net/sched/act_api.c

   1 /*
   2  * net/sched/act_api.c  Packet action API.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Author:      Jamal Hadi Salim
  10  *
  11  *
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/errno.h>
  18 #include <linux/slab.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/init.h>
  21 #include <linux/kmod.h>
  22 #include <linux/err.h>
  23 #include <linux/module.h>
  24 #include <net/net_namespace.h>
  25 #include <net/sock.h>
  26 #include <net/sch_generic.h>
  27 #include <net/pkt_cls.h>
  28 #include <net/act_api.h>
  29 #include <net/netlink.h>
  30
  31 static void tcf_action_goto_chain_exec(const struct tc_action *a,
  32                                        struct tcf_result *res)
  33 {
  34         const struct tcf_chain *chain = rcu_dereference_bh(a->goto_chain);
  35
  36         res->goto_tp = rcu_dereference_bh(chain->filter_chain);
  37 }
  38
  39 static void tcf_free_cookie_rcu(struct rcu_head *p)
  40 {
  41         struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
  42
  43         kfree(cookie->data);
  44         kfree(cookie);
  45 }
  46
  47 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
  48                                   struct tc_cookie *new_cookie)
  49 {
  50         struct tc_cookie *old;
  51
  52         old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
  53         if (old)
  54                 call_rcu(&old->rcu, tcf_free_cookie_rcu);
  55 }
  56
  57 int tcf_action_check_ctrlact(int action, struct tcf_proto *tp,
  58                              struct tcf_chain **newchain,
  59                              struct netlink_ext_ack *extack)
  60 {
  61         int opcode = TC_ACT_EXT_OPCODE(action), ret = -EINVAL;
  62         u32 chain_index;
  63
  64         if (!opcode)
  65                 ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;
  66         else if (opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC)
  67                 ret = 0;
  68         if (ret) {
  69                 NL_SET_ERR_MSG(extack, "invalid control action");
  70                 goto end;
  71         }
  72
  73         if (TC_ACT_EXT_CMP(action, TC_ACT_GOTO_CHAIN)) {
  74                 chain_index = action & TC_ACT_EXT_VAL_MASK;
  75                 if (!tp || !newchain) {
  76                         ret = -EINVAL;
  77                         NL_SET_ERR_MSG(extack,
  78                                        "can't goto NULL proto/chain");
  79                         goto end;
  80                 }
  81                 *newchain = tcf_chain_get_by_act(tp->chain->block, chain_index);
  82                 if (!*newchain) {
  83                         ret = -ENOMEM;
  84                         NL_SET_ERR_MSG(extack,
  85                                        "can't allocate goto_chain");
  86                 }
  87         }
  88 end:
  89         return ret;
  90 }
  91 EXPORT_SYMBOL(tcf_action_check_ctrlact);
  92
  93 struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,
  94                                          struct tcf_chain *goto_chain)
  95 {
  96         a->tcfa_action = action;
  97         rcu_swap_protected(a->goto_chain, goto_chain, 1);
  98         return goto_chain;
  99 }
 100 EXPORT_SYMBOL(tcf_action_set_ctrlact);
 101
 102 /* XXX: For standalone actions, we don't need a RCU grace period either, because
 103  * actions are always connected to filters and filters are already destroyed in
 104  * RCU callbacks, so after a RCU grace period actions are already disconnected
 105  * from filters. Readers later can not find us.
 106  */
 107 static void free_tcf(struct tc_action *p)
 108 {
 109         struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
 110
 111         free_percpu(p->cpu_bstats);
 112         free_percpu(p->cpu_bstats_hw);
 113         free_percpu(p->cpu_qstats);
 114
 115         tcf_set_action_cookie(&p->act_cookie, NULL);
 116         if (chain)
 117                 tcf_chain_put_by_act(chain);
 118
 119         kfree(p);
 120 }
 121
 122 static void tcf_action_cleanup(struct tc_action *p)
 123 {
 124         if (p->ops->cleanup)
 125                 p->ops->cleanup(p);
 126
 127         gen_kill_estimator(&p->tcfa_rate_est);
 128         free_tcf(p);
 129 }
 130
 131 static int __tcf_action_put(struct tc_action *p, bool bind)
 132 {
 133         struct tcf_idrinfo *idrinfo = p->idrinfo;
 134
 135         if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
 136                 if (bind)
 137                         atomic_dec(&p->tcfa_bindcnt);
 138                 idr_remove(&idrinfo->action_idr, p->tcfa_index);
 139                 mutex_unlock(&idrinfo->lock);
 140
 141                 tcf_action_cleanup(p);
 142                 return 1;
 143         }
 144
 145         if (bind)
 146                 atomic_dec(&p->tcfa_bindcnt);
 147
 148         return 0;
 149 }
 150
 151 int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
 152 {
 153         int ret = 0;
 154
 155         /* Release with strict==1 and bind==0 is only called through act API
 156          * interface (classifiers always bind). Only case when action with
 157          * positive reference count and zero bind count can exist is when it was
 158          * also created with act API (unbinding last classifier will destroy the
 159          * action if it was created by classifier). So only case when bind count
 160          * can be changed after initial check is when unbound action is
 161          * destroyed by act API while classifier binds to action with same id
 162          * concurrently. This result either creation of new action(same behavior
 163          * as before), or reusing existing action if concurrent process
 164          * increments reference count before action is deleted. Both scenarios
 165          * are acceptable.
