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(sizeof(struct nla_bitfield32)) /* TCA_ACT_HW_STATS */
 189                 + nla_total_size(0) /* TCA_ACT_STATS nested */
 190                 + nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_FLAGS */
 191                 /* TCA_STATS_BASIC */
 192                 + nla_total_size_64bit(sizeof(struct gnet_stats_basic))
 193                 /* TCA_STATS_PKT64 */
 194                 + nla_total_size_64bit(sizeof(u64))
 195                 /* TCA_STATS_QUEUE */
 196                 + nla_total_size_64bit(sizeof(struct gnet_stats_queue))
 197                 + nla_total_size(0) /* TCA_OPTIONS nested */
 198                 + nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
 199 }
 200
 201 static size_t tcf_action_full_attrs_size(size_t sz)
 202 {
 203         return NLMSG_HDRLEN                     /* struct nlmsghdr */
 204                 + sizeof(struct tcamsg)
 205                 + nla_total_size(0)             /* TCA_ACT_TAB nested */
 206                 + sz;
 207 }
 208
 209 static size_t tcf_action_fill_size(const struct tc_action *act)
 210 {
 211         size_t sz = tcf_action_shared_attrs_size(act);
 212
 213         if (act->ops->get_fill_size)
 214                 return act->ops->get_fill_size(act) + sz;
 215         return sz;
 216 }
 217
 218 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 219                            struct netlink_callback *cb)
 220 {
 221         int err = 0, index = -1, s_i = 0, n_i = 0;
 222         u32 act_flags = cb->args[2];
 223         unsigned long jiffy_since = cb->args[3];
 224         struct nlattr *nest;
 225         struct idr *idr = &idrinfo->action_idr;
 226         struct tc_action *p;
 227         unsigned long id = 1;
 228         unsigned long tmp;
 229
 230         mutex_lock(&idrinfo->lock);
 231
 232         s_i = cb->args[0];
 233
 234         idr_for_each_entry_ul(idr, p, tmp, id) {
 235                 index++;
 236                 if (index < s_i)
 237                         continue;
 238
 239                 if (jiffy_since &&
 240                     time_after(jiffy_since,
 241                                (unsigned long)p->tcfa_tm.lastuse))
 242                         continue;
 243
 244                 nest = nla_nest_start_noflag(skb, n_i);
 245                 if (!nest) {
 246                         index--;
 247                         goto nla_put_failure;
 248                 }
 249                 err = tcf_action_dump_1(skb, p, 0, 0);
 250                 if (err < 0) {
 251                         index--;
 252                         nlmsg_trim(skb, nest);
 253                         goto done;
 254                 }
 255                 nla_nest_end(skb, nest);
 256                 n_i++;
 257                 if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
 258                     n_i >= TCA_ACT_MAX_PRIO)
 259                         goto done;
 260         }
 261 done:
 262         if (index >= 0)
 263                 cb->args[0] = index + 1;
 264
 265         mutex_unlock(&idrinfo->lock);
 266         if (n_i) {
 267                 if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
 268                         cb->args[1] = n_i;
 269         }
 270         return n_i;
 271
 272 nla_put_failure:
 273         nla_nest_cancel(skb, nest);
 274         goto done;
 275 }
 276
 277 static int tcf_idr_release_unsafe(struct tc_action *p)
 278 {
 279         if (atomic_read(&p->tcfa_bindcnt) > 0)
 280                 return -EPERM;
 281
 282         if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 283                 idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
 284                 tcf_action_cleanup(p);
 285                 return ACT_P_DELETED;
 286         }
 287
 288         return 0;
 289 }
 290
 291 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 292                           const struct tc_action_ops *ops)
 293 {
 294         struct nlattr *nest;
 295         int n_i = 0;
 296         int ret = -EINVAL;
 297         struct idr *idr = &idrinfo->action_idr;
 298         struct tc_action *p;
 299         unsigned long id = 1;
 300         unsigned long tmp;
 301
 302         nest = nla_nest_start_noflag(skb, 0);
 303         if (nest == NULL)
 304                 goto nla_put_failure;
 305         if (nla_put_string(skb, TCA_KIND, ops->kind))
 306                 goto nla_put_failure;
 307
 308         mutex_lock(&idrinfo->lock);
 309         idr_for_each_entry_ul(idr, p, tmp, id) {
 310                 ret = tcf_idr_release_unsafe(p);
 311                 if (ret == ACT_P_DELETED) {
 312                         module_put(ops->owner);
 313                         n_i++;
 314                 } else if (ret < 0) {
 315                         mutex_unlock(&idrinfo->lock);
 316                         goto nla_put_failure;
 317                 }
 318         }
 319         mutex_unlock(&idrinfo->lock);
 320
 321         if (nla_put_u32(skb, TCA_FCNT, n_i))
 322                 goto nla_put_failure;
 323         nla_nest_end(skb, nest);
 324
 325         return n_i;
 326 nla_put_failure:
 327         nla_nest_cancel(skb, nest);
 328         return ret;
 329 }
 330
 331 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 332                        struct netlink_callback *cb, int type,
 333                        const struct tc_action_ops *ops,
 334                        struct netlink_ext_ack *extack)
 335 {
 336         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 337
 338         if (type == RTM_DELACTION) {
 339                 return tcf_del_walker(idrinfo, skb, ops);
 340         } else if (type == RTM_GETACTION) {
 341                 return tcf_dump_walker(idrinfo, skb, cb);
 342         } else {
 343                 WARN(1, "tcf_generic_walker: unknown command %d\n", type);
 344                 NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
 345                 return -EINVAL;
 346         }
 347 }
 348 EXPORT_SYMBOL(tcf_generic_walker);
