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 #ifdef CONFIG_INET
  26 DEFINE_STATIC_KEY_FALSE(tcf_frag_xmit_count);
  27 EXPORT_SYMBOL_GPL(tcf_frag_xmit_count);
  28 #endif
  29
  30 int tcf_dev_queue_xmit(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb))
  31 {
  32 #ifdef CONFIG_INET
  33         if (static_branch_unlikely(&tcf_frag_xmit_count))
  34                 return sch_frag_xmit_hook(skb, xmit);
  35 #endif
  36
  37         return xmit(skb);
  38 }
  39 EXPORT_SYMBOL_GPL(tcf_dev_queue_xmit);
  40
  41 static void tcf_action_goto_chain_exec(const struct tc_action *a,
  42                                        struct tcf_result *res)
  43 {
  44         const struct tcf_chain *chain = rcu_dereference_bh(a->goto_chain);
  45
  46         res->goto_tp = rcu_dereference_bh(chain->filter_chain);
  47 }
  48
  49 static void tcf_free_cookie_rcu(struct rcu_head *p)
  50 {
  51         struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
  52
  53         kfree(cookie->data);
  54         kfree(cookie);
  55 }
  56
  57 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
  58                                   struct tc_cookie *new_cookie)
  59 {
  60         struct tc_cookie *old;
  61
  62         old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
  63         if (old)
  64                 call_rcu(&old->rcu, tcf_free_cookie_rcu);
  65 }
  66
  67 int tcf_action_check_ctrlact(int action, struct tcf_proto *tp,
  68                              struct tcf_chain **newchain,
  69                              struct netlink_ext_ack *extack)
  70 {
  71         int opcode = TC_ACT_EXT_OPCODE(action), ret = -EINVAL;
  72         u32 chain_index;
  73
  74         if (!opcode)
  75                 ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;
  76         else if (opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC)
  77                 ret = 0;
  78         if (ret) {
  79                 NL_SET_ERR_MSG(extack, "invalid control action");
  80                 goto end;
  81         }
  82
  83         if (TC_ACT_EXT_CMP(action, TC_ACT_GOTO_CHAIN)) {
  84                 chain_index = action & TC_ACT_EXT_VAL_MASK;
  85                 if (!tp || !newchain) {
  86                         ret = -EINVAL;
  87                         NL_SET_ERR_MSG(extack,
  88                                        "can't goto NULL proto/chain");
  89                         goto end;
  90                 }
  91                 *newchain = tcf_chain_get_by_act(tp->chain->block, chain_index);
  92                 if (!*newchain) {
  93                         ret = -ENOMEM;
  94                         NL_SET_ERR_MSG(extack,
  95                                        "can't allocate goto_chain");
  96                 }
  97         }
  98 end:
  99         return ret;
 100 }
 101 EXPORT_SYMBOL(tcf_action_check_ctrlact);
 102
 103 struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,
 104                                          struct tcf_chain *goto_chain)
 105 {
 106         a->tcfa_action = action;
 107         goto_chain = rcu_replace_pointer(a->goto_chain, goto_chain, 1);
 108         return goto_chain;
 109 }
 110 EXPORT_SYMBOL(tcf_action_set_ctrlact);
 111
 112 /* XXX: For standalone actions, we don't need a RCU grace period either, because
 113  * actions are always connected to filters and filters are already destroyed in
 114  * RCU callbacks, so after a RCU grace period actions are already disconnected
 115  * from filters. Readers later can not find us.
 116  */
 117 static void free_tcf(struct tc_action *p)
 118 {
 119         struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
 120
 121         free_percpu(p->cpu_bstats);
 122         free_percpu(p->cpu_bstats_hw);
 123         free_percpu(p->cpu_qstats);
 124
 125         tcf_set_action_cookie(&p->act_cookie, NULL);
 126         if (chain)
 127                 tcf_chain_put_by_act(chain);
 128
 129         kfree(p);
 130 }
 131
 132 static void tcf_action_cleanup(struct tc_action *p)
 133 {
 134         if (p->ops->cleanup)
 135                 p->ops->cleanup(p);
 136
 137         gen_kill_estimator(&p->tcfa_rate_est);
 138         free_tcf(p);
 139 }
 140
 141 static int __tcf_action_put(struct tc_action *p, bool bind)
 142 {
 143         struct tcf_idrinfo *idrinfo = p->idrinfo;
 144
 145         if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
 146                 if (bind)
 147                         atomic_dec(&p->tcfa_bindcnt);
 148                 idr_remove(&idrinfo->action_idr, p->tcfa_index);
 149                 mutex_unlock(&idrinfo->lock);
 150
 151                 tcf_action_cleanup(p);
 152                 return 1;
 153         }
 154
 155         if (bind)
 156                 atomic_dec(&p->tcfa_bindcnt);
 157
 158         return 0;
 159 }
 160
 161 static int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
 162 {
 163         int ret = 0;
 164
 165         /* Release with strict==1 and bind==0 is only called through act API
 166          * interface (classifiers always bind). Only case when action with
 167          * positive reference count and zero bind count can exist is when it was
 168          * also created with act API (unbinding last classifier will destroy the
 169          * action if it was created by classifier). So only case when bind count
 170          * can be changed after initial check is when unbound action is
 171          * destroyed by act API while classifier binds to action with same id
 172          * concurrently. This result either creation of new action(same behavior
 173          * as before), or reusing existing action if concurrent process
 174          * increments reference count before action is deleted. Both scenarios
 175          * are acceptable.
