOL(__tcf_idr_release);
 172
 173 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
 174 {
 175         struct tc_cookie *act_cookie;
 176         u32 cookie_len = 0;
 177
 178         rcu_read_lock();
 179         act_cookie = rcu_dereference(act->act_cookie);
 180
 181         if (act_cookie)
 182                 cookie_len = nla_total_size(act_cookie->len);
 183         rcu_read_unlock();
 184
 185         return  nla_total_size(0) /* action number nested */
 186                 + nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
 187                 + cookie_len /* TCA_ACT_COOKIE */
 188                 + nla_total_size(0) /* TCA_ACT_STATS nested */
 189                 /* TCA_STATS_BASIC */
 190                 + nla_total_size_64bit(sizeof(struct gnet_stats_basic))
 191                 /* TCA_STATS_QUEUE */
 192                 + nla_total_size_64bit(sizeof(struct gnet_stats_queue))
 193                 + nla_total_size(0) /* TCA_OPTIONS nested */
 194                 + nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
 195 }
 196
 197 static size_t tcf_action_full_attrs_size(size_t sz)
 198 {
 199         return NLMSG_HDRLEN                     /* struct nlmsghdr */
 200                 + sizeof(struct tcamsg)
 201                 + nla_total_size(0)             /* TCA_ACT_TAB nested */
 202                 + sz;
 203 }
 204
 205 static size_t tcf_action_fill_size(const struct tc_action *act)
 206 {
 207         size_t sz = tcf_action_shared_attrs_size(act);
 208
 209         if (act->ops->get_fill_size)
 210                 return act->ops->get_fill_size(act) + sz;
 211         return sz;
 212 }
 213
 214 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 215                            struct netlink_callback *cb)
 216 {
 217         int err = 0, index = -1, s_i = 0, n_i = 0;
 218         u32 act_flags = cb->args[2];
 219         unsigned long jiffy_since = cb->args[3];
 220         struct nlattr *nest;
 221         struct idr *idr = &idrinfo->action_idr;
 222         struct tc_action *p;
 223         unsigned long id = 1;
 224         unsigned long tmp;
 225
 226         mutex_lock(&idrinfo->lock);
 227
 228         s_i = cb->args[0];
 229
 230         idr_for_each_entry_ul(idr, p, tmp, id) {
 231                 index++;
 232                 if (index < s_i)
 233                         continue;
 234                 if (IS_ERR(p))
 235                         continue;
 236
 237                 if (jiffy_since &&
 238                     time_after(jiffy_since,
 239                                (unsigned long)p->tcfa_tm.lastuse))
 240                         continue;
 241
 242                 nest = nla_nest_start_noflag(skb, n_i);
 243                 if (!nest) {
 244                         index--;
 245                         goto nla_put_failure;
 246                 }
 247                 err = tcf_action_dump_1(skb, p, 0, 0);
 248                 if (err < 0) {
 249                         index--;
 250                         nlmsg_trim(skb, nest);
 251                         goto done;
 252                 }
 253                 nla_nest_end(skb, nest);
 254                 n_i++;
 255                 if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
 256                     n_i >= TCA_ACT_MAX_PRIO)
 257                         goto done;
 258         }
 259 done:
 260         if (index >= 0)
 261                 cb->args[0] = index + 1;
 262
 263         mutex_unlock(&idrinfo->lock);
 264         if (n_i) {
 265                 if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
 266                         cb->args[1] = n_i;
 267         }
 268         return n_i;
 269
 270 nla_put_failure:
 271         nla_nest_cancel(skb, nest);
 272         goto done;
 273 }
 274
 275 static int tcf_idr_release_unsafe(struct tc_action *p)
 276 {
 277         if (atomic_read(&p->tcfa_bindcnt) > 0)
 278                 return -EPERM;
 279
 280         if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 281                 idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
 282                 tcf_action_cleanup(p);
 283                 return ACT_P_DELETED;
 284         }
 285
 286         return 0;
 287 }
 288
 289 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 290                           const struct tc_action_ops *ops,
 291                           struct netlink_ext_ack *extack)
 292 {
 293         struct nlattr *nest;
 294         int n_i = 0;
 295         int ret = -EINVAL;
 296         struct idr *idr = &idrinfo->action_idr;
 297         struct tc_action *p;
 298         unsigned long id = 1;
 299         unsigned long tmp;
 300
 301         nest = nla_nest_start_noflag(skb, 0);
 302         if (nest == NULL)
 303                 goto nla_put_failure;
 304         if (nla_put_string(skb, TCA_KIND, ops->kind))
 305                 goto nla_put_failure;
 306
 307         ret = 0;
 308         mutex_lock(&idrinfo->lock);
 309         idr_for_each_entry_ul(idr, p, tmp, id) {
 310                 if (IS_ERR(p))
 311                         continue;
 312                 ret = tcf_idr_release_unsafe(p);
 313                 if (ret == ACT_P_DELETED)
 314                         module_put(ops->owner);
 315                 else if (ret < 0)
 316                         break;
 317                 n_i++;
 318         }
 319         mutex_unlock(&idrinfo->lock);
 320         if (ret < 0) {
 321                 if (n_i)
 322                         NL_SET_ERR_MSG(extack, "Unable to flush all TC actions");
 323                 else
 324                         goto nla_put_failure;
 325         }
 326
 327         ret = nla_put_u32(skb, TCA_FCNT, n_i);
 328         if (ret)
 329                 goto nla_put_failure;
 330         nla_nest_end(skb, nest);
 331
 332         return n_i;
 333 nla_put_failure:
 334         nla_nest_cancel(skb, nest);
 335         return ret;
