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 static 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
 172 int tcf_idr_release(struct tc_action *a, bool bind)
 173 {
 174         const struct tc_action_ops *ops = a->ops;
 175         int ret;
 176
 177         ret = __tcf_idr_release(a, bind, false);
 178         if (ret == ACT_P_DELETED)
 179                 module_put(ops->owner);
 180         return ret;
 181 }
 182 EXPORT_SYMBOL(tcf_idr_release);
 183
 184 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
 185 {
 186         struct tc_cookie *act_cookie;
 187         u32 cookie_len = 0;
 188
 189         rcu_read_lock();
 190         act_cookie = rcu_dereference(act->act_cookie);
 191
 192         if (act_cookie)
 193                 cookie_len = nla_total_size(act_cookie->len);
 194         rcu_read_unlock();
 195
 196         return  nla_total_size(0) /* action number nested */
 197                 + nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
 198                 + cookie_len /* TCA_ACT_COOKIE */
 199                 + nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_HW_STATS */
 200                 + nla_total_size(0) /* TCA_ACT_STATS nested */
 201                 + nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_FLAGS */
 202                 /* TCA_STATS_BASIC */
 203                 + nla_total_size_64bit(sizeof(struct gnet_stats_basic))
 204                 /* TCA_STATS_PKT64 */
 205                 + nla_total_size_64bit(sizeof(u64))
 206                 /* TCA_STATS_QUEUE */
 207                 + nla_total_size_64bit(sizeof(struct gnet_stats_queue))
 208                 + nla_total_size(0) /* TCA_OPTIONS nested */
 209                 + nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
 210 }
 211
 212 static size_t tcf_action_full_attrs_size(size_t sz)
 213 {
 214         return NLMSG_HDRLEN                     /* struct nlmsghdr */
 215                 + sizeof(struct tcamsg)
 216                 + nla_total_size(0)             /* TCA_ACT_TAB nested */
 217                 + sz;
 218 }
 219
 220 static size_t tcf_action_fill_size(const struct tc_action *act)
 221 {
 222         size_t sz = tcf_action_shared_attrs_size(act);
 223
 224         if (act->ops->get_fill_size)
 225                 return act->ops->get_fill_size(act) + sz;
 226         return sz;
 227 }
 228
 229 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 230                            struct netlink_callback *cb)
 231 {
 232         int err = 0, index = -1, s_i = 0, n_i = 0;
 233         u32 act_flags = cb->args[2];
 234         unsigned long jiffy_since = cb->args[3];
 235         struct nlattr *nest;
 236         struct idr *idr = &idrinfo->action_idr;
 237         struct tc_action *p;
 238         unsigned long id = 1;
 239         unsigned long tmp;
 240
 241         mutex_lock(&idrinfo->lock);
 242
 243         s_i = cb->args[0];
 244
 245         idr_for_each_entry_ul(idr, p, tmp, id) {
 246                 index++;
 247                 if (index < s_i)
 248                         continue;
 249                 if (IS_ERR(p))
 250                         continue;
 251
 252                 if (jiffy_since &&
 253                     time_after(jiffy_since,
 254                                (unsigned long)p->tcfa_tm.lastuse))
 255                         continue;
 256
 257                 nest = nla_nest_start_noflag(skb, n_i);
 258                 if (!nest) {
 259                         index--;
 260                         goto nla_put_failure;
 261                 }
 262                 err = tcf_action_dump_1(skb, p, 0, 0);
 263                 if (err < 0) {
 264                         index--;
 265                         nlmsg_trim(skb, nest);
 266                         goto done;
 267                 }
 268                 nla_nest_end(skb, nest);
 269                 n_i++;
 270                 if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
 271                     n_i >= TCA_ACT_MAX_PRIO)
 272                         goto done;
 273         }
 274 done:
 275         if (index >= 0)
 276                 cb->args[0] = index + 1;
 277
 278         mutex_unlock(&idrinfo->lock);
 279         if (n_i) {
 280                 if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
 281                         cb->args[1] = n_i;
 282         }
 283         return n_i;
 284
 285 nla_put_failure:
 286         nla_nest_cancel(skb, nest);
 287         goto done;
 288 }
 289
 290 static int tcf_idr_release_unsafe(struct tc_action *p)
 291 {
 292         if (atomic_read(&p->tcfa_bindcnt) > 0)
 293                 return -EPERM;
 294
 295         if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 296                 idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
 297                 tcf_action_cleanup(p);
 298                 return ACT_P_DELETED;
 299         }
 300
 301         return 0;
 302 }
 303
 304 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 305                           const struct tc_action_ops *ops,
 306                           struct netlink_ext_ack *extack)
 307 {
 308         struct nlattr *nest;
 309         int n_i = 0;
 310         int ret = -EINVAL;
 311         struct idr *idr = &idrinfo->action_idr;
 312         struct tc_action *p;
 313         unsigned long id = 1;
 314         unsigned long tmp;
 315
 316         nest = nla_nest_start_noflag(skb, 0);
 317         if (nest == NULL)
 318                 goto nla_put_failure;
 319         if (nla_put_string(skb, TCA_KIND, ops->kind))
 320                 goto nla_put_failure;
 321
 322         ret = 0;
 323         mutex_lock(&idrinfo->lock);
 324         idr_for_each_entry_ul(idr, p, tmp, id) {
 325                 if (IS_ERR(p))
 326                         continue;
 327                 ret = tcf_idr_release_unsafe(p);
 328                 if (ret == ACT_P_DELETED)
 329                         module_put(ops->owner);
 330                 else if (ret < 0)
 331                         break;
 332                 n_i++;
 333         }
 334         mutex_unlock(&idrinfo->lock);
 335         if (ret < 0) {
 336                 if (n_i)
 337                         NL_SET_ERR_MSG(extack, "Unable to flush all TC actions");
 338                 else
 339                         goto nla_put_failure;
 340         }
 341
 342         ret = nla_put_u32(skb, TCA_FCNT, n_i);
 343         if (ret)
 344                 goto nla_put_failure;
 345         nla_nest_end(skb, nest);
 346
 347         return n_i;
 348 nla_put_failure:
