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         rcu_swap_protected(a->goto_chain, goto_chain, 1);
  92         return goto_chain;
  93 }
  94 EXPORT_SYMBOL(tcf_action_set_ctrlact);
  95
  96 /* XXX: For standalone actions, we don't need a RCU grace period either, because
  97  * actions are always connected to filters and filters are already destroyed in
  98  * RCU callbacks, so after a RCU grace period actions are already disconnected
  99  * from filters. Readers later can not find us.
 100  */
 101 static void free_tcf(struct tc_action *p)
 102 {
 103         struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
 104
 105         free_percpu(p->cpu_bstats);
 106         free_percpu(p->cpu_bstats_hw);
 107         free_percpu(p->cpu_qstats);
 108
 109         tcf_set_action_cookie(&p->act_cookie, NULL);
 110         if (chain)
 111                 tcf_chain_put_by_act(chain);
 112
 113         kfree(p);
 114 }
 115
 116 static void tcf_action_cleanup(struct tc_action *p)
 117 {
 118         if (p->ops->cleanup)
 119                 p->ops->cleanup(p);
 120
 121         gen_kill_estimator(&p->tcfa_rate_est);
 122         free_tcf(p);
 123 }
 124
 125 static int __tcf_action_put(struct tc_action *p, bool bind)
 126 {
 127         struct tcf_idrinfo *idrinfo = p->idrinfo;
 128
 129         if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
 130                 if (bind)
 131                         atomic_dec(&p->tcfa_bindcnt);
 132                 idr_remove(&idrinfo->action_idr, p->tcfa_index);
 133                 mutex_unlock(&idrinfo->lock);
 134
 135                 tcf_action_cleanup(p);
 136                 return 1;
 137         }
 138
 139         if (bind)
 140                 atomic_dec(&p->tcfa_bindcnt);
 141
 142         return 0;
 143 }
 144
 145 int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
 146 {
 147         int ret = 0;
 148
 149         /* Release with strict==1 and bind==0 is only called through act API
 150          * interface (classifiers always bind). Only case when action with
 151          * positive reference count and zero bind count can exist is when it was
 152          * also created with act API (unbinding last classifier will destroy the
 153          * action if it was created by classifier). So only case when bind count
 154          * can be changed after initial check is when unbound action is
 155          * destroyed by act API while classifier binds to action with same id
 156          * concurrently. This result either creation of new action(same behavior
 157          * as before), or reusing existing action if concurrent process
 158          * increments reference count before action is deleted. Both scenarios
 159          * are acceptable.
 160          */
 161         if (p) {
 162                 if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
 163                         return -EPERM;
 164
 165                 if (__tcf_action_put(p, bind))
 166                         ret = ACT_P_DELETED;
 167         }
 168
 169         return ret;
 170 }
 171 EXPORT_SYMBOL(__tcf_idr_release);
 172
 173 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
 174 {
 175         struct tc_cookie *act_cookie;
 176         u32 cookie_len = 0;
 177
 178         rcu_read_lock();
 179         act_cookie = rcu_dereference(act->act_cookie);
 180
 181         if (act_cookie)
 182                 cookie_len = nla_total_size(act_cookie->len);
 183         rcu_read_unlock();
 184
 185         return  nla_total_size(0) /* action number nested */
 186                 + nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
 187                 + cookie_len /* TCA_ACT_COOKIE */
 188                 + nla_total_size(0) /* TCA_ACT_STATS nested */
 189                 /* TCA_STATS_BASIC */
 190                 + nla_total_size_64bit(sizeof(struct gnet_stats_basic))
 191                 /* TCA_STATS_QUEUE */
 192                 + nla_total_size_64bit(sizeof(struct gnet_stats_queue))
 193                 + nla_total_size(0) /* TCA_OPTIONS nested */
 194                 + nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
 195 }
 196
 197 static size_t tcf_action_full_attrs_size(size_t sz)
 198 {
 199         return NLMSG_HDRLEN                     /* struct nlmsghdr */
 200                 + sizeof(struct tcamsg)
 201                 + nla_total_size(0)             /* TCA_ACT_TAB nested */
 202                 + sz;
 203 }
 204
 205 static size_t tcf_action_fill_size(const struct tc_action *act)
 206 {
 207         size_t sz = tcf_action_shared_attrs_size(act);
 208
 209         if (act->ops->get_fill_size)
 210                 return act->ops->get_fill_size(act) + sz;
 211         return sz;
 212 }
 213
 214 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 215                            struct netlink_callback *cb)
 216 {
 217         int err = 0, index = -1, s_i = 0, n_i = 0;
 218         u32 act_flags = cb->args[2];
 219         unsigned long jiffy_since = cb->args[3];
 220         struct nlattr *nest;
 221         struct idr *idr = &idrinfo->action_idr;
 222         struct tc_action *p;
 223         unsigned long id = 1;
 224         unsigned long tmp;
 225
 226         mutex_lock(&idrinfo->lock);
 227
 228         s_i = cb->args[0];
 229
 230         idr_for_each_entry_ul(idr, p, tmp, id) {
 231                 index++;
 232                 if (index < s_i)
 233                         continue;
 234
 235                 if (jiffy_since &&
 236                     time_after(jiffy_since,
 237                                (unsigned long)p->tcfa_tm.lastuse))
 238                         continue;
 239
 240                 nest = nla_nest_start_noflag(skb, n_i);
 241                 if (!nest) {
 242                         index--;
 243                         goto nla_put_failure;
 244                 }
