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         goto_chain = rcu_replace_pointer(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_PKT64 */
 192                 + nla_total_size_64bit(sizeof(u64))
 193                 /* TCA_STATS_QUEUE */
 194                 + nla_total_size_64bit(sizeof(struct gnet_stats_queue))
 195                 + nla_total_size(0) /* TCA_OPTIONS nested */
 196                 + nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
 197 }
 198
 199 static size_t tcf_action_full_attrs_size(size_t sz)
 200 {
 201         return NLMSG_HDRLEN                     /* struct nlmsghdr */
 202                 + sizeof(struct tcamsg)
 203                 + nla_total_size(0)             /* TCA_ACT_TAB nested */
 204                 + sz;
 205 }
 206
 207 static size_t tcf_action_fill_size(const struct tc_action *act)
 208 {
 209         size_t sz = tcf_action_shared_attrs_size(act);
 210
 211         if (act->ops->get_fill_size)
 212                 return act->ops->get_fill_size(act) + sz;
 213         return sz;
 214 }
 215
 216 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 217                            struct netlink_callback *cb)
 218 {
 219         int err = 0, index = -1, s_i = 0, n_i = 0;
 220         u32 act_flags = cb->args[2];
 221         unsigned long jiffy_since = cb->args[3];
 222         struct nlattr *nest;
 223         struct idr *idr = &idrinfo->action_idr;
 224         struct tc_action *p;
 225         unsigned long id = 1;
 226         unsigned long tmp;
 227
 228         mutex_lock(&idrinfo->lock);
 229
 230         s_i = cb->args[0];
 231
 232         idr_for_each_entry_ul(idr, p, tmp, id) {
 233                 index++;
 234                 if (index < s_i)
 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 {
 292         struct nlattr *nest;
 293         int n_i = 0;
 294         int ret = -EINVAL;
 295         struct idr *idr = &idrinfo->action_idr;
 296         struct tc_action *p;
 297         unsigned long id = 1;
 298         unsigned long tmp;
 299
 300         nest = nla_nest_start_noflag(skb, 0);
 301         if (nest == NULL)
 302                 goto nla_put_failure;
 303         if (nla_put_string(skb, TCA_KIND, ops->kind))
 304                 goto nla_put_failure;
 305
 306         mutex_lock(&idrinfo->lock);
 307         idr_for_each_entry_ul(idr, p, tmp, id) {
 308                 ret = tcf_idr_release_unsafe(p);
 309                 if (ret == ACT_P_DELETED) {
 310                         module_put(ops->owner);
 311                         n_i++;
 312                 } else if (ret < 0) {
 313                         mutex_unlock(&idrinfo->lock);
 314                         goto nla_put_failure;
 315                 }
 316         }
 317         mutex_unlock(&idrinfo->lock);
 318
 319         if (nla_put_u32(skb, TCA_FCNT, n_i))
 320                 goto nla_put_failure;
 321         nla_nest_end(skb, nest);
 322
 323         return n_i;
 324 nla_put_failure:
 325         nla_nest_cancel(skb, nest);
 326         return ret;
 327 }
 328
 329 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 330                        struct netlink_callback *cb, int type,
 331                        const struct tc_action_ops *ops,
 332                        struct netlink_ext_ack *extack)
 333 {
 334         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 335
 336         if (type == RTM_DELACTION) {
 337                 return tcf_del_walker(idrinfo, skb, ops);
 338         } else if (type == RTM_GETACTION) {
 339                 return tcf_dump_walker(idrinfo, skb, cb);
 340         } else {
 341                 WARN(1, "tcf_generic_walker: unknown command %d\n", type);
 342                 NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
 343                 return -EINVAL;
 344         }
 345 }
 346 EXPORT_SYMBOL(tcf_generic_walker);
 347
 348 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 349 {
 350         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 351         struct tc_action *p;
 352
 353         mutex_lock(&idrinfo->lock);
 354         p = idr_find(&idrinfo->action_idr, index);
 355         if (IS_ERR(p))
 356                 p = NULL;
 357         else if (p)
 358                 refcount_inc(&p->tcfa_refcnt);
 359         mutex_unlock(&idrinfo->lock);
 360
 361         if (p) {
 362                 *a = p;
 363                 return true;
 364         }
 365         return false;
 366 }
 367 EXPORT_SYMBOL(tcf_idr_search);
 368
 369 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
 370 {
 371         struct tc_action *p;
 372         int ret = 0;
 373
 374         mutex_lock(&idrinfo->lock);
 375         p = idr_find(&idrinfo->action_idr, index);
 376         if (!p) {
 377                 mutex_unlock(&idrinfo->lock);
 378                 return -ENOENT;
 379         }
 380
 381         if (!atomic_read(&p->tcfa_bindcnt)) {
 382                 if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 383                         struct module *owner = p->ops->owner;
 384
 385                         WARN_ON(p != idr_remove(&idrinfo->action_idr,
 386                                                 p->tcfa_index));
 387                         mutex_unlock(&idrinfo->lock);
 388
 389                         tcf_action_cleanup(p);
 390                         module_put(owner);
 391                         return 0;
 392                 }
 393                 ret = 0;
 394         } else {
 395                 ret = -EPERM;
 396         }
 397
 398         mutex_unlock(&idrinfo->lock);
 399         return ret;
 400 }
 401
 402 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 403                    struct tc_action **a, const struct tc_action_ops *ops,
 404                    int bind, bool cpustats, u32 flags)
 405 {
 406         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 407         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 408         int err = -ENOMEM;
 409
 410         if (unlikely(!p))
 411                 return -ENOMEM;
 412         refcount_set(&p->tcfa_refcnt, 1);
 413         if (bind)
 414                 atomic_set(&p->tcfa_bindcnt, 1);
 415
 416         if (cpustats) {
 417                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 418                 if (!p->cpu_bstats)