 336 }
 337
 338 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 339                        struct netlink_callback *cb, int type,
 340                        const struct tc_action_ops *ops,
 341                        struct netlink_ext_ack *extack)
 342 {
 343         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 344
 345         if (type == RTM_DELACTION) {
 346                 return tcf_del_walker(idrinfo, skb, ops, extack);
 347         } else if (type == RTM_GETACTION) {
 348                 return tcf_dump_walker(idrinfo, skb, cb);
 349         } else {
 350                 WARN(1, "tcf_generic_walker: unknown command %d\n", type);
 351                 NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
 352                 return -EINVAL;
 353         }
 354 }
 355 EXPORT_SYMBOL(tcf_generic_walker);
 356
 357 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 358 {
 359         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 360         struct tc_action *p;
 361
 362         mutex_lock(&idrinfo->lock);
 363         p = idr_find(&idrinfo->action_idr, index);
 364         if (IS_ERR(p))
 365                 p = NULL;
 366         else if (p)
 367                 refcount_inc(&p->tcfa_refcnt);
 368         mutex_unlock(&idrinfo->lock);
 369
 370         if (p) {
 371                 *a = p;
 372                 return true;
 373         }
 374         return false;
 375 }
 376 EXPORT_SYMBOL(tcf_idr_search);
 377
 378 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
 379 {
 380         struct tc_action *p;
 381         int ret = 0;
 382
 383         mutex_lock(&idrinfo->lock);
 384         p = idr_find(&idrinfo->action_idr, index);
 385         if (!p) {
 386                 mutex_unlock(&idrinfo->lock);
 387                 return -ENOENT;
 388         }
 389
 390         if (!atomic_read(&p->tcfa_bindcnt)) {
 391                 if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 392                         struct module *owner = p->ops->owner;
 393
 394                         WARN_ON(p != idr_remove(&idrinfo->action_idr,
 395                                                 p->tcfa_index));
 396                         mutex_unlock(&idrinfo->lock);
 397
 398                         tcf_action_cleanup(p);
 399                         module_put(owner);
 400                         return 0;
 401                 }
 402                 ret = 0;
 403         } else {
 404                 ret = -EPERM;
 405         }
 406
 407         mutex_unlock(&idrinfo->lock);
 408         return ret;
 409 }
 410
 411 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 412                    struct tc_action **a, const struct tc_action_ops *ops,
 413                    int bind, bool cpustats)
 414 {
 415         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 416         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 417         int err = -ENOMEM;
 418
 419         if (unlikely(!p))
 420                 return -ENOMEM;
 421         refcount_set(&p->tcfa_refcnt, 1);
 422         if (bind)
 423                 atomic_set(&p->tcfa_bindcnt, 1);
 424
 425         if (cpustats) {
 426                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 427                 if (!p->cpu_bstats)
 428                         goto err1;
 429                 p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 430                 if (!p->cpu_bstats_hw)
 431                         goto err2;
 432                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 433                 if (!p->cpu_qstats)
 434                         goto err3;
 435         }
 436         spin_lock_init(&p->tcfa_lock);
 437         p->tcfa_index = index;
 438         p->tcfa_tm.install = jiffies;
 439         p->tcfa_tm.lastuse = jiffies;
 440         p->tcfa_tm.firstuse = 0;
 441         if (est) {
 442                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 443                                         &p->tcfa_rate_est,
 444                                         &p->tcfa_lock, NULL, est);
 445                 if (err)
 446                         goto err4;
 447         }
 448
 449         p->idrinfo = idrinfo;
 450         p->ops = ops;
 451         *a = p;
 452         return 0;
 453 err4:
 454         free_percpu(p->cpu_qstats);
 455 err3:
 456         free_percpu(p->cpu_bstats_hw);
 457 err2:
 458         free_percpu(p->cpu_bstats);
 459 err1:
 460         kfree(p);
 461         return err;
 462 }
 463 EXPORT_SYMBOL(tcf_idr_create);
 464
 465 /* Cleanup idr index that was allocated but not initialized. */
 466
 467 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
 468 {
 469         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 470
 471         mutex_lock(&idrinfo->lock);
 472         /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 473         WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
 474         mutex_unlock(&idrinfo->lock);
 475 }
 476 EXPORT_SYMBOL(tcf_idr_cleanup);
 477
 478 /* Check if action with specified index exists. If actions is found, increments
 479  * its reference and bind counters, and return 1. Otherwise insert temporary
 480  * error pointer (to prevent concurrent users from inserting actions with same
 481  * index) and return 0.
 482  */
 483
 484 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 485                         struct tc_action **a, int bind)
 486 {
 487         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 488         struct tc_action *p;
 489         int ret;
 490
 491 again:
 492         mutex_lock(&idrinfo->lock);
 493         if (*index) {
 494                 p = idr_find(&idrinfo->action_idr, *index);
 495                 if (IS_ERR(p)) {
 496                         /* This means that another process allocated
 497                          * index but did not assign the pointer yet.