 349
 350 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 351 {
 352         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 353         struct tc_action *p;
 354
 355         mutex_lock(&idrinfo->lock);
 356         p = idr_find(&idrinfo->action_idr, index);
 357         if (IS_ERR(p))
 358                 p = NULL;
 359         else if (p)
 360                 refcount_inc(&p->tcfa_refcnt);
 361         mutex_unlock(&idrinfo->lock);
 362
 363         if (p) {
 364                 *a = p;
 365                 return true;
 366         }
 367         return false;
 368 }
 369 EXPORT_SYMBOL(tcf_idr_search);
 370
 371 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
 372 {
 373         struct tc_action *p;
 374         int ret = 0;
 375
 376         mutex_lock(&idrinfo->lock);
 377         p = idr_find(&idrinfo->action_idr, index);
 378         if (!p) {
 379                 mutex_unlock(&idrinfo->lock);
 380                 return -ENOENT;
 381         }
 382
 383         if (!atomic_read(&p->tcfa_bindcnt)) {
 384                 if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 385                         struct module *owner = p->ops->owner;
 386
 387                         WARN_ON(p != idr_remove(&idrinfo->action_idr,
 388                                                 p->tcfa_index));
 389                         mutex_unlock(&idrinfo->lock);
 390
 391                         tcf_action_cleanup(p);
 392                         module_put(owner);
 393                         return 0;
 394                 }
 395                 ret = 0;
 396         } else {
 397                 ret = -EPERM;
 398         }
 399
 400         mutex_unlock(&idrinfo->lock);
 401         return ret;
 402 }
 403
 404 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 405                    struct tc_action **a, const struct tc_action_ops *ops,
 406                    int bind, bool cpustats, u32 flags)
 407 {
 408         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 409         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 410         int err = -ENOMEM;
 411
 412         if (unlikely(!p))
 413                 return -ENOMEM;
 414         refcount_set(&p->tcfa_refcnt, 1);
 415         if (bind)
 416                 atomic_set(&p->tcfa_bindcnt, 1);
 417
 418         if (cpustats) {
 419                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 420                 if (!p->cpu_bstats)
 421                         goto err1;
 422                 p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 423                 if (!p->cpu_bstats_hw)
 424                         goto err2;
 425                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 426                 if (!p->cpu_qstats)
 427                         goto err3;
 428         }
 429         spin_lock_init(&p->tcfa_lock);
 430         p->tcfa_index = index;
 431         p->tcfa_tm.install = jiffies;
 432         p->tcfa_tm.lastuse = jiffies;
 433         p->tcfa_tm.firstuse = 0;
 434         p->tcfa_flags = flags;
 435         if (est) {
 436                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 437                                         &p->tcfa_rate_est,
 438                                         &p->tcfa_lock, NULL, est);
 439                 if (err)
 440                         goto err4;
 441         }
 442
 443         p->idrinfo = idrinfo;
 444         p->ops = ops;
 445         *a = p;
 446         return 0;
 447 err4:
 448         free_percpu(p->cpu_qstats);
 449 err3:
 450         free_percpu(p->cpu_bstats_hw);
 451 err2:
 452         free_percpu(p->cpu_bstats);
 453 err1:
 454         kfree(p);
 455         return err;
 456 }
 457 EXPORT_SYMBOL(tcf_idr_create);
 458
 459 int tcf_idr_create_from_flags(struct tc_action_net *tn, u32 index,
 460                               struct nlattr *est, struct tc_action **a,
 461                               const struct tc_action_ops *ops, int bind,
 462                               u32 flags)
 463 {
 464         /* Set cpustats according to actions flags. */
 465         return tcf_idr_create(tn, index, est, a, ops, bind,
 466                               !(flags & TCA_ACT_FLAGS_NO_PERCPU_STATS), flags);
 467 }
 468 EXPORT_SYMBOL(tcf_idr_create_from_flags);
 469
 470 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
 471 {
 472         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 473
 474         mutex_lock(&idrinfo->lock);
 475         /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 476         WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
 477         mutex_unlock(&idrinfo->lock);
 478 }
 479 EXPORT_SYMBOL(tcf_idr_insert);
 480
 481 /* Cleanup idr index that was allocated but not initialized. */
 482
 483 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
 484 {
 485         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 486
 487         mutex_lock(&idrinfo->lock);
 488         /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 489         WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
 490         mutex_unlock(&idrinfo->lock);
 491 }
 492 EXPORT_SYMBOL(tcf_idr_cleanup);
 493
 494 /* Check if action with specified index exists. If actions is found, increments
 495  * its reference and bind counters, and return 1. Otherwise insert temporary
 496  * error pointer (to prevent concurrent users from inserting actions with same
 497  * index) and return 0.
 498  */
 499
 500 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 501                         struct tc_action **a, int bind)
 502 {
 503         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 504         struct tc_action *p;
 505         int ret;
 506
 507 again:
 508         mutex_lock(&idrinfo->lock);
 509         if (*index) {
 510                 p = idr_find(&idrinfo->action_idr, *index);
 511                 if (IS_ERR(p)) {
 512                         /* This means that another process allocated
 513                          * index but did not assign the pointer yet.