 419                         goto err1;
 420                 p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 421                 if (!p->cpu_bstats_hw)
 422                         goto err2;
 423                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 424                 if (!p->cpu_qstats)
 425                         goto err3;
 426         }
 427         spin_lock_init(&p->tcfa_lock);
 428         p->tcfa_index = index;
 429         p->tcfa_tm.install = jiffies;
 430         p->tcfa_tm.lastuse = jiffies;
 431         p->tcfa_tm.firstuse = 0;
 432         p->tcfa_flags = flags;
 433         if (est) {
 434                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 435                                         &p->tcfa_rate_est,
 436                                         &p->tcfa_lock, NULL, est);
 437                 if (err)
 438                         goto err4;
 439         }
 440
 441         p->idrinfo = idrinfo;
 442         p->ops = ops;
 443         *a = p;
 444         return 0;
 445 err4:
 446         free_percpu(p->cpu_qstats);
 447 err3:
 448         free_percpu(p->cpu_bstats_hw);
 449 err2:
 450         free_percpu(p->cpu_bstats);
 451 err1:
 452         kfree(p);
 453         return err;
 454 }
 455 EXPORT_SYMBOL(tcf_idr_create);
 456
 457 int tcf_idr_create_from_flags(struct tc_action_net *tn, u32 index,
 458                               struct nlattr *est, struct tc_action **a,
 459                               const struct tc_action_ops *ops, int bind,
 460                               u32 flags)
 461 {
 462         /* Set cpustats according to actions flags. */
 463         return tcf_idr_create(tn, index, est, a, ops, bind,
 464                               !(flags & TCA_ACT_FLAGS_NO_PERCPU_STATS), flags);
 465 }
 466 EXPORT_SYMBOL(tcf_idr_create_from_flags);
 467
 468 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
 469 {
 470         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 471
 472         mutex_lock(&idrinfo->lock);
 473         /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 474         WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
 475         mutex_unlock(&idrinfo->lock);
 476 }
 477 EXPORT_SYMBOL(tcf_idr_insert);
 478
 479 /* Cleanup idr index that was allocated but not initialized. */
 480
 481 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
 482 {
 483         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 484
 485         mutex_lock(&idrinfo->lock);
 486         /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 487         WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
 488         mutex_unlock(&idrinfo->lock);
 489 }
 490 EXPORT_SYMBOL(tcf_idr_cleanup);
 491
 492 /* Check if action with specified index exists. If actions is found, increments
 493  * its reference and bind counters, and return 1. Otherwise insert temporary
 494  * error pointer (to prevent concurrent users from inserting actions with same
 495  * index) and return 0.
 496  */
 497
 498 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 499                         struct tc_action **a, int bind)
 500 {
 501         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 502         struct tc_action *p;
 503         int ret;
 504
 505 again:
 506         mutex_lock(&idrinfo->lock);
 507         if (*index) {
 508                 p = idr_find(&idrinfo->action_idr, *index);
 509                 if (IS_ERR(p)) {
 510                         /* This means that another process allocated
 511                          * index but did not assign the pointer yet.
 512                          */
 513                         mutex_unlock(&idrinfo->lock);
 514                         goto again;
 515                 }
 516
 517                 if (p) {
 518                         refcount_inc(&p->tcfa_refcnt);
 519                         if (bind)
 520                                 atomic_inc(&p->tcfa_bindcnt);
 521                         *a = p;
 522                         ret = 1;
 523                 } else {
 524                         *a = NULL;
 525                         ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 526                                             *index, GFP_KERNEL);
 527                         if (!ret)
 528                                 idr_replace(&idrinfo->action_idr,
 529                                             ERR_PTR(-EBUSY), *index);
 530                 }
 531         } else {
 532                 *index = 1;
 533                 *a = NULL;
 534                 ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 535                                     UINT_MAX, GFP_KERNEL);
 536                 if (!ret)
 537                         idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
 538                                     *index);
 539         }
 540         mutex_unlock(&idrinfo->lock);
 541         return ret;
 542 }
 543 EXPORT_SYMBOL(tcf_idr_check_alloc);
 544
 545 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 546                          struct tcf_idrinfo *idrinfo)
 547 {
 548         struct idr *idr = &idrinfo->action_idr;
 549         struct tc_action *p;
 550         int ret;
 551         unsigned long id = 1;
 552         unsigned long tmp;
 553
 554         idr_for_each_entry_ul(idr, p, tmp, id) {
 555                 ret = __tcf_idr_release(p, false, true);
 556                 if (ret == ACT_P_DELETED)
 557                         module_put(ops->owner);
 558                 else if (ret < 0)
 559                         return;
 560         }
 561         idr_destroy(&idrinfo->action_idr);
 562 }
 563 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 564
 565 static LIST_HEAD(act_base);
 566 static DEFINE_RWLOCK(act_mod_lock);
 567
 568 int tcf_register_action(struct tc_action_ops *act,
 569                         struct pernet_operations *ops)
 570 {
 571         struct tc_action_ops *a;
 572         int ret;
 573
 574         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 575                 return -EINVAL;
 576
 577         /* We have to register pernet ops before making the action ops visible,
 578          * otherwise tcf_action_init_1() could get a partially initialized
 579          * netns.
