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 <linux/rhashtable.h>
  25 #include <linux/list.h>
  26 #include <net/net_namespace.h>
  27 #include <net/sock.h>
  28 #include <net/sch_generic.h>
  29 #include <net/pkt_cls.h>
  30 #include <net/act_api.h>
  31 #include <net/netlink.h>
  32
  33 static int tcf_action_goto_chain_init(struct tc_action *a, struct tcf_proto *tp)
  34 {
  35         u32 chain_index = a->tcfa_action & TC_ACT_EXT_VAL_MASK;
  36
  37         if (!tp)
  38                 return -EINVAL;
  39         a->goto_chain = tcf_chain_get_by_act(tp->chain->block, chain_index);
  40         if (!a->goto_chain)
  41                 return -ENOMEM;
  42         return 0;
  43 }
  44
  45 static void tcf_action_goto_chain_fini(struct tc_action *a)
  46 {
  47         tcf_chain_put_by_act(a->goto_chain);
  48 }
  49
  50 static void tcf_action_goto_chain_exec(const struct tc_action *a,
  51                                        struct tcf_result *res)
  52 {
  53         const struct tcf_chain *chain = a->goto_chain;
  54
  55         res->goto_tp = rcu_dereference_bh(chain->filter_chain);
  56 }
  57
  58 static void tcf_free_cookie_rcu(struct rcu_head *p)
  59 {
  60         struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
  61
  62         kfree(cookie->data);
  63         kfree(cookie);
  64 }
  65
  66 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
  67                                   struct tc_cookie *new_cookie)
  68 {
  69         struct tc_cookie *old;
  70
  71         old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
  72         if (old)
  73                 call_rcu(&old->rcu, tcf_free_cookie_rcu);
  74 }
  75
  76 /* XXX: For standalone actions, we don't need a RCU grace period either, because
  77  * actions are always connected to filters and filters are already destroyed in
  78  * RCU callbacks, so after a RCU grace period actions are already disconnected
  79  * from filters. Readers later can not find us.
  80  */
  81 static void free_tcf(struct tc_action *p)
  82 {
  83         free_percpu(p->cpu_bstats);
  84         free_percpu(p->cpu_qstats);
  85
  86         tcf_set_action_cookie(&p->act_cookie, NULL);
  87         if (p->goto_chain)
  88                 tcf_action_goto_chain_fini(p);
  89
  90         kfree(p);
  91 }
  92
  93 static void tcf_action_cleanup(struct tc_action *p)
  94 {
  95         if (p->ops->cleanup)
  96                 p->ops->cleanup(p);
  97
  98         gen_kill_estimator(&p->tcfa_rate_est);
  99         free_tcf(p);
 100 }
 101
 102 static int __tcf_action_put(struct tc_action *p, bool bind)
 103 {
 104         struct tcf_idrinfo *idrinfo = p->idrinfo;
 105
 106         if (refcount_dec_and_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
 107                 if (bind)
 108                         atomic_dec(&p->tcfa_bindcnt);
 109                 idr_remove(&idrinfo->action_idr, p->tcfa_index);
 110                 spin_unlock(&idrinfo->lock);
 111
 112                 tcf_action_cleanup(p);
 113                 return 1;
 114         }
 115
 116         if (bind)
 117                 atomic_dec(&p->tcfa_bindcnt);
 118
 119         return 0;
 120 }
 121
 122 int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
 123 {
 124         int ret = 0;
 125
 126         /* Release with strict==1 and bind==0 is only called through act API
 127          * interface (classifiers always bind). Only case when action with
 128          * positive reference count and zero bind count can exist is when it was
 129          * also created with act API (unbinding last classifier will destroy the
 130          * action if it was created by classifier). So only case when bind count
 131          * can be changed after initial check is when unbound action is
 132          * destroyed by act API while classifier binds to action with same id
 133          * concurrently. This result either creation of new action(same behavior
 134          * as before), or reusing existing action if concurrent process
 135          * increments reference count before action is deleted. Both scenarios
 136          * are acceptable.
 137          */
 138         if (p) {
 139                 if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
 140                         return -EPERM;
 141
 142                 if (__tcf_action_put(p, bind))
 143                         ret = ACT_P_DELETED;
 144         }
 145
 146         return ret;
 147 }
 148 EXPORT_SYMBOL(__tcf_idr_release);
 149
 150 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
 151 {
 152         struct tc_cookie *act_cookie;
 153         u32 cookie_len = 0;
 154
 155         rcu_read_lock();
 156         act_cookie = rcu_dereference(act->act_cookie);
 157
 158         if (act_cookie)
 159                 cookie_len = nla_total_size(act_cookie->len);
 160         rcu_read_unlock();
 161
 162         return  nla_total_size(0) /* action number nested */
 163                 + nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
 164                 + cookie_len /* TCA_ACT_COOKIE */
 165                 + nla_total_size(0) /* TCA_ACT_STATS nested */
 166                 /* TCA_STATS_BASIC */
 167                 + nla_total_size_64bit(sizeof(struct gnet_stats_basic))
 168                 /* TCA_STATS_QUEUE */
 169                 + nla_total_size_64bit(sizeof(struct gnet_stats_queue))
 170                 + nla_total_size(0) /* TCA_OPTIONS nested */
 171                 + nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
 172 }
 173
 174 static size_t tcf_action_full_attrs_size(size_t sz)
 175 {
 176         return NLMSG_HDRLEN                     /* struct nlmsghdr */
 177                 + sizeof(struct tcamsg)
 178                 + nla_total_size(0)             /* TCA_ACT_TAB nested */
 179                 + sz;
 180 }
 181
 182 static size_t tcf_action_fill_size(const struct tc_action *act)
 183 {
 184         size_t sz = tcf_action_shared_attrs_size(act);
 185
 186         if (act->ops->get_fill_size)
 187                 return act->ops->get_fill_size(act) + sz;
 188         return sz;
 189 }
 190
 191 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 192                            struct netlink_callback *cb)
 193 {
 194         int err = 0, index = -1, s_i = 0, n_i = 0;
 195         u32 act_flags = cb->args[2];
 196         unsigned long jiffy_since = cb->args[3];
 197         struct nlattr *nest;
 198         struct idr *idr = &idrinfo->action_idr;
 199         struct tc_action *p;
 200         unsigned long id = 1;
 201
 202         spin_lock(&idrinfo->lock);
 203
 204         s_i = cb->args[0];
 205
 206         idr_for_each_entry_ul(idr, p, id) {
 207                 index++;
 208                 if (index < s_i)
 209                         continue;
 210
 211                 if (jiffy_since &&
 212                     time_after(jiffy_since,
 213                                (unsigned long)p->tcfa_tm.lastuse))
 214                         continue;
 215
 216                 nest = nla_nest_start(skb, n_i);
 217                 if (!nest) {
 218                         index--;
 219                         goto nla_put_failure;
 220                 }
 221                 err = tcf_action_dump_1(skb, p, 0, 0);
 222                 if (err < 0) {
 223                         index--;
 224                         nlmsg_trim(skb, nest);
 225                         goto done;
 226                 }
 227                 nla_nest_end(skb, nest);
 228                 n_i++;
 229                 if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
 230                     n_i >= TCA_ACT_MAX_PRIO)
 231                         goto done;