 349         nla_nest_cancel(skb, nest);
 350         return ret;
 351 }
 352
 353 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 354                        struct netlink_callback *cb, int type,
 355                        const struct tc_action_ops *ops,
 356                        struct netlink_ext_ack *extack)
 357 {
 358         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 359
 360         if (type == RTM_DELACTION) {
 361                 return tcf_del_walker(idrinfo, skb, ops, extack);
 362         } else if (type == RTM_GETACTION) {
 363                 return tcf_dump_walker(idrinfo, skb, cb);
 364         } else {
 365                 WARN(1, "tcf_generic_walker: unknown command %d\n", type);
 366                 NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
 367                 return -EINVAL;
 368         }
 369 }
 370 EXPORT_SYMBOL(tcf_generic_walker);
 371
 372 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 373 {
 374         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 375         struct tc_action *p;
 376
 377         mutex_lock(&idrinfo->lock);
 378         p = idr_find(&idrinfo->action_idr, index);
 379         if (IS_ERR(p))
 380                 p = NULL;
 381         else if (p)
 382                 refcount_inc(&p->tcfa_refcnt);
 383         mutex_unlock(&idrinfo->lock);
 384
 385         if (p) {
 386                 *a = p;
 387                 return true;
 388         }
 389         return false;
 390 }
 391 EXPORT_SYMBOL(tcf_idr_search);
 392
 393 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
 394 {
 395         struct tc_action *p;
 396         int ret = 0;
 397
 398         mutex_lock(&idrinfo->lock);
 399         p = idr_find(&idrinfo->action_idr, index);
 400         if (!p) {
 401                 mutex_unlock(&idrinfo->lock);
 402                 return -ENOENT;
 403         }
 404
 405         if (!atomic_read(&p->tcfa_bindcnt)) {
 406                 if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 407                         struct module *owner = p->ops->owner;
 408
 409                         WARN_ON(p != idr_remove(&idrinfo->action_idr,
 410                                                 p->tcfa_index));
 411                         mutex_unlock(&idrinfo->lock);
 412
 413                         tcf_action_cleanup(p);
 414                         module_put(owner);
 415                         return 0;
 416                 }
 417                 ret = 0;
 418         } else {
 419                 ret = -EPERM;
 420         }
 421
 422         mutex_unlock(&idrinfo->lock);
 423         return ret;
 424 }
 425
 426 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 427                    struct tc_action **a, const struct tc_action_ops *ops,
 428                    int bind, bool cpustats, u32 flags)
 429 {
 430         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 431         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 432         int err = -ENOMEM;
 433
 434         if (unlikely(!p))
 435                 return -ENOMEM;
 436         refcount_set(&p->tcfa_refcnt, 1);
 437         if (bind)
 438                 atomic_set(&p->tcfa_bindcnt, 1);
 439
 440         if (cpustats) {
 441                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 442                 if (!p->cpu_bstats)
 443                         goto err1;
 444                 p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 445                 if (!p->cpu_bstats_hw)
 446                         goto err2;
 447                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 448                 if (!p->cpu_qstats)
 449                         goto err3;
 450         }
 451         spin_lock_init(&p->tcfa_lock);
 452         p->tcfa_index = index;
 453         p->tcfa_tm.install = jiffies;
 454         p->tcfa_tm.lastuse = jiffies;
 455         p->tcfa_tm.firstuse = 0;
 456         p->tcfa_flags = flags;
 457         if (est) {
 458                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 459                                         &p->tcfa_rate_est,
 460                                         &p->tcfa_lock, NULL, est);
 461                 if (err)
 462                         goto err4;
 463         }
 464
 465         p->idrinfo = idrinfo;
 466         __module_get(ops->owner);
 467         p->ops = ops;
 468         *a = p;
 469         return 0;
 470 err4:
 471         free_percpu(p->cpu_qstats);
 472 err3:
 473         free_percpu(p->cpu_bstats_hw);
 474 err2:
 475         free_percpu(p->cpu_bstats);
 476 err1:
 477         kfree(p);
 478         return err;
 479 }
 480 EXPORT_SYMBOL(tcf_idr_create);
 481
 482 int tcf_idr_create_from_flags(struct tc_action_net *tn, u32 index,
 483                               struct nlattr *est, struct tc_action **a,
 484                               const struct tc_action_ops *ops, int bind,
 485                               u32 flags)
 486 {
 487         /* Set cpustats according to actions flags. */
 488         return tcf_idr_create(tn, index, est, a, ops, bind,
 489                               !(flags & TCA_ACT_FLAGS_NO_PERCPU_STATS), flags);
 490 }
 491 EXPORT_SYMBOL(tcf_idr_create_from_flags);
 492
 493 /* Cleanup idr index that was allocated but not initialized. */
 494
 495 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
 496 {
 497         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 498
 499         mutex_lock(&idrinfo->lock);
 500         /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 501         WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
 502         mutex_unlock(&idrinfo->lock);
 503 }
 504 EXPORT_SYMBOL(tcf_idr_cleanup);
 505
 506 /* Check if action with specified index exists. If actions is found, increments
 507  * its reference and bind counters, and return 1. Otherwise insert temporary
 508  * error pointer (to prevent concurrent users from inserting actions with same
 509  * index) and return 0.
 510  */
 511
 512 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 513                         struct tc_action **a, int bind)
 514 {
 515         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 516         struct tc_action *p;
 517         int ret;
 518
 519 again:
 520         mutex_lock(&idrinfo->lock);
 521         if (*index) {
 522                 p = idr_find(&idrinfo->action_idr, *index);
 523                 if (IS_ERR(p)) {
 524                         /* This means that another process allocated
 525                          * index but did not assign the pointer yet.