 580          */
 581         ret = register_pernet_subsys(ops);
 582         if (ret)
 583                 return ret;
 584
 585         write_lock(&act_mod_lock);
 586         list_for_each_entry(a, &act_base, head) {
 587                 if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
 588                         write_unlock(&act_mod_lock);
 589                         unregister_pernet_subsys(ops);
 590                         return -EEXIST;
 591                 }
 592         }
 593         list_add_tail(&act->head, &act_base);
 594         write_unlock(&act_mod_lock);
 595
 596         return 0;
 597 }
 598 EXPORT_SYMBOL(tcf_register_action);
 599
 600 int tcf_unregister_action(struct tc_action_ops *act,
 601                           struct pernet_operations *ops)
 602 {
 603         struct tc_action_ops *a;
 604         int err = -ENOENT;
 605
 606         write_lock(&act_mod_lock);
 607         list_for_each_entry(a, &act_base, head) {
 608                 if (a == act) {
 609                         list_del(&act->head);
 610                         err = 0;
 611                         break;
 612                 }
 613         }
 614         write_unlock(&act_mod_lock);
 615         if (!err)
 616                 unregister_pernet_subsys(ops);
 617         return err;
 618 }
 619 EXPORT_SYMBOL(tcf_unregister_action);
 620
 621 /* lookup by name */
 622 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 623 {
 624         struct tc_action_ops *a, *res = NULL;
 625
 626         if (kind) {
 627                 read_lock(&act_mod_lock);
 628                 list_for_each_entry(a, &act_base, head) {
 629                         if (strcmp(kind, a->kind) == 0) {
 630                                 if (try_module_get(a->owner))
 631                                         res = a;
 632                                 break;
 633                         }
 634                 }
 635                 read_unlock(&act_mod_lock);
 636         }
 637         return res;
 638 }
 639
 640 /* lookup by nlattr */
 641 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 642 {
 643         struct tc_action_ops *a, *res = NULL;
 644
 645         if (kind) {
 646                 read_lock(&act_mod_lock);
 647                 list_for_each_entry(a, &act_base, head) {
 648                         if (nla_strcmp(kind, a->kind) == 0) {
 649                                 if (try_module_get(a->owner))
 650                                         res = a;
 651                                 break;
 652                         }
 653                 }
 654                 read_unlock(&act_mod_lock);
 655         }
 656         return res;
 657 }
 658
 659 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 660 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 661 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 662                     int nr_actions, struct tcf_result *res)
 663 {
 664         u32 jmp_prgcnt = 0;
 665         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 666         int i;
 667         int ret = TC_ACT_OK;
 668
 669         if (skb_skip_tc_classify(skb))
 670                 return TC_ACT_OK;
 671
 672 restart_act_graph:
 673         for (i = 0; i < nr_actions; i++) {
 674                 const struct tc_action *a = actions[i];
 675
 676                 if (jmp_prgcnt > 0) {
 677                         jmp_prgcnt -= 1;
 678                         continue;
 679                 }
 680 repeat:
 681                 ret = a->ops->act(skb, a, res);
 682                 if (ret == TC_ACT_REPEAT)
 683                         goto repeat;    /* we need a ttl - JHS */
 684
 685                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 686                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 687                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 688                                 /* faulty opcode, stop pipeline */
 689                                 return TC_ACT_OK;
 690                         } else {
 691                                 jmp_ttl -= 1;
 692                                 if (jmp_ttl > 0)
 693                                         goto restart_act_graph;
 694                                 else /* faulty graph, stop pipeline */
 695                                         return TC_ACT_OK;
 696                         }
 697                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 698                         if (unlikely(!rcu_access_pointer(a->goto_chain))) {
 699                                 net_warn_ratelimited("can't go to NULL chain!\n");
 700                                 return TC_ACT_SHOT;
 701                         }
 702                         tcf_action_goto_chain_exec(a, res);
 703                 }
 704
 705                 if (ret != TC_ACT_PIPE)
 706                         break;
 707         }
 708
 709         return ret;
 710 }
 711 EXPORT_SYMBOL(tcf_action_exec);
 712
 713 int tcf_action_destroy(struct tc_action *actions[], int bind)
 714 {
 715         const struct tc_action_ops *ops;
 716         struct tc_action *a;
 717         int ret = 0, i;
 718
 719         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 720                 a = actions[i];
 721                 actions[i] = NULL;
 722                 ops = a->ops;
 723                 ret = __tcf_idr_release(a, bind, true);
 724                 if (ret == ACT_P_DELETED)
 725                         module_put(ops->owner);
 726                 else if (ret < 0)
 727                         return ret;
 728         }
 729         return ret;
 730 }
 731
 732 static int tcf_action_destroy_1(struct tc_action *a, int bind)
 733 {
 734         struct tc_action *actions[] = { a, NULL };
 735
 736         return tcf_action_destroy(actions, bind);
 737 }
 738
 739 static int tcf_action_put(struct tc_action *p)