 176          */
 177         if (p) {
 178                 if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
 179                         return -EPERM;
 180
 181                 if (__tcf_action_put(p, bind))
 182                         ret = ACT_P_DELETED;
 183         }
 184
 185         return ret;
 186 }
 187
 188 int tcf_idr_release(struct tc_action *a, bool bind)
 189 {
 190         const struct tc_action_ops *ops = a->ops;
 191         int ret;
 192
 193         ret = __tcf_idr_release(a, bind, false);
 194         if (ret == ACT_P_DELETED)
 195                 module_put(ops->owner);
 196         return ret;
 197 }
 198 EXPORT_SYMBOL(tcf_idr_release);
 199
 200 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
 201 {
 202         struct tc_cookie *act_cookie;
 203         u32 cookie_len = 0;
 204
 205         rcu_read_lock();
 206         act_cookie = rcu_dereference(act->act_cookie);
 207
 208         if (act_cookie)
 209                 cookie_len = nla_total_size(act_cookie->len);
 210         rcu_read_unlock();
 211
 212         return  nla_total_size(0) /* action number nested */
 213                 + nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
 214                 + cookie_len /* TCA_ACT_COOKIE */
 215                 + nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_HW_STATS */
 216                 + nla_total_size(0) /* TCA_ACT_STATS nested */
 217                 + nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_FLAGS */
 218                 /* TCA_STATS_BASIC */
 219                 + nla_total_size_64bit(sizeof(struct gnet_stats_basic))
 220                 /* TCA_STATS_PKT64 */
 221                 + nla_total_size_64bit(sizeof(u64))
 222                 /* TCA_STATS_QUEUE */
 223                 + nla_total_size_64bit(sizeof(struct gnet_stats_queue))
 224                 + nla_total_size(0) /* TCA_OPTIONS nested */
 225                 + nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
 226 }
 227
 228 static size_t tcf_action_full_attrs_size(size_t sz)
 229 {
 230         return NLMSG_HDRLEN                     /* struct nlmsghdr */
 231                 + sizeof(struct tcamsg)
 232                 + nla_total_size(0)             /* TCA_ACT_TAB nested */
 233                 + sz;
 234 }
 235
 236 static size_t tcf_action_fill_size(const struct tc_action *act)
 237 {
 238         size_t sz = tcf_action_shared_attrs_size(act);
 239
 240         if (act->ops->get_fill_size)
 241                 return act->ops->get_fill_size(act) + sz;
 242         return sz;
 243 }
 244
 245 static int
 246 tcf_action_dump_terse(struct sk_buff *skb, struct tc_action *a, bool from_act)
 247 {
 248         unsigned char *b = skb_tail_pointer(skb);
 249         struct tc_cookie *cookie;
 250
 251         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 252                 goto nla_put_failure;
 253         if (tcf_action_copy_stats(skb, a, 0))
 254                 goto nla_put_failure;
 255         if (from_act && nla_put_u32(skb, TCA_ACT_INDEX, a->tcfa_index))
 256                 goto nla_put_failure;
 257
 258         rcu_read_lock();
 259         cookie = rcu_dereference(a->act_cookie);
 260         if (cookie) {
 261                 if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
 262                         rcu_read_unlock();
 263                         goto nla_put_failure;
 264                 }
 265         }
 266         rcu_read_unlock();
 267
 268         return 0;
 269
 270 nla_put_failure:
 271         nlmsg_trim(skb, b);
 272         return -1;
 273 }
 274
 275 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 276                            struct netlink_callback *cb)
 277 {
 278         int err = 0, index = -1, s_i = 0, n_i = 0;
 279         u32 act_flags = cb->args[2];
 280         unsigned long jiffy_since = cb->args[3];
 281         struct nlattr *nest;
 282         struct idr *idr = &idrinfo->action_idr;
 283         struct tc_action *p;
 284         unsigned long id = 1;
 285         unsigned long tmp;
 286
 287         mutex_lock(&idrinfo->lock);
 288
 289         s_i = cb->args[0];
 290
 291         idr_for_each_entry_ul(idr, p, tmp, id) {
 292                 index++;
 293                 if (index < s_i)
 294                         continue;
 295                 if (IS_ERR(p))
 296                         continue;
 297
 298                 if (jiffy_since &&
 299                     time_after(jiffy_since,
 300                                (unsigned long)p->tcfa_tm.lastuse))
 301                         continue;
 302
 303                 nest = nla_nest_start_noflag(skb, n_i);
 304                 if (!nest) {
 305                         index--;
 306                         goto nla_put_failure;
 307                 }
 308                 err = (act_flags & TCA_ACT_FLAG_TERSE_DUMP) ?
 309                         tcf_action_dump_terse(skb, p, true) :
 310                         tcf_action_dump_1(skb, p, 0, 0);
 311                 if (err < 0) {
 312                         index--;
 313                         nlmsg_trim(skb, nest);
 314                         goto done;
 315                 }
 316                 nla_nest_end(skb, nest);
 317                 n_i++;
 318                 if (!(act_flags & TCA_ACT_FLAG_LARGE_DUMP_ON) &&
 319                     n_i >= TCA_ACT_MAX_PRIO)
 320                         goto done;
 321         }
 322 done:
 323         if (index >= 0)
 324                 cb->args[0] = index + 1;
 325
 326         mutex_unlock(&idrinfo->lock);
 327         if (n_i) {
 328                 if (act_flags & TCA_ACT_FLAG_LARGE_DUMP_ON)
 329                         cb->args[1] = n_i;
 330         }
 331         return n_i;
 332
 333 nla_put_failure:
 334         nla_nest_cancel(skb, nest);
 335         goto done;
 336 }
 337
 338 static int tcf_idr_release_unsafe(struct tc_action *p)
 339 {
 340         if (atomic_read(&p->tcfa_bindcnt) > 0)
 341                 return -EPERM;
 342
 343         if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 344                 idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
 345                 tcf_action_cleanup(p);
 346                 return ACT_P_DELETED;
 347         }
 348
 349         return 0;
 350 }
 351
 352 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 353                           const struct tc_action_ops *ops)
 354 {
 355         struct nlattr *nest;
 356         int n_i = 0;
 357         int ret = -EINVAL;
 358         struct idr *idr = &idrinfo->action_idr;
 359         struct tc_action *p;
 360         unsigned long id = 1;
 361         unsigned long tmp;
 362
 363         nest = nla_nest_start_noflag(skb, 0);
 364         if (nest == NULL)
 365                 goto nla_put_failure;
 366         if (nla_put_string(skb, TCA_KIND, ops->kind))
 367                 goto nla_put_failure;
 368
 369         mutex_lock(&idrinfo->lock);
 370         idr_for_each_entry_ul(idr, p, tmp, id) {
 371                 if (IS_ERR(p))
 372                         continue;
 373                 ret = tcf_idr_release_unsafe(p);
 374                 if (ret == ACT_P_DELETED) {
 375                         module_put(ops->owner);
 376                         n_i++;
 377                 } else if (ret < 0) {
 378                         mutex_unlock(&idrinfo->lock);
 379                         goto nla_put_failure;
 380                 }
 381         }
 382         mutex_unlock(&idrinfo->lock);
 383
 384         if (nla_put_u32(skb, TCA_FCNT, n_i))
 385                 goto nla_put_failure;
 386         nla_nest_end(skb, nest);
 387
 388         return n_i;
 389 nla_put_failure:
 390         nla_nest_cancel(skb, nest);
 391         return ret;
 392 }
 393
 394 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 395                        struct netlink_callback *cb, int type,
 396                        const struct tc_action_ops *ops,
 397                        struct netlink_ext_ack *extack)
 398 {
 399         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 400
 401         if (type == RTM_DELACTION) {
 402                 return tcf_del_walker(idrinfo, skb, ops);
 403         } else if (type == RTM_GETACTION) {
 404                 return tcf_dump_walker(idrinfo, skb, cb);
 405         } else {
 406                 WARN(1, "tcf_generic_walker: unknown command %d\n", type);
 407                 NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