 526                          */
 527                         mutex_unlock(&idrinfo->lock);
 528                         goto again;
 529                 }
 530
 531                 if (p) {
 532                         refcount_inc(&p->tcfa_refcnt);
 533                         if (bind)
 534                                 atomic_inc(&p->tcfa_bindcnt);
 535                         *a = p;
 536                         ret = 1;
 537                 } else {
 538                         *a = NULL;
 539                         ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 540                                             *index, GFP_KERNEL);
 541                         if (!ret)
 542                                 idr_replace(&idrinfo->action_idr,
 543                                             ERR_PTR(-EBUSY), *index);
 544                 }
 545         } else {
 546                 *index = 1;
 547                 *a = NULL;
 548                 ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 549                                     UINT_MAX, GFP_KERNEL);
 550                 if (!ret)
 551                         idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
 552                                     *index);
 553         }
 554         mutex_unlock(&idrinfo->lock);
 555         return ret;
 556 }
 557 EXPORT_SYMBOL(tcf_idr_check_alloc);
 558
 559 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 560                          struct tcf_idrinfo *idrinfo)
 561 {
 562         struct idr *idr = &idrinfo->action_idr;
 563         struct tc_action *p;
 564         int ret;
 565         unsigned long id = 1;
 566         unsigned long tmp;
 567
 568         idr_for_each_entry_ul(idr, p, tmp, id) {
 569                 ret = __tcf_idr_release(p, false, true);
 570                 if (ret == ACT_P_DELETED)
 571                         module_put(ops->owner);
 572                 else if (ret < 0)
 573                         return;
 574         }
 575         idr_destroy(&idrinfo->action_idr);
 576 }
 577 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 578
 579 static LIST_HEAD(act_base);
 580 static DEFINE_RWLOCK(act_mod_lock);
 581
 582 int tcf_register_action(struct tc_action_ops *act,
 583                         struct pernet_operations *ops)
 584 {
 585         struct tc_action_ops *a;
 586         int ret;
 587
 588         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 589                 return -EINVAL;
 590
 591         /* We have to register pernet ops before making the action ops visible,
 592          * otherwise tcf_action_init_1() could get a partially initialized
 593          * netns.
 594          */
 595         ret = register_pernet_subsys(ops);
 596         if (ret)
 597                 return ret;
 598
 599         write_lock(&act_mod_lock);
 600         list_for_each_entry(a, &act_base, head) {
 601                 if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
 602                         write_unlock(&act_mod_lock);
 603                         unregister_pernet_subsys(ops);
 604                         return -EEXIST;
 605                 }
 606         }
 607         list_add_tail(&act->head, &act_base);
 608         write_unlock(&act_mod_lock);
 609
 610         return 0;
 611 }
 612 EXPORT_SYMBOL(tcf_register_action);
 613
 614 int tcf_unregister_action(struct tc_action_ops *act,
 615                           struct pernet_operations *ops)
 616 {
 617         struct tc_action_ops *a;
 618         int err = -ENOENT;
 619
 620         write_lock(&act_mod_lock);
 621         list_for_each_entry(a, &act_base, head) {
 622                 if (a == act) {
 623                         list_del(&act->head);
 624                         err = 0;
 625                         break;
 626                 }
 627         }
 628         write_unlock(&act_mod_lock);
 629         if (!err)
 630                 unregister_pernet_subsys(ops);
 631         return err;
 632 }
 633 EXPORT_SYMBOL(tcf_unregister_action);
 634
 635 /* lookup by name */
 636 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 637 {
 638         struct tc_action_ops *a, *res = NULL;
 639
 640         if (kind) {
 641                 read_lock(&act_mod_lock);
 642                 list_for_each_entry(a, &act_base, head) {
 643                         if (strcmp(kind, a->kind) == 0) {
 644                                 if (try_module_get(a->owner))
 645                                         res = a;
 646                                 break;
 647                         }
 648                 }
 649                 read_unlock(&act_mod_lock);
 650         }
 651         return res;
 652 }
 653
 654 /* lookup by nlattr */
 655 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 656 {
 657         struct tc_action_ops *a, *res = NULL;
 658
 659         if (kind) {
 660                 read_lock(&act_mod_lock);
 661                 list_for_each_entry(a, &act_base, head) {
 662                         if (nla_strcmp(kind, a->kind) == 0) {
 663                                 if (try_module_get(a->owner))
 664                                         res = a;
 665                                 break;
 666                         }
 667                 }
 668                 read_unlock(&act_mod_lock);
 669         }
 670         return res;
 671 }
 672
 673 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 674 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 675 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 676                     int nr_actions, struct tcf_result *res)
 677 {
 678         u32 jmp_prgcnt = 0;
 679         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 680         int i;
 681         int ret = TC_ACT_OK;
 682
 683         if (skb_skip_tc_classify(skb))
 684                 return TC_ACT_OK;
 685
 686 restart_act_graph:
 687         for (i = 0; i < nr_actions; i++) {
 688                 const struct tc_action *a = actions[i];
 689                 int repeat_ttl;
 690
 691                 if (jmp_prgcnt > 0) {
 692                         jmp_prgcnt -= 1;
 693                         continue;
 694                 }
 695
 696                 repeat_ttl = 32;
 697 repeat:
 698                 ret = a->ops->act(skb, a, res);
 699
 700                 if (unlikely(ret == TC_ACT_REPEAT)) {
 701                         if (--repeat_ttl != 0)
 702                                 goto repeat;
 703                         /* suspicious opcode, stop pipeline */
 704                         net_warn_ratelimited("TC_ACT_REPEAT abuse ?\n");
 705                         return TC_ACT_OK;
 706                 }
 707