 740 {
 741         return __tcf_action_put(p, false);
 742 }
 743
 744 /* Put all actions in this array, skip those NULL's. */
 745 static void tcf_action_put_many(struct tc_action *actions[])
 746 {
 747         int i;
 748
 749         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 750                 struct tc_action *a = actions[i];
 751                 const struct tc_action_ops *ops;
 752
 753                 if (!a)
 754                         continue;
 755                 ops = a->ops;
 756                 if (tcf_action_put(a))
 757                         module_put(ops->owner);
 758         }
 759 }
 760
 761 int
 762 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 763 {
 764         return a->ops->dump(skb, a, bind, ref);
 765 }
 766
 767 int
 768 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 769 {
 770         int err = -EINVAL;
 771         unsigned char *b = skb_tail_pointer(skb);
 772         struct nlattr *nest;
 773         struct tc_cookie *cookie;
 774
 775         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 776                 goto nla_put_failure;
 777         if (tcf_action_copy_stats(skb, a, 0))
 778                 goto nla_put_failure;
 779
 780         rcu_read_lock();
 781         cookie = rcu_dereference(a->act_cookie);
 782         if (cookie) {
 783                 if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
 784                         rcu_read_unlock();
 785                         goto nla_put_failure;
 786                 }
 787         }
 788         rcu_read_unlock();
 789
 790         if (a->tcfa_flags) {
 791                 struct nla_bitfield32 flags = { a->tcfa_flags,
 792                                                 a->tcfa_flags, };
 793
 794                 if (nla_put(skb, TCA_ACT_FLAGS, sizeof(flags), &flags))
 795                         goto nla_put_failure;
 796         }
 797
 798         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 799         if (nest == NULL)
 800                 goto nla_put_failure;
 801         err = tcf_action_dump_old(skb, a, bind, ref);
 802         if (err > 0) {
 803                 nla_nest_end(skb, nest);
 804                 return err;
 805         }
 806
 807 nla_put_failure:
 808         nlmsg_trim(skb, b);
 809         return -1;
 810 }
 811 EXPORT_SYMBOL(tcf_action_dump_1);
 812
 813 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 814                     int bind, int ref)
 815 {
 816         struct tc_action *a;
 817         int err = -EINVAL, i;
 818         struct nlattr *nest;
 819
 820         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 821                 a = actions[i];
 822                 nest = nla_nest_start_noflag(skb, i + 1);
 823                 if (nest == NULL)
 824                         goto nla_put_failure;
 825                 err = tcf_action_dump_1(skb, a, bind, ref);
 826                 if (err < 0)
 827                         goto errout;
 828                 nla_nest_end(skb, nest);
 829         }
 830
 831         return 0;
 832
 833 nla_put_failure:
 834         err = -EINVAL;
 835 errout:
 836         nla_nest_cancel(skb, nest);
 837         return err;
 838 }
 839
 840 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 841 {
 842         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 843         if (!c)
 844                 return NULL;
 845
 846         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 847         if (!c->data) {
 848                 kfree(c);
 849                 return NULL;
 850         }
 851         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 852
 853         return c;
 854 }
 855
 856 static const u32 tca_act_flags_allowed = TCA_ACT_FLAGS_NO_PERCPU_STATS;
 857 static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
 858         [TCA_ACT_KIND]          = { .type = NLA_STRING },
 859         [TCA_ACT_INDEX]         = { .type = NLA_U32 },
 860         [TCA_ACT_COOKIE]        = { .type = NLA_BINARY,
 861                                     .len = TC_COOKIE_MAX_SIZE },
 862         [TCA_ACT_OPTIONS]       = { .type = NLA_NESTED },
 863         [TCA_ACT_FLAGS]         = { .type = NLA_BITFIELD32,
 864                                     .validation_data = &tca_act_flags_allowed },
 865 };
 866
 867 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 868                                     struct nlattr *nla, struct nlattr *est,
 869                                     char *name, int ovr, int bind,
 870                                     bool rtnl_held,
 871                                     struct netlink_ext_ack *extack)
 872 {
 873         struct nla_bitfield32 flags = { 0, 0 };
 874         struct tc_action *a;
 875         struct tc_action_ops *a_o;
 876         struct tc_cookie *cookie = NULL;
 877         char act_name[IFNAMSIZ];
 878         struct nlattr *tb[TCA_ACT_MAX + 1];
 879         struct nlattr *kind;
 880         int err;
 881
 882         if (name == NULL) {
 883                 err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
 884                                                   tcf_action_policy, extack);
 885                 if (err < 0)
 886                         goto err_out;
 887                 err = -EINVAL;
 888                 kind = tb[TCA_ACT_KIND];
 889                 if (!kind) {
 890                         NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 891                         goto err_out;
 892                 }
 893                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
 894                         NL_SET_ERR_MSG(extack, "TC action name too long");
 895                         goto err_out;
 896                 }
 897                 if (tb[TCA_ACT_COOKIE]) {
 898                         cookie = nla_memdup_cookie(tb);
 899                         if (!cookie) {