 245                 err = tcf_action_dump_1(skb, p, 0, 0);
 246                 if (err < 0) {
 247                         index--;
 248                         nlmsg_trim(skb, nest);
 249                         goto done;
 250                 }
 251                 nla_nest_end(skb, nest);
 252                 n_i++;
 253                 if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
 254                     n_i >= TCA_ACT_MAX_PRIO)
 255                         goto done;
 256         }
 257 done:
 258         if (index >= 0)
 259                 cb->args[0] = index + 1;
 260
 261         mutex_unlock(&idrinfo->lock);
 262         if (n_i) {
 263                 if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
 264                         cb->args[1] = n_i;
 265         }
 266         return n_i;
 267
 268 nla_put_failure:
 269         nla_nest_cancel(skb, nest);
 270         goto done;
 271 }
 272
 273 static int tcf_idr_release_unsafe(struct tc_action *p)
 274 {
 275         if (atomic_read(&p->tcfa_bindcnt) > 0)
 276                 return -EPERM;
 277
 278         if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 279                 idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
 280                 tcf_action_cleanup(p);
 281                 return ACT_P_DELETED;
 282         }
 283
 284         return 0;
 285 }
 286
 287 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 288                           const struct tc_action_ops *ops)
 289 {
 290         struct nlattr *nest;
 291         int n_i = 0;
 292         int ret = -EINVAL;
 293         struct idr *idr = &idrinfo->action_idr;
 294         struct tc_action *p;
 295         unsigned long id = 1;
 296         unsigned long tmp;
 297
 298         nest = nla_nest_start_noflag(skb, 0);
 299         if (nest == NULL)
 300                 goto nla_put_failure;
 301         if (nla_put_string(skb, TCA_KIND, ops->kind))
 302                 goto nla_put_failure;
 303
 304         mutex_lock(&idrinfo->lock);
 305         idr_for_each_entry_ul(idr, p, tmp, id) {
 306                 ret = tcf_idr_release_unsafe(p);
 307                 if (ret == ACT_P_DELETED) {
 308                         module_put(ops->owner);
 309                         n_i++;
 310                 } else if (ret < 0) {
 311                         mutex_unlock(&idrinfo->lock);
 312                         goto nla_put_failure;
 313                 }
 314         }
 315         mutex_unlock(&idrinfo->lock);
 316
 317         if (nla_put_u32(skb, TCA_FCNT, n_i))
 318                 goto nla_put_failure;
 319         nla_nest_end(skb, nest);
 320
 321         return n_i;
 322 nla_put_failure:
 323         nla_nest_cancel(skb, nest);
 324         return ret;
 325 }
 326
 327 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 328                        struct netlink_callback *cb, int type,
 329                        const struct tc_action_ops *ops,
 330                        struct netlink_ext_ack *extack)
 331 {
 332         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 333
 334         if (type == RTM_DELACTION) {
 335                 return tcf_del_walker(idrinfo, skb, ops);
 336         } else if (type == RTM_GETACTION) {
 337                 return tcf_dump_walker(idrinfo, skb, cb);
 338         } else {
 339                 WARN(1, "tcf_generic_walker: unknown command %d\n", type);
 340                 NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
 341                 return -EINVAL;
 342         }
 343 }
 344 EXPORT_SYMBOL(tcf_generic_walker);
 345
 346 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 347 {
 348         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 349         struct tc_action *p;
 350
 351         mutex_lock(&idrinfo->lock);
 352         p = idr_find(&idrinfo->action_idr, index);
 353         if (IS_ERR(p))
 354                 p = NULL;
 355         else if (p)
 356                 refcount_inc(&p->tcfa_refcnt);
 357         mutex_unlock(&idrinfo->lock);
 358
 359         if (p) {
 360                 *a = p;
 361                 return true;
 362         }
 363         return false;
 364 }
 365 EXPORT_SYMBOL(tcf_idr_search);
 366
 367 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
 368 {
 369         struct tc_action *p;
 370         int ret = 0;
 371
 372         mutex_lock(&idrinfo->lock);
 373         p = idr_find(&idrinfo->action_idr, index);
 374         if (!p) {
 375                 mutex_unlock(&idrinfo->lock);
 376                 return -ENOENT;
 377         }
 378
 379         if (!atomic_read(&p->tcfa_bindcnt)) {
 380                 if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 381                         struct module *owner = p->ops->owner;
 382
 383                         WARN_ON(p != idr_remove(&idrinfo->action_idr,
 384                                                 p->tcfa_index));
 385                         mutex_unlock(&idrinfo->lock);
 386
 387                         tcf_action_cleanup(p);
 388                         module_put(owner);
 389                         return 0;
 390                 }
 391                 ret = 0;
 392         } else {
 393                 ret = -EPERM;
 394         }
 395
 396         mutex_unlock(&idrinfo->lock);
 397         return ret;
 398 }
 399
 400 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 401                    struct tc_action **a, const struct tc_action_ops *ops,
 402                    int bind, bool cpustats)
 403 {
 404         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 405         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 406         int err = -ENOMEM;
 407
 408         if (unlikely(!p))
 409                 return -ENOMEM;
 410         refcount_set(&p->tcfa_refcnt, 1);
 411         if (bind)
 412                 atomic_set(&p->tcfa_bindcnt, 1);