 498                          */
 499                         mutex_unlock(&idrinfo->lock);
 500                         goto again;
 501                 }
 502
 503                 if (p) {
 504                         refcount_inc(&p->tcfa_refcnt);
 505                         if (bind)
 506                                 atomic_inc(&p->tcfa_bindcnt);
 507                         *a = p;
 508                         ret = 1;
 509                 } else {
 510                         *a = NULL;
 511                         ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 512                                             *index, GFP_KERNEL);
 513                         if (!ret)
 514                                 idr_replace(&idrinfo->action_idr,
 515                                             ERR_PTR(-EBUSY), *index);
 516                 }
 517         } else {
 518                 *index = 1;
 519                 *a = NULL;
 520                 ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 521                                     UINT_MAX, GFP_KERNEL);
 522                 if (!ret)
 523                         idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
 524                                     *index);
 525         }
 526         mutex_unlock(&idrinfo->lock);
 527         return ret;
 528 }
 529 EXPORT_SYMBOL(tcf_idr_check_alloc);
 530
 531 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 532                          struct tcf_idrinfo *idrinfo)
 533 {
 534         struct idr *idr = &idrinfo->action_idr;
 535         struct tc_action *p;
 536         int ret;
 537         unsigned long id = 1;
 538         unsigned long tmp;
 539
 540         idr_for_each_entry_ul(idr, p, tmp, id) {
 541                 ret = __tcf_idr_release(p, false, true);
 542                 if (ret == ACT_P_DELETED)
 543                         module_put(ops->owner);
 544                 else if (ret < 0)
 545                         return;
 546         }
 547         idr_destroy(&idrinfo->action_idr);
 548 }
 549 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 550
 551 static LIST_HEAD(act_base);
 552 static DEFINE_RWLOCK(act_mod_lock);
 553
 554 int tcf_register_action(struct tc_action_ops *act,
 555                         struct pernet_operations *ops)
 556 {
 557         struct tc_action_ops *a;
 558         int ret;
 559
 560         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 561                 return -EINVAL;
 562
 563         /* We have to register pernet ops before making the action ops visible,
 564          * otherwise tcf_action_init_1() could get a partially initialized
 565          * netns.
 566          */
 567         ret = register_pernet_subsys(ops);
 568         if (ret)
 569                 return ret;
 570
 571         write_lock(&act_mod_lock);
 572         list_for_each_entry(a, &act_base, head) {
 573                 if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
 574                         write_unlock(&act_mod_lock);
 575                         unregister_pernet_subsys(ops);
 576                         return -EEXIST;
 577                 }
 578         }
 579         list_add_tail(&act->head, &act_base);
 580         write_unlock(&act_mod_lock);
 581
 582         return 0;
 583 }
 584 EXPORT_SYMBOL(tcf_register_action);
 585
 586 int tcf_unregister_action(struct tc_action_ops *act,
 587                           struct pernet_operations *ops)
 588 {
 589         struct tc_action_ops *a;
 590         int err = -ENOENT;
 591
 592         write_lock(&act_mod_lock);
 593         list_for_each_entry(a, &act_base, head) {
 594                 if (a == act) {
 595                         list_del(&act->head);
 596                         err = 0;
 597                         break;
 598                 }
 599         }
 600         write_unlock(&act_mod_lock);
 601         if (!err)
 602                 unregister_pernet_subsys(ops);
 603         return err;
 604 }
 605 EXPORT_SYMBOL(tcf_unregister_action);
 606
 607 /* lookup by name */
 608 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 609 {
 610         struct tc_action_ops *a, *res = NULL;
 611
 612         if (kind) {
 613                 read_lock(&act_mod_lock);
 614                 list_for_each_entry(a, &act_base, head) {
 615                         if (strcmp(kind, a->kind) == 0) {
 616                                 if (try_module_get(a->owner))
 617                                         res = a;
 618                                 break;
 619                         }
 620                 }
 621                 read_unlock(&act_mod_lock);
 622         }
 623         return res;
 624 }
 625
 626 /* lookup by nlattr */
 627 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 628 {
 629         struct tc_action_ops *a, *res = NULL;
 630
 631         if (kind) {
 632                 read_lock(&act_mod_lock);
 633                 list_for_each_entry(a, &act_base, head) {
 634                         if (nla_strcmp(kind, a->kind) == 0) {
 635                                 if (try_module_get(a->owner))
 636                                         res = a;
 637                                 break;
 638                         }
 639                 }
 640                 read_unlock(&act_mod_lock);
 641         }
 642         return res;
 643 }
 644
 645 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 646 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 647 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 648                     int nr_actions, struct tcf_result *res)
 649 {
 650         u32 jmp_prgcnt = 0;
 651         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 652         int i;
 653         int ret = TC_ACT_OK;
 654
 655         if (skb_skip_tc_classify(skb))
 656                 return TC_ACT_OK;
 657
 658 restart_act_graph:
 659         for (i = 0; i < nr_actions; i++) {
 660                 const struct tc_action *a = actions[i];
 661                 int repeat_ttl;
 662
 663                 if (jmp_prgcnt > 0) {
 664                         jmp_prgcnt -= 1;
 665                         continue;
 666                 }
 667
 668                 repeat_ttl = 32;
 669 repeat:
 670                 ret = a->ops->act(skb, a, res);
 671
 672                 if (unlikely(ret == TC_ACT_REPEAT)) {
 673                         if (--repeat_ttl != 0)
 674                                 goto repeat;
 675                         /* suspicious opcode, stop pipeline */