 232         }
 233 done:
 234         if (index >= 0)
 235                 cb->args[0] = index + 1;
 236
 237         spin_unlock(&idrinfo->lock);
 238         if (n_i) {
 239                 if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
 240                         cb->args[1] = n_i;
 241         }
 242         return n_i;
 243
 244 nla_put_failure:
 245         nla_nest_cancel(skb, nest);
 246         goto done;
 247 }
 248
 249 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 250                           const struct tc_action_ops *ops)
 251 {
 252         struct nlattr *nest;
 253         int n_i = 0;
 254         int ret = -EINVAL;
 255         struct idr *idr = &idrinfo->action_idr;
 256         struct tc_action *p;
 257         unsigned long id = 1;
 258
 259         nest = nla_nest_start(skb, 0);
 260         if (nest == NULL)
 261                 goto nla_put_failure;
 262         if (nla_put_string(skb, TCA_KIND, ops->kind))
 263                 goto nla_put_failure;
 264
 265         idr_for_each_entry_ul(idr, p, id) {
 266                 ret = __tcf_idr_release(p, false, true);
 267                 if (ret == ACT_P_DELETED) {
 268                         module_put(ops->owner);
 269                         n_i++;
 270                 } else if (ret < 0) {
 271                         goto nla_put_failure;
 272                 }
 273         }
 274         if (nla_put_u32(skb, TCA_FCNT, n_i))
 275                 goto nla_put_failure;
 276         nla_nest_end(skb, nest);
 277
 278         return n_i;
 279 nla_put_failure:
 280         nla_nest_cancel(skb, nest);
 281         return ret;
 282 }
 283
 284 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 285                        struct netlink_callback *cb, int type,
 286                        const struct tc_action_ops *ops,
 287                        struct netlink_ext_ack *extack)
 288 {
 289         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 290
 291         if (type == RTM_DELACTION) {
 292                 return tcf_del_walker(idrinfo, skb, ops);
 293         } else if (type == RTM_GETACTION) {
 294                 return tcf_dump_walker(idrinfo, skb, cb);
 295         } else {
 296                 WARN(1, "tcf_generic_walker: unknown command %d\n", type);
 297                 NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
 298                 return -EINVAL;
 299         }
 300 }
 301 EXPORT_SYMBOL(tcf_generic_walker);
 302
 303 static bool __tcf_idr_check(struct tc_action_net *tn, u32 index,
 304                             struct tc_action **a, int bind)
 305 {
 306         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 307         struct tc_action *p;
 308
 309         spin_lock(&idrinfo->lock);
 310         p = idr_find(&idrinfo->action_idr, index);
 311         if (IS_ERR(p)) {
 312                 p = NULL;
 313         } else if (p) {
 314                 refcount_inc(&p->tcfa_refcnt);
 315                 if (bind)
 316                         atomic_inc(&p->tcfa_bindcnt);
 317         }
 318         spin_unlock(&idrinfo->lock);
 319
 320         if (p) {
 321                 *a = p;
 322                 return true;
 323         }
 324         return false;
 325 }
 326
 327 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 328 {
 329         return __tcf_idr_check(tn, index, a, 0);
 330 }
 331 EXPORT_SYMBOL(tcf_idr_search);
 332
 333 bool tcf_idr_check(struct tc_action_net *tn, u32 index, struct tc_action **a,
 334                    int bind)
 335 {
 336         return __tcf_idr_check(tn, index, a, bind);
 337 }
 338 EXPORT_SYMBOL(tcf_idr_check);
 339
 340 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
 341 {
 342         struct tc_action *p;
 343         int ret = 0;
 344
 345         spin_lock(&idrinfo->lock);
 346         p = idr_find(&idrinfo->action_idr, index);
 347         if (!p) {
 348                 spin_unlock(&idrinfo->lock);
 349                 return -ENOENT;
 350         }
 351
 352         if (!atomic_read(&p->tcfa_bindcnt)) {
 353                 if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 354                         struct module *owner = p->ops->owner;
 355
 356                         WARN_ON(p != idr_remove(&idrinfo->action_idr,
 357                                                 p->tcfa_index));
 358                         spin_unlock(&idrinfo->lock);
 359
 360                         tcf_action_cleanup(p);
 361                         module_put(owner);
 362                         return 0;
 363                 }
 364                 ret = 0;
 365         } else {
 366                 ret = -EPERM;
 367         }
 368
 369         spin_unlock(&idrinfo->lock);
 370         return ret;
 371 }
 372
 373 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 374                    struct tc_action **a, const struct tc_action_ops *ops,
 375                    int bind, bool cpustats)
 376 {
 377         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 378         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 379         int err = -ENOMEM;
 380
 381         if (unlikely(!p))
 382                 return -ENOMEM;
 383         refcount_set(&p->tcfa_refcnt, 1);
 384         if (bind)
 385                 atomic_set(&p->tcfa_bindcnt, 1);
 386
 387         if (cpustats) {
 388                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 389                 if (!p->cpu_bstats)
 390                         goto err1;
 391                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 392                 if (!p->cpu_qstats)
 393                         goto err2;
 394         }
 395         spin_lock_init(&p->tcfa_lock);
 396         p->tcfa_index = index;
 397         p->tcfa_tm.install = jiffies;
 398         p->tcfa_tm.lastuse = jiffies;
 399         p->tcfa_tm.firstuse = 0;
 400         if (est) {
 401                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 402                                         &p->tcfa_rate_est,
 403                                         &p->tcfa_lock, NULL, est);
 404                 if (err)
 405                         goto err3;
 406         }
 407
 408         p->idrinfo = idrinfo;
 409         p->ops = ops;
 410         INIT_LIST_HEAD(&p->list);
 411         *a = p;
 412         return 0;
 413 err3:
 414         free_percpu(p->cpu_qstats);
 415 err2:
 416         free_percpu(p->cpu_bstats);
 417 err1:
 418         kfree(p);
 419         return err;
 420 }
 421 EXPORT_SYMBOL(tcf_idr_create);
 422
 423 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
 424 {
 425         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 426
 427         spin_lock(&idrinfo->lock);
 428         /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 429         WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
 430         spin_unlock(&idrinfo->lock);
 431 }
 432 EXPORT_SYMBOL(tcf_idr_insert);
 433
 434 /* Cleanup idr index that was allocated but not initialized. */
 435
 436 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
 437 {
 438         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 439
 440         spin_lock(&idrinfo->lock);
 441         /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 442         WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
 443         spin_unlock(&idrinfo->lock);
 444 }
 445 EXPORT_SYMBOL(tcf_idr_cleanup);
 446
 447 /* Check if action with specified index exists. If actions is found, increments
 448  * its reference and bind counters, and return 1. Otherwise insert temporary
 449  * error pointer (to prevent concurrent users from inserting actions with same
 450  * index) and return 0.