 413
 414         if (cpustats) {
 415                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 416                 if (!p->cpu_bstats)
 417                         goto err1;
 418                 p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 419                 if (!p->cpu_bstats_hw)
 420                         goto err2;
 421                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 422                 if (!p->cpu_qstats)
 423                         goto err3;
 424         }
 425         spin_lock_init(&p->tcfa_lock);
 426         p->tcfa_index = index;
 427         p->tcfa_tm.install = jiffies;
 428         p->tcfa_tm.lastuse = jiffies;
 429         p->tcfa_tm.firstuse = 0;
 430         if (est) {
 431                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 432                                         &p->tcfa_rate_est,
 433                                         &p->tcfa_lock, NULL, est);
 434                 if (err)
 435                         goto err4;
 436         }
 437
 438         p->idrinfo = idrinfo;
 439         p->ops = ops;
 440         *a = p;
 441         return 0;
 442 err4:
 443         free_percpu(p->cpu_qstats);
 444 err3:
 445         free_percpu(p->cpu_bstats_hw);
 446 err2:
 447         free_percpu(p->cpu_bstats);
 448 err1:
 449         kfree(p);
 450         return err;
 451 }
 452 EXPORT_SYMBOL(tcf_idr_create);
 453
 454 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
 455 {
 456         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 457
 458         mutex_lock(&idrinfo->lock);
 459         /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 460         WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
 461         mutex_unlock(&idrinfo->lock);
 462 }
 463 EXPORT_SYMBOL(tcf_idr_insert);
 464
 465 /* Cleanup idr index that was allocated but not initialized. */
 466
 467 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
 468 {
 469         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 470
 471         mutex_lock(&idrinfo->lock);
 472         /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 473         WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
 474         mutex_unlock(&idrinfo->lock);
 475 }
 476 EXPORT_SYMBOL(tcf_idr_cleanup);
 477
 478 /* Check if action with specified index exists. If actions is found, increments
 479  * its reference and bind counters, and return 1. Otherwise insert temporary
 480  * error pointer (to prevent concurrent users from inserting actions with same
 481  * index) and return 0.
 482  */
 483
 484 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 485                         struct tc_action **a, int bind)
 486 {
 487         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 488         struct tc_action *p;
 489         int ret;
 490
 491 again:
 492         mutex_lock(&idrinfo->lock);
 493         if (*index) {
 494                 p = idr_find(&idrinfo->action_idr, *index);
 495                 if (IS_ERR(p)) {
 496                         /* This means that another process allocated
 497                          * index but did not assign the pointer yet.
 498                          */
 499                         mutex_unlock(&idrinfo->lock);
 500                         goto again;
 501                 }
 502
 503                 if (p) {
 504                         refcount_inc(&p->tcfa_refcnt);
 505                         if (bind)
 506                                 atomic_inc(&p->tcfa_bindcnt);
 507                         *a = p;
 508                         ret = 1;
 509                 } else {
 510                         *a = NULL;
 511                         ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 512                                             *index, GFP_KERNEL);
 513                         if (!ret)
 514                                 idr_replace(&idrinfo->action_idr,
 515                                             ERR_PTR(-EBUSY), *index);
 516                 }
 517         } else {
 518                 *index = 1;
 519                 *a = NULL;
 520                 ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 521                                     UINT_MAX, GFP_KERNEL);
 522                 if (!ret)
 523                         idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
 524                                     *index);
 525         }
 526         mutex_unlock(&idrinfo->lock);
 527         return ret;
 528 }
 529 EXPORT_SYMBOL(tcf_idr_check_alloc);
 530
 531 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 532                          struct tcf_idrinfo *idrinfo)
 533 {
 534         struct idr *idr = &idrinfo->action_idr;
 535         struct tc_action *p;
 536         int ret;
 537         unsigned long id = 1;
 538         unsigned long tmp;
 539
 540         idr_for_each_entry_ul(idr, p, tmp, id) {
 541                 ret = __tcf_idr_release(p, false, true);
 542                 if (ret == ACT_P_DELETED)
 543                         module_put(ops->owner);
 544                 else if (ret < 0)
 545                         return;
 546         }
 547         idr_destroy(&idrinfo->action_idr);
 548 }
 549 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 550
 551 static LIST_HEAD(act_base);
 552 static DEFINE_RWLOCK(act_mod_lock);
 553
 554 int tcf_register_action(struct tc_action_ops *act,
 555                         struct pernet_operations *ops)
 556 {
 557         struct tc_action_ops *a;
 558         int ret;
 559
 560         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 561                 return -EINVAL;
 562
 563         /* We have to register pernet ops before making the action ops visible,
 564          * otherwise tcf_action_init_1() could get a partially initialized
 565          * netns.