 676                         net_warn_ratelimited("TC_ACT_REPEAT abuse ?\n");
 677                         return TC_ACT_OK;
 678                 }
 679
 680                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 681                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 682                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 683                                 /* faulty opcode, stop pipeline */
 684                                 return TC_ACT_OK;
 685                         } else {
 686                                 jmp_ttl -= 1;
 687                                 if (jmp_ttl > 0)
 688                                         goto restart_act_graph;
 689                                 else /* faulty graph, stop pipeline */
 690                                         return TC_ACT_OK;
 691                         }
 692                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 693                         if (unlikely(!rcu_access_pointer(a->goto_chain))) {
 694                                 net_warn_ratelimited("can't go to NULL chain!\n");
 695                                 return TC_ACT_SHOT;
 696                         }
 697                         tcf_action_goto_chain_exec(a, res);
 698                 }
 699
 700                 if (ret != TC_ACT_PIPE)
 701                         break;
 702         }
 703
 704         return ret;
 705 }
 706 EXPORT_SYMBOL(tcf_action_exec);
 707
 708 int tcf_action_destroy(struct tc_action *actions[], int bind)
 709 {
 710         const struct tc_action_ops *ops;
 711         struct tc_action *a;
 712         int ret = 0, i;
 713
 714         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 715                 a = actions[i];
 716                 actions[i] = NULL;
 717                 ops = a->ops;
 718                 ret = __tcf_idr_release(a, bind, true);
 719                 if (ret == ACT_P_DELETED)
 720                         module_put(ops->owner);
 721                 else if (ret < 0)
 722                         return ret;
 723         }
 724         return ret;
 725 }
 726
 727 static int tcf_action_put(struct tc_action *p)
 728 {
 729         return __tcf_action_put(p, false);
 730 }
 731
 732 /* Put all actions in this array, skip those NULL's. */
 733 static void tcf_action_put_many(struct tc_action *actions[])
 734 {
 735         int i;
 736
 737         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 738                 struct tc_action *a = actions[i];
 739                 const struct tc_action_ops *ops;
 740
 741                 if (!a)
 742                         continue;
 743                 ops = a->ops;
 744                 if (tcf_action_put(a))
 745                         module_put(ops->owner);
 746         }
 747 }
 748
 749 int
 750 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 751 {
 752         return a->ops->dump(skb, a, bind, ref);
 753 }
 754
 755 int
 756 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 757 {
 758         int err = -EINVAL;
 759         unsigned char *b = skb_tail_pointer(skb);
 760         struct nlattr *nest;
 761         struct tc_cookie *cookie;
 762
 763         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 764                 goto nla_put_failure;
 765         if (tcf_action_copy_stats(skb, a, 0))
 766                 goto nla_put_failure;
 767
 768         rcu_read_lock();
 769         cookie = rcu_dereference(a->act_cookie);
 770         if (cookie) {
 771                 if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
 772                         rcu_read_unlock();
 773                         goto nla_put_failure;
 774                 }
 775         }
 776         rcu_read_unlock();
 777
 778         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 779         if (nest == NULL)
 780                 goto nla_put_failure;
 781         err = tcf_action_dump_old(skb, a, bind, ref);
 782         if (err > 0) {
 783                 nla_nest_end(skb, nest);
 784                 return err;
 785         }
 786
 787 nla_put_failure:
 788         nlmsg_trim(skb, b);
 789         return -1;
 790 }
 791 EXPORT_SYMBOL(tcf_action_dump_1);
 792
 793 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 794                     int bind, int ref)
 795 {
 796         struct tc_action *a;
 797         int err = -EINVAL, i;
 798         struct nlattr *nest;
 799
 800         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 801                 a = actions[i];
 802                 nest = nla_nest_start_noflag(skb, i + 1);
 803                 if (nest == NULL)
 804                         goto nla_put_failure;
 805                 err = tcf_action_dump_1(skb, a, bind, ref);
 806                 if (err < 0)
 807                         goto errout;
 808                 nla_nest_end(skb, nest);
 809         }
 810
 811         return 0;
 812
 813 nla_put_failure:
 814         err = -EINVAL;
 815 errout:
 816         nla_nest_cancel(skb, nest);
 817         return err;
 818 }
 819
 820 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 821 {
 822         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 823         if (!c)
 824                 return NULL;
 825
 826         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 827         if (!c->data) {
 828                 kfree(c);
 829                 return NULL;
 830         }
 831         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 832
 833         return c;
 834 }
 835
 836 static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
 837         [TCA_ACT_KIND]          = { .type = NLA_STRING },
 838         [TCA_ACT_INDEX]         = { .type = NLA_U32 },
 839         [TCA_ACT_COOKIE]        = { .type = NLA_BINARY,
 840                                     .len = TC_COOKIE_MAX_SIZE },
 841         [TCA_ACT_OPTIONS]       = { .type = NLA_NESTED },
 842 };
 843
 844 void tcf_idr_insert_many(struct tc_action *actions[])
 845 {
 846         int i;
 847
 848         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 849                 struct tc_action *a = actions[i];
 850                 struct tcf_idrinfo *idrinfo;
 851
 852                 if (!a)
 853                         continue;
 854                 idrinfo = a->idrinfo;
 855                 mutex_lock(&idrinfo->lock);
 856                 /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc if
 857                  * it is just created, otherwise this is just a nop.