 900                                 NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
 901                                 err = -ENOMEM;
 902                                 goto err_out;
 903                         }
 904                 }
 905                 if (tb[TCA_ACT_FLAGS])
 906                         flags = nla_get_bitfield32(tb[TCA_ACT_FLAGS]);
 907         } else {
 908                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
 909                         NL_SET_ERR_MSG(extack, "TC action name too long");
 910                         err = -EINVAL;
 911                         goto err_out;
 912                 }
 913         }
 914
 915         a_o = tc_lookup_action_n(act_name);
 916         if (a_o == NULL) {
 917 #ifdef CONFIG_MODULES
 918                 if (rtnl_held)
 919                         rtnl_unlock();
 920                 request_module("act_%s", act_name);
 921                 if (rtnl_held)
 922                         rtnl_lock();
 923
 924                 a_o = tc_lookup_action_n(act_name);
 925
 926                 /* We dropped the RTNL semaphore in order to
 927                  * perform the module load.  So, even if we
 928                  * succeeded in loading the module we have to
 929                  * tell the caller to replay the request.  We
 930                  * indicate this using -EAGAIN.
 931                  */
 932                 if (a_o != NULL) {
 933                         err = -EAGAIN;
 934                         goto err_mod;
 935                 }
 936 #endif
 937                 NL_SET_ERR_MSG(extack, "Failed to load TC action module");
 938                 err = -ENOENT;
 939                 goto err_out;
 940         }
 941
 942         /* backward compatibility for policer */
 943         if (name == NULL)
 944                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
 945                                 rtnl_held, tp, flags.value, extack);
 946         else
 947                 err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
 948                                 tp, flags.value, extack);
 949         if (err < 0)
 950                 goto err_mod;
 951
 952         if (!name && tb[TCA_ACT_COOKIE])
 953                 tcf_set_action_cookie(&a->act_cookie, cookie);
 954
 955         /* module count goes up only when brand new policy is created
 956          * if it exists and is only bound to in a_o->init() then
 957          * ACT_P_CREATED is not returned (a zero is).
 958          */
 959         if (err != ACT_P_CREATED)
 960                 module_put(a_o->owner);
 961
 962         if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN) &&
 963             !rcu_access_pointer(a->goto_chain)) {
 964                 tcf_action_destroy_1(a, bind);
 965                 NL_SET_ERR_MSG(extack, "can't use goto chain with NULL chain");
 966                 return ERR_PTR(-EINVAL);
 967         }
 968
 969         return a;
 970
 971 err_mod:
 972         module_put(a_o->owner);
 973 err_out:
 974         if (cookie) {
 975                 kfree(cookie->data);
 976                 kfree(cookie);
 977         }
 978         return ERR_PTR(err);
 979 }
 980
 981 /* Returns numbers of initialized actions or negative error. */
 982
 983 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 984                     struct nlattr *est, char *name, int ovr, int bind,
 985                     struct tc_action *actions[], size_t *attr_size,
 986                     bool rtnl_held, struct netlink_ext_ack *extack)
 987 {
 988         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 989         struct tc_action *act;
 990         size_t sz = 0;
 991         int err;
 992         int i;
 993
 994         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
 995                                           extack);
 996         if (err < 0)
 997                 return err;
 998
 999         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1000                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
1001                                         rtnl_held, extack);
1002                 if (IS_ERR(act)) {
1003                         err = PTR_ERR(act);
1004                         goto err;
1005                 }
1006                 sz += tcf_action_fill_size(act);
1007                 /* Start from index 0 */
1008                 actions[i - 1] = act;
1009         }
1010
1011         *attr_size = tcf_action_full_attrs_size(sz);
1012         return i - 1;
1013
1014 err:
1015         tcf_action_destroy(actions, bind);
1016         return err;
1017 }
1018
1019 void tcf_action_update_stats(struct tc_action *a, u64 bytes, u32 packets,
1020                              bool drop, bool hw)
1021 {
1022         if (a->cpu_bstats) {
1023                 _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
1024
1025                 if (drop)
1026                         this_cpu_ptr(a->cpu_qstats)->drops += packets;
1027
1028                 if (hw)
1029                         _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
1030                                            bytes, packets);
1031                 return;
1032         }
1033
1034         _bstats_update(&a->tcfa_bstats, bytes, packets);
1035         if (drop)
1036                 a->tcfa_qstats.drops += packets;
1037         if (hw)
1038                 _bstats_update(&a->tcfa_bstats_hw, bytes, packets);
1039 }
1040 EXPORT_SYMBOL(tcf_action_update_stats);
1041
1042 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
1043                           int compat_mode)
1044 {
1045         int err = 0;
1046         struct gnet_dump d;
1047
1048         if (p == NULL)
1049                 goto errout;
1050
1051         /* compat_mode being true specifies a call that is supposed
1052          * to add additional backward compatibility statistic TLVs.