 566          */
 567         ret = register_pernet_subsys(ops);
 568         if (ret)
 569                 return ret;
 570
 571         write_lock(&act_mod_lock);
 572         list_for_each_entry(a, &act_base, head) {
 573                 if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
 574                         write_unlock(&act_mod_lock);
 575                         unregister_pernet_subsys(ops);
 576                         return -EEXIST;
 577                 }
 578         }
 579         list_add_tail(&act->head, &act_base);
 580         write_unlock(&act_mod_lock);
 581
 582         return 0;
 583 }
 584 EXPORT_SYMBOL(tcf_register_action);
 585
 586 int tcf_unregister_action(struct tc_action_ops *act,
 587                           struct pernet_operations *ops)
 588 {
 589         struct tc_action_ops *a;
 590         int err = -ENOENT;
 591
 592         write_lock(&act_mod_lock);
 593         list_for_each_entry(a, &act_base, head) {
 594                 if (a == act) {
 595                         list_del(&act->head);
 596                         err = 0;
 597                         break;
 598                 }
 599         }
 600         write_unlock(&act_mod_lock);
 601         if (!err)
 602                 unregister_pernet_subsys(ops);
 603         return err;
 604 }
 605 EXPORT_SYMBOL(tcf_unregister_action);
 606
 607 /* lookup by name */
 608 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 609 {
 610         struct tc_action_ops *a, *res = NULL;
 611
 612         if (kind) {
 613                 read_lock(&act_mod_lock);
 614                 list_for_each_entry(a, &act_base, head) {
 615                         if (strcmp(kind, a->kind) == 0) {
 616                                 if (try_module_get(a->owner))
 617                                         res = a;
 618                                 break;
 619                         }
 620                 }
 621                 read_unlock(&act_mod_lock);
 622         }
 623         return res;
 624 }
 625
 626 /* lookup by nlattr */
 627 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 628 {
 629         struct tc_action_ops *a, *res = NULL;
 630
 631         if (kind) {
 632                 read_lock(&act_mod_lock);
 633                 list_for_each_entry(a, &act_base, head) {
 634                         if (nla_strcmp(kind, a->kind) == 0) {
 635                                 if (try_module_get(a->owner))
 636                                         res = a;
 637                                 break;
 638                         }
 639                 }
 640                 read_unlock(&act_mod_lock);
 641         }
 642         return res;
 643 }
 644
 645 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 646 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 647 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 648                     int nr_actions, struct tcf_result *res)
 649 {
 650         u32 jmp_prgcnt = 0;
 651         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 652         int i;
 653         int ret = TC_ACT_OK;
 654
 655         if (skb_skip_tc_classify(skb))
 656                 return TC_ACT_OK;
 657
 658 restart_act_graph:
 659         for (i = 0; i < nr_actions; i++) {
 660                 const struct tc_action *a = actions[i];
 661
 662                 if (jmp_prgcnt > 0) {
 663                         jmp_prgcnt -= 1;
 664                         continue;
 665                 }
 666 repeat:
 667                 ret = a->ops->act(skb, a, res);
 668                 if (ret == TC_ACT_REPEAT)
 669                         goto repeat;    /* we need a ttl - JHS */
 670
 671                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 672                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 673                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 674                                 /* faulty opcode, stop pipeline */
 675                                 return TC_ACT_OK;
 676                         } else {
 677                                 jmp_ttl -= 1;
 678                                 if (jmp_ttl > 0)
 679                                         goto restart_act_graph;
 680                                 else /* faulty graph, stop pipeline */
 681                                         return TC_ACT_OK;
 682                         }
 683                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 684                         if (unlikely(!rcu_access_pointer(a->goto_chain))) {
 685                                 net_warn_ratelimited("can't go to NULL chain!\n");
 686                                 return TC_ACT_SHOT;
 687                         }
 688                         tcf_action_goto_chain_exec(a, res);
 689                 }
 690
 691                 if (ret != TC_ACT_PIPE)
 692                         break;
 693         }
 694
 695         return ret;
 696 }
 697 EXPORT_SYMBOL(tcf_action_exec);
 698
 699 int tcf_action_destroy(struct tc_action *actions[], int bind)
 700 {
 701         const struct tc_action_ops *ops;
 702         struct tc_action *a;
 703         int ret = 0, i;
 704
 705         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 706                 a = actions[i];
 707                 actions[i] = NULL;
 708                 ops = a->ops;
 709                 ret = __tcf_idr_release(a, bind, true);
 710                 if (ret == ACT_P_DELETED)
 711                         module_put(ops->owner);
 712                 else if (ret < 0)
 713                         return ret;
 714         }
 715         return ret;
 716 }
 717
 718 static int tcf_action_destroy_1(struct tc_action *a, int bind)
 719 {
 720         struct tc_action *actions[] = { a, NULL };
 721
 722         return tcf_action_destroy(actions, bind);
 723 }
 724
 725 static int tcf_action_put(struct tc_action *p)
 726 {
 727         return __tcf_action_put(p, false);
 728 }
 729
 730 /* Put all actions in this array, skip those NULL's. */
 731 static void tcf_action_put_many(struct tc_action *actions[])
 732 {
 733         int i;
 734
 735         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 736                 struct tc_action *a = actions[i];
 737                 const struct tc_action_ops *ops;
 738
 739                 if (!a)
 740                         continue;
 741                 ops = a->ops;
 742                 if (tcf_action_put(a))
 743                         module_put(ops->owner);
 744         }
 745 }
 746
 747 int
 748 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 749 {
 750         return a->ops->dump(skb, a, bind, ref);
 751 }
 752
 753 int
 754 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 755 {