 858                  */
 859                 idr_replace(&idrinfo->action_idr, a, a->tcfa_index);
 860                 mutex_unlock(&idrinfo->lock);
 861         }
 862 }
 863
 864 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 865                                     struct nlattr *nla, struct nlattr *est,
 866                                     char *name, int ovr, int bind,
 867                                     bool rtnl_held,
 868                                     struct netlink_ext_ack *extack)
 869 {
 870         struct tc_action *a;
 871         struct tc_action_ops *a_o;
 872         struct tc_cookie *cookie = NULL;
 873         char act_name[IFNAMSIZ];
 874         struct nlattr *tb[TCA_ACT_MAX + 1];
 875         struct nlattr *kind;
 876         int err;
 877
 878         if (name == NULL) {
 879                 err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
 880                                                   tcf_action_policy, extack);
 881                 if (err < 0)
 882                         goto err_out;
 883                 err = -EINVAL;
 884                 kind = tb[TCA_ACT_KIND];
 885                 if (!kind) {
 886                         NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 887                         goto err_out;
 888                 }
 889                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
 890                         NL_SET_ERR_MSG(extack, "TC action name too long");
 891                         goto err_out;
 892                 }
 893                 if (tb[TCA_ACT_COOKIE]) {
 894                         cookie = nla_memdup_cookie(tb);
 895                         if (!cookie) {
 896                                 NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
 897                                 err = -ENOMEM;
 898                                 goto err_out;
 899                         }
 900                 }
 901         } else {
 902                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
 903                         NL_SET_ERR_MSG(extack, "TC action name too long");
 904                         err = -EINVAL;
 905                         goto err_out;
 906                 }
 907         }
 908
 909         a_o = tc_lookup_action_n(act_name);
 910         if (a_o == NULL) {
 911 #ifdef CONFIG_MODULES
 912                 if (rtnl_held)
 913                         rtnl_unlock();
 914                 request_module("act_%s", act_name);
 915                 if (rtnl_held)
 916                         rtnl_lock();
 917
 918                 a_o = tc_lookup_action_n(act_name);
 919
 920                 /* We dropped the RTNL semaphore in order to
 921                  * perform the module load.  So, even if we
 922                  * succeeded in loading the module we have to
 923                  * tell the caller to replay the request.  We
 924                  * indicate this using -EAGAIN.
 925                  */
 926                 if (a_o != NULL) {
 927                         err = -EAGAIN;
 928                         goto err_mod;
 929                 }
 930 #endif
 931                 NL_SET_ERR_MSG(extack, "Failed to load TC action module");
 932                 err = -ENOENT;
 933                 goto err_out;
 934         }
 935
 936         /* backward compatibility for policer */
 937         if (name == NULL)
 938                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
 939                                 rtnl_held, tp, extack);
 940         else
 941                 err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
 942                                 tp, extack);
 943         if (err < 0)
 944                 goto err_mod;
 945
 946         if (!name && tb[TCA_ACT_COOKIE])
 947                 tcf_set_action_cookie(&a->act_cookie, cookie);
 948
 949         /* module count goes up only when brand new policy is created
 950          * if it exists and is only bound to in a_o->init() then
 951          * ACT_P_CREATED is not returned (a zero is).
 952          */
 953         if (err != ACT_P_CREATED)
 954                 module_put(a_o->owner);
 955
 956         if (!bind && ovr && err == ACT_P_CREATED)
 957                 refcount_set(&a->tcfa_refcnt, 2);
 958
 959         return a;
 960
 961 err_mod:
 962         module_put(a_o->owner);
 963 err_out:
 964         if (cookie) {
 965                 kfree(cookie->data);
 966                 kfree(cookie);
 967         }
 968         return ERR_PTR(err);
 969 }
 970
 971 /* Returns numbers of initialized actions or negative error. */
 972
 973 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 974                     struct nlattr *est, char *name, int ovr, int bind,
 975                     struct tc_action *actions[], size_t *attr_size,
 976                     bool rtnl_held, struct netlink_ext_ack *extack)
 977 {
 978         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 979         struct tc_action *act;
 980         size_t sz = 0;
 981         int err;
 982         int i;
 983
 984         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
 985                                           extack);
 986         if (err < 0)
 987                 return err;
 988
 989         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 990                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
 991                                         rtnl_held, extack);
 992                 if (IS_ERR(act)) {
 993                         err = PTR_ERR(act);
 994                         goto err;
 995                 }
 996                 act->order = i;
 997                 sz += tcf_action_fill_size(act);
 998                 /* Start from index 0 */
 999                 actions[i - 1] = act;
1000         }
1001
1002         /* We have to commit them all together, because if any error happened in
1003          * between, we could not handle the failure gracefully.