 451  */
 452
 453 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 454                         struct tc_action **a, int bind)
 455 {
 456         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 457         struct tc_action *p;
 458         int ret;
 459
 460 again:
 461         spin_lock(&idrinfo->lock);
 462         if (*index) {
 463                 p = idr_find(&idrinfo->action_idr, *index);
 464                 if (IS_ERR(p)) {
 465                         /* This means that another process allocated
 466                          * index but did not assign the pointer yet.
 467                          */
 468                         spin_unlock(&idrinfo->lock);
 469                         goto again;
 470                 }
 471
 472                 if (p) {
 473                         refcount_inc(&p->tcfa_refcnt);
 474                         if (bind)
 475                                 atomic_inc(&p->tcfa_bindcnt);
 476                         *a = p;
 477                         ret = 1;
 478                 } else {
 479                         *a = NULL;
 480                         ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 481                                             *index, GFP_ATOMIC);
 482                         if (!ret)
 483                                 idr_replace(&idrinfo->action_idr,
 484                                             ERR_PTR(-EBUSY), *index);
 485                 }
 486         } else {
 487                 *index = 1;
 488                 *a = NULL;
 489                 ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 490                                     UINT_MAX, GFP_ATOMIC);
 491                 if (!ret)
 492                         idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
 493                                     *index);
 494         }
 495         spin_unlock(&idrinfo->lock);
 496         return ret;
 497 }
 498 EXPORT_SYMBOL(tcf_idr_check_alloc);
 499
 500 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 501                          struct tcf_idrinfo *idrinfo)
 502 {
 503         struct idr *idr = &idrinfo->action_idr;
 504         struct tc_action *p;
 505         int ret;
 506         unsigned long id = 1;
 507
 508         idr_for_each_entry_ul(idr, p, id) {
 509                 ret = __tcf_idr_release(p, false, true);
 510                 if (ret == ACT_P_DELETED)
 511                         module_put(ops->owner);
 512                 else if (ret < 0)
 513                         return;
 514         }
 515         idr_destroy(&idrinfo->action_idr);
 516 }
 517 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 518
 519 static LIST_HEAD(act_base);
 520 static DEFINE_RWLOCK(act_mod_lock);
 521
 522 int tcf_register_action(struct tc_action_ops *act,
 523                         struct pernet_operations *ops)
 524 {
 525         struct tc_action_ops *a;
 526         int ret;
 527
 528         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 529                 return -EINVAL;
 530
 531         /* We have to register pernet ops before making the action ops visible,
 532          * otherwise tcf_action_init_1() could get a partially initialized
 533          * netns.
 534          */
 535         ret = register_pernet_subsys(ops);
 536         if (ret)
 537                 return ret;
 538
 539         write_lock(&act_mod_lock);
 540         list_for_each_entry(a, &act_base, head) {
 541                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 542                         write_unlock(&act_mod_lock);
 543                         unregister_pernet_subsys(ops);
 544                         return -EEXIST;
 545                 }
 546         }
 547         list_add_tail(&act->head, &act_base);
 548         write_unlock(&act_mod_lock);
 549
 550         return 0;
 551 }
 552 EXPORT_SYMBOL(tcf_register_action);
 553
 554 int tcf_unregister_action(struct tc_action_ops *act,
 555                           struct pernet_operations *ops)
 556 {
 557         struct tc_action_ops *a;
 558         int err = -ENOENT;
 559
 560         write_lock(&act_mod_lock);
 561         list_for_each_entry(a, &act_base, head) {
 562                 if (a == act) {
 563                         list_del(&act->head);
 564                         err = 0;
 565                         break;
 566                 }
 567         }
 568         write_unlock(&act_mod_lock);
 569         if (!err)
 570                 unregister_pernet_subsys(ops);
 571         return err;
 572 }
 573 EXPORT_SYMBOL(tcf_unregister_action);
 574
 575 /* lookup by name */
 576 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 577 {
 578         struct tc_action_ops *a, *res = NULL;
 579
 580         if (kind) {
 581                 read_lock(&act_mod_lock);
 582                 list_for_each_entry(a, &act_base, head) {
 583                         if (strcmp(kind, a->kind) == 0) {
 584                                 if (try_module_get(a->owner))
 585                                         res = a;
 586                                 break;
 587                         }
 588                 }
 589                 read_unlock(&act_mod_lock);
 590         }
 591         return res;
 592 }
 593
 594 /* lookup by nlattr */
 595 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 596 {
 597         struct tc_action_ops *a, *res = NULL;
 598
 599         if (kind) {
 600                 read_lock(&act_mod_lock);
 601                 list_for_each_entry(a, &act_base, head) {
 602                         if (nla_strcmp(kind, a->kind) == 0) {
 603                                 if (try_module_get(a->owner))
 604                                         res = a;
 605                                 break;
 606                         }
 607                 }
 608                 read_unlock(&act_mod_lock);
 609         }
 610         return res;
 611 }
 612
 613 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 614 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 615 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 616                     int nr_actions, struct tcf_result *res)
 617 {
 618         u32 jmp_prgcnt = 0;
 619         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 620         int i;
 621         int ret = TC_ACT_OK;
 622
 623         if (skb_skip_tc_classify(skb))
 624                 return TC_ACT_OK;
 625
 626 restart_act_graph:
 627         for (i = 0; i < nr_actions; i++) {
 628                 const struct tc_action *a = actions[i];
 629
 630                 if (jmp_prgcnt > 0) {
 631                         jmp_prgcnt -= 1;
 632                         continue;
 633                 }
 634 repeat:
 635                 ret = a->ops->act(skb, a, res);
 636                 if (ret == TC_ACT_REPEAT)
 637                         goto repeat;    /* we need a ttl - JHS */
 638
 639                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 640                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 641                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 642                                 /* faulty opcode, stop pipeline */
 643                                 return TC_ACT_OK;
 644                         } else {
 645                                 jmp_ttl -= 1;
 646                                 if (jmp_ttl > 0)
 647                                         goto restart_act_graph;
 648                                 else /* faulty graph, stop pipeline */
 649                                         return TC_ACT_OK;
 650                         }