 708                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 709                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 710                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 711                                 /* faulty opcode, stop pipeline */
 712                                 return TC_ACT_OK;
 713                         } else {
 714                                 jmp_ttl -= 1;
 715                                 if (jmp_ttl > 0)
 716                                         goto restart_act_graph;
 717                                 else /* faulty graph, stop pipeline */
 718                                         return TC_ACT_OK;
 719                         }
 720                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 721                         if (unlikely(!rcu_access_pointer(a->goto_chain))) {
 722                                 net_warn_ratelimited("can't go to NULL chain!\n");
 723                                 return TC_ACT_SHOT;
 724                         }
 725                         tcf_action_goto_chain_exec(a, res);
 726                 }
 727
 728                 if (ret != TC_ACT_PIPE)
 729                         break;
 730         }
 731
 732         return ret;
 733 }
 734 EXPORT_SYMBOL(tcf_action_exec);
 735
 736 int tcf_action_destroy(struct tc_action *actions[], int bind)
 737 {
 738         const struct tc_action_ops *ops;
 739         struct tc_action *a;
 740         int ret = 0, i;
 741
 742         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 743                 a = actions[i];
 744                 actions[i] = NULL;
 745                 ops = a->ops;
 746                 ret = __tcf_idr_release(a, bind, true);
 747                 if (ret == ACT_P_DELETED)
 748                         module_put(ops->owner);
 749                 else if (ret < 0)
 750                         return ret;
 751         }
 752         return ret;
 753 }
 754
 755 static int tcf_action_put(struct tc_action *p)
 756 {
 757         return __tcf_action_put(p, false);
 758 }
 759
 760 /* Put all actions in this array, skip those NULL's. */
 761 static void tcf_action_put_many(struct tc_action *actions[])
 762 {
 763         int i;
 764
 765         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 766                 struct tc_action *a = actions[i];
 767                 const struct tc_action_ops *ops;
 768
 769                 if (!a)
 770                         continue;
 771                 ops = a->ops;
 772                 if (tcf_action_put(a))
 773                         module_put(ops->owner);
 774         }
 775 }
 776
 777 int
 778 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 779 {
 780         return a->ops->dump(skb, a, bind, ref);
 781 }
 782
 783 static int
 784 tcf_action_dump_terse(struct sk_buff *skb, struct tc_action *a)
 785 {
 786         unsigned char *b = skb_tail_pointer(skb);
 787         struct tc_cookie *cookie;
 788
 789         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 790                 goto nla_put_failure;
 791         if (tcf_action_copy_stats(skb, a, 0))
 792                 goto nla_put_failure;
 793
 794         rcu_read_lock();
 795         cookie = rcu_dereference(a->act_cookie);
 796         if (cookie) {
 797                 if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
 798                         rcu_read_unlock();
 799                         goto nla_put_failure;
 800                 }
 801         }
 802         rcu_read_unlock();
 803
 804         return 0;
 805
 806 nla_put_failure:
 807         nlmsg_trim(skb, b);
 808         return -1;
 809 }
 810
 811 int
 812 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 813 {
 814         int err = -EINVAL;
 815         unsigned char *b = skb_tail_pointer(skb);
 816         struct nlattr *nest;
 817
 818         if (tcf_action_dump_terse(skb, a))
 819                 goto nla_put_failure;
 820
 821         if (a->hw_stats != TCA_ACT_HW_STATS_ANY &&
 822             nla_put_bitfield32(skb, TCA_ACT_HW_STATS,
 823                                a->hw_stats, TCA_ACT_HW_STATS_ANY))
 824                 goto nla_put_failure;
 825
 826         if (a->used_hw_stats_valid &&
 827             nla_put_bitfield32(skb, TCA_ACT_USED_HW_STATS,
 828                                a->used_hw_stats, TCA_ACT_HW_STATS_ANY))
 829                 goto nla_put_failure;
 830
 831         if (a->tcfa_flags &&
 832             nla_put_bitfield32(skb, TCA_ACT_FLAGS,
 833                                a->tcfa_flags, a->tcfa_flags))
 834                 goto nla_put_failure;
 835
 836         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 837         if (nest == NULL)
 838                 goto nla_put_failure;
 839         err = tcf_action_dump_old(skb, a, bind, ref);
 840         if (err > 0) {
 841                 nla_nest_end(skb, nest);
 842                 return err;
 843         }
 844
 845 nla_put_failure:
 846         nlmsg_trim(skb, b);
 847         return -1;
 848 }
 849 EXPORT_SYMBOL(tcf_action_dump_1);
 850
 851 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 852                     int bind, int ref, bool terse)
 853 {
 854         struct tc_action *a;
 855         int err = -EINVAL, i;
 856         struct nlattr *nest;
 857
 858         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 859                 a = actions[i];
 860                 nest = nla_nest_start_noflag(skb, i + 1);
 861                 if (nest == NULL)
 862                         goto nla_put_failure;
 863                 err = terse ? tcf_action_dump_terse(skb, a) :
 864                         tcf_action_dump_1(skb, a, bind, ref);
 865                 if (err < 0)
 866                         goto errout;
 867                 nla_nest_end(skb, nest);
 868         }
 869
 870         return 0;
 871
 872 nla_put_failure:
 873         err = -EINVAL;
 874 errout:
 875         nla_nest_cancel(skb, nest);
 876         return err;
 877 }
 878
 879 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 880 {
 881         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 882         if (!c)
 883                 return NULL;
 884
 885         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 886         if (!c->data) {
 887                 kfree(c);
 888                 return NULL;
 889         }
 890         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 891
 892         return c;
 893 }
 894
 895 static u8 tcf_action_hw_stats_get(struct nlattr *hw_stats_attr)
 896 {
 897         struct nla_bitfield32 hw_stats_bf;
 898
 899         /* If the user did not pass the attr, that means he does
 900          * not care about the type. Return "any" in that case
 901          * which is setting on all supported types.