 514                          */
 515                         mutex_unlock(&idrinfo->lock);
 516                         goto again;
 517                 }
 518
 519                 if (p) {
 520                         refcount_inc(&p->tcfa_refcnt);
 521                         if (bind)
 522                                 atomic_inc(&p->tcfa_bindcnt);
 523                         *a = p;
 524                         ret = 1;
 525                 } else {
 526                         *a = NULL;
 527                         ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 528                                             *index, GFP_KERNEL);
 529                         if (!ret)
 530                                 idr_replace(&idrinfo->action_idr,
 531                                             ERR_PTR(-EBUSY), *index);
 532                 }
 533         } else {
 534                 *index = 1;
 535                 *a = NULL;
 536                 ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 537                                     UINT_MAX, GFP_KERNEL);
 538                 if (!ret)
 539                         idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
 540                                     *index);
 541         }
 542         mutex_unlock(&idrinfo->lock);
 543         return ret;
 544 }
 545 EXPORT_SYMBOL(tcf_idr_check_alloc);
 546
 547 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 548                          struct tcf_idrinfo *idrinfo)
 549 {
 550         struct idr *idr = &idrinfo->action_idr;
 551         struct tc_action *p;
 552         int ret;
 553         unsigned long id = 1;
 554         unsigned long tmp;
 555
 556         idr_for_each_entry_ul(idr, p, tmp, id) {
 557                 ret = __tcf_idr_release(p, false, true);
 558                 if (ret == ACT_P_DELETED)
 559                         module_put(ops->owner);
 560                 else if (ret < 0)
 561                         return;
 562         }
 563         idr_destroy(&idrinfo->action_idr);
 564 }
 565 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 566
 567 static LIST_HEAD(act_base);
 568 static DEFINE_RWLOCK(act_mod_lock);
 569
 570 int tcf_register_action(struct tc_action_ops *act,
 571                         struct pernet_operations *ops)
 572 {
 573         struct tc_action_ops *a;
 574         int ret;
 575
 576         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 577                 return -EINVAL;
 578
 579         /* We have to register pernet ops before making the action ops visible,
 580          * otherwise tcf_action_init_1() could get a partially initialized
 581          * netns.
 582          */
 583         ret = register_pernet_subsys(ops);
 584         if (ret)
 585                 return ret;
 586
 587         write_lock(&act_mod_lock);
 588         list_for_each_entry(a, &act_base, head) {
 589                 if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
 590                         write_unlock(&act_mod_lock);
 591                         unregister_pernet_subsys(ops);
 592                         return -EEXIST;
 593                 }
 594         }
 595         list_add_tail(&act->head, &act_base);
 596         write_unlock(&act_mod_lock);
 597
 598         return 0;
 599 }
 600 EXPORT_SYMBOL(tcf_register_action);
 601
 602 int tcf_unregister_action(struct tc_action_ops *act,
 603                           struct pernet_operations *ops)
 604 {
 605         struct tc_action_ops *a;
 606         int err = -ENOENT;
 607
 608         write_lock(&act_mod_lock);
 609         list_for_each_entry(a, &act_base, head) {
 610                 if (a == act) {
 611                         list_del(&act->head);
 612                         err = 0;
 613                         break;
 614                 }
 615         }
 616         write_unlock(&act_mod_lock);
 617         if (!err)
 618                 unregister_pernet_subsys(ops);
 619         return err;
 620 }
 621 EXPORT_SYMBOL(tcf_unregister_action);
 622
 623 /* lookup by name */
 624 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 625 {
 626         struct tc_action_ops *a, *res = NULL;
 627
 628         if (kind) {
 629                 read_lock(&act_mod_lock);
 630                 list_for_each_entry(a, &act_base, head) {
 631                         if (strcmp(kind, a->kind) == 0) {
 632                                 if (try_module_get(a->owner))
 633                                         res = a;
 634                                 break;
 635                         }
 636                 }
 637                 read_unlock(&act_mod_lock);
 638         }
 639         return res;
 640 }
 641
 642 /* lookup by nlattr */
 643 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 644 {
 645         struct tc_action_ops *a, *res = NULL;
 646
 647         if (kind) {
 648                 read_lock(&act_mod_lock);
 649                 list_for_each_entry(a, &act_base, head) {
 650                         if (nla_strcmp(kind, a->kind) == 0) {
 651                                 if (try_module_get(a->owner))
 652                                         res = a;
 653                                 break;
 654                         }
 655                 }
 656                 read_unlock(&act_mod_lock);
 657         }
 658         return res;
 659 }
 660
 661 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 662 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 663 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 664                     int nr_actions, struct tcf_result *res)
 665 {
 666         u32 jmp_prgcnt = 0;
 667         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 668         int i;
 669         int ret = TC_ACT_OK;
 670
 671         if (skb_skip_tc_classify(skb))
 672                 return TC_ACT_OK;
 673
 674 restart_act_graph:
 675         for (i = 0; i < nr_actions; i++) {
 676                 const struct tc_action *a = actions[i];
 677
 678                 if (jmp_prgcnt > 0) {
 679                         jmp_prgcnt -= 1;
 680                         continue;
 681                 }
 682 repeat:
 683                 ret = a->ops->act(skb, a, res);
 684                 if (ret == TC_ACT_REPEAT)
 685                         goto repeat;    /* we need a ttl - JHS */
 686
