net/sched/act_api.c

   1 /*
   2  * net/sched/act_api.c  Packet action API.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Author:      Jamal Hadi Salim
  10  *
  11  *
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/errno.h>
  18 #include <linux/slab.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/init.h>
  21 #include <linux/kmod.h>
  22 #include <linux/err.h>
  23 #include <linux/module.h>
  24 #include <net/net_namespace.h>
  25 #include <net/sock.h>
  26 #include <net/sch_generic.h>
  27 #include <net/pkt_cls.h>
  28 #include <net/act_api.h>
  29 #include <net/netlink.h>
  30
  31 static int tcf_action_goto_chain_init(struct tc_action *a, struct tcf_proto *tp)
  32 {
  33         u32 chain_index = a->tcfa_action & TC_ACT_EXT_VAL_MASK;
  34
  35         if (!tp)
  36                 return -EINVAL;
  37         a->goto_chain = tcf_chain_get_by_act(tp->chain->block, chain_index);
  38         if (!a->goto_chain)
  39                 return -ENOMEM;
  40         return 0;
  41 }
  42
  43 static void tcf_action_goto_chain_fini(struct tc_action *a)
  44 {
  45         tcf_chain_put_by_act(a->goto_chain);
  46 }
  47
  48 static void tcf_action_goto_chain_exec(const struct tc_action *a,
  49                                        struct tcf_result *res)
  50 {
  51         const struct tcf_chain *chain = a->goto_chain;
  52
  53         res->goto_tp = rcu_dereference_bh(chain->filter_chain);
  54 }
  55
  56 static void tcf_free_cookie_rcu(struct rcu_head *p)
  57 {
  58         struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
  59
  60         kfree(cookie->data);
  61         kfree(cookie);
  62 }
  63
  64 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
  65                                   struct tc_cookie *new_cookie)
  66 {
  67         struct tc_cookie *old;
  68
  69         old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
  70         if (old)
  71                 call_rcu(&old->rcu, tcf_free_cookie_rcu);
  72 }
  73
  74 /* XXX: For standalone actions, we don't need a RCU grace period either, because
  75  * actions are always connected to filters and filters are already destroyed in
  76  * RCU callbacks, so after a RCU grace period actions are already disconnected
  77  * from filters. Readers later can not find us.
  78  */
  79 static void free_tcf(struct tc_action *p)
  80 {
  81         free_percpu(p->cpu_bstats);
  82         free_percpu(p->cpu_bstats_hw);
  83         free_percpu(p->cpu_qstats);
  84
  85         tcf_set_action_cookie(&p->act_cookie, NULL);
  86         if (p->goto_chain)
  87                 tcf_action_goto_chain_fini(p);
  88
  89         kfree(p);
  90 }
  91
  92 static void tcf_action_cleanup(struct tc_action *p)
  93 {
  94         if (p->ops->cleanup)
  95                 p->ops->cleanup(p);
  96
  97         gen_kill_estimator(&p->tcfa_rate_est);
  98         free_tcf(p);
  99 }
 100
 101 static int __tcf_action_put(struct tc_action *p, bool bind)
 102 {
 103         struct tcf_idrinfo *idrinfo = p->idrinfo;
 104
 105         if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
 106                 if (bind)
 107                         atomic_dec(&p->tcfa_bindcnt);
 108                 idr_remove(&idrinfo->action_idr, p->tcfa_index);
 109                 mutex_unlock(&idrinfo->lock);
 110
 111                 tcf_action_cleanup(p);
 112                 return 1;
 113         }
 114
 115         if (bind)
 116                 atomic_dec(&p->tcfa_bindcnt);
 117
 118         return 0;
 119 }
 120
 121 int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
 122 {
 123         int ret = 0;
 124
 125         /* Release with strict==1 and bind==0 is only called through act API
 126          * interface (classifiers always bind). Only case when action with
 127          * positive reference count and zero bind count can exist is when it was
 128          * also created with act API (unbinding last classifier will destroy the
 129          * action if it was created by classifier). So only case when bind count
 130          * can be changed after initial check is when unbound action is
 131          * destroyed by act API while classifier binds to action with same id
 132          * concurrently. This result either creation of new action(same behavior
 133          * as before), or reusing existing action if concurrent process
 134          * increments reference count before action is deleted. Both scenarios
 135          * are acceptable.