 166          */
 167         if (p) {
 168                 if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
 169                         return -EPERM;
 170
 171                 if (__tcf_action_put(p, bind))
 172                         ret = ACT_P_DELETED;
 173         }
 174
 175         return ret;
 176 }
 177 EXPORT_SYMBOL(__tcf_idr_release);
 178
 179 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
 180 {
 181         struct tc_cookie *act_cookie;
 182         u32 cookie_len = 0;
 183
 184         rcu_read_lock();
 185         act_cookie = rcu_dereference(act->act_cookie);
 186
 187         if (act_cookie)
 188                 cookie_len = nla_total_size(act_cookie->len);
 189         rcu_read_unlock();
 190
 191         return  nla_total_size(0) /* action number nested */
 192                 + nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
 193                 + cookie_len /* TCA_ACT_COOKIE */
 194                 + nla_total_size(0) /* TCA_ACT_STATS nested */
 195                 /* TCA_STATS_BASIC */
 196                 + nla_total_size_64bit(sizeof(struct gnet_stats_basic))
 197                 /* TCA_STATS_QUEUE */
 198                 + nla_total_size_64bit(sizeof(struct gnet_stats_queue))
 199                 + nla_total_size(0) /* TCA_OPTIONS nested */
 200                 + nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
 201 }
 202
 203 static size_t tcf_action_full_attrs_size(size_t sz)
 204 {
 205         return NLMSG_HDRLEN                     /* struct nlmsghdr */
 206                 + sizeof(struct tcamsg)
 207                 + nla_total_size(0)             /* TCA_ACT_TAB nested */
 208                 + sz;
 209 }
 210
 211 static size_t tcf_action_fill_size(const struct tc_action *act)
 212 {
 213         size_t sz = tcf_action_shared_attrs_size(act);
 214
 215         if (act->ops->get_fill_size)
 216                 return act->ops->get_fill_size(act) + sz;
 217         return sz;
 218 }
 219
 220 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 221                            struct netlink_callback *cb)
 222 {
 223         int err = 0, index = -1, s_i = 0, n_i = 0;
 224         u32 act_flags = cb->args[2];
 225         unsigned long jiffy_since = cb->args[3];
 226         struct nlattr *nest;
 227         struct idr *idr = &idrinfo->action_idr;
 228         struct tc_action *p;
 229         unsigned long id = 1;
 230
 231         mutex_lock(&idrinfo->lock);
 232
 233         s_i = cb->args[0];
 234
 235         idr_for_each_entry_ul(idr, p, id) {
 236                 index++;
 237                 if (index < s_i)
 238                         continue;
 239
 240                 if (jiffy_since &&
 241                     time_after(jiffy_since,
 242                                (unsigned long)p->tcfa_tm.lastuse))
 243                         continue;
 244
 245                 nest = nla_nest_start(skb, n_i);
 246                 if (!nest) {
 247                         index--;
 248                         goto nla_put_failure;
 249                 }
 250                 err = tcf_action_dump_1(skb, p, 0, 0);
 251                 if (err < 0) {
 252                         index--;
 253                         nlmsg_trim(skb, nest);
 254                         goto done;
 255                 }
 256                 nla_nest_end(skb, nest);
 257                 n_i++;
 258                 if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
 259                     n_i >= TCA_ACT_MAX_PRIO)
 260                         goto done;
 261         }
 262 done:
 263         if (index >= 0)
 264                 cb->args[0] = index + 1;
 265
 266         mutex_unlock(&idrinfo->lock);
 267         if (n_i) {
 268                 if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
 269                         cb->args[1] = n_i;
 270         }
 271         return n_i;
 272
 273 nla_put_failure:
 274         nla_nest_cancel(skb, nest);
 275         goto done;
 276 }
 277
 278 static int tcf_idr_release_unsafe(struct tc_action *p)
 279 {
 280         if (atomic_read(&p->tcfa_bindcnt) > 0)
 281                 return -EPERM;
 282
 283         if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 284                 idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
 285                 tcf_action_cleanup(p);
 286                 return ACT_P_DELETED;
 287         }
 288
 289         return 0;
 290 }
 291
 292 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 293                           const struct tc_action_ops *ops)
 294 {
 295         struct nlattr *nest;
 296         int n_i = 0;
 297         int ret = -EINVAL;
 298         struct idr *idr = &idrinfo->action_idr;
 299         struct tc_action *p;
 300         unsigned long id = 1;
 301
 302         nest = nla_nest_start(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, 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)
 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         if (est) {
 435                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 436                                         &p->tcfa_rate_est,
 437                                         &p->tcfa_lock, NULL, est);
 438                 if (err)
 439                         goto err4;
 440         }
 441
 442         p->idrinfo = idrinfo;
 443         p->ops = ops;
 444         *a = p;
 445         return 0;
 446 err4:
 447         free_percpu(p->cpu_qstats);
 448 err3:
 449         free_percpu(p->cpu_bstats_hw);
 450 err2:
 451         free_percpu(p->cpu_bstats);
 452 err1:
 453         kfree(p);
 454         return err;
 455 }
 456 EXPORT_SYMBOL(tcf_idr_create);
 457
 458 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
 459 {
 460         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 461
 462         mutex_lock(&idrinfo->lock);
 463         /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 464         WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
 465         mutex_unlock(&idrinfo->lock);
 466 }
 467 EXPORT_SYMBOL(tcf_idr_insert);
 468
 469 /* Cleanup idr index that was allocated but not initialized. */
 470
 471 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
 472 {
 473         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 474
 475         mutex_lock(&idrinfo->lock);
 476         /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 477         WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
 478         mutex_unlock(&idrinfo->lock);
 479 }
 480 EXPORT_SYMBOL(tcf_idr_cleanup);
 481
 482 /* Check if action with specified index exists. If actions is found, increments
 483  * its reference and bind counters, and return 1. Otherwise insert temporary
 484  * error pointer (to prevent concurrent users from inserting actions with same
 485  * index) and return 0.