1004          */
1005         tcf_idr_insert_many(actions);
1006
1007         *attr_size = tcf_action_full_attrs_size(sz);
1008         return i - 1;
1009
1010 err:
1011         tcf_action_destroy(actions, bind);
1012         return err;
1013 }
1014
1015 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
1016                           int compat_mode)
1017 {
1018         int err = 0;
1019         struct gnet_dump d;
1020
1021         if (p == NULL)
1022                 goto errout;
1023
1024         /* compat_mode being true specifies a call that is supposed
1025          * to add additional backward compatibility statistic TLVs.
1026          */
1027         if (compat_mode) {
1028                 if (p->type == TCA_OLD_COMPAT)
1029                         err = gnet_stats_start_copy_compat(skb, 0,
1030                                                            TCA_STATS,
1031                                                            TCA_XSTATS,
1032                                                            &p->tcfa_lock, &d,
1033                                                            TCA_PAD);
1034                 else
1035                         return 0;
1036         } else
1037                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1038                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
1039
1040         if (err < 0)
1041                 goto errout;
1042
1043         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1044             gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1045                                      &p->tcfa_bstats_hw) < 0 ||
1046             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1047             gnet_stats_copy_queue(&d, p->cpu_qstats,
1048                                   &p->tcfa_qstats,
1049                                   p->tcfa_qstats.qlen) < 0)
1050                 goto errout;
1051
1052         if (gnet_stats_finish_copy(&d) < 0)
1053                 goto errout;
1054
1055         return 0;
1056
1057 errout:
1058         return -1;
1059 }
1060
1061 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1062                         u32 portid, u32 seq, u16 flags, int event, int bind,
1063                         int ref)
1064 {
1065         struct tcamsg *t;
1066         struct nlmsghdr *nlh;
1067         unsigned char *b = skb_tail_pointer(skb);
1068         struct nlattr *nest;
1069
1070         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1071         if (!nlh)
1072                 goto out_nlmsg_trim;
1073         t = nlmsg_data(nlh);
1074         t->tca_family = AF_UNSPEC;
1075         t->tca__pad1 = 0;
1076         t->tca__pad2 = 0;
1077
1078         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1079         if (!nest)
1080                 goto out_nlmsg_trim;
1081
1082         if (tcf_action_dump(skb, actions, bind, ref) < 0)
1083                 goto out_nlmsg_trim;
1084
1085         nla_nest_end(skb, nest);
1086
1087         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1088         return skb->len;
1089
1090 out_nlmsg_trim:
1091         nlmsg_trim(skb, b);
1092         return -1;
1093 }
1094
1095 static int
1096 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1097                struct tc_action *actions[], int event,
1098                struct netlink_ext_ack *extack)
1099 {
1100         struct sk_buff *skb;
1101
1102         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1103         if (!skb)
1104                 return -ENOBUFS;
1105         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1106                          0, 1) <= 0) {
1107                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1108                 kfree_skb(skb);
1109                 return -EINVAL;
1110         }
1111
1112         return rtnl_unicast(skb, net, portid);
1113 }
1114
1115 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1116                                           struct nlmsghdr *n, u32 portid,
1117                                           struct netlink_ext_ack *extack)
1118 {
1119         struct nlattr *tb[TCA_ACT_MAX + 1];
1120         const struct tc_action_ops *ops;
1121         struct tc_action *a;
1122         int index;
1123         int err;
1124
1125         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1126                                           tcf_action_policy, extack);
1127         if (err < 0)
1128                 goto err_out;
1129
1130         err = -EINVAL;
1131         if (tb[TCA_ACT_INDEX] == NULL ||
1132             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1133                 NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1134                 goto err_out;
1135         }
1136         index = nla_get_u32(tb[TCA_ACT_INDEX]);
1137
1138         err = -EINVAL;
1139         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1140         if (!ops) { /* could happen in batch of actions */
1141                 NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1142                 goto err_out;
1143         }
1144         err = -ENOENT;
1145         if (ops->lookup(net, &a, index) == 0) {
1146                 NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1147                 goto err_mod;
1148         }
1149
1150         module_put(ops->owner);
1151         return a;
1152
1153 err_mod:
1154         module_put(ops->owner);
1155 err_out:
1156         return ERR_PTR(err);
1157 }
1158
1159 static int tca_action_flush(struct net *net, struct nlattr *nla,
1160                             struct nlmsghdr *n, u32 portid,
1161                             struct netlink_ext_ack *extack)
1162 {
1163         struct sk_buff *skb;
1164         unsigned char *b;
1165         struct nlmsghdr *nlh;
1166         struct tcamsg *t;
1167         struct netlink_callback dcb;
1168         struct nlattr *nest;
1169         struct nlattr *tb[TCA_ACT_MAX + 1];
1170         const struct tc_action_ops *ops;
1171         struct nlattr *kind;
1172         int err = -ENOMEM;
1173
1174         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1175         if (!skb)
1176                 return err;
1177
1178         b = skb_tail_pointer(skb);
1179
1180         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1181                                           tcf_action_policy, extack);
1182         if (err < 0)
1183                 goto err_out;
1184
1185         err = -EINVAL;
1186         kind = tb[TCA_ACT_KIND];
1187         ops = tc_lookup_action(kind);
1188         if (!ops) { /*some idjot trying to flush unknown action */
1189                 NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1190                 goto err_out;
1191         }
1192
1193         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1194                         sizeof(*t), 0);
1195         if (!nlh) {
1196                 NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1197                 goto out_module_put;
1198         }
1199         t = nlmsg_data(nlh);
1200         t->tca_family = AF_UNSPEC;
1201         t->tca__pad1 = 0;
1202         t->tca__pad2 = 0;
1203
1204         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1205         if (!nest) {
1206                 NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1207                 goto out_module_put;
1208         }
1209
1210         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1211         if (err <= 0) {
1212                 nla_nest_cancel(skb, nest);
1213                 goto out_module_put;
1214         }
1215
1216         nla_nest_end(skb, nest);
1217
1218         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1219         nlh->nlmsg_flags |= NLM_F_ROOT;
1220         module_put(ops->owner);
1221         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1222                              n->nlmsg_flags & NLM_F_ECHO);
1223         if (err > 0)
1224                 return 0;
1225         if (err < 0)
1226                 NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1227
1228         return err;
1229
1230 out_module_put:
1231         module_put(ops->owner);
1232 err_out:
1233         kfree_skb(skb);
1234         return err;
1235 }
1236
1237 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1238 {
1239         int i;
1240
1241         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1242                 struct tc_action *a = actions[i];
1243                 const struct tc_action_ops *ops = a->ops;
1244                 /* Actions can be deleted concurrently so we must save their
1245                  * type and id to search again after reference is released.