 687                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 688                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 689                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 690                                 /* faulty opcode, stop pipeline */
 691                                 return TC_ACT_OK;
 692                         } else {
 693                                 jmp_ttl -= 1;
 694                                 if (jmp_ttl > 0)
 695                                         goto restart_act_graph;
 696                                 else /* faulty graph, stop pipeline */
 697                                         return TC_ACT_OK;
 698                         }
 699                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 700                         if (unlikely(!rcu_access_pointer(a->goto_chain))) {
 701                                 net_warn_ratelimited("can't go to NULL chain!\n");
 702                                 return TC_ACT_SHOT;
 703                         }
 704                         tcf_action_goto_chain_exec(a, res);
 705                 }
 706
 707                 if (ret != TC_ACT_PIPE)
 708                         break;
 709         }
 710
 711         return ret;
 712 }
 713 EXPORT_SYMBOL(tcf_action_exec);
 714
 715 int tcf_action_destroy(struct tc_action *actions[], int bind)
 716 {
 717         const struct tc_action_ops *ops;
 718         struct tc_action *a;
 719         int ret = 0, i;
 720
 721         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 722                 a = actions[i];
 723                 actions[i] = NULL;
 724                 ops = a->ops;
 725                 ret = __tcf_idr_release(a, bind, true);
 726                 if (ret == ACT_P_DELETED)
 727                         module_put(ops->owner);
 728                 else if (ret < 0)
 729                         return ret;
 730         }
 731         return ret;
 732 }
 733
 734 static int tcf_action_destroy_1(struct tc_action *a, int bind)
 735 {
 736         struct tc_action *actions[] = { a, NULL };
 737
 738         return tcf_action_destroy(actions, bind);
 739 }
 740
 741 static int tcf_action_put(struct tc_action *p)
 742 {
 743         return __tcf_action_put(p, false);
 744 }
 745
 746 /* Put all actions in this array, skip those NULL's. */
 747 static void tcf_action_put_many(struct tc_action *actions[])
 748 {
 749         int i;
 750
 751         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 752                 struct tc_action *a = actions[i];
 753                 const struct tc_action_ops *ops;
 754
 755                 if (!a)
 756                         continue;
 757                 ops = a->ops;
 758                 if (tcf_action_put(a))
 759                         module_put(ops->owner);
 760         }
 761 }
 762
 763 int
 764 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 765 {
 766         return a->ops->dump(skb, a, bind, ref);
 767 }
 768
 769 static int
 770 tcf_action_dump_terse(struct sk_buff *skb, struct tc_action *a)
 771 {
 772         unsigned char *b = skb_tail_pointer(skb);
 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         return 0;
 791
 792 nla_put_failure:
 793         nlmsg_trim(skb, b);
 794         return -1;
 795 }
 796
 797 int
 798 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 799 {
 800         int err = -EINVAL;
 801         unsigned char *b = skb_tail_pointer(skb);
 802         struct nlattr *nest;
 803
 804         if (tcf_action_dump_terse(skb, a))
 805                 goto nla_put_failure;
 806
 807         if (a->hw_stats != TCA_ACT_HW_STATS_ANY &&
 808             nla_put_bitfield32(skb, TCA_ACT_HW_STATS,
 809                                a->hw_stats, TCA_ACT_HW_STATS_ANY))
 810                 goto nla_put_failure;
 811
 812         if (a->used_hw_stats_valid &&
 813             nla_put_bitfield32(skb, TCA_ACT_USED_HW_STATS,
 814                                a->used_hw_stats, TCA_ACT_HW_STATS_ANY))
 815                 goto nla_put_failure;
 816
 817         if (a->tcfa_flags &&
 818             nla_put_bitfield32(skb, TCA_ACT_FLAGS,
 819                                a->tcfa_flags, a->tcfa_flags))
 820                 goto nla_put_failure;
 821
 822         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 823         if (nest == NULL)
 824                 goto nla_put_failure;
 825         err = tcf_action_dump_old(skb, a, bind, ref);
 826         if (err > 0) {
 827                 nla_nest_end(skb, nest);
 828                 return err;
 829         }
 830
 831 nla_put_failure:
 832         nlmsg_trim(skb, b);
 833         return -1;
 834 }
 835 EXPORT_SYMBOL(tcf_action_dump_1);
 836
 837 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 838                     int bind, int ref, bool terse)
 839 {
 840         struct tc_action *a;
 841         int err = -EINVAL, i;
 842         struct nlattr *nest;
 843
 844         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 845                 a = actions[i];
 846                 nest = nla_nest_start_noflag(skb, i + 1);
 847                 if (nest == NULL)
 848                         goto nla_put_failure;
 849                 err = terse ? tcf_action_dump_terse(skb, a) :
 850                         tcf_action_dump_1(skb, a, bind, ref);
 851                 if (err < 0)
 852                         goto errout;
 853                 nla_nest_end(skb, nest);
 854         }
 855
 856         return 0;
 857
 858 nla_put_failure:
 859         err = -EINVAL;
 860 errout:
 861         nla_nest_cancel(skb, nest);
 862         return err;
 863 }
 864
 865 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 866 {
 867         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 868         if (!c)
 869                 return NULL;
 870
 871         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 872         if (!c->data) {
 873                 kfree(c);
 874                 return NULL;
 875         }
 876         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 877
 878         return c;
 879 }
 880
 881 static u8 tcf_action_hw_stats_get(struct nlattr *hw_stats_attr)
 882 {
 883         struct nla_bitfield32 hw_stats_bf;
 884
 885         /* If the user did not pass the attr, that means he does
 886          * not care about the type. Return "any" in that case
 887          * which is setting on all supported types.