 486  */
 487
 488 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 489                         struct tc_action **a, int bind)
 490 {
 491         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 492         struct tc_action *p;
 493         int ret;
 494
 495 again:
 496         mutex_lock(&idrinfo->lock);
 497         if (*index) {
 498                 p = idr_find(&idrinfo->action_idr, *index);
 499                 if (IS_ERR(p)) {
 500                         /* This means that another process allocated
 501                          * index but did not assign the pointer yet.
 502                          */
 503                         mutex_unlock(&idrinfo->lock);
 504                         goto again;
 505                 }
 506
 507                 if (p) {
 508                         refcount_inc(&p->tcfa_refcnt);
 509                         if (bind)
 510                                 atomic_inc(&p->tcfa_bindcnt);
 511                         *a = p;
 512                         ret = 1;
 513                 } else {
 514                         *a = NULL;
 515                         ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 516                                             *index, GFP_KERNEL);
 517                         if (!ret)
 518                                 idr_replace(&idrinfo->action_idr,
 519                                             ERR_PTR(-EBUSY), *index);
 520                 }
 521         } else {
 522                 *index = 1;
 523                 *a = NULL;
 524                 ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 525                                     UINT_MAX, GFP_KERNEL);
 526                 if (!ret)
 527                         idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
 528                                     *index);
 529         }
 530         mutex_unlock(&idrinfo->lock);
 531         return ret;
 532 }
 533 EXPORT_SYMBOL(tcf_idr_check_alloc);
 534
 535 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 536                          struct tcf_idrinfo *idrinfo)
 537 {
 538         struct idr *idr = &idrinfo->action_idr;
 539         struct tc_action *p;
 540         int ret;
 541         unsigned long id = 1;
 542
 543         idr_for_each_entry_ul(idr, p, id) {
 544                 ret = __tcf_idr_release(p, false, true);
 545                 if (ret == ACT_P_DELETED)
 546                         module_put(ops->owner);
 547                 else if (ret < 0)
 548                         return;
 549         }
 550         idr_destroy(&idrinfo->action_idr);
 551 }
 552 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 553
 554 static LIST_HEAD(act_base);
 555 static DEFINE_RWLOCK(act_mod_lock);
 556
 557 int tcf_register_action(struct tc_action_ops *act,
 558                         struct pernet_operations *ops)
 559 {
 560         struct tc_action_ops *a;
 561         int ret;
 562
 563         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 564                 return -EINVAL;
 565
 566         /* We have to register pernet ops before making the action ops visible,
 567          * otherwise tcf_action_init_1() could get a partially initialized
 568          * netns.
 569          */
 570         ret = register_pernet_subsys(ops);
 571         if (ret)
 572                 return ret;
 573
 574         write_lock(&act_mod_lock);
 575         list_for_each_entry(a, &act_base, head) {
 576                 if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
 577                         write_unlock(&act_mod_lock);
 578                         unregister_pernet_subsys(ops);
 579                         return -EEXIST;
 580                 }
 581         }
 582         list_add_tail(&act->head, &act_base);
 583         write_unlock(&act_mod_lock);
 584
 585         return 0;
 586 }
 587 EXPORT_SYMBOL(tcf_register_action);
 588
 589 int tcf_unregister_action(struct tc_action_ops *act,
 590                           struct pernet_operations *ops)
 591 {
 592         struct tc_action_ops *a;
 593         int err = -ENOENT;
 594
 595         write_lock(&act_mod_lock);
 596         list_for_each_entry(a, &act_base, head) {
 597                 if (a == act) {
 598                         list_del(&act->head);
 599                         err = 0;
 600                         break;
 601                 }
 602         }
 603         write_unlock(&act_mod_lock);
 604         if (!err)
 605                 unregister_pernet_subsys(ops);
 606         return err;
 607 }
 608 EXPORT_SYMBOL(tcf_unregister_action);
 609
 610 /* lookup by name */
 611 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 612 {
 613         struct tc_action_ops *a, *res = NULL;
 614
 615         if (kind) {
 616                 read_lock(&act_mod_lock);
 617                 list_for_each_entry(a, &act_base, head) {
 618                         if (strcmp(kind, a->kind) == 0) {
 619                                 if (try_module_get(a->owner))
 620                                         res = a;
 621                                 break;
 622                         }
 623                 }
 624                 read_unlock(&act_mod_lock);
 625         }
 626         return res;
 627 }
 628
 629 /* lookup by nlattr */
 630 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 631 {
 632         struct tc_action_ops *a, *res = NULL;
 633
 634         if (kind) {
 635                 read_lock(&act_mod_lock);
 636                 list_for_each_entry(a, &act_base, head) {
 637                         if (nla_strcmp(kind, a->kind) == 0) {
 638                                 if (try_module_get(a->owner))
 639                                         res = a;
 640                                 break;
 641                         }
 642                 }
 643                 read_unlock(&act_mod_lock);
 644         }
 645         return res;
 646 }
 647
 648 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 649 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 650 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 651                     int nr_actions, struct tcf_result *res)
 652 {
 653         u32 jmp_prgcnt = 0;
 654         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 655         int i;
 656         int ret = TC_ACT_OK;
 657
 658         if (skb_skip_tc_classify(skb))