 651                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 652                         tcf_action_goto_chain_exec(a, res);
 653                 }
 654
 655                 if (ret != TC_ACT_PIPE)
 656                         break;
 657         }
 658
 659         return ret;
 660 }
 661 EXPORT_SYMBOL(tcf_action_exec);
 662
 663 int tcf_action_destroy(struct tc_action *actions[], int bind)
 664 {
 665         const struct tc_action_ops *ops;
 666         struct tc_action *a;
 667         int ret = 0, i;
 668
 669         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 670                 a = actions[i];
 671                 actions[i] = NULL;
 672                 ops = a->ops;
 673                 ret = __tcf_idr_release(a, bind, true);
 674                 if (ret == ACT_P_DELETED)
 675                         module_put(ops->owner);
 676                 else if (ret < 0)
 677                         return ret;
 678         }
 679         return ret;
 680 }
 681
 682 static int tcf_action_put(struct tc_action *p)
 683 {
 684         return __tcf_action_put(p, false);
 685 }
 686
 687 /* Put all actions in this array, skip those NULL's. */
 688 static void tcf_action_put_many(struct tc_action *actions[])
 689 {
 690         int i;
 691
 692         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 693                 struct tc_action *a = actions[i];
 694                 const struct tc_action_ops *ops;
 695
 696                 if (!a)
 697                         continue;
 698                 ops = a->ops;
 699                 if (tcf_action_put(a))
 700                         module_put(ops->owner);
 701         }
 702 }
 703
 704 int
 705 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 706 {
 707         return a->ops->dump(skb, a, bind, ref);
 708 }
 709
 710 int
 711 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 712 {
 713         int err = -EINVAL;
 714         unsigned char *b = skb_tail_pointer(skb);
 715         struct nlattr *nest;
 716         struct tc_cookie *cookie;
 717
 718         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 719                 goto nla_put_failure;
 720         if (tcf_action_copy_stats(skb, a, 0))
 721                 goto nla_put_failure;
 722
 723         rcu_read_lock();
 724         cookie = rcu_dereference(a->act_cookie);
 725         if (cookie) {
 726                 if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
 727                         rcu_read_unlock();
 728                         goto nla_put_failure;
 729                 }
 730         }
 731         rcu_read_unlock();
 732
 733         nest = nla_nest_start(skb, TCA_OPTIONS);
 734         if (nest == NULL)
 735                 goto nla_put_failure;
 736         err = tcf_action_dump_old(skb, a, bind, ref);
 737         if (err > 0) {
 738                 nla_nest_end(skb, nest);
 739                 return err;
 740         }
 741
 742 nla_put_failure:
 743         nlmsg_trim(skb, b);
 744         return -1;
 745 }
 746 EXPORT_SYMBOL(tcf_action_dump_1);
 747
 748 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 749                     int bind, int ref)
 750 {
 751         struct tc_action *a;
 752         int err = -EINVAL, i;
 753         struct nlattr *nest;
 754
 755         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 756                 a = actions[i];
 757                 nest = nla_nest_start(skb, a->order);
 758                 if (nest == NULL)
 759                         goto nla_put_failure;
 760                 err = tcf_action_dump_1(skb, a, bind, ref);
 761                 if (err < 0)
 762                         goto errout;
 763                 nla_nest_end(skb, nest);
 764         }
 765
 766         return 0;
 767
 768 nla_put_failure:
 769         err = -EINVAL;
 770 errout:
 771         nla_nest_cancel(skb, nest);
 772         return err;
 773 }
 774
 775 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 776 {
 777         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 778         if (!c)
 779                 return NULL;
 780
 781         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 782         if (!c->data) {
 783                 kfree(c);
 784                 return NULL;
 785         }
 786         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 787
 788         return c;
 789 }
 790
 791 static bool tcf_action_valid(int action)
 792 {
 793         int opcode = TC_ACT_EXT_OPCODE(action);
 794
 795         if (!opcode)
 796                 return action <= TC_ACT_VALUE_MAX;
 797         return opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC;
 798 }
 799
 800 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 801                                     struct nlattr *nla, struct nlattr *est,
 802                                     char *name, int ovr, int bind,
 803                                     bool rtnl_held,
 804                                     struct netlink_ext_ack *extack)
 805 {
 806         struct tc_action *a;
 807         struct tc_action_ops *a_o;
 808         struct tc_cookie *cookie = NULL;
 809         char act_name[IFNAMSIZ];
 810         struct nlattr *tb[TCA_ACT_MAX + 1];
 811         struct nlattr *kind;
 812         int err;
 813
 814         if (name == NULL) {
 815                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
 816                 if (err < 0)
 817                         goto err_out;
 818                 err = -EINVAL;
 819                 kind = tb[TCA_ACT_KIND];
 820                 if (!kind) {
 821                         NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 822                         goto err_out;
 823                 }
 824                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
 825                         NL_SET_ERR_MSG(extack, "TC action name too long");
 826                         goto err_out;
 827                 }
 828                 if (tb[TCA_ACT_COOKIE]) {
 829                         int cklen = nla_len(tb[TCA_ACT_COOKIE]);
 830
 831                         if (cklen > TC_COOKIE_MAX_SIZE) {
 832                                 NL_SET_ERR_MSG(extack, "TC cookie size above the maximum");
 833                                 goto err_out;
 834                         }
 835
 836                         cookie = nla_memdup_cookie(tb);
 837                         if (!cookie) {
 838                                 NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
 839                                 err = -ENOMEM;
 840                                 goto err_out;
 841                         }
 842                 }
 843         } else {
 844                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
 845                         NL_SET_ERR_MSG(extack, "TC action name too long");
 846                         err = -EINVAL;
 847                         goto err_out;
 848                 }
 849         }
 850
 851         a_o = tc_lookup_action_n(act_name);
 852         if (a_o == NULL) {
 853 #ifdef CONFIG_MODULES
 854                 if (rtnl_held)
 855                         rtnl_unlock();
 856                 request_module("act_%s", act_name);
 857                 if (rtnl_held)
 858                         rtnl_lock();
 859
 860                 a_o = tc_lookup_action_n(act_name);
 861
 862                 /* We dropped the RTNL semaphore in order to
 863                  * perform the module load.  So, even if we
 864                  * succeeded in loading the module we have to
 865                  * tell the caller to replay the request.  We
 866                  * indicate this using -EAGAIN.