 136          */
 137         if (p) {
 138                 if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
 139                         return -EPERM;
 140
 141                 if (__tcf_action_put(p, bind))
 142                         ret = ACT_P_DELETED;
 143         }
 144
 145         return ret;
 146 }
 147 EXPORT_SYMBOL(__tcf_idr_release);
 148
 149 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
 150 {
 151         struct tc_cookie *act_cookie;
 152         u32 cookie_len = 0;
 153
 154         rcu_read_lock();
 155         act_cookie = rcu_dereference(act->act_cookie);
 156
 157         if (act_cookie)
 158                 cookie_len = nla_total_size(act_cookie->len);
 159         rcu_read_unlock();
 160
 161         return  nla_total_size(0) /* action number nested */
 162                 + nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
 163                 + cookie_len /* TCA_ACT_COOKIE */
 164                 + nla_total_size(0) /* TCA_ACT_STATS nested */
 165                 /* TCA_STATS_BASIC */
 166                 + nla_total_size_64bit(sizeof(struct gnet_stats_basic))
 167                 /* TCA_STATS_QUEUE */
 168                 + nla_total_size_64bit(sizeof(struct gnet_stats_queue))
 169                 + nla_total_size(0) /* TCA_OPTIONS nested */
 170                 + nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
 171 }
 172
 173 static size_t tcf_action_full_attrs_size(size_t sz)
 174 {
 175         return NLMSG_HDRLEN                     /* struct nlmsghdr */
 176                 + sizeof(struct tcamsg)
 177                 + nla_total_size(0)             /* TCA_ACT_TAB nested */
 178                 + sz;
 179 }
 180
 181 static size_t tcf_action_fill_size(const struct tc_action *act)
 182 {
 183         size_t sz = tcf_action_shared_attrs_size(act);
 184
 185         if (act->ops->get_fill_size)
 186                 return act->ops->get_fill_size(act) + sz;
 187         return sz;
 188 }
 189
 190 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 191                            struct netlink_callback *cb)
 192 {
 193         int err = 0, index = -1, s_i = 0, n_i = 0;
 194         u32 act_flags = cb->args[2];
 195         unsigned long jiffy_since = cb->args[3];
 196         struct nlattr *nest;
 197         struct idr *idr = &idrinfo->action_idr;
 198         struct tc_action *p;
 199         unsigned long id = 1;
 200
 201         mutex_lock(&idrinfo->lock);
 202
 203         s_i = cb->args[0];
 204
 205         idr_for_each_entry_ul(idr, p, id) {
 206                 index++;
 207                 if (index < s_i)
 208                         continue;
 209
 210                 if (jiffy_since &&
 211                     time_after(jiffy_since,
 212                                (unsigned long)p->tcfa_tm.lastuse))
 213                         continue;
 214
 215                 nest = nla_nest_start(skb, n_i);
 216                 if (!nest) {
 217                         index--;
 218                         goto nla_put_failure;
 219                 }
 220                 err = tcf_action_dump_1(skb, p, 0, 0);
 221                 if (err < 0) {
 222                         index--;
 223                         nlmsg_trim(skb, nest);
 224                         goto done;
 225                 }
 226                 nla_nest_end(skb, nest);
 227                 n_i++;
 228                 if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
 229                     n_i >= TCA_ACT_MAX_PRIO)
 230                         goto done;
 231         }
 232 done:
 233         if (index >= 0)
 234                 cb->args[0] = index + 1;
 235
 236         mutex_unlock(&idrinfo->lock);
 237         if (n_i) {
 238                 if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
 239                         cb->args[1] = n_i;
 240         }
 241         return n_i;
 242
 243 nla_put_failure:
 244         nla_nest_cancel(skb, nest);
 245         goto done;
 246 }
 247
 248 static int tcf_idr_release_unsafe(struct tc_action *p)
 249 {
 250         if (atomic_read(&p->tcfa_bindcnt) > 0)
 251                 return -EPERM;
 252
 253         if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 254                 idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
 255                 tcf_action_cleanup(p);
 256                 return ACT_P_DELETED;
 257         }
 258
 259         return 0;
 260 }
 261
 262 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 263                           const struct tc_action_ops *ops)
 264 {
 265         struct nlattr *nest;
 266         int n_i = 0;
 267         int ret = -EINVAL;
 268         struct idr *idr = &idrinfo->action_idr;
 269         struct tc_action *p;
 270         unsigned long id = 1;
 271
 272         nest = nla_nest_start(skb, 0);
 273         if (nest == NULL)
 274                 goto nla_put_failure;
 275         if (nla_put_string(skb, TCA_KIND, ops->kind))
 276                 goto nla_put_failure;
 277
 278         mutex_lock(&idrinfo->lock);
 279         idr_for_each_entry_ul(idr, p, id) {
 280                 ret = tcf_idr_release_unsafe(p);
 281                 if (ret == ACT_P_DELETED) {
 282                         module_put(ops->owner);
 283                         n_i++;
 284                 } else if (ret < 0) {
 285                         mutex_unlock(&idrinfo->lock);
 286                         goto nla_put_failure;
 287                 }
 288         }
 289         mutex_unlock(&idrinfo->lock);
 290
 291         if (nla_put_u32(skb, TCA_FCNT, n_i))
 292                 goto nla_put_failure;
 293         nla_nest_end(skb, nest);
 294
 295         return n_i;
 296 nla_put_failure:
 297         nla_nest_cancel(skb, nest);
 298         return ret;
 299 }
 300
 301 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 302                        struct netlink_callback *cb, int type,
 303                        const struct tc_action_ops *ops,
 304                        struct netlink_ext_ack *extack)
 305 {
 306         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 307
 308         if (type == RTM_DELACTION) {
 309                 return tcf_del_walker(idrinfo, skb, ops);
 310         } else if (type == RTM_GETACTION) {
 311                 return tcf_dump_walker(idrinfo, skb, cb);
 312         } else {
 313                 WARN(1, "tcf_generic_walker: unknown command %d\n", type);
 314                 NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
 315                 return -EINVAL;
 316         }
 317 }
 318 EXPORT_SYMBOL(tcf_generic_walker);
 319
 320 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 321 {
 322         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 323         struct tc_action *p;
 324
 325         mutex_lock(&idrinfo->lock);
 326         p = idr_find(&idrinfo->action_idr, index);
 327         if (IS_ERR(p))
 328                 p = NULL;
 329         else if (p)
 330                 refcount_inc(&p->tcfa_refcnt);
 331         mutex_unlock(&idrinfo->lock);
 332
 333         if (p) {
 334                 *a = p;
 335                 return true;
 336         }
 337         return false;
 338 }
 339 EXPORT_SYMBOL(tcf_idr_search);
 340
 341 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
 342 {
 343         struct tc_action *p;
 344         int ret = 0;