 902          */
 903         if (!hw_stats_attr)
 904                 return TCA_ACT_HW_STATS_ANY;
 905         hw_stats_bf = nla_get_bitfield32(hw_stats_attr);
 906         return hw_stats_bf.value;
 907 }
 908
 909 static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
 910         [TCA_ACT_KIND]          = { .type = NLA_STRING },
 911         [TCA_ACT_INDEX]         = { .type = NLA_U32 },
 912         [TCA_ACT_COOKIE]        = { .type = NLA_BINARY,
 913                                     .len = TC_COOKIE_MAX_SIZE },
 914         [TCA_ACT_OPTIONS]       = { .type = NLA_NESTED },
 915         [TCA_ACT_FLAGS]         = NLA_POLICY_BITFIELD32(TCA_ACT_FLAGS_NO_PERCPU_STATS),
 916         [TCA_ACT_HW_STATS]      = NLA_POLICY_BITFIELD32(TCA_ACT_HW_STATS_ANY),
 917 };
 918
 919 void tcf_idr_insert_many(struct tc_action *actions[])
 920 {
 921         int i;
 922
 923         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 924                 struct tc_action *a = actions[i];
 925                 struct tcf_idrinfo *idrinfo;
 926
 927                 if (!a)
 928                         continue;
 929                 idrinfo = a->idrinfo;
 930                 mutex_lock(&idrinfo->lock);
 931                 /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc if
 932                  * it is just created, otherwise this is just a nop.
 933                  */
 934                 idr_replace(&idrinfo->action_idr, a, a->tcfa_index);
 935                 mutex_unlock(&idrinfo->lock);
 936         }
 937 }
 938
 939 struct tc_action_ops *tc_action_load_ops(char *name, struct nlattr *nla,
 940                                          bool rtnl_held,
 941                                          struct netlink_ext_ack *extack)
 942 {
 943         struct nlattr *tb[TCA_ACT_MAX + 1];
 944         struct tc_action_ops *a_o;
 945         char act_name[IFNAMSIZ];
 946         struct nlattr *kind;
 947         int err;
 948
 949         if (name == NULL) {
 950                 err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
 951                                                   tcf_action_policy, extack);
 952                 if (err < 0)
 953                         return ERR_PTR(err);
 954                 err = -EINVAL;
 955                 kind = tb[TCA_ACT_KIND];
 956                 if (!kind) {
 957                         NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 958                         return ERR_PTR(err);
 959                 }
 960                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
 961                         NL_SET_ERR_MSG(extack, "TC action name too long");
 962                         return ERR_PTR(err);
 963                 }
 964         } else {
 965                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
 966                         NL_SET_ERR_MSG(extack, "TC action name too long");
 967                         return ERR_PTR(-EINVAL);
 968                 }
 969         }
 970
 971         a_o = tc_lookup_action_n(act_name);
 972         if (a_o == NULL) {
 973 #ifdef CONFIG_MODULES
 974                 if (rtnl_held)
 975                         rtnl_unlock();
 976                 request_module("act_%s", act_name);
 977                 if (rtnl_held)
 978                         rtnl_lock();
 979
 980                 a_o = tc_lookup_action_n(act_name);
 981
 982                 /* We dropped the RTNL semaphore in order to
 983                  * perform the module load.  So, even if we
 984                  * succeeded in loading the module we have to
 985                  * tell the caller to replay the request.  We
 986                  * indicate this using -EAGAIN.
 987                  */
 988                 if (a_o != NULL) {
 989                         module_put(a_o->owner);
 990                         return ERR_PTR(-EAGAIN);
 991                 }
 992 #endif
 993                 NL_SET_ERR_MSG(extack, "Failed to load TC action module");
 994                 return ERR_PTR(-ENOENT);
 995         }
 996
 997         return a_o;
 998 }
 999
1000 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
1001                                     struct nlattr *nla, struct nlattr *est,
1002                                     char *name, int ovr, int bind,
1003                                     struct tc_action_ops *a_o, int *init_res,
1004                                     bool rtnl_held,
1005                                     struct netlink_ext_ack *extack)
1006 {
1007         struct nla_bitfield32 flags = { 0, 0 };
1008         u8 hw_stats = TCA_ACT_HW_STATS_ANY;
1009         struct nlattr *tb[TCA_ACT_MAX + 1];
1010         struct tc_cookie *cookie = NULL;
1011         struct tc_action *a;
1012         int err;
1013
1014         /* backward compatibility for policer */
1015         if (name == NULL) {
1016                 err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1017                                                   tcf_action_policy, extack);
1018                 if (err < 0)
1019                         return ERR_PTR(err);
1020                 if (tb[TCA_ACT_COOKIE]) {
1021                         cookie = nla_memdup_cookie(tb);
1022                         if (!cookie) {
1023                                 NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
1024                                 err = -ENOMEM;
1025                                 goto err_out;
1026                         }
1027                 }
1028                 hw_stats = tcf_action_hw_stats_get(tb[TCA_ACT_HW_STATS]);
1029                 if (tb[TCA_ACT_FLAGS])
1030                         flags = nla_get_bitfield32(tb[TCA_ACT_FLAGS]);
1031
1032                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
1033                                 rtnl_held, tp, flags.value, extack);
1034         } else {
1035                 err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
1036                                 tp, flags.value, extack);
1037         }
1038         if (err < 0)
1039                 goto err_out;
1040         *init_res = err;
1041
1042         if (!name && tb[TCA_ACT_COOKIE])
1043                 tcf_set_action_cookie(&a->act_cookie, cookie);
1044
1045         if (!name)
1046                 a->hw_stats = hw_stats;
1047
1048         return a;
1049
1050 err_out:
1051         if (cookie) {
1052                 kfree(cookie->data);
1053                 kfree(cookie);
1054         }
1055         return ERR_PTR(err);
1056 }
1057
1058 /* Returns numbers of initialized actions or negative error. */
1059
1060 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
1061                     struct nlattr *est, char *name, int ovr, int bind,
1062                     struct tc_action *actions[], int init_res[], size_t *attr_size,
1063                     bool rtnl_held, struct netlink_ext_ack *extack)
1064 {
1065         struct tc_action_ops *ops[TCA_ACT_MAX_PRIO] = {};
1066         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1067         struct tc_action *act;
1068         size_t sz = 0;
1069         int err;
1070         int i;
1071
1072         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1073                                           extack);
1074         if (err < 0)
1075                 return err;
1076
1077         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1078                 struct tc_action_ops *a_o;
1079
1080                 a_o = tc_action_load_ops(name, tb[i], rtnl_held, extack);
1081                 if (IS_ERR(a_o)) {
1082                         err = PTR_ERR(a_o);
1083                         goto err_mod;
1084                 }
1085                 ops[i - 1] = a_o;
1086         }
1087
1088         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1089                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
1090                                         ops[i - 1], &init_res[i - 1], rtnl_held,
1091                                         extack);
1092                 if (IS_ERR(act)) {
1093                         err = PTR_ERR(act);
1094                         goto err;
1095                 }
1096                 sz += tcf_action_fill_size(act);
1097                 /* Start from index 0 */
1098                 actions[i - 1] = act;
1099         }
1100
1101         /* We have to commit them all together, because if any error happened in
1102          * between, we could not handle the failure gracefully.