 408                 return -EINVAL;
 409         }
 410 }
 411 EXPORT_SYMBOL(tcf_generic_walker);
 412
 413 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 414 {
 415         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 416         struct tc_action *p;
 417
 418         mutex_lock(&idrinfo->lock);
 419         p = idr_find(&idrinfo->action_idr, index);
 420         if (IS_ERR(p))
 421                 p = NULL;
 422         else if (p)
 423                 refcount_inc(&p->tcfa_refcnt);
 424         mutex_unlock(&idrinfo->lock);
 425
 426         if (p) {
 427                 *a = p;
 428                 return true;
 429         }
 430         return false;
 431 }
 432 EXPORT_SYMBOL(tcf_idr_search);
 433
 434 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
 435 {
 436         struct tc_action *p;
 437         int ret = 0;
 438
 439         mutex_lock(&idrinfo->lock);
 440         p = idr_find(&idrinfo->action_idr, index);
 441         if (!p) {
 442                 mutex_unlock(&idrinfo->lock);
 443                 return -ENOENT;
 444         }
 445
 446         if (!atomic_read(&p->tcfa_bindcnt)) {
 447                 if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 448                         struct module *owner = p->ops->owner;
 449
 450                         WARN_ON(p != idr_remove(&idrinfo->action_idr,
 451                                                 p->tcfa_index));
 452                         mutex_unlock(&idrinfo->lock);
 453
 454                         tcf_action_cleanup(p);
 455                         module_put(owner);
 456                         return 0;
 457                 }
 458                 ret = 0;
 459         } else {
 460                 ret = -EPERM;
 461         }
 462
 463         mutex_unlock(&idrinfo->lock);
 464         return ret;
 465 }
 466
 467 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 468                    struct tc_action **a, const struct tc_action_ops *ops,
 469                    int bind, bool cpustats, u32 flags)
 470 {
 471         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 472         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 473         int err = -ENOMEM;
 474
 475         if (unlikely(!p))
 476                 return -ENOMEM;
 477         refcount_set(&p->tcfa_refcnt, 1);
 478         if (bind)
 479                 atomic_set(&p->tcfa_bindcnt, 1);
 480
 481         if (cpustats) {
 482                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 483                 if (!p->cpu_bstats)
 484                         goto err1;
 485                 p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 486                 if (!p->cpu_bstats_hw)
 487                         goto err2;
 488                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 489                 if (!p->cpu_qstats)
 490                         goto err3;
 491         }
 492         spin_lock_init(&p->tcfa_lock);
 493         p->tcfa_index = index;
 494         p->tcfa_tm.install = jiffies;
 495         p->tcfa_tm.lastuse = jiffies;
 496         p->tcfa_tm.firstuse = 0;
 497         p->tcfa_flags = flags;
 498         if (est) {
 499                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 500                                         &p->tcfa_rate_est,
 501                                         &p->tcfa_lock, NULL, est);
 502                 if (err)
 503                         goto err4;
 504         }
 505
 506         p->idrinfo = idrinfo;
 507         __module_get(ops->owner);
 508         p->ops = ops;
 509         *a = p;
 510         return 0;
 511 err4:
 512         free_percpu(p->cpu_qstats);
 513 err3:
 514         free_percpu(p->cpu_bstats_hw);
 515 err2:
 516         free_percpu(p->cpu_bstats);
 517 err1:
 518         kfree(p);
 519         return err;
 520 }
 521 EXPORT_SYMBOL(tcf_idr_create);
 522
 523 int tcf_idr_create_from_flags(struct tc_action_net *tn, u32 index,
 524                               struct nlattr *est, struct tc_action **a,
 525                               const struct tc_action_ops *ops, int bind,
 526                               u32 flags)
 527 {
 528         /* Set cpustats according to actions flags. */
 529         return tcf_idr_create(tn, index, est, a, ops, bind,
 530                               !(flags & TCA_ACT_FLAGS_NO_PERCPU_STATS), flags);
 531 }
 532 EXPORT_SYMBOL(tcf_idr_create_from_flags);
 533
 534 /* Cleanup idr index that was allocated but not initialized. */
 535
 536 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
 537 {
 538         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 539
 540         mutex_lock(&idrinfo->lock);
 541         /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 542         WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
 543         mutex_unlock(&idrinfo->lock);
 544 }
 545 EXPORT_SYMBOL(tcf_idr_cleanup);
 546
 547 /* Check if action with specified index exists. If actions is found, increments
 548  * its reference and bind counters, and return 1. Otherwise insert temporary
 549  * error pointer (to prevent concurrent users from inserting actions with same
 550  * index) and return 0.
 551  */
 552
 553 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 554                         struct tc_action **a, int bind)
 555 {
 556         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 557         struct tc_action *p;
 558         int ret;
 559
 560 again:
 561         mutex_lock(&idrinfo->lock);
 562         if (*index) {
 563                 p = idr_find(&idrinfo->action_idr, *index);
 564                 if (IS_ERR(p)) {
 565                         /* This means that another process allocated
 566                          * index but did not assign the pointer yet.
 567                          */
 568                         mutex_unlock(&idrinfo->lock);
 569                         goto again;
 570                 }
 571
 572                 if (p) {
 573                         refcount_inc(&p->tcfa_refcnt);
 574                         if (bind)
 575                                 atomic_inc(&p->tcfa_bindcnt);
 576                         *a = p;
 577                         ret = 1;
 578                 } else {
 579                         *a = NULL;
 580                         ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 581                                             *index, GFP_KERNEL);
 582                         if (!ret)
 583                                 idr_replace(&idrinfo->action_idr,
 584                                             ERR_PTR(-EBUSY), *index);
 585                 }
 586         } else {
 587                 *index = 1;
 588                 *a = NULL;
 589                 ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 590                                     UINT_MAX, GFP_KERNEL);
 591                 if (!ret)
 592                         idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
 593                                     *index);
 594         }
 595         mutex_unlock(&idrinfo->lock);
 596         return ret;
 597 }
 598 EXPORT_SYMBOL(tcf_idr_check_alloc);
 599
 600 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 601                          struct tcf_idrinfo *idrinfo)
 602 {
 603         struct idr *idr = &idrinfo->action_idr;
 604         struct tc_action *p;
 605         int ret;
 606         unsigned long id = 1;
 607         unsigned long tmp;
 608
 609         idr_for_each_entry_ul(idr, p, tmp, id) {
 610                 ret = __tcf_idr_release(p, false, true);
 611                 if (ret == ACT_P_DELETED)
 612                         module_put(ops->owner);
 613                 else if (ret < 0)
 614                         return;
 615         }
 616         idr_destroy(&idrinfo->action_idr);
 617 }
 618 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 619
 620 static LIST_HEAD(act_base);
 621 static DEFINE_RWLOCK(act_mod_lock);
 622
 623 int tcf_register_action(struct tc_action_ops *act,
 624                         struct pernet_operations *ops)
 625 {
 626         struct tc_action_ops *a;
 627         int ret;
 628
 629         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 630                 return -EINVAL;
 631
 632         /* We have to register pernet ops before making the action ops visible,
 633          * otherwise tcf_action_init_1() could get a partially initialized
 634          * netns.