 345
 346         mutex_lock(&idrinfo->lock);
 347         p = idr_find(&idrinfo->action_idr, index);
 348         if (!p) {
 349                 mutex_unlock(&idrinfo->lock);
 350                 return -ENOENT;
 351         }
 352
 353         if (!atomic_read(&p->tcfa_bindcnt)) {
 354                 if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 355                         struct module *owner = p->ops->owner;
 356
 357                         WARN_ON(p != idr_remove(&idrinfo->action_idr,
 358                                                 p->tcfa_index));
 359                         mutex_unlock(&idrinfo->lock);
 360
 361                         tcf_action_cleanup(p);
 362                         module_put(owner);
 363                         return 0;
 364                 }
 365                 ret = 0;
 366         } else {
 367                 ret = -EPERM;
 368         }
 369
 370         mutex_unlock(&idrinfo->lock);
 371         return ret;
 372 }
 373
 374 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 375                    struct tc_action **a, const struct tc_action_ops *ops,
 376                    int bind, bool cpustats)
 377 {
 378         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 379         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 380         int err = -ENOMEM;
 381
 382         if (unlikely(!p))
 383                 return -ENOMEM;
 384         refcount_set(&p->tcfa_refcnt, 1);
 385         if (bind)
 386                 atomic_set(&p->tcfa_bindcnt, 1);
 387
 388         if (cpustats) {
 389                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 390                 if (!p->cpu_bstats)
 391                         goto err1;
 392                 p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 393                 if (!p->cpu_bstats_hw)
 394                         goto err2;
 395                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 396                 if (!p->cpu_qstats)
 397                         goto err3;
 398         }
 399         spin_lock_init(&p->tcfa_lock);
 400         p->tcfa_index = index;
 401         p->tcfa_tm.install = jiffies;
 402         p->tcfa_tm.lastuse = jiffies;
 403         p->tcfa_tm.firstuse = 0;
 404         if (est) {
 405                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 406                                         &p->tcfa_rate_est,
 407                                         &p->tcfa_lock, NULL, est);
 408                 if (err)
 409                         goto err4;
 410         }
 411
 412         p->idrinfo = idrinfo;
 413         p->ops = ops;
 414         *a = p;
 415         return 0;
 416 err4:
 417         free_percpu(p->cpu_qstats);
 418 err3:
 419         free_percpu(p->cpu_bstats_hw);
 420 err2:
 421         free_percpu(p->cpu_bstats);
 422 err1:
 423         kfree(p);
 424         return err;
 425 }
 426 EXPORT_SYMBOL(tcf_idr_create);
 427
 428 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
 429 {
 430         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 431
 432         mutex_lock(&idrinfo->lock);
 433         /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 434         WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
 435         mutex_unlock(&idrinfo->lock);
 436 }
 437 EXPORT_SYMBOL(tcf_idr_insert);
 438
 439 /* Cleanup idr index that was allocated but not initialized. */
 440
 441 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
 442 {
 443         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 444
 445         mutex_lock(&idrinfo->lock);
 446         /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 447         WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
 448         mutex_unlock(&idrinfo->lock);
 449 }
 450 EXPORT_SYMBOL(tcf_idr_cleanup);
 451
 452 /* Check if action with specified index exists. If actions is found, increments
 453  * its reference and bind counters, and return 1. Otherwise insert temporary
 454  * error pointer (to prevent concurrent users from inserting actions with same
 455  * index) and return 0.
 456  */
 457
 458 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 459                         struct tc_action **a, int bind)
 460 {
 461         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 462         struct tc_action *p;
 463         int ret;
 464
 465 again:
 466         mutex_lock(&idrinfo->lock);
 467         if (*index) {
 468                 p = idr_find(&idrinfo->action_idr, *index);
 469                 if (IS_ERR(p)) {
 470                         /* This means that another process allocated
 471                          * index but did not assign the pointer yet.
 472                          */
 473                         mutex_unlock(&idrinfo->lock);
 474                         goto again;
 475                 }
 476
 477                 if (p) {
 478                         refcount_inc(&p->tcfa_refcnt);
 479                         if (bind)
 480                                 atomic_inc(&p->tcfa_bindcnt);
 481                         *a = p;
 482                         ret = 1;
 483                 } else {
 484                         *a = NULL;
 485                         ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 486                                             *index, GFP_KERNEL);
 487                         if (!ret)
 488                                 idr_replace(&idrinfo->action_idr,
 489                                             ERR_PTR(-EBUSY), *index);
 490                 }
 491         } else {
 492                 *index = 1;
 493                 *a = NULL;
 494                 ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 495                                     UINT_MAX, GFP_KERNEL);
 496                 if (!ret)
 497                         idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
 498                                     *index);
 499         }
 500         mutex_unlock(&idrinfo->lock);
 501         return ret;
 502 }
 503 EXPORT_SYMBOL(tcf_idr_check_alloc);
 504
 505 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 506                          struct tcf_idrinfo *idrinfo)
 507 {
 508         struct idr *idr = &idrinfo->action_idr;
 509         struct tc_action *p;
 510         int ret;
 511         unsigned long id = 1;
 512
 513         idr_for_each_entry_ul(idr, p, id) {
 514                 ret = __tcf_idr_release(p, false, true);
 515                 if (ret == ACT_P_DELETED)
 516                         module_put(ops->owner);
 517                 else if (ret < 0)
 518                         return;
 519         }
 520         idr_destroy(&idrinfo->action_idr);
 521 }
 522 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 523
 524 static LIST_HEAD(act_base);
 525 static DEFINE_RWLOCK(act_mod_lock);
 526
 527 int tcf_register_action(struct tc_action_ops *act,
 528                         struct pernet_operations *ops)
 529 {
 530         struct tc_action_ops *a;
 531         int ret;
 532
 533         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 534                 return -EINVAL;
 535
 536         /* We have to register pernet ops before making the action ops visible,
 537          * otherwise tcf_action_init_1() could get a partially initialized
 538          * netns.