 867                  */
 868                 if (a_o != NULL) {
 869                         err = -EAGAIN;
 870                         goto err_mod;
 871                 }
 872 #endif
 873                 NL_SET_ERR_MSG(extack, "Failed to load TC action module");
 874                 err = -ENOENT;
 875                 goto err_out;
 876         }
 877
 878         /* backward compatibility for policer */
 879         if (name == NULL)
 880                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
 881                                 rtnl_held, extack);
 882         else
 883                 err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
 884                                 extack);
 885         if (err < 0)
 886                 goto err_mod;
 887
 888         if (!name && tb[TCA_ACT_COOKIE])
 889                 tcf_set_action_cookie(&a->act_cookie, cookie);
 890
 891         /* module count goes up only when brand new policy is created
 892          * if it exists and is only bound to in a_o->init() then
 893          * ACT_P_CREATED is not returned (a zero is).
 894          */
 895         if (err != ACT_P_CREATED)
 896                 module_put(a_o->owner);
 897
 898         if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN)) {
 899                 err = tcf_action_goto_chain_init(a, tp);
 900                 if (err) {
 901                         struct tc_action *actions[] = { a, NULL };
 902
 903                         tcf_action_destroy(actions, bind);
 904                         NL_SET_ERR_MSG(extack, "Failed to init TC action chain");
 905                         return ERR_PTR(err);
 906                 }
 907         }
 908
 909         if (!tcf_action_valid(a->tcfa_action)) {
 910                 NL_SET_ERR_MSG(extack, "invalid action value, using TC_ACT_UNSPEC instead");
 911                 a->tcfa_action = TC_ACT_UNSPEC;
 912         }
 913
 914         return a;
 915
 916 err_mod:
 917         module_put(a_o->owner);
 918 err_out:
 919         if (cookie) {
 920                 kfree(cookie->data);
 921                 kfree(cookie);
 922         }
 923         return ERR_PTR(err);
 924 }
 925
 926 /* Returns numbers of initialized actions or negative error. */
 927
 928 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 929                     struct nlattr *est, char *name, int ovr, int bind,
 930                     struct tc_action *actions[], size_t *attr_size,
 931                     bool rtnl_held, struct netlink_ext_ack *extack)
 932 {
 933         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 934         struct tc_action *act;
 935         size_t sz = 0;
 936         int err;
 937         int i;
 938
 939         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
 940         if (err < 0)
 941                 return err;
 942
 943         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 944                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
 945                                         rtnl_held, extack);
 946                 if (IS_ERR(act)) {
 947                         err = PTR_ERR(act);
 948                         goto err;
 949                 }
 950                 act->order = i;
 951                 sz += tcf_action_fill_size(act);
 952                 /* Start from index 0 */
 953                 actions[i - 1] = act;
 954         }
 955
 956         *attr_size = tcf_action_full_attrs_size(sz);
 957         return i - 1;
 958
 959 err:
 960         tcf_action_destroy(actions, bind);
 961         return err;
 962 }
 963
 964 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
 965                           int compat_mode)
 966 {
 967         int err = 0;
 968         struct gnet_dump d;
 969
 970         if (p == NULL)
 971                 goto errout;
 972
 973         /* compat_mode being true specifies a call that is supposed
 974          * to add additional backward compatibility statistic TLVs.
 975          */
 976         if (compat_mode) {
 977                 if (p->type == TCA_OLD_COMPAT)
 978                         err = gnet_stats_start_copy_compat(skb, 0,
 979                                                            TCA_STATS,
 980                                                            TCA_XSTATS,
 981                                                            &p->tcfa_lock, &d,
 982                                                            TCA_PAD);
 983                 else
 984                         return 0;
 985         } else
 986                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 987                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
 988
 989         if (err < 0)
 990                 goto errout;
 991
 992         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
 993             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
 994             gnet_stats_copy_queue(&d, p->cpu_qstats,
 995                                   &p->tcfa_qstats,
 996                                   p->tcfa_qstats.qlen) < 0)
 997                 goto errout;
 998
 999         if (gnet_stats_finish_copy(&d) < 0)
1000                 goto errout;
1001
1002         return 0;
1003
1004 errout:
1005         return -1;
1006 }
1007
1008 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1009                         u32 portid, u32 seq, u16 flags, int event, int bind,
1010                         int ref)
1011 {
1012         struct tcamsg *t;
1013         struct nlmsghdr *nlh;
1014         unsigned char *b = skb_tail_pointer(skb);
1015         struct nlattr *nest;
1016
1017         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1018         if (!nlh)
1019                 goto out_nlmsg_trim;
1020         t = nlmsg_data(nlh);
1021         t->tca_family = AF_UNSPEC;
1022         t->tca__pad1 = 0;
1023         t->tca__pad2 = 0;
1024
1025         nest = nla_nest_start(skb, TCA_ACT_TAB);
1026         if (!nest)
1027                 goto out_nlmsg_trim;
1028
1029         if (tcf_action_dump(skb, actions, bind, ref) < 0)
1030                 goto out_nlmsg_trim;
1031
1032         nla_nest_end(skb, nest);
1033
1034         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1035         return skb->len;
1036
1037 out_nlmsg_trim:
1038         nlmsg_trim(skb, b);
1039         return -1;
1040 }
1041
1042 static int
1043 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1044                struct tc_action *actions[], int event,
1045                struct netlink_ext_ack *extack)
1046 {
1047         struct sk_buff *skb;
1048
1049         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1050         if (!skb)
1051                 return -ENOBUFS;
1052         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1053                          0, 1) <= 0) {
1054                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1055                 kfree_skb(skb);
1056                 return -EINVAL;
1057         }
1058
1059         return rtnl_unicast(skb, net, portid);
1060 }
1061
1062 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1063                                           struct nlmsghdr *n, u32 portid,
1064                                           struct netlink_ext_ack *extack)
1065 {
1066         struct nlattr *tb[TCA_ACT_MAX + 1];
1067         const struct tc_action_ops *ops;
1068         struct tc_action *a;
1069         int index;
1070         int err;
1071
1072         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
1073         if (err < 0)
1074                 goto err_out;
1075
1076         err = -EINVAL;
1077         if (tb[TCA_ACT_INDEX] == NULL ||
1078             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1079                 NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1080                 goto err_out;
1081         }