 888          */
 889         if (!hw_stats_attr)
 890                 return TCA_ACT_HW_STATS_ANY;
 891         hw_stats_bf = nla_get_bitfield32(hw_stats_attr);
 892         return hw_stats_bf.value;
 893 }
 894
 895 static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
 896         [TCA_ACT_KIND]          = { .type = NLA_STRING },
 897         [TCA_ACT_INDEX]         = { .type = NLA_U32 },
 898         [TCA_ACT_COOKIE]        = { .type = NLA_BINARY,
 899                                     .len = TC_COOKIE_MAX_SIZE },
 900         [TCA_ACT_OPTIONS]       = { .type = NLA_NESTED },
 901         [TCA_ACT_FLAGS]         = NLA_POLICY_BITFIELD32(TCA_ACT_FLAGS_NO_PERCPU_STATS),
 902         [TCA_ACT_HW_STATS]      = NLA_POLICY_BITFIELD32(TCA_ACT_HW_STATS_ANY),
 903 };
 904
 905 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 906                                     struct nlattr *nla, struct nlattr *est,
 907                                     char *name, int ovr, int bind,
 908                                     bool rtnl_held,
 909                                     struct netlink_ext_ack *extack)
 910 {
 911         struct nla_bitfield32 flags = { 0, 0 };
 912         u8 hw_stats = TCA_ACT_HW_STATS_ANY;
 913         struct tc_action *a;
 914         struct tc_action_ops *a_o;
 915         struct tc_cookie *cookie = NULL;
 916         char act_name[IFNAMSIZ];
 917         struct nlattr *tb[TCA_ACT_MAX + 1];
 918         struct nlattr *kind;
 919         int err;
 920
 921         if (name == NULL) {
 922                 err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
 923                                                   tcf_action_policy, extack);
 924                 if (err < 0)
 925                         goto err_out;
 926                 err = -EINVAL;
 927                 kind = tb[TCA_ACT_KIND];
 928                 if (!kind) {
 929                         NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 930                         goto err_out;
 931                 }
 932                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
 933                         NL_SET_ERR_MSG(extack, "TC action name too long");
 934                         goto err_out;
 935                 }
 936                 if (tb[TCA_ACT_COOKIE]) {
 937                         cookie = nla_memdup_cookie(tb);
 938                         if (!cookie) {
 939                                 NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
 940                                 err = -ENOMEM;
 941                                 goto err_out;
 942                         }
 943                 }
 944                 hw_stats = tcf_action_hw_stats_get(tb[TCA_ACT_HW_STATS]);
 945                 if (tb[TCA_ACT_FLAGS])
 946                         flags = nla_get_bitfield32(tb[TCA_ACT_FLAGS]);
 947         } else {
 948                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
 949                         NL_SET_ERR_MSG(extack, "TC action name too long");
 950                         err = -EINVAL;
 951                         goto err_out;
 952                 }
 953         }
 954
 955         a_o = tc_lookup_action_n(act_name);
 956         if (a_o == NULL) {
 957 #ifdef CONFIG_MODULES
 958                 if (rtnl_held)
 959                         rtnl_unlock();
 960                 request_module("act_%s", act_name);
 961                 if (rtnl_held)
 962                         rtnl_lock();
 963
 964                 a_o = tc_lookup_action_n(act_name);
 965
 966                 /* We dropped the RTNL semaphore in order to
 967                  * perform the module load.  So, even if we
 968                  * succeeded in loading the module we have to
 969                  * tell the caller to replay the request.  We
 970                  * indicate this using -EAGAIN.
 971                  */
 972                 if (a_o != NULL) {
 973                         err = -EAGAIN;
 974                         goto err_mod;
 975                 }
 976 #endif
 977                 NL_SET_ERR_MSG(extack, "Failed to load TC action module");
 978                 err = -ENOENT;
 979                 goto err_out;
 980         }
 981
 982         /* backward compatibility for policer */
 983         if (name == NULL)
 984                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
 985                                 rtnl_held, tp, flags.value, extack);
 986         else
 987                 err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
 988                                 tp, flags.value, extack);
 989         if (err < 0)
 990                 goto err_mod;
 991
 992         if (!name && tb[TCA_ACT_COOKIE])
 993                 tcf_set_action_cookie(&a->act_cookie, cookie);
 994
 995         if (!name)
 996                 a->hw_stats = hw_stats;
 997
 998         /* module count goes up only when brand new policy is created
 999          * if it exists and is only bound to in a_o->init() then
1000          * ACT_P_CREATED is not returned (a zero is).
1001          */
1002         if (err != ACT_P_CREATED)
1003                 module_put(a_o->owner);
1004
1005         if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN) &&
1006             !rcu_access_pointer(a->goto_chain)) {
1007                 tcf_action_destroy_1(a, bind);
1008                 NL_SET_ERR_MSG(extack, "can't use goto chain with NULL chain");
1009                 return ERR_PTR(-EINVAL);
1010         }
1011
1012         return a;
1013
1014 err_mod:
1015         module_put(a_o->owner);
1016 err_out:
1017         if (cookie) {
1018                 kfree(cookie->data);
1019                 kfree(cookie);
1020         }
1021         return ERR_PTR(err);
1022 }
1023
1024 /* Returns numbers of initialized actions or negative error. */
1025
1026 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
1027                     struct nlattr *est, char *name, int ovr, int bind,
1028                     struct tc_action *actions[], size_t *attr_size,
1029                     bool rtnl_held, struct netlink_ext_ack *extack)
1030 {
1031         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1032         struct tc_action *act;
1033         size_t sz = 0;
1034         int err;
1035         int i;
1036
1037         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1038                                           extack);
1039         if (err < 0)
1040                 return err;
1041
1042         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1043                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
1044                                         rtnl_held, extack);
1045                 if (IS_ERR(act)) {
1046                         err = PTR_ERR(act);
1047                         goto err;
1048                 }
1049                 sz += tcf_action_fill_size(act);
1050                 /* Start from index 0 */
1051                 actions[i - 1] = act;
1052         }
1053
1054         *attr_size = tcf_action_full_attrs_size(sz);
1055         return i - 1;
1056
1057 err:
1058         tcf_action_destroy(actions, bind);
1059         return err;
1060 }
1061
1062 void tcf_action_update_stats(struct tc_action *a, u64 bytes, u32 packets,
1063                              bool drop, bool hw)
1064 {
1065         if (a->cpu_bstats) {
1066                 _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
1067
1068                 if (drop)
1069                         this_cpu_ptr(a->cpu_qstats)->drops += packets;
1070
1071                 if (hw)
1072                         _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
1073                                            bytes, packets);
1074                 return;
1075         }
1076
1077         _bstats_update(&a->tcfa_bstats, bytes, packets);
1078         if (drop)
1079                 a->tcfa_qstats.drops += packets;
1080         if (hw)
1081                 _bstats_update(&a->tcfa_bstats_hw, bytes, packets);
1082 }
1083 EXPORT_SYMBOL(tcf_action_update_stats);
1084
1085 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
1086                           int compat_mode)
1087 {
1088         int err = 0;
1089         struct gnet_dump d;
1090
1091         if (p == NULL)
1092                 goto errout;
1093
1094         /* compat_mode being true specifies a call that is supposed
1095          * to add additional backward compatibility statistic TLVs.