 756         int err = -EINVAL;
 757         unsigned char *b = skb_tail_pointer(skb);
 758         struct nlattr *nest;
 759         struct tc_cookie *cookie;
 760
 761         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 762                 goto nla_put_failure;
 763         if (tcf_action_copy_stats(skb, a, 0))
 764                 goto nla_put_failure;
 765
 766         rcu_read_lock();
 767         cookie = rcu_dereference(a->act_cookie);
 768         if (cookie) {
 769                 if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
 770                         rcu_read_unlock();
 771                         goto nla_put_failure;
 772                 }
 773         }
 774         rcu_read_unlock();
 775
 776         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 777         if (nest == NULL)
 778                 goto nla_put_failure;
 779         err = tcf_action_dump_old(skb, a, bind, ref);
 780         if (err > 0) {
 781                 nla_nest_end(skb, nest);
 782                 return err;
 783         }
 784
 785 nla_put_failure:
 786         nlmsg_trim(skb, b);
 787         return -1;
 788 }
 789 EXPORT_SYMBOL(tcf_action_dump_1);
 790
 791 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 792                     int bind, int ref)
 793 {
 794         struct tc_action *a;
 795         int err = -EINVAL, i;
 796         struct nlattr *nest;
 797
 798         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 799                 a = actions[i];
 800                 nest = nla_nest_start_noflag(skb, i + 1);
 801                 if (nest == NULL)
 802                         goto nla_put_failure;
 803                 err = tcf_action_dump_1(skb, a, bind, ref);
 804                 if (err < 0)
 805                         goto errout;
 806                 nla_nest_end(skb, nest);
 807         }
 808
 809         return 0;
 810
 811 nla_put_failure:
 812         err = -EINVAL;
 813 errout:
 814         nla_nest_cancel(skb, nest);
 815         return err;
 816 }
 817
 818 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 819 {
 820         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 821         if (!c)
 822                 return NULL;
 823
 824         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 825         if (!c->data) {
 826                 kfree(c);
 827                 return NULL;
 828         }
 829         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 830
 831         return c;
 832 }
 833
 834 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 835                                     struct nlattr *nla, struct nlattr *est,
 836                                     char *name, int ovr, int bind,
 837                                     bool rtnl_held,
 838                                     struct netlink_ext_ack *extack)
 839 {
 840         struct tc_action *a;
 841         struct tc_action_ops *a_o;
 842         struct tc_cookie *cookie = NULL;
 843         char act_name[IFNAMSIZ];
 844         struct nlattr *tb[TCA_ACT_MAX + 1];
 845         struct nlattr *kind;
 846         int err;
 847
 848         if (name == NULL) {
 849                 err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla, NULL,
 850                                                   extack);
 851                 if (err < 0)
 852                         goto err_out;
 853                 err = -EINVAL;
 854                 kind = tb[TCA_ACT_KIND];
 855                 if (!kind) {
 856                         NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 857                         goto err_out;
 858                 }
 859                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
 860                         NL_SET_ERR_MSG(extack, "TC action name too long");
 861                         goto err_out;
 862                 }
 863                 if (tb[TCA_ACT_COOKIE]) {
 864                         int cklen = nla_len(tb[TCA_ACT_COOKIE]);
 865
 866                         if (cklen > TC_COOKIE_MAX_SIZE) {
 867                                 NL_SET_ERR_MSG(extack, "TC cookie size above the maximum");
 868                                 goto err_out;
 869                         }
 870
 871                         cookie = nla_memdup_cookie(tb);
 872                         if (!cookie) {
 873                                 NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
 874                                 err = -ENOMEM;
 875                                 goto err_out;
 876                         }
 877                 }
 878         } else {
 879                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
 880                         NL_SET_ERR_MSG(extack, "TC action name too long");
 881                         err = -EINVAL;
 882                         goto err_out;
 883                 }
 884         }
 885
 886         a_o = tc_lookup_action_n(act_name);
 887         if (a_o == NULL) {
 888 #ifdef CONFIG_MODULES
 889                 if (rtnl_held)
 890                         rtnl_unlock();
 891                 request_module("act_%s", act_name);
 892                 if (rtnl_held)
 893                         rtnl_lock();
 894
 895                 a_o = tc_lookup_action_n(act_name);
 896
 897                 /* We dropped the RTNL semaphore in order to
 898                  * perform the module load.  So, even if we
 899                  * succeeded in loading the module we have to
 900                  * tell the caller to replay the request.  We
 901                  * indicate this using -EAGAIN.
 902                  */
 903                 if (a_o != NULL) {
 904                         err = -EAGAIN;
 905                         goto err_mod;
 906                 }
 907 #endif
 908                 NL_SET_ERR_MSG(extack, "Failed to load TC action module");
 909                 err = -ENOENT;
 910                 goto err_out;
 911         }
 912
 913         /* backward compatibility for policer */
 914         if (name == NULL)
 915                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
 916                                 rtnl_held, tp, extack);
 917         else
 918                 err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
 919                                 tp, extack);
 920         if (err < 0)
 921                 goto err_mod;
 922
 923         if (!name && tb[TCA_ACT_COOKIE])
 924                 tcf_set_action_cookie(&a->act_cookie, cookie);
 925
 926         /* module count goes up only when brand new policy is created
 927          * if it exists and is only bound to in a_o->init() then
 928          * ACT_P_CREATED is not returned (a zero is).