 635          */
 636         ret = register_pernet_subsys(ops);
 637         if (ret)
 638                 return ret;
 639
 640         write_lock(&act_mod_lock);
 641         list_for_each_entry(a, &act_base, head) {
 642                 if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
 643                         write_unlock(&act_mod_lock);
 644                         unregister_pernet_subsys(ops);
 645                         return -EEXIST;
 646                 }
 647         }
 648         list_add_tail(&act->head, &act_base);
 649         write_unlock(&act_mod_lock);
 650
 651         return 0;
 652 }
 653 EXPORT_SYMBOL(tcf_register_action);
 654
 655 int tcf_unregister_action(struct tc_action_ops *act,
 656                           struct pernet_operations *ops)
 657 {
 658         struct tc_action_ops *a;
 659         int err = -ENOENT;
 660
 661         write_lock(&act_mod_lock);
 662         list_for_each_entry(a, &act_base, head) {
 663                 if (a == act) {
 664                         list_del(&act->head);
 665                         err = 0;
 666                         break;
 667                 }
 668         }
 669         write_unlock(&act_mod_lock);
 670         if (!err)
 671                 unregister_pernet_subsys(ops);
 672         return err;
 673 }
 674 EXPORT_SYMBOL(tcf_unregister_action);
 675
 676 /* lookup by name */
 677 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 678 {
 679         struct tc_action_ops *a, *res = NULL;
 680
 681         if (kind) {
 682                 read_lock(&act_mod_lock);
 683                 list_for_each_entry(a, &act_base, head) {
 684                         if (strcmp(kind, a->kind) == 0) {
 685                                 if (try_module_get(a->owner))
 686                                         res = a;
 687                                 break;
 688                         }
 689                 }
 690                 read_unlock(&act_mod_lock);
 691         }
 692         return res;
 693 }
 694
 695 /* lookup by nlattr */
 696 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 697 {
 698         struct tc_action_ops *a, *res = NULL;
 699
 700         if (kind) {
 701                 read_lock(&act_mod_lock);
 702                 list_for_each_entry(a, &act_base, head) {
 703                         if (nla_strcmp(kind, a->kind) == 0) {
 704                                 if (try_module_get(a->owner))
 705                                         res = a;
 706                                 break;
 707                         }
 708                 }
 709                 read_unlock(&act_mod_lock);
 710         }
 711         return res;
 712 }
 713
 714 /*TCA_ACT_MAX_PRIO is 32, there count up to 32 */
 715 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 716 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 717                     int nr_actions, struct tcf_result *res)
 718 {
 719         u32 jmp_prgcnt = 0;
 720         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 721         int i;
 722         int ret = TC_ACT_OK;
 723
 724         if (skb_skip_tc_classify(skb))
 725                 return TC_ACT_OK;
 726
 727 restart_act_graph:
 728         for (i = 0; i < nr_actions; i++) {
 729                 const struct tc_action *a = actions[i];
 730
 731                 if (jmp_prgcnt > 0) {
 732                         jmp_prgcnt -= 1;
 733                         continue;
 734                 }
 735 repeat:
 736                 ret = a->ops->act(skb, a, res);
 737                 if (ret == TC_ACT_REPEAT)
 738                         goto repeat;    /* we need a ttl - JHS */
 739
 740                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 741                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 742                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 743                                 /* faulty opcode, stop pipeline */
 744                                 return TC_ACT_OK;
 745                         } else {
 746                                 jmp_ttl -= 1;
 747                                 if (jmp_ttl > 0)
 748                                         goto restart_act_graph;
 749                                 else /* faulty graph, stop pipeline */
 750                                         return TC_ACT_OK;
 751                         }
 752                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 753                         if (unlikely(!rcu_access_pointer(a->goto_chain))) {
 754                                 net_warn_ratelimited("can't go to NULL chain!\n");
 755                                 return TC_ACT_SHOT;
 756                         }
 757                         tcf_action_goto_chain_exec(a, res);
 758                 }
 759
 760                 if (ret != TC_ACT_PIPE)
 761                         break;
 762         }
 763
 764         return ret;
 765 }
 766 EXPORT_SYMBOL(tcf_action_exec);
 767
 768 int tcf_action_destroy(struct tc_action *actions[], int bind)
 769 {
 770         const struct tc_action_ops *ops;
 771         struct tc_action *a;
 772         int ret = 0, i;
 773
 774         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 775                 a = actions[i];
 776                 actions[i] = NULL;
 777                 ops = a->ops;
 778                 ret = __tcf_idr_release(a, bind, true);
 779                 if (ret == ACT_P_DELETED)
 780                         module_put(ops->owner);
 781                 else if (ret < 0)
 782                         return ret;
 783         }
 784         return ret;
 785 }
 786
 787 static int tcf_action_put(struct tc_action *p)
 788 {
 789         return __tcf_action_put(p, false);
 790 }
 791
 792 /* Put all actions in this array, skip those NULL's. */
 793 static void tcf_action_put_many(struct tc_action *actions[])
 794 {
 795         int i;
 796
 797         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 798                 struct tc_action *a = actions[i];
 799                 const struct tc_action_ops *ops;
 800
 801                 if (!a)
 802                         continue;
 803                 ops = a->ops;
 804                 if (tcf_action_put(a))
 805                         module_put(ops->owner);
 806         }
 807 }
 808
 809 int
 810 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 811 {
 812         return a->ops->dump(skb, a, bind, ref);
 813 }
 814
 815 int
 816 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 817 {
 818         int err = -EINVAL;
 819         unsigned char *b = skb_tail_pointer(skb);
 820         struct nlattr *nest;