1096          */
1097         if (compat_mode) {
1098                 if (p->type == TCA_OLD_COMPAT)
1099                         err = gnet_stats_start_copy_compat(skb, 0,
1100                                                            TCA_STATS,
1101                                                            TCA_XSTATS,
1102                                                            &p->tcfa_lock, &d,
1103                                                            TCA_PAD);
1104                 else
1105                         return 0;
1106         } else
1107                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1108                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
1109
1110         if (err < 0)
1111                 goto errout;
1112
1113         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1114             gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1115                                      &p->tcfa_bstats_hw) < 0 ||
1116             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1117             gnet_stats_copy_queue(&d, p->cpu_qstats,
1118                                   &p->tcfa_qstats,
1119                                   p->tcfa_qstats.qlen) < 0)
1120                 goto errout;
1121
1122         if (gnet_stats_finish_copy(&d) < 0)
1123                 goto errout;
1124
1125         return 0;
1126
1127 errout:
1128         return -1;
1129 }
1130
1131 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1132                         u32 portid, u32 seq, u16 flags, int event, int bind,
1133                         int ref)
1134 {
1135         struct tcamsg *t;
1136         struct nlmsghdr *nlh;
1137         unsigned char *b = skb_tail_pointer(skb);
1138         struct nlattr *nest;
1139
1140         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1141         if (!nlh)
1142                 goto out_nlmsg_trim;
1143         t = nlmsg_data(nlh);
1144         t->tca_family = AF_UNSPEC;
1145         t->tca__pad1 = 0;
1146         t->tca__pad2 = 0;
1147
1148         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1149         if (!nest)
1150                 goto out_nlmsg_trim;
1151
1152         if (tcf_action_dump(skb, actions, bind, ref, false) < 0)
1153                 goto out_nlmsg_trim;
1154
1155         nla_nest_end(skb, nest);
1156
1157         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1158         return skb->len;
1159
1160 out_nlmsg_trim:
1161         nlmsg_trim(skb, b);
1162         return -1;
1163 }
1164
1165 static int
1166 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1167                struct tc_action *actions[], int event,
1168                struct netlink_ext_ack *extack)
1169 {
1170         struct sk_buff *skb;
1171
1172         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1173         if (!skb)
1174                 return -ENOBUFS;
1175         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1176                          0, 1) <= 0) {
1177                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1178                 kfree_skb(skb);
1179                 return -EINVAL;
1180         }
1181
1182         return rtnl_unicast(skb, net, portid);
1183 }
1184
1185 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1186                                           struct nlmsghdr *n, u32 portid,
1187                                           struct netlink_ext_ack *extack)
1188 {
1189         struct nlattr *tb[TCA_ACT_MAX + 1];
1190         const struct tc_action_ops *ops;
1191         struct tc_action *a;
1192         int index;
1193         int err;
1194
1195         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1196                                           tcf_action_policy, extack);
1197         if (err < 0)
1198                 goto err_out;
1199
1200         err = -EINVAL;
1201         if (tb[TCA_ACT_INDEX] == NULL ||
1202             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1203                 NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1204                 goto err_out;
1205         }
1206         index = nla_get_u32(tb[TCA_ACT_INDEX]);
1207
1208         err = -EINVAL;
1209         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1210         if (!ops) { /* could happen in batch of actions */
1211                 NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1212                 goto err_out;
1213         }
1214         err = -ENOENT;
1215         if (ops->lookup(net, &a, index) == 0) {
1216                 NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1217                 goto err_mod;
1218         }
1219
1220         module_put(ops->owner);
1221         return a;
1222
1223 err_mod:
1224         module_put(ops->owner);
1225 err_out:
1226         return ERR_PTR(err);
1227 }
1228
1229 static int tca_action_flush(struct net *net, struct nlattr *nla,
1230                             struct nlmsghdr *n, u32 portid,
1231                             struct netlink_ext_ack *extack)
1232 {
1233         struct sk_buff *skb;
1234         unsigned char *b;
1235         struct nlmsghdr *nlh;
1236         struct tcamsg *t;
1237         struct netlink_callback dcb;
1238         struct nlattr *nest;
1239         struct nlattr *tb[TCA_ACT_MAX + 1];
1240         const struct tc_action_ops *ops;
1241         struct nlattr *kind;
1242         int err = -ENOMEM;
1243
1244         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1245         if (!skb)
1246                 return err;
1247
1248         b = skb_tail_pointer(skb);
1249
1250         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1251                                           tcf_action_policy, extack);
1252         if (err < 0)
1253                 goto err_out;
1254
1255         err = -EINVAL;
1256         kind = tb[TCA_ACT_KIND];
1257         ops = tc_lookup_action(kind);
1258         if (!ops) { /*some idjot trying to flush unknown action */
1259                 NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1260                 goto err_out;
1261         }
1262
1263         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1264                         sizeof(*t), 0);
1265         if (!nlh) {
1266                 NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1267                 goto out_module_put;
1268         }
1269         t = nlmsg_data(nlh);
1270         t->tca_family = AF_UNSPEC;
1271         t->tca__pad1 = 0;
1272         t->tca__pad2 = 0;
1273
1274         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1275         if (!nest) {
1276                 NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1277                 goto out_module_put;