1082         index = nla_get_u32(tb[TCA_ACT_INDEX]);
1083
1084         err = -EINVAL;
1085         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1086         if (!ops) { /* could happen in batch of actions */
1087                 NL_SET_ERR_MSG(extack, "Specified TC action not found");
1088                 goto err_out;
1089         }
1090         err = -ENOENT;
1091         if (ops->lookup(net, &a, index, extack) == 0)
1092                 goto err_mod;
1093
1094         module_put(ops->owner);
1095         return a;
1096
1097 err_mod:
1098         module_put(ops->owner);
1099 err_out:
1100         return ERR_PTR(err);
1101 }
1102
1103 static int tca_action_flush(struct net *net, struct nlattr *nla,
1104                             struct nlmsghdr *n, u32 portid,
1105                             struct netlink_ext_ack *extack)
1106 {
1107         struct sk_buff *skb;
1108         unsigned char *b;
1109         struct nlmsghdr *nlh;
1110         struct tcamsg *t;
1111         struct netlink_callback dcb;
1112         struct nlattr *nest;
1113         struct nlattr *tb[TCA_ACT_MAX + 1];
1114         const struct tc_action_ops *ops;
1115         struct nlattr *kind;
1116         int err = -ENOMEM;
1117
1118         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1119         if (!skb)
1120                 return err;
1121
1122         b = skb_tail_pointer(skb);
1123
1124         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
1125         if (err < 0)
1126                 goto err_out;
1127
1128         err = -EINVAL;
1129         kind = tb[TCA_ACT_KIND];
1130         ops = tc_lookup_action(kind);
1131         if (!ops) { /*some idjot trying to flush unknown action */
1132                 NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1133                 goto err_out;
1134         }
1135
1136         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1137                         sizeof(*t), 0);
1138         if (!nlh) {
1139                 NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1140                 goto out_module_put;
1141         }
1142         t = nlmsg_data(nlh);
1143         t->tca_family = AF_UNSPEC;
1144         t->tca__pad1 = 0;
1145         t->tca__pad2 = 0;
1146
1147         nest = nla_nest_start(skb, TCA_ACT_TAB);
1148         if (!nest) {
1149                 NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1150                 goto out_module_put;
1151         }
1152
1153         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1154         if (err <= 0) {
1155                 nla_nest_cancel(skb, nest);
1156                 goto out_module_put;
1157         }
1158
1159         nla_nest_end(skb, nest);
1160
1161         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1162         nlh->nlmsg_flags |= NLM_F_ROOT;
1163         module_put(ops->owner);
1164         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1165                              n->nlmsg_flags & NLM_F_ECHO);
1166         if (err > 0)
1167                 return 0;
1168         if (err < 0)
1169                 NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1170
1171         return err;
1172
1173 out_module_put:
1174         module_put(ops->owner);
1175 err_out:
1176         kfree_skb(skb);
1177         return err;
1178 }
1179
1180 static int tcf_action_delete(struct net *net, struct tc_action *actions[],
1181                              struct netlink_ext_ack *extack)
1182 {
1183         int i;
1184
1185         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1186                 struct tc_action *a = actions[i];
1187                 const struct tc_action_ops *ops = a->ops;
1188                 /* Actions can be deleted concurrently so we must save their
1189                  * type and id to search again after reference is released.
1190                  */
1191                 struct tcf_idrinfo *idrinfo = a->idrinfo;
1192                 u32 act_index = a->tcfa_index;
1193
1194                 if (tcf_action_put(a)) {
1195                         /* last reference, action was deleted concurrently */
1196                         module_put(ops->owner);
1197                 } else  {
1198                         int ret;
1199
1200                         /* now do the delete */
1201                         ret = tcf_idr_delete_index(idrinfo, act_index);
1202                         if (ret < 0)
1203                                 return ret;
1204                 }
1205                 actions[i] = NULL;
1206         }
1207         return 0;
1208 }
1209
1210 static int
1211 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1212                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1213 {
1214         int ret;
1215         struct sk_buff *skb;
1216
1217         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1218                         GFP_KERNEL);
1219         if (!skb)
1220                 return -ENOBUFS;
1221
1222         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1223                          0, 2) <= 0) {
1224                 NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1225                 kfree_skb(skb);
1226                 return -EINVAL;
1227         }
1228
1229         /* now do the delete */
1230         ret = tcf_action_delete(net, actions, extack);
1231         if (ret < 0) {
1232                 NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1233                 kfree_skb(skb);
1234                 return ret;
1235         }
1236
1237         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1238                              n->nlmsg_flags & NLM_F_ECHO);
1239         if (ret > 0)
1240                 return 0;
1241         return ret;
1242 }
1243
1244 static int
1245 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1246               u32 portid, int event, struct netlink_ext_ack *extack)
1247 {
1248         int i, ret;
1249         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1250         struct tc_action *act;
1251         size_t attr_size = 0;
1252         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1253
1254         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
1255         if (ret < 0)
1256                 return ret;
1257
1258         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1259                 if (tb[1])
1260                         return tca_action_flush(net, tb[1], n, portid, extack);
1261
1262                 NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1263                 return -EINVAL;
1264         }
1265
1266         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1267                 act = tcf_action_get_1(net, tb[i], n, portid, extack);
1268                 if (IS_ERR(act)) {
1269                         ret = PTR_ERR(act);
1270                         goto err;
1271                 }
1272                 act->order = i;
1273                 attr_size += tcf_action_fill_size(act);
1274                 actions[i - 1] = act;
1275         }
1276
1277         attr_size = tcf_action_full_attrs_size(attr_size);
1278
1279         if (event == RTM_GETACTION)
1280                 ret = tcf_get_notify(net, portid, n, actions, event, extack);
1281         else { /* delete */
1282                 ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1283                 if (ret)
1284                         goto err;
1285                 return 0;
1286         }
1287 err:
1288         tcf_action_put_many(actions);
1289         return ret;
1290 }
1291
1292 static int
1293 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1294                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1295 {
1296         struct sk_buff *skb;
1297         int err = 0;
1298
1299         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1300                         GFP_KERNEL);