1103          */
1104         tcf_idr_insert_many(actions);
1105
1106         *attr_size = tcf_action_full_attrs_size(sz);
1107         err = i - 1;
1108         goto err_mod;
1109
1110 err:
1111         tcf_action_destroy(actions, bind);
1112 err_mod:
1113         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
1114                 if (ops[i])
1115                         module_put(ops[i]->owner);
1116         }
1117         return err;
1118 }
1119
1120 void tcf_action_update_stats(struct tc_action *a, u64 bytes, u64 packets,
1121                              u64 drops, bool hw)
1122 {
1123         if (a->cpu_bstats) {
1124                 _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
1125
1126                 this_cpu_ptr(a->cpu_qstats)->drops += drops;
1127
1128                 if (hw)
1129                         _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
1130                                            bytes, packets);
1131                 return;
1132         }
1133
1134         _bstats_update(&a->tcfa_bstats, bytes, packets);
1135         a->tcfa_qstats.drops += drops;
1136         if (hw)
1137                 _bstats_update(&a->tcfa_bstats_hw, bytes, packets);
1138 }
1139 EXPORT_SYMBOL(tcf_action_update_stats);
1140
1141 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
1142                           int compat_mode)
1143 {
1144         int err = 0;
1145         struct gnet_dump d;
1146
1147         if (p == NULL)
1148                 goto errout;
1149
1150         /* compat_mode being true specifies a call that is supposed
1151          * to add additional backward compatibility statistic TLVs.
1152          */
1153         if (compat_mode) {
1154                 if (p->type == TCA_OLD_COMPAT)
1155                         err = gnet_stats_start_copy_compat(skb, 0,
1156                                                            TCA_STATS,
1157                                                            TCA_XSTATS,
1158                                                            &p->tcfa_lock, &d,
1159                                                            TCA_PAD);
1160                 else
1161                         return 0;
1162         } else
1163                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1164                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
1165
1166         if (err < 0)
1167                 goto errout;
1168
1169         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1170             gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1171                                      &p->tcfa_bstats_hw) < 0 ||
1172             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1173             gnet_stats_copy_queue(&d, p->cpu_qstats,
1174                                   &p->tcfa_qstats,
1175                                   p->tcfa_qstats.qlen) < 0)
1176                 goto errout;
1177
1178         if (gnet_stats_finish_copy(&d) < 0)
1179                 goto errout;
1180
1181         return 0;
1182
1183 errout:
1184         return -1;
1185 }
1186
1187 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1188                         u32 portid, u32 seq, u16 flags, int event, int bind,
1189                         int ref)
1190 {
1191         struct tcamsg *t;
1192         struct nlmsghdr *nlh;
1193         unsigned char *b = skb_tail_pointer(skb);
1194         struct nlattr *nest;
1195
1196         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1197         if (!nlh)
1198                 goto out_nlmsg_trim;
1199         t = nlmsg_data(nlh);
1200         t->tca_family = AF_UNSPEC;
1201         t->tca__pad1 = 0;
1202         t->tca__pad2 = 0;
1203
1204         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1205         if (!nest)
1206                 goto out_nlmsg_trim;
1207
1208         if (tcf_action_dump(skb, actions, bind, ref, false) < 0)
1209                 goto out_nlmsg_trim;
1210
1211         nla_nest_end(skb, nest);
1212
1213         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1214         return skb->len;
1215
1216 out_nlmsg_trim:
1217         nlmsg_trim(skb, b);
1218         return -1;
1219 }
1220
1221 static int
1222 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1223                struct tc_action *actions[], int event,
1224                struct netlink_ext_ack *extack)
1225 {
1226         struct sk_buff *skb;
1227
1228         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1229         if (!skb)
1230                 return -ENOBUFS;
1231         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1232                          0, 1) <= 0) {
1233                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1234                 kfree_skb(skb);
1235                 return -EINVAL;
1236         }
1237
1238         return rtnl_unicast(skb, net, portid);
1239 }
1240
1241 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1242                                           struct nlmsghdr *n, u32 portid,
1243                                           struct netlink_ext_ack *extack)
1244 {
1245         struct nlattr *tb[TCA_ACT_MAX + 1];
1246         const struct tc_action_ops *ops;
1247         struct tc_action *a;
1248         int index;
1249         int err;
1250
1251         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1252                                           tcf_action_policy, extack);
1253         if (err < 0)
1254                 goto err_out;
1255
1256         err = -EINVAL;
1257         if (tb[TCA_ACT_INDEX] == NULL ||
1258             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1259                 NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1260                 goto err_out;
1261         }
1262         index = nla_get_u32(tb[TCA_ACT_INDEX]);
1263
1264         err = -EINVAL;
1265         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1266         if (!ops) { /* could happen in batch of actions */
1267                 NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1268                 goto err_out;
1269         }
1270         err = -ENOENT;
1271         if (ops->lookup(net, &a, index) == 0) {
1272                 NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1273                 goto err_mod;
1274         }
1275
1276         module_put(ops->owner);
1277         return a;
1278
1279 err_mod:
1280         module_put(ops->owner);
1281 err_out:
1282         return ERR_PTR(err);
1283 }
1284
1285 static int tca_action_flush(struct net *net, struct nlattr *nla,
1286                             struct nlmsghdr *n, u32 portid,
1287                             struct netlink_ext_ack *extack)
1288 {
1289         struct sk_buff *skb;
1290         unsigned char *b;
1291         struct nlmsghdr *nlh;
1292         struct tcamsg *t;
1293         struct netlink_callback dcb;
1294         struct nlattr *nest;
1295         struct nlattr *tb[TCA_ACT_MAX + 1];
1296         const struct tc_action_ops *ops;
1297         struct nlattr *kind;
1298         int err = -ENOMEM;
1299
1300         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1301         if (!skb)
1302                 return err;
1303
1304         b = skb_tail_pointer(skb);
1305