 539          */
 540         ret = register_pernet_subsys(ops);
 541         if (ret)
 542                 return ret;
 543
 544         write_lock(&act_mod_lock);
 545         list_for_each_entry(a, &act_base, head) {
 546                 if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
 547                         write_unlock(&act_mod_lock);
 548                         unregister_pernet_subsys(ops);
 549                         return -EEXIST;
 550                 }
 551         }
 552         list_add_tail(&act->head, &act_base);
 553         write_unlock(&act_mod_lock);
 554
 555         return 0;
 556 }
 557 EXPORT_SYMBOL(tcf_register_action);
 558
 559 int tcf_unregister_action(struct tc_action_ops *act,
 560                           struct pernet_operations *ops)
 561 {
 562         struct tc_action_ops *a;
 563         int err = -ENOENT;
 564
 565         write_lock(&act_mod_lock);
 566         list_for_each_entry(a, &act_base, head) {
 567                 if (a == act) {
 568                         list_del(&act->head);
 569                         err = 0;
 570                         break;
 571                 }
 572         }
 573         write_unlock(&act_mod_lock);
 574         if (!err)
 575                 unregister_pernet_subsys(ops);
 576         return err;
 577 }
 578 EXPORT_SYMBOL(tcf_unregister_action);
 579
 580 /* lookup by name */
 581 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 582 {
 583         struct tc_action_ops *a, *res = NULL;
 584
 585         if (kind) {
 586                 read_lock(&act_mod_lock);
 587                 list_for_each_entry(a, &act_base, head) {
 588                         if (strcmp(kind, a->kind) == 0) {
 589                                 if (try_module_get(a->owner))
 590                                         res = a;
 591                                 break;
 592                         }
 593                 }
 594                 read_unlock(&act_mod_lock);
 595         }
 596         return res;
 597 }
 598
 599 /* lookup by nlattr */
 600 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 601 {
 602         struct tc_action_ops *a, *res = NULL;
 603
 604         if (kind) {
 605                 read_lock(&act_mod_lock);
 606                 list_for_each_entry(a, &act_base, head) {
 607                         if (nla_strcmp(kind, a->kind) == 0) {
 608                                 if (try_module_get(a->owner))
 609                                         res = a;
 610                                 break;
 611                         }
 612                 }
 613                 read_unlock(&act_mod_lock);
 614         }
 615         return res;
 616 }
 617
 618 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 619 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 620 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 621                     int nr_actions, struct tcf_result *res)
 622 {
 623         u32 jmp_prgcnt = 0;
 624         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 625         int i;
 626         int ret = TC_ACT_OK;
 627
 628         if (skb_skip_tc_classify(skb))
 629                 return TC_ACT_OK;
 630
 631 restart_act_graph:
 632         for (i = 0; i < nr_actions; i++) {
 633                 const struct tc_action *a = actions[i];
 634
 635                 if (jmp_prgcnt > 0) {
 636                         jmp_prgcnt -= 1;
 637                         continue;
 638                 }
 639 repeat:
 640                 ret = a->ops->act(skb, a, res);
 641                 if (ret == TC_ACT_REPEAT)
 642                         goto repeat;    /* we need a ttl - JHS */
 643
 644                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 645                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 646                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 647                                 /* faulty opcode, stop pipeline */
 648                                 return TC_ACT_OK;
 649                         } else {
 650                                 jmp_ttl -= 1;
 651                                 if (jmp_ttl > 0)
 652                                         goto restart_act_graph;
 653                                 else /* faulty graph, stop pipeline */
 654                                         return TC_ACT_OK;
 655                         }
 656                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 657                         tcf_action_goto_chain_exec(a, res);
 658                 }
 659
 660                 if (ret != TC_ACT_PIPE)
 661                         break;
 662         }
 663
 664         return ret;
 665 }
 666 EXPORT_SYMBOL(tcf_action_exec);
 667
 668 int tcf_action_destroy(struct tc_action *actions[], int bind)
 669 {
 670         const struct tc_action_ops *ops;
 671         struct tc_action *a;
 672         int ret = 0, i;
 673
 674         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 675                 a = actions[i];
 676                 actions[i] = NULL;
 677                 ops = a->ops;
 678                 ret = __tcf_idr_release(a, bind, true);
 679                 if (ret == ACT_P_DELETED)
 680                         module_put(ops->owner);
 681                 else if (ret < 0)
 682                         return ret;
 683         }
 684         return ret;
 685 }
 686
 687 static int tcf_action_destroy_1(struct tc_action *a, int bind)
 688 {
 689         struct tc_action *actions[] = { a, NULL };
 690
 691         return tcf_action_destroy(actions, bind);
 692 }
 693
 694 static int tcf_action_put(struct tc_action *p)
 695 {
 696         return __tcf_action_put(p, false);
 697 }
 698
 699 /* Put all actions in this array, skip those NULL's. */
 700 static void tcf_action_put_many(struct tc_action *actions[])
 701 {
 702         int i;
 703
 704         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 705                 struct tc_action *a = actions[i];
 706                 const struct tc_action_ops *ops;
 707
 708                 if (!a)
 709                         continue;
 710                 ops = a->ops;
 711                 if (tcf_action_put(a))
 712                         module_put(ops->owner);
 713         }
 714 }
 715
 716 int
 717 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 718 {
 719         return a->ops->dump(skb, a, bind, ref);
 720 }
 721
 722 int
 723 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 724 {
 725         int err = -EINVAL;
 726         unsigned char *b = skb_tail_pointer(skb);
 727         struct nlattr *nest;
 728         struct tc_cookie *cookie;
 729