 821
 822         if (tcf_action_dump_terse(skb, a, false))
 823                 goto nla_put_failure;
 824
 825         if (a->hw_stats != TCA_ACT_HW_STATS_ANY &&
 826             nla_put_bitfield32(skb, TCA_ACT_HW_STATS,
 827                                a->hw_stats, TCA_ACT_HW_STATS_ANY))
 828                 goto nla_put_failure;
 829
 830         if (a->used_hw_stats_valid &&
 831             nla_put_bitfield32(skb, TCA_ACT_USED_HW_STATS,
 832                                a->used_hw_stats, TCA_ACT_HW_STATS_ANY))
 833                 goto nla_put_failure;
 834
 835         if (a->tcfa_flags &&
 836             nla_put_bitfield32(skb, TCA_ACT_FLAGS,
 837                                a->tcfa_flags, a->tcfa_flags))
 838                 goto nla_put_failure;
 839
 840         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 841         if (nest == NULL)
 842                 goto nla_put_failure;
 843         err = tcf_action_dump_old(skb, a, bind, ref);
 844         if (err > 0) {
 845                 nla_nest_end(skb, nest);
 846                 return err;
 847         }
 848
 849 nla_put_failure:
 850         nlmsg_trim(skb, b);
 851         return -1;
 852 }
 853 EXPORT_SYMBOL(tcf_action_dump_1);
 854
 855 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 856                     int bind, int ref, bool terse)
 857 {
 858         struct tc_action *a;
 859         int err = -EINVAL, i;
 860         struct nlattr *nest;
 861
 862         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 863                 a = actions[i];
 864                 nest = nla_nest_start_noflag(skb, i + 1);
 865                 if (nest == NULL)
 866                         goto nla_put_failure;
 867                 err = terse ? tcf_action_dump_terse(skb, a, false) :
 868                         tcf_action_dump_1(skb, a, bind, ref);
 869                 if (err < 0)
 870                         goto errout;
 871                 nla_nest_end(skb, nest);
 872         }
 873
 874         return 0;
 875
 876 nla_put_failure:
 877         err = -EINVAL;
 878 errout:
 879         nla_nest_cancel(skb, nest);
 880         return err;
 881 }
 882
 883 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 884 {
 885         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 886         if (!c)
 887                 return NULL;
 888
 889         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 890         if (!c->data) {
 891                 kfree(c);
 892                 return NULL;
 893         }
 894         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 895
 896         return c;
 897 }
 898
 899 static u8 tcf_action_hw_stats_get(struct nlattr *hw_stats_attr)
 900 {
 901         struct nla_bitfield32 hw_stats_bf;
 902
 903         /* If the user did not pass the attr, that means he does
 904          * not care about the type. Return "any" in that case
 905          * which is setting on all supported types.
 906          */
 907         if (!hw_stats_attr)
 908                 return TCA_ACT_HW_STATS_ANY;
 909         hw_stats_bf = nla_get_bitfield32(hw_stats_attr);
 910         return hw_stats_bf.value;
 911 }
 912
 913 static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
 914         [TCA_ACT_KIND]          = { .type = NLA_STRING },
 915         [TCA_ACT_INDEX]         = { .type = NLA_U32 },
 916         [TCA_ACT_COOKIE]        = { .type = NLA_BINARY,
 917                                     .len = TC_COOKIE_MAX_SIZE },
 918         [TCA_ACT_OPTIONS]       = { .type = NLA_NESTED },
 919         [TCA_ACT_FLAGS]         = NLA_POLICY_BITFIELD32(TCA_ACT_FLAGS_NO_PERCPU_STATS),
 920         [TCA_ACT_HW_STATS]      = NLA_POLICY_BITFIELD32(TCA_ACT_HW_STATS_ANY),
 921 };
 922
 923 void tcf_idr_insert_many(struct tc_action *actions[])
 924 {
 925         int i;
 926
 927         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 928                 struct tc_action *a = actions[i];
 929                 struct tcf_idrinfo *idrinfo;
 930
 931                 if (!a)
 932                         continue;
 933                 idrinfo = a->idrinfo;
 934                 mutex_lock(&idrinfo->lock);
 935                 /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc if
 936                  * it is just created, otherwise this is just a nop.
 937                  */
 938                 idr_replace(&idrinfo->action_idr, a, a->tcfa_index);
 939                 mutex_unlock(&idrinfo->lock);
 940         }
 941 }
 942
 943 struct tc_action_ops *tc_action_load_ops(char *name, struct nlattr *nla,
 944                                          bool rtnl_held,
 945                                          struct netlink_ext_ack *extack)
 946 {
 947         struct nlattr *tb[TCA_ACT_MAX + 1];
 948         struct tc_action_ops *a_o;
 949         char act_name[IFNAMSIZ];
 950         struct nlattr *kind;
 951         int err;
 952
 953         if (name == NULL) {
 954                 err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
 955                                                   tcf_action_policy, extack);
 956                 if (err < 0)
 957                         return ERR_PTR(err);
 958                 err = -EINVAL;
 959                 kind = tb[TCA_ACT_KIND];
 960                 if (!kind) {
 961                         NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 962                         return ERR_PTR(err);
 963                 }
 964                 if (nla_strscpy(act_name, kind, IFNAMSIZ) < 0) {
 965                         NL_SET_ERR_MSG(extack, "TC action name too long");
 966                         return ERR_PTR(err);
 967                 }
 968         } else {
 969                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
 970                         NL_SET_ERR_MSG(extack, "TC action name too long");
 971                         return ERR_PTR(-EINVAL);
 972                 }
 973         }
 974
 975         a_o = tc_lookup_action_n(act_name);
 976         if (a_o == NULL) {
 977 #ifdef CONFIG_MODULES
 978                 if (rtnl_held)
 979                         rtnl_unlock();
 980                 request_module("act_%s", act_name);
 981                 if (rtnl_held)
 982                         rtnl_lock();
 983
 984                 a_o = tc_lookup_action_n(act_name);
 985
 986                 /* We dropped the RTNL semaphore in order to
 987                  * perform the module load.  So, even if we
 988                  * succeeded in loading the module we have to
 989                  * tell the caller to replay the request.  We
 990                  * indicate this using -EAGAIN.