1246                  */
1247                 struct tcf_idrinfo *idrinfo = a->idrinfo;
1248                 u32 act_index = a->tcfa_index;
1249
1250                 actions[i] = NULL;
1251                 if (tcf_action_put(a)) {
1252                         /* last reference, action was deleted concurrently */
1253                         module_put(ops->owner);
1254                 } else  {
1255                         int ret;
1256
1257                         /* now do the delete */
1258                         ret = tcf_idr_delete_index(idrinfo, act_index);
1259                         if (ret < 0)
1260                                 return ret;
1261                 }
1262         }
1263         return 0;
1264 }
1265
1266 static int
1267 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1268                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1269 {
1270         int ret;
1271         struct sk_buff *skb;
1272
1273         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1274                         GFP_KERNEL);
1275         if (!skb)
1276                 return -ENOBUFS;
1277
1278         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1279                          0, 2) <= 0) {
1280                 NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1281                 kfree_skb(skb);
1282                 return -EINVAL;
1283         }
1284
1285         /* now do the delete */
1286         ret = tcf_action_delete(net, actions);
1287         if (ret < 0) {
1288                 NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1289                 kfree_skb(skb);
1290                 return ret;
1291         }
1292
1293         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1294                              n->nlmsg_flags & NLM_F_ECHO);
1295         if (ret > 0)
1296                 return 0;
1297         return ret;
1298 }
1299
1300 static int
1301 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1302               u32 portid, int event, struct netlink_ext_ack *extack)
1303 {
1304         int i, ret;
1305         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1306         struct tc_action *act;
1307         size_t attr_size = 0;
1308         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1309
1310         ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1311                                           extack);
1312         if (ret < 0)
1313                 return ret;
1314
1315         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1316                 if (tb[1])
1317                         return tca_action_flush(net, tb[1], n, portid, extack);
1318
1319                 NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1320                 return -EINVAL;
1321         }
1322
1323         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1324                 act = tcf_action_get_1(net, tb[i], n, portid, extack);
1325                 if (IS_ERR(act)) {
1326                         ret = PTR_ERR(act);
1327                         goto err;
1328                 }
1329                 attr_size += tcf_action_fill_size(act);
1330                 actions[i - 1] = act;
1331         }
1332
1333         attr_size = tcf_action_full_attrs_size(attr_size);
1334
1335         if (event == RTM_GETACTION)
1336                 ret = tcf_get_notify(net, portid, n, actions, event, extack);
1337         else { /* delete */
1338                 ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1339                 if (ret)
1340                         goto err;
1341                 return 0;
1342         }
1343 err:
1344         tcf_action_put_many(actions);
1345         return ret;
1346 }
1347
1348 static int
1349 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1350                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1351 {
1352         struct sk_buff *skb;
1353         int err = 0;
1354
1355         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1356                         GFP_KERNEL);
1357         if (!skb)
1358                 return -ENOBUFS;
1359
1360         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1361                          RTM_NEWACTION, 0, 0) <= 0) {
1362                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1363                 kfree_skb(skb);
1364                 return -EINVAL;
1365         }
1366
1367         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1368                              n->nlmsg_flags & NLM_F_ECHO);
1369         if (err > 0)
1370                 err = 0;
1371         return err;
1372 }
1373
1374 static int tcf_action_add(struct net *net, struct nlattr *nla,
1375                           struct nlmsghdr *n, u32 portid, int ovr,
1376                           struct netlink_ext_ack *extack)
1377 {
1378         size_t attr_size = 0;
1379         int loop, ret;
1380         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1381
1382         for (loop = 0; loop < 10; loop++) {
1383                 ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0,
1384                                       actions, &attr_size, true, extack);
1385                 if (ret != -EAGAIN)
1386                         break;
1387         }
1388
1389         if (ret < 0)
1390                 return ret;
1391         ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1392         if (ovr)
1393                 tcf_action_put_many(actions);
1394
1395         return ret;
1396 }
1397
1398 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1399 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1400         [TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1401                              .validation_data = &tcaa_root_flags_allowed },
1402         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1403 };
1404
1405 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1406                          struct netlink_ext_ack *extack)
1407 {
1408         struct net *net = sock_net(skb->sk);
1409         struct nlattr *tca[TCA_ROOT_MAX + 1];