 730         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 731                 goto nla_put_failure;
 732         if (tcf_action_copy_stats(skb, a, 0))
 733                 goto nla_put_failure;
 734
 735         rcu_read_lock();
 736         cookie = rcu_dereference(a->act_cookie);
 737         if (cookie) {
 738                 if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
 739                         rcu_read_unlock();
 740                         goto nla_put_failure;
 741                 }
 742         }
 743         rcu_read_unlock();
 744
 745         nest = nla_nest_start(skb, TCA_OPTIONS);
 746         if (nest == NULL)
 747                 goto nla_put_failure;
 748         err = tcf_action_dump_old(skb, a, bind, ref);
 749         if (err > 0) {
 750                 nla_nest_end(skb, nest);
 751                 return err;
 752         }
 753
 754 nla_put_failure:
 755         nlmsg_trim(skb, b);
 756         return -1;
 757 }
 758 EXPORT_SYMBOL(tcf_action_dump_1);
 759
 760 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 761                     int bind, int ref)
 762 {
 763         struct tc_action *a;
 764         int err = -EINVAL, i;
 765         struct nlattr *nest;
 766
 767         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 768                 a = actions[i];
 769                 nest = nla_nest_start(skb, a->order);
 770                 if (nest == NULL)
 771                         goto nla_put_failure;
 772                 err = tcf_action_dump_1(skb, a, bind, ref);
 773                 if (err < 0)
 774                         goto errout;
 775                 nla_nest_end(skb, nest);
 776         }
 777
 778         return 0;
 779
 780 nla_put_failure:
 781         err = -EINVAL;
 782 errout:
 783         nla_nest_cancel(skb, nest);
 784         return err;
 785 }
 786
 787 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 788 {
 789         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 790         if (!c)
 791                 return NULL;
 792
 793         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 794         if (!c->data) {
 795                 kfree(c);
 796                 return NULL;
 797         }
 798         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 799
 800         return c;
 801 }
 802
 803 static bool tcf_action_valid(int action)
 804 {
 805         int opcode = TC_ACT_EXT_OPCODE(action);
 806
 807         if (!opcode)
 808                 return action <= TC_ACT_VALUE_MAX;
 809         return opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC;
 810 }
 811
 812 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 813                                     struct nlattr *nla, struct nlattr *est,
 814                                     char *name, int ovr, int bind,
 815                                     bool rtnl_held,
 816                                     struct netlink_ext_ack *extack)
 817 {
 818         struct tc_action *a;
 819         struct tc_action_ops *a_o;
 820         struct tc_cookie *cookie = NULL;
 821         char act_name[IFNAMSIZ];
 822         struct nlattr *tb[TCA_ACT_MAX + 1];
 823         struct nlattr *kind;
 824         int err;
 825
 826         if (name == NULL) {
 827                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
 828                 if (err < 0)
 829                         goto err_out;
 830                 err = -EINVAL;
 831                 kind = tb[TCA_ACT_KIND];
 832                 if (!kind) {
 833                         NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 834                         goto err_out;
 835                 }
 836                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
 837                         NL_SET_ERR_MSG(extack, "TC action name too long");
 838                         goto err_out;
 839                 }
 840                 if (tb[TCA_ACT_COOKIE]) {
 841                         int cklen = nla_len(tb[TCA_ACT_COOKIE]);
 842
 843                         if (cklen > TC_COOKIE_MAX_SIZE) {
 844                                 NL_SET_ERR_MSG(extack, "TC cookie size above the maximum");
 845                                 goto err_out;
 846                         }
 847
 848                         cookie = nla_memdup_cookie(tb);
 849                         if (!cookie) {
 850                                 NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
 851                                 err = -ENOMEM;
 852                                 goto err_out;
 853                         }
 854                 }
 855         } else {
 856                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
 857                         NL_SET_ERR_MSG(extack, "TC action name too long");
 858                         err = -EINVAL;
 859                         goto err_out;
 860                 }
 861         }
 862
 863         a_o = tc_lookup_action_n(act_name);
 864         if (a_o == NULL) {
 865 #ifdef CONFIG_MODULES
 866                 if (rtnl_held)
 867                         rtnl_unlock();
 868                 request_module("act_%s", act_name);
 869                 if (rtnl_held)
 870                         rtnl_lock();
 871
 872                 a_o = tc_lookup_action_n(act_name);
 873
 874                 /* We dropped the RTNL semaphore in order to
 875                  * perform the module load.  So, even if we
 876                  * succeeded in loading the module we have to
 877                  * tell the caller to replay the request.  We
 878                  * indicate this using -EAGAIN.
 879                  */
 880                 if (a_o != NULL) {
 881                         err = -EAGAIN;
 882                         goto err_mod;
 883                 }
 884 #endif
 885                 NL_SET_ERR_MSG(extack, "Failed to load TC action module");
 886                 err = -ENOENT;
 887                 goto err_out;
 888         }
 889
 890         /* backward compatibility for policer */
 891         if (name == NULL)
 892                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
 893                                 rtnl_held, extack);
 894         else
 895                 err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
 896                                 extack);
 897         if (err < 0)
 898                 goto err_mod;
 899
 900         if (!name && tb[TCA_ACT_COOKIE])
 901                 tcf_set_action_cookie(&a->act_cookie, cookie);
 902
 903         /* module count goes up only when brand new policy is created
 904          * if it exists and is only bound to in a_o->init() then
 905          * ACT_P_CREATED is not returned (a zero is).