 991                  */
 992                 if (a_o != NULL) {
 993                         module_put(a_o->owner);
 994                         return ERR_PTR(-EAGAIN);
 995                 }
 996 #endif
 997                 NL_SET_ERR_MSG(extack, "Failed to load TC action module");
 998                 return ERR_PTR(-ENOENT);
 999         }
1000
1001         return a_o;
1002 }
1003
1004 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
1005                                     struct nlattr *nla, struct nlattr *est,
1006                                     char *name, int ovr, int bind,
1007                                     struct tc_action_ops *a_o, int *init_res,
1008                                     bool rtnl_held,
1009                                     struct netlink_ext_ack *extack)
1010 {
1011         struct nla_bitfield32 flags = { 0, 0 };
1012         u8 hw_stats = TCA_ACT_HW_STATS_ANY;
1013         struct nlattr *tb[TCA_ACT_MAX + 1];
1014         struct tc_cookie *cookie = NULL;
1015         struct tc_action *a;
1016         int err;
1017
1018         /* backward compatibility for policer */
1019         if (name == NULL) {
1020                 err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1021                                                   tcf_action_policy, extack);
1022                 if (err < 0)
1023                         return ERR_PTR(err);
1024                 if (tb[TCA_ACT_COOKIE]) {
1025                         cookie = nla_memdup_cookie(tb);
1026                         if (!cookie) {
1027                                 NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
1028                                 err = -ENOMEM;
1029                                 goto err_out;
1030                         }
1031                 }
1032                 hw_stats = tcf_action_hw_stats_get(tb[TCA_ACT_HW_STATS]);
1033                 if (tb[TCA_ACT_FLAGS])
1034                         flags = nla_get_bitfield32(tb[TCA_ACT_FLAGS]);
1035
1036                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
1037                                 rtnl_held, tp, flags.value, extack);
1038         } else {
1039                 err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
1040                                 tp, flags.value, extack);
1041         }
1042         if (err < 0)
1043                 goto err_out;
1044         *init_res = err;
1045
1046         if (!name && tb[TCA_ACT_COOKIE])
1047                 tcf_set_action_cookie(&a->act_cookie, cookie);
1048
1049         if (!name)
1050                 a->hw_stats = hw_stats;
1051
1052         return a;
1053
1054 err_out:
1055         if (cookie) {
1056                 kfree(cookie->data);
1057                 kfree(cookie);
1058         }
1059         return ERR_PTR(err);
1060 }
1061
1062 /* Returns numbers of initialized actions or negative error. */
1063
1064 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
1065                     struct nlattr *est, char *name, int ovr, int bind,
1066                     struct tc_action *actions[], int init_res[], size_t *attr_size,
1067                     bool rtnl_held, struct netlink_ext_ack *extack)
1068 {
1069         struct tc_action_ops *ops[TCA_ACT_MAX_PRIO] = {};
1070         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1071         struct tc_action *act;
1072         size_t sz = 0;
1073         int err;
1074         int i;
1075
1076         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1077                                           extack);
1078         if (err < 0)
1079                 return err;
1080
1081         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1082                 struct tc_action_ops *a_o;
1083
1084                 a_o = tc_action_load_ops(name, tb[i], rtnl_held, extack);
1085                 if (IS_ERR(a_o)) {
1086                         err = PTR_ERR(a_o);
1087                         goto err_mod;
1088                 }
1089                 ops[i - 1] = a_o;
1090         }
1091
1092         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1093                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
1094                                         ops[i - 1], &init_res[i - 1], rtnl_held,
1095                                         extack);
1096                 if (IS_ERR(act)) {
1097                         err = PTR_ERR(act);
1098                         goto err;
1099                 }
1100                 sz += tcf_action_fill_size(act);
1101                 /* Start from index 0 */
1102                 actions[i - 1] = act;
1103         }
1104
1105         /* We have to commit them all together, because if any error happened in
1106          * between, we could not handle the failure gracefully.
1107          */
1108         tcf_idr_insert_many(actions);
1109
1110         *attr_size = tcf_action_full_attrs_size(sz);
1111         err = i - 1;
1112         goto err_mod;
1113
1114 err:
1115         tcf_action_destroy(actions, bind);
1116 err_mod:
1117         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
1118                 if (ops[i])
1119                         module_put(ops[i]->owner);
1120         }
1121         return err;
1122 }
1123
1124 void tcf_action_update_stats(struct tc_action *a, u64 bytes, u64 packets,
1125                              u64 drops, bool hw)
1126 {
1127         if (a->cpu_bstats) {
1128                 _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
1129
1130                 this_cpu_ptr(a->cpu_qstats)->drops += drops;
1131
1132                 if (hw)
1133                         _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
1134                                            bytes, packets);
1135                 return;
1136         }
1137
1138         _bstats_update(&a->tcfa_bstats, bytes, packets);
1139         a->tcfa_qstats.drops += drops;
1140         if (hw)
1141                 _bstats_update(&a->tcfa_bstats_hw, bytes, packets);
1142 }
1143 EXPORT_SYMBOL(tcf_action_update_stats);
1144
1145 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
1146                           int compat_mode)
1147 {
1148         int err = 0;
1149         struct gnet_dump d;
1150
1151         if (p == NULL)
1152                 goto errout;
1153
1154         /* compat_mode being true specifies a call that is supposed
1155          * to add additional backward compatibility statistic TLVs.
1156          */
1157         if (compat_mode) {
1158                 if (p->type == TCA_OLD_COMPAT)
1159                         err = gnet_stats_start_copy_compat(skb, 0,
1160                                                            TCA_STATS,
1161                                                            TCA_XSTATS,
1162                                                            &p->tcfa_lock, &d,
1163                                                            TCA_PAD);
1164                 else
1165                         return 0;
1166         } else
1167                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1168                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
1169
1170         if (err < 0)
1171                 goto errout;
1172
1173         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1174             gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1175                                      &p->tcfa_bstats_hw) < 0 ||
1176             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1177             gnet_stats_copy_queue(&d, p->cpu_qstats,
1178                                   &p->tcfa_qstats,
1179                                   p->tcfa_qstats.qlen) < 0)
1180                 goto errout;
1181
1182         if (gnet_stats_finish_copy(&d) < 0)
1183                 goto errout;
1184
1185         return 0;
1186
1187 errout:
1188         return -1;
1189 }
1190
1191 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1192                         u32 portid, u32 seq, u16 flags, int event, int bind,
1193                         int ref)
1194 {
1195         struct tcamsg *t;
1196         struct nlmsghdr *nlh;
1197         unsigned char *b = skb_tail_pointer(skb);
1198         struct nlattr *nest;
1199
1200         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1201         if (!nlh)
1202                 goto out_nlmsg_trim;
1203         t = nlmsg_data(nlh);
1204         t->tca_family = AF_UNSPEC;
1205         t->tca__pad1 = 0;
1206         t->tca__pad2 = 0;
1207
1208         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1209         if (!nest)
1210                 goto out_nlmsg_trim;
1211
1212         if (tcf_action_dump(skb, actions, bind, ref, false) < 0)
1213                 goto out_nlmsg_trim;
1214
1215         nla_nest_end(skb, nest);
1216
1217         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1218         return skb->len;
1219
1220 out_nlmsg_trim:
1221         nlmsg_trim(skb, b);