 659                 return TC_ACT_OK;
 660
 661 restart_act_graph:
 662         for (i = 0; i < nr_actions; i++) {
 663                 const struct tc_action *a = actions[i];
 664
 665                 if (jmp_prgcnt > 0) {
 666                         jmp_prgcnt -= 1;
 667                         continue;
 668                 }
 669 repeat:
 670                 ret = a->ops->act(skb, a, res);
 671                 if (ret == TC_ACT_REPEAT)
 672                         goto repeat;    /* we need a ttl - JHS */
 673
 674                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 675                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 676                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 677                                 /* faulty opcode, stop pipeline */
 678                                 return TC_ACT_OK;
 679                         } else {
 680                                 jmp_ttl -= 1;
 681                                 if (jmp_ttl > 0)
 682                                         goto restart_act_graph;
 683                                 else /* faulty graph, stop pipeline */
 684                                         return TC_ACT_OK;
 685                         }
 686                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 687                         if (unlikely(!rcu_access_pointer(a->goto_chain))) {
 688                                 net_warn_ratelimited("can't go to NULL chain!\n");
 689                                 return TC_ACT_SHOT;
 690                         }
 691                         tcf_action_goto_chain_exec(a, res);
 692                 }
 693
 694                 if (ret != TC_ACT_PIPE)
 695                         break;
 696         }
 697
 698         return ret;
 699 }
 700 EXPORT_SYMBOL(tcf_action_exec);
 701
 702 int tcf_action_destroy(struct tc_action *actions[], int bind)
 703 {
 704         const struct tc_action_ops *ops;
 705         struct tc_action *a;
 706         int ret = 0, i;
 707
 708         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 709                 a = actions[i];
 710                 actions[i] = NULL;
 711                 ops = a->ops;
 712                 ret = __tcf_idr_release(a, bind, true);
 713                 if (ret == ACT_P_DELETED)
 714                         module_put(ops->owner);
 715                 else if (ret < 0)
 716                         return ret;
 717         }
 718         return ret;
 719 }
 720
 721 static int tcf_action_destroy_1(struct tc_action *a, int bind)
 722 {
 723         struct tc_action *actions[] = { a, NULL };
 724
 725         return tcf_action_destroy(actions, bind);
 726 }
 727
 728 static int tcf_action_put(struct tc_action *p)
 729 {
 730         return __tcf_action_put(p, false);
 731 }
 732
 733 /* Put all actions in this array, skip those NULL's. */
 734 static void tcf_action_put_many(struct tc_action *actions[])
 735 {
 736         int i;
 737
 738         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 739                 struct tc_action *a = actions[i];
 740                 const struct tc_action_ops *ops;
 741
 742                 if (!a)
 743                         continue;
 744                 ops = a->ops;
 745                 if (tcf_action_put(a))
 746                         module_put(ops->owner);
 747         }
 748 }
 749
 750 int
 751 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 752 {
 753         return a->ops->dump(skb, a, bind, ref);
 754 }
 755
 756 int
 757 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 758 {
 759         int err = -EINVAL;
 760         unsigned char *b = skb_tail_pointer(skb);
 761         struct nlattr *nest;
 762         struct tc_cookie *cookie;
 763
 764         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 765                 goto nla_put_failure;
 766         if (tcf_action_copy_stats(skb, a, 0))
 767                 goto nla_put_failure;
 768
 769         rcu_read_lock();
 770         cookie = rcu_dereference(a->act_cookie);
 771         if (cookie) {
 772                 if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
 773                         rcu_read_unlock();
 774                         goto nla_put_failure;
 775                 }
 776         }
 777         rcu_read_unlock();
 778
 779         nest = nla_nest_start(skb, TCA_OPTIONS);
 780         if (nest == NULL)
 781                 goto nla_put_failure;
 782         err = tcf_action_dump_old(skb, a, bind, ref);
 783         if (err > 0) {
 784                 nla_nest_end(skb, nest);
 785                 return err;
 786         }
 787
 788 nla_put_failure:
 789         nlmsg_trim(skb, b);
 790         return -1;
 791 }
 792 EXPORT_SYMBOL(tcf_action_dump_1);
 793
 794 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 795                     int bind, int ref)
 796 {
 797         struct tc_action *a;
 798         int err = -EINVAL, i;
 799         struct nlattr *nest;
 800
 801         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 802                 a = actions[i];
 803                 nest = nla_nest_start(skb, a->order);
 804                 if (nest == NULL)
 805                         goto nla_put_failure;
 806                 err = tcf_action_dump_1(skb, a, bind, ref);
 807                 if (err < 0)
 808                         goto errout;
 809                 nla_nest_end(skb, nest);
 810         }
 811
 812         return 0;
 813
 814 nla_put_failure:
 815         err = -EINVAL;
 816 errout:
 817         nla_nest_cancel(skb, nest);
 818         return err;
 819 }
 820
 821 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 822 {
 823         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 824         if (!c)
 825                 return NULL;
 826
 827         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 828         if (!c->data) {
 829                 kfree(c);
 830                 return NULL;
 831         }
 832         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 833
 834         return c;
 835 }
 836
 837 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 838                                     struct nlattr *nla, struct nlattr *est,
 839                                     char *name, int ovr, int bind,
 840                                     bool rtnl_held,