 929          */
 930         if (err != ACT_P_CREATED)
 931                 module_put(a_o->owner);
 932
 933         if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN) &&
 934             !rcu_access_pointer(a->goto_chain)) {
 935                 tcf_action_destroy_1(a, bind);
 936                 NL_SET_ERR_MSG(extack, "can't use goto chain with NULL chain");
 937                 return ERR_PTR(-EINVAL);
 938         }
 939
 940         return a;
 941
 942 err_mod:
 943         module_put(a_o->owner);
 944 err_out:
 945         if (cookie) {
 946                 kfree(cookie->data);
 947                 kfree(cookie);
 948         }
 949         return ERR_PTR(err);
 950 }
 951
 952 /* Returns numbers of initialized actions or negative error. */
 953
 954 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 955                     struct nlattr *est, char *name, int ovr, int bind,
 956                     struct tc_action *actions[], size_t *attr_size,
 957                     bool rtnl_held, struct netlink_ext_ack *extack)
 958 {
 959         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 960         struct tc_action *act;
 961         size_t sz = 0;
 962         int err;
 963         int i;
 964
 965         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
 966                                           extack);
 967         if (err < 0)
 968                 return err;
 969
 970         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 971                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
 972                                         rtnl_held, extack);
 973                 if (IS_ERR(act)) {
 974                         err = PTR_ERR(act);
 975                         goto err;
 976                 }
 977                 act->order = i;
 978                 sz += tcf_action_fill_size(act);
 979                 /* Start from index 0 */
 980                 actions[i - 1] = act;
 981         }
 982
 983         *attr_size = tcf_action_full_attrs_size(sz);
 984         return i - 1;
 985
 986 err:
 987         tcf_action_destroy(actions, bind);
 988         return err;
 989 }
 990
 991 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
 992                           int compat_mode)
 993 {
 994         int err = 0;
 995         struct gnet_dump d;
 996
 997         if (p == NULL)
 998                 goto errout;
 999
1000         /* compat_mode being true specifies a call that is supposed
1001          * to add additional backward compatibility statistic TLVs.
1002          */
1003         if (compat_mode) {
1004                 if (p->type == TCA_OLD_COMPAT)
1005                         err = gnet_stats_start_copy_compat(skb, 0,
1006                                                            TCA_STATS,
1007                                                            TCA_XSTATS,
1008                                                            &p->tcfa_lock, &d,
1009                                                            TCA_PAD);
1010                 else
1011                         return 0;
1012         } else
1013                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1014                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
1015
1016         if (err < 0)
1017                 goto errout;
1018
1019         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1020             gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1021                                      &p->tcfa_bstats_hw) < 0 ||
1022             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1023             gnet_stats_copy_queue(&d, p->cpu_qstats,
1024                                   &p->tcfa_qstats,
1025                                   p->tcfa_qstats.qlen) < 0)
1026                 goto errout;
1027
1028         if (gnet_stats_finish_copy(&d) < 0)
1029                 goto errout;
1030
1031         return 0;
1032
1033 errout:
1034         return -1;
1035 }
1036
1037 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1038                         u32 portid, u32 seq, u16 flags, int event, int bind,
1039                         int ref)
1040 {
1041         struct tcamsg *t;
1042         struct nlmsghdr *nlh;
1043         unsigned char *b = skb_tail_pointer(skb);
1044         struct nlattr *nest;
1045
1046         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1047         if (!nlh)
1048                 goto out_nlmsg_trim;
1049         t = nlmsg_data(nlh);
1050         t->tca_family = AF_UNSPEC;
1051         t->tca__pad1 = 0;
1052         t->tca__pad2 = 0;
1053
1054         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1055         if (!nest)
1056                 goto out_nlmsg_trim;
1057
1058         if (tcf_action_dump(skb, actions, bind, ref) < 0)
1059                 goto out_nlmsg_trim;
1060
1061         nla_nest_end(skb, nest);
1062
1063         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1064         return skb->len;
1065
1066 out_nlmsg_trim:
1067         nlmsg_trim(skb, b);
1068         return -1;
1069 }
1070
1071 static int
1072 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1073                struct tc_action *actions[], int event,
1074                struct netlink_ext_ack *extack)
1075 {
1076         struct sk_buff *skb;
1077
1078         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1079         if (!skb)
1080                 return -ENOBUFS;
1081         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1082                          0, 1) <= 0) {
1083                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1084                 kfree_skb(skb);
1085                 return -EINVAL;
1086         }
1087
1088         return rtnl_unicast(skb, net, portid);
1089 }
1090
1091 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1092                                           struct nlmsghdr *n, u32 portid,
1093                                           struct netlink_ext_ack *extack)
1094 {
1095         struct nlattr *tb[TCA_ACT_MAX + 1];
1096         const struct tc_action_ops *ops;
1097         struct tc_action *a;
1098         int index;
1099         int err;
1100
1101         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla, NULL, extack);
1102         if (err < 0)
1103                 goto err_out;
1104
1105         err = -EINVAL;
1106         if (tb[TCA_ACT_INDEX] == NULL ||
1107             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1108                 NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1109                 goto err_out;
1110         }
1111         index = nla_get_u32(tb[TCA_ACT_INDEX]);
1112
1113         err = -EINVAL;
1114         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1115         if (!ops) { /* could happen in batch of actions */
1116                 NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1117                 goto err_out;
1118         }
1119         err = -ENOENT;
1120         if (ops->lookup(net, &a, index) == 0) {
1121                 NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1122                 goto err_mod;
1123         }
1124
1125         module_put(ops->owner);
1126         return a;
1127
1128 err_mod:
1129         module_put(ops->owner);
1130 err_out:
1131         return ERR_PTR(err);