1278         }
1279
1280         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1281         if (err <= 0) {
1282                 nla_nest_cancel(skb, nest);
1283                 goto out_module_put;
1284         }
1285
1286         nla_nest_end(skb, nest);
1287
1288         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1289         nlh->nlmsg_flags |= NLM_F_ROOT;
1290         module_put(ops->owner);
1291         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1292                              n->nlmsg_flags & NLM_F_ECHO);
1293         if (err > 0)
1294                 return 0;
1295         if (err < 0)
1296                 NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1297
1298         return err;
1299
1300 out_module_put:
1301         module_put(ops->owner);
1302 err_out:
1303         kfree_skb(skb);
1304         return err;
1305 }
1306
1307 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1308 {
1309         int i;
1310
1311         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1312                 struct tc_action *a = actions[i];
1313                 const struct tc_action_ops *ops = a->ops;
1314                 /* Actions can be deleted concurrently so we must save their
1315                  * type and id to search again after reference is released.
1316                  */
1317                 struct tcf_idrinfo *idrinfo = a->idrinfo;
1318                 u32 act_index = a->tcfa_index;
1319
1320                 actions[i] = NULL;
1321                 if (tcf_action_put(a)) {
1322                         /* last reference, action was deleted concurrently */
1323                         module_put(ops->owner);
1324                 } else  {
1325                         int ret;
1326
1327                         /* now do the delete */
1328                         ret = tcf_idr_delete_index(idrinfo, act_index);
1329                         if (ret < 0)
1330                                 return ret;
1331                 }
1332         }
1333         return 0;
1334 }
1335
1336 static int
1337 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1338                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1339 {
1340         int ret;
1341         struct sk_buff *skb;
1342
1343         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1344                         GFP_KERNEL);
1345         if (!skb)
1346                 return -ENOBUFS;
1347
1348         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1349                          0, 2) <= 0) {
1350                 NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1351                 kfree_skb(skb);
1352                 return -EINVAL;
1353         }
1354
1355         /* now do the delete */
1356         ret = tcf_action_delete(net, actions);
1357         if (ret < 0) {
1358                 NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1359                 kfree_skb(skb);
1360                 return ret;
1361         }
1362
1363         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1364                              n->nlmsg_flags & NLM_F_ECHO);
1365         if (ret > 0)
1366                 return 0;
1367         return ret;
1368 }
1369
1370 static int
1371 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1372               u32 portid, int event, struct netlink_ext_ack *extack)
1373 {
1374         int i, ret;
1375         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1376         struct tc_action *act;
1377         size_t attr_size = 0;
1378         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1379
1380         ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1381                                           extack);
1382         if (ret < 0)
1383                 return ret;
1384
1385         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1386                 if (tb[1])
1387                         return tca_action_flush(net, tb[1], n, portid, extack);
1388
1389                 NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1390                 return -EINVAL;
1391         }
1392
1393         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1394                 act = tcf_action_get_1(net, tb[i], n, portid, extack);
1395                 if (IS_ERR(act)) {
1396                         ret = PTR_ERR(act);
1397                         goto err;
1398                 }
1399                 attr_size += tcf_action_fill_size(act);
1400                 actions[i - 1] = act;
1401         }
1402
1403         attr_size = tcf_action_full_attrs_size(attr_size);
1404
1405         if (event == RTM_GETACTION)
1406                 ret = tcf_get_notify(net, portid, n, actions, event, extack);
1407         else { /* delete */
1408                 ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1409                 if (ret)
1410                         goto err;
1411                 return 0;
1412         }
1413 err:
1414         tcf_action_put_many(actions);
1415         return ret;
1416 }
1417
1418 static int
1419 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1420                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1421 {
1422         struct sk_buff *skb;
1423         int err = 0;
1424
1425         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1426                         GFP_KERNEL);
1427         if (!skb)
1428                 return -ENOBUFS;
1429
1430         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1431                          RTM_NEWACTION, 0, 0) <= 0) {
1432                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1433                 kfree_skb(skb);
1434                 return -EINVAL;
1435         }
1436
1437         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1438                              n->nlmsg_flags & NLM_F_ECHO);
1439         if (err > 0)
1440                 err = 0;
1441         return err;
1442 }
1443
1444 static int tcf_action_add(struct net *net, struct nlattr *nla,
1445                           struct nlmsghdr *n, u32 portid, int ovr,
1446                           struct netlink_ext_ack *extack)
1447 {
1448         size_t attr_size = 0;
1449         int loop, ret;
1450         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1451
1452         for (loop = 0; loop < 10; loop++) {
1453                 ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0,
1454                                       actions, &attr_size, true, extack);
1455                 if (ret != -EAGAIN)
1456                         break;
1457         }
1458
1459         if (ret < 0)
1460                 return ret;