1053          */
1054         if (compat_mode) {
1055                 if (p->type == TCA_OLD_COMPAT)
1056                         err = gnet_stats_start_copy_compat(skb, 0,
1057                                                            TCA_STATS,
1058                                                            TCA_XSTATS,
1059                                                            &p->tcfa_lock, &d,
1060                                                            TCA_PAD);
1061                 else
1062                         return 0;
1063         } else
1064                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1065                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
1066
1067         if (err < 0)
1068                 goto errout;
1069
1070         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1071             gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1072                                      &p->tcfa_bstats_hw) < 0 ||
1073             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1074             gnet_stats_copy_queue(&d, p->cpu_qstats,
1075                                   &p->tcfa_qstats,
1076                                   p->tcfa_qstats.qlen) < 0)
1077                 goto errout;
1078
1079         if (gnet_stats_finish_copy(&d) < 0)
1080                 goto errout;
1081
1082         return 0;
1083
1084 errout:
1085         return -1;
1086 }
1087
1088 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1089                         u32 portid, u32 seq, u16 flags, int event, int bind,
1090                         int ref)
1091 {
1092         struct tcamsg *t;
1093         struct nlmsghdr *nlh;
1094         unsigned char *b = skb_tail_pointer(skb);
1095         struct nlattr *nest;
1096
1097         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1098         if (!nlh)
1099                 goto out_nlmsg_trim;
1100         t = nlmsg_data(nlh);
1101         t->tca_family = AF_UNSPEC;
1102         t->tca__pad1 = 0;
1103         t->tca__pad2 = 0;
1104
1105         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1106         if (!nest)
1107                 goto out_nlmsg_trim;
1108
1109         if (tcf_action_dump(skb, actions, bind, ref) < 0)
1110                 goto out_nlmsg_trim;
1111
1112         nla_nest_end(skb, nest);
1113
1114         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1115         return skb->len;
1116
1117 out_nlmsg_trim:
1118         nlmsg_trim(skb, b);
1119         return -1;
1120 }
1121
1122 static int
1123 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1124                struct tc_action *actions[], int event,
1125                struct netlink_ext_ack *extack)
1126 {
1127         struct sk_buff *skb;
1128
1129         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1130         if (!skb)
1131                 return -ENOBUFS;
1132         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1133                          0, 1) <= 0) {
1134                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1135                 kfree_skb(skb);
1136                 return -EINVAL;
1137         }
1138
1139         return rtnl_unicast(skb, net, portid);
1140 }
1141
1142 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1143                                           struct nlmsghdr *n, u32 portid,
1144                                           struct netlink_ext_ack *extack)
1145 {
1146         struct nlattr *tb[TCA_ACT_MAX + 1];
1147         const struct tc_action_ops *ops;
1148         struct tc_action *a;
1149         int index;
1150         int err;
1151
1152         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1153                                           tcf_action_policy, extack);
1154         if (err < 0)
1155                 goto err_out;
1156
1157         err = -EINVAL;
1158         if (tb[TCA_ACT_INDEX] == NULL ||
1159             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1160                 NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1161                 goto err_out;
1162         }
1163         index = nla_get_u32(tb[TCA_ACT_INDEX]);
1164
1165         err = -EINVAL;
1166         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1167         if (!ops) { /* could happen in batch of actions */
1168                 NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1169                 goto err_out;
1170         }
1171         err = -ENOENT;
1172         if (ops->lookup(net, &a, index) == 0) {
1173                 NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1174                 goto err_mod;
1175         }
1176
1177         module_put(ops->owner);
1178         return a;
1179
1180 err_mod:
1181         module_put(ops->owner);
1182 err_out:
1183         return ERR_PTR(err);
1184 }
1185
1186 static int tca_action_flush(struct net *net, struct nlattr *nla,
1187                             struct nlmsghdr *n, u32 portid,
1188                             struct netlink_ext_ack *extack)
1189 {
1190         struct sk_buff *skb;
1191         unsigned char *b;
1192         struct nlmsghdr *nlh;
1193         struct tcamsg *t;
1194         struct netlink_callback dcb;
1195         struct nlattr *nest;
1196         struct nlattr *tb[TCA_ACT_MAX + 1];
1197         const struct tc_action_ops *ops;
1198         struct nlattr *kind;
1199         int err = -ENOMEM;
1200
1201         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1202         if (!skb)
1203                 return err;
1204
1205         b = skb_tail_pointer(skb);
1206
1207         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1208                                           tcf_action_policy, extack);
1209         if (err < 0)
1210                 goto err_out;
1211
1212         err = -EINVAL;
1213         kind = tb[TCA_ACT_KIND];
1214         ops = tc_lookup_action(kind);
1215         if (!ops) { /*some idjot trying to flush unknown action */
1216                 NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1217                 goto err_out;
1218         }
1219
1220         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1221                         sizeof(*t), 0);
1222         if (!nlh) {
1223                 NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1224                 goto out_module_put;
1225         }
1226         t = nlmsg_data(nlh);
1227         t->tca_family = AF_UNSPEC;
1228         t->tca__pad1 = 0;
1229         t->tca__pad2 = 0;
1230
1231         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1232         if (!nest) {
1233                 NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1234                 goto out_module_put;
1235         }
1236
1237         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1238         if (err <= 0) {
1239                 nla_nest_cancel(skb, nest);
1240                 goto out_module_put;
1241         }
1242
1243         nla_nest_end(skb, nest);
1244
1245         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1246         nlh->nlmsg_flags |= NLM_F_ROOT;
1247         module_put(ops->owner);
1248         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1249                              n->nlmsg_flags & NLM_F_ECHO);
1250         if (err > 0)
1251                 return 0;
1252         if (err < 0)
1253                 NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1254
1255         return err;
1256
1257 out_module_put:
1258         module_put(ops->owner);
1259 err_out:
1260         kfree_skb(skb);
1261         return err;
1262 }
1263
1264 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1265 {
1266         int i;
1267
1268         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1269                 struct tc_action *a = actions[i];
1270                 const struct tc_action_ops *ops = a->ops;
1271                 /* Actions can be deleted concurrently so we must save their
1272                  * type and id to search again after reference is released.