1132 }
1133
1134 static int tca_action_flush(struct net *net, struct nlattr *nla,
1135                             struct nlmsghdr *n, u32 portid,
1136                             struct netlink_ext_ack *extack)
1137 {
1138         struct sk_buff *skb;
1139         unsigned char *b;
1140         struct nlmsghdr *nlh;
1141         struct tcamsg *t;
1142         struct netlink_callback dcb;
1143         struct nlattr *nest;
1144         struct nlattr *tb[TCA_ACT_MAX + 1];
1145         const struct tc_action_ops *ops;
1146         struct nlattr *kind;
1147         int err = -ENOMEM;
1148
1149         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1150         if (!skb)
1151                 return err;
1152
1153         b = skb_tail_pointer(skb);
1154
1155         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla, NULL, extack);
1156         if (err < 0)
1157                 goto err_out;
1158
1159         err = -EINVAL;
1160         kind = tb[TCA_ACT_KIND];
1161         ops = tc_lookup_action(kind);
1162         if (!ops) { /*some idjot trying to flush unknown action */
1163                 NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1164                 goto err_out;
1165         }
1166
1167         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1168                         sizeof(*t), 0);
1169         if (!nlh) {
1170                 NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1171                 goto out_module_put;
1172         }
1173         t = nlmsg_data(nlh);
1174         t->tca_family = AF_UNSPEC;
1175         t->tca__pad1 = 0;
1176         t->tca__pad2 = 0;
1177
1178         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1179         if (!nest) {
1180                 NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1181                 goto out_module_put;
1182         }
1183
1184         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1185         if (err <= 0) {
1186                 nla_nest_cancel(skb, nest);
1187                 goto out_module_put;
1188         }
1189
1190         nla_nest_end(skb, nest);
1191
1192         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1193         nlh->nlmsg_flags |= NLM_F_ROOT;
1194         module_put(ops->owner);
1195         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1196                              n->nlmsg_flags & NLM_F_ECHO);
1197         if (err > 0)
1198                 return 0;
1199         if (err < 0)
1200                 NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1201
1202         return err;
1203
1204 out_module_put:
1205         module_put(ops->owner);
1206 err_out:
1207         kfree_skb(skb);
1208         return err;
1209 }
1210
1211 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1212 {
1213         int i;
1214
1215         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1216                 struct tc_action *a = actions[i];
1217                 const struct tc_action_ops *ops = a->ops;
1218                 /* Actions can be deleted concurrently so we must save their
1219                  * type and id to search again after reference is released.
1220                  */
1221                 struct tcf_idrinfo *idrinfo = a->idrinfo;
1222                 u32 act_index = a->tcfa_index;
1223
1224                 actions[i] = NULL;
1225                 if (tcf_action_put(a)) {
1226                         /* last reference, action was deleted concurrently */
1227                         module_put(ops->owner);
1228                 } else  {
1229                         int ret;
1230
1231                         /* now do the delete */
1232                         ret = tcf_idr_delete_index(idrinfo, act_index);
1233                         if (ret < 0)
1234                                 return ret;
1235                 }
1236         }
1237         return 0;
1238 }
1239
1240 static int
1241 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1242                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1243 {
1244         int ret;
1245         struct sk_buff *skb;
1246
1247         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1248                         GFP_KERNEL);
1249         if (!skb)
1250                 return -ENOBUFS;
1251
1252         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1253                          0, 2) <= 0) {
1254                 NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1255                 kfree_skb(skb);
1256                 return -EINVAL;
1257         }
1258
1259         /* now do the delete */
1260         ret = tcf_action_delete(net, actions);
1261         if (ret < 0) {
1262                 NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1263                 kfree_skb(skb);
1264                 return ret;
1265         }
1266
1267         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1268                              n->nlmsg_flags & NLM_F_ECHO);
1269         if (ret > 0)
1270                 return 0;
1271         return ret;
1272 }
1273
1274 static int
1275 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1276               u32 portid, int event, struct netlink_ext_ack *extack)
1277 {
1278         int i, ret;
1279         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1280         struct tc_action *act;
1281         size_t attr_size = 0;
1282         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1283
1284         ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1285                                           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                 attr_size += tcf_action_fill_size(act);
1304                 actions[i - 1] = act;
1305         }
1306
1307         attr_size = tcf_action_full_attrs_size(attr_size);
1308
1309         if (event == RTM_GETACTION)
1310                 ret = tcf_get_notify(net, portid, n, actions, event, extack);
1311         else { /* delete */
1312                 ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1313                 if (ret)
1314                         goto err;
1315                 return 0;
1316         }
1317 err:
1318         tcf_action_put_many(actions);
1319         return ret;
1320 }
1321
1322 static int
1323 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1324                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1325 {
1326         struct sk_buff *skb;
1327         int err = 0;
1328
1329         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1330                         GFP_KERNEL);
1331         if (!skb)
1332                 return -ENOBUFS;
1333
1334         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1335                          RTM_NEWACTION, 0, 0) <= 0) {
1336                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1337                 kfree_skb(skb);
1338                 return -EINVAL;
1339         }
1340
1341         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1342                              n->nlmsg_flags & NLM_F_ECHO);
1343         if (err > 0)
1344                 err = 0;
1345         return err;
1346 }
1347
1348 static int tcf_action_add(struct net *net, struct nlattr *nla,
1349                           struct nlmsghdr *n, u32 portid, int ovr,