 906          */
 907         if (err != ACT_P_CREATED)
 908                 module_put(a_o->owner);
 909
 910         if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN)) {
 911                 err = tcf_action_goto_chain_init(a, tp);
 912                 if (err) {
 913                         tcf_action_destroy_1(a, bind);
 914                         NL_SET_ERR_MSG(extack, "Failed to init TC action chain");
 915                         return ERR_PTR(err);
 916                 }
 917         }
 918
 919         if (!tcf_action_valid(a->tcfa_action)) {
 920                 tcf_action_destroy_1(a, bind);
 921                 NL_SET_ERR_MSG(extack, "Invalid control action value");
 922                 return ERR_PTR(-EINVAL);
 923         }
 924
 925         return a;
 926
 927 err_mod:
 928         module_put(a_o->owner);
 929 err_out:
 930         if (cookie) {
 931                 kfree(cookie->data);
 932                 kfree(cookie);
 933         }
 934         return ERR_PTR(err);
 935 }
 936
 937 /* Returns numbers of initialized actions or negative error. */
 938
 939 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 940                     struct nlattr *est, char *name, int ovr, int bind,
 941                     struct tc_action *actions[], size_t *attr_size,
 942                     bool rtnl_held, struct netlink_ext_ack *extack)
 943 {
 944         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 945         struct tc_action *act;
 946         size_t sz = 0;
 947         int err;
 948         int i;
 949
 950         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
 951         if (err < 0)
 952                 return err;
 953
 954         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 955                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
 956                                         rtnl_held, extack);
 957                 if (IS_ERR(act)) {
 958                         err = PTR_ERR(act);
 959                         goto err;
 960                 }
 961                 act->order = i;
 962                 sz += tcf_action_fill_size(act);
 963                 /* Start from index 0 */
 964                 actions[i - 1] = act;
 965         }
 966
 967         *attr_size = tcf_action_full_attrs_size(sz);
 968         return i - 1;
 969
 970 err:
 971         tcf_action_destroy(actions, bind);
 972         return err;
 973 }
 974
 975 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
 976                           int compat_mode)
 977 {
 978         int err = 0;
 979         struct gnet_dump d;
 980
 981         if (p == NULL)
 982                 goto errout;
 983
 984         /* compat_mode being true specifies a call that is supposed
 985          * to add additional backward compatibility statistic TLVs.
 986          */
 987         if (compat_mode) {
 988                 if (p->type == TCA_OLD_COMPAT)
 989                         err = gnet_stats_start_copy_compat(skb, 0,
 990                                                            TCA_STATS,
 991                                                            TCA_XSTATS,
 992                                                            &p->tcfa_lock, &d,
 993                                                            TCA_PAD);
 994                 else
 995                         return 0;
 996         } else
 997                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 998                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
 999
1000         if (err < 0)
1001                 goto errout;
1002
1003         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1004             gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1005                                      &p->tcfa_bstats_hw) < 0 ||
1006             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1007             gnet_stats_copy_queue(&d, p->cpu_qstats,
1008                                   &p->tcfa_qstats,
1009                                   p->tcfa_qstats.qlen) < 0)
1010                 goto errout;
1011
1012         if (gnet_stats_finish_copy(&d) < 0)
1013                 goto errout;
1014
1015         return 0;
1016
1017 errout:
1018         return -1;
1019 }
1020
1021 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1022                         u32 portid, u32 seq, u16 flags, int event, int bind,
1023                         int ref)
1024 {
1025         struct tcamsg *t;
1026         struct nlmsghdr *nlh;
1027         unsigned char *b = skb_tail_pointer(skb);
1028         struct nlattr *nest;
1029
1030         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1031         if (!nlh)
1032                 goto out_nlmsg_trim;
1033         t = nlmsg_data(nlh);
1034         t->tca_family = AF_UNSPEC;
1035         t->tca__pad1 = 0;
1036         t->tca__pad2 = 0;
1037
1038         nest = nla_nest_start(skb, TCA_ACT_TAB);
1039         if (!nest)
1040                 goto out_nlmsg_trim;
1041
1042         if (tcf_action_dump(skb, actions, bind, ref) < 0)
1043                 goto out_nlmsg_trim;
1044
1045         nla_nest_end(skb, nest);
1046
1047         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1048         return skb->len;
1049
1050 out_nlmsg_trim:
1051         nlmsg_trim(skb, b);
1052         return -1;
1053 }
1054
1055 static int
1056 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1057                struct tc_action *actions[], int event,
1058                struct netlink_ext_ack *extack)
1059 {
1060         struct sk_buff *skb;
1061
1062         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1063         if (!skb)
1064                 return -ENOBUFS;
1065         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1066                          0, 1) <= 0) {
1067                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1068                 kfree_skb(skb);
1069                 return -EINVAL;
1070         }
1071
1072         return rtnl_unicast(skb, net, portid);
1073 }
1074
1075 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1076                                           struct nlmsghdr *n, u32 portid,
1077                                           struct netlink_ext_ack *extack)
1078 {
1079         struct nlattr *tb[TCA_ACT_MAX + 1];
1080         const struct tc_action_ops *ops;
1081         struct tc_action *a;
1082         int index;
1083         int err;
1084
1085         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
1086         if (err < 0)
1087                 goto err_out;
1088
1089         err = -EINVAL;
1090         if (tb[TCA_ACT_INDEX] == NULL ||
1091             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1092                 NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1093                 goto err_out;
1094         }
1095         index = nla_get_u32(tb[TCA_ACT_INDEX]);
1096
1097         err = -EINVAL;
1098         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1099         if (!ops) { /* could happen in batch of actions */
1100                 NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1101                 goto err_out;
1102         }
1103         err = -ENOENT;
1104         if (ops->lookup(net, &a, index) == 0) {
1105                 NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1106                 goto err_mod;
1107         }
1108
1109         module_put(ops->owner);
1110         return a;
1111
1112 err_mod:
1113         module_put(ops->owner);
1114 err_out:
1115         return ERR_PTR(err);
1116 }
1117