1273                  */
1274                 struct tcf_idrinfo *idrinfo = a->idrinfo;
1275                 u32 act_index = a->tcfa_index;
1276
1277                 actions[i] = NULL;
1278                 if (tcf_action_put(a)) {
1279                         /* last reference, action was deleted concurrently */
1280                         module_put(ops->owner);
1281                 } else  {
1282                         int ret;
1283
1284                         /* now do the delete */
1285                         ret = tcf_idr_delete_index(idrinfo, act_index);
1286                         if (ret < 0)
1287                                 return ret;
1288                 }
1289         }
1290         return 0;
1291 }
1292
1293 static int
1294 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1295                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1296 {
1297         int ret;
1298         struct sk_buff *skb;
1299
1300         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1301                         GFP_KERNEL);
1302         if (!skb)
1303                 return -ENOBUFS;
1304
1305         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1306                          0, 2) <= 0) {
1307                 NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1308                 kfree_skb(skb);
1309                 return -EINVAL;
1310         }
1311
1312         /* now do the delete */
1313         ret = tcf_action_delete(net, actions);
1314         if (ret < 0) {
1315                 NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1316                 kfree_skb(skb);
1317                 return ret;
1318         }
1319
1320         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1321                              n->nlmsg_flags & NLM_F_ECHO);
1322         if (ret > 0)
1323                 return 0;
1324         return ret;
1325 }
1326
1327 static int
1328 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1329               u32 portid, int event, struct netlink_ext_ack *extack)
1330 {
1331         int i, ret;
1332         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1333         struct tc_action *act;
1334         size_t attr_size = 0;
1335         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1336
1337         ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1338                                           extack);
1339         if (ret < 0)
1340                 return ret;
1341
1342         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1343                 if (tb[1])
1344                         return tca_action_flush(net, tb[1], n, portid, extack);
1345
1346                 NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1347                 return -EINVAL;
1348         }
1349
1350         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1351                 act = tcf_action_get_1(net, tb[i], n, portid, extack);
1352                 if (IS_ERR(act)) {
1353                         ret = PTR_ERR(act);
1354                         goto err;
1355                 }
1356                 attr_size += tcf_action_fill_size(act);
1357                 actions[i - 1] = act;
1358         }
1359
1360         attr_size = tcf_action_full_attrs_size(attr_size);
1361
1362         if (event == RTM_GETACTION)
1363                 ret = tcf_get_notify(net, portid, n, actions, event, extack);
1364         else { /* delete */
1365                 ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1366                 if (ret)
1367                         goto err;
1368                 return 0;
1369         }
1370 err:
1371         tcf_action_put_many(actions);
1372         return ret;
1373 }
1374
1375 static int
1376 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1377                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1378 {
1379         struct sk_buff *skb;
1380         int err = 0;
1381
1382         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1383                         GFP_KERNEL);
1384         if (!skb)
1385                 return -ENOBUFS;
1386
1387         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1388                          RTM_NEWACTION, 0, 0) <= 0) {
1389                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1390                 kfree_skb(skb);
1391                 return -EINVAL;
1392         }
1393
1394         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1395                              n->nlmsg_flags & NLM_F_ECHO);
1396         if (err > 0)
1397                 err = 0;
1398         return err;
1399 }
1400
1401 static int tcf_action_add(struct net *net, struct nlattr *nla,
1402                           struct nlmsghdr *n, u32 portid, int ovr,
1403                           struct netlink_ext_ack *extack)
1404 {
1405         size_t attr_size = 0;
1406         int loop, ret;
1407         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1408
1409         for (loop = 0; loop < 10; loop++) {
1410                 ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0,
1411                                       actions, &attr_size, true, extack);
1412                 if (ret != -EAGAIN)
1413                         break;
1414         }
1415
1416         if (ret < 0)
1417                 return ret;
1418         ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1419         if (ovr)
1420                 tcf_action_put_many(actions);
1421
1422         return ret;
1423 }
1424
1425 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1426 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1427         [TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1428                              .validation_data = &tcaa_root_flags_allowed },
1429         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1430 };
1431
1432 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1433                          struct netlink_ext_ack *extack)
1434 {
1435         struct net *net = sock_net(skb->sk);
1436         struct nlattr *tca[TCA_ROOT_MAX + 1];