1222         return -1;
1223 }
1224
1225 static int
1226 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1227                struct tc_action *actions[], int event,
1228                struct netlink_ext_ack *extack)
1229 {
1230         struct sk_buff *skb;
1231
1232         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1233         if (!skb)
1234                 return -ENOBUFS;
1235         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1236                          0, 1) <= 0) {
1237                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1238                 kfree_skb(skb);
1239                 return -EINVAL;
1240         }
1241
1242         return rtnl_unicast(skb, net, portid);
1243 }
1244
1245 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1246                                           struct nlmsghdr *n, u32 portid,
1247                                           struct netlink_ext_ack *extack)
1248 {
1249         struct nlattr *tb[TCA_ACT_MAX + 1];
1250         const struct tc_action_ops *ops;
1251         struct tc_action *a;
1252         int index;
1253         int err;
1254
1255         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1256                                           tcf_action_policy, extack);
1257         if (err < 0)
1258                 goto err_out;
1259
1260         err = -EINVAL;
1261         if (tb[TCA_ACT_INDEX] == NULL ||
1262             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1263                 NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1264                 goto err_out;
1265         }
1266         index = nla_get_u32(tb[TCA_ACT_INDEX]);
1267
1268         err = -EINVAL;
1269         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1270         if (!ops) { /* could happen in batch of actions */
1271                 NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1272                 goto err_out;
1273         }
1274         err = -ENOENT;
1275         if (ops->lookup(net, &a, index) == 0) {
1276                 NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1277                 goto err_mod;
1278         }
1279
1280         module_put(ops->owner);
1281         return a;
1282
1283 err_mod:
1284         module_put(ops->owner);
1285 err_out:
1286         return ERR_PTR(err);
1287 }
1288
1289 static int tca_action_flush(struct net *net, struct nlattr *nla,
1290                             struct nlmsghdr *n, u32 portid,
1291                             struct netlink_ext_ack *extack)
1292 {
1293         struct sk_buff *skb;
1294         unsigned char *b;
1295         struct nlmsghdr *nlh;
1296         struct tcamsg *t;
1297         struct netlink_callback dcb;
1298         struct nlattr *nest;
1299         struct nlattr *tb[TCA_ACT_MAX + 1];
1300         const struct tc_action_ops *ops;
1301         struct nlattr *kind;
1302         int err = -ENOMEM;
1303
1304         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1305         if (!skb)
1306                 return err;
1307
1308         b = skb_tail_pointer(skb);
1309
1310         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1311                                           tcf_action_policy, extack);
1312         if (err < 0)
1313                 goto err_out;
1314
1315         err = -EINVAL;
1316         kind = tb[TCA_ACT_KIND];
1317         ops = tc_lookup_action(kind);
1318         if (!ops) { /*some idjot trying to flush unknown action */
1319                 NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1320                 goto err_out;
1321         }
1322
1323         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1324                         sizeof(*t), 0);
1325         if (!nlh) {
1326                 NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1327                 goto out_module_put;
1328         }
1329         t = nlmsg_data(nlh);
1330         t->tca_family = AF_UNSPEC;
1331         t->tca__pad1 = 0;
1332         t->tca__pad2 = 0;
1333
1334         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1335         if (!nest) {
1336                 NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1337                 goto out_module_put;
1338         }
1339
1340         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1341         if (err <= 0) {
1342                 nla_nest_cancel(skb, nest);
1343                 goto out_module_put;
1344         }
1345
1346         nla_nest_end(skb, nest);
1347
1348         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1349         nlh->nlmsg_flags |= NLM_F_ROOT;
1350         module_put(ops->owner);
1351         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1352                              n->nlmsg_flags & NLM_F_ECHO);
1353         if (err > 0)
1354                 return 0;
1355         if (err < 0)
1356                 NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1357
1358         return err;
1359
1360 out_module_put:
1361         module_put(ops->owner);
1362 err_out:
1363         kfree_skb(skb);
1364         return err;
1365 }
1366
1367 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1368 {
1369         int i;
1370
1371         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1372                 struct tc_action *a = actions[i];
1373                 const struct tc_action_ops *ops = a->ops;
1374                 /* Actions can be deleted concurrently so we must save their
1375                  * type and id to search again after reference is released.
1376                  */
1377                 struct tcf_idrinfo *idrinfo = a->idrinfo;
1378                 u32 act_index = a->tcfa_index;
1379
1380                 actions[i] = NULL;
1381                 if (tcf_action_put(a)) {
1382                         /* last reference, action was deleted concurrently */
1383                         module_put(ops->owner);
1384                 } else  {
1385                         int ret;
1386
1387                         /* now do the delete */
1388                         ret = tcf_idr_delete_index(idrinfo, act_index);
1389                         if (ret < 0)
1390                                 return ret;
1391                 }
1392         }
1393         return 0;
1394 }
1395
1396 static int
1397 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1398                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1399 {
1400         int ret;
1401         struct sk_buff *skb;
1402
1403         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1404                         GFP_KERNEL);
1405         if (!skb)
1406                 return -ENOBUFS;
1407
1408         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1409                          0, 2) <= 0) {
1410                 NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1411                 kfree_skb(skb);
1412                 return -EINVAL;
1413         }
1414
1415         /* now do the delete */
1416         ret = tcf_action_delete(net, actions);
1417         if (ret < 0) {
1418                 NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1419                 kfree_skb(skb);
1420                 return ret;
1421         }
1422
1423         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1424                              n->nlmsg_flags & NLM_F_ECHO);
1425         if (ret > 0)
1426                 return 0;
1427         return ret;
1428 }
1429
1430 static int
1431 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1432               u32 portid, int event, struct netlink_ext_ack *extack)
1433 {
1434         int i, ret;
1435         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1436         struct tc_action *act;
1437         size_t attr_size = 0;
1438         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1439
1440         ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1441                                           extack);
1442         if (ret < 0)
1443                 return ret;
1444
1445         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1446                 if (tb[1])
1447                         return tca_action_flush(net, tb[1], n, portid, extack);
1448
1449                 NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1450                 return -EINVAL;
1451         }
1452
1453         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1454                 act = tcf_action_get_1(net, tb[i], n, portid, extack);
1455                 if (IS_ERR(act)) {
1456                         ret = PTR_ERR(act);
1457                         goto err;
1458                 }
1459                 attr_size += tcf_action_fill_size(act);
1460                 actions[i - 1] = act;
1461         }
1462
1463         attr_size = tcf_action_full_attrs_size(attr_size);
1464
1465         if (event == RTM_GETACTION)
1466                 ret = tcf_get_notify(net, portid, n, actions, event, extack);