1118 static int tca_action_flush(struct net *net, struct nlattr *nla,
1119                             struct nlmsghdr *n, u32 portid,
1120                             struct netlink_ext_ack *extack)
1121 {
1122         struct sk_buff *skb;
1123         unsigned char *b;
1124         struct nlmsghdr *nlh;
1125         struct tcamsg *t;
1126         struct netlink_callback dcb;
1127         struct nlattr *nest;
1128         struct nlattr *tb[TCA_ACT_MAX + 1];
1129         const struct tc_action_ops *ops;
1130         struct nlattr *kind;
1131         int err = -ENOMEM;
1132
1133         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1134         if (!skb)
1135                 return err;
1136
1137         b = skb_tail_pointer(skb);
1138
1139         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
1140         if (err < 0)
1141                 goto err_out;
1142
1143         err = -EINVAL;
1144         kind = tb[TCA_ACT_KIND];
1145         ops = tc_lookup_action(kind);
1146         if (!ops) { /*some idjot trying to flush unknown action */
1147                 NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1148                 goto err_out;
1149         }
1150
1151         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1152                         sizeof(*t), 0);
1153         if (!nlh) {
1154                 NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1155                 goto out_module_put;
1156         }
1157         t = nlmsg_data(nlh);
1158         t->tca_family = AF_UNSPEC;
1159         t->tca__pad1 = 0;
1160         t->tca__pad2 = 0;
1161
1162         nest = nla_nest_start(skb, TCA_ACT_TAB);
1163         if (!nest) {
1164                 NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1165                 goto out_module_put;
1166         }
1167
1168         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1169         if (err <= 0) {
1170                 nla_nest_cancel(skb, nest);
1171                 goto out_module_put;
1172         }
1173
1174         nla_nest_end(skb, nest);
1175
1176         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1177         nlh->nlmsg_flags |= NLM_F_ROOT;
1178         module_put(ops->owner);
1179         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1180                              n->nlmsg_flags & NLM_F_ECHO);
1181         if (err > 0)
1182                 return 0;
1183         if (err < 0)
1184                 NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1185
1186         return err;
1187
1188 out_module_put:
1189         module_put(ops->owner);
1190 err_out:
1191         kfree_skb(skb);
1192         return err;
1193 }
1194
1195 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1196 {
1197         int i;
1198
1199         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1200                 struct tc_action *a = actions[i];
1201                 const struct tc_action_ops *ops = a->ops;
1202                 /* Actions can be deleted concurrently so we must save their
1203                  * type and id to search again after reference is released.
1204                  */
1205                 struct tcf_idrinfo *idrinfo = a->idrinfo;
1206                 u32 act_index = a->tcfa_index;
1207
1208                 actions[i] = NULL;
1209                 if (tcf_action_put(a)) {
1210                         /* last reference, action was deleted concurrently */
1211                         module_put(ops->owner);
1212                 } else  {
1213                         int ret;
1214
1215                         /* now do the delete */
1216                         ret = tcf_idr_delete_index(idrinfo, act_index);
1217                         if (ret < 0)
1218                                 return ret;
1219                 }
1220         }
1221         return 0;
1222 }
1223
1224 static int
1225 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1226                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1227 {
1228         int ret;
1229         struct sk_buff *skb;
1230
1231         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1232                         GFP_KERNEL);
1233         if (!skb)
1234                 return -ENOBUFS;
1235
1236         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1237                          0, 2) <= 0) {
1238                 NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1239                 kfree_skb(skb);
1240                 return -EINVAL;
1241         }
1242
1243         /* now do the delete */
1244         ret = tcf_action_delete(net, actions);
1245         if (ret < 0) {
1246                 NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1247                 kfree_skb(skb);
1248                 return ret;
1249         }
1250
1251         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1252                              n->nlmsg_flags & NLM_F_ECHO);
1253         if (ret > 0)
1254                 return 0;
1255         return ret;
1256 }
1257
1258 static int
1259 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1260               u32 portid, int event, struct netlink_ext_ack *extack)
1261 {
1262         int i, ret;
1263         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1264         struct tc_action *act;
1265         size_t attr_size = 0;
1266         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1267
1268         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
1269         if (ret < 0)
1270                 return ret;
1271
1272         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1273                 if (tb[1])
1274                         return tca_action_flush(net, tb[1], n, portid, extack);
1275
1276                 NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1277                 return -EINVAL;
1278         }
1279
1280         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1281                 act = tcf_action_get_1(net, tb[i], n, portid, extack);
1282                 if (IS_ERR(act)) {
1283                         ret = PTR_ERR(act);
1284                         goto err;
1285                 }
1286                 act->order = i;
1287                 attr_size += tcf_action_fill_size(act);
1288                 actions[i - 1] = act;
1289         }
1290
1291         attr_size = tcf_action_full_attrs_size(attr_size);
1292
1293         if (event == RTM_GETACTION)
1294                 ret = tcf_get_notify(net, portid, n, actions, event, extack);
1295         else { /* delete */
1296                 ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1297                 if (ret)
1298                         goto err;
1299                 return 0;
1300         }
1301 err:
1302         tcf_action_put_many(actions);
1303         return ret;
1304 }
1305
1306 static int
1307 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1308                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1309 {
1310         struct sk_buff *skb;
1311         int err = 0;
1312
1313         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1314                         GFP_KERNEL);
1315         if (!skb)
1316                 return -ENOBUFS;
1317
1318         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1319                          RTM_NEWACTION, 0, 0) <= 0) {
1320                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1321                 kfree_skb(skb);
1322                 return -EINVAL;
1323         }
1324
1325         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1326                              n->nlmsg_flags & NLM_F_ECHO);