1410         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1411         int ret = 0, ovr = 0;
1412
1413         if ((n->nlmsg_type != RTM_GETACTION) &&
1414             !netlink_capable(skb, CAP_NET_ADMIN))
1415                 return -EPERM;
1416
1417         ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
1418                                      TCA_ROOT_MAX, NULL, extack);
1419         if (ret < 0)
1420                 return ret;
1421
1422         if (tca[TCA_ACT_TAB] == NULL) {
1423                 NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1424                 return -EINVAL;
1425         }
1426
1427         /* n->nlmsg_flags & NLM_F_CREATE */
1428         switch (n->nlmsg_type) {
1429         case RTM_NEWACTION:
1430                 /* we are going to assume all other flags
1431                  * imply create only if it doesn't exist
1432                  * Note that CREATE | EXCL implies that
1433                  * but since we want avoid ambiguity (eg when flags
1434                  * is zero) then just set this
1435                  */
1436                 if (n->nlmsg_flags & NLM_F_REPLACE)
1437                         ovr = 1;
1438                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1439                                      extack);
1440                 break;
1441         case RTM_DELACTION:
1442                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1443                                     portid, RTM_DELACTION, extack);
1444                 break;
1445         case RTM_GETACTION:
1446                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1447                                     portid, RTM_GETACTION, extack);
1448                 break;
1449         default:
1450                 BUG();
1451         }
1452
1453         return ret;
1454 }
1455
1456 static struct nlattr *find_dump_kind(struct nlattr **nla)
1457 {
1458         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1459         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1460         struct nlattr *kind;
1461
1462         tb1 = nla[TCA_ACT_TAB];
1463         if (tb1 == NULL)
1464                 return NULL;
1465
1466         if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1467                 return NULL;
1468
1469         if (tb[1] == NULL)
1470                 return NULL;
1471         if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], tcf_action_policy, NULL) < 0)
1472                 return NULL;
1473         kind = tb2[TCA_ACT_KIND];
1474
1475         return kind;
1476 }
1477
1478 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1479 {
1480         struct net *net = sock_net(skb->sk);
1481         struct nlmsghdr *nlh;
1482         unsigned char *b = skb_tail_pointer(skb);
1483         struct nlattr *nest;
1484         struct tc_action_ops *a_o;
1485         int ret = 0;
1486         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1487         struct nlattr *tb[TCA_ROOT_MAX + 1];
1488         struct nlattr *count_attr = NULL;
1489         unsigned long jiffy_since = 0;
1490         struct nlattr *kind = NULL;
1491         struct nla_bitfield32 bf;
1492         u32 msecs_since = 0;
1493         u32 act_count = 0;
1494
1495         ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
1496                                      TCA_ROOT_MAX, tcaa_policy, cb->extack);
1497         if (ret < 0)
1498                 return ret;
1499
1500         kind = find_dump_kind(tb);
1501         if (kind == NULL) {
1502                 pr_info("tc_dump_action: action bad kind\n");
1503                 return 0;
1504         }
1505
1506         a_o = tc_lookup_action(kind);
1507         if (a_o == NULL)
1508                 return 0;
1509
1510         cb->args[2] = 0;
1511         if (tb[TCA_ROOT_FLAGS]) {
1512                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1513                 cb->args[2] = bf.value;
1514         }
1515
1516         if (tb[TCA_ROOT_TIME_DELTA]) {
1517                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1518         }
1519
1520         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1521                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1522         if (!nlh)
1523                 goto out_module_put;
1524
1525         if (msecs_since)
1526                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1527
1528         t = nlmsg_data(nlh);
1529         t->tca_family = AF_UNSPEC;
1530         t->tca__pad1 = 0;
1531         t->tca__pad2 = 0;
1532         cb->args[3] = jiffy_since;
1533         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1534         if (!count_attr)
1535                 goto out_module_put;
1536
1537         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1538         if (nest == NULL)
1539                 goto out_module_put;
1540
1541         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1542         if (ret < 0)
1543                 goto out_module_put;
1544
1545         if (ret > 0) {
1546                 nla_nest_end(skb, nest);
1547                 ret = skb->len;
1548                 act_count = cb->args[1];
1549                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1550                 cb->args[1] = 0;
1551         } else
1552                 nlmsg_trim(skb, b);
1553
1554         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1555         if (NETLINK_CB(cb->skb).portid && ret)
1556                 nlh->nlmsg_flags |= NLM_F_MULTI;
1557         module_put(a_o->owner);
1558         return skb->len;
1559
1560 out_module_put:
1561         module_put(a_o->owner);
1562         nlmsg_trim(skb, b);
1563         return skb->len;
1564 }
1565
1566 static int __init tc_action_init(void)
1567 {
1568         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1569         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1570         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1571                       0);
1572
1573         return 0;
1574 }
1575
1576 subsys_initcall(tc_action_init);