1461         ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1462         if (ovr)
1463                 tcf_action_put_many(actions);
1464
1465         return ret;
1466 }
1467
1468 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1469         [TCA_ROOT_FLAGS] = NLA_POLICY_BITFIELD32(TCA_FLAG_LARGE_DUMP_ON),
1470         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1471 };
1472
1473 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1474                          struct netlink_ext_ack *extack)
1475 {
1476         struct net *net = sock_net(skb->sk);
1477         struct nlattr *tca[TCA_ROOT_MAX + 1];
1478         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1479         int ret = 0, ovr = 0;
1480
1481         if ((n->nlmsg_type != RTM_GETACTION) &&
1482             !netlink_capable(skb, CAP_NET_ADMIN))
1483                 return -EPERM;
1484
1485         ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
1486                                      TCA_ROOT_MAX, NULL, extack);
1487         if (ret < 0)
1488                 return ret;
1489
1490         if (tca[TCA_ACT_TAB] == NULL) {
1491                 NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1492                 return -EINVAL;
1493         }
1494
1495         /* n->nlmsg_flags & NLM_F_CREATE */
1496         switch (n->nlmsg_type) {
1497         case RTM_NEWACTION:
1498                 /* we are going to assume all other flags
1499                  * imply create only if it doesn't exist
1500                  * Note that CREATE | EXCL implies that
1501                  * but since we want avoid ambiguity (eg when flags
1502                  * is zero) then just set this
1503                  */
1504                 if (n->nlmsg_flags & NLM_F_REPLACE)
1505                         ovr = 1;
1506                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1507                                      extack);
1508                 break;
1509         case RTM_DELACTION:
1510                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1511                                     portid, RTM_DELACTION, extack);
1512                 break;
1513         case RTM_GETACTION:
1514                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1515                                     portid, RTM_GETACTION, extack);
1516                 break;
1517         default:
1518                 BUG();
1519         }
1520
1521         return ret;
1522 }
1523
1524 static struct nlattr *find_dump_kind(struct nlattr **nla)
1525 {
1526         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1527         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1528         struct nlattr *kind;
1529
1530         tb1 = nla[TCA_ACT_TAB];
1531         if (tb1 == NULL)
1532                 return NULL;
1533
1534         if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1535                 return NULL;
1536
1537         if (tb[1] == NULL)
1538                 return NULL;
1539         if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], tcf_action_policy, NULL) < 0)
1540                 return NULL;
1541         kind = tb2[TCA_ACT_KIND];
1542
1543         return kind;
1544 }
1545
1546 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1547 {
1548         struct net *net = sock_net(skb->sk);
1549         struct nlmsghdr *nlh;
1550         unsigned char *b = skb_tail_pointer(skb);
1551         struct nlattr *nest;
1552         struct tc_action_ops *a_o;
1553         int ret = 0;
1554         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1555         struct nlattr *tb[TCA_ROOT_MAX + 1];
1556         struct nlattr *count_attr = NULL;
1557         unsigned long jiffy_since = 0;
1558         struct nlattr *kind = NULL;
1559         struct nla_bitfield32 bf;
1560         u32 msecs_since = 0;
1561         u32 act_count = 0;
1562
1563         ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
1564                                      TCA_ROOT_MAX, tcaa_policy, cb->extack);
1565         if (ret < 0)
1566                 return ret;
1567
1568         kind = find_dump_kind(tb);
1569         if (kind == NULL) {
1570                 pr_info("tc_dump_action: action bad kind\n");
1571                 return 0;
1572         }
1573
1574         a_o = tc_lookup_action(kind);
1575         if (a_o == NULL)
1576                 return 0;
1577
1578         cb->args[2] = 0;
1579         if (tb[TCA_ROOT_FLAGS]) {
1580                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1581                 cb->args[2] = bf.value;
1582         }
1583
1584         if (tb[TCA_ROOT_TIME_DELTA]) {
1585                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1586         }
1587
1588         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1589                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1590         if (!nlh)
1591                 goto out_module_put;
1592
1593         if (msecs_since)
1594                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1595
1596         t = nlmsg_data(nlh);
1597         t->tca_family = AF_UNSPEC;
1598         t->tca__pad1 = 0;
1599         t->tca__pad2 = 0;
1600         cb->args[3] = jiffy_since;
1601         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1602         if (!count_attr)
1603                 goto out_module_put;
1604
1605         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1606         if (nest == NULL)
1607                 goto out_module_put;
1608
1609         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1610         if (ret < 0)
1611                 goto out_module_put;
1612
1613         if (ret > 0) {
1614                 nla_nest_end(skb, nest);
1615                 ret = skb->len;
1616                 act_count = cb->args[1];
1617                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1618                 cb->args[1] = 0;
1619         } else
1620                 nlmsg_trim(skb, b);
1621
1622         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1623         if (NETLINK_CB(cb->skb).portid && ret)
1624                 nlh->nlmsg_flags |= NLM_F_MULTI;
1625         module_put(a_o->owner);
1626         return skb->len;
1627
1628 out_module_put:
1629         module_put(a_o->owner);
1630         nlmsg_trim(skb, b);
1631         return skb->len;
1632 }
1633
1634 static int __init tc_action_init(void)
1635 {
1636         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1637         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1638         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1639                       0);
1640
1641         return 0;
1642 }
1643
1644 subsys_initcall(tc_action_init);