 841                                     struct netlink_ext_ack *extack)
 842 {
 843         struct tc_action *a;
 844         struct tc_action_ops *a_o;
 845         struct tc_cookie *cookie = NULL;
 846         char act_name[IFNAMSIZ];
 847         struct nlattr *tb[TCA_ACT_MAX + 1];
 848         struct nlattr *kind;
 849         int err;
 850
 851         if (name == NULL) {
 852                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
 853                 if (err < 0)
 854                         goto err_out;
 855                 err = -EINVAL;
 856                 kind = tb[TCA_ACT_KIND];
 857                 if (!kind) {
 858                         NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 859                         goto err_out;
 860                 }
 861                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
 862                         NL_SET_ERR_MSG(extack, "TC action name too long");
 863                         goto err_out;
 864                 }
 865                 if (tb[TCA_ACT_COOKIE]) {
 866                         int cklen = nla_len(tb[TCA_ACT_COOKIE]);
 867
 868                         if (cklen > TC_COOKIE_MAX_SIZE) {
 869                                 NL_SET_ERR_MSG(extack, "TC cookie size above the maximum");
 870                                 goto err_out;
 871                         }
 872
 873                         cookie = nla_memdup_cookie(tb);
 874                         if (!cookie) {
 875                                 NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
 876                                 err = -ENOMEM;
 877                                 goto err_out;
 878                         }
 879                 }
 880         } else {
 881                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
 882                         NL_SET_ERR_MSG(extack, "TC action name too long");
 883                         err = -EINVAL;
 884                         goto err_out;
 885                 }
 886         }
 887
 888         a_o = tc_lookup_action_n(act_name);
 889         if (a_o == NULL) {
 890 #ifdef CONFIG_MODULES
 891                 if (rtnl_held)
 892                         rtnl_unlock();
 893                 request_module("act_%s", act_name);
 894                 if (rtnl_held)
 895                         rtnl_lock();
 896
 897                 a_o = tc_lookup_action_n(act_name);
 898
 899                 /* We dropped the RTNL semaphore in order to
 900                  * perform the module load.  So, even if we
 901                  * succeeded in loading the module we have to
 902                  * tell the caller to replay the request.  We
 903                  * indicate this using -EAGAIN.
 904                  */
 905                 if (a_o != NULL) {
 906                         err = -EAGAIN;
 907                         goto err_mod;
 908                 }
 909 #endif
 910                 NL_SET_ERR_MSG(extack, "Failed to load TC action module");
 911                 err = -ENOENT;
 912                 goto err_out;
 913         }
 914
 915         /* backward compatibility for policer */
 916         if (name == NULL)
 917                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
 918                                 rtnl_held, tp, extack);
 919         else
 920                 err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
 921                                 tp, extack);
 922         if (err < 0)
 923                 goto err_mod;
 924
 925         if (!name && tb[TCA_ACT_COOKIE])
 926                 tcf_set_action_cookie(&a->act_cookie, cookie);
 927
 928         /* module count goes up only when brand new policy is created
 929          * if it exists and is only bound to in a_o->init() then
 930          * ACT_P_CREATED is not returned (a zero is).
 931          */
 932         if (err != ACT_P_CREATED)
 933                 module_put(a_o->owner);
 934
 935         if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN) &&
 936             !rcu_access_pointer(a->goto_chain)) {
 937                 tcf_action_destroy_1(a, bind);
 938                 NL_SET_ERR_MSG(extack, "can't use goto chain with NULL chain");
 939                 return ERR_PTR(-EINVAL);
 940         }
 941
 942         return a;
 943
 944 err_mod:
 945         module_put(a_o->owner);
 946 err_out:
 947         if (cookie) {
 948                 kfree(cookie->data);
 949                 kfree(cookie);
 950         }
 951         return ERR_PTR(err);
 952 }
 953
 954 /* Returns numbers of initialized actions or negative error. */
 955
 956 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 957                     struct nlattr *est, char *name, int ovr, int bind,
 958                     struct tc_action *actions[], size_t *attr_size,
 959                     bool rtnl_held, struct netlink_ext_ack *extack)
 960 {
 961         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 962         struct tc_action *act;
 963         size_t sz = 0;
 964         int err;
 965         int i;
 966
 967         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
 968         if (err < 0)
 969                 return err;
 970
 971         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 972                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
 973                                         rtnl_held, extack);
 974                 if (IS_ERR(act)) {
 975                         err = PTR_ERR(act);
 976                         goto err;
 977                 }
 978                 act->order = i;
 979                 sz += tcf_action_fill_size(act);
 980                 /* Start from index 0 */
 981                 actions[i - 1] = act;
 982         }
 983
 984         *attr_size = tcf_action_full_attrs_size(sz);
 985         return i - 1;
 986
 987 err:
 988         tcf_action_destroy(actions, bind);
 989         return err;
 990 }
 991
 992 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
 993                           int compat_mode)
 994 {
 995         int err = 0;
 996         struct gnet_dump d;
 997
 998         if (p == NULL)
 999                 goto errout;
1000
1001         /* compat_mode being true specifies a call that is supposed
1002          * to add additional backward compatibility statistic TLVs.