1301         if (!skb)
1302                 return -ENOBUFS;
1303
1304         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1305                          RTM_NEWACTION, 0, 0) <= 0) {
1306                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1307                 kfree_skb(skb);
1308                 return -EINVAL;
1309         }
1310
1311         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1312                              n->nlmsg_flags & NLM_F_ECHO);
1313         if (err > 0)
1314                 err = 0;
1315         return err;
1316 }
1317
1318 static int tcf_action_add(struct net *net, struct nlattr *nla,
1319                           struct nlmsghdr *n, u32 portid, int ovr,
1320                           struct netlink_ext_ack *extack)
1321 {
1322         size_t attr_size = 0;
1323         int ret = 0;
1324         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1325
1326         ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0, actions,
1327                               &attr_size, true, extack);
1328         if (ret < 0)
1329                 return ret;
1330         ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1331         if (ovr)
1332                 tcf_action_put_many(actions);
1333
1334         return ret;
1335 }
1336
1337 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1338 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1339         [TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1340                              .validation_data = &tcaa_root_flags_allowed },
1341         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1342 };
1343
1344 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1345                          struct netlink_ext_ack *extack)
1346 {
1347         struct net *net = sock_net(skb->sk);
1348         struct nlattr *tca[TCA_ROOT_MAX + 1];
1349         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1350         int ret = 0, ovr = 0;
1351
1352         if ((n->nlmsg_type != RTM_GETACTION) &&
1353             !netlink_capable(skb, CAP_NET_ADMIN))
1354                 return -EPERM;
1355
1356         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ROOT_MAX, NULL,
1357                           extack);
1358         if (ret < 0)
1359                 return ret;
1360
1361         if (tca[TCA_ACT_TAB] == NULL) {
1362                 NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1363                 return -EINVAL;
1364         }
1365
1366         /* n->nlmsg_flags & NLM_F_CREATE */
1367         switch (n->nlmsg_type) {
1368         case RTM_NEWACTION:
1369                 /* we are going to assume all other flags
1370                  * imply create only if it doesn't exist
1371                  * Note that CREATE | EXCL implies that
1372                  * but since we want avoid ambiguity (eg when flags
1373                  * is zero) then just set this
1374                  */
1375                 if (n->nlmsg_flags & NLM_F_REPLACE)
1376                         ovr = 1;
1377 replay:
1378                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1379                                      extack);
1380                 if (ret == -EAGAIN)
1381                         goto replay;
1382                 break;
1383         case RTM_DELACTION:
1384                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1385                                     portid, RTM_DELACTION, extack);
1386                 break;
1387         case RTM_GETACTION:
1388                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1389                                     portid, RTM_GETACTION, extack);
1390                 break;
1391         default:
1392                 BUG();
1393         }
1394
1395         return ret;
1396 }
1397
1398 static struct nlattr *find_dump_kind(struct nlattr **nla)
1399 {
1400         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1401         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1402         struct nlattr *kind;
1403
1404         tb1 = nla[TCA_ACT_TAB];
1405         if (tb1 == NULL)
1406                 return NULL;
1407
1408         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1409                       NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1410                 return NULL;
1411
1412         if (tb[1] == NULL)
1413                 return NULL;
1414         if (nla_parse_nested(tb2, TCA_ACT_MAX, tb[1], NULL, NULL) < 0)
1415                 return NULL;
1416         kind = tb2[TCA_ACT_KIND];
1417
1418         return kind;
1419 }
1420
1421 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1422 {
1423         struct net *net = sock_net(skb->sk);
1424         struct nlmsghdr *nlh;
1425         unsigned char *b = skb_tail_pointer(skb);
1426         struct nlattr *nest;
1427         struct tc_action_ops *a_o;
1428         int ret = 0;
1429         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1430         struct nlattr *tb[TCA_ROOT_MAX + 1];
1431         struct nlattr *count_attr = NULL;
1432         unsigned long jiffy_since = 0;
1433         struct nlattr *kind = NULL;
1434         struct nla_bitfield32 bf;
1435         u32 msecs_since = 0;
1436         u32 act_count = 0;
1437
1438         ret = nlmsg_parse(cb->nlh, sizeof(struct tcamsg), tb, TCA_ROOT_MAX,
1439                           tcaa_policy, NULL);
1440         if (ret < 0)
1441                 return ret;
1442
1443         kind = find_dump_kind(tb);
1444         if (kind == NULL) {
1445                 pr_info("tc_dump_action: action bad kind\n");
1446                 return 0;
1447         }
1448
1449         a_o = tc_lookup_action(kind);
1450         if (a_o == NULL)
1451                 return 0;
1452
1453         cb->args[2] = 0;
1454         if (tb[TCA_ROOT_FLAGS]) {
1455                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1456                 cb->args[2] = bf.value;
1457         }
1458
1459         if (tb[TCA_ROOT_TIME_DELTA]) {
1460                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1461         }
1462
1463         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1464                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1465         if (!nlh)
1466                 goto out_module_put;
1467
1468         if (msecs_since)
1469                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1470
1471         t = nlmsg_data(nlh);
1472         t->tca_family = AF_UNSPEC;
1473         t->tca__pad1 = 0;
1474         t->tca__pad2 = 0;
1475         cb->args[3] = jiffy_since;
1476         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1477         if (!count_attr)
1478                 goto out_module_put;
1479
1480         nest = nla_nest_start(skb, TCA_ACT_TAB);
1481         if (nest == NULL)
1482                 goto out_module_put;
1483
1484         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1485         if (ret < 0)
1486                 goto out_module_put;
1487
1488         if (ret > 0) {
1489                 nla_nest_end(skb, nest);
1490                 ret = skb->len;
1491                 act_count = cb->args[1];
1492                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1493                 cb->args[1] = 0;
1494         } else
1495                 nlmsg_trim(skb, b);
1496
1497         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1498         if (NETLINK_CB(cb->skb).portid && ret)
1499                 nlh->nlmsg_flags |= NLM_F_MULTI;
1500         module_put(a_o->owner);
1501         return skb->len;
1502
1503 out_module_put:
1504         module_put(a_o->owner);
1505         nlmsg_trim(skb, b);
1506         return skb->len;
1507 }
1508
1509 struct tcf_action_net {
1510         struct rhashtable egdev_ht;
1511 };
1512
1513 static unsigned int tcf_action_net_id;
1514
1515 struct tcf_action_egdev_cb {