1467         else { /* delete */
1468                 ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1469                 if (ret)
1470                         goto err;
1471                 return 0;
1472         }
1473 err:
1474         tcf_action_put_many(actions);
1475         return ret;
1476 }
1477
1478 static int
1479 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1480                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1481 {
1482         struct sk_buff *skb;
1483         int err = 0;
1484
1485         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1486                         GFP_KERNEL);
1487         if (!skb)
1488                 return -ENOBUFS;
1489
1490         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1491                          RTM_NEWACTION, 0, 0) <= 0) {
1492                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1493                 kfree_skb(skb);
1494                 return -EINVAL;
1495         }
1496
1497         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1498                              n->nlmsg_flags & NLM_F_ECHO);
1499         if (err > 0)
1500                 err = 0;
1501         return err;
1502 }
1503
1504 static int tcf_action_add(struct net *net, struct nlattr *nla,
1505                           struct nlmsghdr *n, u32 portid, int ovr,
1506                           struct netlink_ext_ack *extack)
1507 {
1508         size_t attr_size = 0;
1509         int loop, ret, i;
1510         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1511         int init_res[TCA_ACT_MAX_PRIO] = {};
1512
1513         for (loop = 0; loop < 10; loop++) {
1514                 ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0,
1515                                       actions, init_res, &attr_size, true, extack);
1516                 if (ret != -EAGAIN)
1517                         break;
1518         }
1519
1520         if (ret < 0)
1521                 return ret;
1522         ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1523
1524         /* only put existing actions */
1525         for (i = 0; i < TCA_ACT_MAX_PRIO; i++)
1526                 if (init_res[i] == ACT_P_CREATED)
1527                         actions[i] = NULL;
1528         tcf_action_put_many(actions);
1529
1530         return ret;
1531 }
1532
1533 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1534         [TCA_ROOT_FLAGS] = NLA_POLICY_BITFIELD32(TCA_ACT_FLAG_LARGE_DUMP_ON |
1535                                                  TCA_ACT_FLAG_TERSE_DUMP),
1536         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1537 };
1538
1539 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1540                          struct netlink_ext_ack *extack)
1541 {
1542         struct net *net = sock_net(skb->sk);
1543         struct nlattr *tca[TCA_ROOT_MAX + 1];
1544         u32 portid = NETLINK_CB(skb).portid;
1545         int ret = 0, ovr = 0;
1546
1547         if ((n->nlmsg_type != RTM_GETACTION) &&
1548             !netlink_capable(skb, CAP_NET_ADMIN))
1549                 return -EPERM;
1550
1551         ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
1552                                      TCA_ROOT_MAX, NULL, extack);
1553         if (ret < 0)
1554                 return ret;
1555
1556         if (tca[TCA_ACT_TAB] == NULL) {
1557                 NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1558                 return -EINVAL;
1559         }
1560
1561         /* n->nlmsg_flags & NLM_F_CREATE */
1562         switch (n->nlmsg_type) {
1563         case RTM_NEWACTION:
1564                 /* we are going to assume all other flags
1565                  * imply create only if it doesn't exist
1566                  * Note that CREATE | EXCL implies that
1567                  * but since we want avoid ambiguity (eg when flags
1568                  * is zero) then just set this
1569                  */
1570                 if (n->nlmsg_flags & NLM_F_REPLACE)
1571                         ovr = 1;
1572                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1573                                      extack);
1574                 break;
1575         case RTM_DELACTION:
1576                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1577                                     portid, RTM_DELACTION, extack);
1578                 break;
1579         case RTM_GETACTION:
1580                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1581                                     portid, RTM_GETACTION, extack);
1582                 break;
1583         default:
1584                 BUG();
1585         }
1586
1587         return ret;
1588 }
1589
1590 static struct nlattr *find_dump_kind(struct nlattr **nla)
1591 {
1592         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1593         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1594         struct nlattr *kind;
1595
1596         tb1 = nla[TCA_ACT_TAB];
1597         if (tb1 == NULL)
1598                 return NULL;
1599
1600         if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1601                 return NULL;
1602
1603         if (tb[1] == NULL)
1604                 return NULL;
1605         if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], tcf_action_policy, NULL) < 0)
1606                 return NULL;
1607         kind = tb2[TCA_ACT_KIND];
1608
1609         return kind;
1610 }
1611
1612 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1613 {
1614         struct net *net = sock_net(skb->sk);
1615         struct nlmsghdr *nlh;
1616         unsigned char *b = skb_tail_pointer(skb);
1617         struct nlattr *nest;
1618         struct tc_action_ops *a_o;
1619         int ret = 0;
1620         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1621         struct nlattr *tb[TCA_ROOT_MAX + 1];
1622         struct nlattr *count_attr = NULL;
1623         unsigned long jiffy_since = 0;
1624         struct nlattr *kind = NULL;
1625         struct nla_bitfield32 bf;
1626         u32 msecs_since = 0;
1627         u32 act_count = 0;
1628
1629         ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
1630                                      TCA_ROOT_MAX, tcaa_policy, cb->extack);
1631         if (ret < 0)
1632                 return ret;
1633
1634         kind = find_dump_kind(tb);
1635         if (kind == NULL) {
1636                 pr_info("tc_dump_action: action bad kind\n");
1637                 return 0;
1638         }
1639
1640         a_o = tc_lookup_action(kind);
1641         if (a_o == NULL)
1642                 return 0;
1643
1644         cb->args[2] = 0;
1645         if (tb[TCA_ROOT_FLAGS]) {
1646                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1647                 cb->args[2] = bf.value;
1648         }
1649
1650         if (tb[TCA_ROOT_TIME_DELTA]) {
1651                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1652         }
1653
1654         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1655                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1656         if (!nlh)
1657                 goto out_module_put;
1658
1659         if (msecs_since)
1660                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1661
1662         t = nlmsg_data(nlh);
1663         t->tca_family = AF_UNSPEC;
1664         t->tca__pad1 = 0;
1665         t->tca__pad2 = 0;
1666         cb->args[3] = jiffy_since;
1667         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1668         if (!count_attr)
1669                 goto out_module_put;
1670
1671         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1672         if (nest == NULL)
1673                 goto out_module_put;
1674
1675         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1676         if (ret < 0)
1677                 goto out_module_put;
1678
1679         if (ret > 0) {
1680                 nla_nest_end(skb, nest);
1681                 ret = skb->len;
1682                 act_count = cb->args[1];
1683                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1684                 cb->args[1] = 0;
1685         } else
1686                 nlmsg_trim(skb, b);
1687
1688         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1689         if (NETLINK_CB(cb->skb).portid && ret)
1690                 nlh->nlmsg_flags |= NLM_F_MULTI;
1691         module_put(a_o->owner);
1692         return skb->len;
1693
1694 out_module_put:
1695         module_put(a_o->owner);
1696         nlmsg_trim(skb, b);
1697         return skb->len;
1698 }
1699
1700 static int __init tc_action_init(void)
1701 {
1702         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1703         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1704         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1705                       0);
1706
1707         return 0;
1708 }
1709
1710 subsys_initcall(tc_action_init);