1437         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1438         int ret = 0, ovr = 0;
1439
1440         if ((n->nlmsg_type != RTM_GETACTION) &&
1441             !netlink_capable(skb, CAP_NET_ADMIN))
1442                 return -EPERM;
1443
1444         ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
1445                                      TCA_ROOT_MAX, NULL, extack);
1446         if (ret < 0)
1447                 return ret;
1448
1449         if (tca[TCA_ACT_TAB] == NULL) {
1450                 NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1451                 return -EINVAL;
1452         }
1453
1454         /* n->nlmsg_flags & NLM_F_CREATE */
1455         switch (n->nlmsg_type) {
1456         case RTM_NEWACTION:
1457                 /* we are going to assume all other flags
1458                  * imply create only if it doesn't exist
1459                  * Note that CREATE | EXCL implies that
1460                  * but since we want avoid ambiguity (eg when flags
1461                  * is zero) then just set this
1462                  */
1463                 if (n->nlmsg_flags & NLM_F_REPLACE)
1464                         ovr = 1;
1465                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1466                                      extack);
1467                 break;
1468         case RTM_DELACTION:
1469                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1470                                     portid, RTM_DELACTION, extack);
1471                 break;
1472         case RTM_GETACTION:
1473                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1474                                     portid, RTM_GETACTION, extack);
1475                 break;
1476         default:
1477                 BUG();
1478         }
1479
1480         return ret;
1481 }
1482
1483 static struct nlattr *find_dump_kind(struct nlattr **nla)
1484 {
1485         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1486         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1487         struct nlattr *kind;
1488
1489         tb1 = nla[TCA_ACT_TAB];
1490         if (tb1 == NULL)
1491                 return NULL;
1492
1493         if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1494                 return NULL;
1495
1496         if (tb[1] == NULL)
1497                 return NULL;
1498         if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], tcf_action_policy, NULL) < 0)
1499                 return NULL;
1500         kind = tb2[TCA_ACT_KIND];
1501
1502         return kind;
1503 }
1504
1505 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1506 {
1507         struct net *net = sock_net(skb->sk);
1508         struct nlmsghdr *nlh;
1509         unsigned char *b = skb_tail_pointer(skb);
1510         struct nlattr *nest;
1511         struct tc_action_ops *a_o;
1512         int ret = 0;
1513         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1514         struct nlattr *tb[TCA_ROOT_MAX + 1];
1515         struct nlattr *count_attr = NULL;
1516         unsigned long jiffy_since = 0;
1517         struct nlattr *kind = NULL;
1518         struct nla_bitfield32 bf;
1519         u32 msecs_since = 0;
1520         u32 act_count = 0;
1521
1522         ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
1523                                      TCA_ROOT_MAX, tcaa_policy, cb->extack);
1524         if (ret < 0)
1525                 return ret;
1526
1527         kind = find_dump_kind(tb);
1528         if (kind == NULL) {
1529                 pr_info("tc_dump_action: action bad kind\n");
1530                 return 0;
1531         }
1532
1533         a_o = tc_lookup_action(kind);
1534         if (a_o == NULL)
1535                 return 0;
1536
1537         cb->args[2] = 0;
1538         if (tb[TCA_ROOT_FLAGS]) {
1539                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1540                 cb->args[2] = bf.value;
1541         }
1542
1543         if (tb[TCA_ROOT_TIME_DELTA]) {
1544                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1545         }
1546
1547         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1548                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1549         if (!nlh)
1550                 goto out_module_put;
1551
1552         if (msecs_since)
1553                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1554
1555         t = nlmsg_data(nlh);
1556         t->tca_family = AF_UNSPEC;
1557         t->tca__pad1 = 0;
1558         t->tca__pad2 = 0;
1559         cb->args[3] = jiffy_since;
1560         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1561         if (!count_attr)
1562                 goto out_module_put;
1563
1564         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1565         if (nest == NULL)
1566                 goto out_module_put;
1567
1568         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1569         if (ret < 0)
1570                 goto out_module_put;
1571
1572         if (ret > 0) {
1573                 nla_nest_end(skb, nest);
1574                 ret = skb->len;
1575                 act_count = cb->args[1];
1576                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1577                 cb->args[1] = 0;
1578         } else
1579                 nlmsg_trim(skb, b);
1580
1581         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1582         if (NETLINK_CB(cb->skb).portid && ret)
1583                 nlh->nlmsg_flags |= NLM_F_MULTI;
1584         module_put(a_o->owner);
1585         return skb->len;
1586
1587 out_module_put:
1588         module_put(a_o->owner);
1589         nlmsg_trim(skb, b);
1590         return skb->len;
1591 }
1592
1593 static int __init tc_action_init(void)
1594 {
1595         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1596         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1597         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1598                       0);
1599
1600         return 0;
1601 }
1602
1603 subsys_initcall(tc_action_init);