1003          */
1004         if (compat_mode) {
1005                 if (p->type == TCA_OLD_COMPAT)
1006                         err = gnet_stats_start_copy_compat(skb, 0,
1007                                                            TCA_STATS,
1008                                                            TCA_XSTATS,
1009                                                            &p->tcfa_lock, &d,
1010                                                            TCA_PAD);
1011                 else
1012                         return 0;
1013         } else
1014                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1015                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
1016
1017         if (err < 0)
1018                 goto errout;
1019
1020         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1021             gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1022                                      &p->tcfa_bstats_hw) < 0 ||
1023             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1024             gnet_stats_copy_queue(&d, p->cpu_qstats,
1025                                   &p->tcfa_qstats,
1026                                   p->tcfa_qstats.qlen) < 0)
1027                 goto errout;
1028
1029         if (gnet_stats_finish_copy(&d) < 0)
1030                 goto errout;
1031
1032         return 0;
1033
1034 errout:
1035         return -1;
1036 }
1037
1038 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1039                         u32 portid, u32 seq, u16 flags, int event, int bind,
1040                         int ref)
1041 {
1042         struct tcamsg *t;
1043         struct nlmsghdr *nlh;
1044         unsigned char *b = skb_tail_pointer(skb);
1045         struct nlattr *nest;
1046
1047         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1048         if (!nlh)
1049                 goto out_nlmsg_trim;
1050         t = nlmsg_data(nlh);
1051         t->tca_family = AF_UNSPEC;
1052         t->tca__pad1 = 0;
1053         t->tca__pad2 = 0;
1054
1055         nest = nla_nest_start(skb, TCA_ACT_TAB);
1056         if (!nest)
1057                 goto out_nlmsg_trim;
1058
1059         if (tcf_action_dump(skb, actions, bind, ref) < 0)
1060                 goto out_nlmsg_trim;
1061
1062         nla_nest_end(skb, nest);
1063
1064         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1065         return skb->len;
1066
1067 out_nlmsg_trim:
1068         nlmsg_trim(skb, b);
1069         return -1;
1070 }
1071
1072 static int
1073 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1074                struct tc_action *actions[], int event,
1075                struct netlink_ext_ack *extack)
1076 {
1077         struct sk_buff *skb;
1078
1079         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1080         if (!skb)
1081                 return -ENOBUFS;
1082         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1083                          0, 1) <= 0) {
1084                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1085                 kfree_skb(skb);
1086                 return -EINVAL;
1087         }
1088
1089         return rtnl_unicast(skb, net, portid);
1090 }
1091
1092 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1093                                           struct nlmsghdr *n, u32 portid,
1094                                           struct netlink_ext_ack *extack)
1095 {
1096         struct nlattr *tb[TCA_ACT_MAX + 1];
1097         const struct tc_action_ops *ops;
1098         struct tc_action *a;
1099         int index;
1100         int err;
1101
1102         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
1103         if (err < 0)
1104                 goto err_out;
1105
1106         err = -EINVAL;
1107         if (tb[TCA_ACT_INDEX] == NULL ||
1108             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1109                 NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1110                 goto err_out;
1111         }
1112         index = nla_get_u32(tb[TCA_ACT_INDEX]);
1113
1114         err = -EINVAL;
1115         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1116         if (!ops) { /* could happen in batch of actions */
1117                 NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1118                 goto err_out;
1119         }
1120         err = -ENOENT;
1121         if (ops->lookup(net, &a, index) == 0) {
1122                 NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1123                 goto err_mod;
1124         }
1125
1126         module_put(ops->owner);
1127         return a;
1128
1129 err_mod:
1130         module_put(ops->owner);
1131 err_out:
1132         return ERR_PTR(err);
1133 }
1134
1135 static int tca_action_flush(struct net *net, struct nlattr *nla,
1136                             struct nlmsghdr *n, u32 portid,
1137                             struct netlink_ext_ack *extack)
1138 {
1139         struct sk_buff *skb;
1140         unsigned char *b;
1141         struct nlmsghdr *nlh;
1142         struct tcamsg *t;
1143         struct netlink_callback dcb;
1144         struct nlattr *nest;
1145         struct nlattr *tb[TCA_ACT_MAX + 1];
1146         const struct tc_action_ops *ops;
1147         struct nlattr *kind;
1148         int err = -ENOMEM;
1149
1150         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1151         if (!skb)
1152                 return err;
1153
1154         b = skb_tail_pointer(skb);
1155
1156         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
1157         if (err < 0)
1158                 goto err_out;
1159
1160         err = -EINVAL;
1161         kind = tb[TCA_ACT_KIND];
1162         ops = tc_lookup_action(kind);
1163         if (!ops) { /*some idjot trying to flush unknown action */
1164                 NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1165                 goto err_out;
1166         }
1167
1168         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1169                         sizeof(*t), 0);
1170         if (!nlh) {
1171                 NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1172                 goto out_module_put;
1173         }
1174         t = nlmsg_data(nlh);
1175         t->tca_family = AF_UNSPEC;
1176         t->tca__pad1 = 0;
1177         t->tca__pad2 = 0;
1178
1179         nest = nla_nest_start(skb, TCA_ACT_TAB);
1180         if (!nest) {
1181                 NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1182                 goto out_module_put;
1183         }
1184
1185         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1186         if (err <= 0) {
1187                 nla_nest_cancel(skb, nest);
1188                 goto out_module_put;
1189         }
1190
1191         nla_nest_end(skb, nest);
1192
1193         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1194         nlh->nlmsg_flags |= NLM_F_ROOT;
1195         module_put(ops->owner);
1196         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1197                              n->nlmsg_flags & NLM_F_ECHO);
1198         if (err > 0)
1199                 return 0;
1200         if (err < 0)
1201                 NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1202
1203         return err;
1204
1205 out_module_put:
1206         module_put(ops->owner);
1207 err_out:
1208         kfree_skb(skb);
1209         return err;
1210 }
1211
1212 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1213 {
1214         int i;
1215
1216         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1217                 struct tc_action *a = actions[i];
1218                 const struct tc_action_ops *ops = a->ops;
1219                 /* Actions can be deleted concurrently so we must save their
1220                  * type and id to search again after reference is released.