1306         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1307                                           tcf_action_policy, extack);
1308         if (err < 0)
1309                 goto err_out;
1310
1311         err = -EINVAL;
1312         kind = tb[TCA_ACT_KIND];
1313         ops = tc_lookup_action(kind);
1314         if (!ops) { /*some idjot trying to flush unknown action */
1315                 NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1316                 goto err_out;
1317         }
1318
1319         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1320                         sizeof(*t), 0);
1321         if (!nlh) {
1322                 NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1323                 goto out_module_put;
1324         }
1325         t = nlmsg_data(nlh);
1326         t->tca_family = AF_UNSPEC;
1327         t->tca__pad1 = 0;
1328         t->tca__pad2 = 0;
1329
1330         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1331         if (!nest) {
1332                 NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1333                 goto out_module_put;
1334         }
1335
1336         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1337         if (err <= 0) {
1338                 nla_nest_cancel(skb, nest);
1339                 goto out_module_put;
1340         }
1341
1342         nla_nest_end(skb, nest);
1343
1344         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1345         nlh->nlmsg_flags |= NLM_F_ROOT;
1346         module_put(ops->owner);
1347         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1348                              n->nlmsg_flags & NLM_F_ECHO);
1349         if (err > 0)
1350                 return 0;
1351         if (err < 0)
1352                 NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1353
1354         return err;
1355
1356 out_module_put:
1357         module_put(ops->owner);
1358 err_out:
1359         kfree_skb(skb);
1360         return err;
1361 }
1362
1363 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1364 {
1365         int i;
1366
1367         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1368                 struct tc_action *a = actions[i];
1369                 const struct tc_action_ops *ops = a->ops;
1370                 /* Actions can be deleted concurrently so we must save their
1371                  * type and id to search again after reference is released.
1372                  */
1373                 struct tcf_idrinfo *idrinfo = a->idrinfo;
1374                 u32 act_index = a->tcfa_index;
1375
1376                 actions[i] = NULL;
1377                 if (tcf_action_put(a)) {
1378                         /* last reference, action was deleted concurrently */
1379                         module_put(ops->owner);
1380                 } else  {
1381                         int ret;
1382
1383                         /* now do the delete */
1384                         ret = tcf_idr_delete_index(idrinfo, act_index);
1385                         if (ret < 0)
1386                                 return ret;
1387                 }
1388         }
1389         return 0;
1390 }
1391
1392 static int
1393 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1394                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1395 {
1396         int ret;
1397         struct sk_buff *skb;
1398
1399         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1400                         GFP_KERNEL);
1401         if (!skb)
1402                 return -ENOBUFS;
1403
1404         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1405                          0, 2) <= 0) {
1406                 NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1407                 kfree_skb(skb);
1408                 return -EINVAL;
1409         }
1410
1411         /* now do the delete */
1412         ret = tcf_action_delete(net, actions);
1413         if (ret < 0) {
1414                 NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1415                 kfree_skb(skb);
1416                 return ret;
1417         }
1418
1419         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1420                              n->nlmsg_flags & NLM_F_ECHO);
1421         if (ret > 0)
1422                 return 0;
1423         return ret;
1424 }
1425
1426 static int
1427 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1428               u32 portid, int event, struct netlink_ext_ack *extack)
1429 {
1430         int i, ret;
1431         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1432         struct tc_action *act;
1433         size_t attr_size = 0;
1434         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1435
1436         ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1437                                           extack);
1438         if (ret < 0)
1439                 return ret;
1440
1441         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1442                 if (tb[1])
1443                         return tca_action_flush(net, tb[1], n, portid, extack);
1444
1445                 NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1446                 return -EINVAL;
1447         }
1448
1449         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1450                 act = tcf_action_get_1(net, tb[i], n, portid, extack);
1451                 if (IS_ERR(act)) {
1452                         ret = PTR_ERR(act);
1453                         goto err;
1454                 }
1455                 attr_size += tcf_action_fill_size(act);
1456                 actions[i - 1] = act;
1457         }
1458
1459         attr_size = tcf_action_full_attrs_size(attr_size);
1460
1461         if (event == RTM_GETACTION)
1462                 ret = tcf_get_notify(net, portid, n, actions, event, extack);
1463         else { /* delete */
1464                 ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1465                 if (ret)
1466                         goto err;
1467                 return 0;
1468         }
1469 err:
1470         tcf_action_put_many(actions);
1471         return ret;
1472 }
1473
1474 static int
1475 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1476                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1477 {
1478         struct sk_buff *skb;
1479         int err = 0;
1480
1481         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1482                         GFP_KERNEL);
1483         if (!skb)
1484                 return -ENOBUFS;
1485
1486         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1487                          RTM_NEWACTION, 0, 0) <= 0) {
1488                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1489                 kfree_skb(skb);
1490                 return -EINVAL;
1491         }
1492
1493         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1494                              n->nlmsg_flags & NLM_F_ECHO);
1495         if (err > 0)
1496                 err = 0;
1497         return err;
1498 }
1499
1500 static int tcf_action_add(struct net *net, struct nlattr *nla,
1501                           struct nlmsghdr *n, u32 portid, int ovr,
1502                           struct netlink_ext_ack *extack)
1503 {
1504         size_t attr_size = 0;
1505         int loop, ret, i;