1516         struct list_head list;
1517         tc_setup_cb_t *cb;
1518         void *cb_priv;
1519 };
1520
1521 struct tcf_action_egdev {
1522         struct rhash_head ht_node;
1523         const struct net_device *dev;
1524         unsigned int refcnt;
1525         struct list_head cb_list;
1526 };
1527
1528 static const struct rhashtable_params tcf_action_egdev_ht_params = {
1529         .key_offset = offsetof(struct tcf_action_egdev, dev),
1530         .head_offset = offsetof(struct tcf_action_egdev, ht_node),
1531         .key_len = sizeof(const struct net_device *),
1532 };
1533
1534 static struct tcf_action_egdev *
1535 tcf_action_egdev_lookup(const struct net_device *dev)
1536 {
1537         struct net *net = dev_net(dev);
1538         struct tcf_action_net *tan = net_generic(net, tcf_action_net_id);
1539
1540         return rhashtable_lookup_fast(&tan->egdev_ht, &dev,
1541                                       tcf_action_egdev_ht_params);
1542 }
1543
1544 static struct tcf_action_egdev *
1545 tcf_action_egdev_get(const struct net_device *dev)
1546 {
1547         struct tcf_action_egdev *egdev;
1548         struct tcf_action_net *tan;
1549
1550         egdev = tcf_action_egdev_lookup(dev);
1551         if (egdev)
1552                 goto inc_ref;
1553
1554         egdev = kzalloc(sizeof(*egdev), GFP_KERNEL);
1555         if (!egdev)
1556                 return NULL;
1557         INIT_LIST_HEAD(&egdev->cb_list);
1558         egdev->dev = dev;
1559         tan = net_generic(dev_net(dev), tcf_action_net_id);
1560         rhashtable_insert_fast(&tan->egdev_ht, &egdev->ht_node,
1561                                tcf_action_egdev_ht_params);
1562
1563 inc_ref:
1564         egdev->refcnt++;
1565         return egdev;
1566 }
1567
1568 static void tcf_action_egdev_put(struct tcf_action_egdev *egdev)
1569 {
1570         struct tcf_action_net *tan;
1571
1572         if (--egdev->refcnt)
1573                 return;
1574         tan = net_generic(dev_net(egdev->dev), tcf_action_net_id);
1575         rhashtable_remove_fast(&tan->egdev_ht, &egdev->ht_node,
1576                                tcf_action_egdev_ht_params);
1577         kfree(egdev);
1578 }
1579
1580 static struct tcf_action_egdev_cb *
1581 tcf_action_egdev_cb_lookup(struct tcf_action_egdev *egdev,
1582                            tc_setup_cb_t *cb, void *cb_priv)
1583 {
1584         struct tcf_action_egdev_cb *egdev_cb;
1585
1586         list_for_each_entry(egdev_cb, &egdev->cb_list, list)
1587                 if (egdev_cb->cb == cb && egdev_cb->cb_priv == cb_priv)
1588                         return egdev_cb;
1589         return NULL;
1590 }
1591
1592 static int tcf_action_egdev_cb_call(struct tcf_action_egdev *egdev,
1593                                     enum tc_setup_type type,
1594                                     void *type_data, bool err_stop)
1595 {
1596         struct tcf_action_egdev_cb *egdev_cb;
1597         int ok_count = 0;
1598         int err;
1599
1600         list_for_each_entry(egdev_cb, &egdev->cb_list, list) {
1601                 err = egdev_cb->cb(type, type_data, egdev_cb->cb_priv);
1602                 if (err) {
1603                         if (err_stop)
1604                                 return err;
1605                 } else {
1606                         ok_count++;
1607                 }
1608         }
1609         return ok_count;
1610 }
1611
1612 static int tcf_action_egdev_cb_add(struct tcf_action_egdev *egdev,
1613                                    tc_setup_cb_t *cb, void *cb_priv)
1614 {
1615         struct tcf_action_egdev_cb *egdev_cb;
1616
1617         egdev_cb = tcf_action_egdev_cb_lookup(egdev, cb, cb_priv);
1618         if (WARN_ON(egdev_cb))
1619                 return -EEXIST;
1620         egdev_cb = kzalloc(sizeof(*egdev_cb), GFP_KERNEL);
1621         if (!egdev_cb)
1622                 return -ENOMEM;
1623         egdev_cb->cb = cb;
1624         egdev_cb->cb_priv = cb_priv;
1625         list_add(&egdev_cb->list, &egdev->cb_list);
1626         return 0;
1627 }
1628
1629 static void tcf_action_egdev_cb_del(struct tcf_action_egdev *egdev,
1630                                     tc_setup_cb_t *cb, void *cb_priv)
1631 {
1632         struct tcf_action_egdev_cb *egdev_cb;
1633
1634         egdev_cb = tcf_action_egdev_cb_lookup(egdev, cb, cb_priv);
1635         if (WARN_ON(!egdev_cb))
1636                 return;
1637         list_del(&egdev_cb->list);
1638         kfree(egdev_cb);
1639 }
1640
1641 static int __tc_setup_cb_egdev_register(const struct net_device *dev,
1642                                         tc_setup_cb_t *cb, void *cb_priv)
1643 {
1644         struct tcf_action_egdev *egdev = tcf_action_egdev_get(dev);
1645         int err;
1646
1647         if (!egdev)
1648                 return -ENOMEM;
1649         err = tcf_action_egdev_cb_add(egdev, cb, cb_priv);
1650         if (err)
1651                 goto err_cb_add;
1652         return 0;
1653
1654 err_cb_add:
1655         tcf_action_egdev_put(egdev);
1656         return err;
1657 }
1658 int tc_setup_cb_egdev_register(const struct net_device *dev,
1659                                tc_setup_cb_t *cb, void *cb_priv)
1660 {
1661         int err;
1662
1663         rtnl_lock();
1664         err = __tc_setup_cb_egdev_register(dev, cb, cb_priv);
1665         rtnl_unlock();
1666         return err;
1667 }
1668 EXPORT_SYMBOL_GPL(tc_setup_cb_egdev_register);
1669
1670 static void __tc_setup_cb_egdev_unregister(const struct net_device *dev,
1671                                            tc_setup_cb_t *cb, void *cb_priv)
1672 {
1673         struct tcf_action_egdev *egdev = tcf_action_egdev_lookup(dev);
1674
1675         if (WARN_ON(!egdev))
1676                 return;
1677         tcf_action_egdev_cb_del(egdev, cb, cb_priv);
1678         tcf_action_egdev_put(egdev);
1679 }
1680 void tc_setup_cb_egdev_unregister(const struct net_device *dev,
1681                                   tc_setup_cb_t *cb, void *cb_priv)
1682 {
1683         rtnl_lock();
1684         __tc_setup_cb_egdev_unregister(dev, cb, cb_priv);
1685         rtnl_unlock();
1686 }
1687 EXPORT_SYMBOL_GPL(tc_setup_cb_egdev_unregister);
1688
1689 int tc_setup_cb_egdev_call(const struct net_device *dev,
1690                            enum tc_setup_type type, void *type_data,
1691                            bool err_stop)
1692 {
1693         struct tcf_action_egdev *egdev = tcf_action_egdev_lookup(dev);
1694
1695         if (!egdev)
1696                 return 0;
1697         return tcf_action_egdev_cb_call(egdev, type, type_data, err_stop);
1698 }
1699 EXPORT_SYMBOL_GPL(tc_setup_cb_egdev_call);
1700
1701 static __net_init int tcf_action_net_init(struct net *net)
1702 {
1703         struct tcf_action_net *tan = net_generic(net, tcf_action_net_id);
1704
1705         return rhashtable_init(&tan->egdev_ht, &tcf_action_egdev_ht_params);
1706 }
1707
1708 static void __net_exit tcf_action_net_exit(struct net *net)
1709 {
1710         struct tcf_action_net *tan = net_generic(net, tcf_action_net_id);
1711
1712         rhashtable_destroy(&tan->egdev_ht);
1713 }
1714
1715 static struct pernet_operations tcf_action_net_ops = {
1716         .init = tcf_action_net_init,
1717         .exit = tcf_action_net_exit,
1718         .id = &tcf_action_net_id,
1719         .size = sizeof(struct tcf_action_net),
1720 };
1721
1722 static int __init tc_action_init(void)
1723 {
1724         int err;
1725
1726         err = register_pernet_subsys(&tcf_action_net_ops);
1727         if (err)
1728                 return err;
1729
1730         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1731         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1732         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1733                       0);
1734
1735         return 0;
1736 }
1737
1738 subsys_initcall(tc_action_init);