1221                  */
1222                 struct tcf_idrinfo *idrinfo = a->idrinfo;
1223                 u32 act_index = a->tcfa_index;
1224
1225                 actions[i] = NULL;
1226                 if (tcf_action_put(a)) {
1227                         /* last reference, action was deleted concurrently */
1228                         module_put(ops->owner);
1229                 } else  {
1230                         int ret;
1231
1232                         /* now do the delete */
1233                         ret = tcf_idr_delete_index(idrinfo, act_index);
1234                         if (ret < 0)
1235                                 return ret;
1236                 }
1237         }
1238         return 0;
1239 }
1240
1241 static int
1242 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1243                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1244 {
1245         int ret;
1246         struct sk_buff *skb;
1247
1248         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1249                         GFP_KERNEL);
1250         if (!skb)
1251                 return -ENOBUFS;
1252
1253         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1254                          0, 2) <= 0) {
1255                 NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1256                 kfree_skb(skb);
1257                 return -EINVAL;
1258         }
1259
1260         /* now do the delete */
1261         ret = tcf_action_delete(net, actions);
1262         if (ret < 0) {
1263                 NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1264                 kfree_skb(skb);
1265                 return ret;
1266         }
1267
1268         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1269                              n->nlmsg_flags & NLM_F_ECHO);
1270         if (ret > 0)
1271                 return 0;
1272         return ret;
1273 }
1274
1275 static int
1276 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1277               u32 portid, int event, struct netlink_ext_ack *extack)
1278 {
1279         int i, ret;
1280         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1281         struct tc_action *act;
1282         size_t attr_size = 0;
1283         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1284
1285         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
1286         if (ret < 0)
1287                 return ret;
1288
1289         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1290                 if (tb[1])
1291                         return tca_action_flush(net, tb[1], n, portid, extack);
1292
1293                 NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1294                 return -EINVAL;
1295         }
1296
1297         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1298                 act = tcf_action_get_1(net, tb[i], n, portid, extack);
1299                 if (IS_ERR(act)) {
1300                         ret = PTR_ERR(act);
1301                         goto err;
1302                 }
1303                 act->order = i;
1304                 attr_size += tcf_action_fill_size(act);
1305                 actions[i - 1] = act;
1306         }
1307
1308         attr_size = tcf_action_full_attrs_size(attr_size);
1309
1310         if (event == RTM_GETACTION)
1311                 ret = tcf_get_notify(net, portid, n, actions, event, extack);
1312         else { /* delete */
1313                 ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1314                 if (ret)
1315                         goto err;
1316                 return 0;
1317         }
1318 err:
1319         tcf_action_put_many(actions);
1320         return ret;
1321 }
1322
1323 static int
1324 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1325                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1326 {
1327         struct sk_buff *skb;
1328         int err = 0;
1329
1330         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1331                         GFP_KERNEL);
1332         if (!skb)
1333                 return -ENOBUFS;
1334
1335         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1336                          RTM_NEWACTION, 0, 0) <= 0) {
1337                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1338                 kfree_skb(skb);
1339                 return -EINVAL;
1340         }
1341
1342         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1343                              n->nlmsg_flags & NLM_F_ECHO);
1344         if (err > 0)
1345                 err = 0;
1346         return err;
1347 }
1348
1349 static int tcf_action_add(struct net *net, struct nlattr *nla,
1350                           struct nlmsghdr *n, u32 portid, int ovr,
1351                           struct netlink_ext_ack *extack)
1352 {
1353         size_t attr_size = 0;
1354         int ret = 0;
1355         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1356
1357         ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0, actions,
1358                               &attr_size, true, extack);
1359         if (ret < 0)
1360                 return ret;
1361         ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1362         if (ovr)
1363                 tcf_action_put_many(actions);
1364
1365         return ret;
1366 }
1367
1368 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1369 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1370         [TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1371                              .validation_data = &tcaa_root_flags_allowed },
1372         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1373 };
1374
1375 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1376                          struct netlink_ext_ack *extack)
1377 {
1378         struct net *net = sock_net(skb->sk);
1379         struct nlattr *tca[TCA_ROOT_MAX + 1];
1380         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1381         int ret = 0, ovr = 0;
1382
1383         if ((n->nlmsg_type != RTM_GETACTION) &&