1506         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1507         int init_res[TCA_ACT_MAX_PRIO] = {};
1508
1509         for (loop = 0; loop < 10; loop++) {
1510                 ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0,
1511                                       actions, init_res, &attr_size, true, extack);
1512                 if (ret != -EAGAIN)
1513                         break;
1514         }
1515
1516         if (ret < 0)
1517                 return ret;
1518         ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1519
1520         /* only put existing actions */
1521         for (i = 0; i < TCA_ACT_MAX_PRIO; i++)
1522                 if (init_res[i] == ACT_P_CREATED)
1523                         actions[i] = NULL;
1524         tcf_action_put_many(actions);
1525
1526         return ret;
1527 }
1528
1529 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1530         [TCA_ROOT_FLAGS] = NLA_POLICY_BITFIELD32(TCA_FLAG_LARGE_DUMP_ON),
1531         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1532 };
1533
1534 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1535                          struct netlink_ext_ack *extack)
1536 {
1537         struct net *net = sock_net(skb->sk);
1538         struct nlattr *tca[TCA_ROOT_MAX + 1];
1539         u32 portid = NETLINK_CB(skb).portid;
1540         int ret = 0, ovr = 0;
1541
1542         if ((n->nlmsg_type != RTM_GETACTION) &&
1543             !netlink_capable(skb, CAP_NET_ADMIN))
1544                 return -EPERM;
1545
1546         ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
1547                                      TCA_ROOT_MAX, NULL, extack);
1548         if (ret < 0)
1549                 return ret;
1550
1551         if (tca[TCA_ACT_TAB] == NULL) {
1552                 NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1553                 return -EINVAL;
1554         }
1555
1556         /* n->nlmsg_flags & NLM_F_CREATE */
1557         switch (n->nlmsg_type) {
1558         case RTM_NEWACTION:
1559                 /* we are going to assume all other flags
1560                  * imply create only if it doesn't exist
1561                  * Note that CREATE | EXCL implies that
1562                  * but since we want avoid ambiguity (eg when flags
1563                  * is zero) then just set this
1564                  */
1565                 if (n->nlmsg_flags & NLM_F_REPLACE)
1566                         ovr = 1;
1567                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1568                                      extack);
1569                 break;
1570         case RTM_DELACTION:
1571                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1572                                     portid, RTM_DELACTION, extack);
1573                 break;
1574         case RTM_GETACTION:
1575                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1576                                     portid, RTM_GETACTION, extack);
1577                 break;
1578         default:
1579                 BUG();
1580         }
1581
1582         return ret;
1583 }
1584
1585 static struct nlattr *find_dump_kind(struct nlattr **nla)
1586 {
1587         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1588         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1589         struct nlattr *kind;
1590
1591         tb1 = nla[TCA_ACT_TAB];
1592         if (tb1 == NULL)
1593                 return NULL;
1594
1595         if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1596                 return NULL;
1597
1598         if (tb[1] == NULL)
1599                 return NULL;
1600         if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], tcf_action_policy, NULL) < 0)
1601                 return NULL;
1602         kind = tb2[TCA_ACT_KIND];
1603
1604         return kind;
1605 }
1606
1607 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1608 {
1609         struct net *net = sock_net(skb->sk);
1610         struct nlmsghdr *nlh;
1611         unsigned char *b = skb_tail_pointer(skb);
1612         struct nlattr *nest;
1613         struct tc_action_ops *a_o;
1614         int ret = 0;
1615         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1616         struct nlattr *tb[TCA_ROOT_MAX + 1];
1617         struct nlattr *count_attr = NULL;
1618         unsigned long jiffy_since = 0;
1619         struct nlattr *kind = NULL;
1620         struct nla_bitfield32 bf;
1621         u32 msecs_since = 0;
1622         u32 act_count = 0;
1623
1624         ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
1625                                      TCA_ROOT_MAX, tcaa_policy, cb->extack);
1626         if (ret < 0)
1627                 return ret;
1628
1629         kind = find_dump_kind(tb);
1630         if (kind == NULL) {
1631                 pr_info("tc_dump_action: action bad kind\n");
1632                 return 0;
1633         }
1634
1635         a_o = tc_lookup_action(kind);
1636         if (a_o == NULL)
1637                 return 0;
1638
1639         cb->args[2] = 0;
1640         if (tb[TCA_ROOT_FLAGS]) {
1641                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1642                 cb->args[2] = bf.value;
1643         }
1644
1645         if (tb[TCA_ROOT_TIME_DELTA]) {
1646                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1647         }
1648
1649         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1650                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1651         if (!nlh)
1652                 goto out_module_put;
1653
1654         if (msecs_since)
1655                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1656
1657         t = nlmsg_data(nlh);
1658         t->tca_family = AF_UNSPEC;
1659         t->tca__pad1 = 0;
1660         t->tca__pad2 = 0;
1661         cb->args[3] = jiffy_since;
1662         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1663         if (!count_attr)
1664                 goto out_module_put;
1665
1666         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1667         if (nest == NULL)
1668                 goto out_module_put;
1669
1670         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1671         if (ret < 0)
1672                 goto out_module_put;
1673
1674         if (ret > 0) {
1675                 nla_nest_end(skb, nest);
1676                 ret = skb->len;
1677                 act_count = cb->args[1];
1678                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1679                 cb->args[1] = 0;
1680         } else
1681                 nlmsg_trim(skb, b);
1682
1683         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1684         if (NETLINK_CB(cb->skb).portid && ret)
1685                 nlh->nlmsg_flags |= NLM_F_MULTI;
1686         module_put(a_o->owner);
1687         return skb->len;
1688
1689 out_module_put:
1690         module_put(a_o->owner);
1691         nlmsg_trim(skb, b);
1692         return skb->len;
1693 }
1694
1695 static int __init tc_action_init(void)
1696 {
1697         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1698         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1699         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1700                       0);
1701
1702         return 0;
1703 }
1704
1705 subsys_initcall(tc_action_init);