1327         if (err > 0)
1328                 err = 0;
1329         return err;
1330 }
1331
1332 static int tcf_action_add(struct net *net, struct nlattr *nla,
1333                           struct nlmsghdr *n, u32 portid, int ovr,
1334                           struct netlink_ext_ack *extack)
1335 {
1336         size_t attr_size = 0;
1337         int ret = 0;
1338         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1339
1340         ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0, actions,
1341                               &attr_size, true, extack);
1342         if (ret < 0)
1343                 return ret;
1344         ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1345         if (ovr)
1346                 tcf_action_put_many(actions);
1347
1348         return ret;
1349 }
1350
1351 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1352 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1353         [TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1354                              .validation_data = &tcaa_root_flags_allowed },
1355         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1356 };
1357
1358 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1359                          struct netlink_ext_ack *extack)
1360 {
1361         struct net *net = sock_net(skb->sk);
1362         struct nlattr *tca[TCA_ROOT_MAX + 1];
1363         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1364         int ret = 0, ovr = 0;
1365
1366         if ((n->nlmsg_type != RTM_GETACTION) &&
1367             !netlink_capable(skb, CAP_NET_ADMIN))
1368                 return -EPERM;
1369
1370         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ROOT_MAX, NULL,
1371                           extack);
1372         if (ret < 0)
1373                 return ret;
1374
1375         if (tca[TCA_ACT_TAB] == NULL) {
1376                 NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1377                 return -EINVAL;
1378         }
1379
1380         /* n->nlmsg_flags & NLM_F_CREATE */
1381         switch (n->nlmsg_type) {
1382         case RTM_NEWACTION:
1383                 /* we are going to assume all other flags
1384                  * imply create only if it doesn't exist
1385                  * Note that CREATE | EXCL implies that
1386                  * but since we want avoid ambiguity (eg when flags
1387                  * is zero) then just set this
1388                  */
1389                 if (n->nlmsg_flags & NLM_F_REPLACE)
1390                         ovr = 1;
1391 replay:
1392                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1393                                      extack);
1394                 if (ret == -EAGAIN)
1395                         goto replay;
1396                 break;
1397         case RTM_DELACTION:
1398                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1399                                     portid, RTM_DELACTION, extack);
1400                 break;
1401         case RTM_GETACTION:
1402                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1403                                     portid, RTM_GETACTION, extack);
1404                 break;
1405         default:
1406                 BUG();
1407         }
1408
1409         return ret;
1410 }
1411
1412 static struct nlattr *find_dump_kind(struct nlattr **nla)
1413 {
1414         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1415         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1416         struct nlattr *kind;
1417
1418         tb1 = nla[TCA_ACT_TAB];
1419         if (tb1 == NULL)
1420                 return NULL;
1421
1422         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1423                       NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1424                 return NULL;
1425
1426         if (tb[1] == NULL)
1427                 return NULL;
1428         if (nla_parse_nested(tb2, TCA_ACT_MAX, tb[1], NULL, NULL) < 0)
1429                 return NULL;
1430         kind = tb2[TCA_ACT_KIND];
1431
1432         return kind;
1433 }
1434
1435 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1436 {
1437         struct net *net = sock_net(skb->sk);
1438         struct nlmsghdr *nlh;
1439         unsigned char *b = skb_tail_pointer(skb);
1440         struct nlattr *nest;
1441         struct tc_action_ops *a_o;
1442         int ret = 0;
1443         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1444         struct nlattr *tb[TCA_ROOT_MAX + 1];
1445         struct nlattr *count_attr = NULL;
1446         unsigned long jiffy_since = 0;
1447         struct nlattr *kind = NULL;
1448         struct nla_bitfield32 bf;
1449         u32 msecs_since = 0;
1450         u32 act_count = 0;
1451
1452         ret = nlmsg_parse(cb->nlh, sizeof(struct tcamsg), tb, TCA_ROOT_MAX,
1453                           tcaa_policy, cb->extack);
1454         if (ret < 0)
1455                 return ret;
1456
1457         kind = find_dump_kind(tb);
1458         if (kind == NULL) {
1459                 pr_info("tc_dump_action: action bad kind\n");
1460                 return 0;
1461         }
1462
1463         a_o = tc_lookup_action(kind);
1464         if (a_o == NULL)
1465                 return 0;
1466
1467         cb->args[2] = 0;
1468         if (tb[TCA_ROOT_FLAGS]) {
1469                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1470                 cb->args[2] = bf.value;
1471         }
1472
1473         if (tb[TCA_ROOT_TIME_DELTA]) {
1474                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1475         }
1476
1477         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1478                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1479         if (!nlh)
1480                 goto out_module_put;
1481
1482         if (msecs_since)
1483                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1484
1485         t = nlmsg_data(nlh);
1486         t->tca_family = AF_UNSPEC;
1487         t->tca__pad1 = 0;
1488         t->tca__pad2 = 0;
1489         cb->args[3] = jiffy_since;
1490         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1491         if (!count_attr)
1492                 goto out_module_put;
1493
1494         nest = nla_nest_start(skb, TCA_ACT_TAB);
1495         if (nest == NULL)
1496                 goto out_module_put;
1497
1498         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1499         if (ret < 0)
1500                 goto out_module_put;
1501
1502         if (ret > 0) {
1503                 nla_nest_end(skb, nest);
1504                 ret = skb->len;
1505                 act_count = cb->args[1];
1506                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1507                 cb->args[1] = 0;
1508         } else
1509                 nlmsg_trim(skb, b);
1510
1511         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1512         if (NETLINK_CB(cb->skb).portid && ret)
1513                 nlh->nlmsg_flags |= NLM_F_MULTI;
1514         module_put(a_o->owner);
1515         return skb->len;
1516
1517 out_module_put:
1518         module_put(a_o->owner);
1519         nlmsg_trim(skb, b);
1520         return skb->len;
1521 }
1522
1523 static int __init tc_action_init(void)
1524 {
1525         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1526         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1527         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1528                       0);
1529
1530         return 0;
1531 }
1532
1533 subsys_initcall(tc_action_init);