1384             !netlink_capable(skb, CAP_NET_ADMIN))
1385                 return -EPERM;
1386
1387         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ROOT_MAX, NULL,
1388                           extack);
1389         if (ret < 0)
1390                 return ret;
1391
1392         if (tca[TCA_ACT_TAB] == NULL) {
1393                 NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1394                 return -EINVAL;
1395         }
1396
1397         /* n->nlmsg_flags & NLM_F_CREATE */
1398         switch (n->nlmsg_type) {
1399         case RTM_NEWACTION:
1400                 /* we are going to assume all other flags
1401                  * imply create only if it doesn't exist
1402                  * Note that CREATE | EXCL implies that
1403                  * but since we want avoid ambiguity (eg when flags
1404                  * is zero) then just set this
1405                  */
1406                 if (n->nlmsg_flags & NLM_F_REPLACE)
1407                         ovr = 1;
1408 replay:
1409                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1410                                      extack);
1411                 if (ret == -EAGAIN)
1412                         goto replay;
1413                 break;
1414         case RTM_DELACTION:
1415                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1416                                     portid, RTM_DELACTION, extack);
1417                 break;
1418         case RTM_GETACTION:
1419                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1420                                     portid, RTM_GETACTION, extack);
1421                 break;
1422         default:
1423                 BUG();
1424         }
1425
1426         return ret;
1427 }
1428
1429 static struct nlattr *find_dump_kind(struct nlattr **nla)
1430 {
1431         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1432         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1433         struct nlattr *kind;
1434
1435         tb1 = nla[TCA_ACT_TAB];
1436         if (tb1 == NULL)
1437                 return NULL;
1438
1439         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1440                       NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1441                 return NULL;
1442
1443         if (tb[1] == NULL)
1444                 return NULL;
1445         if (nla_parse_nested(tb2, TCA_ACT_MAX, tb[1], NULL, NULL) < 0)
1446                 return NULL;
1447         kind = tb2[TCA_ACT_KIND];
1448
1449         return kind;
1450 }
1451
1452 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1453 {
1454         struct net *net = sock_net(skb->sk);
1455         struct nlmsghdr *nlh;
1456         unsigned char *b = skb_tail_pointer(skb);
1457         struct nlattr *nest;
1458         struct tc_action_ops *a_o;
1459         int ret = 0;
1460         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1461         struct nlattr *tb[TCA_ROOT_MAX + 1];
1462         struct nlattr *count_attr = NULL;
1463         unsigned long jiffy_since = 0;
1464         struct nlattr *kind = NULL;
1465         struct nla_bitfield32 bf;
1466         u32 msecs_since = 0;
1467         u32 act_count = 0;
1468
1469         ret = nlmsg_parse(cb->nlh, sizeof(struct tcamsg), tb, TCA_ROOT_MAX,
1470                           tcaa_policy, cb->extack);
1471         if (ret < 0)
1472                 return ret;
1473
1474         kind = find_dump_kind(tb);
1475         if (kind == NULL) {
1476                 pr_info("tc_dump_action: action bad kind\n");
1477                 return 0;
1478         }
1479
1480         a_o = tc_lookup_action(kind);
1481         if (a_o == NULL)
1482                 return 0;
1483
1484         cb->args[2] = 0;
1485         if (tb[TCA_ROOT_FLAGS]) {
1486                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1487                 cb->args[2] = bf.value;
1488         }
1489
1490         if (tb[TCA_ROOT_TIME_DELTA]) {
1491                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1492         }
1493
1494         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1495                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1496         if (!nlh)
1497                 goto out_module_put;
1498
1499         if (msecs_since)
1500                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1501
1502         t = nlmsg_data(nlh);
1503         t->tca_family = AF_UNSPEC;
1504         t->tca__pad1 = 0;
1505         t->tca__pad2 = 0;
1506         cb->args[3] = jiffy_since;
1507         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1508         if (!count_attr)
1509                 goto out_module_put;
1510
1511         nest = nla_nest_start(skb, TCA_ACT_TAB);
1512         if (nest == NULL)
1513                 goto out_module_put;
1514
1515         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1516         if (ret < 0)
1517                 goto out_module_put;
1518
1519         if (ret > 0) {
1520                 nla_nest_end(skb, nest);
1521                 ret = skb->len;
1522                 act_count = cb->args[1];
1523                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1524                 cb->args[1] = 0;
1525         } else
1526                 nlmsg_trim(skb, b);
1527
1528         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1529         if (NETLINK_CB(cb->skb).portid && ret)
1530                 nlh->nlmsg_flags |= NLM_F_MULTI;
1531         module_put(a_o->owner);
1532         return skb->len;
1533
1534 out_module_put:
1535         module_put(a_o->owner);
1536         nlmsg_trim(skb, b);
1537         return skb->len;
1538 }
1539
1540 static int __init tc_action_init(void)
1541 {
1542         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1543         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1544         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1545                       0);
1546
1547         return 0;
1548 }
1549
1550 subsys_initcall(tc_action_init);