1350                           struct netlink_ext_ack *extack)
1351 {
1352         size_t attr_size = 0;
1353         int ret = 0;
1354         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1355
1356         ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0, actions,
1357                               &attr_size, true, extack);
1358         if (ret < 0)
1359                 return ret;
1360         ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1361         if (ovr)
1362                 tcf_action_put_many(actions);
1363
1364         return ret;
1365 }
1366
1367 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1368 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1369         [TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1370                              .validation_data = &tcaa_root_flags_allowed },
1371         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1372 };
1373
1374 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1375                          struct netlink_ext_ack *extack)
1376 {
1377         struct net *net = sock_net(skb->sk);
1378         struct nlattr *tca[TCA_ROOT_MAX + 1];
1379         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1380         int ret = 0, ovr = 0;
1381
1382         if ((n->nlmsg_type != RTM_GETACTION) &&
1383             !netlink_capable(skb, CAP_NET_ADMIN))
1384                 return -EPERM;
1385
1386         ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
1387                                      TCA_ROOT_MAX, NULL, extack);
1388         if (ret < 0)
1389                 return ret;
1390
1391         if (tca[TCA_ACT_TAB] == NULL) {
1392                 NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1393                 return -EINVAL;
1394         }
1395
1396         /* n->nlmsg_flags & NLM_F_CREATE */
1397         switch (n->nlmsg_type) {
1398         case RTM_NEWACTION:
1399                 /* we are going to assume all other flags
1400                  * imply create only if it doesn't exist
1401                  * Note that CREATE | EXCL implies that
1402                  * but since we want avoid ambiguity (eg when flags
1403                  * is zero) then just set this
1404                  */
1405                 if (n->nlmsg_flags & NLM_F_REPLACE)
1406                         ovr = 1;
1407 replay:
1408                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1409                                      extack);
1410                 if (ret == -EAGAIN)
1411                         goto replay;
1412                 break;
1413         case RTM_DELACTION:
1414                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1415                                     portid, RTM_DELACTION, extack);
1416                 break;
1417         case RTM_GETACTION:
1418                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1419                                     portid, RTM_GETACTION, extack);
1420                 break;
1421         default:
1422                 BUG();
1423         }
1424
1425         return ret;
1426 }
1427
1428 static struct nlattr *find_dump_kind(struct nlattr **nla)
1429 {
1430         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1431         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1432         struct nlattr *kind;
1433
1434         tb1 = nla[TCA_ACT_TAB];
1435         if (tb1 == NULL)
1436                 return NULL;
1437
1438         if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1439                 return NULL;
1440
1441         if (tb[1] == NULL)
1442                 return NULL;
1443         if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], NULL, NULL) < 0)
1444                 return NULL;
1445         kind = tb2[TCA_ACT_KIND];
1446
1447         return kind;
1448 }
1449
1450 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1451 {
1452         struct net *net = sock_net(skb->sk);
1453         struct nlmsghdr *nlh;
1454         unsigned char *b = skb_tail_pointer(skb);
1455         struct nlattr *nest;
1456         struct tc_action_ops *a_o;
1457         int ret = 0;
1458         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1459         struct nlattr *tb[TCA_ROOT_MAX + 1];
1460         struct nlattr *count_attr = NULL;
1461         unsigned long jiffy_since = 0;
1462         struct nlattr *kind = NULL;
1463         struct nla_bitfield32 bf;
1464         u32 msecs_since = 0;
1465         u32 act_count = 0;
1466
1467         ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
1468                                      TCA_ROOT_MAX, tcaa_policy, cb->extack);
1469         if (ret < 0)
1470                 return ret;
1471
1472         kind = find_dump_kind(tb);
1473         if (kind == NULL) {
1474                 pr_info("tc_dump_action: action bad kind\n");
1475                 return 0;
1476         }
1477
1478         a_o = tc_lookup_action(kind);
1479         if (a_o == NULL)
1480                 return 0;
1481
1482         cb->args[2] = 0;
1483         if (tb[TCA_ROOT_FLAGS]) {
1484                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1485                 cb->args[2] = bf.value;
1486         }
1487
1488         if (tb[TCA_ROOT_TIME_DELTA]) {
1489                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1490         }
1491
1492         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1493                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1494         if (!nlh)
1495                 goto out_module_put;
1496
1497         if (msecs_since)
1498                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1499
1500         t = nlmsg_data(nlh);
1501         t->tca_family = AF_UNSPEC;
1502         t->tca__pad1 = 0;
1503         t->tca__pad2 = 0;
1504         cb->args[3] = jiffy_since;
1505         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1506         if (!count_attr)
1507                 goto out_module_put;
1508
1509         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1510         if (nest == NULL)
1511                 goto out_module_put;
1512
1513         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1514         if (ret < 0)
1515                 goto out_module_put;
1516
1517         if (ret > 0) {
1518                 nla_nest_end(skb, nest);
1519                 ret = skb->len;
1520                 act_count = cb->args[1];
1521                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1522                 cb->args[1] = 0;
1523         } else
1524                 nlmsg_trim(skb, b);
1525
1526         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1527         if (NETLINK_CB(cb->skb).portid && ret)
1528                 nlh->nlmsg_flags |= NLM_F_MULTI;
1529         module_put(a_o->owner);
1530         return skb->len;
1531
1532 out_module_put:
1533         module_put(a_o->owner);
1534         nlmsg_trim(skb, b);
1535         return skb->len;
1536 }
1537
1538 static int __init tc_action_init(void)
1539 {
1540         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1541         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1542         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1543                       0);
1544
1545         return 0;
1546 }
1547
1548 subsys_initcall(tc_action_init);